Thermal energy storage for combined cycle power plants

A heat storage system for use in systems requiring low back pressure, the system comprising:

• a container having a first port and a second port;
• wherein said first port receives fluid after heating and said second port allows exit of said fluid when the heat storage system is utilized in the storage mode;
• and
• a storage medium disposed in said container;
• said storage medium comprising high thermal conductivity heat resistance particles;
• said particles being in contact with each other and defining voids between said particles in order to facilitate flow of said fluid in a predetermined direction;
• said predetermined flow direction constituting a longitudinal direction;
• arrangement of said particles constituting a packed bed;
• dimensions of said particles and of said packed bed being selected such that a resultant back pressure is at most a predetermined back pressure;
• wherein the dimensions of said particles are selected such that Biot number magnitude does not exceed 0.1;
• wherein a ratio of a characteristic dimension of said packed bed in the longitudinal dimension of said packed bed to a characteristic dimension of said packed bed in a direction transverse to the longitudinal direction is at most 2.15;
• said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction being indicative of cross sectional area;
• said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction, when said cross-sectional area is substantially circular, being a diameter;
• the characteristic dimension of said packed bed in the longitudinal direction being between about 3.048 m and about 4.57 m.

A system comprising:

• a gas turbine receiving compressed air and fuel for combustion;
• a bypass control connection component;
• and
• a heat storage subsystem comprising;
• a container having a first port and a second port;
• wherein said first port receives fluid exiting the gas turbine and said second port allows exit of said fluid when the heat storage subsystem is utilized in the storage mode;
• a storage medium disposed in said container;
• said storage medium comprising high thermal conductivity heat resistance media;
• said media defining voids in order to facilitate flow of said fluid in a predetermined direction;
• said predetermined flow direction constituting a longitudinal direction;
• arrangement of said media constituting a packed bed;
• dimensions of said media and of said packed bed being selected such that a resultant back pressure to the gas turbine is at most a predetermined back pressure;
• wherein said media comprise particles;
• wherein the dimensions of said particles are selected such that Biot number magnitude does not exceed 0.1;
• wherein a ratio of a characteristic dimension of said packed bed in the longitudinal direction to a characteristic dimension of said packed bed in a direction transverse to the longitudinal direction is at most 2.15;said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction being indicative of cross sectional area;
• said characteristic dimension, of said packed bed in the direction transverse to the longitudinal direction, when said cross-sectional area is substantially circular, being a diameter;
• the characteristic dimension of said packed bed in the longitudinal direction being between about 3.048 m and about 4.57 m;
• said bypass control/connection component controlling flow of a portion of fluid exiting said gas turbine and flowing through said heat storage subsystem occurring under predetermined conditions.

A method for satisfying peak power demand in a combined cycle power plant, the method comprising the steps of:

• providing a thermal storage medium in which thermal energy has been previously stored;
• the thermal storage medium comprising high thermal conductivity heat resistance particles;
• said particles being in contact with each other and defining voids between said particles in order to facilitate flow of a gas in a predetermined direction;
• said predetermined flow direction constituting a longitudinal direction;
• arrangement of said particles constituting a packed bed;
• dimensions of said particles and of said packed bed being selected such that, during a storage mode, a resultant back pressure to a gas turbine is at most a predetermined back pressure;
• wherein the dimensions of said particles are selected such that Biot number magnitude does not exceed 0.1;
• a ratio of a characteristic dimension of said packed bed in the longitudinal direction to a characteristic dimension of said packed bed in a direction transverse to the longitudinal direction, is at most 2.15;
• said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction being indicative of cross sectional area;
• said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction, when said cross-sectional area is substantially circular, being a diameter;
• the characteristic dimension of said packed bed in the longitudinal direction being between about 3.048 m and about 4.57 m;
• flowing gas through the thermal storage medium;
• thereby obtaining, at an exit port of the thermal storage medium, heated gas;
• and
• providing the heated gas to a heat recovery steam generator;
• whereby steam is produced by the heat recovery steam generator and provided to a steam turbine to generate additional power to satisfy the peak power demand.

A system comprising:

• a heat recovery steam generator receiving heated fluid and producing steam;
• a connection control component;
• and
• a heat storage subsystem comprising:
• a container having a first port and a second port;
• wherein said first port receives fluid from a fluid source and said second port allows exit of said fluid when the heat storage subsystem is utilized in a recovery mode;
• a storage medium disposed in said container;
• said storage medium comprising high thermal conductivity heat resistance particles;
• said particles being in contact with each other and defining voids between said particles in order to facilitate flow of said fluid in a predetermined direction;
• said predetermined flow direction constituting a longitudinal direction;
• arrangement of said particles constituting a packed bed;
• dimensions of said particles and of said packed bed being selected such that a resultant back pressure is at most a predetermined back pressure;
• wherein the dimensions of said particles are selected such that Biot number magnitude does not exceed 0.1;
• a ratio of a characteristic dimension of said packed bed in the longitudinal direction to the characteristic dimension of said packed bed in a direction transverse to the longitudinal direction, is at most 2.15;
• said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction being indicative of cross sectional area;
• said characteristic dimension of said packed bed in the direction transverse to the longitudinal direction, when said cross-sectional area is substantially circular, being a diameter;
• the characteristic dimension of said packed bed in the longitudinal direction being between about 3.048 m and about 4.57 m;
• said connection control component controlling flow of fluid exiting said heat storage subsystem through said second port;
• in the recovery mode, fluid exiting said heat storage subsystem through said second port is provided to said heat recovery steam generator.