Performance analysis for 2K heat exchanger for superfluid cryogenic system at KEK

27th International Cryogenics Engineering Conference and International Cryogenic Materials Conference 2018

Kumar, A.^1 ; Nakai, H.^2 ; Nakanishi, K.^2 ; Shimizu, H.^2 ; Kojima, Y.^2 ; Hara, K.^2 ; Honma, T.^2

SOKENDAI (The Graduate University for Advanced Studies), Tsukuba

305-0801, Japan^1

High Energy Accelerator Research Organization (KEK), Tsukuba

305-0801, Japan^2

关键词: Computational flows;    Cryogenic system;    Gaseous helium;    Liquid helium temperature;    Performance analysis;    Production rates;    Superconducting radio frequency;    Test performance;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/502/1/012051/pdf
DOI  :  10.1088/1757-899X/502/1/012051

来源: IOP

【 摘 要 】

The niobium superconducting radio frequency cavities (1.3 GHz) operate at temperatures of 2.0 K or below, cooled with superfluid helium. A 2K heat exchanger increases the production rate of superfluid helium by reducing the inlet liquid helium temperature from 4.4 K to 2.2 K or above, recovering sensible heat of evaporated gaseous helium from the helium tanks of the cavities at 2.0 K. Effectiveness of a heat exchanger is the ratio of actual heat transfer to maximum possible heat transfer between the fluids. The required minimum effectiveness is 85% to cool liquid helium down to 2.2 K. At KEK, we have laminated-fin type 2K heat exchangers for thermal loads up to 100W. The effectiveness of the heat exchanger has been determined by computational flow dynamics, and the results are being verified experimentally using a heat exchanger test stand, specifically designed to test performance of 2K heat exchangers.Published under licence by IOP Publishing Ltd.