Research On Structure Optimization Of The Atmospheric-infrared Combined And Upside-entrainment Gas Stove

With the significantly increase of the proportion of natural gas in the energy structure of China and people’s yearning for high-quality life,high-power and high-performance gas stoves have become hot products being in the current research and development of gas stove industry.The research object of this paper is the atmospheric-infrared combined and upsideentrainment gas stove which nominal heat input is 5.0 k W.In this paper,through the cold state numerical simulation of the outer ring ejector and the mixing chamber,and the thermal state numerical simulation of the combined stove with different energy gathering structures,the above structures of the combined stove are optimized,and the candidate optimized structures are proposed.According to the requirements of the national standard "Domestic Gas Cooking Appliances"(GB 16410-2014),the heat input,the CO in the flue gas and the thermal efficiency of the prototype with optimized structures were experimentally studied,and a combined and upside-entrainment gas stove with better combustion performance was developed.In this study,the numerical simulation of the outer ring ejector is carried out by FLUENT software,and the results show two kinds of outer ring ejector with better performance as follows:(1)The diameter of throat is 13.2 mm,the length of throat is 10.0 mm,and the diameter of diffuser outlet is 18.5 mm;(2)The diameter of throat is 13.2 mm,the length of throat is 10.0 mm,and the diameter of diffuser outlet is 19.8 mm.In view of the poor gas distribution uniformity of the outer ring mixing chamber,three kinds of cover plates with different structures are proposed,including transverse strip opening cover plate,longitudinal strip opening cover plate and extended surface guide plate.The simulation results show that the gas distribution uniformity of the cover plate with longitudinal strip opening is the best.According to the optimized structures proposed by numerical simulation,the corresponding prototypes are made.According to the national standard "Domestic Gas Cooking Appliances"(GB 16410-2014),the experimental results show that the highest converted thermal efficiency of 79.20% and reasonable emission of CO in the flue gas(the CO concentration(α=1)in the dry flue gas is 105 ppm)are obtained when the heating height is 25.10 mm(the original design height is 26.12 mm).The thermal efficiency of the prototype with the outer ring ejector of size(2)is 80.34%,which is 2.06 percentage points higher than that of the prototype,and the emission of CO in the flue gas is reasonable(the CO concentration(α=1)in the dry flue gas is 111 ppm).The experimental results of the prototype with a longitudinal strip tuyere cover plate show that,the CO concentration(α=1) in the dry flue gas is 204 ppm,which is nearly half of 452 ppm of the prototype,and the thermal efficiency has no obvious change.In addition,two kinds of energy gathering structures are proposed in this study,including a new energy gathering ring with convex shaped and a fender ring.The results of thermal state simulation show that the thermal efficiency of the prototype gas stove can be improved by both the new energy gathering ring and the fender ring,and the improvement degree of the fender ring is higher than that of the new energy gathering ring structure.The experimental results show that the CO concentration(α=1)in the dry flue gas using the new energy gathering ring is 68 ppm,which is nearly three times lower than that of the original energy gathering ring(195 ppm),and the thermal efficiency of the new is 0.85 percentage points higher than that of the original.The thermal efficiency of the prototype after adding the fender ring is 80.31%,which is 1.92 percentage points higher than that of the prototype.