Study On The Transformation Of Low Temperature Coal Economizer For 2×300MW Unit Of Baotou No.1 Thermal Power Plant

In view of the problem of high exhaust temperature of unit 1 and 2 in the first phase of Baotou thermal power plant,the solution of adding low temperature coal economizer at the heat surface of the tail of the boiler is proposed.Based on the design parameters of the unit and the actual operating data,the feasibility analysis and Research on the transformation of the low temperature economizer are carried out in this paper.Aiming at the problems existed in the set,and combined with the precipitator retrofit demand,put forward two kinds of scheme:the first one is with the retrofit of electrostatic precipitator for dust collector,the entrance temperature of flue gas from 160 degrees to 95 degrees;the second program with the electric bag dust catcher,can be precipitator entrance temperature from 160 degrees to 120 degrees.Through comparative analysis and analysis,the key technical difficulties in the transformation of the two schemes are analyzed,and the corresponding solutions are given.The equivalent economic enthalpy drop method is applied to analyze and evaluate their economic benefits and environmental benefits.It provides reference for the final implementation of the system.Combined with the unit operation characteristics analysis in the inlet water temperature on the choice of low temperature economizer water points,water points for No.7 and No.6 low inlet low to 70 DEG C water mixed with slobber,5 low inlet backwater;in the heating surface layout scheme selection,choice between the heating surface of the whole cloth in the air preheater and dust remover.The flue gas temperature will close to the acid dew point after installing low temperature economizer.Through calculation,two schemes of reasonable exhaust gas temperature have been determined,and the corresponding wall temperature and temperature of the heat transfer tube have also been determined.At the same time,it also focuses on the comprehensive analysis of the ash deposit,wear and wear of the low temperature economizer,as well as the corrosion protection of the support of the flue.Also consider the installation of low temperature economizer,the output capacity of fan and the influence on the subsequent operation of equipment safety;according to local environmental analysis of the operation of low temperature economizer leakage in the process of detection and anti-freezing measures,to ensure the safety and stability of low temperature economizer can put into operation after the.A detailed comparative analysis based on two reconstruction schemes of economic and environmental evaluation.The results show that the direct economic benefits of coal saving of scheme 1?standard coal by 364 yuan/ton?is 1504700 yuan,which is better than scheme 2,838300 yuan.The quantity of water-saving of scheme 1 is 16820thousand tons a year,and it benefits 218600 yuan a year?effective operating hours 4861h,1.3 yuan/ton?,which is higher 89100 yuan than scheme 2 a year.In terms of operation cost,plan 1 brings high energy saving benefits in all aspects.Meanwhile,the scheme reduces CO₂,NOx and dust consumption most annually,and has the best environmental protection effect.Combined with the above analysis,it is suggested that the implementation plan one.Finally,the investment cost and engineering cost of scheme 1are calculated and summarized.The static investment of two machines are 13626900yuan,dynamic investment is 13984000 yuan,and the total investment of the project is27968000 yuan.From the analysis of coal saving,water saving and electricity consumption,we can recover the cost after 6.8 years;if we add environmental benefits,we can return to it within two years.