Temperature-controlled liquid for coal-based fischer-tropsch synthesis of hydrocarbons and preparation method and application thereof

Abstract

The present application belongs to the technical field of temperature control, and particularly relates to a temperature control liquid for coal-based Fischer-Tropsch synthesis hydrocarbon as well as a preparation method and application thereof. The temperature control liquid mainly comprises coal-based Fischer-Tropsch synthesis hydrocarbon, or the temperature control liquid mainly comprises coal-based Fischer-Tropsch synthesis hydrocarbon and liquid polyolefin. The distillation range of the coal-based Fischer-Tropsch synthesis hydrocarbon is less than or equal to 350 DEG C. The main component of the coal-based Fischer-Tropsch synthesis hydrocarbon is isomeric alkanes and normal alkanes with carbon number of 12-24, wherein the isomeric alkanes account for less than 90% of the total mass, and the normal alkanes account for more than 10% of the total mass. The kinematic viscosity of the coal-based Fischer-Tropsch synthesis hydrocarbon is less than or equal to 2.5 mm 2 / s at 100 DEG C, and 2.0-6.0 mm 2 / s at 40 DEG C. The kinematic viscosity of the liquid polyolefin is less than or equal to 8.0 mm 2 / s at 100 DEG C, and 2.0-20.0 mm 2 / s at 40 DEG C. The temperature control liquid has the characteristics of low density, low electrical conductivity, low kinematic viscosity and high heat conduction efficiency.

Description

Technical Field

[0001] This invention belongs to the field of temperature control technology, and specifically relates to a temperature-controlled liquid for coal-based Fischer-Tropsch synthesis, its preparation method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] With the increasing performance and integration of computing equipment, especially with the advancement of internet and 5G technologies, the rapid development of data centers across various industries has placed higher demands on the heat dissipation of high heat flux density electronic devices. In 2021, my country's data center energy consumption reached 216.6 billion kilowatt-hours, an increase of 44% compared to 2020, accounting for 2.6% of the country's total electricity consumption, equivalent to two years' worth of power generation from the Three Gorges Dam, and showing a year-on-year upward trend. Meanwhile, the average annual power usage effectiveness (PUE) of data centers nationwide in 2021 was 1.492, indicating significant room for energy conservation and emission reduction. The "Three-Year Action Plan for the Development of New Data Centers" issued by the Ministry of Industry and Information Technology clearly states that by the end of 2023, the PUE of newly built large-scale and above data centers should be reduced to below 1.3, and in severely cold and cold regions, efforts should be made to reduce it to below 1.25, setting more stringent standards and requirements for future data center energy consumption optimization. Therefore, achieving low-energy, rapid, and effective removal of heat generated by high-power electronic devices during use is an urgent problem to be solved.

[0004] Heat transfer includes three forms: convection, conduction, and radiation, with radiation being the least efficient. Traditional heat transfer methods primarily utilize convection, where thermally conductive materials transfer heat generated by high-heat-generating devices to a heat sink, and then a fan removes the conducted heat. However, due to the low thermal conductivity of air, air cooling is insufficient for heat dissipation in high-heat-generating devices like chips. Liquids, on the other hand, have a much higher thermal conductivity—25 times that of air—and can remove nearly 3000 times more heat than an equal volume of air. Furthermore, at the same heat dissipation level, liquid cooling reduces noise by 20-35 decibels compared to air cooling. Additionally, liquid cooling systems consume approximately 30%-50% less electricity than air cooling systems. Therefore, liquid conduction can rapidly remove heat generated in heat-generating devices, achieving effective cooling.

[0005] Cooling through liquid conduction can be categorized into direct and indirect cooling. Direct cooling allows the liquid to directly contact the heat-generating device, thus carrying away heat. In indirect cooling, the heat-generating device is encased in an electrically insulating barrier, and a temperature-controlled liquid carries away heat passing through this barrier, indirectly cooling the device. Currently, indirect cooling is the most widely used method for liquid conduction heat dissipation. However, this method suffers from drawbacks such as slow heat dissipation and uneven heat distribution. While the contact surface between the cooling system and the electrically insulating barrier cools quickly, the cooling rate inside the heat-generating device is slow. Direct cooling involves a temperature-controlled liquid circulating within the heat-generating device, carrying away heat during its circulation. This method results in a more uniform heat distribution and higher heat dissipation efficiency, and is currently the trend in cooling technology.

[0006] Currently, the most common heat transfer liquid is water-ethylene glycol, which is used for indirect cooling through pipelines and heat exchange systems. Its advantages are that the liquid itself is inexpensive and the corresponding supporting facilities are mature. Its disadvantage is that water-ethylene glycol is a highly conductive temperature-controlled liquid, and due to the risk of electrical conductivity, it cannot be used in direct cooling systems.

[0007] Compared to highly conductive temperature-controlled liquids, low-conductivity dielectric temperature-controlled liquids offer superior cooling efficiency. Furthermore, due to their low conductivity, they can directly cool heat-generating components, simplifying the device and providing better heat dissipation. However, a drawback is that these temperature-controlled liquids are typically fluorocarbons, silicone fluids, ester coolants, etc. The most commonly used fluorocarbons include chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HFCs), and (per)fluorinated polyethers (PFPEs). Commercial products include 3M from 3M. TM Fluorinert TMTemperature-controlled liquid products such as FC-40, FC-70, and FC-770 utilize fluorocarbon compounds, which possess high chemical inertness, stability, and insulation properties, resulting in excellent cooling and heat dissipation effects. They are commonly used for cooling sensitive electronic components in supercomputer systems, high-voltage transformers, and high-power electronic components, as well as for temperature-controlled coolants in etching equipment, ion implantation equipment, and chemical vapor deposition (CVD) processes in the semiconductor industry. However, these fluorocarbon temperature-controlled liquids also have significant drawbacks. They are highly corrosive greenhouse gases, contributing to global warming, and are difficult to biodegrade, hindering their environmental sustainability and climate-friendliness. Furthermore, fluorocarbons have a significantly higher density, resulting in a greater weight for the same volume of liquid. When applied to computing equipment such as data centers, this significantly increases the load on the floor and requires higher circulation power. In addition, their high cost, coupled with the need for large quantities for immersion direct cooling, greatly limits the prospects for widespread adoption and promotion of these temperature-controlled liquids. Commonly used silicone fluids include Dow's Silicone 5 / 10 / 20 series. Their advantages include high thermal conductivity and non-toxicity. However, they have disadvantages such as a lower flash point at the same viscosity, making them difficult to use safely and prone to viscosity increases or even gelation. Ester coolants are easily hydrolyzed into small molecules such as acids and alcohols. With prolonged use, the acid value of the system gradually increases, leading to increased corrosiveness to metals in equipment and making them unsuitable for long-term use.

[0008] Fischer-Tropsch synthesis is a process that uses syngas (CO + H2) as a feedstock to synthesize liquids primarily composed of saturated straight-chain hydrocarbons under catalytic conditions and appropriate reaction conditions. The syngas used in Fischer-Tropsch synthesis has a wide range of sources, including coal, natural gas, coalbed methane, and biomass such as lignocellulose, and is not constrained by natural petroleum reserves. In particular, Fischer-Tropsch synthesis using coal as a syngas feedstock can cleanly and efficiently utilize abundant coal resources to convert them into oil products and chemicals. Currently, coal is my country's primary energy source, but its utilization rate is very low, accompanied by significant CO2 emissions and environmental pollution. Therefore, developing various petroleum-based alternatives using coal as a feedstock can compensate for the current shortage of petroleum resources. Summary of the Invention

[0009] To overcome the aforementioned problems, the inventors discovered that by selecting coal-based Fischer-Tropsch synthetic hydrocarbons with specific distillation ranges, a temperature-controlled liquid with low density, low electrical conductivity, low kinematic viscosity, and high thermal conductivity can be obtained. Furthermore, this temperature-controlled liquid primarily consists of isoalkanes and n-alkanes with varying carbon numbers, contains no halogens such as fluorine or sulfur, is non-toxic and non-corrosive, and has no impact on global warming, thus achieving sustainability, environmental friendliness, and climate friendliness, overcoming the shortcomings of existing technologies. To further improve thermal conductivity and address the drawbacks of low flash point and high pour point when using coal-based Fischer-Tropsch synthetic hydrocarbons alone, liquid polyolefins can be added to the coal-based Fischer-Tropsch synthetic hydrocarbon base. This significantly improves the low-temperature fluidity of the temperature-controlled liquid, increases its flash point, and enhances its safety in use, in addition to improving thermal conductivity.

[0010] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0011] In a first aspect, the present invention proposes a temperature-controlled liquid, the main component of which is coal-based Fischer-Tropsch hydrocarbons, wherein the distillation range of the coal-based Fischer-Tropsch hydrocarbons is less than or equal to 320°C, preferably, the distillation range of the coal-based Fischer-Tropsch hydrocarbons is 220-300°C, and more preferably, the distillation range of the coal-based Fischer-Tropsch hydrocarbons is 278°C-299°C.

[0012] Fischer-Tropsch synthesis is a process that uses H2 and CO gas as raw materials to generate hydrocarbons through a catalytic reaction. The coal-based Fischer-Tropsch synthesis of hydrocarbons mentioned in this invention uses coal as raw material, which is gasified to produce syngas (H2 and CO), and then the H2 and CO undergo a Fischer-Tropsch synthesis reaction to obtain coal-based Fischer-Tropsch wax. The Fischer-Tropsch synthesis reaction temperature is 180-350℃, the reaction pressure is 0.1-3.0 MPa, the volume ratio of H2 to CO is less than 1.8, and the preferred volume ratio range is 0.9-1.8. The catalysts used in the Fischer-Tropsch synthesis include iron-based catalysts, cobalt-based catalysts, and ruthenium-based catalysts. In addition to the corresponding metals or metal oxides, the catalysts used also contain supported or mixed supports such as silica, alumina, and molecular sieves.

[0013] The coal-based Fischer-Tropsch synthetic wax is almost entirely composed of straight-chain hydrocarbons, typically containing at least 80 wt% straight-chain hydrocarbons with a carbon distribution ranging from C2 to C150. This invention preferably uses Fischer-Tropsch synthetic waxes with a straight-chain hydrocarbon content higher than 80 wt% and a carbon distribution of C30-C100, which are then subjected to hydrocracking and fractionation to obtain the final coal-based Fischer-Tropsch synthetic hydrocarbons for use.

[0014] Hydrocracking reduces the carbon chain length of straight-chain hydrocarbons and converts unsaturated alkenes in the products into saturated alkanes, significantly increasing the content of isoalkanes in the products, especially generating short-chain, long-skeletal isoalkanes. The resulting coal-based Fischer-Tropsch synthesis hydrocarbons are primarily composed of isoalkanes and n-alkanes with 12-24 carbon atoms. Preferably, the main components are isoalkanes and n-alkanes with 14-22 carbon atoms. More preferably, the main components are isoalkanes and n-alkanes with 16-20 carbon atoms.

[0015] Furthermore, in coal-based Fischer-Tropsch synthesis hydrocarbons, isoalkanes account for less than 90% of the total mass and n-alkanes account for more than 10% of the total mass. Preferably, isoalkanes account for less than 85% of the total mass and n-alkanes account for more than 15% of the total mass. More preferably, isoalkanes account for 65-85% of the total mass and n-alkanes account for 15-35% of the total mass.

[0016] Furthermore, the kinematic viscosity of coal-based Fischer-Tropsch hydrocarbons is less than or equal to 2.5 mm at 100°C. 2 Preferably, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is 0.5-2.5 mm / s at 100°C. 2 Furthermore, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is preferably 0.8-2.5 mm / s at 100°C. 2 Furthermore, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is preferably 0.8-2.0 mm / s at 100°C. 2 Furthermore, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is preferably 0.8-1.5 mm / s at 100°C. 2 / s.

[0017] Furthermore, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is 2.0-6.0 mm at 40°C. 2 Preferably, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is 2.0-5.0 mm / s at 40°C. 2 Furthermore, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is preferably 2.0-4.5 mm / s at 40°C. 2 / s, and more preferably, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is 2.5-4.5 mm at 40°C. 2 / s; More preferably, the kinematic viscosity of coal-based Fischer-Tropsch synthetic hydrocarbons is 3.0-4.5 mm at 40°C. 2 / s.

[0018] Furthermore, the mass fraction of coal-based Fischer-Tropsch hydrocarbons accounts for at least 98% of the total temperature-controlled liquid, preferably 99%-100%.

[0019] Furthermore, functional additives can be added to the temperature-controlled liquid as needed, including but not limited to antioxidants and defoamers.

[0020] Alternatively, the antioxidant is a sulfur-free phenolic antioxidant, specifically including: 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2, Any one or more combinations of 2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 4,4'-isopropylidenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(4-methyl-6-nonylphenol), 2,2'-isobutylidenebis(4,6-dimethylphenol) or 2,6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzyl)-4-methylphenol;

[0021] Alternatively, the defoamer may include one or more combinations of polyether-type defoamers, silicone-type defoamers, and polyether-modified silicone-type defoamers.

[0022] Furthermore, the functional additive accounts for 0-2% of the total mass of the temperature-controlled liquid.

[0023] This invention uses Fischer-Tropsch synthetic hydrocarbons with a relatively higher n-alkane content. Compared to synthetic hydrocarbons with a lower n-alkane content, these hydrocarbons have lower kinematic viscosity at 100°C and 40°C, resulting in better heat transfer and temperature control. However, this leads to two problems:

[0024] 1. n-Alkanes have low branching degree and high pour point, only around -30℃. The higher the pour point, the worse the fluidity at low temperatures, thus limiting their application at low temperatures.

[0025] 2. Temperature-controlled liquids have relatively low flash points, and their safety needs to be improved.

[0026] To address the aforementioned issues, this invention also proposes adding liquid polyolefins as the main component of a temperature-controlled liquid based on coal-based Fischer-Tropsch synthetic hydrocarbons. This further improves the heat transfer effect of the temperature-controlled liquid, enhances its low-temperature fluidity, increases its flash point, and facilitates its storage and use at low temperatures, as well as improving its safety in use.

[0027] Secondly, the present invention proposes a temperature-controlled liquid, the main components of which include the aforementioned coal-based Fischer-Tropsch synthetic hydrocarbons and liquid polyolefins.

[0028] The liquid polyolefin is prepared by a metallocene catalyst, and the raw materials for preparing the liquid polyolefin include ethylene, propylene, or one or a mixture of several α-olefins, ethylene-based olefins, disubstituted vinylenes, or trisubstituted vinylenes with 4-20 carbon atoms (C4-C20).

[0029] The structures of the α-olefin (I), vinylidene olefin (II), disubstituted vinylidene olefin (III, IV), and trisubstituted vinylidene olefin (V) are shown below:

[0030]

[0031] R1 includes straight-chain or branched alkanes with 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18 carbon atoms; R2 and R3 include straight-chain or branched alkanes whose sum of carbon atoms is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18 carbon atoms; R2, R3, and R4 include all three types of alkanes. The raw materials for preparing liquid polyolefins are straight-chain or branched alkanes with a sum of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18, wherein the carbon numbers of R1, R2, R3, and R4 may be the same or different. Preferably, the raw materials for preparing liquid polyolefins are C5-C13 α-olefins. More preferably, the raw materials for preparing liquid polyolefins are C5-C13 straight-chain α-olefins.

[0032] Furthermore, the kinematic viscosity of liquid polyolefins is less than or equal to 8.0 mm at 100°C. 2 Preferably, the kinematic viscosity of liquid polyolefin Fischer-Tropsch synthesis hydrocarbons is 1.0-6.0 mm / s at 100°C. 2 Furthermore, preferably, the kinematic viscosity of liquid polyolefin Fischer-Tropsch synthesis hydrocarbons is 1.0-4.0 mm / s at 100°C. 2 Furthermore, preferably, the kinematic viscosity of the liquid polyolefin is 1.0-3.0 mm / s at 100°C. 2 Furthermore, preferably, the kinematic viscosity of the liquid polyolefin is 1.0-2.5 mm / s at 100°C. 2 / s.

[0033] Furthermore, the kinematic viscosity of liquid polyolefins is 2.0-8.0 mm at 40°C. 2 Preferably, the kinematic viscosity of the liquid polyolefin is 2.0-7.0 mm / s at 40°C. 2 / s, and more preferably, the kinematic viscosity of the liquid polyolefin is 2.0-6.5 mm at 40°C. 2 Furthermore, preferably, the kinematic viscosity of the liquid polyolefin is 2.0-6.0 mm² / s at 40°C. 2 Furthermore, preferably, the kinematic viscosity of the liquid polyolefin is 2.0-4.0 mm² / s at 40°C. 2 / s.

[0034] In one or more embodiments, the liquid polyolefin is selected from a mixture of C6α olefin trimers and tetramers, a mixture of C8α olefin dimers and trimers, and a mixture of C10α olefin dimers and trimers.

[0035] 1. Further, when the main component of the temperature control liquid is coal-based Fischer-Tropsch synthetic hydrocarbons, the mass fraction of coal-based Fischer-Tropsch synthetic hydrocarbons accounts for at least 98% of the total temperature control liquid, preferably, the mass fraction of coal-based Fischer-Tropsch synthetic hydrocarbons accounts for 99%-100% of the total temperature control liquid;

[0036] When the main components of the temperature-controlled liquid are coal-based Fischer-Tropsch hydrocarbons and liquid polyolefins, the sum of the mass fractions of the coal-based Fischer-Tropsch hydrocarbons and liquid polyolefins accounts for at least 98% of the total temperature-controlled liquid. Preferably, the sum of the mass fractions of the coal-based Fischer-Tropsch hydrocarbons and liquid polyolefins accounts for 99%-100% of the total temperature-controlled liquid. Further, the amount of liquid polyolefins used is 5-100% of the coal-based Fischer-Tropsch hydrocarbons. Preferably, the amount of liquid polyolefins used is 10-50% of the coal-based Fischer-Tropsch hydrocarbons. More preferably, it is 30-45%.

[0037] 2. Furthermore, the temperature-controlled liquid also includes functional additives, the mass fraction of which is 0-2% of the total temperature-controlled liquid; preferably 0.05-0.5%; the functional additives include, but are not limited to, one or both of antioxidants and defoamers;

[0038] Preferably, the antioxidant is a sulfur-free phenolic antioxidant; more preferably, it includes: 2,6-di-tert-butylphenol,

[0039] 2,6-Di-tert-butyl-p-cresol, 2,6-Di-tert-butyl-4-methylphenol, 2,6-Di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,

[0040] Any one or more combinations of 2'-methylenebis(4-ethyl-6-tert-butylphenol), 4,4'-butylidenebis(3-methyl-6-tert-butylphenol), 4,4'-isopropylidenebis(2,6-di-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-cyclohexylphenol), 2,2'-methylenebis(4-methyl-6-nonylphenol), 2,2'-isobutylidenebis(4,6-dimethylphenol) or 2,6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzyl)-4-methylphenol;

[0041] Preferably, the defoamer includes one or more combinations of polyether-type defoamers, silicone-type defoamers, and polyether-modified silicone-type defoamers.

[0042] Preferably, the antioxidant is 0.05-0.15% and the defoamer is 0.01-0.1%; more preferably, the antioxidant is...

[0043] 0.06-0.1%, defoamer 0.01-0.05%.

[0044] 3. Thirdly, the method for preparing the temperature-controlled liquid described above includes the following steps: taking the above-mentioned coal-based Fischer-Tropsch synthetic hydrocarbon, or mixing liquid polyolefin with coal-based Fischer-Tropsch synthetic hydrocarbon evenly, then adding an antioxidant, stirring until clear and transparent, then adding an antifoaming agent to the obtained clear and transparent solution, stirring until evenly mixed to obtain the final temperature-controlled liquid.

[0045] Fourthly, the present invention also provides an application of the temperature-controlled liquid of the coal-based Fischer-Tropsch synthesis hydrocarbon described above in computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, liquid crystal display manufacturing, cooling media, cleaning fluids, and quality control media.

[0046] Preferably, the computing devices include, but are not limited to, single computers, supercomputers, cloud computing, computer gaming devices, data center servers, 5G base stations, computer server clusters, internet servers, cryptocurrency mining farms, etc.

[0047] Fifthly, the present invention also provides a temperature control system, which includes the temperature control liquid; the temperature control system is used in computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, liquid crystal display manufacturing, cooling media, cleaning fluids, and quality control media.

[0048] Preferably, the computing devices include, but are not limited to, single computers, supercomputers, cloud computing, computer gaming devices, data center servers, 5G base stations, computer server clusters, internet servers, cryptocurrency mining farms, etc.

[0049] The beneficial effects of this invention are as follows:

[0050] (1) The temperature-controlled liquid proposed in this invention, which is mainly composed of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of less than or equal to 320℃, has a lower kinematic viscosity, a higher specific heat capacity within the application temperature range, and a lower density. This helps to reduce the weight of equipment for the same volume, and its application in computing equipment such as data centers helps to reduce the ground load.

[0051] (2) Through experiments and calculations, this invention found that adding liquid polyolefin as the main component of temperature-controlled liquid to coal-based Fischer-Tropsch synthesis hydrocarbons can effectively improve the heat transfer performance of temperature-controlled liquid, improve low-temperature fluidity, increase flash point, facilitate the storage and use of temperature-controlled liquid at low temperatures, and improve the safety of temperature-controlled liquid use.

[0052] (3) For immersion cooling where the temperature-controlled liquid is in direct contact with the heat dissipation device, adding liquid polyolefin as the main component of the temperature-controlled liquid to the base of coal-based Fischer-Tropsch synthetic hydrocarbons can further improve the convective heat transfer coefficient. For pipe cooling where the temperature-controlled liquid is not in direct contact with the heat dissipation device, coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 220-300℃ or low-viscosity liquid polyolefins (kinematic viscosity of 2.0-4.0 mm at 40℃) can be used alone. 2 The temperature-controlled liquid obtained by blending ( / s) with coal-based Fischer-Tropsch synthetic hydrocarbons of the above distillation range has a higher convective heat transfer coefficient, taking into account the low viscosity liquid polyolefin (kinematic viscosity at 40℃ is 2.0-4.0 mm). 2 When used in combination with coal-based Fischer-Tropsch synthetic hydrocarbons of the above distillation range, the heat transfer effect is the best. It has a higher convective heat transfer coefficient in a variety of heat exchange scenarios and can play an excellent cooling role in different application scenarios such as computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, and LCD manufacturing.

[0053] (4) The temperature-controlled liquid proposed in this invention does not contain halogens such as fluorine, is easily biodegradable, and has no impact on global warming, thereby achieving sustainable environmental protection and climate friendliness. At the same time, the temperature-controlled liquid is low in volatility and non-toxic, and does not require complete sealing during use, thus requiring less protection for operators.

[0054] (5) The temperature control liquid proposed in this invention is sulfur-free, has a low acid value, and has no ester bond structure in its molecule. It will not hydrolyze during use. Therefore, the temperature control liquid can be in direct contact with the heat-generating device for a long time without corrosion. It has better compatibility with metal parts and does not require the addition of additional corrosion inhibitors.

[0055] (6) The temperature-controlled liquid proposed in this invention has a simple composition and is easy to produce on a large scale. Moreover, it uses coal-based Fischer-Tropsch synthesis hydrocarbons made from coal, which improves the utilization rate of coal. Detailed Implementation

[0056] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples. The following examples are only for explaining the present invention and do not limit its content. It should be understood that all technologies implemented based on the above content of the present invention are within the scope of the present invention.

[0057] Example 1

[0058] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ according to the following method:

[0059] Take 999g of coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 278-299℃, add 0.8g of antioxidant 2,6-di-tert-butyl-4-methylphenol, stir for 10 minutes until clear and transparent, then add 0.2g of organosilicon defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0060] Example 2

[0061] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 224-245℃ according to the following method:

[0062] Take 999g of coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 224-245℃, add 0.8g of antioxidant 2,6-di-tert-butyl-4-methylphenol, stir for 10 minutes until clear and transparent, then add 0.2g of organosilicon defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0063] Example 3

[0064] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ according to the following method:

[0065] Take 700g of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ and 299.8g of low-viscosity liquid polyolefin (a mixture of C6α olefin trimers and tetramers), mix them evenly, stir for 10 minutes until clear and transparent, then add 0.2g of polyether-type defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0066] Example 4

[0067] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ according to the following method:

[0068] Take 700g of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ and 299.8g of medium-viscosity liquid polyolefin (a mixture of C8α olefin dimers and trimers), mix them evenly, stir for 10 minutes until clear and transparent, then add 0.2g of polyether-modified organosilicon defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0069] Example 5

[0070] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ according to the following method:

[0071] Take 700g of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 278-299℃ and 299.8g of high-viscosity liquid polyolefin (a mixture of C10α olefin dimers and trimers), mix them evenly, stir for 10 minutes until clear and transparent, then add 0.2g of polyether-modified organosilicon defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0072] Example 6

[0073] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 224-245℃ according to the following method:

[0074] Take 700g of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 224-245℃ and 299.8g of medium-viscosity liquid polyolefin (a mixture of C8α olefin dimers and trimers), mix them evenly, stir for 10 minutes until clear and transparent, then add 0.2g of polyether-type defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0075] Example 7

[0076] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 224-245℃ according to the following method:

[0077] Take 700g of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 224-245℃ and 299.8g of high-viscosity liquid polyolefin (a mixture of C10α olefin dimers and trimers), mix them evenly, stir for 10 minutes until clear and transparent, then add 0.2g of polyether-type defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0078] Comparative Example 1

[0079] The temperature-controlled fluid was prepared using Shell GTL base oil GS250 as follows:

[0080] Take 999g of Shell GTL GS250, add 0.8g of antioxidant 2,6-di-tert-butylphenol, stir for 10 minutes until clear and transparent, then add 0.2g of silicone defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0081] Comparative Example 2

[0082] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 330-350℃ according to the following method:

[0083] Take 999g of coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 330-350℃, add 0.8g of antioxidant 2,6-di-tert-butyl-4-methylphenol, stir for 10 minutes until clear and transparent, then add 0.2g of organosilicon defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0084] Comparative Example 3

[0085] Temperature-controlled liquids were prepared using coal-based Fischer-Tropsch synthesis hydrocarbons with a distillation range of 330-350℃ according to the following method:

[0086] Take 700g of coal-based Fischer-Tropsch synthetic hydrocarbons with a distillation range of 330-350℃ and 299.8g of low-viscosity liquid polyolefin (a mixture of C6α olefin trimers and tetramers), mix them evenly, stir for 10 minutes until clear and transparent, then add 0.2g of polyether-type defoamer to the resulting clear and transparent solution, and continue stirring for 10 minutes until evenly mixed to obtain the final temperature-controlled liquid.

[0087] The relevant test methods for the temperature-controlled liquids prepared in Examples 1-7 and Comparative Examples 1-3 are as follows:

[0088] Kinematic viscosity: The kinematic viscosity of the samples was tested at different temperatures according to the ASTM D445 standard;

[0089] Pour point: The pour point of the standard test sample according to ASTM D97;

[0090] Thermal conductivity: The thermal conductivity of the liquid was tested at 40°C using the standard test method for thermal conductivity of liquids as specified in ASTM D2717-2009.

[0091] Specific heat capacity: Tested using DSC at 40°C for temperature-controlled liquids;

[0092] Density: The density of the temperature-controlled liquid at 40°C was tested using the method described in ASTM D1298-1999.

[0093] Distillation range: The distillation range of different Fischer-Tropsch synthetic hydrocarbon samples was tested using the ASTM D86 method;

[0094] Acid value: The acid value of the samples was determined by the potassium hydroxide ethanol solution titration method according to ASTM D664.

[0095] Flash point: The flash point of temperature-controlled liquids was tested using the Cleveland open cup method according to ASTM D92.

[0096] Sulfur content: The sulfur content of the samples was determined using the method described in ASTM D4294.

[0097] Copper strip corrosion: The temperature-controlled liquid was tested at 50°C using the ASTM D130 method.

[0098] Volume resistivity: The temperature-controlled liquid was tested at 25°C using the ASTM D257 method.

[0099] Evaporation loss: The temperature-controlled liquid was tested at 150°C using the NOACK evaporation loss determination method of ASTM D5800.

[0100] Carbon chain carbon number distribution: GC / MS was used to detect Fischer-Tropsch synthesis hydrocarbon samples, and the percentage of alkanes with different carbon numbers in the samples was calculated based on the peak area in different retention time ranges;

[0101] Isomer / n-alkane ratio analysis: The contents of isomers and n-alkanes in the Fischer-Tropsch synthesis hydrocarbon samples were determined by GC / MS, and the isomer / n-alkane ratio was calculated accordingly.

[0102] Table 1 shows the basic performance test results of Fischer-Tropsch synthetic hydrocarbons with different distillation ranges and Shell's base oil GTL GS250:

[0103] Table 1

[0104]

[0105] As can be seen from Table 1, Fischer-Tropsch hydrocarbons with a low boiling range have a lower carbon number in the carbon chain and a relatively lower kinematic viscosity. Compared with Shell's GTL GS250, Fischer-Tropsch hydrocarbons have a significantly higher n-alkane content.

[0106] The acid value and sulfur content of Fischer-Tropsch synthetic hydrocarbons do not vary much across different distillation ranges. However, the sulfur content of GTL GS250 is relatively high. Therefore, it can be concluded that the Fischer-Tropsch synthetic hydrocarbons proposed in this invention generally have extremely low acid values ​​and zero sulfur content, and are non-corrosive to equipment. They will not cause corrosion or damage to equipment that has been immersed for a long time during use.

[0107] The basic performance test results of different liquid polyolefins are shown in Table 2:

[0108] Table 2

[0109]

[0110]

[0111] As can be seen from Table 2, various liquid polyolefins made from olefins with different carbon numbers generally have good low-temperature fluidity. They do not completely solidify at the extreme low temperature of -50℃ and still have good fluidity. Among them, polyolefins with lower carbon numbers have lower kinematic viscosity and better fluidity. At the same time, liquid polyolefins also have extremely low acid values ​​and do not contain sulfur.

[0112] The performance test results of the temperature-controlled liquids in Examples 1-2 and Comparative Examples 1-2 are shown in Table 3:

[0113] Table 3

[0114]

[0115] As can be seen from Table 3, compared with Comparative Examples 1-2, Examples 1-2 have similar properties such as thermal conductivity, density, volume resistivity, evaporation loss, and copper sheet corrosion. Examples 1-2 and Comparative Example 2 have higher specific heat capacity at 40°C than Comparative Example 1, but their pour points are generally higher than Comparative Example 1. The pour point refers to the lowest temperature at which the cooled temperature-controlled liquid can flow. A high pour point indicates that the temperature-controlled liquid is difficult to flow and pour at low temperatures, which is not conducive to its storage and use at low temperatures.

[0116] Volume resistivity represents the insulation properties of the temperature-controlled liquid. The higher the volume resistivity, the stronger the insulation performance of the temperature-controlled liquid. The volume resistivity values ​​of Embodiments 1-2 and Comparative Examples 1-2 of the present invention are quite similar, and both have high volume resistivity. This indicates that when immersing heat dissipation devices such as servers into the temperature-controlled liquid of the present invention during immersion direct cooling, the servers will not be damaged or equipment failures will not occur.

[0117] Based on the NOACK evaporation loss test results, the evaporation losses of Examples 1-2 and Comparative Examples 1-2 are quite similar, with evaporation losses of less than 10% at 150°C. Therefore, the temperature-controlled liquid has low volatility, and in actual use, it is not necessary to completely seal the equipment containing the temperature-controlled liquid, thus requiring less protection for operators.

[0118] Based on the experimental results of copper sheet corrosion, Examples 1-2 and Comparative Examples 1-2 are not corrosive to metals such as copper sheets, so there is no need to add corrosion inhibitors to the formulation of temperature-controlled liquids.

[0119] To further compare the heat transfer effects between different temperature-controlled liquids, the Mouromtseff number at 40℃ (the operating temperature of the temperature-controlled liquid is usually around 40℃) was calculated to measure the heat transfer effect of different temperature-controlled liquids at this temperature. The Mouromtseff number at a certain temperature is expressed by formula (1):

[0120]

[0121] In formula (1), Mo is the Mouromtseff number, ρ is the fluid density, κ is the thermal conductivity, Cp is the specific heat capacity, μ is the kinematic viscosity of the fluid, and a, b, d, and e are empirical values ​​that vary depending on whether the fluid is in laminar or turbulent flow. Specifically, in laminar flow, a = 1, b = 1, d = 1, e = 1; in turbulent flow, a = 0.8, b = 0.67, d = 0.33, e = 0.47. The data comparison is shown in Table 4.

[0122] Table 4

[0123]

[0124] As shown in Table 4, the Mo values ​​and relative Mo values ​​of Examples 1 and 2 are higher than those of the commercial temperature-controlled liquid GTL GS250 of Comparative Example 1. This indicates that the Fischer-Tropsch hydrocarbons of Examples 1 and 2 have better heat transfer performance as temperature-controlled liquids. However, the Mo values ​​and relative Mo values ​​of Fischer-Tropsch hydrocarbons with a distillation range exceeding 320°C (330-350°C for Comparative Example 2) are significantly different from those of Fischer-Tropsch hydrocarbons with a distillation range not exceeding 320°C (Examples 1 and 2). This indicates that Fischer-Tropsch hydrocarbons with a specific distillation range have better heat transfer performance when used alone as temperature-controlled liquids.

[0125] Among them, Example 2, with a distillation range of 224-245℃, exhibited the best heat transfer effect. However, its flash point was only 97℃, close to the flash point standard (93℃) for flammable liquids specified in GB13690-2009. Flash point represents the safety of temperature-controlled liquids; the higher the flash point, the less likely it is to ignite or cause a fire, thus ensuring higher safety. It is particularly suitable for cooling equipment used at high temperatures, preventing combustion and fire caused by excessively high temperatures in the cooling equipment itself. Therefore, considering both the heat transfer effect and safety of temperature-controlled liquids, Example 1, with Fischer-Tropsch synthesis hydrocarbons with a distillation range of 278℃-299℃ as its main component, is the best choice, combining the advantages of a high flash point and good heat transfer performance.

[0126] In summary, the Fischer-Tropsch synthesis hydrocarbons of Examples 1 and 2 have a high content of n-alkanes, low kinematic viscosity, and good heat transfer performance. However, they also have the following problems: First, the pour point is too high, only around -30°C, significantly higher than that of Comparative Example 1, thus limiting their use at low temperatures. Second, the flash point needs to be further improved to enhance the safety of the temperature-controlled liquid. To address these issues, Examples 3-7 add liquid polyolefins as the main component of the temperature-controlled liquid to the Fischer-Tropsch synthesis hydrocarbons of Examples 1 and 2, thereby further improving the heat transfer performance, low-temperature fluidity, and flash point of the temperature-controlled liquid.

[0127] Performance testing: The temperature-controlled liquids obtained in Example 1, Examples 3-7, and Comparative Example 3 were compared and tested. The test results are shown in Table 5.

[0128] Table 5

[0129]

[0130] As shown in Table 5, adding liquid polyolefins to coal-based Fischer-Tropsch hydrocarbons and mixing them uniformly improves the thermal conductivity, specific heat capacity, and flash point of the temperature-controlled liquid. This is particularly beneficial for coal-based Fischer-Tropsch hydrocarbons with a low flash point and a distillation range of 224-245℃, significantly enhancing their safety. Furthermore, the addition of liquid polyolefins significantly lowers the pour point of the temperature-controlled liquid. The pour points of Examples 3-7 are all reduced to below -50℃, overcoming the drawbacks of using coal-based Fischer-Tropsch hydrocarbons alone, which have excessively high pour points and are unsuitable for low-temperature storage, transportation, and use. This allows the liquid to maintain fluidity at -40℃ in semiconductor manufacturing and packaging testing, thus playing a role in heat transfer. The pour point of Comparative Example 3, with its compounded liquid polyolefins, is also significantly lower than that of Comparative Example 2. However, since its main component is still coal-based Fischer-Tropsch hydrocarbons with a distillation range of 330-350℃, the pour point after compounding with liquid polyolefins remains relatively high, making it difficult to meet the requirements for storage, transportation, and use at ultra-low temperatures.

[0131] Similarly, the Mo values ​​of Examples 3-7 and Comparative Examples 2-3 were calculated using the same method described above, with Example 1 used as the standard for comparison. The results are shown in Table 6.

[0132] Table 6

[0133]

[0134] As shown in Table 6, the addition of medium and low viscosity liquid polyolefins to the coal-based Fischer-Tropsch hydrocarbons of Example 1 in Examples 3-4 significantly improved the heat transfer performance of the temperature-controlled liquid compared to Example 1. Similarly, the addition of low viscosity liquid polyolefins to the coal-based Fischer-Tropsch hydrocarbons of Comparative Example 2 in Comparative Example 3 significantly improved the heat transfer performance of the temperature-controlled liquid compared to Comparative Example 2. This indicates that the combination of low and medium viscosity liquid polyolefins with coal-based Fischer-Tropsch hydrocarbons can effectively improve the heat transfer performance of the temperature-controlled liquid.

[0135] In addition, the improvement in heat transfer performance in Examples 5-7 was not significant. In particular, in Examples 5 and 7, after adding a high-viscosity liquid polyolefin, a mixture of C10α olefin dimers and trimers, to the coal-based Fischer-Tropsch hydrocarbons, the Mo value of the temperature-controlled liquid actually decreased. This may be related to the fact that the high kinematic viscosity of the high-viscosity liquid polyolefin at 40°C is unfavorable for heat transfer. Therefore, in the preferred scheme for preparing temperature-controlled liquids using a blend of coal-based Fischer-Tropsch hydrocarbons and liquid polyolefins, the kinematic viscosity of the liquid polyolefin at 40°C should be 2.0-6.0 mm. 2 / s.

[0136] Regarding the comparison of the relative Mo values ​​under laminar and turbulent flow conditions, the differences in Mo values ​​between different embodiments and the comparative examples under laminar flow conditions are more significant, while the Mo values ​​under turbulent flow conditions are closer. This is because turbulence itself enhances heat transfer, promoting heat transfer between the temperature-controlled liquid and the heat dissipation device. However, for temperature-controlled liquids in large equipment such as data center servers, which have a large volume, using turbulence to enhance heat transfer results in high energy consumption, affecting the lifespan and safety of the equipment, high noise levels, and the temperature-controlled liquid itself being prone to splashing. Therefore, in practical applications of immersion cooling, the temperature-controlled liquid mainly flows in laminar flow. In addition to the flow state, the surface shape of the cooled heat dissipation device also affects the cooling effect. To compare the heat transfer effects of different temperature-controlled liquids in different application scenarios such as computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, and LCD manufacturing, the convective heat transfer coefficient of the temperature-controlled liquid is further calculated.

[0137] The calculation of the convective heat transfer coefficient when the temperature-controlled liquid flows parallel across a flat plate is used to simulate the scenario in immersion cooling where the temperature-controlled liquid flows directly over the top of the heat dissipation device.

[0138] Assuming a temperature-controlled liquid flows parallel to a 2m long plate at a velocity (v) of 0.1m / s at 40℃, where the characteristic length L is 2m, calculate the dimensionless Reynolds number, Prandtl number, and Nusselt number using the following formulas. From this, the convective heat transfer coefficient h can be further calculated, where the unit of h is W / (m²). 2 ·K), defined as the temperature difference between heat transfer interfaces being 1K, 1m 2The amount of heat that the wall surface area can transfer per second, h, directly reflects the convective heat transfer capacity of the temperature-controlled liquid.

[0139] Dynamic viscosity: η = ρμ;

[0140] Reynolds numbers, Prandtl numbers, and Nusselt numbers:

[0141]

[0142] Among them, Re L ≤5*10 5 This indicates that the boundary layer of the temperature-controlled liquid flow is laminar, with 0.6 ≤ Pr ≤ 10. 5 The following formula is applicable to the calculation of Nu:

[0143]

[0144] Flat plate convective heat transfer coefficient h 平板 The calculation formula is as follows:

[0145]

[0146] The calculation of the convective heat transfer coefficient when the temperature-controlled liquid flows through the cylinder perpendicular to the pipe axis is used to simulate the scenario of the temperature-controlled liquid flowing from the side of the cylindrical heat dissipation device during immersion cooling.

[0147] Assuming the temperature-controlled liquid flows at 40°C at a velocity (v) of 0.1 m / s through a cylinder with an outer diameter of 250 mm, and a characteristic length L of 250 mm, calculate the dimensionless Reynolds number and Prandtl number using the formulas above, and calculate the dimensionless Nusselt number using the following formulas:

[0148]

[0149] Among them, the calculated Reynolds number is 10 < Re L ≤1.5*10 5 This indicates that the boundary layer of the temperature-controlled liquid flow is laminar, with a Reynolds number of 4000 ≤ Re L For a value ≤40000, referring to the table, we find C = 0.193 and n = 0.618. The corresponding convective heat transfer coefficient h can be calculated using the following formula. 圆管

[0150]

[0151] The calculation of the convective heat transfer coefficient when the temperature-controlled liquid flows through the cube at a 45° angle to the side length of the cube is used to simulate the scenario of the temperature-controlled liquid flowing from the side of the cube heat dissipation device during immersion cooling.

[0152] Assuming the temperature-controlled liquid flows at 0.1 m / s (v) through a cube with a side length of 500 mm at 40 °C, where the characteristic length L is the diagonal of the cube, L = 707.1 mm, calculate the dimensionless Reynolds number, Prandtl number, and Nusselt number using the above formulas, where 5000 ≤ Re L For a value ≤500000, referring to the table, when the fluid flows through the cube at a 45° angle to the side length of the cube, C = 0.246 and n = 0.588. Therefore, the corresponding convective heat transfer coefficient h can be calculated. 方管

[0153]

[0154] The calculation of the convective heat transfer coefficient inside the temperature-controlled liquid tube is used to simulate the scenario of traditional in-tube cooling rather than immersion cooling, that is, the temperature-controlled liquid does not directly contact the heat dissipation device.

[0155] Assuming the temperature-controlled liquid flows at 0.5 m / s through a heat exchange tube with an inner diameter (d) of 25 mm and a length (L) of 2 m at 40 °C, calculate the dimensionless Reynolds number and Prandtl number using the following formulas, and then calculate the in-tube convective heat transfer coefficient h of the temperature-controlled liquid using the in-tube convective heat transfer formula. 管内 .

[0156] Reynolds number and Prandtl number:

[0157]

[0158]

[0159] The calculated Reynolds number is 2000≤Re f ≤4000 represents the transitional state between laminar and turbulent flow, with Prandtl numbers 0.6≤Pr≤10. 5 The Darsier drag coefficient f and the in-pipe convective heat transfer coefficient h are calculated using the Gnilinsky formula. 管内 :

[0160] f = (1.82lgRe) f -1.64) -2 ;

[0161]

[0162] The plate convective heat transfer coefficient h of Comparative Examples 1-3 and Examples 1-7 was calculated using the method described above. 平板 The convective heat transfer coefficient h of a cylinder 圆管 The convective heat transfer coefficient h of a cube 方管 and the convective heat transfer coefficient h inside the pipe 管内 The results are listed in Table 7.

[0163] Table 7

[0164]

[0165]

[0166] As shown in Table 7, during the immersion cooling process, the temperature-controlled liquid comes into direct contact with the heat dissipation device. Under the condition that the temperature-controlled liquid flows through a flat plate, cylinder, and cube, the convective heat transfer coefficients of Examples 1-2 and Comparative Examples 1-2 are very close, and the heat transfer efficiency advantage is not obvious. Under this condition, the scheme of preparing the temperature-controlled liquid by compounding Fischer-Tropsch hydrocarbons and liquid polyolefins shows that the convective heat transfer coefficients of Examples 3-7 and Comparative Example 3 are significantly improved compared with Examples 1, 2 and Comparative Example 2, which use Fischer-Tropsch hydrocarbons alone. This indicates that the scheme of using Fischer-Tropsch hydrocarbons and liquid polyolefins in immersion cooling where the compounded temperature-controlled liquid comes into direct contact with heat-generating devices of different shapes such as straight and curved surfaces has a better heat transfer effect. Compared with the commercial temperature-controlled liquid GS250 of Comparative Example 1, the convective heat transfer coefficients are significantly improved.

[0167] Under pipe cooling conditions where the temperature-controlled liquid and the heat dissipation device do not directly contact each other, the convective heat transfer coefficient h of Examples 1-2 using coal-based Fischer-Tropsch hydrocarbons alone is significantly higher than that of Comparative Example 2. This indicates that Fischer-Tropsch hydrocarbons with a distillation range of 220-300°C have better heat transfer performance in the pipe. Among them, Example 2, with a lower distillation range and kinematic viscosity, has the highest convective heat transfer coefficient, while the convective heat transfer coefficient of coal-based Fischer-Tropsch hydrocarbons with a distillation range higher than 300°C is significantly reduced. Fischer-Tropsch hydrocarbons with a distillation range of 220-300°C can achieve a heat transfer effect that significantly surpasses that of commercially available temperature-controlled liquid GTL GS250 when used alone.

[0168] In addition, under the condition of in-tube cooling, the heat transfer effect of using Fischer-Tropsch hydrocarbons and liquid polyolefins to prepare temperature-controlled liquids is not as good as using Fischer-Tropsch hydrocarbons alone. Except for Example 3 and Comparative Example 3, the in-tube convective heat transfer coefficients of Examples 4-7, which are Fischer-Tropsch hydrocarbons combined with medium and high viscosity liquid polyolefins, are actually reduced to varying degrees compared with Examples 1-2, which use Fischer-Tropsch hydrocarbons alone. In particular, the in-tube convective heat transfer coefficients of Examples 5 and 7, which are combined with high viscosity liquid polyolefins, are reduced very significantly. However, in Examples 3 and Comparative Example 3, which are based on Examples 1 and Comparative Example 2 respectively, the in-tube convective heat transfer coefficients are further significantly improved by combining Fischer-Tropsch hydrocarbons with low viscosity liquid polyolefins.

[0169] Therefore, as a more preferred technical solution, coal-based Fischer-Tropsch synthetic hydrocarbons are combined with low-viscosity liquid polyolefins (kinematic viscosity at 40°C is 2.0-4.0 mm). 2When used as a raw material, it exhibits a higher convective heat transfer coefficient in various heat exchange scenarios, and can provide excellent cooling effects in different application scenarios such as computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, and LCD manufacturing.

[0170] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. 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. Although the specific embodiments of the present invention have been described above, they are not intended to limit the protection scope of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A temperature controlled liquid, characterized in that, The main components of the temperature-controlled liquid are coal-based Fischer-Tropsch hydrocarbons and liquid polyolefins, with the sum of the mass fractions of the coal-based Fischer-Tropsch hydrocarbons and liquid polyolefins accounting for at least 98% of the total temperature-controlled liquid; the amount of liquid polyolefins is 30-50% of the coal-based Fischer-Tropsch hydrocarbons by mass percentage. The distillation range of coal-based Fischer-Tropsch hydrocarbons is less than or equal to 320℃; the main components of coal-based Fischer-Tropsch hydrocarbons are isoalkanes and n-alkanes with 12-24 carbon atoms, of which isoalkanes account for less than 90% of the total mass and n-alkanes account for more than 10% of the total mass; the kinematic viscosity of coal-based Fischer-Tropsch hydrocarbons is less than or equal to 2.5 mm at 100℃. 2 / s, 2.0-6.0 mm at 40℃ 2 / s; The kinematic viscosity of the liquid polyolefin is less than or equal to 8.0 mm 2 / s at 40°C of 2.0-6.0 mm 2 / s; the raw material for producing the liquid polyolefin includes one or a mixture of several of ethylene, propylene or an α-olefin having a carbon number of 4-20, an ethynyl olefin, a disubstituted vinylene olefin or a trisubstituted vinylene olefin.

2. A temperature-controlled liquid according to claim 1, wherein, The distillation range of coal-based Fischer-Tropsch synthesis hydrocarbons is 220-300℃.

3. A temperature-controlled liquid according to claim 1, wherein, The boiling range of coal-based Fischer-Tropsch synthesis hydrocarbons is 278℃-299℃.

4. A temperature-controlled liquid according to claim 1, wherein, Coal-based Fischer-Tropsch synthesis mainly consists of isoalkanes and n-alkanes with 14-22 carbon atoms.

5. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesis mainly consists of isoalkanes and n-alkanes with 16-20 carbon atoms.

6. A temperature-controlled liquid according to claim 4 or 5, wherein, Isomers comprise less than 85% of the total mass, while n-alkanes comprise more than 15% of the total mass.

7. A temperature-controlled liquid according to claim 4 or 5, wherein Isoalkanes account for 65-85% of the total mass, and n-alkanes account for 15-35% of the total mass.

8. A temperature-controlled liquid according to claim 1, wherein, The structural formulas of the α-olefin (I), vinylidene olefin (II), disubstituted vinylidene olefin (III, IV), and trisubstituted vinylidene olefin (V) are shown below. (I) (I) (III) (IV) (V)； R1 includes straight-chain or branched alkanes with 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18 carbon atoms; R2 and R3 include straight-chain or branched alkanes whose combined carbon number is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18 carbon atoms; and R2, R3, and R4 include straight-chain or branched alkanes whose combined carbon number is 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, and 18 carbon atoms.

9. A temperature-controlled liquid according to claim 1, wherein, The raw material for preparing liquid polyolefins is C5-C13 α-olefins.

10. A temperature-controlled liquid as claimed in claim 1, wherein, The raw material for preparing liquid polyolefins is a C5-C13 straight-chain α-olefin.

11. A temperature-controlled liquid according to claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 0.5-2.5 mm 2 / s at 100°C.

12. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 0.8-2.5 mm 2 / s at 100°C.

13. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 0.8-2.0 mm 2 / s at 100°C.

14. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 0.8-1.5 mm 2 / s at 100°C.

15. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 2.0-5.0 mm 2 / s at 40°C.

16. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 2.0-4.5 mm 2 / s at 40°C.

17. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 2.5-4.5 mm 2 / s at 40°C.

18. A temperature-controlled liquid as claimed in claim 1, wherein, Coal-based Fischer-Tropsch synthesized hydrocarbon has a kinematic viscosity of 3.0-4.5 mm 2 / s at 40°C.

19. A temperature-controlled liquid as claimed in claim 1, wherein, The kinematic viscosity of the liquid polyolefin is 1.0-6.0 mm 2 / s at 100°C.

20. A temperature-controlled liquid as claimed in claim 1, wherein, The kinematic viscosity of the liquid polyolefin is 1.0-4.0 mm 2 / s at 100°C.

21. A temperature-controlled liquid as claimed in claim 1, wherein, The kinematic viscosity of the liquid polyolefin is 1.0-3.0 mm 2 / s at 100°C.

22. A temperature-controlled liquid as claimed in claim 1, wherein, The kinematic viscosity of the liquid polyolefin is 1.0-2.5 mm 2 / s at 100°C.

23. A temperature-controlled liquid as claimed in claim 1, wherein, The kinematic viscosity of the liquid polyolefin is 2.0-4.0 mm 2 / s at 40°C.

24. A temperature-controlled liquid as defined in claim 1, wherein, The liquid polyolefin is selected from a mixture of C6α olefin trimers and tetramers, a mixture of C8α olefin dimers and trimers, and a mixture of C10α olefin dimers and trimers.

25. A temperature-controlled liquid as claimed in claim 1, wherein, The combined mass fraction of coal-based Fischer-Tropsch synthetic hydrocarbons and liquid polyolefins accounts for 99%-100% of the total mass fraction of the temperature-controlled liquid.

26. A temperature-controlled liquid as defined in claim 1, wherein, The amount of liquid polyolefin used is 30-45% of that used in coal-based Fischer-Tropsch synthesis.

27. A temperature-controlled liquid as defined in claim 1, wherein, The temperature-controlled liquid also includes functional additives, which include one or two of antioxidants and defoamers; the mass fraction of the functional additives accounts for 0-2% of the total temperature-controlled liquid.

28. A temperature-controlled liquid as claimed in claim 27, wherein, The functional additives account for 0.05-0.5% of the total mass of the temperature-controlled liquid.

29. A temperature-controlled liquid as claimed in claim 27, wherein, The antioxidant is a sulfur-free phenolic antioxidant.

30. A temperature-controlled liquid as claimed in claim 27, wherein, The antioxidants include: 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-p-cresol, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,4-dimethyl-6-tert-butylphenol, 4,4'-methylenebis(2,6-di-tert-butylphenol), 4,4'-bis(2,6-di-tert-butylphenol), 4,4'-bis(2-methyl-6-tert-butylphenol), 2,2'-methylenebis(4-methyl-6-tert-butylphenol), 2,2'-methylenebis(… The following are any one or a combination of 4-ethyl-6-tert-butylphenol, 4,4'-butylidene bis(3-methyl-6-tert-butylphenol), 4,4'-isopropylidene bis(2,6-di-tert-butylphenol), 2,2'-methylene bis(4-methyl-6-cyclohexylphenol), 2,2'-methylene bis(4-methyl-6-nonylphenol), 2,2'-isobutylidene bis(4,6-dimethylphenol), or 2,6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzyl)-4-methylphenol.

31. A temperature-controlled liquid as claimed in claim 27, wherein, The defoamer includes one or more combinations of polyether-type defoamers, silicone-type defoamers, and polyether-modified silicone-type defoamers.

32. A temperature-controlled liquid as claimed in claim 27, wherein, The antioxidant is 0.05-0.15%, and the defoamer is 0.01-0.1%.

33. A temperature-controlled liquid as claimed in claim 27, wherein, The antioxidant is 0.06-0.1%, and the defoamer is 0.01-0.05%.

34. A method of preparing a temperature-controlled liquid according to any one of claims 1-33, wherein, The method includes the following steps: mixing liquid polyolefin with coal-based Fischer-Tropsch synthetic hydrocarbons evenly, then adding an antioxidant, stirring until clear and transparent, then adding an antifoaming agent to the resulting clear and transparent solution, and stirring until evenly mixed to obtain the final temperature-controlled liquid.

35. The application of the temperature-controlled liquid according to any one of claims 1-33 in computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, liquid crystal display manufacturing, cooling media, cleaning fluids, and quality control media.

36. The use according to claim 35, wherein The computing devices include single computers, supercomputers, cloud computing, computer gaming devices, data center servers, 5G base stations, computer server clusters, internet servers, and cryptocurrency mining farms.

37. A temperature control system, characterized by, The system includes the temperature-controlled liquid as described in any one of claims 1-33; the temperature control system is used in computing devices, chip manufacturing, semiconductor manufacturing and packaging testing, liquid crystal display manufacturing, cooling media, cleaning fluids, and quality control media.

38. A temperature control system according to claim 37, wherein, The computing devices include single computers, supercomputers, cloud computing, computer gaming devices, data center servers, 5G base stations, computer server clusters, internet servers, and cryptocurrency mining farms.

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