Patent Description:
Well completion in the oil and gas industry often involves hydraulic fracturing (often referred to as fracking or fracing) to increase the release of oil and gas in rock formations to provide an oil or gas well. Hydraulic fracturing involves pumping a fluid (e.g., frac fluid) containing a combination of water, chemicals, and proppant (e.g., sand, ceramics) into a well at high pressures. The high pressures of the fluid increases crack size and crack propagation through the rock formation to release oil and gas, while the proppant prevents the cracks from closing once the fluid is depressurized. Hydraulic fracturing operations use high-pressure pumps to increase the pressure of the frac fluid. Unfortunately, the proppant in the frac fluid may interfere with the operation of the rotating equipment. In certain circumstances, the solids may slow or prevent the rotating components from rotating.

<CIT> discloses a pressure exchange apparatus for exchanging pressures comprising a rotating body having a plurality of first flow paths and second flow paths disposed around a rotation axis so as to penetrate in the rotation axis direction.

<CIT> discloses a system including a rotary isobaric pressure exchanger (IPX) configured to exchange pressures between a first fluid and second fluid. The rotary IPX includes a first end cover including a first fluid aperture configured to route the first fluid. The rotary IPX also includes a first piston integral with the first end cover. The first piston <NUM> includes a first hydraulic path configured to route the first fluid to or from the first fluid aperture.

<CIT> shows a pressure exchanger transferring pressure energy from a liquid in a first liquid system to a liquid in a second liquid system, having a housing with inlet and outlet connection openings for each liquid and a rotor arranged in the housing for rotation about a longitudinal axis.

The invention is defined in the independent claim.

The present disclosure is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like references indicate similar elements. It should be noted that different references to "an" or "one" embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.

Embodiments described herein are related to a motorized hydraulic energy transfer system.

Many industrial processes operate at an elevated pressure and have high-pressure waste streams. One way of providing a high pressure to operations requiring elevated pressure is to transfer pressure from a high-pressure fluid (e.g., high-pressure waste fluid) to a usable fluid for the high-pressure operations (e.g., frac fluid). A particular efficient type of pressure exchange is a rotary pressure exchanger. A rotary pressure exchanger uses a cylindrical rotor with longitudinal channels aligned parallel to the rotational axis. The rotor spins inside a sleeve enclosed by two end covers. Pressure energy is transferred directly from the high-pressure stream to the low-pressure stream in the channels of the rotor. Some fluid that remains in the channels serves as a barrier that inhibits mixing between the streams. The channels of the rotor charge and discharge as the pressure transfer process repeats itself.

High-pressure fluid entering a pressure exchanger causes components (e.g., seals) of the pressure exchanger to be under high pressure. Conventional pressure exchangers are limited in amount of pressure that can be transferred between fluids. In some conventional pressure exchangers, the seals limit the amount of pressure that can be transferred (e.g., high-pressure fluid cannot have a pressure higher than the seals can support). In some conventional pressure exchangers, one or more additional components (e.g., pressure compensators, canned motors, etc.) are used to help compensate for the seals. The manufacturing of the additional parts and coupling of the additional components to the pressure exchangers is an additional cost, an additional component that can fail, and are not readily available.

The devices and systems disclosed herein provide a hydraulic energy transfer system (e.g., rotary isobaric pressure exchanger (IPX)) that is capable of operating with high-pressure incoming fluid (e.g., upwards of <NUM> kilo pounds per square inch (ksi), or up to a pressure of an incoming fluid) while maintaining a centerbore under low pressure (e.g., under <NUM> pounds per square inch (psi) or as low as an outgoing fluid). The hydraulic energy transfer system includes a low-pressure port designed to receive a first fluid under a first pressure. The hydraulic energy transfer system includes a rotor fluidly coupled to (e.g., in a flow path of) the low-pressure port. The rotor forms a set of rotating longitudinal channels designed to receive and exchange pressure between the first fluid and a second fluid. The hydraulic energy transfer system may further include a shaft routed through a centerbore formed by the hydraulic energy transfer system. The shaft may be attached to the rotor. The hydraulic energy transfer system may form a low-pressure passageway from the low-pressure port to an opening of one of the channels in the set of channels of the rotor. The hydraulic energy transfer system may further form a fluid passageway from the low-pressure passageway to the centerbore. The fluid passageway may result in the centerbore and shaft being under a low pressure (e.g., lower than the pressure of the first incoming fluid at a high pressure).

The hydraulic energy transfer system (e.g., rotary IPX) may include an assembly (e.g., cartridge assembly) having a first seal plate that forms a first hydraulic chamber (e.g., hydraulic chamber structure) to receive a first fluid under a first pressure. The assembly may further include a first end cover connected to the first seal plate, the first end cover forming a first set of apertures configured to direct flow of the first fluid from the first hydraulic chamber into a first side of a rotor via the first set of apertures. The assembly may further include a rotor connected to the first end cover, the rotor may form a set of rotating longitudinal channels to receive the first fluid on a side of the rotor from the first end cover, receive a second fluid on a second side of the rotor, and exchange pressure between the first fluid and the second fluid. The assembly may further include a shaft routed through a centerbore formed by the assembly. The shaft may be attached to the rotor. The assembly may form a fluid passageway from the first hydraulic chamber to the centerbore. A first pressure of the first hydraulic chamber may be communicated to the centerbore formed by the first seal plate, the first end cover, and the rotor via the fluid passageway. This first pressure may be a low pressure (e.g., <NUM> psi) resulting in the centerbore being held at the low pressure while the rotor is in operation.

The devices and systems disclosed herein have advantages over conventional solutions. The hydraulic energy transfer system may have a low-pressure centerbore (e.g., under <NUM> psi, or substantially equivalent to a low-pressure fluid entering the system) within a rotary IPX operating with an incoming high-pressure fluid (e.g., <NUM> ksi or substantially equivalent to an incoming high-pressure fluid). The low-pressure centerbore allows for the use of an easily sourced, compact, and reliable shaft seal without requiring custom manufacturing or designing conventional pressure compensators and/or canned motor systems combinations. The low-pressure centerbore may allow for a wider variety of shaft seals and/or motor systems capable of coupling to the rotary IPX, such as seal and motor system designed for various operations and functionality. The low-pressure centerbore may also allow for instrumentation through the low-pressure centerbore that may not be possible in a high-pressure centerbore. This may include taking real time measurements within the rotary IPX. For example, diagnostic measurements may be performed while the rotary IPX is in operation.

<FIG> illustrates a schematic diagram of a fluid handling system <NUM> including a hydraulic energy transfer system <NUM> (e.g., rotary IPX) and a motor system <NUM>, according to certain embodiments. The fluid handling system <NUM> (e.g., a frac system or hydraulic fracturing system) includes a hydraulic energy transfer system <NUM>, a motor system <NUM> coupled to the hydraulic energy transfer system <NUM>, first fluid pumps <NUM>, and second fluid pumps <NUM>. The hydraulic energy transfer system <NUM> transfers work and/or pressure between a first fluid (e.g., a pressure exchange fluid, such as a proppant-free fluid) and a second fluid (e.g., frac fluid, such as a proppant-laden fluid). The first fluid may include low-pressure (LP) proppant free fluid out <NUM> that is directed from the hydraulic energy transfer system <NUM> and high-pressure (HP) proppant free fluid in <NUM> that is directed from first fluid pumps <NUM> to the hydraulic energy transfer system <NUM>. The second fluid may include low-pressure (LP) frac fluid in <NUM> that is directed toward the hydraulic energy transfer system <NUM> and high-pressure (HP) frac fluid out <NUM> that is directed from the hydraulic energy transfer system <NUM> to a frac site (e.g., rock formation <NUM>). These fluids may be multi-phase fluids such as gas/liquid flows, gas/solid particulate flow, liquid/solid particulate flows, gas/liquid/solid particulate flows, or any other multi-phase flow. For example, the multi-phase fluids may also be non-Newtonian fluids (e.g., shear thinning fluid), highly viscous fluids, non-Newtonian fluids containing proppant, or highly viscous fluids containing proppant. Further, the first fluid may be at a pressure between approximately <NUM>,<NUM> kPa to <NUM>,<NUM> kPa, <NUM>,<NUM> kPa to <NUM>,<NUM> kPa, <NUM>,<NUM> kPa to <NUM>,<NUM> kPa, <NUM>,<NUM> kPa to <NUM>,<NUM> kPa, and/or greater than a second pressure of the second fluid. The hydraulic energy transfer system <NUM> may or may not completely equalize pressure between the first and second fluids. Accordingly, the hydraulic energy transfer system <NUM> may operate isobarically, or substantially isobarically.

The hydraulic energy transfer system <NUM> may also be described as a hydraulic protection system, a hydraulic buffer system, or a hydraulic isolation system, because the hydraulic energy transfer system <NUM> may block or limit contact between a frac fluid and various hydraulic fracturing equipment (e.g., high-pressure pumps, second fluid pumps <NUM>), while still exchanging work and/or pressure between the first and second fluids. By blocking or limiting contact between various pieces of hydraulic fracturing equipment and the second fluid (e.g., proppant containing fluid). Moreover, the hydraulic energy transfer system <NUM> may enable the hydraulic fracturing system, for example, high-pressure pumps that are not designed for abrasive fluids (e.g., frac fluids and/or corrosive fluids). In some embodiments, the hydraulic energy transfer system may be a rotating isobaric pressure exchanger (e.g., rotary IPX). Rotating isobaric pressure exchangers may be generally defined as devices that transfer fluid pressure between a high-pressure inlet stream and a low-pressure inlet stream at efficiencies in excess of approximately <NUM>%, <NUM>%, <NUM>%, <NUM>%, or <NUM>% without utilizing centrifugal technology. Centrifugal technology may include a device spinning a fluid at a high speed to separate fluids of different densities. The fluids are forced outward from a radial direction about a central rotating axis. The notation of "first" fluid and "second" fluid is merely exemplary and not used to identify or limit each fluid to any specified limitation herein.

In some embodiments, the hydraulic energy transfer system <NUM> may include or be a part of a refrigeration system (e.g. trans-critical carbon dioxide refrigeration system) that uses a fluid in a supercritical state. For example, the first and/or second fluid may include a refrigerant (e.g. carbon dioxide).

To facilitate rotation, the hydraulic energy transfer system <NUM> may couple to a motor system <NUM> (e.g., an out-board motor system) or may include a motor system <NUM> within a casing of the hydraulic energy transfer system (e.g., an in-board motor system). For example, the motor system may include an electric motor, a hydraulic motor, a pneumatic motor, another rotary drive, or any combination thereof. In operation, the motor system <NUM> enables the hydraulic energy transfer system <NUM> to rotate with highly viscous and/or fluids that have solid particles, powders, debris, etc. For example, the motor system <NUM> may facilitate startup with highly viscous or particulate-laden fluids, which enables a rapid start of the hydraulic energy transfer system <NUM>. The motor system <NUM> may also provide additional force that enables the hydraulic energy transfer system <NUM> to grind through particulate to maintain a proper operating speed (e.g., rpm) with a highly viscous/particulate-laden fluid. Additionally, the motor system <NUM> may also substantially extend the operating range of the hydraulic energy transfer system <NUM>. For example, the motor system <NUM> may enable the hydraulic energy transfer system <NUM> to operate with good performance at lower or higher flow rates than a "free-wheeling" hydraulic energy transfer system without a motor system, because the motor system <NUM> may facilitate control of the speed (e.g., rotating speed) of the hydraulic energy transfer system <NUM> and control of the degree of mixing between the first and second fluids. For example, during well completion operations the fluid handling system <NUM> pumps a pressurized particulate-laden fluid that increases the release of oil and gas in rock formations <NUM> by propagating and increasing the size of cracks <NUM>. In order to block the cracks <NUM> from closing once the fluid handling system <NUM> depressurizes, the fluid handling system <NUM> uses fluids that have solid particles, powders, debris, etc. that enter and keep the cracks <NUM> open.

In order to pump this particulate-laden fluid into the well, the fluid handling system <NUM> may include one or more first fluid pumps <NUM> and one or more second fluid pumps <NUM> coupled to the hydraulic energy transfer system <NUM>. For example, the hydraulic energy transfer system <NUM> may be a rotary IPX. In operation, the hydraulic energy transfer system <NUM> transfers pressures without any substantial mixing between a first fluid (e.g., proppant free fluid) pumped by the first fluid pumps <NUM> and a second fluid (e.g., proppant containing fluid or frac fluid) pumped by the second fluid pumps <NUM>. In this manner, the hydraulic energy transfer system <NUM> blocks or limits wear on the first fluid pumps <NUM> (e.g., high-pressure pumps), while enabling the fluid handling system <NUM> to pump a high-pressure frac fluid into the well (e.g., rock formation <NUM>) to release oil and gas. In order to operate in corrosive and abrasive environments, the hydraulic energy transfer system <NUM> may be made from materials resistant to corrosive and abrasive substances in either the first and second fluids. For example, the hydraulic energy transfer system <NUM> may be made out of ceramics (e.g., alumina, cermets such as carbide, oxide, nitride, or boride hard phases, etc.) within a metal matrix (e.g., Co, Cr or Ni or any combination thereof) such as tungsten carbide in a matrix of CoCr, Ni, NiCr or Co.

The hydraulic energy transfer system <NUM> may include a low-pressure port designed to receive a first fluid under a first pressure. The hydraulic energy transfer system <NUM> may further include a rotor (e.g., rotor <NUM> of <FIG>) fluidly coupled to (e.g., in a flow path of the low-pressure port). The hydraulic energy transfer system <NUM> may further include a shaft (e.g., shaft <NUM> of <FIG>) routed through a centerbore formed by the hydraulic energy transfer system <NUM>. The shaft may be attached to the rotor. The hydraulic energy transfer system <NUM> may form a low-pressure passageway from the low-pressure port to the rotor. The hydraulic energy transfer system <NUM> may further form a fluid passageway from the low-pressure passageway to the centerbore. The fluid passageway may result in the centerbore and shaft being under a low pressure (e.g., lower than the pressure of the first incoming fluid at a high pressure).

<FIG> illustrates a perspective view of a hydraulic energy transfer system <NUM> (e.g., rotary IPX), according to certain embodiments. Some elements of <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. The hydraulic energy transfer system <NUM> may include a rotor enclosed by a center vessel <NUM>. The center vessel <NUM> may be coupled to (e.g., connected, adhered to, or in contact with) housing 210A and housing 210B by seals. The hydraulic energy transfer system <NUM> may further include ports 204A-D and a motor system <NUM>.

As shown in <FIG>, the hydraulic energy transfer system <NUM> may include ports 204A-D. In some embodiments, a first pair of ports 204A-B is disposed on a first side of the hydraulic energy transfer system <NUM>, and a second pair of ports 204C-D is disposed on a second side of the hydraulic energy transfer system. In some embodiments, the first fluid (e.g., proppant free fluid) and/or second fluid (e.g., proppant containing fluid or frac fluid) is received and outputted on the same side of the hydraulic energy transfer system <NUM>. For example, port 204B may receive a first fluid and port 204A may output the first fluid. Port 204C may input a second fluid and port 204D may output the second fluid. In some embodiments, a high-pressure first fluid enters a port (e.g., ports 204A-B) on a first side of the hydraulic energy transfer system <NUM> and transfers pressure to a second fluid that enter a port (e.g., ports 204C-D) on a second side of the hydraulic energy transfer system <NUM>. The high-pressure second fluid may be outputted by a port (e.g., ports 204C-D) on a second side of the hydraulic energy transfer system <NUM>. It should be noted the role of each port 204A-D may be interchangeable based on the desired flow path of the first and second fluid.

In some embodiments, ports 204A-B may be integrated into housing 210A and ports 204C-D are integrated into housing 210B. Pressures from the first and second fluid enclosed by the hydraulic energy transfer system <NUM> may be applied to the housing. For example, the housing may experience a compression force resulting from the pressurized first fluid and pressurized second fluid entering and exiting ports 204A-D.

As shown in <FIG> the housing 210A-B is coupled to the center vessel <NUM> through seals. The seals may include a fluid seal (e.g., piston seals, rod seals, wiper seals, wear rings, clamps, gaskets, and the like) that prevent the first and second fluid from flowing through a contact surface disposed between the housing 210A-B and the center vessel <NUM>. In some embodiments, the center vessel <NUM> is selectively coupled to the housing 210A-B such that the center vessel <NUM> can easily be removed, replaced, repaired, and/or reinstalled.

As shown in <FIG> the motor system <NUM> is coupled to the housing 210A. As discussed further in other embodiments, the motor system <NUM> facilitates operation of a rotor enclosed by center vessel <NUM> by providing torque for grinding through particulate, maintaining the operating speed of the rotor, controlling the mixing of fluids within the hydraulic energy transfer system <NUM> (e.g., changing the rotating speed of a rotor enclosed within the center vessel <NUM>), or starting the rotor with highly viscous or particulate-laden fluids.

In some embodiments, one of ports 204A-D may be a low-pressure port designed to receive a first fluid under a first pressure. The hydraulic energy transfer system <NUM> may further include a rotor (e.g., disposed within center vessel <NUM>) fluidly coupled to (e.g., in a flow path of the low-pressure port). The hydraulic energy transfer system <NUM> may further include a shaft (e.g., shaft <NUM> of <FIG>) routed through a centerbore formed by the hydraulic energy transfer system <NUM>. The shaft may be attached to the rotor. The hydraulic energy transfer system <NUM> may form a low-pressure passageway from the low-pressure port to the rotor. The hydraulic energy transfer system <NUM> may further form a fluid passageway from the low-pressure passageway to the centerbore. The fluid passageway may result in the centerbore and shaft being under a low pressure (e.g., lower than the pressure of the first incoming fluid at a high pressure).

In the some embodiments, the hydraulic energy transfer system <NUM> may be a frac system. However, it should be appreciated that the hydraulic energy transfer system <NUM> may be any suitable system capable of handling an abrasive (e.g., particulate-laden) fluid. For example, the hydraulic energy transfer system <NUM> may be configured for water injection, for well recovery, and fluid transportation using the hydraulic energy transfer system <NUM> as a pump. In embodiments in which the fluid handling system is a frac system, the frac system pumps a pressurized particulate-laden fluid that increases the release of oil and gas in rock formations by propagating and increasing the size of cracks.

<FIG> illustrates a cross-sectional view of a hydraulic energy transfer system <NUM> (e.g., hydraulic energy transfer system <NUM> of <FIG>, hydraulic energy transfer system <NUM> of <FIG>, etc.), according to certain embodiments. Some elements of <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. The hydraulic energy transfer system <NUM> may include a motor system <NUM> coupled to a housing endcap 312A through shaft <NUM>. The shaft <NUM> may be disposed in a centerbore formed by the hydraulic energy transfer system <NUM>. The centerbore (depicted in <FIG> with shaft <NUM> enclosed) may include a shaft seal <NUM> that seals fluid from a motor side of the centerbore and fluid from the rotor side of the centerbore from interacting and/or mixing. The hydraulic energy transfer system includes a housing endcap 312A that integrates ports 204A-B and housing endcap 312B that integrates ports 204C-D. The hydraulic energy transfer system may further include a center vessel <NUM> disposed between the housing endcaps 312A-B. The center vessel <NUM> may enclose a cartridge assembly <NUM>. In some embodiments, housing endcaps 312A-B are integrated together to form a single casing that encloses the cartridge assembly <NUM>, Alternatively or additionally, the housing endcaps 312A-B may be integrated with the center vessel <NUM> (e.g. to completely enclose the cartridge assembly).

As shown in <FIG>, the hydraulic energy transfer system <NUM> may include one or more adapter plates 362A-B. The one or more adapter plates 362A-B may be coupled to (e.g., connected, adhered to, or in contact with) the one or more housing endcaps 312A-B. For example, the adapter plates 362A-B and the housing endcaps 312A-B may be coupled together with fasteners, adhesives, or other adhering techniques known in the art (e.g., welding, brazing, riveting, etc.) Alternatively, the adapter plates 362A-B may be integrated with housing endcaps 312A-B. The one or more adapter plates 362A-B may include recesses or bores configured to receive the cartridge assembly <NUM>. For example, the cartridge assembly may include one or more pistons (e.g., piston <NUM>) that permit axial movement of the cartridge assembly <NUM> relative to the housing endcaps 312A-B within the center vessel <NUM>.

As shown in <FIG>, and as will be discussed in greater detail in association with other figures, the hydraulic energy transfer system <NUM> includes a cartridge assembly <NUM>. The cartridge assembly <NUM> may include piston <NUM>. In some embodiments, the hydraulic energy transfer system <NUM> may include more pistons beyond piston <NUM>. Piston <NUM> may be coupled to one or more seal plates 314A-B. For example, piston <NUM> may be coupled to, incorporated with, or integrated into seal plate 314A. The seal plate 314A may be coupled to end cover 316A. End cover 316A may be coupled to a sleeve <NUM>. Sleeve <NUM> may be coupled to end cover 316B. The end cover 316B may be coupled to seal plate 314B. The sleeve <NUM> may enclose a rotor <NUM>. In some embodiments, the cartridge assembly <NUM> is adapted to receive a first fluid from ports 204A-B (e.g. a high-pressure first fluid may enter through port 204A and a low-pressure first fluid may exit through port 204B) and a second fluid from ports 204C-D (e.g. a low-pressure second fluid may enter through port 204D and a high-pressure second fluid may exit through 204B). The cartridge assembly is further to transfer pressure from one of a high-pressure first fluid to a low-pressure second fluid or a high-pressure second fluid to a low-pressure first fluid. It should be noted, the flow path of high-pressure fluid and low low-pressure fluid as well as the first fluid and the second fluid can be generalized to any port 204A-D and any hydraulic chamber 326A-B and not limited to a specific flow path identified herein. It should also be noted, that the use of "first" and "second" is exemplary, and the limitations described for the first fluid could apply to the second fluid.

In some embodiments, the hydraulic energy transfer system <NUM> includes piston <NUM>. The piston may be coupled to adapter plates 362A-B and/or seal plate 314A-B. The piston may be adapted to permit axial movement of the cartridge assembly relative to the adapter plate 362A and/or 362B while maintaining a seal between the cartridge assembly <NUM> and adapter plate 362A-B. For example, the piston <NUM> may axially move towards or away from the adapter plate 362A-B to increase a compression force on the cartridge assembly <NUM> and laterally shift the cartridge assembly <NUM> between housing endcaps 312A-B.

As shown in <FIG>, the hydraulic energy transfer system <NUM> forms a passageway <NUM> (e.g., low-pressure passageway). Passageway <NUM> may be disposed between port 204B and seal plate 314A. For example passageway <NUM> may transfer fluid from port 204B to hydraulic chamber 326A. In another example, the passageway <NUM> may transfer fluid from hydraulic chamber 326A to port 204B. In some embodiments, the passageway <NUM> transfers fluid of a high pressure (e.g., pressure of the highest pressure fluid entering the system) or fluid of a low pressure (e.g., pressure of the lowest pressure fluid entering the system).

As shown in <FIG>, the hydraulic energy transfer system <NUM> forms a fluid passageway <NUM> disposed between passageway <NUM> and the centerbore <NUM>). For example, the fluid passageway <NUM> may allow fluid to pass between passageway <NUM> and the centerbore <NUM> (e.g. on the rotor side of shaft seal <NUM> or on the motor side of shaft seal <NUM>). Fluid passageway <NUM> may be formed by one or more of housing endcaps 312A-B, piston <NUM>, seal plates 314A-B, end covers 316A-B, and/or rotor <NUM>. Fluid passageway <NUM> allows fluid to flow between passageway <NUM> and the centerbore <NUM> (e.g. on the rotor side of shaft seal <NUM> or on the motor side of shaft seal <NUM>). Fluid passageway <NUM> may be disposed between one of ports 204A-D and the rotor <NUM>. In some embodiments, the pressure of a fluid disposed within fluid passageway <NUM> is communicated to the shaft and flows through apertures in seal plate 314A, end cover 316A, and/or rotor <NUM>. In some embodiments, fluid passageway <NUM> is formed between a centerbore <NUM> formed by the system and piston <NUM>, the port 204B, and/or passageway <NUM>. The centerbore <NUM> may include a channel formed through one or more components of the hydraulic energy transfer system <NUM>. The centerbore <NUM> may include substantially the same diameter. The center may be designed to receive a shaft <NUM>. There may be a gap between the shaft <NUM> and the surface of the centerbore <NUM>. For example, the shaft <NUM> may be designed to rotate and the centerbore <NUM> may provide sufficient space to eliminate contact between the shaft <NUM> and the surface of the centerbore <NUM>.

As shown in <FIG>, the hydraulic energy transfer system <NUM> includes a motor system <NUM>. As illustrated, the motor system <NUM> includes a shaft <NUM> that couples to the rotor <NUM> through a housing endcap 312A. Specifically, the shaft <NUM> may be routed through an aperture in the housing endcap 312A, an aperture in the seal plate 314A, an aperture in the end cover 316A, and into an aperture of the rotor <NUM>. Apertures formed by one or more of housing endcap 312A, the seal plate 314A, the end cover 316A, rotor <NUM>, end cover 316B, seal plate 314B and/or housing endcap 312B may form a centerbore <NUM> of the system. The seal plate 314A and the end cover 316A may form corresponding portions of a centerbore <NUM> formed by the hydraulic energy transfer system <NUM>. To facilitate rotation of the shaft <NUM>, the motor system <NUM> may also include one or more bearings 320A-B that support the shaft <NUM>. The bearings 320A may be disposed within or external to the housing endcap 312A-B. In some embodiments, the shaft <NUM> may extend completely through the rotor <NUM> and the end cover 316B. This may enable the shaft <NUM> to be supported by the end cover 316B and/or seal plate 314B on opposite sides of the rotor <NUM>.

In operation, the motor system <NUM> facilitates operation of the rotor <NUM> by providing torque for grinding through particulate, maintaining the operating speed of the rotor <NUM>, controlling the mixing of fluids within the hydraulic energy transfer system <NUM> (e.g., changing the rotating speed of the rotor <NUM>), and/or starting the rotor <NUM> with highly viscous or particulate-laden fluids. The motor may be coupled to a controller (not illustrated) that uses feedback from sensor to control the motor system. The controller may include a processor and a memory (not illustrated) that stores non-transitory computer instructions executable by a processor. For example, as the controller receives feedback from one or more sensor, the processor executes instructions stored in the memory to control power output from the motor system.

In some embodiments, a controller using sensor feedback may control the extent of mixing between the first and second fluids in the hydraulic energy transfer system <NUM> which may be used to improve overall operability. For example, varying the proportions of the first and second fluids entering the hydraulic energy transfer system <NUM> allows an operator to control the amount of fluid mixing occurring within the system. Three possible characteristics of rotary IPX that affect mixing are: (<NUM>) the aspect ratio of the rotor channels <NUM> (<NUM>) the short duration of exposure between the first and second fluids, and (<NUM>) the creation of a fluid barrier (e.g., an interface) between the first and second fluids within the rotor channels <NUM>. First, the rotor channels <NUM> are generally long and narrow, which stabilizes the flow within the rotary IPX. In addition the first and second fluids may move through the channels <NUM> in a plug flow regime with minimal axial mixing. Second, in certain embodiments, the speed of the rotor <NUM> reduces contact between the first and second fluids. For example, the speed of the rotor <NUM> may reduce contact times between the first and second fluids to less than approximately <NUM> seconds, <NUM> seconds, or <NUM> seconds. Third, a small portion of the rotor channel <NUM> is used for the exchange of pressure between the first and second fluids. A volume of fluid may remain in the channel <NUM> as a barrier between the first and second fluids. All these mechanisms may limit mixing within the cartridge assembly <NUM> Moreover, in some embodiments, the cartridge assembly <NUM> may be designed to operate with one or more internal pistons that isolate the first and second fluids while enabling pressure transfer.

<FIG> illustrates a perspective view of a cartridge assembly <NUM> of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM>-<NUM> of <FIG> or a rotary IPX), according to certain embodiments. Some elements of <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. The cartridge assembly <NUM> transfers pressure and/or work between first and second fluids (e.g., proppant free fluid and proppant laden fluid) with minimal mixing of the fluids. In some embodiments the cartridge assembly <NUM> is a selectively removable element of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM>-<NUM> of <FIG>).

As shown in <FIG>, the cartridge assembly may have a cylindrical body including a rotor sleeve <NUM>, a pair of end covers 404A-B, and a pair of seal plates 406A-B. The cartridge assembly <NUM> may include a rotor sleeve <NUM>. The rotor sleeve <NUM> includes a generally cylindrical structure. In some embodiments, the rotor sleeve <NUM> may include divots or inlets disposed along the circumference of the cylindrical structure to receive securing devices (e.g., compression rods 430A-C). The rotor sleeve <NUM> may enclose a rotor device (e.g., rotor <NUM> of <FIG>). The rotor sleeve <NUM> may contact at a first side a first end cover 404A and contact at a second side a second end cover 404B. The end cover may include a cylindrical structure. In some embodiments, the diameters of the end covers 404A-B are substantially equal to the diameter of the rotor sleeve <NUM>. The rotor sleeve <NUM> may include one or more substantially flat surfaces to contact the end covers 404A-B. For example, the rotor sleeve may be coupled to and held together by a friction fit at the contact surface between the rotor sleeve <NUM> and the end covers 404A-B. The contact surfaces between the rotor sleeve <NUM> and the end covers 404A-B may include a coating or abrasive texture that promotes friction between the rotor sleeve <NUM> and the end covers 404A-B The contact surface between the rotor sleeve and the end covers may form a seal to prevent the first and second fluid from exiting the cartridge assembly between the rotor sleeve <NUM> and the end covers 404A-B. In some embodiments, the rotor sleeve <NUM> and the end covers 404A-B may be coupled together with fasteners, adhesives, or other adhering techniques known in the art (e.g., welding, brazing, riveting, etc.) In some embodiments a contact surface between the seal plates 406A-B and end covers 404A-B as well as a contact surface between the end covers and a housing (e.g. adapter plates 362A-B or housing endcaps 312A-B of <FIG>).

In some embodiments, the end covers 404A-B are configured to or adapted to direct flow of a first fluid and a second fluid in and out of a rotor enclosed by the rotor sleeve <NUM>. As will be discussed further, the end covers 404A-B may each include a surface that is adapted to couple with the rotor enclosed by rotor sleeve <NUM>. The end covers may have a cylindrical shape (e.g., similar to the rotor sleeve). The end covers 404A-B are coupled to seal plates 406A-B. The coupling of the end covers 404A-B and the seal plates 406A-B may include similar coupling techniques disclosed regarding the coupling between the rotor sleeve <NUM> and the end covers 404A. Additionally, the seal plates 406A-B may form a seal between the end covers 404A-B and the seal plates 406A-B. The seal plates 406A-B may also include a cylindrical structure.

As shown in <FIG>, the cartridge assembly <NUM> may include one or more seals <NUM> (e.g., face seals, cartridge seals, radial shaft seals, O-rings, etc.) that are disposed on one or more of the ends of the cartridge assembly. The one or more seals <NUM> may couple or connect the cartridge assembly <NUM> to a casing (e.g., housing) of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM>-<NUM> of <FIG>). In some embodiments, one or more seals <NUM> may couple the cartridge assembly <NUM> to the housing of the hydraulic energy transfer system using a friction fit. For example, the pressure of the first and second fluid may apply a force (e.g., a compression force) on the housing of the hydraulic energy transfer system and/or the cartridge assembly to create a friction interface between the hydraulic energy transfer system and the cartridge assembly that generates a seal and holds the cartridge assembly <NUM> in place. For example, the pressurized first fluid and the pressurized second fluid may result in compression forces directed toward the longitudinal center of the cartridge assembly <NUM>.

In some embodiments, cartridge assembly <NUM> is designed to generate a net force in a longitudinal direction of the assembly. For example, the cartridge assembly <NUM> may include a first side, depicted in <FIG> proximate seal plate 406A, and a second side depicted proximate seal plate 406B. The compression forces may be adapted to provide a net force directed towards the first side or the second side of the cartridge assembly. This may result in the seal plate 406A, end cover 404A, rotor sleeve <NUM>, end cover 404B, and/or seal plate 406B being under a force from a neighboring element such that each element compresses and forms a seal with each adjacent element. For example, the seal plate <NUM> may form a seal against the end cover due to this net force. In some embodiments, the net force created across the cartridge assembly <NUM> results in a friction fit between the elements (e.g., seal plate 406A, end cover 404A, rotor sleeve <NUM>, end cover 404B, and seal plate 406B. ) For example, each of these elements may be held in place from the friction generated from a net force applied through the cartridge assembly <NUM>. In some embodiments, these elements may be held together using alignment pins.

In some embodiments, the seal plates 406A-B, the end covers 404A-B, and the sleeve is held together by compression forces based on the pressurized fluid flowing through the cartridge assembly <NUM>. In some embodiment, the cartridge assembly <NUM> may include one or more compression rods 430A-C. The compression rods 430A-C may include fasteners that are affixed at one or more ends of the compression rods 430A-C and are coupled to the seal plates 403A-C, the end covers 404A-B, and/or the rotor sleeve <NUM>. The compression rods 430A-C may be adapted to compress the cartridge assembly <NUM> together. For example, a central compression force is applied to the seal plates 406A-B against the end covers 404A-B, and a compression force is applied to the end covers 404A-B against the rotor sleeve <NUM>. In some embodiments, the cartridge assembly is held together with a combination of fluid compression forces and external compression forces (e.g., using compression rods 430A-C). The rotor sleeve <NUM> enables an enclosed rotor to rotate about a central axis while the cartridge assembly <NUM> is compressed together.

In some embodiments, the cartridge assembly <NUM> is enclosed by a fluid disposed in a cavity created between the casing of the hydraulic energy transfer system and the cartridge assembly <NUM>. This fluid may include a fluid bearing comprising a thin layer of rapidly moving pressurized liquid and/or gas between a surface of the cartridge assembly <NUM> and the casing of the hydraulic energy transfer system.

As shown in <FIG>, one or more of the seal plates 406A-B may be piston <NUM> which is disposed on a distal end of a radial surface of a cylindrical protruding structure of the seal plate 406A. As discussed in other embodiments, the seal plates 406A-B include a surface for applying pressure. One or more of pistons <NUM> is configured to axially slide through a coupling point (e.g. a recess or bore of an adapter plate (e.g. adapter plate 362A of <FIG>)) to permit relative movement between the cartridge assembly <NUM> and a casing (e.g., housing endcaps 312A-B of <FIG>) of a hydraulic energy transfer system (e.g., <NUM>-<NUM> hydraulic energy transfer system of <FIG>).

In some embodiments, a seal plate 406A may form a high-pressure hydraulic chamber (e.g., 410B) and a low-pressure hydraulic chamber (e.g., 410A). The high-pressure hydraulic chamber (e.g., 410B) may enclose one of the first fluid or the second fluid at a high pressure (e.g., around <NUM> ksi) while the low-pressure hydraulic chamber (e.g., 410A) may include one of the first fluid or the second fluid at a low-pressure (e.g., <NUM> psi). In some embodiments, the high-pressure hydraulic chamber and the low-pressure hydraulic chamber enclose the same fluid, however in other embodiments, the high-pressure hydraulic chamber may include one of the first fluid or the second fluid and the low-pressure hydraulic chamber may include the one of the first fluid or the second fluid that is not included in the high-pressure hydraulic chamber.

As discussed further in other embodiments, the seals plates 406A-B may be designed such that the pressurized fluids in the hydraulic chamber 410A-B generate a substantially similar force to opposing internal cartridge forces (e.g. to reduce the net force on the end covers 404A-B). Reducing the net on the end cover may reduce the deflections of the bearing surfaces of a rotor disposed within the rotor sleeve <NUM>. It should be noted, as a result of a low-pressure centerbore <NUM> (e.g., provided by the fluid passageway <NUM>), forces can be generated that can alter the seals and contact points between the seal plates 406A-B, end covers 404A-B, and rotor sleeve <NUM>. The seal plates are designed to counter these forces to minimize net force on the end covers 404A-B. The efficiency of the pressure transfer between the first and second fluids may be improved by minimizing the deflections caused net forces (e.g. pressure imbalance) on the end covers 404A-B.

The cartridge assembly <NUM> may further include a centerbore <NUM> and a shaft seal <NUM>. In some embodiments, the shaft seal <NUM> is disposed within the housing (e.g., housing endcap 312A or adapter plate 362A of <FIG>). In some embodiments, the cartridge assembly <NUM> may form a fluid passageway <NUM> (e.g., fluid passageway structure) in hydraulic communication with the shaft and a hydraulic chamber 410A. In other embodiments, the fluid passageway <NUM> may be formed by one or more of housing endcaps 312A-B, piston <NUM>, seal plates 314A-B, end covers 316A-B, and/or rotor <NUM>. Fluid passageway <NUM> allows fluid to flow between hydraulic chamber 410A and centerbore <NUM>. In some embodiments, the pressure of a fluid disposed within fluid passageway <NUM> is communicated to the centerbore <NUM> and flows through apertures in one of the seal plate 406A, end cover end cover 404A, rotor 430C, end cover 404B, and seal plate 406B. In some embodiments, fluid passageway <NUM> is formed between a centerbore <NUM> formed by the cartridge assembly <NUM> and piston <NUM> and/or the hydraulic chamber 410A. The fluid passageway <NUM> communicates pressure from the seal plate (e.g., pressure of the fluid located in one of the hydraulic chambers 410A-B) to the centerbore <NUM> disposed along a central axis of the cartridge assembly <NUM>. The fluid passageway <NUM> may be formed by one of machining or drilling a recess through piston <NUM>, seal plate 406A, end cover 404A, the rotor disposed within the rotor sleeve <NUM>, end cover 404B, seal plate 406B or any combination thereof. In some embodiments the diameter of fluid passageway <NUM> may be within <NUM>-<NUM>.

In some embodiments fluid passageway <NUM> is substantially uniform in diameter. In some embodiments, the diameter of the fluid passageway is smaller than one of a fluid passageway between hydraulic chamber 410A and the rotor disposed within the rotor sleeve <NUM>. In some embodiments, the hydraulic chamber 410A encloses either the first or second fluid and communicates the pressure of the fluid enclosed in the hydraulic chamber to the centerbore <NUM>. For example, the hydraulic chamber 410A may enclose fluid of a low pressure (<NUM> psi). This fluid communicates this low pressure to the centerbore <NUM>. The cartridge assembly may form a centerbore <NUM> that encloses a shaft. The centerbore <NUM> may be routed through seal plate 406A, end cover 404A, and the rotor enclosed within the rotor sleeve <NUM>. The centerbore <NUM> may be adapted to receive one or more components (e.g., motor shaft, crank, rotary attachment, etc.) of a motor system (e.g., motor system <NUM> of <FIG>). The centerbore <NUM> may further include a shaft seal <NUM> that seals and separates a portion of the centerbore <NUM> that is enclosed by the cartridge assembly <NUM> and a portion of the centerbore <NUM> that is disposed external to the cartridge assembly <NUM> (e.g., housing endcap 312A of <FIG>). For example, the shaft seal may hydraulically seal a first region of the centerbore <NUM> proximate the rotor enclosed by the rotor sleeve <NUM> from a second region of the centerbore <NUM> external to the cartridge assembly <NUM>.

In operation, the hydraulic chambers 410A-B enable the first and second fluids (e.g., proppant free fluid) to enter and exit the cartridge assembly. One of hydraulic chambers 410A-B may receive a high-pressure first fluid and after exchanging pressure, the other hydraulic chamber 410A-B may be used to route a low-pressure fluid out of the cartridge assembly <NUM>. The cartridge assembly may also include hydraulic chambers (not shown) on a lower side (proximate shaft seal <NUM>) opposite hydraulic chambers 410A-B. The hydraulic chambers on the lower side may be configured to receive one of the first or second fluids.

<FIG> illustrates an exploded view of a cartridge assembly <NUM> of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM> of <FIG>, hydraulic energy transfer system <NUM>-<NUM> of <FIG>, rotary IPX, etc.), according to certain embodiments. Some elements of <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. The cartridge assembly <NUM> may include a rotor sleeve <NUM> enclosing a rotor <NUM>, end covers 404A-B, and seal plates 406A-B.

The rotor <NUM> may include a cylindrical structure that is adapted to rotate within the rotor sleeve <NUM>. The rotor <NUM> may further include one or more channels <NUM> extending substantially longitudinally through the rotor <NUM> with openings at each end. The channels <NUM> may be arranged symmetrically about a central axis. The openings of the channels <NUM> may be arranged for hydraulic communication between both end covers 404A-B. For example, the rotor <NUM> is designed to rotate and during rotation the channels <NUM> are exposed to a fluid at high-pressure and fluid at low-pressure that are directed to the channels by apertures 506A-D formed by end covers <NUM> A-B. Apertures 506A-D may be in the form of arcs or segments of a circle (e.g., C-shaped).

As shown in <FIG>, the end covers 404A-B may include a flat surface to contact the rotor sleeve <NUM> and another flat surface to contact the seal plates 406A. As described in other embodiments, the end covers 404A, the seal plates 406A-B, and the rotor sleeve <NUM>, may all be coupled with friction fit interfaces. For example, compression forces external to the cartridge assembly <NUM> may hold the end covers 404A, the seal plates 406A-B, the rotor sleeve <NUM>, and the rotor <NUM> in place and maintain a hydraulic seal at each contact point. In some embodiments, the rotor <NUM> rotates on bearing surface created by the rotor sleeve <NUM> and a surface of the end covers 404A-B.

<FIG> illustrates a cross-sectional view of a cartridge assembly <NUM> of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM> of <FIG>, hydraulic energy transfer system <NUM>-<NUM> of <FIG>, a rotary IPX, etc.), according to certain embodiments. Some elements of <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. As shown in <FIG>, the cartridge assembly <NUM> may include a seal plate 406A coupled to an end cover 404A. The end cover 404A may be coupled to a rotor sleeve <NUM> and a rotor <NUM>. The rotor sleeve <NUM> and the rotor <NUM> may be coupled to a second end cover 404B. The second end cover may be coupled to a second seal plate 406B.

As shown in <FIG>, the cartridge assembly <NUM> may include a centerbore <NUM> that is adapted to receive a motor system (e.g., motor shaft, crank, rotary elements, etc.). The cartridge assembly <NUM> may form a centerbore <NUM> routed through the seal plate 406A, the end cover 404A, and the rotor <NUM>. In some embodiments, the system may further form a centerbore <NUM> routed through end cover 404B and seal plate 406B. In a further embodiment the <NUM> may be disposed along a central axis of the cartridge assembly <NUM>. The cartridge assembly may form a centerbore <NUM> that is routed through both ends of the cartridge assembly <NUM> (e.g., above the piston <NUM> and through the hydraulic chamber 410C-D). The centerbore <NUM> may receive a shaft that may be coupled to the rotor with a shaft coupling <NUM>.

In some embodiments, the centerbore <NUM> may form a passage (e.g., hole, slot, clearance, centerbore, etc.) through a seal plate 406A, an end cover 404A, and the rotor <NUM>. This passage may communicate a pressure (e.g., low pressure, <NUM> psi) to a centerbore <NUM> of the rotor <NUM>. In some embodiments, the cartridge assembly <NUM> includes a passage external to the cartridge assembly <NUM> that is in hydraulic communication between the centerbore <NUM> and a low-pressure fluid flow of a first or second fluid disposed external to the cartridge assembly.

In some embodiments, to compensate for the lower pressure distribution on the inside of the cartridge assembly <NUM> due to a low-pressure centerbore <NUM>, a larger low-pressure distribution is on the outside of the cartridge to balance forces (i.e. minimize deflections). In one embodiment, the force balance is adjusted by altering the diameter of piston <NUM>. Piston <NUM> may include plenums 363A-Badapted to counter a force resulting from a low-pressure centerbore <NUM> by applying a compression force generated by a pressurized fluid disposed within hydraulic chamber 410A. For example, there is a low pressure plenum 363A above the piston <NUM>, and a high pressure plenum 323B. By changing the piston <NUM> diameter the relative plenum 363A-B areas changes which can adjust the net force. For example, the size of low pressure plenum 363A may be increased (by increasing piston <NUM> diameter) which corresponds to a decrease high pressure plenum size 363B. In some embodiments, a top seal plate (e.g., seal plate 406A) may set a pressure balance by applying a compression force on the cartridge assembly <NUM>. Seal plate 406A may include two hydraulic chambers 410A-B and a piston <NUM>. The piston <NUM> may include one or more radial seals (e.g., radial O-rings) that seal into one or more receiving bores of a casing (e.g., housing endcaps 312A-B). The seal plate 406A may include one or more face seals to seal the seal plate onto end cover 404A. In some embodiments the seal plate 406A and end cover 404A are used in combination to establish separate sealed flow paths between hydraulic chambers 410A-B (e.g., a high-pressure chamber and a low-pressure chamber) on the cartridge assembly <NUM> to ports on a casing (e.g., housing) of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM>-<NUM> of <FIG>).

In some embodiments, piston <NUM> include a radial seal (e.g., radial O-rings) that maintain pressure-containment of the cartridge assembly <NUM> by axially moving under pressures. In some embodiments, the piston <NUM> allows for relative movement between the casing and the cartridge assembly <NUM>. In some embodiments, the piston <NUM> accommodates variations in cartridge heights. For example, the cartridge height may be variable due to standard machine tolerance and material removal during repair, replacement, resurfacing of the cartridge assembly <NUM> or parts associated of the cartridge assembly <NUM>.

In some embodiments, a bottom seal plate (e.g., seal plate 406B) is omitted. For example, one or more face seals of the seal plate 406B are integrated into the casing and couples to the end cover 404B. For example, a seal created at a contact surface between the casing and end cover 404B may be created by increasing a compression force generated by plenums 363A-B.

<FIG> illustrate seal plates 700A-B of a cartridge assembly (e.g., cartridge assembly <NUM> of <FIG>), according to certain embodiments. Some elements in <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. Seal plate 700A-B may be an upper seal plate (e.g., seal plate 406A of <FIG>) of a hydraulic energy transfer system (e.g., hydraulic energy transfer system <NUM> of <FIG>). <FIG> illustrates a upper surface of a seal plate 700A while <FIG> may show a lower surface of a seal plate 700B. The upper surface of the seal plate may be designed to connect to or contact a housing (e.g., housing endcaps 312A from <FIG>). <FIG> shows a top surface of the seal plate 700A. As shown in <FIG>, the seal plate 700A may include a first surface (e.g., a top surface) that includes one or more hydraulic chambers 410A-B, piston <NUM>, a fluid passageway <NUM>, a centerbore <NUM>, and a shaft seal <NUM>.

In some embodiments, the seal plate 700A forms a centerbore <NUM> routed through a center of seal plate 700A that is adapted to receive a shaft. In other embodiments, the seal plate forms a bore disposed off-center that is adapted to receive the shaft. In some embodiments, the centerbore <NUM> is disposed within a hydraulic chamber 410A or through piston <NUM>. In other embodiments, the centerbore <NUM> is disposed outside the piston <NUM> as not to be routed through piston <NUM>.

In some embodiments, a first hydraulic chamber 410A includes one of the first fluid or the second fluid (e.g., proppant free fluid or proppant laden fluid) having a first pressure and a second hydraulic chamber 410B that includes the first fluid or the second fluid having a second pressure that is greater than the first pressure. For example, both hydraulic chambers 410A-B may include the same fluid but with different pressures.

As discussed previously, hydraulic chambers 410A-B can input and/or output the first and/or second fluids. The hydraulic chambers 410A-B are fluidly coupled to a port on a casing (e.g., housing) of a hydraulic energy transfer system (e.g., hydraulic energy transfer systems <NUM>-<NUM> of <FIG>). For example hydraulic chamber 410A may be an inlet port that transfers fluid into a cartridge assembly and hydraulic chamber 410B may be an outlet port the transfers fluid out of a cartridge assembly.

In some embodiments, the fluid passageway <NUM> (e.g., fluid passageway structure) is in hydraulic communication with the centerbore <NUM> and the seal plate <NUM>. For example, the fluid passageway <NUM> may communicate fluid from one of hydraulic chamber 410A, or piston <NUM> to the centerbore <NUM>. For example, hydraulic chamber 410A may enclose fluid at a low pressure (e.g., <NUM> psi) and communicate this pressure to the centerbore <NUM>. The centerbore <NUM> of the seal plate may communicate this pressure to the centerbore <NUM> of the rotor, resulting in a centerbore <NUM> under a pressure that is less than a pressure of a casing of a hydraulic energy transfer system that may enclose the cartridge assembly (e.g., cartridge assembly <NUM> of <FIG>).

In some embodiments, seals 704A-B are designed to create a hydraulic seal between the seal plates 700A-B and corresponding end covers (e.g., end covers 404A-B of <FIG>). As shown in <FIG>, a second surface (e.g., a bottom surface) of the seal plate 700B may include one or more seals 704A-B. The seals 704A-B may include a shaft seal or a face seal (e.g., O-rings, gaskets, end face mechanical seals, etc.) to couple the second surface of the seal plate 700B to an end cover (e.g., end cover 404A-B of <FIG>). For example, the shape of the face seal may enclose a surface that is to contact an end cover. The enclosed surface may create high-pressure and low-pressure areas that result in forces applied to the end cover due to the pressurized fluid enclosed in seal plate <NUM>. In a further example, seal 704B may create a low-pressure area enclosed by seal 704B and seal 704A may create a high-pressure area enclosed by seal 704A. In some embodiments, the relative size and geometry of the regions created by seals 704A-B may be designed to ensure adequate contact pressure between seal plates 406A-B and their respective adjacent end covers 404A-B to enable proper sealing between the components. In some embodiments, the seal plates 700A-B may form a fluid passageway <NUM> from the centerbore <NUM> to one of hydraulic chambers 410A-B.

<FIG> illustrate end covers 800A-B of a cartridge assembly (e.g., cartridge assembly <NUM> of <FIG>), according to certain embodiments. Some elements in <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. <FIG> show a first surface (e.g., top surface) of the end cover 800A includes one or more apertures 506A-B and a centerbore <NUM>. The top surface may be configured to be coupled to, connected with, or integrated with one of seal plates 700A-B. <FIG> show a second surface (e.g., a bottom surface) of the end cover 800B. The bottom surface may be configured to be coupled to, connect with, or integrate with a rotor.

The one or more apertures 506A-B are formed by the end cover and are adapted to direct fluid flow from a seal plate (e.g., seal plate 406A-B of <FIG>) to and from channels (e.g., channels <NUM> of <FIG>) of a rotor (e.g., rotor <NUM> of <FIG>). In some embodiments, the apertures 506A-B are larger than the openings of the channels (e.g., channels <NUM> of <FIG>). For example, apertures 506A-B may be designed in the form of arcs or segments of a circle (e.g., C-shaped).

<FIG> illustrate end covers 900A-B of a cartridge assembly (e.g., cartridge assembly <NUM> of <FIG>), according to certain embodiments. Some elements in <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. As shown in <FIG>, the end cover 900A may form one or more apertures 506A-B and a centerbore <NUM>. As shown in <FIG>, the end cover 900B may include a centerbore <NUM> and apertures 506A-B. Embodiments and corresponding elements illustrated in <FIG> may include or be similar to features of end cover 800A-B as disclosed in association with <FIG>. In some embodiments, the end covers 900A-B forms one or more fluid passageways. For example, the fluid passageway may be formed from the centerbore <NUM> to an aperture 506A-B.

<FIG> shows a first surface (e.g., top surface) of the end cover 900A including one or more apertures 506A-B. The top surface may be configured to be coupled to, connected with, or integrated with a rotor (e.g., rotor <NUM> of <FIG>). <FIG> shows a second surface (e.g., a bottom surface) of the end cover 900B. The bottom surface may be configured to be coupled to, connect with, or integrated with a seal plate (e.g., seal plates 1000A-B). End cover 900A-B may be a bottom end cover (e.g., end cover 316B of <FIG>) in a hydraulic energy system (e.g., hydraulic energy transfer system <NUM> of <FIG>).

<FIG> illustrate seal plates 1000A-B of a cartridge assembly (e.g., cartridge assembly <NUM> of <FIG>), according to certain embodiments. Some elements in <FIG> may have the same number as other figures, and these elements may be substantially similar to those elements having the same number in other figures. As shown in <FIG>, the seal plate 1000A may include one or more seals 704A-B, one or more hydraulic chambers 410A-B, and a centerbore <NUM>. As shown in <FIG>, the seal plate 1000B may include a centerbore <NUM>, and one or more hydraulic chambers 410A-B. Embodiments and corresponding elements illustrated in <FIG> may include or be similar to features of seal plate 700A-B as disclosed in association with <FIG>. In some embodiments, the seal plate 1000A-B forms one or more fluid passageways. For example, the fluid passageway may be formed from the centerbore <NUM> to one of hydraulic chambers 410A-B.

<FIG> show a first surface (e.g., top surface) of the seal plate 1000A and includes one or more seals 704A-B, hydraulic chambers 410A-B, and a centerbore <NUM>. The top surface may be configured to be coupled to, connected with, or integrated with one of end covers 900A-B. <FIG> shows a second surface (e.g., a bottom surface) of the seal plate 1000B. The bottom surface may be configured to be coupled to, connect with, or integrate with a housing (e.g., housing endcap 312B of <FIG>). Seal plate 1000A-B may be a bottom seal plate (e.g., seal plate 314B of <FIG>) in a hydraulic energy system (e.g., hydraulic energy transfer system <NUM> of <FIG>).

The preceding description sets forth numerous specific details such as examples of specific systems, components, methods, and so forth, in order to provide a good understanding of several embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that at least some embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram format in order to avoid unnecessarily obscuring the present disclosure. Thus, the specific details set forth are merely exemplary. Particular implementations may vary from these exemplary details and still be contemplated to be within the scope of the present disclosure.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. " When the term "about," "substantially," or "approximately" is used herein, this is intended to mean that the nominal value presented is precise within ±<NUM>%.

Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operation may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be in an intermittent and/or alternating manner. In one embodiment, multiple metal bonding operations are performed as a single step.

Claim 1:
A pressure exchanger (<NUM>, <NUM>) comprising:
a rotor (<NUM>) configured to exchange pressure between a first fluid and a second fluid;
a first seal plate (406A) having a first substantially planar seal plate surface and a second substantially planar seal plate surface disposed opposite the first substantially planar seal plate surface,
wherein a piston (<NUM>) extends from the first substantially planar seal plate surface to form a substantially planar piston surface that has a first surface area and is substantially parallel to the first substantially planar seal plate surface, wherein the first seal plate (406A) and the piston (<NUM>) form a first hydraulic chamber (410A) routed from a first opening formed by the substantially planar piston surface to a second opening formed by the second substantially planar seal plate surface, and wherein the first hydraulic chamber (410A) is configured to direct flow of the first fluid at a first pressure between the substantially planar piston surface and the second substantially planar seal plate surface;
wherein the rotor (<NUM>) forms a set of rotating longitudinal channels configured to: receive the first fluid on a side of the rotor (<NUM>); receive the second fluid on a second side of the rotor; and exchange the pressure between the first fluid and the second fluid;
characterized by
a first end cover (404A) forming a first set of apertures (506A, 506B) configured to direct flow of the first fluid between the first hydraulic chamber (410A) and the rotor (<NUM>), and
a first seal structure (704B) configured to create a hydraulic seal between the first seal plate (406A) and a substantially planar end cover surface of the first end cover (404A), wherein the first seal structure (704B) forms a first boundary of a first region of the second substantially planar seal plate surface, wherein the first region of the second substantially planar seal plate surface has a second surface area, wherein the second opening is formed within the first region, and wherein the second surface area is larger than the first surface area, wherein the substantially planar end cover surface is coupled to the second substantially planar seal plate surface via the first seal structure (704B); and
by the set of rotating longitudinal channels being configured to: receive the first fluid on a side of the rotor from the first end cover.