Refrigeration Cycle Equipment

Abstract

Provided is a refrigeration cycle device comprising a refrigeration circuit that includes a compressor, wherein a refrigerant is enclosed in the refrigeration circuit, the refrigerant contains a first component and a second component, the first component comprises 1,1,2-trifluoroethylene, the second component comprises at least one type of substance selected from the group consisting of hydrocarbons having 1-5 carbon atoms and fluorinated hydrocarbons having 1-5 carbon atoms, the mass-based content C1 of the first component in the refrigerant is 50 mass% or more, the percentage (C2 / C1) × 100 of the mass-based content C2 of the second component relative to the mass-based content C1 of the first component in the refrigerant is 15% or more and less than 50%, a refrigerator oil is filled in the compressor, and the refrigerator oil is compatible with the second component.

Description

[Technical Field]

[0001] The present disclosure relates to a refrigeration cycle device. [Background technology]

[0002] In recent years, there has been a demand for reducing greenhouse gas emissions in order to prevent global warming. Refrigerants with lower global warming potential (GWP) are being considered for use in refrigeration cycle devices such as air conditioners. 1,1,2-trifluoroethylene (hereinafter also referred to as HFO-1123) is being considered as such a refrigerant (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2012 / 157764 Summary of the Invention [Problem to be solved by the invention]

[0004] However, HFO-1123 is prone to disproportionation reactions under high temperature and pressure conditions, and therefore there is a need for technology to suppress the disproportionation reactions of HFO-1123.

[0005] An object of the present disclosure is to provide a refrigeration cycle device that can suppress the disproportionation reaction of HFO-1123. [Means for solving the problem]

[0006] The refrigeration cycle device according to the present disclosure comprises: a refrigeration circuit including a compressor; A refrigerant is sealed in the refrigeration circuit, The refrigerant includes a first component and a second component, the first component comprises 1,1,2-trifluoroethylene; the second component is composed of at least one selected from the group consisting of hydrocarbons having a carbon number of 1 to 5 and fluorohydrocarbons having a carbon number of 1 to 5, The mass-based content C1 of the first component in the refrigerant is 50 mass% or more, The percentage (C2 / C1)×100 of the mass-based content C2 of the second component to the mass-based content C1 of the first component in the refrigerant is 15% or more and less than 50%, The compressor is filled with refrigerating machine oil, The refrigerating machine oil is compatible with the second component. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a refrigeration cycle device that can suppress the disproportionation reaction of HFO-1123. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic configuration diagram showing a refrigeration cycle device according to a first embodiment. [Figure 2] 1 is a cross-sectional view of a compressor according to a first embodiment. [Figure 3] 1 is a graph showing the relationship between the mixing ratio of propane (R290) or difluoromethane (R32) and the temperature generated during the disproportionation reaction of HFO-1123. [Figure 4] 1 is a graph showing the relationship between the degree of superheat of refrigeration oil (for example, PVE oil) and the amounts of HFO-1123 and propane (R290) dissolved in the refrigeration oil. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0010] Embodiment 1 <Refrigeration cycle equipment> An overview of the refrigeration cycle apparatus of this embodiment will be described. The refrigeration cycle apparatus of this embodiment includes a refrigeration circuit including a compressor. FIG. 1 is a schematic configuration diagram showing a refrigeration cycle apparatus according to Embodiment 1. The refrigeration cycle apparatus 100 can include a refrigeration circuit 5 including a compressor 1, a condenser 2, an expansion valve 3, and an evaporator 4. The compressor 1 and the condenser 2 are connected by a refrigerant pipe 5a, the condenser 2 and the expansion valve 3 are connected by a refrigerant pipe 5b, the expansion valve 3 and the evaporator 4 are connected by a refrigerant pipe 5c, and the evaporator 4 and the compressor 1 are connected by a refrigerant pipe 5d. A refrigerant is sealed in the refrigeration circuit 5. The refrigerant circulates through the compressor 1, the refrigerant pipe 5a, the condenser 2, the refrigerant pipe 5b, the expansion valve 3, the refrigerant pipe 5c, the evaporator 4, the refrigerant pipe 5d, and the compressor 1 in this order.

[0011] The compressor 1 draws in a refrigerant, compresses it, and discharges it in a high-temperature, high-pressure gas state. The rotation speed of the compressor 1 is controlled by, for example, an inverter circuit. The amount of refrigerant discharged is adjusted by controlling the rotation speed.

[0012] The refrigerant compressed by the compressor 1 into a high-temperature, high-pressure gas state flows into the condenser 2. The condenser 2 exchanges heat between the refrigerant and a heat source to cool the refrigerant to a low-temperature, high-pressure liquid state. Examples of heat sources include air, water, and brine. In the first embodiment, the heat source of the condenser 2 is outside air, which is outdoor air. The condenser 2 exchanges heat between the outside air and the refrigerant. Furthermore, in the first embodiment, the condenser 2 has a condenser blower 6 that blows outside air to the condenser 2 to promote heat exchange. The air volume of the condenser blower 6 can be adjusted.

[0013] The low-temperature, high-pressure liquid refrigerant cooled by the condenser 2 flows into the expansion valve 3. The expansion valve 3 reduces the pressure of the refrigerant and expands it into a low-temperature, low-pressure liquid state. The expansion valve 3 is composed of a refrigerant flow rate control means such as an electronic expansion valve or a temperature-sensitive expansion valve, a capillary tube, or the like.

[0014] A low-temperature, low-pressure liquid refrigerant that has been decompressed and expanded by the expansion valve 3 flows into the evaporator 4. Heat exchange occurs between the refrigerant and the object to be cooled, causing the refrigerant to absorb heat from the object to be cooled, thereby cooling the object. When cooling the object to be cooled, the refrigerant evaporates and becomes a high-temperature, low-pressure gas. In the first embodiment, the object to be cooled is indoor air, and the evaporator 4 exchanges heat between the indoor air and the refrigerant. Furthermore, in the first embodiment, an evaporator blower 7 is provided that blows indoor air to the evaporator 4 to promote heat exchange in the evaporator 4. The air volume of the evaporator blower 7 can be adjusted.

[0015] The compressor 1 draws in the refrigerant that has become a high-temperature, low-pressure gas in the evaporator 4, and compresses it again.

[0016] The refrigeration cycle apparatus 100 may include a control device 17. The control device 17 is, for example, a microcomputer. Although Fig. 1 only shows the connection between the control device 17 and the compressor 1, the control device 17 is connected not only to the compressor 1 but also to the condenser 2, the expansion valve 3, and the evaporator 4.

[0017] The control device 17 controls the pressure and / or temperature of the refrigerant circulating through the refrigeration cycle apparatus 100 to such conditions that a disproportionation reaction of the refrigerant (HFO-1123) does not occur or a chain reaction of the disproportionation reaction can be suppressed. For example, by controlling the pressure of the refrigerant in the flow path from the compressor 1 to the expansion valve 3 (i.e., the high-pressure side) so that it does not exceed a certain pressure, even if a disproportionation reaction occurs in a part of the refrigeration cycle apparatus 100, such as the compressor 1, the diffusion of the reaction can be prevented.

[0018] The temperature and / or pressure conditions at which the disproportionation reaction of the refrigerant does not occur or at which the propagation of the disproportionation reaction can be suppressed can be appropriately set depending on the components of the refrigerant.

[0019] The refrigeration cycle device 100 may be, for example, a device capable of both cooling and heating, a device capable of only cooling, or a device capable of only heating, and is applicable to various types of refrigeration and air conditioning devices.

[0020] ≪Refrigerant≫ In this embodiment, a refrigerant is sealed in a refrigeration circuit. The refrigerant includes a first component and a second component. The first component is 1,1,2-trifluoroethylene (HFO-1123). HFO-1123 has a low GWP of less than 1, a high operating pressure, and a small refrigerant volumetric flow rate, resulting in low pressure loss and excellent cycle performance. The mass-based content C1 of the first component in the refrigerant (hereinafter also referred to as "first component content C1") is 50 mass% or more. This allows the refrigerant to have a low GWP and excellent cycle performance.

[0021] The content C1 of the first component in the refrigerant is 50% by mass or more, and can be 50% by mass to 85% by mass, 70% by mass to 85% by mass, or 80% by mass to 85% by mass.

[0022] In the present disclosure, the mass content C1 of the first component in the refrigerant sealed in the refrigeration circuit is the mass content C1 of the first component in the refrigerant before operation of a refrigeration cycle apparatus including the refrigeration circuit. The mass content C1 of the first component is considered to be the same as the mass content C1 of the first component in the refrigerant before it is sealed in the refrigeration circuit. That is, the mass content C1 of the first component in the refrigerant in a refrigerant cylinder filled with the refrigerant to be sealed in the refrigeration circuit is considered to be the same as the mass content C1 of the first component in the refrigerant sealed in the refrigeration circuit. The mass content C2 of the second component in the refrigerant (hereinafter also referred to as "second component content C2") and the mass content C3 of the third component in the refrigerant (hereinafter also referred to as "second component content C3") are also similar to those described above.

[0023] The second component comprises at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms and fluorohydrocarbons having 1 to 5 carbon atoms.

[0024] The second component, when mixed with HFO-1123, can suppress the disproportionation reaction of HFO-1123. In the present disclosure, suppressing the disproportionation reaction of HFO-1123 means suppressing the propagation of the disproportionation reaction of HFO-1123.

[0025] The percentage (C2 / C1) × 100, where C2 is the mass-based content of the second component relative to C1 is the mass-based content of the first component in the refrigerant, is 15% or more and less than 50%. Even a small amount of the second component effectively inhibits the disproportionation reaction of HFO-1123. Therefore, when the percentage (C2 / C1) × 100 is 15% or more, an excellent effect of inhibiting the disproportionation reaction of HFO-1123 can be obtained. Furthermore, when the percentage (C2 / C1) × 100 is less than 50%, the content of HFO-1123 in the refrigerant can be increased. Therefore, the refrigerant has a low GWP, and a refrigeration cycle device equipped with a refrigeration circuit containing the refrigerant exhibits excellent cycle performance.

[0026] Japanese Patent Application Laid-Open Publication No. 2018-112396 discloses a technique for mixing R32 (difluoromethane) with HFO-1123 to suppress the disproportionation reaction of HFO-1123. However, the technique disclosed in this patent document requires a large amount of R32 in the refrigerant to suppress the chain reaction of the disproportionation reaction in actual use. For example, an example is shown in which HFO-1123 is 40% and R32 is 60%, in which the ratio of R32 exceeds the ratio of HFO-1123. This significantly impairs the properties of HFO-1123, such as low GWP, high operating pressure, and small refrigerant volumetric flow rate, which results in low pressure loss and makes it easy to ensure performance.

[0027] On the other hand, the percentage of the second component relative to HFO-1123 in this embodiment (C2 / C1) × 100 is lower than the percentage of R32 relative to HFO-1123 in the above patent document, but an excellent effect of suppressing the disproportionation reaction of HFO-1123 can be obtained. In this embodiment, the ratio of the second component in the refrigerant can be reduced and the ratio of HFO-1123 can be increased, thereby achieving the characteristics of HFO-1123, such as low GWP, high operating pressure, and small refrigerant volumetric flow rate, which result in small pressure loss and make it easier to ensure performance.

[0028] The percentage (C2 / C1)×100 is 15% or more and less than 50%, and can be 10% or more and 30% or less, 10% or more and 15% or less, 15% or more and 30% or less, or 15% or more and 20% or less.

[0029] The second component is propane (C3H8, R290), methane (CH4), ethane (C2H6), butane (C4H 10 ), isobutane (iso-C4H 10 Preferably, the refrigerant is at least one selected from the group consisting of propylene (C3H6), fluoromethane (CH3F, R41), fluoroethane (C2H5F, R161), and 1,1-difluoroethane (C2H4F2, R152a). These compounds have an excellent effect of suppressing the disproportionation reaction of HFO-1123. Furthermore, because these compounds have a low GWP (for example, propane has a GWP of 6), even when mixed with HFO-1123, the GWP of the entire refrigerant can be kept low.

[0030] The second component can be composed of one of the above compounds, or can be composed of two or more of the above compounds.

[0031] The second component preferably does not contain difluoromethane or difluoroiodomethane. Difluoromethane has a high GWP of 675 (see the IPCC Fourth Assessment Report). On the other hand, the first component, HFO-1123, has a low GWP of less than 1. Therefore, in a mixed refrigerant containing the first and second components, when the second component is difluoromethane and the percentage (C2 / C1) of the mass content (C2) of the second component relative to the mass content (C1) of the first component in the mixed refrigerant is 15% or more and less than 50%, the GWP of the mixed refrigerant is likely to be high, for example, double digits or more. Such a mixed refrigerant with a high GWP is contrary to one of the objectives of the present disclosure, which is to provide a refrigerant with a low GWP. Difluoroiodomethane, like trifluoroiodomethane, has a weaker CI bond compared to the C—H, C—F, and C—Cl bonds present in conventional refrigerants, and is therefore expected to have high metal reactivity, making it unsuitable as a component of a mixed refrigerant. Preferably, the refrigerant does not contain difluoromethane and difluoroiodomethane.

[0032] The range of the percentage (C2 / C1) × 100 is preferably selected appropriately for each composition of the second component from the viewpoint of improving the effect of suppressing the disproportionation reaction of HFO-1123. When the second component is propane, the percentage (C2 / C1) × 100 is 15% or more and less than 50%, preferably 15% or more and less than 30%, and more preferably 15% or more and less than 20%. When the second component is butane, the percentage (C2 / C1) × 100 is 15% or more and less than 50%, preferably 10% or more and less than 30%, and more preferably 10% or more and less than 15%. When the second component is isobutane, the percentage (C2 / C1) × 100 is 15% or more and less than 50%, preferably 10% or more and less than 30%, and more preferably 10% or more and less than 15%.

[0033] To facilitate a deeper understanding of the present disclosure, the suppression effect of the second component on the disproportionation reaction of HFO-1123 will be described in detail below. While the following description focuses on the case where propane (R290) is used as the second component, the following description also applies to second components other than propane.

[0034] FIG. 3 is a graph showing the relationship between the mixing ratio of propane (R290) or difluoromethane (R32) and the temperature generated during the disproportionation reaction of HFO-1123 when propane (R290) or difluoromethane (R32) is mixed with HFO-1123. Difluoromethane (R32) is a refrigerant whose mixing with HFO-1123 has been studied. In this graph, the "R32 or R290 mixing ratio [mass %]" on the horizontal axis indicates the mixing ratio of R32 or R290 when the mass of HFO-1123 is taken as 100%. For example, a mixing ratio of R290 of 15% means that 15% by mass of R290 is mixed with 100% by mass of HFO-1123. In this graph, the "temperature [K] generated during the disproportionation reaction of HFO-1123" on the vertical axis indicates the temperature [K] generated during the disproportionation reaction of HFO-1123 at the mixing ratio of R32 or R290 shown on the horizontal axis. The "temperature [K] generated during the disproportionation reaction of HFO-1123" is the temperature at a pressure of 6 MPa. The lower the temperature generated during the disproportionation reaction of HFO-1123, the more easily the disproportionation reaction is suppressed from propagating.

[0035] As shown in Figure 3, when propane (R290) is mixed with HFO-1123, the temperature generated during the disproportionation reaction of HFO-1123 drops sharply as the propane mixing ratio increases when the propane mixing ratio is approximately 12% or higher. This confirms that a propane mixing ratio of 15% or higher to HFO-1123 is highly effective in suppressing the disproportionation reaction of HFO-1123.

[0036] On the other hand, when difluoromethane (R32) is mixed with HFO-1123, increasing the mixing ratio of difluoromethane only slightly reduces the temperature generated during the disproportionation reaction of HFO-1123. Therefore, in order to obtain the effect of inhibiting the disproportionation reaction by mixing difluoromethane (R32) with HFO-1123, it is necessary to increase the mixing ratio of difluoromethane. However, increasing the mixing ratio of difluoromethane increases the GWP, and the cycle performance of refrigeration cycle devices equipped with a refrigeration circuit in which this refrigerant is sealed decreases.

[0037] As described above, propane (R290) can suppress the disproportionation reaction of HFO-1123 in a smaller amount than difluoromethane (R32). Therefore, a refrigerant that uses R290 to suppress the disproportionation reaction of HFO-1123 can maintain the excellent performance of HFO-1123, has a low GWP, and a refrigeration cycle device equipped with a refrigeration circuit in which this refrigerant is sealed has good cycle performance.

[0038] The behavior of propane (R290) during disproportionation can be explained by changes in the chemical reaction. HFO-1123 is known to undergo the disproportionation reaction shown in formula (A) below. CF2=CHF→1.5C+0.5CF4+HF+250kJ / mol (A)

[0039] When the R290 mixing ratio is approximately 12% or less (the section indicated by (1) in Figure 3), where the effect of suppressing the temperature generated during the disproportionation reaction is small, the chemical reaction shown in the following formula (B) is dominant. C3H8+2CF4=8HF+5C[gr]+212kJ / mol (B)

[0040] In the chemical reaction represented by formula (B), the reaction heat is large and new reaction propagation is easily induced, so the effect of inhibiting the disproportionation reaction of HFO-1123 is small.

[0041] When the R290 mixing ratio exceeds approximately 12% (the section indicated by (2) in Figure 3), which has a large effect of suppressing the temperature generated during the disproportionation reaction, the chemical reaction shown in the following formula (C) is dominant. C3H8=2CH4+C[gr]+45kJ / mol (C)

[0042] In the chemical reaction represented by formula (C), the reaction heat is small and the energy required to generate new reaction propagation is small, so the effect of suppressing the disproportionation reaction of HFO-1123 is large.

[0043] Chemical reactions with similar tendencies to those of the above formulas (B) and (C) also occur when a compound other than propane, specifically a hydrocarbon having 1 to 5 carbon atoms and a fluorohydrocarbon having 1 to 5 carbon atoms, is used as the second component.

[0044] Whether the chemical reaction of formula (B) or formula (C) prevails is presumably influenced by the ratio of hydrogen (H) to fluorine (F) present in the refrigerant. When the H / F ratio exceeds 1, the prevailing chemical reaction is likely to change from formula (B) to formula (C), which is presumably responsible for lowering the temperature at which the disproportionation reaction occurs and improving the effect of suppressing the propagation of the disproportionation reaction.

[0045] In this embodiment, the refrigerant may be composed of a first component and a second component. The refrigerant may contain impurities in addition to the first and second components, as long as the refrigerant exhibits the effects of the present disclosure. That is, in this embodiment, the refrigerant may be composed of the first component, the second component, and impurities.

[0046] When the refrigerant is composed of a first component and a second component, the mass-based content C1 of the first component in the refrigerant can be 70 mass% or more and 85 mass% or less, 75 mass% or more and 85 mass% or less, or 80 mass% or more and 85 mass% or less.

[0047] The refrigerant may further contain a third component in addition to the first and second components, which will be described in detail in the second embodiment below.

[0048] <Compressor>

[0049] The compressor of the refrigeration cycle device according to the first embodiment will be described. In this embodiment, any type of compressor can be used as the compressor 1 as long as it is a high-pressure shell type in which the inside of the container is in a discharge pressure atmosphere (i.e., a high-pressure state equivalent to the discharge pressure of the refrigerant). For example, a single-cylinder rotary compressor, a multi-cylinder rotary compressor, or a scroll compressor can be used.

[0050] 2 is a cross-sectional view of the compressor 1 according to the embodiment 1. The compressor 1 includes a sealed container 20, a compression element 30, an electric element 40, and a shaft 50.

[0051] The sealed container 20 accommodates therein the compression element 30 and the electric element 40 in an airtight manner. The sealed container 20 is fitted with a suction pipe 21 for drawing in the refrigerant and a discharge pipe 22 for discharging the refrigerant.

[0052] The sealed container 20 is divided into two parts, an upper container 20a and a lower container 20b, which are hermetically joined by a method such as arc welding. The sealed container can withstand a pressure of 20 MPa (G) or more, and even if a chain reaction of disproportionation reactions occurs inside and the pressure rises, the container can remain safe without bursting up to a certain level of pressure.

[0053] The compression element 30 is housed in the sealed container 20. Specifically, the compression element 30 is installed in the lower part inside the sealed container 20. The compression element 30 compresses the refrigerant sucked into the suction pipe 21. The position of the compression element 30 does not necessarily have to be the lower part, and in the case of a scroll compressor in particular, it is often housed in the upper part.

[0054] The electric element 40 is housed in the sealed container 20. Depending on the type of compressor, the electric element 40 is installed at the bottom or top of the sealed container 20. The refrigerant compressed by the compression element 30 passes through a flow path around the electric element and is then discharged from the discharge pipe 22. The electric element 40 drives the compression element 30. The electric element 40 is a concentrated winding brushless DC motor.

[0055] The compressor 1 is filled with refrigeration oil. Specifically, the bottom of the sealed container 20 is filled with refrigeration oil 25 that lubricates the sliding parts of the compression element 30. This refrigeration oil has the ability to dissolve the refrigerant. Details of the refrigeration oil will be described later.

[0056] The following describes in detail the compression element 30. The compression element 30 includes a cylinder 31, a rolling piston 32, a vane (not shown), a main bearing 33, and an auxiliary bearing .

[0057] The outer periphery of the cylinder 31 is generally circular in plan view. A cylinder chamber, which is a generally circular space in plan view, is formed inside the cylinder 31. Both axial ends of the cylinder 31 are open.

[0058] A vane groove (not shown) that communicates with the cylinder chamber and extends in the radial direction is provided in the cylinder 31. A back pressure chamber that is a space that is generally circular in plan view and communicates with the vane groove is formed outside the vane groove.

[0059] The rolling piston 32 is ring-shaped. The rolling piston 32 moves eccentrically within the cylinder chamber. The rolling piston 32 is slidably fitted onto an eccentric shaft portion 51 of a shaft 50.

[0060] The vane is shaped like a flat, roughly rectangular parallelepiped. The vane is placed in the vane groove of the cylinder 31. The vane is constantly pressed against the rolling piston 32 by a vane spring attached to the back of the vane. Because the pressure inside the sealed container 20 is high, when the compressor 1 starts operating, a force due to the difference between the pressure inside the sealed container 20 and the pressure inside the cylinder chamber acts on the back of the vane. For this reason, the vane spring is used mainly to press the vane against the rolling piston 32 when the compressor 1 starts up (when there is no difference in pressure between the sealed container 20 and the cylinder chamber).

[0061] Main bearing 33 has a generally inverted T-shape in side view. Main bearing 33 is slidably fitted to main shaft portion 52, which is the portion of shaft 50 above eccentric shaft portion 51. Main bearing 33 closes the cylinder chamber of cylinder 31 and the upper side of the vane groove.

[0062] The sub-bearing 34 is generally T-shaped in side view. The sub-bearing 34 is slidably fitted to the sub-shaft portion 53, which is the portion of the shaft 50 below the eccentric shaft portion 51. The sub-bearing 34 closes the cylinder chamber of the cylinder 31 and the lower side of the vane groove.

[0063] The main bearing 33 is equipped with a discharge valve (not shown). A discharge muffler 35 is attached to the outside of the main bearing 33. The high-temperature, high-pressure gas refrigerant discharged through the discharge valve enters the discharge muffler 35 once, and is then released from the discharge muffler 35 into the space within the sealed container 20. The discharge valve and the discharge muffler 35 may be provided on the sub-bearing 34, or on both the main bearing 33 and the sub-bearing 34.

[0064] The discharge muffler 35 has one or more discharge holes (not shown) with a diameter of 10 mm or less formed therein for releasing the discharge gas into the sealed container 20. Even if a disproportionation reaction occurs inside the cylinder 31 due to seizure of sliding parts or the like, the reaction must pass through narrow flow paths such as the discharge port and discharge hole in order to propagate inside the sealed container. At this time, the reaction heat propagates to surrounding parts, lowering the temperature and suppressing the disproportionation reaction.

[0065] The cylinder 31, main bearing 33, and sub-bearing 34 are made of materials such as gray cast iron, sintered steel, and carbon steel. The rolling piston 32 is made of alloy steel containing chromium or the like. The shaft 50 is made of spheroidal graphite cast iron, for example. The vanes are made of high-speed tool steel, for example.

[0066] The cylinder 31, main bearing 33, sub-bearing 34, rolling piston 32, shaft 50, and vane are sliding parts, and the combination of their materials, in conjunction with the action of the refrigerating machine oil, is designed to prevent seizure when sliding against each other, thereby reducing the possibility of high temperatures occurring that could trigger a disproportionation reaction.

[0067] A suction muffler 23 is provided beside the sealed container 20. The suction muffler 23 draws low-pressure gas refrigerant from the refrigeration circuit 5. The suction muffler 23 prevents the liquid refrigerant from returning directly into the cylinder chamber of the cylinder 31. The suction muffler 23 is connected to the suction port of the cylinder 31 via the suction pipe 21. The main body of the suction muffler 23 is fixed to the side of the sealed container 20 by welding or the like.

[0068] The following describes in detail the electric element 40. In this embodiment, the electric element 40 can be either a concentrated winding brushless DC (Direct Current) motor or a motor other than a concentrated winding brushless DC motor (for example, a distributed winding or induction motor).

[0069] The electric element 40 includes a stator 41 and a rotor 42. The stator 41 is fixed in contact with the inner circumferential surface of the sealed container 20. The rotor 42 is installed inside the stator 41 with a gap of about 0.3 to 1 mm therebetween. The discharged refrigerant can pass through this gap. Because the gap is narrow, even if a disproportionation reaction occurs, the heat generated by the disproportionation reaction is absorbed by the stator and rotor as the refrigerant passes through this gap. This prevents the disproportionation reaction from spreading above and below the electric element.

[0070] Stator 41 includes stator core 43 and stator winding 44. Stator core 43 is manufactured by punching out a plurality of electromagnetic steel sheets having a thickness of 0.1 to 1.5 mm into a predetermined shape, stacking them in the axial direction, and fixing them together by caulking, welding, or the like.

[0071] The stator winding 44 is wound around the stator core 43 by concentrated winding via an insulating member 48. Unlike distributed winding, concentrated winding does not need to span between stator slots (not shown), and therefore does not have any protruding wire (coil ends) above or below the stator to connect to other slots. This prevents sparks and welding due to conduction between wires of different phases, which could be the starting point for a disproportionation reaction, and the resulting high temperatures, even if an insulation defect occurs.

[0072] The insulating member 48 may be made of, for example, PET (polyethylene terephthalate), PBT (polybutylene terephthalate), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer), PTFE (polytetrafluoroethylene), LCP (liquid crystal polymer), PPS (polyphenylene sulfide), or phenolic resin. Lead wires 45 are connected to the stator winding 44.

[0073] The insulating member does not lose its insulating properties due to melting or the like at least at temperatures at which a disproportionation reaction may begin (e.g., 150°C). Therefore, even if the pressure and temperature reach the disproportionation reaction limit, sparks and welding due to conduction between electric wires of different phases, which are the starting point of the reaction, and the resulting generation of high temperatures can be prevented.

[0074] A plurality of elongated notches are formed at approximately equal intervals in the circumferential direction on the outer periphery of the stator core 43. Each notch serves as a passage for the gas refrigerant discharged from the discharge muffler 35 to the space inside the sealed container 20. Each notch also serves as a passage for refrigeration oil returning from above the electric element 40 to the bottom of the sealed container 20.

[0075] The above-mentioned notch allows communication between the top and bottom of the electric element 40. Because the notch has an elongated shape, the perimeter is long compared to the area of ​​the notch. Therefore, even if a disproportionation reaction occurs, the stator core 43 and the lower sealed container 20b absorb the reaction heat, thereby suppressing the propagation of the disproportionation reaction to the top and bottom of the electric element 40.

[0076] The rotor 42 includes a rotor core 46 and permanent magnets (not shown). Like the stator core 43, the rotor core 46 is manufactured by punching out a plurality of electromagnetic steel sheets having a thickness of 0.1 to 1.5 mm into a predetermined shape, stacking them in the axial direction, and fixing them by caulking, welding, or the like. The permanent magnets are inserted into a plurality of insertion holes formed in the rotor core 46. For example, a ferrite magnet or a rare earth magnet is used as the permanent magnet.

[0077] Rotor core 46 has through holes formed therein that penetrate substantially in the axial direction and have a diameter that is ⅕ or less of the axial length of rotor 42. Similar to the notches in stator core 43, each through hole serves as a passage for the gas refrigerant that is discharged from discharge muffler 35 into the space within sealed container 20.

[0078] The through-holes also allow communication between the top and bottom of the electric element 40. The through-holes are sufficiently small relative to the axial length of the rotor 42. Therefore, even if a disproportionation reaction occurs, the rotor core 46 absorbs the reaction heat, thereby suppressing the propagation of the disproportionation reaction to the top and bottom of the electric element 40.

[0079] A power supply terminal 24 (for example, a glass terminal) for connection to an external power supply is attached to the top of the sealed container 20. The power supply terminal 24 is fixed to the sealed container 20 by, for example, welding. A lead wire 45 from the electric element 40 is connected to the power supply terminal 24.

[0080] A discharge pipe 22 having open axial ends is attached to the top of the sealed container 20. The gas refrigerant discharged from the compression element 30 passes through the discharge pipe 22 from the space within the sealed container 20 and is discharged to the external refrigeration circuit 5.

[0081] The operation of the compressor 1 will now be described. Electric power is supplied from the power supply terminals 24 to the stator 41 of the electric element 40 via the lead wires 45. This causes the rotor 42 of the electric element 40 to rotate. The rotation of the rotor 42 causes the shaft 50 fixed to the rotor 42 to rotate. As the shaft 50 rotates, the rolling piston 32 of the compression element 30 rotates eccentrically within the cylinder chamber of the cylinder 31 of the compression element 30. The space between the cylinder 31 and the rolling piston 32 is divided into two by the vanes of the compression element 30. As the shaft 50 rotates, the volumes of these two spaces change. In one space, the volume gradually expands, and refrigerant is drawn in through the suction muffler 23. In the other space, the volume gradually contracts, and the gas refrigerant therein is compressed. The compressed gas refrigerant is then discharged from the discharge muffler 35 into the space within the sealed container 20. The discharged gas refrigerant passes through the electric element 40 and is discharged to the outside of the sealed container 20 from the discharge pipe 22 at the top of the sealed container 20 .

[0082] ≪Refrigerating machine oil≫ In this embodiment, the compressor is filled with refrigerating machine oil. The refrigerating machine oil is miscible with the second component. Here, "the refrigerating machine oil is miscible with the second component" means that there is a temperature at which the second component and the refrigerating machine oil do not separate into two layers. This makes it possible to increase the difference in the amount of each component in the refrigerant that dissolves in the refrigerating machine oil, and to change the component ratio of the refrigerant depending on the temperature and pressure state of the refrigerant. The mechanism will be described later.

[0083] The solubility of the second component in the refrigerating machine oil is preferably greater than that of the first component. Here, "the solubility of the second component in the refrigerating machine oil is greater than that of the first component" means, for example, that the solubility of the second component in the refrigerating machine oil is greater than that of the first component at temperatures where the refrigerating machine oil has a superheat of 10 K or higher and 60 K or lower. This further improves the effect of suppressing the disproportionation reaction of HFO-1123. It also provides an effect of suppressing the flammability of the refrigerant. The mechanism behind this is explained below. The following explanation will be given for the case where polyvinyl ether oil (hereinafter also referred to as "PVE oil") is used as the refrigerating machine oil and propane (R290) is used as the second component. However, the following explanation also applies to second components other than propane.

[0084] 4 is a graph showing the relationship between the degree of superheat of refrigeration oil (PVE oil) and the amounts of HFO-1123 and propane (R290) dissolved in the refrigeration oil. In the graph, the horizontal axis represents the degree of superheat [K] of the refrigeration oil, and the vertical axis represents the amount of refrigerant dissolved in the refrigeration oil at each degree of superheat, i.e., the respective amounts of HFO-1123 and propane (R290) dissolved in the refrigeration oil.

[0085] In this embodiment, as shown in the graph of Fig. 4, at each degree of superheat of the refrigerating machine oil in a range of about 5 K to 60 K, the amount of R290 (the second component) that dissolves in the refrigerating machine oil is greater than the amount of HFO-1123 (the first component) that dissolves in the refrigerating machine oil. That is, at each degree of superheat of the refrigerating machine oil in a range of about 5 K to 60 K, the solubility of the second component in the refrigerating machine oil is greater than the solubility of the first component in the refrigerating machine oil. As shown in the graph of Fig. 4, for the refrigerant as a whole, the lower the degree of superheat of the refrigerating machine oil, the greater the amount of refrigerant that dissolves in the refrigerating machine oil, and as the degree of superheat of the refrigerating machine oil increases, the amount of refrigerant that dissolves in the refrigerating machine oil decreases.

[0086] During operation of the refrigeration cycle apparatus, the degree of heating of the gas discharged from the compressor 12 is controlled so as not to become abnormally high (the temperature of the discharge gas is kept within a certain range). Therefore, the degree of superheat of the refrigeration oil (slightly lower than the degree of superheat of the discharge gas) is also controlled within a certain range. Under typical operating conditions, the degree of superheat of the refrigeration oil is considered to be around 10 K to 30 K. For example, as shown in the graph of FIG. 4, under typical operating conditions where the degree of superheat of the refrigeration oil is 20 K, the amount of R290 dissolved in the refrigeration oil is greater than the amount of HFO-1123 dissolved, resulting in a large amount of R290 present in the refrigeration oil. Therefore, the ratio of R290 in the refrigerant circulating through the refrigeration circuit 5 is smaller than the ratio of R290 in the refrigerant at the time of charging.

[0087] Since the second component, R290, is flammable, when a refrigerant contains the second component, the flammability tends to increase. As described above, by using a refrigeration oil in which the solubility of R290 is greater than that of HFO-1123, the ratio of R290 in the refrigerant circulating through the refrigeration circuit 5 decreases during operation of the refrigeration cycle device. This reduces the flammability of the circulating refrigerant. Therefore, even if the refrigerant leaks from the refrigeration cycle device 10, it is less likely to burn, resulting in improved safety.

[0088] Under normal operating conditions, the temperature of the discharge gas is controlled within a certain range, so there is no risk of disproportionation reactions occurring. Therefore, under normal operating conditions, there is no problem even if the ratio of R290, which has a high disproportionation reaction suppression effect, in the refrigerant is low.

[0089] On the other hand, if an abnormality occurs in the operating conditions, resulting in high-temperature, high-pressure conditions that may cause a disproportionation reaction, the heating level of the discharge gas increases significantly, and the superheat level of the refrigerating machine oil also increases significantly. For example, as shown in the graph in FIG. 4, when the superheat level of the refrigerating machine oil is 50 K, the solubility of HFO-1123 and R290 in the refrigerating machine oil is generally lower than when the superheat level of the refrigerating machine oil is 20 K. Furthermore, when the superheat level of the refrigerating machine oil is 50 K, the difference between the solubility of HFO-1123 and the solubility of R290 is also smaller than when the superheat level of the refrigerating machine oil is 20 K. Therefore, when the superheat level of the refrigerating machine oil is 50 K, the composition of the refrigerant circulating through the refrigeration circuit 5 is closer to the composition at the time of charging, and the disproportionation reaction can be sufficiently suppressed by the second component, R290.

[0090] As described above, for example, when the degree of superheat of the refrigerating machine oil is in the range of 10 K or more and 60 K or less, the solubility of the second component in the refrigerating machine oil is greater than the solubility of the first component in the refrigerating machine oil, thereby achieving a flammability suppression effect and an effect of suppressing the occurrence and propagation of the disproportionation reaction.

[0091] The refrigerating machine oil is preferably at least one selected from the group consisting of polyol ester oil, polyvinyl ether oil, mineral oil, and alkylbenzene oil. The mineral oil may be naphthenic mineral oil or paraffinic mineral oil. In these types of refrigerating machine oil, the solubility of the second component in the refrigerating machine oil is greater than the solubility of the first component at each superheat in the range of about 5 K to 60 K.

[0092] The refrigerating machine oil may be one of the above refrigerating machine oils, or may be two or more of the above refrigerating machine oils.

[0093] Embodiment 2 In the second embodiment, a configuration in which the refrigerant contains a third component in addition to the first and second components will be described. The second embodiment can have the same configuration as the first embodiment except for the refrigerant. Therefore, the refrigerant will be described below.

[0094] ≪Refrigerant≫ In this embodiment, the refrigerant contains a third component in addition to the first and second components. The third component is preferably at least one selected from the group consisting of refrigerants with a global warming potential of 1000 or less and flammability classification of Class 1 (non-flammable) or Class 2L (slightly flammable) according to ISO 817:2014. If the second component is a highly flammable compound such as propane (R290), the refrigerant becomes flammable. By including a non-flammable or slightly flammable third component in the refrigerant, the flammability of the refrigerant can be reduced. Therefore, in the event of a refrigerant leak from a refrigeration cycle device, the flammability of the refrigerant can be reduced, thereby improving safety.

[0095] The third component is preferably at least one selected from the group consisting of 2,3,3,3-tetrafluoro-1-propene (R1234yf), difluoromethane (R32), trans-1,3,3,3-tetrafluoropropene (R1234ze(E)), and cis-1,3,3,3-tetrafluoropropene (R1234ze(Z)). These compounds are non-flammable or slightly flammable and have an excellent effect of suppressing the flammability of the refrigerant. Furthermore, these compounds have the effect of suppressing the disproportionation reaction of HFO-1123. Therefore, when the refrigerant contains the third component, the effect of suppressing the occurrence and propagation of the disproportionation reaction of HFO-1123 is improved, thereby improving the safety of the refrigeration cycle device.

[0096] The third component can be composed of one of the above compounds, or two or more of the above compounds.

[0097] The third component preferably does not contain difluoroiodomethane. Like trifluoroiodomethane, difluoroiodomethane has a weaker CI bond than the C—H bonds, C—F bonds, and C—Cl bonds found in conventional refrigerants, and is therefore expected to have high metal reactivity, making it unsuitable as a component of a mixed refrigerant. The refrigerant preferably does not contain difluoroiodomethane.

[0098] In this embodiment, the refrigerant may be composed of a first component, a second component, and a third component. The refrigerant may contain impurities in addition to the first component, the second component, and the third component, as long as the refrigerant exhibits the effects of the present disclosure. That is, in this embodiment, the refrigerant may be composed of the first component, the second component, the third component, and impurities.

[0099] When the refrigerant is composed of a first component, a second component, and a third component, the mass-based content C1 of the first component, the mass-based content C2 of the second component, and the mass-based content C3 of the third component in the refrigerant can be, for example, (b1) to (b4) below. (b1) The content C1 of the first component is 65% by mass or more and 75% by mass or less, the content C2 of the second component is 10% by mass or more and 20% by mass or less, and the content C3 of the third component is 5% by mass or more and 25% by mass or less. (b2) The content C1 of the first component is 75% by mass or more and 85% by mass or less, the content C2 of the second component is 11% by mass or more and 17% by mass or less, and the content C3 of the third component is 1% by mass or more and 15% by mass or less. (b3) The content C1 of the first component is 50% by mass or more and 65% by mass or less, the content C2 of the second component is 8% by mass or more and 13% by mass or less, and the content C3 of the third component is 22% by mass or more and 42% by mass or less. (b4) The content C1 of HFO-1123 (first component) is 68% by mass, the content C2 of propane (R290, second component) is 17% by mass, and the content C3 of 2,3,3,3-tetrafluoro-1-propene (R1234yf, third component) is 15% by mass.

[0100] Embodiment 3 The third embodiment can be configured in the same manner as the first and second embodiments except that the first component of the refrigerant is trans-1,2-difluoroethylene (R1132(E)). R1132(E) has a similar structure, including a molecular structure, to HFO-1123, so even when R1132(E) is selected as the first component, the same effects as those of the first and second embodiments can be obtained.

[0101] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0102] REFRIGERATED CYCLE DEVICE, 17 CONTROL DEVICE, 20 COMPRESSORS, 3 EXPANSION VALVE, 4 EVAPORATOR, 5 REFRIGERATED CIRCUITS, 5a-5d REFRIGERATED PIPE, 6 CONDENSOR AIR DRAINER, 7 EVAPORATOR AIR DRAINER, 17 CONTROL DEVICE, 20 SEALED ENCLOSED ENCLOSURE, 20a UPPER ENCLOSURE, 20b LOWER ENCLOSURE, 21 SUCTION PIPE, 22 DISCHARGE PIPE, 23 SUCTION MUFFLER, 24 POWER TERMINAL, 25 REFRIGERATED CYCLE OIL, 30 COMPRESSION ELEMENT, 31 CYLINDER, 32 ROLLING PISTON, 33 MAIN BEARING, 34 SUB-BEARING, 35 DISCOVERY, 40 ELECTRIC ELEMENT, 41 STATE, 42 ROTOR, 43 STATE CURRENT CORE, 44 STATE CURRENT WINDING, 45 LEAD WIRE, 46 ROTOR CURRENT CORE, 48 INSULATED ENCLOSURE, 50 SHAFT, 51 ECCENTRIC SHAFT, 52 MAIN SHAFT, 53 SUB-SHAFT, 100 REFRIGERATED CYCLE DEVICE.

Claims

1. a refrigeration circuit including a compressor; A refrigerant is sealed in the refrigeration circuit, the refrigerant comprises a first component and a second component, and is free of difluoroiodomethane; the first component comprises 1,1,2-trifluoroethylene; the second component is composed of at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms and fluorohydrocarbons having 1 to 5 carbon atoms, The mass-based content C1 of the first component in the refrigerant is 50 mass% or more, The percentage (C2 / C1)×100 of the mass-based content C2 of the second component to the mass-based content C1 of the first component in the refrigerant is 15% or more and less than 50%, The compressor is filled with refrigerating machine oil, The refrigeration cycle device, wherein the refrigeration oil is compatible with the second component.

2. a refrigeration circuit including a compressor; A refrigerant is sealed in the refrigeration circuit, the refrigerant comprises a first component and a second component, and is free of difluoroiodomethane; the first component comprises trans-1,2-difluoroethylene; the second component is composed of at least one selected from the group consisting of hydrocarbons having 1 to 5 carbon atoms and fluorohydrocarbons having 1 to 5 carbon atoms, The mass-based content C1 of the first component in the refrigerant is 50 mass% or more, The percentage (C2 / C1)×100 of the mass-based content C2 of the second component to the mass-based content C1 of the first component in the refrigerant is 15% or more and less than 50%, The compressor is filled with refrigerating machine oil, The refrigeration cycle device, wherein the refrigeration oil is compatible with the second component.

3. The refrigeration cycle device according to claim 1 or 2, wherein the second component comprises at least one selected from the group consisting of propane, methane, ethane, butane, isobutane, propylene, fluoromethane, fluoroethane, and 1,1-difluoroethane.

4. The refrigerant further comprises a third component, 3. The refrigeration cycle device according to claim 1, wherein the third component is at least one selected from the group consisting of refrigerants having a global warming potential of 1000 or less and a flammability rating of Class 1 (non-flammable) or Class 2L (slightly flammable) according to ISO 817:2014.

5. The refrigeration cycle device according to claim 4, wherein the third component comprises at least one selected from the group consisting of 2,3,3,3-tetrafluoro-1-propene, difluoromethane, trans-1,3,3,3-tetrafluoropropene, and cis-1,3,3,3-tetrafluoropropene.

6. The refrigeration cycle device according to claim 1 or 2, wherein a solubility of the second component in the refrigerating machine oil is greater than a solubility of the first component in the refrigerating machine oil.

7. The refrigeration cycle device according to claim 6, wherein the refrigeration oil is at least one oil selected from the group consisting of polyol ester oil, polyvinyl ether oil, mineral oil, and alkylbenzene oil.

8. 3. The refrigeration cycle device according to claim 1, wherein the second component does not contain difluoromethane or difluoroiodomethane.

9. 3. The refrigeration cycle device according to claim 1, wherein the refrigerant does not contain difluoromethane or difluoroiodomethane.

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