CN-224229736-U - Zero evaporation device for liquid helium

Abstract

The utility model relates to the technical field of liquid helium zero evaporation, in particular to a liquid helium zero evaporation device which comprises a liquid helium dewar, a cold end and a helium refrigerator, wherein the liquid helium dewar, the cold end and the helium refrigerator are connected through a plurality of layers of vacuum heat insulation pipelines to form a closed circulation loop, a pressure sensor in the liquid helium dewar is used for monitoring pressure, the working state of the helium refrigerator is controlled through a pressure control valve, helium flows into the helium refrigerator through the cold end, and is liquefied and flows back to the liquid helium dewar after multistage heat exchange, compression, expansion refrigeration and J-T valve throttling to realize zero evaporation in the liquid helium storage process.

Inventors

• LIU CHANGHAI
• LI SIHAN
• YANG SHANJU

Assignees

• 启承悬浮科技(南通)有限公司

Dates

Publication Date

20260512

Application Date

20250630

Claims (7)

1. 1. The liquid helium zero evaporation device comprises a liquid helium Dewar (1), a cold end (2) and a helium refrigerator (3), and is characterized by further comprising a multi-layer heat insulation vacuum pipeline (4), a pressure sensor (5) and a pressure control valve (6), wherein the helium refrigerator (3) is arranged outside the liquid helium Dewar (1), the multi-layer heat insulation vacuum pipeline (4) is arranged between the liquid helium Dewar (1) and the helium refrigerator (3), the cold end (2) is arranged at the input end of the liquid helium Dewar (1), the pressure control valve (6) is arranged inside the cold end (2), the pressure sensor (5) is arranged at the input end of the pressure control valve (6), the cold end (2) comprises a cold end air inlet (201), a cold end air outlet (202), a cold end liquid inlet (203) and a cold end liquid outlet (204), and the helium refrigerator (3) comprises a first heat exchanger (31), a second heat exchanger (32), a third heat exchanger (33), a compressor (34), a cooler (35), a first-stage turboexpander (36), a second-stage turboexpander (37) and a J-T valve (38).
2. 2. The liquid helium zero evaporation device according to claim 1, wherein two multi-layer heat-insulating vacuum pipelines (4) are arranged, the multi-layer heat-insulating vacuum pipelines (4) are respectively used as an input section and an output section and are connected with the liquid helium Dewar (1), a pressure control valve (6) is connected with the output section of the multi-layer heat-insulating vacuum pipeline (4), and the pressure control valve (6) is arranged in the cold end (2).
3. 3. The liquid helium zero-evaporation device according to claim 1, wherein the output end of the cold end air outlet (202) is provided with a first heat exchanger (31), the output end of the first heat exchanger (31) is provided with a second heat exchanger (32), the output end of the second heat exchanger (32) is provided with a third heat exchanger (33), the output end of the third heat exchanger (33) is provided with a compressor (34), and the output end of the compressor (34) is provided with a cooler (35).
4. 4. A liquid helium zero evaporation device according to claim 3 is characterized in that a first-stage turboexpander (36) is arranged between the second heat exchanger (32) and the first heat exchanger (31), a second-stage turboexpander (37) and a J-T valve (38) are arranged between the first heat exchanger (31) and a cold end liquid inlet (203), and the output end of the cooler (35) sequentially passes through the third heat exchanger (33), the second heat exchanger (32), the first-stage turboexpander (36), the first heat exchanger (31), the second-stage turboexpander (37) and the J-T valve (38) in series and then is connected with the cold end liquid inlet (203).
5. 5. A liquid helium zero evaporation device according to claim 1, wherein helium enters the device from a cold end air inlet (201) of the cold end (2), and helium liquid is discharged from a cold end liquid outlet (204) of the cold end (2).
6. 6. A liquid helium zero evaporation apparatus according to claim 3, wherein the compressor (34) and the first and second turbo-expanders (36, 37) of the helium refrigerator (3) are gas bearings for supporting the rotor system.
7. 7. A liquid helium zero evaporation device according to claim 1, wherein the upper limit value and the lower limit value of the pressure control valve (6) are respectively 0.5MPa and 0.12MPa, when the internal pressure of the liquid helium Dewar (1) is higher than the upper limit value of the pressure control valve (6), the helium refrigerator (3) is started according to rated power, when the internal pressure of the liquid helium Dewar (1) is between the lower limit value and the upper limit value of the pressure control valve (6), the helium refrigerator (3) is started under rated power, and when the internal pressure of the liquid helium Dewar (1) is lower than the lower limit value of the pressure control valve (6), the helium refrigerator (3) is stopped.

Description

Zero evaporation device for liquid helium Technical Field The utility model relates to the technical field of liquid helium zero evaporation, in particular to a liquid helium zero evaporation device. Background Helium is an indispensable rare strategic material for development of high-tech industry, the temperature of liquid helium is as low as-269 ℃, is only higher than absolute zero, is extremely easy to vaporize and needs a special storage device, so that efficient storage of liquid helium is important for guaranteeing supply and reducing cost, and mainly comprises a liquid helium tank, a liquid helium Dewar and the like, wherein the liquid helium tank is the most widely used liquid helium storage and transportation carrier in the world at present, such as a liquid helium tank of the well-distributed Anareidae, can realize seamless connection of liquid helium in links of filling, transportation, storage and the like, and has the advantages of long nondestructive storage time and the like. Because liquid helium has small latent heat, small density, strong thermal conductivity and diffusivity and is easy to be subjected to thermal evaporation, the storage equipment is pressurized, when the pressure exceeds the allowable pressure, the pressure needs to be discharged for decompression, so that a great amount of liquid helium is lost and wasted, the storage cost is increased, meanwhile, the reduction of the liquid helium reserves can influence the operation of related equipment, such as a hospital nuclear magnetic resonance spectrometer depends on the liquid helium to maintain the low temperature of a superconducting coil, and the excessive liquid helium evaporation can cause the equipment to be unable to normally operate. Disclosure of utility model In order to solve the problems that the storage cost is increased and the equipment work is affected due to the fact that the storage of helium and the reduction of reserves in the application process of the equipment are caused by the fact that the physical characteristics of helium are easy to evaporate in the existing liquid helium equipment, the utility model provides a liquid helium zero evaporation device. The liquid helium zero evaporation device comprises a liquid helium Dewar, a cold end, a helium refrigerator, a multi-layer heat insulation vacuum pipeline, a pressure sensor and a pressure control valve, wherein the helium refrigerator is arranged outside the liquid helium Dewar, the multi-layer heat insulation vacuum pipeline is arranged between the liquid helium Dewar and the helium refrigerator, the cold end is arranged at the input end of the liquid helium Dewar, the pressure control valve is arranged inside the cold end, the pressure sensor is arranged at the input end of the pressure control valve, the cold end comprises a cold end air inlet, a cold end air outlet, a cold end liquid inlet and a cold end liquid outlet, and the helium refrigerator comprises a first heat exchanger, a second heat exchanger, a third heat exchanger, a compressor, a cooler, a first-stage turboexpander, a second-stage turboexpander and a J-T valve. Further, two multi-layer heat insulation vacuum pipelines are arranged, the multi-layer heat insulation vacuum pipelines are respectively used as an input section and an output section and are connected with the liquid helium Dewar, a pressure control valve is connected with the output section of the multi-layer heat insulation vacuum pipeline, and the pressure control valve is arranged in the cold end. Further, the output end of the cold end air outlet is provided with a first heat exchanger, the output end of the first heat exchanger is provided with a second heat exchanger, the output end of the second heat exchanger is provided with a third heat exchanger, the output end of the third heat exchanger is provided with a compressor, and the output end of the compressor is provided with a cooler. Further, a first-stage turboexpander is arranged between the second heat exchanger and the first heat exchanger; a second-stage turboexpander and a J-T valve are arranged between the first heat exchanger and the cold end liquid inlet, and the output end of the cooler is sequentially connected in series through a third heat exchanger, a second heat exchanger, a first-stage turboexpander, the first heat exchanger, the second-stage turboexpander and the J-T valve and then connected with the cold end liquid inlet. Further, helium enters the device from a cold end air inlet of the cold end, and helium liquid is discharged from a cold end liquid outlet of the cold end. Further, a compressor in the helium refrigerator, a primary turbine expander and a secondary turbine expander both adopt gas bearings to support a rotor system. Further, the upper limit value and the lower limit value of the pressure control valve are respectively 0.5MPa and 0.12MPa, when the internal pressure of the liquid helium Dewar is higher than the upper limit value of th