| 摘要 |
A system and method for increasing the specific output of a combined cycle power plant and providing flexibility in the power plant rating, both without a commensurate increase in the plant heat rate, is disclosed. The present invention demonstrates that the process of upgrading thermal efficiencies of combined cycles can often be accomplished through the strategic use of additional fuel and/or heat input. In particular, gas turbines that exhaust into HRSGs can be supplemental fired to obtain much higher steam turbine outputs and greater overall plant ratings, but without a penalty on efficiency. This system and method by in large defines a high efficiency combined cycle power plant that is predominantly a Rankine (bottoming) cycle. Exemplary embodiments of the present invention include a load (1304) driven by a topping cycle engine (TCE) (1302), powered by a topping cycle fluid (TCF) (1301) that exhausts (1305) into a heat recovery device (HRD) (1306). Said HRD (1306) is fired with a supplementary fuel and/or provided an additional heat source (1314) to produce more energetic and/or a larger quantity of the bottoming cycle fluid (BCF) (1309) that is used to power a bottoming cycle engine (BCE) (1310) which drives a load (1311) (potentially the same load (1304) as the topping cycle engine (1302)). Energy contained in either the TCF (1301) or BCF (1308) is used to power the TCE (1302) and BCE (1310) respectively, but these fluids, and/or their respective engine exhausts, may also be used to support a wide variety of cogeneration applications.
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