Pre-cooling device before filling of liquid helium storage tank

Abstract

The invention discloses a pre-cooling device before filling of a liquid helium storage tank, and relates to the technical field of pre-cooling of liquid helium storage tanks. The pre-cooling device comprises the liquid helium storage container, a throttle valve, a low-temperature pump, a heat exchanger, a compressor, a safety valve, an injection device, a liquid helium storage tank, a densitometer, a one-way valve, a second injection device, a control unit, various stop valves and the like. A method of liquid hydrogen preliminary pre-cooling, helium soaking pre-cooling and liquid helium evaporation pre-cooling is adopted, compared with other pre-cooling devices, cold energy of helium in the liquid helium storage container is fully utilized, the liquid helium consumption is reduced, and the process economic benefits are improved. A helium soaking pre-cooling method is adopted, the liquid helium storage tank is further cooled, residual hydrogen is liquefied and discharged, it is guaranteed that the purity of a product is qualified, meanwhile, a liquid helium evaporation pre-cooling method is adopted, the heat exchange rate of helium and the liquid helium storage tank is increased, and the pre-cooling time is shortened.

Description

technical field [0001] The invention relates to the technical field of pre-cooling of liquid helium storage tanks, in particular to a pre-cooling device for liquid helium storage tanks before filling. Background technique [0002] Helium has a very low boiling point (4.2K), critical temperature (5.15K) and critical pressure (0.226MPa), which can easily achieve ultra-low temperature cooling that cannot be achieved by other low-temperature liquids, so it is used in aerospace, nuclear weapons, submarines, and saturation diving operations. , nuclear magnetic resonance, semiconductor and other scientific and technological fields have played an irreplaceable role. At present, my country's annual helium demand exceeds 2.2 × 10 7 m 3 , but my country only has one in Sichuan with an annual output of 6 × 10 4 m 3 The helium extraction plant in Hetianhe Gas Field and Ake Gas Field is still under construction. Almost all helium supply depends on imports, and the international helium...

AI Technical Summary

Problems solved by technology

However, these methods have not penetrated into the liquid helium temperature zone. If they are directly applied to the precooling of liquid helium storage tanks, there will be the following problems: (1) As liquid helium is currently the natural resource with the lowest boiling point, it is difficult to find a low boiling point. The low-temperature working fluid of liquid helium directly precools the storage tank to the liquid helium temperature zone; (2) if the storage tank is directly pre-cooled by using liquid helium as the cold source, it will face the problems of large consumption of liquid helium resources and high price. Even if the method of circulating precooling is adopted, it is restricted by the capacity of the helium liquefaction device of the natural gas helium extraction plant, and the time cost is huge; (3) if the method of precooling liquid helium and other cryogenic working fluids is used, considering the quality of the liquid helium product The purity requirement is extremely high. How to ensure that the residual amount of other low-temperature working fluids in the storage tank will not affect the quality of the externally infused liquid helium product is a problem that must be faced by this method.

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