COOLING OF WATER FLOWING THROUGH A NIGHT SKY RADIATOR

摘要

Experimental and theoretical studies of nocturnal cooling of water flowing through a two parallel plates radiator was carried out. The radiator plate was covered by a polyethylene windscreen cover. The experimental study was conducted for a gravity flow open loop system. The study includes the effect of average water flow rate, uncovered versus covered supply warm water tank, and windscreen cover thickness on the performance. A new definition of the performance was expressed by an overall efficiency. A thorough radiation model was developed which calculates the radiation heat losses from both the cover and the radiator plate considering multiple reflections and absorption between cover and plate. Energy balance was then applied on the cover, the radiator plate and the water. Experimental results were used for verification of the model.