Energy Storage Science and Technology ›› 2020, Vol. 9 ›› Issue (1): 101-108.doi: 10.12028/j.issn.2095-4239.2019.0166

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Simulation study on thermal storage process of paraffin phase change materials

ZOU Yong(), QIU Rudong, WANG Xia   

  1. School of Mathematics and Physics, Anhui University of Technology, Ma’anshan 243032, Anhui, China
  • Received:2019-07-23 Revised:2019-08-10 Online:2020-01-05 Published:2020-01-10

Abstract:

Solar energy is the first choice for developing clean energy because of its wide distribution, large reserves, and easy access. However, solar energy is affected by adverse weather conditions and seasons. Efficient methods for storing solar energy remain an urgent problem. Thus, understanding the factors that influence the thermal storage process of the phase change materials (PCMs) is important to improve the solar energy utilization rate. In this study, a two-dimensional (2-d) computational fluid dynamics model is developed on a shell-and-tube phase change energy storage heat exchanger. The melting process of the PCMs (paraffin wax) is numerically simulated using a solidification and melting model in FLUENT. The effects of the natural convection, paraffin thickness, and wall temperature on the heat transfer characteristics of the heat exchanger are studied during the charging process. Natural convection is demonstrated to significantly affect the growth of the PCM interface shape. The total melting time of paraffin increases with its thickness; however, it is not clear if a higher wall temperature of the heat-carrier fluid results in a faster melting rate. The influence of the wall temperature on the melting time significantly weakens when it exceeds the threshold.

Key words: tube shell phase change energy storage, paraffin wax, natural convection, heat source temperature, numerical simulation

CLC Number: