Helium low-temperature system with rapid rewarming function

Abstract

The invention relates to the technical field of low-temperature refrigeration, in particular to a rapid rewarming helium low-temperature system which comprises a cold box, a first-stage heat exchanger and a second-stage heat exchanger. The high-purity helium source is used for releasing helium to be mixed with helium at a high-pressure inlet of the final-stage heat exchanger to realize temperature mixing; and the regulating valve is arranged between the high-purity helium source and the high-pressure inlet of the final-stage heat exchanger and is used for regulating the helium flow or air pressure of the high-purity helium source entering the cold box. The high-purity helium source is mixed with helium at a high-pressure inlet of a last-stage heat exchanger in the helium low-temperature system to achieve temperature mixing, the temperature of the helium in the helium low-temperature system is increased, the heated helium passes through the last-stage heat exchanger and plays a role in heating the heat exchanger, meanwhile, the heated helium exchanges heat with helium in a low-pressure pipeline, the temperature of backflow helium is increased, and the temperature of the backflow helium is increased. The rewarming of low-temperature helium in the cold box can be realized more quickly, so that the energy consumption of a helium low-temperature system in the rewarming process can be reduced, the energy is saved, and the rewarming benefit of the helium low-temperature system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of cryogenic refrigeration, and particularly to a helium cryogenic system with rapid rewarming. Background Art

[0002] Helium cryogenic systems are currently widely used in large scientific projects, helium resources, and scientific research fields that require a low-temperature environment. Especially for scientific research fields, the helium cryogenic system will stop operating after running for a period of time. When stopping, in order to avoid damage to the equipment caused by the increased pressure after the low-temperature helium gas in the system is rewarmed, or waste of helium resources caused by the release of helium gas from the safety valve, the helium cryogenic system usually rewarms the system without shutting down the compressor, so that the high-purity helium gas in the low-temperature part of the helium cryogenic system is rewarmed to room temperature, and the rewarmed high-purity helium gas enters the helium buffer tank through the gas management panel. During the rewarming process, relying only on the normal-temperature helium gas at the inlet of the cold box to exchange heat with each stage of the heat exchanger in turn, since the helium cryogenic system uses a regenerative heat exchange method, the rewarming time is relatively long, and the long-term operation causes the power consumption of the system to continuously increase. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention provides a helium cryogenic system with rapid rewarming, aiming to solve the problem of increased energy consumption caused by the long rewarming time of the helium cryogenic system.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A helium cryogenic system with rapid rewarming, comprising:

[0006] A cold box, in which a final heat exchanger is provided;

[0007] A high-purity helium gas source, used to release helium gas and mix it with the helium gas at the high-pressure inlet of the final heat exchanger to achieve temperature blending;

[0008] A regulating valve, arranged between the high-purity helium gas source and the high-pressure inlet of the final heat exchanger, used to regulate the helium gas flow or pressure of the high-purity helium gas source entering the cold box.

[0009] Preferably, it further includes a heater, which is arranged between the regulating valve and the high-purity helium gas source, and is used to heat the helium gas released by the high-purity helium gas source.

[0010] Preferably, the high-purity helium gas source is a helium buffer tank or a helium gas cylinder group, or the high-purity helium gas source is the normal-temperature end of the high-pressure pipeline.

[0011] Preferably, it further includes a low-pressure pipeline, a high-pressure pipeline and a compressor. The high-pressure pipeline and the low-pressure pipeline form a circulation loop. The compressor is arranged between the low-pressure pipeline and the high-pressure pipeline. The cold box is arranged in the circulation loop formed by the low-pressure pipeline and the high-pressure pipeline.

[0012] Preferably, a helium pre-cooling module, a multi-stage turbine expansion unit and a heat exchanger group are further arranged in the cold box. The helium pre-cooling module is used to be arranged on the inlet side of the cold box and before the multi-stage turbine expansion unit, and is used to pre-cool the helium entering the cold box. The multi-stage turbine expansion unit includes a first turbine expansion unit and a second turbine expansion unit, and is used to perform a multi-stage cooling process on the helium entering the cold box. The heat exchanger group is used to perform a multi-stage heat exchange process on the helium entering the cold box.

[0013] Preferably, the helium pre-cooling module includes a helium gas passage regulating valve connected to the high-pressure pipeline, a liquid nitrogen pre-cooling heat exchanger connected to the high-pressure outlet of the first heat exchanger of the heat exchanger group, a liquid nitrogen inlet pipeline connected to the liquid nitrogen pre-cooling heat exchanger, a liquid nitrogen inlet regulating valve arranged on the liquid nitrogen inlet pipeline, and a nitrogen gas outlet pipeline sequentially connected to the liquid nitrogen pre-cooling heat exchanger and the nitrogen gas outlet of the first heat exchanger of the heat exchanger group. The helium pre-cooling module pre-cools the helium by the liquid nitrogen introduced through the liquid nitrogen inlet pipeline. The helium gas passage regulating valve is used to regulate the amount of helium entering the liquid nitrogen pre-cooling heat exchanger. The liquid nitrogen inlet regulating valve is used to regulate the amount of liquid nitrogen entering the liquid nitrogen pre-cooling heat exchanger. The nitrogen gas outlet pipeline is used to discharge the nitrogen gas after liquid nitrogen heat exchange.

[0014] Preferably, the heat exchanger group includes a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a sixth heat exchanger and a seventh heat exchanger sequentially arranged in the circulation loop formed by the low-pressure pipeline and the high-pressure pipeline.

[0015] Preferably, the first turbine expansion unit includes a first turbine, a second turbine and a first inlet regulating valve. The first inlet regulating valve is arranged between the high-pressure outlet of the second heat exchanger and the inlet of the first turbine. The outlet of the first turbine is connected to the intake pipeline of the fourth heat exchanger. The inlet of the second turbine is connected to the outlet pipeline of the fourth heat exchanger. The outlet of the second turbine is connected to the low-pressure pipeline between the fifth heat exchanger and the sixth heat exchanger.

[0016] The second turbine expansion unit includes a third turbine, a third inlet regulating valve, a cryogenic regulating valve and a third outlet switching valve. The third inlet regulating valve is arranged between the high-pressure outlet of the sixth heat exchanger and the inlet of the third turbine; the cryogenic regulating valve is arranged on the high-pressure pipeline and is located between the sixth heat exchanger and the seventh heat exchanger; the third outlet switching valve is arranged between the outlet of the third turbine and the seventh heat exchanger, where the seventh heat exchanger is the final heat exchanger.

[0017] Preferably, it further includes a high-precision oil filtering module and a gas management module. The high-precision oil filtering module is arranged at the high-pressure outlet of the compressor. The gas management module is used to adjust and control the inlet and outlet pressures of the compressor. The gas management module includes a buffer tank, a buffer regulating valve, a system loading valve, a system unloading valve and a system bypass valve. The system bypass valve is connected between the high-pressure pipeline and the low-pressure pipeline. The system loading valve and the system unloading valve are connected between the high-pressure pipeline and the low-pressure pipeline. The system buffer tank is connected between the system loading valve and the system unloading valve through the buffer regulating valve.

[0018] Preferably, it further includes a liquid helium dewar arranged outside the cold box. The inlet of the liquid helium dewar is connected to the high-pressure outlet of the final heat exchanger, and a first throttle valve is arranged on the high-pressure pipeline between the final heat exchanger and the liquid helium dewar. The gas-phase outlet of the liquid helium dewar is connected to the low-pressure inlet of the final heat exchanger, and a low-pressure regulating valve is arranged on the low-pressure pipeline between the final heat exchanger and the liquid helium dewar.

[0019] The beneficial effects of a helium cryogenic system with rapid rewarming described in the present invention are as follows:

[0020] The mixing of the high-purity helium gas source and the helium gas at the high-pressure inlet of the final heat exchanger in the helium cryogenic system realizes temperature blending, increasing the temperature of the helium gas in the helium cryogenic system. The heated helium gas passes through the final heat exchanger, warming up the heat exchanger. At the same time, the heated helium gas exchanges heat with the helium gas in the low-pressure pipeline, increasing the temperature of the refluxing helium gas. Compared with the existing helium cryogenic systems, it can more quickly realize the rewarming of the low-temperature helium gas in the cold box. Since the system rewarming is accelerated, the operation time of the compressor is reduced, thereby reducing the energy consumption of the helium cryogenic system during the rewarming process, saving energy, and increasing the benefit of the helium cryogenic system rewarming. At the same time, the regulating valve can adjust the pressure or flow rate of the high-purity helium gas entering the cold box, ensuring that the temperature change of the helium gas after temperature blending is within a controllable range, thus ensuring the safety of the helium cryogenic system. Description of the Drawings

[0021] Figure 1 is the overall structural schematic diagram of the helium cryogenic system with rapid rewarming of the first preferred embodiment of the present invention;

[0022] Figure 2 It is a schematic diagram of the overall structure of the rapid rewarming helium cryogenic system according to the second preferred embodiment of the present invention;

[0023] Figure 3 It is a schematic diagram of the overall structure of the rapid rewarming helium cryogenic system according to the third preferred embodiment of the present invention;

[0024] Figure 4 It is a schematic diagram of the overall structure of the rapid rewarming helium cryogenic system according to the fourth preferred embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1, cold box; 11, helium gas passage regulating valve; 12, liquid nitrogen precooling heat exchanger; 13, liquid nitrogen inlet pipeline; 14, liquid nitrogen inlet regulating valve; 15, nitrogen outlet pipeline; 16, first heat exchanger; 17, second heat exchanger; 18, third heat exchanger; 19, fourth heat exchanger; 110, fifth heat exchanger; 111, sixth heat exchanger; 112, seventh heat exchanger; 113, first turbine; 114, second turbine; 115, first inlet regulating valve; 116, third turbine; 117, third inlet regulating valve; 118, low-temperature regulating valve; 119, third outlet switch valve;

[0027] 2, high-purity helium gas source;

[0028] 3, regulating valve;

[0029] 4, heater;

[0030] 5, low-pressure pipeline;

[0031] 6, high-pressure pipeline;

[0032] 7, compressor;

[0033] 8, high-precision oil filtering module;

[0034] 9, buffer tank; 91, buffer regulating valve; 92, system loading valve; 93, system unloading valve; 94, system bypass valve;

[0035] 10, liquid helium dewar; 101, first throttle valve; 102, low-pressure regulating valve. Detailed implementation manners

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0037] As Figure 1 - Figure 4 shown, the present invention discloses a rapid rewarming helium cryogenic system, including:

[0038] A cold box 1, in which a final heat exchanger is arranged;

[0039] A high-purity helium gas source 2 is used to release helium gas to mix with the helium gas at the high-pressure inlet of the last-stage heat exchanger to achieve temperature blending.

[0040] A regulating valve 3 is arranged between the high-purity helium gas source 2 and the high-pressure inlet of the last-stage heat exchanger, and is used to adjust the helium gas flow rate or pressure of the high-purity helium gas source 2 entering the cold box 1.

[0041] The high-purity helium gas source 2 mixes with the helium gas at the high-pressure inlet of the last-stage heat exchanger in the helium cryogenic system to achieve temperature blending, increasing the temperature of the helium gas in the helium cryogenic system. The heated helium gas passes through the last-stage heat exchanger, heating the heat exchanger, and at the same time, the heated helium gas exchanges heat with the helium gas in the low-pressure pipeline 5, increasing the temperature of the reflux helium gas. Compared with the existing helium cryogenic system, it can more quickly achieve the rewarming of the low-temperature helium gas in the cold box 1. Since the system rewarming is accelerated, the running time of the compressor 7 is reduced, thereby reducing the energy consumption of the helium cryogenic system during the rewarming process, saving energy, and increasing the benefit of the rewarming of the helium cryogenic system. At the same time, the regulating valve 3 can adjust the pressure or flow rate of the high-purity helium gas of the high-purity helium gas source 2 entering the cold box 1, ensuring that the temperature change of the helium gas after temperature blending is within a controllable range, thereby ensuring the safety of the helium cryogenic system.

[0042] Specifically, the helium cryogenic system further includes a low-pressure pipeline 5, a high-pressure pipeline 6 and a compressor 7. The high-pressure pipeline 6 and the low-pressure pipeline 5 form a circulation loop. The compressor 7 is arranged between the low-pressure pipeline 5 and the high-pressure pipeline 6, and the cold box 1 is arranged in the circulation loop formed by the low-pressure pipeline 5 and the high-pressure pipeline 6.

[0043] Specifically, a helium gas precooling module, a multi-stage turbine expansion unit and a heat exchanger group are further arranged in the cold box 1. The helium gas precooling module is used to be arranged on the inlet side of the cold box 1 and before the multi-stage turbine expansion unit, and is used to precool the helium gas entering the cold box 1. The multi-stage turbine expansion unit includes a first turbine expansion unit and a second turbine expansion unit, and is used to perform a multi-stage cooling process on the helium gas entering the cold box 1. The heat exchanger group is used to perform a multi-stage heat exchange process on the helium gas entering the cold box 1.

[0044] Specifically, the helium pre-cooling module includes a helium gas passage regulating valve 113 connected to the high-pressure pipeline 6, a liquid nitrogen pre-cooling heat exchanger 12 connected to the high-pressure outlet of the first heat exchanger 16 of the heat exchanger group, a liquid nitrogen inlet pipeline 13 connected to the liquid nitrogen pre-cooling heat exchanger 12, a liquid nitrogen inlet regulating valve 14 provided on the liquid nitrogen inlet pipeline 13, and a nitrogen gas outlet pipeline 15 connected in sequence between the liquid nitrogen pre-cooling heat exchanger 12 and the high-pressure outlet of the first heat exchanger 16 of the heat exchanger group; the helium pre-cooling module pre-cools helium gas with the liquid nitrogen introduced through the liquid nitrogen inlet pipeline 13, the helium gas passage regulating valve 113 is used to regulate the amount of helium gas entering the liquid nitrogen pre-cooling heat exchanger 12, the liquid nitrogen inlet regulating valve 14 is used to regulate the amount of liquid nitrogen entering the liquid nitrogen pre-cooling heat exchanger 12, and the nitrogen gas outlet pipeline 15 is used to discharge the nitrogen gas after heat exchange with the liquid nitrogen.

[0045] Specifically, the heat exchanger group includes a first heat exchanger 16, a second heat exchanger 17, a third heat exchanger 18, a fourth heat exchanger 19, a fifth heat exchanger 110, a sixth heat exchanger 111, and a seventh heat exchanger 112 sequentially arranged in the circulation loop formed by the low-pressure pipeline 5 and the high-pressure pipeline 6.

[0046] Specifically, the first turbine expansion unit includes a first turbine 113, a second turbine 114, and a first inlet regulating valve 115. The first inlet regulating valve 115 is provided between the high-pressure outlet of the second heat exchanger 17 and the inlet of the first turbine 113. The outlet of the first turbine 113 is connected to the intake pipeline of the fourth heat exchanger 19. The inlet of the second turbine 114 is connected to the outlet pipeline of the fourth heat exchanger 19. The outlet of the second turbine 114 is connected to the low-pressure pipeline 5 between the fifth heat exchanger 110 and the sixth heat exchanger 111.

[0047] The second turbine expansion unit includes a third turbine 116, a third inlet regulating valve 117, a cryogenic regulating valve 118, and a third outlet switching valve 119. The third inlet regulating valve 117 is provided between the high-pressure outlet of the sixth heat exchanger 111 and the inlet of the third turbine 116; the cryogenic regulating valve 118 is provided on the high-pressure pipeline 6 and is located between the sixth heat exchanger 111 and the seventh heat exchanger 112; the third outlet switching valve 119 is provided between the outlet of the third turbine 116 and the seventh heat exchanger 112, where the seventh heat exchanger 112 is the final heat exchanger.

[0048] Specifically, it further includes a liquid helium dewar 10 provided outside the cold box 1. The inlet of the liquid helium dewar 10 is connected to the high-pressure outlet of the final heat exchanger, and a first throttle valve 101 is provided on the high-pressure pipeline 6 between the final heat exchanger and the liquid helium dewar 10. The gas-phase outlet of the liquid helium dewar 10 is connected to the low-pressure inlet of the final heat exchanger, and a low-pressure regulating valve 102 is provided on the low-pressure pipeline 5 between the final heat exchanger and the liquid helium dewar 10.

[0049] The compressor 7 pressurizes the helium (room temperature gas) in the low-pressure pipeline 5 to form high-pressure room temperature helium. The high-pressure room temperature helium enters the high-pressure pipeline 6. The high-pressure room temperature helium in the high-pressure pipeline 6 successively enters the first heat exchanger 16 and the liquid nitrogen precooling stage heat exchanger. In the first heat exchanger 16 and the liquid nitrogen precooling stage heat exchanger, the high-pressure room temperature helium is cooled by the liquid nitrogen entering the liquid nitrogen inlet pipeline 13 and the low-pressure helium in the first heat exchanger 16, and then forms high-pressure low-temperature gas, which enters the second heat exchanger 17.

[0050] The high-pressure low-temperature helium entering the second heat exchanger 17 is cooled by the low-pressure return gas and then divided into two paths. One path enters the first turbine 113 of the first turbine expansion unit to expand and cool down. The cooled helium enters the fourth heat exchanger 19, is cooled by the low-pressure return gas in the fourth heat exchanger 19, and then enters the second turbine 114 of the first turbine expansion unit to expand and cool down again. The expanded and cooled helium enters the low-pressure pipeline 5 to form low-pressure return gas. The other path enters the third heat exchanger 18, is cooled by the low-pressure return gas in the third heat exchanger 18, enters the high-pressure side of the fourth heat exchanger 19, is cooled by the low-pressure return gas in the fourth heat exchanger 19, enters the high-pressure side of the fifth heat exchanger 110, is cooled by the low-pressure return gas in the fifth heat exchanger 110, enters the high-pressure side of the sixth heat exchanger 111, is cooled by the low-pressure return gas in the sixth heat exchanger 111, and then is divided into two paths. Normally, the third inlet regulating valve 117 and the low-temperature regulating valve 118 will not be opened simultaneously, including the following two methods: when the third inlet regulating valve 117 is opened, the low-temperature regulating valve 118 will be closed, so that the low-temperature helium enters the third turbine 116 of the second turbine expansion unit to expand and cool down. The cooled helium enters the seventh heat exchanger 112. The third inlet regulating valve 117 set at the inlet of the third turbine 116 can adjust the amount of helium entering, and the third outlet switch valve 119 set at the outlet of the third turbine 116 can control the outlet flow or pressure of the third turbine expansion unit. When the third inlet regulating valve 117 is closed and the low-temperature regulating valve 118 is opened, the low-temperature helium directly enters the seventh heat exchanger 112, and the low-temperature regulating valve 118 can adjust the passing amount of this path of helium. A high-purity helium source 2 is connected to the high-pressure pipeline 6 between the sixth heat exchanger 111 and the seventh heat exchanger 112. The high-purity helium released by the high-purity helium source 2 is mixed and temperature-adjusted with the helium at the high-pressure inlet of the seventh heat exchanger 112, increasing the temperature of the helium in the low-temperature helium system. The heated helium passes through the final heat exchanger, playing a role in heating the final heat exchanger. At the same time, the heated helium exchanges heat with the helium in the low-pressure pipeline 5, increasing the temperature of the refluxing helium.

[0051] After passing through the final heat exchanger, it enters the liquid helium dewar 10. After passing through the final heat exchanger, the temperature of the temperature-adjusted high-purity helium will also increase accordingly, thus increasing the temperature of the high-purity helium entering the liquid helium dewar 10 and accelerating the rewarming of the liquid helium dewar 10.

[0052] Among them, liquid nitrogen enters the liquid nitrogen side of the liquid nitrogen precooling stage heat exchanger through the liquid nitrogen inlet pipe 13, exchanges heat with the high-pressure normal-temperature gas entering the liquid nitrogen precooling stage heat exchanger, and becomes normal-temperature nitrogen after temperature rise, and is discharged to the atmosphere through the nitrogen outlet pipe 15.

[0053] It should be noted that during the rewarming process, the seventh heat exchanger 112 can play a role in heat buffering, which can prevent the outlet temperature of the seventh heat exchanger 112 from rising sharply, resulting in too rapid temperature rise inside the liquid helium dewar 10, and then leading to too rapid pressure rise, causing dangerous problems, and ensuring the safety of the rewarming of the entire system.

[0054] When the helium cryogenic system is used for helium extraction, the low-temperature helium gas is throttled and divided into gas-liquid two phases. The liquid phase enters the liquid helium dewar 10 to accumulate liquid, and the gas phase is discharged from the gas phase outlet of the liquid helium dewar 10 and returns to the low-pressure side of the heat exchanger group through the low-pressure pipe 5. When the liquid helium level in the liquid helium dewar 10 reaches the preset value, the liquid helium product in the liquid helium dewar 10 is transported away.

[0055] As Figure 1 shown, in some embodiments, it further includes a high-precision oil filtering module 8 and a gas management module. The high-precision oil filtering module 8 is arranged at the high-pressure outlet of the compressor 7. The gas management module is used to adjust and control the inlet and outlet pressures of the compressor 7. The gas management module includes a buffer tank 9, a buffer regulating valve 91, a system loading valve 92, a system unloading valve 93 and a system bypass valve 94. The system bypass valve 94 is connected between the high-pressure pipe 6 and the low-pressure pipe 5. The system loading valve 92 and the system unloading valve 93 are connected between the high-pressure pipe 6 and the low-pressure pipe 5. The buffer tank 9 is connected between the system loading valve 92 and the system unloading valve 93 through the buffer regulating valve 91.

[0056] Although the exhaust of the helium screw compressor 7 undergoes multiple filtrations and purifications, there is still inevitably lubricating oil vapor in the helium cryogenic system. These vapors will solidify in the helium cryogenic system at low temperatures. Therefore, setting up the high-precision oil filtering module 8 can filter out the lubricating oil and prevent the pipeline from being blocked by the solidified lubricating oil.

[0057] As Figure 2 shown, in the first preferred embodiment, the high-purity helium gas source 2 is a helium gas buffer tank 9 or a helium gas cylinder group.

[0058] As Figure 3 shown, in the second preferred embodiment, the helium cryogenic system further includes a heater 4. The heater 4 is arranged between the regulating valve 3 and the helium gas buffer tank 9 and is used to heat the helium gas released by the high-purity helium gas source 2.

[0059] As Figure 4 shown, in the third preferred embodiment, the high-purity helium gas source 2 is the normal-temperature end of the high-pressure pipe 6.

[0060] As shown in the figure, in the fourth preferred embodiment, the helium cryogenic system further includes a heater 4 disposed between the regulating valve 3 and the normal temperature end of the high-pressure pipeline 6 of the high-purity helium gas source 2 for heating the helium gas released from the normal temperature end of the high-pressure pipeline 6.

[0061] To increase the temperature of the high-purity helium gas source 2, a heater 4 can be provided to heat the incoming high-purity helium gas, thereby further accelerating the rewarming efficiency.

[0062] The above description is only a preferred embodiment of the present invention and does not impose any limitation on the technical scope of the present invention. Therefore, any minor modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A helium cryogenic system with rapid rewarming, characterized in that: include: A cold box, wherein a final-stage heat exchanger is provided in the cold box; A high-purity helium source, used to release helium and mix it with the helium at the high-pressure inlet of the final-stage heat exchanger to achieve temperature conversion; The regulating valve is provided between the high-purity helium source and the high-pressure inlet of the final-stage heat exchanger, and is used to regulate the flow rate or pressure of helium from the high-purity helium source entering the cold box.

2. The rapid rewarming helium cryogenic system according to claim 1, characterized in that: The device further comprises a heater, which is arranged between the regulating valve and the high-purity helium source and is used to heat the helium released by the high-purity helium source.

3. The rapid rewarming helium cryogenic system according to claim 1 or 2, characterized in that: The high-purity helium source is a helium buffer tank or a helium cylinder group, or the high-purity helium source is the room temperature end of the high-pressure pipeline.

4. The rapid rewarming helium cryogenic system according to claim 1, characterized in that: It also includes a low-pressure pipeline, a high-pressure pipeline and a compressor. The high-pressure pipeline and the low-pressure pipeline form a circulation loop. The compressor is arranged between the low-pressure pipeline and the high-pressure pipeline. The cold box is arranged in the circulation loop formed by the low-pressure pipeline and the high-pressure pipeline.

5. The rapid rewarming helium cryogenic system according to claim 4, characterized in that: The cold box is also provided with a helium pre-cooling module, a multi-stage turbine expander unit and a heat exchanger unit. The helium pre-cooling module is used to be arranged on the inlet side of the cold box and is located before the multi-stage turbine expander unit, and is used to pre-cool the helium entering the cold box; the multi-stage turbine expander unit includes a first turbine expander unit and a second turbine expander unit, and is used to perform a multi-stage cooling process on the helium entering the cold box; the heat exchanger unit is used to perform a multi-stage heat exchange process on the helium entering the cold box.

6. The rapid rewarming helium cryogenic system according to claim 5, characterized in that: The helium precooling module includes a helium passage regulating valve connected to the high-pressure pipeline, a liquid nitrogen precooling heat exchanger connected to the high-pressure outlet of the first heat exchanger of the heat exchanger group, a liquid nitrogen inlet pipeline connected to the liquid nitrogen precooling heat exchanger, a liquid nitrogen inlet regulating valve arranged on the liquid nitrogen inlet pipeline, and a nitrogen outlet pipeline sequentially connected to the liquid nitrogen precooling heat exchanger and the first heat exchanger of the heat exchanger group; the helium precooling module precools the helium through the liquid nitrogen introduced through the liquid nitrogen inlet pipeline, the helium passage regulating valve is used to regulate the amount of helium entering the liquid nitrogen precooling heat exchanger, the liquid nitrogen inlet regulating valve is used to regulate the amount of liquid nitrogen entering the liquid nitrogen precooling heat exchanger, and the nitrogen outlet pipeline is used to discharge the nitrogen after the liquid nitrogen heat exchange.

7. The rapid rewarming helium cryogenic system according to claim 5, characterized in that: The heat exchanger group includes a first heat exchanger, a second heat exchanger, a third heat exchanger, a fourth heat exchanger, a fifth heat exchanger, a sixth heat exchanger and a seventh heat exchanger, which are sequentially arranged in a circulation loop formed by the low-pressure pipeline and the high-pressure pipeline.

8. The rapid rewarming helium cryogenic system according to claim 7, characterized in that: The first turboexpander unit includes a first turbine, a second turbine, and a first inlet regulating valve. The first inlet regulating valve is disposed between the high-pressure outlet of the second heat exchanger and the inlet of the first turbine. The outlet of the first turbine is connected to the inlet pipe of the fourth heat exchanger. The inlet of the second turbine is connected to the outlet pipe of the fourth heat exchanger. The outlet of the second turbine is connected to the low-pressure pipe between the fifth and sixth heat exchangers. The second turbine expansion unit includes a third turbine, a third inlet regulating valve, a low-temperature regulating valve and a third outlet switching valve. The third inlet regulating valve is arranged between the high-pressure outlet of the sixth heat exchanger and the inlet of the third turbine; the low-temperature regulating valve is arranged on the high-pressure pipeline and is located between the sixth heat exchanger and the seventh heat exchanger; the third outlet switching valve is arranged between the outlet of the third turbine and the seventh heat exchanger, wherein the seventh heat exchanger is the final stage heat exchanger.

9. The rapid rewarming helium cryogenic system according to claim 1, characterized in that: It also includes a high-precision oil filter module and a gas management module. The high-precision oil filter module is arranged at the high-pressure outlet of the compressor. The gas management module is used to adjust and control the inlet and outlet pressures of the compressor. The gas management module includes a buffer tank, a buffer regulating valve, a system loading valve, a system unloading valve and a system bypass valve. The system bypass valve is connected between the high-pressure pipeline and the low-pressure pipeline, the system loading valve and the system unloading valve are connected between the high-pressure pipeline and the low-pressure pipeline, and the buffer tank is connected between the system loading valve and the system unloading valve through the buffer regulating valve.

10. The rapid rewarming helium cryogenic system according to claim 1, characterized in that: It also includes a liquid helium dewar disposed outside the cold box, the inlet of the liquid helium dewar is connected to the high-pressure outlet of the final-stage heat exchanger, and the high-pressure pipeline between the final-stage heat exchanger and the liquid helium dewar is provided with a first throttle valve, the gas phase outlet of the liquid helium dewar is connected to the low-pressure inlet of the final-stage heat exchanger, and the low-pressure pipeline between the final-stage heat exchanger and the liquid helium dewar is provided with a low-pressure regulating valve.

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