Theoretical and experimental study of heat transfer in wall heating panels

• Increasing water inlet temperature will chiefly increase panel surface temperature.
• Embedding larger diameter pipes will slightly increase panel surface temperature.
• Faxen–Rydberg–Huber expression can predict temperature field in the wall panels.

This paper presents the analysis of the impact of basic geometric parameters – pipe diameter and the spacing between the pipes, and technological parameters – volumetric flow and heating water inlet temperature, on a temperature field on the wall heating panel surfaces, formed during the steady conditions. The analysis was conducted by using the Mikheev's criterion equation, which describes the process of convection heat transfer from the heating fluid to the inner surface of the pipe, and Faxen–Rydberg–Huber expression, which describes the two-dimensional temperature field in the wall, with series of embedded heated pipes having uniform temperature. The quality of obtained theoretical results was checked experimentally, by measurements conducted using thermal imaging camera. Based on the analysis of the obtained results, and depending on the impact they have on the increase of the panel surface average temperature, the ranking of analyzed parameters was performed.