Field Test Of Heat And Humidity And Heat Transfer Study In The Ventilation Corridor Of Underground Power Station

Hydropower is a clean and low-carbon renewable energy source.It has comprehensive functions such as flood control,water supply,shipping and irrigation,and has significant economic,social and ecological benefits.In recent years,the total installed capacity of hydropower in China has continued to rise,and the number of underground power stations has continued to increase.There are many electromechanical equipment and their auxiliary equipment arranged in the underground power station.The heat dissipation of the equipment directly affects the thermal environment inside the power station.At the same time,the underground power stations are mostly buried underground,and the problem of the dehumidification of the envelope structure is particularly serious.These factors jointly determine the hot and humid environment inside the station.In order to ensure the safe operation of electromechanical equipment in the power station and the staff have a healthy and comfortable working environment,the ventilation and air conditioning system in the power station becomes very important.The inlet corridor is the main channel for introducing outdoor fresh air into the air conditioning system in the power station,including the traffic tunnel,the wind tunnel and the dedicated wind tunnel.Therefore,the heat and humidity environment in the corridor directly affects the environment and the energy consumption of the ventilation and air conditioning system in the power station.To this end,this paper uses field test,theoretical analysis and numerical simulation to study the hot and humid environment problems in the inlet gallery of underground power stations.The main contents include the following aspects:(1)First of all,field test was conducted on the hot and humid environment in the traffic tunnel of the Jixi Pumped Storage Power Station in Anhui Province.The hot and humid environment in the traffic tunnel under three working conditions was tested by starting and stopping the traffic tunnel entrance and the fan in the ventilation and safety tunnel.According to the test results,the variation law of heat and humidity environment in traffic tunnel was analyzed.At the same time,the heat and humidity environment in the traffic tunnels of three different periods are compared and analyzed.The delay and attenuation laws of the traffic temperature in different periods are obtained.(2)Secondly,according to the field test results of several underground power stations,the results are compiled into a rough estimate of the air inlet corridor by using the criterion correlation of the forced turbulent heat transfer in the air tube obtained by heat transfer.The criterion for the heat transfer coefficient of the convective heat transfer surface between air and rock wall is defined by the dimensionless criterion number.At the same time,using the test results of the three working conditions of the traffic tunnel in the Jixi construction period,The criterion association of the convective mass transfer coefficient is estimated when the wall of the corridor is wetted by a large area and the air velocity is in the range of 0.3~0.5 m/s.According to the field test results,the simplified calculation formula of corridor ventilation is verified.The results show that the simplified calculation formula could be used to predict the variation of air temperature in the corridor along the depth direction.(3)Finally,the numerical simulation method is used to study the influence of slope and curve effect on the ventilation and heat transfer of the corridor.The results show that the slope effect within the engineering range has little effect on the heat transfer in the inlet gallery.The curve effect will change the temperature and humidity distribution of the air in the corridor section at a certain distance before and after the curve.If there is a straight section of sufficient length(greater than 60 times equivalent diameter of the corridor section)after the curve,the curve effect will not produce the overall heat transfer effect of the air flowing through the corridor.