DEVELOPMENT OF A NOVEL DESICCANT CHILLER WITH REGENERATIVE EVAPORATIVE COOLING

摘要

A novel desiccant chiller with regenerative evaporative cooling component is proposed in thisrnpaper. The unit is configured by desiccant wheel, cross flow heat exchanger, regenerativernevaporative cooler, water pump and fan, etc.. The unique feature for this system is that it canrnnot only handle the latent heat efficiently in principle of desiccant dehumidification, but alsorncan produce the chilled water as low as 15 ℃ using the regenerative evaporative cooler. Thus,rnthe novel unit can condition the process air to a reasonable temperature and humidity levelrnjust by open cycle desiccant cooling, and only consume a small amount of electricity forrnpump and fan. The regenerative evaporative cooling here can have strong cooling capacityrnbecause it uses part of dry air from the desiccant wheel. Compared with the traditional desiccantrncooling system, the novel unit can cool the process air to a lower temperature level withoutrnincreasing the humidity like the direct evaporative cooler. Due to the use of the compositerndesiccant materials and the specialty developed coating measure, the desiccant wheel can berndriven by low grade thermal energy (50-90 ℃, and the thermal COP of the system can reachrnas high as 1.0. Thus the solar thermal and waste heat can be used efficiently. The objective ofrnthis paper is to investigate the performance of this novel unit and identify the optimal operationrnparameters for practical application.