System for compressing steam from a nuclear steam supply system to operate a turbogenerator
View Patent ↗A power generation system and related method for repowering a fossil-fueled power plant using a carbon-free nuclear steam supply system (NSSS) which replaces the existing fossil plant steam generator which burns fossil fuel such as coal, oil, or natural gas. The existing fossil plant energy conversion system including the turbine-generator (turbogenerator) and auxiliary components of the Rankine cycle is retained. The NSSS may include a small modular reactor (SMR) unit comprising a reactor vessel with nuclear fuel core and steam generator which receives heated primary coolant from the reactor to produce main steam to operate the Rankine cycle. The main steam output by the SMR unit is compressed in a steam compressor to increase its pressure to a level necessary to operate the turbogenerator. The compressor may be operated via a portion of the main steam. An intercooler of the compressor may be used for main steam reheating.
1 . A power plant fueled by nuclear fuel comprising:
a nuclear steam supply system comprising a nuclear reactor which heats a primary coolant that circulates through a steam generator configured and operable to heat and convert a liquid secondary working fluid to main steam at a first pressure;
an energy conversion system comprising a turbogenerator including a steam turbine fluidly coupled to the steam generator and operably coupled to an electric generator configured to produce electricity; and
a steam compressor in fluid communication with the steam turbine and the steam generator;
the steam compressor being configured and operable to receive main steam at the first pressure from the steam generator, and increase pressure of the main steam from the first pressure to a higher second pressure to operate the turbogenerator;
wherein the steam compressor is driven by a steam turbine compressor drive mechanically coupled to the steam compressor;
wherein the steam turbine compressor drive is fluidly coupled to the steam generator and configured to operate with a portion of the main steam discharged at the first pressure by the steam generator.
2 . The power plant according to claim 1 , wherein the steam compressor includes a first compression stage operable to increase the pressure of the main steam from the first pressure to a transitional pressure, and a second compression stage operable to increase the pressure of the main steam from the transitional pressure to the second pressure.
3 . The power plant according to claim 2 , further comprising an intercooler fluidly interposed between the first and second compression stages, the intercooler operable to cool the main steam flowing from the first compression stage to the second compression stage.
4 . The power plant according to claim 3 , wherein the intercooler is a shell and tube heat exchanger.
5 . The power plant according to claim 3 , wherein the main steam flowing from the first compression stage to the second compression stage is cooled via main steam at a third pressure discharged from the steam turbine after passing through a portion of the steam turbine, the main steam at the third pressure having a temperature less than the temperature of the main steam leaving the first compression stage of the steam compressor.
6 . The power plant according to claim 5 , wherein the steam turbine of the turbogenerator includes, in operable fluid coupling:
a high pressure turbine which receives and operates with the main steam from the steam generator at the second pressure, an intermediate pressure turbine which receives and operates with the main steam discharged from the high pressure turbine at the third pressure less than the second pressure, and a low pressure turbine which receives and operates with the main steam discharged from the intermediate pressure turbine at a fourth pressure less than the third pressure; and
wherein the main steam discharged at the third pressure after passing through a portion of the steam turbine is discharged from the high pressure turbine.
7 . The power plant according to claim 6 , wherein the main steam at the third pressure is reheated in the intercooler to produce reheated main steam via heat absorbed from the main steam flowing through the intercooler from the first compression stage of the steam compressor, and wherein the reheated main steam flows to the intermediate pressure turbine.
8 . The power plant according to claim 7 , further comprising a reheater heat exchanger fluidly coupled between the intermediate pressure turbine and the low pressure turbine, the reheater heat exchanger configured and operable to increase a temperature of the main steam discharged by the intermediate pressure turbine via absorbing heat from a portion of the main steam discharged by the steam generator at the second pressure which flows through the reheater heat exchanger.
9 . The power plant according to claim 8 , wherein the reheater heat exchanger is a shell and tube heat exchanger.
10 . The power plant according to claim 1 , wherein a majority portion of the main steam at the first pressure discharged by the steam generator flows to the steam turbine of the turbogenerator.
11 . The power plant according to claim 1 , wherein the steam turbine compressor drive includes a first steam turbine fluidly and mechanically coupled to a second steam turbine, the second steam turbine operating at a main steam pressure less than the first steam turbine.
12 . The power plant according to claim 11 , wherein main steam flows from the first steam turbine to the second steam turbine through a moisture separator.
13 . The power plant according to claim 2 , wherein the second pressure produced by the second compression stage of the steam compressor is less than a design inlet steam pressure of the turbogenerator.
14 . The power plant according to claim 2 , wherein the second pressure produced by the second compression stage of the steam compressor at least meets a design inlet steam pressure of the turbogenerator.
15 . A power plant fueled by nuclear fuel comprising:
a nuclear steam supply system comprising a nuclear reactor which heats a primary coolant that circulates through a steam generator configured and operable to heat and convert a liquid secondary working fluid to main steam at a first pressure;
an energy conversion system comprising a turbogenerator including a steam turbine fluidly coupled to the steam generator and operably coupled to an electric generator configured to produce electricity; and
a steam compressor in fluid communication with the steam turbine and the steam generator, the steam compressor comprising a first compression stage operable to increase the pressure of the main steam from the first pressure to a transitional pressure, and a second compression stage operable to increase the pressure of the main steam from the transitional pressure to a second pressure for introduction to the steam turbine; and
an intercooler fluidly interposed between the first and second compression stages of the steam compressor, the intercooler operable to cool the main steam flowing from the first compression stage to the second compression stage;
wherein the main steam flowing from the first compression stage to the second compression stage is cooled via main steam at a third pressure discharged from the steam turbine after passing through a portion of the steam turbine, the main steam at the third pressure having a temperature less than the temperature of the main steam leaving the first compression stage of the steam compressor.
16 . The power plant according to claim 15 , wherein the intercooler is a shell and tube heat exchanger.
17 . The power plant according to claim 15 , wherein the steam turbine includes a high pressure turbine and an intermediate pressure turbine in operable fluid coupling, and the intercooler comprises:
a cooling fluid path disposed between the first compression stage and the second compression stage of the steam compressor; and
a reheating fluid path disposed between the high pressure turbine and the intermediate pressure turbine of the steam turbine, the reheating fluid path and cooling fluid path configured to flow the main steam in opposite directions.
18 . A power plant fueled by nuclear fuel comprising:
a nuclear steam supply system comprising a nuclear reactor which heats a primary coolant that circulates through a steam generator configured and operable to heat and convert a liquid secondary working fluid to main steam at a first pressure;
an energy conversion system comprising a turbogenerator including a steam turbine fluidly coupled to the steam generator and operably coupled to an electric generator configured to produce electricity, the steam turbine including a high pressure turbine, an intermediate pressure turbine, and a low pressure turbine in successively arranged in operable fluid coupling;
a steam compressor in fluid communication with the steam turbine and the steam generator and operable to increase the pressure of the main steam from the first pressure to a second pressure, the steam compressor including a first compression stage and a second compression stage; and
a heat exchanger comprising:
a cooling fluid path disposed between the first compression stage and the second compression stage of the steam compressor and configured to flow the main steam between the first compression stage and the second compression stage; and
a reheating fluid path disposed between the high pressure turbine and the intermediate pressure turbine of the steam turbine, the reheating fluid path configured to flow the main steam between the high pressure turbine and the intermediate pressure turbine;
wherein the heat exchanger is configured to transfer enthalpy from the main steam flowing through the cooling fluid path to the main steam flowing through the reheating fluid path.
19 . The power plant according to claim 18 , wherein the heat exchanger is a shell and tube heat exchanger.
20 . The power plant according to claim 18 , wherein the first compression stage of the steam compressor is operable to increase the pressure of the main steam from the first pressure to a transitional pressure, and the second compression stage of the steam compressor is operable to increase the pressure of the main steam from the transitional pressure to the second pressure for introduced to the high pressure turbine.