Immersed cooling equipment

Abstract

A submerged cooling apparatus comprising 1) a heat exchanger (50), 2) a tank (10) containing a submerged coolant and heat generating means, and 3) means for recirculating the submerged coolant between the tank (10) and the heat exchanger (50), where the submerged coolant (30) is characterized by a compound of Formula (1): where each R and x are defined herein. The cooling immersion apparatus may be used to dissipate heat from heat generating devices such as data center servers.

Description

Background Technology

[0001] This invention relates to an immersion cooling device that can be used to dissipate heat from heat-generating devices such as data center servers.

[0002] Addressing overheating in data centers remains a major challenge for data center managers, as high temperatures and overheating can severely impact the lifespan and performance of data centers. Air cooling and liquid cooling are two of the most common methods used for thermal management, with liquid cooling being the preferred option due to its higher heat removal efficiency.

[0003] Liquid cooling can be direct or indirect. For direct cooling, server components are placed in direct contact with a medium liquid known as an immersion coolant. Heat generated by the server is absorbed by the fluid, which is continuously pumped from a tank containing the immersion coolant and recirculated through a heat exchanger. Examples of immersion coolants include Novec fluoride (fluorocarbon fluid) solutions and medium- to long-chain alkyl-modified organopolysiloxanes (AMS fluids), as disclosed in WO 2022 / 089214 A1 (Tang). However, these types of immersion coolants have drawbacks for various reasons. For example, fluorocarbon fluids are expensive and prone to evaporation, posing a health threat to operators; the AMS fluid described by Tang inherently contains low but significant concentrations of residual dimethylcyclic siloxanes, which are prohibited by many end-users; furthermore, the disclosed AMS fluid does not exhibit a flash point above 150°C and a flash depth of less than 25 mm. 2 The combination of kinematic viscosity (cSt) and viscosity ( / s) is a particularly desirable property for submerged coolants. Therefore, in the field of submerged coolants, there is a desire to discover a safe and environmentally friendly low-viscosity, high-flash-point medium. Summary of the Invention

[0004] This invention addresses a need in the art by providing an immersion cooling apparatus comprising: 1) a heat exchanger, 2) a tank containing an immersion coolant and a heating element, and 3) a component for recirculating the immersion coolant between the tank and the heat exchanger, wherein the immersion coolant is characterized by a compound of formula 1:

[0005]

[0006] Each R is independently C4-C 18 - Hydrocarbon group; and n is 1 to 3. The device of the present invention can be used to remove heat from heat-generating devices such as data center servers. Attached Figure Description

[0007] Figure 1 This is a diagram of an immersion cooling system. Detailed Implementation

[0008] This invention relates to an immersion cooling device, comprising: 1) a heat exchanger, 2) a tank containing an immersion coolant and a heating element, and 3) a component for recirculating the immersion coolant between the tank and the heat exchanger, wherein the immersion coolant is characterized by a compound of formula 1:

[0009]

[0010] Each R is independently C4-C 18 - A hydrocarbon group; and n is 1 to 3. Each R can be a straight-chain or branched C6-C group. 16 -Alkyl groups or straight-chain or branched C8-C 12 -alkyl group, and x is 0 to 20 or to 10.

[0011] As used herein, the term "heat-generating device" refers to any material that generates heat, which can be transferred to an immersion coolant and recirculated through a heat exchanger and returned to the tank. Examples of heat-generating devices include data center servers; batteries, electric motors, and charging stations for electric vehicles; power electronics, such as inverters and converters, and semiconductors, including insulated-gate bipolar transistors and metal-oxide-semiconductor semiconductors; and telecommunications equipment.

[0012] As used herein, “alkyl group” refers to a straight-chain alkyl, branched alkyl, cycloalkyl, or aralkyl group. Examples of suitable R groups include diisobutyl, -n-hexyl, n-octyl, n-decyl, n-dodecyl, n-hexadecyl, and 2-propylphenyl, as well as combinations thereof.

[0013] Compounds of Formula 1 can be conveniently prepared by reacting an alkene with a compound of Formula 1a, as shown in reaction scheme 1:

[0014] Option 1

[0015]

[0016] Where R 1 For C2-C 16 hydrocarbon group; and R 2 It is H or methyl, provided that R is H or methyl. 1 When it is phenyl, R 2 Methyl. Compounds of formula 1a are usually provided as mixtures of n=1, 2 and 3, with n=1 being the predominant number.

[0017] The preferred immersion coolant of Formula 1 has a flash point above 150°C, and preferably above 200°C, and a kinematic viscosity of less than 30 cSt, more preferably less than 20 cSt, and even more preferably less than 15 cSt at 25°C. The immersion coolant prepared as in Formula 1 does not contain dimethylcyclic siloxane.

[0018] Figure 1 A specific example of an immersion cooling device is illustrated. A tank (10) houses a data server (20) immersed in an immersion coolant (30). Heat generated by the data server (20) is transferred to the immersion coolant (30), a portion of which is pumped from the tank (10) by a pump (60) through a recirculation conduit (40) and a heat exchanger (50), and then returned to the tank (10). In this illustrative example, the recirculation conduit (40) and the pump (60) constitute components for recirculating the immersion coolant between the tank and the heat exchanger.

[0019] The device of the present invention provides an inexpensive and environmentally friendly way to remove heat from a heating device.

[0020] Example

[0021] Flash point measurement

[0022] Using approximately 2–4 mL of sample material (placed in a sample cup), perform a SETA flash point (closed cup) measurement using ASTM D93. The expected flash point is set at 100 °C. Increase the temperature at a rate of 10 °C / min until the test sample temperature is 20 °C lower than the expected flash point. Then increase the temperature rate at a decreasing rate of 5–6 °C / min.

[0023] kinematic viscosity measurement

[0024] Kinematic viscosity is measured using ASTM D445 by loading 14–18 mL of sample material into a clean, dry Ubbelohde viscometer tube of appropriate size. The sample-filled tube is placed in a constant-temperature water bath and equilibrated at 25°C for 20 minutes before measurement. Suction is applied to the tube, and the outflow time (the time, in seconds, for the sample to pass between two graduations on the tube) is recorded. The viscosity is then automatically calculated and summarized.

[0025] In the following examples, the Pt catalyst refers to a mixture of tetramethyldivinyldisiloxane (20 pbw), isopropanol (70 pbw), and a platinum complex of 1,3-diethyl-1,1,3,3-tetramethyldisiloxane (10 pbw). The compounds of Formula 1a (a mixture of n=1, 2, and 3, where n=1 is predominant) are purified by distillation prior to use to remove high molecular weight impurities.

[0026] Preparation of 1-hexyl-substituted cyclic siloxanes as immersion coolants

[0027] 1-Hexene (389.1 g) was loaded into a 1-L four-necked flask equipped with a water-cooled condenser suitable for N2 bubbling, a thermocouple, and a mechanical stirrer. The headspace was purged with N2 for 5 minutes, after which the flask temperature was raised to 58°C. Then, Pt catalyst (0.75 g, 852 ppm) was added to the flask. The external heat source was removed, and compound 1a (243.3 g) was added to the flask at a rate of approximately 4 mL / min. The temperature was raised from 65°C to 95°C, and the external heat source was reintroduced after the addition was complete. Stirring was continued at approximately 82°C for 2 hours, after which the contents of the flask were transferred to a 1000 mL receiving flask. Volatiles were removed under vacuum at 100°C for 120 minutes, leaving a clear liquid (574.5 g). The flash point was measured to be 289°C, and the kinematic viscosity was measured to be 16 cSt.

[0028] Preparation of 2-octyl-substituted cyclic siloxanes as immersion coolants

[0029] 1-Octene (755.1 g) was loaded into a 2-L four-necked flask equipped with a water-cooled condenser suitable for N2 bubbling, a thermocouple, and a mechanical stirrer. The headspace was purged with N2 for 5 minutes, after which the flask temperature was raised to 58°C. Then, Pt catalyst (1.25 g, 852 ppm) was added to the flask. The external heat source was removed, and compound of formula 1a (367.8 g) was added to the flask at a rate of approximately 4 mL / min. The flask temperature was maintained between 65°C and 85°C, and the external heat source was reintroduced after the addition was complete. Stirring was continued at approximately 82°C for 5 hours, after which the contents of the flask were transferred to a 2000 mL receiving flask. Volatiles were removed under vacuum at 130°C for 6 minutes, leaving a clear liquid (1030.6 g). The flash point was measured to be >300°C, and the kinematic viscosity was measured to be 28.6 cSt.

[0030] A class of low-viscosity, high-flash-point immersion coolants has been discovered that effectively remove heat from heating devices, are safe to handle, and are environmentally friendly.

Claims

1. An immersion cooling device, comprising: 1) a heat exchanger, 2) a tank containing a submerged coolant and a heating element, and 3) a component for recirculating the submerged coolant between the tank and the heat exchanger, wherein the submerged coolant is characterized by a compound of formula 1: Each R is independently C4-C 18 - Hydrocarbon group; and n is 1 to 3.

2. The immersion cooling device according to claim 1, wherein each R is a straight-chain or branched C6-C 12 -alkyl group or 2-propylphenyl group.

3. The immersion cooling device according to claim 2, wherein each R is independently diisobutyl, n-hexyl, n-octyl, n-decyl, n-dodecyl, n-hexadecyl or 2-propylphenyl.

4. The immersion cooling device according to claim 2, wherein each R is independently diisobutyl, n-hexyl, n-octyl, n-decyl, or n-dodecyl.

5. The immersion cooling device according to claim 2, wherein the immersion coolant has a flash point above 150°C and a kinematic viscosity of less than 30 cSt at 25°C.

6. The immersion cooling device according to claim 2, wherein the immersion coolant has a flash point above 200°C and a kinematic viscosity of less than 20 cSt at 25°C.

7. The immersion cooling device according to any one of claims 1 to 6, wherein the heating device is a data center server, an electric vehicle battery, an electric vehicle motor, an electric vehicle charging station, an inverter, a converter, a semiconductor or telecommunications equipment.

8. The immersion cooling device according to claim 7, wherein the heating device is a data center server.

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