FBCDZ-10-No36型通风机进气风道气流稳定性分析

Analysis on stability of air flow in intake air duct of FBCDZ-10-No36 mode ventilator

根据某矿压入式轴流主通风机在进气风道入口安装片式消声器,在运行1个月后,第1级部分叶片表面出现裂纹的情况,探讨了影响叶轮入口气流不稳定的主要因素,据此对吸声片尾部和进气风道结构进行了改进,并对改进前后风道内的流场进行数值模拟。结果表明:进气风道入口安装消声器后,在吸声片尾迹中卡门涡街阵列、弯曲风道内流动和风道拐弯处分离流动的共同作用下,叶轮入口截面主流速度分布不均匀程度增强、截面气流压力脉动明显加剧,成为引起叶片疲劳破坏的主要原因;结构改进显著提高了风道内以及叶轮入口截面气流的均匀性和稳定性,从而保证了叶片工作的安全性。

According to an axial main ventilator with a forced ventilation in a mine,a piece type muffler was installed at the entrance of the air intake duct. After one month of the operation,the cracks were occurred on some board surfaces at the first stage. The paper had a discussion on the main factors affected to the air flow unstability at the entrance of the impeller. Thus a construction was conducted on the sound absorption board tail and the air intake duct structure and a numerical simulation was conducted on the flow field within the air duct after and before the reconstruction. The results showed that after a muffler was installed at the entrance of air intake duct,under a joint role of the array of Karman vortex street in the wake of the sound absorption board,air flow within the bending air duct and the separated flow at the turning corner of the air duct,the uniformity of the cross sectional main flow velocity distribution at the entrance of the impeller would be increased and the cross sectional airflow pressure pulse would be obviously increased and would become the main causes of the blade fatigue failure. The structure improved could obviously increase the uniformity and stability of the cross sectional air flow within the air duct and at the entrance of the impeller and could ensure the safety of the blade.