Refrigeration circuit and refrigeration circuit device with such a refrigeration circuit

Abstract

A refrigerant circuit includes a compressor. The refrigerant is enclosed within the circuit. The refrigerant contains 1,1,2-trifluoroethylene and propane. The C1 content, based on the mass of 1,1,2-trifluoroethylene in the refrigerant, is at least 70% by mass and at most 85% by mass. The C2 content, based on the mass of propane in the refrigerant, is at least 15% by mass and at most 30% by mass.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a refrigeration cycle and a refrigeration cycle device including the same. STATE OF THE ART

[0002] From the perspective of preventing global warming, there has recently been a call for reducing greenhouse gases. A refrigerant with a lower global warming potential (GWP) has also been investigated for refrigerants used in refrigeration cycle devices such as air conditioners. 1,1,2-trifluoroethylene (hereinafter also referred to as HFO-1123) has been investigated as one such refrigerant with low global warming potential and excellent cycle performance (e.g., PTL 1). REFERENCE LISTPATENT LITERATURE

[0003] PTL 1: WO2012 / 157764 SUMMARY OF THE INVENTIONTECHNICAL PROBLEM

[0004] However, HFO-1123 is likely to undergo a disproportionation reaction at high temperatures and high pressures. Therefore, a technique to suppress the disproportionation reaction of HFO-1123, a higher coefficient of performance (COP) of the refrigeration cycle, and a reduction in the displacement of a compressor have been called for.

[0005] The object of the present disclosure is to provide a technique capable of achieving suppression of the disproportionation reaction of HFO-1123, a higher COP of a refrigeration cycle device, and a reduction of the displacement volume of a compressor. SOLUTION TO THE TASK

[0006] A refrigeration cycle according to the present disclosure is a refrigeration cycle with a compressor. The refrigerant is enclosed in the refrigeration cycle. The refrigerant contains 1,1,2-trifluoroethylene and propane. The C1 content, based on the mass of 1,1,2-trifluoroethylene in the refrigerant, is at least 70 mass% and at most 85 mass%. The C2 content, based on the mass of propane in the refrigerant, is at least 15 mass% and at most 30 mass%.

[0007] The refrigeration cycle device according to the present disclosure is a refrigeration cycle device having a refrigerant cycle. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0008] According to the present disclosure, a refrigeration cycle device can be provided which can achieve suppression of the disproportionation reaction of HFO-1123, a larger COP and a reduction of the displacement volume of a compressor. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic configuration diagram showing a refrigeration cycle device according to a first embodiment. Fig. 2 is a cross-sectional view of a compressor according to the first embodiment. Fig. Figure 3 shows a graph of the relationship between the mixing ratio of propane (R290) or difluoromethane (R32) and the temperature at the time of the disproportionation reaction of HFO-1123. Fig. Figure 4 shows a graph of the relationship between the mixing ratio of HFO-1123 and propane (R290) and a temperature gradient. Fig. Figure 5 shows a graph of the relationship between the mixing ratio of HFO-1123 and propane (R290) and a density of saturated gas. Fig. Figure 6 shows a graph of the relationship between the mixing ratio between HFO-1123 and propane (R290) and the theoretical COP. Fig. Figure 7 shows a graph of the relationship between the mixing ratio between HFO-1123 and propane (R290) and the pressure loss. Fig. Figure 8 shows a graph of the relationship between the mixing ratio between HFO-1123 and propane (R290) and the displacement volume of the compressor. Fig. Figure 9 shows a graph of the relationship between the mixing ratio of HFO-1123 and propane (R290) and the COP. Fig. Figure 10 shows a graphical representation of the relationship between the degree of superheating of the compressor oil (e.g., PVE oil) and the amount of dissolution of HFO-1123 and propane (R290) dissolved in the compressor oil. DESCRIPTION OF THE EMBODIMENTS

[0009] An embodiment of the present disclosure will be described below with reference to the drawings. First embodiment.<Kältekreislauf und Kältekreislaufvorrichtung>

[0010] An overview of a refrigeration cycle and a refrigeration cycle device in the present embodiment will be described. The refrigeration cycle device in the present embodiment includes a refrigeration cycle with a compressor. Fig. 1 is a schematic configuration diagram showing a refrigeration cycle device according to a first embodiment. A refrigeration cycle device 100 may include a refrigeration cycle 5 including a compressor 1, a condenser 2, an expansion valve 3, and an evaporator 4. Compressor 1 and condenser 2 are connected by a refrigerant line 5a, condenser 2 and expansion valve 3 are connected by a refrigerant line 5b, expansion valve 3 and evaporator 4 are connected by a refrigerant line 5c, and evaporator 4 and compressor 1 are connected by a refrigerant line 5d. Refrigerant is enclosed in the refrigeration cycle 5.The refrigerant circulates sequentially through the compressor 1, the refrigerant line 5a, the condenser 2, the refrigerant line 5b, the expansion valve 3, the refrigerant line 5c, the evaporator 4, the refrigerant line 5d and the compressor 1.

[0011] Compressor 1 draws in refrigerant, compresses it into a gaseous state at high temperature and high pressure, and discharges the compressed refrigerant. The number of revolutions of compressor 1 is controlled, for example, by an inverter circuit or similar. By controlling the number of revolutions, the amount of discharged refrigerant is adjusted.

[0012] The refrigerant compressed in the compressor 1 to a high-temperature, high-pressure gas state flows into the condenser 2. The condenser 2 effects heat exchange 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, i.e., outdoor air. The condenser 2 effects heat exchange between the outside air and the refrigerant. Furthermore, in the first embodiment, to accelerate the heat exchange in the condenser 2, a condenser fan 6 is provided, which blows outside air into the condenser 2. The condenser fan 6 is capable of regulating the air volume.

[0013] The liquid refrigerant cooled in the condenser 2 at low temperature and high pressure flows into the expansion valve 3. The expansion valve 3 relaxes the refrigerant by reducing the pressure into a liquid state of low temperature and low pressure. The expansion valve 3 is implemented, for example, by an electronic expansion valve, a thermostatic expansion valve or a capillary (capillary tube) to regulate the refrigerant flow.

[0014] The low-temperature, low-pressure liquid refrigerant, which has been expanded by the pressure reduction in the expansion valve 3, flows into the evaporator 4. Heat exchange takes place between the refrigerant and the object to be cooled, and the object's heat is absorbed by the refrigerant, so that the object is cooled. As the object to be cooled is cooled, the refrigerant evaporates and changes into a high-temperature, low-pressure gas. In the first embodiment, the object to be cooled is the room air, and the evaporator 4 effects heat exchange between the room air and the refrigerant. Furthermore, in the first embodiment, to accelerate the heat exchange in the evaporator 4, an evaporator fan 7 is provided, which blows room air to the evaporator 4. The evaporator fan 7 is capable of regulating the air volume.

[0015] Compressor 1 draws the refrigerant in the gaseous state at high temperature and low pressure into the evaporator 4 and recompresses the refrigerant. The refrigerant thus circulates through the refrigeration cycle device 100.

[0016] The refrigeration cycle device 100 may include a control unit 17. The control unit 17 is, for example, a microcomputer. Although Fig. 1 only shows the connection between the control unit 17 and the compressor 1, the control unit 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 unit 17 controls the pressure and / or temperature of the refrigerant circulating through the refrigeration cycle device 100 to a state where a disproportionation reaction of the refrigerant (HFO-1123) does not occur or a chain disproportionation reaction can be suppressed. For example, the control unit controls the pressure and / or temperature so that the pressure of the refrigerant in a flow passage from the compressor 1 to the expansion valve 3 (i.e., on the high-pressure side) does not reach a pressure equal to or higher than a certain value. Even if a disproportionation reaction occurs in a part of the refrigeration cycle device 100, such as the compressor 1, its propagation can be prevented.

[0018] The temperature and / or pressure conditions under which the disproportionation reaction of the refrigerant does not occur or the propagation of the disproportionation reaction can be suppressed can be adjusted accordingly depending on the refrigerant component.

[0019] The refrigeration cycle device 100 may be, for example, a device that can do both cooling and heating, a device that can do only cooling, and a device that can do only heating, and may be applied to various types of refrigeration air conditioners. <<Kältemittel> >

[0020] In the present embodiment, the refrigerant is enclosed in the refrigeration cycle. The refrigerant contains 1,1,2-trifluoroethylene and propane. The content C1 (hereinafter also referred to as "C1 content of HFO-1123"), based on the mass of 1,1,2-trifluoroethylene (HFO-1123) in the refrigerant, is at least 70 mass% and at most 85 mass%, and the content C2 (hereinafter also referred to as "C2 content of propane"), based on the mass of propane (R290) in the refrigerant, is at least 15 mass% and at most 30 mass%.

[0021] HFO-1123 has a low GWP of less than 1, a high operating pressure, and a low refrigerant volume flow rate, thus exhibiting lower pressure loss and excellent cycle performance. In the present embodiment, the C1 content, based on the mass of 1,1,2-trifluoroethylene (HFO-1123) in the refrigerant, is not less than 70 mass% and not more than 85 mass%. Thus, the refrigerant has a low GWP, and the refrigeration cycle device, including the refrigeration cycle in which such refrigerant is enclosed, has a high COP and excellent cycle performance.

[0022] The lower limit of the content C1 of HFO-1123 in the refrigerant is not less than 70 mass percent, preferably not less than 75 mass percent, and more preferably not less than 78 mass percent. The upper limit of the content C1 of HFO-1123 in the refrigerant is not more than 85 mass percent, preferably not more than 83 mass percent, and more preferably not more than 82 mass percent. The content C1 of HFO-1123 in the refrigerant is not less than 70 mass percent and not more than 85 mass percent, preferably not less than 75 mass percent and not more than 83 mass percent, and further preferably not less than 78 mass percent and not more than 82 mass percent.

[0023] In the present disclosure, the content C1, based on the mass of 1,1,2-trifluoroethylene in the refrigerant enclosed in the refrigeration cycle, refers to the content, based on the mass of 1,1,2-trifluoroethylene in the refrigerant before the activation of the refrigeration cycle device enclosing the refrigeration cycle. The content C1 of 1,1,2-trifluoroethylene is considered to be equal to the content, based on the mass of 1,1,2-trifluoroethylene in the refrigerant before the refrigerant is sealed in the refrigeration cycle.In other words, the content based on the mass of 1,1,2-trifluoroethylene in the refrigerant in a refrigerant cylinder filled with refrigerant and to be included in the refrigeration cycle is considered to be equal to the content C1 based on the mass of 1,1,2-trifluoroethylene in the refrigerant included in the refrigeration cycle, which also applies to the content C2 (hereinafter also referred to as "propane content C2") based on the mass of propane in the refrigerant.

[0024] Propane 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 lower limit for the C2 content, based on the mass of propane in the refrigerant, is not less than 15 mass percent, preferably not less than 17 mass percent, and more preferably not less than 18 mass percent. The upper limit for the C2 content of propane in the refrigerant is not more than 30 mass percent, preferably not more than 25 mass percent, and more preferably not more than 22 mass percent. The C2 content of propane in the refrigerant is at least 15 mass percent and at most 30 mass percent, preferably at least 17 mass percent and at most 25 mass percent, and more preferably at least 18 mass percent and at most 22 mass percent.

[0026] The percentage (C2 / C1)×100 of the C2 content, based on the mass of propane, to the C1 content, based on the mass of HFO-1123 in the refrigerant is preferably not less than 15% and less than 50%. Even a small amount of propane excellently suppresses the disproportionation reaction of HFO-1123. Therefore, when the percentage (C2 / C1)×100 is not less than 15%, an excellent effect in suppressing the disproportionation reaction of HFO-1123 can be achieved. 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 value, and the refrigeration cycle device including the refrigeration cycle in which this refrigerant is included can have excellent cycle performance.

[0027] Japanese Patent Laid-Open No. 2018-112396 discloses a technique for blending R32 (difluoromethane) with HFO-1123 to suppress the disproportionation reaction of HFO-1123. However, according to the technique in this patent literature, the R32 content in the refrigerant should be increased to suppress the chain disproportionation reaction in practice. For example, an example is shown where HFO-1123 accounts for 40% and R32 for 60%, with the content of R32 being higher than that of HFO-1123. Therefore, such properties of HFO-1123 as low GWP, high operating pressure, and low refrigerant flow rate, which leads to lower pressure loss, and the ability to ensure performance, are severely compromised.

[0028] On the other hand, the percentage (C2 / C1)×100 of propane to HFO-1123 in the present embodiment is lower than the percentage of R32 to HFO-1123 in the patent literature, but the excellent effect of suppressing the disproportionation reaction of HFO-1123 can be achieved. Since the proportion or ratio of propane in the refrigerant can be low and the ratio of HFO-1123 can be high in the present embodiment, such characteristics of HFO-1123 as low GWP, high operating pressure and low refrigerant flow rate, which leads to less pressure loss, and the readiness to ensure performance can be achieved.

[0029] The percentage (C2 / C1)×100 is preferably not lower than 15% and not lower than 50%, preferably not lower than 17% and not higher than 43%, and more preferably not lower than 21% and not higher than 28%.

[0030] For a deeper understanding of the present disclosure, details of the effect of suppressing the disproportionation reaction of HFO-1123 by propane are described below.

[0031] Fig. Figure 3 shows a graph illustrating the relationship between the mixing ratio of propane (R290) or difluoromethane (R32) and the temperature generated at the time of the disproportionation reaction of HFO-1123 in an example where propane (R290) or difluoromethane (R32) is mixed with HFO-1123. Difluoromethane (R32) is a refrigerant whose mixing with HFO-1123 has been conventionally studied. In the graph, the "R32 or R290 mixing ratio [mass %]" on the abscissa represents the mixing ratio of R32 or R290 to the mass of HFO-1123, which is defined as 100%. For example, a mixing ratio of 15% R290 means that 15% by mass of R290 is mixed with 100% by mass of HFO-1123.In the graph, the "temperature generated at the time of the disproportionation reaction of HFO-1123 [K]" on the ordinate represents the temperature [K] generated during the disproportionation reaction of HFO-1123 at the mixing ratio of R32 or R290 indicated on the abscissa. The "temperature generated at the time of the disproportionation reaction of HFO-1123 [K]" is a temperature at a pressure of 6 MPa. Since the temperature generated at the time of the disproportionation reaction of HFO-1123 is lower, the propagation of the disproportionation reaction is more easily suppressed.

[0032] As in Fig. As shown in Figure 3, when propane (R290) is mixed with HFO-1123 at a mixing ratio of at least 12%, the temperature generated at the time of the disproportionation reaction of HFO-1123 decreases abruptly with increasing mixing ratio. Therefore, it is confirmed that the effect of suppressing the disproportionation reaction of HFO-1123 is high when the mixing ratio of propane with HFO-1123 is not less than 15%.

[0033] In contrast, when difluoromethane (R32) is mixed with HFO-1123, the temperature generated during the disproportionation reaction of HFO-1123 decreases only slightly despite increasing the mixing ratio of difluoromethane. Therefore, to achieve the effect of suppressing the disproportionation reaction by mixing difluoromethane (R32) with HFO-1123, the mixing ratio of difluoromethane should be increased. However, increasing the mixing ratio of difluoromethane leads to an increase in the GWF of the refrigerant, and the refrigeration cycle device, including the refrigeration cycle in which this refrigerant is enclosed, also reduces the cycle performance.

[0034] As described above, propane (R290) in a smaller amount than difluoromethane (R32) can achieve the effect of suppressing the disproportionation reaction of HFO-1123. Therefore, a refrigerant containing R290 to suppress the disproportionation reaction of HFO-1123 can maintain the excellent performance of HFO-1123 and have a low GWF, and the refrigeration cycle device including the refrigeration cycle in which such a refrigerant is included has satisfactory cycle performance.

[0035] A function of propane (290) at the time of the occurrence of the disproportionation reaction can be explained by a change in the nature of the chemical reaction. HFO-1123 is known to cause a disproportionation reaction, which is shown in formula (A) below. CF2=CHF→1.5C+0.5CF4+HF+250 kJ / mol

[0036] In a range of the mixing ratio of R290 not higher than approximately 12% (a range defined by (1) in Fig. 3), where the effect of suppressing the temperature generated at the time of the disproportionation reaction is small, the chemical reaction shown in formula (B) below is dominant. C3H8+2CF4=8HF+5C[gr]+212 kJ / mol

[0037] In the chemical reaction shown in formula (B), the heat of reaction is large and the propagation of a new reaction tends to be induced, so the effect of suppressing the disproportionation reaction of HFO-1123 is small.

[0038] In a range of the mixing ratio of R290 that exceeds approximately 12% (a section corresponding to (2) in Fig. 3), where the effect of suppressing the temperature generated at the time of disproportionation reaction is large, the chemical reaction shown in a formula (C) below is dominant. C3H8=2CH4+C[gr]+45 kJ / mol

[0039] In the chemical reaction shown in formula (C), the heat of reaction is small and the energy for generating a new reaction continuation is low, so the effect of suppressing the disproportionation reaction of HFO-1123 is large.

[0040] Which of the chemical reactions represented by formula (B) and formula (C) dominates is estimated to be influenced by the ratio between hydrogen (H) and fluorine (F) in the refrigerant. It is assumed that in the present embodiment, the H / F ratio in the refrigerant exceeds 1, and therefore, the dominant chemical reaction tends to change from formula (B) to the above formula (C), the temperature generated at the time of the disproportionation reaction is lowered, and the effect of suppressing the propagation of the disproportionation reaction is enhanced.

[0041] For a better understanding of the present disclosure, the basic refrigerant characteristics (temperature gradient, saturated gas density and theoretical COP) of a refrigerant formed from HFO-1123 and propane (R290) are described using the Fig. 4 to 6. Conditions for the Fig. The basic refrigerant characteristics shown in Figures 4 to 6 are a condensing temperature of 45°C, an evaporating temperature of 10°C, a degree of subcooling at the condenser outlet of 5 K and a degree of superheating at the evaporator outlet of 0 K.

[0042] Fig. Figure 4 shows a graph showing the relationship between the mixing ratio of HFO-1123 and propane (R290) and a temperature gradient. In the graph, the "R290 content [%]" on the abscissa represents the R290 content in the refrigerant, where the refrigerant as a whole, formed from HFO-1123 and propane (R290), is defined as 100 mass percent. In the graph, a "temperature gradient temperature [K]" on the ordinate represents a temperature gradient temperature [K] of the refrigerant containing R290 at the content indicated on the abscissa.

[0043] As from Fig. As shown in Figure 4, the temperature gradient is highest when the R290 content in the refrigerant is 50%. In other words, the closer the R290 content in the refrigerant is to 50%, the more likely a temperature difference in the heat exchanger (condenser and evaporator) and heat exchange loss are.

[0044] Fig. Figure 5 shows a graph showing the relationship between the mixing ratio of HFO-1123 and propane (R290) and the saturated gas density. In the graph, the "R290 content [%]" on the abscissa represents the R290 content in the refrigerant, where the refrigerant as a whole, formed from HFO-1123 and propane (R290), is defined as 100 mass percent. In the graph, the "saturated gas density ratio [%]" on the ordinate represents a percentage of the saturated gas density in the refrigerant containing R290 at the content indicated on the abscissa, where the saturated gas density in the refrigerant containing R290 at a content of 0%, that is, containing HFO-1123 at a content of 100 mass percent, is defined as 100%.

[0045] R290 is a lower pressure refrigerant than HFO-1123. The higher the R290 content in the refrigerant, the lower the density of the saturated gas, as in Fig. 5 shown.

[0046] Fig. Figure 6 shows a graph showing the relationship between the mixing ratio of HFO-1123 and propane (R290) and the theoretical COP. In the graph, the "R290 content [%]" on the abscissa represents the R290 content in the refrigerant, where the refrigerant as a whole, formed from HFO-1123 and propane (R290), is defined as 100 mass percent. In the graph, the "theoretical COP ratio [%]" on the ordinate represents a percentage of the theoretical COP of the refrigerant containing R290 at the content indicated on the abscissa, where the theoretical COP of the refrigerant containing R290 at a content of 0%, that is, HFO-1123 with a content of 100 mass percent, is defined as 100%.The theoretical COP is a ratio (= ΔH / ΔL) of ΔH, which represents a specific enthalpy difference between an inlet side and an outlet side of the evaporator, to ΔL, which represents a specific enthalpy difference between a suction side and an outlet side of the compressor, which ratio can be read off in a Mollier diagram of the refrigerant.

[0047] R290 has a higher theoretical COP than HFO-1123. The higher the R290 content in the refrigerant, the higher the theoretical COP, as shown in Fig. 6 shown.

[0048] Based on the above-mentioned basic refrigerant properties, the performance characteristics (pressure drop, compressor displacement, and COP) during actual operation of the refrigeration cycle device, including the refrigeration cycle in which the refrigerant composed of HFO-1123 and propane (R290) is enclosed, were investigated. The device and cooling capacity of the refrigeration cycle device were adjusted to be identical to the device and cooling capacity inside the refrigeration cycle device, including the refrigeration cycle incorporating refrigerant composed of HFO-1123 (refrigerant containing HFO-1123 at a content of 100 mass percent). The results are described below.

[0049] Fig. Figure 7 shows a graph showing the relationship between the mixing ratio of HFO-1123 and propane (R290) and the pressure loss. In the graph, the "R290 content [%]" on the abscissa represents the R290 content in the refrigerant, where the refrigerant as a whole, formed from HFO-1123 and propane (R290), is defined as 100 mass percent. In the graph, the "Pressure Loss Ratio [%]" on the ordinate represents the percentage pressure loss of the refrigerant containing R290 at the content indicated on the abscissa, where the pressure loss of the refrigerant containing HFO-1123 at a content of 100 mass percent is defined as 100%.

[0050] The higher the R290 content in the refrigerant, the lower the density of the saturated gas (see Fig. 5). With decreasing density of the saturated gas, the flow velocity of the refrigerant increases. On the other hand, the higher the content of R290 in the refrigerant, the higher the amount of latent heat. With increasing amount of latent heat, the flow velocity of the refrigerant decreases. Since the influence of increasing the amount of latent heat on reducing the flow velocity is greater than the influence of decreasing the density of the saturated gas on increasing the flow velocity, the flow velocity consequently decreases. By reducing the flow velocity, the pressure loss is lower. Therefore, the higher the content of R290 in the refrigerant, the lower the pressure loss, as shown in Fig. 7 shown.

[0051] Fig. Figure 8 shows a graph showing the relationship between the mixing ratio of HFO-1123 and propane (R290) and the displacement volume of the compressor. In the graph, the "R290 content [%]" on the abscissa represents the content of R290 in the refrigerant, where the refrigerant as a whole formed from HFO-1123 and propane (R290) is defined as 100 mass percent. In the graph, a "displacement volume ratio [%]" on the ordinate represents a percentage of the displacement volume of the compressor when R290-containing refrigerant with the content indicated on the abscissa is used, where the displacement volume of the compressor at the time when R290-containing refrigerant with a content of 0%, that is, containing HFO-1123 with a content of 100 mass percent, is defined as 100%.

[0052] The higher the R290 content in the refrigerant, the lower the density of the saturated gas (see Fig. 5). The higher the R290 content, the larger the displacement volume of the compressor, as in Fig. 8, the mechanism of which is described below.

[0053] The nominal cooling capacity Q [W] of the refrigeration cycle device is calculated using the following expression (I): Q=Gr⋅ΔH where Gr is a quantity of circulating refrigerant [kg / s] and ΔH is the specific enthalpy difference (latent heat) [kJ / kg] between the outlet side and the inlet side of the evaporator.

[0054] Gr is calculated in an expression (II) below: Gr=Vst⋅ηv⋅f⋅ρs where Vst is the displacement [cc] of the compressor, ηv is the volumetric efficiency [-], f is the frequency [1 / f] of the compressor and ρs is the suction density [kg / m 3 ] of the compressor.

[0055] The displacement of the compressor is defined as Vst•f. Based on the above expressions (I) and (II), the displacement is expressed in one of the following expressions (III). Vst⋅f=Q / (ΔH⋅ηv⋅ρs)

[0056] The higher the proportion of R290, the larger ΔH. However, the influence of the reduction in ρs is greater, and consequently the properties are such that the displacement volume is larger.

[0057] Fig. 9 shows a graph showing the relationship between the mixing ratio of HFO-1123 and propane (R290) and the COP. In the graph, the "R290 content [%]" on the abscissa represents the content of R290 in the refrigerant, where the refrigerant as a whole formed from HFO-1123 and propane (R290) is defined as 100 mass percent. In the graph, a "COP ratio [%]" on the ordinate represents a percentage of the COP of the refrigeration cycle device using a refrigerant containing R290 with the content indicated on the abscissa, where the COP of the refrigeration cycle device using a refrigerant containing R290 with a content of 0%, that is, containing HFO-1123 with a content of 100 mass percent, is defined as 100%.

[0058] When the content of R290 in the refrigerant is 50%, the temperature gradient is the largest and the heat exchange loss is also large (see Fig. 4). The higher the R290 content in the refrigerant, the greater the pressure loss (see Fig. 7). The higher the content of R290 in the refrigerant, the higher the theoretical COP (see Fig. 6). As can be seen from Fig. As can be seen from Figure 9, the percentage COP has an initial peak when the R290 content in the refrigerant is between 15 and 30%, then decreases, gradually increases when the R290 content exceeds approximately 50% and then reaches its maximum when the R290 content is 100%.

[0059] From the above performance characteristics, it is confirmed that the refrigeration cycle device including the refrigeration cycle in which the refrigerant having a content C1, based on the mass of HFO-1123 (1,1,2-trifluoroethylene), of not less than 70 mass% and not more than 85 mass% and a content C2, based on the mass of R290 (propane), of not less than 15 mass% and not more than 30 mass% is enclosed, has a high COP and a small displacement volume of the compressor.

[0060] If the mixing ratio of propane with HFO-1123 is equal to or higher than 15%, as in Fig. As shown in Figure 3, the effect of suppressing the disproportionation reaction of HFO-1123 is high. In a refrigerant in which the C1 content, based on the mass of HFO-1123 (1,1,2-trifluoroethylene), is not less than 70 mass% and not more than 85 mass%, and the C2 content, based on the mass of R290 (propane), is not less than 15 mass% and not more than 30 mass%, the mixing ratio of propane to HFO-1123 is equal to or higher than 15%. Therefore, the refrigeration cycle device with the refrigeration cycle incorporating this refrigerant achieves the high effect of suppressing the disproportionation reaction of HFO-1123.

[0061] In the present embodiment, the refrigerant is preferably formed from 1,1,2-trifluoroethylene and propane. As long as the refrigerant exhibits the effect described in the present disclosure, it may contain an impurity in addition to 1,1,2-trifluoroethylene and propane. In other words, in the present embodiment, the refrigerant may be formed from 1,1,2-trifluoroethylene, propane, and the impurity.

[0062] If the refrigerant is formed from 1,1,2-trifluoroethylene and propane, the content C1, based on the mass of 1,1,2-trifluoroethylene in the refrigerant, and the content C2, based on the mass of propane in the refrigerant, can be adjusted, for example, to (a1) to (a3) ​​below: (a1) the content C1 of 1,1,2-trifluoroethylene is not less than 70 mass percent and not more than 85 mass percent and the content C2 of propane is not less than 15 mass percent and not more than 30 mass percent; (a2) the content C1 of 1,1,2-trifluoroethylene is not less than 75% by mass and not more than 83% by mass and the content C2 of propane is not less than 17% by mass and not more than 25% by mass; and (a3) the content C1 of 1,1,2-trifluoroethylene is not less than 78% by mass and not more than 82% by mass and the content C2 of propane is not less than 18% by mass and not more than 22% by mass. < <kompressor>>

[0063] The compressor of the refrigeration cycle device according to the first embodiment will be described. In the present embodiment, any compressor can be used as compressor 1, as long as it is a high-pressure shell type in which the interior of a container is in an atmosphere with a discharge pressure (that is, in a high-pressure state as high as 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.

[0064] Fig. Figure 2 is a cross-sectional view of the compressor 1 according to the first embodiment. The compressor 1 includes a gas-tight container 20, a compression element 30, a motor element 40, and a shaft 50.

[0065] Compression element 30 and motorization element 40 are housed in a gas-tight manner in the gas-tight container 20. Attached to the gas-tight container 20 are a suction line 21 for sucking in the refrigerant and a pressure line 22 for discharging the refrigerant.

[0066] The gas-tight container 20 has a two-part structure with an upper container 20a and a lower container 20b, which are gas-tightly connected to each other by a method such as arc welding. The gas-tight container can withstand a pressure of 20 MPa (G) or more. Even if a chain disproportionation reaction occurs and the pressure inside the gas-tight container increases, the gas-tight container can maintain pressure safety to a certain extent without bursting.

[0067] The compression element 30 is housed in the gas-tight container 20. Specifically, the compression element 30 is provided in a lower region inside the gas-tight container 20. The compression element 30 compresses the refrigerant drawn in through the suction line 21. The position of the compression element 30 does not necessarily have to be in the lower part; in scroll compressors, in particular, the compression element is often located in the upper part.

[0068] The motor element 40 is housed in the gas-tight container 20. The motor element 40 is provided in the lower or upper part of the gas-tight container 20, with the position varying depending on the shape or the like of the compressor. The refrigerant compressed by the compression element 30 flows through a flow channel around the motor element and is then discharged from the outlet pipe 22. The motor element 40 drives the compression element 30. The motor element 40 is a brushless concentrated-winding (DC) motor.

[0069] Compressor 1 is filled with compressor oil. Specifically, a lower portion of the gas-tight container 20 is filled with compressor oil 25 to lubricate a sliding portion of the compression element 30. This compressor oil is refrigerant-soluble. Details of the compressor oil will be described later.

[0070] Details of the compression element 30 will be described later. The compression element 30 includes a cylinder 31, a rolling piston 32, a vane (not shown), a main bearing 33, and a sub-bearing 34.

[0071] The outer circumference of cylinder 31 is substantially circular in plan view. A cylinder chamber is provided in cylinder 31, which represents a substantially circular space in plan view. The cylinder 31 has opposite, axially open ends.

[0072] The cylinder 31 is provided with a vane groove (not shown) that communicates with the cylinder space and extends in the radial direction. A backpressure chamber is provided on the outside of the vane groove, which, in plan view, is a substantially circular space that communicates with the vane groove.

[0073] The rolling piston 32 is ring-shaped. The rolling piston 32 performs an eccentric movement within the cylinder chamber. The rolling piston 32 is slidably mounted on an eccentric shaft portion 51 of the shaft 50.

[0074] The vane has the shape of a substantially flat parallelepiped. The vane is arranged in the vane groove of the cylinder 31. The vane is constantly pressed against the rolling piston 32 by a vane spring provided in a rear part. Since the interior of the gas-tight container 20 is under high pressure, when the compressor 1 starts, a force generated by the difference between the pressure inside the gas-tight container 20 and the pressure inside the cylinder chamber is exerted on the rear side of the vane. Therefore, the vane spring is mainly used to press the vane against the rolling piston 32 when the compressor 1 starts (when there is no pressure difference between the interior of the gas-tight container 20 and the interior of the cylinder chamber).

[0075] The main bearing 33 has, in a side view, essentially the shape of an inverted T. The main bearing 33 is slidably mounted on the main shaft portion 52, which is located above the eccentric shaft portion 51 of the shaft 50. The main bearing 33 closes the cylinder space in the cylinder 31 and a top surface of the vane groove.

[0076] The auxiliary bearing 34 has a substantially T-shaped shape in side view. The auxiliary bearing 34 is slidably mounted on a secondary shaft portion 53 located below the eccentric shaft portion 51 of the shaft 50. The auxiliary bearing 34 closes the cylinder chamber in the cylinder 31 and a bottom side of the vane groove.

[0077] The main bearing 33 includes a discharge valve (not shown). A discharge muffler 35 is attached to the outside of the main bearing 33. The high-temperature and high-pressure refrigerant gas discharged through the discharge valve enters the discharge muffler 35 once and is then discharged from the discharge muffler 35 into the space of the gas-tight container 20. The discharge valve and discharge muffler 35 may be disposed in the sub-bearing 34 or in both the main bearing 33 and the sub-bearing 34.

[0078] The exhaust muffler 35 is provided with one or more exhaust holes (not shown), each having a diameter of no more than 10 mm, to guide the exhaust gas into the gas-tight container 20. When a disproportionation reaction occurs inside the cylinder 31 due to seizure or the like of a sliding component, the reaction should propagate into the gas-tight container through a narrow flow channel such as an exhaust port or the exhaust hole. At this time, the reaction heat is transferred to the peripheral components, thereby lowering the temperature and suppressing the disproportionation reaction.

[0079] The material for the cylinder 31, the main bearing 33, and the secondary bearing 34 is gray cast iron, sintered steel, carbon steel, or similar. A material for the rolling piston 32 is, for example, alloyed, chromium-containing steel or similar. A material for the shaft 50 is, for example, spheroidal graphite cast iron. A material for the blade is, for example, high-speed steel.

[0080] The cylinder 31, the main bearing 33, the sub-bearing 34, the rolling piston 32, the shaft 50, and the blade described above are sliding components, and the combination of their materials, along with a function of the compressor oil, is designed to prevent seizure when sliding against each other. The likelihood of a temperature so high that a disproportionation reaction occurs is thus reduced.

[0081] Adjacent to the gas-tight vessel 20 is an intake silencer 23. The intake silencer 23 draws in low-pressure gaseous refrigerant from the refrigeration cycle 5. The intake silencer 23 prevents liquid refrigerant from directly entering the cylinder chamber of the cylinder 31 when liquid refrigerant flows back. The intake silencer 23 is connected to an intake port of the cylinder 31, with an intake line 21 interposed therebetween. A main body of the intake silencer 23 is attached to a side surface of the gas-tight vessel 20 by welding or the like.

[0082] Details of the motorizing element 40 will be described later. In the present embodiment, both a concentrated-winding brushless DC motor and a motor other than the concentrated-winding brushless DC motor (e.g., a distributed-winding motor or an induction motor) can be used as the motorizing element 40.

[0083] The motorizing element 40 includes a stator 41 and a rotor 42. The stator 41 is fixed to contact an inner peripheral surface of the gas-tight container 20. The rotor 42 is mounted on the inside of the stator 41, with an air gap of approximately 0.3 to 1 mm therebetween. The leaking refrigerant can flow through this air gap. Because the air gap is narrow, even if a disproportionation reaction occurs, the heat generated by the disproportionation reaction is lost to the stator or the rotor while the refrigerant flows through this gap. Therefore, the propagation of the disproportionation reaction to areas above and below the motorizing element can be suppressed.

[0084] The stator 41 includes a stator iron core 43 and a stator winding 44. The stator iron core 43 is manufactured by punching a plurality of electromagnetic steel plates each having a thickness of 0.1 to 1.5 mm in a prescribed shape, stacking them in the axial direction, and fixing them together by swaging, welding, or the like.

[0085] The stator winding 44 is wound around the stator iron core 43 by concentrated winding with an insulating member 48 interposed therebetween. The winding wound by concentrated winding does not need to span a slot (not shown) in the stator as in the distributed winding, and therefore, no protrusion (coil end) of an electric wire is provided for the electric wire to reach another slot above and below the stator. Thus, even if the insulation fails, sparking or melting due to conduction between electric wires with different phases can be prevented, which can cause the initiation of a disproportionation reaction and the resulting generation of a high temperature.

[0086] Examples of materials for the insulating element 48 include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), liquid crystal polymer (LCP), polyphenylene sulfide (PPS), and phenolic resin. A lead 45 is connected to the stator winding 44.

[0087] The insulation provided by the insulating element is not compromised by the fact that it melts at least at a temperature (e.g., 150°C) at which a disproportionation reaction can begin. Therefore, even if the pressure and temperature reach a disproportionation reaction limit, sparks or fusions due to conduction between electrical wires of different phases, which could cause the initiation of a reaction and the resulting generation of a high temperature, can be prevented.

[0088] A plurality of elongated grooves are circumferentially arranged at substantially equal intervals around the outer periphery of the stator iron core 43. Each groove serves as one of the passages for the gaseous refrigerant exiting the outlet muffler 35 into the space of the gas-tight container 20. Each groove also serves as a passage for the compressor oil flowing back from the area above the motorizing element 40 to the lower area of ​​the gas-tight container 20.

[0089] The areas above and below the motor element 40 are connected to each other by the grooves. Since the groove has an elongated shape, the circumferential length is large relative to the area of ​​the groove. Even if a disproportionation reaction occurs, the stator iron core 43 or the lower gas-tight container 20b dissipates the reaction heat, and the spread of the disproportionation reaction to the areas above and below the motor element 40 can be suppressed.

[0090] The rotor 42 includes a rotor iron core 46 and a permanent magnet (not shown). The rotor iron core 46 is manufactured by stamping a plurality of electromagnetic steel plates, each 0.1 to 1.5 mm thick, into a prescribed shape, stacking them in the axial direction, and securing them together by swaging, welding, or the like, similar to the stator iron core 43. The permanent magnet is inserted into a plurality of insertion holes in the rotor iron core 46. A ferrite magnet or a rare earth magnet, for example, is used as the permanent magnet.

[0091] The rotor iron core 46 is provided with a through-hole whose diameter is no larger than 1 / 5 of the axial length of the rotor 42 and which extends substantially axially through the rotor iron core. Each through-hole serves as one of the passages for the gaseous refrigerant escaping from the outlet damper 35 into the space of the gas-tight container 20, similar to the groove in the stator iron core 43.

[0092] The regions above and below the motor element 40 are also connected to each other through the through-hole. The through-hole is sufficiently smaller than the axial length of the rotor 42. Even if a disproportionation reaction occurs, the rotor iron core 46 dissipates the reaction heat, and the spread of the disproportionation reaction to the regions above and below the motor element 40 can be suppressed.

[0093] A power supply connector 24 (e.g., a glass connector) connected to an external power supply is attached to an upper end portion of the gas-tight container 20. The power supply connector 24 is fixed to the gas-tight container 20, e.g., by welding. The line 45 from the motorization element 40 is connected to the power supply connector 24.

[0094] An outlet pipe 22 with opposite axially open ends is attached to the upper end of the gas-tight container 20. The gaseous refrigerant escaping from the compression element 30 is discharged from the space of the gas-tight container 20 through the outlet pipe 22 into the refrigeration circuit 5.

[0095] The operation of compressor 1 is described. Electrical energy is transmitted from power supply connection 24 via line 45 to stator 41 of motor element 40. Rotor 42 of motor element 40 thus rotates. As rotor 42 rotates, shaft 50 attached to rotor 42 rotates. As shaft 50 rotates, rolling piston 32 of compression element 30 rotates eccentrically within the cylinder chamber of cylinder 31 of compression element 30. The space between cylinder 31 and rolling piston 32 is divided into two spaces by the vane of compression element 30. As shaft 50 rotates, the volume of the two spaces changes. In one space, the volume gradually increases, so that refrigerant is drawn in from intake silencer 23. In the other space, the volume gradually decreases, so that the gaseous refrigerant contained therein is compressed.The compressed refrigerant is once discharged from the outlet muffler 35 into the space of the gas-tight container 20. The discharged gaseous refrigerant passes through the motorizing element 40 and is discharged to the outside from the outlet pipe 22 at the upper end part of the gas-tight container 20. <<Hubvolumen Vst des Kompressors> >

[0096] In the present embodiment, the displacement Vst [cc] of the compressor, the rated cooling capacity Q [W] of the refrigeration cycle device including the refrigeration cycle in the present embodiment, and f [1 / s] of the compressor are preferably related to the following expression (1). Q / f⋅0.168 <Vst<Q / f⋅0,189

[0097] The refrigeration cycle device satisfying the relationship in expression (1) can achieve the suppression of the disproportionation reaction, the large COP in actual operation and the small displacement volume of the compressor.

[0098] Expression (1) is derived from expression (I) and an expression (II) in a subsequent process. Expression (I) and expression (II) are subsequently converted into an expression (IV): Vst=Q / (ΔH⋅ηv⋅f⋅ρs) where ΔH and ρs can be calculated based on the conditions of condensation temperature of 45°C, evaporation temperature of 10°C, subcooling degree of the condenser outlet of 5 K and superheating degree of the evaporator outlet of 0 K of HFO-1123. ΔH is set to 111.5 [kJ / kg] and ρs to 66 [kg / m 3 ] set.

[0099] Starting from Fig. 8, the displacement volume of the compressor for a refrigerant consisting of 1,1,2-trifluoroethylene and propane, when the content of C2, based on the mass of propane, is not less than 15% by mass and 30% by mass, is not less than 111% and not more than 125%.

[0100] When ηv is set to 0.9, 1.11•Vst is defined as the lower limit value and 1.25•Vst as the upper limit value in expression (IV), the following expression (1) is derived, which expresses the relationship between the displacement Vst [cc] of the compressor, the rated cooling capacity Q [W] of the refrigeration cycle device including the refrigeration cycle in the present embodiment, and the frequency f [1 / s] of the compressor. Q / f⋅0.168 <Vst<Q / f⋅0,189 <<Kompressoröl> >

[0101] In the present embodiment, the compressor is filled with compressor oil. Both propane-compatible and propane-incompatible compressor oils can be used as compressor oil. "Propane-compatible compressor oil" means the presence of a temperature at which propane and compressor oil do not separate into two layers. "Propane-incompatible compressor oil" means that there is no temperature at which propane and compressor oil are incompatible with each other.

[0102] In an example where propane-compatible compressor oil is used as the compressor oil, the solubility of propane in the compressor oil is preferably higher than the solubility of HFO-1123 in the compressor oil. For example, the solubility of propane in the compressor oil being higher than the solubility of HFO-1123 in the compressor oil means that the solubility of propane in the compressor oil is higher than the solubility of HFO-1123 in the compressor oil at any temperature within a range where a degree of superheat of the compressor oil is not lower than 10 K and not higher than 60 K. The effect of suppressing the disproportionation reaction of HFO-1123 is thus further enhanced. In addition, an effect of suppressing the flammability of the refrigerant can be achieved, the mechanism of which will be described below.

[0103] Fig. Figure 10 shows a graph showing the relationship between the degree of superheat of the compressor oil (polyvinyl ether oil or PVE oil) and the amount of HFO-1123 and propane (R290) dissolved in the compressor oil. In the graph, the abscissa represents the degree of superheat [K] of the compressor oil, and the ordinate represents the amount of refrigerant dissolved in the compressor oil, i.e., the amount of HFO-1123 and propane (R290) dissolved in the compressor oil at each degree of superheat.

[0104] As can be seen from the diagram in Fig. As can be seen from Figure 10, at any superheat level within a range where the superheat level of the compressor oil is approximately not lower than 5 K and not higher than 60 K, the amount of R290 solution in the compressor oil is greater than the amount of HFO-1123 solution in the compressor oil. In other words, at any superheat level within the range where the superheat level of the compressor oil is approximately not lower than 5 K and not higher than 60 K, the solubility in the compressor oil is higher than the solubility in the compressor oil. Regarding the refrigerant as a whole, the diagram in Fig. 10, that the amount of refrigerant solution in the compressor oil is larger when the degree of superheat of the compressor oil is lower, and that the amount of refrigerant solution in the compressor oil decreases when the degree of superheat of the compressor oil increases.

[0105] During operation of the refrigeration cycle device, the degree of superheat of the gas discharged from the compressor 12 is controlled so that it does not become abnormally high (so that the temperature of the discharged gas is within a certain range). Therefore, the degree of superheat of the compressor oil (which is slightly lower than the superheat of the discharge gas) is also controlled so that it is within a certain range. Under general operating conditions, the degree of superheat of the compressor oil is approximately 10 K to 30 K. As shown in the diagram in Fig. For example, as shown in Figure 10, at a compressor oil superheat level of 20 K, which represents the general operating conditions, the amount of R290 solution in the compressor oil is greater than the amount of HFO-1123 solution, and a large amount of R290 is present in the compressor oil. Therefore, the ratio of R290 in the refrigerant circulating through the refrigeration cycle 5 is lower than the ratio of R290 in the refrigerant at the time of confinement.

[0106] R290 is flammable. Therefore, if the refrigerant contains R290, it tends to be more flammable. By using compressor oil, whose solubility of R290 is higher than that of HFO-1123, the proportion or ratio of R290 in the refrigerant circulating through the refrigeration cycle 5 is low during operation of the refrigeration cycle device. This reduces the flammability of the circulating refrigerant. Even if refrigerant leaks from the refrigeration cycle device 10, effects such as a reduced likelihood of burns and improved safety can be achieved.

[0107] Since the temperature of the discharged gas is controlled to remain within a certain range under general operating conditions, there is no possibility of disproportionation reaction occurring under these conditions. Therefore, lowering the R290 ratio with the high effect of suppressing the disproportionation reaction in the refrigerant is not a problem under general operating conditions.

[0108] On the other hand, when a high-temperature and high-pressure condition is set, in which the operating conditions may become abnormal and a disproportionation reaction may occur, the degree of superheat of the discharged gas increases sharply, and the degree of superheat of the compressor oil also increases sharply. As can be seen from the diagram in Fig. 10, the solubility of HFO-1123 and R290 in compressor oil at a superheat degree of 50 K is generally lower than the solubility in compressor oil at a superheat degree of 20 K. In addition, the difference between the solubility of HFO-1123 and the solubility of R290 at a superheat degree of 50 K is also smaller than that at a superheat degree of 20 K. Therefore, at a superheat degree of the compressor oil of 50 K, the composition of the refrigerant circulating through the refrigeration cycle 5 is close to the composition at the time of sealing, and the effect of suppressing the disproportionation reaction by R290 can be sufficiently achieved.

[0109] For example, as stated above, in the range of superheat degree of compressor oil which is not lower than 10 K and not higher than 60 K, the solubility of propane in compressor oil is higher than the solubility of HFO-1123 in compressor oil, so that the effect of suppressing flammability and the effect of suppressing the occurrence and propagation of disproportionation reaction can be achieved.

[0110] Propane-compatible compressor oil is preferably made from at least one oil from the group of polyol ester oils, polyvinyl ether oils, mineral oils, and alkylbenzene oils. Naphthene-based mineral oil and paraffin-based mineral oil can be used as the mineral oil. The solubility of propane in such a compressor oil is higher than the solubility of HFO-1123 in this oil.

[0111] The compressor oil can consist of one of the above-mentioned compressor oils. Alternatively, the compressor oil can consist of at least two of the above-mentioned compressor oils.

[0112] When propane-incompatible compressor oil is used as the compressor oil, the effect of suppressing the disproportionation reaction caused by propane can be achieved even during the operation of the refrigeration cycle device. Furthermore, the effect of suppressing the flammability of the refrigerant can be achieved, the mechanism of action of which is described below.

[0113] In an example where the refrigerant contains HFO-1123 and propane, the solubility of each component in the refrigerant varies. As the temperature and pressure conditions change during the operation of the refrigeration cycle device, the amount of dissolution of each component in the refrigerant also varies. Therefore, the composition of the refrigerant circulating through the refrigeration cycle also varies. As the refrigerant composition changes and the propane content in the refrigerant decreases, the effect of propane on suppressing the disproportionation reaction may also decrease. On the other hand, to increase the propane content in the refrigerant during the operation of the refrigeration cycle device, the propane content in the refrigerant may be increased at the time the refrigerant is included in the refrigeration cycle. However, propane is highly flammable, so the refrigerant burns more easily as the propane content increases.

[0114] If the compressor oil is incompatible with propane, the propane content in the refrigerant will not decrease even during the operation of the refrigeration cycle device, and the effect of suppressing the disproportionation reaction caused by propane can be achieved. Furthermore, since the propane content in the refrigerant does not need to be increased, the effect of suppressing the flammability of the refrigerant can be achieved.

[0115] The solubility of propane in compressor oil is preferably lower than the solubility of HFO-1123 in compressor oil. For example, the solubility of propane in compressor oil is lower than the solubility of HFO-1123 in compressor oil. For example, the solubility of propane in compressor oil is lower than the solubility of HFO-1123 in compressor oil at any temperature within a range where the superheat degree of the compressor oil is not lower than 10 K and not higher than 60 K. Thus, the propane content in the refrigerant during the operation of the refrigeration cycle device will not be lower than the propane content in the refrigerant at the time the refrigerant is sealed in the refrigeration cycle (before the start of operation of the refrigeration cycle device). Therefore, the effect of suppressing the disproportionation reaction by propane can be achieved even during the operation of the refrigeration cycle device.

[0116] Polyalkylene glycol oil (hereinafter referred to as PAG oil) is preferably used as a propane-incompatible compressor oil. HFO-1123 and propane are poorly soluble in PAG oil. Therefore, by using PEG oil as the compressor oil, the composition of the compressor oil is less likely to change, and the effect of suppressing the disproportionation reaction caused by propane can be achieved even during the operation of the refrigeration cycle device.

[0117] The solubility of propane in PAG oil is preferably lower than the solubility of HFO-1123 in PAG oil. Thus, the propane content in the refrigerant during operation of the refrigeration cycle device will not be lower than the propane content in the refrigerant at the time the refrigerant is sealed in the refrigeration cycle (before the start of operation of the refrigeration cycle device). Therefore, the effect of suppressing the disproportionation reaction by propane can be achieved even during operation of the refrigeration cycle device.

[0118] It is to be understood that the embodiments and examples disclosed herein are in all respects illustrative and not restrictive. The scope of the present disclosure is defined by the terms of the claims rather than by the above description and is intended to include all changes within the scope and meaning consistent with the terms of the claims. LIST OF REFERENCE SYMBOLS

[0119] 1 Compressor; 2 Condenser; 3 Expansion valve; 4 Evaporator; 5 Refrigeration circuit; 5a to 5d Refrigerant line; 6 Condenser fan; 7 Evaporator fan; 17 Control unit; 20 Gas-tight vessel; 20a Upper vessel; 20b Lower vessel; 21 Suction line; 22 Discharge line; 23 Suction muffler; 24 Power supply connection; 25 Compressor oil; 30 Compression element; 31 Cylinder; 32 Rolling piston; 33 Main bearing; 34 Subsidiary bearing; 35 Discharge muffler; 40 Motorizing element; 41 Stator; 42 Rotor; 43 Stator iron core; 44 Stator winding; 45 Line; 46 Rotor iron core; 48 Insulating element; 50 Shaft; 51 Eccentric shaft part; 52 Main shaft part; 53 Subsidiary shaft part; 100 refrigeration cycle device. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2012 / 157764

[0003] JP 2018-112396

[0027] < / kompressor>

Claims

[1] Refrigeration cycle, which includes: a compressor, where a refrigerant is enclosed in the refrigeration circuit, the refrigerant contains 1,1,2-trifluoroethylene and propane, the content C1, based on the mass of 1,1,2-trifluoroethylene in the refrigerant, is not less than 70 mass% and not more than 85 mass%, and the C2 content, based on the mass of propane in the refrigerant, is not less than 15 mass% and not more than 30 mass%. [2] Refrigeration circuit according to claim 1, wherein a relationship in the following expression (1) is satisfied, where Vst [cc] represents a displacement of the compressor, Q [W] represents the rated cooling capacity of a refrigeration cycle device including the refrigeration cycle, and f [1 / s] represents a frequency of the compressor Q / f⋅0.168 <Vst<Q / f⋅0,189 [3] Refrigeration cycle according to claim 1 or 2, wherein the refrigerant is formed from 1,1,2-trifluoroethylene and propane. [4] Refrigeration cycle according to one of claims 1 to 3, wherein a percentage (C2 / C1)×100 of C2 to C1 is at least 15% and less than 50%. [5] Refrigeration cycle device comprising the refrigeration cycle according to one of claims 1 to 4.

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