Pressure exchanger

Abstract

To optimize a pressure exchanger by one or more of minimizing mixing, enhancing efficiency, controlling cavitation, controlling noise, and / or controlling vibration.SOLUTION: A pressure exchanger includes a rotor configured to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The pressure exchanger further includes a first end cover 310, which forms a high-pressure-in port 312 configured to provide the first fluid at the first pressure and forms a low-pressure-out port 312 configured to receive the first fluid at a third pressure from ducts. The pressure exchanger further includes a second end cover 310 that forms a low-pressure-in port 312 configured to provide the second fluid at the second pressure into the ducts and forms a high-pressure-out port 312 configured to receive the second fluid from the ducts at a fourth pressure.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] The present disclosure relates to a pressure exchanger. [Background technology]

[0002] Pressure exchangers exchange pressure between fluids, and in some cases mixing of the fluids may occur.

[0003] The present disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings. [Brief description of the drawings]

[0004] [Figure 1A] 1 illustrates a schematic diagram of a fluid processing system including a hydraulic energy transfer system, according to certain embodiments. [Figure 1B] 1 illustrates a schematic diagram of a fluid processing system including a hydraulic energy transfer system, according to certain embodiments. [Figure 1C] 1 illustrates a schematic diagram of a fluid processing system including a hydraulic energy transfer system, according to certain embodiments. [Figure 1D] 1 illustrates a schematic diagram of a fluid processing system including a hydraulic energy transfer system, according to certain embodiments. [Figure 2A] FIG. 2 is an exploded perspective view of a pressure exchanger according to certain embodiments. [Figure 2B] FIG. 2 is an exploded perspective view of a pressure exchanger according to certain embodiments. [Figure 2C] FIG. 2 is an exploded perspective view of a pressure exchanger according to certain embodiments. [Figure 2D] FIG. 2 is an exploded perspective view of a pressure exchanger according to certain embodiments. [Figure 2E] FIG. 2 is an exploded perspective view of a pressure exchanger according to certain embodiments. [Figure 3A] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3B] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3C] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3D] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3E] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3F] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3G] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3H] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3I] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3J] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3K] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3L] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3M] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3N] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3O] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 3P] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4A] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4B] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4C] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4D] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4E]1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4F] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4G] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4H] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4I] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4J] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 4K] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5A-5B] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5C] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5D] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5E] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5F] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5G] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Fig. 5H-5I] 1 illustrates components of a pressure exchanger, according to certain embodiments. [Figure 5J] 1 illustrates components of a pressure exchanger, according to certain embodiments. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] Embodiments described herein relate to optimizing pressure exchangers by one or more of minimizing mixing, increasing efficiency, controlling cavitation, controlling noise, and / or controlling vibration.

[0006] High pressure fluids may be used by systems such as hydraulic fracturing (e.g., fracking or fracing), desalination, refrigeration, mud pumping, etc. A pump may be used to provide the high pressure fluid. Certain fluids (e.g., brine, viscous fluids, sand, powder, debris, ceramic, etc.) may damage and reduce the efficiency of the pump. A pressure exchanger may be used to exchange pressure between two fluids. A pump may be used to increase the pressure of a first fluid (e.g., substantially no solid particles, low viscosity, water, etc.). A pressure exchanger may receive a high pressure first fluid (e.g., water) and a low pressure second fluid (e.g., fluid with solid particles, high viscosity fluid, brine) and transfer pressure from the high pressure first fluid to the low pressure second fluid.

[0007] In a pressure exchanger, liquid-liquid pressure exchange occurs via a "fluid plug" that oscillates in a rotor duct. The "fluid plug" is not insulating, and mixing can occur between the two fluids exchanging pressure energy. Mixing can depend on several factors, such as the distance traveled by the "fluid plug" (e.g., the portion of the rotor duct that the "fluid plug" travels through, the distance in the rotor duct that the "fluid plug" traverses over the rotor length normalized in one revolution), turbulence, diffusion, jetting, rotor inlet and outlet losses, etc. The efficiency of a pressure exchanger can be directly proportional to the distance traveled by the "fluid plug," while the mixing of the pressure exchanger can be inversely proportional to the distance traveled. Conventional attempts to improve the efficiency of a pressure exchanger by increasing the distance traveled also increase mixing inside the pressure exchanger. A less efficient pressure exchanger uses more energy and causes other components (e.g., pumps) to be used more and wear more. Pressure exchangers that mix fluids can, for example, cause increased specific energy consumption (e.g., in seawater reverse osmosis (SWRO) plants), cause contamination of the fluids (e.g., when performing pressure exchange with toxic fluids, fluids with solid particles, more viscous fluids, etc.), and cause wear of components (e.g., wear of pumps due to solid particles introduced into the water).

[0008] In a pressure exchanger (e.g., a rotary isobaric pressure exchanger), a rotating duct conveys high pressure (HP) fluid from an HP port (e.g., kidney) to a low pressure (LP) port, and conveys LP fluid from the LP port to the HP port. The duct fluid experiences rapid pressurization or depressurization as it approaches its paired port. The frequency and speed of pressurization or depressurization depend on the rotor revolutions per minute (RPM), the number of pressure exchange cycles per revolution, and the pressure difference between the HP and LP ports. Rapid pressurization and depressurization creates high velocity fluid jets that create flow and pressure pulses that generate noise and increase vibration levels. This can create bubbles if the local fluid pressure (e.g., due to high velocity) falls below the vapor pressure for that temperature. The bubbles break when they move to an area of ​​higher pressure, resulting in cavitation and the influx of surrounding fluid, creating localized very high pressure spikes. When this occurs adjacent to a solid wall it can cause pitting damage (e.g. cavitation) which accumulates over time, further amplifying noise and vibration levels.

[0009] The devices, systems, and methods of the present disclosure provide for optimizing pressure exchangers for efficiency, mixing, cavitation, sound, and vibration.

[0010] The pressure exchanger includes a rotor configured to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The rotor defines a duct routed from a first distal end to a second distal end. The pressure exchanger further includes a first end cover forming a high pressure in (HPin) port configured to supply the first fluid at the first pressure to the duct. The first end cover forms a low pressure out (LPout) port configured to receive the first fluid at a third pressure from the duct. The pressure exchanger further includes a second end cover forming a low pressure in (LPin) port configured to supply the second fluid at the second pressure to the duct and a high pressure out (HPout) port configured to receive the second fluid at a fourth pressure from the duct.

[0011] In some embodiments, the HPin port is configured to supply a first fluid at a first pressure substantially axially into the duct. The first end cover may include one or more of radial sidewalls that are closer to each other than the radial sidewalls of the HPout port, a fillet between the radial sidewall and the inner sidewall, a radial sidewall that forms a ramp, a non-planar three-dimensional ramp, both of the inserts, and the like.

[0012] In some embodiments, one or more side walls (e.g., radial side walls) of the first end cover that form the HPin or LPout ports are substantially planar (e.g., not curved). In some embodiments, the rotor forms ducts in at least three concentric rows. In some embodiments, the pressure exchanger includes a spacer disposed in the first end cover, where the spacer is disposed between the interconnect (e.g., the metallic interconnect) and the first end cover (e.g., the ceramic end cover).

[0013] In some embodiments, the second end cover forms a first spot face proximate the LPin port and a second spot face proximate the HPout port. In some embodiments, the first end cover does not include spot faces 340 proximate the LPout and HPin ports. In some embodiments, the first and second spot faces 340 are staggered, e.g., one or more of which include a C-chamfer, include a radius that is shorter than the duct radius of the corresponding duct formed by the rotor, and include different recesses for the ducts of different concentric rows. In some embodiments, the second end cover forms a preload hole proximate the first spot face.

[0014] The present disclosure has advantages over conventional solutions. In some embodiments, the pressure exchanger of the present disclosure exchanges pressure with greater efficiency over conventional systems. This provides reduced energy usage and reduced use and wear of other components (e.g., pumps). In some embodiments, the pressure exchanger of the present disclosure exchanges pressure with less mixing of fluids compared to conventional systems. This provides reduced plant specific energy consumption, reduced contamination of fluids, reduced wear of components (e.g., pumps), etc. In some embodiments, the pressure exchanger of the present disclosure generates less noise, less vibration, and less damage (e.g., pitting damage, cavitation) compared to conventional systems. This provides reduced wear, less maintenance, less component replacement, less downtime, etc.

[0015] Although some embodiments of the present disclosure are described with respect to rotors and end covers of pressure exchangers, embodiments of the present disclosure may be applied to other components and other devices (e.g., adapter plates).

[0016] Although some embodiments of the present disclosure are described in relation to isobaric pressure exchangers, pressure exchangers, and hydraulic energy transfer systems, the present disclosure may be applied to other systems and devices (e.g., non-isobaric pressure exchangers, rotating components that are not pressure exchangers, non-rotary pressure exchangers, systems that do not include a pressure exchanger, etc.).

[0017] Although some embodiments of the present disclosure are described in the context of pressure exchange between fluids used in fracking, desalination, and / or refrigeration systems, the present disclosure may also be applied to other types of systems. Fluids may refer to liquids, gases, transcritical fluids, supercritical fluids, subcritical fluids, and / or combinations thereof.

[0018] Although some embodiments of the present disclosure are described with respect to a pressure exchanger having a sleeve, in some embodiments the pressure exchanger of the present disclosure is sleeved (e.g., has a sleeve) and in some embodiments the pressure exchanger of the present disclosure is sleeveless (e.g., does not have a sleeve and has a center post).

[0019] Although some embodiments of the present disclosure are described with respect to a pressure exchanger having a single cycle, in some embodiments, the pressure exchanger of the present disclosure is a multiple cycle pressure exchanger.

[0020] 1A-1D show schematic diagrams of fluid treatment systems 100A-D including a hydraulic energy transfer system 110 (eg, a pressure exchanger) according to certain embodiments.

[0021] Each hydraulic energy transfer system 110 of FIGS. 1A-D may include a pressure exchanger including a rotor configured to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The rotor forms a duct routed from a first distal end to a second distal end. The pressure exchanger includes a first end cover forming a high pressure in (HPin) port configured to supply the first fluid at the first pressure to the duct. The first end cover forms a low pressure out (LPout) port configured to receive the first fluid at a third pressure from the duct. The pressure exchanger further includes a second end cover forming a low pressure in (LPin) port configured to supply the second fluid at the second pressure to the duct and a high pressure out (HPout) port configured to receive the second fluid at a fourth pressure from the duct.

[0022] 1A-D includes an HPin port configured to deliver a first fluid at a first pressure substantially axially into a duct of a rotor of the hydraulic energy transfer system 110. In some embodiments, one or more side walls (e.g., radial side walls) of the end cover that form the HPin port or the LPout port are substantially planar (e.g., not curved). In some embodiments, the second end cover forms a first spot face proximate the LPin port and a second spot face proximate the HPout port.

[0023] FIG. 1A shows a schematic diagram of a fluid treatment system 100A including a hydraulic energy transfer system 110, in accordance with certain embodiments.

[0024] In some embodiments, the hydraulic energy transfer system 110 includes a pressure exchanger (PX). The hydraulic energy transfer system 110 (e.g., PX) receives a low pressure (LP) in fluid 120 (e.g., low pressure inlet flow, low pressure in (LPin)) from an LPin system 122. The hydraulic energy transfer system 110 also receives a high pressure (HP) in fluid 130 (e.g., high pressure inlet flow, high pressure in (HPin)) from an HPin system 132. The hydraulic energy transfer system 110 (e.g., PX) exchanges pressure between the HPin fluid 130 and the LPin fluid 120 and provides an LPout fluid 140 (e.g., low pressure outlet flow, low pressure out (LPout)) to an LPout system 142 and provides an HPout fluid 142 (e.g., high pressure outlet flow, high pressure out (HPout)) to an HPout system 150.

[0025] In some embodiments, the hydraulic energy transfer system 110 includes a PX that exchanges pressure between the HPin fluid 130 and the LPin fluid 120. The PX may be referred to as an isobaric pressure exchanger (IPX). The PX (e.g., IPX) may be a device that transfers fluid pressure between the HPin fluid 130 and the LPin fluid 120 with an efficiency of greater than about 50%, 60%, 70%, 80%, 90% or greater (e.g., without using centrifugal techniques, substantially isobaric pressure exchange). High pressure (e.g., HPin fluid 130, HPout fluid 150) refers to a pressure greater than low pressure (e.g., LPin fluid 120, LPout fluid 140). The LPin fluid 120 of the PX may be pressurized and exit the PX at a high pressure (e.g., HPout fluid 150, which is at a pressure greater than the LPin fluid 120), and the HPin fluid 130 may be depressurized and exit the PX at a low pressure (e.g., LPout fluid 140, which is at a pressure less than the HPin fluid 130). The PX may operate with the HPin fluid 130 directly applying a force to pressurize the LPin fluid 120, with or without a fluid separator between the fluids. Examples of fluid separators that may be used with the PX include, but are not limited to, pistons, bladders, diaphragms, and the like. In some embodiments, the PX may be a rotary device. Rotary PXs, such as those manufactured by Energy Recovery Inc. of San Leandro, Calif., may not have isolation valves because the effective valving action is achieved within the device via the relative motion of the rotor to the end cover. A rotary PX may also be designed to work with internal pistons that isolate the fluids and provide pressure exchange with relatively little mixing of the inlet fluid streams. A reciprocating PX may include a piston that moves back and forth within a cylinder to transfer pressure between the fluid streams. For example, but not limited to, any PX, including rotary PX, reciprocating PX, or combinations thereof, or multiple PXs may be used in the present disclosure. Additionally, a PX may be located on a skid separate from other components of the fluid treatment system 100 (e.g., in situations where a PX is being added to an existing fluid treatment system).

[0026] In some embodiments, the motor 160 is coupled to the hydraulic energy transmission system 110 (e.g., to PX). In some embodiments, the motor 160 controls the speed (e.g., RPM) of a rotor of the hydraulic energy transmission system 110 (e.g., to increase the pressure of the HPout fluid 150 or decrease the pressure of the LPout fluid 140). In some embodiments, the motor 160 generates energy (e.g., acts as a generator) based on pressure exchanges within the hydraulic energy transmission system 110.

[0027] The hydraulic energy transfer system 110 may be a hydraulic protection system (e.g., hydraulic buffer system, hydraulic separation system) that exchanges work and / or pressure with another fluid while blocking or limiting contact between the fluid (e.g., solid particle-containing fluid, fracking fluid, viscous fluid, toxic fluid) and various equipment (e.g., hydraulic fracturing equipment, high pressure pumps). By blocking or limiting contact between the various equipment (e.g., fracturing equipment, pumps) and a particular fluid (e.g., solid particle-containing fluid), the hydraulic energy transfer system 110 increases the life and performance of the various equipment (e.g., fracturing equipment, high pressure fluid pumps) while reducing wear, tear, and contamination. The use of equipment (e.g., high pressure fluid pumps) that is not designed for abrasive fluids (e.g., fracking fluids and / or corrosive fluids) may reduce the cost of equipment that may be used in the fluid treatment system 100.

[0028] The hydraulic energy transfer system 110 may include a hydraulic turbocharger or hydraulic pressure exchange system, such as a rotary PX. The PX may include one or more chambers (e.g., 1-100) that facilitate pressure transfer and pressure equalization between volumes of a first fluid and a second fluid (e.g., gas, liquid, multiphase fluid). In some embodiments, the PX may transfer pressure between a first fluid (e.g., a pressure exchange fluid, such as a proppant-free or substantially proppant-free fluid) and a second fluid that may be highly viscous and / or contain solid particles (e.g., fracking fluids containing sand, proppant, powder, debris, ceramic). The solid particle fluid causes wear and / or erosion of parts of the PX, such as the rotor and end covers of the PX. The fluid (e.g., abrasive particles within the fluid) may cause wear at the interface between the rotor and each end cover as the rotor rotates relative to the end cover. Replacement of worn parts of the PX may be costly.

[0029] The hydraulic energy transfer system 110 may be used in various types of systems, such as fracking systems, desalination systems, and refrigeration systems.

[0030] Figure IB shows a schematic diagram of a fluid treatment system 100B including a hydraulic energy transfer system 110, according to certain embodiments. Features in Figure IB that have the same or similar reference numbers as features in Figure 1A may have the same or similar components, features, etc. as in Figure 1A.

[0031] Fluid treatment system 100B may be a fracking system (e.g., a hydraulic fracturing system). In some embodiments, fluid treatment system 100B includes more components, fewer components, the same routing, different routing, etc. than those shown in FIG. 1B.

[0032] The LPin fluid 120 and the HPout fluid 150 may be fracking fluids (e.g., fluids containing solid particles, proppant-containing fluids, etc.). The HPin fluid 130 and the LPout fluid 140 may be fluids that are substantially free of solid particles (e.g., proppant-free fluids, water, filtered fluids, etc.).

[0033] The LPin system 122 may include one or more low pressure fluid pumps for supplying the LPin fluid 120 to the hydraulic energy transmission system 110 (e.g., PX). The HPin system 132 may include one or more high pressure fluid pumps 134 for supplying the HPin fluid 130 to the hydraulic energy transmission system 110.

[0034] A hydraulic energy transfer system 110 exchanges pressure between LPin fluid 120 (e.g., low pressure fracking fluid) and HPin fluid 130 (e.g., high pressure water) to provide HPout fluid 150 (e.g., high pressure fracking fluid) to an HPout system 152, which provides LPout fluid 140 (e.g., low pressure water). The HPout system 152 may include a rock formation 154 (e.g., a well) that includes cracks 156. Solid particles (e.g., proppant) from the HPout fluid 150 may be provided into the cracks 156 in the rock formation.

[0035] In some embodiments, the LPout fluid 140, the high pressure fluid pump 134, and the HPin fluid 130 are part of a first loop (e.g., a fluid loop that does not include a proppant). The LPout fluid 140 may be fed to the high pressure fluid pump to produce the HPin fluid 130, which becomes the LPout fluid 140 upon exiting the hydraulic energy transfer system 110.

[0036] In some embodiments, the LPin fluid 120, the HPout fluid 150, and the low pressure fluid pump 124 are part of a second loop (e.g., a proppant-containing fluid loop). The HPout fluid 150 may be fed into the rock formation 154 and then pumped out of the rock formation 154 by the low pressure fluid pump 124 to produce the LPin fluid 120.

[0037] In some embodiments, the fluid treatment system 100B is used in well completion operations in the oil and gas industry to perform hydraulic fracturing (e.g., fracking, fracing) to increase the release of oil and gas in a rock formation 154. The HPout system 152 may include a rock formation 154 (e.g., a well). Hydraulic fracturing may include pumping an HPout fluid 150, including a combination of water, chemicals, and solid particles (e.g., sand, ceramic, proppant), at high pressure into the well (e.g., rock formation 154). The LPin fluid 120 and the HPout fluid 150 may include fluids containing particles that increase the release of oil and gas in the rock formation 154 by propagating and increasing the size of cracks 156 in the rock formation 154. The high pressure of the HPout fluid 150 causes cracks 156 to initiate, expand in size, and propagate through the rock formations 154, releasing more oil and gas, while solid particles (e.g., powder, debris, etc.) enter the cracks 156 and keep them open (e.g., preventing the cracks 156 from closing once the HPout fluid 150 is depressurized).

[0038] To pump the particle-laden fluid into the rock formation 154 (e.g., a well), the fluid treatment system 100B may include one or more high pressure fluid pumps 134 and one or more low pressure fluid pumps 124 coupled to a hydraulic energy transfer system 110. For example, the hydraulic energy transfer system 110 may be a hydraulic turbocharger or PX (e.g., a rotary PX). In operation, the hydraulic energy transfer system 110 transfers pressure without implementing any substantial mixing between a first fluid (e.g., HPin fluid 130, a proppant-free fluid) pumped by the high pressure fluid pump 134 and a second fluid (e.g., LPin fluid 120, a proppant-containing fluid, a fracking fluid) pumped by the low pressure fluid pump 124. In this manner, the hydraulic energy transfer system 110 prevents or limits wear on the high pressure fluid pump 134 while simultaneously enabling the fluid treatment system 100B to pump the high pressure fracking fluid (e.g., HPout fluid 150) into the rock formation 154 to release oil and gas. To operate in corrosive and abrasive environments, the hydraulic energy transmission system 110 may be made from materials that are resistant to the corrosive and abrasive substances contained in either the first fluid or the second fluid. For example, the hydraulic energy transmission system 110 may be made from a ceramic (e.g., a cermet such as alumina, carbide, oxide, nitride, or boride hard phase) in 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.

[0039] In some embodiments, the hydraulic energy transfer system 110 comprises a PX (e.g., a rotary PX) where an HPin fluid 130 (e.g., a first fluid, a fluid that does not contain solid particles at high pressure) flows into a first side of the PX. Here, the HPin fluid 130 contacts an LPin fluid 120 (e.g., a second fluid, a low-pressure fracking fluid) that flows into the PX on a second side. The contact between the fluids allows the HPin fluid 130 to increase the pressure of the second fluid (e.g., the LPin fluid 120), which then pushes a second out fluid (e.g., the HPout fluid 150) of the PX into the well (e.g., the rock formation 154) for fracturing operations. The first fluid (e.g., the LPout fluid 140) also exits the PX, but at a lower pressure after exchanging pressure with the second fluid. As previously mentioned, the second fluid may be a low-pressure fracking fluid that may contain abrasive particles that may wear down the interface between the rotor and each end cover as the rotor rotates against each end cover.

[0040] 1C shows a schematic diagram of a fluid treatment system 100C including a hydraulic energy transfer system 110, according to certain embodiments. Fluid treatment system 100C may be a desalination system (e.g., removing salt and / or other minerals from water). In some embodiments, fluid treatment system 100C includes more components, fewer components, the same routing, different routing, etc. than those shown in FIG. 1C.

[0041] The LPin system 122 may include a feed pump 126 (e.g., low pressure fluid pump 124) that receives in seawater 170 (e.g., a reservoir feed or a direct ocean feed) and supplies the LPin fluid 120 (e.g., low pressure seawater, feed) to the hydraulic energy transfer system 110 (e.g., PX). The HPin system 132 may include a membrane 136 that supplies the HPin fluid 130 (e.g., high pressure brine) to the hydraulic energy transfer system 110 (e.g., PX). The hydraulic energy transfer system 110 exchanges pressure between the HPin fluid 130 and the LPin fluid 120 to supply the HPout fluid 150 (e.g., high pressure seawater) to the HPout system 152 and the LPout fluid 140 (e.g., low pressure brine) to the LPout system 142 (e.g., a geological mass, ocean, sea, wastewater, etc.).

[0042] The membrane 136 may be a membrane separator configured to separate fluids passing through the membrane, such as a reverse osmosis membrane. The membrane 136 may provide a concentrated feedwater or concentrate (e.g., brine) HPin fluid 130 to the hydraulic energy transfer system 110. The pressure of the HPin fluid 130 may be used to compress a low pressure feedwater (e.g., LPin fluid 120) to a high pressure feedwater (e.g., HPout fluid 150). For simplicity and explanation, the term feedwater is used. However, fluids other than water may be used in the hydraulic energy transfer system 110. The hydraulic energy transfer system 110 may also be used for other applications, such as industrial wastewater.

[0043] A circulation pump 158 (e.g., a centrifugal pump) delivers HPout fluid 150 (e.g., high pressure seawater) to the membrane 136. The membrane 136 filters the HPout fluid 150 to deliver LP drinking water 172 and HPin fluid 130 (e.g., high pressure brine). The LPout system 142 delivers out brine 174 (e.g., to a geological body, ocean, sea, wastewater, etc.).

[0044] In some embodiments, a high pressure fluid pump 176 is disposed between the feedwater pump 126 and the membrane 136. The high pressure fluid pump 176 increases the pressure of the low pressure seawater (e.g., LPin fluid 120, providing the high pressure feedwater) that is mixed with the high pressure seawater provided by the circulation pump 158.

[0045] In some embodiments, use of the hydraulic energy transfer system 110 reduces the load on the high pressure fluid pump 176. In some embodiments, the fluid treatment system 100C provides the LP potable water 172 without the use of the high pressure fluid pump 176. In some embodiments, the fluid treatment system 100C provides the LP potable water 172 using the high pressure fluid pump 176 intermittently.

[0046] In some examples, a hydraulic energy transfer system 110 (e.g., PX) receives an LPin fluid 120 (e.g., low pressure feedwater) at about 30 pounds per square inch (PSI) (about 207 kPa) and an HPin fluid 130 (e.g., high pressure brine or concentrate) at about 980 PSI (about 6757 kPa). The hydraulic energy transfer system 110 (e.g., PX) transfers pressure from the high pressure concentrate (e.g., HPin fluid 130) to the low pressure feedwater (e.g., LPin fluid 120). The hydraulic energy transfer system 110 (e.g., PX) outputs an HPout fluid 150 (e.g., high pressure (compressed) feedwater) at about 965 PSI (about 6653 kPa) and outputs an LPout fluid 140 (e.g., low pressure concentrate) at about 15 PSI (about 103 kPa). Because of this, the hydraulic energy transmission system 110 (e.g., PX) can be approximately 97% efficient because the input volume is approximately equal to the output volume of the hydraulic energy transmission system 110 (e.g., PX) and 965 PSI (approximately 6653 kPa) is approximately 97% of 980 PSI (approximately 6757 kPa).

[0047] 1D shows a schematic diagram of a fluid treatment system 100D including a hydraulic energy transfer system 110, according to certain embodiments. Fluid treatment system 100D may be a refrigeration system. In some embodiments, fluid treatment system 100D includes more components, fewer components, the same routing, different routing, etc. than those shown in FIG. 1D.

[0048] A hydraulic energy transfer system 110 (e.g., PX) receives LPin fluid 120 from an LPin system 122 (e.g., low pressure lift device 128, low pressure fluid pump, etc.) and receives HPin fluid 130 from an HPin system 132 (e.g., condenser 138). The hydraulic energy transfer system 110 (e.g., PX) may exchange pressure between the LPin fluid 120 and the HPin fluid 130 to provide HPout fluid 150 to the HPout system 152 (e.g., high pressure lift device 159) and provide LPout fluid 140 to the LPout system 142 (e.g., evaporator 144). The evaporator 144 may provide fluid to the compressor 178 and the low pressure lift device 128. The condenser 138 may receive fluid from the compressor 178 and the high pressure lift device 159.

[0049] Fluid treatment system 100D may be a closed system. LPin fluid 120, HPin fluid 130, LPout fluid 140 and HPout fluid 150 may all be fluids (eg, refrigerants) that circulate in the closed system of fluid treatment system 100D.

[0050] In some embodiments, the fluid of the fluid treatment system 100D may include solid particles. For example, solid particles (e.g., solid particles from welding) may be entrained in the fluid in the fluid treatment system 100D due to piping, equipment, connections (e.g., welding of pipes, soldering of pipes), etc. Solid particles in the fluid and / or high pressure of the fluid may cause wear and / or erosion of the PX components (e.g., rotors, end covers) of the hydraulic energy transfer system 110.

[0051] 2A-2E are exploded perspective views of a rotary PX 40 (eg, a rotary pressure exchanger, a rotary liquid piston compressor (LPC)) according to certain embodiments.

[0052] PX40 includes a rotor 46 configured to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The rotor 46 forms a channel 70 (e.g., a duct) routed from a first distal end (e.g., opening 72) to a second distal end (e.g., opening 74). PX40 further includes an end cover 64 forming an HPin port (e.g., outlet aperture 78) configured to supply the first fluid at the first pressure to the channel 70. The end cover 64 forms an LPout port (e.g., outlet aperture 76) configured to receive the first fluid at a third pressure from the channel 70. PX40 further includes an end cover 66 forming an LPin port (e.g., outlet aperture 80) configured to supply the second fluid at the second pressure to the channel 70, and forming an HPout port (e.g., outlet aperture 82) configured to receive the second fluid at a fourth pressure from the channel 70.

[0053] In some embodiments, the PX 40 of Figures 2A-E has an HPin port (e.g., exit aperture 76) configured to supply a first fluid at a first pressure substantially axially into a channel 70 of a rotor 46 of the PX 40. In some embodiments, one or more side walls (e.g., radial side walls) of the end cover 64 that form the HPin port (e.g., exit aperture 76) or the LPout port are substantially planar (e.g., not curved). In some embodiments, the end cover 66 forms a first spot face proximate the LPin port (e.g., exit aperture 80) and a second spot face proximate the HPout port (e.g., exit aperture 82).

[0054] The PX 40 is configured to transfer pressure and / or work between a first fluid (e.g., a proppant-free fluid or supercritical carbon dioxide, HPin fluid 130) and a second fluid (e.g., fracking fluid or superheated carbon dioxide gas, LPin fluid 120) with minimal fluid mixing. The rotary PX 40 may include a generally cylindrical body portion 42 including a sleeve 44 (e.g., rotor sleeve) and a rotor 46. The rotary PX 40 may also include two end caps 48 and 50 including manifolds 52 and 54, respectively. The manifold 52 includes respective inlet and outlet ports 56 and 58, and the manifold 54 includes respective inlet and outlet ports 60 and 62. In operation, the inlet ports 56, 60 allow the first and second fluids to enter and exchange pressure with the rotary PX 40, while the outlet ports 58, 62 allow the first and second fluids to exit the rotary PX 40. In operation, the inlet port 56 may receive a first fluid (e.g., HPin fluid 130) at high pressure and, after exchanging pressure, may use the outlet port 58 to pump the first fluid (e.g., LPout fluid 140) at low pressure out of the rotary PX 40. Similarly, the inlet port 60 may receive a second fluid (e.g., LPin fluid 120) at low pressure and use the outlet port 62 to pump the second fluid (e.g., HPout fluid 150) at high pressure out of the rotary PX 40. The end caps 48 and 50 are disposed within the respective manifolds 52 and 54 and include respective end covers 64 and 66 (e.g., end plates) that enable fluid-sealing contact with the rotor 46.

[0055] As noted above, one or more components of PX 40, such as rotor 46, end cover 64 and / or end cover 66, may be constructed from a wear-resistant material (e.g., carbide, cemented carbide, silicon carbide, tungsten carbide, etc.) having a hardness greater than a predetermined threshold (e.g., a Vickers Hardness number of at least 1000, 1250, 1500, 1750, 2000, 2250 or more). For example, tungsten carbide may provide increased durability and improved wear resistance to abrasive fluids compared to other materials, such as alumina ceramic.

[0056] The rotor 46 may be cylindrical and disposed within the sleeve 44, which allows the rotor 46 to rotate about an axis 68. The rotor 46 may have a number of channels 70 (e.g., ducts, rotor ducts) that run generally longitudinally through the rotor 46, with openings 72 and 74 (e.g., rotor ports) at each end symmetrically disposed about the longitudinal axis 68. The openings 72 and 74 of the rotor 46 are disposed to be in fluid communication with the inlet and outlet apertures 76 and 78 (e.g., end cover inlet and end cover outlet ports) and 80 and 82 (e.g., end cover inlet and end cover outlet ports) of the end covers 64 and 66, respectively, in such a way that the channels 70 are exposed to high and low pressure fluids during rotation. As shown, the inlet and outlet apertures 76 and 78, 80 and 82 may be designed in the shape of an arc or a portion of a circle (e.g., C-shaped).

[0057] In some embodiments, a controller using sensor feedback (e.g., revolutions per minute measured via a tachometer or optical encoder, or volumetric flow rate measured via a flow meter) may control the degree of mixing of the first and second fluids in the rotary PX 40. This controller may be used to improve the operability of a fluid treatment system (e.g., fluid treatment systems 100A-100D of FIGS. 1A-1D). For example, by varying the volumetric flow rates of the first and second fluids entering the rotary PX 40, a plant operator (e.g., a system operator) can control the amount of fluid mixing in the PX 40. Additionally, by varying the rotational speed of the rotor 46, an operator can also control the mixing. Three characteristics of the rotary PX 40 that affect mixing include (1) the aspect ratio of the rotor channel 70, (2) the exposure time between the first and second fluids, and (3) the creation of a fluid barrier (e.g., an interface) between the first and second fluids in the rotor channel 70. First, the rotor channel 70 (e.g., a duct) is generally long and narrow, which stabilizes the flow in the rotary PX 40. Furthermore, the first and second fluids may move through the channel 70 in a plug-flow manner with minimal axial mixing. Second, in certain embodiments, the speed of the rotor 46 reduces the contact between the first and second fluids. For example, the speed of the rotor 46 (e.g., a rotor speed of about 1200 RPM) may reduce the contact time between the first and second fluids to less than about 0.15 seconds, 0.10 seconds, or 0.05 seconds. Third, a small portion of the rotor channel 70 is used to exchange pressure between the first and second fluids. Thus, a certain amount of fluid remains in the channel 70 as a barrier between the first and second fluids. Any of these mechanisms may limit mixing in the rotary PX 40. Additionally, in some embodiments, the rotary PX40 may be designed to operate with all or part of an internal piston or other barrier that isolates the first and second fluids while allowing pressure transmission.

[0058] 2B-2E are exploded views of one embodiment of the rotary PX 40, showing the sequence of positions of a single rotor channel 70 within the rotor 46 as the channel 70 rotates through one complete cycle. Note that FIGS. 2B-2E are simplified views of the rotary PX 40, showing one rotor channel 70, and showing the channel 70 as having a circular cross-sectional shape. In other embodiments, the rotary PX 40 may include multiple channels 70 having the same or different cross-sectional shapes (e.g., circular, elliptical, square, rectangular, polygonal, etc.). Thus, FIGS. 2B-2E are simplified for illustrative purposes, and other embodiments of the rotary PX 40 may have different configurations than those shown in FIGS. 2A-2E. As will be described in more detail below, the rotary PX 40 facilitates pressure exchange between a first fluid and a second fluid by allowing the first and second fluids to briefly contact each other within the rotor 46. In certain embodiments, this exchange is performed at a rate that limits intermixing of the first and second fluids. The speed of the pressure wave passing through the rotor channel 70 (as soon as the channel is exposed to the aperture 76), the rate of diffusion of the fluids, and the rotational speed of the rotor 46 determine whether and to what extent any intermixing occurs.

[0059] FIG. 2B is an exploded perspective view of one embodiment of a rotary PX 40 (e.g., a rotary LPC) according to certain embodiments. In FIG. 2B, the channel opening 72 is in a first position. In the first position, the channel opening 72 is in fluid communication with an aperture 78 in the end cover 64 and thus the manifold 52, while the opposite channel opening 74 is in fluid communication with an aperture 82 in the end cover 66 and extends therefrom into the manifold 54. As discussed below, the rotor 46 may rotate in a clockwise direction as indicated by arrow 84. In operation, a low pressure second fluid 86 passes through the end cover 66 and into the channel 70 where it contacts the first fluid 88 at a dynamic fluid interface 90. The second fluid 86 then pushes the first fluid 88 out of the channel 70, through the end cover 64, and out of the rotary PX 40. However, due to the short contact time, there is minimal mixing between the second fluid 86 and the first fluid 88.

[0060] 2C is an exploded perspective view of one embodiment of a rotating PX 40 (e.g., a rotating LPC) in accordance with certain embodiments. In FIG. 2C, the channel 70 has been rotated clockwise through an arc of approximately 90 degrees. In this position, the opening 74 (e.g., outlet) is not in fluid communication with the apertures 80 and 82 in the end cover 66, and the opening 72 is not in fluid communication with the apertures 76 and 78 in the end cover 64. Thus, a low pressure second fluid 86 is temporarily contained within the channel 70.

[0061] FIG 2D is an exploded perspective view of one embodiment of a rotating PX 40 (e.g., a rotating LPC) according to certain embodiments. In FIG 2D, the channel 70 has been rotated through an arc of approximately 60 degrees from the position shown in FIG 2B. The opening 74 is now in fluid communication with the aperture 80 in the end cover 66, and the opening 72 in the channel 70 is now in fluid communication with the aperture 76 in the end cover 64. In this position, a first fluid 88 at high pressure flows in and pressurizes a second fluid 86 at low pressure, forcing the second fluid 86 out of the rotor channel 70 and through the aperture 80.

[0062] FIG 2E is an exploded perspective view of one embodiment of a rotary PX 40 (e.g., a rotary LPC) in accordance with certain embodiments. In FIG 2E, the channel 70 has rotated through an arc of approximately 270 degrees from the position shown in FIG 2B. In this position, the opening 74 is no longer in fluid communication with the apertures 80 and 82 in the end cover 66, and the opening 72 is no longer in fluid communication with the apertures 76 and 78 in the end cover 64. Thus, the first fluid 88 is no longer pressurized and is temporarily retained within the channel 70 until the rotor 46 rotates another 90 degrees to begin the cycle again.

[0063] Figures 3A-P show components of a pressure exchanger 300 (e.g., PX 40 of Figures 2A-E), according to certain embodiments. Features in Figures 3A-P having similar names and / or reference numbers as features in one or more of Figures 1A-2E may include the same or similar structure, materials, function, and / or the like as features in one or more of Figures 1A-2E. In some embodiments, one or more features of PX 300 of Figures 3A-P reduce mixing of fluids within PX 300.

[0064] FIG 3A shows a perspective view of an end cover 310 (e.g., one or more of end covers 64 and / or 66 of FIGS. 2A-E). FIG 3B shows a perspective cutaway view of an end cover 310 (e.g., end cover 64 of FIG. 3A and / or one or more of end covers 66 of FIGS. 2A-E). FIG 3C shows a cutaway view of components of pressure exchanger 300 (e.g., those of FIGS. 3A and / or 3B, one or more of end covers 64 and / or 66 of FIGS. 2A-E, one or more rotors 46 of FIGS. 2A-E).

[0065] In some embodiments, the PX 300 comprises a rotor 320 and an end cover 310. The rotor 320 is configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The rotor 320 forms a duct 322 (e.g., channel 70 of FIGS. 2A-E) routed from a first distal end of the rotor 320 to a second distal end of the rotor 320.

[0066] The PX 300 may include a first and a second end cover 310. The first end cover 310 is disposed at a first distal end of the rotor 320, and the second end cover 310 is disposed at a second distal end of the rotor 320.

[0067] End cover 310 is disposed at the distal end of rotor 320. End cover 310 forms ports 312 (e.g., apertures 76 and 78 in FIGS. 2A-E, apertures 80 and 82 in FIGS. 2A-E, inlets, outlets, HPin ports, HPout ports, LPin ports, LPout ports).

[0068] In some embodiments, end cover 310 (e.g., disposed at a first distal end of rotor 320) forms an HPin port configured to supply a first fluid at a first pressure substantially axially into duct 322 and an LPout port configured to receive the first fluid at a third pressure from duct 322, the third pressure being lower than the first pressure.

[0069] In some embodiments, end cover 310 (e.g., disposed at a second distal end of rotor 320) forms an LPin port configured to supply a second fluid at a second pressure into duct 322 and an HPout port configured to receive the second fluid at a fourth pressure from duct 322, the fourth pressure being higher than the second pressure.

[0070] In some embodiments, the PX300 may include two ramps to reduce rotor incidence losses and prevent interface distortion.

[0071] In some embodiments, end cover inserts 330 (eg, made from polycarbonate, fiber-reinforced PTFE, and / or PEEK) further guide the flow.

[0072] In some embodiments, the end cover 310 has a 3D ramp.

[0073] In some embodiments, the end cover 310 has the HPin kidney closure at least 2 degrees earlier than the HPout to avoid flow acceleration as the duct closes.

[0074] In some embodiments, the end cover 310 has a fillet (eg, a large fillet) at the HPin kidney exit diameter corner (eg, to reduce mixing through the inner row ducts).

[0075] In some embodiments, the PX300 has a slower opening of the HPin kidney than the HPout, which acts to move the interface away from the HPout, reducing mixing at the HPout.

[0076] In some embodiments, the spot face is placed at the HPout open (rather than at the HPin open), which reduces mixing at the HPout and avoids disturbing the interface adjacent to the HPin open.

[0077] In some embodiments, the HPout fluid is used as the bearing fluid and the centerbore fluid (eg, this reduces mixing of HPin into HPout through axial clearance leakage).

[0078] In some embodiments, the length to depth (L / D) ratio and circularity of the duct 322 are maximized.

[0079] In some embodiments, a honeycomb shaped flow straightener is used as an insert in the duct 322 to reduce mixing.

[0080] In some embodiments, the end cover 310 includes radial sidewalls 314 (e.g., leading radial sidewall 314A, trailing radial sidewall 314B) that form the ports 312 (e.g., HPin port, HPout port, LPin port, LPout), an inner wall 316, and an outer wall 318. The leading radial sidewall 314A is the first radial sidewall that the duct 322 sees as it rotates. The trailing radial sidewall 314B is the sidewall of the same port that the rotor's duct 322 sees after the leading radial sidewall 314A. In some embodiments, the ports 312 are similarly sized. In some embodiments, the radial sidewalls 314 of the HPin ports are at least 2 degrees (e.g., 4 degrees, 6 degrees, 8 degrees, 10 degrees) closer to each other than the radial sidewalls 314 of the HPout ports are to each other (see, e.g., FIGS. 3G-H). For example, FIG. 3G may be the HPout port and FIG. 3H may be the HPin port.

[0081] In some embodiments, for example, at least one of the radial sidewalls 314 (e.g., a trailing radial sidewall) forming the HPin port is configured to close against the duct 322 formed by the rotor 320 by at least two degrees (e.g., 4 degrees, 6 degrees, 8 degrees, 10 degrees) before at least one of the second radial sidewalls (e.g., a trailing radial sidewall) forming the HPout port closes against the duct 322 (e.g., this can reduce mixing of the corresponding fluids between the HPin and HPout and reduce mixing of the HPin entering the HPout).

[0082] In some embodiments, at least one of the radial sidewalls 314 (e.g., a trailing radial sidewall) forming the LPin port is configured to close at least 2 degrees (e.g., 4 degrees, 6 degrees, 8 degrees, 10 degrees) against the duct 322 formed by the rotor 320 before at least one of the second radial sidewalls (e.g., a trailing radial sidewall) forming the LPout port closes against the duct 322 (e.g., this can reduce mixing of the corresponding fluids between LPin and LPout and reduce mixing of LPin entering LPout).

[0083] In some embodiments, one or more radial sidewalls of the LPout port are biased to reduce mixing in the LPout port.

[0084] In some embodiments, the radial sidewalls 314 that define the HPin ports each have substantially straight edges that match corresponding substantially straight edges of the ducts 322 defined by the rotor 320 (e.g., this can maximize the exposure time of the ducts 322 to the port, increasing efficiency).

[0085] In some embodiments, the first end cover 310 defines a first port and a second port, where a first substantially straight radial edge of the first port and a second substantially straight radial edge of the second port substantially coincide with a corresponding substantially straight edge of the duct 322 of the rotor 320. In some embodiments, the second end cover 310 defines a third port and a fourth port, where a third substantially straight radial edge of the third port and a fourth substantially straight radial edge of the fourth port substantially coincide with a corresponding substantially straight edge of the duct 322 of the rotor 320.

[0086] In some embodiments, at least one of the radial sidewalls (e.g., the leading radial sidewall) forming the HPin port is configured to open into the duct 322 formed by the rotor 320 at least 2 degrees (e.g., 4 degrees, 6 degrees, 8 degrees, 10 degrees) later than at least one of the second radial sidewalls (e.g., the leading radial sidewall) forming the HPout port opens into the duct 322.

[0087] In some embodiments, the end cover 310 (e.g., forming the HPin port) forms a fillet (e.g., a generally triangular cross-sectional concave strip of material that rounds the interior angle between the two surfaces) between at least one of the radial sidewalls 314 and the inner wall 316. In some embodiments, the end cover 310 forming the HPout port may form the HPout port without a fillet between the radial sidewall 314 and the inner wall 316. The fillet of the end cover 310 (e.g., forming the HPin port) is configured to close the HPin port against the duct 322 of the rotor 320 before the HPout of the end cover forming the HPout port closes against the duct 322.

[0088] The fillet may be located at the HPin port exit ID corner. The rotor 320 may form multiple annular rows of ducts 322 with the outer row being generally trapezoidal in shape and the innermost row being triangular in shape. Due to the decrease in circularity from the outer ducts to the inner ducts, the innermost row of ducts with triangular shape may contribute more to the mixing at HPout (per unit flow area) than the outer row of ducts. By increasing the diameter of the fillet at the HPout port ID exit corner, the mixing contribution from the inner ducts can be reduced. The fillet at the HPin port bottom corner results in a decrease in the fluid (e.g., brine concentrate, fluid being pressure exchanged) exiting the inner row of ducts 322 out of the HPout row.

[0089] In some embodiments, the radial sidewalls 314 of the end cover 310 (e.g., forming the LPin and HPout ports) each form a ramp (e.g., a sidewall having a slope, a sidewall that is not perpendicular to the face of the end cover) (see, e.g., FIGS. 3A-E), and the radial sidewall 314 of the other end cover forms the HPin port (e.g., and also the LPout port) without forming a ramp.

[0090] In some embodiments, the radial sidewalls 314 of the end cover 310 (e.g., forming the LPin and HPout ports) each form a ramp (e.g., a sidewall having a slope, a sidewall that is not perpendicular to the face of the end cover) (see, e.g., FIGS. 3A-E), and the radial sidewalls 314 of the other end cover forming the HPin ports (e.g., and also the LPout port) each form a ramp.

[0091] The first radial sidewall includes a leading radial sidewall and a trailing radial sidewall on the HPin port, each having a varying ramp angle measured from about 30 degrees to 70 degrees relative to the plane of the rotor 320.

[0092] In some embodiments, the leading and trailing radial sidewalls on the LPin port form a ramp in the direction of rotation, the ramp having a varying ramp angle measured from about 30 degrees to 70 degrees relative to the plane of the rotor 320.

[0093] In some embodiments, the radial sidewall 314 of the end cover 310 (e.g., defining the LPin and HPout ports) defines a non-planar three-dimensional ramp (see, e.g., ramps 317A-B in FIG. 3E). In some embodiments, the first radial sidewall defines a non-planar three-dimensional ramp defined by at least two helices located at the innermost and outermost radii of the port. In some embodiments, the corresponding ramps of the non-planar three-dimensional ramps are defined by helices having a pitch proportional to the radius, with the corresponding ramps positioned to reduce the angle of incidence (e.g., to reduce the angle of incidence so that the absolute velocity (c) is similar at any radius of the port).

[0094] The ramp 317 may be associated with a speed triangle 319. The speed triangle 319 may include the following:

[0095] c ID =(u ID )×tan(α ID )

[0096] c OD =(u OD )×tan(α OD )

[0097] α ID = Kidney ramp angle at the inside diameter (ID) of the kidney (port 312 in end cover 310)

[0098] α OD = Kidney ramp angle at the outside diameter (OD) of the kidney (port 312 in end cover 310)

[0099] u ID = tangential velocity at the inside diameter of the port

[0100] u OD = tangential velocity at the outside diameter of the port

[0101] c ID = absolute velocity at the inside diameter of the port

[0102] c OD = absolute velocity at the outside diameter of the port

[0103] The flow exiting the rotor 320 of the PX 300 may have a combination of axial and tangential components of flow velocity. The axial and tangential components of flow velocity are a function of the rotor speed and the radial position of the duct 322. In some embodiments, the outlet kidney (e.g., port 312 of the end cover 310) is shaped to allow a smooth transition from this three-dimensional (3D) velocity field of the rotor 320 to a one-dimensional (1D) velocity field along a fixed conduit (e.g., port 312 of the end cover 310). Alternatively, shock losses may occur due to flow separation and vortex formation at the outlet kidney (e.g., port 312 of the end cover 310). The outlet ramp may have a single ramp angle based on the design flow rate, the target RPM, the radial center position of the duct 322, and / or the like. The outlet kidney (e.g., port 312 of cover 310) may also have dual ramps at the beginning and end of the outlet kidney due to similar considerations. In some embodiments, a 3D shaped outlet kidney (e.g., port 312 of end cover 310) may have a ramp angle that varies continuously with radial position. To overcome the difficulty of manufacturing a 3D ramp, an injection molded plastic insert with a specific shape may be embedded in the outlet kidney (e.g., port 312 of end cover 310).

[0104] In some embodiments, the end cover 310 includes an insert 330 disposed in the HPin port where the insert is configured to guide the flow and reduce the angle of incidence of the flow at the rotor 320 (see, e.g., FIG. 3F).

[0105] In some embodiments, the end cover 310 forms a first spot face proximate the HPin port (e.g., no spot face at the HPin port, which may reduce mixing of corresponding fluids between the HPin and HPout ports) and a second spot face proximate the LPout port (see, e.g., FIGS. 3L-O). In some embodiments, the first end cover 310 forms a second spot face proximate the LPout port without forming a spot face at the LPin port, which reduces mixing of corresponding fluids between the LPin and LPout ports.

[0106] In some embodiments, the pressure exchanger 300 (e.g., PX40) is configured to use a second fluid supplied via the LPin port and / or the HPout port as a bearing fluid and / or a centerbore fluid (see, e.g., Figures 3I-K).

[0107] FIG. 3P illustrates a PX 300, according to certain embodiments. The rotor 320 may include an insert 330 disposed within the duct 322. The insert may provide a length to diameter ratio of about 5 to about 10. The insert may be a honeycomb shaped insert. The insert may be a honeycomb shaped flow straightener that is press-fit or shrink-fitted into the duct. The insert 330 may maximize the length to diameter (L / D) and circularity of the duct 322. The insert 330 may be a honeycomb shaped flow straightener within the duct 322 that reduces mixing of the fluids.

[0108] Unsteady fluid flow turbulence in the duct 322 can cause (e.g., be a major source of) mixing in the duct. This causes a shift and elongation of the "mixing zone" between the two fluids in the duct 322. In some embodiments, to mitigate this, the aspect ratio (e.g., length to diameter - L / D) of the duct geometry is increased by inserting an insert 330 (e.g., a honeycomb shaped flow straightener) into the duct 322. The flow straightener may be press-fit or shrink-fit into the duct, or may be mechanically or adhesively attached (e.g., with an adhesive) to the duct wall. The insert 330 (e.g., flow straightener) may have a shape other than a honeycomb shape, and the insert 330 may divide a duct of a particular L / D ratio into multiple ducts of larger L / D ratios. Breaking the duct into multiple smaller ducts also reduces cavitation and noise by spreading out in time the pressurization and depressurization events at the kidney openings (eg, openings at ports 312 in end cover 310).

[0109] In some embodiments, the pressure exchanger 300 is used to minimize mixing of the two fluids inside the pressure exchanger 300. In the pressure exchanger 300, liquid-liquid pressure exchange may occur via a "liquid plug" oscillating in the rotor duct. This "liquid plug" may not be impermeable, and traditionally, a small amount of mixing may occur between the two fluids exchanging pressure energy. Mixing may depend on one or more factors, such as the distance traveled by the "liquid plug" (e.g., traversed by a portion of the duct 322 of the rotor 320), turbulence, diffusion, jets, inlet and / or outlet losses of the rotor 320, etc. The efficiency of the pressure exchanger 300 may be directly proportional to the distance traveled by the "liquid plug". Mixing of the first and second fluids in the pressure exchanger 300 may be inversely proportional to the distance traveled (and to the efficiency of the pressure exchanger 300). In some instances, a shorter travel distance results in less mixing and less efficiency. In some instances, longer travel distances result in increased mixing and increased efficiency (e.g., features that increase efficiency by increasing travel distances have traditionally increased mixing within the pressure exchanger as well). In some applications (e.g., SWRO plants), the efficiency of the pressure exchanger 300 should be maximized and mixing within the pressure exchanger 300 should be minimized to reduce actual energy consumption (e.g., of the SWRO plant).

[0110] The pressure exchanger 300 may have one or more features configured to reduce mixing within the pressure exchanger 300 without having a negative impact on the efficiency of the pressure exchanger 300 (e.g., minimize efficiency reduction, maintain efficiency, or increase efficiency compared to a pressure exchanger without such features).

[0111] Features of pressure exchanger 300 (see, e.g., end cover 310 in FIGS. 3A-H) may provide for reduced rotor incidence angle losses (e.g., two ramps at the inlet of port 312 reduce the incidence angle). The incidence angle may be the angle between the ideal c velocity vector and the actual c velocity vector.

[0112] The flow in the duct 322 of the rotor 320 has both an axial velocity component (e.g., velocity component c(m)=w of the two ramps in FIG. 3C) and a tangential velocity component (e.g., velocity component u of FIG. 3C). The axial component may be constant in any plane in the axial direction of the rotor 320, while the tangential component varies linearly with respect to the radial coordinate. As the flow passes through the HPin and LPin ports (e.g., HPin and LPin kidneys) and enters the rotor 320, the flow may be accelerated to a velocity with a combination of axial and tangential velocity components at every radius just before the fluid enters the duct 322 of the rotor 320. Conventionally, shock losses may occur due to the oblique incidence angle, resulting in separation and mixing of the flow by enhancing vortex formation. The end cover 310 guides the flow according to a given rated flow rate and target RPM of the rotor, resulting in reduced mixing and reduced pressure loss due to sudden flow direction changes.

[0113] In some embodiments, the end cover 310 includes two ramps (e.g., a ramp on each radial sidewall 314) to provide a substantial tangential flow velocity component in addition to the axial flow velocity component. In some embodiments, the end cover 310 includes a 3D ramp (e.g., further optimization of the kidney geometry) to provide a smooth fluid input from the port 312 to the duct 322 (see, e.g., the right side of FIG. 3C).

[0114] In some embodiments, an insert 330 (e.g., made from one or more components) may be embedded in the port 312 (see, e.g., FIG. 3F). The insert 330 may be made from an alumina ceramic, a plastic material such as polycarbonate, fiber-reinforced PTFE, and / or PEEK, and / or the like.

[0115] The end cover 310 of FIG. 3H may reduce the effective width of the port 312 (eg, kidney) by opening the HPin port 312 a few degrees slower than baseline, thus reducing efficiency.

[0116] The HPin port may close earlier than the HPout port (e.g., the radial sidewalls 314 of the HPin port are closer to each other than the radial sidewalls 314 of the HPout port). This may reduce mixing at the HPout port caused by fluid inertia. When the pressure exchanger is used for energy recovery in certain applications (e.g., in a SWRO plant), mixing at the HPout port is undesirable. The flow in the duct 322 of the rotor 320 accelerates as the duct 322 crosses the HP port. The average duct flow velocity starts at about zero when the duct 322 opens to the HP port and reaches a maximum value at the moment it begins to exit the port (e.g., kidney).

[0117] Conventionally, the HPin and HPout ports close at the same time (e.g., they are the same size and the radial sidewalls are the same distance from each other). This can lead to the duct flow being suddenly stopped during the short time that the fluid in the duct 322 exits the port 312. Because the duct flow velocity is changed very quickly from a maximum value to a value of about zero in a very short time, the inertia of the duct fluid can cause a localized large spike in the duct pressure. This can cause a fluid jet to spurt into the HPout port through the rapidly closing opening between the duct 322 and the HPout port. At this moment, the mixing zone (e.g., the "liquid plug") has traveled a maximum extent through the duct and can be in close proximity (e.g., very close) to the HPout port. The jet into the HPout port can transport the fluid from the mixing zone as well as some of the fluid behind the mixing zone to the HPout port, increasing the undesired mixing in the HPout port.

[0118] The present disclosure can mitigate this increased mixing by closing the HPin port a few degrees before the HPout port. This causes the duct 322 to reach peak velocity before it closes to the HPout port. The duct flow slows as the fluid in duct 322 exits the HPout port, greatly reducing pressure spikes due to fluid inertia. The mixing zone fluid jet into the HPout port is greatly reduced, and as a result, mixing at the HPout port is greatly reduced.

[0119] The HPin port may open later than the HPout port. By delaying the opening of the HPin port relative to the HPout port, the average position of the interface between the two fluids is biased to be closer to the HPin port than the LPin port. This moves the interface away from the HPout, reducing mixing of the HPin at the HPout. This feature may be selectively utilized when reducing mixing is a high priority and a small tradeoff in efficiency is acceptable. By delaying the opening of the HPin by a few degrees relative to the HPout, the interface may be moved away from the HPout, reducing mixing at the HPout.

[0120] The kidney exit ramps (e.g., radial sidewalls 314) of the end cover 310 can be configured to guide the flow into the HPout and LPout ports while minimizing shock losses at the exit (e.g., shock losses due to flow separation).

[0121] The flow exiting the duct 322 of the rotor 320 into the outlet ports (e.g., the outlet, HPout, and LPout ports) has both axial and tangential components of velocity. The axial velocity component may not vary significantly with radius, while the tangential velocity component varies linearly with radius. The outlet port walls may be configured to provide a smooth exit of the duct flow through the port without separation. The side walls of the end cover 310 that form the port 312 may be configured to accommodate the change in the ratio of the tangential and axial components of velocity with respect to radius. By preventing flow separation at the outlet, both differential pressure (DP) losses and mixing losses are reduced (e.g., the mixing zone may be closest to the duct at the outlet port).

[0122] The spot face 340 may be positioned to reduce mixing (see, for example, FIGS. 3L-O). The spot face 340 may be used on the port 312 to gradually pressurize or depressurize the duct 322 of the rotor 320 (e.g., instead of sudden pressure equalization through a high-velocity jet into or out of the rotor duct). The spot face 340 reduces the velocity of the jet due to the pressure difference between the duct 332 and the port 312 by increasing the flow resistance through a narrow gap. In some embodiments, the spot face 340 is positioned at the HPout port without being positioned at the HPin port. This allows the depth of the spot face 340 to be compensated and pressure equalization can be achieved by a jet of HPout fluid, rather than HPin fluid, entering the low pressure rotor duct. The "liquid plug" may be furthest away from the HPout port when pressure equalization occurs and mixing is reduced.

[0123] In some embodiments, the second fluid (e.g., the HPout fluid exiting the HPout port) may be used as a bearing fluid and / or a centerbore fluid. In the pressure exchanger 300 (e.g., a rotary pressure exchanger), the first fluid (e.g., the HPin fluid) or the second fluid (e.g., the HPout fluid) may be used as a bearing fluid for the radial and axial bearings. If the pressure difference between the HPin and HPout fluids meets a threshold amount (e.g., small), the performance of the bearings (e.g., stiffness and load capacity) does not change significantly depending on which fluid is selected. If the pressure difference between the HPin and HPout fluids meets a threshold amount (e.g., small), the HPout fluid can be used as the bearing fluid and mixing at the HPout port can be reduced. By providing the HPout fluid to the radial and axial bearings, the HPin fluid can be isolated and the possibility of increased mixing through leakage from the bearing gaps can be prevented.

[0124] The HPout fluid is supplied to the radial bearings of the pressure exchanger and may be used to fill the center bore of the rotor (see, for example, FIGS. 3I-J).

[0125] 3I, the PX 300 may include a fluid bypass 350 (e.g., HPout fluid bypass) according to certain embodiments. Fluid may enter between the housing 352 and the end cover 310 (e.g., LPin end cover) and flow between the housing 352 and the sleeve 301 through openings in the sleeve 301 (e.g., to supply the radial bearings of the pressure exchanger and / or fill the center bore). In some embodiments, the fluid bypass 350 (e.g., HPout fluid bypass) may go around a gasket (e.g., an O-ring) between the housing 352 and the end cover 310 and supply the PX radial bearings through holes in the sleeve.

[0126] 3J, the PX 300 may include a fluid bypass 350 (e.g., an HPout fluid bypass) and / or a slot 354 according to certain embodiments. The fluid bypass 350 may be a gasket (e.g., an O-ring) HPout fluid bypass and may feed the PX radial bearing through a hole in the sleeve. A slot 354 in the end cover 310 (e.g., an HPout end cover) may be used to communicate the HPout fluid to a center bore 356 (e.g., a central portion of the rotor 320 between the rotor 320 and the shaft).

[0127] In some embodiments, the length-to-diameter (L / D) ratio and circularity of the duct 322 are maximized. Mixing in the rotor duct can be a strong function of turbulence, and its effects can be greatly reduced by controlling the L / D ratio and circularity of the duct. Inserts can be added to the rotor 320 to achieve a desired duct shape, approach "liquid plug" flow, and achieve reduced mixing in the rotor duct.

[0128] The present disclosure may be used in a rotary pressure exchanger to reduce mixing of two fluids exchanging pressure energy.

[0129] The present disclosure may include features such as ramps (eg, kidney ramps), spot faces 340, filters, etc. (eg, to reduce mixing).

[0130] The present disclosure reduces mixing of fluids in the pressure exchanger and improves the overall energy consumption per unit volume (e.g., of potable water produced in a SWRO plant). The present disclosure is applicable to different pressure exchanger applications (e.g., isobaric pressure exchangers) such as SWRO, sCO2, industrial wastewater, etc. The present disclosure may also be applicable to pressure exchanger architectures such as rotor-sleeved or sleeveless pressure exchangers (e.g., rotor with center post), and motorized or non-motorized PX. The present disclosure may be similarly applicable to different applications for reducing mixing of LPin into LPout as appropriate.

[0131] Figures 4A-K show components of a pressure exchanger 300 (e.g., PX 40 of Figures 2A-E, pressure exchanger 300 of one or more of Figures 3A-P) according to certain embodiments. Features in Figures 4A-K having similar names and / or reference numbers as features in one or more of Figures 1A-2E and / or one or more of Figures 3A-P may include the same or similar structure, materials, function, and / or the like as features in one or more of Figures 1A-2E and / or one or more of Figures 3A-P. In some embodiments, one or more features of PX 300 of Figures 4A-K increase the efficiency of the fluid in PX 300.

[0132] In some embodiments, the pressure exchanger 300 may include a rotor 320 and an end cover 310. The rotor 320 is configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The rotor 320 defines a duct 322 routed from a first distal end of the rotor 320 to a second distal end of the rotor 320.

[0133] In some embodiments, the radial edges of the kidney inlet and outlet of the end cover 310 may coincide with those of the rotor 320.

[0134] In some embodiments, the PX 300 uses streamlined (lofted) spacers in the end cover 310.

[0135] In some embodiments, non-metallic PVC spacers are used in the PX 300 to handle axial thrust and to prevent fretting between the ceramic end covers 310 and the metallic interfaces.

[0136] In some embodiments, the radial and axial bearing clearances are optimized for a target circumferential groove pressure.

[0137] In some embodiments, the ports in the end cover 310 are maximized to be substantially the same size as one duct 322 in the rotor 320 plus one wall sealing area to reduce differential pressure (DP) losses.

[0138] In some embodiments, the pressure loads are substantially balanced on both rotor faces of rotor 320.

[0139] In some embodiments, the duct shape of the duct 322 substantially matches the ports (eg, kidneys) of the end cover 310 (eg, trapezoidal or triangular rather than circular).

[0140] In some embodiments, an end cover 310 (e.g., a first end cover) is disposed at a distal end (e.g., a first distal end) of the rotor 320, and the end cover 310 forms an HPin port configured to supply a first fluid at a first pressure into the duct 322 and an LPout port configured to receive the first fluid at a third pressure from the duct 322, the third pressure being lower than the first pressure. One or more side walls (e.g., radial side walls 314) of the end cover forming the HPin port and / or the LPout port are substantially planar (e.g., straight edges 401, not curved edges 402) (see, e.g., FIG. 4B). In some embodiments, the one or more side walls of the first end cover 310 forming the HPin port have substantially straight edges 401 that substantially match corresponding substantially straight edges of the duct 322 formed by the rotor 320.

[0141] In some embodiments, end cover 310 is disposed at a distal end (e.g., a second distal end) of rotor 320, and the end cover forms an LPin port configured to supply a second fluid at a second pressure to duct 322 and forms an HPout port configured to receive the second fluid at a fourth pressure from duct 322, the fourth pressure being higher than the second pressure.

[0142] In some embodiments, the end cover 310 (e.g., forming an HPin port and an LPout port, forming an LPin port and an HPout port) includes a substantially planar radial sidewall 314 (e.g., a non-curved radial sidewall 314) forming the ports 312 (e.g., HPin port, HPout port), an inner wall 316, and an outer wall 318. The first substantially radial sidewall 314 may be disposed between a center of the end cover 310 and an outer periphery of the end cover 310. The inner wall 316 may be proximate the center of the end cover 310, and the outer wall 318 may be proximate the outer periphery of the end cover 310.

[0143] The rotor 320 may form concentric rows of ducts 322 (see, e.g., FIGS. 4C-D). The ratio of the multiple concentric rows to the rotor 320 diameter in inches may be about 0.3 to about 0.45 (e.g., about 0.375 to about 0.42). The rotor 320 may form at least three concentric rows of ducts 322.

[0144] The pressure exchanger 300 may include a first interconnect 420 configured to supply a first fluid to an HPin port of the end cover 310, and a first spacer 410 (see, e.g., FIG. 4E) disposed within the end cover 310 disposed between the first interconnect and the HPin port (see, e.g., FIG. 4F). The pressure exchanger 300 may include a second interconnect 420 configured to receive the first fluid from an LPout port of the end cover 310, and a second spacer 410 (see, e.g., FIG. 4E) disposed within the first end cover disposed between the LPin port and the second interconnect (see, e.g., FIG. 4F). In some embodiments, the first spacer and / or the second spacer are thermoplastic materials. In some embodiments, the first spacer and / or the second spacer are polyvinyl chloride (PVC).

[0145] 4G-4H show PX 300, according to certain embodiments. In some embodiments, PX 300 may have bearing stiffness tuned to reduce leakage by centering rotor 320 and optimizing diametral clearance 303 (e.g., radial clearance) and axial clearance 304 (e.g., axial bearing clearance, height difference between sleeve and rotor or center post and rotor).

[0146] In the PX 300 (e.g., rotary pressure exchanger), the rotor 430 is separated from the stator (e.g., end cover 310, sleeve 301) with small radial (e.g., diametral clearance 303 between sleeve 301 and rotor 320 or center post 302 and rotor 320) and axial (e.g., axial clearance 304 between end cover 310 and rotor 320) clearances. During operation, the rotor 320 is suspended in the clearances by the stiffness of the fluid film in the radial and axial bearings generated by hydrodynamic and hydrostatic effects, respectively. For minimum bearing flow (leakage losses), the rotor 320 should have minimum clearance and be axially centered (e.g., minimum axial eccentricity). The minimum clearances are set by manufacturing constraints and material stiffness constraints. Minimal eccentricity may be achieved by maintaining the ratio between diametral clearance 303 and axial clearance 304 within a narrow range of about 1 to about 3.5. Such an arrangement may provide an intermediate plenum pressure (e.g., optimal intermediate plenum pressure) between the two bearings (e.g., in circumferential plenum 305). As a result, axial rotor eccentricity is low (e.g., minimal axial rotor eccentricity), and in so doing, leakage losses are minimized.

[0147] In some embodiments, the ratio of diametral clearance 303 (e.g., diametral clearance, radial clearance, radial clearance) to axial clearance 304 is between about 1 and about 3.5. Diametral clearance 303 is between rotor 320 and sleeve 301 or between rotor 320 and center post 302. Axial clearance 304 is between rotor 320 and end cover 310.

[0148] Figure 4I illustrates a rotor 320, according to certain embodiments. Figure 4J illustrates an end cover 310, according to certain embodiments. Figure 4K illustrates a PX 300 with the rotor 320 stacked on the end cover 310, according to certain embodiments. As shown in Figures 4I-K, the seal angle 313 between the ports 312 of the end cover 310 can be at least equal to the duct angle 323 of the rotor 320 plus the duct wall angle 324.

[0149] In some embodiments, the angular spacing between the HPin and LPout ports of the first end cover 310 substantially matches the corresponding angular spacing between a first leading radial sidewall of the first duct 322 of the rotor 320 and a second leading radial sidewall of the second duct 322 adjacent to the first duct 322.

[0150] Fluid flow in the ducts of a rotary pressure exchanger can be unsteady, with rapid acceleration and deceleration in both directions during each revolution. This creates a pressure loss through the rotor that is necessary to overcome the inertia of the fluid. Other than reducing the rotor speed (which can result in increased mixing), this inertial pressure loss can also be minimized by maximizing the flow area of ​​the kidneys (e.g., ports 312 of the end cover 310). This results in lower acceleration for the same flow rate, providing reduced inertial pressure loss. To prevent direct communication between one kidney and the next (e.g., between ports 312), a minimum amount of sealing angle of the end cover 310 can be maintained that is substantially equal (e.g., equal) to the angular spacing between the ducts 322 (duct angle 323 plus duct wall angle 324).

[0151] The present disclosure may optimize the pressure exchanger 300 (eg, an isobaric pressure exchanger) for efficiency, mixing, cavitation, noise, and cost.

[0152] Traditionally, features that attempt to increase efficiency by increasing travel distance end up increasing mixing inside the pressure exchanger. The present disclosure can maximize efficiency (e.g., by reducing mixing, by maintaining the same amount of mixing) at similar travel distances as traditional pressure exchangers without having a negative impact on mixing performance.

[0153] The present disclosure may be used in different pressure exchanger applications (e.g., isobaric pressure exchangers) such as SWRO, sCO2, industrial wastewater (e.g., using pressure exchangers for energy recovery), etc. The present disclosure may also be used in pressure exchanger architectures such as rotor-sleeved or sleeveless pressure exchangers (e.g., rotor with center post), and different motorized or non-motorized pressure exchangers.

[0154] The present disclosure may be used to reduce pressure loss due to fluid inertia using the radial edges of the inlet and outlet of the ports 312 (e.g., kidneys). Traditionally, a significant amount of pressure loss in the rotor 320 occurs due to sudden acceleration and deceleration of the flow inside the rotor 320. The differential pressure that causes the flow to accelerate inside the duct 322 of the rotor 320 (e.g., the pressure loss when the flow is accelerated inside the rotor duct in terms of dQ / dt) may be given as shown in Equation 1:

[0155]

number

[0156] Q duct is the flow rate through each duct 322.

[0157] dQ duct / dt is the rate of change of flow in duct 322 (eg, acceleration, deceleration).

[0158] L duct is the length of the duct 322.

[0159] Aduct is the area of ​​the duct 322.

[0160] dt is the time that the duct 322 is open to the port 312 (eg, kidney).

[0161] dP fluid_inertia (For example, ΔP fluid_inertia ) is the pressure loss of a fluid due to acceleration and / or deceleration.

[0162] Since dt = ω × dθ, Equation 1 can be rewritten as Equation 2 (for example, the pressure loss during acceleration of the flow inside the rotor duct is expressed in terms of dQ / dθ):

[0163]

number

[0164] In formula 2, dP fluid_inertia (For example, ΔP fluid_inertia ) can be reduced by reducing dQ / dθ.

[0165] Conventional end covers may have curved edge sidewalls that form the ports. In some embodiments, the end cover 310 of the present disclosure includes a substantially planar radial sidewall 314 (e.g., radial edge end cover 310). Using radial edge ports may cause an increase in the effective kidney angle for the center and outermost ducts (e.g., about 26% for the outermost duct) compared to curved edge ports. The radial edges of the ports 312 may cause the trapezoidal shape of the ports 312 to match the trapezoidal shape of the ducts 322 of the rotor 320.

[0166] In some embodiments, pressure loss due to fluid inertia can be reduced by maximizing rotor flow through selection of the number and shape of rotor ducts. Within rotor 320, duct passages serve to convey the flow from the inlet port to the outlet port. The greatest amount of pressure loss can occur within rotor 320. By increasing the flow area of ​​the rotor ducts, pressure loss can be reduced without having a negative effect on mixing. The constraint can be that the stress is below the material strength of rotor 320.

[0167] In some embodiments, the rotor 320 has a trapezoidal shaped duct 322 with large fillets that utilize the available area by maximizing the flow area of ​​the duct and preventing high stress concentrations (see, for example, FIG. 4C).

[0168] In some embodiments, the number of concentric rows is selected to maximize the rotor duct flow area while minimizing the maximum duct area and meeting material strength criteria, which helps achieve an effective hydraulic diameter similar to a circular equivalent (e.g., preventing high aspect ratio ducts).

[0169] In some embodiments, the rotor 320 has an odd number of ducts 322 (e.g., a non-even number of ducts) to prevent the ducts 322 from being symmetrically opened at the same time on opposite symmetrical positions across a port, reducing noise and vibration in the pressure exchanger 300.

[0170] In some embodiments, the rotor 320 has staggered ducts that reduce the overall amount of duct volume that is pressurized and / or depressurized at one time, which reduces noise and vibration in the pressure exchanger.

[0171] In some embodiments, the rotor 320 has at least two concentric rows of ducts 322. In some embodiments, the rotor 320 has at least three concentric rows of ducts 322.

[0172] In some embodiments, a spacer (e.g., a lofted spacer, a streamlined spacer) is used to provide flow to the HPout port, and the LPout port is guided to minimize shock losses at the exit due to flow separation.

[0173] The flow exiting the rotor duct into the outlet port has both axial and tangential components of velocity. The axial velocity component may not vary significantly with the radius of the rotor 320. The tangential component varies linearly with the radius. The outlet port (e.g., LPout port, HPout port) walls may be designed to allow the duct flow to exit through the port 312 smoothly without separation. The port side walls (e.g., kidney walls) may be configured to accommodate the change in the ratio of the tangential and axial components of velocity with respect to the radius. By preventing flow separation at the outlet, both differential pressure losses and mixing losses are reduced. The mixing zone may be closest to the duct outlet at the outlet port (e.g., outlet kidney) of the end cover 310.

[0174] Spacers 410 (e.g., streamlined spacers, streamlined lofted spacers) may be used to reduce pressure loss. In some embodiments, spacers may be used to eliminate the use of thrust rings and / or reduce pressure loss due to sudden area changes between the LP ports and the interconnect. Spacers 419 (e.g., lofted spacers) may be used to smooth the flow and avoid pressure loss due to sudden area changes. In some embodiments, PX 300 may include a spacer 410 with a lofted shape that transitions from the rounded shape of the interconnect to the non-rounded shape of the corresponding port in first end cover 310.

[0175] A non-metallic spacer 410 (e.g., a non-metallic streamlined spacer) may be used to handle axial thrust and avoid fretting corrosion between the ceramic end cover 310 and the metallic interconnects (e.g., end covers 310 using interconnects without the spacer 410 may have fretting corrosion issues). The spacer 410 (e.g., streamlined spacer) may be made of polyvinyl chloride (PVC) (e.g., this may eliminate the need for thrust rings used in conventional pressure exchangers). The thrust rings transfer the axial force from the ceramic cartridge to the housing through the seal plate and bearing plate. The use of a PVC spacer 419 (e.g., injection molded for cost reduction) acts as a buffer material between the metallic LP interconnects and the ceramic end cover 310. This allows the freedom to choose any material (e.g., 2507 Super Duplex, AL6XN) as the LP interconnect material that is compatible with the application fluid (e.g., seawater application) and pressure rating.

[0176] In some embodiments, the leading and trailing radial sidewalls of the LPout and HPout ports are not axial. The leading and trailing radial sidewalls of the LPout and HPout ports may be inclined at an angle substantially proportional to the revolutions per minute of the rotor. The angle may be between about 30 and about 70 degrees.

[0177] The losses of fluid acceleration and deceleration (e.g., fluid inertia) can be offset by increasing the available time to fill the rotor ducts by increasing the effective angular extent of the ports by making the port edges radial (e.g., substantially planar radial sidewalls 314), and by maximizing the flow area of ​​the rotor while meeting stress and manufacturing constraints to reduce the peak fluid velocity (e.g., V) inside the rotor 320. max ) can be reduced.

[0178] In some embodiments, the spacer 410 (e.g., a lofted spacer) can help reduce fretting corrosion between the super duplex or stainless steel metal and aluminum oxide (AL2O3), and can smooth the flow in and out of the ports to reduce fluid loss due to friction. This can avoid the use of more exotic materials such as titanium for the interconnect 420. The spacer (e.g., a lofted spacer) can combine three functions: smooth the flow, reduce fluid loss due to sudden area changes, act as a compatible material between the metallic interconnect 420 and the brittle ceramic, and handle the net thrust of the cartridge due to pressure imbalance. This can prevent the use of a separate thrust ring.

[0179] For example, trapezoidal shaped ducts 322, an odd number of ducts 322, at least three concentric rows of ducts 322 while keeping the volume of a single duct to a minimum, and / or similar features may be used to maximize rotor efficiency.

[0180] Figures 5A-J show components of a pressure exchanger 300 (e.g., PX 40 of Figures 2A-E, pressure exchanger 300 of one or more of Figures 3A-4K) according to certain embodiments. Features in Figures 5A-J having similar names and / or reference numbers as features in one or more of Figures 1A-2E and / or one or more of Figures 3A-4K may include the same or similar structure, materials, function, and / or the like as features in one or more of Figures 1A-2E and / or one or more of Figures 3A-4K. In some embodiments, one or more features of PX 300 of Figures 5A-J reduce cavitation and / or noise of PX 300.

[0181] The pressure exchanger 300 includes a rotor 320 and an end cover 310. The rotor 320 is configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure. The rotor 320 defines a duct 322 routed from a first distal end of the rotor 320 to a second distal end of the rotor 320.

[0182] End cover 310 (e.g., disposed at a distal end of rotor 320) forms an HPin port configured to supply a first fluid at a first pressure into duct 322 and forms an LPout port configured to receive the first fluid at a third pressure from duct 322, the third pressure being lower than the first pressure.

[0183] In some embodiments, the PX300 provides a spot face at the LPin open but not at the LPout open (eg, so that reduced pressure in the HP duct occurs at LPin, which is at a higher pressure than LPout).

[0184] In some embodiments, the duct opens to a spot face that is at the ID of the duct rather than the OD of the duct (e.g., by adjusting the angle of the edge of the spot face or curving the wall of the spot face towards or away from the duct).

[0185] In some embodiments, the spot face has a shorter radial extent than that of the duct 322 (eg, reducing the diameter at which the duct opens to the kidney, reducing tangential velocity and the likelihood of cavitation).

[0186] In some embodiments, the PX 300 includes split spot faces (e.g., in one or more end covers 310), either one for each row of ducts or grouped together for sets of ducts, allowing the spot faces to be adjusted separately for each row of ducts 322.

[0187] In some embodiments, the PX300 optimizes adjacent row duct volumes and staggered ducts.

[0188] In some embodiments, the spot face geometry may include (a) a substantially constant depth spot face, (b) a substantially linear depth spot face, (c) a stepped-out EC (end cover), and / or (d) a pre-load hole.

[0189] In some embodiments, the spot face angle range, radius range, and ramp angle may be optimized for different fluids and operating environments.

[0190] In some embodiments, the rotor 320 may include a C-chamfer on the trailing edge of the rotor duct wall, which increases the flow coefficient (Cd).

[0191] End cover 310 (e.g., disposed at a distal end of rotor 320) forms an LPin port configured to supply a second fluid at a second pressure into duct 322 and forms an HPout port configured to receive the second fluid at a fourth pressure, higher than the second pressure, from duct 322 (e.g., FIG. 5B). End cover 310 forms a first spot face 340 proximate the LPin port and a second spot face 340 proximate the HPout port.

[0192] In some embodiments, the end cover 310 forms an LPout port without forming a spot face 340 adjacent to the LPout port, and forms an HPin port without forming a spot face 340 adjacent to the HPin port (e.g., FIG. 5A).

[0193] In some embodiments, for SWRO, a spot face 340 is formed adjacent to the LPin port and a spot face 340 is formed adjacent to the HPout port to minimize mixing at the HPout port (e.g., a spot face at LPout that could cause cavitation is not formed at LPout because the LPout pressure is lower than the threshold pressure).

[0194] In some embodiments, for refrigeration, a spot face 340 is formed adjacent to the LPout port and a spot face 340 is formed adjacent to the HPout port to minimize mixing at the LPout and HPout ports (e.g., the LPout pressure is higher than the threshold pressure so there is a low risk of cavitation).

[0195] In some embodiments, the end cover 310 forms a C-chamfer 311 at the LPin port that is configured to vary the corresponding angle of the first spot face 340 for each concentric row of ducts of the rotor 320 (see, e.g., FIG. 5C ). The C-chamfer 311 at the LPin port is configured to vary the corresponding angle for each duct exposed to the spot face, which can vary the amount of pressurization (e.g., pressurization and / or depressurization) of the ducts in different rows.

[0196] In some embodiments, the first spot face 340 has a radial extent that is smaller than the duct radial extent of the corresponding duct 322 formed by the rotor 320 (see, for example, FIGS. 5D-F).

[0197] In some embodiments, the first spot face 340 (e.g., a split spot face) comprises a first recess associated with the first concentric row of ducts 322 and a second recess associated with the second concentric row of ducts 322 (e.g., see FIG. 5G).

[0198] In some embodiments, rotor 320 forms concentric, staggered ducts 322 (see, eg, FIGS. 5H-I).

[0199] In some embodiments, the duct openings of the rotor 320 to the corresponding end cover spot faces are on the duct inner diameter by adjusting the angle of the spot face edges or by curving the spot faces for each duct opening.

[0200] In some embodiments, the end cover 310 (e.g., forming the LPin and HPout ports) defines a preload hole proximate the first spot face 340. The preload hole is configured to pressurize and / or depressurize at least a portion of the pressure exchanger proximate the end cover 310 (e.g., forming the LPin and HPout ports).

[0201] 5J shows a rotor according to certain embodiments. In some embodiments, the rotor 320 forms a C-chamfer on the trailing edge of the rotor duct wall. The C-chamfer on the training edge of the rotor duct wall can increase the flow coefficient (Cd) of the rotor 320.

[0202] Adding a C-chamfer or fillet on the trailing edge of the rotor duct wall may increase the effective area (flow coefficient) for the reduced pressure jet entering the low pressure kidney from the high pressure duct. This increase in effective area may reduce the jet velocity and the resulting drop in local fluid static pressure, thereby reducing the likelihood of cavitation. Similarly, a C-chamfer or fillet may be used on the leading edge of the rotor duct wall to increase the effective area (flow coefficient) for the pressurized jet entering the duct 322 from the kidney. In some embodiments, these features also reduce noise and vibration by reducing the peak jet velocity.

[0203] The present disclosure may provide control of cavitation, noise, and vibration in a pressure exchanger 300 (eg, a rotary isobaric pressure exchanger).

[0204] In a pressure exchanger (e.g., a rotary isobaric pressure exchanger), a rotating duct conveys high pressure fluid from a high pressure kidney (port) towards a low pressure kidney and low pressure fluid from a low pressure kidney to a high pressure kidney. The fluid in the duct experiences rapid pressurization and depressurization whenever it approaches a paired kidney. The frequency and speed of pressurization and / or depressurization depend on the rotor RPM, the number of cycles per revolution of the pressure exchanger, and the pressure difference between the HP and LP kidneys. This rapid pressurization and / or depressurization creates high velocity fluid jets, generating noise, creating flow and pressure oscillations, and increasing vibration levels. This can create bubbles if the local fluid pressure falls below the vapor pressure for that temperature (e.g., due to a high velocity of local fluid pressure). These bubbles break when they move to an area of ​​higher pressure, causing cavitation and the inflow of surrounding fluid, creating very high local pressure spikes. If these occur adjacent to a solid wall they can cause pitting damage which can accumulate over time, causing cavitation and also amplifying noise and vibration levels.

[0205] The spot faces 340 (e.g., channels, notches, recesses) can be used to control the rate of pressurization or depressurization of the rotor duct 322, thereby reducing noise, vibration, and risk of cavitation damage. The present disclosure includes spot faces 340 with increased effectiveness without adversely affecting other performance parameters of the pressure exchanger, such as mixing or efficiency.

[0206] In some embodiments, the pressure exchanger 300 may have a spot face 340 at the LPin port without having a spot face 340 at the LPout port.

[0207] As the duct 322 carrying high pressure fluid approaches the LPin and LPout ports, the rate of depressurization of the duct fluid can be controlled by incorporating spot faces 340 at either or both of the LPin port inlet and the LPout port inlet. The pressure at the LPout port is less than the pressure at the LPin port due to viscous and inertial losses in the duct 322 of the rotor 320. In some embodiments (e.g., a typical SWRO), the LPout pressure can be approximately half of the LPin pressure while using the pressure exchanger 300 as an energy recovery device. Thus, by placing a spot face 340 of a given geometry at the LPin inlet but not the LPout inlet, depressurization of the duct occurs with a smaller pressure gradient (e.g., lower jet velocity), which can result in reduced cavitation potential, noise, and vibration levels.

[0208] In some embodiments, the pressure exchanger 300 includes a spot face 340 at the LPin port (eg, but not at the LPout port) and / or at the HPout port (eg, but not at the HPin port).

[0209] As the duct 322 carrying low pressure fluid approaches the HP port, the rate of pressurization of the duct can be controlled by incorporating a spot face 340 at either or both of the inlets of the HPin and HPout ports. The pressure at the HPout port is less than the pressure at the HPin port due to viscous and inertial losses in the rotor duct. Thus, by placing a spot face 340 of a given geometry at the HPout inlet rather than the HPin inlet, pressurization of the duct occurs with a smaller pressure gradient (e.g., lower jet velocity), resulting in reduced cavitation potential, noise, and vibration levels.

[0210] In some embodiments, the duct 322 opens to a spot face 340 at the duct inner diameter (ID) rather than at the duct outer diameter (OD). The fluid in the duct 322 experiences a rotational motion, e.g., the tangential component of the fluid's velocity increases linearly with radius. In addition, the pressure of the fluid in the duct increases from the ID to the OD due to the centrifugal head caused by the centripetal acceleration of the fluid. When a duct carrying high pressure fluid approaches the spot face 340 of the inlet of the low pressure kidney, a reduction in pressure occurs through a jet along the spot face 340 from the ID of the duct rather than the OD of the duct. This can be achieved by adjusting the relative angle between the spot face 340 and the duct 322 to bring them closer together. This can also be achieved by curving the duct wall and / or the wall of the spot face 340 closer or further away from the duct 322.

[0211] In some embodiments, a C-chamfer at the LPin port (e.g., LPin open) can change the included angle of the spot face 340 for different rows of ducts 322. In some embodiments, the spot face 340 can be contoured to the duct 322. In some embodiments, the spot face 340 can have a shorter radial extent than that of the duct 322. Both the tangential velocity and pressure of the fluid in the rotor duct can increase with respect to the radial coordinate. A way to prevent jetting and decompression at the maximum radius is by shortening the radial extent of the spot face 340 (e.g., a spot face 340 having a smaller radial extent that is shorter than the radial extent of the duct 322).

[0212] In some embodiments, the end cover 310 forms split spot faces 340 (eg, one for each row of ducts, or grouped together for sets of rows).

[0213] The pressure exchanger 300 may include multiple rows of ducts 322 formed by the rotor 320. Each row may have a different duct geometry resulting in a different volume of fluid to be pressurized and / or depressurized. The tangential velocity and pressure of the fluid may vary from row to row. A tailored spot face 340 for each row of ducts 322 may be more effective at reducing noise, vibration, and cavitation than a single spot face 340 that covers all rows. In some embodiments, a single spot face 340 with a geometry that varies along the radius (e.g., with respect to the ramp angle) is used.

[0214] In some embodiments, the ducts may be volumetrically optimized (e.g., trapezoidal shaped ducts in one or more rows). In some embodiments, the ducts in adjacent concentric rows may be staggered.

[0215] Smaller sized ducts can be created by splitting the rotor duct into multiple rows instead of a single row while keeping the overall rotor duct volume substantially the same. Staggering the rows of ducts so that the ducts in each row approach the kidneys at different moments allows for depressurization and / or pressurization of a single duct in a single row at a time. This allows for a shallower ramp of the spot face 340 and reduced pressure gradient across the duct wall.

[0216] Staggering the rows of ducts can result in more uniform flow and pressure (eg, individual duct volumes are minimized), which can result in reduced vibration levels.

[0217] In some embodiments, various spot face 340 geometries may be used and may be combined with one or more pre-compression or decompression holes.

[0218] In some embodiments, one or more of the angular extent, radial extent, and / or slope of the spot face 340 may be optimized for different fluids.

[0219] The depth, radius, and angular extent of the spot face 340 may depend on the pressure exchanger geometry (e.g., duct size, duct wall thickness), pressure exchanger flow rate, HP / LP pressure ratio, rotor RPM, fluid type, etc. In some embodiments, the more compressible the fluid, the larger the volume of the spot face 340 can be to pressurize and / or depressurize the rotor duct.

[0220] The present disclosure may be used to reduce cavitation potential, noise, and / or vibration levels. In addition to reducing RPM, the present disclosure may reduce the number of cycles of pressure exchangers, include pre-load and / or decompression holes, and / or use spot faces 340, and the like.

[0221] The present disclosure may reduce noise emissions, vibration levels, and potential for cavitation in energy recovery applications using pressure exchangers.

[0222] The present disclosure may be used for the use of pressure exchangers for energy recovery in, for example, SWRO, transcritical CO2 refrigeration / heat pumps, industrial wastewater, etc.

[0223] In the above description, numerous specific details are described, such as examples of specific systems, components, methods, etc., to fully understand some embodiments of the present disclosure. However, it will be apparent to one skilled in the art that at least some embodiments of the present disclosure may be practiced without such specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram form to avoid unnecessarily obscuring the present disclosure. Thus, the specific details described are merely exemplary. A particular implementation may vary from such example details and still be considered within the scope of the present disclosure. The description of the system herein may include a description of one or more optional components. Components may be included in combinations not specifically discussed in the present disclosure, and such components may still be within the scope of the present disclosure.

[0224] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that 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. Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". When the terms "about", "substantially" or "approximately" are used herein, this is intended to mean that the stated nominal value is accurate to within 10%. In addition, the terms "first", "second", "third", "fourth", etc., used herein are intended as labels to distinguish different elements and do not necessarily have an ordinal meaning according to their numerical designations.

[0225] As used herein, the terms "above," "below," "between," "disposed on," and "on" refer to the relative location of a layer of material or component with respect to another layer or component. For example, a layer that is disposed above, across, or below another layer may be in direct contact with the other layer or there may be one or more intervening layers. Further, a layer that is disposed between two layers may be in direct contact with the two layers or there may be one or more intervening layers. Similarly, unless expressly stated otherwise, a feature that is disposed between two features may be in direct contact with the adjacent feature or there may be one or more intervening layers or components.

[0226] Although the method operations herein are shown and described in a particular order, the order of the method operations may be changed such that certain operations may be performed in the reverse order or certain operations may be performed, at least in part, simultaneously with other operations. In other embodiments, different operation instructions or sub-operations may be performed intermittently and / or interleaved. In one embodiment, multiple metallurgical bonding operations are performed as a single step.

[0227] It is to be understood that the above description is intended to be illustrative, and not limiting. Many other embodiments will be apparent to those skilled in the art upon reading and understanding the above description. Thus, the scope of the present disclosure should be determined with reference to the appended claims, along with the full scope of equivalents to which each claim is entitled.

Claims

1. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor forming a duct routed from a first distal end of the rotor to a second distal end of the rotor; a first end cover disposed at the first distal end of the rotor, the first end cover defining a high pressure in (HPin) port configured to supply the first fluid at the first pressure substantially axially into the duct, and the first end cover defining a low pressure out (LPout) port configured to receive the first fluid from the duct at a third pressure lower than the first pressure; a second end cover disposed at the second distal end of the rotor, the second end cover defining a low pressure in (LPin) port configured to supply the second fluid at the second pressure into the duct, and a high pressure out (HPout) port configured to receive the second fluid at a fourth pressure higher than the second pressure from the duct.

2. the first end cover includes a first radial sidewall, a first inner wall, and a first outer wall forming the HP in port, the first radial sidewall being disposed between a first center of the first end cover and a first outer periphery of the first end cover, the first inner wall being proximate the first center of the first end cover, and the first outer wall being proximate the first outer periphery of the first end cover; the second end cover includes a second radial sidewall, a second inner wall, and a second outer wall forming the HPout port, the second radial sidewall being disposed between a second center of the second end cover and a second outer periphery of the second end cover, the second inner wall being proximate to the second center of the second end cover and the second outer wall being proximate to the second outer periphery of the second end cover; and 2. The pressure exchanger of claim 1, wherein the first radial sidewalls of the HPin port are at least two degrees closer to each other than the second radial sidewalls of the HPout port are.

3. 2. The pressure exchanger of claim 1, wherein a leading radial sidewall of the HPin port is configured to open to a corresponding duct of the rotor after a corresponding leading radial sidewall of an HPout port opens to the corresponding duct of the rotor at least twice.

4. 2. The pressure exchanger of claim 1, wherein a trailing radial sidewall of the HPin port closes against a corresponding duct of the rotor at least twice before a corresponding trailing radial sidewall of the HPout port closes against the corresponding duct of the rotor to reduce mixing between corresponding HPin and HPout ports.

5. The pressure exchanger of claim 1 , wherein one or more radial sidewalls of the HPout port are biased to reduce mixing in the LPout port.

6. 2. The pressure exchanger of claim 1, wherein a trailing radial sidewall of the LPin port closes against a corresponding duct of the rotor at least twice before a corresponding trailing radial sidewall of the LPout port closes against the corresponding duct of the rotor to reduce mixing between the corresponding LPin port and the LPout port.

7. 2. The pressure exchanger of claim 1, wherein a leading radial sidewall of the LPin port closes against a corresponding duct of the rotor at least two degrees before a corresponding leading radial sidewall of the LPout port closes against the corresponding duct of the rotor, reducing mixing of corresponding fluids between the LPin port and the LPout port.

8. the first end cover forms a fillet between at least one of the first radial sidewalls and the first inner wall; and 3. The pressure exchanger of claim 2, wherein the fillet of the first end cover is configured to close the HPin port to a duct of the rotor before the HPout port of the second end cover closes to the duct.

9. the first radial side walls of the first end cover each define a ramp; and 3. The pressure exchanger of claim 2, wherein said second radial side wall of said second end cover does not define a ramp and defines said HPin port.

10. the first radial side walls of the first end cover each define a ramp in a rotational direction; and 3. The pressure exchanger of claim 2, wherein the second radial sidewall of the second end cover forms the HPin port having a ramp in the direction of rotation, and the first radial sidewall forms a leading sidewall and a trailing sidewall on the HPin port, the leading sidewall and the trailing sidewall each having a corresponding varying ramp angle measured from about 30 degrees to about 70 degrees relative to a plane of the rotor.

11. 3. The pressure exchanger of claim 2, wherein a leading radial sidewall and a trailing radial sidewall on the LPin port form a ramp in a rotational direction, the ramp having a varying ramp angle measured from about 30 degrees to about 70 degrees relative to a plane of the rotor.

12. 3. The pressure exchanger of claim 2, wherein the first radial sidewall defines a non-planar three-dimensional ramp defined by at least two helices at an innermost and outermost radius of the port.

13. 13. The pressure exchanger of claim 12, wherein the corresponding ramps of the non-planar three-dimensional ramps are defined by helices, the helices having pitches proportional to the radius on which the corresponding ramps are positioned to reduce the angle of incidence.

14. 2. The pressure exchanger of claim 1, wherein the pressure exchanger comprises an insert disposed in the HPin port, the insert configured to guide flow and reduce an angle of incidence of the flow at the rotor.

15. 2. The pressure exchanger of claim 1, further comprising an insert disposed in the LPin port, the insert configured to guide flow and reduce an angle of incidence of the flow at the rotor.

16. 2. The pressure exchanger of claim 1, wherein the first end cover does not form a spot face at the HPin port and forms a first spot face proximate the HPout port to reduce mixing of corresponding fluids between the HPin port and the HPout port.

17. 2. The pressure exchanger of claim 1, wherein the first end cover does not form a spot face at the LPin port and forms a second spot face proximate the LPout port to reduce mixing of corresponding fluids between the LPin port and the LPout port.

18. The pressure exchanger of claim 1 , wherein the pressure exchanger is configured to use the second fluid provided through the HPout port as a bearing fluid and a centerbore fluid.

19. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor forming a duct routed from a first distal end of the rotor to a second distal end of the rotor; an insert disposed within the duct, the insert providing a length to diameter ratio of about 5 to about 10.

20. 20. The pressure exchanger of claim 19, wherein the insert is a honeycomb shaped flow straightener that is press-fit, shrink-fit, or adhesively bonded to the duct.

21. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor forming a duct routed from a first distal end of the rotor to a second distal end of the rotor; a first end cover disposed at the first distal end of the rotor, the first end cover defining a high pressure in (HPin) port configured to supply the first fluid at the first pressure into the duct, and the first end cover defining a low pressure out (LPout) port configured to receive the first fluid at a third pressure lower than the first pressure from the duct, one or more side walls of the first end cover defining the HPin port or the LPout port being substantially planar; a second end cover disposed at the second distal end of the rotor, the second end cover defining a low pressure in (LPin) port configured to supply the second fluid at the second pressure into the duct, and a high pressure out (HPout) port configured to receive the second fluid at a fourth pressure higher than the second pressure from the duct.

22. 22. The pressure exchanger of claim 21, wherein the one or more side walls of the first end cover forming the HPin port have substantially straight edges, the substantially straight edges substantially coinciding with corresponding substantially straight edges of a duct formed by the rotor.

23. the first end cover includes a first substantially planar radial sidewall, a first inner wall, and a first outer wall forming the HP in port, the first substantially planar radial sidewall being disposed between a first center of the first end cover and a first outer periphery of the first end cover, the first inner wall being proximate the first center of the first end cover and the first outer wall being proximate the first outer periphery of the first end cover; 22. The pressure exchanger of claim 21, wherein the second end cover comprises a second substantially planar radial sidewall, a second inner wall, and a second outer wall forming the HPout port, the second substantially planar radial sidewall being disposed between a second center of the second end cover and a second outer periphery of the second end cover, the second inner wall being proximate the second center of the second end cover, and the second outer wall being proximate the second outer periphery of the second end cover.

24. 22. The pressure exchanger of claim 21, wherein said rotor forms said ducts in a plurality of concentric rows, and the ratio of the number of concentric rows to the length in inches of the diameter of said rotor is between about 0.3 and about 0.

45.

25. 22. The pressure exchanger of claim 21, wherein the rotor defines the ducts in at least three concentric rows.

26. The pressure exchanger comprises: a first interconnect configured to supply the first fluid to the HPin port of the first end cover; a first spacer disposed within the first end cover between the first interconnect and the LPin port; a second interconnect configured to receive the first fluid from the LPout port of the first end cover; and a second spacer disposed within the first end cover between the LPout port and the second interconnect; and 22. The pressure exchanger of claim 21 further comprising:

27. 27. The pressure exchanger of claim 26, wherein at least one of the first spacer or the second spacer is a thermoplastic material.

28. 27. The pressure exchanger of claim 26, wherein at least one of the first spacer or the second spacer is polyvinyl chloride (PVC).

29. 22. The pressure exchanger of claim 21, wherein an angular spacing between the HPin port and the LPout port of the first end cover substantially corresponds to a corresponding angular spacing between a first leading radial sidewall of a first duct of the rotor and a second leading radial sidewall of a second duct adjacent the first duct.

30. 22. The pressure exchanger of claim 21, wherein an angular spacing between the LP in port and the HP out port of the first end cover substantially corresponds to a corresponding angular spacing between a first leading radial sidewall of a first duct of the rotor and a second leading radial sidewall of a second duct adjacent the first duct.

31. the ratio of radial clearance to axial clearance is from about 1 to about 3.5; the radial clearance is between the rotor and a sleeve or between the rotor and a center post; and 22. The pressure exchanger of claim 21, wherein the axial clearance is a height difference between the sleeve and the rotor or a height difference between the centre post and the rotor.

32. The leading and trailing radial sidewalls of the LPout and HPout ports are not axially oriented; the leading and trailing radial sidewalls of the LPout and HPout ports are inclined at an angle substantially proportional to rotor revolutions per minute; and 22. The pressure exchanger of claim 21, wherein the angle is between about 30 degrees and about 70 degrees.

33. 22. The pressure exchanger of claim 21, further comprising a spacer having a lofted shape that transitions the rounded shape of the interconnect of the first end cover to the non-rounded shape of the corresponding port.

34. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor forming a duct routed from a first distal end of the rotor to a second distal end of the rotor; a first end cover forming a first port and a second port, a first substantially straight radial edge of the first port and a second substantially straight radial edge of the second port substantially coinciding with corresponding substantially straight edges of the duct of the rotor.

35. 35. The pressure exchanger of claim 34, further comprising a second end cover forming a third port and a fourth port, a third substantially straight radial edge of the third port and a fourth substantially straight radial edge of the fourth port substantially coinciding with the corresponding substantially straight edges of the duct of the rotor.

36. 35. The pressure exchanger of claim 34, wherein said rotor forms said ducts in a plurality of concentric rows, and the ratio of the number of concentric rows to the length in inches of the diameter of said rotor is between about 0.3 and about 0.

45.

37. 35. The pressure exchanger of claim 34, wherein said rotor defines said ducts in at least three concentric rows.

38. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor forming a duct routed from a first distal end of the rotor to a second distal end of the rotor; a first end cover disposed at the first distal end of the rotor, the first end cover defining a first port and a second port; a first interconnect configured to supply the first fluid to the first port of the first end cover; a first spacer disposed within the first end cover between the first interconnect and the first port.

39. The pressure exchanger comprises: a second end cover disposed at the second distal end of the rotor, the second end cover defining a third port and a fourth port; a second interconnect configured to supply the second fluid to the third port of the second end cover; and a second spacer disposed within the second end cover between the second interconnect and the third port.

39. The pressure exchanger of claim 38.

40. 40. The pressure exchanger of claim 39, wherein at least one of the first spacer or the second spacer is a thermoplastic material.

41. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor forming a duct routed from a first distal end of the rotor to a second distal end of the rotor, the rotor forming a C-chamfer on a trailing edge rotor duct wall; a first end cover disposed at the first distal end of the rotor, the first end cover defining a high pressure in (HPin) port configured to supply the first fluid at the first pressure into the duct, and the first end cover defining a low pressure out (LPout) port configured to receive the first fluid from the duct at a third pressure lower than the first pressure; a second end cover disposed at the second distal end of the rotor, the second end cover defining a low pressure in (LPin) port configured to supply the second fluid at the second pressure into the duct, and a high pressure out (HPout) port configured to receive the second fluid at a fourth pressure higher than the second pressure from the duct.

42. 42. The pressure exchanger of claim 41, wherein said second end cover defines a first spot face proximate said HPout port.

43. 43. The pressure exchanger of claim 42, wherein the pressure exchanger does not form a spot face adjacent the LPout port of a first end cover and forms a second spot face adjacent the LPin port of a second end cover and reduces pressure to a high pressure (HP) duct of the rotor at the LPin port.

44. 42. The pressure exchanger of claim 41, wherein said first end cover does not form a spot face adjacent said HPin port but forms said HPin port.

45. 43. The pressure exchanger of claim 42, wherein the second end cover forms a C-chamfer at the LPin port, the C-chamfer configured to change a corresponding angle for each concentric row of the ducts of the rotor of the first spot face.

46. 46. ​​The pressure exchanger of claim 45, wherein the C chamfer of the LPin port is configured to vary the angle for each duct exposed to the first spot face to vary the amount of pressurization of different rows of ducts.

47. 43. The pressure exchanger of claim 42, wherein the first spot face has a radial extent less than a duct radial extent of a corresponding duct formed by the rotor to reduce a radius at which a rotor duct opens to an end cover port, reducing tangential velocities and potential for cavitation.

48. 43. The pressure exchanger of claim 42, wherein the first spot face comprises a first recess associated with a first concentric row of the ducts and a second recess associated with a second concentric row of the ducts.

49. 42. The pressure exchanger of claim 41, wherein said rotor forms said ducts in staggered concentric rows.

50. 42. The pressure exchanger of claim 41, wherein the rotor duct opening to a corresponding end cover spot face is at a duct inner diameter by adjusting the angle of a spot face edge or the angle of a curved spot face wall to the duct opening.

51. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor defining a duct routed from a first distal end of the rotor to a second distal end of the rotor, the rotor defining the duct in at least two concentric rows including a first concentric row of the ducts and a second concentric row of the ducts; a first end cover disposed at the first distal end of the rotor, the first end cover forming a first port, a second port, and a split spot face proximate to the first port, the split spot face comprising a first recess associated with the first concentric row of the ducts and a second recess associated with the second concentric row of the ducts.

52. 52. The pressure exchanger of claim 51, wherein corresponding ducts in said first and second concentric rows are staggered.

53. 52. A pressure exchanger as claimed in claim 51, wherein said split spot faces have a radial extent less than a duct radial extent of a corresponding duct formed by said rotor.

54. 52. The pressure exchanger of claim 51, wherein the pressure exchanger forms the split spot face adjacent a low pressure in (LPin) port and does not form a spot face adjacent a low pressure out (LPout) port, and reduces pressure in a high pressure (HP) duct of the rotor at the LPin port.

55. 52. The pressure exchanger of claim 51, wherein the rotor forms a C-chamfer on a trailing edge rotor duct wall.

56. 52. The pressure exchanger of claim 51, wherein the rotor forms the ducts in at least three concentric rows including the first concentric row of the ducts, the second concentric row of the ducts, and a third concentric row of the ducts.

57. A pressure exchanger, comprising: a rotor configured to rotate to exchange pressure between a first fluid at a first pressure and a second fluid at a second pressure, the rotor defining a duct routed from a first distal end of the rotor to a second distal end of the rotor, the rotor defining the duct in at least two concentric rows including a first concentric row of the ducts and a second concentric row of the ducts; a first end cover disposed at the first distal end of the rotor, the first end cover forming a first port, a second port, and a spot face, the first end cover forming a C-chamfer on the first port configured to vary a corresponding angle of the spot face for each concentric row of ducts of the rotor, and the C-chamfer of the first port configured to vary an angle for each duct exposed to the spot face to vary an amount of pressurization of different rows of ducts.

58. 58. The pressure exchanger of claim 57, wherein said rotors form said ducts in staggered concentric rows.

59. 58. The pressure exchanger of claim 57, wherein the pressure exchanger forms the spot face adjacent a low pressure in (LPin) port and does not form a spot face adjacent a low pressure out (LPout) port, and reduces pressure in a high pressure (HP) duct of the rotor at the LPin port.

60. 58. The pressure exchanger of claim 57, wherein the rotor forms a C-chamfer on a trailing edge rotor duct wall.

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