JP5536420B2 - Separate type air conditioner - Google Patents

Description

The present invention relates to a separate type air conditioner .

  A parallel flow type in which a plurality of flat tubes are arranged between two header pipes, and a plurality of refrigerant passages in the flat tubes communicate with the inside of the header pipe, and fins such as corrugated fins are arranged between the flat tubes. Heat exchangers are widely used in car air conditioners and building air conditioners. Examples of this type of heat exchanger can be found in US Pat.

  In a parallel flow type heat exchanger, a receiver tank may be connected to one of the two header pipes. The receiver tank serves as a buffer that adjusts the amount of refrigerant in the heat exchanger, performs gas-liquid separation of the refrigerant, and removes moisture and foreign substances in the refrigerant with filter means inserted therein. It is provided for the purpose. Examples of parallel flow heat exchangers having a receiver tank can be seen in Patent Documents 3-6.

  In the parallel flow type heat exchanger, a plurality of flat tubes are divided into several groups, and after flowing the refrigerant from the first header pipe to the second header pipe through the first group of flat tubes, the flat flow of the second group is obtained. Follow the zigzag path, such as returning the refrigerant from the second header pipe to the first header pipe through the tube, and again flowing the refrigerant from the first header pipe to the second header pipe through the third group of flat tubes. It is often done to flow the refrigerant in the form. The number of times the refrigerant changes the flow direction between the first header pipe and the second header pipe is referred to as “number of turns” as described in Patent Document 2.

JP 63-34466 A JP-A-6-213534 JP 11-270927 A JP 2001-336863 A JP 2003-42601 A JP 2009-162468 A

When a device equipped with a heat exchanger is moved, a so-called pump-down operation in which all the refrigerant in the refrigeration cycle is concentrated on a specific heat exchanger may be required. An object of the present invention is to prevent the pump-down operation from adversely affecting the heat exchanger .

In order to achieve the above object, the present invention provides two header pipes arranged in parallel at a distance from each other, and a plurality of refrigerant pipes arranged between the two header pipes and provided inside the header pipe. A pump having an outdoor unit equipped with a side flow type parallel flow type heat exchanger having a flat tube communicated with the inside thereof, and concentrating refrigerant in the refrigeration cycle including the heat exchanger in the outdoor unit In a separate air conditioner that sends refrigerant to the heat exchanger at a high pressure during a down operation , a receiver tank is connected to the heat exchanger, and the capacity of the receiver tank is the entire capacity of the refrigeration cycle including the heat exchanger. from the refrigerant liquid amount, and capacity of the heat exchanger, is set to minus the capacity of the high-pressure side refrigerant pipe, when the pump-down operation is performed, and the heat exchanger Said receiver tank, wherein with a volume of the combined capacity of each of the high-pressure side refrigerant pipe, all refrigerant in the refrigeration cycle is characterized by accepting a liquid state.

According to this configuration, when performing the pump-down operation in which the refrigerant is concentrated on the heat exchanger side, the refrigerant can be received without difficulty and there is no need to worry about the occurrence of abnormally high pressure .

In the heat exchanger configured as described above, it is preferable that the receiver tank is disposed in a flow path of an air flow passing through the heat exchanger .

According to this configuration, heat exchange between the receiver tank and the external air is promoted, and the heat exchange capability of the heat exchanger can be further enhanced .

In the heat exchanger having the above-described configuration, it is preferable that the supercooling region of the heat exchanger is set to an area that is equal to or larger than an area that can ensure the degree of supercooling required at the rated capacity .

According to this configuration, the capacity of the heat exchanger can be reliably exhibited at the rated capacity .

In the heat exchanger having the above-described configuration, the plurality of flat tubes are knitted so as to form one or more turns, and one of the two header pipes is on the refrigerant pipe connection side, from the vicinity of both ends thereof. The refrigerant inlet / outlet on the refrigerant inflow side and the refrigerant inlet / outlet on the refrigerant outflow side protrude in the lateral direction, and the receiver tank is disposed so as to be sandwiched between these refrigerant inlets and outlets. When the heat exchanger is used as a condenser, the connection location is preferably set to a location where the supercooling region will continue after one turn or more .

According to this configuration, the receiver tank is disposed in the empty space between the refrigerant pipes connected so as to form a right angle with the header pipe in the vicinity of both ends of the header pipe. There is no need for space, and the effective space in the equipment equipped with the heat exchanger is not eroded. In addition, when the receiver tank is connected to the header pipe, when the heat exchanger is used as a condenser, the supercooling region is set to be continued after one turn or more. State .

  In addition, the present invention is an air conditioner in which the heat exchanger configured as described above is mounted on an outdoor unit.

According to this configuration, when performing the pump-down operation in which the refrigerant is concentrated on the heat exchanger side, the refrigerant can be received without difficulty, and an air conditioner that does not have to worry about occurrence of abnormal high pressure can be provided.

In the present invention, the capacity of the receiver tank is set to a value obtained by subtracting the capacity of the heat exchanger and the capacity of the high-pressure side refrigerant pipe from the total refrigerant liquid amount in the refrigeration cycle including the heat exchanger. During down operation, all the refrigerant in the refrigeration cycle can be received in the liquid state with the combined capacity of the heat exchanger, receiver tank, and high-pressure side refrigerant piping. There is no need to worry about the occurrence of abnormally high pressure.

It is a typical front view of the heat exchanger which is 1st Embodiment of this invention. It is a typical horizontal sectional view of the outdoor unit of the air conditioner carrying the heat exchanger of FIG. It is a typical front view of the heat exchanger which is 2nd Embodiment of this invention. It is a typical vertical sectional view explaining the structural example of the parallel flow type heat exchanger of a side flow system.

  An example of the structure of a parallel flow heat exchanger that forms the basis of the embodiment of the present invention will be described with reference to FIG. In FIG. 4, the upper side of the paper is the upper side in the vertical direction, and the lower side of the paper is the lower side in the vertical direction. Further, the left side of the paper is the left side in the left-right direction, and the right side of the paper is the right side in the left-right direction.

  The heat exchanger 1 is used in a side flow system, and two vertical header pipes 2 and 3 are arranged in parallel at intervals in the horizontal direction. The flat tubes 4 are arranged at a predetermined pitch in the vertical direction. The flat tube 4 is an elongated molded product obtained by extruding a metal, and a refrigerant passage 5 through which a refrigerant flows is formed. Since the flat tube 4 is disposed so that the extrusion direction, which is the longitudinal direction, is horizontal, the refrigerant flow direction of the refrigerant passage 5 is also horizontal. A plurality of refrigerant passages 5 having the same cross-sectional shape and cross-sectional area are arranged in the depth direction of FIG. 4, and therefore the vertical cross section of the flat tube 4 has a harmonica shape. Each refrigerant passage 5 communicates with the inside of the header pipes 2 and 3. Corrugated fins 6 are arranged between the adjacent flat tubes 4.

  Outer flat corrugated fins 6a are arranged on the flat surfaces facing the outer side of the flat tubes 4 located on the outermost side among the flat tubes 4 in which a plurality of tubes are arranged in parallel. A side plate 10 is disposed outside the outermost corrugated fin 6a.

  The header pipes 2 and 3, the flat tube 4, the corrugated fin 6, the outermost corrugated fin 6 a, and the side plate 10 are all made of a metal having good heat conductivity such as aluminum, and the flat tube 4 is The corrugated fin 6 and the outermost corrugated fin 6a are fixed to the flat tube 4 and the side plate 10 is fixed to the outermost corrugated fin 6a by brazing or welding.

  The refrigerant outlets 7 and 8 are provided only on the header pipe 3 side. That is, the header pipe 3 becomes a header pipe on the refrigerant pipe connection side. The refrigerant inlet / outlet 7 protrudes laterally from the vicinity of the upper end of the header pipe 3, and the refrigerant inlet / outlet 8 protrudes laterally from the vicinity of the lower end of the header pipe 3. In the structure of the embodiment, the refrigerant outlets 7 and 8 protrude so as to be parallel to each other and perpendicular to the axis of the header pipe 3, but it is not necessary to strictly observe this structure. When viewed from the front, one or both of the refrigerant outlets 7 and 8 may be slightly inclined with respect to the axis of the header pipe 3. Further, there is no problem even if the refrigerant inlets and outlets 7 and 8 are not kept parallel when viewed from the front or top surface. The refrigerant outlets 7 and 8 are fixed to the header pipe 3 by brazing or welding.

  Two partition plates 9a and 9c are provided in the header pipe 3 at intervals in the vertical direction. Inside the header pipe 2, the partition plates are located at a height intermediate between the partition plates 9a and 9c. 9b is provided.

  When the heat exchanger 1 is used as a condenser, the refrigerant flows in from the upper refrigerant inlet / outlet port 7 as indicated by solid line arrows in FIG. The refrigerant entering from the refrigerant inlet / outlet 7 is blocked by the partition plate 9 a and travels toward the header pipe 2 via the flat tube 4. This refrigerant flow is represented by a left-pointing block arrow. The refrigerant that has entered the header pipe 2 is blocked by the partition plate 9 b and travels to the header pipe 3 via another flat tube 4. This is the first turn, and the refrigerant flow after the turn is represented by a block arrow pointing to the right. The refrigerant that has entered the header pipe 3 is dammed up by the partition plate 9 c, and further travels toward the header pipe 2 via another flat tube 4. This is the second turn, and the flow of the refrigerant after the turn is represented by a left-pointing block arrow. The refrigerant that has entered the header pipe 2 is folded back and travels again to the header pipe 3 via another flat tube 4. This is the third turn, and the refrigerant flow after the turn is represented by a block arrow pointing to the right. The refrigerant finally flows out from the refrigerant inlet / outlet 8.

  Thus, the refrigerant follows the zigzag path while repeating the turn and flows from the top to the bottom. Here, the case where the number of partition plates is three is shown, but this is only an example, and the number of partition plates and the number of times of the resulting turn can be set as desired.

  In the configuration of FIG. 4, a plurality of flat tubes 4 positioned in the height region between the refrigerant inlet / outlet 7 and the partition plate 9a constitute a single flow path, and the height between the partition plate 9a and the partition plate 9b. A plurality of flat tubes 4 located in the region constitute another flow path, and a plurality of flat tubes 4 located in the height region between the partition plate 9b and the partition plate 9c further separate flow paths. The plurality of flat tubes 4 that are configured and located in the height region between the partition plate 9c and the refrigerant inlet / outlet port 8 constitutes another separate flow path. These collected flow paths will be referred to as a first flow path 11, a second flow path 12, a third flow path 13, and a fourth flow path 14 in the order described. In FIG. 4, the code | symbol which shows another of a flow path is put in the block arrow.

  When the heat exchanger 1 is used as an evaporator, the refrigerant flow is reversed. That is, the refrigerant enters the header pipe 3 from the refrigerant inlet / outlet 8 as shown by a dotted arrow in FIG. 4, is dammed up by the partition plate 9c and goes to the header pipe 2 via the fourth flow path 14, and in the header pipe 2, the partition plate 9b It is dammed and headed to the header pipe 3 via the third flow path 13, and the header pipe 3 is dammed by the partition plate 9 a, is directed to the header pipe 2 again via the second flow path 12, and is turned back by the header pipe 2 to be the first flow. It goes to the header pipe 3 again via the path 11, and flows out from the refrigerant inlet / outlet port 7 as indicated by a dotted line arrow.

  In 1st Embodiment of this invention, the receiver tank 20 is arrange | positioned in the form shown in FIG. 1 at the heat exchanger 1 of the above structures. In the heat exchanger 1 of FIG. 1, when the vertical widths of the first to fourth flow paths are compared, the first flow path 11 is the widest, the second flow path 12 is the next, and the third flow The path 13 is narrower and the fourth flow path 14 is narrower. For example, the lower position of the flow path is set to have a narrower vertical width. Needless to say, a wide flow path includes a large number of flat tubes 4, and a narrow flow path includes a small number of flat tubes 4.

  The receiver tank 20 is attached to a header pipe 3 which is a refrigerant pipe connection side header pipe. The receiver tank 20 is sandwiched between the refrigerant inlets 7 and 8 and is arranged in parallel to the header pipe 3 and at a distance from the header pipe 3, and is a pair of refrigerant inlets and outlets arranged at intervals in the vertical direction. The pipes 21 and 22 are connected to the header pipe 3.

  Inside the header pipe 3, a partition plate 9 d is provided between the connection points of the refrigerant inlet / outlet pipes 21 and 22. The partition plate 9d partitions the second flow path 12 and the third flow path 13 in the same manner as the partition plate 9b.

  The receiver tank 20 and the refrigerant inlet / outlet pipes 21 and 22 are made of the same material as the header pipe 3, and the refrigerant inlet / outlet pipes 21 and 22 are fixed to the receiver tank 20 and the header pipe 3 by brazing or welding. The refrigerant inlet / outlet pipes 21 and 22 are passages for the refrigerant and also function as a fixing member that fixes the receiver tank 20 to the header pipe 3.

  The refrigerant inlet / outlet pipe 21 faces the lower part of the second flow path 12, and the refrigerant inlet / outlet pipe 22 faces the middle part of the third flow path 13. When the heat exchanger 1 is used as a condenser, the first flow path 11 and the second flow path 12 exist before the refrigerant inlet / outlet pipe 21. That is, the flow path counts one turn in front of the refrigerant inlet / outlet pipe 21. Similarly, when the heat exchanger 1 is used as a condenser, the third flow path 13 and the fourth flow path 14 exist after the refrigerant inlet / outlet pipe 22. That is, after the refrigerant inlet / outlet pipe 22, the flow path counts one turn.

  When the heat exchanger 1 is used as a condenser, a gaseous, that is, overheated refrigerant flows into the header pipe 3 from the refrigerant inlet / outlet 7. The superheated refrigerant passes through the first flow path 11 from the right to the left, turns, passes through the second flow path 12 from the left to the right, and returns to the header pipe 3. During this reciprocation, the overheated refrigerant dissipates heat and liquefaction proceeds.

  The refrigerant inlet / outlet pipe 21 that is a fixing member of the receiver tank 20 appears after the turn from the first flow path 11 to the second flow path 12 is over, and at that time, the superheated state becomes a gas-liquid two-phase state, Since the refrigerant temperature is considerably lowered, the amount of heat transmitted to the receiver tank 20 via the refrigerant inlet / outlet pipe 21 is small, and unnecessary heat is not given to the refrigerant in the receiver tank 20 that is about to flow into the supercooling region.

  In order to reinforce the fixing of the receiver tank 20 by the refrigerant inlet / outlet pipes 21 and 22, a fixing member such as a stay or a bracket may be added. It is desirable to suppress heat conduction to the receiver tank 20 by setting it at a location one turn or more away from the refrigerant inflow side when used as a receiver.

  The refrigerant that has entered the header pipe 3 from the second flow path 12 is blocked by the partition plate 9 d and enters the receiver tank 20. The receiver tank 20 functions as buffer means for adjusting the amount of refrigerant in the heat exchanger 1 and gas-liquid separation means for refrigerant.

  The capacity of the receiver tank 20 (the volume of the internal space in which the refrigerant can be received. The other components are used in the same meaning) is the total amount of refrigerant liquid in the refrigeration cycle including the heat exchanger 1 (the estimated maximum enclosed amount). The capacity of the heat exchanger 1 and the capacity of the high-pressure side refrigerant pipe (pipe for sending high-pressure refrigerant discharged from the compressor described later to the heat exchanger 1) Set more than what you subtracted. This is important for the pump down operation described later.

  The refrigerant that has entered the header pipe 3 from the second flow path 12 once enters the receiver tank 20 and then enters the third flow path 13 that becomes the supercooling region. Then, it passes through the third flow path 13 from the right to the left, turns, passes through the fourth flow path 14 that is also a supercooling region from the left to the right, and returns to the header pipe 3. Heat exchange proceeds and condenses while passing through the third flow path 13 and the fourth flow path 14, and the refrigerant becomes supercooled. Since the supercooling region continues for one turn or more after the refrigerant inlet / outlet pipe 22, the refrigerant can be reliably brought into a supercooled state.

  The area of the supercooling region including the third flow path 13 and the fourth flow path 14 can ensure the required degree of supercooling at the time of the rated capacity, that is, when performing the operation that exhibits the capacity set as the rating. Set to an area greater than or equal to the area.

  If the area of the supercooling region including the third flow path 13 and the fourth flow path 14 is set to an area that is less than the area that can ensure the required degree of supercooling, the receiver tank 20 is a liquid refrigerant. If the refrigerant is not added until the liquid is full, a further degree of supercooling cannot be secured, and the refrigerant is consumed wastefully.

  As shown in FIG. 2, the heat exchanger 1 can be mounted on an outdoor unit of a separate type air conditioner using a heat pump cycle. The outdoor unit 30 shown in FIG. 2 includes a sheet metal casing 30a having a substantially rectangular planar shape. The long side of the casing 30a is a front face 30F and a back face 30B, and the short sides are a left side face 30L and a right side face 30R. An exhaust port 31 is formed on the front surface 30F, a rear intake port 32 is formed on the rear surface 30B, and a side intake port 33 is formed on the left side surface 30L. The exhaust port 31 is composed of a set of a plurality of horizontal slit-shaped openings, and the rear intake port 32 and the side intake port 33 are composed of lattice-shaped openings. A top plate and a bottom plate (not shown) are added to the four sheet metal members of the front surface 30F, the back surface 30B, the left side surface 30L, and the right side surface 30R to form a hexahedral housing 30a.

  Inside the housing 30a, a planar L-shaped heat exchanger 1 is disposed immediately inside the rear intake port 32 and the side intake port 33. In order to force heat exchange between the heat exchanger 1 and the external air, a blower 34 is disposed between the heat exchanger 1 and the exhaust port 31. The blower 34 is a combination of an electric motor 34a and a propeller fan 34b.

  In order to improve the blowing efficiency, a bell mouth 35 surrounding the propeller fan 34b is attached to the inner surface of the front surface 30F of the housing 30a. The space inside the right side surface 30R of the housing 30a is separated from the air flow flowing from the rear intake port 32 to the exhaust port 31 by the partition wall 36, and the compressor 37 is accommodated therein. The receiver tank 20 is on the left side of the partition wall 36, and the rear intake port 32 extends to the back of the receiver tank 20.

  When the blower 34 is operated, external air is sucked into the housing 30a from the rear air inlet 32 and the side air inlet 33. The sucked air passes through the heat exchanger 1 and exchanges heat with the heat exchanger 1. The air after heat exchange is sucked into the propeller fan 34b and is discharged out of the housing 30a through the exhaust port 31.

  The receiver tank 20 is located in the flow path of the air flow that passes through the heat exchanger 1, and a part of the air sucked from the rear intake port 32 passes through the outside of the receiver tank 20. Thereby, heat exchange between the receiver tank 20 and the external air is promoted, and the heat exchange capability of the heat exchanger 1 can be further increased.

  When the separate air conditioner including the outdoor unit 30 is moved, a pump-down operation is performed in which all the refrigerant in the refrigeration cycle including the heat exchanger 1 is concentrated on the outdoor unit 30 side. This is an operation in which the compressor 37 is operated with the refrigerant outlet of the heat exchanger 1 closed, and the entire amount of refrigerant is sent to the heat exchanger 1 at high pressure. The heat exchanger 1 of the parallel flow type has a smaller capacity than the heat exchange capacity, and in the conventional one, when the pump down operation is performed, the pressure inside the heat exchanger 1 rises abnormally and exceeds the pressure limit. May damage the reliability of the product.

  In the configuration of the embodiment, as described above, the capacity of the receiver tank 20 is obtained by subtracting the capacity of the heat exchanger 1 and the capacity of the high-pressure side refrigerant pipe from the total refrigerant liquid amount in the refrigeration cycle including the heat exchanger 1. Since it is set to be higher than that, it is possible to receive all the refrigerant in the refrigeration cycle in the liquid state with the combined capacity of the heat exchanger 1, the receiver tank 20, and the high-pressure side refrigerant pipe. . For this reason, there is no need to worry about abnormally high pressure occurring in the heat exchanger 1.

  FIG. 3 shows a second embodiment of the present invention. The second embodiment differs from the first embodiment in that the first flow path 11, the second flow path 12, the third flow path 13, and the fourth flow path 14 are not from the top to the bottom but from the bottom to the top. It is that they are lined up. When the heat exchanger 1 is used as a condenser, the refrigerant flows in from the lower refrigerant inlet / outlet 7 and flows out from the upper refrigerant inlet / outlet 8. When the heat exchanger 1 is used as an evaporator, the refrigerant flows in from the upper refrigerant inlet / outlet 8 and flows out from the lower refrigerant inlet / outlet 7.

  The receiver tank 20 is connected to the header pipe 3 by a refrigerant inlet / outlet pipe 21 facing the upper part of the second flow path 12 and a refrigerant inlet / outlet pipe 22 facing the middle part of the third flow path 13. It is also fixed. As in the first embodiment, the flow path counts one turn before the refrigerant inlet / outlet pipe 21 and also counts one turn after the refrigerant inlet / outlet pipe 22. When the additional fixing member is used, the consideration that the heat exchanger 1 is disposed at a position separated by one turn or more from the refrigerant inflow side when the heat exchanger 1 is used as a condenser is the same as in the first embodiment.

  Although the embodiments of the present invention have been described above, the scope of the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  The present invention is widely applicable to side flow parallel flow heat exchangers.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2, 3 Header pipe 4 Flat tube 5 Refrigerant passage 6 Corrugated fin 7, 8 Refrigerant inlet / outlet 9a, 9b, 9c, 9d Partition plate 11 1st flow path 12 2nd flow path 13 3rd flow path 14 4th Flow path 20 Receiver tank 21, 22 Refrigerant inlet / outlet pipe 30 Outdoor unit 34 Blower 37 Compressor

Claims (1)

Two header pipes arranged in parallel at intervals, and a plurality of flat tubes arranged between the two header pipes and having a refrigerant passage provided therein communicated with the inside of the header pipe An outdoor unit equipped with a parallel flow type heat exchanger of the side flow type, and during the pump-down operation in which the refrigerant in the refrigeration cycle including the heat exchanger is concentrated on the outdoor unit, the refrigerant is supplied to the heat exchanger. In a separate air conditioner that sends in high pressure ,
A receiver tank is connected to the heat exchanger, and the capacity of the receiver tank is obtained by subtracting the capacity of the heat exchanger and the capacity of the high-pressure side refrigerant pipe from the total amount of refrigerant liquid in the refrigeration cycle including the heat exchanger. It is set to what was,
When the pump-down operation is performed, all the refrigerant in the refrigeration cycle is received in a liquid state with the combined capacity of the heat exchanger, the receiver tank, and the high-pressure side refrigerant pipe. This is a separate type air conditioner .

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