Study On Energy Consumption Analysis And Energy Saving Forecast Of Ventilation And Air Conditioning System In Subway Station

With the rapid development of rail transit in China,the problem of energy consumption in subway stations is also concerned.Among the energy consumption components of subway stations,the ventilation and air conditioning system accounts for the largest proportion.Some studies show that the energy consumption of ventilation and air conditioning system in subway stations accounts for about 1/3 to 1/2 of the total energy consumption of subway stations.The survey found that in most subway stations,the air conditioning temperature is too low in summer,resulting in a large amount of cold waste,not only bring excessive energy consumption,but also bring discomfort to passengers.However,there is little comprehensive understanding of the actual energy consumption of subway stations in China,especially the lack of detailed changes in the operation of ventilation and air conditioning system.Based on this,taking a subway station as the research object,this paper conducts an in-depth study on the energy consumption status and characteristics of the ventilation and air conditioning system,the changes of the thermal environment inside the station,and the correlation between temperature and humidity outside the station and energy consumption.In view of the fact that there are so many factors affecting the energy consumption of air conditioning system and the energy consumption calculation is complex,it is difficult to accurately calculate the energy consumption of air conditioning system.Taking a subway station in Beijing as the research object,this paper records the basic data of the ventilation and air conditioning system and the thermal environment parameters of the station in detail.It is learned that the air-conditioning system of this station consumes about 130,000 k W·h in the air-conditioning season.In the four-month operation,the energy consumption is the highest in July,when it is about 40 million,and the energy consumption is the lowest in September,when it is about 23 million,the quarterly electricity consumption per unit building area is 62k W·h/m².Among all the energy consumption statistics of air-conditioning system,the water chiller has the largest proportion of energy consumption,accounting for about 69%of the total energy consumption.The changes of temperature,humidity and CO₂ of the station hall and platform are further analyzed.The temperature of the platform floor varies in the range of 24.8??27.5?,the temperature of the station floor varies in the range of 26.8??29?,and the temperature of the station floor is lower than that of the outside temperature of 4??5?for a long time.Secondly,the CO₂ concentration in the station conforms to the requirements of relevant design specifications,and the trend of CO2 concentration change in a day can well reflect the trend of passenger flow.At the same time,through the analysis of ventilation and air conditioning system energy consumption and the meteorological parameters and the temperature and humidity within the station correlation detection,and air conditioning system energy consumption and stand outside temperature and humidity,standing room temperature and humidity have significant correlation,and humidity platform platform with smaller temperature correlation,analysis of the causes may be due to the train station standing,shielding door open,the temperature influence of the platform.In the investigation,it is found that the operation mode of the ventilation and air conditioning system in the subway station is single and cannot be adjusted reasonably according to the changes of meteorological parameters and other factors.Aiming at the above problems,this paper proposes to establish a prediction model of energy consumption of ventilation and air conditioning system in subway station based on BP neural network.The establishment of the model takes the actual running data as the training sample,and through the fitting comparison between the predicted results and the measured data,the prediction accuracy of the model is judged.Finally,taking the operation situation of July as an example,the energy saving potential of ventilation and air conditioning system in subway station is further analyzed.