A liquid hydrogen multiphase flow loop thermal management system

Abstract

This invention specifically relates to a liquid hydrogen multiphase flow loop thermal management system, belonging to the field of superconducting magnet thermal management technology. This invention incorporates nanoscale magnetic catalyst particles into the liquid hydrogen working fluid. On one hand, the nanoscale magnetic catalyst particles act as a catalyst, stimulating the secondary hydrogen conversion reaction during the evaporation and condensation of the hydrogen working fluid. The endothermic and exothermic conversion process occurs simultaneously with the phase change process. On the other hand, the nanoparticles can increase the overall heat capacity of the working fluid, thus improving the heat carrying capacity per unit mass of the working fluid from two perspectives. This invention includes two infusion valves and an injection valve in the adiabatic section. By controlling the flow direction and the filtration effect of the filter, the concentration of the nanoscale magnetic catalyst particles is adjusted, thereby changing the heat carrying capacity of the working fluid and thus regulating the start-up performance and heat transfer limit of the heat pipe.

Description

Technical Field

[0001] This invention specifically relates to a liquid hydrogen multiphase flow loop thermal management system, belonging to the field of superconducting magnet thermal management technology. Background Technology

[0002] Superconducting magnetic energy storage technology is a highly advanced energy storage technology, commonly used for generator power oscillation regulation and grid peak shaving and valley filling. It boasts an energy storage efficiency exceeding 90%, far surpassing conventional methods such as compressed air energy storage and phase change energy storage. However, superconducting magnets are extremely sensitive to ambient temperatures, requiring cooling to the liquid hydrogen temperature range (approximately -260°C). Currently, pulsating heat pipes are a commonly used heat transfer element for cooling superconducting magnets. Compared to traditional heat pipes, pulsating heat pipes offer advantages such as superior heat transfer performance, flexibility, adaptability, small size, low cost, and long heat transfer distance, making them promising for applications in cryogenic fields.

[0003] Currently, heat pipe technology in the liquid hydrogen temperature range is not mature and is still in the research and exploration stage. The available working fluids are very limited. Some research teams use liquid helium as a heat transfer medium for cooling superconducting magnets, but liquid helium heat pipes have a very low heat transfer limit and are prone to burning out, causing the working fluid to stagnate at both ends of the heat pipe and stop flowing. Patent application CN115752048A discloses a low-temperature pulsating heat pipe with anti-dry-burning properties, using liquid hydrogen as the heat transfer medium. It places the evaporation section in the middle of the heat pipe and connects parallel tubes to prevent localized burning out. This invention significantly improves the heat transfer limit compared to liquid helium heat pipes, mainly because the latent heat of vaporization of liquid hydrogen is much higher than that of liquid helium, approximately 23 times that of liquid helium. For some extreme low-temperature environments, the size of pulsating heat pipes cannot be made very large, but high requirements are placed on the heat transfer limit. Liquid hydrogen itself does not have a particularly high latent heat, only about 1 / 5 that of water, which is no longer sufficient to meet the heat transfer requirements under some extreme conditions. Furthermore, when the latent heat of vaporization of the working fluid is high, although the heat transfer limit is relatively large, the starting inertia is also large, and the required starting temperature difference is also large. This is a contradiction inherent in the properties of heat pipes. If the heat load provided by the superconducting magnet changes and the thermal conductivity of the working fluid is insufficient, the heat pipe is prone to burning out. Summary of the Invention

[0004] The technical problem to be solved by this invention is: how to adjust the heat carrying capacity of the working fluid according to the thermal management requirements to match the corresponding start-up conditions, so as to enable the thermal management system to obtain the best overall heat transfer performance.

[0005] To solve the above-mentioned technical problems, the technical solution proposed by this invention is: a liquid hydrogen multiphase flow loop thermal management system, including a pulsating heat pipe, an evaporation-side heat-conducting plate, a condensation-side heat-conducting plate, and a working fluid control device; the pulsating heat pipe is a closed-loop pipeline formed by continuous bending, and the pulsating heat pipe is sequentially divided into an evaporation section, an adiabatic section, and a condensation section along the pipeline; the evaporation-side heat-conducting plate has an evaporation section mounting groove that matches the shape of the evaporation section, and the evaporation section of the pulsating heat pipe is embedded in the evaporation section mounting groove and tightly fitted to the groove wall; a superconducting magnet is connected to the outer surface of the evaporation-side heat-conducting plate; the condensation-side heat-conducting plate has a condensation section mounting groove that matches the shape of the condensation section, and the condensation section of the pulsating heat pipe is embedded in the condensation section mounting groove and tightly fitted to the groove wall; the adiabatic section is located between the evaporation section and the condensation section and does not contact the evaporation-side heat-conducting plate and the condensation-side heat-conducting plate, thereby achieving thermal isolation;

[0006] The pulsating heat pipe is evacuated and filled with a working fluid, which is a multiphase mixture of liquid hydrogen and nanoparticles of a secondary positive hydrogen conversion catalyst. A microchannel is provided on the outer side of the condensation-side heat-conducting plate away from the condensation section mounting groove. The microchannel is integrally formed on the condensation-side heat-conducting plate, which is made of a high thermal conductivity metal. Cooling water adapted to the liquid hydrogen temperature range flows through the microchannel to achieve cooling of the liquid hydrogen in the condensation section.

[0007] The working fluid control device comprises an infusion valve A, an infusion valve B, a nanofilter, and a syringe. Infusion valve A and infusion valve B are respectively installed on the adiabatic section of the pulsating heat pipe. The nanofilter is connected to either infusion valve A or infusion valve B. The working fluid control device is used to adjust the concentration of the secondary nephrohydrogen conversion catalyst nanoparticles in the working fluid, thereby achieving performance regulation of the liquid hydrogen multiphase flow loop thermal management system. When the working fluid control device needs to reduce the concentration of the secondary nephrohydrogen conversion catalyst nanoparticles in the working fluid, the syringe is connected to the nanofilter, and the flow is controlled by the syringe... The suction action draws the working fluid out of the pulsating heat pipe through the infusion valve connected to the nanofilter. The secondary hydrogen conversion catalyst nanoparticles in the working fluid remain in the nanofilter, while the liquid hydrogen in the working fluid enters the syringe. The syringe containing liquid hydrogen is then pulled out and reinserted into the input valve not connected to the nanofilter, injecting liquid hydrogen into the pulsating heat pipe, thus reducing the concentration of the secondary hydrogen conversion catalyst nanoparticles in the working fluid. When the working fluid control device needs to increase the concentration of the secondary hydrogen conversion catalyst nanoparticles in the working fluid, the process is reversed.

[0008] Furthermore, the cross-section of the microchannel is rectangular or circular, with a hydraulic diameter of less than 1 mm.

[0009] Furthermore, both the evaporation section and the condensation section are equipped with Tesla valve structures; the pipe cross-sections of the evaporation section, the condensation section, the insulation section, and the Tesla valve are all flat.

[0010] Furthermore, the infusion valve A and infusion valve B have the same structure, both including a flow channel and a valve switch. The flow channel is interconnected with the insulation section, and the valve switch is located at the junction of the insulation section and the flow channel to control the on / off connection between the flow channel and the pulsating heat pipe.

[0011] Furthermore, the nanofilter includes a housing, a nanofiltration membrane, and a filter valve. The nanofiltration membrane divides the interior of the housing into a storage area and a filtrate area. The storage area is connected to either the infusion valve A or the infusion valve B via a hose. The filter valve is located in the filtrate area. The nanofiltration membrane is used to trap the nanoparticles of the positive hydrogen conversion catalyst, allowing pure liquid hydrogen to pass through and enter the filtrate area.

[0012] Furthermore, the syringe includes a barrel, an injection piston, and a syringe valve. The syringe valve is located at the head of the barrel and is used to control the connection between the syringe and an external pipeline. The injection piston is located inside the barrel. The syringe achieves the suction and injection of the working fluid in the pulsating heat pipe by pulling or pushing the injection piston to move within the barrel.

[0013] Furthermore, the secondary orthohydrogen conversion catalyst nanoparticles are one or more of Ni(X) / Al2O3, Ni(I) / Al2O3, Ni(B) / Al2O3, Cr2O3 / Al2O3, and Tb2O3 / Zr2O3.

[0014] The beneficial effects of this invention are as follows: 1. This invention incorporates nano-sized magnetic catalyst particles into the liquid hydrogen working fluid. On the one hand, the nano-sized magnetic catalyst particles act as a catalyst during the evaporation and condensation of the hydrogen working fluid, stimulating the secondary positive hydrogen conversion reaction. The endothermic and exothermic conversion process occurs simultaneously with the phase change process. On the other hand, the nanoparticles can increase the overall heat capacity of the working fluid, thereby improving the heat carrying capacity per unit mass of the working fluid from two perspectives. 2. This invention is equipped with two infusion valves and an injection valve in the adiabatic section. By controlling the flow direction and the filtration effect of the filter, the concentration of the nano-magnetic catalyst particles can be adjusted, thereby changing the heat carrying capacity of the working fluid and thus adjusting the start-up performance and heat transfer limit of the heat pipe. 3. This invention is equipped with Tesla valves in the evaporation and condensation sections, which can accelerate the flow rate and promote unidirectional flow of the working fluid, reduce gas-liquid convection, reduce the probability of the secondary positive hydrogen reaction occurring in the adiabatic section, and the Tesla valves can increase the heat transfer area of ​​the evaporation and condensation sections. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the liquid hydrogen multiphase flow loop thermal management system in an embodiment of the present invention.

[0016] Figure 2 This is a schematic diagram of the assembly of the liquid hydrogen multiphase flow loop thermal management system in an embodiment of the present invention.

[0017] Figure 3 This is a schematic diagram of the pulsating heat pipe and its cross-section in an embodiment of the thermal management system of the present invention.

[0018] Figure 4 This is a schematic diagram of the infusion valve structure of the thermal management system in an embodiment of the present invention.

[0019] Figure 5 This is a schematic diagram of the nanofiltration membrane structure of the thermal management system in an embodiment of the present invention.

[0020] Figure 6 This is a schematic diagram of the heat-conducting plate structure on the condenser side in an embodiment of the present invention. Detailed Implementation

[0021] The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the liquid hydrogen multiphase flow loop thermal management system of the present invention.

[0022] Example

[0023] The liquid hydrogen multiphase flow loop thermal management system in this embodiment, such as Figures 1 to 5 As shown, a liquid hydrogen multiphase flow loop thermal management system includes a pulsating heat pipe 100, an evaporation-side heat-conducting plate 500, a condensation-side heat-conducting plate 600, and a working fluid control device. The pulsating heat pipe 100 is a closed-loop pipeline formed by continuous bending. The pulsating heat pipe 100 is divided into an evaporation section 101, an adiabatic section 102, and a condensation section 103 along the pipeline. Both the evaporation section 101 and the condensation section 103 are equipped with Tesla valve structures. The Tesla valve structures are used to promote unidirectional flow of the working fluid and reduce gas-liquid convection. The pipeline cross-sections of the evaporation section 101, the condensation section 103, the adiabatic section 102, and the Tesla valve are all flat to increase the heat transfer area with the evaporation-side heat-conducting plate 500 and the condensation-side heat-conducting plate 600, thereby improving the heat transfer efficiency between the pulsating heat pipe 100 and the heat-conducting plate.

[0024] The pulsating heat pipe 100 is internally evacuated and filled with a working fluid, which is a multiphase mixture of liquid hydrogen and secondary hydrogen conversion catalyst nanoparticles. The secondary hydrogen conversion catalyst nanoparticles are one or more of Ni(X) / Al2O3, Ni(I) / Al2O3, Ni(B) / Al2O3, Cr2O3 / Al2O3, and Tb2O3 / Zr2O3. When the concentration of secondary hydrogen conversion catalyst nanoparticles in the pulsating heat pipe 100 decreases, the secondary hydrogen conversion reaction weakens, the heat carrying capacity per unit of working fluid decreases, the heat transfer limit decreases, and the start-up inertia decreases, making it suitable for low-load thermal conditions of superconducting magnets. When the concentration of nanoparticles in the pulsating heat pipe 100 increases, the secondary hydrogen conversion reaction intensifies, the heat carrying capacity per unit of working fluid increases, the heat transfer limit increases, and the start-up inertia increases, making it suitable for high-load thermal conditions of superconducting magnets.

[0025] An evaporation-side heat-conducting plate 500 has an evaporation section mounting groove that matches the shape of the evaporation section 101. The evaporation section 101 of the pulsating heat pipe 100 is embedded in the evaporation section mounting groove and is tightly fitted to the groove wall. A superconducting magnet is connected to the outer surface of the evaporation-side heat-conducting plate 500. A condensation section mounting groove that matches the shape of the condensation section 103 is formed in the condensation section heat-conducting plate 600. The condensation section 103 of the pulsating heat pipe 100 is embedded in the condensation section mounting groove and is tightly fitted to the groove wall. An insulation section 102 is located between the evaporation section 101 and the condensation section 103 and does not contact the evaporation-side heat-conducting plate 500 and the condensation-side heat-conducting plate 501, thus achieving thermal isolation.

[0026] The condensing-side heat-conducting plate 600 has a microchannel on the outside of the condensing section mounting groove. The microchannel is integrally formed on the condensing-side heat-conducting plate. The condensing-side heat-conducting plate is made of a high thermal conductivity metal. Cooling water adapted to the liquid hydrogen temperature range flows through the microchannel to achieve cooling of liquid hydrogen in the condensing section. The microchannel has a rectangular or circular cross-section and a hydraulic diameter of less than 1 mm.

[0027] The working fluid control device consists of infusion valve A201, infusion valve B202, nanofilter 300, and syringe 400. Infusion valve A201 and infusion valve B202 are respectively installed on the adiabatic section 102 of the pulsating heat pipe 100. Infusion valve A201 and infusion valve B202 have the same structure, both including a flow channel 2001 and a valve switch 2002. The flow channel 2001 is connected to the adiabatic section 102. The valve switch 2002 is located at the junction of the adiabatic section 102 and the flow channel 2001 and is used to control the on / off connection between the flow channel 2001 and the pulsating heat pipe 100.

[0028] The nanofilter 300 is connected to either infusion valve A201 or infusion valve B202. In this embodiment, it is connected to infusion valve A201. The nanofilter 300 includes a housing 301, a nanofiltration membrane 302, and a filter valve 303. The nanofiltration membrane 302 divides the interior of the housing 301 into a storage area 304 and a filtrate area 305. The storage area 304 is connected to the infusion valve A201 via a hose. The filter valve 303 is located in the filtrate area 305. The nanofiltration membrane 302 is used to trap the nanoparticles of the positive hydrogen conversion catalyst, allowing pure liquid hydrogen to pass through and enter the filtrate area 305.

[0029] The syringe 400 includes a barrel 401, an injection piston 402, and a syringe valve 403. The syringe valve 403 is located at the head of the barrel 401 and is used to control the connection between the syringe 400 and the external pipeline. The injection piston 402 is located inside the barrel 401. The syringe 400 achieves the suction and injection of the working fluid in the pulsating heat pipe 100 by pulling or pushing the injection piston 402 to move within the barrel 401.

[0030] The working fluid control device is used to adjust the concentration of the secondary orthohydrogen conversion catalyst nanoparticles in the working fluid, thereby changing the endothermic capacity of the working fluid and matching different heat load conditions of the conductive magnet. This allows for the regulation of the start-up performance and heat transfer limit of the thermal management system. Specific steps include a working fluid concentration reduction adjustment step and a working fluid concentration increase adjustment step.

[0031] The steps for adjusting the concentration reduction are as follows:

[0032] Step 1: Connect the head of syringe 400 to the filtrate area 305 of nanofilter 300, open the valve switches of syringe valve 403, filter valve 303 and infusion valve A201, and close the valve switch of infusion valve B202.

[0033] Step 2: Pull the injection piston 402 to draw the working fluid inside the pulsating heat pipe 100 into the storage area 304 of the nanofilter 300 under negative pressure. After being filtered by the nanofiltration membrane 302, the nanoparticles of the positive hydrogen conversion catalyst are retained in the storage area 304 to form a concentrated solution. The filtered pure liquid hydrogen enters the filtrate area 305 and flows into the cylinder 401 of the syringe 400.

[0034] Step 3: Based on the heat load requirements of the superconducting magnet, push the injection piston 402 to re-inject the concentrated solution in the storage area 304 into the pulsating heat pipe 100, and control the amount of concentrated solution re-injected to adjust the retention base of nanoparticles.

[0035] Step 4: Close the valve switches of syringe valve 403, filter valve 303 and infusion valve A201, disconnect syringe 400 from nanofilter 300, connect the head of syringe 400 to infusion valve B201, and open the valve switches of syringe valve 403 and infusion valve B202.

[0036] Step 5: Push the injection piston 402 to inject pure liquid hydrogen from the syringe 400 into the pulsating heat pipe 100, thereby reducing the concentration of the secondary positive hydrogen conversion catalyst nanoparticles in the working fluid.

[0037] Concentration increase adjustment steps

[0038] By reversing the above steps, the concentrated solution in the storage area 304 is quantitatively drawn into the syringe 400, and then injected into the pulsating heat pipe 100 through the infusion valve A201 or the infusion valve B202, thereby increasing the concentration of the secondary positive hydrogen conversion catalyst nanoparticles in the working fluid.

[0039] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A liquid hydrogen multiphase flow loop thermal management system, comprising a pulsating heat pipe, an evaporation-side heat-conducting plate, a condensation-side heat-conducting plate, and a working fluid control device; the pulsating heat pipe is a closed-loop pipeline formed by continuous bending, and the pulsating heat pipe is sequentially divided into an evaporation section, an adiabatic section, and a condensation section along the pipeline; the evaporation-side heat-conducting plate has an evaporation section mounting groove matching the shape of the evaporation section, the evaporation section of the pulsating heat pipe is embedded in the evaporation section mounting groove and tightly fitted to the groove wall, and a superconducting magnet is connected to the outer surface of the evaporation-side heat-conducting plate; the condensation-side heat-conducting plate has a condensation section mounting groove matching the shape of the condensation section, the condensation section of the pulsating heat pipe is embedded in the condensation section mounting groove and tightly fitted to the groove wall; the adiabatic section is located between the evaporation section and the condensation section and does not contact the evaporation-side heat-conducting plate and the condensation-side heat-conducting plate, achieving thermal isolation, characterized in that: The pulsating heat pipe is evacuated and filled with a working fluid, which is a multiphase mixture of liquid hydrogen and nanoparticles of a secondary positive hydrogen conversion catalyst. A microchannel is provided on the outer side of the condensation-side heat-conducting plate away from the condensation section mounting groove. The microchannel is integrally formed on the condensation-side heat-conducting plate, which is made of a high thermal conductivity metal. Cooling water adapted to the liquid hydrogen temperature range flows through the microchannel to achieve cooling of the liquid hydrogen in the condensation section. The working fluid control device comprises an infusion valve A, an infusion valve B, a nanofilter, and a syringe. Infusion valve A and infusion valve B are respectively installed on the adiabatic section of the pulsating heat pipe. The nanofilter is connected to either infusion valve A or infusion valve B. The working fluid control device is used to adjust the concentration of the secondary nephrohydrogen conversion catalyst nanoparticles in the working fluid, thereby achieving performance regulation of the liquid hydrogen multiphase flow loop thermal management system. When the working fluid control device needs to reduce the concentration of the secondary nephrohydrogen conversion catalyst nanoparticles in the working fluid, the syringe is connected to the nanofilter, and the flow is controlled by the syringe... The suction action draws the working fluid out of the pulsating heat pipe through the infusion valve connected to the nanofilter. The secondary hydrogen conversion catalyst nanoparticles in the working fluid remain in the nanofilter, while the liquid hydrogen in the working fluid enters the syringe. The syringe containing liquid hydrogen is then pulled out and reinserted into the input valve not connected to the nanofilter, injecting liquid hydrogen into the pulsating heat pipe, thus reducing the concentration of the secondary hydrogen conversion catalyst nanoparticles in the working fluid. When the working fluid control device needs to increase the concentration of the secondary hydrogen conversion catalyst nanoparticles in the working fluid, the process is reversed.

2. The liquid hydrogen multiphase flow loop thermal management system according to claim 1, characterized in that: The microchannel has a rectangular or circular cross-section and a hydraulic diameter of less than 1 mm.

3. The liquid hydrogen multiphase flow loop thermal management system according to claim 1, characterized in that: Both the evaporation section and the condensation section are equipped with Tesla valve structures; the pipe cross-sections of the evaporation section, the condensation section, the insulation section, and the Tesla valve are all flat.

4. The liquid hydrogen multiphase flow loop thermal management system according to claim 1, characterized in that: The infusion valve A and infusion valve B have the same structure, both including a flow channel and a valve switch. The flow channel is interconnected with the insulation section, and the valve switch is located at the junction of the insulation section and the flow channel to control the on / off connection between the flow channel and the pulsating heat pipe.

5. The liquid hydrogen multiphase flow loop thermal management system according to claim 1, characterized in that: The nanofilter includes a housing, a nanofiltration membrane, and a filter valve. The nanofiltration membrane divides the interior of the housing into a storage area and a filtrate area. The storage area is connected to either infusion valve A or infusion valve B via a hose. The filter valve is located in the filtrate area. The nanofiltration membrane is used to trap the nanoparticles of the positive hydrogen conversion catalyst, allowing pure liquid hydrogen to pass through and enter the filtrate area.

6. The liquid hydrogen multiphase flow loop thermal management system according to claim 1, characterized in that: The syringe includes a barrel, an injection piston, and a syringe valve. The syringe valve is located at the head of the barrel and is used to control the connection between the syringe and an external pipeline. The injection piston is located inside the barrel. The syringe draws in and injects the working fluid in the pulsating heat pipe by pulling or pushing the injection piston to move within the barrel.

7. The liquid hydrogen multiphase flow loop thermal management system according to claim 1, characterized in that: The intermediate-hydrogen conversion catalyst nanoparticles are one or more of Ni(X) / Al2O3, Ni(I) / Al2O3, Ni(B) / Al2O3, Cr2O3 / Al2O3, and Tb2O3 / Zr2O3.

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