The Research On Tunnel Ventilation Control System For Energy Saving Based On Fuzzy Control

It’s necessary to set mechanical ventilation for guarantee the air quality anddriving safety in long tunnel. Conve ntiona l contro l strategy can meet theenvironme nta l requireme nts of tunne l, but its e nergy cons umptio n is unacceptable. Soit’s necessary to adopt a proper control strategy to control the switch of jet fans fordecreas ing the concentration o f pollutant be low the required leve l and to minimizeelectrica l power consumption for cost-effective simulta neous ly. In this paper, controlstrategy of tunne l ventilatio n syste m was reseached. The ma in contents inc lude:(1) Firstly, tunne l ventilatio n one-dime ns iona l syste m was analysed. The a irdyna mics equation and the pollutants one-dimens io nal transport equation in tunne lwere establis hed, and the solving process of pollutants one-d imens iona l transportequation was introduced.(2) The simulation of tunne l ventilatio n syste m was finis hed using FLUENT. Theresults illustrated that the influence of the different ve loc ity in jet active region to thediffus ion o f polluta nts was s mall. So the number o f jet fans was only needed tocomp ute, and it is not necessary to consider the choise of fans when the controller wasbuilt.(3) In order to ensuring the ava ilab ility of controlle r, the ma ximum va lue ofpolluta nt concentratio n was comp uted taking different a ir speed and source ite m inFLUENT. The polluta nts one-dimens io na l transport equation was mod ified us ing theresults. So the modified equation was described the actual syste m more accurately.(4) The tunnel ve ntilation contro l syste m was built based on fuzzy reasoning.The inputs o f fuzzy controller inc lude traffic flow and the deviation va lue of COconcentration which is the D-va lue between actua l concentratio n and designconcentration of CO. The output of fuzzy controller is the number of jet fans that mustbe switched. The me mbership functions of traffic flow, the deviation va lue of COconcentration and the number of jet fans were designed through analys is the airdyna mics equation and the pollutants one-dimens iona l transport equation. The methodof solving fuzzy imp lication relations hip is Ma mdani method and the method of fuzzyrelation synthetic is ma x-min compos ition. The simulation results indicated that thefuzzy controller was more effic ient tha n conve ntiona l controller in energy saving. Butthe frequenc y of switching the jet fans was increased.(5) A kind of tunne l ventilatio n control strategy which based on T-S fuzzy modelwas proposed in this research. Firstly a fuzzy identification based on T-S mode l was used to identify the road tunne l ve ntilation syste m, whic h inc ludes fuzzy c-meansclustering algorithm for identifying the antecedent parameters and recurs ive leastsquare method used to identify its conseque nt part. The n the polluta nt concentrationin the next sa mpling was pred icted by the identified syste m. The optima l number ofjet fans was calculated based on the require me nt that the ma x CO concentration issma ller tha n the design concentration o f CO. Fina lly the T-S model was update byactua l CO concentration in line to ensure its adaptability. The simulation resultsindicated that this contro l strategy can not only decrease energy consume, but a lsoinduce the freque ncy of switc hing the jet fa ns.