Influencing Analysis Of Thermal Economic Efficiency On Mix-burning Lignite For Power Plant

Facing the increasingly nervous supplies of coal, and rising prices, the actual operation of the power plant burned in the coal quality has been greatly deviated from the design value, the surrounding the lignite relatively rich resources for the power plant, mixing with a certain percentage of the burning lignite is to improve the economic benefit of power plant in an effective way.The prominent characteristics of lignite is moisture higher, volatile a high, low calorific value, if direct power plant boiler combustion, used for thermal efficiency, reduce the power plant will lead to the dry and burning with lignite lignite problem to improve the power plant efficient have very important significance.Based on a300MW power plant unit, for example, qualitative analysis of the post to co-firing of lignite boiler, steam turbine and auxiliary equipment, the impact of the transformation and the corresponding recommendations; and to matrix analysis, based on a compiled using MATLAB complete set of thermo-dynamic system is calculated; were blended with lignite thermal power plant economic theoretical research, the following recommendations and conclusions:(1) proposed a transformation of the power plant proposal:for burning pulverized coal tangentially, blended with lignite, the inscribed circle diameter increases; way to equality with the wind with the wind; the first and second wind ratio and wind speed are increased accordingly. In the mill before the installation of lignite dryer, and heating gas extraction steam turbine, and then dried lignite, this method through theoretical calculations are feasible.(2) by comparing before and after drying lignite combustion within the boil- er, heating surface heat, smoke and wind mill to contribute to the resistance to change, do not come to dry lignite drying than1.05%boiler efficiency, reducing the amount of coal18.14t/h, fans and milling system power consumption incre-ased4.4%.(3) calculate and analyze blended with30%and50%lignite boiler and ste-am turbine thermal performance, obtained with the increase in the proportion of lignite co-firing, boiler efficiency, turbine inlet increases, the absolute power tu-rbine efficiency drop blended with50%of the lignite after thermal efficiency of the whole plant down nearly1%.(4) economic analysis of the power plant, power generation cost of lignite mixed with the decline in the proportion of the increase, when blended with30%of the lignite, the generation cost per kWh lower0.025yuan/kWh, the average run for300days power plant, can reduce the cost of54million yuan; blended with50%of the lignite, the generation cost per kilowatt reduction0.047yuan/kWh, the year is101.52million yuan, economic benefits are considerable.