综合管廊燃气舱燃气管道泄漏扩散规律研究

The study of gas leakage and diffusion law on utility tunnel’s gas tan

利用Fluent对管廊的三维模型进行模拟并搭建实验台,用N2和CO2分别代替燃气和空气,实验验证Fluent的模拟结果。重点研究燃气的泄漏扩散规律及泄漏口压力、孔径、朝向等因素对扩散的影响。结果表明:未通风时燃气以波峰波谷的形式对称扩散,且有浓度分层;泄漏口压力对燃气浓度的影响较大;泄漏口孔径对燃气扩散半径和浓度影响较大;泄漏口朝向对燃气浓度的影响较大,泄漏口位于防火分区中心比位于两端更危险;通风后燃气不再以波峰波谷和对称的规律扩散,通风次数越多,燃气越易在泄漏口下游积聚。建议通风时先低速再高速。

Fluent was used to build the 3 D model of the utility tunnel. Experiment platform was built, and the gas and atmosphere was replaced by N2 and CO2, to verify this method. The diffusion law of gas leakage and the influence of leakage outlet’s pressure,pore diameter and orientation on gas diffusion were mainly studied.The results showed that: When there is no ventilation, gas diffuses symmetrically in the form of wave peaks and troughs, and there is a concentration stratification;the pressure of the leakage outlet has a great influence on the gas concentration;the aperture of the leakage outlet has a great influence on the gas diffusion radius and concentration;the direction of the leakage outlet has a great influence on the gas concentration, and the leakage outlet is more dangerous at the center of the fire prevention zone than at both ends;after ventilation, gas is no longer diffused in a regular pattern of wave peaks and troughs and symmetries;the more the ventilation, the more gas is likely to accumulate downstream of the leakage outlet. It is recommended to ventilate at a low speed firstly and then at a high speed.