Numerical Analysis of Heat and Moisture Transfer in Underground Air-conditioning Systems

Abstract

In view of the influence of humidity of room air on room heat load, indoor environment and building energy consumption in underground intermittent air-conditioning systems, numerical simulation was used to dynamically analyze the coupling condition of room air temperature and relative humidity. Based on an experimental simplified model that considers dynamical moisture transfer on the soil wall, an energy equation with variable of enthalpy is solved, with the addition of solving the transport equation of water vapor percent in moist air. Results are presented in terms of temperature, humidity and heat flux at the interface between room air and the floor, showing the importance of the approach presented and the model robustness for long-term simulations with a high time step. Finally, the results are compared with those of simulation without consideration of humidity. The results show that room air temperature with moisture transfer is 0.6~1.5? less, and the average conjugate heat flux on soil wall is 20% higher than that without humidity.