Analysis on Coupled Heat Transfer of Phase Change Material Ceiling and Air in Tunnel

Abstract:

Phase change material (PCM) ceiling is constructed by hydrated salt CaCl2·6H2O in the underground railway tunnel.The heat dissipation of moving train is simplified as a moving heat source which generates equivalent heat.The 3D model of moving train is established to simulate numerically the dynamic range of the tunnel of the nonsteadystate thermal environment in short time.Coupled heat transfer model (CHT model) of PCM and air in the tunnel is established,in addition,solution is given and compared with that of the 3D model,which validates the CHTmodel.The CHTmodel is used to simulate the heat absorption of PCM and tunnel temperature in the long time,and the results show that the PCM ceiling can absorb 56.9% of the heat emitted by train under the simulated operating condition.