Experimental investigation on the thermal performance of a novel radiant heating and cooling terminal integrated with a flat heat pipe

摘要

Intermittent heating and cooling are energy efficient measures for building indoor thermal environment, and improvements to the thermal response speed of the indoor terminal are particularly important for thermal comfort. In this study, a novel integrated flat-heat-pipe radiant heating and cooling terminal was proposed. The flat-heat-pipe is used as the radiant panel in this terminal, providing a quick thermal response speed and high thermal uniformity. Moreover, the proposed radiant terminal could also be operated in both winter and summer owing to its integrated flat structure. In this study, an experimental rig was built for studying the thermal performance of the flat heat pipe terminal, including the heat response speed, heating/cooling capacity, heating/cooling temperature, and heat transfer coefficient. The experimental results show that the heating/cooling response speed ranges from 550 s to 1810 s and the vertical temperature difference is less than 1.4 degrees C/m. In addition, the heat transfer capacity showed a significant increase of 36.1% to 42.6% when the emissivity of the surface of the flat heat pipe increased from 0.1 to 0.9. The heating/cooling temperature is significantly influenced by the heat source temperature and heat transfer ability on the source side and is less influenced by the flow rate. Overall, this novel terminal has good thermal performance and is worthy of further optimization. (C) 2019 Elsevier B.V. All rights reserved.