US 6,230,480 B1Granted

High power density combined cycle power plant

OwnerWilliam Scott Rollins, IIIinventor

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Abstract

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 driven by a topping cycle engine (TCE), powered by a topping cycle fluid (TCF) which exhausts into a heat recovery device (HRD). The HRD is fired with a supplementary fuel or provided an additional heat source to produce more energetic and/or a larger quantity of the bottoming cycle fluid (BCF) which is used to power a bottoming cycle engine, (BCE) which drives a load (potentially the same load as the topping cycle engine). Energy contained in either the TCF or BCF is used to power the TCE and BCE respectively, but these fluids, and/or their respective engine exhausts, may also be used to support a wide variety of cogeneration applications.

Claims15

Dependent claims

A combined cycle power plant system comprising:

(a) at least one topping cycle energy transport fluid (TCF);
(b) at least one topping cycle engine (TCE) having topping cycle energy transport fluid (TCF) input(s), fuel and/or heat input(s) (CFT), topping cycle energy transport fluid exhaust output(s), and driven load output(s) (TCL);
(c) at least one substantially continuously fired heat recovery device (HRD) having topping cycle energy transport fluid exhaust inputs(s), fuel and/or heat input(s) (CFB), bottoming cycle energy transport (BCF) fluid input(s), HP and/or IP and/or LP bottoming cycle energy transport fluid output(s), and topping cycle energy transport fluid exhaust (TCF) output(s);
(d) at least one bottoming cycle fluid (BCF);
(e) at least one bottoming cycle engine (BCE) having HP and/or IP and/or LE bottoming cycle energy transport fluid (BCF) input(s), bottoming cycle energy transport fluid (BCF) output(s), and driven load output(s) (BCL);
(f) at least one heat exchanger (HEX) having bottoming cycle energy transport fluid (BCF) input(s) and bottoming cycle energy transport fluid (BCF) output(s);
(g) at least one fluid transport device (FTD) having bottoming cycle energy transport fluid (BCF) input(s) and bottoming cycle energy transport fluid (BCF) output(s);
and
(h) at least one control suitably adapted for maintaining a substantially optimum HRD exhaust temperature having inputs comprising HRD exhaust temperature and having outputs comprising operational control of the CFB,
wherein
said TCF supplies said TCE energy transport fluid (TCF) input(s);
a combustible fuel and/or heat (CTF) supplies said TCE fuel and/or heat input(s);
said TCE exhaust output(s) supplies said HRD exhaust input(s);
one or more fuel and/or heat source(s) (CFB) supplies said HRD fuel and/or heat input(s);
said HRD HP and/or IP and/or LP pressure fluid output(s) supplies said BCE HP and/or IP and/or LP pressure fluid input(s);
said HRD ambient exhaust output(s) may be vented to the atmosphere (directly or indirectly) or may be recirculated by a FTD to said TCE input(s);
said bottoming cycle engine (BCE) BCF output(s) is input to said heat exchanger BCF input(s);
said heat exchanger (HEX) BCF output(s) is connected to said FTD input(s);
and
said FTD output(s) is connected to said HRD BCF input(s).

17 more elements

A combined cycle power plant system comprising:

(a) at least one topping cycle energy transport fluid (TCF);
(b) at least one topping cycle engine (TCE) having topping cycle energy transport fluid (TCF) input(s), fuel and/or heat input(s) (CFT), topping cycle energy transport fluid exhaust output(s), and driven load output(s) (TCL);
(c) at least one substantially continuously fired heat recovery device (HRD) that operates at a predominantly single pressure having topping cycle energy transport fluid exhaust inputs(s), fuel and/or heat input(s) (CFB), bottoming cycle energy transport (BCF) fluid input(s), bottoming cycle energy transport fluid output(s), and topping cycle energy transport fluid exhaust (TCF) output(s);
(d) at least one bottoming cycle fluid (BCF);
(e) at least one bottoming cycle engine (BCE) having bottoming cycle energy transport fluid (BCF) input(s), bottoming cycle energy transport fluid (BCF) output(s), and driven load output(s) (BCL);
(f) at least one heat exchanger (HEX) having bottoming cycle energy transport fluid (BCF) input(s) and bottoming cycle energy transport fluid (BCF) output(s);
(g) at least one fluid transport device (FTD) having bottoming cycle energy transport fluid (BCF) input(s) and bottoming cycle energy transport fluid (BCF) output(s);
and
(h) at least one control suitably adapted for maintaining a substantially optimum HRD exhaust temperature having inputs comprising HRD exhaust temperature, and having outputs comprising operational control of the CFB,
wherein
said TCF supplies said TCE energy transport fluid (TCF) input(s);
a combustible fuel (CF) supplies said TCE fuel and/or heat input(s);
said TCE exhaust output(s) supplies said HRD exhaust input(s);
one or more fuel and/or heat source(s) (CFB) supplies said HRD fuel and/or heat input(s);
said HRD pressure fluid output(s) supplies said BCE pressure fluid input(s);
said HRD ambient exhaust output(s) may be vented to the atmosphere (directly or indirectly) or may be recirculated by a FTD to said TCE input(s);
said bottoming cycle engine (BCE) BCF output(s) is input to said heat exchanger BCF input(s);
said heat exchanger (HEX) BCF output(s) is connected to said FTD input(s);
and
said FTD output(s) is connected to said HRD BCF input(s).

17 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/359,813Filed 23 Jul 1999 · us provisional application
Priority: 31 Aug 1998
Granted: 15 May 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

F01K 23/106
With exhaust fluid of one cycle heating the fluid in another cycle: with water evaporated or preheated at different pressures in exhaust boiler
F01K 23/105
With afterburner in exhaust boiler: regulating means specially adapted therefor
Y02E 20/14
Combustion technologies with mitigation potential: combined heat and power generation [CHP]
Y02E 20/16
Combustion technologies with mitigation potential: combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]