Thermal Performance Diagnosis And Heat Supply Analysis For A600MW Supercritical Steam Turbine

At present, there is still a large gap between the average coal consumption of powersupply of thermal power unit of China and that of the developed countries. Accompaniedwith the growing consumption of coal resources, tighter supply of electricity and coal, andthe increasingly larger pressure of environment, strengthening research on solvingenergy-saving and emission reduction problems of coal-fired generators has become thekey factor to keep economic sustainable development. Steam turbine, one of the mostimportant equipment in thermal power plant, exerts great effect on the economic and safetyin power plant operation.In this paper, thermal performance test was carried out on a600MW supercriticalpower unit, and running parameters under different conditions were obtained. The mainperformance indexes were calculated, and energy-loss analysis was carried out. Severalheat supply reconstruct schemes were discussed, and economic benefit after rebuilding wasanalyzed.A program was compiled based on matlab. Heat consumption rate, cylinder efficiencyand coal consumption rate can be calculated by this program. The program could input thetest data and output the calculation results automatically. Calculation efficiency is improved.According to the results, the power unit performance was evaluated.Based on equivalent enthalpy drop method, energy-loss analysis was carried out on theresearched unit. Quantitative analysis has been applied in studying the influence of crucialparameters in regenerative system and condenser undercooling on coal consumptiondeviation. Results show that deviation from the design value of No.1high press heaterterminal temperature difference and condenser undercooling result in coal consumptionincreasing greatly.Using off-design method, thermoeconomic indexes of a600MW co-generation powerunit reconstructed from condensing unit were respectively calculated, evaluated andcompared systematically under different conditions of boiler loads and steam extraction.The effects of steam extraction flow on unit electric power and coal consumption rate were discussed. The results shows that the electric power and coal consumption rate decreases asthe extraction flow rate increases. Under the condition of heat-supply steam extracted fromreheater outlet, the unit can achieve lower coal consumption rate and more thermoeconomicbenefits than other extraction conditions. The thermoeconomic indexes of actualheat-supply unit was calculated and analyzed.This paper has reference value for performance diagnosis and rebuilding for heatsupply analysis on power units of the same type.