Refrigerant for replacing R134a as well as preparation method and application of refrigerant

Abstract

The invention belongs to the technical field of refrigerants, and particularly relates to a refrigerant for replacing R134a as well as a preparation method and application of the refrigerant. The refrigerant for replacing R134a is prepared from the following components in parts by weight: 60 to 80 parts of 1, 1, 1, 2-tetrafluoroethane and 20 to 40 parts of 1, 1-difluoroethane. As a refrigerant for replacing R134a, the refrigerant provided by the invention generally has the advantages of excellent environmental protection property, high refrigeration efficiency and good safety.

Description

Technical Field

[0001] This invention belongs to the field of refrigerant technology, specifically relating to a refrigerant for replacing R134a, its preparation method and application. Background Technology

[0002] R134a refrigerant is a widely used HFC refrigerant in air conditioning and heat pump systems, and its main component is tetrafluoroethane. Although R134a has excellent refrigeration performance, its GWP value is relatively high (approximately 1430). In addition, R32 alone, although having a lower GWP (approximately 675), has mild flammability (A2L safety class) and a higher discharge temperature; R152a alone has higher flammability (A2 safety class) and poor refrigeration efficiency; R1216 (hexafluoropropylene) alone has an extremely low GWP (<1), but its thermophysical properties differ significantly from R134a, resulting in poor system compatibility.

[0003] Existing alternatives such as R290, R1234yf, and R410A, while offering improvements in GWP or safety, suffer from issues such as flammability, increased GWP, or significant decreases in refrigeration performance. Therefore, developing a low-GWP, high-performance, safe alternative refrigerant compatible with R134a systems has become an urgent need in the air conditioning industry. The purpose of this invention is to provide a novel hybrid refrigerant with a significantly lower GWP than R134a, while maintaining similar thermodynamic properties and operating characteristics, specifically optimized for refrigeration systems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a low-GWP alternative refrigerant, R134a, for use in air conditioning systems, its preparation method, and its applications. This refrigerant offers advantages such as excellent environmental friendliness, high refrigeration efficiency, and good safety.

[0005] The technical solution provided by this invention is as follows: A low-GWP alternative refrigerant for replacing R134a is a near-azeotropic mixture comprising the following components in parts by weight: 60-80 parts of 1,1,1,2-tetrafluoroethane (R134a, CH2FCF3) and 20-40 parts of 1,1-difluoroethane (R152a, CH3CHF2).

[0006] Based on the above technical solution: The refrigerant provided by this invention has the advantages of significantly reducing the global warming potential by about 24%-35% compared with the existing HFC-134a refrigerant, and having a volumetric cooling capacity and COP that are comparable to or slightly better than those of the existing HFC-134a refrigerant. The refrigerant provided by this invention has the advantage of higher safety (by adding R134a to suppress flammability) compared to using 1,1-difluoroethane alone; The refrigerant provided by this invention has the advantages of lower operating pressure, higher refrigeration performance, better system compatibility, and no need for large-scale modification of existing R134a systems compared to using 1,1,1,2-tetrafluoroethane alone.

[0007] Preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 60-70 parts of 1,1,1,2-tetrafluoroethane and 25-30 parts of 1,1-difluoroethane.

[0008] Preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 60-70 parts of 1,1,1,2-tetrafluoroethane and 31-35 parts of 1,1-difluoroethane.

[0009] Preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 71-80 parts of 1,1,1,2-tetrafluoroethane and 25-30 parts of 1,1-difluoroethane.

[0010] Preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 71-80 parts of 1,1,1,2-tetrafluoroethane and 31-35 parts of 1,1-difluoroethane.

[0011] More preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 62 parts of 1,1,1,2-tetrafluoroethane and 28 parts of 1,1-difluoroethane.

[0012] More preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 70 parts of 1,1,1,2-tetrafluoroethane and 30 parts of 1,1-difluoroethane.

[0013] More preferably, the refrigerant used to replace R134a comprises the following components in parts by weight: 78 parts of 1,1,1,2-tetrafluoroethane and 32 parts of 1,1-difluoroethane.

[0014] Specifically: The refrigerant used to replace R134a is any combination of the following proportions: The parts of 1,1,1,2-tetrafluoroethane are 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, and 80. The parts of 1,1-difluoroethane are 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, and 40.

[0015] The present invention also provides a method for preparing the above-mentioned refrigerant to replace R134a, comprising the following steps: According to the stated weight ratio, 1,1,1,2-tetrafluoroethane and 1,1-difluoroethane in gaseous or liquid phases are injected into a pressure-resistant container at room temperature, and mixed evenly in the liquid phase using a physical mixing method. After standing, the near-azeotropic R134a alternative refrigerant can be obtained.

[0016] The present invention also provides applications of the above-mentioned refrigerant for replacing R134a, for replacing R134a refrigerant in air-cooled systems; or for replacing R134a refrigerant in water-cooled systems; or for replacing R134a working fluid in heat pumps.

[0017] The beneficial effects of this invention are as follows: The GWP value of the refrigerant of this invention is significantly reduced by about 18% to 36% compared with R134a, demonstrating outstanding environmental advantages and conforming to the future development direction of refrigerants; The refrigerant has an extremely low glide temperature and is a near-azeotropic mixture. It is stable in the system and does not easily undergo component separation. Compared to HFC-134a, the refrigerant of this invention has a higher latent heat of vaporization and equivalent or higher refrigeration performance, resulting in higher system energy efficiency. The evaporation and condensation pressures of the refrigerant are very close to those of HFC-134a, and the compressor refrigeration oil is interchangeable (POE oil can usually be used), making it easy to directly replace the refrigerant. The ODP (Ozone Depletion Potential) is zero, meaning it does not damage the ozone layer. By adjusting the formula, a flexible balance can be achieved between GWP, cooling performance, and safety. Detailed Implementation

[0018] The principles and features of the present invention are described below. The embodiments given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0019] Unless otherwise specified, the test methods used in the embodiments are conventional methods; unless otherwise specified, the materials and reagents used are commercially available.

[0020] Example 1 A refrigerant for replacing R134a comprises the following components in parts by weight: 65 parts of 1,1,1,2-tetrafluoroethane and 35 parts of 1,1-difluoroethane.

[0021] The preparation method of refrigerant is as follows: Following the above proportions, high-purity 1,1,1,2-tetrafluoroethane (R134a) and 1,1-difluoroethane (R152a) raw materials are precisely measured and injected sequentially into clean, dry pressure-resistant steel cylinders at room temperature (20-25℃) and in a liquid phase. After evacuating the cylinders to remove air, a small amount of inert gas (such as nitrogen) is introduced for cleaning, followed by another evacuation. Finally, the mixed working fluid is filled into the cylinders and placed on a rolling mixer for at least 2 hours to ensure uniform mixing of all components. After standing for 24 hours, it is ready for use.

[0022] Example 2 A refrigerant for replacing R134a comprises the following components in parts by weight: 69 parts of fluoroethane and 31 parts of 1,1-difluoroethane.

[0023] The refrigerant is prepared as follows: same as in Example 1.

[0024] Example 3 A refrigerant for replacing R134a comprises the following components in parts by weight: 74 parts of 1,1,1,2-tetrafluoroethane and 26 parts of 1,1-difluoroethane.

[0025] The refrigerant is prepared as follows: same as in Example 1.

[0026] Example 4 A refrigerant for replacing R134a comprises the following components in parts by weight: 78 parts of fluoroethane and 22 parts of 1,1-difluoroethane.

[0027] The refrigerant is prepared as follows: same as in Example 1.

[0028] Example 5 A refrigerant for replacing R134a comprises the following components in parts by weight: 80 parts of 1,1,1,2-tetrafluoroethane and 20 parts of 1,1-difluoroethane.

[0029] The refrigerant is prepared as follows: same as in Example 1.

[0030] Example 6 A refrigerant for replacing R134a comprises the following components in parts by weight: 70 parts of 1,1,1,2-tetrafluoroethane and 30 parts of 1,1-difluoroethane.

[0031] The refrigerant is prepared as follows: same as in Example 1.

[0032] Example 7 A refrigerant for replacing R134a comprises the following components in parts by weight: 60 parts of 1,1,1,2-tetrafluoroethane and 40 parts of 1,1-difluoroethane.

[0033] The refrigerant is prepared as follows: same as in Example 1.

[0034] The infusion volumes for the seven embodiments described above are shown in Table 1: Table 1 Comparison of relative R134a perfusion volume in Examples 1-7:

[0035] The selected design condition is: medium temperature condition. The unit type is suitable for temperate air conditioning of T1 climate type (GB / T7725-2004), and the following values ​​are taken: evaporation temperature = 7.2℃, subcooling = 5℃, condensation temperature = 54.4℃, superheat = 7℃. The compressor isentropic efficiency is 0.8 in the calculation.

[0036] According to the requirements of the national standard GB / T 7725-2022 "Room Air Conditioners", the following data were experimentally measured on the Gree split wall-mounted room air conditioner: KFR-32GW / (32583)FNAa-A3, and the performance parameters were compared: coefficient of performance (COP), relative coefficient of performance (COP), volumetric cooling capacity (Qv), relative unit volumetric cooling capacity (Qv), condensing pressure, GWP, latent heat of vaporization, temperature glide, and lower flammability limit, as shown in Table 2.

[0037] Table 2 Comparison of performance parameters of 7 embodiments of the present invention with R134a

[0038] As can be seen from the data in the table above, compared with R134a, the present invention has the following advantages in performance: Significantly improved environmental friendliness: The GWP values ​​of all embodiments were lower than those of R134a, with a significant reduction. Among them, the GWP of Embodiment 7 was the lowest, which was 36.5% lower than that of R134a.

[0039] Excellent cooling performance: The cooling capacity per unit volume of all embodiments is close to that of R134a, and the COP is better than that of R134a, indicating that they have better energy-saving effect.

[0040] Excellent thermodynamic properties: condensing pressures are all slightly lower than R134a, ensuring good compatibility with existing R134a systems and allowing for direct refill replacement. Near-azeotropic glide temperature (<0.2℃) ensures stable operation of the refrigeration system.

[0041] Based on the above-mentioned performance advantages, this invention has the following advantages when replacing R134a: 1) High feasibility of substitution: Since the working pressure and thermal properties are very close to those of R134a, it can be directly replaced by filling in the existing R134a system without replacing major components (such as compressors and heat exchangers) and lubricating oil, resulting in low modification costs.

[0042] 2) Improve system energy efficiency: The equivalent cooling capacity per unit volume and the slightly higher COP value are expected to enable the system to maintain or slightly improve its cooling capacity and operating efficiency after replacement.

[0043] 3) Meets environmental regulations: The significantly reduced GWP value enables systems using this refrigerant to meet current and future environmental regulations, extending the equipment's lifespan.

[0044] 4) Stable and reliable operation: The near-azeotropic characteristic reduces performance fluctuations and operational risks caused by component separation in different parts of the system.

[0045] 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A refrigerant for replacing R134a, characterized in that, It includes the following components in parts by weight: 60-80 parts of 1,1,1,2-tetrafluoroethane and 20-40 parts of 1,1-difluoroethane.

2. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 60-70 parts of 1,1,1,2-tetrafluoroethane and 25-30 parts of 1,1-difluoroethane.

3. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 60-70 parts of 1,1,1,2-tetrafluoroethane and 31-35 parts of 1,1-difluoroethane.

4. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 71-80 parts of 1,1,1,2-tetrafluoroethane and 25-30 parts of 1,1-difluoroethane.

5. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 71-80 parts of 1,1,1,2-tetrafluoroethane and 31-35 parts of 1,1-difluoroethane.

6. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 62 parts of 1,1,1,2-tetrafluoroethane and 28 parts of 1,1-difluoroethane.

7. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 70 parts of 1,1,1,2-tetrafluoroethane and 30 parts of 1,1-difluoroethane.

8. The refrigerant for replacing R134a according to claim 1, characterized in that, It includes the following components in parts by weight: 78 parts of 1,1,1,2-tetrafluoroethane and 32 parts of 1,1-difluoroethane.

9. A method for preparing a refrigerant to replace R134a according to any one of claims 1 to 8, characterized in that, Includes the following steps: According to the stated weight ratio, 1,1,1,2-tetrafluoroethane and 1,1-difluoroethane in gaseous or liquid phases are injected into a pressure-resistant container at room temperature, and mixed evenly in the liquid phase using a physical mixing method. After standing, the near-azeotropic R134a alternative refrigerant can be obtained.

10. An application of the refrigerant according to any one of claims 1 to 8 for replacing R134a, characterized in that: Used to replace R134a refrigerant in air-cooled systems; Alternatively, it can be used to replace R134a refrigerant in water-cooling systems; Alternatively, it can be used to replace the R134a working fluid in heat pumps.

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