| Along with the vigorous development of highway construction in our county,the emerging of highway tunnels is in large numbers. In order to ensure long-term security,stability,economic operation,the design of tunnel ventilation system must be reasonable,including the choice of ventilation and control methods,calculation of ventilation system and etc..Road tunnel ventilation system is used for reducing the pollutant concentrations inside the tunnel. The control method used is the core of the ventilation system. For the highway tunnel ventilation system is a discrete, multi-variable time-delay system,lacking of access to acquired the accurate mathematical model,so the control system often have greater lag,can not reduce the pollutant concentration promptly and effectively. It is harmful for the physical and mental health of the driver within the tunnel. Fuzzy control system does not ask the exact model. It can be avoided through the establishment of the tunnel precise mathematical model of this problem by using fuzzy control and can adapt to the characteristics of road tunnel ventilation system better.Though the analysis to the conditions of the selected tunnel ventilation and the advantages and disadvantages of various methods of ventilation , understanding the advantages of the ventilation for the tunnel with double vertical(oblique) well jet ventilation supply and exhaust plus. Through the calculation of wind amount, the air resistance and other related data in tunnels, in-depth understanding of the selection principle of the tunnel jet fans and deepen the understanding of the tunnel ventilation system; Through the analysis and the comparison of various methods of ventilation control,determining to use pre-feedback fuzzy control to control the tunnel jet fans. Use frequency control technology to control the axial fans installed in the two-vertical(oblique) wells. Use the combination of the both to coordinate the tunnel ventilation system.In order to reduce the lag of the output of the ventilation control system,a traffic flow forecasting model has been established. Using the model we can predict a rough increment value of pollutants concentration inside the tunnel for the next time. Based on the independence between the carbon monoxide(CO) concentration and smok(eVI) concentration,two independent fuzzy controllers has been establishment : CO concentration fuzzy controller and smoke concentration fuzzy controller. According to the set concentration of pollutants and the predicted incremental value and the value feedback from the sensors inside the tunnel,calculate the error values and the error variation.Then the two fuzzy controller use fuzzy speculative respectively corresponding operation to get their outputs,according to outputs to decision the number of jet fans increased or decreased to start or stop.Use the software MATLAB and SIMULINK to simulate the system and optimize the curve of triangular membership function.The design of Ventilation system requires a comprehensive consideration. So according to the control of jet fans in the tunnel and the number of running jet fans,use frequency technology to adjust the frequency of the axial fans installed in vertical(oblique) wells when the number of running jet fans changed. It also used to solve the problem of coordination when the pollutants concentrations change inside the tunnel. At the same time,the application of frequency conversion can also save power consumption , and improve economics benefits within the operation of the tunnel ventilation system.
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