Operating Characteristics of a 420-MW Combined Cycle Heat and Power Plant1,2

Abstract

Thermal tests of the combined cycle (steam-gas) unit at the CHPP No. 26 Mosenergo have been carried out, with measurements of the power and efficiency of the steam-gas unit, as well as the flow rates and parameters of the heat transfer media (air, combustion products, water, and steam) over a wide range of electrical loads and ambient air temperatures. The maximum electric power of the combined cycle unit was varied from 430 MW in the winter with ambient temperatures below -10°C to 380 MW in the summer at 30°C. The efficiency ranged from 59.8 to 58%. The performance indicators of the combined cycle unit were also determined for combined electricity and heat production. For a guaranteed thermal load of 140 Gcal/h, the electrical power of the steam turbine is reduced by 17 MW, the power of the combined cycle plant is about 400 MW, and its electrical efficiency is 57%. The performance characteristics of the combined cycle unit and the gas-turbine unit are given for different operating modes, together with data on the steam capacity, the parameters of the steam in the boiler-utilizer loops, and the efficiency of the cylinders of the steam turbine.