Cryogenic performance of a compact high-effectiveness mesh-based counter-flow heat exchanger

Abstract

Compact effective Counter Flow Heat EXchangers (CFHEX) are critical components of almost all thermodynamic cycles, e.g. cryocooler-based remote cooling circuits that can enable a large number of high technology cryogenic applications. It is essential for such applications that these CFHEXs match the overall performance of the system. This paper presents the test setup, experimental performance results and the analysis of a novel mesh-based CFHEX in the 50 K–290 K temperature and 1 bar–5 bar pressure ranges. The measurements are compared to the numerical predictions for a range of mass flow rates and fluid stream pressures. A maximum average effectiveness of 94.9 % (NTU = 18.6) is achieved with a combined pressure drop of only 15 mbar at nominal system operating conditions with helium gas. The static loss along the CFHEX is measured and analysed. The numerical model is correlated with the experimental findings and further improvements to the design are suggested. In addition, a new friction factor model is proposed for the woven mesh matrix. Global implications of the CFHEX performance on the remote cooling system are quantified and discussed.