Influence of swirl angle of swirling slice on combustion characteristics of low heat value coal-bed methane

Based on the self-developed combustion test system of low heat value coal-bed methane, four combustors with different swirl angle of swirling slices were designed for the experimental research.Influence of swirl angle of combustor on flow velocity, gas temperature and flame structure in the combustor was investigated.The results show that the swirl angle of combustor has an important influence on the flow velocity, gas temperature and flame structure.When swirl angle increases, the maximal axial velocity moves to the back of combustion chamber but the peak of axial temperature moves to the front and the peak temperature first increases then decreases.When the swirl angle of swirling slices is 45°, the distribution of velocity and temperature in the combustion chamber is more uniform, the average flame length is shorter, the average diameter of flame is maximal and the fullness of flame is better.