A method for using a pressure exchanger to reduce flow as a choke that includes receiving a flow of high pressure fluid at the pressure exchanger, filling a chamber of the pressure exchanger with high pressure fluid, and discharging a portion of the fluid in the chamber at a low pressure.

A system exchanges pressure and heat from a source stream to a sink stream. The system includes a source exchanger and a sink exchanger. The source exchanger includes a first pressure exchanger and a first heat exchanger. The first pressure exchanger converts pressure of the source stream to electrical energy. The first heat exchanger converts temperature from the source stream via a first temperature differential to electrical energy. The sink exchanger includes a second pressure exchanger and a second heat exchanger. The second pressure exchanger uses electrical energy received from the source exchanger to change a pressure of the sink stream. The second heat exchanger uses electrical energy received from the source exchanger to change a temperature of the sink stream. Related apparatus, systems, techniques, and articles are also described.

A system exchanges pressure and heat from a source stream to a sink stream. The system includes a source exchanger and a sink exchanger. The source exchanger includes a first pressure exchanger and a first heat exchanger. The first pressure exchanger converts pressure of the source stream to electrical energy. The first heat exchanger converts temperature from the source stream via a first temperature differential to electrical energy. The sink exchanger includes a second pressure exchanger and a second heat exchanger. The second pressure exchanger uses electrical energy received from the source exchanger to change a pressure of the sink stream. The second heat exchanger uses electrical energy received from the source exchanger to change a temperature of the sink stream. Related apparatus, systems, techniques, and articles are also described.

A rotary liquid piston compressor and a power generation system including a first fluid loop. The first fluid loop includes a pump that circulates a liquid. A second fluid loop that generates power by circulating a supercritical fluid. The second fluid loop includes a turbine that rotates and powers a generator as the supercritical fluid flows through the turbine. A rotary liquid piston compressor fluidly coupled to the first fluid loop and the second fluid loop. The rotary liquid piston compressor exchanges pressure between the liquid circulating in the first fluid loop and the supercritical fluid circulating in the second fluid loop.

A system for reverse osmosis, RO, including a first RO stage (10) with a first feed inlet (11), a first brine outlet (12), and a first permeate outlet (13); a second RO stage (20) with a second feed inlet (21), a second brine outlet (22), and a second permeate outlet (23); and a pressure exchanger, PE, (40) connected between the second brine outlet (22) and the first feed inlet (11), wherein a first pressure difference ?p.sub.1 between the first brine outlet (12) and the second feed inlet (21) corresponds to a second pressure difference ?p.sub.2 between the second brine outlet (22) and the pressure exchanger (40). The invention further discloses a method for operating such a system for reverse osmosis (100).

Energy storage and retrieval systems are disclosed, along with methods of storing and retrieving the energy. The systems include an energy storage system and a trilateral cycle. The energy storage system includes low- and high-temperature energy storage tanks storing one or more energy storage media that exchange heat with a working fluid in both a gradient heat exchanger and a substantially isothermal heat exchanger in the trilateral cycle. Pressure changing devices transport the energy storage medium/media between the storage tanks and through the heat exchangers. The working fluid rejects heat to the energy storage medium and drives a turbine when the system is charging, and the energy storage medium rejects heat to the working fluid when the system is discharging. In some embodiments, the energy storage medium drives a second turbine when the system is discharging.

Energy storage and retrieval systems are disclosed, along with methods of storing and retrieving the energy. The systems include an energy storage system and a trilateral cycle. The energy storage system includes low- and high-temperature energy storage tanks storing one or more energy storage media that exchange heat with a working fluid in both a gradient heat exchanger and a substantially isothermal heat exchanger in the trilateral cycle. Pressure changing devices transport the energy storage medium/media between the storage tanks and through the heat exchangers. The working fluid rejects heat to the energy storage medium and drives a turbine when the system is charging, and the energy storage medium rejects heat to the working fluid when the system is discharging. In some embodiments, the energy storage medium drives a second turbine when the system is discharging.

A rotary pressure exchanger includes a housing and a rotor mounted within the housing for rotation about an axis of rotation defining an axial direction. The rotor extends from a first rotor end in the axial direction to a second rotor end, a plurality of channels is inside the rotor for transferring pressure from the first fluid to the second fluid, and each channel extends parallel to the axis of rotation. The plurality of channels includes a set of first channels and a set of second channels, and the rotor includes a divider arranged between the first rotor end and the second rotor end for separating the first channels from the second channels, Each first channel extends from the first rotor end in the axial direction to the divider, and each second channel extends from the second rotor end in the axial direction to the divider.

A rotary pressure exchanger includes a housing and a rotor mounted within the housing for rotation about an axis of rotation defining an axial direction. The rotor extends from a first rotor end in the axial direction to a second rotor end, a plurality of channels is inside the rotor for transferring pressure from the first fluid to the second fluid, and each channel extends parallel to the axis of rotation. The plurality of channels includes a set of first channels and a set of second channels, and the rotor includes a divider arranged between the first rotor end and the second rotor end for separating the first channels from the second channels, Each first channel extends from the first rotor end in the axial direction to the divider, and each second channel extends from the second rotor end in the axial direction to the divider.

A pressure exchanger (1) including a housing (2), a drive shaft (3) and a cylinder drum (4) rotatably arranged in the housing (2) is described, the cylinder drum (4) including two front faces and at least one cylinder (5) between the front faces, wherein the housing (2) includes a port flange (7, 8) at each end of the cylinder drum (4) and at least at one end of the cylinder drum (4) a pressure shoe (18) is arranged between the cylinder drum (4) and the port flange of this end. Such a pressure exchanger should be operated in a cost-effective manner. To this end an adjustable stop arrangement (19) is arranged between the pressure shoe (18) and the cylinder drum (4).