Development of highly effective cryogenic printed circuit heat exchanger (PCHE) with low axial conduction

This paper presents the results of an experimental investigation of the thermal and hydraulic performance of a printed circuit heat exchanger (PCHE) for use in the cryogenic temperature region. Compact PCHEs with multiple corrugated, longitudinal flow microchannels were fabricated using chemical etching and diffusion bonding to evaluate their thermal and hydraulic performance. The testing of the PCHEs was conducted with helium gas at cryogenic temperatures. The pressure drop and thermal effectiveness values obtained from the measured pressures and temperatures are discussed. The thermal performance was predominantly affected by the axial conduction heat transfer in the low Reynolds number ranges of theses experiments. A simple performance calculation model is presented, and the effectiveness calculated from the model is compared with the experimental data. The design of the cryogenic PCHE was then modified to reduce axial conduction losses.

► We fabricated two types of cryogenic PCHE (printed circuit heat exchanger). ► Conventional PCHE include large axial conduction loss in cryogenic environment. ► Thicker PCHE has more heat transfer area, but showed lower performance. ► Modified PCHE has longer axial conduction length and increased thermal performance.