| Trapped vortex combustor (TVC) is presented as a new combustion technology which has been widely concerned in recent years with a high combustion efficiency, high flame stabilization and low pollution emission. Vortex is formed from the influence of the viscous and inertial of fluid when the airflow bypass the obstructions. At first, gas and air are ignited in this area, then high-temperature gas ignited downstream gas so as to achieve the purpose of flame stabilization.The scale of detailed chemical mechanism is large. And it is difficult to be applied to complex combustion calculations. So most simulation does not contain the further consideration of chemical mechanism. What’s more, it can’t describe characteristics of the flame fully and accurately, especially in forecasting pollutant emissions. Therefore, it is necessary for us to simplify the detailed mechanism on the premise of ensuring the accuracy and then applied it to the actual combustion simulation.Taking methane as fuel. Firstly, the detailed mechanism of methane Gri-Mech3.0 is Simplified to 17 components 23 steps by sensitivity analysis. And it verifies the consistency of simplified mechanism and the detailed mechanism in predicting combustion and emissions characteristics. Secondly, introducing a simplified mechanism simulation, and exploring the flow characteristics and pollution emission characteristics of annual TVC with different equivalence ratios and mass flow rates. The conclusions are as following:The results show that the annual TVC can be steadily maintained when the equivalence ratio is between 0.6 and 0.85. As the ratio increasing, the total pressure loss coefficient, Outlet temperature and pollutants emissions become increase, and temperature distribution more homogeneous. The flame combustion can be steadily maintained when the quality entrance is between 0.45 and 0.65. As the flow increasing, outlet temperature, temperature distribution and pollutants emissions become slightly reduce. |
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