Mitigation of air flow maldistribution in evaporators

Flow maldistribution in evaporators can lead to significant performance and capacity degradation. A significant amount of work has previously been published to overcome this issue. For a fixed air side maldistribution, various methods have been proposed to significantly reduce the effect on performance. Refrigerant compensation has been proposed to reduce the effects of maldistribution in variable air flow systems. However, little work has been found in open literature relative to modifying the refrigerant circuitry to make it less vulnerable to variable air-side maldistribution. The purpose of this paper is to fill this gap in the open literature with a simple and easy to understand case study. The performance of a proposed interleaved circuitry approach, and active refrigerant flow control are compared to standard coil circuitry for different cases of maldistribution. The results show that the interleaved circuitry recovers less of the performance losses than equalization of the exit superheats by active control of refrigerant distribution. However, the implementation cost in an actual system is expected to be much lower and the long term reliability is expected to be better than for an active control approach