Theoretical and numerical investigation of heat transfer characteristics of an integrated cookstove under different atmospheric pressures based on theoretical models of solid flame and impingement heat transfer

摘要

At present, the problems of the efficient use of energy and heat transfer characteristics of the stoves on plateaus have attracted much attention. In this work, a three-dimensional numerical calculation and theoretical analysis model of impact flame heat transfer was established for the integrated cookstoves widely used in China and verified with the experimental thermal efficiency value. It was found that, with decreased atmospheric pressure, the combustion intensity in the furnace decreases, the flame combustion temperature significantly decreases, the heat transfer rate of the stove decreases, and the total thermal efficiency decreases by 7.5% under pressure of 0.05 MPa compared with normal pressure. By using jet impinged and solid flame models, a heat transfer mathematical model suitable for the inner wok and water jacket of the integrated stove was established. The heat transfer error between theoretical calculation and three-dimensional numerical calculation was no more than 6%. In addition, some methods are proposed to improve the thermal efficiency of integrated stoves under a high-altitude and low-pressure environment. This study not only theoretically reveals the change law of heat transfer characteristics of convective shock and flame radiation heat transfer under low pressure but also has constructive theoretical guiding significance for the improvement of thermal efficiency of highland stoves.