| For the combined cycle unit, the load regulation characteristic can bethought of as lumped effect of the gas turbine, the heat recovery boiler and thesteam turbine. The changes of the output power following the fuelconsumption step changes are caused by the gas turbine load changes at theearly stage and the steam turbine load changes at the later stage. This paper isfocused on the combined cycle unit load follow control optimization whenAGC is activated. Based on the analysis and settings of the gas turbine loadchange rate, the steam turbine load change rate and the combined cycle unitload change rate, optimal combined cycle unit load following control mode isproposed, which takes into account of the high and low limit of the combinedcycle unit load, the load following coordination control characteristic andother aspects. This control mode can not only meet the requirements of gridload response, but also has the best economic benefit while maximizing thelife span of the combined cycle unit. |
