Double-thermal-shield negative-pressure low-temperature heat exchanger test device

Abstract

The invention relates to a double-thermal-shield negative-pressure low-temperature heat exchanger test device, and belongs to the technical field of ultra-low temperature. The device includes a low-temperature cold-box and external equipment. The low-temperature cold box is composed of a box body, liquid nitrogen and liquid helium thermal-shields, a 4.5K liquid helium slot, a 1.8K super-flow helium slot, a tested heat exchanger, a heater and a pneumatic regulating valve. The external equipment is composed of liquid nitrogen and liquid helium Dewars, a helium steel cylinder, a gas cabinet, a manual regulating valve, a heater, a room-temperature decompression pump and a vacuum pump. A vacuum is made by the vacuum pump to reduce heat transfer of gas in the cold box, the double cold screens are arranged to reduce radiation leakage heat, the helium steel cylinder provides liquid supply power for the liquid helium Dewar and can adjust pressure entering the 4.5K liquid helium slot, the gas cabinet can recover helium from evaporation of the 4.5K liquid helium slot, a bypass valve is arranged at an inlet of the tested heat exchanger, high-pressure path flow can be reduced, and working statedeviation running of experiment is realized. The device can carry out experiment in a multi-working-state manner, and has the advantages of a simple structure, reliable operation, controllable variable parameters and the like.

Description

technical field [0001] The invention relates to a test device for a low-temperature heat exchanger, in particular to a test device for a negative-pressure low-temperature heat exchanger with double cold screens. Background technique [0002] Superfluid helium systems are widely used in the fields of nuclear fusion and high-energy physics. Superfluid helium is almost non-viscous, easily penetrates into the magnet, and can quickly eliminate thermal disturbances. Using superfluid helium to cool superconducting magnets and accelerators can improve stability and reduce energy consumption and operating costs. Superfluid helium has very high thermal conductivity, much higher thermal conductivity than metal, and has excellent flow and heat transfer properties. It is often used to cool superconducting magnets in many applications. The superfluid helium cryogenic system generally includes a 4.5K helium cryogenic system and a 1.8K / 2K superfluid helium cryogenic subsystem. The superfl...

AI Technical Summary

Problems solved by technology

Different from ordinary heat exchangers, the application conditions of negative pressure heat exchangers are more stringent, the requirements for efficiency and pressure drop are also higher, and factors such as the influence of variable properties must be considered, so its design is more complicated

Images