Boiler Of Low Temperature Economizer System Optimization Design And Thermal Economic Analysis

Low temperature economizer technology is sufficient to conserve energy, protectthe environment, and use the exhaust heat deeply of boiler, the current problem is thepower plant boiler flue gas temperature is too high,this technology has become apractical method to reduce the exhaust gas temperature effectively of boiler powerplant in recent years. In this paper, based on the basis of previous studies, accordingto the the principle of thermal equilibrium, establish optimal design model of lowtemperature economizer, application of computer programming calculation andoptimization, to get the optimal equipment parameters. Through the analysis andcomparison, Selecting the optimal location in flue gas side and the optimalconnections in the water side of low temperature economizer. Combining with thepractical project of the power plant and calculating the optimal parameters ofequipment; by using the equivalent enthalpy drop method and the concept of wasteheat utilization, calculating the thermal economic indicators of the system afterapplication of low temperature economizer.First, considering the low temperature environment of it, through the analysisand comparison to the corrosion resistant materials and the heat transfer performanceof tube types, and then obtained the appropriate pipe and tube type. Select the lowtemperature economizer tubes related parameters as decision variables, calculate heattransfer by the thermal equilibrium theory, set related constraints,assuming the lowtemperature economizer outlet flue gas temperature as a variable, establish its optimaldesign model, after the calculation of procedures and optimization then obtain theoptimum results.Secondly, combined with the actual project of600MW unit of one power plant,select the most reasonable arrangement of low temperature economizer in the rear ofboiler. Calculate the dew point temperature of flue gas by the characteristics of coal,control entrance condensed water temperature of low temperature economizer, to avoid the effect of low temperature corrosion. Thermal analysis to its series parallelsystem on the water side then select the optimum connection mode. Through theoptimization design of low temperature economizer and after the determination ofrelevant parameters, by using the equivalent enthalpy drop method and waste heatutilization concepts, and analyzing the thermal systems which with the lowtemperature economizer, calculating the thermal economic index such as the standardof coal consumption,coal consumption rate, thermal efficiency of unit and so on.