KR101841869B1 - Refrigeration cycle device - Google Patents

Abstract

A four-way valve 13, an outdoor heat exchanger 14, an expansion valve 15, and an indoor heat exchanger (not shown) are connected to a refrigerant circuit 11a through which a refrigerant containing HFO- 16 are connected. The refrigeration cycle apparatus 10 controls the pressure of the refrigerant at the flow path (that is, the high pressure side) from the compressor 12 of the refrigerant circuit 11a to the expansion valve 15 to be equal to or lower than the threshold value by the control mechanism. Thus, even if a disproportionation reaction of HFO-1123 occurs in a part of the compressor 12 or the like, its diffusion can be prevented.

Description

REFRIGERATION CYCLE DEVICE

The present invention relates to a refrigeration cycle apparatus.

In recent years, reduction of greenhouse gases is required from the viewpoint of preventing global warming. The refrigerant used in the refrigeration cycle apparatus such as an air conditioner is also considered to be lower than the global warming coefficient (GWP). At present, the GWP of R410A which is widely used as an air conditioner is 2088, which is a very large value. The GWP of difluoromethane (R32), which is being introduced in the recent years, has a considerably large value of 675.

As refrigerants having a low GWP, carbon dioxide (R744: GWP = 1), ammonia (R717: GWP = 0), propane (R290: GWP = 6), 2,3,3,3-tetrafluoropropene (R1234yf: GWP = 4), 1,3,3,3-tetrafluoropropene (R1234ze: GWP = 6), and the like.

Since these low GWP refrigerants have the following problems, it is difficult to apply them to general air conditioners.

R744: Since the operating pressure is very high, there is a problem of ensuring pressure resistance. Furthermore, since the critical temperature is as low as 31 占 폚, it is a problem to secure performance for use in an air conditioner.

· R717: Because of its high toxicity, there is a problem of ensuring safety.

· R290: Since it is lubricious, there is a problem of ensuring safety.

R1234yf / R1234ze: There is a problem of performance deterioration due to an increase in pressure loss due to a low operating pressure and a large volumetric flow rate.

As a refrigerant for solving the above problem, there is 1,1,2-trifluoroethylene (HFO-1123) (see, for example, Patent Document 1). This refrigerant has the following advantages, in particular.

· Since the operating pressure is high and the volumetric flow rate of the refrigerant is small, the pressure loss is small and the performance is easily ensured.

· GWP is less than 1, and advantage is high as global warming measure.

International Publication No. 2012/157764

Andrew E. Feiring, Jon D. Hulburt, "Trifluoroethylene deflagration ", Chemical & Engineering News (22 Dec 1997) Vol. 75, No. 51, pp. 6

HFO-1123 has the following problems.

(1) When ignition energy is applied in a state of high temperature and high pressure, explosion occurs (see, for example, Non-Patent Document 1).

(2) The atmospheric life is very small, less than 2 days. The chemical stability of the refrigeration cycle system may be lowered.

In order to apply HFO-1123 to a refrigeration cycle apparatus, it is necessary to solve the above-mentioned problem.

With regard to the task of (1), it has been found that explosion occurs due to a chain of disproportionation reactions. The conditions under which this phenomenon occurs are the following two points.

(1a) Ignition energy (high temperature part) is generated inside the refrigeration cycle device (particularly, compressor), and a disproportionation reaction occurs.

(1b) In the state of high temperature and high pressure, the disproportionation reaction successively diffuses.

(2), it is necessary to secure the chemical stability of the refrigeration cycle system.

An object of the present invention is to prevent, for example, explosion of HFO-1123 by a disproportionation reaction in a compressor. The present invention aims at avoiding the establishment of the condition (1b) in particular.

In the refrigeration cycle apparatus according to one aspect of the present invention,

A refrigerant circuit to which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are connected and in which a refrigerant containing 1,1,2-trifluoroethylene circulates,

And a control mechanism for controlling the pressure of the refrigerant in the flow path from the compressor to the expansion mechanism of the refrigerant circuit to be equal to or lower than a threshold value.

In the present invention, a refrigerant containing 1,1,2-trifluoroethylene is applied to a refrigeration cycle apparatus. The control mechanism of the refrigeration cycle apparatus controls the pressure of the refrigerant in the flow path from the compressor of the refrigerant circuit to the expansion mechanism to be equal to or less than the threshold value. Thereby, in the refrigeration cycle apparatus, the disproportionation reaction of HFO-1123 is prevented from diffusing as a chain reaction, and explosion due to the disproportionation reaction can be prevented.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a circuit diagram of a refrigeration cycle apparatus (in cooling operation) according to Embodiment 1; FIG.
2 is a circuit diagram of a refrigeration cycle apparatus (at the time of heating) according to Embodiment 1. Fig.
3 is a longitudinal sectional view of a compressor according to a first embodiment.
4 is an enlarged view of a longitudinal section of a compressor according to Embodiment 1 and a plan view of a bypass valve provided in a compressor according to Embodiment 1. Fig.
5 is an electrical connection diagram of a stator and a pressure fuse of an electric element provided in a compressor according to Embodiment 1. Fig.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment Mode 1.

1 and 2 are circuit diagrams of a refrigeration cycle apparatus 10 according to the present embodiment. Fig. 1 shows a refrigerant circuit 11a at the time of cooling. Fig. 2 shows a refrigerant circuit 11b at the time of heating.

In the present embodiment, the refrigeration cycle apparatus 10 is an air conditioner. The present embodiment can also be applied to the refrigeration cycle apparatus 10 other than the air conditioner (for example, a heat pump cycle apparatus).

1 and 2, the refrigeration cycle apparatus 10 includes refrigerant circuits 11a and 11b through which refrigerant circulates.

A compressor 12, a four-way valve 13, an outdoor heat exchanger 14, an expansion valve 15, and an indoor heat exchanger 16 are connected to the refrigerant circuits 11a and 11b. The compressor (12) compresses the refrigerant. The four-way valve (13) switches the direction in which the refrigerant flows during cooling and heating. The outdoor heat exchanger (14) is an example of the first heat exchanger. The outdoor heat exchanger (14) operates as a condenser at the time of cooling and dissipates heat of the refrigerant compressed by the compressor (12). The outdoor heat exchanger 14 operates as an evaporator at the time of heating and performs heat exchange between the outdoor air and the refrigerant expanded at the expansion valve 15 to heat the refrigerant. The expansion valve 15 is an example of an expansion mechanism. The expansion valve (15) expands the refrigerant released from the condenser. The indoor heat exchanger (16) is an example of the second heat exchanger. The indoor heat exchanger (16) operates as a condenser at the time of heating and radiates heat of the refrigerant compressed by the compressor (12). The indoor heat exchanger 16 operates as an evaporator at the time of cooling and performs heat exchange between the indoor air and the refrigerant expanded at the expansion valve 15 to heat the refrigerant.

The refrigeration cycle apparatus 10 further includes a control device 17.

The control device 17 is, for example, a microcomputer. Although not shown in the figure, only the connection between the control device 17 and the compressor 12 is shown, the control device 17 is connected not only to the compressor 12 but also to each element connected to the refrigerant circuits 11a and 11b have. The control device 17 monitors or controls the state of each element.

The refrigeration cycle apparatus 10 further includes a pressure sensor 91 and a pressure switch 92. The pressure sensor 91 and the pressure switch 92 will be described later.

A bypass valve 93 is further connected to the refrigerant circuits 11a and 11b. The bypass valve 93 will also be described later.

In this embodiment, a refrigerant containing 1,1,2-trifluoroethylene (HFO-1123) is used as the refrigerant circulating through the refrigerant circuits 11a and 11b. The refrigerant may be HFO-1123 alone or a mixture containing 1% or more of HFO-1123. That is, if the refrigerant used in the refrigeration cycle apparatus 10 contains 1 to 100% of HFO-1123, the present embodiment can be applied and the following effects can be obtained.

As a suitable refrigerant, a mixture of HFO-1123 and difluoromethane (R32) can be used. For example, a mixture containing 40 wt% of HFO-1123 and 60 wt% of R32 can be used. Either or both of HFO-1123 and R32 of this mixture may be replaced with another substance. HFO-1123 may be substituted with a mixture of HFO-1123 and other ethylenic fluorohydrocarbons. Examples of other ethylenic fluorinated hydrocarbons include fluoroethylene (HFO-1141), 1,1-difluoroethylene (HFO-1132a), trans-1,2-difluoroethylene (HFO-1132 -1,2-difluoroethylene (HFO-1132 (Z)) can be used. R32 is at least one selected from 2,3,3,3-tetrafluoropropene (R1234yf), trans-1,3,3,3-tetrafluoropropene (R1234ze (E)), cis- Tetrafluoropropene (R1234ze (Z)), 1,1,1,2-tetrafluoroethane (R134a), and 1,1,1,2,2-pentafluoroethane (R125) It may be substituted. Alternatively, R32 may be substituted with a mixture of any two or more of R32, R1234yf, R1234ze (E), R1234ze (Z), R134a and R125.

When using any refrigerant, it is necessary to consider the above-mentioned problem (1). Particularly, it is necessary to avoid the establishment of the above-mentioned condition (1b). That is, in the refrigeration cycle apparatus 10, it is necessary to avoid the disproportionation reaction from being successively spread.

The refrigerating cycle apparatus 10 controls the pressure of the refrigerant at the flow path (that is, the high pressure side) from the compressor 12 of the refrigerant circuits 11a and 11b to the expansion valve 15 to be equal to or lower than a threshold value do. Thus, diffusion of the disproportionation reaction can be prevented.

3 is a longitudinal sectional view of the compressor 12. Fig. In this figure, the hatching showing the cross section is omitted.

In the present embodiment, the compressor 12 is a one-cylinder rotary compressor. Further, even if the compressor 12 is a multi-cylinder rotary compressor or a scroll compressor, if the interior of the container is a discharge pressure atmosphere (i.e., a state of a high pressure equivalent to the discharge pressure of the refrigerant) .

3, the compressor 12 includes a sealed container 20, a compression element 30, a transmission element 40, and an axis 50. [

The closed container 20 is an example of a container. The hermetically sealed container 20 is provided with a suction pipe 21 for suctioning the refrigerant and a discharge pipe 22 for discharging the refrigerant.

The compression element (30) is accommodated in the closed container (20). Specifically, the compression element 30 is installed in the inner lower portion of the closed container 20. The compression element (30) compresses the refrigerant sucked into the suction pipe (21).

The electromotive element 40 is also contained in the hermetically sealed container 20. Specifically, the electric element 40 is installed at a position in the sealed container 20 where the refrigerant compressed by the compression element 30 passes before being discharged from the discharge pipe 22. That is, the electric element 40 is installed inside the hermetically sealed container 20 and above the compression element 30. The electromotive element 40 drives the compression element 30. The electric element 40 is a motor of concentrated winding.

At the bottom of the hermetically sealed container 20, refrigerator oil for lubricating the sliding portion of the compression element 30 is stored. For example, POE (polyol ester), PVE (polyvinyl ether) and AB (alkylbenzene) are used in the freezer flow path.

The compressor 12 further includes a bypass valve 94, a pressure fuse 95, and a relief valve 96. These will be described later. A spring 97 is attached to the bypass valve 94.

Hereinafter, the details of the compression element 30 will be described.

The compression element 30 is provided with a cylinder 31, a rolling piston 32, a vane (not shown), a main shaft receiver 33, and an auxiliary shaft 34.

The outer periphery of the cylinder 31 is substantially circular in plan view (plan view). Inside the cylinder 31, a cylinder chamber, which is a space having a substantially circular shape in plan view, is formed. Both ends in the axial direction of the cylinder 31 are open.

The cylinder 31 is provided with a vane groove (not shown) communicating with the cylinder chamber and extending in the radial direction. On the outer side of the vane groove, a back pressure chamber, which is a substantially circular space in plan view communicating with the vane groove, is formed.

The cylinder 31 is provided with a suction port (not shown) through which gas refrigerant is sucked from the refrigerant circuits 11a and 11b. The suction port extends from the outer peripheral surface of the cylinder 31 to the cylinder chamber.

The cylinder 31 is provided with a discharge port (not shown) through which the refrigerant compressed in the cylinder chamber is discharged. The discharge port is formed by notching the upper end surface of the cylinder 31.

The rolling piston 32 is ring-shaped. The rolling piston (32) eccentrically moves in the cylinder chamber. The rolling piston 32 is slidably fitted to the eccentric shaft portion 51 of the shaft 50.

The shape of the vane is a flat rectangular parallelepiped. The vane is installed in the vane groove of the cylinder 31. The vane is always pressed against the rolling piston 32 by the vane spring provided in the back pressure chamber. When the compressor 12 starts operating, the pressure in the hermetically sealed container 20 is increased due to the difference between the pressure in the hermetically sealed container 20 and the pressure in the cylinder chamber on the back surface of the vane The force works. Therefore, the vane spring is mainly used for pressing the vane to the rolling piston 32 at the time of starting the compressor 12 (when there is no difference in the pressure inside the sealed container 20 and the cylinder chamber).

The main shaft receiver 33 has a substantially inverted T shape when viewed from the side. The main shaft receiver 33 is slidably engaged with the main shaft portion 52 which is a portion above the eccentric shaft portion 51 of the shaft 50. [ The main shaft receiver 33 closes the upper side of the cylinder chamber and the vane groove of the cylinder 31.

The anchor holder 34 is roughly a T-shaped phenomenon at the side. The shaft holder 34 is slidably engaged with the sub-shaft portion 53 which is a portion lower than the eccentric shaft portion 51 of the shaft 50. The shaft holder (34) closes the lower side of the cylinder chamber and the vane groove of the cylinder (31).

The main shaft receiver 33 is provided with a discharge valve (not shown). A discharge muffler 35 is attached to the outside of the main shaft receiver 33. [ The high-temperature and high-pressure gas refrigerant discharged through the discharge valve enters the discharge muffler 35 once and is then discharged from the discharge muffler 35 into the space inside the sealed container 20. [ The discharge valve and the discharge muffler 35 may be provided either on the spindle receiver 34 or on both the main spindle 33 and the spindle receiver 34. [

The material of the cylinder 31, the main shaft receiver 33, and the auxiliary shaft receiver 34 is gray cast iron, sintered steel, carbon steel and the like. The material of the rolling piston 32 is, for example, an alloy steel containing chromium or the like. The material of the vane is, for example, high speed tool steel.

A suction muffler 23 is provided on the side of the closed container 20. The suction muffler 23 sucks low-pressure gas refrigerant from the refrigerant circuits 11a and 11b. The suction muffler 23 prevents the liquid refrigerant from directly entering the cylinder chamber of the cylinder 31 when the liquid refrigerant returns. The suction muffler 23 is connected to the suction port of the cylinder 31 through the suction pipe 21. [ The main body of the suction muffler 23 is fixed to the side surface of the closed container 20 by welding or the like.

Hereinafter, the details of the electric element 40 will be described.

In this embodiment, the electric element 40 is a brushless direct current (DC) motor. The present embodiment can also be applied to a motor other than the brushless DC motor (for example, an induction motor) as the electric element 40. [

The electromotive element 40 includes a stator 41 and a rotor 42.

The stator 41 is held in contact with the inner peripheral surface of the closed container 20 and fixed. The rotor 42 is installed on the inside of the stator 41 through a gap of about 0.3 to 1 mm.

The stator 41 includes a stator core 43 and a stator winding 44. The stator iron core 43 is manufactured by punching a plurality of sheets of electro-magnetic steel sheets each having a thickness of 0.1 to 1.5 mm into a predetermined shape, stacking them in the axial direction, and fixing them by caulking, welding or the like. The stator winding 44 is wound around the stator core 43 by a concentrated winding through the insulating member 48. [ The insulating member 48 may be made of a material such as PET (polyethylene terephthalate), PBT (polybutylene terephthalate), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (tetrafluoroethylene (Perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), LCP (liquid crystal polymer), PPS (polyphenylene sulfide), and phenol resin. A lead wire 45 is connected to the stator winding 44.

On the outer periphery of the stator core 43, a plurality of notches are formed at substantially equal intervals in the circumferential direction. Each of the notches becomes one of the passages of the gas refrigerant discharged from the discharge muffler 35 into the space in the closed container 20. [ Each of the notches may also be a passage of a refrigerating machine oil returning from the top of the electric element 40 to the bottom of the hermetically sealed container 20. [

The rotor 42 includes a rotor iron core 46 and a permanent magnet (not shown). The rotor iron core 46 is manufactured by punching a plurality of electromagnetic steel sheets having a thickness of 0.1 to 1.5 mm in a predetermined shape, stacking them in the axial direction, fixing them by caulking, welding or the like, similarly to the stator iron core 43 . The permanent magnet is inserted into a plurality of insertion holes formed in the rotor iron core (46). As the permanent magnet, for example, a ferrite magnet or a rare earth magnet is used.

The rotor iron core (46) is provided with a plurality of through holes penetrating in the substantially axial direction. Each of the through holes becomes one of the passages of the gas refrigerant discharged from the discharge muffler 35 into the space in the closed container 20, like the notch of the stator iron core 43. [

A power terminal 24 (for example, a glass terminal) connected to an external power source is attached to the top of the sealed container 20. The power supply terminal 24 is fixed to the hermetically sealed container 20 by, for example, welding. A lead wire 45 from the electric element 40 is connected to the power supply terminal 24.

A discharge pipe 22 having both ends open in the axial direction is attached to the end of the hermetically sealed container 20. The gas refrigerant discharged from the compression element 30 flows from the space in the hermetically sealed container 20 through the discharge pipe 22 and is discharged to the external refrigerant circuits 11a and 11b.

Hereinafter, the operation of the compressor 12 will be described.

Electric power is supplied from the power supply terminal 24 to the stator 41 of the electric element 40 through the lead wire 45. [ As a result, the rotor 42 of the electric element 40 rotates. By the rotation of the rotor 42, the shaft 50 fixed to the rotor 42 rotates. As the shaft 50 rotates, the rolling piston 32 of the compression element 30 eccentrically rotates in the cylinder chamber of the cylinder 31 of the compression element 30. The space between the cylinder 31 and the rolling piston 32 is divided into two by the vane of the compression element 30. As the shaft 50 rotates, the volume of these two spaces changes. In one of the spaces, the refrigerant is sucked from the suction muffler 23 by gradually expanding the volume. In the other space, by gradually reducing the volume, the gas refrigerant in the inside is compressed. The compressed gas refrigerant is once discharged from the discharge muffler 35 into the space in the closed container 20. [ The discharged gas refrigerant passes through the electric element 40 and is discharged out of the closed vessel 20 from the discharge pipe 22 in the closed portion of the closed vessel 20. [

Hereinafter, a practical funeral of the control mechanism according to the present embodiment will be described. But any one of them may be applied, or a combination of several or all of them may be applied.

As described above, the control mechanism controls the pressure of the refrigerant at the high pressure side of the refrigerant circuits 11a, 11b to be equal to or less than the threshold value.

The refrigerant containing HFO-1123 tends to undergo a chain reaction of the disproportionation reaction at a higher pressure. In this embodiment, even if a disproportionation reaction occurs in a part of the compressor 12 or the like, the diffusion can be prevented by controlling the high pressure side so as not to exceed a predetermined pressure.

In the practical example described below, one threshold value is set. When two or more thread funeral are combined, two or more thresholds are set. In this case, the diffusion of the disproportionation reaction can be prevented in multiple stages by sequentially applying the limit from the gentle threshold value.

First, a first example in which a first value is set as a threshold value will be described.

In the first example, the control device 17 and the pressure sensor 91 shown in Figs. 1 and 2 function as a main part of the control mechanism. The control device 17 reduces the rotational speed of the electric element 40 of the compressor 12 when the pressure of the refrigerant at the high pressure side of the refrigerant circuits 11a and 11b reaches the first value. For example, the first value is set to 4 to 5 MPa.

The control device 17 may predict that the pressure exceeds the first value with a tendency of the pressure change (tendency), and perform deceleration control of the electric element 40 before the pressure exceeds the first value . When it is determined that the pressure change is abrupt and the abnormality such as the circuit clogging is apparently occurring, the control device 17 may perform the stop control of the electric element 40 instead of the deceleration control.

The pressure on the high pressure side can be detected with high precision by the pressure sensor 91 provided on the high pressure pipe of the refrigerant circuits 11a and 11b. It is also possible to use a method of measuring the temperature of the heat exchanger or the compressor 12 without using the pressure sensor 91 and estimating the pressure on the high pressure side from the temperature.

In the first example, the operation of the compressor 12 is stopped without stopping. Therefore, the pressure condition during operation of the compressor 12 does not change significantly. Therefore, the operation can be continued without impairing the operation state of the refrigeration cycle apparatus 10. [ Further, since the control device 17 can recognize that the protective operation has been performed, it is also possible to control the state of the compressor 12 or other elements so that the pressure does not again exceed the first value.

Next, a second example in which the second value is set as the threshold value will be described.

4 is an enlarged view of the longitudinal section of the compressor 12 and a plan view of the bypass valve 94 provided in the compressor 12. As shown in Fig.

In the second example, the bypass valve 93 shown in Figs. 1 and 2 or the bypass valve 94 shown in Figs. 3 and 4 functions as a main part of the control mechanism. The bypass valve 93 connected to the refrigerant circuits 11a and 11b is connected to the refrigerant circuit for bypassing the compressor 12 when the pressure difference between the refrigerant before and after being compressed by the compressor 12 reaches the second value, . The bypass valve 94 provided in the compression element 30 of the compressor 12 is configured to bypass the compression element 30 when the pressure difference between the refrigerant before and after being compressed by the compression element 30 reaches the second value Thereby opening the refrigerant passage for the refrigerant. Specifically, when the pressure difference between the refrigerant before and after being compressed by the compression element 30 reaches the second value, the bypass valve 94 is opened by the action of the spring 97, Thereby making the path and the discharge muffler 35 communicate with each other. For example, the second value is set to 3.5 to 4.5 MPa.

The bypass valves 93 and 94 are opened when the pressure difference between the high pressure and the low pressure exceeds the second value, thereby preventing the rise of the high pressure. For example, by forming a bypass between the discharge muffler 35 of the compressor 12 and the suction portion of the cylinder 31, the bypass valve 94 allows the high-pressure transfer path in the compressor 12 It is possible to reliably lower the high pressure even when it is closed.

In the second example, the bypass valves 93 and 94 operate only while the pressure difference between the high pressure and the low pressure exceeds the second value. Therefore, the operation can be continued without impairing the operation state of the refrigeration cycle apparatus 10. [

Next, a third example in which the third value is set as the threshold value will be described.

5 is an electrical connection diagram of the stator 41 and the pressure fuse 95 of the electric element 40 of the compressor 12. As shown in Fig.

In the third example, the pressure switch 92 shown in Figs. 1 and 2 or the pressure fuse 95 shown in Figs. 3 and 5 functions as a main part of the control mechanism. The pressure switch 92 provided in the high pressure pipe of the refrigerant circuits 11a and 11b mechanically stops the feeding of the refrigerant to the compressor 12 when the pressure of the refrigerant at the high pressure side of the refrigerant circuits 11a and 11b reaches the third value . The pressure fuse 95 provided in the electric element 40 of the compressor 12 is configured such that when the pressure of the refrigerant at the high pressure side of the refrigerant circuits 11a and 11b reaches the third value, Stop. Specifically, the pressure fuse 95 cuts off the electric current between the electric element 40 and the external power source when the pressure of the refrigerant at the high pressure side of the refrigerant circuits 11a, 11b reaches the third value. The third value is set to a value higher than the first value. For example, the third value is set to 5 to 6 MPa.

The pressure fuse 95 is more suitable than the pressure switch 92 because it can operate even when the discharge pipe 22 of the compressor 12 is closed. As the pressure fuse 95, it is preferable to use an automatic return type. 5, the pressure fuse 95 blocks the neutral point of the three-phase stator winding 44 connected by Y wiring, thereby stopping the flow of current to the electric element 40 do. Thereby, the operation of the compressor 12 can be stopped.

In the third example, since the compressor 12 is stopped, the operation state of the refrigeration cycle apparatus 10 can not be maintained. However, it is possible to ensure safety in a state in which the return operation of the refrigeration cycle apparatus 10 is possible.

Next, a fourth example in which the fourth value is set as the threshold value will be described.

In the fourth example, the control device 17 shown in Figs. 1 and 2 and the relief valve 96 shown in Fig. 3 function as main parts of the control mechanism. The relief valve 96 is used to discharge the refrigerant out of the hermetically sealed container 20 of the compressor 12. The control device 17 opens the relief valve 96 when the pressure of the refrigerant at the high pressure side of the refrigerant circuits 11a and 11b reaches the fourth value. The fourth value is set to a value higher than the third value. For example, the fourth value is set to 5.5 to 6.5 MPa.

In the fourth example, the refrigerant is discharged to the outside of the refrigeration cycle. Therefore, the refrigeration cycle apparatus 10 can not perform normal operation thereafter. However, safety can be ensured more reliably.

As described above, two or more of the four yarn funeral services from the first to fourth examples can be used in combination to provide more reliable protection. The operation priority order of the four thread funerals is the highest in the first example, and goes down in the order of the second example, the third example, and the fourth example. Thereby, protection can be made at the initial stage by a means with little influence on the operation state. The operation of the refrigeration cycle apparatus 10 can be stopped when a certain abnormality occurs in the refrigeration cycle apparatus 10, such as an abnormality of the sensor.

As described above, according to this embodiment, diffusion of the disproportionation reaction of HFO-1123 can be prevented. Therefore, it is possible to prevent the explosion of the refrigerant containing HFO-1123 by the disproportionation reaction.

Although the embodiment of the present invention has been described above, it is also possible to partially implement this embodiment. For example, any one or a few of the elements denoted by the reference numerals in the drawings may be omitted or replaced by other elements. Further, the present invention is not limited to this embodiment, and various modifications are possible in accordance with necessity.

10: Refrigeration cycle device
11a, 11b: refrigerant circuit
12: Compressor
13: Four-way valve
14: outdoor heat exchanger
15: Expansion valve
16: Indoor heat exchanger
17: Control device
20: Closed container
21: suction pipe
22: Discharge tube
23: Suction muffler
24: Power terminal
30: compression element
31: Cylinder
32: Rolling piston
33:
34:
35: Discharge muffler
40: electric element
41: Stator
42: Rotor
43: stator core
44: stator winding
45: Lead wire
46: rotor iron core
48: Insulation member
50: Axis
51: eccentric shaft portion
52:
53:
91: Pressure sensor
92: Pressure switch
93: Bypass valve
94: Bypass valve
95: Pressure fuse
96: relief valve
97: spring

Claims (17)

A refrigerant circuit in which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are connected and a refrigerant which contains 1,1,2-trifluoroethylene and in which a chain reaction of a disproportionation reaction tends to occur, Wow,
If the pressure of the refrigerant in the flow path from the compressor to the expansion mechanism of the refrigerant circuit reaches a first value of 4 MPa or more and 5 MPa or less so that explosion does not occur due to the chain reaction of the disproportionation reaction of the refrigerant, When the pressure of the refrigerant in the flow path from the compressor to the expansion mechanism of the refrigerant circuit reaches a third value higher than the first value when the pressure of the refrigerant in the refrigerant circuit is 5 MPa to 6 MPa, And a control mechanism for stopping the supply of electric power to the electric element of the compressor. delete The method according to claim 1,
Wherein the control mechanism opens the bypass valve for opening the flow path of the refrigerant for bypassing the compression element of the compressor to the compressor when the pressure difference of the refrigerant before and after being compressed by the compression element of the compressor reaches the second value And a refrigerating cycle device. The method of claim 3,
Wherein the compression element of the compressor comprises a cylinder for sucking the refrigerant from the refrigerant circuit into an internal cylinder chamber and compressing the refrigerant in the cylinder chamber and a cylinder for compressing the refrigerant compressed by the cylinder into a space And a discharge muffler for discharging,
Wherein the bypass valve is configured such that, when the pressure difference of the refrigerant before and after being compressed by the compression element of the compressor reaches the second value, a bypass path is formed between a path through which the refrigerant is sucked from the cylinder to the cylinder chamber, Cycle device. The method of claim 3,
And the second value is a value of 3.5 MPa to 4.5 MPa. The method according to claim 1,
The control mechanism is connected to the refrigerant circuit, and when the pressure difference between the refrigerant before and after being compressed by the compressor reaches a second value of 3.5 MPa to 4.5 MPa, the flow path of the refrigerant for bypassing the compressor And a bypass valve for opening the bypass valve. delete The method according to claim 1,
Wherein when the pressure of the refrigerant in the flow path from the compressor to the expansion mechanism of the refrigerant circuit reaches the third value, the control mechanism causes the three-phase stator winding of the electric element of the compressor, A pressure fuse of an automatic return type is provided in the container of the compressor for interrupting the supply of electric power between the electric element of the compressor and the external power source by blocking the neutral point. delete delete The method according to claim 1,
Wherein the control mechanism is provided with a relief valve for discharging the refrigerant out of the container of the compressor and the pressure of the refrigerant in the flow path from the compressor to the expansion mechanism of the refrigerant circuit is 5.5 MPa to 6.5 And when the pressure reaches a fourth value which is higher than the third value, the relief valve is opened. The method according to any one of claims 1, 3, 4, 6, 8, and 11,
Wherein the refrigerant is 1,1,2-trifluoroethylene. The method according to any one of claims 1, 3, 4, 6, 8, and 11,
Wherein the refrigerant is a mixture containing 1% or more of 1,1,2-trifluoroethylene. A refrigerant circuit in which a compressor, a first heat exchanger, an expansion mechanism, and a second heat exchanger are connected and a refrigerant which contains 1,1,2-trifluoroethylene and in which a chain reaction of a disproportionation reaction tends to occur, Wow,
When the pressure of the refrigerant in the flow path from the compressor to the expansion mechanism of the refrigerant circuit reaches a threshold value so that an explosion does not occur due to a chain reaction of the disproportionation reaction of the refrigerant, And a control mechanism provided in the container of the compressor for blocking the neutral point of the three-phase stator windings connected by the compressor and the automatic return type pressure fuse for interrupting energization between the electric element of the compressor and the external power source. . 15. The method of claim 14,
Wherein the threshold value is a value of 5 MPa to 6 MPa. 16. The method according to claim 14 or 15,
Wherein the refrigerant is 1,1,2-trifluoroethylene. 16. The method according to claim 14 or 15,
Wherein the refrigerant is a mixture containing 1% or more of 1,1,2-trifluoroethylene.

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