Use as refrigerant in compressors, compressors and refrigeration cycle apparatus

Abstract

Inhibition of propagation of disproportionation reaction of refrigerant. Use of a composition as a refrigerant in a compressor (21) comprising one or two or more selected from the group consisting of ethylene-based fluorinated olefin, 2,3,3,3-tetrafluoropropene (HFO-1234yf) and 1,3,3,3-tetrafluoropropene (HFO-1234ze), in which the flow rate of the refrigerant flowing around the ignition energy generation site (86a, 91a, 93a) inside the compressor (21) under a prescribed high pressure condition is 1 m / s or more.

Description

Technical Field

[0001] This relates to the use of refrigerant in compressors, compressors, and refrigeration cycle devices. Background Technology

[0002] Previously, hydrofluoroolefins (HFO refrigerants) with lower Global Warming Potential (GWP) than HFC refrigerants have been of interest in refrigeration devices. For example, 1,2-difluoroethylene (HFO-1132) was also studied as a refrigerant with low GWP in Patent Document 1 (Japanese Patent Application Publication No. 2019-196312). Summary of the Invention

[0003] The problem that the invention aims to solve

[0004] Although this HFO refrigerant has a low GWP, its low stability makes it prone to a self-decomposition reaction called disproportionation under certain conditions. Disproportionation refers to a chemical reaction in which two or more molecules of the same type react with each other, transforming into two or more different types of substances. Furthermore, the disproportionation reaction of HFO refrigerants can sometimes propagate.

[0005] The purpose of this invention is to suppress the propagation of refrigerant disproportionation reaction.

[0006] Methods for solving problems

[0007] The inventors of this application conducted repeated and in-depth research to suppress the propagation of refrigerant disproportionation reactions. As a result, they discovered that refrigerant disproportionation reactions tend to propagate more easily in areas with slow refrigerant flow rates, while the propagation of disproportionation reactions can be suppressed in areas with fast refrigerant flow rates. Based on the above insights, the inventors of this application conducted further repeated research, thereby completing the content of this invention. This invention provides the following aspects regarding the use of refrigerant in compressors, compressors, and refrigeration cycle devices.

[0008] The first viewpoint regarding the use of the composition as a refrigerant in a compressor is that the refrigerant flowing around the ignition energy generation site inside the compressor under specified high-pressure conditions has a flow rate of 1 m / s or more. The composition comprises one or more of the following: ethylene-based fluoroolefins, 2,3,3,3-tetrafluoropropylene (HFO-1234yf), and 1,3,3,3-tetrafluoropropylene (HFO-1234ze).

[0009] It should be noted that, under specified high-pressure conditions, there is no particular limitation on the location of ignition energy generation within the compressor. For example, if the compressor has teeth and windings wound on the teeth, the ignition energy generation location may include the windings inside the compressor. Additionally, for example, if the compressor has a crankshaft and a bearing portion that rotatably supports the crankshaft, the ignition energy generation location may include the contact portion between the crankshaft and the bearing portion.

[0010] Depending on its intended use as a refrigerant in the compressor, the propagation of refrigerant disproportionation within the compressor can be suppressed in areas with high refrigerant flow rates around the ignition energy generation site inside the compressor.

[0011] It should be noted that the compressor can be a compressor in which the refrigerant flow velocity around the ignition energy generation part inside the compressor is 5 m / s or higher under specified high pressure conditions, or it can be a compressor with a flow velocity of 10 m / s or higher. The faster the refrigerant flow velocity around the ignition energy generation part inside the compressor, the more effectively the propagation of disproportionation can be suppressed.

[0012] The second viewpoint's use as a refrigerant in a compressor is the same as the first viewpoint's use as a refrigerant in a compressor, wherein the composition comprises one or more of the following: 1,2-difluoroethylene (HFO-1132), 1,1-difluoroethylene (HFO-1132a), 1,1,2-trifluoroethylene (HFO-1123), monofluoroethylene (HFO-1141), and perhaloolefins.

[0013] It should be noted that 1,2-difluoroethylene can be trans-1,2-difluoroethylene [(E)-HFO-1132], cis-1,2-difluoroethylene [(Z)-HFO-1132], or a mixture thereof.

[0014] The third viewpoint's use as a refrigerant in a compressor is the same as the second viewpoint's use as a refrigerant in a compressor, wherein the composition comprises 1,2-difluoroethylene (HFO-1132) and / or 1,1,2-trifluoroethylene (HFO-1123).

[0015] The fourth viewpoint's use as a refrigerant in a compressor is any one of the uses of refrigerant in a compressor in viewpoints 1 to 3, wherein the specified high-pressure condition is that the pressure of the refrigerant flowing in the compressor's discharge pipe is 1 MPa or higher.

[0016] Regarding its use as a refrigerant in compressors, by ensuring that the pressure of the refrigerant flowing in the compressor's discharge pipe is 1 MPa or higher, the propagation of the resulting disproportionation can be suppressed even under conditions where refrigerant disproportionation is likely to occur.

[0017] The compressor in point 5 is a compressor that compresses refrigerant. The refrigerant includes one or more of the following: ethylene-based fluoroolefins, 2,3,3,3-tetrafluoropropylene (HFO-1234yf), and 1,3,3,3-tetrafluoropropylene (HFO-1234ze). In the compressor, under specified high-pressure conditions, the flow velocity of the refrigerant circulating around the ignition energy generation site inside the compressor is 1 m / s or more.

[0018] It should be noted that, under specified high-pressure conditions, there is no particular limitation on the location of ignition energy generation within the compressor. For example, if the compressor has teeth and windings wound on the teeth, the ignition energy generation location may include the windings inside the compressor. Additionally, for example, if the compressor has a crankshaft and a bearing portion that rotatably supports the crankshaft, the ignition energy generation location may include the contact portion between the crankshaft and the bearing portion.

[0019] This compressor can suppress the propagation of refrigerant disproportionation within the compressor, in areas with high refrigerant flow rates around the ignition energy generation site.

[0020] The refrigeration cycle device of the sixth viewpoint includes a refrigerant circuit. The refrigerant circuit includes the compressor of the fifth viewpoint.

[0021] In this refrigeration cycle device, the propagation of refrigerant disproportionation circulating in the refrigerant circuit can be suppressed. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the refrigeration cycle device.

[0023] Figure 2 This is a block diagram of a refrigeration cycle device.

[0024] Figure 3 This is a side cross-sectional view showing a schematic configuration of the compressor.

[0025] Figure 4 This is a top cross-sectional view showing the periphery of the compressor's cylinder chamber.

[0026] Figure 5 This is a diagram showing the flow velocity distribution inside the compressor. Detailed Implementation

[0027] The following examples illustrate the use of compressors and refrigeration cycle devices and the refrigerants therein, but these descriptions do not limit the scope of the present invention.

[0028] (1) Refrigeration cycle device 1

[0029] The refrigeration cycle device 1 is a device that processes the heat load of the target space by performing a vapor compression refrigeration cycle, such as an air conditioning device for regulating the air in the target space.

[0030] Figure 1 The diagram shows a schematic configuration of the refrigeration cycle device. Figure 2 The diagram shows a block diagram of the refrigeration cycle device.

[0031] The refrigeration cycle device 1 mainly includes: an outdoor unit 20; an indoor unit 30; a liquid-side refrigerant connecting pipe 6 and a gas-side refrigerant connecting pipe 5 connecting the outdoor unit 20 and the indoor unit 30; a remote control (not shown); and a controller 7 for controlling the operation of the refrigeration cycle device 1.

[0032] In the refrigeration cycle device 1, the following refrigeration cycle is performed: the refrigerant sealed in the refrigerant circuit 10 is compressed, cooled or condensed, depressurized, heated or evaporated, and then compressed again. In this embodiment, the refrigerant circuit 10 is filled with refrigerant for performing a vapor compression refrigeration cycle.

[0033] (2) Refrigerant

[0034] The refrigerant filled in the refrigerant circuit 10 is one or more refrigerants selected from the group consisting of fluoroolefins selected from ethylene groups, 2,3,3,3-tetrafluoropropylene (HFO-1234yf), and 1,3,3,3-tetrafluoropropylene (HFO-1234ze). It should be noted that, regarding the combustion rate as defined in ISO 817, 1.2 cm / s for 1,3,3,3-tetrafluoropropylene (HFO-1234ze) is lower than 1.5 cm / s for 2,3,3,3-tetrafluoropropylene (HFO-1234yf), and is therefore preferred. Furthermore, regarding the Lower Flammability Limit (LFL) as defined in ISO 817, 65,000 vol. ppm (6.5%) of 1,3,3,3-tetrafluoropropylene (HFO-1234ze) is preferred because it is higher than 62,000 vol. ppm (6.2%) of 2,3,3,3-tetrafluoropropylene (HFO-1234yf). The refrigerant may contain one or more compounds selected from the group consisting of 1,2-difluoroethylene (HFO-1132), 1,1-difluoroethylene (HFO-1132a), 1,1,2-trifluoroethylene (HFO-1123), monofluoroethylene (HFO-1141), and perhaloolefins. Particularly preferred components of the refrigerant are 1,2-difluoroethylene (HFO-1132) and / or 1,1,2-trifluoroethylene (HFO-1123).

[0035] Examples of fluoroolefins derived from the ethylene family include 1,2-difluoroethylene (HFO-1132), 1,1-difluoroethylene (HFO-1132a), 1,1,2-trifluoroethylene (HFO-1123), monofluoroethylene (HFO-1141), and perhaloolefins. Examples of perhaloolefins include trifluorochloroethylene (CFO-1113) and tetrafluoroethylene (FO-1114).

[0036] It should be noted that refrigeration oil is filled in the refrigerant circuit 10 along with the aforementioned refrigerant.

[0037] (3) Outdoor Unit 20

[0038] The outdoor unit 20 is connected to the indoor unit 30 via the liquid-side refrigerant connecting pipe 6 and the gas-side refrigerant connecting pipe 5, forming part of the refrigerant circuit 10. The outdoor unit 20 mainly includes a compressor 21, a four-way switching valve 22, an outdoor heat exchanger 23, an outdoor expansion valve 24, an outdoor fan 25, a receiver 41, a gas-side shut-off valve 28, and a liquid-side shut-off valve 29.

[0039] Compressor 21 is a device that compresses low-pressure refrigerant in the refrigeration cycle to high pressure. Here, compressor 21 can be a hermetically sealed compressor with a positive displacement compression element such as a rotary or scroll compressor, driven by a compressor motor. In this embodiment, a rotary compressor is used. The compressor motor is used to change capacity, and its operating frequency can be controlled by an inverter.

[0040] The four-way switching valve 22 switches the flow path of the refrigerant circuit 10. Specifically, the four-way switching valve 22 can switch between: a state in which the discharge side of the compressor 21 is connected to the outdoor heat exchanger 23 while the suction side of the compressor 21 is connected to the gas side shut-off valve 28; and a state in which the discharge side of the compressor 21 is connected to the gas side shut-off valve 28 while the suction side of the compressor 21 is connected to the outdoor heat exchanger 23.

[0041] The outdoor heat exchanger 23 functions as a radiator or condenser for the high-pressure refrigerant in the refrigeration cycle during cooling operation and as an evaporator for the low-pressure refrigerant in the refrigeration cycle during heating operation.

[0042] The outdoor expansion valve 24 is located between the liquid-side outlet of the outdoor heat exchanger 23 in the refrigerant circuit 10 and the liquid-side shut-off valve 29. The outdoor expansion valve 24 is an electrically operated expansion valve capable of adjusting the valve opening.

[0043] Outdoor fan 25 draws outdoor air into outdoor unit 20, where it exchanges heat with refrigerant in outdoor heat exchanger 23, generating an airflow to be exhausted to the outside. Outdoor fan 25 is driven by outdoor fan motor.

[0044] The receiver 41 is located between the suction side of the compressor 21 and one of the connection ports of the four-way switching valve 22, and is a refrigerant container that can store the remaining refrigerant in the refrigerant circuit 10 as liquid refrigerant.

[0045] The liquid-side shut-off valve 29 is a manual valve located in the outdoor unit 20 at the connection point of the refrigerant-connected piping 6.

[0046] The gas-side shut-off valve 28 is a manual valve located in the outdoor unit 20 at the connection point of the gas-side refrigerant connecting pipe 5.

[0047] The outdoor unit 20 has an outdoor unit control unit 27, which controls the operation of each component constituting the outdoor unit 20. The outdoor unit control unit 27 has a microcomputer including a CPU, memory, etc. The outdoor unit control unit 27 is connected to the indoor unit control unit 34 of each indoor unit 30 via a communication line to transmit and receive control signals, etc.

[0048] The outdoor unit 20 is equipped with a discharge pressure sensor 61, a discharge temperature sensor 62, a suction pressure sensor 63, a suction temperature sensor 64, an outdoor heat exchange temperature sensor 65, and an external gas temperature sensor 66. These sensors are electrically connected to the outdoor unit control unit 27 and send detection signals to it. The discharge pressure sensor 61 detects the pressure of the refrigerant flowing in the discharge pipe, which connects the discharge side of the compressor 21 to one of the connection ports of the four-way switching valve 22. The discharge temperature sensor 62 detects the temperature of the refrigerant flowing in the discharge pipe. The suction pressure sensor 63 detects the pressure of the refrigerant flowing in the suction pipe, which connects the suction side of the compressor 21 to the receiver 41. The suction temperature sensor 64 detects the temperature of the refrigerant flowing in the suction pipe. The outdoor heat exchange temperature sensor 65 detects the temperature of the refrigerant flowing in the outdoor heat exchanger 23 at the outlet on the liquid side, opposite to the side connected to the four-way switching valve 22. The external gas temperature sensor 66 detects the outdoor air temperature before it passes through the outdoor heat exchanger 23.

[0049] (4) Indoor Unit 30

[0050] The indoor unit 30 is installed, for example, on the wall or ceiling of the interior space that is the target space. The indoor unit 30 is connected to the outdoor unit 20 via the liquid-side refrigerant connecting pipe 6 and the gas-side refrigerant connecting pipe 5, forming part of the refrigerant circuit 10.

[0051] The indoor unit 30 has an indoor heat exchanger 31 and an indoor fan 32.

[0052] In the indoor heat exchanger 31, the liquid side is connected to the liquid-side refrigerant connecting pipe 6, and the gas side is connected to the gas-side refrigerant connecting pipe 5. The indoor heat exchanger 31 functions as an evaporator for the low-pressure refrigerant in the refrigeration cycle during cooling operation and as a condenser for the high-pressure refrigerant in the refrigeration cycle during heating operation.

[0053] The indoor fan 32 draws indoor air into the indoor unit 30, where it exchanges heat with the refrigerant in the indoor heat exchanger 31, generating an airflow to be exhausted to the outside. The indoor fan 32 is driven by an indoor fan motor.

[0054] In addition, the indoor unit 30 has an indoor unit control unit 34, which controls the operation of each component constituting the indoor unit 30. The indoor unit control unit 34 has a microcomputer including a CPU, memory, etc. The indoor unit control unit 34 is connected to the outdoor unit control unit 27 via a communication line to transmit and receive control signals, etc.

[0055] The indoor unit 30 is equipped with an indoor liquid-side heat exchange temperature sensor 71, an indoor air temperature sensor 72, etc. These sensors are electrically connected to the indoor unit control unit 34 and send detection signals to it. The indoor liquid-side heat exchange temperature sensor 71 detects the temperature of the refrigerant flowing through the outlet on the liquid refrigerant side of the indoor heat exchanger 31. The indoor air temperature sensor 72 detects the indoor air temperature before it passes through the indoor heat exchanger 31.

[0056] (5) Controller 7

[0057] In the refrigeration cycle unit 1, the outdoor unit control unit 27 and the indoor unit control unit 34 are connected via a communication line, thereby forming a controller 7 that controls the operation of the refrigeration cycle unit 1.

[0058] The controller 7 mainly has a CPU (central processing unit) and memory such as ROM and RAM. It should be noted that the various processing and control based on the controller 7 are realized by the integrated functions of the various parts included in the outdoor unit control unit 27 and / or the indoor unit control unit 34.

[0059] (6) Operating Mode

[0060] The refrigeration cycle device 1 is capable of performing at least a refrigeration operation mode and a heating operation mode.

[0061] The controller 7 determines whether it is in cooling or heating operation mode based on instructions received from the remote control or other means, and then executes the command.

[0062] In the refrigeration operation mode, the compressor 21, for example, performs capacity control on the operating frequency to ensure that the evaporation temperature of the refrigerant in the refrigerant circuit 10 reaches the target evaporation temperature.

[0063] The gaseous refrigerant discharged from compressor 21 condenses in outdoor heat exchanger 23 via four-way switching valve 22. The refrigerant flowing through outdoor heat exchanger 23 is depressurized as it passes through outdoor expansion valve 24.

[0064] The refrigerant, depressurized by the outdoor expansion valve 24, flows through the liquid-side shut-off valve 29 in the liquid-side refrigerant connecting pipe 6 and is delivered to the indoor unit 30. Thereafter, the refrigerant evaporates in the indoor heat exchanger 31 and flows to the gas-side refrigerant connecting pipe 5. The refrigerant flowing through the gas-side refrigerant connecting pipe 5 passes through the gas-side shut-off valve 28, the four-way switching valve 22, and the receiver 41, and is then drawn back into the compressor 21.

[0065] In heating operation mode, compressor 21, for example, performs capacity control on the operating frequency to ensure that the condensation temperature of the refrigerant in refrigerant circuit 10 reaches the target condensation temperature.

[0066] The gaseous refrigerant discharged from compressor 21 flows through four-way switching valve 22 and gas-side refrigerant connecting pipe 5, and then flows into the gas-side end of indoor heat exchanger 31 of indoor unit 30, where it condenses or releases heat. The refrigerant that condenses or releases heat in indoor heat exchanger 31 flows through liquid-side refrigerant connecting pipe 6 and into outdoor unit 20.

[0067] The refrigerant passing through the liquid-side shut-off valve 29 of the outdoor unit 20 is depressurized at the outdoor expansion valve 24. The refrigerant depressurized at the outdoor expansion valve 24 evaporates in the outdoor heat exchanger 23, passes through the four-way switching valve 22 and the receiver 41, and is then drawn back into the compressor 21.

[0068] (7) Detailed composition of compressor 21

[0069] like Figure 3 As shown, the compressor 21 in this embodiment is a single-cylinder rotary compressor, which includes a housing 81 and a drive mechanism 82 and a compression mechanism 88 disposed within the housing 81. The compressor 21 has the compression mechanism 88 disposed below the drive mechanism 82 inside the housing 81.

[0070] (7-1) Drive mechanism

[0071] The drive mechanism 82 is housed in the upper part of the internal space of the housing 81 and drives the compression mechanism 88. The drive mechanism 82 has a motor 83 as a drive source and a crankshaft 84 mounted on the motor 83 as a drive shaft.

[0072] Motor 83 is a motor used to drive the rotation of crankshaft 84, and mainly includes rotor 85 and stator 86. The rotor 85 has the crankshaft 84 embedded within its internal space and rotates together with it. The rotor 85 is constructed of laminated electromagnetic steel plates and magnets embedded in the rotor body. Stator 86 is arranged radially outward of rotor 85 at predetermined intervals. Multiple stators 86 are arranged circumferentially at predetermined intervals. Stator 86 is constructed of laminated electromagnetic steel plates and coils 86a wound around a stator body 86c having teeth 86b, and multiple coils are arranged circumferentially. Motor 83 causes rotor 85 to rotate together with crankshaft 84 by the electromagnetic force generated in the stator 86 by allowing current to flow through the coils 86a. Power is supplied to the coils 86a of stator 86 through wiring (not shown) connected to a terminal portion 98 located at the upper end of housing 81.

[0073] The crankshaft 84 is fitted onto the rotor 85 and rotates around the rotating shaft. Additionally, as... Figure 4 As shown, the crank pin 84a, which is the eccentric portion of the crankshaft 84, is inserted into the roller 89a (described later) of the piston 89 of the compression mechanism 88, and is embedded in the roller 89a in a state that can transmit the rotational force from the rotor 85. The crankshaft 84 rotates with the rotor 85, causing the crank pin 84a to rotate eccentrically, and causing the roller 89a of the piston 89 of the compression mechanism 88 to revolve. That is, the crankshaft 84 has the function of transmitting the driving force of the motor 83 to the compression mechanism 88.

[0074] (7-2) Compression mechanism

[0075] The compression mechanism 88 is housed in the lower part of the housing 81. The compression mechanism 88 compresses the refrigerant drawn in through the suction pipe 99. The compression mechanism 88 is a rotary compression mechanism, mainly composed of a front end cap 91, a cylinder 92, a piston 89, and a rear end cap 93. In addition, the refrigerant compressed in the compression chamber S1 of the compression mechanism 88 is discharged from the front end cap discharge hole 91c formed in the front end cap 91 through the silencer space S2 surrounded by the front end cap 91 and the silencer 94, into the space where the motor 83 is located and the lower end of the discharge pipe 95 is located.

[0076] (7-2-1) Cylinder

[0077] Cylinder 92 is a cast metal component. Cylinder 92 has a cylindrical central portion 92a, a first outer extension 92b extending radially outward from the central portion 92a, and a second outer extension 92c extending from the central portion 92a to the opposite side of the first outer extension 92b. An intake port 92e for drawing in low-pressure refrigerant in the refrigeration cycle is formed in the first outer extension 92b. The cylindrical space inside the inner circumferential surface 92a1 of the central portion 92a becomes the cylinder chamber 92d into which the refrigerant drawn in through the intake port 92e flows. The intake port 92e extends from the cylinder chamber 92d toward the outer circumferential surface of the first outer extension 92b and opens on the outer circumferential surface of the first outer extension 92b. The front end of an intake pipe 99 is inserted into this intake port 92e. Furthermore, a piston 89 and the like for compressing the refrigerant flowing into the cylinder chamber 92d are housed within the cylinder chamber 92d.

[0078] In the cylinder chamber 92d formed by the cylindrical central portion 92a of the cylinder 92, the lower end, i.e., the first end, is open, and the upper end, i.e., the second end, is also open. The lower end of the central portion 92a, the first end, is blocked by the rear end cap 93, which will be described later. In addition, the upper end of the central portion 92a, the second end, is blocked by the front end cap 91, which will be described later.

[0079] Furthermore, a blade swing space 92f is formed in the cylinder 92, which includes the bushing 89c and blades 89b, described later. The blade swing space 92f spans the central portion 92a and the first outer extension 92b, and the blades 89b of the piston 89 are swingably supported in the cylinder 92 by means of the bushing 89c. When viewed from above, the blade swing space 92f is configured such that the vicinity of the intake port 92e extends from the cylinder chamber 92d to the outer periphery.

[0080] (7-2-2) Front end cap

[0081] like Figure 3 As shown, the front end cap 91 has: a front end cap circular plate portion 91b that blocks the opening of the second end, which is the upper end of the cylinder 92; and an upper bearing portion 91a that extends upward from the periphery of the front end cap opening at the center of the front end cap circular plate portion 91b. The upper bearing portion 91a is cylindrical and functions as a bearing for the crankshaft 84.

[0082] In the front head circular plate portion 91b, Figure 4 A front end discharge port 91c is formed at the planar position shown. Refrigerant compressed in the compression chamber S1, which has a changing volume within the cylinder chamber 92d of the cylinder 92, is intermittently discharged from the front end discharge port 91c. A discharge valve is provided on the circular plate portion 91b of the front end to open and close the outlet of the front end discharge port 91c. This discharge valve opens due to the pressure difference when the pressure in the compression chamber S1 is higher than the pressure in the muffler space S2, allowing refrigerant to be discharged from the front end discharge port 91c into the muffler space S2.

[0083] (7-2-3) Muffler

[0084] like Figure 3 As shown, the muffler 94 is installed on the upper surface of the periphery of the front end plate portion 91b of the front end cap 91. The muffler 94, together with the upper surface of the front end plate portion 91b and the outer peripheral surface of the upper bearing portion 91a, forms the muffler space S2 to reduce noise accompanying refrigerant discharge. As described above, the muffler space S2 and the compression chamber S1 are connected through the front end cap discharge hole 91c when the discharge valve is open.

[0085] Additionally, the muffler 94 has: a central muffler opening (not shown) that passes through the upper bearing portion 91a; and a muffler discharge hole that allows refrigerant to flow from the muffler space S2 to the upper motor 83 housing space.

[0086] It should be noted that the muffler space S2, the storage space of the motor 83, the space above the motor 83 where the discharge pipe 95 is located, and the space below the compression mechanism 88 where lubricating oil is stored are all connected to form a high-pressure space with equal pressure.

[0087] (7-2-4) Rear end cap

[0088] The rear end cap 93 has: a rear end cap circular plate portion 93b that blocks the opening of the first end, which is the lower end of the cylinder 92; and a lower bearing portion 93a that serves as a bearing extending downward from the peripheral portion of the central opening of the rear end cap circular plate portion 93b. Figure 4 As shown, the front end cap circular plate portion 91b, the rear end cap circular plate portion 93b, and the central portion 92a of the cylinder 92 form the cylinder chamber 92d. The upper bearing portion 91a and the lower bearing portion 93a are cylindrical flange portions that provide axial support for the crankshaft 84.

[0089] (7-2-5) Piston

[0090] Piston 89 is disposed in cylinder chamber 92d and mounted on crank pin 84a, which is an eccentric portion of crankshaft 84. Piston 89 is an integral component of roller 89a and blade 89b. Blade 89b of piston 89 is disposed in blade swing space 92f formed in cylinder 92, and as described above, is swingably supported in cylinder 92 by bushing 89c. In addition, blade 89b can slide with bushing 89c, swing during operation, and repeatedly move away from or towards crankshaft 84.

[0091] like Figure 4As shown, the rollers 89a and blades 89b of the piston 89 form a compression chamber S1 whose volume changes due to the revolution of the piston 89, in the form of separating the cylinder chamber 92d. The compression chamber S1 is a space surrounded by the inner circumferential surface 92a1 of the central part 92a of the cylinder 92, the upper surface of the rear end plate portion 93b, the lower surface of the front end plate portion 91b, and the piston 89. As the piston 89 revolutions, the volume of the compression chamber S1 changes, and the low-pressure refrigerant drawn in through the suction port 92e is compressed into high-pressure refrigerant, which is then discharged from the front end discharge port 91c into the muffler space S2.

[0092] (7-3) Actions

[0093] In the compressor 21 described above, the volume of the compression chamber S1 changes due to the movement of the piston 89 of the compression mechanism 88, which revolves by the eccentric rotation of the crank pin 84a. Specifically, firstly, during the revolution of the piston 89, low-pressure refrigerant is drawn into the compression chamber S1 through the suction port 92e. As the refrigerant is drawn in, the volume of the compression chamber S1 facing the suction port 92e gradually increases. Then, as the piston 89 revolves, the connection between the compression chamber S1 and the suction port 92e is broken, and the compression of the refrigerant in the compression chamber S1 begins. Subsequently, the volume of the compression chamber S1, which is now connected to the front head discharge port 91c, becomes quite small, and the pressure of the refrigerant increases. Then, with further revolution of the piston 89, the high-pressure refrigerant pushes open the discharge valve from the front head discharge port 91c and is discharged into the muffler space S2. The refrigerant introduced into the muffler space S2 is discharged from the muffler discharge port of the muffler 94 into the space above the muffler space S2. The refrigerant discharged to the outside of the muffler space S2 passes through the space between the rotor 85 and the stator 86 of the motor 83, cools the motor 83, and is then discharged from the discharge pipe 95.

[0094] (8) Compressor control

[0095] When the compressor 21 is operating in cooling mode and heating mode, the controller 7 sets the specified target evaporation temperature and target condensation temperature as target values ​​to control the operating frequency.

[0096] Here, the controller 7 controls the compressor so that even if a refrigerant disproportionation reaction occurs inside the compressor 21, it can suppress the spread of the disproportionation reaction to the surrounding area where the disproportionation reaction occurs.

[0097] In this control, the controller 7 controls the operating frequency so that, when the discharge pressure of the compressor 21 reaches 1 MPa or higher, the flow velocity of the gaseous refrigerant circulating around the ignition energy generation site is 1 m / s or higher. Here, to ensure that the flow velocity of the gaseous refrigerant circulating around the ignition energy generation site is 1 m / s or higher, the operating frequency in the aforementioned capacity control is increased. The method for ensuring that the flow velocity of the gaseous refrigerant circulating around the ignition energy generation site is 1 m / s or higher is not particularly limited. For example, data such as a formula or table relating parameters including the operating frequency of the compressor 21 to the refrigerant flow velocity around the ignition energy generation site can be predetermined through simulation analysis and stored in a memory, and the operating frequency of the compressor 21 can be controlled based on this data. Furthermore, the area around the ignition energy generation site can be, for example, a range of 5 cm, 3 cm, or 1 cm from the ignition energy generation site. In addition, the area surrounding the ignition energy generation site can be, for example, within 5 cm of the ignition energy generation site, within 3 cm of the ignition energy generation site, or within 1 cm of the ignition energy generation site, be the area with the slowest flow rate.

[0098] It should be noted that the controller 7 can use the refrigerant pressure detected by the discharge pressure sensor 61 as the discharge pressure of the compressor 21.

[0099] In addition, the periphery of coil 86a, the periphery of upper bearing portion 91a, and the periphery of lower bearing portion 93a can be cited as ignition energy generating parts.

[0100] Regarding the area surrounding coil 86a, if the insulation film of the wire is poorly manufactured during the manufacturing of coil 86a, or if the insulation film peels off due to some contact, the energy required for ignition can be easily generated when electricity is applied.

[0101] In addition, regarding the periphery of the upper bearing portion 91a and the periphery of the lower bearing portion 93a, the sliding surfaces between them and the crankshaft 84 are prone to generating the energy required for ignition due to friction during driving.

[0102] (9) Features of the implementation method

[0103] In the refrigeration cycle apparatus 1 of this embodiment, a refrigerant that is prone to disproportionation is used. This disproportionation reaction occurs with a certain probability under specified high-temperature, high-pressure, and ignition energy conditions. Furthermore, the disproportionation reaction can sometimes propagate from its point of origin to surrounding areas.

[0104] In contrast, the inventors used 1,2-difluoroethylene (HFO-1132) as a refrigerant, prepared a prescribed flow path connected to an ignition source, changed the refrigerant flow rate, and conducted an experiment to observe the propagation of the disproportionation reaction at the ignition source using an ultra-slow-motion camera. Based on the experimental results, it was confirmed that compared to a refrigerant flow rate slower than 1 m / s, a refrigerant flow rate of 1 m / s or higher could suppress the propagation of the disproportionation reaction, thus confirming that the faster the refrigerant flow rate, the better the effect of suppressing the propagation of the disproportionation reaction.

[0105] Here, the inventors analyzed the refrigerant flow rate distribution inside the compressor 21 through simulation. The simulation results are shown below. Figure 5 Here, in the simulation, the refrigerant velocity distribution inside compressor 21 was analyzed under operating conditions of a refrigerant discharge pressure of 2.6 MPa and a discharge temperature of 90°C. Figure 5 It is known that near the upper end and near the lower end of the compressor housing 81, close to the refrigerant oil, the refrigerant flow rate is less than 1 m / s, indicating a relatively slow flow rate. However, in the narrow passage around the upper bearing portion 91a and inside the discharge pipe 95, the refrigerant flow rate is found to be 10 m / s or more, indicating a relatively fast flow rate. Furthermore, around the rotor 85 and in the gap of the motor 83, a flow rate of 5 m / s to 10 m / s is found, making it an area where sufficient flow velocity is easily achieved. Additionally, around the coil 86a of the stator 86, around the stator body 86c of the stator 86, around the lower bearing portion 93a, around the rotor 85, and in the area from these locations to the discharge pipe 95, a refrigerant flow rate of 1 m / s to 5 m / s is found, representing a certain level of flow velocity.

[0106] Furthermore, in the compressor 21 using the refrigerant of this embodiment and the refrigeration cycle device 1 equipped with the compressor 21, the refrigerant flowing through the periphery of the ignition energy generation part of the compressor 21, namely the coil 86a, the upper bearing part 91a, and the lower bearing part 93a, is configured to have a flow rate of 1 m / s or more under a specified high pressure condition. Therefore, in the compressor 21 and refrigeration cycle device 1 of this embodiment, although an unstable refrigerant is used, even if a refrigerant disproportionation reaction occurs inside the compressor 21, the propagation of this disproportionation reaction to the surrounding area of ​​the generation part can be suppressed.

[0107] (10) Other implementation methods

[0108] (10-1) Other implementation methods A

[0109] In the above embodiment, the example is given where the compressor 21 is operating at a discharge pressure of 1 MPa or higher, and the operating frequency is controlled to ensure that the flow velocity of the gaseous refrigerant flowing around the ignition energy generation area, i.e., the periphery of the coil 86a, the periphery of the upper bearing portion 91a, and the periphery of the lower bearing portion 93a, is 1 m / s or higher.

[0110] In contrast, in situations where disproportionation reactions are more likely to occur, such as when the discharge pressure of compressor 21 is 3 MPa or higher, or when it is 5 MPa or higher, the operating frequency can be controlled so that the flow rate of the gaseous refrigerant flowing around the ignition energy generation parts, namely the periphery of coil 86a, the periphery of upper bearing 91a, and the periphery of lower bearing 93a, is 1 m / s or higher.

[0111] (10-2) Other implementation methods B

[0112] In the above embodiment, the case in which the flow rate of the refrigerant flowing around the ignition energy generating part, i.e., the coil 86a, the upper bearing part 91a, and the lower bearing part 93a, is 1 m / s or more is described as an example to suppress the propagation of the disproportionation reaction.

[0113] In contrast, the flow rate is not limited to 1 m / s. For example, it can be configured such that the flow rate of the refrigerant circulating around the ignition energy generation site is 3 m / s or more, 5 m / s or more, or even 10 m / s or more. Thus, the higher the flow rate of the refrigerant circulating around the ignition energy generation site of the compressor 21, the more effectively the propagation of the disproportionation reaction can be suppressed.

[0114] (10-3) Other implementation methods C

[0115] The above embodiments are illustrated using a rotary compressor as compressor 21 as an example.

[0116] In contrast, compressors that suppress the propagation of disproportionation reactions by increasing the flow rate of refrigerant around the ignition energy generation site are not limited to rotary compressors; known scroll compressors or oscillating compressors can also be used.

[0117] (Postscript)

[0118] The embodiments of the present invention have been described above. However, it should be understood that various changes can be made to the methods and details without departing from the spirit and scope of the present invention as set forth in the claims.

[0119] Symbol Explanation

[0120] 1. Refrigeration cycle device

[0121] 10 Refrigerant Circuit

[0122] 21 Compressor

[0123] 86A coil (ignition energy generation part)

[0124] 91a upper bearing section (ignition energy generation part)

[0125] 93a lower bearing section (ignition energy generation area)

[0126] 95 discharge pipe

[0127] Existing technical documents

[0128] Patent documents

[0129] Patent Document 1: Japanese Patent Application Publication No. 2019-196312

Claims

1. Use of a composition as a refrigerant in a compressor (21), the composition comprising one or more of a group selected from ethylene-based fluoroolefins, 2,3,3,3-tetrafluoropropylene and 1,3,3,3-tetrafluoropropylene, wherein the refrigerant flowing around an ignition energy generating portion (86a, 91a, 93a) inside the compressor (21) under a specified high pressure condition has a flow velocity of 1 m / s or more, the ignition energy generating portion (86a, 91a, 93a) being a winding or a contact portion between a crankshaft and a bearing inside the compressor, and the specified high pressure condition being a condition where the pressure of the refrigerant flowing in the discharge pipe of the compressor is 1 MPa or more.

2. The use as described in claim 1, wherein, The ethylene-based fluoroolefins include one or more selected from the group consisting of 1,2-difluoroethylene, 1,1-difluoroethylene, 1,1,2-trifluoroethylene, monofluoroethylene, and perhaloethylene.

3. The use as described in claim 2, wherein, The ethylene-based fluoroolefins include 1,2-difluoroethylene and / or 1,1,2-trifluoroethylene.

4. A compressor (21) for compressing one or more refrigerants selected from the group consisting of fluoroolefins selected from the ethylene system, 2,3,3,3-tetrafluoropropylene, and 1,3,3,3-tetrafluoropropylene, wherein, Under specified high pressure conditions, the refrigerant flowing around the ignition energy generating parts (86a, 91a, 93a) inside the compressor has a flow rate of 1 m / s or more. The ignition energy generating parts (86a, 91a, 93a) are the windings inside the compressor or the contact part between the crankshaft and the bearing. The specified high pressure conditions are conditions where the pressure of the refrigerant flowing in the discharge pipe of the compressor is 1 MPa or more.

5. A refrigeration cycle device (1) comprising: a refrigerant circuit (10) having a compressor (21) as claimed in claim 4.

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