Optimization simulation of tube-type phase change heat storage unit

Tube heat exchangers are widely used in the field of phase change heat storage because of their firm structure, large heat transfer area and strong adaptability to the use of materials. However, due to the low thermal conductivity of most phase change materials, the heat transfer performance of the heat exchanger is poor, so improving the heat storage efficiency of the phase change heat storage is a hot spot at home and abroad. In this paper, the two-dimensional unsteady simulation optimization was conducted to study the influences of the shape of the heat exchanger structure, the number of fins and the center distance on the thermal storage performance. And the change trend of temperature and liquid phase ratio of phase change materials during melting process is explored. The results show that the heat storage performance of square heat exchanger is better than that of the circular heat exchanger. Compared with the heat storage heat exchanger without fins, the heat storage performance of the heat storage heat exchanger is improved significantly, and the melting time of phase change material is shortened by 66%. Within a certain range, the pressure drop increases as the center distance decreases, but the heat storage performance increases accordingly.