Experimental research on a novel porous ceramic tube type indirect evaporative cooler

Traditional indirect evaporative coolers (IEC) made of metal foil or polymer suffer from poor surface hydrophilicity in the wet channels and large amount of continuously circulated water. To solve the two problems, a kind of novel porous ceramics material was proposed for manufacturing the IEC in this paper for its high hydrophilicity and water storage features. The high hydrophilic property can improve the cooler efficiency's by increasing the heat and mass transfer area and the water storage behavior enables intermittent water supply so as to reduce the energy consumption of the pump. A porous ceramics tube type IEC was designed, fabricated and tested. The influences of secondary air to primary air ratio and spraying water flow rate were studied. Dynamic performance of the IEC was tested in a typical day of Xi'an, China. Besides, comparisons were made between the novel IEC and other IECs. Experimental results show that the cooling efficiency of the IEC remains stable for 100 min after the tube is fully wetted by 5 min water spray of 150 L/h flow rate. The novel IEC saves 95% of the pump energy consumption compared with traditional one and the highest COP is 34.9.