VAV Application In The Subway Environmental Control System

As a main public transportation means for its efficiency in improving the trafficcondition, subway will be developed rapidly in the future two or three decades in ourcountry. The control of subway environmental systems is becoming more and moreimportant in the subway engineering, so how to optimize the design of subwayenvironmental control system and decrease its operating cost is an important topicworthy of concern.The purpose of the study is to obtain an optimal energy-efficient mode of subwayenvironment ventilation systems that can ensure subway systems operate in thenormal condition and keep the thermal comfort of passengers.Based on enormous domestic and foreign researches on this subject, combinedwith the Rebuild Project of Tianjin Subway, this thesis lays emphasis on followingaspects:Combined with the original design of the 1# line of Tianjin Subway, provide twocontrol modes: Real-time control and graded control by frequency conversion.Experimental study on the performance of axial fans is done in this thesis. Theresult shows that frequency conversion control on fans is economical.Three-dimensional models of the two typical stations have been built, and thevelocity and temperature fields of the subway ventilation systems are simulated.Experimental study and simulations show that it is feasible to use the gradedcontrol by frequency conversion proposed in the thesis, it is economical,reliable andpracticable.