大型地下洞室群变频施工通风系统运行管理研究

针对传统的大型地下洞室群施工通风管理中存在的系统匹配性差、安装不规范、风管漏风率高、风机能耗大等问题,以确保工作面通风效果,节能降耗,规范管理为目标,依托金沙江白鹤滩水电站地下厂房洞室群,通过对大型地下洞室群施工通风系统选型配置、安装验收、运行维护等方面管理进行研究,形成了一整套通风效果良好、高效节能的变频施工通风系统运行管理体系。采用FLUENT流体数值计算软件,建立洞室群三维非稳态湍流模型,研究了主厂房施工期污染物逸散规律,并通过现场污染物测试进行了验证。数值仿真计算和现场测试结果表明:变频施工通风系统布置合理,运营维护到位,风管漏风率小于9. 5%,洞内气流组织顺畅,作业面爆破通风15 min内污染物即可随风流排出洞外,达到相关规范要求;变频风机根据不同工序调节开度,可节省电能49. 5%以上,节能效果明显。研究成果对大埋深水电站地下洞室群施工通风运行维护管理具有一定的参考意义。

Study on operation and management of frequency-conversion ventilation system for construction of large sized underground cavern group

Aiming at the problems of poor system matching performance，non-standardized installation，high air leakage rate of ventilation pipe，high energy consumption of ventilator，etc. in the management of the construction ventilation for conventional large sized underground cavern group and taking ensuring ventilation effect of working face，energy-saving and consumption-reducing and standardizing management as the study object，a set of operation and management system for an efficient and energysaving construction ventilation system with better ventilation effect is formed through the study made on the managements in the aspects of type selection and allocation，installation acceptance，operation and，maintenance，etc. on the basis of the cavern group for the underground powerhouse of Baihetan Hydropower Station on Jinshajiang Ｒiver; for which a 3 － D unsteady turbulence model for the cavern group is established，and then the law of the pollutant emission during the construction of the main power house is studied and verified through the in situ pollutant detection. The results from the numerical simulation and the in situ detection show that the layout of the frequency-conversion ventilation system for the construction is reasonable with proper operation and maintenance，while the air leakage rate is less than 9. 5% ，the air-flow in the cavern is smooth and the pollutant can be discharged out of the cavern within 15 min by the ventilation of the working face，thus the requirement of the relevant specification is reached. Adjusting the opening of the frequency-conversion ventilator in accordance with different construction processes，the electric energy can be saved by over 49. 5% with a significant energy-saving effect. The study result has a certain referential significance for the management of the operation and maintenance of the construction ventilation for the underground cavern group of the hydropower station with a large buried depth.