面向煤矿瓦斯的径流式涡轮叶顶间隙内流分析

In-flow analysis of runoff turbine tip clearance for mine gas

针对煤矿瓦斯的径流式涡轮,采用ANSYS软件对不同叶顶间隙下叶轮的气动性能和泄漏涡流特性进行模拟,计算雷诺平均N-S模型。计算结果表明,随叶顶间隙增大,叶轮气动损失和泄露涡流强度均逐渐增大,总温逐渐减小。减小叶顶间隙能有效提高涡轮效率,但当叶顶间隙过小时会出现瓦斯流动方向与压力梯度方向相反现象,根据计算结果建议叶顶间隙取为叶轮出口叶高的0.3%。

For the radial turbine of coal mine gas,the ANSYS software was used to simulate the aerodynamic performance and leakage vortex characteristics of the impeller under different tip clearances,and the Reynolds average N-S model was calculated.The calculation results showed that with the increase of the tip clearance,the impeller aerodynamic loss and leakage vortex intensity increased gradually,and the total temperature gradually decreased.Reducing the tip clearance could effectively improve the turbine efficiency.However,when the tip clearance was too small,the gas flow direction and the pressure gradient direction would be opposite.According to the calculation results,the tip clearance was recommended to be 0.3%of the impeller outlet leaf height.