Study On Construction Procedure And Ventilation Strategy Of Underground Powerhouse Of Pumped Storage Power Station

As a new type of green energy storage and electrical energy peak smoothing facility,more than 100 reservoir pumped storage power stations were built,and more are under construction and planned in recent years in China.During the construction process of underground powerhouse of the pumped storage power station,ventilation and smoke dispersion is a particularly important factor related to the speed of construction progress,and the life safety of construction workers.This thesis studied the reasonable ventilation strategy,to discharge the pollutants generated during blasting,and makes the environment safe for construction work in the shortest time.The details are as follows:Based on the existing specifications and design manual,the air volume required for construction ventilation is calculated.According to the existing construction ventilation mode,the worst working conditions of three different stages of blasting construction period of pumped storage power station are simulated and calculated.The diffusion law of dust and harmful gas after blasting and the air distribution of ventilation are obtained.Several improved schemes are put forward and simulated,until a reasonable ventilation scheme that meets the ventilation time requirements in each stage is found,and then to improve the construction process for the highest efficiency.The research show that the time of reaching the standard of pollutant concentration is greatly shortened when the relay jet fan is installed in the tunnel for ventilation before the shaft is opened.In the first stage,the time to reach the standard was reduced from 38.3 minutes to19.9 minutes,in the second stage,the time to reach the standard was reduced from 88.2 minutes to 24.9 minutes.In the third stage,when the shaft has been opened,the exhaust fan required by the normal operation of the plant is installed in advance at the wellhead,the combination of permanent and temporary.Meanwhile,to block off individual locations of drainage channel,to moves down the air supply outlet,to ensure that the non-constructing space maintains positive pressure,air supply can avoid short circuit,and downstream air distribution is adopted,so that the pollutants can be controlled in the minimum level,the time for reaching the standard of blasting pollutant concentration was reduced from 71.6 minutes to 24.9 minutes.Compare with the schedule of the existing construction process,the shaft and drainage channel were drilled 8months and 9 months ahead of schedule respectively,much shorten the whole construction period and reduce the construction investment.The research provide basis for the ventilation design and construction process arrangement of the underground powerhouse construction.The research conclusions provide support for possible revision of the corresponding engineering technical specifications and the ventilation design and construction schedule of similar projects.