Development of technologies to increase efficiency and reliability of combined cycle power plant with double-pressure heat recovery steam generator

Abstract

To increase the efficiency of a combined cycle power plant, it was suggested in a double-pressure heat recovery steam generator to carry out a reheat of water steam that had been spent in a high pressure cylinder of a steam turbine. The researchers introduce a mathematical algorithm and calculation methodology of the waste-heat boiler. It is proved that after re-superheat of water vapour in a double-circuit waste-heat boiler after the high-pressure superheater (with vapour already used in the high-pressure cylinder of a condensing steam turbine), a CHP-plant efficiency and reliability increase. Calculations for the combined cycle gas turbine unit PGU-450 were performed. It is shown that when the reheater is installed in the recovery steam generator, its efficiency increases by 2.15%. At the same time the efficiency of CCGT for power generation is increased by 3.36%, the degree of dry water steam used in the turbine is increased by 0.082. Consequently, the specific consumption of conventional fuel for electric power generation is reduced by 6.1%. Re-superheating of the total flow of water vapour allows to increase CGP-450 steam-gas unit efficiency by increasing the parameters of the steam entering the low-pressure cylinder of the steam turbine.

Power Market Formation for Clean Energy Production as the Prerequisite for the Country’s Energy Security

“…The initial data for calculating the specific cost of production of energy products at various prices for fossil fuels and the formation of quotas for greenhouse gas emissions are provided in Table 3, which follows. The table contains model parameters of the existing and future environmentally friendly power generation plants at thermal power plants: gas turbine plants (GTU TPP without CO 2 capture) [61], combined cycle plants (CCGTU TPP without CO 2 capture and storage) [62], combined cycle plants with CO 2 capture and storage (CCGTU TPP with CO 2 capture and storage) [63], and oxygen-fuel plants (TPP with the oxygen-fuel cycle) (which are discussed in this paper). According to the functional model (1), the dependences of the unit cost of the electricity production on the price of fossil fuels (coal gasification) were obtained with an increase in the initial steam parameters by supplying the purified oxygen to the combustion chamber.…”