Experimental and numerical investigation of the cross-flow PCM heat exchanger for the energy saving of building HVAC

The present study describes the design of a crossflow shell-and-tube heat exchanger with staggered tube array containing phase change material (PCM) to absorb the heat from the warm air stream ejected from building HVAC, and to release heat into the cold air stream entering building. A real scale prototype was constructed to validate the numerical model. The results showed consistent agreements between the modeling and experiment. Then, the numerical simulation was comprehensively used to study the effects of geometrical and operational parameters on the overall thermal performance, including the numbers of tube rows, operational time, and tube diameter. Furthermore, the study investigated the possible heat transfer enhancement using multiple melting temperatures in regions of tube array, and the use of dispersed highly conductive material in PCM. This PCM heat exchanger has potential of increasing the energy efficiency and saving overall energy cost. (C) 2016 Elsevier B.V. All rights reserved.