相变墙体传热性能数值模拟及适宜相变温度确定

Numerical Simulation of Heat Transfer Performance of Phase Change Wall and Determination of Suitable Phase Change Temperature

相变温度的适宜性对相变墙体隔热性能具有重要的影响,在相变墙体研究中首先要科学确定墙体的适宜相变温度。以徐州地区夏季南向墙体表面空气综合温度为边界条件,利用ANSYS软件对外侧相变墙体的传热过程进行模拟计算,对比分析不同相变温度的相变墙体的温度分布及变化情况,以墙体内表面温度为依据,判定外侧相变墙体的适宜相变温度;根据稳态传热理论,在不考虑相变材料层的热阻变化的情况下得出了相变墙体适宜相变温度的计算公式,适宜相变温度随相变层位置由外到内逐渐减小。研究结果表明:在夏季工况下,相变材料层位置对墙体适宜相变温度具有重要的影响,外侧相变墙体的适宜相变温度为相变材料层外表面温度平均值,徐州地区夏季南向外侧相变墙体的适宜相变温度为31℃。

The suitability of the phase change temperature has an important influence on the heat insulation performance of the phase change wall. It is necessary to scientifically determine the suitable phase change temperature of the wall. The comprehensive temperature of the surface of the south wall in Xuzhou area in summer was used as the boundary condition, and the ANSYS software was used to simulate and calculate the heat transfer process of the outer phase change wall. The temperature distribution and change of the phase change wall with different phase change temperatures were compared and analyzed. According to the internal surface temperature of the wall, the appropriate phase change temperature of the outer phase change wall was determined;and according to the steady-state heat transfer theory, a calculation formula for the suitable phase change temperature of the phase change wall was proposed without considering the thermal resistance change of the phase change material layer. The suitable phase change temperature gradually decreased with the position of the phase change layer from the outside to the inside. Results showed that the position of the phase change material layer has an important influence on the suitable phase change temperature of the wall under summer conditions, and the suitable phase change temperature for the outer phase change wall was the average temperature of the outer surface of the phase change material layer under summer conditions. The suitable phase change temperature for the south outer phase change wall in Xuzhou area was 31 ℃ in summer.