Characteristic Study of Combustion in Central Reverse Flame Chamber
|School||Harbin Institute of Technology|
|Keywords||central reverse flame combustion chamber numerical simulation optimize experiment|
Central reverse flame chamber possesses characteristics of more uniform of temperature distribution, lower production of Nitrogen Oxides, higher combustion efficiency, more reasonable load of stay bolt tube and stay bolt plates, more simple of manufacturing process, more compact of structure than other oil-boiler chamber. Central reverse flame chamber will be a new direction for middle and small oil-boiler. People design it by imitating foreign products, so there is no ideal calculation method and theoretical basis in China. These questions obviously restrain applications of central reverse flame chamber.This paper researched and analysed combustion, flow, heat transfer based on mass conservation equation, momentum conservation equation, energy conservation equation, composition equation by computer simulation. Numerical computation of combustion processes combined with combustion theory, experiments and burner design based on computer. It is a good method to guid experiments and design work. Numerical simulation provides strong support for designing central reverse flame chamber.Geometric model was founded from the combustion device in the laboratory. Then the combustion processes of the combustor was simulated by FLUENT6.2 software. At the same time, this paper analyzed the influences of different nozzles and slenderness ratio on combustion.The temperature field, velocity field, the field of NOx concentration, average temperature of outlet flue gas and combustion efficiency were computed in different nozzles and slenderness ratio. Then the combustion chamber was optimized by analysing the fields. To validate the results, the same fields of combustion chamber were simulated in the same conditions. By the frontal results contrast with the back results, the conclusions were obtained: temperature was well-distributed, flue-gas temperature of exit was lower, combustion efficiency was improved, NOx emission was decreased in optimized combustion chamber, as the fact that optimal combustion chamber was reasonable and optimized in volume and mass. Distribution of temperature in axial direction and radial direction, combustion efficency, NOx emission of outlet were measured in a central reverse flame furnace based on optimization results. Numerical simulation results tally well with the testing results.