Design and performance of a novel compact high-effectiveness transparent-wall counter-flow heat exchanger fabricated using additive manufacturing

Abstract

Compact high-effectiveness counter-flow heat exchangers (CFHEX) are an essential building block of remote cooling systems and Reverse Turbo-Brayton coolers. This technology enables a wide variety of on-ground and space applications, including the cooling of infrared detectors, cryogenic chains of quantum computers and ultra-sensitive superconducting SQUID sensors. A mesh-based CFHEX design was previously proposed for such applications and demonstrated a great potential to meet the high effectiveness and compactness needs [1]. This paper presents a novel improved mesh-based CFHEX concept with a “transparent” inner wall and outlines the methods used for its manufacturing. Two of such CFHEXs are constructed and integrated in a technology demonstrator of a remote cooling system. Their performance is tested in the ▪ temperature, 1bar–5bar pressure and 50mg/s–250mg/s helium mass flow rate ranges. An effectiveness of ▪ (NTU=39–124) has been experimentally achieved with a pressure drop of less than 10mbar per stream at the nominal operating conditions of the system. The experimental effectiveness and pressure drop results are analysed and compared to numerical predictions. The implications of the achieved high effectiveness on the final performance of the designed remote cooling system are also discussed.