Theoretical and experimental research on the performance of new building environment control systems based on cooling dehumidification under positive pressure

Abstract

A significant amount of energy consumed by building environment control systems is used for dehumidification. However, the conventional cooling dehumidification method is energy-intensive as the low required dew-point temperature and reheating. In this paper, two different new building environment control systems based on cooling dehumidification under positive pressure are proposed, which can realize dehumidification with a natural cooling source at ambient temperature. The cooling dehumidification model under positive pressure is proposed and verified by experiments, and the errors are within ± 4.16 %. Influences of pressure ratio and cooling source temperature on system performances are analyzed by simulation. The result shows that proposed systems can achieve the dehumidified air with a humidity ratio of 8.18 g/kgDA and a temperature of 20℃, and the dehumidification energy efficiency of new systems can achieve 6.11 kg/kWh. At a cooling source temperature of 18 °C and pressure ratio of 1.6, the total dehumidification rate of the system can reach 19.49 g/s. Reheating in front of the expander can reduce the detrimental dehumidification proportion to 0 %. The coefficient of performance (COP) of the new system can reach 6.26, which is superior to other dehumidification methods.