【作者】 刘雪朋；

【导师】 王晓玲；

【作者基本信息】 天津大学 ， 环境工程， 2008， 硕士

【摘要】 在水电站地下主厂房施工中,通风问题是影响施工人员的健康安全及施工方案的实施,制约工程进度的重要因素。传统的施工通风设计计算主要通过地下洞室通风一维常规计算理论和施工设计人员的经验来确定。针对传统通风方案凭经验确定的不足,本文提出了基于计算流体力学(CFD)对水电站地下主厂房施工通风进行模拟的方法,从而合理优化施工通风参数和资源配置,以期为水电站地下主厂房通风设计提供理论和参考依据。本文从水电站地下主厂房内流体流动的实际情况出发,建立了以高雷诺数k -ε封闭模型为基础的三维非稳态单相流模型。在CO运移模型的动量方程中考虑了浮力的影响;在粉尘扩散模型的动量源项中考虑了相间曳力、升力和虚拟质量力的作用,并考虑了密度差的影响。采用PISO算法对某水电站地下主厂房一层施工通风过程进行了模拟,分析了主厂房一层爆破施工通风污染物运移规律,得到如下结论:1、利用CFD对Nakayama等的池岛矿井巷道风流和甲烷分布进行模拟并与其试验数据、计算结果进行了对比。结果表明了本文模拟结果与Nakayama等的验结果基本吻合。2、采用稀、疏、密三种不同网格密度对主厂房一层上游施工通风进行了模拟,在考虑计算机的容量和运行时间的情况下,得到了合理的网格划分。3、结合某水电工程对其主厂房一层爆破施工通风进行了模拟。结果表明了在主厂房施工通风过程中,风管附近形成明显的涡流区;工作面不同位置处的速度差别很大;X-Y剖面不同高度处的风速分布趋势相同。4、运用三维非稳态单相流模型对爆破产生的CO和粉尘在主厂房一层的迁移过程进行了数值模拟。模拟表明了工作面不同位置处的污染物浓度不同;X-Y剖面不同高度处的污染物分布趋势相似;且CO和粉尘具有相似的运移规律。5、对主厂房一层上游两种不同通风方案进行了数值模拟,比较了不同通风方案的风量和压力分布,得到了优化的通风方案。更多还原

【Abstract】 Problems on construction ventilation can be harmful to the health of constructors and can be a great disadvantage for the construction scheme and project progress to be actualized in the underground cavern construction of power station. However, the traditional ventilation design is based on the empirical correlations and the builder and designer’s experience. For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground powerhouse was simulated by the computational fluid dynamics (CFD) to optimize ventilation parameter. In this paper, a 3-D transient single phase models combining high Reynolds number k -εequation for an underground powerhouse was presented. The effect of buoyancy was considered in the momentum equation of the CO transport model, while the effects of inter-phase drag force, lift force, virtual mass force, and density difference between gas and solid, were taken into account in the momentum source of the dust transport model. The PISO algorithm was used to simulate ventilation in the explosion processes of the underground powerhouse. Contaminations migration regularity during the construction ventilation of the first layer of underground powerhouse is analyzed. The simulated results are as follows:Firstly, methane gas distribution of the mine roadway of Ikejima is simulated by CFD. The simulated results are well in agreement with the experimental and numerical simulation work by Nakayama in methane gas distribution. Secondary, three different mesh densities of the coarse, normal and fine are adopted to simulate the ventilation of upstream in the first layer of underground powerhouse. Considering the computer capability and CPU time, the independence of the mesh plotting is obtained.Thirdly, the blasting ventilation in the first layer of underground powerhouse is simulated. There is an eddy zone around the air duct during the ventilation of the underground powerhouse. The velocity has a great deal of difference in the different position at the heading face, while the velocity distribution has the same tendency in different heights at the X-Y section.Fourthly, using a 3-Dsingle phase model, the dynamic CO and dust diffusion in the first layer of underground powerhouse are simulated. The contaminant concentration has a great deal of difference in the different position at the heading face, while the contaminant concentration distribution has the same tendency in different heights at the X-Y section. The migration rule of CO is similar with the migration tendency of the dust.Fifthly, the two ventilation schemes are modelled in the first layer upstream of underground powerhouse. The air volume and pressure distributions of the different ventilation schemes are compared to obtain the optimized ventilation scheme.更多还原