The Research And Application Of Heat Pipe Technology On Reducing Temperature Of Exhaust Gas In Power Plant

Under the big situation of energy conservation and emission reduction in ourcountry, electric power industry also puts forward the development goals of “energysaving, environment protection and high efficiency”. As the main generating stationfor a long period of time in the future, the power plants should pay special attentionto the efficiency of coal-fired boilers. Increasing the efficiency of boiler can reducecoal consumption rate of power plant, and reduce environmental damage fromburning coal, which improves the economic benefit, at the same time, social benefitwill change greatly, and exhaust temperature is an important index to the boilerefficiency.The objects of this study are two350MW boiler units in Jilin province. In thispaper, firstly, analyzes the reasons of high gas temperature of current coal-firedpower plant, and summarizes five measures in operation and structure, newtechnology and automatic control devices, etc. After a comprehensive analysis, heatpipe component is used in the transformation which has high heat transfer efficiency,and transforming the tri-section regenerative air preheater into the heat pipe airpreheater. Secondly, due to the various forms of heat pipe heat exchanger, and itscomplex structure, then how to choose the form is one of the important parts inengineering application. So after determining the reconstruction program, theparameter design of heat pipe air preheater is studied based on optimization theory.This paper explains in detail how to determine the optimal design variables andcorrelative variable of the optimal object. The objective function in this study is setunder the target of the largest annual net income, and the constraint conditions areposed in actual process and technical parameters, and using the complex shapeoptimization method solves the eight optimization parameters, which are tubediameter of heat pipe heat exchanger, bundle horizontal tube spacing, fin pitch of heat and cold leg, fin thickness of heat and cold leg, wind velocity of heat and coldfluid. Lastly, through the post processing, hoses the best scheme selection of heatpipe air preheater and verifies the rationality of the improvement from the economicperspective. Checking results are that it needs only3months to recover the investedfunds of equipment modification and it has a good economic prospects.In order to validate the situation after transformation, the subject bases Fluentthat is one of the large CFD software, porous medium model will be introduced tothe heat pipe air preheater, and makes the three-dimensional numerical simulation toit internal flow field. Through the analysis of simulation to the internal pressure fieldand temperature field, the paper makes the following conclusion: the temperature offlue gas is change from411℃down to149℃from the entrance to the exit of airpreheater, compared with the situation before the input of heat pipe air preheater,exhaust gas temperature has a ideal reconstruction effect.