Study on the heat transfer characteristics of a shell-and-tube phase change energy storage heat exchanger

Natural convective has significant effects on the heat transfer effect and the growth of PCM's interface shape. So the discussion of the influence on multi-tube heat exchanger by natural convective is conductive to the enhancement of heat transfer and reduction in charging time. In this paper, a CFD model on the shell-and-tube phase change energy storage heat exchanger was established. In addition, the effects of the number of inner tubes and inlet temperature on the heat transfer characteristics of the heat exchanger were studied during charging process. The results indicated that the thermal disturbance between heat pipes were improved natural convection, and significantly enhance the convection heat transfer in the charging process; both adopting smaller diameter pipe and higher inlet temperature could shorten the melting time of phase change material (PCM); the influence of temperature of heat carried fluid on the melting time was significantly weakened when it exceeded a limited value. This study provided a reference value for the structure geometrical parameter optimal design of heat exchanger.