The present disclosure provides pumped heat energy storage systems that can be used to store and extract electrical energy. A pumped heat energy storage system of the present disclosure can store energy by operating as a heat pump, 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 also 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. Shared powertrains and reversible powertrains are disclosed to circulate the working fluid.

An apparatus for reducing windage loss of steam turbines according to an embodiment of the present disclosure is to reduce or minimize damage to a blade caused by a rise in temperature at an outlet stage of a high-pressure turbine.

An apparatus for reducing windage loss of steam turbines according to an embodiment of the present disclosure is to reduce or minimize damage to a blade caused by a rise in temperature at an outlet stage of a high-pressure turbine.

A piping system of a steam turbine plant is provided with: steam piping connected to a steam turbine; bypass piping which branches from the steam piping at a branching portion and which is connected to a condenser; a steam check valve provided between the branching portion of the steam piping and the steam turbine; and a turbine bypass valve provided in the bypass piping. A piping system cleaning method includes the steps of: connecting at least one valve of the steam check valve and the turbine bypass valve and a connecting portion provided between the turbine bypass valve of the bypass piping and the condenser, by using temporary piping having a foreign matter collecting portion; closing a flow path on the outlet side of the valve; cleaning the steam piping by supplying steam to the steam piping; and sending the steam to the condenser through the temporary piping.

A system includes an electric generator, a power electronics system, a first heat exchanger, and a second heat exchanger. The electric generator includes a turbine wheel, a rotor, and a stator. The turbine wheel is configured to receive process gas and rotate in response to expansion of the process gas flowing through the electric generator. The rotor is configured to rotate with the turbine wheel. The electric generator is configured to generate electrical power upon rotation of the rotor within the stator. The power electronics system is configured to receive the electrical power from the electric generator and convert the electrical power to specified power characteristics. A heat transfer fluid receives waste heat from the power electronics system through the first heat exchanger. The heat transfer fluid transfers the received waste heat to the process gas through the second heat exchanger.

A system includes an electric generator, a power electronics system, a first heat exchanger, and a second heat exchanger. The electric generator includes a turbine wheel, a rotor, and a stator. The turbine wheel is configured to receive process gas and rotate in response to expansion of the process gas flowing through the electric generator. The rotor is configured to rotate with the turbine wheel. The electric generator is configured to generate electrical power upon rotation of the rotor within the stator. The power electronics system is configured to receive the electrical power from the electric generator and convert the electrical power to specified power characteristics. A heat transfer fluid receives waste heat from the power electronics system through the first heat exchanger. The heat transfer fluid transfers the received waste heat to the process gas through the second heat exchanger.

A start-up method of a steam turbine plant includes a first step and a second step. The first step is performed at an aeration start time. In the first step, a reheat steam pressure of an aeration boiler is set to be a reheat steam pressure required by a steam turbine or less. Besides, a reheat steam pressure of a standby boiler is set to be a reheat steam pressure required for the standby boiler or more. The second step is performed when a load of the steam turbine becomes a predetermined value. In the second step, the reheat steam pressure of the aeration boiler is increased to the same degree as the reheat steam pressure of the standby boiler. After that, steam from the aeration boiler and steam from the standby boiler are merged to be supplied to the steam turbine.

A start-up method of a steam turbine plant includes a first step and a second step. The first step is performed at an aeration start time. In the first step, a reheat steam pressure of an aeration boiler is set to be a reheat steam pressure required by a steam turbine or less. Besides, a reheat steam pressure of a standby boiler is set to be a reheat steam pressure required for the standby boiler or more. The second step is performed when a load of the steam turbine becomes a predetermined value. In the second step, the reheat steam pressure of the aeration boiler is increased to the same degree as the reheat steam pressure of the standby boiler. After that, steam from the aeration boiler and steam from the standby boiler are merged to be supplied to the steam turbine.

Systems and methods are provided for the recovery mechanical power from heat energy sources using a common working fluid comprising, in some embodiments, an organic refrigerant flowing through multiple heat exchangers and expanders. The distribution of heat energy from the source may be portioned, distributed, and communicated to each of the heat exchangers so as to permit utilization of up to all available heat energy. In some embodiments, the system utilizes up to and including all of the available heat energy from the source. The expanders may be operatively coupled to one or more generators that convert the mechanical energy of the expansion process into electrical energy, or the mechanical energy may be communicated to other devices to perform work.

The system includes a methane reformer, a combined cycle power generator, and a switch. The reformer is configured to react methane with steam. The combined cycle power generator includes a steam turbine, a gas turbine, a power generator, and a water boiler. The steam turbine is configured to rotate in response to receiving steam. The gas turbine is configured to rotate in response to receiving a mixture of fuel and air. The power generator is configured to convert rotational energy from the steam turbine and the gas turbine into electricity. In a first position, the switch is configured to direct exhaust from the gas turbine to the reformer, thereby providing heat to the reformer. In a second position, the switch is configured to direct exhaust from the gas turbine to the water boiler, thereby providing heat to the water boiler to generate steam.