文摘
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 analysed 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.
