Experimental Study of the Performance of a Desiccant Cooling/Heat Recovery System for Wind Cowls

An experimental study was carried out to investigate the performance of a heat recovery/desiccant system suitable for use in wind cowls. Use of a micro heat and mass cell cycle core (MHM3C), allows a substantial amount of heat or coolth energy to be recovered from the exhaust air and this is transferred into the intake fresh air. The intake fresh air is also dehumidified, if the core is incorporated with desiccant pads and operates in conjunction with a desiccant regeneration and storage system (DRSS). Experiments were carried out to investigate the parameters governing system’s performance and operating characteristics. These parameter included air temperature/humidity, air flow rate, desiccant solution temperature/concentration and flow rate, desiccant regeneration temperature, cooling temperature and cooling water flow rate. Results indicated that the efficiency of heat recovery was around 75%. When the desiccant cycle was in operation, the moisture in the intake fresh air was transferred to both the concentrated (strong) desiccant solution and the exhaust air, and the transfer rates were 1,555g/h and 3,610g/h respectively, under the pre-set testing conditions. The combined desiccant cycle/heat recovery operation created a cooling output of 5.32kW; of which the heat recovery was responsible for 60.8% and remained was made up by the desiccant cycle. Heat energy of 3.14kW was consumed for regeneration of the strong desiccant solution and 0.8kW coolth energy used for cooling the hot strong solution. If the heat for regeneration were provided by waste or solar energy, the estimated COP of the combined system would be 5.9.