Refrigeration cycle apparatus and refrigeration machine oil

Abstract

This invention provides a refrigeration cycle device and a refrigeration oil that achieve good cooling capacity and coefficient of performance. A refrigeration cycle device using a working fluid comprising a refrigerant and a refrigeration oil, wherein the refrigerant comprises HFO-1132(E) and HFO-1234yf, the refrigeration cycle device includes a refrigerant circuit, the refrigerant circuit having a compressor for circulating the working fluid, wherein, for the working fluid, the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigeration oil to the weight of the refrigeration oil is defined as S (%), the ratio of the weight of the refrigeration oil to the total weight of HFO-1132(E) and HFO-1234yf is defined as Q (%), and the ratio of HFO-1132(E) to the total weight of HFO-1132(E) and HFO-1234yf is defined as Q (%). Let A be the ratio of the weight of HFO-1132(E) to the total weight of HFO-1234yf, and Sa be the ratio of the weight of HFO-1132(E) dissolved in the refrigerant oil to the weight of the refrigerant oil. Under the operating conditions of a refrigerant discharge temperature of 58°C and a discharge pressure of 1.5MPa, the value of X represented by X=[{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]Sa+{A / (100-QS)} satisfies 0.84A-4.57≤X≤0.76A+21.82.

Description

Technical Field

[0001] This invention relates to refrigeration cycle devices and refrigeration oil. Background Technology

[0002] In recent years, in order to mitigate global warming, research has been conducted on refrigerants with low Global Warming Potential (GWP) used in refrigeration cycle devices such as air conditioning units.

[0003] For example, in Patent Document 1 (Japanese Patent Application Publication No. 2015-200480), refrigerants with low GWP such as trans-1,2-difluoroethylene (HFO-1132(E)) and propylene-based fluorinated hydrocarbons such as 2,3,3,3-tetrafluoropropylene (HFO-1234yf) were proposed as refrigerants. Summary of the Invention

[0004] The problem that the invention aims to solve

[0005] Here, when using a mixed refrigerant containing both HFO-1132(E) and HFO-1234yf as the refrigerant, it is known that HFO-1132(E) and HFO-1234yf have different solubilities for the refrigeration oil used as lubricant in the compressor, resulting in a difference between the composition of the refrigerant filling the refrigerant circuit and the composition of the refrigerant circulating when the refrigeration cycle is performed in the refrigerant circuit.

[0006] Therefore, when using a mixed refrigerant containing both HFO-1132(E) and HFO-1234yf with refrigeration oil, it is expected to achieve good cooling capacity and coefficient of performance.

[0007] Methods for solving problems

[0008] The refrigeration cycle device of the first viewpoint is a refrigeration cycle device using a working fluid, which includes a refrigerant and a refrigeration oil. The refrigerant includes trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoropropylene (HFO-1234yf). The refrigeration cycle device has a refrigerant circuit. The refrigerant circuit has a compressor for circulating the working fluid. For the working fluid, under operating conditions where the discharge temperature of the refrigerant discharged from the compressor is 58°C and the discharge pressure is 1.5 MPa, the value of X represented by X=[{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]Sa+{A / (100-QS)} satisfies 0.84A-4.57≤X≤0.76A+21.82. Here, S(%) is the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigeration oil (i.e., the first total weight) to the weight of the refrigeration oil. Q(%) is the ratio of the weight of the refrigeration oil to the total weight of HFO-1132(E) and HFO-1234yf (i.e., the second total weight). A(%) is the ratio of the weight of HFO-1132(E) to the second total weight. Sa(%) is the ratio of the weight of HFO-1132(E) dissolved in the refrigeration oil to the weight of the refrigeration oil.

[0009] Here, the first total weight refers to the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigerant oil within the HFO-1132(E) and HFO-1234yf filling the refrigerant circuit, not the total weight of HFO-1132(E) and HFO-1234yf filling the refrigerant circuit. Furthermore, the second total weight refers to the total weight of HFO-1132(E) and HFO-1234yf filling the refrigerant circuit, and is a value independent of whether or not it is dissolved in the refrigerant oil.

[0010] In this refrigeration cycle device, the ratio (cooling capacity ratio) of the cooling capacity of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigerant oil to the cooling capacity of a refrigerant composed of refrigerant presumably filling the refrigerant circuit is ensured to be 90% or more. Furthermore, the ratio (coefficient of performance ratio) of the coefficient of performance of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigerant oil to the coefficient of performance of a refrigerant composed of refrigerant presumably filling the refrigerant circuit is ensured to be 99% or more.

[0011] The refrigeration cycle device of the second viewpoint is the same as the refrigeration cycle device of the first viewpoint, wherein, under the above operating conditions, it further satisfies 0.92A-2.26≤X.

[0012] This refrigeration cycle device can ensure a refrigeration capacity ratio of over 95%.

[0013] The refrigeration cycle device of the third viewpoint is the same as the refrigeration cycle device of the first viewpoint, wherein, under the above operating conditions, A≤X is further satisfied.

[0014] This refrigeration cycle device can ensure a refrigeration capacity ratio of over 100%.

[0015] The refrigeration cycle device of the fourth viewpoint is similar to the refrigeration cycle device of any one of the views from the first to the third viewpoint, wherein the weight proportion of HFO-1132(E) in the refrigerant is 22% to 24% and the weight proportion of HFO-1234yf in the refrigerant is 76% to 78%, or the weight proportion of HFO-1132(E) in the refrigerant is 30.5% to 32.5% and the weight proportion of HFO-1234yf in the refrigerant is 67.5% to 69.5%. This refrigeration cycle device further satisfies 20 ≤ Q ≤ 70.

[0016] The refrigeration cycle device of the fifth viewpoint is the same as the refrigeration cycle device of any one of the first to fourth viewpoints, wherein S(%) under the above operating conditions is 10 or more.

[0017] In this refrigeration cycle device, the lubrication performance of the compressor can be well maintained when the refrigerant is compressed.

[0018] The refrigeration cycle device of viewpoint 6 is a refrigeration cycle device using a working fluid comprising a refrigerant and a refrigeration oil. The refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoropropylene (HFO-1234yf). The refrigeration cycle device includes a refrigerant circuit. The refrigerant circuit has a compressor for circulating the working fluid. The compressor includes a compression element for compressing the refrigerant and an oil reservoir for storing the refrigeration oil. For the working fluid, under operating conditions where the discharge temperature of the refrigerant discharged from the compressor is 58°C and the discharge pressure is 1.5 MPa, the value of Xa, represented by Xa=[{(-1.3257T+1.0919) / (R+233.27T-207.91)}+1]Ta+{A / (100-RT)}, satisfies 0.84A-4.57≤Xa≤0.76A+21.82. Here, T(%) is the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir, i.e., the third total weight, to the weight of the refrigeration oil in the oil reservoir. R(%) is the ratio of the weight of the refrigeration oil in the oil reservoir to the total weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight. A(%) is the ratio of the weight of HFO-1132(E) to the second total weight. Ta(%) is the ratio of the weight of HFO-1132(E) dissolved in the oil reservoir to the weight of the refrigeration oil in the oil reservoir.

[0019] Here, the third total weight refers to the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir within HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit, not the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit. Furthermore, the second total weight refers to the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit, and is a value independent of whether or not it is dissolved in the refrigerant oil.

[0020] In this refrigeration cycle device, the ratio (cooling capacity ratio) of the cooling capacity of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigerant oil to the cooling capacity of a refrigerant composed of refrigerant presumably filling the refrigerant circuit is ensured to be 90% or more. Furthermore, the ratio (coefficient of performance ratio) of the coefficient of performance of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigerant oil to the coefficient of performance of a refrigerant composed of refrigerant presumably filling the refrigerant circuit is ensured to be 99% or more.

[0021] The refrigeration cycle device of the seventh viewpoint is the same as the refrigeration cycle device of the sixth viewpoint, wherein, under the above operating conditions, it further satisfies 0.92A-2.26≤Xa.

[0022] This refrigeration cycle device can ensure a refrigeration capacity ratio of over 95%.

[0023] The refrigeration cycle device of the eighth viewpoint is the same as the refrigeration cycle device of the sixth viewpoint, wherein, under the above operating conditions, A≤Xa is further satisfied.

[0024] This refrigeration cycle device can ensure a refrigeration capacity ratio of over 100%.

[0025] The refrigeration cycle device of the ninth viewpoint is similar to the refrigeration cycle devices of any of the sixth to eighth viewpoints, wherein the weight proportion of HFO-1132(E) in the refrigerant is 22% to 24% and the weight proportion of HFO-1234yf in the refrigerant is 76% to 78%, or the weight proportion of HFO-1132(E) in the refrigerant is 30.5% to 32.5% and the weight proportion of HFO-1234yf in the refrigerant is 67.5% to 69.5%. This refrigeration cycle device further satisfies 20 ≤ R ≤ 70.

[0026] The refrigeration cycle device of the 10th viewpoint is the same as the refrigeration cycle device of any one of the 6th to 9th viewpoints, wherein T(%) under the above operating conditions is 10 or more.

[0027] In this refrigeration cycle device, the lubrication performance of the compressor can be well maintained when the refrigerant is compressed.

[0028] The refrigeration cycle device of the 11th viewpoint is the same as the refrigeration cycle device of any of the 1st to 10th views, wherein A (%) is 15 or more and 40 or less.

[0029] In this refrigeration cycle device, good refrigeration capacity can be easily ensured, and even if refrigerant leaks, its flammability is suppressed to a small extent.

[0030] The refrigeration cycle device of the 12th viewpoint is the same as the refrigeration cycle device of any of the 1st to 11th views, wherein the second total weight of the refrigerant is 95% or more.

[0031] It should be noted that the second total weight of the refrigerant is preferably 99% or more, and more preferably 99.5% or more.

[0032] The refrigeration cycle device of the 13th viewpoint is the same as the refrigeration cycle device of any of the 1st to 12th views, wherein the refrigeration oil contains at least one selected from the group consisting of polyol ester (POE), polyvinyl ether (PVE) and polyalkylene glycol (PAG).

[0033] The refrigeration oil of the refrigeration cycle device in viewpoint 14 is the refrigeration oil used as the working fluid in a refrigeration cycle device together with a refrigerant containing trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoropropylene (HFO-1234yf). The refrigeration cycle device has a refrigerant circuit, which has a compressor for circulating the working fluid. For the working fluid, under operating conditions where the discharge temperature of the refrigerant discharged from the compressor is 58°C and the discharge pressure is 1.5 MPa, the value of X represented by X=[{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]Sa+{A / (100-QS)} satisfies 0.84A-4.57≤X≤0.76A+21.82.

[0034] Here, S(%) is the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigeration oil (i.e., the first total weight) to the weight of the refrigeration oil. Q(%) is the ratio of the weight of the refrigeration oil to the total weight of HFO-1132(E) and HFO-1234yf (i.e., the second total weight). A(%) is the ratio of the weight of HFO-1132(E) to the second total weight. Sa(%) is the ratio of the weight of HFO-1132(E) dissolved in the refrigeration oil to the weight of the refrigeration oil.

[0035] Here, the first total weight refers to the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigerant oil within the HFO-1132(E) and HFO-1234yf filling the refrigerant circuit, not the total weight of HFO-1132(E) and HFO-1234yf filling the refrigerant circuit. Furthermore, the second total weight refers to the total weight of HFO-1132(E) and HFO-1234yf filling the refrigerant circuit, and is a value independent of whether or not it is dissolved in the refrigerant oil.

[0036] According to the refrigeration oil in this refrigeration cycle device, the ratio (cooling capacity ratio) of the cooling capacity of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigeration oil to the cooling capacity of a refrigerant composed of refrigerant presumably filling the refrigerant circuit circulating in the refrigerant circuit can be ensured to be 90% or more. Furthermore, the ratio (coefficient of performance ratio) of the coefficient of performance of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigeration oil to the coefficient of performance of a refrigerant composed of refrigerant presumably filling the refrigerant circuit circulating in the refrigerant circuit can be ensured to be 99% or more.

[0037] The refrigeration oil in the refrigeration cycle device of viewpoint 15 is the refrigeration oil used as the working fluid in a refrigeration cycle device together with a refrigerant containing trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoropropylene (HFO-1234yf). The refrigeration cycle device includes a refrigerant circuit with a compressor for circulating the working fluid. The compressor includes a compression element for compressing the refrigerant and an oil reservoir for storing the refrigeration oil. For the working fluid, under operating conditions where the discharge temperature of the refrigerant discharged from the compressor is 58°C and the discharge pressure is 1.5 MPa, the value of Xa, represented by Xa=[{(-1.3257T+1.0919) / (R+233.27T-207.91)}+1]Ta+{A / (100-RT)}, satisfies 0.84A-4.57≤Xa≤0.76A+21.82. Here, T(%) is the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir, i.e., the third total weight, to the weight of the refrigeration oil in the oil reservoir. R(%) is the ratio of the weight of the refrigeration oil in the oil reservoir to the total weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight. A(%) is the ratio of the weight of HFO-1132(E) to the second total weight. Ta(%) is the ratio of the weight of HFO-1132(E) dissolved in the oil reservoir to the weight of the refrigeration oil in the oil reservoir.

[0038] Here, the third total weight refers to the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir within HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit, not the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit. Furthermore, the second total weight refers to the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit, and is a value independent of whether or not it is dissolved in the refrigerant oil.

[0039] According to the refrigeration oil in this refrigeration cycle device, the ratio (cooling capacity ratio) of the cooling capacity of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigeration oil to the cooling capacity of a refrigerant composed of refrigerant presumably filling the refrigerant circuit circulating in the refrigerant circuit can be ensured to be 90% or more. Furthermore, the ratio (coefficient of performance ratio) of the coefficient of performance of refrigerant circulating in the refrigerant circuit but not dissolved in the refrigeration oil to the coefficient of performance of a refrigerant composed of refrigerant presumably filling the refrigerant circuit circulating in the refrigerant circuit can be ensured to be 99% or more. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the refrigeration cycle device.

[0041] Figure 2 This is a schematic cross-sectional diagram of the compressor.

[0042] Figure 3 It is a graph showing the curve formed by connecting the plotted points of aQS relative to Q.

[0043] Figure 4 This is a graph showing the approximation of aQS relative to Q.

[0044] Figure 5 It is a graph showing the relationship between X and A.

[0045] Figure 6 It is a graph showing the value of X relative to Sa for each Q. Detailed Implementation

[0046] Hereinafter, embodiments of the refrigeration cycle device and the refrigeration oil of the refrigeration cycle device of the present invention will be described.

[0047] (1) Refrigeration cycle device

[0048] The refrigeration cycle device 1 of this embodiment handles the heat load by performing a vapor compression refrigeration cycle. The refrigeration cycle device 1 includes a refrigerant circuit 10.

[0049] The refrigerant circuit 10 has a compressor 2, a first heat exchanger 3, an expansion valve 4, a second heat exchanger 5, and is filled with a working fluid containing refrigerant and refrigeration oil.

[0050] Compressor 2, first heat exchanger 3, expansion valve 4, and second heat exchanger 5 are sequentially connected in refrigerant circuit 10 via refrigerant piping. Refrigerant circuit 10 includes a switching valve 6, which switches between a first operating state and a second operating state. In the first operating state, the first heat exchanger 3 functions as a refrigerant radiator, and the second heat exchanger 5 functions as a refrigerant evaporator. In the second operating state, the first heat exchanger 3 functions as a refrigerant evaporator, and the second heat exchanger 5 functions as a refrigerant radiator. The first operating state is, for example, a cooling operation, and the second operating state is, for example, a heating operation.

[0051] The compressor 2 is a positive displacement compressor or the like driven by a compressor electric motor, and has a compression element 21 and an oil reservoir 37. The compressor electric motor can be driven by receiving power from an inverter device (not shown).

[0052] Expansion valve 4, for example, can adjust the valve opening, thereby adjusting the pressure of the refrigerant passing through.

[0053] It should be noted that the refrigeration cycle unit 1 has a control unit 7, which includes a microcomputer, memory, etc., and is used to drive and control various actuators. The control unit 7 can control the operating status of the compressor 2, the valve opening degree of the expansion valve 4, etc.

[0054] As for the refrigeration cycle device 1, there is no particular limitation. Examples include room air conditioners, cabinet air conditioners, cold storage, automotive air conditioners, water heaters, dehumidifiers, freezers, cold storage warehouses, vending machines, display cases, cooling devices in chemical plants, etc.

[0055] (2) Compressor

[0056] There are no particular limitations on compressor 2; for example, various compressors such as scroll compressors and rotary compressors can be used.

[0057] Here, with Figure 2 The scroll compressor shown is used as an example for illustration.

[0058] The compressor 2 includes a housing 20, a compression element 21, a drive motor 24, a crankshaft 25, a lower bearing 26, a counterweight 30, and an oil reservoir 37.

[0059] The housing 20 has a generally cylindrical component 20a with openings at the top and bottom, and an upper cover 20b and a lower cover 20c respectively disposed at the upper and lower ends of the cylindrical component 20a. The housing 20 houses the compressor 2, which includes a compressor element 21, a drive motor 24, a crankshaft 25, and a lower bearing 26. An oil reservoir 37 is formed from the lower end of the interior of the housing 20 to a predetermined height. The oil reservoir 37 has an oil storage space 37a for storing refrigerant oil used to lubricate the compressor element 21, etc. An oil temperature sensor 38 for detecting the temperature of the stored refrigerant oil is provided in the oil reservoir 37. At the upper part of the housing 20, a suction pipe 12, which draws in low-pressure gaseous refrigerant from the refrigerant circuit 10 and supplies gaseous refrigerant to the compressor element 21, is provided, passing through the upper cover 20b. The lower end of the suction pipe 12 is connected to the fixed scroll member 22 of the compressor element 21. The suction pipe 12 is connected to the compression chamber Sc of the compression element 21. A discharge pipe 13 is provided in the middle of the cylindrical component 20a of the outer casing 20 for the refrigerant to be discharged outside the outer casing 20. The end of the discharge pipe 13 inside the outer casing 20 is configured to protrude into the high-pressure space Sh formed below the housing 27 of the compression element 21. The high-pressure refrigerant in the refrigeration cycle, compressed by the compression element 21, flows in the discharge pipe 13.

[0060] The compression element 21 mainly has a housing 27, a fixed scroll member 22 disposed above the housing 27, and a movable scroll member 23 that is combined with the fixed scroll member 22 to form a compression chamber Sc.

[0061] The fixed scroll member 22 has a flat fixed side end plate 22a, a scroll-shaped fixed side scroll tooth 22b protruding downward from the lower surface of the fixed side end plate 22a, and an outer edge portion 22c surrounding the fixed side scroll tooth 22b. At the center of the fixed side end plate 22a, a non-circular discharge port 22d, communicating with the compression chamber Sc of the compression element 21, is formed penetrating through the fixed side end plate 22a in the thickness direction. The refrigerant compressed in the compression chamber Sc is discharged from the discharge port 22d and flows into the high-pressure space Sh through a refrigerant passage (not shown) formed in the fixed scroll member 22 and the housing 27. It should be noted that this compressor 2 is a high-pressure dome-shaped compressor in which high-pressure refrigerant exists in the region outside the compression element 21 within the housing 20.

[0062] The movable scroll member 23 has a flat movable side end plate 23a, a scroll-shaped movable side scroll tooth 23b protruding upward from the upper surface of the movable side end plate 23a, and a cylindrical boss portion 23c protruding from the back of the movable side end plate 23a. The fixed side scroll tooth 22b of the fixed scroll member 22 and the movable side scroll tooth 23b of the movable scroll member 23 are combined in a state where the lower surface of the fixed side end plate 22a faces the upper surface of the movable side end plate 23a. A compression chamber Sc is formed between adjacent fixed side scroll teeth 22b and movable side scroll teeth 23b. As the movable scroll member 23 revolves relative to the fixed scroll member 22 as described later, the volume of the compression chamber Sc changes periodically, and refrigerant is drawn in, compressed, and discharged in the compression element 21. The boss portion 23c is a cylindrical portion with its upper end sealed. The movable scroll member 23 is connected to the crankshaft 25 by inserting the eccentric portion 25b of the crankshaft 25 (described later) into the hollow portion of the boss portion 23c. An eccentric space 28 is defined by the boss portion 23c and the housing 27. The eccentric space 28 is connected to the high-pressure space Sh via the oil supply path 39 of the crankshaft 25 (described later), and high pressure acts on the eccentric space 28. This pressure presses the lower surface of the movable side plate 23a within the eccentric space 28 upwards toward the fixed scroll member 22. This force causes the movable scroll member 23 to be tightly fitted with the fixed scroll member 22. The movable scroll member 23 is supported on the housing 27 via a cross ring 29 disposed in the "cross ring space Sr". The cross ring 29 is a component that prevents the movable scroll member 23 from rotating and causes it to revolve. By using the cross ring 29, when the crankshaft 25 rotates, the movable scroll member 23 connected to the crankshaft 25 in the boss portion 23c revolves relative to the fixed scroll member 22 without rotating on its own, and the refrigerant in the compression chamber Sc is compressed.

[0063] The housing 27 is pressed into the inner side of the cylindrical member 20a and is fixed to the cylindrical member 20a circumferentially over its entire outer periphery. Furthermore, the housing 27 and the fixed scroll member 22 are fixed in such a way that the upper end face of the housing 27 is in close contact with the lower surface of the outer edge 22c of the fixed scroll member 22. The housing 27 has a recess 27a disposed in the center of its upper surface and an upper bearing portion 27b disposed below the recess 27a. The side of the eccentric space 28 is divided by the inner side of the recess 27a. An upper bearing 35, a cylindrical metal member that supports the main shaft 25a of the crankshaft 25, is disposed in the upper bearing portion 27b. The upper bearing 35 supports the main shaft 25a, into which it is inserted, allowing for free rotation. Additionally, a cross-ring space Sr is formed in the housing 27, in which a cross-ring 29 is disposed.

[0064] The drive motor 24 has an annular stator 33 fixed to the inner wall of the cylindrical member 20a, and a rotor 32 rotatably housed inside the stator 33 through a small gap (air gap passage). The stator 33 is configured to have coils. The rotor 32 is connected to the movable scroll member 23 via a crankshaft 25 arranged to extend vertically along the axis of the cylindrical member 20a. As the rotor 32 rotates, the movable scroll member 23 revolves relative to the fixed scroll member 22.

[0065] The crankshaft 25 transmits the driving force of the drive motor 24 to the movable scroll member 23. The crankshaft 25 is configured to extend vertically along the axis of the cylindrical member 20a, connecting the rotor 32 of the drive motor 24 to the movable scroll member 23 of the compression element 21. The crankshaft 25 has a main shaft 25a whose central axis coincides with the axis of the cylindrical member 20a, and an eccentric portion 25b that is eccentric relative to the axis of the cylindrical member 20a. As described above, the eccentric portion 25b is inserted into the boss portion 23c of the movable scroll member 23. It should be noted that a cylindrical metal component, namely a pin bearing 31, is provided radially outside the eccentric portion 25b to provide shaft support for it. The main shaft 25a is supported by the pin bearing 31, the upper bearing 35 of the upper bearing portion 27b of the housing 27, and the lower bearing 26, allowing it to rotate freely. The main shaft 25a is connected to the rotor 32 of the drive motor 24 between the upper bearing 35 and the lower bearing 26. An oil supply path 39 for supplying refrigerant oil to the compression element 21 and the like is formed inside the crankshaft 25. The lower end of the main shaft 25a is located within the oil storage space 37a of the oil reservoir 37 formed in the lower part of the housing 20, and the refrigerant oil in the oil storage space 37a is supplied to the compression element 21 and the like through the oil supply path 39.

[0066] The counterweight 30, distinct from the crankshaft 25, is ring-shaped and embedded in the main shaft 25a. The counterweight 30 has a cylindrical portion 30a and an eccentric portion 30b formed on a circumferential part of the cylindrical portion 30a. The center of gravity of the counterweight 30 as a whole is eccentrically offset from the axis of the crankshaft 25 in a predetermined direction. The movable scroll member 23 is supported near its center by the eccentric portion 25b of the crankshaft 25, allowing it to slide freely. Consequently, the movable scroll member 23 is also eccentrically offset in the same direction as the eccentric portion 25b.

[0067] The lower bearing 26 is positioned below the drive motor 24. The lower bearing 26 is fixed to the lower inner side of the cylindrical component 20a. The lower bearing 26 constitutes the bearing on the lower end side of the crankshaft 25 and is a metal component that supports the main shaft 25a of the crankshaft 25 in a freely rotatable cylindrical shape.

[0068] The compressor 2 described above operates as follows.

[0069] First, when the drive motor 24 starts, the rotor 32 rotates relative to the stator 33, and the crankshaft 25, which is fixed to the rotor 32, rotates. As the crankshaft 25 rotates, the movable scroll member 23, connected to the crankshaft 25, revolves relative to the fixed scroll member 22. Furthermore, low-pressure gaseous refrigerant in the refrigeration cycle is drawn into the compression chamber Sc from the periphery through the suction pipe 12. As the movable scroll member 23 revolves, the suction pipe 12 becomes disconnected from the compression chamber Sc. And, as the volume of the compression chamber Sc decreases, the pressure in the compression chamber Sc begins to rise.

[0070] The refrigerant in the compression chamber Sc is compressed as the volume of the compression chamber Sc decreases, eventually becoming a high-pressure gaseous refrigerant. This high-pressure gaseous refrigerant is discharged from the outlet 22d located near the center of the fixed side end plate 22a. Then, the high-pressure gaseous refrigerant flows into the high-pressure space Sh through a refrigerant passage (not shown) formed in the fixed scroll member 22 and the housing 27. The high-pressure gaseous refrigerant in the refrigeration cycle, compressed by the compression element 21, flowing into the high-pressure space Sh, is discharged from the outlet pipe 13.

[0071] (3) Refrigeration oil

[0072] In the refrigerant circuit 10, refrigeration oil is sealed in along with the refrigerant.

[0073] As a refrigeration oil used with refrigerant, known refrigeration oils can be used. Preferably, at least one or more of the following are selected from the group consisting of polyol esters (POE), polyvinyl ether (PVE), and polyalkylene glycols (PAG).

[0074] Refrigeration oil may contain, for example, known acid scavengers, extreme pressure agents, and antioxidants.

[0075] It should be noted that there are no particular limitations on the solubility of HFO-1132(E) and HFO-1234yf in refrigeration oils. For example, the solubility can be adjusted by modifying the molecular structure of the organic compounds contained in the refrigeration oil, such as the number of carbon atoms and the presence or absence of branched chains. For instance, when the refrigeration oil contains polyol esters, the solubility of HFO-1132(E) and HFO-1234yf can be adjusted by changing the number of carbon atoms and the branched structure of the carbon chains of the fatty acids constituting the polyol ester, as well as the number of carbon atoms, the number of hydroxyl groups, and the branched structure of the carbon chains of the polyol constituting the polyol ester. Similarly, when the refrigeration oil contains polyvinyl ether, the solubility of HFO-1132(E) and HFO-1234yf can be adjusted by changing the number of carbon atoms, the branched structure, and the functional groups of the side chains constituting the polyol ether. Furthermore, when the refrigeration oil contains polyalkylene glycols, the solubility of HFO-1132(E) and HFO-1234yf can be adjusted by changing the ratio of propylene oxide to ethylene oxide constituting the polyalkylene glycol. These polyol esters, polyvinyl ethers, and polyalkylene glycols can be, for example, substances known as refrigeration oils or commercially available substances.

[0076] (4) Refrigerant

[0077] The refrigerants used in the refrigeration cycle unit 1 include trans-1,2-difluoroethylene (HFO-1132(E)) and 2,3,3,3-tetrafluoropropylene (HFO-1234yf).

[0078] It should be noted that the content of HFO-1132(E) and HFO-1234yf in the refrigerant is preferably 95% by weight or more, more preferably 99% by weight or more, and even more preferably 99.5% by weight or more.

[0079] It should be noted that the preferred refrigerant contains HFO-1132(E) at a weight ratio of 22% to 24% and HFO-1234yf at a weight ratio of 76% to 78% or more, or HFO-1132(E) at a weight ratio of 30.5% to 32.5% and HFO-1234yf at a weight ratio of 67.5% to 69.5% or more.

[0080] (5) Relationship between refrigerant and refrigeration oil

[0081] (5-1) Regarding the refrigeration oil in the overall refrigerant circuit

[0082] In this embodiment, for the working fluid containing refrigerant and refrigeration oil, under the operating conditions of a refrigerant discharge temperature of 58°C and a discharge pressure of 1.5MPa from compressor 2, the value of X represented by X=[{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]Sa+{A / (100-QS)} satisfies 0.84A-4.57≤X≤0.76A+21.82.

[0083] Here, S(%) is the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigerant oil, i.e., the first total weight, to the weight of the refrigerant oil. It should be noted that the first total weight refers to the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigerant oil within the HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit 10, and not the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit 10.

[0084] Q(%) is the ratio of the weight of the refrigerant oil to the combined weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight. Furthermore, the second total weight refers to the combined weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit 10, and is a value independent of whether or not it is dissolved in the refrigerant oil.

[0085] A(%) is the ratio of the weight of HFO-1132(E) to the second total weight.

[0086] Sa(%) is the ratio of the weight of HFO-1132(E) dissolved in the refrigeration oil to the weight of the refrigeration oil.

[0087] It should be noted that in this instruction manual, "·" and "×" are sometimes used. Both "·" and "×" refer to the product.

[0088] According to this refrigeration cycle device 1, it is possible to ensure that the cooling capacity of the refrigerant circulating in the refrigerant circuit 10 without dissolving in the refrigeration oil is at least 90% higher than the cooling capacity of a refrigerant composed of refrigerant presumably filling the refrigerant circuit 10. Furthermore, it is possible to ensure that the coefficient of performance (COP) of the refrigerant circulating in the refrigerant circuit 10 without dissolving in the refrigeration oil is at least 99% higher than the COP of a refrigerant presumably filling the refrigerant circuit 10.

[0089] It should be noted that, from the viewpoint of ensuring a cooling capacity ratio of over 95%, it is preferable to further satisfy 0.92A-2.26≤X under the above operating conditions of a refrigerant discharge temperature of 58°C and a discharge pressure of 1.5MPa.

[0090] Furthermore, from the viewpoint of ensuring a cooling capacity ratio of over 100%, it is preferable that, under the aforementioned operating conditions of a refrigerant discharge temperature of 58°C and a discharge pressure of 1.5 MPa, A≤X is further satisfied.

[0091] From the viewpoint of easily ensuring cooling capacity, A (%) is preferably 15 wt% or more. Furthermore, from the viewpoint of suppressing combustion in case of leakage, A (%) is preferably 40% or less, more preferably 35% or less.

[0092] The refrigerant and refrigeration oil used in the refrigeration cycle device 1 are particularly preferably of the following weight ratios: the refrigerant contains HFO-1132(E) at a weight ratio of 22% to 24% and the refrigerant contains HFO-1234yf at a weight ratio of 76% to 78%; or the refrigerant contains HFO-1132(E) at a weight ratio of 30.5% to 32.5% and the refrigerant contains HFO-1234yf at a weight ratio of 67.5% to 69.5% and satisfies 20 ≤ Q ≤ 70.

[0093] From the viewpoint of maintaining good lubrication performance in compressor 2 when refrigerant is compressed, it is preferable that the S(%) is 10 or more under the above operating conditions of refrigerant discharge temperature of 58°C and discharge pressure of 1.5MPa.

[0094] (Experimental Example)

[0095] By determining the weight percentage (%) of HFO-1132(E) in the refrigerant filled in the refrigerant circuit 10 and circulating in the refrigerant that is not dissolved in the refrigeration oil, the conditions for ensuring a cooling capacity ratio of 90% or higher and a coefficient of performance ratio of 99% or higher were established. Furthermore, conditions for ensuring a cooling capacity ratio of 95% or higher and a coefficient of performance ratio of 99% or higher, as well as conditions for ensuring a cooling capacity ratio of 100% or higher and a coefficient of performance ratio of 99% or higher, were also established.

[0096] It should be noted that the weight percentage (%) of HFO-1234yf in the circulating refrigerant that is not dissolved in the refrigeration oil is the value obtained by subtracting the weight percentage (%) of HFO-1132(E) from 100(%).

[0097] Specifically, in addition to S, Q, A, and Sa mentioned above, the following parameters are also used. It should be noted that, in the following text, S(%) is the ratio of the weight of the refrigerant dissolved in the refrigerant oil in refrigerant circuit 10 to the weight of the refrigerant oil; Q(%) is the ratio of the weight of the refrigerant oil in refrigerant circuit 10 to the weight of the refrigerant; A(%) is the ratio of the weight of HFO-1132(E) in refrigerant circuit 10 to the weight of the refrigerant; and Sa(%) is the ratio of the weight of HFO-1132(E) dissolved in the refrigerant oil in refrigerant circuit 10 to the weight of the refrigerant oil.

[0098] The composition of the refrigerant filling the refrigerant circuit 10 is set as HFO-1132(E) / HFO-1234yf=A / B(wt%). Here, A is the same as above.

[0099] The weight of the refrigerant filled in the refrigerant circuit 10, i.e., the refrigerant filling amount, is denoted as Wr (g). Therefore, the weight of HFO-1132(E) filled in the refrigerant circuit 10 is expressed as Wr·A (g), and the weight of HFO-1234yf filled in the refrigerant circuit 10 is expressed as Wr·B (g).

[0100] The weight of the refrigeration oil filled in the refrigerant circuit 10, i.e. the oil quantity, is set as Wo (g).

[0101] The weight ratio of HFO-1234yf dissolved in the refrigerant circuit 10 to the weight of the refrigerant oil is set as Sb, and Sb is represented by Sb=S-Sa.

[0102] Here, the weight of the refrigerant dissolved in the refrigeration oil in refrigerant circuit 10 is denoted as Wro(g), which is represented by Wro(g) = Wo·S. It should be noted that the weight of HFO-1132(E) dissolved in the refrigeration oil in refrigerant circuit 10 is represented by Wo·Sa, and the weight of HFO-1234yf dissolved in the refrigeration oil in refrigerant circuit 10 is represented by Wo·Sb.

[0103] The weight of refrigerant that is not dissolved in the refrigerant oil but circulates in refrigerant circuit 10 is expressed as Wr-Wro (g). It should be noted that the weight of HFO-1132(E) that is not dissolved in the refrigerant oil but circulates in refrigerant circuit 10 is expressed as Wr·A-Wo·Sa, and the weight of HFO-1234yf that is not dissolved in the refrigerant oil but circulates in refrigerant circuit 10 is expressed as Wr·B-Wo·Sb.

[0104] In this case, if the weight percentage (%) of HFO-1132(E) in the refrigerant circulating in the refrigerant circuit 10 that is not dissolved in the refrigeration oil is set as X, then it is expressed as follows.

[0105] X=(Wr·A-Wo·Sa) / (Wr-Wro)

[0106] =(Wr·A-Wo·Sa) / (Wr·A-Wo·Sa+Wr·B-Wo·Sb)

[0107] =(Wr·A-Wo·Sa) / (Wr·A-Wo·Sa+Wr·(100-A)-Wo·(S-Sa))

[0108] =(Wr·A-Wo·Sa) / (Wr·A-Wo·Sa+Wr·100-Wr·A-Wo·S+Wo·Sa)

[0109] =(Wr·A-Wo·Sa) / (Wr·100-Wo·S)

[0110] =(Wr·A) / (Wr·100-Wo·S)-(Wo·Sa) / (Wr·100-Wo·S)

[0111] Furthermore, regarding X, it can be represented as follows by using the coefficients "aQS" and "bQS".

[0112] X=aQS·Sa+bQS

[0113] Here, aQS=-(Wo) / (Wr·100-Wo·S), bQS=(Wr·A) / (Wr·100-Wo·S).

[0114] Here, regarding "aQS", the line is obtained by plotting the value of aQS as the value of Q changes according to the value of S (see reference). Figure 3 )like Figure 4 The approximation, as shown by the curve, can be represented as follows. It should be noted that... Figure 3 , Figure 4 The example illustrates the case where A is 23%, S varies within the range of 10% to 100%, and Q varies within the range of 10% to 90%.

[0115] aQS={(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1

[0116] In addition, regarding "bQS", it can be elaborated as follows.

[0117] bQS=(Wr·A) / (Wr·100-Wo·S)

[0118] =(Wr·A / Wr) / (Wr·100 / Wr-Wo·S / Wr)

[0119] =A / (100-Wo·S / Wr)

[0120] =A / (100-Q·S)

[0121] As mentioned above, X can ultimately be represented as follows.

[0122] X=aQS·Sa+bQS

[0123] =[{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]·Sa+{A / (100-Q·S)}

[0124] Here, if a significant amount of HFO-1132(E) dissolves in the refrigerant oil, reducing the concentration of HFO-1132(E) in the refrigerant circulating in the refrigerant circuit 10, there is a tendency for a decrease in cooling capacity. Therefore, assuming the cooling capacity of the refrigerant circulating in the refrigerant circuit 10, which is composed of refrigerant filled in the refrigerant circuit 10, is set to 100, the ratio of the cooling capacity of the refrigerant circulating in the refrigerant circuit 10 that is not dissolved in the refrigerant oil (cooling capacity ratio) can be expressed as a function of the weight of HFO-1132(E) used in the refrigerant, i.e., A. Furthermore, to ensure that the cooling capacity ratio is 90% or higher, X needs to satisfy the following condition in its relationship with A. It should be noted that if the compressor 2 used in the refrigeration cycle device 1 can be capacity controlled, the degree of reduction in compressor efficiency can be minimized, and the reduction in cooling capacity can be compensated for.

[0125] X≥0.84A-4.57

[0126] Furthermore, if HFO-1234yf dissolves more into the refrigerant oil, increasing the concentration of HFO-1132(E) in the refrigerant circulating in the refrigerant circuit 10, there is a tendency for the coefficient of performance (COP) to decrease. Therefore, assuming the COP of the refrigerant circulating in the refrigerant circuit 10 is 100, the ratio of the COP of the refrigerant circulating in the refrigerant circuit 10 without dissolving in the refrigerant oil (COP ratio) can be expressed as a function of the weight of HFO-1132(E) used in the refrigerant. Furthermore, to ensure a COP ratio of 99% or higher, X must satisfy the following condition in its relationship with A. It should be noted that while the COP is primarily determined by the composition of the refrigerant circulating in the refrigerant circuit 10, the decrease in COP can be compensated by providing a heat medium supply mechanism, such as a fan, capable of controlling the supply of heat mediums like air to the first heat exchanger 3 and the second heat exchanger 5.

[0127] X≤0.76A+21.82

[0128] Based on the above, in order to ensure that the cooling capacity ratio is above 90% and the coefficient of performance is above 99%, X needs to satisfy the following relationship.

[0129] 0.84A - 4.57 ≤ X ≤ 0.76A + 21.82

[0130] It should be noted that, in order to ensure a cooling capacity ratio of over 95%, the following conditions must be met. It should also be noted that if the compressor 2 used in the refrigeration cycle unit 1 can perform capacity control, then the reduction in cooling capacity can be compensated for while maintaining compressor efficiency well.

[0131] X≥0.92A-2.26

[0132] It should be noted that the following conditions must be met in order to ensure that the cooling capacity ratio is above 100%.

[0133] X≥A

[0134] Figure 5 It is a graph showing the relationship between X and A.

[0135] exist Figure 5 The graph shows that the further down the flow path, the more HFO-1132(E) dissolves into the refrigeration oil, resulting in a lower cooling capacity compared to the working fluid. Additionally, in... Figure 5 The graph shows that the higher the HFO-1234yf moves, the more it dissolves into the refrigeration oil, resulting in a lower coefficient of performance (COP) for the working fluid.

[0136] It should be noted that, Figure 5 The line shown in (1) is the line with a cooling capacity ratio of 90%, and below it, it indicates a cooling capacity ratio of less than 90%. Figure 5 The line shown in (2) is the line with a cooling capacity ratio of 95%, and below it, it indicates a cooling capacity ratio of less than 95%. Figure 5 The line shown in (3) is the line with a cooling capacity ratio of 100%, and below it, it indicates a cooling capacity ratio of less than 100%. Figure 5 The line shown in (4) represents a coefficient of performance ratio of 99%, and lines above it indicate coefficients of performance ratios less than 99%. Figure 5 In the figure, the shaded range indicates that, based on ensuring a cooling capacity ratio of 90% or more and a coefficient of performance ratio of 99% or more, the value of A is preferably 15 wt% or more from the viewpoint of ensuring cooling capacity and preferably 35 wt% or less from the viewpoint of suppressing flammability.

[0137] Figure 6 It is a graph showing the value of X relative to Sa for each Q.

[0138] It should be noted that, in Figure 6 In the example, with A being 23% and S being 60%, the case of Q varying within the range of 10% to 90% is illustrated. Figure 6 The dashed line (1) shown represents the lower limit of X required to ensure a cooling capacity ratio of over 90%. Figure 6 The dashed line (2) shown represents the lower limit of X required to ensure a cooling capacity ratio of 95% or higher. Figure 6 The dashed line (3) shown represents the lower limit of X required to ensure a cooling capacity ratio of over 100%. Figure 6 The dashed line (4) shown represents the upper limit of X required to ensure a performance coefficient ratio of 99% or higher.

[0139] exist Figure 6 From the viewpoint of maintaining good lubrication performance in compressor 2, S is preferably 10% by weight or more, and Sa is also preferably 10% by weight or more. Figure 6 In the diagram, the shaded range represents the preferred range for maintaining good lubrication performance in compressor 2 while ensuring a cooling capacity ratio of 90% or higher and a coefficient of performance of 99% or higher. The upper limit of Sa in this shaded range, 60% by weight, is due to... Figure 6 The example below shows the case where S is 60%.

[0140] It should be noted that, based on the above... Figure 4 , Figure 5 , Figure 6 It can understand the behavior of other parameters when each parameter changes.

[0141] It should be noted that the refrigeration capacity (sometimes also expressed as cooling capacity or capacity) and coefficient of performance (COP) of the mixed refrigerant HFO-1132(E) and HFO-1234yf were obtained by performing theoretical calculations of the mixed refrigerant refrigeration cycle using the Reference Fluid Thermodynamic and Transport Properties Database (REFPROP 10.0) created by the National Institute of Science and Technology (NIST) under the following conditions.

[0142] Evaporation temperature: 5℃

[0143] Condensation temperature: 45℃

[0144] Overheating: 5K

[0145] Supercooling: 5K

[0146] Compressor efficiency: 70%

[0147] It should be noted that the formulas for calculating cooling capacity and COP are as follows.

[0148] Cooling capacity = Refrigerant circulation volume × Enthalpy difference of cooling effect

[0149] COP = Enthalpy difference of cooling effect / Enthalpy difference of compression work

[0150] (5-2) Regarding the refrigerant oil in the compressor's oil reservoir

[0151] In the above (5-1), the parameters of the refrigeration oil are studied in terms of the refrigeration oil filling the refrigerant circuit 10 as a whole. However, from the point of view that most of the refrigeration oil in the refrigerant circuit 10 exists in the oil reservoir 37 of the compressor 2, and the amount of refrigeration oil flowing out of the compressor 2 to other parts of the refrigerant circuit 10 is substantially negligible, the relationship between the refrigerant and the refrigeration oil can also be determined as follows.

[0152] For the working fluid containing refrigerant and refrigeration oil, under the operating conditions of a refrigerant discharge temperature of 58℃ and a discharge pressure of 1.5MPa from compressor 2, the value of Xa represented by Xa=[{(-1.3257T+1.0919) / (R+233.27T-207.91)}+1]Ta+{A / (100-RT)} can satisfy 0.84A-4.57≤Xa≤0.76A+21.82.

[0153] Here, T(%) is the ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir 37, i.e., the third total weight, to the weight of the refrigerant oil in the oil reservoir 37. The third total weight refers to the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigerant oil in the oil reservoir 37, which is filled in the refrigerant circuit 10, and not the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit 10.

[0154] R(%) is the ratio of the weight of the refrigerant oil in the oil reservoir 37 to the total weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight. Furthermore, the second total weight refers to the total weight of HFO-1132(E) and HFO-1234yf filled in the refrigerant circuit 10, and is a value independent of whether or not it is dissolved in the refrigerant oil.

[0155] A(%) is the same as described in (5-1), and is the ratio of the weight of HFO-1132(E) to the second total weight.

[0156] Ta(%) is the ratio of the weight of HFO-1132(E) dissolved in the oil reservoir 37 to the weight of the refrigeration oil in the oil reservoir 37.

[0157] According to this refrigeration cycle device 1, it is possible to ensure that the cooling capacity of the refrigerant circulating in the refrigerant circuit 10 without dissolving in the refrigeration oil is at least 90% higher than the cooling capacity of a refrigerant composed of refrigerant presumably filling the refrigerant circuit 10. Furthermore, it is possible to ensure that the coefficient of performance (COP) of the refrigerant circulating in the refrigerant circuit 10 without dissolving in the refrigeration oil is at least 99% higher than the COP of a refrigerant presumably filling the refrigerant circuit 10.

[0158] It should be noted that, from the viewpoint of ensuring a cooling capacity ratio of over 95%, it is preferable to further satisfy 0.92A-2.26≤Xa under the above operating conditions of a refrigerant discharge temperature of 58°C and a discharge pressure of 1.5MPa.

[0159] Furthermore, from the viewpoint of ensuring a cooling capacity ratio of over 100%, it is preferable that, under the aforementioned operating conditions of a refrigerant discharge temperature of 58°C and a discharge pressure of 1.5 MPa, A ≤ Xa is further satisfied.

[0160] From the viewpoint of easily ensuring cooling capacity, A (%) is preferably 15 wt% or more. Furthermore, from the viewpoint of suppressing combustion in case of leakage, A (%) is preferably 40% or less, more preferably 35% or less.

[0161] The refrigerant and refrigeration oil used in the refrigeration cycle device 1 are particularly preferably those in which the weight ratio of HFO-1132(E) in the refrigerant is 22% to 24% by weight and the weight ratio of HFO-1234yf in the refrigerant is 76% to 78% by weight, or the weight ratio of HFO-1132(E) in the refrigerant is 30.5% to 32.5% by weight and the weight ratio of HFO-1234yf in the refrigerant is 67.5% to 69.5% by weight, and satisfy 20 ≤ R ≤ 70.

[0162] From the viewpoint of maintaining good lubrication performance in compressor 2 when refrigerant is compressed, it is preferable that T(%) is 10 or more under the above operating conditions of refrigerant discharge temperature of 58°C and discharge pressure of 1.5MPa.

[0163] (Postscript)

[0164] The embodiments of the present invention have been described above, but it should be understood that various changes in manner and details can be made without departing from the spirit and scope of the present invention as set forth in the claims.

[0165] Symbol Explanation

[0166] 1. Refrigeration cycle device

[0167] 2. Compressor

[0168] 10 Refrigerant Circuit

[0169] 21 Compression element

[0170] 37 Oil Storage Section

[0171] Existing technical documents

[0172] Patent documents

[0173] Patent Document 1: Japanese Patent Application Publication No. 2015-200480

Claims

1. A refrigeration cycle device (1) that uses a working fluid comprising a refrigerant and refrigeration oil, wherein the refrigerant comprises trans-1,2-difluoroethylene, i.e., HFO-1132(E), and 2,3,3,3-tetrafluoropropylene, i.e., HFO-1234yf, wherein, The refrigeration cycle device includes a refrigerant circuit (10), which has a compressor (2) for circulating the working fluid. For the working fluid The ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigeration oil, i.e., the first total weight, to the weight of the refrigeration oil is set as S. The weight of the refrigeration oil relative to the combined weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight, is set as Q. Let the ratio of the weight of HFO-1132(E) to the second total weight be A. If the weight ratio of HFO-1132(E) dissolved in the refrigeration oil to the weight of the refrigeration oil is set as Sa, Under operating conditions where the refrigerant discharged from the compressor has a discharge temperature of 58°C and a discharge pressure of 1.5 MPa, The value of X represented by X = [{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]Sa+{A / (100-QS)} satisfies 0.84A-4.57≤X≤0.76A+21.

82. The units for S, Q, A, and Sa are respectively.

2. The refrigeration cycle device as described in claim 1, wherein, Under the aforementioned operating conditions, the condition 0.92A-2.26≤X is further satisfied.

3. The refrigeration cycle device as described in claim 1, wherein, Under the aforementioned operating conditions, A≤X is further satisfied.

4. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein, The refrigerant contains HFO-1132(E) at a weight ratio of 22% to 24% and HFO-1234yf at a weight ratio of 76% to 78%, or HFO-1132(E) at a weight ratio of 30.5% to 32.5% and HFO-1234yf at a weight ratio of 67.5% to 69.5%. The condition 20 ≤ Q ≤ 70 is satisfied.

5. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein, Under the operating conditions, S is 10 or more, and the unit of S is ( ).

6. A refrigeration cycle device (1) that uses a working fluid comprising a refrigerant and refrigeration oil, wherein the refrigerant comprises trans-1,2-difluoroethylene, i.e., HFO-1132(E), and 2,3,3,3-tetrafluoropropylene, i.e., HFO-1234yf, wherein, The refrigeration cycle device includes a refrigerant circuit (10), which has a compressor (2) for circulating the working fluid. The compressor (2) includes a compression element (21) for compressing the refrigerant and an oil reservoir (37) for storing the refrigeration oil. For the working fluid The ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir (i.e., the third total weight) to the weight of the refrigeration oil in the oil reservoir is set as T. The ratio of the weight of the refrigeration oil in the oil reservoir to the combined weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight, is set as R. Let the ratio of the weight of HFO-1132(E) to the second total weight be A. If the weight ratio of the HFO-1132(E) dissolved in the oil reservoir to the weight of the refrigeration oil in the oil reservoir is set to Ta, Under operating conditions where the refrigerant discharged from the compressor has a discharge temperature of 58°C and a discharge pressure of 1.5 MPa, The value of Xa represented by Xa=[{(-1.3257T+1.0919) / (R+233.27T-207.91)}+1]Ta+{A / (100-RT)} satisfies 0.84A-4.57≤Xa≤0.76A+21.

82. The units for T, R, A, and Ta are respectively.

7. The refrigeration cycle apparatus as described in claim 6, wherein, Under the aforementioned operating conditions, the condition 0.92A-2.26≤Xa is further satisfied.

8. The refrigeration cycle apparatus as described in claim 6, wherein, Under the aforementioned operating conditions, A ≤ Xa is further satisfied.

9. The refrigeration cycle apparatus according to any one of claims 6 to 8, wherein, The refrigerant contains HFO-1132(E) at a weight ratio of 22% to 24% and HFO-1234yf at a weight ratio of 76% to 78%, or HFO-1132(E) at a weight ratio of 30.5% to 32.5% and HFO-1234yf at a weight ratio of 67.5% to 69.5%. The condition 20 ≤ R ≤ 70 is satisfied.

10. The refrigeration cycle apparatus according to any one of claims 6 to 9, wherein, Under the operating conditions, T is 10 or more, and the unit of T is ( ).

11. The refrigeration cycle apparatus according to any one of claims 1 to 10, wherein, The value of A is between 15 and 40, and the unit of A is %.

12. The refrigeration cycle apparatus according to any one of claims 1 to 11, wherein, The second total weight of the refrigerant is 95% or more.

13. The refrigeration cycle apparatus according to any one of claims 1 to 12, wherein, The refrigeration oil contains at least one of the following: polyol ester (POE), polyvinyl ether (PVE), and polyalkylene glycol (PAG).

14. A refrigeration oil for a refrigeration cycle device, wherein the refrigeration oil of the refrigeration cycle device (1) is used as a working fluid together with a refrigerant comprising trans-1,2-difluoroethylene, i.e., HFO-1132(E) and 2,3,3,3-tetrafluoropropylene, i.e., HFO-1234yf, wherein, The refrigeration cycle device includes a refrigerant circuit (10), which has a compressor (2) for circulating the working fluid. For the working fluid The ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the refrigeration oil, i.e., the first total weight, to the weight of the refrigeration oil is set as S. The weight of the refrigeration oil relative to the combined weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight, is set as Q. Let the ratio of the weight of HFO-1132(E) to the second total weight be A. If the weight ratio of HFO-1132(E) dissolved in the refrigeration oil to the weight of the refrigeration oil is set as Sa, Under operating conditions where the refrigerant discharged from the compressor has a discharge temperature of 58°C and a discharge pressure of 1.5 MPa, The value of X represented by X = [{(-1.3257S+1.0919) / (Q+233.27S-207.91)}+1]Sa+{A / (100-QS)} satisfies 0.84A-4.57≤X≤0.76A+21.

82. The units for S, Q, A, and Sa are respectively.

15. A refrigeration oil for a refrigeration cycle device, wherein the refrigeration oil is used as a working fluid in a refrigeration cycle device (1) comprising a refrigerant containing trans-1,2-difluoroethylene, i.e., HFO-1132(E) and 2,3,3,3-tetrafluoropropylene, i.e., HFO-1234yf, wherein, The refrigeration cycle device includes a refrigerant circuit (10), which has a compressor (2) for circulating the working fluid. The compressor (2) includes a compression element (21) for compressing the refrigerant and an oil reservoir (37) for storing the refrigeration oil. For the working fluid The ratio of the total weight of HFO-1132(E) and HFO-1234yf dissolved in the oil reservoir (i.e., the third total weight) to the weight of the refrigeration oil in the oil reservoir is set as T. The ratio of the weight of the refrigeration oil in the oil reservoir to the combined weight of HFO-1132(E) and HFO-1234yf, i.e., the second total weight, is set as R. Let the ratio of the weight of HFO-1132(E) to the second total weight be A. If the weight ratio of the HFO-1132(E) dissolved in the oil reservoir to the weight of the refrigeration oil in the oil reservoir is set to Ta, Under operating conditions where the refrigerant discharged from the compressor has a discharge temperature of 58°C and a discharge pressure of 1.5 MPa, The value of Xa represented by Xa=[{(-1.3257T+1.0919) / (R+233.27T-207.91)}+1]Ta+{A / (100-RT)} satisfies 0.84A-4.57≤Xa≤0.76A+21.

82. The units for T, R, A, and Ta are respectively.

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