Abstract: In the gas-fired heating water heater, the heat exchange process of the heat exchanger is mainly convection heat exchange and radiation heat exchange. According to the combustion characteristics of the wall mounted furnace, the radiation heat exchange accounts for a small proportion and is mainly convection heat exchange. Introduce a new round tube heat exchanger for the atmospheric gas-fired heating water heater. The heat exchanger is composed of several parallel fins, and the fins are arranged with convex structures according to the simulation results, and on the premise of not affecting the flue gas resistance, the wind-proof folding edge is added on the upper part of the fin to change the flue gas flow direction, so as to improve the heat exchanger area of the heat exchanger. The heat exchanger is composed of round tubes, and the assembly is simple. The research shows that the circular tube heat exchanger with this structure has the advantages of small volume, high thermal efficiency, low cost, simple production process and modularization, and has high development value.

Key words: Round tube heat exchanger, Simulation analysis, Convection heat transfer