Study On Environmental Monitoring And Ventilation Control Of Urban Utility Tunnel

Urban utility tunnel is a kind of urban infrastructure which adapts to the future urban development and integrates intellectualization,technology and integration.It plays an important role in reducing urban traffic pressure,facilitating urban residents'life,beautifying urban landscape and saving urban underground space.Urban utility tunnel is a closed underground tunnel building,which contains a variety of pipelines and other electrical equipment.During its operation,with the accumulation of flammable and harmful gases and the change of temperature and humidity will have a significant impact on the personal safety of maintenance personnel and the use of equipment.At present,with the rapid development of utility tunnel in China,the traditional manual inspection management mode can no longer meet the demand.In addition,ventilation system as an Important component of urban utility tunnel,the single factor control method adopted at this stage also has the disadvantage of low reliability.In view of the above problems,a urban utility tunnel project in a city is used as an actual object in this paper.An environmental monitoring system of utility tunnel based on PLC is designed,an environmental assessment method for utility tunnel based on multi-sensor data fusion is proposed.And on the basis of the evaluation results,the controller of ventilation system is designed.The specific research contents are as follows:1.An environmental monitoring system of utility tunnel based on PLC is designed.The system is with a distributed structure of three-level:The lower level are various environmental sensors,which are used to collect the data of the internal environment?O₂,CO,CH₄,etc.?of the utility tunnel;The middle level is the area controller PLC,which is connected to various sensors and execution components to process the data collected by the sensor and transmit the data to the upper monitoring center through Ethernet communication;the upper level is the monitoring center,It can realize real-time display of environmental data,query of historical data,information warning and other functions.2.Considering the diversity of the environmental impact indexes,the volatility of the measured data and the uncertainty caused by the sensor reliability,an environmental assessment method for utility tunnel based on multi-sensor data fusion is proposed.Firstly,the outliers of environmental data are eliminated by box-plot method to ensure authenticity and validity;Then the data fusion method is used to process and fuse the data measured by multiple sensors,and the assessment level of the utility tunnel environment is obtained;Finally,the feasibility and validity of the proposed method are verified by evaluating the environment of a utility tunnel in a city.3.Combining the environmental assessment results and the ventilation system characteristics of utility tunnel,the comfort and safety ventilation fuzzy controller are designed respectively.With the help of simulation software,the fuzzy controller and the PID controller are simulated and compared.The results show that the fuzzy controller can control the ventilation of utility tunnel quickly and steadily.In this paper,the environmental assessment and ventilation control of utility tunnel are studied by using multi-sensor data fusion method and fuzzy control method.The results show that these methods can evaluate the environment of the utility tunnel reasonably and control the ventilation of the utility tunnel effectively,it provides some reference for the follow-up study of the utility tunnel.