The present disclosure provides pumped thermal energy storage systems that can be used to store 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. Systems of the present disclosure can employ solar heating for improved storage efficiency.

The present disclosure provides pumped thermal energy storage systems that can be used to store 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. Systems of the present disclosure can employ solar heating for improved storage efficiency.

A waste heat recovery apparatus includes a heat exchanger, an expander, a condenser, a first tank, a reflux portion, a first passage portion, and a second passage portion. The heat exchanger is configured to generate steam. The expander is configured to recover heat energy of the generated steam as power. The condenser is configured to condense the steam passing through the expander. An inlet portion of the condenser is arranged above an outlet portion of the expander. The first tank is configured to store the working fluid liquefied by the condenser. The reflux portion is configured to reflux the liquid-state working fluid in the first tank to the heat exchanger. The first passage portion connects the outlet portion of the expander and the inlet portion of the condenser to each other. The second passage portion connects the first passage portion and the first tank to each other.

In one embodiment, a thermal energy storage power plant includes a thermal accumulator to accumulate thermal energy and heat a thermal medium with the thermal energy, and a steam generator to generate steam using the thermal medium. The plant further includes a first path to convey the thermal medium from the accumulator to the generator, and a second path to convey the thermal medium from the generator to the accumulator. The plant further includes an auxiliary module provided on the first path, and a bypass path to convey the thermal medium flowing through the second path to the auxiliary module by bypassing the accumulator, wherein the auxiliary module is supplied with a first thermal medium from the accumulator via the first path, supplied with a second thermal medium from the second path via the bypass path, and supplies a third thermal medium to the generator via the first path.

Configurations and related processing schemes of direct or indirect (or both) inter-plants heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect (or both) inter-plants heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of direct or indirect inter-plants heating systems (or both) synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect inter-plants heating systems (or both) synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

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 power generation system includes an Organic Rankine Cycle (ORC) electric generator thermally coupled to a stack of industrial heat pumps (IHPs). The ORC requires heat to generate electricity. The IHPs require electricity to generate heat. The IHPs have an efficiency much greater than 100% because some of the output heat from an IHP is pre-existing heat extracted from available source water, The temperature of the source water can be as low as 70? F. By configuring the IHPs to maximize their efficiency, the electricity required to operate the IHPs can be reduced below the output electricity from the ORC. The surplus electricity produced by the ORC is available for export. This coupled ORC/Heat Pump system is an electric generator that requires no fuel to operate and produces no emissions. The required energy is provided by the heat extracted from the source water by the IHPs.

Configurations and related processing schemes of direct or indirect inter-plants heating systems (or both) synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect inter-plants heating systems (or both) synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.

Configurations and related processing schemes of direct or indirect (or both) inter-plants heating systems synthesized for grassroots medium grade crude oil semi-conversion refineries to increase energy efficiency from specific portions of low grade waste heat sources are described. Configurations and related processing schemes of direct or indirect (or both) inter-plants heating systems synthesized for integrated medium grade crude oil semi-conversion refineries and aromatics complex for increasing energy efficiency from specific portions of low grade waste sources are also described.