TECHNICAL FIELD

[0001] The present disclosure relates to fluid handling systems, and, more particularly, fluid handling systems including a compressor.

BACKGROUND

[0002] Systems use fluids at different pressures. Systems use pumps or compressors to increase pressure of fluid.

BRIEF DESCRIPTION OF THE DRAWINGS

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

[0004] FIGS. 1A-B illustrate schematic diagrams of fluid handling systems including a compressor, according to certain embodiments.

[0005] FIGS. 2A-E are exploded perspective views of pressure exchangers (PXs), according to certain embodiments.

[0006] FIG. 3 is a cross-sectional view of a compressor, according to certain embodiments. [0007] FIG. 4 is a schematic diagram of a fluid handling system including a compressor, according to certain embodiments.

[0008] FIG. 5A is a cross-sectional view of a compressor head, according to certain embodiments.

[0009] FIG. 5B illustrates a valve plate, according to certain embodiments.

[0010] FIG. 5C illustrates a valve plate assembly, according to certain embodiments.

[0011] FIG. 6 is a flow diagram illustrating an example method for operating a compressor, according to certain embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

[0012] Embodiments described herein are related to fluid handling systems that include a compressor (e.g., fluid handling systems, heat transfer systems, pressure exchanger systems, carbon dioxide (CO2) refrigeration systems, CO2 heat pump systems etc.).

[0013] Systems may use fluids at different pressures. These systems may include hydraulic fracturing (e.g., fracking or fracing) systems, desalinization systems, refrigeration systems, heat pump systems, energy generation systems, mud pumping systems, slurry pumping systems, industrial fluid systems, waste fluid systems, fluid transportation systems, etc. Pumps or compressors may be used to increase pressure of fluid to be used by systems. [0014] Conventionally, refrigeration systems provide process fluid to compressors to increase the pressure of the process fluid (e.g., a refrigeration fluid such as CO2, R-744, R- 134a, hydrocarbons, hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), ammonia (NH3), refrigerant blends, R-407A, R-404A, etc.). Compressors are lubricated by oil. Conventionally, lubricating oil is exposed to the process fluid (e.g., at a high pressure) within housing of the compressor. This causes the process fluid to dissolve in the lubricating oil which affects the lubricating properties of the oil. The oil exposed to the process fluid may suffer from reduced viscosity and other reduced lubricating performance attributes, leading to insufficient lubrication of the compressor. Conventional compressors can thus experience excess wear and premature failure from the effects of dissolved process fluid in the lubricating oil, especially when the process fluid is at a high pressure (e.g., above 600 pounds per square inch (PSI)). The impurities in the process fluid of conventional systems can cause damage to components of the refrigeration system and decreased efficiency of the refrigeration system.

[0015] The systems, devices, and methods of the present disclosure provide fluid handling systems (e.g., for refrigeration, for cooling, for heating, etc.) that include a compressor that addresses the shortcomings of conventional compressors discussed above.

[0016] In some embodiments, a system (e.g., fluid handling system, refrigeration system, heat pump system, heat transfer system, CO2 refrigeration system, CO2 heat pump system, etc.) includes a compressor (e.g., a reciprocating compressor, a centrifugal compressor, an axial compressor, a screw compressor, etc.). The compressor may include a first portion configured to house a motor. In some embodiments, the first portion includes a motor housing (e.g., to house a motor) and a crankcase (e.g., to house a crankshaft and/or lubricating oil). The interior of the crankcase may be fluidly coupled to the interior of the motor housing. The compressor may further include a second portion that is configured to be fluidly coupled to the system (e.g., a pressure exchanger (PX) of the system). In some embodiments, the second portion of the compressor is fluidly isolated (e.g., substantially fluidly isolated) from the first portion (e.g., fluid substantially does not flow between the first portion and the second portion of the compressor). The second portion of the compressor may include a compressor inlet and a compressor outlet. In some embodiments, the compressor (e.g., the second portion of the compressor) is configured to receive a first fluid at a first pressure (e.g., via the compressor inlet), compress the first fluid, and provide the first fluid at a second pressure (e.g., via the compressor outlet). In some embodiments, the second pressure is higher than the first pressure.

[0017] In some embodiments, the first portion of the compressor (e.g., the motor housing) is configured to receive a third fluid. In some embodiments, the third fluid is to adjust temperature (e.g., cool or warm) the motor and/or other components of the compressor. In some embodiments, the crankcase is configured to receive the third fluid from the motor housing and output the third fluid. The third fluid may be provided to the first portion of the compressor at a third pressure that is lower than the first pressure.

[0018] In some embodiments, the system further includes a PX that is configured to exchange pressure between the first fluid and a second fluid. In some embodiments, the PX may receive the first fluid via a first PX inlet and the second fluid via a second PX inlet. The PX may exchange pressure between the first fluid and the second fluid. The first fluid may exit the PX via a first PX outlet and the second fluid may exit the PX via a second PX outlet. In some embodiments, when entering the PX, the first fluid may be at a higher pressure than the second fluid and when exiting the PX, the second fluid may be at a higher pressure than the first fluid (e.g., due to the pressure exchange between the first fluid and the second fluid). In some embodiments, when entering the PX, the first fluid may be at a lower pressure than the second fluid and when exiting the PX, the second fluid may be at a lower pressure than the first fluid (e.g., due to the pressure exchange between the first fluid and the second fluid). [0019] The systems, devices, and methods of the present disclosure have advantages over conventional solutions. The systems of the present disclosure may provide better lubrication properties for a compressor when compared to conventional systems. For example, by providing the third fluid to the motor housing of the compressor at the third pressure (e.g., lower than the first pressure), the third fluid may be less likely to dissolve in the lubrication oil in the motor housing and/or in the crankcase. This may lead to better oil lubrication properties when compared to conventional systems. Additionally, the better lubrication properties may lead to less wear on components of the compressor (e.g., bearings, bearing surfaces, etc.) when compared to conventional systems, in turn leading to less compressor maintenance and longer compressor life when compared to conventional systems. Further, the systems of the present disclosure may provide less compressor down time (e.g., due to less maintenance as a result of the better lubrication qualities), leading to increased productivity of the system. The systems of the present disclosure also have less impurities in the process fluid compared to conventional systems. This avoids damage to components of the refrigeration system and provides an increased efficiency of the refrigeration system compared to conventional systems.

[0020] Although some embodiments of the present disclosure are described in relation to pressure exchangers, energy recovery devices, hydraulic energy transfer systems, and compressors, the current disclosure can be applied to other systems and devices (e.g., pressure exchanger that is not isobaric, rotating components that are not a pressure exchanger, a pressure exchanger that is not rotary, systems that do not include pressure exchangers, etc.).

[0021] Although some embodiments of the present disclosure are described in relation to compressors, the current disclosure can be applied to other devices, such as pumps, boosters, mechanical devices that increase fluid pressure, etc.

[0022] Although some embodiments of the present disclosure are described in relation to exchanging pressure between fluid used in fracing systems, desalinization systems, heat pump systems, and/or refrigeration systems, the present disclosure can be applied to other types of systems. Fluids can refer to liquid, gas, transcritical fluid, supercritical fluid, subcritical fluid, and/or combinations thereof.

[0023] FIG. 1A illustrates a schematic diagram of a fluid handling system 100 A that includes a hydraulic energy transfer system 110, according to certain embodiments.

[0024] In some embodiments, a hydraulic energy transfer system 110 includes a pressure exchanger (e.g., PX). The hydraulic energy transfer system 110 (e.g., PX) receives low pressure (LP) fluid in 120 (e.g., via a low-pressure inlet) from an LP in system 122. The hydraulic energy transfer system 110 also receives high pressure (HP) fluid in 130 (e.g., via a high-pressure inlet) from HP in system 132. The hydraulic energy transfer system 110 (e.g., PX) exchanges pressure between the HP fluid in 130 and the LP fluid in 120 to provide LP fluid out 140 (e.g., via low-pressure outlet) to LP fluid out system 142 and to provide HP fluid out 150 (e.g., via high-pressure outlet) to HP fluid out system 152. A controller 180 may cause an adjustment of flowrates of HP fluid in 130 and LP fluid out 140 by one or more flow valves, pumps, and/or compressors (not illustrated). The controller 180 may cause flow valves to actuate.

[0025] In some embodiments, the hydraulic energy transfer system 110 includes a PX to exchange pressure between the HP fluid in 130 and the LP fluid in 120. In some embodiments, the PX is substantially or partially isobaric (e.g., an isobaric pressure exchanger (IPX)). The PX may be a device that transfers fluid pressure between HP fluid in 130 and LP fluid in 120 at efficiencies (e.g., pressure transfer efficiencies, substantially isobaric) in excess of approximately 50%, 60%, 70%, 80%, 90%, or greater (e.g., without utilizing centrifugal technology). High pressure (e.g., HP fluid in 130, HP fluid out 150) refers to pressures greater than the low pressure (e.g., LP fluid in 120, LP fluid out 140). LP fluid in 120 of the PX may be pressurized and exit the PX at high pressure (e.g., HP fluid out 150, at a pressure greater than that of LP fluid in 120), and HP fluid in 130 may be at least partially depressurized and exit the PX at low pressure (e.g., LP fluid out 140, at a pressure less than that of the HP fluid in 130). The PX may operate with the HP fluid in 130 directly applying a force to pressurize the LP fluid in 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/or the like. In some embodiments, PXs may be rotary devices. Rotary PXs, such as those manufactured by Energy Recovery, Inc. of San Leandro, Calif., may not have any separate valves, since the effective valving action is accomplished internal to the device via the relative motion of a rotor with respect to end covers. In some embodiments, rotary PXs operate with internal pistons to isolate fluids and transfer pressure with relatively little mixing of the inlet fluid streams. In some embodiments, rotary PXs operate without internal pistons between the fluids. Reciprocating PXs may include a piston moving back and forth in a cylinder for transferring pressure between the fluid streams. Any PX or multiple PXs may be used in the present disclosure, such as, but not limited to, rotary PXs, reciprocating PXs, or any combination thereof. In addition, the PX may be disposed on a skid separate from the other components of a fluid handling system 100A (e.g., in situations in which the PX is added to an existing fluid handling system). In some examples, the PX may be fastened to a structure that can be moved from one site to another. The PX may be coupled to a system (e.g., pipes of a system, etc.) that has been built on-site. The structure to which the PX is fastened may be referred to as a ‘skid.’

[0026] In some embodiments, a motor 160 is coupled to hydraulic energy transfer system 110 (e.g., to a PX). In some embodiments, the motor 160 controls the speed of a rotor of the hydraulic energy transfer system 110 (e.g., to increase pressure of HP fluid out 150, to decrease pressure of HP fluid out 150, etc.). In some embodiments, motor 160 generates energy (e.g., acts as a generator) based on pressure exchanging in hydraulic energy transfer system 110.

[0027] The hydraulic energy transfer system 110 may include a hydraulic turbocharger or hydraulic pressure exchanger, such as a rotating PX. The PX may include one or more chambers and/or channels (e.g., 1 to 100) to facilitate pressure transfer between first and second fluids (e.g., gas, liquid, multi-phase fluid). In some embodiments, the PX may transfer pressure between a first fluid (e.g., pressure exchange fluid, such as a proppant free fluid, substantially proppant free fluid, lower viscosity fluid, fluid that has lower than a threshold amount of certain chemicals, etc.) and a second fluid that may have a higher viscosity (e.g., be highly viscous), include more than a threshold amount of certain chemicals, and/or contain solid particles (e.g., frac fluid and/or fluid containing sand, proppant, powders, debris, ceramics, contaminants, particles from welded or soldered joints, etc.).

[0028] In some embodiments, LP in system 122 includes a booster 123 (e.g., a pump and/or a compressor) to increase pressure of fluid to form LP fluid in 120. In some embodiments, LP in system 122 includes an ejector to increase pressure of fluid to form LP fluid in 120. In some embodiments, LP in system 122 receives a gas from LP out system 142. In some embodiments, LP in system 122 receives fluid from a receiver (e.g., a flash tank, etc.). The receiver may receive LP fluid out 140 output from hydraulic energy transfer system 110. In some embodiments, LP in system 122 may include a compressor having a first portion and a second portion as described herein.

[0029] In some embodiments, HP out system 152 includes a booster 153 (e.g., a pump and/or a compressor) to increase pressure of HP fluid out 150. In some embodiments, one or more of HP out system 152, HP in system 132, LP out system 142, or LP in system 122 includes a compressor (e.g., booster 153, booster 123, a compressor other than booster 123 or booster 123, etc.) having a first portion and a second portion as described herein. In some embodiments, a first portion of the compressor (e.g., a motor housing and/or a crankcase) may be configured to receive a low pressure fluid (e.g., a portion of LP fluid in 120). The low pressure fluid may flow through the first portion of the compressor and may cool a motor housed within the first portion. In some embodiments, a second portion of the compressor the compressor may be configured to receive the HP fluid out 150 and increase pressure of HP fluid out 150. In some embodiments, the HP fluid out 150 received at the second portion of the compressor substantially does not mix with the low pressure fluid received by the first portion of the compressor (e.g., the second portion of the compressor is substantially isolated from the first portion of the compressor). The first portion of the booster 153 may house lubricating oil to lubricate one or more components of the booster 153.

[0030] Fluid handling system 100 A may additionally include one or more sensors to provide sensor data (e.g., flowrate data, pressure data, velocity data, etc.) associated with the fluids of fluid handling system 100 A. Controller 180 may control one or more flow rates of fluid handling system 100 A based on the sensor data. In some embodiments, controller 180 causes one or more flow valves to actuate based on sensor data received. [0031] One or more components of the hydraulic energy transfer system 110 may be used in different types of systems, such as fracing systems, desalination systems, refrigeration and heat pump systems (e.g., FIG. IB), slurry pumping systems, industrial fluid systems, waste fluid systems, fluid transportation systems, heat transfer systems, etc.

[0032] FIG. IB illustrates a schematic diagram of a fluid handling system 100B including a hydraulic energy transfer system 110, according to certain embodiments. Fluid handling system 100B may be a refrigeration system or a heat pump system. In some embodiments, fluid handling system 100B is a thermal energy (e.g., heat) transport system (e.g., heat transport system, thermal transport system). Fluid handling system 100B may be configured to cool and/or heat an environment (e.g., an indoor space, a refrigerator, a freezer, etc.). In some embodiments, fluid handling system 100B includes more components, less components, same routing, different routing, and/or the like than that shown in FIG. IB. Some of the features in FIG. IB that have similar reference numbers as those in FIG. 1 A may have similar properties, functions, and/or structures as those in FIG. 1 A.

[0033] Hydraulic energy transfer system 110 (e.g., PX) may receive LP fluid in 120 from LP in system 122 (e.g., low pressure lift device 128, low pressure fluid pump, low pressure booster, low pressure compressor, low pressure ejector, etc.) and HP fluid in 130 from HP in system 132 (e.g., condenser 138, gas cooler, heat exchanger, etc.). The hydraulic energy transfer system 110 (e.g., PX) may exchange pressure between the LP fluid in 120 and HP fluid in 130 to provide HP fluid out 150 to HP out system 152 (e.g., high pressure lift device 159, high pressure fluid pump, high pressure booster, high pressure compressor, high pressure ejector, etc.) and to provide LP fluid out 140 to LP out system 142 (e.g., evaporator 144, heat exchanger, etc.). The LP out system 142 (e.g., evaporator 144) may provide the fluid to compressor 178 and low pressure lift device 128. The evaporator 144 may provide the fluid to compressor 178. The condenser 138 may receive fluid from compressor 178 and high pressure lift device 159. Controller 180 may control one or more components of fluid handling system 100B. High pressure lift device 159 may be a high pressure booster and low pressure lift device 128 may be a low pressure booster.

[0034] The fluid handling system 100B may be a closed system. LP fluid in 120, HP fluid in 130, LP fluid out 140, and HP fluid out 150 may all be a fluid (e.g., refrigerant, the same fluid) that is circulated in the closed system of fluid handling system 100B.

[0035] Fluid handling system 100B may additionally include one or more sensors configured to provide sensor data associated with the fluid. One or more flow valves may control flowrates of the fluid based on sensor data received from the one or more sensors. In some embodiments, controller 180 causes one or more flow valves (not illustrated) to actuate based on sensor data received.

[0036] In some embodiments, fluid handling system 100B includes a compressor as described herein. For example, the high pressure lift device 159, low pressure lift device 128, and/or compressor 178 may be a compressor having two portions. A first portion may be configured to house a motor and may further be configured to receive a low pressure fluid (e.g., a cooling fluid, a portion of LP fluid in 120, etc.). A second portion of the high pressure lift device 159 may be configured to receive the HP fluid out 150 and increase pressure of the HP fluid out 150. In some embodiments, the second portion is fluidly isolated (e.g., substantially fluidly isolated) from the first portion. The first portion may house lubricating oil to lubricate one or more components of the high pressure lift device 159, low pressure lift device 128, and/or compressor 178.

[0037] FIGS. 2A-E are exploded perspective views a rotary PX 40 (e.g., rotary pressure exchanger, rotary liquid piston compressor (LPC)), according to certain embodiments. Some of the features in one or more of FIGS. 2A-E may have similar properties, functions, and/or structures as those in one or more of FIGS. 1A-B. PX 40 of FIGS. 2A-E may be part of a system that includes a compressor 278 as described herein. The compressor 278 may have two portions. The first portion of the compressor may house a motor (e.g., and lubricating oil) and may be configured to receive a low pressure fluid (e.g., a cooling fluid). The second portion of the compressor 278 may be fluidly coupled to the PX 40. The second portion may be fluidly isolated from the first portion. The compressor 278 may receive a first fluid at a first pressure into the second portion via a first compressor inlet, increase the pressure of the first fluid from the first pressure to a second pressure, and provide the first fluid at the second pressure via the first compressor outlet.

[0038] PX 40 is configured to transfer pressure and/or work between a first fluid (e.g., refrigerant, particle free fluid, proppant free fluid, supercritical carbon dioxide, HP fluid in 130) and a second fluid (e.g., refrigerant, slurry fluid, frac fluid, superheated gaseous carbon dioxide, LP fluid in 120) with minimal mixing of the fluids. The rotary PX 40 may include a generally cylindrical body portion 42 that includes a sleeve 44 (e.g., rotor sleeve) and a rotor 46. The rotary PX 40 may also include two end caps 48 and 50 that include manifolds 52 and 54, respectively. Manifold 52 includes respective inlet port 56 and outlet port 58, while manifold 54 includes respective inlet port 60 and outlet port 62. In operation, these inlet ports 56, 60 enable the first and second fluids to enter the rotary PX 40 to exchange pressure, while the outlet ports 58, 62 enable the first and second fluids to then exit the rotary PX 40. In operation, the inlet port 56 may receive a high-pressure first fluid (e.g., HP fluid in 130), and after exchanging pressure, the outlet port 58 may be used to route a low-pressure first fluid (e.g., LP fluid out 140) out of the rotary PX 40. Similarly, the inlet port 60 may receive a low-pressure second fluid (e.g., LP fluid in 120) from a booster having a first portion fluidly isolated from a second portion, and the outlet port 62 may be used to route a high-pressure second fluid (e.g., HP fluid out 150) out of the rotary PX 40 to a booster having a first portion fluidly isolated from a second portion. The end caps 48 and 50 include respective end covers 64 and 66 (e.g., end plates) disposed within respective manifolds 52 and 54 that enable fluid sealing contact with the rotor 46.

[0039] One or more components of the PX 40, such as the rotor 46, the end cover 64, and/or the end cover 66, may be constructed from a wear-resistant material (e.g., carbide, cemented carbide, silicon carbide, tungsten carbide, etc.) with a hardness greater than a predetermined threshold (e.g., a Vickers hardness number that is at least 1000, 1250, 1500, 1750, 2000, 2250, or more). In some examples, tungsten carbide may be more durable and may provide improved wear resistance to abrasive fluids as compared to other materials, such as alumina ceramics. Additionally, in some embodiments, one or more components of the PX 40, such as the rotor 46, the end cover 64, the end cover 66, and/or other sealing surfaces of the PX 40, may include an insert. In some embodiments, the inserts may be constructed from one or more wear-resistant materials (e.g., carbide, cemented carbide, silicon carbide, tungsten carbide, etc.) with a hardness greater than a predetermined threshold (e.g., a Vickers hardness number that is at least 1000, 1250, 1500, 1750, 2000, 2250, or more) to provide improved wear resistance.

[0040] The rotor 46 may be cylindrical and disposed in the sleeve 44, which enables the rotor 46 to rotate about the axis 68. The rotor 46 may have a plurality of channels 70 (e.g., ducts, rotor ducts) extending substantially longitudinally through the rotor 46 with openings 72 and 74 (e.g., rotor ports) at each end arranged symmetrically about the longitudinal axis 68. The openings 72 and 74 of the rotor 46 are arranged for hydraulic communication with inlet and outlet apertures 76 and 78 (e.g., end cover inlet port and end cover outlet port) and 80 and 82 (e.g., end cover inlet port and end cover outlet port) in the end covers 64 and 66, in such a manner that during rotation the channels 70 are exposed to fluid at high-pressure and fluid at low-pressure. As illustrated, the inlet and outlet apertures 76 and 78 and 80 and 82 may be designed in the form of arcs or segments of a circle (e.g., C-shaped).

[0041] In some embodiments, a controller (e.g., controller 180 of FIGS. 1A-B) using sensor data (e.g., revolutions per minute measured through a tachometer or optical encoder, volumetric flow rate measured through flowmeter, etc.) may control the extent of mixing between the first and second fluids in the rotary PX 40, which may be used to improve the operability of the fluid handling system (e.g., fluid handling systems 100A-B of FIGS. 1A- B). In some examples, varying the volumetric flow rates of the first and/or second fluids entering the rotary PX 40 allows the operator (e.g., system operator, plant operator) to control the amount of fluid mixing within the PX 40. In addition, varying the rotational speed of the rotor 46 (e.g., via a motor) also allows the operator to control mixing. Three characteristics of the rotary PX 40 that affect mixing are: (1) the aspect ratio of the rotor channels 70; (2) the duration of exposure between the first and second fluids; and (3) the creation of a barrier (e.g., fluid barrier, piston, interface) between the first and second fluids within the rotor channels 70. First, the rotor channels 70 (e.g., ducts) are generally long and narrow, which stabilizes the flow within the rotary PX 40. In addition, the first and second fluids may move through the channels 70 in a plug flow regime with minimal axial mixing. Second, in certain embodiments, the speed of the rotor 46 reduces contact between the first and second fluids. In some examples, the speed of the rotor 46 (e.g., rotor speed of approximately 1200 revolutions per minute (RPM)) may reduce contact times between the first and second fluids to less than approximately 0.15 seconds, 0.10 seconds, or 0.05 seconds. Third, the rotor channel 70 (e.g., a small portion of the rotor channel 70) is used for the exchange of pressure between the first and second fluids. In some embodiments, a volume of fluid remains in the channel 70 as a barrier between the first and second fluids. All these mechanisms may limit mixing within the rotary PX 40. Moreover, in some embodiments, the rotary PX 40 may be designed to operate with internal pistons or other barriers, either complete or partial, that isolate the first and second fluids while enabling pressure transfer.

[0042] FIGS. 2B-2E are exploded views of an embodiment of the rotary PX 40 illustrating the sequence of positions of a single rotor channel 70 in the rotor 46 as the channel 70 rotates through a complete cycle. It is noted that FIGS. 2B-2E are simplifications of the rotary PX 40 showing one rotor channel 70, and the channel 70 is shown as having a circular cross- sectional shape. In other embodiments, the rotary PX 40 may include a plurality of channels 70 with the same or different cross-sectional shapes (e.g., circular, oval, square, rectangular, polygonal, etc.). Thus, FIGS. 2B-2E are simplifications for purposes of illustration, and other embodiments of the rotary PX 40 may have configurations different from those shown in FIGS. 2A-2E. As described in detail below, the rotary PX 40 facilitates pressure exchange between first and second fluids (e.g., higher pressure refrigerant and lower pressure refrigerant, etc.) by enabling the first and second fluids to briefly contact each other within the rotor 46. In some embodiments, the PX facilitates pressure exchange between first and second fluids by enabling the first and second fluids to contact opposing sides of a barrier (e.g., a reciprocating barrier, a piston, not shown). In some embodiments, this exchange happens at speeds that result in limited mixing of the first and second fluids. The speed of the pressure wave traveling through the rotor channel 70 (as soon as the channel is exposed to the aperture 76), the diffusion speeds of the fluids, and/or the rotational speed of rotor 46 may dictate whether any mixing occurs and to what extent.

[0043] FIG. 2B is an exploded perspective view of an embodiment of a rotary PX 40 (e.g., 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 the aperture 78 in end cover 64 and therefore with the manifold 52, while the opposing channel opening 74 is in hydraulic communication with the aperture 82 in end cover 66 and by extension with the manifold 54. The rotor 46 may rotate in the clockwise direction indicated by arrow 84. In operation, low-pressure second fluid 86 (e.g., low pressure refrigerant) passes through end cover 66 and enters the channel 70, where it contacts the first fluid 88 at a dynamic fluid interface 90. The second fluid 86 then drives the first fluid 88 out of the channel 70, through end cover 64, and out of the rotary PX 40. However, because of the short duration of contact, there is minimal mixing between the second fluid 86 (e.g., low pressure refrigerant) and the first fluid 88 (e.g., high pressure refrigerant). In some embodiments, low pressure second fluid 86 contacts a first side of a barrier (e.g., a piston, not shown) disposed in channel 70 that is in contact (e.g., on an opposing side of the barrier) by first fluid 88. The second fluid 86 drives the barrier which pushes first fluid 88 out of the channel 70. In such embodiments, there is negligible mixing between the second fluid 86 and the first fluid 88. [0044] FIG. 2C is an exploded perspective view of an embodiment of a rotary PX 40 (e.g., rotary LPC), according to certain embodiments. In FIG. 2C, the channel 70 has rotated clockwise through an arc of approximately 90 degrees. In this position, the opening 74 (e.g., outlet) is no longer in fluid communication with the apertures 80 and 82 of end cover 66, and the opening 72 is no longer in fluid communication with the apertures 76 and 78 of end cover 64. Accordingly, the low-pressure second fluid 86 is temporarily contained within the channel 70.

[0045] FIG. 2D is an exploded perspective view of an embodiment of a rotary PX 40 (e.g., rotary LPC), according to certain embodiments. In FIG. 2D, the channel 70 has rotated through approximately 60 degrees of arc from the position shown in FIG. 2B. The opening 74 is now in fluid communication with aperture 80 in end cover 66, and the opening 72 of the

-l i channel 70 is now in fluid communication with aperture 76 of the end cover 64. In this position, high-pressure first fluid 88 enters and pressurizes the low-pressure second fluid 86, driving the second fluid 86 out of the rotor channel 70 and through the aperture 80.

[0046] FIG. 2E is an exploded perspective view of an embodiment of a rotary PX 40 (e.g., rotary LPC), according to certain embodiments. In FIG. 2E, the channel 70 has rotated through approximately 270 degrees of arc 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 of end cover 66, and the opening 72 is no longer in fluid communication with the apertures 76 and 78 of end cover 64. Accordingly, the first fluid 88 is no longer pressurized and is temporarily contained within the channel 70 until the rotor 46 rotates another 90 degrees, starting the cycle over again.

[0047] FIG. 3 is a cross-sectional view of a compressor 300, according to certain embodiments. In some embodiments, compressor 300 is a booster (e.g., a high pressure booster, a low pressure booster, HP booster 412 of FIG. 4, LP booster 414 of FIG. 4, booster 123 and/or booster 153 of FIG. 1A, etc.). In some embodiments, compressor 300 has the same or similar features and/or functionality as low pressure lift device 128, high pressure lift device 159, and/or compressor 178 of FIG. IB. In some embodiments compressor 300 has the same or similar features and/or functionality as compressor 278of FIGS. 2A-E. The compressor 300 may “boost” (e.g., increase) pressure of fluid received by the compressor 300. In some embodiments, compressor 300 includes a motor housing 310 and a crankcase 320. The motor housing 310 and the crankcase 320 may form a first portion of the compressor 300. In some examples, the motor housing 310 and the crankcase 320 may be (e.g., may be manufactured as, may be cast as) a single unit (e.g., are integral to each other). In other examples, the motor housing 310 and the crankcase 320 may be joined (e.g., by welding, by one or more fasteners, etc. after manufacturing). The motor housing 310 may form an inner volume and may be configured to house a motor 312 (e.g., an electric motor) within the inner volume. The motor 312 may be supported and/or fastened in the inner volume of the motor housing 310 by one or more motor mounts (not illustrated). The motor mounts may include one or more fasteners to removably secure the motor 312 within the motor housing 310.

[0048] In some embodiments, the crankcase 320 may house the crankshaft 324. The crankcase 320 may form a sump (e.g., bottom of an interior volume of the crankcase 320) configured to collect lubricating oil 322. In some embodiments, the crankcase includes one or more ports, passageways, conduits, etc. for the lubricating oil 322 to flow from the sump to lubricated surfaces and/or lubricated bearings of the compressor 300. In some examples, the lubricating oil 322 is used to lubricate one or more bearings supporting the crankshaft 324. The interior of the crankcase 320 may be fluidly coupled to the interior of the motor housing 310. In some embodiments, one or more ports, passageways, openings, etc. connect the interior of the motor housing 310 to the interior of the crankcase 320. As illustrated in FIG. 3, the interior of the crankcase 320 may be fluidly coupled to the interior of the motor housing 310 by a cooling flow port 328. Cooling flow port 328 may be a port (e.g., a passageway) for fluid (e.g., a low pressure fluid, a cooling fluid, etc.) to flow from the motor housing 310 to the crankcase 320.

[0049] In some embodiments, the motor housing 310 includes a cooling inlet 370. In some examples, the inlet is a port and/or a passageway for a fluid (e.g., cooling fluid 371) to enter the interior of the motor housing 310. The cooling fluid 371 may be a low pressure fluid (e.g., a low pressure gas) and may cool the motor 312 as the cooling fluid 371 flows through the motor housing 310. In some embodiments, the cooling fluid 371 is a fluid to warm the motor 312. In some embodiments, the cooling fluid 371 may be CO2. In some embodiments, the pressure of the fluid is sufficiently low so as to not dissolve in the lubricating oil 322. In some examples, the pressure of the cooling fluid 371 is approximately 600 PSI. In some examples, the pressure of the cooling fluid 371 is between approximately 200 PSI and approximately 800 PSI. After entering the motor housing 310 via the cooling inlet 370, the cooling fluid 371 may flow through the cooling flow port 328 (e.g., one or more ports and/or passageways, etc.) to the crankcase 320. Inside the crankcase 320, the lubricating oil 322 may be exposed to the cooling fluid 371, but because of the relatively low pressure of the cooling fluid (e.g., approximately 600 PSI in some embodiments, a low pressure, etc.), a minimal amount of the cooling fluid 371 may dissolve in the lubricating oil 322. Thus, the lubricating oil 322 may substantially maintain its lubrication properties. The cooling fluid 371 may flow out of the crankcase 320 via a cooling outlet 372. In some embodiments, the cooling fluid 371 may be output from the cooling outlet 372 to an oil separator (e.g., oil separator 474 of FIG. 4) to separate any lubricating oil 322 from the cooling fluid 371. The oil separator may provide any lubricating oil 322 separated from the cooling fluid 371 back to the sump of the crankcase 320. In some embodiments, the cooling fluid 371 flows in a closed circuit. In some examples, the cooling fluid 371 is warmed by the motor 312 (e.g., the cooling fluid 371 cools the motor 312) and flows from the compressor 300 to a heat exchanger (e.g., a condenser, a cooling tower, etc.) where the cooling fluid 371 is cooled. The cooling fluid 371 may flow from the heat exchanger to the motor housing 310 to cool the motor 312. [0050] In some embodiments, the compressor 300 includes a cylinder 340 and a cylinder head 350 (e.g., compressor head 500 of FIG. 5A). In some embodiments, the compressor 300 includes multiple cylinders and multiple cylinder heads, each cylinder head corresponding to a cylinder. In some embodiments, the cylinder 340 is coupled to the crankcase 320. Cylinder 340 may be a piston housing (e.g., cylinder 340 may house a piston 342). Cylinder 340 may include an inner volume. In some embodiments, the cross section of the inner volume of the cylinder 340 is circular. However, in other embodiments, the cross section of the inner volume of the cylinder 340 is ovular, square, or any other suitable shape. The piston 342 may be disposed within the inner volume of the cylinder 340. In some embodiments, the piston 342 is coupled to the crankshaft 324 via a connecting rod 326. The piston 342 may be coupled to the connecting rod 326 by a wrist pin (not illustrated). The wrist pin may include one or more bearings and/or bushings to interface the piston 342 to the wrist pin and/or to interface the wrist pin to the connecting rod 326. The connecting rod 326 may include one or more bearings and/or bushings to interface with the crankshaft 324. Each of the bearings and/or bushings discussed herein may be lubricated by the lubricating oil 322.

[0051] In some embodiments, the piston 342 separates a cooling fluid portion of the compressor 300 (e.g., a first portion) from a process fluid portion of the compressor 300 (e.g., a second portion, a refrigerant portion). The cooling fluid portion of the compressor 300 may include the motor housing 310 and the crankcase 320 as discussed herein. The process fluid portion of the compressor 300 may include an upper interior volume of the cylinder 340 (e.g., a volume above the piston 342) and the cylinder head 350. In some embodiments, the second portion of the compressor 300 (e.g., the process fluid portion, the refrigerant portion) is configured to be fluidly isolated from the cooling fluid portion of the compressor 300 (e.g., the cooling fluid portion). Sealing surfaces of the piston 342 (e.g., outer sealing surfaces, sealing rings, etc.) may substantially seal the interfacing surfaces of the piston 342 with the inner walls of the cylinder 340. In some examples, the piston 342 includes multiple replaceable sealing rings (not illustrated) to fluidly isolate the crankcase 320 from the upper volume of the cylinder 340 (e.g., the volume above the piston 342). The multiple replaceable sealing rings may include one or more pressure sealing rings and one or more oil sealing rings. In some examples, multiple pressure sealing rings are disposed around the piston 342 near a top of the piston, and one or more oil sealing rings are disposed around the piston 342 below the multiple pressure sealing rings. The sealing rings may be made of metal in some embodiments. [0052] In some embodiments, the cylinder head 350 includes a suction side 352 and a discharge side 354. The suction side 352 may form a suction interior volume. The suction interior volume may include one or more chambers and/or passageways for ingress of a process fluid 361 (e.g., a refrigerant, CO2) into the cylinder 340. In some embodiments, the process fluid 361 is introduced into the suction side 352 of the cylinder head 350 via the compressor inlet 360. In some embodiments, the process fluid 361 is introduced into the suction side 352 at a high pressure. In some examples, the process fluid 361 is received by the compressor 300 at approximately 1,200 PSI. In some examples, the process fluid 361 is received by the compressor 300 at a pressure between approximately 700 PSI and approximately 1,600 PSI. In some embodiments, the compressor 300 is configured to receive the first fluid at the first pressure output from a high pressure outlet of a PX (e.g., a high pressure outlet of PX 410 of FIG. 4). In some embodiments, the process fluid 361 is the same fluid as the cooling fluid 371 (e.g., but at a higher pressure). In some examples, both the process fluid 361 and the cooling fluid 371 are a refrigerant such as CO2.

[0053] The cylinder head 350 may be coupled to the top of the cylinder 340 by one or more fasteners (not illustrated). In some examples, the cylinder head 350 is fastened to the cylinder 340 by multiple bolts. A valve plate assembly 355 may be disposed between the cylinder head 350 and the cylinder 340. A bottom surface of the valve plate assembly 355 may define a top of the inner volume of the cylinder 340. The valve plate assembly 355 may include one or more valves. In some embodiments, the valve plate assembly 355 includes an intake valve 356 and a discharge valve 358. The intake valve 356 may open to allow the process fluid 361 to enter the upper volume of the cylinder 340. The discharge valve 358 may open to allow the process fluid 361 to exit the upper volume of the cylinder 340. In some embodiments, the intake valve 356 and/or the discharge valve 358 may be reed valves. In other embodiments, the intake valve 356 and/or the discharge valve 358 may be poppet valves. In some embodiments, one of the intake valve 356 or the discharge 358 may be a reed valve while the other is a poppet valve. In some embodiments, the cylinder head 350 may include one or more springs coupled to the intake valve 356 and/or the discharge valve 358 to close the valves and/or hold the valves in a closed position. Each of the intake valve 356 and the discharge valve 358 may seal a valve opening when in the closed position.

[0054] The operation of the piston 342, the intake valve 356 and/or the discharge valve 358 may be cyclic. In some examples, as the piston 342 moves downward along the longitudinal axis of the inner volume of the cylinder 340 (e.g., responsive to the crankshaft 324 rotating), a negative pressure is induced in the upper volume of the cylinder 340 (e.g., the interior volume of the cylinder 340 above the piston 342). The intake valve 356 may open and process fluid 361 may be drawn into the cylinder 340 from the suction side 352 via the open intake valve 356. When the piston 342 reaches the bottom of its stroke, the intake valve 356 may close. As the piston 342 moves upward, a positive pressure is induced in the upper volume of the cylinder 340. The discharge valve 358 may open and the process fluid 361 in the upper volume of the cylinder 340 may be pushed from the cylinder 340 to the discharge side 354 via the open discharge valve 358. As the piston 342 reaches the top of its stroke, the discharge valve 358 may close, completing one cycle. The cycle may then start again as the piston 342 begins a downward stroke responsive to the rotation of the crankshaft 324.

[0055] The process fluid 361 may be compressed as the piston 342 moves upward in the inner volume of the cylinder 340. In some embodiments, the pressure of the process fluid 361 is increased between approximately 50 PSI and approximately 60 PSI by the movement (e.g., compression) of the piston 342. The compressed process fluid 361 may exit the discharge side 354 of the cylinder head 350 via a compressor outlet 362. In some embodiments, the discharge side forms a discharge interior volume. The discharge side 354 may include one or more chambers and/or passageways for the egress of the process fluid 361 from the cylinder 340 to the compressor outlet 362. In some embodiments, the compressor 300 is configured to output the first fluid at the second pressure to a PX (e.g., via a low pressure inlet of the PX). [0056] FIG. 4 is a schematic diagram of a fluid handling system 400 including a compressor (e.g., a high pressure booster, a low pressure booster, compressor 300, etc.), according to certain embodiments. In some embodiments, one or more of HP booster 424, LP booster 414, and/or compressor 422 has same or similar features and/or functionality as one or more of booster 123 of FIG. 1A, booster 153 of FIG. 1A, compressor 178 of FIG. IB, low pressure lift device 128 of FIG. IB, high pressure lift device 159 of FIG. IB, compressor 278 of FIGS. 2A-E, and/or compressor 300 of FIG. 3. In some embodiments, the fluid handling system 400 is a thermal energy transport system. PX 410 may be a rotary pressure exchanger. In some embodiments, PX 410 is an isobaric or substantially isobaric pressure exchanger. PX 410 may be configured to exchange pressure between a first fluid and a second fluid. In some embodiments, PX 410 is coupled to a motor 460 (e.g., rotation of a rotor of PX 410 is controlled by the motor 460). In some embodiments, the motor 460 controls the rotational speed of the PX 410. Mass flow (e.g., of the first fluid and/or of the second fluid) through the PX 410 may be related to the rotational speed of the PX 410. In some embodiments, the pressure of the fluid (e.g., the first fluid) in the condenser 429 may be related to the rotational speed of the PX 410. In some embodiments, a controller (e.g., controller 480) receives sensor data from one or more sensors of motor 460.

[0057] In some embodiments, PX 410 is to receive the first fluid at a high pressure (e.g., HP fluid in 130 of FIGS. 1A-B) via a high pressure inlet. In some embodiments, PX 410 is to receive the second fluid at a low pressure (e.g., LP fluid in 120 of FIGS. 1A-B) via a low pressure inlet. Although there is a reference to “high pressure” and “low pressure,” “high pressure” and “low pressure” may be relative to one another and may not connote certain pressure values (e.g., the pressure of the HP fluid in 130 is higher than the pressure of LP fluid in 120). PX 410 may exchange pressure between the first fluid and the second fluid. PX 410 may provide the first fluid via a low pressure outlet (e.g., LP fluid out 140) and may provide the second fluid via a high pressure outlet (e.g., HP fluid out 150). In some embodiments, the first fluid provided via the low pressure outlet is at a low pressure and the second fluid provided via the high pressure outlet is at a high pressure.

[0058] In some embodiments, fluid handling system 400 includes a condenser 429 (e.g., a gas cooler), an evaporator 418, and a compressor 422. In some embodiments, fluid handling system 400 is a refrigeration system. In some embodiments, the condenser 429 is a heat exchanger that provides the heat from the refrigerant (e.g., the first fluid) to an environment. [0059] In some embodiments, condenser 429 is a heat exchanger that condenses fluid flowing through the condenser 429 (e.g., while cooling the fluid). The phase of the refrigerant may change from gas to liquid (e.g., condense) within the condenser 429. In some embodiments, condenser 429 is a heat exchanger that does not condense fluid flowing through the condenser 429 (e.g., cools the fluid without condensing the fluid). In some embodiments, the pressure of the fluid within the condenser 429 is above the critical pressure of the fluid. In some embodiments, the condenser 429 is a gas cooler and does not condense the fluid (e.g., in a gaseous state). The condenser 429 may provide the heat from the fluid (e.g., gas) to a corresponding environment. In some embodiments, the temperature of the fluid in the condenser 429 may be lowered, but the fluid may not condense (e.g., the fluid does not change phase from gas to liquid). In some embodiments, above the critical pressure of the fluid (e.g., of the refrigerant), the thermodynamic distinction between liquid and gas phases of the fluid within the condenser 429 disappears and there is only a single state of fluid called the supercritical state.

[0060] Fluid handling system 400 may include a flash tank 413 (e.g., a receiver). In some embodiments, flash tank 413 is a receiver configured to receive a flow of fluid (e.g., first fluid) output from the low pressure outlet of the PX 410. Flash tank 413 may form a chamber to collect the first fluid from the first outlet of the PX 410. Flash tank 413 may receive the first fluid in a two-phase state (e.g., liquid and gas). In some embodiments, flash tank 413 is a tank constructed of welded sheet metal. Flash tank 413 may be made of steel (e.g., steel sheet metal, steel plates, etc.). The first fluid (at a low pressure) may separate into gas and liquid inside the flash tank 413. The liquid of the first fluid may settle at the bottom of the flash tank 413 while the gas of the first fluid may rise to the top of the flash tank 413. The liquid may flow from the flash tank 413 toward the evaporator 418 (e.g., via expansion valve 416). The chamber of flash tank 413 may be maintained at a set pressure (e.g., a predetermined pressure). The pressure may be set by a user (e.g., an operator, a technician, an engineer, etc.) and/or by a controller (e.g., controller 480). In some embodiments, the pressure of the flash tank 413 is controlled by one or more valves (e.g., flash gas valve 420, a pressure regulator valve, a safety valve, etc.). In some embodiments, the flash tank 413 includes at least one pressure sensor (e.g., pressure transducer).

[0061] Fluid handling system 400 may include PX shutoff valve 464. The PX shutoff valve 464 may control a flow of first fluid (e.g., high pressure fluid) to the high pressure inlet of the PX 410. In some embodiments, the PX shutoff valve 464 is controlled by controller 480. Controller 480 may cause the PX shutoff valve 464 to actuate (e.g., open and/or close) based on sensor data received from one or more sensors of fluid handling system 400. In some embodiments, the PX shutoff valve 464 may be caused to actuate by a user (e.g., manually, by user command via the controller 480).

[0062] Fluid handling system 400 may include a parallel valve 448. Parallel valve 448 may be an expansion valve or a flow control valve. In some embodiments, parallel valve 448 selectively regulates a flow of fluid from the outlet of condenser 429 to the flash tank 413 in parallel with the PX 410. In some embodiments parallel valve 448 controls the pressure of the condenser 429 (e.g., gas cooler) by selectively opening or closing an orifice (e.g., of the parallel valve 448). In some embodiments, parallel valve 448 can be actuated to selectively regulate the flow of fluid or to selectively regulate the pressure of the fluid within the condenser 429. Parallel valve 448 may selectively provide a portion of fluid output by the condenser 429 to the expansion tank 413. In some examples, parallel valve 448 can be actuated to be further opened to flow more fluid from the condenser 429 to the flash tank 413, or parallel valve 448 can be actuated to be further closed to flow less fluid from the condenser 429 to the flash tank 413 The fluid may expand as the fluid flows through the parallel valve 448, causing a decrease in pressure and/or temperature of the fluid. In some embodiments, the controller 480 may cause the parallel valve 448 to actuate (e.g., open or close) based on sensor data received from one or more sensors of fluid handling system 400. [0063] Fluid handling system 400 may include an expansion valve 416. In some embodiments, expansion valve 416 is disposed along a flow path between flash tank 413 and the evaporator 418. Expansion valve 416 may be an adjustable valve (e.g., an electronic expansion valve, a thermostatic expansion valve, a ball valve, a gate valve, a poppet valve, etc.). Expansion valve 416 may be controllable by a user (e.g., a technician, an operator, an engineer, etc.) or by controller 480. In some embodiments, the expansion valve 416 is caused to actuate by controller 480 based on sensor data (e.g., pressure sensor data, flowrate sensor data, temperature sensor data, etc.). In some embodiments, expansion valve 416 is a thermal expansion valve. Expansion valve 416 may actuate (e.g., open and/or close) based on temperature data associated with the evaporator 418 (e.g., temperature data of the refrigeration fluid exiting the evaporator). In some examples, a sensing bulb (e.g., a temperature sensor, a pressure sensor dependent upon temperature, etc.) of the expansion valve 416 may increase or decrease pressure on a diaphragm of the expansion valve 416, causing a poppet valve coupled to the diaphragm to open or close, thus causing more or less flow of fluid to the evaporator 418, thereby causing more or less expansion of the fluid. The sensing bulb of the expansion valve may be positioned proximate to the downstream end of the evaporator 418 (e.g., proximate the fluid outlet of the evaporator 418) and may be fluidly coupled to the diaphragm via a sensing capillary (e.g., a conduit between the sensing bulb and the expansion valve 416). In some embodiments, expansion valve 416 is controlled and actuated entirely based on electronic commands (e.g., from controller 480).

[0064] Fluid handling system 400 may include a flash gas valve 420 to regulate a flow of gas on a flash gas bypass flow path (e.g., from the flash tank 413). In some embodiments, flash gas valve 420 is a bypass valve that regulates a flow of gas from a gas outlet of the flash tank 413 to be combined with output of the evaporator 418. In some embodiments, the flow of gas from the flash tank 413 flows along the flash gas bypass flow path to bypass the evaporator 418. In some embodiments, the flash gas flow path is between flash tank 413 and a location downstream of an outlet of the evaporator 418. The gas flowing along the flash gas bypass flow path may be combined with output of the evaporator 418. The flash gas valve 420 may cause gas collected in the flash tank 413 to expand (e.g., decrease in pressure) as the gas flows toward the compressor 422. The flash gas valve 420 may, in some embodiments, be an adjustable valve. In some embodiments, the flash gas valve 420 is caused to actuate by controller 480 based on sensor data. [0065] In some embodiments, LP booster 414 receives a flow of fluid from flash tank 413. In some embodiments, LP booster 414 receives a flow of gas from flash tank 413. In some examples, LP booster 414 receives a portion of the gas flowing along the flash gas bypass flow path between flash tank 413 and the flash gas valve 420. In some embodiments, the LP booster 414 receives the fluid and increases pressure of the fluid to form the second fluid (e.g., at the second pressure). The fluid is provided at the increased pressure (e.g., second pressure) to the second inlet of the PX 410 as the second fluid. In some embodiments, LP booster 414 is a compressor (e.g., compressor 300 of FIG. 3) or pump that operates over a low pressure differential to “boost” the pressure of the gas received from flash tank 413. In some embodiments, the HP booster 424 is a compressor (e.g., compressor 300 of FIG. 3) or pump that operates over a low pressure differential to “boost” the pressure of the fluid (e.g., second fluid) received from the second outlet of the PX 410. In some embodiments, a compressor is configured to increase pressure of a fluid substantially made up of gas, while a pump is configured to increase pressure of a fluid substantially made up of liquid.

[0066] In some embodiments, fluid handling system 400 includes a cooling line valve 470. The cooling line valve 470 may be disposed along a flow path between the flash tank 413 and the LP booster 414. In some embodiments, the cooling line valve 470 is to direct cooling fluid (e.g., a portion of fluid flowing between the flash tank 413 and the LP booster 414) to the HP booster 424 (e.g., compressor 300 of FIG. 3) via the cooling inlet line 471. In some embodiments, the cooling line valve 470 may be controllable (e.g., by a user and/or by controller 480). In some examples, the cooling line valve 470 may be caused to actuate (e.g., open or close) based on sensor data received by controller 480, such as temperature sensor data (e.g., temperature of a motor of the HP booster 424), and/or flowrate sensor data (e.g., flowrate of cooling fluid provided to the HP booster 424). The cooling fluid may be returned from the HP booster 424 via the cooling outlet line 473. In some embodiments, the cooling fluid output from the HP booster 424 is provided to an oil separator 474. The oil separator 474 may separate lubricating oil (e.g., of the HP booster 424) from the cooling fluid. In some embodiments, the cooling fluid is provided to the LP booster 414.

[0067] In some examples, evaporator 418 may provide heat absorbed by system 400 from a heat source (e.g., a cold reservoir) to a refrigeration fluid. The heat may be rejected to a heat sink (e.g., a hot reservoir) via the condenser 429. In some embodiments, the refrigeration fluid facilitates heat transfer from an environment associated with the evaporator to an environment associated with the condenser. Compressor 422 of fluid handling system 400 may increase corresponding pressure of the refrigeration fluid along a flow path between the evaporator 418 and the condenser 429. In some embodiments, the refrigeration fluid is CO2 or another refrigeration fluid. The refrigeration fluid may flow substantially in a cycle (e.g., from condenser 429 to PX 410 to evaporator 418 to compressor 422 to condenser 429, etc.). [0068] In some embodiments, both LP booster 414 and HP booster 424 may be configured to increase (e.g., “boost”) pressure of the second fluid. For instance, LP booster 414 may increase pressure of the second fluid output from evaporator 418 (e.g., received from the PX 410). HP booster 424 may increase pressure of the second fluid output from the PX 410. The second fluid may be provided (e.g., by HP booster 424) to combine with fluid output from the compressor 422 (e.g., upstream of an inlet of the condenser 429) to be provided to the condenser 429. LP booster 414 may increase pressure less than a threshold amount (e.g., LP booster 414 may operate over a pressure differential that is less than a threshold amount). In some examples, LP booster 414 may increase pressure of the second fluid approximately 10 to 60 psi. The second fluid may experience pressure loss (e.g., due to fluid friction loss in piping) as the second fluid flows from the LP booster 414 to the second inlet of the PX 410. HP booster 424 may increase pressure of the second fluid between the second outlet of the PX 410 and an inlet of the condenser 429. HP booster 424 may increase pressure less than a threshold amount (e.g., HP booster 424 may operate over a pressure differential that is less than a threshold amount). In some examples, HP booster 424 may increase pressure of the second fluid approximately 10 to 60 psi. HP booster 424 may increase pressure of the second fluid to a pressure that substantially matches the pressure of fluid output from the compressor 422 (e.g., the pressure of condenser 429).

[0069] In contrast to LP booster 414 and HP booster 424, the compressor 422 may increase pressure of fluid more than a threshold amount (e.g., compressor 422 may operate over a pressure differential that is greater than a threshold amount). In some examples, the compressor 422 may increase pressure of the fluid greater than approximately 200 psi. In some embodiments, controller 480 controls a flowrate of fluid through the PX 410 by controlling a flowrate of LP booster 414. In some examples, controller 480 may set a flowrate of LP booster 414 to control a flowrate of first fluid through the PX 410.

[0070] In some embodiments, evaporator 418 is a heat exchanger configured to exchange (e.g., provide) corresponding thermal energy from an environment (e.g., a medium of an environment) to a refrigeration fluid. In some examples, evaporator 418 may receive heat (e.g., thermal energy) from air of the environment and provide the heat to the refrigeration fluid. In some embodiments, the environment is a refrigerated space such as the inside of a refrigerator or freezer, an interior space (e.g., of a building or vehicle), or any other space that is to be kept cool. In some examples, the environment can be the interior of a freezer or refrigeration section at a supermarket or warehouse.

[0071] In some embodiments, the condenser 429 is a heat exchanger configured to transfer corresponding thermal energy (e.g., heat) between refrigeration fluid and an environment. In some embodiments, the condenser 429 is to provide thermal energy from the refrigeration fluid to another environment (e.g., an environment different from the environment associated with the evaporator 418). In some examples, condenser 429 may reject heat (e.g., thermal energy) to air of an outside (e.g., exterior) environment. In some embodiments, the condenser 429 exchanges thermal energy (e.g., rejects heat) to an outside space. In some examples, condenser 429 may be placed outside a supermarket or warehouse building (e.g., on a roof of the building) and reject heat to the outside environment. In another example, condenser 429 may be placed in the ground and facilitate the transfer of thermal energy between the refrigeration fluid and the ground. In some embodiments, condenser 429 rejects heat to an interior space while evaporator 418 absorbs heat from an exterior space (e.g., as in a heat pump configuration that is providing heating). Thermal energy rejected from the condenser 429 may be used to heat an enclosed (e.g., substantially enclosed) space. In another example, the evaporator 418 may be placed in the ground and facilitate the transfer of thermal energy from the ground to the refrigeration fluid.

[0072] Fluid handling system 400 may include a controller 480 (e.g., controller 180 of FIGS. 1A-B) Controller 480 may control the boosters and/or compressors of system 400. Controller 480 may receive sensor data from one or more sensors of system 400. The sensors may include pressure sensors, flowrate sensors, and/or temperature sensors. In some embodiments, controller 480 controls a motor coupled to PX 410 (e.g., motor 460). In some embodiments, controller 480 receives motor data from one or more motor sensors associated with the motor 460. Motor data received from motor sensors may include current motor speed (e.g., revolutions per minute), total motor run time, motor run time between maintenance operations, and/or total motor revolutions. Motor data may be indicative of a performance state of the motor.

[0073] In some embodiments, controller 480 receives sensor data indicative of a temperature of a refrigerated space (e.g., the cold reservoir proximate evaporator 418) and/or a temperature of a heated space (e.g., the hot reservoir proximate condenser 429). Controller 480 may control LP booster 414, HP booster 424, and/or compressor 422 based on sensor data received from one or more sensors of the fluid handling system 400 (e.g., one or more fluid flowrate sensors, temperature sensors, pressure sensors, etc.). In some embodiments, one or more sensors (e.g., pressure sensors, flow sensors, temperature sensors, etc.) are disposed proximate inlets and/or outlets of the various components of the fluid handling system 400. In some embodiments, one or more sensors are disposed internal to the components of the fluid handling system 400. In some examples, a pressure sensor may be disposed proximate the inlet of the compressor 422 and an additional pressure sensor may be disposed proximate the outlet of the compressor 422. In some examples, a temperature sensor may be disposed proximate the inlet of the evaporator 418 and another temperature sensor may be disposed proximate the outlet of the evaporator 418. In some examples, a temperature sensor may be disposed internal to the condenser 429. In some examples, a flow sensor may be located at each of the inlets and outlets of the PX 410 to measure a flow of the first fluid and the second fluid into and out of the PX 410.

[0074] Described herein are references to “first fluid” and “second fluid.” In some embodiments, the first fluid and the second fluid are the same type of fluid (e.g., are a refrigeration fluid flowing in a fluid handling system). “First fluid” may refer to fluid flowing through the PX 410 from the high pressure inlet to the low pressure outlet of the PX 410 and/or fluid flowing to or from the high pressure inlet and/or the low pressure outlet of the PX 410. “Second fluid” may refer to fluid flowing through the PX 410 from the low pressure inlet to the high pressure outlet of the PX 410 and/or fluid flowing to or from the low pressure inlet and/or the high pressure outlet of the PX 410. In some embodiments, the first fluid may be a refrigerant fluid in a supercritical state (e.g., supercritical CO2). In some embodiments, the first fluid may be a refrigerant fluid in a liquid state (e.g., liquid CO2). In some embodiments, the second fluid may be a refrigerant fluid in a gaseous state (e.g., CO2 vapor). In some embodiments, the second fluid may be a refrigerant fluid in a two-phase state (e.g., a liquid-gas mixture of CO2). In some embodiments, the second fluid may be a refrigerant fluid in a liquid state (e.g., liquid CO2).

[0075] In some embodiments, system 400 is a heat pump system capable of heating an environment (e.g., an indoor space). In such a heat pump system, the condenser 429 is placed indoors and the evaporator 418 is placed outdoors. In a heat pump system, the evaporator absorbs heat from the ambient and vaporize the two phase refrigerant fluid flowing through the evaporator before sending it to the inlet of the compressor. In some embodiments, to switch from refrigeration or air-cooling system to a heat pump system, a reversing valve may be used to cause the fluid flow exiting the compressor 422 to be switchable between being directed towards the inlet of the outdoor unit or towards the inlet of the indoor unit. In some embodiments, one or more valves and piping may be used to cause fluid flow to be directed in the same direction through all of the components (e.g., one or more the PX 410, LP booster 414, HP booster 424, compressor 422, and/or the like) while switching the fluid flow from indoor unit to outdoor unit.

[0076] The direction of transfer of thermal energy (e.g., heat transfer) of the system 400 may be reversible in some embodiments. For example, in refrigeration / air-conditioning / air cooling implementations of system 400, the condenser 429 placed outdoors rejects heat (e.g., provide corresponding thermal energy from the refrigeration fluid to the corresponding environment) and the evaporator 418 absorbs heat (e.g., provide corresponding thermal energy from the corresponding environment to the refrigeration fluid). While in heat pump implementation of system 400, the condenser 429 placed indoors rejects heat to its indoor environment and evaporator 418 absorbs heat from its outdoor environment. In some embodiments, system 400 includes one or more valves (e.g., a reversing valve, diversion valve(s), etc.) to reverse the function of system 400 (e.g., reverse the flow of thermal energy facilitated by system 400). In some embodiments, one or more flows of refrigeration fluid (e.g., to/from the PX 410, to/from the HP booster 424, to/from the LP booster 414, to/from the compressor 422, to/from the condenser 429, and/or to/from the evaporator 418) may be reversed and/or diverted. In some examples, one or more reversing or diversion valves included in system 400 in some embodiments can direct fluid from the compressor 422 toward the outdoor unit. Similar valves may direct fluid from the compressor 422 to the indoor unit.

[0077] Reversibility of system 400 may be controlled (e.g., via controller 480, via a programmable thermostat disposed in the indoor space, via user input, etc.). In some examples, the controller 480 may determine (e.g., based on temperature data, based on user input, based on a schedule) whether to use system 400 to heat an indoor space or to cool an indoor space. In some embodiments, the controller 480 may cause one or more valves (e.g., reversing valve, diversion valve(s), etc.) to actuate to cause fluid flow through the system to reverse. In embodiments where the function of system 400 is reversible (e.g., reversible between heating and cooling an indoor space), evaporator 418 may be an interior heat exchanger (e.g., disposed within an interior space, disposed in an air handler system providing airflow to an indoor space) and the condenser 429 may be an exterior heat exchanger (e.g., disposed outside the interior space). In other embodiments the evaporator 418 may be an outdoor heat exchanger and condenser 429 may be an indoor heat exchanger. [0078] FIG. 5A is a cross-sectional view of a compressor head 500, according to certain embodiments. FIG. 5B illustrates a valve plate 551, according to certain embodiments. FIG. 5C illustrates a valve plate assembly 555, according to certain embodiments. In some embodiments, the valve plate assembly 555 (e.g., valve plate assembly 355 of FIG. 3) is coupled to a bottom surface of the compressor head 500 (e.g., cylinder head 350) as described herein.

[0079] Compressor head 500 may be configured to couple to a top of a piston housing (e.g., cylinder 340). The head 500 may include an inlet 560 (e.g., compressor inlet 360) and an outlet 562 (e.g., compressor outlet 362). In some embodiments, the compressor head forms multiple passageways and/or chamber to direct a flow of process fluid 516 (e.g., refrigerant) to the piston housing. The suction side 552 of the compressor head 500 may form a chamber and/or a passageway to provide the process fluid 561 a path of ingress into the piston housing via the inlet 560 and/or via the intake valve 556. The discharge side 554 of the compressor head 500 may form a chamber and/or a passageway to provide the process fluid 561 a path of egress from the piston housing via the discharge valve 558 and/or the outlet 562. In some embodiments, a partition separates the suction side 552 from the discharge side 554. In some embodiments, the partition includes a thermal insulator (e.g., a thermally insulating material and/or structure) to thermally insulate the process fluid 561 on the suction side 552 from the process fluid 561 on the discharge side 554.

[0080] In some embodiments, the valve plate assembly 555 includes a valve plate 551. The plate 551 may form two or more openings (e.g., valve openings). In some embodiments, the plate 551 forms an intake valve opening 557 and a discharge valve opening 559. The plate 551 may form multiple bolt holes 588 to facilitate fastening the valve plate assembly 555 and/or the compressor head 500 to the top of a piston housing (e.g., cylinder 340). In some embodiments, the intake valve 556 is coupled to the plate 551 and disposed within one opening formed by the plate 551. The discharge valve 558 may be coupled to the plate 551 and disposed within another opening formed by the plate 551. In some embodiments, the intake valve 556 and the discharge valve 558 are reed valves. In some examples, the intake valve 556 and the discharge valve 558 include one or more petals 563 (e.g., thin strips, thin metal strips, thin carbon strips, etc.) to form a check valve that seals an opening formed in the plate 551. The petals of the intake valve 556 and the discharge valve 558 may be coupled to the plate 551 at one end (e.g., at a root end of the petal 563). The intake valve 556 and the discharge valve 558 may only allow flow in one direction. In some examples, the intake valve 556 allows flow of fluid (e.g., process fluid 561) out of the compressor head (e.g., and into the piston housing) and the discharge valve allows flow of fluid into the compressor head (e.g., out of the piston housing). In some embodiments, the intake valve 556 may open responsive to a negative pressure in the inner volume of the piston housing (e.g., as described with reference to FIG. 3). In some embodiments, the discharge valve 558 may open responsive to a positive pressure in the inner volume of the piston housing (e.g., as described with reference to FIG. 3).

[0081] FIG. 6 is a flow diagram illustrating an example method associated with a compressor (e.g., HP booster 424, LP booster 414, and/or compressor 422 has same or similar features and/or functionality as one or more of booster 123 of FIG. 1A, booster 153 of FIG. 1A, compressor 178 of FIG. IB, low pressure lift device 128 of FIG. IB, high pressure lift device 159 of FIG. IB, compressor 278 of FIGS. 2A-E, and/or compressor 300 of FIG. 3, HP booster 424 of FIG. 4, LP booster 414 of FIG. 4, compressor 422 of FIG. 4, and/or the like), according to certain embodiments. For simplicity of explanation, method 600 is depicted and described as a series of operations. However, operations in accordance with this disclosure can occur in various orders and/or concurrently and with other operations not presented and described herein. Furthermore, in some embodiments, not all illustrated operations are performed to implement method 600 in accordance with the disclosed subject matter. In addition, those skilled in the art will understand and appreciate that method 600 could alternatively be represented as a series of interrelated states via a state diagram or events.

[0082] At block 602, a compressor (e.g., compressor 300 of FIG. 3, HP booster 424 of FIG. 4, LP booster 414 of FIG. 4) may receive a first fluid at a first pressure. The first fluid may be a refrigeration fluid (e.g., refrigerant, CO2) as described herein. The compressor may be a reciprocating compressor, a centrifugal compressor, a screw compressor, and/or an axial compressor. In some embodiments, the compressor receives the first fluid at a first inlet of a first portion of the compressor. The first portion of the compressor may correspond to a portion of the compressor configured to compress the first fluid (e.g., a piston housing, a cylinder, a compressor wheel housing, a compressor rotor housing, etc.). The first portion of the compressor may be fluidly coupled to a pressure exchanger. In some embodiments, the compressor is configured to receive the fluid at the first pressure from a high pressure outlet of a pressure exchanger (e.g., PX 410 of FIG. 4).

[0083] At block 604, the compressor may increase pressure of the first fluid from the first pressure to a second pressure. In some embodiments, the second pressure is between approximately 50 PSI and approximately 60 PSI greater than the first pressure (e.g., a difference between the first pressure and the second pressure is between approximately 50 PSI and approximately 60 PSI). The compressor may increase the pressure of the first fluid by a piston, a screw, or a rotor (e.g., having blades or vanes).

[0084] At block 606, the compressor may output the first fluid at the second pressure via a first outlet of the first portion of the compressor. In some embodiments, the compressor outputs the first fluid via a compressor head (e.g., cylinder head) or a compressor manifold. In some embodiments, the compressor is configured to provide the fluid at the second pressure to a low pressure inlet of a pressure exchanger.

[0085] At block 608, the compressor may receive a second fluid. The second fluid may be a cooling fluid as described herein. In some embodiments, the second fluid is a same type of fluid as the first fluid (e.g., the first fluid and the second fluid are both a refrigerant such as CO2, etc.). The second fluid may be received by the compressor at a third pressure that is lower than the first pressure. The compressor may receive the second fluid at a second inlet (e.g., a cooling inlet, cooling inlet 370 of FIG. 3) of a second portion of the compressor. The second portion of the compressor may correspond to a portion of the compressor configured to house one or more mechanical components of the compressor. In some examples, the second portion of the compressor may be configured to house a motor that drives the compressor. In some examples, the second portion of the compressor may be configured to house a crankshaft and/or a driveshaft. In some examples, the second portion of the compressor houses one or more bearings and/or bushings. The second portion of the compressor may house lubricating oil that can be used to lubricate components of the compressor. The lubricating oil may be exposed to the second fluid inside the second portion of the compressor. However, because the second fluid is received at the third pressure (e.g., a relatively low pressure), the second fluid may resist dissolving in the lubricating oil which leads to the lubricating oil maintain its lubricating properties. In some embodiments, the compressor is configured to provide the fluid at the second pressure to a low pressure inlet of a pressure exchanger. In some embodiments, the first portion of the compressor and the second portion of the compressor are fluidly isolated from one another (e.g., substantially fluidly isolated from one another).

[0086] At block 610, the compressor may output the second fluid (e.g., the cooling fluid) via a second outlet of the second portion of the compressor. The second fluid may be output via a cooling outlet (e.g., cooling outlet 372 of FIG. 3). In some embodiments, the second fluid is output to an oil separator to separate any oil from the second fluid.

[0087] The preceding description sets forth numerous specific details, such as examples of specific systems, components, methods, and so forth, in order to provide a good understanding of several embodiments of the present disclosure. It will be apparent to one skilled in the art, however, that at least some embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram format in order to avoid unnecessarily obscuring the present disclosure. Thus, the specific details set forth are merely exemplary. Particular implementations may vary from these exemplary details and still be contemplated to be within the scope of the present disclosure.

[0088] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. In addition, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” When the term “about,” “substantially,” or “approximately” is used herein, this is intended to mean that the nominal value presented is precise within ±10%. Also, the terms "first," "second," "third," "fourth," etc. as used herein are meant as labels to distinguish among different elements and can not necessarily have an ordinal meaning according to their numerical designation.

[0089] The terms “over,” “under,” “between,” “disposed on,” and “on” as used herein refer to a relative position of one material layer or component with respect to other layers or components. In some examples, one layer disposed on, over, or under another layer may be directly in contact with the other layer or may have one or more intervening layers.

Moreover, one layer disposed between two layers may be directly in contact with the two layers or may have one or more intervening layers. Similarly, unless explicitly stated otherwise, one feature disposed between two features may be in direct contact with the adjacent features or may have one or more intervening layers.

[0090] Unless specifically stated otherwise, terms such as “actuating,” “adjusting,” “causing,” “controlling,” “determining,” “identifying,” “increasing,” “outputting,” “providing,” “receiving,” “regulating,” or the like, refer to actions and processes performed or implemented by computer systems that manipulates and transforms data represented as physical (electronic) quantities within the computer system registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. Also, the terms "first," "second," "third," "fourth," etc. as used herein are meant as labels to distinguish among different elements and may not have an ordinal meaning according to their numerical designation.

[0091] Examples described herein also relate to an apparatus for performing the methods described herein. This apparatus may be specially constructed for performing the methods described herein, or it may include a general purpose computer system selectively programmed by a computer program stored in the computer system. Such a computer program may be stored in a computer-readable tangible storage medium.

[0092] The methods and illustrative examples described herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used in accordance with the teachings described herein, or it may prove convenient to construct more specialized apparatus to perform methods described herein and/or each of their individual functions, routines, subroutines, or operations. Examples of the structure for a variety of these systems are set forth in the description above.

[0093] Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be altered so that certain operations may be performed in an inverse order or so that certain operation may be performed, at least in part, concurrently with other operations. In another embodiment, instructions or sub-operations of distinct operations may be in an intermittent and/or alternating manner. In one embodiment, multiple metal bonding operations are performed as a single step.

[0094] It is to be understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which each claim is entitled.