JP4946840B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus including an expansion mechanism, and more particularly to a positive displacement expansion mechanism that generates power by expansion of a fluid.

  Conventionally, as disclosed in Patent Documents 1 and 2, a refrigerant circuit that performs a refrigeration cycle is provided with an expansion mechanism for recovering power from the refrigerant in addition to a compression mechanism. The power recovered from the high-pressure refrigerant by the expansion mechanism is transmitted to the compression mechanism connected via the drive shaft, and is used to drive the compression mechanism.

  By the way, since the refrigerant circuit is a closed circuit, the circulation amount of the refrigerant passing through the compression mechanism per unit time (corresponding to the mass flow rate, the same shall apply hereinafter) and the circulation amount of the refrigerant passing through the expansion mechanism must always match. I must. However, when the expansion mechanism is designed at a certain design specification point (for example, heating rating), when operated under conditions that deviate from the design specification point, the amount of circulation between the compression mechanism and the amount of circulation in the expansion mechanism is between. Excess or deficiency will occur. Specifically, for example, when the circulation rate between the compression mechanism and the expansion mechanism is matched at the time of heating rating, the optimum suction volume of the expansion mechanism is the heating rating at the cooling rating when the suction pressure of the compression mechanism increases. Since it becomes larger than the case of time, the refrigerant is insufficient and overexpansion occurs.

Therefore, in Patent Documents 1 and 2, high-pressure refrigerant is injected into the expansion process of the expansion mechanism, or a passage for bypassing the expansion mechanism is provided, and the bypass amount is adjusted by the control valve, so that the compression mechanism side of the refrigerant circuit And the refrigerant flow rate on the expansion mechanism side are balanced.
JP 2004-150748 A JP 2001-116371 A

  However, as described above, if the high-pressure refrigerant is injected into the expansion mechanism during the expansion process or the refrigerant bypasses the expansion mechanism, the refrigerant circulation amount can be balanced between the compression mechanism and the expansion mechanism. In principle, only a part of the energy of the high-pressure refrigerant to be recovered for power is recovered by the expansion mechanism, which is not a preferable configuration from the viewpoint of efficiency.

  The present invention has been made in view of the above points, and an object of the present invention is to make the intake amount of the refrigerant of the expansion mechanism variable while recovering the energy of the high-pressure refrigerant to the maximum by the expansion mechanism. An object of the present invention is to obtain a refrigeration apparatus configured to

  In order to achieve the above object, in the refrigeration apparatus (1) according to the present invention, the expansion mechanism (50, 100, 200), the main suction hole (55, 103, 201) first communicating with the fluid chamber (72, 82, 230) in the suction process, An auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) that communicates with the main suction hole (55, 103, 201) is provided.

  Specifically, each of the first and second inventions has a first member (71, 81, 102, 112, 210) and a second member (75, 85, 116, 124, 220) that move relatively eccentrically, and is formed between the two members. A refrigeration apparatus including an expansion mechanism (50, 100, 200) that generates power by expansion of a fluid in a fluid chamber (72, 82, 230) is an object.

  The expansion mechanism (50, 100, 200) includes a main suction hole (55, 103, 201) that first communicates with the fluid chamber (72, 82, 230) and the suction path (24) in the suction step, and the main suction hole (55, 103, 201). Assume that auxiliary suction holes (56, 104, 113, 114, 203, 204, 205) for communicating the fluid chambers (72, 82, 230) and the suction passages (27) after communication are provided.

  With this configuration, in the suction process of the expansion mechanism (50, 100, 200), it becomes possible to sequentially introduce fluid into the fluid chamber (72, 82, 230) from the plurality of suction holes (55, 56, 103, 104, 113, 114, 201, 203, 204, 205). 72, 82, 230), the amount of fluid circulation can be adjusted.

  Therefore, even when the operating conditions change, the circulation flow rate of the expansion mechanism (50, 100, 200) and the compression mechanism (40) can be balanced, and all the fluid is put into the fluid chamber (72, 82, 230) in the suction process. Since it can be introduced, power recovery can be performed efficiently by the expansion mechanism (50, 100, 200).

  In the above-described configuration, the expansion chamber (50, 100, 200) is partitioned in the fluid chamber (72, 82, 230) so that at least the suction process and the discharge process are performed independently in the fluid chamber (72, 82, 230). It shall be (first and second inventions). For example, if the suction process and the discharge process are performed independently, such as a multi-stage type or a scroll type, the high-pressure fluid introduced into the fluid chamber in the suction process is expanded in the expansion mechanism (50, 100, 200). Without being carried out, it can be prevented from flowing out as it is. Therefore, with the configuration as described above, the fluid can be sufficiently expanded in the expansion mechanism (50, 100, 200).

The auxiliary suction holes (56, 104, 113, 114, 203, 204, 205) are provided so as to open from below with respect to the fluid chambers (72, 230). Thus, by providing the auxiliary suction hole (56,104,113,114,203,204,205) so as to open from below the fluid chamber (72,230), when the fluid is not introduced from the auxiliary suction hole (56,104,113,114,203,204,205), the suction hole (56,104,113,114,203,204,205) The refrigerating machine oil in the expansion mechanism (50, 100, 200) accumulates in the suction passage (27) connected to (). Then, the suction passage (27) can prevent a dead volume in which the fluid in the fluid chamber (72, 230) is accumulated, and the fluid can be efficiently expanded in the fluid chamber (72, 230). .

  On-off valve control means for controlling the on-off valve (61) provided on the suction passage (27) connected to the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) based on the pressure of the fluid introduced into the expansion mechanism (50, 100, 200) (93) (first and second inventions). By controlling the on-off valve (61) by the on-off valve control means (93), the flow rate introduced into the fluid chamber (72, 82, 230) can be controlled. That is, by controlling the on-off valve (61) based on the pressure of the fluid introduced into the expansion mechanism (50, 100, 200), an optimum pressure for the expansion mechanism (50, 100, 200), that is, an optimum circulation amount is obtained. Thus, the flow rate can be controlled and the fluid can be efficiently expanded by the expansion mechanism (50, 100, 200).

  Specifically, a plurality of the auxiliary suction holes (56, 104, 113, 114, 203, 204, 205) are provided, and an opening / closing valve (61) is provided on the suction passage (27) connected to each auxiliary suction hole (56, 104, 113, 114, 203, 204, 205). When the pressure is larger than a target value, the control means (93) opens and closes the fluid chamber (72, 82, 230) and the suction passage (27) in order through the auxiliary suction holes (56, 104, 113, 114, 203, 204, 205). It is assumed that the valve (61) is sequentially opened (first invention).

  Thereby, when the pressure of the fluid introduced into the expansion mechanism (50, 100, 200) is larger than the target value, that is, when it is necessary to increase the amount of circulation to the expansion mechanism (50, 100, 200), the on-off valve (61) By opening in order, the amount of circulation introduced into the fluid chamber (72, 82, 230) can be increased stepwise. Therefore, even if the amount of circulation required in the liquid chamber (72, 82, 230) changes greatly, fluid can be quickly introduced into the fluid chamber (72, 82, 230) by opening control of the on-off valve (61). Is possible.

  On the other hand, when the pressure is smaller than the target value, the on-off valve control means (93) sequentially opens the on-off valve (61) from the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) that finally communicates with the fluid chamber (72, 82, 230). Is controlled to be closed (second invention).

  Thereby, when the pressure of the fluid introduced into the expansion mechanism (50, 100, 200) is smaller than a target value, that is, when the circulation amount of the expansion mechanism (50, 100, 200) is large and needs to be reduced, the on-off valve (61 ) In order, the amount of circulation introduced into the fluid chamber (72, 82, 230) can be reduced stepwise. Therefore, even if the amount of circulation required in the fluid chamber (72, 82, 230) changes greatly, the amount of inflow into the fluid chamber (72, 82, 230) is quickly reduced by the closing control of the on-off valve (61). It becomes possible to make it.

  The bypass flow control means includes a bypass flow control means (94) for controlling a bypass flow control valve (66) provided in a bypass circuit (65) that bypasses the expansion mechanism (50, 100, 200). (94) controls the bypass flow rate adjustment valve (66) so that the pressure becomes a target value, and the on-off valve control means (93) sets the bypass flow rate adjustment valve (66) to a predetermined opening. In this case, the on-off valve (61) is controlled to open / close (first and second inventions). Here, the predetermined opening means an opening that is sufficiently large that the opening cannot be increased any more when the opening / closing valve (61) is opened, and the opening / closing valve (61) is closed. In this case, it means that the opening degree is almost zero.

  By doing so, the circulation amount of the fluid introduced into the fluid chamber (72, 82, 230) of the expansion mechanism (50, 100, 200) can be finely adjusted by the bypass flow rate adjustment valve (66) on the bypass circuit (65), and When the bypass flow rate adjusting valve (66) cannot be adjusted, the circulation amount of the fluid chamber (72, 82, 230) can be increased or decreased quickly and reliably by the opening / closing control of the opening / closing valve (61). As a result, the flow rate can be adjusted quickly and reliably so as to obtain an optimum circulation amount for the expansion mechanism (50, 100, 200).

  Furthermore, in the configuration comprising the flow rate control means (92) for controlling the flow rate adjustment valve (60) provided on the suction passage (24) connected to the main suction hole (55, 103, 201), the flow rate control means ( 92) The expansion mechanism (50, 100, 200) is operated by the flow rate adjusting valve (60) when the pressure is smaller than the target value even when the bypass flow rate adjusting valve (66) and the on-off valve (61) are all closed. The flow rate is adjusted (third invention).

  That is, when reducing the circulation amount of the fluid of the expansion mechanism (50, 100, 200), circulation of the fluid introduced from the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) by closing the bypass flow rate adjusting valve (66) and the on-off valve (61). Reduce the amount so that the fluid is introduced only from the main suction hole (55,103,201) into the fluid chamber (72,82,230), and if the amount of circulating fluid is still too much, the flow rate adjustment valve (60) adjusts the flow rate. Assumed to be performed. Thereby, the amount of introduction into the fluid chamber (72, 82, 230) can be reliably and rapidly reduced.

  The expansion mechanism (50, 100) has a plurality of rotary mechanism parts (70, 80, 101, 111, 121) connected in series in order from the smallest displacement volume, and the main suction hole (55, 103) and the auxiliary suction hole (56, 104, 113, 114). Is preferably provided in the rotary mechanism portion (70, 101, 111) on the upstream side of the rotary mechanism portion (80, 121) in the final stage (fourth invention). Thus, by using the multistage rotary type expansion mechanism (50, 100), high pressure fluid can be prevented from blowing from the suction side to the discharge side, and the fluid can be efficiently expanded by the expansion mechanism (50, 100). .

  In particular, the expansion mechanism (50) has two rotary mechanism parts (70, 80) connected in series, and the main suction hole (55) is connected to the rotary mechanism part (70) of the front stage having a small displacement volume. And an auxiliary suction hole (56) is preferably provided (fifth invention).

  By using such a two-stage rotary expansion mechanism, it is possible to reliably prevent the fluid from being blown through with a simple configuration, and thus it is possible to reduce the manufacturing cost.

  In addition, in the configuration in which a plurality of rotary mechanism portions (70, 80, 101, 111, 121) are connected in series as described above, the auxiliary suction holes (56, 104, 113, 114) are angles obtained geometrically based on a desired displacement volume. It is assumed that it is provided at an angular position obtained by adding a predetermined correction value to the position (sixth invention).

  As a result, when the refrigerant flows into the fluid chamber (72,230) from the auxiliary suction hole (56,104,113,114), the amount of the inflow is increased so that the amount of inflow is increased in consideration of the amount of decrease in the amount due to pressure loss. By increasing the angular position where the holes (56, 104, 113, 114) are provided, a necessary amount of refrigerant can be introduced into the fluid chamber (72, 230). Therefore, the necessary amount of refrigerant can be reliably passed through the expansion mechanism (50, 100).

  In particular, in the above-described configuration, the desired displacement volume is preferably a displacement volume required during cooling operation (seventh invention).

  By doing so, the pressure on the low pressure side becomes higher than that during the heating operation, and the refrigerant flows into the fluid chamber (72, 230) even during the cooling operation in which a larger amount of refrigerant flow is required by the expansion mechanism (50, 100). In consideration of the pressure loss at the time, a necessary refrigerant flow rate can be caused to flow in the fluid chamber (72, 230). Therefore, it is possible to prevent the expansion mechanism (50, 100) from running out of refrigerant and causing overexpansion during the cooling operation.

  The expansion mechanism (200) includes a pair of scroll members (210, 220) in which a spiral wrap is formed on the end plate, and at least a pair of wraps (211, 221) of the scroll members (210, 220) are engaged with each other. The main suction hole (201) and the auxiliary suction holes (203, 204, 205) at a position communicating with the fluid chamber (231, 232) in the suction process of the scroll mechanism. Is provided (eighth invention).

  By using such a scroll-type expansion mechanism, it is possible to prevent a high-pressure fluid from being blown through without using multiple stages as in the rotary type.

In the above configuration, it is preferable that a supercritical refrigeration cycle is performed using a refrigerant composed of CO ₂ as the fluid (9th invention). Thereby, the refrigerant circuit suitable for the environment can be configured.

  In the refrigeration apparatus according to the present invention, the expansion mechanism (50, 100, 200) includes the main suction hole (55, 103, 201) that first communicates with the fluid chamber (72, 82, 230) in the suction process, and the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) that communicates thereafter. Because it is provided, the flow rate of the fluid to the fluid chamber (72, 82, 230) can be controlled, and the circulation amount of the fluid in the expansion mechanism (50, 100, 200) can be optimized even if the operation condition changes greatly. it can. Therefore, the fluid can be efficiently expanded by the expansion mechanism (50, 100, 200), and power can be recovered efficiently.

  According to the present invention, since the expansion mechanism (50, 100, 200) is independent of at least the suction process and the discharge process, the expansion mechanism (50, 100, 200) does not blow through even if a high-pressure fluid is introduced. Can be reliably inflated.

  According to the present invention, the on-off valve control means (93) for controlling the on-off valve (61) based on the pressure of the fluid introduced into the expansion mechanism (50, 100, 200) is provided. 61) By opening / closing control of the expansion mechanism (50, 100, 200), the circulation amount can be increased or decreased so that the fluid circulation amount becomes an optimum flow rate, and power can be efficiently recovered by the expansion mechanism (50, 100, 200). .

  Further, according to the first aspect of the invention, the on-off valve control means (93) is configured such that when the pressure is greater than the target value, the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) and the fluid passage (72, 82, 230) and the suction path (27 The on-off valve (61) is controlled to be opened sequentially so that the flow rate of the fluid can be communicated with each other in order, so that the fluid flow rate can be quickly and reliably increased to the flow rate required by the expansion mechanism (50, 100, 200). it can.

  Further, according to the second invention, the on-off valve control means (93) is arranged so that the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) that communicates with the fluid chamber (72, 82, 230) lastly when the pressure is smaller than the target value. Since the on-off valve (61) is controlled to be closed in order, the flow rate of the fluid can be quickly and reliably reduced to the flow rate required by the expansion mechanism (50, 100, 200).

  According to each of the first and second inventions, first, the bypass flow rate adjustment valve (66) is controlled so that the pressure becomes a target value, and the bypass flow rate adjustment valve (66) is set to a predetermined opening degree. In this case, since the on-off valve (61) is controlled to open and close, the circulation amount of the fluid in the expansion mechanism (50, 100, 200) can be adjusted quickly and smoothly, and power can be recovered efficiently.

  Further, according to the third invention, when the fluid circulation amount of the expansion mechanism (50, 100, 200) is decreased, the circulation amount is too large even if the on-off valve (61) and the bypass flow rate adjustment valve (66) are closed. In this case, the flow rate is further adjusted by the flow rate adjustment valve (60), so that the circulation rate of the fluid in the expansion mechanism (50, 100, 200) can be reduced quickly and smoothly in a wide range, and the power recovery is performed more efficiently. be able to.

  Further, according to the fourth invention, the expansion mechanism (50, 100) is a multi-stage rotary type, so that the introduced high-pressure fluid can be prevented from being blown through, and the expansion mechanism (50, 100) can efficiently remove the fluid. Can be inflated. In particular, as in the fifth aspect of the invention, by using a two-stage rotary expansion mechanism, the structure can be simplified and the manufacturing cost can be reduced while reliably preventing high-pressure fluid from being blown through.

  Further, according to the sixth invention, the auxiliary suction hole (56, 104, 113, 114) is provided at an angular position obtained by adding a correction value to an angular position obtained geometrically based on a desired displacement volume. Considering the decrease in the refrigerant inflow due to the pressure loss when the refrigerant flows into the fluid chamber (72,230) from the auxiliary suction hole (56,104,113,114), the required refrigerant flow rate in the fluid chamber (72,230) is ensured. And overexpansion in the expansion mechanism (50, 100) can be prevented. In particular, according to the seventh invention, the desired displacement volume is a displacement volume required during the cooling operation, and therefore, it is possible to reliably prevent overexpansion in the expansion mechanism (50, 100) during the cooling operation.

  Further, according to the eighth invention, since the expansion mechanism (200) is of a scroll type, it is possible to reliably prevent high-pressure fluid from being blown through without using multiple stages, and an efficient expansion mechanism (200) is provided. can get.

According to the ninth invention, since the fluid is a CO ₂ refrigerant and the refrigeration apparatus is configured to perform a supercritical refrigeration cycle, a refrigeration apparatus suitable for the environment can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature and is not intended to limit the present invention, its application, or its use.

Embodiment 1
-Overall configuration of air conditioner-
FIG. 1 shows a refrigerant circuit (10) of an air conditioner (1) as a refrigeration apparatus according to Embodiment 1 of the present invention. The air conditioner (1) includes an outdoor unit (2) and an indoor unit (3). The outdoor unit (2) has a bridge circuit consisting of a compression / expansion unit (20), an outdoor heat exchanger (14), a four-way selector valve (12), and a check valve (11, 11, 11, 11). Part (13) is housed. On the other hand, the indoor heat exchanger (15) is accommodated in the indoor unit (3). Although not specifically shown, each of the heat exchangers (14, 15) is provided with a fan so that the outside air and the inside air are blown to the heat exchangers (14, 15). It is configured.

The outdoor unit (2) and the indoor unit (3) are connected by a pair of connecting pipes (16, 17), so that the compressor / expansion unit (20) and the heat exchanger (14, 15) are connected. The refrigerant circuit (10) is configured as a closed circuit to which are connected. In this embodiment, the refrigerant circuit (10) is filled with carbon dioxide ( CO ₂ ) as a refrigerant.

  The compression / expansion unit (20) includes a casing (21) formed in a vertically long cylindrical sealed container shape. The casing (21) houses a compression mechanism (40), an expansion mechanism (50), and an electric motor (26). That is, in the casing (21), the compression mechanism (40), the electric motor (26), and the expansion mechanism (50) are arranged in order from the bottom to the top. The details of the compression / expansion unit (20) will be described later. As a characteristic part of the present invention, the expansion mechanism (50) is provided with a plurality of suction ports (55, 56) as suction holes. The refrigerant intake amount is variable. FIG. 1 shows an example in which two suction ports of the expansion mechanism (50) are provided.

  Here, in the refrigerant circuit (10), an accumulator (18) is provided on the suction side of the compression mechanism (40) of the compression / expansion unit (20). Further, on the suction side of the expansion mechanism (50), a front throttle valve (60) and an on-off valve (61) are provided corresponding to the plurality of suction ports (55, 56). Specifically, in the suction process of the expansion mechanism (50), the front throttle valve (60) communicates second on the suction path connected to the first suction port (55) that first communicates with the fluid chamber (72). On-off valves (61) are provided on the suction passages connected to the second suction port (56), respectively. The front throttle valve (60) is the flow regulating valve of the present invention, the first suction port (55) is the main suction hole of the present invention, and the second suction port (56) is the auxiliary suction hole of the present invention. Respectively.

  The refrigerant circuit (10) is provided with a bypass pipe (65) that constitutes a bypass circuit so as to bypass the suction side and the discharge side of the expansion mechanism (50). The bypass pipe (65) is provided with a bypass valve (66) as a bypass flow rate adjusting valve of the present invention. By adjusting the refrigerant flow rate of the bypass pipe (65) by the bypass valve (66), the flow rate of the refrigerant flowing through the expansion mechanism (50) can be adjusted.

  Each of the heat exchangers (14, 15) is a cross fin type fin-and-tube heat exchanger. In the outdoor heat exchanger (14), the refrigerant circulating in the refrigerant circuit (10) exchanges heat with outdoor air, and in the indoor heat exchanger (15), the refrigerant circulating in the refrigerant circuit (10) is indoors. Exchange heat with air.

  The four-way selector valve (12) has four ports. The first port of the four-way selector valve (12) is on the discharge side of the compression mechanism (40), the second port is on one end of the indoor heat exchanger (15), and the third port is on the outdoor heat exchanger (14). The other end and the fourth port are connected to the suction side of the compression mechanism (40), respectively.

  The four-way switching valve (12) has a state in which the first port communicates with the second port and a state in which the third port communicates with the fourth port (a state indicated by a solid line in FIG. 1). The first port and the third port communicate with each other, and the second port and the fourth port communicate with each other (state indicated by a broken line in FIG. 1).

  The bridge circuit portion (13) is a combination of four check valves (11, 11, 11, 11) in a bridge shape, and the refrigerant circuit (10 The refrigerant is always supplied to the expansion mechanism (50) in a fixed direction even when the refrigerant flow in the reverse direction is. By doing so, it is not necessary to control the four-way switching valve in addition to the case where another four-way switching valve is provided in addition to the four-way switching valve (12), and the configuration is simplified. In this embodiment, the bridge circuit portion (13) constituted by the check valves (11, 11, 11, 11) is provided, but this is not restrictive, and another four-way switching valve is provided. You may do it.

−Configuration of compression / expansion unit−
As shown in FIG. 2, the compression / expansion unit (20) includes a casing (21) which is a vertically long and cylindrical sealed container. Inside the casing (21), a compression mechanism (40), an electric motor (26), and an expansion mechanism (50) are arranged in order from the bottom to the top. Further, the casing (21) has a suction pipe (22), a discharge pipe (23), and an introduction pipe (24, 27) and a lead-out pipe forming a part of the suction passage of the present invention so as to penetrate the trunk portion. (25) is provided. The suction pipe (22) is connected to the compression mechanism (40), and the introduction pipe (24, 27) and the outlet pipe (25) are connected to the expansion mechanism (50). The discharge pipe (23) is provided in a space between the electric motor (26) and the expansion mechanism (50) in the casing (21) so that one end side is open. Of the introduction pipes (24, 27), the first introduction pipe (24) is connected to the first suction port (55), and the second introduction pipe (27) is connected to the second suction port (56). Yes. That is, the front throttle valve (60) is provided outside the casing (21) of the first introduction pipe (24) and downstream of the branch position with the second introduction pipe (27). The on-off valve (61) is provided outside the casing (21) of the second introduction pipe (27) and downstream of the branch position with the first introduction pipe (24). As described above, the front throttle valve (60) is provided downstream of the branch position with respect to the second introduction pipe (27), thereby expanding from the first introduction pipe (24), that is, the first suction port (55). Only the flow rate of the refrigerant introduced into the mechanism (50) can be adjusted, and the flow rate can be finely adjusted.

  The compression mechanism (40) constitutes an oscillating piston type rotary compressor. The compression mechanism (40) includes two cylinders (41, 42) and two pistons (47, 47). In the compression mechanism (40), the rear head (44), the first cylinder (41), the intermediate plate (46), the second cylinder (42), and the front head (45) are sequentially arranged from bottom to top. Are in a stacked state.

  The compression mechanism (40) is provided with a first crankshaft (31) for drivingly connecting to the electric motor (26). The lower part of the first crankshaft (31) passes through the rear head (44), the first cylinder (41), the intermediate plate (46), the second cylinder (42), and the front head (45). It is arranged.

  Specifically, two compression-side eccentric portions (32, 33) are formed in the axial direction below the first crankshaft (31). These compression side eccentric parts (32, 33) are eccentric with respect to the axis of the first crankshaft (31). The eccentric direction of the lower first compression side eccentric portion (32) and the upper second compression side eccentric portion (33) are shifted by 180 °. The first compression side eccentric portion (32) is positioned in the first cylinder (41), and the second compression side eccentric portion (33) is positioned in the second cylinder (42).

  Cylindrical pistons (47, 47) are fitted on the first and second compression side eccentric parts (32, 33), respectively. These pistons (47, 47) are positioned one by one inside the first and second cylinders (41, 42), whereby the outer peripheral surface of the piston (47, 47) and the cylinder (41 , 42) are formed with compression chambers (43, 43), respectively. Although not particularly illustrated, a flat blade is provided on the side surface of the piston (47) so as to extend radially outward, and this blade is connected to the cylinder (41, 41) via a swing bush. 42) is supported.

  The first crankshaft (31) has an engagement hole (34) on the upper end surface. The engagement hole (34) is a hexagonal cross-section hole extending downward along the axis of the first crankshaft (31) and is formed at the lower end of the second crankshaft (35) described later. It engages with the mating protrusion (38).

  One suction port (48) is provided in each of the first and second cylinders (41, 42). Each suction port (48) passes through the cylinder (41, 42) in the radial direction, and is open to the inner peripheral surface of the cylinder (41, 42) so that one end side communicates with the compression chamber (43). The other end communicates with the suction pipe (22).

  Each of the front head (44) and the rear head (45) is provided with one discharge port. A discharge port provided in the front head (44) allows the compression chamber (43) in the second cylinder (42) to communicate with the internal space of the casing (21). On the other hand, the discharge port provided in the rear head (45) allows the compression chamber (43) in the first cylinder (41) to communicate with the internal space of the casing (21). Each discharge port is provided with a discharge valve consisting of a reed valve at its end, and is opened and closed by this discharge valve. Thereby, the gas refrigerant discharged from the compression mechanism (40) into the internal space of the casing (21) is sent out from the compression / expansion unit (20) through the discharge pipe (23). In FIG. 2, the discharge port and the discharge valve are not shown.

  The compression mechanism (40) is fixed to the casing (21) by a ring-shaped mounting plate (49). Specifically, the outer peripheral side of the mounting plate (49) is fixed on the inner surface of the casing (21) by welding, and the front head (44) of the compression mechanism (40) is not shown on the mounting plate (49). It is fastened and fixed by bolts.

  The electric motor (26) is disposed at the central portion in the longitudinal direction of the casing (21). The electric motor (26) includes a stator (27) and a rotor (28). The stator (27) is fixed on the inner peripheral surface of the casing (21) on the outer peripheral side thereof. The rotor (28) is disposed inside the stator (27) and is penetrated by the upper part of the first crankshaft (31).

  As shown in FIGS. 4 and 5, the expansion mechanism (50) is a so-called oscillating piston type rotary expander, and the expansion mechanism (50) includes a pair of first members. Two cylinders (71, 81) and pistons (75, 85) as second members are provided. The expansion mechanism (50) also includes a front head (51), an intermediate plate (53), and a rear head (52). In this expansion mechanism (50), each cylinder (71, 81), front head (51), intermediate plate (53), and rear head (52) constitute a fixed member, and each piston (75, 85) is a movable member. Is configured.

  In the expansion mechanism (50), the front head (51), the first cylinder (71), the intermediate plate (53), the second cylinder (81), and the rear head (52) are stacked in order from bottom to top. It is in a state. In this state, the lower end surface of the first cylinder (71) is closed by the front head (51), and the upper end surface thereof is closed by the intermediate plate (53). On the other hand, the lower end surface of the second cylinder (81) is closed by the intermediate plate (53), and the upper end surface thereof is closed by the rear head (52).

  Each of the cylinders (71, 81) is generally formed in a ring-shaped thick plate shape. The inner diameter of the second cylinder (81) is larger than the inner diameter of the first cylinder (71). The thickness (height) of the second cylinder (81) is larger than the thickness (height) of the first cylinder (71).

  The expansion mechanism (50) includes a second crank so as to pass through the front head (51), the first cylinder (71), the intermediate plate (53), the second cylinder (81), and the rear head (52). A shaft (35) is provided. The second crankshaft (35) has an engaging projection (38) projecting from its lower end surface. This engagement protrusion (38) is a hexagonal columnar protrusion extending downward from the lower end surface of the second crankshaft (35). The cross-sectional shape of the engagement protrusion (38) is a hexagon corresponding to the cross-sectional shape of the engagement hole (34) of the first crankshaft (31). The first crankshaft (31) and the second crankshaft (35) insert the engaging projection (38) of the second crankshaft (35) into the engaging hole (34) of the first crankshaft (31). To form a single shaft (30).

  Two expansion side eccentric portions (36, 37) are formed on the upper portion of the second crank shaft (35) corresponding to the cylinders (71, 81). The axis of the two expansion side eccentric parts (36, 37) is eccentric with respect to the axis of the second crankshaft (35). The lower first expansion side eccentric part (36) and the upper second expansion side eccentric part (37) have the same eccentric direction with respect to the axis of the second crankshaft (35). However, the amount of eccentricity of the second expansion side eccentric part (37) is larger than the amount of eccentricity of the first expansion side eccentric part (36). The first expansion side eccentric part (36) is arranged in the first cylinder (71), and the second expansion side eccentric part (37) is arranged in the second cylinder (81).

  Cylindrical pistons (75, 85) are fitted on the first and second expansion side eccentric parts (36, 37), respectively. A first piston (75) fitted around the first expansion side eccentric part (36) is fitted inside the first cylinder (71) and fitted around the second expansion side eccentric part (37). Two pistons (85) are positioned in the second cylinder (81), respectively.

  As shown in FIG. 4, the first piston (75) has an outer peripheral surface on the inner peripheral surface of the first cylinder (71), a lower end surface on the front head (51), and an upper end surface on the intermediate plate (53). ). Thereby, a first fluid chamber (72) is formed in the first cylinder (71) between the inner peripheral surface thereof and the outer peripheral surface of the first piston (75).

  On the other hand, the second piston (85) has an outer peripheral surface in sliding contact with the inner peripheral surface of the second cylinder (81), a lower end surface in contact with the intermediate plate (53), and an upper end surface in sliding contact with the rear head (52). . Thereby, a second fluid chamber (82) is formed in the second cylinder (81) between the inner peripheral surface thereof and the outer peripheral surface of the second piston (85).

  Each of the first and second pistons (75, 85) is integrally provided with one blade (76, 86). The blades (76, 86) are formed in a plate shape extending radially outward from the outer peripheral surface of the piston (75, 85).

  Each of the cylinders (71, 81) is provided with a pair of bushes (77, 87). Each bush (77, 87) is a small piece formed such that the inner surface is a flat surface and the outer surface is a circular arc surface. Each of the pair of bushes (77, 87) has a blade (76, 86) so that its inner surface slides with the blade (76, 86) and its outer surface slides with the cylinder (71, 81). ) Is inserted. As a result, the blade (76, 86) integrally formed with the piston (75, 85) is supported by the cylinder (71, 81) via the bush (77, 87), and the cylinder (71, 81) It can be rotated and moved forward and backward.

  The first fluid chamber (72) in the first cylinder (71) is partitioned by the first blade (76), and the left side of the first blade (76) in FIG. (73), and the right side is the first low pressure chamber (74) on the low pressure side. Similarly, the second fluid chamber (82) in the second cylinder (81) is also partitioned by the second blade (86), and the left side of the second blade (86) in FIG. 2 high pressure chambers (83), and the right side thereof is the low pressure side second low pressure chamber (84).

  The first cylinder (71) and the second cylinder (81) are arranged such that the positions of the bushes (77, 87) in the respective circumferential directions coincide. In other words, the arrangement angle of the second cylinder (81) with respect to the first cylinder (71) is 0 °. Further, as described above, the first expansion side eccentric part (36) and the second expansion side eccentric part (37) are eccentric in the same direction with respect to the axis of the second crankshaft (35). Accordingly, at the same time as the first blade (76) is most retracted to the outside of the first cylinder (71), the second blade (86) is also most retracted to the outside of the second cylinder (81). .

  The intermediate plate (53) is provided with a communication path (54) so as to penetrate the plate (53) in the thickness direction. On the surface of the intermediate plate (53) on the first cylinder (71) side, one end of the communication path (54) opens at a position on the right side of the first blade (76) in FIG. On the other hand, on the surface of the intermediate plate (53) on the second cylinder (81) side, the other end of the communication path (54) is opened at the left side of the second blade (86). That is, the communication path (54) is provided so as to connect the first low pressure chamber (74) and the second high pressure chamber (83). As described above, the first low pressure chamber (74) and the second high pressure chamber (83) communicated with each other via the communication path (54) form one expansion chamber (59).

  The second cylinder (81) is formed with an outflow port (57). The outflow port (57) opens at a position slightly on the right side of the bush (87) in FIG. 4 on the inner peripheral surface of the second cylinder (81), and can communicate with the second low pressure chamber (84). ing. As shown in FIGS. 1 and 2, the outflow port (57) communicates with the outlet pipe (25).

  As one of the characteristic portions of the present invention, the front head (51) has first and second suctions for introducing refrigerant into the first fluid chamber (72) of the first cylinder (71). Ports (55, 56) are formed. As shown in FIG. 3, these suction ports (55, 56) extend radially inward from the outer peripheral surface of the front head (51), and the end portions thereof are bent upward so that the front head (51) It is formed so as to open on the upper surface. That is, in FIG. 4, when the first fluid chamber (72) is viewed from above, the first suction port (55) extends in the radial direction and opens at a position slightly to the left of the bush (77). The two suction ports (56) extend in the radial direction, and are provided so as to open at a position forming a predetermined angle (for example, 160 degrees) so as to be located on the substantially opposite side to the first suction port (55). Details of the angular position of the second suction port (56) will be described later.

  Here, the first suction port (55) is provided in the first introduction pipe (24) provided with the front throttle valve (60), and the second suction port (56) is provided in the opening / closing valve (61). The second introduction pipe (27) communicates.

  Thus, by providing a plurality of suction ports (55, 56) for introducing the refrigerant into the first fluid chamber (72), the amount of refrigerant introduced into the fluid chamber (72) can be easily adjusted. It can be carried out. That is, when the circulation amount (mass flow rate, the same applies hereinafter) of the refrigerant is insufficient only by the first suction port (55), the refrigerant is introduced also from the second suction port (56), so that the expansion mechanism ( 50) can secure the necessary amount of refrigerant circulation.

  Further, as described above, by connecting the suction port (55, 56) from the lower side to the first fluid chamber (72), for example, the on-off valve (61) is closed to close the second suction port (56). When the refrigerant is not introduced from the refrigerant, the refrigerating machine oil in the fluid chamber (72) accumulates in the second suction port (56) and fills the space. Therefore, the second suction port (56 ) Can be prevented from entering the refrigerant. That is, with the configuration as described above, the second suction port (56) can be prevented from becoming dead volume, so that the refrigerant can be efficiently expanded by the expansion mechanism (50).

  Here, in the expansion mechanism (50) configured as described above, the front head (51) that closes both ends of the first cylinder (71), the first bush (77), and the first cylinder (71). The intermediate plate (53), the first piston (75), and the first blade (76) constitute a first rotary mechanism (70). Further, the second cylinder (81), the second bush (87), the intermediate plate (53) and the rear head (52) for closing both ends of the second cylinder (81), the second piston (85), The two blades (86) constitute the second rotary mechanism (80).

  That is, the expansion mechanism (50) is a two-stage rotary expander including a first rotary mechanism (70) and a second rotary mechanism (80). Therefore, unlike the single-stage rotary expander, the suction port and the outflow port do not communicate with each other through the fluid chamber, and the high-pressure refrigerant introduced from the intake port is prevented from blowing through to the outflow port. Can do. In particular, when a plurality of suction ports are provided as in the present embodiment, the suction port and the outflow port communicate with each other in a single stage, so that the suction process and the discharge process are made independent by using two or more stages. The high pressure refrigerant can be reliably prevented from being blown through, and the high pressure refrigerant can be sufficiently expanded in the expansion chamber (59).

  In addition, the said expansion mechanism (50) is being fixed to the casing (21) via the ring-shaped mounting plate (58) similarly to the said compression mechanism (40). Specifically, the outer peripheral side of the mounting plate (58) is fixed to the inner surface of the casing (21) by welding, and the front head (51) of the expansion mechanism (50) is not shown on the mounting plate (58). It is fixed by.

-Angular position of the second suction port-
Next, how to determine the angular position of the second suction port (56) provided in the expansion mechanism (50) (the angle when the position of the blade (76, 86) is 0 °) will be described in detail below.

  As described above, by providing the second suction port (56) in addition to the first suction port (55), a larger amount of refrigerant can be caused to flow into the first fluid chamber (72). The volume of the fluid chamber (72, 82) with which the second suction port (56) communicates varies depending on the angular position where the second suction port (56) is provided. The displacement volume can be determined geometrically. Specifically, for example, as shown by a thick solid line in FIG. 16, it is possible to geometrically calculate the amount of refrigerant flowing into the expansion mechanism (50) with respect to the angular position of the second suction port (56). .

  However, since the geometrically required refrigerant inflow amount does not consider the suction pressure loss of the second suction port (56), the actual refrigerant inflow amount is smaller than the geometrically required refrigerant inflow amount. . That is, as shown in FIG. 16, the measured value (black triangle) of the refrigerant inflow amount is geometrical due to the pressure loss when the refrigerant flows into the first fluid chamber (72) from the second suction port (56). This is less than the ideal refrigerant flow rate that is theoretically required. As can be seen from FIG. 16, the second suction port (56) is provided at an angular position where the volume change of the fluid chamber (72, 82) communicating with the second suction port (56) is relatively large. Since the influence of the suction pressure loss at the second suction port (56) becomes larger, the actual refrigerant inflow amount (solid triangle) is greatly reduced compared to the geometrically required refrigerant inflow amount (thick solid line). To do.

  Therefore, in the present embodiment, the correction value is added to the angular position corresponding to the geometrically calculated refrigerant inflow amount in consideration of the decrease in the refrigerant inflow amount due to the pressure loss at the time of refrigerant intake as described above. Thus, the second suction port (56) is provided at an angular position corresponding to the actual refrigerant inflow amount.

  Here, in this embodiment, the expansion ratio of the expansion mechanism (50) is set so as to be optimal during the rated operation of heating. Therefore, as will be described in detail later, during the rated operation of cooling, Since the pressure on the low-pressure side is higher than that during rated operation, it is necessary to increase the inflow amount of the high-pressure refrigerant. Therefore, it is necessary to set the position of the second suction port (56) so that the necessary refrigerant inflow amount can be supplied from the second suction port (56) during rated operation of the cooling.

  FIG. 17 shows a calculation example of the angular position of the second suction port (56). In FIG. 17, the performance of the outdoor heat exchanger (14) (outdoor heat exchange) and the indoor heat exchanger (15) (indoor heat exchange) of the air conditioner (1) is changed (up or down) based on the actually measured values. In this case, the angular position of the second suction port (56) is obtained so that the refrigerant flow rate required for the heating rated operation and the cooling rated operation in each case can be secured. Here, in FIG. 17, the high pressure indicates the discharge pressure from the compression mechanism (40), and the low pressure indicates the suction pressure of the compression mechanism (40). Further, the gas cooler outlet temperature is substantially equal to the inlet temperature of the expansion mechanism (50).

  As shown in FIG. 17, in this calculation example, the expansion ratio at the rated operation of heating is 2.7 to 3.0, whereas the displacement required at the rated operation of cooling is 1.3. It is ˜1.6 times (this ratio is called displacement volume ratio). Then, the angular position of the second suction port (56), which is geometrically determined from the displacement ratio and expansion ratio required during rated operation of the cooling, is calculated based on the thick solid line in FIG.

  On the other hand, when the angular position of the second suction port (56) for obtaining the displacement required during the rated operation of the cooling is obtained using the approximate curve (thin solid line) of the actual measurement values in FIG. The value shown at the right end of

  Therefore, as shown in FIG. 17, the correction value of about 50 to 65 ° is added to the geometrically determined angular position of the second suction port (56), so that it is necessary during the rated operation of the cooling. The angular position where the displacement volume can be obtained can be obtained. In addition, you may correct | amend by adding about 60 degrees with respect to the angular position of the said 2nd suction | inhalation port (56) calculated | required geometrically. Even in this case, it is possible to obtain a flow rate that is closer to the required refrigerant flow rate than when the angle correction is not performed.

  Here, as shown in FIG. 16, the relationship between the angular position of the second suction port (56) and the refrigerant flow rate obtained geometrically (indicated by a thick broken line) even under different conditions (when the refrigerant flow rates are different). On the other hand, as described above, the geometrically determined angular position of the second suction port (56) is corrected in consideration of the pressure loss during the suction of the second suction port (56) (shown by a thin broken line). Thus, the measured values (white triangles) almost coincide. Therefore, the angular position of the second suction port (56) can be obtained with sufficiently high accuracy by the correction method as described above. In the present embodiment, the position of the second suction port (56) is preferably provided at an angular position larger than 120 ° at which the refrigerant flow rate changes by 10% or more, as is apparent from FIG. As shown in FIG. 17, it is more preferable to provide in the range of 150 to 200 °.

-Driving action-
The operation of the air conditioner (1) will be described. Here, the operation of the air conditioner (1) during the cooling operation and the heating operation will be described, and then the operation of the expansion mechanism (50) will be described.

<Cooling operation>
During the cooling operation, the four-way selector valve (12) is switched to the state indicated by the broken line in FIG. When the electric motor (26) of the compression / expansion unit (20) is energized in this state, the refrigerant circulates in the direction of the broken line arrow in the refrigerant circuit (10) to perform a vapor compression refrigeration cycle.

  The refrigerant compressed by the compression mechanism (40) is discharged from the compression / expansion unit (20) through the discharge pipe (23). In this state, the refrigerant pressure is higher than the critical pressure. This discharged refrigerant is sent to the outdoor heat exchanger (14) to radiate heat to the outdoor air.

  The high-pressure refrigerant radiated by the outdoor heat exchanger (14) flows into the expansion mechanism (50) through the introduction pipes (24, 27). In the expansion mechanism (50), the high-pressure refrigerant expands, and power is recovered from the high-pressure refrigerant. The low-pressure refrigerant after expansion is sent to the indoor heat exchanger (15) through the outlet pipe (25).

  In the indoor heat exchanger (15), the refrigerant that has flowed in absorbs heat from the room air and evaporates, thereby cooling the room air. The low-pressure gas refrigerant exiting from the indoor heat exchanger (15) is sucked into the compression mechanism (40) through the suction pipe (22). The compression mechanism (40) compresses and discharges the sucked refrigerant again.

<Heating operation>
During the heating operation, the four-way selector valve (12) is switched to the state shown by the solid line in FIG. When the electric motor (26) of the compression / expansion unit (20) is energized in this state, the refrigerant circulates in the direction of the solid arrow in the refrigerant circuit (10) to perform a vapor compression refrigeration cycle.

  The refrigerant compressed by the compression mechanism (40) is discharged from the compression / expansion unit (20) through the discharge pipe (23). In this state, the refrigerant pressure is higher than the critical pressure. This discharged refrigerant is sent to the indoor heat exchanger (15). In the indoor heat exchanger (15), the refrigerant that has flowed in dissipates heat to the room air, and the room air is heated.

  The refrigerant radiated by the indoor heat exchanger (15) flows into the expansion mechanism (50) through the introduction pipe (24, 27). In the expansion mechanism (50), the high-pressure refrigerant expands, and power is recovered from the high-pressure refrigerant. The low-pressure refrigerant after expansion is sent to the outdoor heat exchanger (14) through the outlet pipe (25) and absorbs heat from the outdoor air to evaporate. The low-pressure gas refrigerant discharged from the outdoor heat exchanger (14) is sucked into the compression mechanism (40) through the suction pipe (22). The compression mechanism (40) compresses and discharges the sucked refrigerant again.

<Operation of expansion mechanism>
The operation of the expansion mechanism (50) will be described with reference to FIG.

  First, a process in which the supercritical high pressure refrigerant flows into the first high pressure chamber (73) of the first rotary mechanism (70) will be described. When the second crankshaft (35) is slightly rotated from the state where the rotation angle is 0 °, the contact position between the first piston (75) and the first cylinder (71) passes through the opening of the first suction port (55). The high-pressure refrigerant begins to flow from the first suction port (55) into the first high-pressure chamber (73). Thereafter, as the rotation angle of the second crankshaft (35) gradually increases to 60 °, 180 °, and 270 °, the high-pressure refrigerant flows into the first high-pressure chamber (73). The high-pressure refrigerant flows from the first suction port (55) into the first high-pressure chamber (73) until the rotation angle of the second crankshaft (35) reaches about 360 ° (until the first suction port is closed). )Continue.

  At this time, if the on-off valve (61) is in an open state, the rotation angle of the second crankshaft (35) becomes a predetermined angle (eg, 160 ° in the present embodiment), and the first piston (75) When the contact position with the first cylinder (71) passes through the opening of the second suction port (56), the high-pressure refrigerant begins to flow into the first high-pressure chamber (73) also from the second suction port (56). . The inflow of the high-pressure refrigerant from the second suction port (56) into the first high-pressure chamber (73) continues until the second suction port (56) is closed.

  Therefore, the first high pressure is maintained until the rotation angle of the second crankshaft (35) exceeds 360 ° and reaches the angle (520 ° in the present embodiment) until the second suction port (56) is closed. The high-pressure refrigerant flows into the chamber (73) from the first and second suction ports (55, 56), compared to the conventional configuration in which only the first suction port (55) is provided. The suction process can be extended and more high-pressure refrigerant can be introduced.

  Next, the process in which the refrigerant expands in the expansion mechanism (50) will be described. As shown in FIG. 5, when the second crankshaft (35) is slightly rotated from 0 ° (360 °), the first high pressure chamber (73) of the first cylinder (71) and the second cylinder (81) The second high pressure chamber (83) communicates with the other through the communication passage (54), and the refrigerant starts to flow from the first high pressure chamber (73) to the second high pressure chamber (83). As described above, while the high-pressure refrigerant is flowing from the second suction port (56) into the first high-pressure chamber (73), the first high-pressure chamber (73) and the second high-pressure chamber (83) are almost free. Although the refrigerant does not expand, after the second suction port (56) is closed (after the rotation angle reaches about 520 °), the rotation angle of the second crankshaft (35) is 540 °, 630 °. As the volume gradually increases, the volume of the first high-pressure chamber (73), that is, the first low-pressure chamber (74) gradually decreases, and at the same time, the volume of the second high-pressure chamber (83) gradually increases. As a result, the expansion chamber (59) The volume of will gradually increase. This increase in the volume of the expansion chamber (59) continues until just before the rotation angle of the second crankshaft (35) reaches 720 °. And the refrigerant | coolant in an expansion chamber (59) expands in the process in which the volume of an expansion chamber (59) increases, and a 2nd crankshaft (35) is rotationally driven by expansion | swelling of this refrigerant | coolant. Thus, the refrigerant in the first low pressure chamber (74) flows through the communication passage (54) while being expanded to the second high pressure chamber (83).

  Next, the process in which the refrigerant flows out from the second low pressure chamber (84) of the second rotary mechanism (80) will be described. When the refrigerant expands in the second high pressure chamber (83), the second high pressure chamber (83) starts to communicate with the outflow port (57) from the time when the rotation angle of the second crankshaft (35) is 720 °, It becomes a 2nd low pressure chamber (84). That is, the refrigerant begins to flow out from the second low pressure chamber (84) to the outflow port (57). Thereafter, the rotation angle of the second crankshaft (35) gradually increases to 810 °, 900 °, and 990 °, and until the rotation angle reaches 1080 °, the second low pressure chamber (84). The low-pressure refrigerant after expansion flows out from.

  FIG. 6 shows the relationship between the suction volume change and the pressure change of the expansion chamber (59) in the expansion mechanism (50). In FIG. 6, the broken line indicates a graph when high-pressure refrigerant is introduced only from the first suction port (55) and no overexpansion occurs, and the thin solid line indicates high-pressure refrigerant introduced only from the first suction port (55). Thus, a graph in the case where overexpansion has occurred, and a thick solid line respectively show a graph in the case where high-pressure refrigerant is introduced also from the second suction port (56).

  For example, when overexpansion has not occurred in the expansion mechanism (50) (in the case of the broken line in FIG. 6), the high-pressure refrigerant in the supercritical state is in the first high-pressure chamber (73) between points a and b. ) Flows in. Thereafter, the first high pressure chamber (73) communicates with the communication passage (54) and switches to the first low pressure chamber (74). In the expansion chamber (59) composed of the first low pressure chamber (74) and the second high pressure chamber (83), the internal high pressure refrigerant suddenly drops in pressure from point b to point c and becomes saturated. The saturated refrigerant expands while partially evaporating, and gradually drops in pressure to point d. The second high pressure chamber (83) communicates with the outflow port (57) and switches to the second low pressure chamber (84). The refrigerant in the second low pressure chamber (84) is sent out to the outflow port (35) until point e. At this time, the density ratio between the intake refrigerant and the exhaust refrigerant coincides with the design expansion ratio, and the operation with high power recovery efficiency is performed.

  On the other hand, the high pressure or the low pressure may deviate from the design value due to switching between the cooling operation and the heating operation or a change in the outside air temperature. That is, in FIG. 6, when the expansion mechanism (50) is designed so that the pressure and the suction volume change as indicated by the broken line when the air conditioner (1) is rated for heating, when the cooling mechanism is switched to the cooling operation, The pressure on the side increases to the level of the thin solid line, and an overexpanded region (D) is generated.

  On the other hand, as described above, by introducing the high-pressure refrigerant also from the second suction port (56), the suction capacity in the range obtained by adding the thick solid line region (C) to the region B in FIG. Change and pressure change occur, and more power can be recovered accordingly.

  The above-described configuration can recover power more efficiently than in the case of the injection method in the conventional expansion process (FIG. 7). That is, as shown in FIG. 7, in the configuration in which the injection is performed, in addition to the region B where the power is recovered by the high-pressure refrigerant introduced from the first suction port (55), only the portion of the region C is recovered as the effect of the injection. Can not do. On the other hand, as shown by the alternate long and short dash line in FIG. 7, more power can be recovered with the above-described configuration.

  By the way, the refrigerant circuit (10) is a closed circuit, and the flow rate of the refrigerant in the expansion mechanism (50) needs to coincide with the flow rate of the refrigerant in the compression mechanism (40). ) Is configured not only to simply increase the refrigerant circulation amount of the expansion mechanism (50) as described above, but also to adjust the refrigerant circulation amount to an appropriate amount.

  Hereinafter, control of each valve (60, 61, 66) for controlling the flow rate of the refrigerant of the expansion mechanism (50) will be described in detail.

<Valve control>
Open / close control of the front throttle valve (60) provided in the first introduction pipe (24), the on-off valve (61) provided in the second introduction pipe (27), and the bypass valve (66) provided in the bypass pipe (65) Or flow control is demonstrated, referring FIGS. 8-12.

  In the air conditioner (1) according to the present embodiment, as shown in FIG. 8, pressure detection means (90) for detecting the pressure of the high-pressure refrigerant introduced into the expansion mechanism (50) is provided. This pressure detection means (90) is comprised by the pressure sensor (illustration omitted) etc. which detect the pressure of the discharge side of a compression mechanism (40), for example. The pressure value of the high-pressure refrigerant detected by the pressure detection means (90) is sent to the controller (91).

  Here, the controller (91) includes a front throttle valve flow rate control unit (92) for controlling the flow rate of the front throttle valve (60), and an open / close control unit for performing open / close control of the open / close valve (61). (93) and a bypass valve flow rate control unit (94) for controlling the flow rate of the bypass valve (66), and based on the pressure value detected by the pressure detection means (90), The control units (92, 93, 94) are configured to control the valves (60, 61, 66).

  The front throttle valve flow control unit (92) is the flow control means of the present invention, the open / close control unit (93) is the open / close valve control means of the present invention, and the bypass valve flow control unit (94) is the present invention. Correspond to the bypass flow rate control means.

  Hereinafter, specific control of each valve (60, 61, 62) will be described based on the flowchart of FIG. The initial state is a state in which the on-off valve (61) is closed.

  First, when the flow of FIG. 9 starts, the pressure of the high-pressure refrigerant introduced into the expansion mechanism (50) is detected by the pressure detection means (90) in step S1. The pressure value is compared with a preset target value (step S2). If the pressure value is larger than the target value (in the case of YES), first, the bypass valve (66) so that the pressure value becomes the target value. To finely adjust the refrigerant circulation to the expansion mechanism (50). When the opening degree of the bypass valve (66) reaches a predetermined value (YES in step S4), the on-off valve (61) is opened to increase the refrigerant circulation amount of the expansion mechanism (50). Thus, the refrigerant is adjusted to have the same circulation amount as that of the compression mechanism (40) (step S5). Even when the on-off valve (61) is opened as described above, the circulation amount is finely adjusted by the bypass valve (66). If the opening degree of the bypass valve (66) is smaller than a predetermined value in step S4, the process returns to step S2 until the pressure value reaches the target value or the opening degree of the bypass valve (66). The opening degree of the bypass valve (66) is increased until a predetermined value is reached.

  Here, the target value is set to a pressure value at which COP is maximized, and the predetermined value of the opening degree of the bypass valve (66) corresponds to the predetermined opening degree of the present invention, and the bypass valve (66) is It means the opening that cannot be opened any more, or that the flow rate cannot be adjusted much even if it is opened further.

  On the other hand, if the pressure value is less than or equal to the target value (NO in step S2), the process proceeds to step S6 to determine whether or not the pressure value is smaller than the target value. If it is determined that the pressure value is not smaller than the target value (NO in step S6), since the pressure value is equal to the target value, the process returns to the start (return) and starts this flow again.

  If it is determined in step S6 that the pressure value is smaller than the target value (in the case of YES), the bypass valve (66) is closed in subsequent step S7 so that the pressure value becomes the target value. Then, the refrigerant circulation amount to the expansion mechanism (50) is finely adjusted. If the pressure value is still smaller than the target value (YES in step S8), in the subsequent step S9, the on-off valve (61) is closed and the refrigerant is circulated to the expansion mechanism (50). Reduce the amount. At this time, since the refrigerant circulation amount of the compression mechanism (40) is small, it is necessary to reduce the expansion mechanism (50) accordingly. At this time, fine adjustment of the refrigerant circulation amount to the expansion mechanism (50) is performed by the bypass valve (66).

  If the pressure value is smaller than the target value even when the on-off valve (61) is closed in step 9, the bypass valve (66) is fully closed or almost fully closed (in the case of YES in step S10). If it is smaller than the target value (YES in step S12), the front throttle valve (60) is throttled to adjust the refrigerant circulation amount (step S13). After that, it returns to the start (return) and starts this flow again.

  On the other hand, when it is determined in steps S8, S10, and S12 that the pressure value is not smaller than the target value (in the case of NO), the pressure value is equal to the target value, so the process returns to the start (return) ) Start this flow again.

  FIG. 10 schematically shows the relationship between the refrigerant circulation amount of the expansion mechanism (50) and the opening degree of the valves (60, 61, 66) in an example of the valve control according to the flowchart shown in FIG. FIG. 11 shows the relationship between the refrigerant suction volume and the pressure when the on-off valve is opened, and FIG. 10 to 12 are examples in which a plurality of suction ports of the expansion mechanism (50) are provided. In this case, only the number of on-off valves is increased accordingly, so that FIG. In this case, a step for opening other open / close valves or closing them may be added.

  As shown in FIG. 10, when the pressure value of the high-pressure refrigerant is larger than the target value, the front throttle valve (60) is fully opened, and step (STP) proceeds (the numerical value of STP increases). If the difference between the pressure value and the target value is small, fine adjustment of the flow rate of the high-pressure refrigerant introduced into the expansion mechanism (50) so that the pressure value becomes the target value by the bypass valve (66), When the opening degree of the bypass valve (66) exceeds a predetermined opening degree (80% in the figure), the on-off valve (61) is opened. In the example of FIG. 10, there are provided three suction ports of the expansion mechanism (50). The second suction port is a second suction valve, and the third suction port is a third suction port. It is a valve.

  Conversely, when the pressure value decreases and the difference from the target value gradually decreases, the step (STP) proceeds in a decreasing direction, and the flow rate is controlled by the bypass valve (66) while the on-off valve (61) When the pressure value is still smaller, the bypass valve (66) is fully closed, and the refrigerant circulation amount is adjusted by the front throttle valve (60).

  That is, as shown in FIG. 11, when the refrigerant circulation amount of the expansion mechanism (50) is increased, the refrigerant circulation amount can be increased stepwise by sequentially opening the plurality of on-off valves. At the same time, the refrigerant circulation amount can be increased smoothly by adjusting the refrigerant circulation amount by the bypass valve (66) until the on-off valve is opened. Thus, by sequentially opening the plurality of on-off valves, as shown in FIG. 12, the refrigerant suction volume can be increased.

  On the other hand, when the refrigerant circulation amount of the expansion mechanism (50) is reduced, the refrigerant circulation amount can be reduced stepwise by the closing control of the on-off valve, and the bypass valve is closed until the on-off valve is closed. By adjusting the refrigerant circulation amount by (66), the refrigerant circulation amount can be reduced smoothly. Furthermore, even if the on-off valve is closed and the bypass valve (66) is fully closed, the refrigerant circulation amount can be adjusted by the front throttle valve (60).

  Therefore, by controlling the refrigerant circulation amount as described above, the refrigerant circulation amount to the expansion mechanism (50) can be increased and decreased quickly and smoothly in a wide range, and the refrigerant circulation amount of the compression mechanism (40) can be increased and decreased. Can keep balance with.

-Effect of Embodiment 1-
As described above, in this embodiment, the expansion mechanism (50) is provided with the first and second suction ports (55, 56), and the first introduction pipe (24) communicating with the first suction port (55) is provided. Is provided with a front throttle valve (60) and an open / close valve (61) in the second introduction pipe (27) communicating with the second suction port (56), respectively, so that the refrigerant circulation amount of the compression mechanism (40) is provided. The high-pressure refrigerant introduced into the expansion mechanism (50) can be quickly and reliably increased / decreased in accordance with the increase / decrease of the refrigerant, and the refrigerant circulation amount of the high-pressure refrigerant introduced into the expansion mechanism (50) can be reduced. ), The power can be efficiently recovered from the energy of the high-pressure refrigerant.

  Further, by opening the suction port (55, 56) below the first fluid chamber (72), the refrigerating machine oil in the fluid chamber (72) is accumulated in the suction port (55, 56). Thus, accumulation of refrigerant can be prevented. That is, by providing the suction port (55, 56) in the fluid chamber (72) so as to open from below, it is possible to prevent the suction port (55, 56) from becoming dead volume, and to expand. The mechanism (50) can efficiently expand the refrigerant.

  In addition, a bypass pipe (65) that bypasses the expansion mechanism (50) is provided, and a bypass valve (66) is provided in the bypass pipe (65), so that an abrupt refrigerant by opening / closing control of the on-off valve (61) is provided. The increase and decrease of the circulation amount can be reduced, and the refrigerant circulation amount of the expansion mechanism (50) can be changed smoothly according to the refrigerant circulation amount of the compression mechanism (40).

  Furthermore, since the expansion mechanism (50) is a two-stage rotary expander having a first rotary mechanism (70) and a second rotary mechanism (80), like a single-stage rotary expander, The suction port and the outflow port do not communicate with each other through the fluid chamber, and the high-pressure refrigerant introduced from the suction port can be prevented from blowing through to the outflow port. Therefore, in the expansion mechanism (50), the high-pressure refrigerant can be sufficiently expanded in the fluid chamber (72, 82).

  Further, the second suction port (56) is provided at an angular position obtained by performing a predetermined correction with respect to the angular position obtained geometrically so as to ensure the displacement required during rated operation of the cooling. As a result, the necessary flow rate of refrigerant flows in the fluid chamber (72) to compensate for the reduced flow rate due to the pressure loss when the refrigerant flows into the fluid chamber (72) from the second suction port (56). It is possible to prevent the refrigerant flow to the expansion mechanism (50) from becoming insufficient due to insufficient expansion during the cooling operation.

-Modification 1 of Embodiment 1-
As shown in FIG. 13, the first modification differs from the first embodiment in that a check valve (95) is provided in the second suction port (56) of the expansion mechanism (50).

  Specifically, the check valve (95) allows only the refrigerant to flow into the first fluid chamber (72) in the second suction port (56) and prevents the refrigerant from flowing in the opposite direction. Is provided. This ensures that the refrigerant flows back from the fluid chamber (72) even when the on-off valve (61) is closed and the high-pressure refrigerant is not introduced from the second suction port (56). Can be prevented. That is, the dead volume of the second suction port (56) can be reliably reduced, and the refrigerant can be efficiently expanded by the expansion mechanism (50).

-Modification 2 of Embodiment 1
As shown in FIG. 14, Modification 2 is different from the above embodiment in that the expansion mechanism is a three-stage rotary expander including three rotary mechanism portions.

  Specifically, the expansion mechanism (100) includes a first rotary mechanism portion (101) and a second rotary mechanism portion (111) having substantially the same configuration as that of the first embodiment, and further larger above them. A third rotary mechanism (121) having a diameter is provided.

  Since these rotary mechanism parts (101, 111, 121) have substantially the same configuration as in the first embodiment, detailed description thereof is omitted, but the first suction port (103) is connected to the first cylinder (102) of the first rotary mechanism part (101). ) And a second suction port (104), and a third suction port (113) and a fourth suction port (114) are provided in the second cylinder (112) of the second rotary mechanism (111), respectively. The outflow port (123) is provided in the third cylinder (122) of the third rotary mechanism (121).

  A communication path (115) is provided between the second cylinder (112) and the third cylinder (122). Specifically, in FIG. 14, the communication path (115) extends outward from the outer peripheral surface of the cylindrical second piston (116) disposed in the second cylinder (112). A bush for supporting a third blade (125) extending radially outward from a third piston (124) disposed in the third cylinder (122) from the right side of the bush (118) of the two blades (117) (126) is provided to extend to the left side.

  As a result, the fluid chamber of the second cylinder (112) communicates with the fluid chamber of the third cylinder (122), so that the first cylinder (102) to the second cylinder (112) as in the first embodiment. The refrigerant not only expands while moving to (), but also expands when moving from the second cylinder (112) into the third cylinder (122).

  By providing the expansion mechanism (100) having such a configuration with the plurality of suction ports (103, 104, 113, 114) as described above, the three-stage rotary expander can recover the power of the high-pressure refrigerant as in the first embodiment. The refrigerant circulation amount of the expansion mechanism (100) can be adjusted while performing efficiently.

<< Embodiment 2 >>
Next, a second embodiment of the present invention will be described in detail based on the drawings. As shown in FIG. 15, the second embodiment is different from the first embodiment in which the expansion mechanism (50) includes two rotary mechanism portions (70, 80), and the expansion mechanism is a scroll mechanism (200). It is composed. Since the configuration other than the expansion mechanism is the same as that of the first embodiment, description and illustration are omitted.

  Specifically, the scroll mechanism (200) includes a fixed scroll (220) fixed to a casing (not shown) and a movable scroll (210) held on the casing via an Oldham ring (not shown). I have.

  The fixed scroll (220) constitutes a scroll member, and includes a flat fixed end plate (not shown) and a spiral fixed wrap (221) erected on the fixed end plate. On the other hand, the movable scroll (210) constitutes a scroll member and includes a flat plate-like movable mirror plate (not shown) and a spiral movable wrap (211) standing on the movable mirror plate. The fixed wrap (221) of the fixed scroll (220) and the movable wrap (211) of the movable scroll (210) mesh with each other, and a plurality of fluid chambers (230) are formed between the two.

  The fixed scroll (220) has a suction port (201) and an outflow port (202), as well as a second suction port (203, 203), a third suction port (204, 204), and a fourth suction port (205, 205). Are formed two by two. The suction port (201) opens near the winding start side end of the fixed wrap (221). On the other hand, the outflow port (202) opens in the vicinity of the end of the fixed wrap (221) on the winding end side. As will be described later, the second to fourth suction ports (203, 204, 205) are provided at positions that sequentially communicate with the space on the side where the fixed wrap (221) starts to be rolled in the suction process.

  In the plurality of fluid chambers (230), a space sandwiched between the inner surface of the fixed wrap (221) and the outer surface of the movable wrap (211) is a chamber A (231) as the first fluid chamber (230). Is configured. In addition, a space sandwiched between the outer surface of the fixed wrap (221) and the inner surface of the movable wrap (211) constitutes a B chamber (232) as the second fluid chamber (230).

  When the movable scroll (210) revolves with respect to the fixed scroll (220), the second to fourth suction ports (203, 204, 205) are the second suction port (203, 203), the third suction port (204, 204), and the fourth suction port. (205, 205) starts to communicate with the fluid chamber (230) in this order until the next formed fluid chamber (230) starts to be divided into two chambers (the movable scroll (210) is 540 ° with respect to the fixed scroll (220). Until the revolution), the fluid chamber (230) communicates.

  The introduction pipes connected to the second to fourth suction ports (203, 204, 205) are each provided with an on-off valve (not shown). As in the first embodiment, according to the high pressure (the discharge pressure of the compressor), It is configured to be controlled to open and close. Also in this embodiment, it is assumed that a pre-throttle valve is provided in the introduction pipe connected to the suction port (201), and a bypass valve is provided in the bypass pipe that bypasses the expansion mechanism. The control of the valve is the same as in the first embodiment.

-Driving action-
Next, the expansion operation of the scroll mechanism (200) will be described. In the following description, an expansion operation when the pressure on the high pressure side is higher than the target value and the second to fourth suction ports (203, 204, 205) are opened will be described.

  First, the high-pressure refrigerant introduced from the suction port (201) flows into one fluid chamber (230) sandwiched between the vicinity of the winding start of the fixed wrap (221) and the vicinity of the winding start of the movable wrap (211). That is, the high-pressure refrigerant is introduced from the suction port (201) into the fluid chamber (230).

  Here, in FIG. 15, the winding start side end of the fixed wrap (221) is in contact with the inner surface of the movable wrap (211), and at the same time the winding start side end of the movable wrap (211) is the fixed wrap (221). The state in contact with the inner surface is set to 0 ° as a reference.

  As the movable scroll (210) revolves and its revolution angle increases from 60 ° to 360 °, the fluid chamber (230) expands, and the second suction port ( 203, 203), the third suction port (204, 204), and the fourth suction port (205, 205) communicate with each other in this order. At this time, when the revolution angle of the movable scroll (210) exceeds 180 °, the fluid chamber (230) is gradually divided into two spaces, and when the revolution angle becomes 360 °, the fluid chamber (230) is partitioned into the A chamber (231) and the B chamber (232).

  Subsequently, until the revolution angle of the movable scroll (210) reaches 540 ° through 420 °, 480 °, the second to fourth suction ports (203, 204, 205) are provided in the A chamber (231) and the B chamber (232). Are communicated and high-pressure refrigerant is introduced. That is, the range until the revolution angle reaches 540 ° corresponds to the suction process.

  Thereafter, when the revolution angle of the movable scroll (210) exceeds 540 °, the second to fourth suction ports (203, 204, 205) are closed with respect to the chamber A (231) and the chamber B (232), The volumes of the A chamber (231) and the B chamber (232) are expanded, and the refrigerant begins to expand in the A chamber (231) and the B chamber (232).

  The expansion process in the A chamber (231) continues until the revolution angle of the movable scroll (210) reaches 1020 °, and when the movable scroll (210) further rotates, the A chamber (231) is discharged from the outflow port ( 202), the refrigerant in the A chamber (231) flows out from the outflow port (202) to the outside, and the discharge process is started.

  On the other hand, the expansion process in the B chamber (232) continues until the revolution angle of the movable scroll (210) reaches 840 °, and when the movable scroll (210) further rotates, the B chamber (232) flows out. In communication with the port (202), the refrigerant in the B chamber (232) flows out from the outflow port (202) to the outside, and the discharge process is started.

  In the above embodiment, four suction ports are provided. However, the present invention is not limited to this. As in the first embodiment, only two suction ports may be provided, or three or five or more may be provided. .

-Effect of Embodiment 2-
As described above, according to this embodiment, even in the expansion mechanism constituted by the scroll mechanism (200), as in the first embodiment, by providing a plurality of suction ports (201, 203, 204, 205), power can be recovered efficiently. The refrigerant circulation amount of the expansion mechanism can be increased. That is, for example, even when the pressure value on the high pressure side is larger than the target value and the refrigerant circulation amount of the expansion mechanism needs to be increased, the necessary refrigerant circulation amount can be reduced by introducing the high-pressure refrigerant from the suction port (203, 204, 205). The refrigerant circulation amount of the expansion mechanism and the refrigerant circulation amount of the compression mechanism can be balanced.

<< Other Embodiments >>
The present invention may be configured as follows with respect to the above embodiment.

  In the first embodiment, each rotary mechanism (70, 80) of the expansion mechanism (50) is configured by a swinging piston type rotary fluid machine. However, the present invention is not limited thereto, and a rolling piston type rotary fluid is used. You may comprise each rotary mechanism part (70,80) with a machine. In this case, in each rotary mechanism (70, 80), the blade (76, 86) is formed separately from the piston (75, 85). Further, the bushes (77, 87) are omitted from the rotary mechanism portions (70, 80). The blade (76, 86) follows the movement of the piston (75, 85) in the radial direction of the cylinder (71, 81) with its tip pressed against the outer peripheral surface of the piston (75, 85). Reciprocate to.

  In the first embodiment, the two suction ports (55, 56) are provided in the expansion mechanism (50). However, the present invention is not limited to this, and three or more suction ports may be provided. Furthermore, in the second embodiment, the four suction ports (201, 203, 204, 205) are provided in the scroll mechanism (200). However, the number is not limited to this, and two or three, or five or more may be provided.

  Further, in the first embodiment, on the suction path connected to the first suction port (55) of the expansion mechanism (50), on the downstream side of the branch position with the suction path connected to the second suction port (56), Although the throttle valve (60) is provided, this is not restrictive, and the throttle valve (60) may be provided upstream of the branch position. In this case, the entire flow rate of the first and second suction ports (55, 56) is adjusted by the front throttle valve.

  As described above, the present invention is useful for a refrigeration apparatus including an expansion mechanism that generates power by expansion of a fluid.

It is a schematic block diagram of the refrigerant circuit of the air conditioning apparatus which concerns on Embodiment 1. It is a longitudinal cross-sectional view of a compression / expansion unit. It is an expanded sectional view which shows the longitudinal cross-section of an expansion mechanism. It is an expanded sectional view which shows the cross section of the principal part in an expansion mechanism. In the expansion mechanism of Embodiment 1, it is principal part sectional drawing which shows the state of each rotary mechanism part for every 90 degrees of rotation angles of a crankshaft. It is a graph which shows the relationship between the suction | inhalation capacity | capacitance of the refrigerant | coolant of an expansion mechanism, and a pressure. FIG. 7 is a view corresponding to FIG. 6 for comparing the case of injection with the present invention. It is a figure which shows schematic structure of the control apparatus which controls each valve. It is a flowchart which shows the control flow of each valve. It is a figure which shows an example of control of each valve. It is the figure which showed typically the relationship between the total valve opening degree of each valve, and the refrigerant | coolant circulation amount of an expansion mechanism. It is a graph which shows an example of the relationship between the suction | inhalation capacity | capacitance and the pressure of a refrigerant | coolant at the time of making a some suction port open. FIG. 6 is a diagram corresponding to FIG. 3 according to a first modification of the first embodiment. FIG. 5 is a diagram corresponding to FIG. 4 according to a second modification of the first embodiment. In the expansion mechanism of Embodiment 2, it is a cross-sectional view which shows the state for every rotation angle of 60 degrees of a movable scroll. It is a graph which shows an example of the relationship between the angle position of a 2nd suction port, and a refrigerant | coolant flow rate. It is a figure which shows the calculation result of the angular position of the 2nd suction port at the time of changing the performance of a heat exchanger.

1 Air conditioning equipment (refrigeration equipment)
10 Refrigerant circuit 20 Compression / Expansion unit 24 First introduction pipe (suction passage)
27 Second introduction pipe (suction path)
40 Compression mechanism 50 Expansion mechanism 55 First suction port (main suction hole)
56 Second suction port (auxiliary suction hole)
59 Expansion chamber 60 Front throttle valve (flow adjustment valve)
61 On-off valve 65 Bypass pipe (bypass circuit)
66 Bypass valve (Bypass flow control valve)
70 First Rotary Mechanism 71 First Cylinder (First Member)
72 First fluid chamber (fluid chamber)
75 First piston (second member)
80 Second rotary mechanism 81 First cylinder (first member)
82 Second fluid chamber (fluid chamber)
85 Second piston (second member)
90 Pressure detecting means 92 Front throttle valve flow control unit (flow control means)
93 Open / close control unit (open / close valve control means)
94 Bypass valve flow control unit (Bypass flow control means)
95 Check valve 100 Expansion mechanism 101 First rotary mechanism 102 First cylinder (first member)
103 1st suction port (main suction hole)
104 Second suction port (auxiliary suction hole)
111 Second rotary mechanism 112 Second cylinder (first member)
113 Third suction port (auxiliary suction hole)
114 Fourth suction port (auxiliary suction hole)
116 Second piston (second member)
121 Third rotary mechanism 122 Third cylinder (first member)
124 3rd piston (2nd member)
200 Scroll mechanism (expansion mechanism)
201 Suction port (main suction hole)
203 Second suction port (auxiliary suction hole)
204 Third suction port (auxiliary suction hole)
205 4th suction port (auxiliary suction hole)
210 Movable scroll (first member, scroll member)
211 Movable wrap (wrap)
220 Fixed scroll (second member, scroll member)
221 Fixed wrap (wrap)
230 Fluid chamber 231 A chamber (fluid chamber)
232 Room B (fluid chamber)

Claims (9)

The first member (71, 81, 102, 112, 210) and the second member (75, 85, 116, 124, 220) that are relatively eccentrically moved, the power is generated by the expansion of the fluid in the fluid chamber (72, 82, 230) formed between the two members. A refrigeration apparatus having an expansion mechanism (50, 100, 200) to be generated,
In the expansion mechanism (50, 100, 200), first in the suction process, after the main suction hole (55, 103, 201) communicating with the fluid chamber (72, 82, 230) and the suction path (24), the main suction hole (55, 103, 201) is communicated. An auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) for communicating the fluid chamber (72, 82, 230) and the suction passage (27) is provided,
In the expansion mechanism (50, 100, 200), the fluid chamber (72, 82, 230) is partitioned so that at least the suction process and the discharge process are performed independently in the fluid chamber (72, 82, 230).
The auxiliary suction hole (56,104,113,114,203,204,205) is provided so as to open from below to the fluid chamber (72,230),
On-off valve control means (93) for controlling the on-off valve (61) provided on the suction passage (27) connected to the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) based on the pressure of the fluid introduced into the expansion mechanism (50, 100, 200). )
A plurality of the auxiliary suction holes (56,104,113,114,203,204,205) are provided, and an opening / closing valve (61) is provided on the suction passage (27) connected to each of the auxiliary suction holes (56,104,113,114,203,204,205),
The on-off valve control means (93) is configured so that the fluid chamber (72, 82, 230) and the suction passage (27) are sequentially communicated by the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) when the pressure is larger than a target value. , Control the opening of the on-off valve (61) in order,
A bypass flow rate control means (94) for controlling a bypass flow rate adjustment valve (66) provided in the bypass circuit (65) that bypasses the expansion mechanism (50, 100, 200);
The bypass flow rate control means (94) controls the bypass flow rate adjustment valve (66) so that the pressure becomes a target value,
The open / close valve control means (93) controls opening / closing of the open / close valve (61) when the bypass flow rate adjusting valve (66) reaches a predetermined opening degree. The first member (71, 81, 102, 112, 210) and the second member (75, 85, 116, 124, 220) that are relatively eccentrically moved, the power is generated by the expansion of the fluid in the fluid chamber (72, 82, 230) formed between the two members. A refrigeration apparatus having an expansion mechanism (50, 100, 200) to be generated,
In the expansion mechanism (50, 100, 200), first in the suction process, after the main suction hole (55, 103, 201) communicating with the fluid chamber (72, 82, 230) and the suction path (24), the main suction hole (55, 103, 201) is communicated. An auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) for communicating the fluid chamber (72, 82, 230) and the suction passage (27) is provided,
In the expansion mechanism (50, 100, 200), the fluid chamber (72, 82, 230) is partitioned so that at least the suction process and the discharge process are performed independently in the fluid chamber (72, 82, 230).
The auxiliary suction hole (56,104,113,114,203,204,205) is provided so as to open from below to the fluid chamber (72,230),
On-off valve control means (93) for controlling the on-off valve (61) provided on the suction passage (27) connected to the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) based on the pressure of the fluid introduced into the expansion mechanism (50, 100, 200). )
A plurality of the auxiliary suction holes (56,104,113,114,203,204,205) are provided, and an opening / closing valve (61) is provided on the suction passage (27) connected to each of the auxiliary suction holes (56,104,113,114,203,204,205),
The on-off valve control means (93) closes the on-off valve (61) in order from the auxiliary suction hole (56, 104, 113, 114, 203, 204, 205) last communicating with the fluid chamber (72, 82, 230) when the pressure is smaller than a target value. Control
A bypass flow rate control means (94) for controlling a bypass flow rate adjustment valve (66) provided in the bypass circuit (65) that bypasses the expansion mechanism (50, 100, 200);
The bypass flow rate control means (94) controls the bypass flow rate adjustment valve (66) so that the pressure becomes a target value,
The open / close valve control means (93) controls opening / closing of the open / close valve (61) when the bypass flow rate adjusting valve (66) reaches a predetermined opening degree. In claim 1 or 2,
A flow rate control means (92) for controlling a flow rate adjustment valve (60) provided on the suction passage (24) connected to the main suction hole (55,103,201),
When the pressure is smaller than a target value even when the bypass flow rate adjustment valve (66) and the on-off valve (61) are all closed, the flow rate control means (92) is operated by the flow rate adjustment valve (60). A refrigeration apparatus that adjusts the flow rate of an expansion mechanism (50, 100, 200). In any one of Claim 1 to 3,
The expansion mechanism (50, 100) has a plurality of rotary mechanism parts (70, 80, 101, 111, 121) connected in series in order from the smallest displacement volume,
The main suction hole (55, 103) and the auxiliary suction hole (56, 104, 113, 114) are provided in the rotary mechanism part (70, 101, 111) on the front stage side of the final stage rotary mechanism part (80, 121). In claim 4,
The expansion mechanism (50) has two rotary mechanism parts (70, 80) connected in series,
A refrigerating apparatus characterized in that the main suction hole (55) and the auxiliary suction hole (56) are provided in a rotary mechanism part (70) in a preceding stage having a small displacement volume. In claim 4 or 5,
The auxiliary suction hole (56, 104, 113, 114) is provided at an angular position obtained by adding a predetermined correction value to an angular position obtained geometrically based on a desired displacement volume. Refrigeration equipment. In claim 6,
The desired displacement volume is a displacement volume necessary for cooling operation. In any one of Claim 1 to 3,
The expansion mechanism (200) includes a pair of scroll members (210, 220) in which a spiral wrap is formed on the end plate, and at least a pair of fluids is obtained by meshing the wraps (211, 221) of the scroll members (210, 220) with each other. A scroll mechanism constituting the chamber (231,232),
The refrigeration apparatus, wherein the main suction hole (201) and the auxiliary suction holes (203, 204, 205) are provided at positions communicating with the fluid chamber (231, 232) in the suction process of the scroll mechanism. In any one of Claims 1-8,
A refrigeration apparatus configured to perform a supercritical refrigeration cycle using a refrigerant composed of CO ₂ as the fluid.

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