Conversion of combined cycle power plant to compressed air energy storage power plant
View Patent ↗An apparatus and method converts a power generation combined cycle (CC) power plant to a load management compressed air energy storage (CAES) power plant. The CC power plant includes at least one combustion turbine, a heat recovery steam generator (HRSG) to receive exhaust heat from an associated combustion turbine, a steam turbine associated with the HRSG, and an electric generator associated with the steam turbine. An air storage stores compressed air. At least one compressor supplies the air storage with compressed air so that off peak energy can be converted to compressed air energy stored in the air storage. Compressed air from the storage is received by the HRSG and the HRSG provides heat to compressed air received from the air storage. The steam turbine receives heated compressed air from the HRSG and expands the heated compressed air to produce power.
1. A method of converting a combined cycle power plant to a compressed air energy storage power plant, the combined cycle power plant including at least one combustion turbine, a heat recovery steam generator (HRSG) constructed and arranged to receive exhaust heat from an associated combustion turbine, a steam turbine associated with the HRSG, and an electric generator associated with the steam turbine, the method comprising the steps of:
providing an air storage constructed and arranged to store compressed air,
providing at least one compressor constructed and arranged to supply the air storage with compressed air,
ensuring that compressed air from the storage can be received by the HRSG,
utilizing the HRSG to provide heat to compressed air received from the air storage, and
utilizing the steam turbine to receive heated compressed air from the HRSG and to expand the heated compressed air to produce power.
2. The method of claim 1 , further comprising:
permitting a portion of airflow expanded by the steam turbine to be extracted and injected, under certain conditions, into the combustion turbine assembly for power augmentation.
3. The method of claim 1 , wherein prior to the step of utilizing the HRSG, the method includes modifying the HRSG by adding heat transfer components to the HRSG for enhancing the compressed air preheating.
4. The method of claim 1 , wherein prior to the step of utilizing the HRSG, the method includes modifying the HRSG by converting the HRSG to an optimized recuperator.
5. The method of claim 1 , wherein prior to the step of utilizing the steam turbine, the method includes modifying the steam turbine by converting the steam turbine to an air expander based on inlet compressed air mass flow and temperature parameters and exhaust atmospheric pressure.
6. The method of claim 1 , wherein a number of combustion turbines are provided and a HRSG is associated with each combustion turbine, the method including utilizing each HRSG to heat compressed air received from the air storage, with each HRSG being constructed and arranged to deliver heated compressed air to the steam turbine.
7. The method of claim 1 , further providing an additional bottom cycle expander receiving heated compressed air from the HRSG.