Combined cycle electric power plant and a heat recovery steam generator with improved fluid level control therefor
First Claim
1. A combined cycle electric power plant comprising:
- a. at least one gas turbine including an exit through which heated exhaust gases pass;
b. means for generating steam coupled to said gas turbine exit for transferring heat from the exhaust gases to a fluid passing through said steam generating means;
c. a steam turbine coupled to said steam generating means and driven by the steam supplied thereby;
d. means for generating electric power by the driving power of said turbines;
e. condenser means for receiving and converting the spent steam from said steam turbine into condensate, said condenser means including a hotwell storage portion for receiving and storing the condensate;
f. said steam generating means including a deaerator for receiving condensate from said condenser and storing the received condensate in a storage portion thereof, a feedwater pump for directing the stored fluid from said deaerator storage portion to a first heat exchange tube, a main drum associated with said first heat exchange tube for receiving the heated fluid therefrom, and a second heat exchange tube associated with said main drum for receiving fluid therefrom and for heating the fluid by the exhaust gases from said gas turbine into superheated steam to be directed to said steam turbine;
g. condensate valve means for controlling the flow of condensate from said condenser hotwell storage portion to said deaerator; and
h. means for controlling the operation of said turbines and said steam generating means comprising fluid level control means responsive to the flow of superheated steam to said steam turbine for regulating the flow of condensate into said deaerator storage portion in accordance therewith.
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Accused Products
Abstract
A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. A condenser receives the spent steam from the steam turbine for converting it into condensate. The steam generator includes a deaerator for receiving the condensate flow from the condenser and for storing it in a storage portion, a feedwater pump for directing the stored condensate through a first heat exchange tube whereby heat is transferred from the gas turbine exhaust gases to the fluid, a main drum for receiving and storing the heated fluid and a second heat exchange tube for heating the fluid by the gas turbine exhaust gases into superheated steam to be supplied to the steam turbine. A water make-up system is associated with the condenser and includes a water make-up storage tank, a return valve for extracting condensate from that supplied to the deaerator for storage in the water make-up storage tank, and a make-up valve for returning water from the water make-up storage tank into the condenser. Fluid level control is provided for maintaining the fluid level within a hotwell storage portion of the condenser, and within the storage portion of the deaerator, by controlling the position of the condensate valve. In particular, the fluid level control is responsive primarily to a measurement of the superheated steam as supplied to said steam turbine and in particular to a difference signal between the flow of superheated steam to said steam turbine and the condensate flow to said deaerator for the control of the position of the condensate valve, and secondarily, to measurements of the fluid level within the deaerator storage portion and the hotwell storage portion to trim the effect of the aforementioned difference signal upon the position of the condensate valve.
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Citations
32 Claims
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1. A combined cycle electric power plant comprising:
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a. at least one gas turbine including an exit through which heated exhaust gases pass; b. means for generating steam coupled to said gas turbine exit for transferring heat from the exhaust gases to a fluid passing through said steam generating means; c. a steam turbine coupled to said steam generating means and driven by the steam supplied thereby; d. means for generating electric power by the driving power of said turbines; e. condenser means for receiving and converting the spent steam from said steam turbine into condensate, said condenser means including a hotwell storage portion for receiving and storing the condensate; f. said steam generating means including a deaerator for receiving condensate from said condenser and storing the received condensate in a storage portion thereof, a feedwater pump for directing the stored fluid from said deaerator storage portion to a first heat exchange tube, a main drum associated with said first heat exchange tube for receiving the heated fluid therefrom, and a second heat exchange tube associated with said main drum for receiving fluid therefrom and for heating the fluid by the exhaust gases from said gas turbine into superheated steam to be directed to said steam turbine; g. condensate valve means for controlling the flow of condensate from said condenser hotwell storage portion to said deaerator; and h. means for controlling the operation of said turbines and said steam generating means comprising fluid level control means responsive to the flow of superheated steam to said steam turbine for regulating the flow of condensate into said deaerator storage portion in accordance therewith. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A fluid level control system for a combined cycle electric power plant comprising at least one gas turbine including an exit through which heated exhaust gases pass, means for generating steam coupled to said gas turbine exit for transferring heat from the exhaust gases to a fluid passing through said steam generating means, a steam turbine coupled to said steam generating means and driven by the steam supplied thereby, means for generating electric power by the driving power of said turbines, condenser means for receiving and converting the spent steam from said steam turbine into condensate, said condenser means including a hotwell storage portion for receiving and storing the condensate, said steam generating means including a deaerator for receiving condensate from said condenser and storing the received condensate in a storage portion thereof, a feedwater pump for directing the stored fluid from said deaerator storage portion to a first heat exchange tube, a main drum associated with said first heat exchange tube for receiving the heated fluid therefrom, and a second heat exchange tube associated with said main drum for receiving fluid therefrom and for heating the fluid in the exhaust gases from said gas turbine into superheated steam to be directed to said steam turbine, and condensate valve means, for controlling the flow of condensate from said condenser hotwell portion to said deaerator,
said fluid level control means responsive to the flow of superheated steam to said steam turbine for controlling the position of said condensate valve means to regulate the flow of condensate into said deaerator storage portion in accordance therewith.
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28. A fluid level control system for an electric power plant comprising a heat source, means for generating steam coupled to said gas turbine exit for transferring heat from said source to a fluid passing through said steam generating means;
- a steam turbine coupled to said steam generating means and driven by the steam supplied thereby, means for generating electric power by the driving power of said turbine, condenser means for receiving and converting the spent steam from said steam turbine into condensate, said condenser means comprising a hotwell portion for receiving and storing the condensate, said steam generating means including a deaerator for receiving condensate from said condenser and storing the receiver condensate in a storage portion thereof, a feedwater pump for directing the stored fluid from said deaerator storage portion to a first heat exchange tube, a main drum associated with said heat exchange tube for receiving the heated fluid therefrom, and a second heat exchange tube associated with said main drum for receiving fluid therefrom and for heating the fluid by the heat supplied from said source into superheated steam to be directed to said steam turbine, and condensate valve means for controlling the flow of condensate from said condenser hotwell storage portion to said deaerator,
said fluid level control system responsive to the flow of superheated steam to said steam turbine for controlling the position of said condensate valve means to regulate the flow of condensate into said deaerator storage portion in accordance therewith. - View Dependent Claims (29, 30, 31, 32)
- a steam turbine coupled to said steam generating means and driven by the steam supplied thereby, means for generating electric power by the driving power of said turbine, condenser means for receiving and converting the spent steam from said steam turbine into condensate, said condenser means comprising a hotwell portion for receiving and storing the condensate, said steam generating means including a deaerator for receiving condensate from said condenser and storing the receiver condensate in a storage portion thereof, a feedwater pump for directing the stored fluid from said deaerator storage portion to a first heat exchange tube, a main drum associated with said heat exchange tube for receiving the heated fluid therefrom, and a second heat exchange tube associated with said main drum for receiving fluid therefrom and for heating the fluid by the heat supplied from said source into superheated steam to be directed to said steam turbine, and condensate valve means for controlling the flow of condensate from said condenser hotwell storage portion to said deaerator,
Specification