Thermal performance investigation of a novel heating terminal integrated with flat heat pipe and heat transfer enhancement

摘要

Comfort heating with fast thermal response rate, which is applicable for intermittent heating, requires of small thermal inertia and a large heat transfer coefficient for heating terminals. However, existing heating terminals are generally inconsistent in terms of the response rate and thermal comfort. Therefore, a novel radiant-convective heating terminal integrated with a flat heat pipe and heat transfer enhancement is proposed in this research. The flat heat pipe, which acts as the radiant panel, provides quick thermal response and high radiation uniformity. Additionally, fins are attached to the back of the flat heat pipe to enhance the heat transfer ability via both natural and forced convection. The heating performance, including the response rate, radiation temperature, heating power was studied experimentally, and influential factors, such as heat source temperature, ambient temperature, and forced convection, were also considered. The results suggested that the heating terminal had a response rate of 920-1125 s, which is superior to other conventional radiant terminals, and the surface temperature distribution exhibited high uniformity. Furthermore, the heating power in the natural convection mode was approximately 498-724 W at the heat source temperature of 50 degrees C. When the forced convection was activated, the heating power and exergy efficiency increased by up to 62% and 25% respectively. Overall, the novel flat heat pipe heating terminal showed great potential for intermittent heating applications. (C) 2021 Published by Elsevier Ltd.