JP2018025326A - Refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance reliability of a refrigeration cycle device which uses a working fluid including HFO1123.SOLUTION: A refrigeration cycle device is constituted by sealing a working fluid including 1,1,2-trifluoroethylene and difluoromethane in a refrigeration cycle circuit constituted by connecting a compressor, a condenser, an expansion valve and an evaporator in an annular manner. A pipeline 118 disposed between the compressor 102 and a heat exchanger which becomes the condenser or the evaporator in the refrigeration cycle circuit has a fragile part 119 in which strength in one portion is weaker than that of other portions. Thereby, when the working fluid causes a disproportionation reaction by an outside energy source, an irreversible change occurs instantly such as rupture of the fragile part in the pipeline, the working fluid inside is discharged to the outside and the pressure is lowered. Thus, the breakage and the like of the compressor due to the continuing pressure increase can be prevented, and reliability of the refrigeration cycle device can be secured.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a refrigeration cycle apparatus using a working fluid containing HFO1123.

  In general, the refrigeration cycle apparatus comprises a compressor, a four-way valve if necessary, a radiator (or a condenser), a decompressor such as a capillary tube or an expansion valve, an evaporator, etc., and constitutes a refrigeration cycle. Cooling or heating action is performed by circulating a refrigerant inside.

  As refrigerants in these refrigeration cycle apparatuses, chlorofluorocarbons (fluorocarbons are described as ROO or ROOXX are defined by the US ASHRAE 34 standard. Hereinafter, they are indicated as ROO or RXX. ) Or halogenated hydrocarbons derived from methane or ethane are known.

  R410A is often used as the refrigerant for the refrigeration cycle apparatus as described above, but the global warming potential (GWP) of the R410A refrigerant is as large as 2090, which is problematic from the viewpoint of preventing global warming.

  Thus, from the viewpoint of preventing global warming, for example, HFO1123 (1,1,2-trifluoroethylene) and HFO1132 (1,2-difluoroethylene) have been proposed as refrigerants having a small GWP (for example, patents). Document 1 or Patent document 2).

International Publication No. 2012/157774 International Publication No. 2012/157765

  However, HFO1123 (1,1,2-trifluoroethylene) and HFO1132 (1,2-difluoroethylene) are less stable than conventional refrigerants such as R410A and disproportionate when they generate radicals. There is a possibility of changing to another compound by the reaction. Since the disproportionation reaction increases in pressure with a large heat release, the reliability of the compressor and the refrigeration cycle apparatus may be reduced. For this reason, when using HFO1123 and HFO1132 for a compressor and a refrigerating cycle device, it is necessary to suppress this disproportionation reaction.

  Such a disproportionation reaction occurs when high energy is added in a refrigerant atmosphere that has become excessively high in temperature and pressure.

  For example, the discharge pressure (high pressure side of the refrigeration cycle) rises excessively due to a state that is not under a predetermined operating condition, that is, due to the stop of the blower fan on the condenser side, blockage of the refrigeration cycle circuit, or the like.

  Under such a condition, a compressor lock abnormality occurs, and even under this lock abnormality, if power supply to the compressor is continued, excessive power is supplied to the motor of the compressor, and the motor generates heat abnormally. As a result, a phenomenon called a layer short is caused between the conductors of the stator windings constituting the stator of the electric motor, which becomes a high energy source and induces a disproportionation reaction.

  And when disproportionation reaction generate | occur | produces, the pressure in a compressor rises abnormally and there exists a possibility that a compressor may be damaged.

  The present invention has been made in view of these points, and an object thereof is to improve the safety of a refrigeration cycle apparatus using a working fluid containing HFO 1123 by preventing a compressor from being damaged when a disproportionation reaction occurs. It is what.

  In order to achieve the above object, the present invention is a refrigeration cycle apparatus configured by enclosing a working fluid containing 1,1,2-trifluoroethylene and difluoromethane in a refrigeration cycle circuit, wherein the refrigeration cycle circuit is configured as described above. When the working fluid undergoes a disproportionation reaction by an external energy source, the piping between the compressor and the heat exchanger that becomes a condenser or evaporator causes an irreversible change, and the working fluid in the compressor is It is configured to discharge to the outside.

  According to the above configuration, when the working fluid causes a disproportionation reaction due to an external energy source, an irreversible change such as instantaneously breaking the piping is caused to release the internal working fluid to the outside and lower the pressure. It is possible to prevent the compressor from being damaged due to an increase in pressure, and to ensure the reliability of the refrigeration cycle apparatus.

  The present invention can provide a safe and highly reliable refrigeration cycle apparatus using a working fluid containing HFO 1123 with the above configuration.

1 is a schematic configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention. Schematic configuration diagram of an internal high-pressure compressor constituting the refrigeration cycle apparatus according to Embodiment 1 of the present invention. Schematic configuration diagram of an internal low-pressure compressor shown as a compressor constituting the refrigeration cycle apparatus according to Embodiment 1 of the present invention. Schematic configuration diagram of a concentrated winding motor of an internal high-pressure compressor constituting the refrigeration cycle apparatus according to Embodiment 1 of the present invention. Schematic configuration diagram of a distributed winding motor of an internal high-pressure compressor constituting the refrigeration cycle apparatus according to Embodiment 1 of the present invention. The expanded sectional view which shows the piping from the internal high pressure type compressor which comprises the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. The expanded sectional view which shows the other example of the piping from the internal high pressure type compressor which comprises the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. FIG. 3 is a relationship diagram of pressure and time showing disproportionation reaction characteristics of a working fluid used in the refrigeration cycle apparatus according to Embodiment 1 of the present invention. FIG. 3 is a relationship diagram of pressure and temperature showing disproportionation reaction characteristics of a working fluid used in the refrigeration cycle apparatus according to Embodiment 1 of the present invention.

  A first invention includes a refrigeration cycle circuit configured by annularly connecting a compressor, a condenser, an expansion valve, and an evaporator, and the refrigeration cycle circuit includes 1,1,2-trifluoroethylene. And a working fluid containing difluoromethane, and the piping between the compressor of the refrigeration cycle circuit and the heat exchanger that becomes a condenser or an evaporator is connected to the outside of the working fluid. When a disproportionation reaction is caused by an energy source, an irreversible change is caused to discharge the working fluid in the compressor to the outside.

  According to the above configuration, when the working fluid causes a disproportionation reaction due to an external energy source, an irreversible change such as instantaneously breaking the piping is caused to release the internal working fluid to the outside and lower the pressure. It is possible to prevent the compressor from being damaged due to an increase in pressure, and to ensure the reliability of the refrigeration cycle apparatus.

  According to a second aspect, in the first aspect, the pipe has a weakened portion having a weaker strength than other portions.

  As a result, the fragile part of the piping causes an irreversible change such as breakage and instantaneously discharges the working fluid in the compressor to prevent an abnormal pressure rise of the compressor, preventing the compressor from being damaged and the like. Can be ensured.

  According to a third aspect of the present invention, in the second aspect, the weakened portion is configured such that a part of the weakened portion becomes weaker than the other portion as the temperature rises.

  As a result, the strength of the piping is ensured over the entire area when the disproportionation reaction does not occur, so the reliability is improved, and when the temperature rises to cause the disproportionation reaction, the weakened portion weakens. Thus, the fragile part causes an irreversible change such as breakage, and the working fluid in the compressor is instantaneously released to prevent an abnormal pressure increase of the compressor and to ensure the reliability of the refrigeration cycle apparatus.

  According to a fourth invention, in the first or second invention, the weakened portion is configured such that a pipe wall thickness of a part of the pipe is made thinner than a pipe wall thickness of the other part.

  As a result, the fragile part where the pipe wall thickness is reduced causes an irreversible change such as breakage, and the working fluid in the compressor is released instantaneously to prevent an abnormal pressure rise of the compressor, and the compressor can be damaged. The reliability of the refrigeration cycle apparatus can be ensured by preventing.

  According to a fifth invention, in the first or second invention, the pipe is provided with a portion where stress generated by the pressure during the disproportionation reaction of the working fluid is concentrated to cause an irreversible reaction such as fracture.

  As a result, when an irreversible reaction occurs, the stress concentration portion of the pipe instantaneously undergoes irreversible deformation such as fracture, and the working fluid in the compressor is discharged to the outside, and the compressor is not subjected to any special configuration. It is possible to prevent breakage and ensure the reliability of the refrigeration cycle apparatus.

  According to a sixth invention, in the first to fifth inventions, the pipe has an inner diameter of 7 mm or more.

  As a result, when the pipe breaks, the working fluid in the compressor can be instantaneously released to prevent an abnormal pressure rise of the compressor, and the compressor can be prevented from being damaged and the reliability of the refrigeration cycle apparatus can be ensured. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a refrigeration cycle apparatus 100 according to a first embodiment of the present invention. The refrigeration cycle apparatus 100 of the present embodiment is a so-called separate type air conditioner in which an indoor unit 101a and an indoor unit 101a are connected to each other by a refrigerant pipe, a control wiring, and the like.

  The indoor unit 101a blows air to the indoor heat exchanger 103 and the indoor heat exchanger 103, and the indoor fan 107a which is a cross-flow fan (cross flow fan) that blows out the air heat-exchanged by the indoor heat exchanger 103 into the room. It has. The outdoor unit 101 b includes a compressor 102, an expansion valve 104 that is a decompression unit, an outdoor heat exchanger 105, a four-way valve 106, and an outdoor fan 107 b that is a propeller fan that blows air to the outdoor heat exchanger 105.

  The indoor unit 101a includes a pipe connection portion 112 so that the indoor unit 101a and the outdoor unit 101b can be separated. The outdoor unit 101b includes a pipe connection part 112, a three-way valve 108 provided between the pipe connection part 112 and the four-way valve 106, and a two-way valve 109 provided between the pipe connection part 112 and the expansion valve 104. I have. The indoor unit 101 a includes an electric motor driving device 115 that drives an electric motor provided in the compressor 102.

  And one pipe connection part 112 of the indoor unit 101a and the pipe connection part 112 on the side where the two-way valve 109 of the outdoor unit 101b is provided are connected by a liquid pipe 111a which is one of refrigerant pipes. Yes. Further, the other pipe connecting portion 112 of the indoor unit 101a and the pipe connecting portion 112 on the side where the three-way valve 108 of the outdoor unit 101b is provided are connected by a gas pipe 111b which is one of refrigerant pipes. .

  As described above, the refrigeration cycle apparatus 100 of the present embodiment is mainly configured by connecting the refrigerant 102 in the order of the compressor 102, the indoor heat exchanger 103, the expansion valve 104, and the outdoor heat exchanger 105 to configure a refrigeration cycle circuit. doing. In the refrigeration cycle circuit, the flow direction of the refrigerant discharged from the compressor 102 is changed between the compressor 102 and the indoor heat exchanger 103 or the outdoor heat exchanger 105, either the indoor heat exchanger 103 or the outdoor heat exchanger 105. A four-way valve 106 for switching between the two is provided.

  By providing the four-way valve 106, the refrigeration cycle apparatus 100 of the present embodiment can switch between the cooling operation and the heating operation. That is, during the cooling operation, the four-way valve 106 is switched so that the discharge side of the compressor 102 communicates with the outdoor heat exchanger 105 and the indoor heat exchanger 103 communicates with the suction side of the compressor 102. As a result, the indoor heat exchanger 103 acts as an evaporator, absorbs heat from the ambient atmosphere (indoor air), and the outdoor heat exchanger 105 acts as a condenser, and the heat absorbed in the room is converted into the ambient atmosphere (outdoor air). ). On the other hand, during the heating operation, the four-way valve 106 is switched so that the discharge side of the compressor 102 and the indoor heat exchanger 103 communicate with each other, and the outdoor heat exchanger 105 and the suction side of the compressor 102 communicate with each other. Thus, the outdoor heat exchanger 105 acts as an evaporator, absorbs heat from (outdoor air), the indoor heat exchanger 103 acts as a condenser, and the heat absorbed outside is radiated to the indoor air.

  The four-way valve 106 is an electromagnetic valve type that switches between cooling and heating by an electrical signal from a control device (not shown).

  The refrigeration cycle circuit includes a bypass unit 113 that bypasses the four-way valve 106 and communicates the suction side and the discharge side of the compressor 102, and an on-off valve 113a that opens and closes the refrigerant flow in the bypass unit 113. Yes.

A relief valve 114 that is an electronically controlled on-off valve is provided on the discharge side of the compressor 102. The relief valve 114 may be provided between the discharge portion of the compressor 102 and the expansion valve 104, or between the discharge portion of the compressor 102 and the three-way valve 108. In order to quickly escape, it is desirable to be provided between the discharge part of the compressor 102 and the four-way valve 106.

  The refrigeration cycle circuit includes a high pressure side pressure detection means 116 provided between the discharge side of the compressor 102 and the inlet of the expansion valve 104. The high pressure side pressure detecting means 116 may be configured to electrically detect and measure the strain of the diaphragm to be pressurized with a strain gauge or the like. Furthermore, you may comprise with the metal bellows and metal diaphragm which detect a pressure mechanically.

  The refrigeration cycle circuit includes a discharge temperature detecting means 117 provided between the discharge side of the compressor 102 and the inlet of the condenser. In this embodiment, since either the indoor heat exchanger 103 or the outdoor heat exchanger 105 becomes a condenser by switching the four-way valve 106, the discharge temperature detecting means 117 is connected to the discharge side of the compressor 102 and the four-way valve. It is provided between the entrances of 106. The discharge temperature detection means 117 is composed of a thermistor, a thermocouple, or the like, and electrically detects the temperature.

  The detection values of the high pressure side pressure detection means 116 and the discharge temperature detection means 117 are electrically transmitted to the control device.

  A working fluid (refrigerant) is enclosed in the refrigeration cycle circuit. The working fluid will be described. The working fluid sealed in the refrigeration cycle apparatus 100 of the present embodiment is a two-component mixed working fluid composed of (1) HFO1123 (1,1,2-trifluoroethylene) and (2) R32 (difluoromethane). In particular, it is a mixed working fluid having R32 of 30 wt% or more and 60 wt% or less.

  By mixing 30 wt% or more of R32 with HFO1123, the disproportionation reaction of HFO1123 can be suppressed. Further, the higher the concentration of R32, the more the disproportionation reaction can be suppressed. This is because the action of mitigating the disproportionation reaction due to the small polarization of R32 to the fluorine atom and the behavior at the time of phase change such as condensation and evaporation are integrated because HFO1123 and R32 have similar physical characteristics. The disproportionation reaction of HFO1123 can be suppressed by the action of reducing the disproportionation reaction opportunity due to.

  Further, the mixed refrigerant of HFO1123 and R32 has an azeotropic boiling point with R32 being 30% by weight and HFO1123 being 70%, and there is no temperature slip, so that it can be handled in the same manner as a single refrigerant. That is, if R32 is mixed by 60% by weight or more, temperature slip increases, and handling similar to that of a single refrigerant may be difficult. Therefore, it is desirable to mix R32 at 60% by weight or less. In particular, it is desirable to mix R32 in an amount of 40 wt% to 50 wt% in order to prevent disproportionation and to make the temperature slip smaller because it approaches the azeotropic point and to facilitate device design.

  Tables 1 and 2 show that the pressure, temperature of the refrigeration cycle, and the displacement of the compressor are the same when the mixing ratio of R32 is 30 wt% to 60 wt% of the mixed working fluid of HFO1123 and R32 Refrigeration capacity and cycle efficiency (COP) are calculated and compared with R410A and HFO1123.

  First, calculation conditions in Tables 1 and 2 will be described. In recent years, in order to improve the cycle efficiency of equipment, the performance of heat exchangers has increased, and in actual operating conditions, the condensation temperature tends to decrease, the evaporation temperature tends to increase, and the discharge temperature also tends to decrease . Therefore, considering the actual operating conditions, the cooling calculation conditions in Table 1 correspond to the cooling operation of the refrigeration cycle apparatus 100 (indoor dry bulb temperature 27 ° C., wet bulb temperature 19 ° C., outdoor dry bulb temperature 35 ° C.). The evaporation temperature was 15 ° C., the condensation temperature was 45 ° C., the superheated degree of the refrigerant sucked in the compressor was 5 ° C., and the supercooling degree at the condenser outlet was 8 ° C.

  The heating calculation conditions in Table 2 are the calculation conditions corresponding to the heating operation of the refrigeration cycle apparatus 100 (indoor dry bulb temperature 20 ° C., outdoor dry bulb temperature 7 ° C., wet bulb temperature 6 ° C.), and the evaporation temperature is 2 ° C, the condensation temperature was 38 ° C, the superheated degree of the refrigerant sucked into the compressor was 2 ° C, and the supercooling degree at the outlet of the condenser was 12 ° C.

  From Table 1 and Table 2, mixing R32 at 30 wt% or more and 60 wt% or less increases the refrigeration capacity by about 20% compared to R410A during cooling and heating operation, and the cycle efficiency (COP) is It becomes 94 to 97%, and the global warming potential can be reduced to 10 to 20% of R410A.

  As described above, in the two-component system of HFO 1123 and R32, taking into consideration the prevention of disproportionation, the magnitude of temperature slip, the capacity during cooling operation / heating operation, and COP (that is, compression described later) When a mixing ratio suitable for an air-conditioning apparatus using an air conditioner is specified, a mixture containing 30% by weight or more and 60% by weight or less R32 is desirable, and a mixture containing 40% by weight or more and 50% by weight or less R32 is more desirable. Is desirable.

  Next, each component constituting the refrigeration cycle circuit will be described.

  As the indoor heat exchanger 103 and the outdoor heat exchanger 105, a fin-and-tube heat exchanger, a parallel flow type (microtube type) heat exchanger, or the like is used. In addition, it is not a separate type air conditioner as shown in FIG. 1, for example, when using a brine (brine is used for air conditioning of a living space) as a surrounding medium of the indoor heat exchanger 103, or a two-way type When using the refrigerant of a refrigerating cycle, you may use a double tube heat exchanger, a plate type heat exchanger, and a shell and tube heat exchanger (not shown) as a form of a heat exchanger. In this case, the indoor heat exchanger 103 does not necessarily cool and heat the object to be cooled and heated (in the case of a separate type air conditioner, directly), and thus is not necessarily arranged indoors. As the expansion valve 104, for example, a pulse motor drive type electronic expansion valve is used.

  Details of the compressor 102 will be described with reference to FIG. The compressor 102 is a so-called hermetic rotary compressor, and is an internal high-pressure compressor in which a portion including an electric motor is filled with a high-pressure working fluid. The compressor may be an internal low-pressure compressor in which a portion including the electric motor shown in FIG. 3 is filled with a low-pressure working fluid, and the internal configuration is the same. Therefore, the internal high-pressure compressor shown in FIG. 2 is used. In the configuration of the internal low-pressure compressor in FIG. 3, the same parts as those in FIG.

  The compressor 102 contains an electric motor 102e and a compression mechanism 102c inside a sealed container 102g as an outer shell, and the inside is filled with high-temperature and high-pressure discharged refrigerant and refrigerating machine oil, and the bottom part is an oil storage part 102f that stores refrigerating machine oil. It has become. The electric motor (motor) 102e is a so-called brushless motor. The electric motor 102e includes a rotor 1021e connected to the compression mechanism 102c, and a stator 1022e provided around the rotor 1021e.

  The stator 1022e is provided with a three-phase stator winding, and a coil end 1023e is formed at the end of the stator 1022e in the vertical direction. The ends of the three-phase stator windings are lead wires 102i. In other words, the stator 1022e includes three lead wires 102i extending from each of the three-phase stator windings. The other ends of the three lead wires 102i are connected to the power supply terminal 102h. The power supply terminal 102 h includes three terminals, and each terminal is connected to the motor driving device 115. The three-phase stator winding is insulated by an insulator (not shown).

  As shown in FIG. 2, each of the three lead wires 102i extends from a position away from the coil end 1023e in the horizontal cross section of the electric motor 102e. More specifically, in each of the three lead wires 102i, the interval between adjacent lead wires 102i on the stator 1022e side (coil end 1023e side described later) is equal to the interval between adjacent lead wires on the power supply terminal 102h side. It is getting bigger. Further, the three lead wires 102i may be arranged at about 120 degrees around the rotation center of the rotor 1021e in the horizontal section of the electric motor 102e.

  FIG. 4 is a cross-sectional view of the electric motor 102e. The electric motor 102e is a so-called concentrated winding electric motor. The stator 1022e is composed of one tooth 31 and an annular yoke 32 connecting the teeth 31, and is disposed on the substantially cylindrical rotor core 33 and the outer peripheral portion thereof, facing the inner peripheral portion of the stator 1022e. A rotor 1021e made of a permanent magnet 34 is held rotatably about the crankshaft 102m. The permanent magnet 34 is fixed by inserting a ring 35 of non-magnetic material such as stainless steel into the outer periphery.

  Note that the permanent magnet may be fixed using an adhesive such as an epoxy resin.

  In the above description, the permanent magnets 34 are arranged as a structure in which the permanent magnets 34 are arranged on the outer periphery of the rotor core 33. However, the permanent magnets are arranged in the rotor core (not shown). Also good.

  On the other hand, the stator 1022e is fixed inside the sealed container 102g by being shrink-fitted into the shell of the compressor. The fixing method of the stator 1022e is not limited to this, and may be fixed by a method such as welding.

  The teeth 31 are provided with a three-phase stator winding, and a current is passed through the winding so that a rotating magnetic field is generated in the rotor 1021e by the switching element of the inverter type electric motor driving device 115. The rotating magnetic field can be generated at a variable speed by an inverter, and is operated at a high speed immediately after the start of operation of the compressor 102 and at a low speed during a stable operation.

  By providing a notch or groove or hole 37 in the outer periphery of the stator 1022e, there is a portion that penetrates the entire length of the stator 1022e between the pressure-sealed container 102g and the stator 1022e or in the stator 1022e itself, Refrigeration is performed by passing through the refrigeration oil.

  When the electric motor 102e is a concentrated winding electric motor, the winding resistance can be reduced, the copper loss can be greatly reduced, and the total motor length can be reduced.

  The electric motor 102e has been described as a concentrated winding electric motor, but may be a distributed winding electric motor. FIG. 5 is a cross-sectional view of the distributed winding motor 102e. The stator 1022e is composed of a plurality of teeth 61 and an annular yoke 62 connecting the teeth 61, and is disposed on the substantially cylindrical rotor core 63 and the outer peripheral portion thereof so as to face the inner peripheral portion of the stator 1022e. A rotor 1021e made of a permanent magnet 64 is held rotatably about the crankshaft 102m. The permanent magnet 64 is fixed by inserting a ring 66 made of non-magnetic material such as stainless steel into the outer periphery. The stator 1022e is fixed inside the sealed container 102g by being shrink-fitted into the shell of the compressor.

  By providing a notch 67, a groove, or a hole in the outer peripheral portion of the stator 1022e, the refrigerating machine oil passes therethrough to perform a refrigeration action.

  The rotor 1021e has four poles, and the number of teeth of the stator 1022e is 12 or 24, which is equal to the number of slots. Each slot is provided with a three-phase winding.

  The number of rotor poles and the number of stator slots may be 6 poles 9 slots, 6 poles 18 slots, 4 poles 6 slots, 8 poles 12 slots, 10 poles 12 slots.

  In the compressor 102 configured as described above, the low-pressure refrigerant flowing out of the evaporator is sucked from the suction pipe 102a through the four-way valve 106 and is pressurized by the compression mechanism 102c. The discharged refrigerant that has been pressurized and becomes high temperature and pressure is discharged from the discharge muffler 102l, passes through gaps (between the rotor 1021e and the stator 1022e, between the stator 1022e and the sealed container 102g) formed around the electric motor 102e, It flows into the discharge space 102d. Then, it discharges out of the compressor 102 from the discharge pipe 102b, and goes to a condenser via the four-way valve 106.

  The compression mechanism 102c is connected to the electric motor 102e via the crankshaft 102m. In the electric motor 102e, electric power received from an external power source is converted from electrical energy to mechanical (rotational) energy. In the compression mechanism 102c, the compression work which pressurizes a refrigerant | coolant is performed using the mechanical energy transmitted via the crankshaft 102m from the electric motor 102e.

  Here, as described above, when the state is not the predetermined operating condition, that is, when the blower fan on the condenser side is stopped, the refrigeration cycle circuit is blocked, etc., the discharge pressure of the working fluid (high pressure side of the refrigeration cycle) is excessive. To rise.

In this state, if the power supply to the compressor 102 is continued, the power is excessively supplied to the electric motor 102e constituting the compressor 102, the electric motor 102e generates abnormal heat, and the stator winding 40 of the electric motor 102e is heated. The insulation of the wire is damaged, and the conductors of the windings are in direct contact with each other, causing a layer short circuit. As a result, the working fluid generates a disproportionation reaction starting from the layer short, and the pressure in the compressor 102 rapidly rises to about 4 times in about 0.2 sec as shown in FIG. That is, as shown in the present embodiment, a working fluid in which a disproportionation reaction hardly occurs, for example, a working fluid in which the mixing ratio of R32 to HFO1123 is 30 wt% or more and 60 wt% or less is used. Becomes excessively high temperature and high pressure, and when a high energy source is added in the refrigerant atmosphere under such high temperature and high pressure, a disproportionation reaction occurs and the pressure in the compressor 102 rapidly increases. there is a possibility.

  Therefore, in this refrigeration cycle apparatus, the pipe 118 between the compressor 102 and the heat exchanger that becomes a condenser or an evaporator changes irreversibly due to the pressure when the working fluid causes a disproportionation reaction by an external energy source. And the working fluid in the compressor is discharged to the outside.

  As a result, in this refrigeration cycle apparatus, when the working fluid undergoes a disproportionation reaction and the pressure rises, a strong force is applied by the pressure of the disproportionation reaction, and the piping 118 itself is broken by this strong force, and the compressor 102 The working fluid inside is discharged to the outside. Therefore, it is possible to prevent the compressor 102 and the like from being increased in pressure and damaged, and to ensure the reliability of the refrigeration cycle apparatus even if a disproportionation reaction of the working fluid occurs.

  Here, a pressure responsive type safety valve is known as one that discharges the internal working fluid when the pressure rises. However, with this safety valve, the valve opening cannot follow the pressure rise that occurs in about 0.2 sec. May cause damage.

  However, if the piping 118 itself is broken as in the present invention, the working fluid can be released instantaneously, and the pressure rises by a disproportionation reaction in which the pressure rises to about 4 times in an extremely short time of about 0.2 sec. Even in this case, the working fluid is discharged to the outside, and the pressure in the compressor 102 can be instantaneously reduced to prevent the compressor 102 and the like from being damaged.

  Here, the pressure at which the pipe 118 is broken, that is, the pressure when the disproportionation reaction occurs will be considered.

  As described above, this disproportionation reaction occurs when high energy is applied to the working fluid in an atmosphere in which the working fluid is excessively hot and high in pressure.

  Therefore, first, the pressure when high energy is applied is one condition. This high energy is a high energy source having the highest probability of occurrence of a layer short circuit that occurs when the insulator of the stator winding of the electric motor 102e serving as the drive source of the compressor 102 is melted and broken. The disproportionation reaction generation pressure at the temperature at which the insulator melts becomes the breaking pressure of the pipe 118.

  Here, as for the insulator used for the stator winding of the electric motor serving as the drive source of the compressor, the one having a low melting temperature is usually 150 ° C. ± 10%.

  On the other hand, the relationship between the pressure and temperature at which the working fluid causes a disproportionation reaction is as shown in FIG. That is, FIG. 9 shows the disproportionation reaction occurrence region in the working fluid in which the ratio of HFO1123 and R32 is 60:40 (HFO1123 / R32 = 60/40), and the upper side of the broken line in the figure is the region where disproportionation reaction occurs. Temperature and pressure have an inversely proportional relationship.

  Under such a correlation between pressure and temperature, the pressure causing the disproportionation reaction when the insulator of the stator winding of the electric motor 102e is melted at 150 ° C. ± 10% is 9 MPa, as shown in FIG. And 9 MPa ± 10%.

  Therefore, the pipe 118 may be configured to break when the pressure becomes 9 MPa ± 10% or more.

  The pipe 118 may have any structure as long as it is destroyed by a rapid pressure generated during the disproportionation reaction of the working fluid, and the following can be considered as an example.

  One of them is a configuration in which a weakened portion 119 having a lower strength than other portions is provided in a part of the pipe 118 connected to the discharge pipe 102b of the compressor 102 as shown in FIG.

  For example, the pipe 118 is made of copper, and the weakened part 119 that is a part of the pipe 118 is made of aluminum. Alternatively, since the discharge pipe 102b can be regarded as a part of the pipe 118, the discharge pipe 102b is made of aluminum and the pipe 118 is made of copper.

  Such a combination of materials is not limited to this, and any combination of materials in which one of the strengths is weaker than the strength of the other may be mentioned. To name a few, a copper alloy and an aluminum alloy, Iron alloy and lead alloy, nickel alloy and resin, and so on.

  As a result, the fragile portion 119 of the pipe 118 undergoes an irreversible change such as destruction, and the working fluid in the compressor 102 is released instantaneously to prevent an abnormal pressure rise of the compressor 102 and prevent the compressor from being damaged. Thus, the reliability of the refrigeration cycle apparatus can be ensured.

  Further, as another configuration example, the weakened portion 119 shown in FIG. 6 has a configuration in which a part of the weakened portion 119 becomes weaker than the other portion as the temperature rises.

  For example, it is often the same as in the above case, but the material constituting the fragile portion 119 is made of aluminum, and the pipe 118 is made of brass. The material selection in this case is not limited to this, and any material may be used as long as it becomes weaker than the other part of the pipe 118 when the temperature of the fragile part 119 rises.

  The temperature at which the strength is weakened is preferably the melting temperature of the insulator of the electric motor 102e described above, for example, a temperature of about 150 ° C. ± 10%.

  By adopting such a configuration, the fragile portion 119 has a sufficient strength because the temperature is low at the normal time when the disproportionation reaction does not occur, and the refrigeration cycle operation can be performed without impairing the reliability. Then, when the temperature rises to a temperature at which the disproportionation reaction occurs, the strength of the fragile portion 119 weakens and the fragile portion 119 causes an irreversible change such as breakage, and the working fluid in the compressor 102 is instantaneously released. An abnormal pressure increase of the compressor 102 can be prevented and the reliability of the refrigeration cycle apparatus can be ensured.

  Furthermore, as another configuration example, the weakened portion 119 shown in FIG. 6 is configured such that the tube wall thickness is thinner than the tube wall thickness of other portions.

  For example, the pipe wall thickness of the pipe 118 is 0.8 mm, and the pipe wall thickness of the fragile portion 119 is as thin as about 0.5 mm.

  As a result, when the working fluid undergoes an irreversible change and the pressure rises suddenly, the fragile portion 119 breaks instantaneously due to the pressure, and instantaneously discharges the working fluid in the compressor to cause an abnormal pressure rise in the compressor. To prevent the compressor from being damaged and to ensure the reliability of the refrigeration cycle apparatus.

Furthermore, as another configuration example, as shown in FIG. 7, a part of the pipe is fixed to a wall body 121 having a hole or a groove through which the pipe passes, and the pressure rises when the working fluid becomes non-uniform. The portion 120 or 120a where the stress concentrates due to the displacement indicated by the arrow A of the compressor 102 generated in (1) is provided.

  That is, the compressor 102 expands and displaces by about 10 mm due to a pressure increase due to non-uniformity according to experiments. The piping 118 is also displaced in accordance with the expansion displacement of the compressor 102. Therefore, it is necessary to provide the pipe 118 with a portion 120 or 120a that breaks when displaced by about 10 mm. The fracture of the stress concentration portion 120 or 120a is about 10 mm, and preferably the allowable amplitude of the compressor is within 1 mm. Therefore, the stress concentration site 120 or 120a is set to break when displaced more than that, that is, 2 mm or more, more preferably 5 mm or more. deep.

  As a result, when a disproportionation reaction of the working fluid occurs, the piping 118 causes the stress concentration portion 120 or 120a to instantaneously cause irreversible deformation such as breakage and release the working fluid in the compressor 102 to the outside. Thus, the compressor 102 can be prevented from being damaged without providing a special configuration, and the reliability of the refrigeration cycle apparatus can be ensured.

  In any case, the pipe 118 discharges the working fluid to the outside in a time shorter than the pressure rise time of 0.2 sec at the time of disproportionation. Therefore, the inner diameter is preferably set to 7 mm or more.

  In this way, by setting the inner diameter of the pipe 118 to 7 mm or more, the working fluid can be discharged to the outside before 0.2 sec, which is a pressure that can damage the compressor 102 due to the disproportionation reaction. Damage to the machine 102 can be prevented.

  As described above, in the present embodiment, the rotary compressor has been described as an example. However, this may be any other type, for example, a scroll type, a reciprocating type positive displacement compressor, a centrifugal compressor, or the like. It may be a compressor.

  As described above, the present invention can improve the safety of a refrigeration cycle apparatus using a working fluid containing HFO 1123, and is used for residential and commercial air conditioners, car air conditioners, water heaters, refrigerators and refrigerators, showcases, dehumidification It can be widely applied to applications such as machines.

DESCRIPTION OF SYMBOLS 100 Refrigeration cycle apparatus 101a Indoor unit 101b Outdoor unit 102 Compressor 102a Suction pipe 102b Discharge pipe 102c Compression mechanism 102e Electric motor 102f Oil storage part 102g Sealed container 102h Feed terminal 102i Lead wire 1021e Rotor 1022e Stator 1023e Coil end Coil end Exchanger 104 Expansion valve 105 Outdoor heat exchanger 106 Four-way valve 107a Indoor fan 107b Outdoor fan 108 Three-way valve 109 Two-way valve 111a Liquid pipe 111b Gas pipe 112 Pipe connection 113 Bypass means 113a On-off valve 114 Relief valve 118 Pipe 119 Fragile part 120, 120a Stress concentrating part 121 Wall body

Claims (6)

A refrigeration cycle circuit configured by annularly connecting a compressor, a condenser, an expansion valve, and an evaporator is provided, and the refrigeration cycle circuit includes 1,1,2-trifluoroethylene and difluoromethane. A refrigeration cycle apparatus configured by enclosing a working fluid, wherein a pipe between the compressor of the refrigeration cycle circuit and a heat exchanger serving as a condenser or an evaporator is disproportionated by an external energy source. A refrigeration cycle apparatus configured to cause an irreversible change when a reaction occurs and to discharge the working fluid in the compressor to the outside. The refrigeration cycle apparatus according to claim 1, wherein a part of the pipe has a fragile part whose strength is weaker than that of the other part. The refrigeration cycle apparatus according to claim 2, wherein a part of the fragile part is weaker than the other part as the temperature rises. The refrigeration cycle apparatus according to claim 1 or 2, wherein the fragile portion is configured such that a pipe wall thickness of a part of the pipe is made thinner than a pipe wall thickness of the other part. The refrigeration cycle apparatus according to claim 1 or 2, wherein the pipe is provided with a site where stress generated by pressure during the disproportionation reaction of the working fluid is concentrated to cause an irreversible reaction such as fracture. The refrigeration cycle apparatus according to any one of claims 1 to 5, wherein the pipe has an inner diameter of 7 mm or more.

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