Environment-friendly mixed refrigerant containing CO2

Abstract

The invention belongs to the technical field of refrigerants, and discloses a CO2-containing environment-friendly mixed refrigerant which is formed by mixing at least one of three components of propylene, 1, 1-difluoroethane and trifluoroethylene with carbon dioxide, specifically, the CO2-containing environment-friendly mixed refrigerant can be composed of two components of carbon dioxide and propylene, or three components of carbon dioxide, propylene and 1, 1-difluoroethane, or three components of carbon dioxide, propylene and 1, 1-difluoroethane. Or consists of three components, namely carbon dioxide, propylene and trifluoroethylene. The components of the mixed refrigerant and the proportion of all the components are improved, the obtained mixed refrigerant is high in energy efficiency, low in exhaust temperature and large in refrigerating capacity per unit volume, and compared with the prior art, the actual problems that an existing R32 refrigerant is high in GWP value and high in exhaust temperature, and an R290 refrigerant is low in refrigerating capacity per unit volume, low in energy efficiency and poor in heating performance can be solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of refrigerants, and more specifically, relates to an environmentally friendly mixed refrigerant containing CO2. The mixed refrigerant is an environmentally friendly mixed refrigerant that can replace R32, R410A and R290, and can be used as an air-conditioning refrigerant in particular. Its comprehensive performance is better than that of the existing R32 air conditioner and the R290 air conditioner that has not yet been fully promoted and applied. Background Art

[0002] As people pay more attention to the depletion of the ozone layer and the intensification of the greenhouse effect, countries around the world have gradually phased out chlorine-containing refrigerants with an ODP greater than zero, and have begun to restrict the use of hydrofluorocarbon (HFC) refrigerants with high global warming potential (GWP). In October 2016, the Kigali Amendment to the Montreal Protocol clarified the control of 18 HFCs, and the task of finding alternative refrigerants with excellent performance is urgent.

[0003] In recent years, difluoromethane (R32) has been widely used in the field of household air conditioning as a transitional substitute for R410A. It has a higher unit volumetric cooling capacity and system application performance coefficient (COP) and a lower GWP. However, according to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR6), the GWP of R32 was revised to 771, which is higher than the limit of the European Parliament's fluorinated gas regulation (F-gas) for refrigerants used in household air conditioners. According to the regulations of the European Parliament, after 2025, fluorinated greenhouse gases with a GWP of 750 or higher will be banned in split air conditioning systems with a charge of less than 3 kg. Therefore, research on alternatives to R32 used in air conditioners is also imminent.

[0004] Currently, natural refrigerant propane (R290) is one of the main ideas for replacing R32 refrigerants. However, the unit volume cooling capacity of air-conditioning systems using R290 as refrigerant is too low, and the unit volume cooling capacity of R290 is only about 50% of that of R32, which leads to large compressor size and high vibration and noise of R290 air-conditioning systems. At the same time, due to the small unit volume cooling capacity of R290, the large suction volume of the compressor, the high evaporator flow rate and large flow resistance, the heating capacity of R290 air-conditioning systems is much lower than that of R32 air-conditioning systems.

[0005] In view of the above-mentioned R32 refrigerant replacement problem and the practical problems in the actual application of single-component hydrocarbon refrigerants such as R290, mixed refrigerants are an effective way to solve the above problems. Mixed refrigerants can be mixed with a variety of refrigerants with different performance characteristics, using the advantages of different refrigerants to regulate the various performance of the mixed refrigerant, avoiding the shortcomings of single-component refrigerants, and then forming a mixed refrigerant with good comprehensive characteristics, and solving the problem of refrigerant replacement in the field of refrigeration and air conditioning. Summary of the invention

[0006] In view of the above defects or improvement needs of R32 refrigerant replacement and the prior art, the purpose of the present invention is to provide an environmentally friendly mixed refrigerant containing CO2, wherein by improving the components of the mixed refrigerant and the proportion of each component, it can solve the practical problems of the existing R32 refrigerant with high GWP value and high exhaust temperature, and the R290 refrigerant with low unit volume refrigeration capacity, low energy efficiency and poor heating performance. The mixed refrigerant obtained by the present invention has high energy efficiency, low exhaust temperature and large unit volume refrigeration capacity, and can be used in the following occasions: (1) The unit volume refrigeration capacity is higher than that of R32 air conditioner, and there is no need to replace the compressor when replacing R32; (2) When used in newly developed air conditioners, the unit volume refrigeration capacity is higher, and the cooling and heating COP is higher than that of the existing R32 air conditioner, and the energy-saving effect is obvious. It can be applied to refrigeration equipment such as household and commercial air conditioning systems, heat pump water heaters, and automotive air conditioners.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided an environmentally friendly mixed refrigerant containing CO2, characterized in that it is a mixture of at least one of the three components of propylene, 1,1-difluoroethane and trifluoroethylene and carbon dioxide;

[0008] The mixed refrigerant is composed of two components, carbon dioxide and propylene, wherein the mass percentage of carbon dioxide in the mixed refrigerant is 5% to 12%, and the mass percentage of propylene in the mixed refrigerant is 88% to 95%; the GWP value of the mixed refrigerant is less than 150;

[0009] Alternatively, the mixed refrigerant is composed of three components: carbon dioxide, propylene and 1,1-difluoroethane, wherein the mass percentage of carbon dioxide in the mixed refrigerant is 5% to 15%, the mass percentage of propylene in the mixed refrigerant is 33% to 85%, and the mass percentage of 1,1-difluoroethane in the mixed refrigerant is 10% to 55%; the GWP value of the mixed refrigerant is less than 150;

[0010] Alternatively, the mixed refrigerant is composed of three components: carbon dioxide, propylene and trifluoroethylene, wherein the mass percentage of carbon dioxide in the mixed refrigerant is 5% to 15%, the mass percentage of propylene in the mixed refrigerant is 20% to 70%, and the mass percentage of trifluoroethylene in the mixed refrigerant is 20% to 65%; the GWP value of the mixed refrigerant is less than 150.

[0011] As a further preferred embodiment of the present invention, the mixed refrigerant consists of two components, carbon dioxide and propylene, and the mass ratio of carbon dioxide to propylene in the mixed refrigerant is 0.05:0.95, or 0.08:0.92, or 0.1:0.9, or 0.12:0.88.

[0012] As a further preferred embodiment of the present invention, the mixed refrigerant is composed of three components: carbon dioxide, propylene and 1,1-difluoroethane. The mass ratio of carbon dioxide, propylene and 1,1-difluoroethane in the mixed refrigerant is 0.1:0.8:0.1, or 0.1:0.75:0.15, or 0.1:0.7:0.2, or 0.1:0.65:0.25, or 0.1:0.6:0.3, or 0.1:0.55:0.35, or 0.1:0.5:0.4, or 0.1:0.45:0.45, or 0.1:0.4:0.5, or 0.12:0.78:0.1, or 0.12:0.68:0.2, or 0.12:0.63:0.25, or 0.12:0.58:0.3, or 0.12:0.53:0.35, or 0.12:0.48:0.4, or 0.12:0.43:0.45, or 0.12:0.38:0.5, or 0.12:0.33:0.55, or 0.15:0.75:0.1, or 0.15:0.7:0.15, or 0.15:0.65:0.2, or 0.15:0.6:0.25, or 0.15:0.55:0.3, or 0.15:0.5:0.35, or 0.15:0.45:0.4, or 0.15:0.4:0.45, or The ratio is 0.15:0.35:0.5, or 0.05:0.85:0.1, or 0.05:0.8:0.15, or 0.05:0.75:0.2, or 0.05:0.7:0.25, or 0.05:0.65:0.3, or 0.05:0.6:0.35, or 0.05:0.55:0.4, or 0.05:0.5:0.45, or 0.05:0.45:0.5.

[0013] As a further preference of the present invention, the mixed refrigerant is composed of three components: carbon dioxide, propylene and trifluoroethylene, and the mass ratio of carbon dioxide, propylene and trifluoroethylene in the mixed refrigerant is 0.05:0.4:0.55, or 0.05:0.45:0.5, or 0.05:0.5:0.45, or 0.05:0.55:0.4, or 0.05:0.6:0.35, or 0.05:0.65:0.3, or 0.1:0.4:0.5, or 0.1:0.45:0.45, or 0.1:0.5:0.4, or 0.1:0.55:0.35, or 0.1:0.6:0 .3, or 0.1:0.65:0.25, or 0.1:0.7:0.2, or 0.08:0.42:0.5, or 0.08:0.47:0.45, or 0.08:0.52:0.4, or 0.08:0.57:0.35, or 0.08:0.62:0.3, or 0.15:0.2:0.65, or 0.15:0.25:0.6, or 0.15:0.3:0.55, or 0.15:0.35:0.5, or 0.15:0.4:0.45, or 0.15:0.45:0.4, or 0.15:0.5:0.35.

[0014] According to another aspect of the present invention, the present invention provides the use of the above-mentioned environmentally friendly mixed refrigerant containing CO2 as a refrigerant.

[0015] As a further preferred embodiment of the present invention, the application is specifically as a refrigerant for household air conditioners, central air conditioners, heat pump water heaters or automobile air conditioners.

[0016] As a further preference of the present invention, the application is specifically used to replace R32, R410A or R290.

[0017] Through the above technical scheme conceived by the present invention, compared with the prior art, the mixed refrigerant in the present invention is a mixture of at least one of the three components of propylene, 1,1-difluoroethane and trifluoroethylene with carbon dioxide (the sum of the mass percentage concentrations of each component in the mixed refrigerant is 100%), and the advantages and disadvantages of each component when used independently as a refrigerant are as follows:

[0018] Carbon dioxide (R744): The advantages are large cooling capacity per unit volume, non-flammable, safe and environmentally friendly; the disadvantages are low cooling and heating COP, high pressure and high exhaust temperature.

[0019] Propylene (R1270): The advantages are high COP for cooling and heating, environmental protection, moderate pressure and moderate exhaust temperature; the disadvantages are safety level A3, flammable and explosive, low cooling capacity per unit volume, about 60-70% of R32.

[0020] 1,1-Difluoroethane (R152a): Its advantages are high COP for cooling and heating, environmental protection, moderate pressure and low exhaust temperature; its disadvantages are safety level A2, flammability and explosion, low cooling capacity per unit volume, about 30-40% of R32.

[0021] Trifluoroethylene (R1123): The advantage is that the cooling capacity per unit volume is large; the cooling capacity per unit volume is equivalent to that of R32. The disadvantage is that the COP for cooling and heating is small, which is about 10% lower than that of R32. The safety level is A2L and it is flammable.

[0022] The present invention uses at least one of the three components of propylene, 1,1-difluoroethane and trifluoroethylene to mix with carbon dioxide to form a mixed refrigerant:

[0023] (1) When CO2 is mixed with propylene, or CO2 is mixed with propylene and 1,1-difluoroethane, by controlling the ratio of CO2, propylene and 1,1-difluoroethane, the corresponding mixed refrigerant has better cooling and heating COP and unit volume cooling capacity, and can be used to replace R32 and R290 in air conditioning or other refrigeration systems, and achieve the following goals: 1) The cooling and heating COP is higher than that of single-component R32 and R290 air conditioning systems; 2) The unit volume cooling capacity is higher than that of R290 air conditioning systems and reaches 85% or more of R32 air conditioning systems; 3) The flammability of the mixed refrigerant is lower than that of R290 refrigerant; 4) The GWP value of the mixed refrigerant is lower than 150; 5) The exhaust temperature is lower than that of R32 air conditioning systems.

[0024] (2) When CO2 is mixed with R1123 and propylene, by controlling the proportion of each component, the resulting mixed refrigerant has a high unit volume refrigeration capacity and a small temperature glide. Moreover, when propylene is involved in the system, in addition to the advantages of high unit volume refrigeration capacity, it also has the advantages of high cooling and heating COP, which can make up for the disadvantage of low COP of R1123 refrigerant, and the mixed refrigerant has an extremely low GWP value. The mixed refrigerant obtained by using CO2, R1123 and propylene in a specific mass ratio according to the present invention has excellent characteristics of high COP, high unit volume refrigeration capacity and low GWP, and is used to replace R32 in air conditioning or other refrigeration systems, and achieves the following goals: 1) The COP of cooling and heating is higher than that of a single-component R32 air-conditioning system; 2) The unit volume refrigeration capacity is higher than that of an R290 air-conditioner, and higher than or equivalent to that of an R32 air-conditioning system; 3) The flammability of the mixed refrigerant is lower than that of an R290 refrigerant; 4) The GWP value of the mixed refrigerant is lower than 150; 5) The exhaust temperature is lower than that of an R32 air-conditioning system.

[0025] The invention has an ODP value of 0 and a GWP value of less than 150, and has outstanding environmental advantages. In addition, the mixed refrigerant formed by CO2 and the flammable refrigerants propylene, 1,1-difluoroethane, and trifluoroethylene utilizes the flame retardant properties of CO2 to improve the safety of the mixed refrigerant.

[0026] Specifically, the mixed refrigerant in the present invention can achieve the following beneficial effects:

[0027] 1. The refrigerant used in the present invention has a low GWP value. Within the mass concentration range of the mixture involved in the present invention, the GWP value of the mixture does not exceed 150, which meets the requirements of the EU F-gas regulations for alternative refrigerants and is used to replace R32 in household air conditioners and automotive air conditioners. According to the test and application conditions of existing conventional air conditioners, the evaporation temperature of refrigeration is in the range of about 7-13°C, and fluctuates slightly according to different working conditions; the evaporation temperature of heating is about 2°C. If it is a freezing and refrigeration application, such as a refrigerator, the evaporation temperature can be as low as -15°C (such as a self-cascade refrigerator). The mixed refrigerant obtained by the present invention contains CO2. When mixed with other components, if the boiling points of each component are very different (that is, the slip temperature is very large), then the mixed refrigerant needs to be fractionated in the system. The mixed refrigerant used in air conditioning requires a slip temperature as low as possible to meet the application conditions of air conditioning (that is, refrigerants with too high a slip temperature, such as mixed refrigerants used in self-cascade refrigerators, cannot be used in air conditioning devices). The present invention mixes CO2 with at least one of propylene, 1,1-difluoroethane and trifluoroethylene, and adjusts the ratio of each component, so that the slip temperature is small and it is very suitable for application in air-conditioning systems.

[0028] Refrigerant substitution is one of the bottleneck problems in the air-conditioning industry. The widely used R32 refrigerant has a high GWP value and belongs to the regulated refrigerant. However, due to the widespread use of R32 in the air-conditioning industry, the compressor, heat exchanger, throttling mechanism, control method, etc. of the air-conditioning system are closely matched with R32, among which the most important are the compressor and heat exchanger. Since R32 has a high unit volumetric cooling capacity and a small compressor size, R32 air conditioners generally have the characteristics of low cost, low noise and high capacity. At the same time, the R32 heat exchanger has a small volumetric flow rate, small specific volume and small resistance of the heat exchanger. Therefore, when designing a heat exchanger with heating performance, the structure of the heat exchanger does not need too much optimization. Up to now, there has been no alternative refrigerant with similar properties to R32.

[0029] At present, in the process of replacing R32 in the air conditioning industry, R290 is used as a potential substitute. However, the physical properties of R290 are too different from those of R32, as shown in the following: the unit volume cooling capacity of R290 is only about 50% of that of R32. This results in a large compressor displacement of the R290 air conditioner and a large number of branches in the heat exchanger. This causes the R290 air conditioner to have high costs, high vibration and noise, and poor thermal performance. Especially in terms of heating performance, due to the high flow resistance of R290, the heat exchanger needs to adopt a multi-branch design, sacrificing heat transfer performance.

[0030] However, CO2 refrigerants in the prior art are difficult to apply to air conditioners. This is because: CO2 has a high cooling capacity per unit volume, but the low critical temperature characteristic of CO2 results in a low cycle thermal coefficient of CO2 refrigerants used in air-conditioning systems, making it difficult to meet the national standards for air conditioner energy efficiency levels.

[0031] In response to the above problems, how to find a product with high cooling capacity per unit volume (equivalent to or not much different from R32) and high cycle thermal coefficient (meeting the energy efficiency level required by national standards) is the main problem currently encountered by the air-conditioning industry.

[0032] The present invention forms a mixed refrigerant by mixing at least one of the three components of propylene, 1,1-difluoroethane and trifluoroethylene with carbon dioxide, and at the same time controls the ratio of each component to achieve a compromise between the thermal coefficient and the unit volume refrigeration capacity, and the corresponding mixed refrigerant has an appropriate temperature glide characteristic, so that the temperature difference between the air conditioner and the cold and heat source is reduced, making up for the disadvantage of the low thermal characteristics of CO2. The mixed refrigerant obtained by the present invention has the characteristics of high unit volume refrigeration capacity, high thermal coefficient and appropriate temperature glide. It is precisely because of these characteristics that the mixed refrigerant obtained by the present invention can be applied to air conditioning systems.

[0033] 2. The refrigerant used in the present invention has a low GWP value. Within the mass concentration range of the mixture involved in the present invention, the GWP value of the mixture does not exceed 750, which meets the requirements of the EU F-gas regulations for alternative refrigerants and is used to replace R32 and R410A in refrigeration equipment with a cooling capacity greater than 12kW.

[0034] 3. The COP value of the refrigerant provided by the present invention is higher than the COP values ​​of R32, R410A and R290, and has a significant energy-saving advantage.

[0035] 4. The unit volume refrigeration capacity of the refrigerant provided by the present invention is close to that of R32 and R410A, and higher than that of R290. It can be directly used to replace R32 and R410A without replacing too many components, or only changing some components.

[0036] 5. Under specific component ratio conditions, the refrigerant provided by the present invention has a higher refrigeration capacity per unit volume than R32.

[0037] 6. The system charge amount of the refrigerant provided by the present invention is much smaller than that of R32 and R410A, which can save the amount of refrigerant and reduce the risk of refrigerant leakage.

[0038] 7. The refrigerant provided by the present invention has a lower exhaust temperature than R32, which is beneficial to improving the low-temperature heating capacity and is also beneficial to the operation of the refrigeration compressor, making the refrigeration compressor more reliable.

[0039] 8. The refrigerant CO2 component of the present invention can reduce the combustion characteristics of the mixed refrigerant and improve the safety of the refrigerant application.

[0040] In summary, the refrigerant provided by the present invention is a mixed refrigerant with high energy efficiency, which can be used to directly replace R32 without replacing refrigeration components, has high COP, low exhaust temperature, large refrigeration capacity per unit volume, and small refrigerant filling amount. The ODP value of the present invention is 0, the GWP value is lower than 150, the environmental protection advantage is outstanding, and it has broad application prospects. It can be used to replace high GWP refrigerants such as R32 and R410A. It is applicable to refrigeration equipment such as household and commercial air-conditioning systems, heat pump water heaters, and automotive air-conditioning. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] The mixed refrigerant in the present invention is composed of two, three or more of carbon dioxide (R744), propylene (R1270), trifluoroethylene (R1123) and 1,1-difluoroethane (R152a), wherein the proportion of carbon dioxide is 1-30% and is a required component.

[0043] The basic physical properties of the four components are shown in Table 1.

[0044] Table 1: Basic physical properties of the four components

[0045]

[0046]

[0047] Based on the present invention, the mixed refrigerant formed by the above components can be prepared by conventional methods in the prior art, for example, comprising the following steps: mixing gaseous carbon dioxide, gaseous trifluoroethylene, gaseous propylene and gaseous 1,1-difluoroethane in proportion to obtain the mixed refrigerant.

[0048] For another example, the preparation method may also include the following steps: liquid carbon dioxide, liquid trifluoroethylene, liquid propylene and liquid 1,1-difluoroethane are uniformly mixed according to a certain proportion to obtain the mixed refrigerant.

[0049] The above refrigerants can be dissolved in each other according to the principle of like dissolves like, and thus can be charged into the refrigerant tank in the order of boiling point from high to low according to the weight ratio for physical mixing. Alternatively, they can be charged into the compressor in the order of boiling point from high to low according to the weight ratio, and can be used after being evenly mixed.

[0050] The following are specific embodiments:

[0051] Example 1: Pure carbon dioxide and pure propylene refrigerants are taken, and in a liquid state, 8% by mass of carbon dioxide and 92% by mass of propylene are fully physically mixed to obtain a mixed refrigerant.

[0052] Example 2: Pure carbon dioxide, pure propylene and pure 1,1-difluoroethane refrigerants are taken, and in a liquid phase, 10% by mass of carbon dioxide, 60% by mass of propylene and 30% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0053] Example 3: Pure carbon dioxide, pure propylene and pure 1,1-difluoroethane refrigerants are taken, and in a liquid phase, 12% by mass of carbon dioxide, 58% by mass of propylene and 30% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0054] Example 4: Pure carbon dioxide, pure propylene and pure trifluoroethylene refrigerants are taken, and in a liquid state, 8% by mass of carbon dioxide, 42% by mass of propylene and 50% by mass of trifluoroethylene are fully physically mixed to obtain a mixed refrigerant.

[0055] Example 5: Pure carbon dioxide, pure propylene and pure trifluoroethylene refrigerants are taken, and in a liquid state, 10% by mass of carbon dioxide, 30% by mass of propylene and 60% by mass of trifluoroethylene are fully physically mixed to obtain a mixed refrigerant.

[0056] Example 6: Pure carbon dioxide and pure propylene refrigerants are taken, and in a liquid state, 5% by mass of carbon dioxide and 95% by mass of propylene are fully physically mixed to obtain a mixed refrigerant.

[0057] Example 7: Pure carbon dioxide and pure propylene refrigerants are taken, and in a liquid phase, 12% by mass of carbon dioxide and 88% by mass of propylene are fully physically mixed to obtain a mixed refrigerant.

[0058] Example 8: Pure carbon dioxide, pure propylene and 1,1-difluoroethane refrigerants are taken, and in a liquid phase, 5% by mass of carbon dioxide, 45% by mass of propylene and 50% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0059] Example 9: Pure carbon dioxide, pure propylene and 1,1-difluoroethane refrigerants are taken, and in a liquid phase, 10% by mass of carbon dioxide, 80% by mass of propylene and 10% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0060] Example 10: Pure carbon dioxide, pure propylene and 1,1-difluoroethane refrigerants are taken, and in a liquid phase, 10% by mass of carbon dioxide, 40% by mass of propylene and 50% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0061] Example 11: Pure carbon dioxide, pure propylene and 1,1-difluoroethane refrigerants are taken, and in a liquid state, 15% by mass of carbon dioxide, 33% by mass of propylene and 52% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0062] Example 12: Pure carbon dioxide, pure propylene and 1,1-difluoroethane refrigerants are taken, and in a liquid state, 15% by mass of carbon dioxide, 30% by mass of propylene and 55% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0063] Example 13: Pure carbon dioxide, pure propylene and 1,1-difluoroethane refrigerants are taken, and in a liquid state, 15% by mass of carbon dioxide, 75% by mass of propylene and 10% by mass of 1,1-difluoroethane are fully physically mixed to obtain a mixed refrigerant.

[0064] Example 14: Take pure carbon dioxide, pure propylene and trifluoroethylene refrigerants, and in a liquid state, take 5% by mass of carbon dioxide, 40% by mass of propylene and 55% by mass of trifluoroethylene for thorough physical mixing to obtain a mixed refrigerant.

[0065] Example 15: Take pure carbon dioxide, pure propylene and trifluoroethylene refrigerants, and in a liquid state, take 5% by mass of carbon dioxide, 65% by mass of propylene and 30% by mass of trifluoroethylene for thorough physical mixing to obtain a mixed refrigerant.

[0066] Example 16: Take pure carbon dioxide, pure propylene and trifluoroethylene refrigerants, and in a liquid state, take 10% by mass of carbon dioxide, 40% by mass of propylene and 50% by mass of trifluoroethylene for thorough physical mixing to obtain a mixed refrigerant.

[0067] Example 17: Take pure carbon dioxide, pure propylene and trifluoroethylene refrigerants, and in a liquid state, take 10% by mass of carbon dioxide, 70% by mass of propylene and 20% by mass of trifluoroethylene for thorough physical mixing to obtain a mixed refrigerant.

[0068] Example 18: Take pure carbon dioxide, pure propylene and trifluoroethylene refrigerants, and in a liquid state, take 15% by mass of carbon dioxide, 20% by mass of propylene, and 65% by mass of trifluoroethylene for thorough physical mixing to obtain a mixed refrigerant.

[0069] Example 19: Take pure carbon dioxide, pure propylene and trifluoroethylene refrigerants, and in a liquid state, take 15% by mass of carbon dioxide, 50% by mass of propylene and 35% by mass of trifluoroethylene for thorough physical mixing to obtain a mixed refrigerant.

[0070] To compare the performance, the above embodiment is used to perform theoretical cycle calculation of the air conditioning system with R32 and R290, and the refrigeration condition of the air conditioner is: evaporation temperature is 10°C, condensation temperature is 47.5°C, condenser outlet temperature is 38°C, compressor inlet temperature is 20°C, and compressor isentropic efficiency is 0.7; the heating condition is: evaporation temperature is 2°C, condensation temperature is 45°C, condenser outlet temperature is 35°C, compressor inlet temperature is 5°C, and compressor isentropic efficiency is 0.7. The calculated parameters are shown in Tables 2 and 3 below.

[0071] Table 2: Refrigeration cycle performance parameters of R32, R290 and Examples 1-5

[0072]

[0073] Table 3: Heating cycle performance parameters of R32, R290 and Examples 1-5

[0074]

[0075] According to the theoretical calculation results of the above working conditions, it can be concluded that:

[0076] 1. The GWP value of the mixed refrigerant in Example 1 is about 20, the COP is 11% higher than that of the R32 direct cooling cycle, and the unit volume refrigeration capacity reaches 80.7% of that of the R32, and the exhaust temperature is 73.27°C, which is about 30°C lower than that of the R32 system. The heating COP is 2.2% higher than that of the R32 system, and the volume heating capacity can reach 75.9% of that of the R32 system. In the process of replacing the R32 air conditioner application, the compressor does not need to be replaced.

[0077] 2. The GWP value of the mixed refrigerant in Example 2 is about 49.3, the COP is 18.9% higher than that of the R32 direct cooling cycle, and the unit volume refrigeration capacity reaches 87.9% of that of R32, and the exhaust temperature is 70.43°C, which is about 32°C lower than that of the R32 system. The heating COP is 2.4% higher than that of the R32 system, and the volume heating capacity can reach 78.1% of the R32 system. In the process of replacing the R32 air conditioner application, the compressor does not need to be replaced.

[0078] 3. The GWP value of the mixed refrigerant in Example 3 is about 48.92, the COP is 13.9% higher than that of the R32 direct cooling cycle, and the unit volume refrigeration capacity reaches 90.1% of that of the R32, and the exhaust temperature is 72.6°C, which is about 30°C lower than that of the R32 system. The heating COP is about 1.5% lower than that of the R32 system, and the volume heating capacity can reach 79.8% of the R32 system. In the process of replacing the R32 air conditioner application, the compressor does not need to be replaced.

[0079] 4. The mixed refrigerant of Example 4 has a GWP value of <3, a COP that is 15.8% higher than the R32 direct cooling cycle, and a unit volumetric refrigeration capacity that is 7.4% higher than that of the R32 system. The exhaust temperature is 65.72°C, which is about 37°C lower than that of the R32 system. The heating COP is equivalent to that of the R32 system, and the volumetric heating capacity is equivalent to that of the R32 system. In the process of replacing the R32 air conditioner application, the compressor size can remain unchanged, and the energy efficiency ratio is higher.

[0080] 5. The mixed refrigerant GWP value of Example 5 is <3, the COP is 12.5% ​​higher than the R32 direct cooling cycle, and the unit volume refrigeration capacity is 13.5% higher than that of R32. The exhaust temperature is 65.33°C, which is about 37°C lower than that of the R32 system. The heating COP is 2.8% higher than that of the R32 system, and the volume heating capacity is 9% higher than that of the R32 system. In the process of replacing R32 air conditioning applications, the compressor size can be further reduced, and the energy efficiency ratio is higher.

[0081] In addition, the mixed refrigerants obtained in Examples 6-19 also have relatively good thermal performance (of course, the overall performance is slightly inferior to that of Examples 1-5), as shown in Tables 4 to 6.

[0082] Table 4: Thermodynamic properties of the mixed refrigerants obtained in Examples 6-7

[0083]

[0084]

[0085] Table 5: Thermodynamic properties of the mixed refrigerants obtained in Examples 8-13

[0086]

[0087] Table 6: Thermodynamic properties of the mixed refrigerants obtained in Examples 14-19

[0088]

[0089]

[0090] It can be seen that the mixed refrigerant of the present invention is an environmentally friendly refrigerant, has no ozone layer damage, and has a very low greenhouse effect. The GWP of the above embodiments does not exceed 150, meeting the requirements of the EU F-gas regulations for environmentally friendly refrigerants for household air conditioners. The present invention can be widely used in various fields of refrigeration, especially in refrigeration devices such as household air conditioners, central air conditioners, heat pump water heaters, and automobile air conditioners.

[0091] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An environmentally friendly mixed refrigerant containing CO2, characterized in that: It is a mixture of at least one of the three components of propylene, 1,1-difluoroethane, and trifluoroethylene with carbon dioxide; The mixed refrigerant is composed of two components, carbon dioxide and propylene, wherein the mass percentage of carbon dioxide in the mixed refrigerant is 5% to 12%, and the mass percentage of propylene in the mixed refrigerant is 88% to 95%; the GWP value of the mixed refrigerant is less than 150; Alternatively, the mixed refrigerant is composed of three components: carbon dioxide, propylene and 1,1-difluoroethane, wherein the mass percentage of carbon dioxide in the mixed refrigerant is 5% to 15%, the mass percentage of propylene in the mixed refrigerant is 33% to 85%, and the mass percentage of 1,1-difluoroethane in the mixed refrigerant is 10% to 55%; the GWP value of the mixed refrigerant is less than 150; Alternatively, the mixed refrigerant is composed of three components: carbon dioxide, propylene and trifluoroethylene, wherein the mass percentage of carbon dioxide in the mixed refrigerant is 5% to 15%, the mass percentage of propylene in the mixed refrigerant is 20% to 70%, and the mass percentage of trifluoroethylene in the mixed refrigerant is 20% to 65%; the GWP value of the mixed refrigerant is less than 150.

2. The environmentally friendly mixed refrigerant containing CO2 as claimed in claim 1, characterized in that: The mixed refrigerant consists of two components, carbon dioxide and propylene. The mass ratio of carbon dioxide to propylene in the mixed refrigerant is 0.05:0.95, or 0.08:0.92, or 0.1:0.9, or 0.12:0.

88.

3. The environmentally friendly mixed refrigerant containing CO2 as claimed in claim 1, characterized in that: The mixed refrigerant is composed of three components: carbon dioxide, propylene and 1,1-difluoroethane. The mass ratio of carbon dioxide, propylene and 1,1-difluoroethane in the mixed refrigerant is 0.1:0.8:0.1, or 0.1:0.75:0.15, or 0.1:0.7:0.2, or 0.1:0.65:0.25, or 0.1:0.6:0.3, or 0.1:0.55:0.35, or 0.1:0.5:0 .4, or 0.1:0.45:0.45, or 0.1:0.4:0.5, or 0.12:0.78:0.1, or 0.12:0.68:0.2, or 0.12:0.63:0.25, or 0.12:0.58:0.3, or 0.12:0.53:0.35, or 0.12:0.48:0.4, or 0.12:0.43:0.45, or 0.12:0 .38:0.5, or 0.12:0.33:0.55, or 0.15:0.75:0.1, or 0.15:0.7:0.15, or 0.15:0.65:0.2, or 0.15:0.6:0.25, or 0.15:0.55:0.3, or 0.15:0.5:0.35, or 0.15:0.45:0.4, or 0.15:0.4:0.45, or 0 .15:0.35:0.5, or 0.05:0.85:0.1, or 0.05:0.8:0.15, or 0.05:0.75:0.2, or 0.05:0.7:0.25, or 0.05:0.65:0.3, or 0.05:0.6:0.35, or 0.05:0.55:0.4, or 0.05:0.5:0.45, or 0.05:0.45:0.

5.

4. The environmentally friendly mixed refrigerant containing CO2 as claimed in claim 1, characterized in that: The mixed refrigerant is composed of three components: carbon dioxide, propylene and trifluoroethylene. The mass ratio of carbon dioxide, propylene and trifluoroethylene in the mixed refrigerant is 0.05:0.4:0.55, or 0.05:0.45:0.5, or 0.05:0.5:0.45, or 0.05:0.55:0.4, or 0.05:0.6:0.35, or 0.05:0.65:0.3, or 0.1:0.4:0.5, or 0.1:0.45:0.45, or 0.1:0.5:0.4, or 0.1:0.55:0.35, or 0.1:0.6:0.3, or 0.1:0.65:0.25, or 0.1:0.7:0.2, or 0.08:0.42:0.5, or 0.08:0.47:0.45, or 0.08:0.52:0.4, or 0.08:0.57:0.35, or 0.08:0.62:0.3, or 0.15:0.2:0.65, or 0.15:0.25:0.6, or 0.15:0.3:0.55, or 0.15:0.35:0.5, or 0.15:0.4:0.45, or 0.15:0.45:0.4, or 0.15:0.5:0.

35.

5. Use of the environmentally friendly mixed refrigerant containing CO2 as claimed in any one of claims 1 to 4 as a refrigerant.

6. The use according to claim 5, characterized in that The application is specifically as a refrigerant for household air conditioners, central air conditioners, heat pump water heaters or automobile air conditioners.

7. The use according to claim 5, characterized in that The application is specifically to replace R32, R410A or R290.

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