The single-working-medium vapor combined cycle is provided in this invitation and belongs to the field of energy and power technology. A single-working-medium vapor combined cycle method consisting of eleven processes which are conducted with M.sub.1 kg of working medium and M.sub.2 kg of working medium separately or jointly: performing a pressurization process to set a state (1) to (2) of the M.sub.1 kg of working medium, performing a heat-absorption and vaporization process to set a state (2) to (3) of the M.sub.1 kg of working medium, performing a depressurization process to set a state (3) to (4) of the M.sub.1 kg of working medium, performing a pressurization process to set a state (1) to (e) of the H kg of working medium, performing a heat-absorption process to set a state (e) to (7) of the H kg of working medium, performing a pressurization process to set a state (7) to (4) of the M.sub.2 kg of working medium, performing a heat-absorption process to set a state (4) to (5) of the (M.sub.1+M.sub.2) kg of working medium, performing a depressurization process to set a state (5) to (6) of the (M.sub.1+M.sub.2) kg of working medium, performing a mixed heat-releasing process to set a state (6) to (7) of the (M.sub.1+M.sub.2) kg of working medium and H kg of working medium, performing a depressurization process to set a state (7) to (8) of the (M.sub.1+H) kg of working medium, performing a heat-releasing and condensation process to set a state (8) to (1) of the (M.sub.1+H) kg of working medium.

Systems and methods for transferring and converting heat to a power cycle using a plurality of heat transfer fluids, loops and heat exchange devices to convert heat to useful work and/or power. Power is generated using intermediate heat transfer loops (IHTL) and an intermediate heat transfer fluid (IHTF) to cool the hot exhaust power cycle fluid (PCF) stream that is at or above its critical conditions. The temperature of the IHTF can be increased by 100° C., 150° C., 200° C., 250° C., 300° C., 350° C., 400° C., 450° C., 500° C., 550° C. or more by exchanging heat with the PCF, either directly or indirectly.

An energy storage-combined cooling, heating and power (S-CCHP) system for a building receives energy from a source, for example an intermittent source, and stores the energy in first and second high temperature energy storage (HTES) units. A Brayton cycle using the first HTES unit produces hot and pressurized air that is further heated in the second HTES unit. The heated air drives a turbine to generate electricity for the building. A portion of the compressed air from the Brayton cycle is diverted to a hot water heat exchanger, then to another turbine to produce electricity to the building. The hot water heat exchanger heats water for the building and the other turbine exhaust cools water for building cooling. Heat exchangers are strategically placed to optimize the thermal efficiency of the cycle. In some embodiments the heat transfer fluid is humidified to improve thermal energy transfer properties.

An energy storage-combined cooling, heating and power (S-CCHP) system for a building receives energy from a source, for example an intermittent source, and stores the energy in first and second high temperature energy storage (HTES) units. A Brayton cycle using the first HTES unit produces hot and pressurized air that is further heated in the second HTES unit. The heated air drives a turbine to generate electricity for the building. A portion of the compressed air from the Brayton cycle is diverted to a hot water heat exchanger, then to another turbine to produce electricity to the building. The hot water heat exchanger heats water for the building and the other turbine exhaust cools water for building cooling. Heat exchangers are strategically placed to optimize the thermal efficiency of the cycle. In some embodiments the heat transfer fluid is humidified to improve thermal energy transfer properties.

A method for preventing formation of droplets in a heat exchanger, in which a second medium transfers heat to a first. The method is performed by a controller which receives different temperature values (T.sub.1, T.sub.2, T.sub.3) and a pressure (P) value to be used for calculating a boiling point temperature value (T.sub.B) and determining a first temperature difference (ΔT.sub.1) and a second temperature difference (ΔT.sub.2). Generating a flow control signal, for controlling the flow of the first medium into the heat exchanger, based on the first temperature difference (ΔT.sub.1), the second temperature difference (ΔT.sub.2) and the first temperature value T.sub.1 and sending the flow control signal to a regulator device for controlling the flow of the first medium in the heat exchanger.

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.

The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

The present invention provides methods and system for power generation using a high efficiency combustor in combination with a CO.sub.2 circulating fluid. The methods and systems advantageously can make use of a low pressure ratio power turbine and an economizer heat exchanger in specific embodiments. Additional low grade heat from an external source can be used to provide part of an amount of heat needed for heating the recycle CO.sub.2 circulating fluid. Fuel derived CO.sub.2 can be captured and delivered at pipeline pressure. Other impurities can be captured.

A heat-pipe type heat extraction integrated with combined cooling power and heating exploitation-utilization integrated geothermal system includes an underground heat pipe, a steam pump, a first absorption bed, a second absorption bed, a first condenser, an electronic expansion valve, an evaporator, a liquid storage tank, a balance valve, a steam turbine, an generator connected to the steam turbine, a second condenser, a heat utilization device connected to the second condenser, a pressurizing pump connected to the second condenser, and relevant linkage valve assemblies. The system controls a flow direction and a flow rate after heat pipe steam is extracted from the ground through the steam pump and the regulating valves on the refrigeration side and the power generation side, so as to select the refrigeration/electric heating single-mode heat utilization or adjust flow distribution during refrigeration/electric heating dual-mode combined use.

Methods and systems for generating power (and optionally heat) from a high value heat source using a plurality of circulating loops comprising a primary heat transfer loop, several power cycle loops and an intermediate heat transfer loop that transfers heat from the high-temperature heat transfer loop to the several power cycle loops. The intermediate heat transfer loop is arranged to eliminate to the extent practical the shell and tube heat exchangers especially those heat exchangers that have a very large pressure difference between the tube side and shell side, to eliminate shell and tube, plate type, double pipe and similar heat exchangers that transfer heat directly from the primary heat transfer loop to the several power cycle loops with very high differential pressures and to maximize the use of heat transfer coils similar in design as are used in a heat recovery steam generator commonly used to transfer heat from gas turbine flue gas to steam or other power cycle fluids as part of a combined cycle power plant.