Feasible study of a self-cooled solid desiccant cooling system based on desiccant coated heat exchanger

Solid desiccant cooling technology has become a research focus for its features of energy-saving and eco-friendly. However, widely adopted rotary desiccant wheel cooling system canʹt realize inner-cooling dehumidification process. In this paper, a novel self-cooled solid desiccant cooling system (SCDHE) is developed by integrating desiccant coated heat exchanger and regenerative evaporative cooler. In the system, regenerative evaporative cooler is adopted to produce chilled water, which is again pumped into desiccant coated heat exchanger in dehumidification process to realize self-cooled dehumidification process. Similarly, in regeneration process, hot water heated by low grade thermal energy is adopted to regenerate the coated desiccant material. A mathematical model is established to validate the feasibility and to analyze performance of this novel system. Also, effects of ambient air condition are predicted. It is found that SCDHE system is feasible, it can provide satisfied supply air to conditioned room under simulated ARI summer condition, and the required regeneration temperature is from 50 to 80 °C which is lower than rotary wheel desiccant cooling system. Also, there exists an optimal switch time and suitable control mode for system to obtain enhanced performance in terms of cooling power. Compared with conventional DCHE cooling system without regenerative evaporative cooling, SCDHE system can provide satisfied supply air while conventional system cannot, also it can obtain increased cooling power. Under simulation condition, cooling power of SCDHE system increases by about 30% compared with conventional DCHE cooling system.