Power plant
OwnerGlenn B. Warreninventor
Life of this patent
Estimating the term…
Abstract
A steam turbine-generator power plant is described wherein solar energy is used to preheat feedwater to a steam generator. Two parallel feedwater supply branches are proposed for preheating the feedwater upstream from the steam generator. A first preheater branch utilizes extraction steam from the steam turbine for preheating feedwater and is called an extraction branch. A second preheater branch utilizes solar energy for preheating feedwater and is called a solar branch. The two branches are joined upstream from the steam generator and the proportion of flow from each branch is based on the temperature difference between the extraction branch and the solar branch. A variable speed pump is used to pump feedwater from the solar branch at a rate proportional to the temperature difference between the two branches.
Claims7
A power plant comprising a steam turbine which drives a load, a steam generator providing steam to said steam turbine and a feedwater preheating system for supplying preheated feedwater to said steam generator, said feedwater preheating system comprising:
- an extraction branch including at least one preheater, said preheater being fluidly connected to said turbine through a steam extraction line whereby feedwater may be preheated by extraction steam;
- a solar branch at least one solar heat exchanger, said solar heat exchanger providing a heat exchange relationship between available solar heat and the feedwater whereby feedwater may be preheated by solar heat;
- a first flow divider junction upstream from said extraction branch inlet and said solar branch inlet whereby feedwater is divided between at least two branches;
- a second flow junction downstream from said extraction branch outlet and said solar branch outlet whereby the feedwater flow is rejoined upstream from said steam generator;
- and,
- means for proportioning the feedwater flow between said extraction branch and said solar branch whereby the solar branch flow is increased and the extraction branch flow is decreased during periods when solar heat is available.
In a power plant of the type wherein a steam turbine is connected to drive a load, said steam turbine being supplied with steam from a steam generator which, in turn, is fluidly connected to a feedwater supply;
- means are provided for preheating feedwater upstream from said steam generator said means comprising:
- an extraction branch including a plurality of preheaters, each preheater being fluidly connected in a heat exchange relation with said steam turbine whereby extraction steam may be used to preheat feedwater to the steam generator;
- a solar branch including a plurality of solar heat exchangers, each solar heat exchanger providing a heat exchange relation between available solar heat and the feedwater flow;
- a first junction upstream from said extraction branch inlet and said solar branch inlet whereby the feedwater may be divided between at least two branches;
- a second junction downstream from said extraction branch outlet and said solar branch outlet whereby the feedwater flow is rejoined upstream from said steam generator;
- a first thermal sensor means at the outlet end of said solar branch;
- a second thermal sensor means at the outlet end of said extraction branch;
- and,
- pump means downstream from said first thermal sensor means and upstream from said second junction;
- and,
- control means for actuating said pump means whenever the solar branch temperature exceeds the extraction branch temperature whereby the extraction branch flow is decreased and the solar branch flow is increased by an amount proportional to the temperature difference.
Dependencies are inferred from the claim text.