The Effect of Flow Distribution in Parallel Channels of Counterflow Heat Exchangers

It has long been known that poor flow distribution in parallel channels causes a degradation in heat exchanger performance. Examples of this can be found in air liquefaction plants, where the gradual plugging of a few of the tubes in a parallel array reduces performance of the plant, not only because of the increased pressure drop, but also because of a reduction in the thermal effectiveness of the exchangers. As this paper will illustrate, the reduction in performance can be particularly severe in balanced flow cryogenic heat exchangers of very high thermal effectiveness.