Heat transfer composition and application thereof

Abstract

The invention discloses a heat transfer composition and application thereof, and the heat transfer composition comprises the following components in percentage by mass: 60 to 95 percent of Z-1-chloro-2, 3, 3-trifluoropropene and 5 to 40 percent of 1, 1, 1, 3, 3, 3-hexafluoroisopropyl methyl ether. The heat transfer composition disclosed by the invention has the advantages of excellent environmental performance, good safety performance, large expansion work, high acting efficiency, low evaporation pressure, low temperature slippage and the like.

Description

Technical Field

[0001] The present invention relates to the field of heat transfer working fluids, and particularly to a heat transfer composition and its application. Background Art

[0002] In recent years, global warming has been intensifying, and the government is implementing various policies conducive to energy conservation and emission reduction.

[0003] In the industrial field, especially in industries such as petrochemical, sewage treatment, and printing and dyeing, a large amount of industrial waste heat is often generated, and waste heat recovery needs to be carried out through methods such as heat pump systems or work systems to improve the comprehensive utilization rate of industrial energy and promote energy conservation and emission reduction.

[0004] According to the "List of Controlled Ozone-Depleting Substances in China" (Announcement No. 44, 2021, by the Ministry of Ecology and Environment, the National Development and Reform Commission, and the Ministry of Industry and Information Technology), China will gradually reduce the production and use of hydrofluorocarbons (HFCs). Among them, for the ninth category of hydrofluorocarbons such as R245fa, according to the provisions of the "Protocol" and related amendments, the production and use in 2024 should be frozen at the baseline level, reduced by 10% on the frozen level in 2029, reduced by 30% in 2035, reduced by 50% in 2040, and reduced by 80% in 2045. The baseline level is the average value of HFCs from 2020 to 2022 plus 65% of the HCFCs baseline level, calculated in units of carbon dioxide equivalent.

[0005] Due to the environmental protection issues of R245fa, some studies on the replacement of R245fa working fluids have been carried out in the prior art, such as:

[0006] The heat transfer composition for replacing R245fa in CN114907816A uses a composition of HFC-143, HCFO-1233zd(E) and / or HCFO-1224yd(Z), and HFO-1336mzz(E) to replace HFC-245fa for application in a work system, which has the advantages of safety, environmental protection, strong phase change heat transfer ability, high heating capacity / cooling capacity per unit volume, etc. However, the critical temperature of one of its main components, HFC-143, is only 73.1, which is not suitable for use in a work system.

[0007] The recovered heat composition for replacing R245fa in WO2012064477A3 uses a composition of HFO-1336mzz(E) and HFE-236ea to replace HFC-245fa, which has the advantages of non-toxicity, non-flammability, and the ability to improve the efficiency of the R245fa system. However, its main component, HFE-236ea, has a low work efficiency, and the boiling point differences of the composition components are large, with a temperature glide > 3°C.

[0008] In summary, there is an urgent need to develop a heat transfer composition that can replace R245fa in a work system and is safe, environmentally friendly, and efficient. Summary of the Invention

[0009] To solve the above technical problems, the present invention provides a heat transfer composition with excellent environmental performance, good safety performance, large expansion work, high work efficiency, low evaporation pressure, and low temperature glide. This heat transfer composition replaces R245fa and is used in a work system.

[0010] Basic physical property data of the heat transfer composition substances:

[0011] Z-1-chloro-2,3,3-trifluoropropene (HCFO-1233yd(Z)), with the molecular formula C3H2F3Cl, molecular weight of 130.5, standard boiling point of 54 °C, critical temperature of 224.43 °C, critical pressure of 4.27 MPa, non-toxic and non-flammable, and GWP < 1.

[0012] 1,1,1,3,3,3-hexafluoroisopropyl methyl ether (HFE-356mmz), with the molecular formula C4H4F6O, molecular weight of 182.06, standard boiling point of 50.95 °C, critical temperature of 186.43 °C, critical pressure of 2.699 MPa, non-toxic, and GWP = 25.

[0013] Pentafluoropropane (hereinafter referred to as R245fa) has a critical temperature of 153.86 °C, a critical pressure of 3.651 MPa, and a boiling point of 15.14 °C. It is a commonly used working fluid in systems such as organic Rankine cycles. It belongs to the HFC class of working fluids, has an ODP of 0 and a GWP of 858, and belongs to Class B1 in the ASHRAE classification and is a toxic refrigerant.

[0014] The object of the present invention is achieved by the following technical solutions:

[0015] In a first aspect, the present invention provides a heat transfer composition, which comprises Z-1-chloro-2,3,3-trifluoropropene with a mass percentage content of 60 - 95% and 1,1,1,3,3,3-hexafluoroisopropyl methyl ether with a mass percentage content of 5 - 40%.

[0016] Further, the heat transfer composition comprises Z-1-chloro-2,3,3-trifluoropropene with a mass percentage content of 75 - 95% and 1,1,1,3,3,3-hexafluoroisopropyl methyl ether with a mass percentage content of 5 - 25%.

[0017] Still further, the heat transfer composition comprises Z-1-chloro-2,3,3-trifluoropropene with a mass percentage content of 85 - 95% and 1,1,1,3,3,3-hexafluoroisopropyl methyl ether with a mass percentage content of 5 - 15%.

[0018] As an embodiment, the heat transfer composition of the present invention further comprises an auxiliary agent, which is selected from at least one of 1-butyne, 1-pentene, 2,2-dimethylbutane, cis-2-butene, trans-2-butene, pentane, cyclopentane, isopentane, and neopentane. Preferably, the auxiliary agent is selected from at least one of 1-pentene, pentane, or isopentane.

[0019] The mass of the auxiliary agent accounts for 1-3% of the total mass of the heat transfer composition. The purpose of adding the auxiliary agent is to improve the compatibility of the heat transfer composition with the lubricating oil and enhance the cyclic heat transfer efficiency.

[0020] As an embodiment, the heat transfer composition of the present invention further comprises a lubricating oil, which is selected from at least one of dibasic acid ester oil, polyol carbonate oil, perfluoropolyether oil, fluorinated silicone oil, naphthenic mineral oil, polyalphaolefin, alkylbenzene, or alkylnaphthalene.

[0021] The temperature glide of the heat transfer composition of the present invention is ≤ 0.5°C.

[0022] The heat transfer composition of the present invention is non-flammable, with an ODP value of approximately 0 and a GWP value < 15. The ODP value is based on CFC-11 as a reference value of 1.0, and the GWP value is based on CO2 as a reference value of 1.0 (100 years).

[0023] The work system absorbs thermal energy from a heat source for doing work. Generally, the temperature of the heat source is 80-140°C. The required working fluid should have good evaporation performance within this temperature range, such as a large evaporation enthalpy, a low evaporation pressure, etc., and thus should have a relatively large critical temperature and boiling point; as a component of the composition, it should have a similar boiling point to reduce the temperature glide; and it should have good environmental and safety performance, etc.

[0024] In a second aspect, the present invention further provides an application of a heat transfer composition, wherein the heat transfer composition replaces R245fa in a work system, and the work system comprises a condenser, an evaporator, a working fluid pump, and an expander.

[0025] Furthermore, the work system further comprises a subcooler.

[0026] Compared with R245fa, the evaporation pressure of the heat transfer composition of the present invention used in the work system is reduced by more than 60%.

[0027] Compared with R245fa, the work efficiency of the heat transfer composition of the present invention used in the work system is increased by more than 5%.

[0028] Compared with R245fa, the output work of the heat transfer composition of the present invention used in the work system is increased by more than 14%. Further, it is increased by more than 30%.

[0029] In the present invention, above a certain value, including this value and values greater than this value, for example, above 60% includes 60% and values greater than 60%.

[0030] As an embodiment, the evaporation temperature of the work system of the present invention is 80 - 140 °C, and the condensation temperature is 30 - 70 °C.

[0031] The work system described in the present invention includes, but is not limited to, an organic Rankine cycle system.

[0032] As an embodiment, the work system described in the present invention includes a shell-and-tube subcooler.

[0033] Based on a large number of tests and theoretical studies on the relevant physical properties of HCFO-1233yd(Z) and HFE-356mmz, the present invention finally obtains a heat transfer composition, which has the advantages of excellent environmental performance, good safety performance, large expansion work, high work efficiency, low evaporation pressure, and temperature slip < 0.5 °C.

[0034] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0035] 1. The ODP value of the heat transfer composition of the present invention is about 0, and GWP < 15, with excellent environmental performance.

[0036] 2. The heat transfer composition of the present invention is non-flammable, low-toxic, and has good safety performance.

[0037] 3. When the heat transfer composition of the present invention is applied to a work system, it has large expansion work, high work efficiency, and low evaporation pressure. Description of the Drawings

[0038] Figure 1 It is a working schematic diagram of a work system. 1 is an evaporator, 2 is an expander, 3 is a motor, 4 is a condenser, and 5 is a working fluid pump.

[0039] Figure 2 It is a working schematic diagram of a work system with a subcooler. 1 is an evaporator, 2 is an expander, 3 is a motor, 4 is a condenser, 5 is a subcooler, and 6 is a working fluid pump. Detailed Embodiments

[0040] The present invention will be further described below in conjunction with specific embodiments, but the present invention is not limited to these specific embodiments. Those skilled in the art should recognize that the present invention covers all alternative solutions, improvement solutions, and equivalent solutions that may be included within the scope of the claims.

[0041] I. Heat Transfer Composition

[0042] The preparation method of the heat transfer composition in the embodiments of the present invention is to physically mix Z-1-chloro-2,3,3-trifluoropropene and 1,1,1,3,3,3-hexafluoroisopropyl methyl ether in the liquid phase according to the mass percentages of the respective components. The heat transfer compositions involved in the embodiments and comparative examples of the present invention are specifically as follows:

[0043] Example 1: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 95:5.

[0044] Example 2: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 90:10.

[0045] Example 3: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 85:15.

[0046] Example 4: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 80:20.

[0047] Example 5: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 75:25.

[0048] Example 6: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 70:30.

[0049] Example 7: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 65:35.

[0050] Example 8: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 60:40.

[0051] Comparative Example 1: Physically mix HCFO-1233yd(Z) and HFE-356mmz in the liquid phase according to a mass percentage of 40:60.

[0052] II. Basic Physical Properties of the Heat Transfer Composition

[0053] (I) Flammability

[0054] The following Table 1 gives the combustion grades of each example, specifically as follows:

[0055] Table 1 Flammability

[0056] Example Combustion rating Example 1 1 Example 2 1 Example 3 1 Example 4 1 Example 5 1 Example 6 1 Example 7 1 Example 8 1 Comparative example 1 2 HCFO-1233yd(Z) 1 HFE-356mmz 2 R245fa 1

[0057] The above flammability test adopted the national standard GB / T 12474-2008. As can be seen from Table 1 above, the heat transfer compositions of all embodiments of the present invention are non-flammable, and HCFO-1233yd(Z) inhibits the flammability of HFE-356mmz in the composition.

[0058] (II) Temperature glide and environmental performance

[0059] Table 2 below gives the data such as temperature glide and environmental performance of the heat transfer compositions of each embodiment and comparative example, which are specifically as follows:

[0060] Table 2 Temperature glide, evaporation enthalpy and environmental performance

[0061]

[0062] The temperature glide of the heat transfer compositions of each embodiment under standard atmospheric pressure is ≤0.5°C, and GWP < 15.

[0063] (III) Stability

[0064] The heat transfer compositions of each embodiment and comparative example were added to a heat-resistant glass bottle containing a test piece of SPCC and stored at the boiling point (54°C) of HCFO-1233yd(Z) for 7 days. Record the pH change of the working fluid before and after the experiment, which is specifically as follows:

[0065] Table 3 Working fluid stability

[0066]

[0067]

[0068] The stability of the heat transfer compositions of each embodiment is good.

[0069] III. Application of heat transfer composition in a power cycle

[0070] In the power system, the organic working fluid absorbs the high-temperature waste heat of the industry to become steam with a certain temperature and pressure, and then does work through an expander to drive power generation. The power system can effectively recover waste heat, which is of great significance for China to achieve carbon peak and carbon neutrality.

[0071] The performance indicators of the heat transfer composition power system are: evaporation pressure (p), work efficiency (η), and system output work (w).

[0072] Appendix Figure 1The working schematic diagrams of the heat compositions of each example and comparative example in the power generation system are given. When the power generation system is working, the heat transfer composition is transported to the evaporator via the working fluid pump and heated to high-temperature and high-pressure gas in the evaporator. The high-temperature and high-pressure gas drives the power generation by pushing the expander, and the expander drives the motor to generate electricity, completing the recovery and utilization of waste heat. After the working fluid finishes driving the expander to do work, it turns into low-temperature and low-pressure gas. The low-temperature and low-pressure gas releases the remaining heat through the condenser and is reconverted into low-temperature and low-pressure liquid, and then is transported to the evaporator by the working fluid pump to absorb heat. And so on in a cycle.

[0073] In the power generation system, the system output work (w) is expressed as: the work done by the working fluid in the expander minus the work consumed by the working fluid pump. The greater the expansion work, the more electricity can be generated per unit of working fluid.

[0074] The power generation efficiency (η) is expressed as: the ratio of the expansion work minus the work of the working fluid pump to the heat absorbed by the working fluid in the evaporator. The higher the power generation efficiency, the better the system performance.

[0075] Table 8 gives the performance data of the heat compositions of each example and comparative example under different working conditions of the power generation system, which are specifically as follows:

[0076] Table 8 Performance under the working conditions of the power generation system

[0077]

[0078]

[0079] As can be seen from Table 8 above, in the working conditions of the power generation system, the relative system output work of Comparative Example 1 is smaller than that of each example, the cycle efficiency is slightly lower than that of each example, and the evaporation pressure is slightly higher than that of each example.

[0080] Compared with R245fa, for the cycle efficiency of the heat transfer composition of each example, the system evaporation pressure is reduced by 62%-69%, the power generation efficiency is increased by 5%-14%, and the output work is increased by 14%-43%. Considering the comprehensive expansion work, cycle efficiency and safety, the application effect of each example in the power generation system is significantly better than that of R245fa, and the comprehensive advantages of the heat transfer composition of each example of the present invention are significantly higher than those of the commonly used R245fa and its substitutes at present.

[0081] In the power generation system, a subcooler is usually connected to the outlet of the condenser to obtain the subcooling degree, as shown in the appendix Figure 2 , the subcooling degree means stronger heat transfer ability at the high-pressure end, and also means lower dryness after flashing through the throttling element, improving the utilization rate of the evaporator. A lower subcooling degree can obtain a higher COP and higher volumetric heating / cooling capacity.

[0082] Experimental analysis was carried out in a shell-and-tube subcooler with an inner diameter of 10 mm, an outer diameter of 30 mm, and a total length of 1300 mm. The heat transfer composition of each example / control was the heat source side, and water was the cold side. The inlet temperature of the heat transfer composition was set at 30 °C, and the inlet temperature of water was 20 °C.

[0083] Table 9 gives the performance data of heat exchange of each example, control, and R245fa in the shell-and-tube subcooler, which are specifically as follows:

[0084] Table 9 Heat transfer performance in the shell-and-tube subcooler

[0085]

[0086] As can be seen from Table 9 above, under the same subcooler and inlet and outlet conditions, the outlet temperature of the heat transfer composition of each example is similar to that of R245fa, the outlet temperature of water is higher than that of R245fa, and the heat transfer amount is higher than that of R245fa. The heat transfer amount of the subcooler in each example exceeds that of R245fa by more than 5.7%, having a more excellent heat transfer ability. Therefore, the heat transfer composition of the embodiments of the present invention has a better utilization rate in the subcooler, can obtain a higher COP and volumetric refrigeration / heating capacity than R245fa, and has a better application effect than R245fa in a chiller / heat pump system with a subcooler / superheater.

Claims

1. A heat transfer composition, characterized in that: The heat transfer composition comprises 60-95% by mass of Z-1-chloro-2,3,3-trifluoropropene and 5-40% by mass of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether.

2. The heat transfer composition according to claim 1, wherein: The heat transfer composition comprises 75-95% by mass of Z-1-chloro-2,3,3-trifluoropropene and 5-25% by mass of 1,1,1,3,3,3-hexafluoroisopropyl methyl ether.

3. The heat transfer composition according to any one of claims 1-2, characterized in that: The heat transfer composition further comprises an auxiliary agent selected from at least one of 1-butyne, 1-pentene, 2,2-dimethylbutane, cis-butene, trans-butene, pentane, cyclopentane, isopentane, and neopentane, and the mass of the auxiliary agent accounts for 1-3% of the total mass of the heat transfer composition.

4. The heat transfer composition according to any one of claims 1-2, characterized in that: The heat transfer composition further comprises a lubricating oil selected from at least one of a dibasic acid ester oil, a polyol carbonate oil, a perfluoropolyether oil, a fluorinated silicone oil, a naphthenic mineral oil, a polyalphaolefin, an alkylbenzene, or an alkylnaphthalene.

5. Use of the heat transfer composition according to any one of claims 1-4, characterized in that: The heat transfer composition replaces R245fa in a power generation system, and the power generation system comprises a condenser, an evaporator, a working fluid pump, and an expander.

6. Use of the heat transfer composition according to claim 5, characterized in that: The power generation system further comprises a subcooler.

7. Use of the heat transfer composition according to any one of claims 5-6, characterized in that: Compared with R245fa, the evaporation pressure of the heat transfer composition used in the power generation system is reduced by more than 60%.

8. Use of the heat transfer composition according to any one of claims 5-6, characterized in that: Compared with R245fa, the power generation efficiency of the heat transfer composition used in the power generation system is increased by more than 5%.

9. Use of the heat transfer composition according to any one of claims 5-6, characterized in that: Compared with R245fa, the output work of the heat transfer composition used in the power generation system is increased by more than 14%.

10. Use of the heat transfer composition according to any one of claims 5-6, characterized in that: The evaporation temperature of the power generation system is 80-140 °C, and the condensation temperature is 30-70 °C.

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