A boiler includes one or more evaporators configured to heat water which has flowed therein to a specific heat maximum temperature at constant pressure or more in which a specific heat at constant pressure is maximized using a heated fluid and one or more reheaters configured to heat the steam which has come from the boiler using the heated fluid. All the reheaters configured to supply steam to a low-pressure steam turbine are disposed only at a downstream side of the high-pressure evaporator. All the reheaters heat reheating steam (FRHS) containing steam which has passed through a high-pressure steam turbine configured to receive steam supplied from the high-pressure evaporator and having a temperature lower than a specific heat maximum temperature at constant pressure in the high-pressure evaporator to less than the specific heat maximum temperature at constant pressure.

A boiler includes one or more evaporators configured to heat water which has flowed therein to a specific heat maximum temperature at constant pressure or more in which a specific heat at constant pressure is maximized using a heated fluid and one or more reheaters configured to heat the steam which has come from the boiler using the heated fluid. All the reheaters configured to supply steam to a low-pressure steam turbine are disposed only at a downstream side of the high-pressure evaporator. All the reheaters heat reheating steam (FRHS) containing steam which has passed through a high-pressure steam turbine configured to receive steam supplied from the high-pressure evaporator and having a temperature lower than a specific heat maximum temperature at constant pressure in the high-pressure evaporator to less than the specific heat maximum temperature at constant pressure.

The present disclosure provides pumped thermal energy storage systems that can be used to store and extract electrical energy. A pumped thermal energy storage system of the present disclosure can store energy by operating as a heat pump or refrigerator, whereby net work input can be used to transfer heat from the cold side to the hot side. A working fluid of the system is capable of efficient heat exchange with heat storage fluids on a hot side of the system and on a cold side of the system. The system can extract energy by operating as a heat engine transferring heat from the hot side to the cold side, which can result in net work output.

Method and apparatus for improving the energy efficiency of existing gas turbine combined cycle plants in which a compressor pressurises air which is combusted with fuel in a combustion chamber, followed by a turbine and a high temperature heat exchanger and a low temperature heat exchanger. In the secondary circulation after the steam turbine II, steam is condensed in the condenser into water, which is pressurised to the maximum pressure by means of a pump and preheated in low temperature heat exchanger and vaporised in a high temperature heat exchanger. After the high temperature heat exchanger, steam enters the steam turbine wherefrom a tap is taken, if necessary, which is injected after preheating into the combustion chamber of the gas turbine process or at the latest the beginning of the vanes of the turbine. Before steam turbine II, the enthalpy of steam (and additional water) at below 1 atm is increased by means of the condensation heat of the water contained in the combustion gases, after which intermediate superheating is applied to the saturated Rankine circulation steam using the excess heat of the low temperature heat exchanger.

Disclosed is a combined energy supply system of wind, photovoltaic, solar thermal power and medium-based heat storage, capable of storing the energy which would have been “abandoned wind” and “abandoned light” temporarily in the form of heat by medium-based energy storage. Heat is released during peaks in the power grid to generate power, which serves the function of adjusting the peaks in the power grid. With the medium-based energy storage, unstable photovoltaic electric energy can be converted into stable heat energy output when a relatively large fluctuation occurs in wind and photovoltaic power generation, and therefore the stable supply of energy sources can be guaranteed efficiently. Furthermore, a second heater can also be used for heating the low-temperature media outputted by a first medium tank (100), or a third heater is used for heating water in a heat exchanger (500), and therefore the energy storage of the medium or the heating efficiency of the heat exchanger is improved.

A power plant can comprise a gas turbine productive of an exhaust gas, a steam turbine, a heat recovery steam generator that extracts heat from gas turbine exhaust gas and supplies fluid to the steam turbine, a thermal storage unit storing a thermal storage working medium that is configured to discharge thermal energy into the fluid supplied from the heat recovery steam generator to supplement power generation by the steam turbine, a first heat exchanger disposed within the heat recovery steam generator to transfer thermal energy from the exhaust gas to the thermal storage working medium, and a second heat exchanger in flow communication with the heat recovery steam generator and the thermal storage unit, the second heat exchanger facilitating a direct heat transfer of thermal energy from the thermal storage working medium in the thermal storage unit to the fluid supplied from the heat recovery steam generator.

An improved heat engine that includes an organic refrigerant exhibiting a boiling point below −35° C.; a heat source having a temperature of less than 82° C.; a heat sink; a sealed, closed-loop path for the organic refrigerant, the sealed, closed-loop path having both a high-pressure zone that absorbs heat from the heat source, and a low-pressure zone that transfers heat to the heat sink; a positive-displacement decompressor providing a pressure gradient through which the organic refrigerant in the gaseous phase flows continuously from the high-pressure zone to the low-pressure zone, the positive-displacement decompressor extracting mechanical energy due to the pressure gradient; and a positive-displacement hydraulic pump, which provides continuous flow of the organic refrigerant in the liquid phase from the low-pressure zone to the high-pressure zone, the hydraulic pump and the positive-displacement decompressor maintaining a pressure differential between the two zones of between about 20 to 42 bar.

A power plant comprises supplies of hydrogen fuel, oxygen fuel and water, a boiler comprising a burner for combusting hydrogen and oxygen to produce heat, combustion products and low/intermediate-pressure steam and a first heat exchanger configured to heat water to generate high-pressure steam, and a steam turbine comprising a first turbine configured to be driven only with the high-pressure steam to provide input to a first electrical generator and a second turbine configured to be driven by low/intermediate-pressure steam from the boiler. A method of operating a steam plant comprises combusting hydrogen fuel in a boiler to produce combustion products and LP/IP steam, turning a turbine with the combustion products, condensing water from the combustion products in a condenser, heating water from the condenser in a heat exchanger within the boiler to produce HP steam and turning a turbine with the steam from the first heat exchanger.

A turbine engine assembly includes a core engine generating a high energy gas flow that is expanded through a turbine section, a hydrogen fuel system supplying hydrogen fuel to a combustor through a fuel flow path, a condenser extracting water from the high energy gas flow, an evaporator inputting thermal energy into the water extracted by the condenser to generate a steam flow, and at least one superheater receiving the steam flow from the evaporator and input thermal energy for heating the steam flow. The steam flow from the at least one superheater is injected into the core flow path upstream of the turbine section.

A turbine engine assembly includes a core engine generating a high energy gas flow that is expanded through a turbine section, a hydrogen fuel system supplying hydrogen fuel to a combustor through a fuel flow path, a condenser extracting water from the high energy gas flow, an evaporator inputting thermal energy into the water extracted by the condenser to generate a steam flow, and at least one superheater receiving the steam flow from the evaporator and input thermal energy for heating the steam flow. The steam flow from the at least one superheater is injected into the core flow path upstream of the turbine section.