Research On The Comprehensive Index Of Thermal Power Unit With Considering Environmental Constraints

Economic development has caused continuing growth of energy demands andpollutant emissions in the world. Unlike many industrialized countries, the primaryenergy in China is still coal. These power plants constitute almost half of the totalpollutant emissions. On the basis of ensuring the safe operation of units, more and moreattentions are paied on energy conservation and pollutant emission, it is becoming a hottopic of research at home and abroad that to improve the economic benefit of thermalpower unit, and reduce the loss and pollutant emissions. Therefore, the energyconservation and environment protection in pulverized coal-fired power plants, willcontribute significantly to worldwide efforts in reducing pollutants. At present, tomeasure the operation efficiency of unit in coal-fired power plants, many evaluationmodels are established on the basis of the first and second law thermodynamics.Compared with other commonly used models, the index data of operation is more simpleand practical to evaluate the level of energy conservation and operation economy. In thepresent paper, a system of small index assessment and comprehensive evaluation modelwere utilized to evaluate the operation data of thermal power units, thus an evaluation ofoperation level could be achieved. Meanwhile, the deficiency in the process of equipmentoperation could be found out, which provides an effective way to improve the operationefficiency.Based on the research on the main operation indicators of thermal power units,the thesis establishes typical small index competition evaluation system, aimming atevaluating the actual operating data of the unit. Through the results, the operationlevels of each unit are sorted, and the influence of environmental constraints on thethermal power units are investigated simultaneously. When applying with the systemof typical small index competition evaluation, the impact of load variation on otherindicators are ignored, which will affect the accuracy of system. Considering theproblem, the thesis establishes the relation equations between the loading rate andindicators to judge the index reference value under different loads, which improvesthe accuracy of evaluation.The thesis analyzes the advantages and disadvantages of the small indexcompetition evaluation system. Considering the issues of tedious calculation andinsufficient contact between the indicators, comprehensive evaluation method is proposed. The comprehensive model, which is used for evaluating the actualoperating data of the unit, is built based on the AHP and fuzzy comprehensiveevaluation method. Deficiencies existed in the unit operation are found out throughthe analysis on the evaluation data, which provides reference for improving theoperation of the unit, and promoting the unit’s operating economy. The comparisonbetween the small index competition evaluation and comprehensive evaluationindicates that the comprehensive evaluation is the method of effectiveness andpracticality.