Azeotropic and azeotrope-like mixture and preparation method thereof

Abstract

The invention relates to a binary azeotropic and azeotrope-like mixture composition and a preparation method thereof. In a normal-temperature liquid phase, a first component and a second component are uniformly mixed to obtain the binary mixed heat exchange working medium; the first component is perfluoro (4-methyl-2-pentene), and the second component is hexafluorobutene; the perfluoro (4-methyl-2-pentene) and hexafluorobutene copolymer is prepared from the following components in parts by weight: 25.9 parts of perfluoro (4-methyl-2-pentene) and 74.1 parts of hexafluorobutene, the binary mixture prepared by the invention is an azeotropic mixture, and has higher latent heat of vaporization and lower global warming potential value. Except the azeotropic point, the components which are close to the azeotropic point and have the respective change within 1% by weight are azeotrope-like mixtures.

Description

Technical Field

[0001] The present invention relates to the field of heat exchange working fluids, and in particular to a binary azeotropic mixture and azeotrope-like mixture and a preparation method thereof. Background Art

[0002] The successful synthesis and application of Freon in the 1930s enabled the refrigeration industry to achieve unprecedented great development. Since then, refrigeration devices have become more stable and reliable, with superior performance, and gradually made refrigeration an independent discipline. However, subsequent research found that Freon, especially HCFCs and CFCs, has a great destructive effect on the atmospheric environment, mainly reflected in the destruction of the ozone layer and the promotion of global warming. At present, the international community has adopted regulations such as the Vienna Convention, the Montreal Protocol on Substances that Deplete the Ozone Layer, and the Kyoto Protocol to restrict the use of HCFCs and CFCs heat exchange working fluids. In the past few decades, many industries have been working hard to find alternatives to chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs). DuPont Fluorochemicals in the United States, which was later spun off to become Chemours, and Honeywell in the United States were the first to propose the fourth-generation olefin-based heat exchange working fluids of hydrofluoroolefins (HFOs) and hydrochlorofluoroolefins (HCFOs) and became the mainstream. These heat exchange working fluids are widely used in many fields such as refrigeration, foaming, cleaning, insecticide, flame retardant, and propellant.

[0003] With the continuous innovation of technology, the demand for data processing and data transmission has not only increased, the power consumption of data center chips has been rising continuously, the graphics processing has been enhanced, and the requirement for computing power has been gradually increasing, resulting in a sharp increase in the energy density of data centers, leading to the continuous evolution of the heat dissipation method from air cooling to single-phase liquid cooling and then to two-phase liquid cooling, which puts forward requirements for heat exchange working fluids, especially the application demand for two-phase working fluids.

[0004] Japanese Patent JP7422740B2: Provided is an azeotropic composition formed by selecting from n-butane and isobutane and a second component of Z-1,1,1,4,4,4-hexafluorobut-2-ene (Z-HFO-1336mzz). The molar ratio of n-butane and isobutane in this invention patent is about 10%. The combustible content in this invention is relatively high and it is flammable.

[0005] US Patent US20220025146A1: Disclosed is an azeotropic or azeotrope-like composition containing Z-1,1,1,4,4,4-hexafluoro-2-butene and methyl perfluoropropyl ether. It also discloses the application occasions such as using this azeotropic or azeotrope-like composition as a foaming agent, heat exchange working fluid, solvent, aerosol propellant, heat transfer medium, fire extinguishing agent, and dielectric. The AEL of methyl perfluoropropyl ether contained in this invention is only 350 PPM, which has certain toxicity and a relatively high GWP, about 420.

[0006] Patent WO2014022638A1: An azeotropic or azeotrope-like composition is disclosed, which is composed of E-1,3,4,4,4-pentafluoro-3-trifluoromethyl-1-butene and Z-1,1,1,4,4,4-hexafluoro-2-butene. The use of this azeotropic or azeotrope-like composition as a blowing agent, heat transfer working fluid, solvent, aerosol propellant, heat transfer medium, fire extinguishing agent, dielectric, etc. is also disclosed. E-1,3,4,4,4-pentafluoro-3-trifluoromethyl-1-butene is difficult to synthesize and has a high cost.

[0007] The azeotropic or azeotrope-like compositions formed by the above patents either have rare raw materials, or have high toxicity, high GWP or are flammable. The mixture with a specific ratio provided by the present invention is an azeotropic and azeotrope-like compound, with a GWP of about 7, being environmentally friendly, having a high latent heat of vaporization of about 140 kJ / kg, a boiling point of about 32 °C, and low toxicity. It can be used as a two-phase liquid heat exchange medium for data centers, and can also be used in heat pumps, cleaning agents, blowing agents, fire extinguishing agents, dielectrics, etc. Summary of the Invention

[0008] To effectively solve the problems faced by existing working fluids, the present invention provides a composition and preparation method of a binary azeotropic working fluid. The key to this method is to operate in a normal temperature liquid phase environment. Normal temperature generally refers to an environmental temperature of 20 °C - 30 °C, which is easy to achieve and does not require additional temperature control equipment, reducing the preparation cost. In the liquid phase state, the intermolecular forces and motion states of substances are conducive to the full mixing of the two components.

[0009] During specific operation, the first component perfluoro(4-methyl-2-pentene) and the second component hexafluorobutene are added to a suitable mixing container. The mixing container needs to have good corrosion resistance because perfluoro(4-methyl-2-pentene) and hexafluorobutene may corrode some common materials. For example, a stainless steel container can be selected. At the same time, to ensure uniform mixing, a stirring device can be used for stirring. The stirring speed should be reasonably adjusted according to the container size and the amount of materials, generally controlled at 100 - 300 revolutions per minute, and the stirring time should be no less than 30 minutes to ensure full contact and mixing of the two components, and finally obtain a binary mixed heat transfer working fluid.

[0010] Component Ratio Range

[0011] The binary mixed heat transfer working fluid involved in the present invention has various ranges of the proportions of its components, specifically as follows:

[0012] First proportion range: By weight, it consists of 10 - 20 parts of perfluoro(4-methyl-2-pentene) and 80 - 90 parts of hexafluorobutene. At this proportion, due to the relatively large proportion of hexafluorobutene, the boiling point of the heat transfer working fluid is relatively low, which is suitable for some refrigeration scenarios with high low-temperature requirements, such as low-temperature refrigeration equipment. At the same time, the heat transfer working fluid at this proportion has good fluidity and can circulate more smoothly in the refrigeration system.

[0013] Second proportion range: By weight, it consists of 20 - 30 parts of perfluoro(4-methyl-2-pentene) and 70 - 80 parts of hexafluorobutene. This proportion enables the heat transfer working fluid to achieve a good balance between the latent heat of vaporization and the refrigeration efficiency. The appropriate increase in perfluoro(4-methyl-2-pentene) helps to improve the stability of the heat transfer working fluid, enabling it to maintain good refrigeration performance under different working conditions.

[0014] Third proportion range: By weight, it consists of 30 - 40 parts of perfluoro(4-methyl-2-pentene) and 60 - 70 parts of hexafluorobutene. At this time, the comprehensive performance of the heat transfer working fluid is relatively prominent, its global warming potential is further reduced, and at the same time, the latent heat of vaporization can also meet the requirements of most conventional refrigeration equipment, and it is widely used in fields such as commercial air conditioners.

[0015] Fourth proportion range: By weight, it consists of 40 - 50 parts of perfluoro(4-methyl-2-pentene) and 50 - 60 parts of hexafluorobutene. At this proportion, the synergistic effect of the two components enhances the chemical stability of the heat transfer working fluid, enabling it to better adapt to complex refrigeration environments and reducing the decomposition and loss of the heat transfer working fluid in the system.

[0016] Fifth proportion range: By weight, it consists of 50 - 60 parts of perfluoro(4-methyl-2-pentene) and 40 - 50 parts of hexafluorobutene. The heat transfer working fluid at this proportion has a relatively high density and can carry more cooling capacity in a refrigeration system of the same volume, improving the refrigeration efficiency. At the same time, its boiling point is also relatively high, which is suitable for some occasions with high requirements for temperature control accuracy.

[0017] Sixth proportion range: By weight, it consists of 60 - 70 parts of perfluoro(4-methyl-2-pentene) and 30 - 40 parts of hexafluorobutene. With the further increase in the proportion of perfluoro(4-methyl-2-pentene), the solubility of the heat transfer working fluid is improved, enabling it to better dissolve with the lubricating oil in the refrigeration system and reducing the occurrence of problems such as poor lubrication.

[0018] Seventh proportion range: By weight, it consists of 70 - 80 parts of perfluoro(4-methyl-2-pentene) and 20 - 30 parts of hexafluorobutene. The heat transfer working fluid at this proportion has a relatively high flash point and higher safety, which is suitable for some refrigeration application scenarios with strict safety requirements.

[0019] Eighth proportion range: By weight, it consists of 80 - 90 parts of perfluoro(4 - methyl - 2 - pentene) and 10 - 20 parts of hexafluorobutene. At this time, perfluoro(4 - methyl - 2 - pentene) dominates, the chemical properties of the heat - transfer working fluid are more stable, the material compatibility with the refrigeration system is better, and the service life of the refrigeration equipment can be extended.

[0020] Specific proportion azeotrope

[0021] When the binary mixed heat - transfer working fluid consists of 25.9 parts of perfluoro(4 - methyl - 2 - pentene) and 74.1 parts of hexafluorobutene by weight, an azeotrope is formed. An azeotrope refers to a special mixture in which, under a certain pressure, the boiling point of the mixture remains constant and the compositions of the gas phase and the liquid phase are the same. In the present invention, the boiling point of this azeotrope is about 32°C.

[0022] When the binary mixed heat - transfer working fluid consists of 25.0 parts of perfluoro(4 - methyl - 2 - pentene) and 75.0 parts of hexafluorobutene by weight, a pseudo - azeotrope is formed.

[0023] When the binary mixed heat - transfer working fluid consists of 27.2 parts of perfluoro(4 - methyl - 2 - pentene) and 72.8 parts of hexafluorobutene by weight, a pseudo - azeotrope is formed.

[0024] The formation of this azeotrope and pseudo - azeotrope is of great significance. In the refrigeration cycle, azeotropes and pseudo - azeotropes can maintain stable boiling points and compositions, making the operation of the refrigeration system more stable and reliable. Compared with non - azeotropic mixtures, azeotropes do not show component separation during evaporation and condensation, avoiding fluctuations in refrigeration performance caused by component changes. At the same time, the boiling point of 32°C enables this azeotrope to have good heat - exchange performance under normal - temperature environments and can meet various heat - exchange requirements.

[0025] In summary, the preparation method of the binary mixed heat - transfer working fluid of the present invention not only solves the environmental and performance problems of existing heat - transfer working fluids by reasonably selecting components and proportions, but also further improves the stability and efficiency of the refrigeration system by forming an azeotrope, and has broad application prospects.

[0026] Reaction mechanism

[0027] The binary mixed heat - transfer working fluid consists of perfluoro(4 - methyl - 2 - pentene) and hexafluorobutene, and these two compounds form an azeotrope through physical mixing under normal temperature and pressure. The following is a detailed explanation of its reaction mechanism:

[0028] Intermolecular forces: Both perfluoro(4-methyl-2-pentene) and hexafluorobutene are fluorinated hydrocarbons with low polarity and high chemical stability. When these two components are mixed, the intermolecular forces between them (such as London dispersion forces) enable them to mix uniformly.

[0029] Azeotropic phenomenon: Due to the different volatilities of perfluoro(4-methyl-2-pentene) and hexafluorobutene, they can form an azeotropic mixture at a certain ratio. The boiling point of the azeotrope is lower than the individual boiling points of any component, and this phenomenon is called azeotropy.

[0030] Thermodynamic equilibrium: At the azeotropic point of 32 °C, the two components in the mixed heat transfer fluid reach the gas-liquid equilibrium state. At this time, the mole fractions of each component in the gas phase and the liquid phase are the same, and the total pressure is equal to the sum of the vapor pressures of each component.

[0031] Evaporation and condensation: During the refrigeration process, when the mixed heat transfer fluid absorbs heat, it changes from the liquid state to the gaseous state (evaporation), thereby taking away heat. When releasing heat, the gaseous heat transfer fluid will re-condense into the liquid state (condensation), completing a refrigeration cycle.

[0032] Technical effects

[0033] The binary mixed heat transfer fluid of the present invention has the following remarkable technical effects:

[0034] High-efficiency refrigeration performance: Since the azeotrope formed by perfluoro(4-methyl-2-pentene) and hexafluorobutene has a low boiling point (32 °C), this enables the heat transfer fluid to evaporate rapidly at a lower temperature, thereby improving the refrigeration efficiency. It is very suitable as a two-phase liquid cooling technology in data centers and has a high latent heat of vaporization.

[0035] Environmental protection characteristics: Compared with traditional Freon-based heat transfer fluids, the binary mixed heat transfer fluid of the present invention does not contain chlorine atoms, so it will not damage the ozone layer and meets international environmental protection requirements. In addition, the global warming potential (GWP) of this heat transfer fluid is relatively low. Calculated according to the 5th edition of the IPCC, the GWP value is about 7, which helps to slow down global climate change.

[0036] High safety: Both perfluoro(4-methyl-2-pentene) and hexafluorobutene are chemically stable compounds, not easily flammable or explosive, so they have high safety during storage and use.

[0037] Good compatibility: The binary mixed heat transfer fluid of the present invention can be compatible with existing refrigeration equipment, without the need for large-scale modification and upgrading of the equipment, reducing the cost of replacing the heat transfer fluid.

[0038] Significant energy-saving effect: Due to the high latent heat of vaporization of this heat transfer working fluid, the heat transfer working fluid per unit mass can absorb more heat, thereby reducing the energy consumption of refrigeration equipment and achieving the goal of energy conservation and emission reduction.

[0039] In summary, the binary mixed heat transfer working fluid of the present invention not only has good refrigeration performance and environmental protection characteristics, but also performs excellently in terms of safety, compatibility and energy conservation. It is an ideal new heat transfer working fluid to replace traditional Freon-based heat transfer working fluids. Description of the drawings

[0040] Figure 1 It is a test device diagram.

[0041] 1: Dynamic balance instrument - Xiaxi VLE1000 2: Pump 3: Manual two-way valve 4: Pipeline adapter

[0042] 5: Electronic flow controller 6: Chromatographic six-way injection valve 7: Vaporization chamber 8: Chromatographic column 9: Detector

[0043] 10: Agilent gas chromatograph analyzer 8890

[0044] V: Gas phase region of the analysis sample L: Liquid phase region of the analysis sample

[0045] Figure 2 It is a test diagram of the binary mixing component ratio of the example and the comparative example and the deviation of the gas-liquid phase ratio of each component at dynamic equilibrium. Detailed implementation manners

[0046] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following combines the drawings and preferred embodiments to describe in detail the specific implementation manners, structures, features and their effects of the present invention as follows.

[0047] Testing method: The cyclic analysis method is adopted, mainly referring to that the analyte with unknown components reaches system equilibrium by the forced two-phase flow mode of the liquid phase, gas phase or gas-liquid two-phase circulation pump in a closed equilibrium kettle, and then gas-liquid two-phase samples are taken respectively for component analysis; Sampling: The six-way valve is used for sample sampling; The instruments used are: Xiaxi VLE1000. The component analysis instrument is: Agilent 8890.

[0048] Example 1

[0049] A preparation method of a binary mixed heat transfer working fluid, characterized in that at normal temperature and liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat transfer working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0050] By weight, it consists of 25.9 g of perfluoro(4-methyl-2-pentene) and 74.1 g of hexafluorobutene.

[0051] Example 2

[0052] A preparation method of a binary mixed heat exchange working fluid, characterized in that, at normal temperature in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0053] By weight, it consists of 25.0 g of perfluoro(4-methyl-2-pentene) and 75.0 g of hexafluorobutene.

[0054] Example 3

[0055] A preparation method of a binary mixed heat exchange working fluid, characterized in that, at normal temperature in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0056] By weight, it consists of 27.2 g of perfluoro(4-methyl-2-pentene) and 72.8 g of hexafluorobutene.

[0057] Comparative Example 1

[0058] A preparation method of a binary mixed heat exchange working fluid, characterized in that, at normal temperature in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0059] By weight, it consists of 10 parts of perfluoro(4-methyl-2-pentene) and 90 parts of hexafluorobutene.

[0060] Comparative Example 2

[0061] A preparation method of a binary mixed heat exchange working fluid, characterized in that, at normal temperature in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0062] By weight, it consists of 20 parts of perfluoro(4-methyl-2-pentene) and 80 parts of hexafluorobutene.

[0063] Comparative Example 3

[0064] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0065] By weight, it is composed of 30 parts of perfluoro(4-methyl-2-pentene) and 70 parts of hexafluorobutene.

[0066] Comparative Example 4

[0067] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0068] By weight, it is composed of 40 parts of perfluoro(4-methyl-2-pentene) and 60 parts of hexafluorobutene.

[0069] Comparative Example 5

[0070] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0071] By weight, it is composed of 50 parts of perfluoro(4-methyl-2-pentene) and 50 parts of hexafluorobutene.

[0072] Comparative Example 6

[0073] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0074] By weight, it is composed of 60 parts of perfluoro(4-methyl-2-pentene) and 40 parts of hexafluorobutene.

[0075] Comparative Example 7

[0076] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and in the liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0077] By weight, it is composed of 70 parts of perfluoro(4-methyl-2-pentene) and 30 parts of hexafluorobutene.

[0078] Comparative Example 8

[0079] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0080] By weight, it is composed of 80 parts of perfluoro(4-methyl-2-pentene) and 20 parts of hexafluorobutene.

[0081] Comparative Example 9

[0082] A preparation method of a binary mixed heat exchange working fluid, characterized in that at normal temperature and liquid phase, the first component and the second component are mixed evenly to obtain the binary mixed heat exchange working fluid; the first component is perfluoro(4-methyl-2-pentene), and the second component is hexafluorobutene.

[0083] By weight, it is composed of 90 parts of perfluoro(4-methyl-2-pentene) and 10 parts of hexafluorobutene.

[0084] Table 1 Component ratios and gas-liquid phase deviations of examples and comparative examples

[0085]

[0086]

[0087] Table 2 Physical property data of Example 1

[0088] cis-Hexafluorobutene Perfluoro(4-methyl-2-pentene) Azeotrope Specific heat / J / kg.k 1200 1130 1181.9 Boiling point / °C 33.4 47 30.5 Latent heat (BP) / kJ / kg 160 95.66 143.3 Molecular weight 164 300 199.2 GWP 2 20 6.7 <![CDATA[Density / g / cm 3 > 1360 1626 1428.9 AEL (PPM) 500 1000 500

[0089] Through the data analysis of the above examples and comparative examples, only Example 1 forms an azeotrope. Examples 2 and 3 vary by ±1% in weight ratio based on Example 1, and the gas-liquid phase components obtained vary within 0.4% each. This change region is basically an azeotrope-like region.

[0090] As described above, it is only the preferred embodiments of the present invention, and there is no any form of limitation to the present invention. Although the present invention has been disclosed as above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments with equivalent changes within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a binary mixed heat exchange medium, characterized in that: In the liquid phase at room temperature, the first component and the second component are evenly mixed to obtain a binary mixed heat exchange medium; the first component is perfluoro(4-methyl-2-pentene) and the second component is hexafluorobutene.

2. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 10-20 parts of perfluoro(4-methyl-2-pentene) and 80-90 parts of hexafluorobutene.

3. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 20-30 parts of perfluoro(4-methyl-2-pentene) and 70-80 parts of hexafluorobutene.

4. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 30-40 parts of perfluoro(4-methyl-2-pentene) and 60-70 parts of hexafluorobutene.

5. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 40-50 parts of perfluoro(4-methyl-2-pentene) and 50-60 parts of hexafluorobutene.

6. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 50-60 parts of perfluoro(4-methyl-2-pentene) and 40-50 parts of hexafluorobutene.

7. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 60-70 parts of perfluoro(4-methyl-2-pentene) and 30-40 parts of hexafluorobutene.

8. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 70-80 parts of perfluoro(4-methyl-2-pentene) and 20-30 parts of hexafluorobutene.

9. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 80-90 parts of perfluoro(4-methyl-2-pentene) and 10-20 parts of hexafluorobutene.

10. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it is composed of 25.9 parts of perfluoro(4-methyl-2-pentene) and 74.1 parts of hexafluorobutene.

11. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it consists of 25.0 parts of perfluoro(4-methyl-2-pentene) and 75.0 parts of hexafluorobutene.

12. The method for preparing a binary mixed heat exchange medium according to claim 1, characterized in that: By weight, it is composed of 27.2 parts of perfluoro(4-methyl-2-pentene) and 72.8 parts of hexafluorobutene.

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