Plate heat exchangers are often applied as evaporators in industrial refrigeration and heat pump systems. In the design and modelling of such heat exchangers the flow and liquid/vapour distribution is often assumed to be ideal. However, maldistribution may occur and will cause each channel to behave differently due to the variation of the mass flux and vapour quality. To evaluate the effect of maldistribution on the performance of plate heat exchangers, a numerical model is developed in which the mass, momentum and energy balances are applied individually to each channel, including suitable correlations for heat transfer and pressure drop. The flow distribution on both the refrigerant and secondary side is determined based on equal pressure drop while the liquid/vapour distribution is imposed to the model. Results show that maldistribution may cause up to a 25 % reduction of the overall heat transfer coefficient, compared to a lumped model with uniform distribution.
|Title of host publication||Proceedings of the 24th IIR International Congress of Refrigeration|
|Number of pages||8|
|Publisher||International Institute of Refrigeration|
|Publication status||Published - 2015|
|Event||24th IIR International Congress of Refrigeration: Improving Quality of Life, Preserving the Earth - Yokohama, Japan|
Duration: 16 Aug 2015 → 22 Aug 2015
Conference number: 24
|Conference||24th IIR International Congress of Refrigeration|
|Period||16/08/2015 → 22/08/2015|
Jensen, J. K., Kærn, M. R., Ommen, T. S., Markussen, W. B., Reinholdt, L., & Elmegaard, B. (2015). Effect of Liquid/Vapour Maldistribution on the Performance of Plate Heat Exchanger Evaporators. In Proceedings of the 24th IIR International Congress of Refrigeration International Institute of Refrigeration.