Method for determining the characteristics of a gas-steam CHP plant with a steam turbine compressor drive

Abstract

A new type of maneuverable gas-steam CHPP (gas genset -CHP) with a steam turbine drive of a low-pressure compressor is considered. A mathematical model of technological processes in the elements of this plant has been developed. The proposed scheme of a gas-steam plant with a LPC steam drive with an excess air coefficient α = 1.2 in the CS and steam supply from ST1 to the mixing chamber allows, at a small level of GV and πΣK, to reduce the metal consumption of the design of compressors and ST1. The expansion of the gas-steam mixture in the GST contributes to an increase in the temperature in front of the WHB and increases its steam output. The installation between the stages of the fuel afterburning chamber evaporator with a fan for supplying air to it makes it possible to increase the thermal and electrical power of the CCGT with an increase in the indicators of the joint cogeneration generation of heat and electricity. The technological scheme of the gas-steam gas genset -CHP is relatively simple and has lower capital costs compared to the binary cycle CCGT. The introduction of steam into the combustion chamber of the gas turbine engine improves the environmental performance of the gas genset -CHP. Due to the use of the steam drive of the plant compressor in the waste heat boiler of a two-stage evaporator with an afterburner, condensation of the steam component of the gas-steam mixture, as well as two counter-pressure steam turbines, this scheme has increased thermal efficiency and high maneuverability with a significant increase in the generation of electrical and thermal energy during the heating periods of the year.