Surface temperature distribution prediction model for prefabricated ceiling radiant panel

Abstract

Prefabricated ceiling radiant panel is one type of efficient and lightweight radiant heating and cooling terminal, which has been widely used in many commercial and residential buildings. The surface temperature distribution of radiant terminal is a crucial factor that affects the local thermal discomfort for heating and the surface condensation risk for cooling. However, the existing research on surface temperature distribution lacked a correlation with the average surface temperature prediction model, which was not convenient for guiding the design and control of radiant heating and cooling systems. Therefore, this paper proposed a new simplified model of radiant panels, and the calculation errors of heat transfer and average surface temperature were within ±5 % and ±1 %, respectively. Furthermore, a surface temperature distribution prediction model was established, and the definition of surface temperature uniformity was also determined through derivation. The calculation results indicated that the root mean square error between the predicted surface temperatures at each measurement point and experimental values was 0.8 °C for heating and 0.4 °C for cooling, and the corresponding relative errors of surface temperature uniformity were 5.7 % and 8.9 %. Finally, the effects of water supply temperature, water mass flow rate, pipe spacing, pipe diameter and thickness of heat distribution plate on the surface temperature distribution were quantitatively analyzed. The results showed that the water mass flow rate, pipe spacing (more than 150 mm) and the thickness of the heat distribution plate clearly influenced the surface temperature uniformity.