Enhancing Thermal Efficiency of Panel Radiators Through Turbulence-Inducing Modifications in Water Channels

Abstract

This study aims to improve the thermal efficiency of panel radiators, which are widely used in building heating systems. By promoting turbulent flow inside the water channels, heat transfer can be increased without raising energy use. In the modified design, small 90° rectangular blocks (5 mm wide and 10 mm long) are added inside the vertical channels to create turbulence. This design distinguishes itself from other methods by creating turbulence through indentations in the sheet metal that forms the channel, rather than using additional turbulators such as twisted tape inserts or wire coil inserts. This unique strategy not only boosts heat transfer performance but also leads to energy savings, reduced emissions, and more efficient heating in both residential and commercial buildings. With the modified design, due to increased friction, the pressure rise shows a 1.36% increase compared to the current design. Meanwhile, the temperature of the water circulating in the panel radiator channels has decreased further compared to the current design, resulting in a 1.21% increase in ΔT. This indicates that the modified design transfers more heat from the water to the environment, causing the water's outlet temperature to drop more significantly. Additionally, with the modified design, the water contact surface area has decreased by 0.64 m², while the water heat flux has increased by approximately 25% compared to the current design. The higher heat flux achieved with a smaller water contact surface area demonstrates the efficiency of the system compared to the existing design.