Pistons and related methods may be configured to separate fluids and to at least partially prohibit one fluid from traveling to one side of the piston from another side of the piston. Pressure exchange devices and systems may include such pistons.

Pistons and related methods may be configured to separate fluids and to at least partially prohibit one fluid from traveling to one side of the piston from another side of the piston. Pressure exchange devices and systems may include such pistons.

A system includes a hydraulic energy transfer system configured to exchange pressures between a first fluid and a second fluid, wherein the first fluid has a pressure higher than the second fluid. The hydraulic transfer system includes a cylindrical rotor configured to rotate circumferentially about a rotational axis and having a first end face and a second end face disposed opposite each other, a first end cover having a first surface that interfaces with the first end face of the cylindrical rotor, and a hybrid hydrodynamic-hydrostatic bearing system configured to resist axial displacement of the cylindrical rotor.

Lifting device (10) for vertically lifting liquids, where the lifting device (10) comprises: a lifting line arrangement (18) for guiding a liquid from an open lower reservoir (16) to an upper reservoir (14); a lowering line arrangement (20) for guiding the liquid from the upper reservoir (14) to the lower reservoir (16); a pressure converter (12) with an actuating member (36), the pressure converter (12) being configured to convert a liquid pressure in the lowering line arrangement (20) into a liquid pressure in the lifting line arrangement (18) by means of a substantially linear movement of the actuating member (36); and a pump member (38) for pumping the liquid in the lifting line arrangement (18) towards the upper reservoir (14) and/or for pumping the liquid in the lowering line arrangement (20) towards the pressure converter (12).

Lifting device (10) for vertically lifting liquids, where the lifting device (10) comprises: a lifting line arrangement (18) for guiding a liquid from an open lower reservoir (16) to an upper reservoir (14); a lowering line arrangement (20) for guiding the liquid from the upper reservoir (14) to the lower reservoir (16); a pressure converter (12) with an actuating member (36), the pressure converter (12) being configured to convert a liquid pressure in the lowering line arrangement (20) into a liquid pressure in the lifting line arrangement (18) by means of a substantially linear movement of the actuating member (36); and a pump member (38) for pumping the liquid in the lifting line arrangement (18) towards the upper reservoir (14) and/or for pumping the liquid in the lowering line arrangement (20) towards the pressure converter (12).

A heat exchanger generally employs a method for supplying liquid having critical pressure or higher or high pressure in order to suppress boiling. However, gas obtained by a evaporator behind the heat exchanger has relatively low pressure, and therefore supplying the liquid to the heat exchanger requires a system for converting an energy form of the obtained gas into kinetic energy or electrical energy, and increasing the pressure by a mechanical pump. Thus, the complicated system involving an efficiency loss is only solution, and it is difficult to achieve simplification of a system or reduction in the weight of a propellant supply device in a moving body, specifically, a flying object.

A heat exchanger generally employs a method for supplying liquid having critical pressure or higher or high pressure in order to suppress boiling. However, gas obtained by a evaporator behind the heat exchanger has relatively low pressure, and therefore supplying the liquid to the heat exchanger requires a system for converting an energy form of the obtained gas into kinetic energy or electrical energy, and increasing the pressure by a mechanical pump. Thus, the complicated system involving an efficiency loss is only solution, and it is difficult to achieve simplification of a system or reduction in the weight of a propellant supply device in a moving body, specifically, a flying object.

At least one pressure exchange unit with a hollow cylindrical body, a piston sliding in the body, the piston including a piston head separating the interior of the cylindrical body into a downstream chamber and an upstream chamber, the downstream chamber being provided with a device for the admission and discharge of water to be treated, the upstream chamber being provided with a five-way distributor linkage including, for hydraulic balancing, two pressurized liquid supply orifices, two orifices for the evacuation of the liquid and an opening in communication with the upstream chamber.

At least one pressure exchange unit with a hollow cylindrical body, a piston sliding in the body, the piston including a piston head separating the interior of the cylindrical body into a downstream chamber and an upstream chamber, the downstream chamber being provided with a device for the admission and discharge of water to be treated, the upstream chamber being provided with a five-way distributor linkage including, for hydraulic balancing, two pressurized liquid supply orifices, two orifices for the evacuation of the liquid and an opening in communication with the upstream chamber.

Apparatus and methods for utilizing pressure exchangers as a source of pressure oscillations. An example method includes operating a plurality of pressure exchangers to pressurize a stream of fluid, injecting the pressurized stream of fluid into a wellbore extending into a sub-terranean formation, and controlling rotational speed and rotational position of a rotor of each of the pressure exchangers to control amplitude and/or frequency of pressure oscillations within the pressurized stream of fluid being injected into the wellbore.