Mixed refrigerant and preparation method thereof and air conditioning system

Abstract

The present invention provides a mixed refrigerant and a preparation method thereof and an air-conditioning system, wherein the refrigerant comprises a first component, a second component and a third component, wherein the first component is 3,3,3-trifluoropropyne, the second component is trifluoroiodomethane, and the third component is at least one of 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane. The mixed refrigerant of the present invention has a GWP far less than 150, an ODP of 0, is green and safe, and has obvious environmental advantages. The mixed refrigerant has a thermal performance equivalent to that of R290, a unit volume refrigeration capacity better than that of R290, and a safety higher than that of R290, and becomes a mixed refrigerant capable of replacing R290; 3,3,3-trifluoropropyne is combined with trifluoroiodomethane, 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane, and the obtained atmospheric boiling point is as low as -40°C, which is close to the boiling point of R290, has good refrigeration and heating performance, and the temperature glide is lower than 4°C.

Description

Technical Field

[0001] The present invention relates to the field of refrigeration technology, and more specifically to a mixed refrigerant and a preparation method thereof, and an air-conditioning system. Background Art

[0002] As people's environmental awareness increases, they pay more and more attention to environmental protection. In the field of air conditioning, the requirements for refrigerants are getting higher and higher. After several generations of changes, the global warming potential (GWP) and ozone depletion potential (ODP) of refrigerants are getting lower and lower. The development of refrigerants can be summarized into four stages: the first stage (1830-1930), the principle of this stage is "whatever can be used", the refrigerants used are all natural refrigerants, and the types are limited; the second stage (1931-1990), this period began to use synthetic refrigerants, which greatly improved the refrigeration efficiency, safety and durability The third stage (1991-2010) mainly used some hydrocarbons (HCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs) and natural refrigerants that had no or little destructive effect on the ozone layer. The fourth stage (2010 to date) put forward new requirements for refrigerants: ODP value of 0, low global warming potential GWP, and high refrigeration efficiency. The refrigerants currently used mainly include low-GWP HFCS and unsaturated hydrofluorocarbons (HFOs), mixed refrigerants, hydrocarbons (HCs) and some natural refrigerants (propane, ammonia, carbon dioxide and water).

[0003] Propane (R290) is a natural and environmentally friendly refrigerant with the advantages of low GWP, no ozone layer damage, and easy availability, and has great development potential. However, its flammable and explosive properties greatly limit its scope of application. Therefore, finding a refrigerant with performance comparable to that of propane (R290), low GWP value, and high safety is of great significance for energy conservation and emission reduction. Therefore, the existing technology needs further improvement and development. Summary of the invention

[0004] In view of the various deficiencies in the prior art and in order to solve the above problems, a mixed refrigerant and a preparation method thereof and an air-conditioning system are proposed to solve the low safety shortcomings of the refrigerants in the prior art and to design a mixed refrigerant that can replace propane and has a lower GWP value and higher safety.

[0005] According to one aspect of the present invention, a mixed refrigerant is provided, comprising a first component, a second component and a third component, wherein the first component is 3,3,3-trifluoropropyne, the second component is trifluoroiodomethane, and the third component is at least one of 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane.

[0006] Furthermore, in terms of mass percentage, the mixed refrigerant includes 48-88% of the first component, 4-40% of the second component and 4-12% of the third component.

[0007] Furthermore, in terms of mass percentage, the mixed refrigerant includes 52-76% of the first component, 16-40% of the second component and 4-8% of the third component.

[0008] Furthermore, in terms of mass percentage, the mixed refrigerant includes 60-68% of the first component, 28-36% of the second component and 4-8% of the third component.

[0009] Furthermore, in terms of mass percentage, the mixed refrigerant includes 48-68% of the first component, 20-40% of the second component and 12% of the third component.

[0010] Furthermore, in terms of mass percentage, the mixed refrigerant includes 68-88% of the first component, 12-40% of the second component and 4-12% of the third component.

[0011] Furthermore, the mixed refrigerant includes, by mass percentage, 76% of 3,3,3-trifluoropropyne, 20% of trifluoroiodomethane and 4% of 1,1,2,2-tetrafluoroethane.

[0012] Furthermore, the third component is 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane, wherein the mass ratio of 1,1,2,2-tetrafluoroethane to 1,1,1,2-tetrafluoroethane is 1:1.

[0013] According to another aspect of the present invention, a method for preparing a mixed refrigerant is provided, comprising the following steps: mixing the components of the mixed refrigerant according to their corresponding mass percentages in a liquid phase state at room temperature to obtain the mixed refrigerant.

[0014] According to another aspect of the present invention, an air conditioning system is provided. The air conditioning system includes a refrigerant. The refrigerant includes the mixed refrigerant of the present invention.

[0015] Due to the adoption of the above technical solution, the beneficial technical effects of the present invention are:

[0016] 1. The mixed refrigerant of the present invention is green, safe and environmentally friendly. The GWP of the mixed refrigerant is much less than 150, and the ODP is 0, which has obvious environmental advantages. At the same time, the thermal performance of the mixed refrigerant is equivalent to that of R290, the refrigeration capacity per unit volume is better than that of R290, and the safety level is higher than that of R290, so it can become a mixed refrigerant that can replace R290;

[0017] 2. The present invention combines 3,3,3-trifluoropropyne with trifluoroiodomethane, 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane, and regulates the amount of each component, so that the boiling point of the mixed refrigerant is lower than the boiling point of each component alone, and is close to the boiling point of R290, has good cooling and heating performance, and the temperature glide is lower than 4°C. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the embodiments of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making any creative work should all fall within the scope of protection of this application.

[0019] Terminology explanation:

[0020] R290: Propane.

[0021] TFP: 3,3,3-trifluoropropyne.

[0022] R13I1: trifluoroiodomethane.

[0023] R134: 1,1,2,2-Tetrafluoroethane.

[0024] R134a: 1,1,1,2-Tetrafluoroethane.

[0025] ODP value: ozone depletion potential.

[0026] Relative unit volume cooling capacity Qv: the ratio of unit volume cooling capacity of mixed refrigerant to R290.

[0027] Relative coefficient of performance COP: the ratio of the coefficient of performance of the mixed refrigerant to R290.

[0028] Temperature glide: The change in phase change temperature when a mixed refrigerant undergoes phase change at a constant pressure.

[0029] As described in the background of the present invention, the prior art has the problem that the refrigerant is flammable and explosive and has low safety. In order to solve the above problem, in a typical embodiment of the present invention, a mixed refrigerant is provided, including a first component, a second component and a third component, wherein the first component is 3,3,3-trifluoropropyne, the second component is trifluoroiodomethane, and the third component is at least one of 1,1,2,2-tetrafluoroethane and 1,1,1,2-tetrafluoroethane.

[0030] TFP has a GWP value of 11 and a standard boiling point of -48°C. Its GWP value and standard boiling point are relatively low, but its flammability is relatively high and its safety category is A3. Therefore, TFP cannot take into account safety performance when used alone as a refrigerant. R13I1 has a safety category of A1 and can be used as a flame retardant to reduce the flammability of mixed refrigerants. R134 and R134a have higher GWP values, but their relative volumetric cooling capacity is relatively large. The basic parameters of each component are shown in Table 1 below. Each component has its own advantages and disadvantages. In particular, from the perspective of flame retardancy, TFP has high flammability, while R13I1, R134 and R134a have good flame retardancy. Therefore, these components are specifically combined, and the appropriate components and the amount of each component are adjusted to prepare a mixed refrigerant, so that the prepared mixed refrigerant has high safety performance, and the volumetric cooling capacity is better than R290, the relative volumetric cooling capacity is greater than 1, the relative performance coefficient is ≥0.9, the GWP value is less than 150, and the lowest GWP value can reach 52.56, which meets the low GWP environmental protection requirements and has good cooling and heating performance. And the temperature glide is less than 4°C. R13I1, R134a, and R134 have low boiling points. When mixed with TFP with a lower boiling point, a new mixed refrigerant is formed. After calculation and experimental testing, it is found that the boiling point of the mixed refrigerant is as low as -40°C. The boiling point of the mixed refrigerant is close to that of R290. When the volumetric cooling capacity of the mixed refrigerant is close to that of R290 and the lubricant is not considered, they can be used as a substitute in the same model, further reducing the development cost. In addition, in general, the lower the boiling point of the refrigerant, the easier it is for the liquid to evaporate at normal temperature and pressure, that is, the lower the boiling point of the refrigerant is, the refrigerant can absorb a lot of heat when it evaporates from liquid to gas. The lower the boiling point of the refrigerant, the lower the evaporation temperature, and the better the refrigeration effect.

[0031] Table 1 Basic parameters of each component

[0032]

[0033] Among them, A1 is non-flammable, A2L is weakly flammable, A2 is flammable, and A3 is flammable and explosive.

[0034] The preparation method of the mixed refrigerant of the present invention is: the first step: combining the first component, the second component and the third component in a certain mass ratio, and the preferred combination is shown in Table 2.

[0035] Table 2 Combination of mixed refrigerants

[0036] Combination TFP R13I1 R134 and / or R134a Quality ratio 48-88％ 4-40％ 4-12％

[0037] As the main component of the mixed refrigerant, TFP has a volumetric cooling capacity and performance similar to R290, a lower GWP value, but a higher flammability. As the main component, TFP reduces the bubble point of the mixed refrigerant, and its GWP value is lower, which also reduces the overall GWP value of the mixed refrigerant. As a flammable refrigerant, R13I1 is added to reduce the flammability, but if only R13I1 is added, its relative volumetric cooling capacity is low, and the mixed refrigerant will not achieve the desired effect of a relative volumetric cooling capacity greater than 0.9, and the safety is not as good as adding a certain third component. Therefore, the first component, the second component and the third component are mixed, and only when the usage ratio of the three reaches a certain range can the various properties of the prepared mixed refrigerant be taken into account.

[0038] Among them, the GWP value of R134 is 1120, the standard boiling point is -20°C, the GWP value of R134a is 1300, and the standard boiling point is -26°C. Therefore, the present invention can also prepare a safe, environmentally friendly refrigerant with good cooling and heating performance by adding R134 and R134a at the same time and then adjusting the dosage ratio of each component.

[0039] In order to further improve the relative Qv and relative COP of the mixed refrigerant while balancing the environmental performance, safety performance and thermophysical properties such as temperature glide and atmospheric pressure bubble point temperature, thereby obtaining a mixed refrigerant with better comprehensive performance, a preferred combination is shown in Table 3, and the relative volumetric cooling capacity of the mixed refrigerant is greater than or equal to 1.

[0040] Table 3 Combination of mixed refrigerants

[0041] Combination TFP R13I1 R134a Quality ratio 52-76％ 16-40％ 4-8％

[0042] In order to further improve the relative Qv and relative COP of the mixed refrigerant while balancing the environmental performance, safety performance and thermophysical properties such as temperature glide and atmospheric pressure bubble point temperature, thereby obtaining a mixed refrigerant with better comprehensive performance, a preferred combination is shown in Table 4, and the relative volumetric cooling capacity of the mixed refrigerant is greater than or equal to 1.05.

[0043] Table 4 Combination of mixed refrigerants

[0044] Combination TFP R13I1 R134a Quality ratio 60-68％ 28-36％ 4-8％

[0045] In order to further improve the relative Qv and relative COP of the mixed refrigerant while balancing the environmental performance, safety performance and thermophysical properties such as temperature glide and atmospheric pressure bubble point temperature, thereby obtaining a mixed refrigerant with better comprehensive performance, a preferred combination method is shown in Table 5, and the relative volumetric cooling capacity of the mixed refrigerant is greater than or equal to 1.

[0046] Table 5 Combination of mixed refrigerants

[0047] Combination TFP R13I1 R134 Quality ratio 48-68％ 20-40％ 12％

[0048] In order to further improve the relative Qv and relative COP of the mixed refrigerant while balancing the environmental performance, safety performance and thermophysical properties such as temperature glide and atmospheric pressure bubble point temperature, thereby obtaining a mixed refrigerant with better comprehensive performance, a preferred combination is shown in Table 6, and the relative volumetric cooling capacity of the mixed refrigerant is greater than or equal to 1.09.

[0049] Table 6 Combination of mixed refrigerants

[0050] Combination TFP R13I1 R134 Quality ratio 68-88％ 12-40％ 4-12％

[0051] Step 2: Physically mix the components and their corresponding mass proportions in a liquid state at room temperature, and obtain the corresponding refrigerant after uniform mixing.

[0052] According to the above method, a number of specific embodiments and comparative examples are given below, wherein the proportions of the substances are all mass percentages, and the sum of the mass percentages of the substances of each refrigerant is 100%. In each embodiment and comparative example, each substance is physically mixed in liquid phase at a fixed mass ratio under normal temperature and pressure liquid phase state, and a refrigerant is obtained by mixing evenly. The embodiments and comparative examples are shown in Table 7.

[0053] Table 7 Different Examples and Comparative Examples

[0054]

[0055]

[0056] The design conditions are: evaporation temperature is 10°C, condensation temperature is 40°C, superheat is 5°C, subcooling is 5°C, and the adiabatic efficiency of the compressor is 0.75. The cycle performance parameters of the refrigerants in the above embodiments and comparative examples and the refrigerant R290 in the refrigeration system are theoretically calculated, and the GWP (calculated by linear addition of mass percentage), relative unit volume refrigeration capacity Qv (ratio with the unit volume refrigeration capacity of R290), relative performance coefficient COP (ratio with the performance coefficient of R290), safety category and temperature glide are compared. The temperature glide refers to the change in phase change temperature when the refrigerant mixture undergoes phase change at a constant pressure. The results are shown in Table 8.

[0057] Table 8 Performance comparison results of the embodiments and comparative examples with R290

[0058]

[0059]

[0060] As can be seen from Table 8, the bubble point temperature difference between Comparative Example 1-4 and Example 1-16 is too large, the bubble point temperature of Comparative Example 1-4 is much higher than the bubble point temperature of Example 1-16, and the temperature glide of Comparative Example 1-4 is greater than 4 degrees Celsius. If the temperature glide is too large, the heat exchanger needs to be re-optimized and designed, while the temperature glide of Example 1-16 is less than 4°C. It can be seen that even if the same components are selected, but the component dosage is not within the mass ratio provided in this application, the performance of the mixed refrigerant cannot reach the effect of the mixed refrigerant prepared by the embodiment of the present application. For the dosage ratio between the components of the present application, the dosage ratio is changed, and the performance effect of the mixed refrigerant prepared by it will also have unexpected effects. Only under the conditions of 48-88% of the first component, 4-40% of the second component and 4-12% of the third component can the prepared mixed refrigerant have good thermodynamic properties, a volumetric cooling capacity greater than R290, and a coefficient of performance (COP) equivalent to R290. The temperature glide of the mixed refrigerant is less than 4°C, and its safety level is better than R290, the ozone depletion potential ODP value is zero, the global warming potential GWP value is less than 150, and the environmental performance is excellent. Further observation of Table 8 shows that when the mixed refrigerant is 76% 3,3,3-trifluoropropyne, 20% trifluoroiodomethane and 4% 1,1,2,2-tetrafluoroethane, its relative unit volumetric cooling capacity reaches 1.13, the relative performance coefficient is 0.95, the temperature glide is 1.47°C, the bubble point temperature is -43.7°C, the safety level is A2L, and the volumetric cooling capacity is better than R290.

[0061] The mixed refrigerant obtained in each embodiment can be applied to air-conditioning systems, and can completely replace R290 while greatly improving safety performance, which is of great significance for energy conservation and emission reduction.

[0062] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A mixed refrigerant, characterized in that: It comprises a first component, a second component and a third component, wherein the first component is 3,3,3-trifluoropropyne, the second component is trifluoroiodomethane, and the third component is 1,1,2,2-tetrafluoroethane; In terms of mass percentage, the mixed refrigerant includes 76% of 3,3,3-trifluoropropyne, 20% of trifluoroiodomethane and 4% of 1,1,2,2-tetrafluoroethane.

2. The method for preparing a mixed refrigerant according to claim 1, characterized in that: The following steps are involved: The components of the mixed refrigerant are mixed according to their corresponding mass percentages in a liquid phase state at room temperature to obtain the mixed refrigerant.

3. An air conditioning system, characterized in that: The air conditioning system includes a refrigerant, and the refrigerant includes the mixed refrigerant according to claim 1.

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