An Experimental and Analytical Study of a Radiative Cooling System with Flat Plate Collectors

摘要

A nocturnal radiative cooling system with flat plate solar collectors in Beijing,is assessed both experimentally and numerically.A cooling loop,including a radiator,a storage tank,pump,radiant floor and connecting pipes has been studied experimentally.The heat loss of an uncovered night-sky radiator was analyzed according to radiation and convection theory.The water is circulated through the flat-plate radiator having 2 m2 of collector area at night to be cooled by convection and radiation to sky.The results indicate that the minimum temperature of the floor surface is 19.5 °C.Vertical temperature field is uniform.Design temperature can increase 1 °C compared with conventional heat convection.The average net cooling reached 26 W/m2,as condensation does not occur.It is possible to increase the total cooling capacity while maintaining a low pressure drop.It demonstrates the feasibility of cooling using fluid medium through nocturnal radiation.