A control system is provided for a turbine valve. The turbine valve has a first coil and a second coil to control or sense movement of a mechanical valve positioner. Two valve positioners are provided with each valve positioner having two drive circuits to drive the first and second coils. Switches are provided such that only one drive circuit is connected to each coil at a time. The control system may also include a hydraulic pilot valve section and a main hydraulic valve section. Feedbacks are used to determine a pilot valve error and a main valve error which are combined to determine a turbine valve error. The turbine valve error is repeatedly determined to minimize the error.

Thermal battery systems for management (e.g., load management) of electrical power sources, and related methods, are generally described. Thermal battery systems in certain embodiments have an electric heater, a thermal storage system, a heat exchange system and an electricity generator. The electric heater is configured to be connected in electrical communication with an electric power source, such as an electric power grid and to heat the thermal storage system. The electric heater may be a separate unit from the thermal storage system and heat the thermal storage system indirectly by heating a first fluid that is circulated through the thermal storage system during charging, or the electric heater may be integrated directly into the thermal storage system to heat it directly. The thermal storage system is configured to store thermal energy from the electric heater during a charging mode of the thermal storage system, and to heat the first fluid, which is then supplied to a heat exchange system during a discharging mode of the thermal storage system. The heat exchange system comprises at least one heat exchanger, and in some cases, at least a first and a second heat exchanger connected in series. The heat exchange system is positioned downstream from the thermal storage system and is configured to transfer heat from the heated first fluid to a second compressed fluid. The electricity generator may comprise at least one gas turbine and compressor. The compressor is configured to supply the second compressed fluid to the heat exchange system. The turbine is positioned with an inlet in fluid communication with and downstream from the heat exchange system so that the heated compressed second fluid is discharged from an outlet of the heat exchange system into the inlet of the turbine so that the turbine is able to generate electrical power therefrom. The power generated can be returned to the electrical power source, e.g., an electrical power grid.

In a seawater leakage detection device in a feedwater system, a method for detecting seawater leakage in a feedwater system, and a steam turbine plant, an ammonia addition device configured to add ammonia as a pH adjusting agent to feedwater at an upstream side of a high-pressure drum in a feedwater line, an acid electrical conductivity meter configured to measure an acid electrical conductivity of drum water in the high-pressure drum, and a control device configured to control the ammonia addition device such that a pH value of drum water in the heat recovery steam generator expresses alkalinity equal to or greater than a preset predetermined value, calculate a chlorine ion concentration of drum water on the basis of the acid electrical conductivity measured by the acid electrical conductivity meter, and determine whether leakage of seawater is detected are provided.

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.

Apparatus for extracting useful work or electricity from low grade thermal sources comprising a chamber, a source of heated dense heat transfer fluid in communication with the chamber, a source of motive fluid in communication with the chamber, wherein the motive fluid comprises a liquid phase, a flow control mechanism cooperating with the source of heated dense heat transfer fluid and with the source of motive fluid to deliver said fluids into the chamber in a manner that said fluids come into direct contact with each other in the chamber to effect a phase change of the motive fluid from liquid to gas to increase the pressure within the chamber to yield pressurized fluids, and a work extracting mechanism in communication with the chamber that extracts work from the pressurized fluids by way of pressure let down.

Apparatus for extracting useful work or electricity from low grade thermal sources comprising a chamber, a source of heated dense heat transfer fluid in communication with the chamber, a source of motive fluid in communication with the chamber, wherein the motive fluid comprises a liquid phase, a flow control mechanism cooperating with the source of heated dense heat transfer fluid and with the source of motive fluid to deliver said fluids into the chamber in a manner that said fluids come into direct contact with each other in the chamber to effect a phase change of the motive fluid from liquid to gas to increase the pressure within the chamber to yield pressurized fluids, and a work extracting mechanism in communication with the chamber that extracts work from the pressurized fluids by way of pressure let down.

A control system for cost optimal operation of an energy facility including equipment includes a controller configured to provide a cost function comprising a cost term defining a cost as a function of a rate variable and an equipment usage variable, simulate the cost of operating the energy facility over an optimization period at each of a plurality of different values of the rate variable which define a plurality of different costs per unit of the equipment usage variable, select a value of the rate variable that results in a lowest cost of operating the energy facility over the optimization period, perform an online optimization of the cost function with the rate variable set to the selected value to generate one or more setpoints for the equipment, and operate the equipment during the optimization period in accordance with the generated setpoints.

A control system for cost optimal operation of an energy facility including equipment includes a controller configured to provide a cost function comprising a cost term defining a cost as a function of a rate variable and an equipment usage variable, simulate the cost of operating the energy facility over an optimization period at each of a plurality of different values of the rate variable which define a plurality of different costs per unit of the equipment usage variable, select a value of the rate variable that results in a lowest cost of operating the energy facility over the optimization period, perform an online optimization of the cost function with the rate variable set to the selected value to generate one or more setpoints for the equipment, and operate the equipment during the optimization period in accordance with the generated setpoints.

The combined cycle power device of the present invention belongs to the field of energy and power technology. A combined cycle power device comprises an expander, the second expander, a compressor, a pump, a high-temperature heat exchanger, the second high-temperature heat exchanger, a condenser and an evaporator. An evaporator connects the second expander. The condenser passes through a pump and connects the evaporator. The second expander passes through the second high-temperature heat exchanger and connects the high-temperature heat exchanger. The compressor connects the high-temperature heat exchanger. The high-temperature heat exchanger connects an expander. The evaporator connects the compressor and the condenser. The expander connects the evaporator. The high-temperature heat exchanger and the second high-temperature heat exchanger connect the outside. The condenser connects the outside. The expander and the second expander connect the compressor and transmit power.

A hydrogen production system includes: a hydrogen production device connected to an electric power system and configured to produce hydrogen by electrolyzing pure water; an output control unit capable of controlling an amount of power supplied from the electric power system to the hydrogen production device according to request from the electric power system; a first pure water line for supplying pure water to the hydrogen production device; a first adjustment device capable of adjusting an amount of pure water supplied to the hydrogen production device via the first pure water line; and a first control unit configured to control the first adjustment device, based on a power amount signal indicating information on an amount of power supplied from the electric power system to the hydrogen production device.