A CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture

Abstract

This invention proposes a CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture, wherein the mass fraction of CO2 is 10%-64%, the mass fraction of R41 is 10%-47%, and the mass fraction of R170 is 26%-52%. This ternary near-azeotropic refrigerant mixture simultaneously possesses a low gas per watt (GWP) value and a low temperature glide, maintaining near-azeotropy even at -90°C. Furthermore, under the same operating conditions, systems using this ternary near-azeotropic refrigerant mixture exhibit lower exhaust temperatures and lower power consumption per unit volume compared to the more commonly used R134a and R290 systems, as well as a higher coefficient of performance (COP). h This ternary near-azeotropic refrigerant mixture has high application value and market prospects, and can be used in refrigeration or heat pump systems.

Description

Technical Field

[0001] This invention relates to the field of refrigerant technology, and in particular to a near-azeotropic refrigerant mixture. Background Technology

[0002] Refrigerants are the medium through which energy conversion is accomplished in refrigeration equipment such as air conditioners, refrigerators, and freezers. Among them, hydrofluorocarbons (HFCs) are currently commonly used refrigerants. However, due to the high global warming potential (GWP) of HFCs, the Kigali Amendment stipulates that most developed countries will reduce their use of HFCs starting in 2019, and developing countries will freeze their consumption of HFCs by 2024. It can be seen that finding low-GWP alternative refrigerants with less environmental impact is an urgent task for the refrigeration / heat pump industry and will become an inevitable trend in future product development.

[0003] There are two main development directions for alternative refrigerants: one is new artificially synthesized compounds, but these may have potential hazards and are expensive; the other is natural working fluids, such as CO2, NH3, and HCS, among which CO2 is considered the most promising refrigerant. This is because CO2 has zero ozone depletion potential (ODP=0), low global warming potential (GWP=1), is non-flammable, non-toxic, inexpensive, and has high thermodynamic properties. Therefore, CO2 refrigeration systems have been widely used in air conditioning (including residential and automotive air conditioning), heat pumps (including heat pump water heaters and heat pump air blowers), freezers (including residential and commercial freezers), and cascade refrigeration systems. However, CO2 refrigeration systems also have some inherent drawbacks: high operating pressure, low efficiency, and compressor exhaust overheating, which need to be addressed.

[0004] To address the aforementioned shortcomings, several non-azeotropic CO2-based refrigerant mixtures, such as CO2 / R290, CO2 / R600, and CO2 / R32, have been researched and applied in recent years. In their paper, "An Investigation of Heat Pump System Using CO2 / Propane Mixture as a Working Fluid," Zhang et al. selected R290 as the most suitable candidate component for mixing with CO2 from six CO2 mixtures (CO2 / R290, CO2 / R600a, CO2 / R600, CO2 / R1270, CO2 / R170, CO2 / R601, and CO2 / RE170). They experimentally studied the performance of a heat pump system with a small amount of R290 added to CO2 and compared it with pure CO2. The results showed that adding R290 to CO2 effectively reduces the exhaust pressure of the heat pump system and improves system performance. In their paper "Thermodynamic Analysis of Different CO2 Cascade Refrigeration Cycles," Liu et al. analyzed five different cascade refrigeration cycles (CO2 / NH3, CO2 / R22, CO2 / R32, CO2 / R290, and CO2 / R404a). The results showed that, under given operating conditions, the CO2 / NH3 cycle had the highest COP, while the CO2 / R32 and CO2 / R290 cycles had essentially the same COP. Except for the CO2 / R404a cycle, the COP of the different cascade refrigeration cycles decreased with increasing condensation temperature. However, the temperature glide (temperature glide refers to the temperature change during a phase change in a mixture at a constant pressure) and mass transfer resistance of non-azeotropic working fluids during boiling result in a lower heat transfer coefficient than that of pure refrigerants and azeotropic / near-azeotropic mixtures. Furthermore, in the application of non-azeotropic working fluids, it is difficult to overcome the inherent compositional changes that occur during leakage or replenishment.

[0005] Therefore, azeotropic / near-azeotropic mixtures are attracting increasing attention as refrigerants and are being given preference among different types of mixtures because they can combine the advantages of each component and overcome the inherent defects of non-azeotropic working fluids, exhibiting the same characteristics as pure working fluids at boiling. In practical applications, it has been found that azeotropic / near-azeotropic refrigerants have significantly higher heat transfer performance than non-azeotropic refrigerants.

[0006] R410A is one of the most widely used mixed refrigerants in the Chinese market. It is a typical near-azeotropic working fluid. The refrigerant temperature glide is less than 0.2℃ throughout the entire operating range, which makes the migration of the mixture components very small and is conducive to refrigerant replenishment. However, its GWP value (about 2100) is very high, which makes R410A have a serious greenhouse effect and cannot meet the requirements of environmental protection.

[0007] Patent document (CN 111662685 A) discloses a ternary mixed refrigerant containing carbon dioxide (CO2) and difluoromethane (R32), wherein the other component is trifluoroiodomethane (CF3I), fluoromethane (CH3F), ethane (C2H6), 1,1-difluoroethylene (C2H2F2), ethylene (C2H4), fluoroethylene (C2H3F), acetylene (C2H2), propane (C3H8), propylene (C3H6) and / or fluoroethane (CH2FCH3). It has a low GWP value and a small contribution to the greenhouse effect. However, its temperature glide is as high as 22.1℃. It is a non-azeotropic working fluid. If this refrigerant is used in refrigeration or heat pump systems, it is difficult to overcome the component migration problem during operation. Moreover, when the refrigerant leaks, the component concentration will deviate from the design concentration. When replenishing the refrigerant, the original refrigerant must be completely vented before the new refrigerant is injected. This will inevitably lead to a large amount of refrigerant waste and increase a lot of unnecessary refrigerant emissions. Even with a low GWP value, it will still enhance the greenhouse effect and increase the user's operating costs.

[0008] Currently, no ternary near-azeotropic refrigerant mixture has been found that simultaneously possesses both very low temperature glide and extremely low GWP value. Therefore, to meet market demands, there is an urgent need to develop a ternary near-azeotropic refrigerant mixture that offers excellent heat transfer performance, meets environmental protection requirements, and does not increase operating costs due to high temperature glide, serving as a substitute for commonly used refrigerants such as R134a and R290. Summary of the Invention

[0009] In view of this, the present invention provides a CO2 / R41 / R170 ternary near-azeotropic mixed refrigerant, which not only has a very low temperature glide, but also an extremely low GWP value. With low temperature glide and high heat transfer performance, it can effectively solve the above-mentioned problems existing in existing refrigerants.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A ternary near-azeotropic refrigerant mixture of CO2 / R41 / R170 is composed of CO2, R41 and R170, wherein the mass fraction of CO2 is 10%-64%, the mass fraction of R41 is 10%-47%, and the mass fraction of R170 is 26%-52%. The ternary near-azeotropic refrigerant mixture exhibits a temperature glide of less than 0.2℃ when its bubble point temperature is below 0℃.

[0012] As one of the preferred embodiments of the present invention, the mass fraction of CO2 is 10%-60%, the mass fraction of R41 is 10%-42%, and the mass fraction of R170 is 30%-48%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -20℃ to 0℃.

[0013] As one of the preferred embodiments of the present invention, the mass fraction of CO2 is 10%-58%, the mass fraction of R41 is 10%-38%, and the mass fraction of R170 is 32%-52%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -40℃ to 0℃.

[0014] As one of the preferred embodiments of the present invention, the mass fraction of CO2 is 10%-54%, the mass fraction of R41 is 10%-38%, and the mass fraction of R170 is 36%-52%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -60℃ to 0℃.

[0015] As one of the preferred embodiments of the present invention, the mass fraction of CO2 is 20%-50%, the mass fraction of R41 is 10%-30%, and the mass fraction of R170 is 40%-50%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -80℃ to 0℃.

[0016] As one of the preferred embodiments of the present invention, the mass fraction of CO2 is 27%-47%, the mass fraction of R41 is 11%-25%, and the mass fraction of R170 is 42%-48%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -90℃ to 0℃.

[0017] The ternary near-azeotropic mixed refrigerant prepared by the present invention using a certain mass fraction of CO2, R170, and R41 has the following advantages:

[0018] I. The ternary near-azeotropic refrigerant described in this invention possesses a low GWP value and temperature glide, thus allowing for direct refrigerant replacement within existing CO2 systems while minimizing environmental impact, without requiring equipment replacement or redesign. This avoids system instability issues caused by refrigerant component migration. Furthermore, refrigerant replenishment does not require complete venting; it can be added directly. These advantages significantly reduce operating costs, facilitating market application and promotion.

[0019] Second, the excellent characteristic of the ternary near-azeotropic mixed refrigerant described in this invention, which has a temperature glide of less than 0.2℃ when the bubble point temperature is -90℃, has extremely high application value and market prospects in refrigeration and heat pump systems.

[0020] Third, compared to the commonly used R134a and R290 refrigerants, the CO2 / R41 / R170 ternary near-azeotropic mixed refrigerant proposed in this invention has a lower exhaust temperature and unit power consumption, as well as a higher coefficient of performance (COP / COP) under the same operating conditions. h )and efficiency. Attached Figure Description

[0021] Figure 1 The temperature glide of the CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture at a bubble point of -10°C;

[0022] Figure 2 This is a schematic diagram of a heat pump water heater (HPWH) system.

[0023] Figure 3 This is a pressure-enthalpy diagram for a heat pump water heater (HPWH) system.

[0024] Figure 4 COP for CO2 / R41 / R170 systems, R134a systems and R290 systems h Follow T e and T gc,o The change graph;

[0025] Figure 5 The exhaust temperature of CO2 / R41 / R170 system, R134a system and R290 system varies with T e and T gc,o The change graph.

[0026] Figure 6 The power consumption per unit volume of CO2 / R41 / R170, R134a, and R290 systems varies with T. e and T gc,o The change graph;

[0027] Figure 7 For CO2 / R41 / R170 systems, R134a systems and R290 systems Efficiency varies with T e and T gc,o The change graph.

[0028] in, Figure 2In the text, 0-7, 0'-7', and 0”-7” represent CO2 / R41 / R170, R134a, and R290 cycles, respectively; 11-evaporator; 12-regenerator; 13-compressor; 14-air cooler (condenser); 15-expansion valve; 16-water. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. The described embodiments are only possible technical implementations of the present invention and not all possible implementations. Those skilled in the art can obtain other embodiments in conjunction with the embodiments of the present invention without creative effort, and these embodiments are also within the protection scope of the present invention.

[0030] This embodiment provides a ternary near-azeotropic refrigerant mixture, which is composed of CO2, R170, and R41. All three components, CO2, R170, and R41, are readily available. CO2 is a linearly symmetrical molecule and is nonpolar; R170 (ethane) has a completely identical carbon-carbon configuration, is absolutely symmetrical, has a molecular dipole moment of 0, and is nonpolar; R41 has a tetrahedral configuration and is very weakly polar. According to the principle of "like dissolves like," the three substances can be miscible in any proportion under the same temperature and pressure. The C=O bond energy in the CO2 molecule is very high, the C-H bond in the R170 molecule is difficult to break, and both the C-H and C-F bonds in the R41 molecule are difficult to break. Under refrigeration / heat pump operation conditions, the three substances are chemically stable and will not undergo a chemical reaction when mixed.

[0031] like Figure 1 As shown, when the bubble point temperature is -10℃, the temperature glide changes with the proportion of each component. It can be seen that the temperature glide of CO2 / R41 / R170 refrigerant at a bubble point temperature of -10℃ is between 0 and 7℃. Since non-azeotropic mixtures are prone to leakage during operation, component migration can occur, adversely affecting the system. To overcome this problem, the portion with a temperature glide less than 0.2℃ (near-azeotropic refrigerant mixture) is selected. Table 1 shows the mass ratio of CO2 / R170 / R41 refrigerant at different bubble point temperatures when the temperature glide is less than 0.2℃.

[0032] Table 1. Component ratios when the temperature glide of the CO2 / R41 / R170 mixed refrigerant is less than 0.2℃ at different bubble point temperatures.

[0033]

[0034]

[0035] As can be seen from Table 1, the ternary near-azeotropic refrigerant of the present invention can reach a minimum bubble point temperature of -90℃ when the temperature glide is less than 0.2℃, indicating that the refrigeration system using the ternary near-azeotropic refrigerant proposed in this invention can be used in extremely low temperature environments.

[0036] To further verify the superiority of the ternary near-azeotropic mixed refrigerant described in this invention, this embodiment takes a heat pump water heater system as an example and selects standard operating conditions: the ambient temperature is 16℃, and the inlet and outlet water temperatures of the heat pump water heater are 17℃ and 65℃, respectively. The performance of the heat pump system using CO2 / R41 / R170 mixed refrigerant, the heat pump system using R134a as refrigerant, and the heat pump system using R290 as refrigerant are calculated respectively.

[0037] In this embodiment, energy and Thermodynamic analysis is based on the following premises:

[0038] (1) Heat pump water heater system, ambient temperature is 16℃, hot water inlet and outlet water temperatures are 17℃ and 65℃ respectively;

[0039] (2) The system cycles of the three refrigerants studied were all operating under stable conditions;

[0040] (3) Compression and expansion processes are adiabatic rather than isentropic;

[0041] (4) The heat loss and pressure drop of the refrigerant flowing in the heat exchanger and connecting pipes are ignored;

[0042] (5) The refrigerant is saturated at the evaporator outlet;

[0043] (6) The lubricating oil does not flow with the refrigerant;

[0044] I. Energy Thermodynamic Analysis

[0045] Evaporator cooling capacity:

[0046]

[0047]

[0048]

[0049] Heating capacity of air cooler / condenser:

[0050]

[0051]

[0052]

[0053] Energy balance of the regenerator:

[0054]

[0055]

[0056]

[0057] Regenerator efficiency:

[0058]

[0059]

[0060]

[0061] Compressor output power:

[0062]

[0063]

[0064]

[0065] Compressor isentropic efficiency:

[0066] ε is =(h 2s -h1) / (h2-h1) (16)

[0067] ε' is =(h 2s’ -h 1’ ) / (h 2’ -h 1’ (17)

[0068] ε” is =(h 2s” -h 1” ) / (h 2” -h 1” (18)

[0069] Where, ε is It can also be calculated from the following expression:

[0070]

[0071]

[0072]

[0073] COP h It can be calculated by the following formula:

[0074]

[0075]

[0076]

[0077] In CO2 / R41 / R170, R134a and R290 systems, the evaporation temperature (T) is guaranteed. e The heat transfer temperature difference between the air cooler / condenser and the external fluid is the same (ΔT). m )same.

[0078] For a CO2 / R41 / R170 HPWH system: the heat transfer temperature difference between the air cooler and the hot water can be obtained through the following calculations:

[0079]

[0080] For an R134a HPWH system: the heat transfer temperature difference between the condenser and the hot water can be calculated using the following formula:

[0081]

[0082] Where T c This is the condensation temperature of the R134a HPWH system, in °C.

[0083] For an R290 HPWH system: the heat transfer temperature difference between the condenser and the hot water can be calculated using the following formula:

[0084]

[0085] Where T' c This is the condensation temperature of the R134a HPWH system, in °C.

[0086] two, Thermodynamic analysis

[0087] Irreversible losses of the compressor:

[0088] I com =T en (s2-s1) (28)

[0089] I' com =T en (s 2’ -s 1’ (29)

[0090] I” com =T en (s 2” -s 1” (30)

[0091] Among them, T en The ambient temperature of the HPWH system is 16℃.

[0092] Irreversible capillary loss:

[0093] I cap =T en (s5-s4) (31)

[0094] I' cap =T en ( x5’ -s 4’ (32)

[0095] I” cap =T en (s 5” -s 4” (33)

[0096] Irreversible losses in internal heat exchangers:

[0097] I ihe =T en [(s1-s0)+(s4-s3)] (34)

[0098] I' ihe =T en [(s 1’ -s 0’ )+(s 4’ -s 3’ (35)

[0099] I” ihe =T en [(s 1” -s 0” )+(s 4” -s 3” (36)

[0100] Irreversible losses in the evaporator:

[0101] I e =T en (s0-s5)-(h0-h5) (37)

[0102] I' e =T en (s 0’ -s 5’ )-(h 0’ -h 5’ (38)

[0103] I” e =T en (s0” -s 5” )-(h 0” -h 5” (39)

[0104] Irreversible losses in air coolers / condensers:

[0105] I gc =T en (h0-h5) / T evef -T en (s0-s5) (40)

[0106] I' cond =T en (h 0' -h 5’ ) / T evef -T en (s 0’ -s 5’ (41)

[0107] I” cond =T en (h 0” -h 5” ) / T evef -T en (s 0” -s 5” (42)

[0108] in,

[0109]

[0110] In the above formula, T6 represents the hot water inlet temperature in the HPWH system, which is 17℃, and T7 represents the hot water outlet temperature in the HPWH system, which is 65℃.

[0111] Irreversible nature of the entire system:

[0112] I total =I com +I ihe +I cap +I e +I gc (44)

[0113] I' total =I' com +I' ihe +I' cap +I' e +I cond (45)

[0114] I” total =I” com +I”ihe +I” cap +I” e +I' cond (46)

[0115] The whole system efficiency:

[0116] η = 1 - I total / w com (47)

[0117] η'=1-I' total / w' com (48)

[0118] η”=1-I” total / w” com (49)

[0119] The specific research method is as follows:

[0120] Step 1: Adjust the water valve to control the hot water flow, maintaining the inlet and outlet water temperatures at 17℃ and 65℃ respectively. Adjust the opening of the expansion valve and measure the corresponding evaporation temperature (T). e ) and air cooler outlet temperature (T gc,o As a baseline parameter, the evaporation temperature and the heat transfer temperature difference between the air cooler / condenser and the external fluid are kept the same in the three systems to be compared (ΔT). m The parameters are the same. ΔT m It can be calculated using equation (25).

[0121] Step 2: Using the evaporation temperature (T) e ) and air cooler outlet temperature (T gc,o Using the evaporation temperature and the heat transfer temperature difference between the air cooler / condenser and the external fluid as reference parameters, the COP of the three systems was obtained. h Other performance indicators include exhaust temperature.

[0122] Step 3: Input the external conditions of the three systems into the thermodynamic formulas (equations (28) to (49)) to obtain the irreversible losses of each system. efficiency.

[0123] In this embodiment, T is selected. e = -90℃~0℃, T gc,o =35℃.

[0124] In the R134a system, parameter T e and ΔT mInput the energy thermodynamic formulas (equations (2), (5), (8), (11), (14), (17), (20), (23), (26)) to obtain the performance parameters of the R134a system, as shown in Table 2.

[0125] In the R290 system, parameter T e and ΔT m Input the energy thermodynamic formulas (equations (3), (6), (9), (12), (15), (18), (21), (24), (27)) to obtain the performance parameters of the R290 system, as shown in Table 2.

[0126] In the CO2 / R41 / R170 system, the parameters are input into the above formulas (1), (4), (7), (10), (13), (16), (19), and (22) to obtain the COP of the system under different ratios. h As shown in Tables 3-8.

[0127] Table 2 shows the COP of the systems described in the comparative examples. h

[0128]

[0129] Table 3. COP of the system described in this invention under different refrigerant ratios. h (T e =0℃, T gc,o =35℃)

[0130]

[0131]

[0132] Table 4. COP of the system described in this invention under different refrigerant ratios. h (T e = -20℃, T gc,o =35℃)

[0133]

[0134]

[0135] Table 5. COP of the system described in this invention under different refrigerant ratios. h (T e = -40℃, T gc,o =35℃)

[0136]

[0137]

[0138]

[0139] Table 6. COP of the system described in this invention under different refrigerant ratios. h (T e = -60℃, T gc,o =35℃)

[0140]

[0141]

[0142] Table 7. COP of the system described in this invention under different refrigerant ratios. h (T e = -80℃, T gc,o =35℃)

[0143]

[0144]

[0145] Table 8. COP of the system described in this invention under different refrigerant ratios. h (T e = -90℃, T gc,o =35℃)

[0146]

[0147]

[0148] By comparing the comparative examples in Tables 3 and 4 with those in Table 2, it can be seen that under the operating conditions of evaporation temperature of 0℃ and -20℃, and air cooler outlet temperature of 35℃, the COP of CO2 / R41 / R170 is... h It is significantly superior to the R134a and R290 refrigerants commonly used in current refrigeration / heat pump systems.

[0149] When the evaporation temperature is below -40°C (including -40°C), R134a and R290 refrigerants are difficult to operate, while the ternary near-azeotropic mixed refrigerant described in this invention can still operate, and the COP of the system is higher than 1. This indicates that the ternary near-azeotropic mixed refrigerant described in this invention has a wider applicable temperature range and a wider range of uses.

[0150] like Figure 2 , Figure 3As shown, in a heat pump water heater (HPWH) system with regeneration, the refrigerant enters the regenerator from the evaporator outlet, passes sequentially through the compressor, air cooler / condenser, regenerator, and expansion valve, and finally returns to the evaporator, forming a system cycle. 0-7, 0'-7', and 0”-7” represent the CO2 / R41 / R170, R134a, and R290 cycles, respectively.

[0151] like Figures 4-7 As shown, under the same conditions, the COP of the CO2 / R41 / R170 system... h Exhaust temperature, unit power consumption, Its efficiency is significantly better than that of the R134a and R290 systems.

[0152] Therefore, the CO2 / R41 / R170 ternary near-azeotropic refrigerant used in this invention has excellent characteristics such as 0 ODP, low GWP, and small temperature glide. Compared with the commonly used R134a and R290 refrigerants on the market, under the same conditions, the CO2 / R41 / R170 near-azeotropic refrigerant has a lower discharge temperature and unit power consumption, as well as a higher coefficient of performance (COP) and higher coefficient of performance (COP). This refrigerant offers superior overall performance and can be used in refrigeration or heat pump systems. Most importantly, compared to existing ternary non-azeotropic refrigerants, it simultaneously exhibits low temperature glide and low GWP (Gross Potentially Positive Temperature Shift), which helps overcome system instability caused by component migration. Furthermore, it can be added directly without complete venting. This refrigerant can also directly replace existing CO2 refrigerants without requiring equipment replacement, and its efficiency is higher than commonly used R134a and R290 systems. Therefore, this refrigerant further meets market demands and possesses significant market value.

[0153] The technical features of the embodiments described above can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. It should be noted that the terms "in one embodiment," "for example," and "again," etc., in this application are intended to illustrate the application and not to limit it. The embodiments described above only illustrate several implementations of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A near-azeotropic ternary refrigerant mixture of CO2 / R41 / R170, characterized in that: It is composed of CO2, R41 and R170, wherein the mass fraction of CO2 is 10%-64%, the mass fraction of R41 is 10%-47%, and the mass fraction of R170 is 26%-52%. The ternary near-azeotropic mixed refrigerant has a temperature glide of less than 0.2℃ when the bubble point temperature is below 0℃.

2. The CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture according to claim 1, characterized in that: The mass fraction of CO2 is 10%-60%, the mass fraction of R41 is 10%-42%, and the mass fraction of R170 is 30%-48%; the bubble point temperature of the ternary near-azeotropic refrigerant mixture is -20℃ to 0℃.

3. The CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture according to claim 1, characterized in that: The mass fraction of CO2 is 10%-58%, the mass fraction of R41 is 10%-38%, and the mass fraction of R170 is 32%-52%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -40℃ to 0℃.

4. The CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture according to claim 1, characterized in that: The mass fraction of CO2 is 10%-54%, the mass fraction of R41 is 10%-38%, and the mass fraction of R170 is 36%-52%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -60℃ to 0℃.

5. The CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture according to claim 1, characterized in that: The mass fraction of CO2 is 20%-50%, the mass fraction of R41 is 10%-30%, and the mass fraction of R170 is 40%-50%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -80℃ to 0℃.

6. The CO2 / R41 / R170 ternary near-azeotropic refrigerant mixture according to claim 1, characterized in that: The mass fraction of CO2 is 27%-47%, the mass fraction of R41 is 11%-25%, and the mass fraction of R170 is 42%-48%; the bubble point temperature of the ternary near-azeotropic mixed refrigerant is -90℃ to 0℃.

Images