Heat transfer enhancement of an electric air heating furnace by inserting silicon carbide ceramic foam panels

Silicon carbide ceramic foams are used to achieve high performances in many industrial heat exchange systems. This paper experimentally investigated the heat transfer characteristics of air flowing through high-temperature silicon carbide ceramic foams in an electric air heating furnace heated by resistance wires and silicon–carbon sticks. It was found that for an air inlet flow rate of 200 m3/h, the air outlet temperature reached 981 °C after about 2 h when five silicon carbide ceramic foam panels were inserted inside the furnace, while it only reached about 650 °C when no ceramic foam was inserted. The heat transfer enhancement was due to that the ceramic foams enlarged the heat transfer area between air and hot solid surfaces. The results also showed that the position of the ceramic foam in the furnace played an important role in its effect on the heat transfer. This study well validated that silicon carbide ceramic foam can be used as radiant energy absorbers and heat exchangers especially in volumetric solar receivers in concentrated solar power (CSP) plants.