An optimum-design general criterion for steam-gas combined plants is illustrated by which the characteristics of the gas and steam sections can be established to obtain maximum overall efficiency of the plant. The methodology is based on the choice, as an independent variable of the temperature, of the exhaust gases at the recovery boiler inlet. Consideration is given to gas units operating according to a Brayton cycle, with and without afterburning and in accordance with reheat-gas-turbine cycles, and to steam units realized with superheat, superheat reheat, and extraction- heater steam cycles. It is concluded that in order to obtain high-performance combined plants it is not advisable to adopt particularly complicated steam sections, that is, fitted with regeneration and superheat reheating; it is, on the other hand, desirable to match turbo-gas plants operating according to a multiple expansion with reheating cycles, and steam plants with simple superheating.
A STEAM-GAS COMBINED PLANTS OPTIMIZATION / G., Negri di Montenegro; R., Bettocchi; Cantore, Giuseppe; Borghi, Massimo; G., Naldi. - STAMPA. - 1:(1986), pp. 129-135. (Intervento presentato al convegno 21st Intersociety Energy Conversion Engineering Conference: Advancing toward Technology Breakout in Energy Conversion tenutosi a San Diego, CA nel August 25-29).