矿用防爆柴油机排气栅栏气流特性的研究

 防爆柴油机排气栅栏是用来熄灭排气系统中易燃气体，降低排气温度的安全装置，但是排气栅栏的安装，却增加了排气系统的阻力，从而影响防爆柴油机的动力性和经济性。本文利用UG软件建立了防爆柴油机排气栅栏的三维几何模型，应用FLUENT软件对排气栅栏内部流场进行了模拟，并对长方管和短方管两种不同结构的排气栅栏进行了对比分析。结果表明，气流流经排气栅栏时，由于进口段与进口方管之间存在截面突变，最大压降位于栅栏段处，进口方管边侧存在低压区，方管边侧的低压区与周围的高压区形成压差，使气流逆向，形成涡流，减弱了栅栏段两侧的压降。长方管排气栅栏可有效降低涡流强度，减小气流损失，提高流场稳定性，从而改善防爆柴油机的排气性能。

CFD Simulation of the Mine Flameproof Diesel Engine Outlet Flame Trap

Outlet flame trap is a kind of safety device, which can quenche flammable gas and reduce gas temperature in exhaust system for flameproof diesel engine. However, its installation increases exhaust system resistance， and influences performance and fuel economy of flameproof diesel engine. In order to decrease pressure loss, three dimensional model of outlet flame trap is established by using UG software. Then, with the applying of FLUENT software, CFD simulation of outlet flame trap is conducted. Moreover, this paper analyzed research that compared long square tube outlet flame trap and short square tube outlet flame trap. According to the simulation results, when gas flowing through outlet flame trap, since cross section suddenly changes between the imported segment and import square tube，the maximum pressure drop exists in the location of the fence segment, and the low pressure region exists in the import square tube sides. Low pressure region located in the square tube makes gas flow reverse, forms swirl, and weakens pressure drop. Long square cube outlet flame trap can reduce the intensity of swirl, decrease gas loss, enhance stability of flow field, and improve exhaust performance of outlet flame trap in flameproof diesel engine.