A coupled heat transfer model of phase change, radiation and heat conduction at steady state under solar irradiation in a semitransparent PCM-glazed unit was developed. Interior energy transfer of PCM-glazed unit was simulated with controlling volume method and Bouguer-Beer Law. Effects of radiation physical parameters, internal and external environment on heat transfer coefficient were investigated.It shows that it is necessary to consider semitransparent property of PCM-glazed unit as calculating heat transfer coefficient.Except for radiation physical property and environment, liquid fraction and light transmittance of PCM affect heat transfer coefficient as well.

An evaporation model at steady state was bulit to analyse effect of solar radiation on evaporation of still water surface at low airflow velocity. It considers convective heat and mass transfer from water surface to airflow,interior heat transfer and solar radiation absorbing spectrum of water. Finite volume method combined with Monte Carlo method and spectral band model are used to simulate energy and mass transfer among water interior,surface and airflow. Effect of solar irradiance on evaporation rate of water surface was analysed at different airflow velocity,humidity,temperature,forward and inverse temperature difference. It shows that solar irradiance effect on evaporation of still water surface is great at low airflow velocity.