JP6861341B2 - Refrigeration cycle equipment - Google Patents

Description

The present invention relates to a refrigeration cycle apparatus using a working fluid containing HFO1123 or HFO1132.

In general, a refrigeration cycle device is composed of a compressor, a four-way valve, a radiator (or condenser), a decompressor such as a capillary tube or an expansion valve, an evaporator, etc., which are connected by piping to form a refrigeration cycle. Cooling or heating is performed by circulating a refrigerant inside.

As the refrigerant in these refrigeration cycle devices, fluorocarbons (fluorocarbons are described as R ○○ or R ○○○ are specified by the US ASHRAE34 standard. Hereinafter, they are referred to as R ○○ or R ○○○. ), A halogenated hydrocarbon derived from methane or ethane is known.

R410A is often used as the refrigerant for refrigeration cycle equipment 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.

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

International Publication No. 2012/157964 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 when radicals are generated, they undergo an autolysis reaction. May change to another compound. Since the autolysis reaction involves a large amount of heat release, the reliability of the compressor or refrigeration cycle device may be reduced.

Therefore, when HFO1123 or HFO1132 is used in a compressor or a refrigeration cycle device, it is necessary to suppress this autolysis reaction.

Such an autolysis reaction occurs when high energy is applied in a refrigerant atmosphere where the temperature and pressure are excessively high and high pressure, which is the starting point.

For example, the discharge pressure (high pressure side of the refrigeration cycle) rises excessively due to a state under normal operating conditions, that is, a blower fan stop on the condenser side, a blockage of the refrigeration cycle circuit, or the like. As a result, the temperature also rises excessively.

Under such a state, a lock abnormality of the compressor occurs, and even under this lock abnormality, if the power supply to the compressor is continued, the electric power is excessively supplied to the electric motor of the compressor, and the electric motor generates abnormal heat. As a result, the conductors of the stator windings that make up the stator of the motor cause a phenomenon called layer short, which becomes a high energy source and induces an autolysis reaction.

Then, once the autolysis reaction occurs, the pressure inside the compressor momentarily rises abnormally due to the chain reaction, and the compressor may be damaged. Therefore, it is important to prevent the occurrence of autolysis reaction.

The present invention has been made in view of an excessively high temperature and high pressure phenomenon of a working fluid that induces such a self-decomposition reaction, and improves the reliability of a compressor or a refrigeration cycle device using a working fluid containing HFO1123 or HFO1132. The purpose is to make it.

In order to achieve the above object, the present invention constitutes a refrigeration cycle apparatus by encapsulating a working fluid containing 1,1,2-trifluoroethylene or difluoroethylene in a refrigeration cycle circuit, and a compressor is provided in the refrigeration cycle apparatus. The configuration is such that a plurality of protective devices are provided to detect the abnormality of the compressor and stop the operation of the compressor.

According to the above configuration, while the refrigeration cycle device has a low warming coefficient, the operation of the compressor is stopped when the temperature or pressure of the working fluid becomes higher than that during normal use, so that the temperature of the working fluid can be adjusted. Damage to the compressor or the like due to an excessive increase in pressure can be prevented, and the reliability of the compressor or refrigeration cycle device can be improved.

With the above configuration, the present invention can provide a safe and reliable refrigeration cycle apparatus using a working fluid containing HFO1123 or HFO1132.

Schematic block diagram of the refrigeration cycle apparatus according to the first embodiment of the present invention. Schematic configuration diagram showing an enlarged main part of the compressor constituting the refrigeration cycle apparatus according to the first embodiment. Schematic configuration diagram of a centralized winding electric motor of a compressor constituting the refrigeration cycle device according to the first embodiment. Enlarged schematic cross-sectional view of a main part of a compressor constituting the refrigeration cycle apparatus according to the first embodiment. Characteristic diagram showing the autolysis reaction region of the working fluid used in the refrigeration cycle apparatus according to the first embodiment. Enlarged schematic cross-sectional view of a main part of a compressor constituting the refrigeration cycle apparatus according to the second embodiment of the present invention.

In the first invention, a compressor, a condenser, an expansion valve, and an evaporator are connected in a ring shape to form a refrigeration cycle circuit, and 1,1,2-trifluoroethylene or 1,1,2-trifluoroethylene or 1,1,2-trifluoroethylene or The refrigeration cycle device is configured by enclosing a working fluid containing difluoroethylene, and is further provided with a plurality of protective devices that detect an abnormality in the compressor and stop the operation of the compressor.

As a result, while making the refrigeration cycle device with a low warming coefficient, the operation of the compressor is stopped in the event of an abnormality where the temperature and pressure of the working fluid are higher than those during normal use, so that the excessive temperature and pressure of the working fluid are excessive. It is possible to prevent damage to the compressor and the like due to an increase in the pressure, and improve the reliability of the compressor and the refrigeration cycle device.

In the second invention, in the first invention, at least one of the plurality of protective devices is composed of a temperature detecting means for detecting the discharge side temperature of the working fluid, and the other is the pressure on the discharge side of the working fluid. It is composed of a pressure detecting means that directly or indirectly detects.

As a result, the operation of the compressor can be stopped in the event of an abnormality in which the temperature and pressure of the working fluid are detected and the temperature and pressure become higher than those during normal use, and an excessive rise in the temperature and pressure of the working fluid can be prevented. , 2-It is possible to prevent the self-decomposition reaction peculiar to the working fluid containing 2-trifluoroethylene or difluoroethylene. As a result, damage to the compressor and the like can be prevented, and the reliability of the compressor and the refrigeration cycle device can be improved.

According to the third invention, in the second invention, the temperature detecting means for detecting the discharge side temperature of the working fluid is provided in the vicinity of the electric motor of the compressor to detect the temperature in the vicinity of the electric motor.

As a result, the temperature of the electric motor that causes a layer short or the like, which is the starting point of the autolysis reaction, can be quickly detected without delay, and the occurrence of the autolysis reaction can be reliably prevented.

A fourth aspect of the present invention is the first to third aspect of the invention, wherein the plurality of protective devices stop the operation of the compressor when the combination of the detected values of the protective devices exceeds the threshold value for preventing abnormality.

As a result, the operation of the compressor is stopped only when the combination of the detected values of a plurality of abnormal events such as temperature and pressure exceeds the threshold value for preventing abnormalities, which is a peculiar condition for the autolysis reaction to occur. It is possible to prevent a malfunction that occurs when the compressor is stopped because the detected value alone is abnormal, that is, a malfunction that stops the operation of the compressor even though there is no possibility that a self-decomposition reaction will occur. As a result, it is possible to prevent the occurrence of an accurate autolysis reaction, and a more reliable refrigeration cycle device can be obtained.

In the fifth aspect of the invention, in the fourth aspect of the invention, the plurality of protective devices are compressed when the detection value of any one of the protective devices is further closer to the abnormal value side than the maximum abnormal threshold value of the combination of the detected values of the protective devices. It is configured to stop the operation of.

As a result, even if one of the plurality of protective devices is out of order and an abnormality cannot be determined by combining a plurality of detected values, the detected values of the remaining protective devices are further on the abnormal value side than the maximum abnormal threshold value. When it is detected, the operation of the compressor can be stopped, the certainty of preventing the occurrence of the autolysis reaction can be increased, and a highly reliable refrigeration cycle device can be obtained.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to this embodiment.

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

The indoor unit 101a is an indoor blower fan 107a, which is a once-through fan (cross-flow fan) that blows air to the indoor heat exchanger 103 and the indoor heat exchanger 103 and blows out the air heat-exchanged by the indoor heat exchanger 103 into the room. It has. The outdoor unit 101b includes a compressor 102, an expansion valve 104 as a depressurizing means, an outdoor heat exchanger 105, a four-way valve 106, and an outdoor blower fan 107b which is a propeller fan that blows air to the outdoor heat exchanger 105. Further, the outdoor unit 101b includes an electric motor driving device 115 for driving an electric motor provided in the compressor 102.

The indoor unit 101a and the outdoor unit 101b are provided with a pipe connection portion 112, and the outdoor unit unit 101b is further provided with a three-way valve 108 and a pipe connection portion 112 between the pipe connection portion 112 and the four-way valve 106. A two-way valve 109 provided between the expansion valve 104 and the expansion valve 104 is provided.

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

As described above, the refrigerating cycle device 100 of the present embodiment is mainly connected by the refrigerant pipes in the order of the compressor 102, the indoor heat exchanger 103, the expansion valve 104, and the outdoor heat exchanger 105 to form a refrigerating cycle circuit. doing. The refrigeration cycle circuit sets the flow direction of the refrigerant discharged from the compressor 102 between the compressor 102 and the indoor heat exchanger 103 or the outdoor heat exchanger 105 to be either the indoor heat exchanger 103 or the outdoor heat exchanger 105. It is equipped with a four-way valve 106 that switches between the two.

By providing the four-way valve 106, the refrigeration cycle device 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 and the outdoor heat exchanger 105 are communicated with each other and the indoor heat exchanger 103 and the suction side of the compressor 102 are communicated with each other. As a result, the indoor heat exchanger 103 acts as an evaporator to absorb heat from the ambient air (indoor air), the outdoor heat exchanger 105 acts as a condenser, and the heat absorbed indoors is used as the ambient air (outdoor air). ) To dissipate heat. 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 are communicated with each other and the outdoor heat exchanger 105 and the suction side of the compressor 102 are communicated with each other. As a result, the outdoor heat exchanger 105 acts as an evaporator to absorb heat from (outdoor air), and the indoor heat exchanger 103 acts as a condenser to dissipate the heat absorbed outdoors to the indoor air.

As the four-way valve 106, a solenoid valve type that switches between cooling and heating by an electric signal from a control device (not shown) is used.

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

A working fluid (refrigerant) is sealed in the refrigeration cycle circuit. Hereinafter, the working fluid will be described.

The working fluid sealed in the refrigerating cycle device 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 in which R32 is 30% by weight or more and 60% by weight or less.

By mixing R32 with HFO1123 in an amount of 30% by weight or more, the autolysis reaction of HFO1123 can be suppressed. Further, the higher the concentration of R32, the more the autolysis reaction can be suppressed. This is because the action of alleviating the autolysis reaction due to the small polarization of R32 to the fluorine atom and the behavior during phase changes such as condensation and evaporation are integrated because HFO1123 and R32 have similar physical characteristics. The autolysis reaction of HFO1123 can be suppressed by the action of reducing the reaction opportunity of autolysis.

Further, the mixed refrigerant of HFO1123 and R32 has a co-boiling point of 30% by weight of R32 and 70% of HFO1123, and has no temperature slip, so that it can be handled in the same manner as a single refrigerant. That is, if R32 is mixed in an amount of 60% by weight or more, the temperature slip becomes large and it may be difficult to handle the same as a single refrigerant. Therefore, it is desirable to mix R32 in an amount of 60% by weight or less. In particular, it is desirable to mix R32 in an amount of 40% by weight or more and 50% by weight or less in order to prevent autolysis, reduce the temperature slip as it approaches the co-boiling point, and facilitate the design of the device.

Tables 1 and 2 show the case where the pressure, temperature, and compressor push-out volume of the refrigeration cycle are the same in the mixed working fluid of HFO1123 and R32 at a mixing ratio in which R32 is 30% by weight or more and 60% by weight or less. Refrigeration capacity and cycle efficiency (COP) were calculated and compared to R410A and HFO1123.

First, the 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 been improved, and in the actual operating state, the condensation temperature tends to decrease, the evaporation temperature tends to increase, and the discharge temperature also tends to decrease. .. Therefore, in consideration of the actual operating conditions, the cooling calculation conditions in Table 1 correspond to the cooling operation of the refrigeration cycle device 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 superheat degree of the suction refrigerant of the compressor was 5 ° C., and the supercooling degree of the condenser outlet was 8 ° C.

The heating calculation conditions in Table 2 correspond to the heating operation of the refrigeration cycle device 100 (indoor dry-bulb temperature 20 ° C, outdoor dry-bulb temperature 7 ° C, wet-bulb temperature 6 ° C), and the evaporation temperature is 2. The temperature was 38 ° C, the condensation temperature was 38 ° C, the superheat degree of the suction refrigerant of the compressor was 2 ° C, and the supercooling degree of the condenser outlet was 12 ° C.

From Tables 1 and 2, by mixing R32 in an amount of 30% by weight or more and 60% by weight or less, the refrigerating capacity is increased by about 20% and the cycle efficiency (COP) is increased during cooling and heating operations as compared with R410A. It becomes 94 to 97%, and the warming coefficient can be reduced to 10 to 20% of R410A.

As described above, in the two-component system of HFO1123 and R32, the prevention of self-decomposition, the magnitude of temperature slip, the capacity during cooling operation and heating operation, and COP are comprehensively considered (that is, the compressor described later). A mixture containing R32 of 30% by weight or more and 60% by weight or less is desirable, and more preferably, a mixture containing R32 of 40% by weight or more and 50% by weight or less is preferable. desirable.

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

For the indoor heat exchanger 103 and the outdoor heat exchanger 105, a fin-and-tube type heat exchanger, a parallel flow type (microtube type) heat exchanger, or the like is used. In addition, other heat exchangers may be used.

Next, the compressor 102 will be described with reference to FIG. The compressor 102 is a so-called closed 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 102 has an electric motor 102e and a compression mechanism 102c housed inside a closed container 102g, which is the outer shell thereof. It has become. The electric motor 102e is a so-called brushless motor. The electric motor 102e includes a rotor 1021e connected to the crankshaft 102m of 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, respectively. That is, 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 102h includes three terminals, and each terminal is connected to the electric 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 distant position of 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 distance between the adjacent lead wires 102i on the stator 1022e side (the coil end 1023e side described later) is the distance between the adjacent lead wires on the power supply terminal 102h side. It's getting bigger. Further, the three lead wires 102i are arranged approximately every 120 degrees around the rotation center of the rotor 1021e in the horizontal cross section of the electric motor 102e. FIG. 3 is a cross-sectional view of the electric motor 102e. The electric motor 102e is a so-called centralized winding electric motor. The stator 1022e is composed of one tooth 31 and an annular yoke 32 connecting the teeth 31, and is arranged on a substantially cylindrical rotor core 33 and its outer peripheral portion so as to face the inner peripheral portion of the stator 1022e. A rotor 1021e composed of a permanent magnet 34 is rotatably held around a crankshaft 102m. The permanent magnet 34 is fixed by inserting a ring 35 made of a non-magnetic material such as stainless steel into the outer circumference.

The permanent magnet may be fixed by using an adhesive such as epoxy resin.

Further, as a method of arranging the permanent magnets, the structure in which the permanent magnets 34 are arranged on the outer peripheral portion of the rotor core 33 has been described above, but as a structure in which the permanent magnets are arranged inside the rotor core (not shown). May be good.

On the other hand, the stator 1022e is fixed inside the closed 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, for example, welding or the like.

The teeth 31 is provided with a three-phase stator winding, and a switching element of an inverter-type electric motor drive device (not shown) causes a current to flow through the winding so that a rotating magnetic field is generated in the rotor 1021e. There is. 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 or at a low speed during stable operation or the like.

By providing a notch, a groove, or a hole 37 in the outer peripheral portion of the stator 1022e, there is a portion penetrating the entire length of the stator 1022e between the closed container 102g and the stator 1022e or in the stator 1022e itself. Refrigerating machine oil is allowed to pass through.

By making the electric motor 102e a centrally wound electric motor, the winding resistance can be reduced, the copper loss can be significantly reduced, and the total length of the motor can be reduced.

Although the electric motor 102e has been described as being a centralized winding electric motor, it may be a distributed winding electric motor.

The compression mechanism 102c has a cylinder 1022c forming the compression chamber 1021c and a rolling piston 1023c arranged in the compression chamber 1021c in the cylinder 1022c. The rolling piston 1023c rotates in the compression chamber while abutting against a vane (not shown) due to the rotation of the crankshaft 102m, and sucks and compresses the refrigerant from the suction pipe 102a. The compressed refrigerant moves from the discharge muffler 102l to the discharge refrigerant space 102d in the closed container 102g, and is discharged from the discharge pipe 102b to the outside of the compressor 102.

The compression mechanism 102c is of a type having two upper and lower cylinders 1022c, but this may be a type in which the cylinder 1022c has only one stage.

Further, in order to prevent liquid compression in the compression chamber 1021c, an accumulator 119 is provided in the suction pipe 102a. The accumulator 119 separates the refrigerant into gas and liquid, and guides only the refrigerant gas to the suction pipe 102a. In the accumulator 119, a refrigerant gas introduction pipe 1191 is connected to the upper part of the cylindrical container 1190, and a refrigerant gas outlet pipe 1192 is connected to the lower part. One end of the refrigerant gas outlet pipe 1192 is connected to the suction pipe 102a, and the other end of the refrigerant gas outlet pipe 1192 extends to the upper part of the internal space of the container 1190.

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

The compression mechanism 102c is connected to the electric motor 102e via a crankshaft 102m. In the electric motor 102e, the electric power received from the external power source is converted from the electric energy to the mechanical (rotational) energy. In the compression mechanism 102c, the compression work of boosting the refrigerant is performed by using the mechanical energy transmitted from the electric motor 102e via the crankshaft 102m.

Here, as described above, if the operating conditions are not normal, that is, if the blower fan on the condenser side is stopped, the refrigeration cycle circuit is blocked, or the like, the discharge pressure of the working fluid (high pressure side of the refrigeration cycle) becomes excessive. The temperature of the working fluid also rises excessively.

If the power supply to the compressor 102 is continued in this state, 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 generated. The insulation of the coil is damaged, and the wires of the windings come into direct contact with each other, which may cause a layer short circuit. That is, even if a working fluid in which an autolysis reaction is unlikely to occur, for example, a working fluid in which R32 is mixed with HFO1123 is used, the refrigerant becomes excessively high temperature and high pressure, and the refrigerant atmosphere under such high temperature and high pressure is created. When a high energy source is added, a self-decomposition reaction may occur and the pressure in the compressor 102 may rise sharply.

FIG. 5 is a characteristic diagram showing the region where the autolysis reaction occurs. For example, FIG. 5 is a characteristic diagram showing the autolysis reaction region of the working fluid in which the mixing ratio of R32 to HFO1123 is 30% by weight or more and 60% by weight or less.

In FIG. 5, the autolysis reaction region is a region on the right side of the autolysis reaction threshold value A, and when the temperature and pressure of the working fluid are related and the combination of both becomes a predetermined temperature and pressure combination, the autolysis reaction occurs. Wake up. The combination condition of the temperature and the pressure at which the self-decomposition reaction occurs has an inversely proportional correlation. For example, the self-decomposition reaction occurs when the temperature is low but the pressure is high, and conversely, even if the pressure is low. Occurs when the temperature is high.

Therefore, in this refrigeration cycle device, when the temperature and pressure of the discharge side portion of the compressor 102 reaches a predetermined combination region of temperature and pressure before the self-decomposition reaction occurs (hereinafter, referred to as a self-decomposition reaction prevention region), the electric motor 102e The operation of the compressor 102 is stopped by shutting off the power supply to the compressor 102.

Specifically, as shown in FIG. 4, a first protective device 120 mainly composed of the temperature detecting means 120a is provided on the discharge side portion of the compressor 102, in this example, the discharge pipe portion, and the first protective device 120 is provided. In addition, a second protective device 121 mainly composed of the pressure detecting means 121a is provided on the discharge side portion of the compressor 102. Then, the combination of the temperature and the pressure detected by the temperature detecting means 120a constituting the first protective device 120 and the pressure detecting means 121a constituting the second protective device 121 is the self-decomposition reaction prevention threshold value (B) shown in FIG. When the abnormality prevention threshold value) or higher, that is, the self-decomposition reaction prevention region is reached, the power supply to the electric motor 102e is cut off and the operation of the compressor 102 is stopped.

Further, in this embodiment, the temperature detected by the temperature detecting means 120a is an extremely abnormal temperature at which there is a concern that a self-decomposition reaction may occur even at the temperature alone, for example, the first and first temperatures shown in FIG. 5C. (Ii) The temperature is 280 ° C or higher, which is the maximum abnormal threshold of the combination of the detected values of the protective devices 120 and 121, or the pressure detected by the pressure detecting means 121a is so extreme that there is a concern that a self-decomposition reaction may occur even if the pressure alone is used. When the abnormal pressure, for example, the pressure of 9 MPa or more, which is the maximum abnormal threshold of the combination of the detected values of the first and second protective devices 120 and 121 shown in FIG. 5D, is reached, the other condition, that is, the pressure or temperature, prevents the self-decomposition reaction. Even if the area is not reached, the power supply to the electric motor 102e is cut off to stop the operation of the compressor 102.

The specific temperatures and pressures of the autolysis reaction prevention threshold B and the maximum abnormal thresholds C and D change according to the type and amount of the refrigerant to be mixed, and are therefore appropriately set according to the characteristics of the working fluid used. do it. For example, in the case of a working fluid obtained by mixing HFO1123 and R32 or a mixture of different types of refrigerants other than the ratio illustrated in this embodiment, the self-decomposition reaction prevention threshold value B and the maximum abnormal threshold values C and D are set. The specific temperature and pressure will naturally be different.

Further, in the present embodiment, the pressure detecting means 121a is composed of pressure indirect detecting means such as a current detecting sensor that detects an event caused by the pressure fluctuation, for example, the driving current of the electric motor 102e in this example. It is provided in one of the lead wires 102i of the stator winding of the electric motor 102e. The pressure indirect detecting means for detecting the event that fluctuates with the pressure fluctuation is not limited to the current detection sensor, and any means may be used as long as it can detect the event that occurs with the pressure fluctuation.

The refrigeration cycle apparatus configured as described above has a temperature and pressure before the working fluid in the compressor 102 undergoes a self-decomposition reaction, that is, when the temperature and pressure rise to a combination of temperature and pressure equal to or higher than the self-decomposition reaction prevention threshold B. The detection means 120a and the pressure detection means 121a, that is, the first protection device 120 and the second protection device 121 detect and operate to stop the power supply to the electric motor 102e.

As a result, it is possible to suppress the temperature and pressure in the compressor 102 from rising to the temperature and pressure in the autolysis reaction region, and it is possible to prevent the occurrence of the autolysis reaction.

Further, since the power supply to the motor 102e is stopped when both the temperature and pressure values reach the temperature and pressure equal to or higher than the autolysis reaction prevention threshold value B, the operation for reliable autolysis reaction prevention without malfunction is performed. It can be performed.

That is, if the configuration is such that the temperature detection means 120a and the pressure detection means 121a operate when the detection value of any one of them becomes the self-decomposition reaction prevention threshold B or higher, the temperature reaches the self-decomposition reaction prevention threshold B or higher. It will operate when the pressure rises to a high pressure equal to or higher than the self-decomposition reaction prevention threshold B even though it is not present. However, under this condition, the autolysis reaction did not occur, resulting in a malfunction.

However, if the configuration is such that the operation is performed when both the temperature and pressure values are equal to or higher than the autolysis reaction prevention threshold value B as in the present embodiment, the conditions under which the autolysis reaction occurs, that is, the detected values of both temperature and pressure. Compressor 102 only when the combination of
Since the operation of the above is stopped, it is possible to prevent a malfunction due to the fact that one of the detected values exceeds the autolysis reaction prevention threshold value B, and it is possible to perform a reliable operation for preventing the autolysis reaction. That is, it can be a highly reliable self-decomposition reaction prevention device.

Further, in this embodiment, when the temperature detected by the temperature detecting means 120a becomes an extremely abnormal temperature such that a self-decomposition reaction may occur even at the temperature alone, the pressure detected by the pressure detecting means 121a prevents the self-decomposition reaction. Even if the pressure does not reach the threshold value B or higher, the first protective device 120 (temperature detecting means 120a) operates to stop the power supply to the electric motor 102e. Similarly, when the pressure detected by the pressure detecting means 121a becomes an extremely abnormal pressure such that a self-decomposition reaction may occur even with the pressure alone, the pressure detected by the temperature detecting means 120a becomes the self-decomposition reaction prevention threshold value B. Even if the temperature does not reach the above temperature, the second protective device 121 (pressure detecting means 121a) operates to stop the power supply to the electric motor 102e.

That is, when either the temperature or the pressure in the compressor 102 rises to an extremely abnormal temperature or pressure, the operation of the compressor 102 is stopped, the occurrence of a self-decomposition reaction is prevented, and safety is ensured.

Therefore, even if the protection device on either side of the first protection device 120 or the second protection device 121 is out of order, the operation of the compressor 102 can be reliably stopped, and the safety can be greatly improved. ..

Further, since the temperature detecting means 120a serving as the first protection device 120 and the pressure detecting means 121a serving as the second protection device 121 are both provided in the compressor 102 and unitized, the compressor has a self-decomposition reaction prevention function. It becomes possible to provide as.

As described above, this refrigeration cycle device can prevent the autolysis reaction of the working fluid and enhance the safety, but the temperature detecting means 120a constituting the first protection device 120 supplies power when the predetermined temperature is detected. Anything can be used as long as it stops. For example, it may be composed of a bimetal switch, a thermal fuse, a thermal reactor, etc. that directly cuts off the power supply to the motor 102e, or the detected temperature may be sent to a control circuit, for example, the motor drive device 115 to indirectly supply power to the motor 102e. It can be configured by a thermistor or the like that is stopped at, and is not particularly limited.

Further, the pressure detecting means 121a constituting the second protection device 121 includes a pressure switch for directly detecting the pressure, a piezoelectric element, or the like, in addition to the pressure indirect detecting means for indirectly detecting the pressure like the current switch described above. Can be configured. Then, like the temperature detecting means 120a, the pressure detecting means 121a also directly stops the power supply to the electric motor 102e by its own operation, or sends a signal to the control circuit to indirectly reach the electric motor 102e. The power supply may be stopped, and the present invention is not particularly limited.

(Embodiment 2)
FIG. 6 is an enlarged view of a main part of the compressor 102 in the refrigeration cycle apparatus of the second embodiment.

In the second embodiment, the temperature detecting means 120a constituting the first protection device 120 is provided in the stator winding 40 portion of the electric motor 102e so as to detect the temperature in the vicinity of the electric motor in particular. Specifically, the thermistor is provided in a portion of the electric motor 102e that is directly related to the layer short, for example, an insulating paper portion that insulates the stator winding 40. Further, the pressure detecting means 121a constituting the second protective device 121 is composed of a pressure switch, a piezoelectric element, or the like, and is configured to directly detect the pressure on the discharge side.

According to the above configuration, not only the same effect as that of the first embodiment can be obtained, but also the temperature can be detected more quickly, and the autolysis reaction can be more reliably prevented.

That is, when the temperature detecting means 120a is provided in the discharge pipe portion of the compressor 102 as shown in the first embodiment, the temperature of the electric motor 102e is continuously energized in a state where the refrigeration cycle circuit is blocked, for example. When the rise abnormality occurs, the temperature rise of the discharge pipe portion is delayed as compared with the temperature rise of the electric motor 102e because there is no flow of the working fluid. As a result, before the temperature of the discharge pipe portion exceeds the self-decomposition reaction prevention threshold value B, the insulation of the stator winding 40 of the electric motor 102e may be damaged, a layer short may occur, and a self-decomposition reaction may occur.

However, if the temperature detecting means 120a is provided in the stator winding 40 portion of the electric motor 102e as in the present embodiment, the temperature of the stator winding 40 of the electric motor 102e, that is, the temperature in the vicinity of the electric motor can be quickly detected. The motor 102e can be stopped before the layer short circuit occurs due to the insulation damage of the stator winding 40. Therefore, the autolysis reaction can be prevented more reliably.

(Other embodiments)
In the embodiment of the present invention, the prevention of the autolysis reaction can be further ensured by adding the following configuration.

That is, the four-way valve 106 is switched in the pressure equalizing direction in accordance with the stop of the power supply to the stator winding 40 of the electric motor 102e shown in the first and second embodiments, that is, the compressor 102 (cooling in the case of heating operation). Add a configuration to the operation, if it is a cooling operation, to a heating operation).

Alternatively, the on-off valve 113a is opened at the same time as the power supply to the compressor 102 is stopped, and the discharge side and the suction side of the compressor 102 are communicated with each other via the bypass means 113.

With this configuration, the high-voltage side pressure in the refrigeration cycle circuit can be reduced at the same time as the motor is stopped, so that the occurrence of a self-decomposition reaction can be prevented more reliably.

In the embodiment of the present invention, the compressor has been described by taking a rotary compressor as an example, but this may be another type, for example, a positive displacement compressor such as a scroll type or a reciprocating type, or a centrifugal type compressor. Any compressor such as a machine may be used. Of course, it may be either a high pressure type or a low pressure type.

Further, in the first and second embodiments, the plurality of protective devices, that is, the temperature detecting means 120a serving as the first protective device 120 and the pressure detecting means 121a serving as the second protective device 121 are both provided in the compressor 102. However, when the temperature detecting means 120a is composed of a current detection sensor or the like, the temperature detecting means 120a may be provided on the control circuit side. Further, the pressure detecting means 121a may be provided not in the compressor 102 but in a piping path where the discharge pressure from the compressor 102 can be detected. The same effect can be obtained with such a configuration.

Further, in the first and second embodiments, the combination of the temperature detected by the temperature detecting means 120a serving as the first protection device 120 and the pressure detected by the pressure detecting means 121a serving as the second protection device 121 prevents the autolysis reaction. When the threshold value B or higher is reached, the power supply to the electric motor 102e is cut off. However, if only one of the detected values becomes an extremely abnormal value that may cause an autolysis reaction, even if the other detected value does not reach the autolysis reaction prevention threshold value B or higher. The configuration may be such that the power supply to the electric motor 102e is simply stopped, and claim 1 includes this.

As described above, the present invention can improve the reliability of the refrigeration cycle device using the working fluid containing HFO1123 or HFO1132, and can improve the reliability of each air conditioner for residential and commercial use, car air conditioner, water heater, refrigerator / freezer, showcase. It can be widely applied to applications such as cases and dehumidifiers.

100 Refrigeration cycle device 101a Indoor unit unit 101b Outdoor unit 102 Compressor 102a Suction pipe 102b Discharge pipe 102c Compression mechanism 102e Electric motor 102g Sealed container 1021e Rotor 1022e Refrigerant 103 Indoor heat exchanger 104 Expansion valve 105 Outdoor heat exchanger 106 Valve 107a Indoor blower fan 107b Outdoor blower fan 119 Accumulator 1190 Container 1191 Refrigerant gas introduction pipe 1192 Refrigerant gas outlet pipe 120 First protection device 120a Temperature detection means 121 Second protection device 121a Pressure detection means A Self-decomposition reaction threshold B Self-decomposition reaction Prevention threshold (abnormality prevention threshold)
C, D maximum abnormal threshold

Claims (3)

A compressor, a condenser, an expansion valve, and an evaporator are connected in a ring shape to form a refrigeration cycle circuit, and the refrigeration cycle circuit contains a working fluid containing 1,1,2-trifluoroethylene or difluoroethylene. A refrigeration cycle device configured by encapsulating the compressor, further comprising a plurality of protective devices for detecting an abnormality in the compressor and stopping the operation of the compressor , and at least one of the plurality of the protective devices is a working fluid. In addition to being composed of temperature detecting means for detecting the discharge side temperature, the other has a pressure detecting means for directly or indirectly detecting the pressure on the discharge side of the working fluid, and the temperature detecting means is a stator winding of an electric motor. A refrigeration cycle device provided on a wire portion and the pressure detecting means is provided on one of the lead wires of the stator winding of the electric motor. The refrigeration cycle device according to claim 1, wherein the plurality of protective devices are configured to stop the operation of the compressor when the combination of the detected values of the protective devices exceeds the threshold value of abnormality. A plurality of protection devices in claim 2 in which one of the detection value has a configuration for stopping the detection value maximum operation abnormality threshold becomes more outliers side of the compressor of the combination values of each protection device of each protector The refrigeration cycle device described.

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