Performance evaluation of counter flow heat exchangers considering the effect of heat in leak and longitudinal conduction for low-temperature applications Original Research Article

Counter flow heat exchangers are commonly used in cryogenic systems because of their high effectiveness. In addition to operating and design parameters, the thermal performance of these heat exchangers is strongly governed by various losses such as longitudinal conduction through wall, heat in leak from surrounding, flow maldistribution, etc. Design based on conventional procedure, which normally does not take these losses into consideration, could be misleading and actual performance could be quite different than the predictions. In this paper, the numerical model developed earlier is extended to take into consideration the effect of heat in leak and the predictions are compared with the experimental results. The study is further extended to understand quantitative effect of heat in leak and axial conduction parameters on degradation of heat exchanger performance for 300–80 K and 80–20 K temperature range.