Flow boiling heat transfer in a plate heat exchanger with mixed chevron angle plates

This study designed a 120-plates PHE with combination of 60 plates with 65° chevron angle and 60 plates with 35° chevron angle. The plates with 65° chevron angle were assembled in the half part of the PHE which near the inlet port to provide higher flow resistance in comparing to the other 35° plates. The 35° chevron angle plates were put away from the inlet port to reduce the flow resistance caused by the longer flow path. It is aimed to reduce the flow maldistribution in the multiplate heat exchanger and improve its heat transfer performance. Refrigerant R-410A flow boiling heat transfer performance in the mixed angle PHE and another PHE with 65° chevron angle was tested for comparison. The test results show that heat transfer coefficient in the mixed chevron angle PHE is 20% to 70% higher than that in the 65° chevron angle PHE with 25% lower pressure drops. The mixed angle plates apparently reduced the liquid refrigerant flow deficient region and provided a better heat transfer performance.