Refrigeration cycle device

Abstract

The present invention provides a refrigeration cycle device that comprises a refrigeration circuit including a compressor, a condenser, an expansion mechanism, and an evaporator, wherein: a refrigerant is sealed in the refrigeration circuit; the refrigerant includes HFO1123 and at least one selected from the group consisting of R32, R1234yf, and R1234ze(E); in an XY coordinate plane in which the mass ratio of HFO1123 is defined as an X-axis and the global warming potential of the refrigerant is defined as a Y-axis, when coordinates (0, 675) are defined as a point A, coordinates (100, 1) are defined as a point B, coordinates (10, 300) are defined as a point C, coordinates (40, 150) are defined as a point D, and coordinates (65, 10) are defined as a point E, measurement coordinates (X, Y) of the refrigerant exist within a first range that is surrounded by a first straight line connecting the point A and the point B, a second straight line connecting the point A and the point C, a third straight line connecting the point C and the point D, a fourth straight line connecting the point D and the point E, and a fifth straight line connecting the point E and the point B.

Description

Refrigeration cycle equipment

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

[0002] Currently, the refrigerant used in refrigeration cycle devices such as air conditioners and refrigerators is generally difluoromethane (also known as methylene fluoride, Freon 32, HFC-32, R32, etc.; hereinafter referred to as "R32"). The global warming potential (GWP) of R32 is 675. In recent years, due to F-gas regulations in Europe and other factors, there has been a demand for the use of refrigerants with lower GWP.

[0003] An example of such a refrigerant is 1,1,2-trifluoroethylene (hereinafter also referred to as "HFO1123") (GWP: 0.3). Another example of a refrigerant is R454C (GWP: 146). R454C is a refrigerant containing 21.5 mass% of R32 and 78.5 mass% of 2,3,3,3-tetrafluoropropene (hereinafter also referred to as "R1234yf") (GWP: 4). In this way, refrigerants with low GWP that can replace R32 have been developed (see Patent Documents 1 to 3).

[0004] On the other hand, although refrigerants with lower GWP than R32 have been developed, no refrigerant with better performance than R32 has been found at present. However, since it will be necessary to use refrigerants with even lower GWP in the near future, measures are urgently needed.

[0005] From the perspective of preventing global warming, an index called LCCP (Life Cycle Climate Performance: product life pore load) is known (see Non-Patent Document 1). LCCP is a comprehensive global warming impact index that takes into account both the impact of the refrigerant (direct impact) and the impact of power consumption (indirect impact), and is obtained as a numerical value that takes into account the direct and indirect impacts calculated using a predetermined formula. Examples of direct impacts include the refrigerant charge amount and GWP, while examples of indirect impacts include the annual power consumption and carbon dioxide emissions.

[0006] JP 2019-32108 A JP 2017-133827 A JP 2023-153834 A

[0007] Shigeharu Taira et al., ``LCCP Evaluation for Air-To-Air Heat Pumps Using Next -Generation Refrigerants'' The Japan Refrigeration and Air Conditioning Industry Association, 17,November,2023

[0008] However, no refrigerant has yet been investigated that has a lower GWP than R32 and is superior to R32 in terms of LCCP.

[0009] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a refrigeration cycle device that can suppress performance degradation while reducing the effects of global warming.

[0010] a refrigeration circuit including a compressor, a condenser, an expansion mechanism, and an evaporator, wherein a refrigerant is sealed in the refrigeration circuit, and the refrigerant includes HFO1123 and at least one selected from the group consisting of R32, R1234yf, and R1234ze(E); In an XY coordinate plane with the mass fraction of HFO1123 as the X axis and the global warming potential of the refrigerant as the Y axis, when point A is at coordinate (0,675), point B is at coordinate (100,1), point C is at coordinate (10,300), point D is at coordinate (40,150), and point E is at coordinate (65,10), the measurement coordinates (X, Y) of the refrigerant lie within a first range surrounded by a first line connecting point A and point B, a second line connecting point A and point C, a third line connecting point C and point D, a fourth line connecting point D and point E, and a fifth line connecting point E and point B.

[0011] According to the present disclosure, it is possible to provide a refrigeration cycle device that can suppress performance degradation while reducing the effects of global warming.

[0012] FIG. 1 is a schematic diagram showing an example of a refrigeration cycle apparatus according to Embodiments 1 to 3. FIG. 2 is a graph showing the relationship between the mass ratio of HFO1123 and the GWP of the refrigerant in Embodiment 1. FIG. 3 is a graph showing the relationship between the GWP of the refrigerant and performance required to achieve an LCCP equivalent to that of R32. FIG. 4 is a graph showing the relationship between the mass ratio of HFO1123 and the COP under intermediate heating conditions when the GWP of the refrigerant is 10 or greater but less than 150. FIG. 5 is a graph showing the relationship between the mass ratio of HFO1123 and the COP under intermediate heating conditions when the GWP of the refrigerant is 200 or greater but less than 300. FIG. 6 is a graph showing the relationship between the mass ratio of HFO1123 and the COP under intermediate heating conditions when the GWP of the refrigerant is less than 10. FIG. 7 is a graph showing the relationship between the mass ratio of HFO1123 and the GWP of the refrigerant in Embodiment 2. Fig. 8 is another graph showing the relationship between the mass ratio of HFO1123 and the GWP of the refrigerant in embodiment 2. Fig. 9 is a graph showing the relationship between the mass ratio of HFO1123 and the GWP of the refrigerant in embodiment 3. Fig. 10 is another graph showing the relationship between the mass ratio of HFO1123 and the GWP of the refrigerant in embodiment 3.

[0013] Hereinafter, embodiments of the present disclosure will be described.

[0014] Embodiment 1. An overview of the refrigeration circuit and refrigeration cycle device of this embodiment will be described. Figure 1 is a schematic diagram showing an example of a refrigeration cycle device according to embodiment 1. Note that Figure 1 functionally shows only the connections and arrangement of the main devices related to the present invention in the refrigeration cycle device 100, and does not necessarily show the configuration of all the devices or their physical spatial arrangement.

[0015] 1, a refrigeration cycle apparatus 100 includes a refrigerant circuit 10 including a compressor 1, a condenser 2, an expansion mechanism 3, and an evaporator 4. The compressor 1 and the condenser 2 are connected by a refrigerant pipe 10a, the condenser 2 and the expansion mechanism 3 are connected by a refrigerant pipe 10b, the expansion mechanism 3 and the evaporator 4 are connected by a refrigerant pipe 10c, and the evaporator 4 and the compressor 1 are connected by a refrigerant pipe 10d. A refrigerant is sealed in the refrigerant circuit 10. The refrigerant circulates through the compressor 1, the refrigerant pipe 10a, the condenser 2, the refrigerant pipe 10b, the expansion mechanism 3, the refrigerant pipe 10c, the evaporator 4, the refrigerant pipe 10d, and the compressor 1 in this order.

[0016] The compressor 1 draws in a refrigerant, compresses it, and discharges the refrigerant in a high-temperature, high-pressure gas state. The rotation speed of the compressor 1 is controlled by, for example, an inverter circuit. The amount of refrigerant discharged is adjusted by controlling the rotation speed.

[0017] The condenser 2 receives the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1. The condenser 2 exchanges heat between the refrigerant and a medium outside the refrigerant circuit 10, thereby cooling the refrigerant to a low-temperature, high-pressure liquid state. Examples of the medium include air, water, and brine. To promote heat exchange in the condenser 2, the condenser 2 may be equipped with a blower, a pump, or the like that can adjust the flow rate of the medium.

[0018] The low-temperature, high-pressure liquid refrigerant cooled by the condenser 2 flows into the expansion mechanism 3. The expansion mechanism 3 reduces the pressure of the refrigerant and expands it into a low-temperature, low-pressure two-phase state. The expansion mechanism 3 is composed of a refrigerant flow rate control means such as an electronic expansion valve, a temperature-sensing type, or a differential pressure type expansion mechanism, a capillary tube, or the like.

[0019] The evaporator 4 receives the low-temperature, low-pressure, two-phase refrigerant that has been decompressed and expanded by the expansion mechanism 3. The evaporator 4 exchanges heat between the refrigerant and a medium outside the refrigerant circuit 10, heating the refrigerant to a high-temperature, low-pressure gas state. Examples of the medium include air, water, and brine. To promote heat exchange in the evaporator 4, the evaporator 4 may be equipped with a blower, pump, or the like that can adjust the flow rate of the medium.

[0020] The compressor 1 draws in the refrigerant that has become a high-temperature, low-pressure gas in the evaporator 4 and compresses it again. As a result, the refrigerant circulates within the refrigeration cycle device 100, and transfers heat from the external medium from the evaporator 4 side to the condenser 2 side.

[0021] The refrigeration cycle apparatus 100 may include a control device 20. The control device 20 is, for example, a microcomputer. The control device 20 is connected to the compressor 1 and each actuator and sensor provided in the refrigeration cycle apparatus 100.

[0022] The control device 20 controls each actuator of the refrigeration cycle device 100 based on a preset control constant or a control constant learned based on feedback from each sensor. The control device 20 may also determine the type of refrigerant filled based on a set value that can be manually changed from the outside or feedback from each sensor, and change the control constant for each type of refrigerant filled.

[0023] Furthermore, the control device 20 controls the pressure and / or temperature of the refrigerant circulating through the refrigeration cycle apparatus 100 to such conditions that a disproportionation reaction of the refrigerant (HFO1123) does not occur or that a chain reaction of the disproportionation reaction can be suppressed. Details of the disproportionation reaction will be described later. For example, by controlling the refrigerant pressure in the flow path from the compressor 1 to the expansion mechanism 3 (i.e., the high-pressure side) so that it does not exceed a certain pressure, even if a disproportionation reaction occurs in a part of the refrigeration cycle apparatus 100, such as the compressor 1, the disproportionation reaction can be prevented from spreading.

[0024] The refrigeration cycle device 100 may be used, for example, for air conditioning and may be a device capable of both cooling and heating, a device capable of only cooling, or a device capable of only heating, and is applicable to various types of refrigeration cycle devices.

[0025] Examples of refrigeration cycle devices for air conditioning (air conditioners) include room air conditioners, window air conditioners, mobile air conditioners, package air conditioners, and multi-air conditioners for buildings.

[0026] <Refrigerant> Next, the refrigerant sealed in the refrigerant circuit in this embodiment will be described. The refrigerant in this embodiment includes HFO1123 and at least one selected from the group consisting of R32, R1234yf, and trans-1,3,3,3-tetrafluoropropene (hereinafter also referred to as "R1234ze(E)") (GWP:1). These refrigerants are non-toxic and slightly flammable refrigerants, and belong to the A2L safety classification of the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers).

[0027] Here, the reason for selecting the above refrigerants in this embodiment will be explained. Refrigerants investigated other than the above refrigerants are non-toxic and non-flammable refrigerants belonging to ASHRAE A1, including 1-chloro-1,3,3,3-tetrafluoropropene (hereinafter also referred to as "R1224yd(Z)") (GWP: 1), 1-chloro-3,3,3-tetrafluoropropene (hereinafter also referred to as "R1233zd(E)") (GWP: 1), and 1,1,1,4,4,4-hexafluoro-2-butene (hereinafter also referred to as "R1336mzz(Z)") (GWP: 2). Table 1 shows a comparison of the characteristics of the refrigerants belonging to A2L and A1. The calculation conditions for the various characteristics in Table 1 were a condensing temperature of 28°C, an evaporating temperature of 3°C, a degree of subcooling of 5°C, a degree of suction superheat of 3°C, and a compressor efficiency of 0.7.

[0028]

[0029] As can be seen from Table 1, HFO1123 has a lower theoretical COP (Coefficient of Performance) than other refrigerants, but the impact of pressure loss is significantly smaller. The theoretical COP is the COP when the condensation temperature, evaporation temperature, degree of subcooling, and degree of suction superheat are the same for each refrigerant, without taking into account the impact of pressure loss. It differs from the actual COP when actually used in a refrigeration cycle device. When the impact of refrigerant pressure loss is large, the evaporation temperature actually decreases and the condensation temperature increases, resulting in a decrease in the actual COP. Therefore, when HFO1123 is used as a refrigerant in a refrigeration cycle device, it is considered to have higher performance than other refrigerants.

[0030] On the other hand, HFO1123 is prone to disproportionation reactions. A disproportionation reaction is a chemical reaction in which two or more molecules react with each other and decompose into two or more different types of products. A disproportionation reaction starts when three conditions, namely temperature, pressure, and ignition energy, are met, and the reaction causes an increase in temperature and pressure, which may cause malfunctions in the refrigeration cycle device. Therefore, studies have been conducted to suppress the disproportionation reaction by imposing restrictions on the temperature, pressure, and ignition energy of the refrigeration cycle. Furthermore, the disproportionation reaction can also be suppressed by increasing the proportion of refrigerants that do not cause the disproportionation reaction. Therefore, in this embodiment, HFO1123 and another refrigerant are used in combination.

[0031] From Table 1, R32 has a theoretical COP, pressure loss effect, and Vst (compressor stroke volume) of 100%, and is therefore considered to have better performance than other refrigerants. However, because its GWP is 675, which is higher than other refrigerants, it is preferable to reduce the mass ratio of R32 in the refrigerant from the perspective of reducing the impact of global warming.

[0032] As shown in Table 1, R1234yf and R1234ze(E) have similar theoretical COP, pressure loss effect, and Vst. Furthermore, their pressure loss effect is significantly smaller than that of the refrigerants belonging to A1 in Table 1. Therefore, when used as a refrigerant in a refrigeration cycle device, they are considered to have better performance than the refrigerants belonging to A1.

[0033] As described above, the refrigerant sealed in the refrigerant circuit in this embodiment contains HFO1123 and at least one selected from the group consisting of R32, R1234yf, and R1234ze(E).

[0034] <Mass Ratio of HFO1123 and GWP of Refrigerant> In the refrigerant of this embodiment, the mass ratio of HFO1123 to at least one selected from the group consisting of R32, R1234yf, and R1234ze(E) is within a predetermined range. This makes it possible to reduce the impact of global warming while suppressing performance degradation. Here, the mass ratio of each refrigerant in the refrigerant refers to the mass ratio of each refrigerant in the refrigerant before operation of a refrigeration cycle device including the refrigeration circuit. The mass ratio of each refrigerant is considered to be the same as the mass ratio of each refrigerant in the refrigerant before it is sealed in the refrigeration circuit. In other words, the mass ratio of each refrigerant in a refrigerant cylinder filled with the refrigerant to be sealed in the refrigeration circuit is considered to be the same as the mass ratio of each refrigerant in the refrigeration circuit.

[0035] 2 is a graph showing the relationship between the mass fraction of HFO1123 and the GWP of the refrigerant in this embodiment. In an XY coordinate plane with the mass fraction of HFO1123 on the X axis and the GWP of the refrigerant on the Y axis, when point A is at coordinate (0,675), point B is at coordinate (100,1), point C is at coordinate (10,300), point D is at coordinate (40,150), and point E is at coordinate (65,10), the measurement coordinates (X,Y) of the refrigerant lie within a first range (the shaded area in FIG. 2 ) surrounded by a first line connecting points A and B, a second line connecting points A and C, a third line connecting points C and D, a fourth line connecting points D and E, and a fifth line connecting points E and B. The first line represents a refrigerant consisting of HFO1123 and R32. The first line indicates that the refrigerant of this embodiment contains the highest amount of high-performance R32, and therefore performance degradation is most suppressed.

[0036] Figure 3 is a graph showing the relationship between the GWP of a refrigerant and the performance required to achieve an LCCP equivalent to that of R32. The graph shown in Figure 3 was created by the inventors of the present disclosure based on the content of discussions held by the LCCP Evaluation and Study Working Group sponsored by the Japan Refrigeration and Air Conditioning Industry Association. Here, "performance" refers to the COP under intermediate heating conditions (hereinafter also referred to as "heating intermediate COP"). The heating intermediate COP was adopted because it is the condition that contributes most to the calculation of the APF (Annual Performance Factor: annual energy consumption efficiency), which is a method for evaluating energy efficiency in Japan.

[0037] Referring to Figure 3, the working group evaluated the LCCP of R32 in Japan (Tokyo) as 5034 (unit: kg-CO ２ ) (direct effect: 594, indirect effect: 4440). Here, for a refrigerant with a GWP of 0 (hereinafter referred to as "refrigerant A"), the direct effect of refrigerant A is 0, and therefore the LCCP evaluation result for refrigerant A is 4440. Comparing the LCCP evaluation results for both refrigerants, the LCCP of refrigerant A is 88.2% of the LCCP of R32. In other words, if the indirect effect is all annual power consumption, it is estimated that refrigerant A's performance is equivalent to that of R32 if it is 88.2% or higher.

[0038] From the above, for example, for a refrigerant with a GWP of 150, if the performance is 90.8% or higher, it is equivalent to the LCCP of R32, and for a refrigerant with a GWP of 300, if the performance is 93.4% or higher, it is equivalent to the LCCP of R32. Below, the relationship between the mass ratio of HFO1123 and the GWP of the refrigerant will be considered based on this performance. Note that refrigerants containing HFO1123 and at least one selected from the group consisting of R32 and R1234yf are considered below.

[0039] Fig. 4 is a graph showing the relationship between the mass ratio of HFO1123 and the heating intermediate COP when the GWP is equal to or greater than 10 and less than 150. Table 2 shows specific examples of refrigerants used in this embodiment and their characteristics. Fig. 4 and Table 2 mainly confirm performance when the GWP is around 150. The reason for confirming performance when the GWP is around 150 is that European F-gas regulations restrict the use of refrigerants with a GWP of 150 or more.

[0040] The heating intermediate COP was calculated assuming a cooling rated capacity of 4.0 kW. The dashed line in Fig. 4 is calculated by converting the GWP on the horizontal axis of the dashed line in Fig. 3 into the mass ratio of HFO1123. The same applies to Figs. 5 and 6 described below. In Table 2, "OK" means that the refrigerant is included in this embodiment, and "NG" means that the refrigerant is not included in this embodiment. The same applies to Tables 3 and 4 described below.

[0041] In Figure 4, the mass ratio of R32 is set to 21.5 mass% when the mass ratio of HFO1123 is up to 78.5 mass%. As mentioned above, R32 has the best performance among refrigerants used in refrigeration cycle devices, so it is preferable to increase the mass ratio of R32 in the refrigerant as much as possible. On the other hand, considering that the GWP is to be less than 150 and that the refrigerant will be used in combination with other refrigerants, the maximum mass ratio of R32 in the refrigerant is 21.5 mass%. Furthermore, when the mass ratio of HFO1123 is higher than 78.5 mass%, the refrigerant is considered to consist of HFO1123 and R32.

[0042]

[0043] From Figure 4, it can be seen that when the GWP is 10 or more but less than 150, the refrigerant of this embodiment exceeds the heating intermediate COP required to achieve the LCCP equivalent to that of R32 when the mass ratio of HFO1123 is approximately 40 mass% (point D in Figure 2). Furthermore, the heating intermediate COP is highest when the mass ratio of HFO1123 is 75 mass%, and it is believed that the refrigeration cycle device will exhibit the highest performance when the GWP is set to the above conditions. Furthermore, it is preferable that the mass ratio of HFO1123 be 65 mass% or more but 95 mass% or less, and that the difference between the heating intermediate COP and the performance equivalent to the LCCP of each refrigerant No. be 3% or more. On the other hand, as described above, when the mass ratio of HFO1123 is high, disproportionation reactions are likely to occur. Therefore, from the perspective of suppressing disproportionation reactions, it is preferable that the mass ratio of HFO1123 be 65 mass% or more but 80 mass% or less.

[0044] Fig. 5 is a graph showing the relationship between the mass ratio of HFO1123 and the heating intermediate COP when the GWP is equal to or greater than 200 but less than 300. Table 3 shows specific examples of refrigerants according to the present embodiment and their characteristics. Fig. 5 and Table 3 mainly confirm performance when the GWP is around 300. The reason for confirming performance when the GWP is around 300 is that refrigerants with compositions having a GWP of around 300 have been submitted to the ASHRAE in the United States.

[0045] In Figure 5, the mass ratio of R32 is set to 43 mass% when the mass ratio of HFO1123 is up to 57 mass%. This is because the maximum mass ratio of R32 in the refrigerant is 43 mass% when considering that the GWP is less than 300 and that it will be used in combination with other refrigerants. Furthermore, when the mass ratio of HFO1123 is higher than 57 mass%, the refrigerant is considered to consist of HFO1123 and R32.

[0046]

[0047] 5, when the GWP is 200 or more but less than 300, the refrigerant of this embodiment exceeds the heating intermediate COP required to achieve an LCCP equivalent to that of R32 when the mass ratio of HFO1123 is approximately 10 mass% (point C in FIG. 2). Furthermore, the heating intermediate COP is highest when the mass ratio of HFO1123 is 50 mass%, and it is believed that the refrigeration cycle device will exhibit the highest performance when the GWP is set to the above conditions. Furthermore, it is preferable that the difference between the heating intermediate COP of each refrigerant number and the performance equivalent to the LCCP of R32 be 3% or more when the mass ratio of HFO1123 is 40 mass% or more but less than 70 mass%.

[0048] Fig. 6 is a graph showing the relationship between the mass ratio of HFO1123 and the heating intermediate COP when the GWP is less than 10. Table 4 shows specific examples of refrigerants according to this embodiment and their characteristics. The reason for checking the performance when the GWP is less than 10 is that the impact on global warming is extremely reduced and the refrigerant is considered to be permanently usable.

[0049] In Fig. 6, the mass ratio of R32 is set to 0 mass % because R32, which has a GWP of 675, cannot be contained since the GWP would be less than 10.

[0050]

[0051] From Figure 6, it can be seen that when the GWP is less than 10, the refrigerant of this embodiment exceeds the heating intermediate COP, which is necessary to be equivalent to the LCCP of R32, from when the mass ratio of HFO1123 is approximately 65 mass % (point E in Figure 2).

[0052] The refrigerant in this embodiment may be composed of HFO1123 and at least one selected from the group consisting of R32, R1234yf, and R1234ze(E). The refrigerant in this embodiment may also contain other components. The blending ratios of the other components are set within a range that does not impair the main effects of this embodiment. For example, the total content of the above components in the refrigerant may be 90% by mass or more and 100% by mass or less.

[0053] The refrigerant in this embodiment may further contain a refrigerating machine oil. Examples of the refrigerating machine oil include commonly used refrigerating machine oils (ester-based lubricating oils, ether-based lubricating oils, fluorine-based lubricating oils, mineral-based lubricating oils, hydrocarbon-based lubricating oils, etc.). In this case, it is preferable to select a refrigerating machine oil that is excellent in terms of stability, etc.

[0054] The refrigerant in this embodiment may further contain a stabilizer as needed, for example, when a high level of stability is required under severe operating conditions. The stabilizer is a component that improves the refrigerant's stability against heat and oxidation. Examples of stabilizers include known stabilizers conventionally used in refrigeration cycle devices, such as oxidation resistance improvers, heat resistance improvers, and metal deactivators.

[0055] The refrigerant in this embodiment may further contain a polymerization inhibitor, such as hydroquinone, hydroquinone methyl ether, or benzotriazole.

[0056] <Disproportionation Reaction> As described above, as the mass ratio of HFO1123 in the refrigerant increases, the disproportionation reaction is more likely to occur. The disproportionation reaction can be suppressed, for example, by the following methods.

[0057] A compressor, which has electrical contacts with the refrigerant, is a device that is prone to disproportionation reactions in a refrigeration cycle system. Energy sources for the compressor include frictional heat in sliding parts, melting of windings, and discharge due to short circuits between windings.

[0058] According to A.4 of the "Report of the Study Group on the Self-Decomposition Reaction of HFO Refrigerants, March 2023, New Energy and Industrial Technology Development Organization," the energy generated varies greatly depending on the coil winding method of the induction motor (constant speed compressor), with a maximum of 100 mJ of energy confirmed for concentrated winding motors and a maximum of 40 J for distributed winding motors. It is also said that inverter compressors generate energy of around several hundred mJ.

[0059] Therefore, measures to prevent disproportionation reactions in compressors include using concentrated winding motors, using inverter compressors, etc. Also, by using a low-pressure shell-type compressor, the space where the motor is installed becomes a low-pressure section, and the pressure and temperature decrease, which is thought to suppress the disproportionation reactions.

[0060] According to "Development of methods to suppress the disproportionation reaction of HFO1123 and probabilistic analysis of the disproportionation reaction JETI Japan energy & technology intelligence 67(3):2019.3", even with pure HFO1123, if the ignition energy is 0.5 J, the probability of the disproportionation reaction occurring is 10 －７ It has been confirmed that it is %.

[0061] Furthermore, the propagation of the disproportionation reaction may cause malfunctions in the refrigeration cycle device. Therefore, if there is a factor that inhibits the propagation, it may be possible to take measures against the disproportionation reaction.

[0062] Factors that inhibit the disproportionation reaction include, for example, the flow of refrigerant molecules and structures. When refrigerant molecules are flowing, the heat generated by the disproportionation reaction disperses, making self-decomposition more difficult. Furthermore, when there is a structure around the refrigerant molecules, the energy (heat) is absorbed by the material of the structure, inhibiting self-decomposition.

[0063] From this perspective, we will consider possible measures for the compressor in the refrigeration cycle system. The flow of refrigerant molecules exists because the refrigerant circulates when the compressor is running. To speed up the flow of refrigerant molecules, we can narrow the flow path through which the high-temperature, high-pressure gas refrigerant passes and increase the flow velocity of the refrigerant molecules. Specific examples include reducing the shell diameter of the compressor and reducing the flow path through the compressor motor.

[0064] Furthermore, when it comes to structures, there are the aspects of heat capacity and gaps. If the heat capacity is large, the temperature rise is small when the same amount of energy is applied, so the structure is less likely to become hot, which serves as a countermeasure against disproportionation reactions. Therefore, a countermeasure is to increase the heat capacity of the compressor. Specifically, this can be done by increasing the size of the compressor or changing the components used in the compressor to ones with a larger heat capacity.

[0065] If the gap is small, the number of refrigerant molecules between the structures will decrease, which will help prevent disproportionation reactions.Specifically, this can be done by reducing the compressor shell diameter or the flow path through the compressor motor.

[0066] Disproportionation reactions can be addressed by increasing protective measures beyond the compressor. Disproportionation reactions begin when three conditions—temperature, pressure, and ignition energy—are met. Therefore, measures are taken to protect the refrigeration cycle equipment to prevent high temperatures and pressures. Specifically, for example, multiple temperature sensors are installed to protect the discharge temperature. If there is a temperature difference between the sensors or if the value is similar to that of the outside air temperature sensor, the sensor is deemed disconnected and the compressor is stopped. If there is a pressure sensor detecting the discharge pressure, multiple pressure sensors can be installed, and if there is a pressure difference between the sensors, the compressor is stopped. Furthermore, if there is a mechanism, such as a pressure switch, that shuts off when a preset abnormal value is reached, the abnormal value can be set lower than the R32 setting.

[0067] From the above, it can be seen that the refrigeration cycle device of this embodiment can reduce the effects of global warming while suppressing performance degradation.

[0068] 7 is a graph showing the relationship between the mass fraction of HFO1123 and the GWP of the refrigerant in Embodiment 2. In an XY coordinate plane with the mass fraction of HFO1123 on the X axis and the GWP of the refrigerant on the Y axis, when coordinates (30,300) are defined as point F, coordinates (50,150) are defined as point G, and coordinates (75,10) are defined as point H, the measurement coordinates (X,Y) of the refrigerant lie within a second range bounded by the second line, the third line, the fourth line, the sixth line connecting points A and F, the seventh line connecting points F and G, the eighth line connecting points G and H, and the ninth line connecting points E and H.

[0069] 8 is another graph showing the relationship between the mass fraction of HFO1123 and the GWP of the refrigerant in Embodiment 2. The measurement coordinates (X, Y) of the refrigerant are within a third range surrounded by the first line, the sixth line, the seventh line, the eighth line, and the tenth line connecting point B and point H.

[0070] As can be seen from Tables 1 and 2, when the mass ratio of HFO1123 is about 50 mass%, the pressure becomes about the same as that of R32 alone (see the high pressure and low pressure in Tables 1 and 2). In other words, when the GWP is around 150, when the mass ratio of HFO1123 exceeds 50 mass%, the high pressure in particular becomes higher than that of R32.

[0071] As can be seen from Tables 1 and 3, when the mass ratio of HFO1123 is about 30 mass%, the pressure becomes about the same as that of R32 alone (see the high pressure and low pressure in Tables 1 and 3). In other words, when the GWP is around 300, when the mass ratio of HFO1123 exceeds 30 mass%, the high pressure in particular becomes higher than that of R32.

[0072] From Tables 1 and 4, when the mass ratio of HFO1123 is 70 to 80 mass%, the pressure becomes similar to that of R32 alone (see the high pressure and low pressure in Tables 1 and 4). In other words, when the GWP is around 10, if the mass ratio of HFO1123 exceeds, for example, 75 mass%, the high pressure in particular becomes higher than that of R32.

[0073] From the above, when the measurement coordinates (X, Y) of the refrigerant are within the second range, the high pressure is lower than that of R32, so it can also be produced by replacing the refrigerant in an existing refrigeration cycle device.

[0074] If the refrigerant measurement coordinates (X, Y) are within the third range, the high-pressure pressure is higher than that of R32, so measures such as changing the specifications of the existing refrigeration cycle equipment are considered. For example, the thickness of the compressor, condenser, and each refrigerant pipe in the refrigeration cycle equipment can be increased. For example, if the thickness is not changed, the high-pressure protection value and condensation temperature protection value can be lowered compared to those of the existing refrigeration cycle equipment. Note that the discharge temperature tends to be difficult to increase, so there is no need to change the discharge temperature protection value.

[0075] In this way, in the second embodiment as well, it is possible to reduce the effects of global warming while suppressing performance degradation.

[0076] Embodiment 3. Figure 9 is a graph showing the relationship between the mass fraction of HFO1123 and the GWP of the refrigerant in Embodiment 3. In an XY coordinate plane with the mass fraction of HFO1123 on the X axis and the GWP of the refrigerant on the Y axis, when coordinates (40, 300) are designated as point I, coordinates (60, 150) are designated as point J, and coordinates (90, 10) are designated as point K, the measurement coordinates (X, Y) of the refrigerant lie within a fourth range bounded by the second line, the third line, the fourth line, the eleventh line connecting points A and I, the twelfth line connecting points I and J, the thirteenth line connecting points J and K, and the fourteenth line connecting points E and K.

[0077] 10 is another graph showing the relationship between the mass fraction of HFO1123 and the GWP of the refrigerant in Embodiment 3. The measurement coordinates (X, Y) of the refrigerant are located within a fifth range surrounded by the first line, the eleventh line, the twelfth line, the thirteenth line, and the fifteenth line connecting point B and point K.

[0078] As can be seen from Tables 1 and 2, when the mass ratio of HFO1123 is about 60 mass%, Vst is about the same as that of R32 alone. In other words, when the GWP is around 150, if the mass ratio of HFO1123 is less than 60 mass%, the required Vst is greater than that of R32.

[0079] As can be seen from Tables 1 and 3, when the mass ratio of HFO1123 is about 40 mass%, Vst becomes about the same as that of R32 alone. In other words, when the GWP is around 300, if the mass ratio of HFO1123 is less than 40 mass%, the required Vst becomes larger than that of R32.

[0080] As can be seen from Tables 1 and 4, when the mass ratio of HFO1123 is about 90 mass%, Vst becomes about the same as that of R32 alone. In other words, when the GWP is around 10, when the mass ratio of HFO1123 is less than 90 mass%, the required Vst becomes larger than that of R32.

[0081] As described above, when the refrigerant measurement coordinates (X, Y) are within the fourth range, the required Vst is greater than that of R32, so measures such as changing the specifications of the existing refrigeration cycle equipment are considered. For example, Vst may be increased compared to that of the existing refrigeration cycle equipment. For example, if Vst is not changed, the maximum rotation speed (frequency) may be increased at the same Vst.

[0082] When the measurement coordinates (X, Y) of the refrigerant are within the fifth range, the required Vst is smaller than that of R32, and therefore it can also be produced by replacing the refrigerant in an existing refrigeration cycle device.

[0083] In this way, also in the third embodiment, it is possible to reduce the effects of global warming while suppressing performance degradation.

[0084] The embodiments and examples disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present disclosure is defined by the claims, not the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0085] REFRIGERATION CYCLE DEVICES 1 Compressor, 2 Condenser, 3 Expansion mechanism, 4 Evaporator, 10 Refrigerant circuit, 10a, 10b, 10c, 10d Refrigerant piping, 20 Control device, 100 Refrigeration cycle device

Claims

1. A refrigeration system comprising a refrigeration circuit including a compressor, a condenser, an expansion mechanism, and an evaporator, wherein a refrigerant is sealed in the refrigeration circuit, and the refrigerant includes HFO1123 and at least one selected from the group consisting of R32, R1234yf, and R1234ze(E), In an XY coordinate plane with the mass fraction of HFO1123 as the X axis and the global warming potential of the refrigerant as the Y axis, when point A is at coordinate (0,675), point B is at coordinate (100,1), point C is at coordinate (10,300), point D is at coordinate (40,150), and point E is at coordinate (65,10), the measurement coordinates (X, Y) of the refrigerant lie within a first range surrounded by a first line connecting point A and point B, a second line connecting point A and point C, a third line connecting point C and point D, a fourth line connecting point D and point E, and a fifth line connecting point E and point B.

2. The refrigeration cycle apparatus of claim 1, wherein, on the XY coordinate plane, when coordinate (30, 300) is defined as point F, coordinate (50, 150) is defined as point G, and coordinate (75, 10) is defined as point H, the measurement coordinate (X, Y) of the refrigerant exists within a second range surrounded by the second line, the third line, the fourth line, a sixth line connecting point A and point F, a seventh line connecting point F and point G, an eighth line connecting point G and point H, and a ninth line connecting point E and point H.

3. The refrigeration cycle apparatus of claim 1, wherein, on the XY coordinate plane, when coordinate (30, 300) is defined as point F, coordinate (50, 150) is defined as point G, and coordinate (75, 10) is defined as point H, the measurement coordinate (X, Y) of the refrigerant exists within a third range surrounded by the first line, a sixth line connecting point A and point F, a seventh line connecting point F and point G, an eighth line connecting point G and point H, and a tenth line connecting point B and point H.

4. The refrigeration cycle apparatus of claim 1, wherein, on the XY coordinate plane, when coordinate (40, 300) is defined as point I, coordinate (60, 150) is defined as point J, and coordinate (90, 10) is defined as point K, the measurement coordinate (X, Y) of the refrigerant exists within a fourth range surrounded by the second line, the third line, the fourth line, an eleventh line connecting point A and point I, a twelfth line connecting point I and point J, a thirteenth line connecting point J and point K, and a fourteenth line connecting point E and point K.

5. The refrigeration cycle apparatus of claim 1, wherein, on the XY coordinate plane, when coordinate (40, 300) is defined as point I, coordinate (60, 150) is defined as point J, and coordinate (90, 10) is defined as point K, the measurement coordinate (X, Y) of the refrigerant exists within a fifth range surrounded by the first line, an eleventh line connecting point A and point I, a twelfth line connecting point I and point J, a thirteenth line connecting point J and point K, and a fifteenth line connecting point B and point K.

Images