Characterisation and optimisation of flexible transfer lines for liquid helium. Part I: Experimental results. (April 2016)

• Record Type: Journal Article
• Authors: Dittmar, N.; Haberstroh, Ch.; Hesse, U.; Krzyzowski, M.
• Is Part Of: Cryogenics. Volume 75(2016)
• Page Start: 6
• Page End: 12
• Publication Date: 2016-04
• Subjects: Liquid helium -- Flexible cryogenic transfer line -- Liquid helium decant station -- Transfer losses; Low temperature engineering -- Periodicals; Low temperature research -- Periodicals; 536.56
• DOI: 10.1016/j.cryogenics.2015.11.005
• Languages: English
• ISSNs: 0011-2275

Abstract

Highlights: The unavoidable liquid helium transfer at a decant station was analysed. Flexible transfer lines were equipped with temperature and pressure sensors. Unique experimental data of heat leak and pressure drop could be obtained. Design changes resulted in reduced evaporation losses. The final transfer line design features a transfer rate increase of 46%. Abstract: The transfer of liquid helium (LHe) into mobile dewars or transport vessels is a common and unavoidable process at LHe decant stations. During this transfer reasonable amounts of LHe evaporate due to heat leak and pressure drop. Thus generated helium gas needs to be collected and reliquefied which requires a huge amount of electrical energy. Therefore, the design of transfer lines used at LHe decant stations has been optimised to establish a LHe transfer with minor evaporation losses which increases the overall efficiency and capacity of LHe decant stations. This paper presents the experimental results achieved during the thermohydraulic optimisation of a flexible LHe transfer line. An extensive measurement campaign with a set of dedicated transfer lines equipped with pressure and temperature sensors led to unique experimental data of this specific transfer process. The experimental results cover the heat leak, the pressure drop, the transfer rate, the outlet quality, and the cool-down and warm-up behaviour of the examined transfer lines. Based on the obtained results the design of the considered flexible transfer line has been optimised, featuring reduced heat leak and pressure drop.