Study on indoor comfort of floor radiant cooling and displacement ventilation system in large space

Radiant cooling and displacement ventilation system has an extensive application in large space building where there has a significant stratification of heat and mass. This paper focuses on the effects of the floor cooling proportion on the indoor comfort under radiant cooling and displacement ventilation system in large space. By simplifying the building model according to a practical waiting hall in certain railway station, a three-dimensional space model describing the comfort distribution characteristics in working area with composite system is presented. The discrete ordinates radiation model and indoor zero equation model are used to describe the indoor temperature and humidity distribution law. Floor temperature, inlet parameters and the indoor comfort control conditions are researched. The indoor thermal and moist environment is analyzed based on CFD simulation. The simulation results provide that the temperature and velocity of supply air had similar influencing characteristic on the indoor comfort. Meanwhile, the cooling capacity of floor could be higher when the supply air temperature was higher and the air supply velocity was lower and the optimum cooling proportion of floor was 0.76 to 0.77 in this paper. More importantly, the compound system could be applicable in indoor comfort control in large space.