Method for measuring speed of piston and device for detecting characteristics of piston

Abstract

The invention provides a method for measuring the speed of a piston and equipment for detecting the characteristics of the piston. The method includes passing a piston in a chamber through at least one sensor; inducing an electrical characteristic in the at least one sensor by means of the piston; measuring a change over time of an electrical characteristic in the at least one sensor; and calculating the speed of the piston based on a change in the electrical characteristic in the at least one sensor.

Description

[0001] This application is a divisional application of the invention patent application with application date of November 18, 2020, application number 2020800833875 (PCT / US2020 / 060929), and invention name “Fluid exchange equipment and related control devices, systems and methods”.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 947,403, filed on December 12, 2019, entitled "FLUID EXCHANGE DEVICES AND RELATED CONTROLS, SYSTEMS, AND METHODS," the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] The present disclosure relates generally to exchange devices. More specifically, embodiments of the present disclosure relate to fluid exchange devices and systems and methods for exchanging one or more of a property (eg, pressure) between fluids. Background Art

[0005] Industrial processes often involve hydraulic systems, which include pumps, valves, impellers, etc. Pumps, valves, and impellers can be used to control the flow of fluids used in hydraulic processes. For example, some pumps can be used to increase (e.g., supercharge) the pressure in a hydraulic system, and other pumps can be used to move fluids from one location to another. Some hydraulic systems include valves, which are used to control the flow direction of the fluid. Valves can include control valves, ball valves, gate valves, stop valves, check valves, isolation valves, combinations thereof, and the like.

[0006] Some industrial processes involve the use of corrosive, abrasive, and / or acidic fluids. These types of fluids may increase the amount of wear on hydraulic system components. Increased wear may result in increased maintenance and repair costs or the need to replace equipment prematurely. For example, abrasive, corrosive, or acidic fluids may increase wear on the internal components of a pump, such as impellers, shafts, blades, nozzles, etc. Some pumps are repairable, and an operation may choose to replace worn parts to repair a worn pump, which may result in increased downtime for the worn pump, resulting in the need for redundant pumps or resulting in reduced productivity. Other operations may replace the worn pump at a higher expense but with less downtime.

[0007] Well completion operations in the oil and gas industry often involve hydraulic fracturing (often referred to as fracking or fracturing) to increase the release of oil and gas from rock formations. Hydraulic fracturing involves pumping a fluid (e.g., fracture fluid, fracking fluid, etc.) containing a combination of water, chemicals, and proppants (e.g., sand, ceramics) into a well at high pressure. The high pressure of the fluid increases the size of the cracks and the propagation of the cracks through the rock formation, thereby releasing more oil and gas, while the proppants prevent the cracks from closing after the fluid is depressurized. Fracturing operations use high-pressure pumps to increase the pressure of the fracturing fluid. However, the proppants in the fracturing fluid increase the wear and maintenance of the high-pressure pumps due to their abrasive properties and substantially reduce the operating life of the high-pressure pumps. Summary of the invention

[0008] Some embodiments of the present disclosure may include an apparatus for detecting piston characteristics. The apparatus may include a coil arranged around a chamber. The apparatus may also include a piston including one or more detection features (e.g., magnetic members) arranged annularly around a surface of the piston. The piston may be configured to travel within the chamber. At least one coil may be configured to generate a signal based on the proximity of one or more magnetic members.

[0009] In some embodiments, the at least one coil can include at least two coils, and the at least two coils can be spaced apart a first distance along the axis of the chamber. In some embodiments, the first distance is greater than about one inch (2.54 cm). In some embodiments, a third coil arranged about the chamber can be positioned a second distance from one of the at least two coils (e.g., where the first distance is equal to the second distance).

[0010] Another embodiment of the present disclosure may include a system for exchanging pressure between at least two fluid streams. The system may include a pressure exchange device for exchanging at least one characteristic between the fluids. The pressure exchange device may include at least one chamber. At least one chamber may include: a first end for receiving a clean fluid having a first characteristic; and a second end for receiving a dirty fluid having a second characteristic. The chamber may also include at least one piston located in at least one chamber. At least one piston may be configured to separate the clean fluid from the dirty fluid. The chamber may also include a valve device configured to selectively connect the clean fluid to the dirty fluid through at least one piston, thereby at least partially transferring the first characteristic of the clean fluid to the dirty fluid. The chamber may also include at least one sensor, the sensor including at least one coil arranged circumferentially around at least one chamber. The sensor may be configured to detect a characteristic (e.g., velocity, position, acceleration, jerk) of at least one piston.

[0011] Another embodiment of the present disclosure may include a method of measuring piston velocity. The method may include passing the piston through at least one sensor (e.g., a first coil). The method may also include inducing an electrical characteristic (e.g., current and / or voltage) in the first coil with the piston. The method may also include measuring a change in current in the first coil over time. The method may also include calculating the velocity of the piston based on the change in current in the first coil.

[0012] Another embodiment of the present disclosure may include a method for controlling a pressure exchange device. The method may include supplying a high-pressure cleaning fluid to a high-pressure inlet of a valve, the valve being configured to direct the high-pressure cleaning fluid to flow to a first chamber. The method may also include transferring a first pressure from the high-pressure cleaning fluid to a low-pressure dirty fluid by a first piston in the first chamber. The method may also include receiving a low-pressure dirty fluid in a second chamber. The method may also include monitoring the positions of the first piston and the second piston. The method may also include changing the position of the valve in response to the position of the second piston. The method may also include, in a retention phase, stopping the flow of the low-pressure cleaning fluid from the second chamber while maintaining the flow of the high-pressure cleaning fluid into the first chamber. The method may also include redirecting the high-pressure cleaning fluid flow to the second chamber after the retention phase.

[0013] In some embodiments, the method further comprises changing the dwell phase in response to the position of the first piston. In some embodiments, the method further comprises: monitoring one or more of a speed or an acceleration of the first piston; and changing the dwell phase in response to one or more of a speed or an acceleration of the first piston.

[0014] Another embodiment of the present disclosure may include a system for exchanging pressure between at least two fluid streams. The system may include a first chamber. The first chamber may include a first clean end configured to receive a clean fluid. The first chamber may also include a first dirty end configured to receive a dirty fluid. The first chamber may also include a first piston configured to separate the clean fluid from the dirty fluid. The first chamber may also include a first clean-side piston sensor including at least one first clean-side piston sensor coil configured to detect one or more characteristics of the movement of the first piston. The first chamber may also include a first dirty-side piston sensor including at least one first dirty-side piston sensor coil configured to detect one or more characteristics of the movement of the first piston. The system may also include a second chamber. The second chamber may include a second clean end configured to receive a clean fluid. The second chamber may also include a second dirty end configured to receive a dirty fluid. The second chamber may also include a second piston configured to separate the clean fluid from the dirty fluid. The second chamber may also include a second clean-side piston sensor including at least one second clean-side piston sensor coil configured to detect one or more characteristics of the movement of the second piston. The second chamber may also include a second dirty-side piston sensor including at least one second dirty-side piston sensor coil configured to detect one or more characteristics of the movement of the second piston. The system may also include a valve device configured to selectively place the clean fluid and the dirty fluid in communication through at least one of the first piston and the second piston.

[0015] In some embodiments, the first dirty-side piston sensor is configured to detect whether the first piston passes by the first dirty-side piston sensor; and wherein the second dirty-side piston sensor is configured to detect whether the second piston passes by the second dirty-side piston sensor.

[0016] In some embodiments, the first clean-side piston sensor is configured to detect the speed of the first piston; and wherein the second clean-side piston sensor is configured to detect the speed of the second piston.

[0017] In some embodiments, the first dirty-side piston sensor is configured to detect the speed of the first piston, and wherein the second dirty-side piston sensor is configured to detect the speed of the second piston.

[0018] Another embodiment of the present disclosure may include a system for exchanging pressure between at least two fluid streams. The system may include at least two pressure exchange devices. The pressure exchange device may include a first chamber and a first piston, the first piston being configured to travel in the first chamber. The pressure exchange device may also include a second chamber and a second piston, the second piston being configured to travel in the second chamber. The pressure exchange device may also include a control valve configured to control the movement of the first piston and the second piston by selectively directing the flow of the high-pressure cleaning fluid into one or more chambers of the first chamber and the second chamber. The first piston and the second piston may be configured to exchange pressure from the high-pressure cleaning fluid to the low-pressure dirty fluid. The control valve may be configured to maintain a period difference of approximately 180 degrees between the first piston and the second piston. The control valve of the first pressure exchange device may be configured to maintain the period of the first piston and the second piston of the first pressure exchange device and the period of the first piston and the second piston of the second pressure exchange device at an equal period difference.

[0019] In some embodiments, the system can include a third pressure exchanging device, wherein the equal period difference is 120 degrees.

[0020] Another embodiment of the present disclosure may include a method for detecting a piston, the method comprising: detecting the piston with a first sensor; measuring a voltage level in the first sensor; detecting the piston with a second sensor; measuring a voltage level in the second sensor; and comparing the voltage level in the first sensor with the voltage level in the second sensor to determine whether the piston has passed both the first sensor and the second sensor.

[0021] Another embodiment of the present disclosure may include a method for measuring the speed of a piston, the method comprising: passing the piston past a first sensor; measuring a change in voltage over time in the first sensor in response to the passage of the piston; calculating the speed using the change in voltage over time; if the speed exceeds a threshold speed level, measuring another change in voltage over time in the first sensor in response to the passage of the piston; and calculating another speed using the other change in voltage over time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] While the specification appended hereto contains claims which particularly point out and distinctly claim what are regarded as embodiments of the present disclosure, various features and advantages of the embodiments of the present disclosure may be more readily ascertained from the following description of example embodiments of the present disclosure when read in conjunction with the accompanying drawings, in which:

[0023] Figure 1 is a schematic diagram of a hydraulic fracturing system according to an embodiment of the present disclosure;

[0024] Figure 2is a cross-sectional view of a fluid exchanger device according to an embodiment of the present disclosure;

[0025] Figure 3A is a cross-sectional view of a control valve in a first position according to an embodiment of the present disclosure;

[0026] Figure 3B is a cross-sectional view of a control valve in a second position according to an embodiment of the present disclosure;

[0027] Figure 4 is a partial cross-sectional view of a fluid exchanger device according to an embodiment of the present disclosure;

[0028] Figure 5 is a side view of a sensor according to an embodiment of the present disclosure;

[0029] Figure 6 is a side view of a sensor according to an embodiment of the present disclosure;

[0030] Figure 7 is a perspective view of a piston according to an embodiment of the present disclosure;

[0031] Figure 8 is a perspective view of a piston according to an embodiment of the present disclosure;

[0032] Fig.9A is a partial cross-sectional view of a portion of a fluid exchanger device according to an embodiment of the present disclosure;

[0033] Fig. 9B Is Fig.9A A graph of a signal generated by a portion of a fluid exchanger device shown in;

[0034] Fig. 10A is a partial cross-sectional view of a portion of a fluid exchanger device according to an embodiment of the present disclosure;

[0035] Fig. 10B Is Fig. 10A A graph of a signal generated by a portion of a fluid exchanger device shown in;

[0036] Fig.11 is a graph showing the relationship between the rate of change of signal voltage and piston speed according to an embodiment of the present disclosure;

[0037] Fig.12 is a graph of the relationship between signal voltage and piston speed according to an embodiment of the present disclosure;

[0038] Fig.13 is a flow chart of a control process of a fluid exchanger device according to an embodiment of the present disclosure;

[0039] Fig.14 is a partial cross-sectional view of a fluid exchanger device according to an embodiment of the present disclosure;

[0040] Fig.15 is a partial cross-sectional view of a fluid exchanger device according to an embodiment of the present disclosure;

[0041] Fig.16 is a flow chart of a control process for an embodiment of a fluid exchange device according to an embodiment of the present disclosure; and

[0042] Fig.17 is a partial cross-sectional view of a fluid exchanger system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0043] The illustrations presented herein are not meant to be actual views of any particular fluid exchanger or its components, but are merely idealized representations employed to describe illustrative embodiments. The drawings are not necessarily to scale. Elements common between the drawings may retain the same reference numerals.

[0044] As used herein, relational terms such as "first", "second", "top", "bottom", etc. are generally used for clear and convenient understanding of the present disclosure and the drawings, and do not imply or depend on any particular preference, orientation or order unless the context clearly indicates otherwise.

[0045] As used herein, the term "and / or" means and includes any and all combinations of one or more of the associated listed items.

[0046] As used herein, the terms "vertical" and "lateral" refer to the orientation depicted in the accompanying drawings.

[0047] As used herein, the term "substantially" or "approximately" in relation to a given parameter means and includes, to the extent that a person skilled in the art would understand that a given parameter, characteristic or condition complies with a minor degree of variation, such as within acceptable manufacturing tolerances. For example, a substantially complied parameter may be at least 90% complied, at least 95% complied, at least 99% complied, or even 100% complied.

[0048] As used herein, the term "fluid" can mean and include fluids of any type and composition. Fluid can take liquid form, gaseous form or their combination, and can include some solid materials in some cases. In some embodiments, fluid can be converted between liquid form and gaseous form during cooling or heating process as described herein. In some embodiments, the term fluid includes a pumpable mixture of gas, liquid and / or liquid and solid.

[0049] Embodiments of the present disclosure may be directed to exchange devices (e.g., pressure exchangers) that can be used to exchange one or more properties between fluids. Such exchangers (e.g., pressure exchangers) are sometimes referred to as "flow work exchangers" or "isobaric devices" and are machines for exchanging pressure energy from a relatively high-pressure flowing fluid system to a relatively low-pressure flowing fluid system.

[0050] In some industrial processes, it is necessary to increase the pressure in certain parts of the operation to achieve the desired result, after which the pressurized fluid is decompressed. In other processes, some of the fluids used in the process are available at high pressure, while other fluids are available at low pressure, and it is desirable to exchange pressure energy between the two fluids. Therefore, in some applications, if pressure can be efficiently transferred between two fluids, great economic improvements can be achieved.

[0051] In some embodiments, the exchangers disclosed herein may be similar to and include various components and configurations of the pressure exchangers disclosed in US Pat. No. 5,797,429, issued Aug. 25, 1998 to Shumway, the disclosure of which is incorporated herein by reference in its entirety.

[0052] Although some embodiments of the present disclosure are described as being used and employed as a pressure exchanger between two or more fluids, those skilled in the art will appreciate that embodiments of the present disclosure may be used in other implementations, such as, for example, exchanging other properties (e.g., temperature, density, etc.) and / or components between one or more fluids and / or a mixture of two or more fluids.

[0053] In some embodiments, pressure exchangers can be used to protect moving parts (e.g., pumps, valves, impellers, etc.) in processes where high pressures are required for fluids that could damage moving parts (e.g., abrasive fluids, corrosive fluids, acidic fluids, etc.).

[0054] For example, pressure exchange devices according to embodiments of the present disclosure may be implemented in hydrocarbon-related processes such as hydraulic fracturing or other drilling operations (eg, subterranean downhole drilling operations).

[0055] As discussed above, well completion operations in the oil and gas industry often involve hydraulic fracturing, drilling operations, or other downhole operations that use high-pressure pumps to increase the pressure of downhole fluids (e.g., fluids intended to be directed into a subterranean formation or wellbore, such as fracturing fluids, drilling fluids, drilling muds). The proppants, chemicals, additives, etc. in these fluids that produce muds often increase the wear and maintenance of the high-pressure pumps.

[0056] In some embodiments, a hydraulic fracturing system can include a hydraulic energy transfer system that transfers pressure between a first fluid (e.g., a clean fluid, such as a fluid that is partially (e.g., mostly) or substantially free of proppant or a pressure exchange fluid) and a second fluid (e.g., a fracturing fluid, such as a proppant-containing fluid, an abrasive fluid, or a dirty fluid). Such a system can at least partially (e.g., substantially, mainly, completely) isolate the high-pressure first fluid from the second dirty fluid, while still being able to pressurize the second dirty fluid with the high-pressure first fluid without having to pass the second dirty fluid directly through a pump or other pressurizing device.

[0057] Although some embodiments discussed herein may be directed to fracturing operations, in other embodiments, the exchanger systems and devices disclosed herein may be used for other operations. For example, the devices, systems and / or methods disclosed herein may be used for other downhole operations, such as, for example, downhole drilling operations.

[0058] Figure 1 A system diagram of an embodiment of a hydraulic fracturing system 100 is shown that utilizes a pressure exchanger between a first fluid stream (e.g., a clean fluid stream) and a second fluid stream (e.g., a fracturing fluid stream). Although not explicitly described, it should be understood that each component of the system 100 can be directly connected to or coupled to an adjacent (e.g., upstream or downstream) component via a fluid conduit (e.g., a pipe). The hydraulic fracturing system 100 can include one or more devices for pressurizing the first fluid stream, such as, for example, a fracturing pump 102 (e.g., a reciprocating pump, a centrifugal pump, a vortex pump, etc.). The system 100 can include a plurality of fracturing pumps 102, such as at least two fracturing pumps 102, at least four fracturing pumps 102, at least ten fracturing pumps 102, at least sixteen fracturing pumps, or at least twenty fracturing pumps 102. In some embodiments, the fracturing pump 102 can provide a relatively and substantially clean fluid from a fluid source 101 to a pressure exchanger 104 at high pressure. In some embodiments, fluid may be provided to each pump 102 individually (eg, in a parallel configuration). After being pressurized in the pumps 102, the high pressure cleaning fluid 110 may be combined and delivered to the pressure exchanger 104 (eg, in a serial configuration).

[0059] As used herein, a "clean" fluid may describe a fluid that is at least partially or substantially free (e.g., substantially completely free or completely free) of chemicals and / or proppants typically found in downhole fluids, and a "dirty" fluid may describe a fluid that at least partially contains chemicals, other additives and / or proppants typically found in downhole fluids.

[0060] The pressure exchanger 104 can transfer pressure from the high pressure cleaning fluid 110 to a low pressure fracturing fluid (e.g., fracturing fluid 112) to provide a high pressure fracturing fluid 116. The cleaning fluid can be discharged from the pressure exchanger 104 as a low pressure liquid 114 after the pressure is transferred to the low pressure fracturing fluid 112. In some embodiments, the low pressure fluid 114 can be an at least partially or substantially clean fluid that is substantially free of chemicals and / or proppants, except for small amounts of chemicals and / or proppants that may be transferred from the fracturing fluid 112 to the low pressure fluid 114 in the pressure exchanger 104.

[0061] In some embodiments, the pressure exchanger 104 may include one or more pressure exchanger devices (e.g., operating in parallel). In such a configuration, the high pressure input may be separated and provided to the input of each of the pressure exchanger devices. When the high pressure fracturing fluid leaves the pressure exchanger 104, the output of each of the pressure exchanger devices may be combined. For example, and as described below with reference to Figure 4 As discussed, the pressure exchanger 104 may include two or more (e.g., three) pressure exchanger devices operating in parallel. As shown, the pressure exchanger 104 may be disposed on a mobile platform (e.g., a truck trailer) that may be relatively easily installed at and removed from a fracking well site.

[0062] The low-pressure clean fluid 114, after being discharged from the pressure exchanger 104, can travel to a mixing chamber 106 (e.g., a blender unit, a mixing unit, etc.) and be collected in the mixing chamber. In some embodiments, the low-pressure fluid 114 can be converted (e.g., modified, transformed, etc.) into a low-pressure fracturing fluid 112 in the mixing chamber 106. For example, a proppant can be added to the low-pressure clean fluid 114 in the mixing chamber 106 to form the low-pressure fracturing fluid 112. In some embodiments, the low-pressure clean fluid 114 can be discharged as waste.

[0063] In many hydraulic fracturing operations, a separate process may be used to heat the fracturing fluid 112 before the fracturing fluid 112 is discharged downhole (e.g., to ensure proper mixing of the proppant in the fracturing fluid). In some embodiments, the use of a low-pressure clean fluid 114 to produce the fracturing fluid 112 can eliminate the step of heating the fracturing fluid. For example, since the fracturing pump 102 pressurizes the high-pressure clean fluid 110, the low-pressure clean fluid 114 may be at an already elevated temperature. After the pressure of the high-pressure clean fluid 110 that has been heated by the fracturing pump 102 is transferred, the low-pressure clean fluid 114 now retains at least a portion of the thermal energy when it is transferred from the pressure exchanger 104 to the mixing chamber 106. In some embodiments, the use of a low-pressure clean fluid 114 that is at an already elevated temperature to produce the fracturing fluid can eliminate the step of heating the fracturing fluid. In other embodiments, the increase in the temperature of the low-pressure clean fluid 114 may result in a reduction in the amount of heating required for the fracturing fluid.

[0064] After the proppant is added to the low-pressure fluid, now the fracturing fluid 112, the low-pressure fracturing fluid 112 may be discharged from the mixing chamber 106. The low-pressure fracturing fluid 112 may then enter the pressure exchanger 104 on the fracturing fluid end through a fluid conduit 108 connected (e.g., coupled) between the mixing chamber 106 and the pressure exchanger 104. After entering the pressure exchanger 104, the low-pressure fracturing fluid 112 may be pressurized by the pressure transmitted from the high-pressure cleaning fluid 110 through the pressure exchanger 104. The high-pressure fracturing fluid 116 may then exit the pressure exchanger 104 and be transmitted downhole.

[0065] Hydraulic fracturing systems generally require high operating pressures for the high pressure fracturing fluid 116. In some embodiments, the desired pressure of the high pressure fracturing fluid 116 may be between about 8,000 PSI (55,158 kPa) and about 12,000 PSI (82,737 kPa), such as between about 9,000 PSI (62,052 kPa) and about 11,000 PSI (75,842 kPa), or about 10,000 PSI (68,947 kPa).

[0066] In some embodiments, the high pressure cleaning fluid 110 can be pressurized to a pressure that is at least substantially the same as or slightly greater than the desired pressure of the high pressure fracturing fluid 116. For example, the high pressure cleaning fluid 110 can be pressurized to between about 0 PSI (0 kPa) and about 1000 PSI (6,894 kPa) above the desired pressure of the high pressure fracturing fluid 116, such as between about 200 PSI (1,379 kPa) and about 700 PSI (4,826 kPa) above the desired pressure, or between about 400 PSI (2,758 kPa) and about 600 PSI (4,137 kPa) above the desired pressure to account for any pressure loss during the pressure and exchange process.

[0067] Figure 2 An embodiment of a pressure exchanger 200 is shown. The pressure exchanger 200 can be a linear pressure exchanger in the sense that the pressure exchanger is operated by moving or translating an actuation assembly substantially along a linear path. For example, the actuation assembly can be moved linearly to selectively place low-pressure and high-pressure fluids in at least partial communication (e.g., indirect communication, where the pressure of the high-pressure fluid can be transferred to the low-pressure fluid), as discussed in detail below.

[0068] The linear pressure exchanger 200 may include one or more (e.g., two) chambers 202a, 202b (e.g., tanks, collectors, cylinders, tubes, pipes, etc.). The chambers 202a, 202b (e.g., parallel chambers 202a, 202b) may include pistons 204a, 204b configured to substantially maintain a high pressure clean fluid 210 and a low pressure clean fluid 214 (e.g., a clean side) separated from a high pressure dirty fluid 216 and a low pressure dirty fluid 212 (e.g., a dirty side) while enabling pressure transfer between the respective fluids 210, 212, 214, and 216. The pistons 204a, 204b may be sized (e.g., an outer diameter of the pistons 204a, 204b relative to an inner diameter of the chambers 202a, 202b) to enable the pistons 204a, 204b to travel through the chambers 202a, 202b while minimizing fluid flow around the pistons 204a, 204b.

[0069] The linear pressure exchanger 200 may include a clean control valve 206 (e.g., with a control system) configured to control the flow of a high pressure clean fluid 210 and a low pressure clean fluid 214. Each of the chambers 202a, 202b may include one or more dirty control valves 207a, 207b, 208a, and 208b configured to control the flow of a low pressure dirty fluid 212 and a high pressure dirty fluid 216.

[0070] although Figure 2The embodiments contemplate a linear pressure exchanger 200, but other embodiments may include other types of pressure exchangers involving other mechanisms for selectively placing low-pressure and high-pressure fluids in at least partial communication (e.g., rotary actuators, such as those disclosed in U.S. Patent 9,435,354, issued on September 6, 2016, the disclosure of which is incorporated herein by reference in its entirety).

[0071] In some embodiments, the cleaning control valve 206 can selectively allow (e.g., input, place, etc.) a high-pressure cleaning fluid 210 provided from the high-pressure inlet port 302 to enter the first chamber 202a on the clean side 220a of the piston 204a, and the cleaning control valve includes an actuating rod 203 that moves one or more stops 308 along (e.g., linearly along) the body 205 of the valve 206. The high-pressure cleaning fluid 210 can act on the piston 204a, thereby moving the piston 204a in a direction toward the dirty side 221a of the piston 204a and compressing the dirty fluid in the first chamber 202a to produce a high-pressure dirty fluid 216. The high-pressure dirty fluid 216 can leave the first chamber 202a through the dirty discharge control valve 208a (e.g., outlet valve, high-pressure outlet). At substantially the same time, the low-pressure dirty fluid 212 can enter the second chamber 202b through the dirty fill control valve 207b (e.g., inlet valve, low-pressure inlet). The low-pressure dirty fluid 212 can act on the dirty side 221b of the piston 204b, thereby moving the piston 204b in the second chamber 202b in a direction toward the clean side 220b of the piston 204b. When the piston 204b moves in a direction toward the clean side 220b of the piston 204b, the low-pressure clean fluid 214 can be discharged (e.g., emptied, drained, etc.) through the clean control valve 206, thereby reducing the space on the clean side 220b of the piston 204b in the second chamber 202b. When each piston 204a, 204b moves a substantial length (e.g., a majority of the length) of the corresponding chamber 202a, 202b, a cycle of the pressure exchanger is completed (the "cycle" may be half a cycle of the piston 204a, 204b moving in one direction along the length of the chamber 202a, 202b, while a full cycle includes the piston 204a, 204b moving in one direction along the length of the chamber 202a, 202b, and then moving in the other direction to return to a substantially initial position). In some embodiments, only a portion of the length may be utilized (e.g., in the case of reduced capacity). After a cycle is completed, the actuating rod 203 of the cleaning control valve 206 may change position to enable the high-pressure cleaning fluid 210 to enter the second chamber 202b, thereby changing the second chamber 202b to a high-pressure chamber and changing the first chamber 202a to a low-pressure chamber, and repeating the process.

[0072] In some embodiments, each chamber 202a, 202b can have a higher pressure on one side of the piston 204a, 204b to move the piston in a direction away from the higher pressure. For example, the high pressure chamber can experience a pressure between about 8,000 PSI (55,158 kPa) to about 13,000 PSI (89,632 kPa), with the highest pressure in the high pressure cleaning fluid 210, to move the piston 204a, 204b away from the high pressure cleaning fluid 210, thereby compressing and discharging the dirty fluid to produce the high pressure dirty fluid 216. In contrast, the low pressure chamber 202a, 202b can experience a much lower pressure, wherein the relatively higher pressure in the low pressure dirty fluid 212 in the low pressure chamber 202a, 202b is still sufficient to move the piston 204a, 204b in a direction away from the low pressure dirty fluid 212, thereby discharging the low pressure cleaning fluid 214. In some embodiments, the pressure of the low-pressure dirty fluid 212 can be between about 100 PSI (689 kPa) and about 700 PSI (4826 kPa), such as between about 200 PSI (1379 kPa) and about 500 PSI (3447 kPa), or between about 300 PSI (2068 kPa) and about 400 PSI (2758 kPa).

[0073] Refer again Figure 1 In some embodiments, the hydraulic fracturing system 100 can include an optional device (e.g., a pump) to pressurize the low-pressure dirty fluid 212 when it is provided to the chambers 202a, 202b (e.g., to a pressure level suitable for moving the pistons 204a, 204b toward the clean side).

[0074] Refer again Figure 2 , if any fluid squeezes past the pistons 204a, 204b (e.g., leaks, leaks out, etc.), it will generally tend to flow from the higher pressure fluid to the lower pressure fluid. The high pressure clean fluid 210 can be maintained at the highest pressure in the system so that the high pressure clean fluid 210 can generally be substantially uncontaminated. The low pressure clean fluid 214 can be maintained at the lowest pressure in the system. Therefore, the low pressure clean fluid 214 is likely to be contaminated by the low pressure dirty fluid 212. In some embodiments, the low pressure clean fluid 214 can be used to produce the low pressure dirty fluid 212 to substantially offset any damage caused by the contamination. Similarly, any contamination of the high pressure dirty fluid 216 by the high pressure clean fluid 210 will also have minimal effect on the high pressure dirty fluid 216.

[0075] In some embodiments, the dirt control valves 207a, 207b, 208a, 208b may be check valves (e.g., flap valves, non-return valves, return valves, holding valves, or one-way valves). For example, one or more of the dirt control valves 207a, 207b, 208a, 208b may be ball check valves, diaphragm check valves, swing check valves, tilting disc check valves, flap valves, stop check valves, lift check valves, in-line check valves, duckbill valves, etc. In other embodiments, one or more of the dirt control valves 207a, 207b, 208a, 208b may be actuated valves (e.g., solenoid valves, pneumatic valves, hydraulic valves, electronic valves, etc.), which are configured to receive a signal from a controller and open or close in response to the signal.

[0076] The dirty control valves 207a, 207b, 208a, 208b may be arranged in an opposing configuration such that when the chambers 202a, 202b are in a high pressure configuration, the high pressure dirty fluid opens the dirty discharge control valves 208a, 208b, while the pressure in the chambers 202a, 202b keeps the dirty fill control valves 207a, 207b closed. For example, the dirty discharge control valves 208a, 208b include check valves that open in a first direction away from the chambers 202a, 202b, while the dirty fill control valves 207a, 207b include check valves that open in a second, opposite direction into the chambers 202a, 202b.

[0077] The dirty drain control valves 208a, 208b can be connected to downstream components (e.g., fluid conduits, separate or common manifolds) such that high pressure in the downstream components causes the dirty drain control valves 208a, 208b to remain closed in the chambers 202a, 202b in a low pressure configuration. Such a configuration enables low pressure dirty fluid to open the dirty fill control valves 207a, 207b and enter the chambers 202a, 202b.

[0078] Figure 3A and Figure 3B 1 shows a cross-sectional view of an embodiment of a cleaning control valve 300 in two different positions. In some embodiments, the cleaning control valve 300 can be similar to the cleaning control valve 206 discussed above. The cleaning control valve 300 can be a multi-port valve (e.g., a 4-way valve, a 5-way valve, a The cleaning control valve 300 may have one or more high pressure inlet ports (e.g., one port 302), one or more low pressure outlet ports (e.g., two ports 304a, 304b), and one or more chamber connection ports (e.g., two ports 306a, 306b). The cleaning control valve 300 may include at least two stops 308 (e.g., plugs, pistons, disks, valve members, etc.). In some embodiments, the cleaning control valve 300 may be a linearly actuated valve. For example, the stop 308 may be linearly actuated so that the stop 308 moves along a substantially straight line (e.g., along the longitudinal axis L300 of the cleaning control valve 300).

[0079] The cleaning control valve 300 may include an actuator 303 configured to actuate the cleaning control valve 300 (e.g., an actuator coupled to the valve stem 301 of the cleaning control valve 300). In some embodiments, the actuator 303 may be electronic (e.g., a solenoid, a rack and pinion, a ball screw, a segmented spindle, a moving coil, etc.), pneumatic (e.g., a tie rod cylinder, a diaphragm actuator, etc.), or hydraulic. In some embodiments, the actuator 303 may enable the cleaning control valve 300 to move the valve stem 301 and the stopper 308 at a variable rate (e.g., a variable speed, an adjustable speed, etc.).

[0080] Figure 3A The cleaning control valve 300 is shown in a first position. In the first position, the stopper 308 can be positioned so that high-pressure cleaning fluid can enter the cleaning control valve 300 through the high-pressure inlet port 302 and exit through the chamber connection port 306a to enter the first chamber. In the first position, low-pressure cleaning fluid can travel through the cleaning control valve 300 between the chamber connection port 306b and the low-pressure outlet port 304b (e.g., can exit through the low-pressure outlet port 304b).

[0081] Figure 3B The cleaning control valve 300 is shown in a second position. In the second position, the stopper 308 can be positioned so that high-pressure cleaning fluid can enter the cleaning control valve 300 through the high-pressure inlet port 302 and exit through the chamber connection port 306b to enter the second chamber. The low-pressure cleaning fluid can travel through the cleaning control valve 300 between the chamber connection port 306a and the low-pressure outlet port 304a (e.g., can exit through the low-pressure outlet port 304a).

[0082] Now refer to Figure 2 , Figure 3A and Figure 3B, the cleaning control valve 206 is shown in a first position in which the high pressure inlet port 302 is connected to the chamber connection port 306a, thereby providing high pressure cleaning fluid to the first chamber 202a. After the cycle is completed, the cleaning control valve 206 can move the stopper 308 to the second position, thereby connecting the high pressure inlet port 302 to the second chamber 202b through the chamber connection port 306b.

[0083] In some embodiments, the cleaning control valve 206 can pass through a substantially fully closed position at the middle portion of the stroke between the first position and the second position. For example, in the first position, the stopper 308 can maintain the fluid passage between the high-pressure inlet port 302 and the chamber connection port 306a and the fluid passage between the chamber connection port 306b and the low-pressure outlet port 304b. In the second position, the stopper 308 can maintain the fluid passage between the high-pressure inlet port 302 and the chamber connection port 306b, and the fluid passage between the chamber connection port 306a and the low-pressure outlet port 304a. The transition between the first position and the second position may involve at least substantially closing the two fluid passages to change the connection of the chamber connection port 306a from the high-pressure inlet port 302 to the low-pressure outlet port 304a, and to change the connection of the chamber connection port 306b from the low-pressure outlet port 304b to the high-pressure inlet port 302. The fluid passage can be substantially closed at least at the middle portion of the stroke to enable the connection to be changed.

[0084] In the case of fluids operating at high pressure, opening and closing valves may cause pressure pulsations (e.g., water hammer) that may cause damage to components in the system when high pressure is suddenly introduced into or removed from the system. Therefore, pressure pulsations may occur in the middle of the stroke when the fluid passage is closed and opened, respectively.

[0085] In some embodiments, the actuator 303 can be configured to move the stopper 308 along the stroke of the cleaning control valve 206 at a variable speed. When the stopper 308 moves from the first position to the second position, the stopper 308 can move at a high rate when traversing the first portion of the stroke, which does not involve the new introduction of flow from the high-pressure inlet port 302 into the chamber connection ports 306a, 306b. When the stopper 308 approaches the closed position at the middle portion of the stroke (for example, when the stopper 308 blocks the chamber connection ports 306a, 306b during the transition between the high-pressure inlet port 302 connection and the low-pressure outlet port 304a, 304b connection), the stopper 308 can decelerate to a low rate. When the high-pressure inlet port 302 is placed in communication with one of the chamber connection ports 306a, 306b, the stopper 308 can continue to be at a lower rate. After traversing the chamber connection ports 306a, 306b, the stopper 308 can accelerate to another high velocity as the stopper 308 approaches the second position. The low velocity at the mid-portion of the stroke can slow down the speed at which the cleaning control valve 206 opens and closes, thereby enabling the cleaning control valve to gradually introduce high pressure into the chambers 202a, 202b and / or gradually remove high pressure from the chambers.

[0086] In some embodiments, the stopper 308 can be arranged so that the outflow from one of the chamber connection ports 306a, 306b can be stopped, while the high-pressure flow into the other of the chamber connection ports 306a, 306b can continue. For example, such an arrangement can enable the cleaning control valve 300 to independently control the movement of the pistons 204a, 204b in the chambers 202a, 202b.

[0087] In some embodiments, the movement of the pistons 204a, 204b can be controlled by adjusting the rate of fluid flow (e.g., the rate of inflow of fluid); and / or the pressure difference between the clean side 220a, 220b of the pistons 204a, 204b and the dirty side 221a, 221b of the pistons 204a, 204b caused at least in part by the movement of the clean control valve 206. In some embodiments, it may be desirable to move the pistons 204a, 204b in the low pressure chambers and the pistons 204a, 204b in the high pressure chambers at substantially the same speed by manipulating the pressure difference in each of the low pressure chambers 202a, 202b and the high pressure chambers 202a, 202b and / or by controlling the flow rate of fluid into and out of the chambers 202a, 202b. However, the pistons 204a, 204b in the low pressure chambers 202a, 202b may tend to move at a greater speed than the pistons 204a, 204b in the high pressure chambers 202a, 202b.

[0088] In some embodiments, the pressure difference and / or the rate of fluid flow can be changed to control the acceleration and deceleration of the pistons 204a, 204b (e.g., by manipulating and / or changing the stroke of the cleaning control valve 206, and / or by manipulating the pressure in the fluid flow with one or more pumps). For example, when the pistons 204a, 204b are located near the clean end 224 of the chambers 202a, 202b at the beginning of the high-pressure stroke, increasing the flow rate and / or pressure of the high-pressure cleaning fluid 210 can increase the pressure difference and / or the rate of fluid flow in the chambers 202a, 202b. Increasing the pressure difference and / or the rate of fluid flow can cause the pistons 204a, 204b to accelerate to a faster rate or move at a faster rate. In another example, when the pistons 204a, 204b approach the dirty end 226 of the chambers 202a, 202b at the end of the high-pressure stroke, the flow rate and / or pressure of the high-pressure cleaning fluid 210 can be reduced. Reducing the pressure differential and / or the rate of fluid flow may cause the pistons 204a, 204b to slow down and / or stop before reaching the dirty end of the respective chamber 202a, 202b.

[0089] Can utilize similar control to the stroke of cleaning control valve 206 to prevent piston 204a, 204b from traveling to the farthest range of the cleaning end of chamber 202a, 202b.For example, by preventing any other fluid flow and slowing down and / or stopping piston 204a, 204b, cleaning control valve 206 can close one of chamber connection ports 306a, 306b before piston 204a, 204b contacts the farthest range of the cleaning end of chamber 202a, 202b.In some embodiments, cleaning control valve 206 can open one of chamber connection ports 306a, 306b before piston 204a, 204b contacts the farthest range of the cleaning end of chamber 202a, 202b, to communicate with high pressure inlet port 302, thereby slowing down, stopping and / or reversing the motion of piston 204a, 204b.

[0090] If the piston 204a, 204b reaches the clean end 224 or dirty end 226 of the corresponding chamber 202a, 202b, the high-pressure fluid can bypass the piston 204a, 204b and mix with the low-pressure fluid. In some embodiments, it may be desirable to mix the fluids. For example, if the piston 204a, 204b reaches the dirty end 226 of the corresponding chamber 202a, 202b during the high-pressure stroke, the high-pressure cleaning fluid 210 can bypass the piston 204a, 204b (e.g., by traveling around the piston 204a, 204b or traveling through the valve in the piston 204a, 204b) to rinse any residual contaminants from the surface of the piston 204a, 204b. In some embodiments, it may be undesirable to mix the fluids. For example, if pistons 204a, 204b reach the clean end 224 of the respective chambers 202a, 202b during the low pressure stroke, low pressure dirty fluid 212 may bypass pistons 204a, 204b and mix with the low pressure clean fluid, thereby contaminating the clean area in the clean control valve 206 with the dirty fluid.

[0091] Figure 4 A pressure exchanger system 400 is shown that includes a control system 401 (e.g., a local and / or remote control system) and two chambers 402 located between a clean manifold 406 and a dirty manifold 408. As shown, the chambers 402 can be elongated hollow tubes (e.g., tubular chambers). In some embodiments, the clean manifold 406 can include a clean control valve 300 ( Figure 2 , Figure 3A and Figure 3B ), the clean control valve is configured to control the flow of fluid within chamber 402. Chamber 402 may include one or more pistons 404 (e.g., disks) disposed within chamber 402. Piston 404 may be configured to translate axially through chamber 402 and transfer pressure characteristics, for example, from high pressure fluid flowing through clean manifold 406 to fluid flowing into dirty manifold 408, or from fluid flowing through dirty manifold 408 to low pressure fluid flowing through clean manifold 406.

[0092] As discussed below, one or more sensors (e.g., sensor 207 ( Figure 2 ), sensors discussed below) can be implemented with the control system 401 to operate the pressure exchanger system 400. For example, sensors can be utilized to determine one or more of the position, velocity, and / or acceleration of the piston 700.

[0093] In some embodiments, the sensors and systems can be similar to the sensors and systems disclosed in U.S. patent application 16 / 678,998, filed on November 8, 2019, entitled “FLUIDEXCHANGE DEVICES AND RELATED CONTROLS, SYSTEMS, AND METHODS,” the disclosure of which is incorporated herein by reference in its entirety.

[0094] As discussed above, contact between the piston 404 and the clean manifold 406 may inadvertently allow dirty fluid from the dirty manifold 408 to bypass 404 (e.g., leak from 404) and contaminate the clean manifold 406. Contamination of the clean manifold 406 may contaminate clean fluid passing through the fracturing system components, which may damage the equipment and / or reduce the life of the equipment. The pressure exchanger system 400 (e.g., via the control system 401) can be configured to substantially prevent (e.g., reduce the occurrence of) the piston 404 reaching the clean manifold 406.

[0095] For example, the control system 401 of the pressure exchanger system 400 can be configured to stop the piston 404 near the backoff point 410 (e.g., interrupt the movement of the piston) so that the piston 404 does not contact the cleaning manifold 406. The pressure exchanger system 400 can include one or more sensors (e.g., a low pressure fill sensor 412) on the first side positioned along the chamber 402 before the backoff point 410. The low pressure fill sensor 412 can be configured to detect when the piston 404 passes the low pressure fill sensor 412 while advancing toward the cleaning manifold 406.

[0096] In some embodiments, low pressure fill sensor 412 can be configured to detect the position and / or speed of piston 404 as piston 404 passes low pressure fill sensor 412. For example, low pressure fill sensor 412 can be configured to detect the speed of piston 404 and the direction of movement of piston 404.

[0097] The control system 401 of the pressure exchanger system 400 may include a cleaning control valve 300 ( Figure 3A and Figure 3B ) changes operation (e.g., by substantially closing and / or opening fluid flow into or out of one or more of the chambers 402) when the associated piston 404 approaches a retraction point 410, such as detected by a low-pressure fill sensor 412. For example, as discussed below, the clean control valve 300 can decrease the supply of low-pressure fluid through the dirty manifold 408 and / or increase the supply of high-pressure fluid through the clean control valve 300 when the piston 404 approaches the retraction point 410.

[0098] The control system 401 of the pressure exchanger system 400 can control the cleaning control valve 300 based on the position and / or speed of the piston 404. For example, the control system 401 can calculate the time and / or distance required for the piston 404 to slow down and stop based on the measured speed of the piston 404. For example, a piston 404 traveling at a higher speed may require (e.g., applied by the cleaning control valve 300) a larger distance or a larger reaction force to stop. During the time required to close the cleaning control valve 300, the piston 404 traveling at a higher speed can travel a greater distance than the piston 404 traveling at a lower speed.

[0099] The pressure exchanger system 400 may include one or more sensors (e.g., a primary high pressure fill sensor 414 and a secondary high pressure fill sensor 416) located on the second side, one or more sensors arranged along the chamber 402 between the low pressure fill sensor 412 and the dirty manifold 408. The primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 may be configured to detect when the piston 404 passes each of the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416. In some embodiments, the primary high pressure fill sensor 414 and / or the secondary high pressure fill sensor 416 may be configured to measure at least one of the direction, velocity, or acceleration of the piston 404 as the piston 404 passes the primary high pressure fill sensor 414 and / or the secondary high pressure fill sensor 416. Information from the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 may be interpreted by the control system 401 of the pressure exchanger system 400 to determine when the piston 404 has completed the high pressure stroke. In some embodiments, information from primary high pressure fill sensor 414 and / or secondary high pressure fill sensor 416 (e.g., by comparing data from sensors 414, 416 and known offsets between sensors 414, 416) can be interpreted to determine whether piston 404 slows down, speeds up, or maintains velocity as piston 404 approaches dirty manifold 408. In some embodiments, information from primary high pressure fill sensor 414 and / or secondary high pressure fill sensor 416 can be interpreted to determine the time required for piston 404 to complete a high pressure stroke and / or can be utilized to determine one or more actions to facilitate the end of piston 404 movement and / or preparation for a return stroke.

[0100] Figure 5 1 shows an embodiment of a sensor 500 (eg, an electromagnetic coil, an inductor, etc.). The sensor 500 may be used as a low pressure fill sensor 412, a primary high pressure fill sensor 414, and a secondary high pressure fill sensor 416 ( Figure 4 ) One or more of. The sensor 500 may be configured to wrap around the chamber 402 of the pressure exchanger system 400 ( Figure 4 ). In some embodiments, the sensor 500 can be formed into the chamber 402. In some embodiments, the sensor 500 can be clamped to the outer surface of the chamber 402. In some embodiments, the sensor 500 can be attached to the outer surface of the chamber 402. For example, the sensor 500 can be attached to the outer surface of the chamber 402 with mechanical fasteners such as screws, bolts, studs, screws, rivets, clamps, etc. In some embodiments, the sensor 500 can be attached to the outer surface of the chamber 402 using an adhesive such as glue, epoxy, or using other attachment processes such as soldering, brazing, welding, etc.

[0101] The sensor 500 may include one or more coils to measure one or more of position, velocity, acceleration, and / or jerk (e.g., sensed and / or determined by two, three, four, or more sensor components such as coils). For example, the sensor 500 may include a first coil 502. The first coil 502 may include a conductive member wound multiple times around a first winding structure 504. The first winding structure 504 may include a first inner ridge 506 and a first outer ridge 508, the first inner ridge and the first outer ridge being configured to hold the first coil 502 on the first winding structure 504. For example, the first inner ridge 506 and the first outer ridge 508 may form a substantially annular groove around the first winding structure 504. The first coil 502 may be disposed within the annular groove around the first winding structure 504 such that the first coil 502 is axially supported by the first inner ridge 506 on a first end and axially supported by the first outer ridge 508 on a second end.

[0102] The sensor 500 may also include a second coil 510. The second coil 510 may include a conductive member wound multiple times around a second winding structure 512. The second winding structure 512 may include a second inner ridge 514 and a second outer ridge 516. The second inner ridge 514 and the second outer ridge 516 may form a substantially annular groove around the second winding structure 512. The second coil 510 may be disposed within the annular groove around the second winding structure 512 such that the second coil 510 is axially supported on a first end by the second inner ridge 514 and axially supported on a second end by the second outer ridge 516.

[0103] In some embodiments, the first winding structure 504 and the second winding structure 512 can be separated by an optional separation region 518. In other embodiments, the first winding structure 504 and the second winding structure 512 can be fixed to the chamber 402 ( Figure 4) and are spaced apart along them without a separation region 518. The separation region 518 can be configured to maintain a common distance between the first winding structure 504 and the second winding structure 512. In some embodiments, the common distance between the first winding structure 504 and the second winding structure 512 can be at least about 0.5 inches (1.27 cm), such as at least about 1 inch (2.54 cm), or at least about 4 inches (10.16 cm).

[0104] In some embodiments, the conductive member of the first coil 502 can be wound about 50 times to about 300 times, such as about 60 times to about 140 times, or about 70 times to about 100 times around the first winding structure 504. In some embodiments, the second coil 510 can be wound about 50 times to about 300 times, such as about 60 times to about 140 times, or about 70 times to about 100 times around the second winding structure 512. In some embodiments, the first coil 502 and the second coil 510 can include substantially the same number of windings.

[0105] The sensor 500 may include a module 520 (e.g., located locally or remotely) configured to receive signals from each of the first coil 502 and the second coil 510. In some embodiments, the module 520 may include a processor and / or a memory device, which may be a control system 401 ( Figure 4 ) or is separate from the control system. In some embodiments, module 520 may not be implemented, where such processing is performed by the control system 401 ( Figure 4 ) locally and / or remotely.

[0106] When the module 520 is implemented, the signals from the first coil 502 and the second coil 510 can be processed by the processor and stored in the memory of the module 520. In some embodiments, the module 520 may include a transmitter configured to transmit the signals from the first coil 502 and the second coil 510 to a computing device (e.g., the control system 401). For example, the computing device may be configured to process the signals from the first coil 502 and the second coil 510 to determine the characteristics of the piston movement, such as whether the piston has passed the sensor 500, at what speed the piston travels when passing the sensor 500, in what direction the piston travels when passing the sensor 500, etc. In some embodiments, the module 520 may be configured to determine the characteristics of the movement of the piston and transmit the final determined characteristics to the computing device. The computing device may be configured to send a control signal to the cleaning control valve 300 based on the characteristics transmitted by the module 520. In some embodiments, the module 520 may be configured to determine the characteristics of the movement of the piston and provide control instructions to the computing device and / or directly to the cleaning control valve 300. In some embodiments, the first coil 502 and the second coil 510 can be directly coupled to a computing device via a wired connection, such that the computing device receives raw data directly from the first coil 502 and the second coil 510. The computing device can then process the raw data to determine the motion characteristics of the piston and / or provide control instructions to the cleaning control valve 300.

[0107] Figure 6 An embodiment of a sensor 600 is shown. The sensor 600 may include a first coil 602 including a plurality of windings of a conductive member wound around a first winding structure 604. The sensor 600 may also include a second coil 606 including a plurality of windings of a conductive member wound around a second winding structure 608. The sensor 600 may also include a third coil 610 including a plurality of windings of a conductive member wound around a third winding structure 612. The first winding structure 604 and the second winding structure 608 may be spaced apart (e.g., by an optional first separation region 614 configured to maintain a substantially common distance between the first winding structure 604 and the second winding structure 608). The second winding structure 608 and the third winding structure 612 may be spaced apart (e.g., by an optional second separation region 616 configured to maintain a substantially common distance between the second winding structure 608 and the third winding structure 612).

[0108] In some embodiments, the distance between the first winding structure 604 and the second winding structure 608 can be substantially the same as the distance between the second winding structure 608 and the third winding structure 612. In some embodiments, the distance between the first winding structure 604 and the second winding structure 608 can be greater than the distance between the second winding structure 608 and the third winding structure 612. In some embodiments, the distance between the first winding structure 604 and the second winding structure 608 can be less than the distance between the second winding structure 608 and the third winding structure 612.

[0109] The sensor 600 may include a module 618 configured to receive a signal from each of the first coil 602, the second coil 606, and the third coil 610. In some embodiments, the module 618 may include a processor and / or a memory device. For example, the signals from the first coil 602, the second coil 606, and the third coil 610 may be processed by the processor and stored in the memory of the module 618. In some embodiments, the module 618 may include a transmitter configured to transmit the signals from the first coil 602, the second coil 606, and the third coil 610 to a computing device (e.g., the control system 401). For example, the computing device may be configured to process the signals from the first coil 602, the second coil 606, and the third coil 610 to determine whether the piston 404 ( Figure 4 ), such as whether the piston has passed the sensor 600, at what speed the piston traveled when passing the sensor 600, in what direction the piston traveled when passing the sensor 600, the acceleration or deceleration of the piston (e.g., if the piston 404 is accelerating or decelerating), etc. In some embodiments, the module 618 can be configured to determine the motion characteristics of the piston and transmit the final determined characteristics to the computing device. The computing device can be configured to send a control signal to the cleaning control valve 300 based on the characteristics transmitted by the module 618. In some embodiments, the module 618 can be configured to determine the motion characteristics of the piston and provide control instructions to the computing device and / or directly to the cleaning control valve 300. In some embodiments, the first coil 602, the second coil 606, and the third coil 610 can be directly coupled to the computing device via a wired connection, so that the computing device receives raw data directly from the first coil 602, the second coil 606, and the third coil 610. The computing device can then process the raw data to determine the characteristics of the motion of the piston and / or provide control instructions to the cleaning control valve 300.

[0110] Figure 7 204a, 204b, 404 disclosed herein, for example, with reference to Figure 2 and Figure 4 . The piston 700 may include one or more magnetic members 702, which are arranged in a substantially annular ring (e.g., a circumferential ring) around a cylindrical side surface 704 of the piston 700, wherein the magnetic members 702 are sensed (e.g., triggered) by the sensors discussed herein. In other embodiments, the piston may lack such magnetic members, and the sensor may be configured to detect other characteristics of the piston, such as, for example, the material of the piston. In other embodiments, a detection mechanism (e.g., an electric field, a magnetic field, such as an electric field, a magnetic field, etc. generated by a battery or other power source) may be implemented.

[0111] In some embodiments, the magnetic member 702 may be disposed (e.g., embedded) within the side surface 704 of the piston 700. For example, the magnetic member 702 may be disposed so that only one face of the magnetic member 702 exposes the side surface 704 of the piston 700. The face of the magnetic member 702 may correspond to the magnetic pole (e.g., north pole or south pole) of each of the magnetic members 702 in a uniform or alternating manner. In some embodiments, the magnetic member 702 may be arranged so that the same magnetic pole of each of the magnetic members 702 exposes the side surface 704 of the piston 700. For example, the north pole of each of the magnetic members 702 may expose the side surface 704 of the piston 700. In other embodiments, the south pole of each of the magnetic members 702 may expose the side surface 704 of the piston 700.

[0112] In some embodiments, a substantially annular ring of magnetic members 702 may be formed in a central region of the piston 700 (e.g., at a known offset from the front end and / or rear end of the piston 700). In some embodiments, a substantially annular ring of magnetic members 702 may be formed near the ends of the piston 700. In some embodiments, the magnetic members 702 may be arranged at substantially equal intervals around the side surface 704 of the piston 700 (e.g., such that the angle between each of the magnetic members 702 and the radial position of the adjacent magnetic member 702 is substantially the same).

[0113] In some embodiments, the magnetic member 702 can be formed into the piston 700. For example, the piston 700 can be molded around the magnetic member 702. In some embodiments, the magnetic member 702 can be disposed within the side surface 704 of the piston 700 at a sufficient distance so that the magnetic member 702 is completely enclosed within the piston 700 (e.g., so that no surface of the magnetic member 702 is exposed from the side surface 704 of the piston 700). In some embodiments, the magnetic member 702 can be fixed to a blind hole drilled into the side surface 704 of the piston 700. For example, the magnetic member 702 can be fixed using an adhesive (e.g., epoxy, glue, etc.), welding, soldering, brazing, complementary threads, fasteners, or a combination. In some embodiments, the magnetic member 702 can be fixed in an annular groove formed in the side surface 704 of the piston 700. In some embodiments, the magnetic member 702 may be a single annular magnetic member having substantially the same outer diameter as the piston 700, the single annular magnetic member being arranged such that the axis of the annular magnetic member is substantially coaxial with the axis of the piston 700. In some embodiments, the magnetic member 702 may be a single disc-shaped magnetic member having substantially the same outer diameter as the piston 700, the single disc-shaped magnetic member being arranged such that the axis of the disc-shaped magnetic member is substantially coaxial with the axis of the piston 700.

[0114] The magnetic part 702 can be a permanent magnetic part, such as an aluminum nickel cobalt magnetic part (aluminum, nickel, cobalt magnetic parts), a rare earth magnetic part (for example, a neodymium magnetic part, a samarium cobalt magnetic part, etc.), a ceramic magnetic part (for example, a hard ferrite magnetic part, a barium magnetic part, a strontium magnetic part, etc.), etc.

[0115] The piston 700 may include a port 708 extending from a first face 706 of the piston 700 to a second face (not shown) of the piston 700. The port 708 may include a check valve configured to selectively allow flow through the port 708 of the piston 700, as described in detail in U.S. Patent Application 16 / 678,819, entitled “VALVES INCLUDING ONE OR MORE FLUSHING FEATURES AND RELATED ASSEMBLIES, SYSTEMS, AND METHODS,” filed on November 8, 2019, the disclosure of which is incorporated herein by reference in its entirety.

[0116] Figure 8 700 is shown. In some embodiments, the piston 700 may include multiple rows of magnetic members 702. Figure 8As shown in , the piston 700 may include a first row 802 of magnetic members 702 and a second row 804 of magnetic members 702. In some embodiments, the first row 802 of magnetic members 702 and the second row 804 of magnetic members 702 may be adjacent to each other. For example, the first row 802 and the second row 804 of magnetic members 702 may be separated by an axial distance that is substantially equal to or less than a distance between adjacent magnetic members 702 in the same rows 802, 804. In some embodiments, the magnetic members 702 in each of the first row 802 and the second row 804 may be substantially radially aligned. In some embodiments, the magnetic members 702 in each of the first row 802 and the second row 804 may be staggered, such as Figure 8 As shown in , the radial positions of the magnetic members 702 in the first row 802 and / or the second row 804 correspond to (eg, are aligned with) the spaces between the radial positions of the magnetic members 702 in the adjacent first row 802 and / or the second row 804 .

[0117] In some embodiments, the first row 802 of magnetic members 702 and the second row 804 of magnetic members 702 can be spaced apart by a considerable distance (e.g., much greater than the distance between adjacent magnetic members 702 in the same row 802, 804). For example, the first row 802 of magnetic members 702 can be positioned near the first end 806 of the piston 700, and the second row 804 of magnetic members 702 can be positioned near the second end 808 of the piston 700.

[0118] In some embodiments, the first row 802 can induce a first signal in the sensor when the piston 700 passes the sensor, and the second row 804 can induce a second signal in the sensor when the piston 700 passes the sensor. For example, the sensor may include the coil discussed above. When the first row 802 magnetic members 702 pass the sensor, the first row 802 magnetic members 702 can induce a first current in the coil. When the second row 804 magnetic members 702 pass the sensor, the second row 804 magnetic members 702 can induce a second current in the coil. The sensor can generate a signal having an "M" shaped wave having two peaks corresponding to the first induced current and the second induced current. When the speed of the piston 700 increases, the two peaks can be substantially merged into a single peak due to the residual current in the coil.

[0119] Fig.9A An embodiment of a chamber portion 900 of one of the chambers 402 of the pressure exchanger system 400 is shown. The chamber portion 900 may include a sensor 500 configured to measure a motion characteristic of the piston 700 as the piston 700 travels from the first position 902 to the second position 904 as indicated by arrow 906. Fig. 9BGraph 908 shows a first signal 916 and a second signal 918 generated by sensor 500 as piston 700 passes sensor 500. First signal 916 can correspond to a signal generated by first coil 502 of sensor 500, and second signal 918 can correspond to a signal generated by second coil 510 of sensor 500. In other embodiments, a single coil can be used to achieve a similar effect, where multiple locations on piston 700 can be detected by a single coil (e.g., multiple elements, such as the magnets discussed above). In other embodiments, multiple coils and multiple detection locations on piston 700 can be used.

[0120] When the piston 700 passes by the sensor 500, the magnetic member 702 can generate a signal in each of the first coil 502 and the second coil 510 of the sensor 500. For example, when the magnetic member 702 passes by each of the first coil 502 and the second coil 510, the magnetic field or magnetic flux generated by the magnetic member 702 can induce an electronic response (e.g., a current) in each of the first coil 502 and the second coil 510, which changes as the position of the magnetic member 702 relative to the first coil 502 and the second coil 510 changes. In some embodiments, the current in the first coil 502 and the second coil 510 can be directly measured. In some embodiments, the current of the first coil 502 and the second coil 510 can be converted to a voltage, such as by passing the current through a resistor, and the voltage can be measured.

[0121] As the magnetic member 702 on the piston 700 approaches the first coil 502, the response (e.g., the current and / or the corresponding voltage) may increase, as shown in the first region 920 of the graph 908. When the magnetic member 702 on the piston 700 passes the first coil 502, the current and / or the corresponding voltage may reach a first peak value 910, after which the current and / or the corresponding voltage may begin to decrease, as shown in the second region 922 of the graph 908. Similarly, when the magnetic member 702 on the piston 700 approaches the second coil 510, the current and / or the corresponding voltage may increase as the piston 700 moves away from the first coil 502, as shown in the first region 920 of the graph 908. Subsequently, when the magnetic member 702 on the piston 700 passes the second coil 510, the current and / or the corresponding voltage may reach a second peak value 912, and then the current and / or the corresponding voltage may decrease as the piston moves away from the second coil 510, as shown in the second region 922 of the graph 908.

[0122] The time difference 914 between the first peak 910 of the first coil 502 and the second peak 912 of the second coil 510 can correspond to the time between when the magnetic member 702 passes the first coil 502 and when the magnetic member 702 passes the second coil 510. Therefore, the speed of the piston 700 can be determined by the distance between the first coil 502 and the second coil 510 (e.g., the spacing between the coils 502, 510 or the separation area 518 of the sensor 500). Figure 5 ) defined) and the time difference 914 between the first peak 910 and the second peak 912 (for example, speed is equal to distance divided by time change).

[0123] The direction of the piston 700 can be determined by which of the first coil 502 and the second coil 510 recorded the first peak 910 and the second peak 912, respectively. Fig.9A and Fig. 9B As shown in FIG. , the piston 700 first passes the first coil 502, which in turn records the first peak 910, and then passes the second coil 510, which records the second peak 912. If the piston 700 passes the sensor 500 in the opposite direction, the second coil 510 will record the first peak 910, and the first coil 502 will record the second peak 912. Therefore, the direction of the piston 700 can be determined by determining which of the corresponding first coil 502 and second coil 510 records the first peak 910 and the second peak 912.

[0124] Fig. 10A An embodiment of a chamber portion 900 of one of the chambers 402 of the pressure exchanger system 400 is shown. The chamber portion 900 may include a sensor 500 configured to measure a motion characteristic of the piston 700 as the piston 700 travels from the first position 1002 to the second position 1004 as indicated by arrow 1006 and reverses direction to travel back to the first position 1002 as indicated by arrow 1008. Fig. 10B Graph 1010 shows first signal 916 and second signal 918 generated by sensor 500 as piston 700 approaches sensor 500. First signal 916 may correspond to a signal generated by first coil 502 of sensor 500, and second signal 918 may correspond to a signal generated by second coil 510 of sensor 500.

[0125] The signal generated by sensor 500 can be interpreted to determine whether piston 700 has passed by sensor 500 (e.g., completely passed, partially passed), or to determine whether piston 700 has stopped near sensor 500 and reversed direction before passing by sensor 500. When the magnetic member 702 on piston 700 approaches the first coil 502, the current and / or corresponding voltage generated by the first coil 502 can rise in the first region 920 of graph 908. The current and / or corresponding voltage can reach a first peak 910 before dropping in the second region 922 of graph 1010, indicating that the magnetic member 702 is moving away from the first coil 502. Similarly, when the magnetic member 702 on piston 700 approaches the second coil 510, the current and / or corresponding voltage generated by the second coil 510 can rise in the first region 920 of graph 908. The current and / or corresponding voltage can reach a second peak 912 before dropping in the second region 922 of graph 1010, indicating that the magnetic member 702 is moving away from the second coil 510.

[0126] As shown in graph 1010, the first peak 910 and the second peak 912 occur substantially simultaneously, where the second peak 912 is much smaller (e.g., lower amperage or voltage) than the first peak 910. When the first peak 910 and the second peak 912 occur substantially simultaneously, it can indicate that the magnetic member 702 on piston 700 is in a position where it is substantially simultaneously close to the first coil 502 and the second coil 510. However, detecting a lack of a significant time interval between the peaks 910, 912 of the first coil 502 and the second coil 510 indicates that the magnetic member 702 and piston 700 did not pass by the first coil 502 and the second coil 510 simultaneously.

[0127] In additional embodiments, the measurement results can be compared to determine whether piston 700 has passed. For example, the measurement results (e.g., peaks 910, 912 or maximum voltage levels) of each coil 502, 510 can be compared to determine whether piston 700 has passed. If the peaks 910, 912 are within a selected amount, such as for example greater than 75% (e.g., 80%, 90%, 95% or greater), then this comparison can be used to determine that piston 700 has passed.

[0128] Fig.11 Graph 1100 is shown, which depicts the relationship (e.g., calculated and / or determined empirically) between the rate at which the voltage corresponding to the current generated in the first coil 502 and the second coil 510 rises in millivolts (mV) / second and the speed of piston 700 (e.g., disk) in feet per second (ft / s). Such data can be used to analyze and / or predict the amount by which the voltage rises over time or other characteristics expected and / or indicated by a particular speed of the piston.

[0129] As shown in graph 1100, and also referring to Figure 4 , Figure 7 , Fig.9A and Fig. 9B , the rate at which the voltage rises can be related to the speed of the piston 700. As the speed of the piston 700 increases, the amount of time and / or level of the reaction force increases. For example, in order to prevent the piston 700 from contacting the cleaning manifold 406, the time required to actuate the cleaning control valve 300 and slow the piston 700 to a stop can increase.

[0130] The speed of the piston 700 can be estimated from the detected slope of one or more of the first signal 916 and the second signal 918 from the corresponding first coil 502 and the second coil 510. Such a slope can be compared with a known value of the rate at which the first signal 916 and the second signal 918 rise to a selected voltage (e.g., 15 mV as shown). Using the known value of the rise time for the selected piston 700 speed, the speed can be approximately calculated based on the slope observed in the current stroke before the piston 700 completely passes the sensor 500. For example, the speed can be calculated before the first peak 910 is reached, such as at about 50% of the first peak 910, or at about 75% of the first peak 910. Calculating the speed of the piston 700 before the first peak 910 enables the computing device (e.g., the control system 401) and / or the module 520 to generate a command to the cleaning control valve 300 with sufficient time to successfully reduce the speed and / or stop the piston 700, for example, before the backoff point 410.

[0131] Fig.12 A graph 1200 is shown that illustrates the relationship between the velocity of the piston 700 (e.g., disk) and the peak voltage (e.g., calculated and / or empirically determined) corresponding to the current generated in the first coil 502 and the second coil 510, as shown by the first peak 910 and the second peak 912, respectively. As shown in the graph 1200, and also referring to Figure 4 , Figure 7 , Fig.9A and Fig. 9B , the expected or predetermined peak voltage (e.g., the magnitude or other characteristics of the voltage) can be related to the speed of the piston 700. As described above, the amount of time and / or level of the reaction force may increase as the speed of the piston 700 increases. For example, in order to prevent the piston 700 from contacting the cleaning manifold 406, the time required to actuate the cleaning control valve 300 and slow the piston 700 to a stop may increase.

[0132] The speed of the piston 700 can be estimated from one or more of the first peak 910 and the second peak 912. Estimating the speed of the piston 700 from the first peak 910 or the second peak 912 can enable calculations and / or instructions to be completed before one or more of the entire curves shown in the graph 908 develop. For example, after the peak voltage is detected from one of the coils 502, 510, the approximate speed of the piston 700 can be determined (e.g., before the time migration between the known peaks 910, 912). Therefore, instructions can be provided to the cleaning control valve 300 at an earlier time, which can enable the computing device and / or module 520 to generate instructions to the cleaning control valve 300 and have enough time to successfully stop the piston 700 before the backoff point 410.

[0133] Fig.13 A method of controlling a pressure exchanger 1300 is shown. Figures 4 to 12 As the piston 700 travels along the chamber portion 900 and approaches the sensor 500, the magnetic member 702 may begin to induce a current in the first coil 502 and the second coil 510, thereby generating a first signal 916 and a second signal 918. For simplicity, unless a comparison between the first signal 916 of the first coil 502 and the second signal 918 of the second coil 510 is discussed, only the signal of one of the first coil 502 and the second coil 510 is processed.

[0134] As the signal value rises, the signal value can reach a threshold value, as shown in action 1302. For example, when the piston 700 travels in the chamber portion 900, the signal value can be substantially constant until the piston 700 enters a threshold distance from the sensor 500. After the piston 700 crosses the threshold distance, the signal value can begin to rise. The rise in the signal value may be relatively slow (e.g., a lower rise) for the first distance, and then begin to increase at a larger rate as the piston 700 approaches the sensor 500. In some embodiments, a larger or relatively constant rate of increase in the signal value can be a region of the signal that provides more valuable information about the motion characteristics of the piston 700. For example, the threshold signal value can enable the processor to identify a region of the signal where the signal value changes at a higher rate. In some embodiments, the threshold signal value can be between about 1 millivolt (mV) and about 7mV, such as between about 2mV and about 6mV, or about 5mV.

[0135] After reaching the threshold signal, the generated signal can begin or continue to be stored and / or analyzed in a memory device in action 1304. For example, signals below the threshold can be treated as noise and not considered. The memory device can be located in the sensor 500, such as in the module 520 and / or in the control system 401. In some embodiments, the memory device can be a separate component directly coupled to the sensor 500. In some embodiments, the memory device can be a component of a computing device (e.g., control system 401) coupled to the sensor through a network connection such as a server, a switch, a cloud, wireless, a network cable, etc.

[0136] When the signal value increases above the threshold, the processor can optionally perform a calculation as the signal is recorded in act 1306. In some embodiments, the processor can be part of module 520 and / or control system 401. If early determination of the velocity of piston 700 is required or desired, the processor can selectively calculate the slope of the increase in the signal value in act 1308, such as an average slope, an instantaneous slope (e.g., the slope between two adjacent data points in the signal), etc. As described above in Fig.11 As discussed in , the slope of increase in a signal value such as voltage or current can be related to the speed of the piston 700.

[0137] As the signal value continues to increase, the signal value may reach a peak value. When the signal value begins to decrease, the peak value may be determined. The time when the peak value occurs may be marked, as shown in action 1310. In action 1312, the peak value may also be recorded when the peak value is identified. As discussed above, the peak value may be used to estimate the speed of the piston 700.

[0138] If early determination of piston 700 velocity is implemented, after one or both of the slope and the peak value are determined, the processor may process the slope and / or the peak value in act 1314. The processor may determine the velocity of piston 700 based on one or more of the slope of the signal and the peak value of the signal. For example, as discussed above, the slope of the signal and / or the peak value of the signal may be correlated to the velocity of piston 700. Thus, the velocity of piston 700 may be estimated using the slope of the signal and / or the peak value of the signal.

[0139] In the case of implementation, in action 1316, the estimated speed of the piston 700 can be compared with a threshold speed. For example, as discussed above, if the piston 700 is traveling at a high rate, the processor may need to send a command to the cleaning control valve 300 in advance to avoid a collision between the piston 700 and the cleaning manifold 406. If the estimated speed of the piston 700 is greater than the threshold speed, the estimated speed can be used to calculate the time when the cleaning control valve 300 should be closed in action 1322. The threshold speed can be between about 7 ft / s and 12 ft / s, between about 15 ft / s (4.572 m / s) and about 25 ft / s (7.62 m / s), such as between about 17 ft / s (5.182 m / s) and about 22 ft / s (6.706 m / s), or between about 17 ft / s (5.182 m / s) and about 20 ft / s (6.096 m / s).

[0140] As discussed above, in some embodiments, the slope of the signal can be evaluated before the signal reaches a peak value. Therefore, before the signal reaches a peak value, the speed can be estimated based on the slope of the signal. This can enable the processor to determine whether to take early action by comparing the estimated speed with the threshold speed before the signal reaches a peak value. In some embodiments, the speed estimated by the signal slope can be compared with a separate threshold speed. For example, the speed estimated by the signal slope can be compared with a higher threshold speed, such as between about 15ft / s (4.572m / s) and about 30ft / s (9.144m / s), or between about 22ft / s (6.706m / s) and about 25ft / s (7.62m / s), or 30ft / s (9.144m / s). If the estimated speed of the piston 700 is greater than the higher threshold speed, the speed estimated by the signal slope can be used to calculate the time (such as immediately, such as if a negative waiting time is calculated) that the cleaning control valve 300 should be closed in action 1322.

[0141] In the case of implementation, after determining the peak value, the processor can evaluate the speed of the peak value of the signal. In some embodiments, such an estimation can be used as a confirmation or average calculation that the speed estimated by the signal slope is less than the upper threshold speed, as discussed below. In other embodiments, only the peak value estimation of the speed can be implemented.

[0142] After estimating the speed based on the peak value, the speed estimated by the peak value can be compared with the lower threshold speed. If the speed estimated by the peak value is greater than the lower threshold speed, the speed estimated by the peak value can be used to calculate the time when the cleaning control valve 300 should be closed in action 1322. In some embodiments, the speed estimated by the peak value can be averaged with the speed estimated by the signal slope, and the average estimated speed can be compared with the lower threshold speed. In some embodiments, the average speed can be used to calculate the time when the cleaning control valve 300 should be closed in action 1322.

[0143] If the speed estimated by the signal slope and / or the speed estimated by the peak value is below a threshold speed, the processor may wait for a complete data set from sensor 500 to be processed.

[0144] In some embodiments, a processor compares a measurement (e.g., a speed measurement) to a threshold measurement (e.g., a lower speed threshold) to determine whether to utilize the speed measurement or wait and perform another measurement (e.g., to ensure that the slope utilized is a reliable measurement, i.e., sufficiently separated from or not substantially interfered with by a noise floor, for example). For example, at a first reading (e.g., at a first selected level), a first speed calculation can be performed. If the first speed is less than a lower speed threshold, a row wait time calculation can be performed, or the system can wait for a detected signal peak (e.g., such peaks may be close in time due to a relatively low speed). If the first speed is greater than the lower speed threshold, the system can take another reading and calculate a second (e.g., assumedly higher) speed for a selected amount of time and / or until a second selected level is detected (e.g., a voltage that is closer to or even reaches an expected peak level). Wait time calculations or other operations can then be performed with the second higher speed.

[0145] In the case where such velocity prediction is not implemented, the process can skip such prediction calculations, for example, by keeping only Fig.13 Described in the left hand column.

[0146] As the piston 700 moves away from the sensor 500, the signal value can decrease until the signal value reaches a decreasing threshold, as shown in action 1318. In some embodiments, the threshold value can be substantially the same as the first threshold value. In some embodiments, the threshold value can be different from the first threshold value. For example, the second threshold value can be greater than the first threshold value to take into account the residual current in the first coil 502 and / or the second coil 510.

[0147] After the signal value drops below the threshold, the complete data set of signal values ​​representative of the motion characteristics of piston 700 may be processed by the processor in act 1320. In some embodiments, other factors may indicate that the piston is moving away from sensor 500 (e.g., measurement time, decreasing slope in one or more of the detection coils, etc.).

[0148] During the processing action, the time at which the peak occurs can be evaluated relative to the time of the peak in the adjacent coil (e.g., as discussed above). For example, the time of the first peak 910 can be compared to the time of the second peak 912. The time difference between the time of the first peak 910 and the time of the second peak 912 can be identified. This time difference plus the known distance between the first coil 502 and the second coil 510 can be used to calculate the speed of the piston 700.

[0149] As discussed above, if the time difference is small enough (e.g., below a threshold) such that the first peak 910 and the second peak 912 occur substantially simultaneously, the processor can identify that the piston 700 has not passed the sensor 500. The processor can also verify the conclusion that the piston 700 has not passed the sensor 500 by comparing the peak signal values ​​of the first peak 910 and the second peak 912 to determine whether the second peak 912 is less than the first peak 910. In some embodiments, corrective action can be taken (e.g., with the valve 300) to correct the travel of the piston 700 intended to pass one of the sensors 500.

[0150] In some embodiments, the optional third coil 610 can provide a third signal having a third peak value. The third peak value can be compared to the first peak value 910 and the second peak value 912. For example, the velocity between the first coil 602 and the second coil 606 can be compared to the calculated velocity between the second coil 606 and the third coil 610. The difference between the calculated velocities can be used to calculate the acceleration (e.g., velocity rate) of the piston 700 as the piston 700 passes the sensor 500.

[0151] If the processor has not yet calculated when to close the purge control valve 300 based on the estimated speed from the intermediate reading calculation, the processor may calculate when to close the purge control valve 300 based on the speed calculated from the complete data set of the sensor 500 in act 1322. In some embodiments, such a calculation may be compared to the intermediate reading calculation.

[0152] After calculating the time to close the cleaning control valve 300 in act 1322, the time can be adjusted in act 1324 by the time required to perform the calculation. For example, the processor can identify the time when the calculation was started and the time when the time was calculated, and adjust (e.g., subtract) the calculated time by the amount of time the processor took to complete the calculation. In some embodiments, the calculation time can be between about 10 milliseconds (ms) and about 70 ms, such as between about 20 ms and about 50 ms.

[0153] The processor may wait (e.g., allow the calculated dwell time to elapse) until the calculated closing time has elapsed, and then send a command to the cleaning control valve 300 to close (e.g., also taking into account the actual time required to move the valve 300) in action 1326. The command may be provided to the cleaning control valve 300 so that the cleaning control valve 300 may have sufficient time to close to stop the piston 700 at or near the backoff point 410. The backoff point 410 may be defined as having sufficient space between the backoff point 410 and the cleaning manifold 406 so that the piston 700 may exceed the backoff point 410 by a small amount, i.e., equivalent to a margin of error, without colliding with the cleaning manifold 406.

[0154] As discussed above, the pressure exchanger system 400 may include more than one chamber. As the pistons travel within the chambers, the pistons may become unbalanced (e.g., the pistons may not reach opposite ends of the respective chambers at the same time). As the pistons become unbalanced, the efficiency of the pressure exchanger system 400 may decrease and / or damage to the system may occur. Therefore, correcting the imbalance in the pressure exchanger system 400 may enable the efficiency of the system to be improved or at least maintained at an acceptable or optimized level.

[0155] Fig.14 A pressure exchanger system 400 is shown having a first piston 1402 in a first chamber 1406 and a second piston 1404 in a second chamber 1408. As noted above, any sensor detected event may include detecting and / or determining one or more of the position, velocity, and / or acceleration of the pistons 1402, 1404.

[0156] As discussed above, in some embodiments it may be advantageous for the second piston 1404 to arrive at the dirty manifold 408 substantially simultaneously with the first piston 1402 arriving at the retraction point 410 (e.g., to balance the pistons 1402, 1404). In some conditions, when the first piston 1402 moves toward the clean manifold 406 under the influence of the dirty fluid, the high pressure clean fluid flowing into the clean manifold 406 may not be sufficient to move the second piston 1404 to a desired position close to the dirty manifold 408 (e.g., adjacent to or in contact with the end at the dirty manifold). Such a state may be referred to as a lean state. Fig.14 A lean condition is shown in which the first piston 1402 is positioned in the retraction point 410 and the second piston 1404 has not yet reached the dirty manifold 408 .

[0157] In the lean state, the control of the pressure exchanger system 400 can be adjusted to maintain the balance between the first chamber 1406 and the second chamber 1408. For example, the pressure exchanger system 400 can evaluate the readings from the sensors in the pressure exchanger system 400 to determine the position of each of the corresponding pistons 1402, 1404. For example, as described above, when the first piston 1402 approaches the cleaning manifold 406, the low pressure fill sensor 412 can detect and / or determine the position and / or speed of the first piston 1402. The cleaning control valve 300 can be controlled accordingly to substantially stop the first piston 1402 at or near the retraction point 410, thereby preventing the first piston 1402 from colliding with the cleaning manifold 406. The second piston 1404 can travel in the second chamber 1408 in the opposite direction. The primary high pressure fill sensor 414 may report when the second piston 1404 passes the primary high pressure fill sensor 414, and the secondary high pressure fill sensor 416 may also report when the second piston 1404 passes the secondary high pressure fill sensor 416. If the clean control valve 300 is controlled to close the first chamber 1406 to stop the first piston 1402 at the retraction point 410 before one or more of the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 report that the second piston 1404 has passed, then the control of the clean control valve 300 may be changed to allow the high pressure clean fluid to continue to move the second piston 1404 to the dirty manifold 408.

[0158] In some embodiments, the first stop 1410 and the second stop 1412 of the cleaning control valve 300 can be positioned such that the first stop 1410 can substantially block the first chamber 1406, while the second stop 1412 allows the high pressure cleaning fluid to continue to pass through the cleaning manifold 406 into the second chamber 1408. Thus, the movement of the cleaning control valve 300 can be adjusted so that the cleaning control valve 300 can be retained in a position where flow out of the first chamber 1406 is substantially blocked, while flow into the second chamber 1408 continues.

[0159] In some embodiments, the pressure exchanger system 400 can be configured to enable the cleaning control valve 300 to dwell in a position that keeps the first chamber 1406 substantially closed while enabling flow into the second chamber 1408 until the second piston 1404 passes the secondary high pressure fill sensor 416, as indicated by a signal processed from the secondary high pressure fill sensor 416. In some embodiments, the pressure exchanger system 400 can determine whether the second piston 1404 has passed the secondary high pressure fill sensor 416 during a completed stroke. The pressure exchanger system 400 can then adjust the dwell time of the cleaning control valve 300 to allow the high pressure cleaning fluid to flow into the second chamber 1408 for a longer period of time during a subsequent stroke of the second piston 1404.

[0160] In some embodiments, the clean control valve 300 can be retained in a position that maintains the first chamber 1406 and the second chamber 1408 at least partially open (eg, open to at least one inlet (eg, a high pressure inlet)), thereby driving both pistons 1402 , 1404 toward the dirty manifold 408 .

[0161] In some cases, high pressure clean fluid flowing into clean manifold 406 may cause second piston 1404 to move to a desired position near dirty manifold 408 under the influence of dirty fluid before first piston 1402 moves to a desired position near clean manifold 406. This state may be referred to as a surplus state. Fig.15 A rich condition is shown in which the second piston 1404 reaches the dirty manifold 408 before the first piston 1402 stops at or near the back-off point 410 .

[0162] This state may be used to flush one of chambers 1406, 1408 and / or to hold piston 1404 when piston 1402 reaches a desired position (eg, retraction point 410).

[0163] Each of the first piston 1402 and the second piston 1404 may include a check valve 1502. The check valve 1502 may be configured to allow high pressure cleaning fluid to pass through the first piston 1402 or the second piston 1404 when the first piston 1402 or the second piston 1404 reaches the dirty manifold 408. For example, Fig.15 As shown in , the dirty manifold 408 can stop the movement of the second piston 1404, such as by contacting the dirty manifold 408 or by another type of stop such as a ridge, a buffer, a spring, etc. After the second piston 1404 stops, the pressure from the high-pressure cleaning fluid built up on the opposite side of the second piston 1404 can be released by the check valve 1502, thereby allowing the high-pressure cleaning fluid to flow through the second piston 1404 into the dirty manifold 408. The check valve 1502 can be constructed similar to the check valve described in U.S. Patent Application No. 16 / 678,819, entitled “VALVES INCLUDING ONE ORMORE FLUSHING FEATURES AND RELATED ASSEMBLIES, SYSTEMS, AND METHODS” filed on November 8, 2019, the disclosure of which is incorporated herein by reference in its entirety.

[0164] In some embodiments, a flush condition may be desirable to clear debris from the first piston 1402 or the second piston 1404. For example, the pressure exchanger system 400 can monitor the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 to determine whether the second piston 1404 passes the primary high pressure fill sensor 414 and / or the secondary high pressure fill sensor 416. As shown, the valve 300 can interrupt flow from the chamber 1406 (e.g., the stopper 1410) to keep the piston 1402 substantially fixed or near a desired position when performing a flushing operation.

[0165] In some embodiments, the velocity of the second piston 1404 can be calculated by the pressure exchanger system 400 at one or both of the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416. In some embodiments, the acceleration of the second piston 1404 can be calculated by comparing the velocity calculation values ​​at the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416. In some embodiments, one or more of the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 can be configured to directly detect the acceleration of the second piston 1404 as the second piston 1404 passes by the primary high pressure fill sensor 414 and / or the secondary high pressure fill sensor 416. For example, one or more of the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 can include the third coil 610 ( Figure 6As discussed above, the third coil 610 may enable the primary high pressure fill sensor 414 or the secondary high pressure fill sensor 416 to detect acceleration of the second piston 1404 .

[0166] The pressure exchanger system 400 can adjust the control of the clean control valve 300 so that the second piston 1404 travels at a desired speed and / or accelerates at a desired rate as the second piston 1404 passes the secondary high pressure fill sensor 416 so that the second piston 1404 will reach the dirty manifold 408 before the clean control valve 300 stops the high pressure clean fluid flow into the second chamber 1408.

[0167] Fig.16 A method of balancing a pressure exchanger system 1600 is shown. Also refer to Fig.14 and Fig.15 In some embodiments, pressure exchanger system 400 may substantially balance first chamber 1406 and second chamber 1408 by monitoring primary high pressure fill sensor 414 and secondary high pressure fill sensor 416 independently of low pressure fill sensor 412 .

[0168] The low pressure fill sensor 412 can be used to stop the movement of the pistons 1402, 1404 before the pistons 1402, 1404 contact the cleaning manifold, as described above. However, the balance between the first chamber 1406 and the second chamber 1408 can be substantially controlled by the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416. In some embodiments, data from the low pressure fill sensor 412 can be utilized. For example, in each of the following determination lists, the position of the pistons 1402, 1404 at the cleaning end can be verified (e.g., through data from the low pressure fill sensor 412) to ensure that the pistons 1402, 1404 do not contact the cleaning end (e.g., the cleaning manifold 406).

[0169] In action 1602, the pressure exchanger system 400 can determine whether the second piston 1404 has passed the primary high pressure fill sensor 414. The primary high pressure fill sensor 414 can include at least two coils, so that the primary high pressure fill sensor 414 can determine whether the second piston 1404 has passed the primary high pressure fill sensor 414 by comparing the time difference between the signal peaks of the at least two coils.

[0170] If the primary high pressure fill sensor 414 indicates that the second piston 1404 has passed the primary high pressure fill sensor 414, a processor in the pressure exchanger system 400 (e.g., the control system 401 ( Figure 4)) can calculate the velocity of the second piston 1404 in act 1604. In some embodiments, the processor can also calculate the acceleration of the second piston 1404, such as by calculating it through a third coil on the primary high pressure fill sensor 414.

[0171] The pressure exchanger system 400 can then determine in act 1606 whether the second piston 1404 has passed the secondary high pressure fill sensor 416. The secondary high pressure fill sensor 416 can include at least two coils, so that the secondary high pressure fill sensor 416 can determine whether the second piston 1404 has passed the secondary high pressure fill sensor 416 by comparing the time difference between the signal peaks of the at least two coils.

[0172] If the secondary high pressure fill sensor 416 indicates that the second piston 1404 has passed the secondary high pressure fill sensor 416, the processor in the pressure exchanger system 400 can calculate the speed of the second piston 1404 in action 1608. In some embodiments, the processor can also calculate the acceleration of the second piston 1404, such as by calculating it through a third coil on the secondary high pressure fill sensor 416.

[0173] The processor may determine in act 1610 whether the second piston 1404 has passed both the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416. For example, if the signal generated by the primary high pressure fill sensor 414 sensor indicates that the second piston 1404 is close to but has not passed the primary high pressure fill sensor 414 (e.g., two peaks associated with the two coils occur at substantially the same time), the processor may mark that the second piston 1404 has not passed the primary high pressure fill sensor 414. In act 1616, the processor may then increase the dwell time of the cleaning control valve 300 so that the high pressure cleaning fluid continues to flow into the second chamber 1408 for a longer time after it stops flowing out of the first chamber 1406. Similarly, if the second piston 1404 has passed the primary high pressure fill sensor 414 but has not passed the secondary high pressure fill sensor 416 as indicated by the signals from the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416, the processor may increase the dwell time of the cleaning control valve 300 in act 1616.

[0174] In some embodiments, if the second piston 1404 does not pass the primary high pressure fill sensor 414, the residence time can be increased in larger increments, and if the second piston 1404 passes the primary high pressure fill sensor 414 but does not pass the secondary high pressure fill sensor 416, the residence time can be increased in smaller increments. In some embodiments, the magnitude of the increments can also be defined by the magnitude of the peak value of the signal. For example, the magnitude of the peak value can correspond to the distance between the second piston 1404 and the primary high pressure fill sensor 414 or the secondary high pressure fill sensor 416 when the second piston 1404 reverses direction. Therefore, a smaller magnitude of the peak value can indicate that the second piston 1404 decelerated to a stop at a greater distance from the primary high pressure fill sensor 414 or the secondary high pressure fill sensor 416, which in turn can indicate that a larger change in the residence time is necessary. In some embodiments, the backoff point 410 can be modified (e.g., temporarily modified). For example, the backoff point 410 may be moved toward the dirty manifold 408 to increase the likelihood that the pistons 1402 , 1404 travel a sufficient distance toward the dirty manifold 408 (eg, past the sensors 414 , 416 ).

[0175] If the second piston 1404 passes both the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416, then in act 1612, the speed calculated in acts 1604 and 1608 can be compared to a threshold speed. For example, the threshold speed of the secondary high pressure fill sensor 416 can be between about 1 ft / s (0.3048 m / s) and about 5 ft / s (1.524 m / s), such as between about 1 ft / s (0.3048 m / s) and about 3 ft / s (0.9144 m / s). In act 1614, the dwell time can be adjusted to bring the speed closer to the threshold speed.

[0176] In some embodiments, the speed of the second piston 1404 at the primary high pressure fill sensor 414 can be compared to the speed of the second piston 1404 at the secondary high pressure fill sensor 416. For example, the speed can indicate whether the second piston 1404 has decelerated between the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416, which indicates that the cleaning control valve 300 has begun to close. In some embodiments, the dwell time can be adjusted so that no deceleration is detected between the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416. In some embodiments, the dwell time can be adjusted so that the deceleration between the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416 is close to a threshold acceleration value. In some embodiments, the dwell time can be adjusted based on the speed of the second piston 1404 when the second piston 1404 passes the secondary high pressure fill sensor 416 and the deceleration of the second piston 1404 between the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416.

[0177] In some embodiments, the residence time can be increased by a feedback loop algorithm such as a proportional integral derivative (PID) loop, a step and wait algorithm, etc. In some embodiments, the residence time can be increased by a combination of control algorithms. For example, if the second piston 1404 does not pass the primary high pressure fill sensor 414, the residence time can be increased substantially by an algorithm designed to provide a coarse adjustment (e.g., a larger adjustment). If the second piston 1404 passes both the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416, the residence time can be adjusted to approximate the desired speed and / or acceleration by an algorithm designed to provide a fine adjustment (e.g., a smaller adjustment).

[0178] As mentioned above, only one fill sensor 414 may be used. In such a configuration, data (e.g., velocity) from passing pistons 1402, 1404 may be used to determine whether pistons 1402, 1404 are likely to travel a desired distance from or toward the dirty manifold 408.

[0179] In some embodiments, the pressure exchanger system 400 can adjust algorithm parameters based on the state of the cleaning control valve 300. For example, the pressure exchanger system 400 can adjust the threshold between a minimum threshold and a maximum threshold based on the state of the cleaning control valve 300. If the cleaning control valve 300 has been indicated to shield the first chamber 1406 after the second piston 1404 passes both the primary high pressure fill sensor 414 and the secondary high pressure fill sensor 416, then the control thresholds such as the speed threshold and / or the acceleration threshold can be set to a minimum value so that the first piston 1402 does not remain at the retraction point 410 for an unnecessary amount of time.

[0180] As described above, in some embodiments, the speed or acceleration of the pistons 1402, 1404 may not change with the speed of the pistons 1402, 1404. Fig.16 is determined by the process carried out on the left hand side.

[0181] Fig.17 A system including more than one pressure exchanger is shown, for example, a pressure exchanger stack 1700. The pressure exchanger stack 1700 may include a plurality of pressure exchanger systems 400. Each pressure exchanger system 400 may include a first chamber 1406 and a second chamber 1408 having respective first pistons 1402 and second pistons 1404. Each pressure exchanger system 400 may be controlled such that the period difference (e.g., offset) of the first piston 1402 and the second piston 1404 of each respective pressure exchanger system 400 is equal. The difference in period of the first piston 1402 and the second piston 1404 between each pressure exchanger system 400 may enable the pressure exchanger stack 1700 to generate a substantially constant pressure. For example, the dirty manifold 408 of each individual pressure exchanger system 400 may be coupled together to substantially form a single dirty manifold 408. In some embodiments, the dirty manifold 408 of each individual pressure exchanger system 400 can be coupled by piping to maintain the pressure of the fluid output by the dirty manifold 408 at substantially the same pressure. Thus, placing each of the pressure exchanger systems 400 in the pressure exchanger stack 1700 in a different cycle can enable the pressure in the dirty manifold 408 to be collectively substantially constant (e.g., substantially free of pulsation, water hammer, etc.).

[0182] The cycle of each of the pressure exchanger systems 400 can be defined in degrees as a portion of the cycle. For example, at 0 degrees and 360 degrees, the first piston 1402 can be positioned at the setback point 410, and the second piston 1404 can be positioned at the dirty manifold 408. At 180 degrees, the first piston 1402 can be positioned at the dirty manifold 408, and the second piston 1404 can be positioned at the setback point 410. At 90 degrees and 270 degrees, each of the first piston 1402 and the second piston 1404 can pass through the central portion of the corresponding first chamber 1406 and the second chamber 1408 in opposite directions.

[0183] In some embodiments, the period of each of the pressure exchanger systems 400 in the pressure exchanger stack 1700 may be adjusted by dividing 360 degrees by the number of pressure exchanger systems 400 in the pressure exchanger stack 1700. For example, Fig.17A pressure exchanger stack 1700 is shown having three pressure exchanger systems 400. The period of each pressure exchanger system 400 may differ or be offset by 120 degrees from an adjacent pressure exchanger system 400. In a pressure exchanger stack 1700 having four pressure exchanger systems 400, the period of each pressure exchanger system 400 may differ or be offset by 90 degrees from an adjacent pressure exchanger system 400.

[0184] The cycle can be adjusted so that at least one chamber 1406, 1408 is in the high pressure stroke at all times, thereby always providing high pressure to the dirty manifold 408. For example, the dirty manifolds 408 can be coupled together into a single manifold, and offsetting the cycle as described above can provide a substantially constant pressure in the dirty manifold 408. Fig.17 , the top pressure exchanger system 400 may be at a stage in the cycle where the high and low pressure chambers are switched between the first chamber 1406 and the second chamber 1408 by the clean control valve 300 in the clean manifold. Thus, the top pressure exchanger system 400 may not be providing high pressure to the dirty manifold 408. The intermediate pressure exchanger system 400 may be in the middle of the stroke such that the second chamber 1408 is providing high pressure to the dirty manifold 408. The bottom pressure exchanger system 400 may be near the switching point of the cycle such that, while still providing high pressure to the dirty manifold 408, the pressure is steadily decreasing as the clean control valve 300 begins to close.

[0185] If the cycles become synchronized (e.g., the pistons 1404, 1402 in more than one pressure exchanger system 400 are at substantially the same position in the cycle), the pressure exchanger stack 1700 may begin to experience pressure spikes or pulses. Pressure spikes may damage components in the pressure exchanger stack 1700 and / or adjacent components such as pipes, pumps, connections, couplings, manifolds, etc.

[0186] In some embodiments, the period of each individual pressure exchanger system 400 can be adjusted by the residence time of the cleaning control valve 300. For example, if the period of the first pressure exchanger system 400 is too close to the period of an adjacent pressure exchanger system 400, the residence time of one of the first pressure exchanger system 400 and the adjacent pressure exchanger system 400 can be adjusted to hold the first piston 1402 at the retraction point 410 and the second piston 1404 at the fouled manifold 408 for a period of time sufficient to place the periods of each of the first pressure exchanger system 400 and the adjacent pressure exchanger system 400 in the correct period interval. In some embodiments, the residence can be adjusted to hold the first piston 1402 at the fouled manifold 408 and the second piston 1404 at the retraction point 410 until the period interval is correct. In some embodiments, a small amount of residence time can be added to the out-of-sync pressure exchanger systems 400 such that the periods will slowly approach the correct interval over several periods.

[0187] The pressure exchanger can reduce the amount of wear experienced by high-pressure pumps, turbines, and valves in systems with abrasive, corrosive, or acidic fluids. The reduction in wear can allow the system to operate for longer periods with less downtime, thereby increasing the revenue or productivity of the system. Additionally, since fewer parts are likely to be worn, the maintenance costs can be reduced. In operations such as fracking operations where abrasive fluids are used at high temperatures, maintenance and downtime can result in losses of millions of dollars in a single operation. Embodiments of the present disclosure can result in a reduction in the wear experienced by components of systems that use abrasive, corrosive, or acidic fluids at high temperatures. The reduction in wear will result in cost savings and increased revenue production.

[0188] Although the present disclosure has been described herein with respect to certain illustrated embodiments, those skilled in the art will recognize and understand that the present disclosure is not so limited. Rather, many additions, deletions, and modifications can be made to the illustrated embodiments without departing from the scope of the disclosure as claimed in the claims, including their statutory equivalents. Additionally, features from one embodiment can be combined with features of another embodiment while still being encompassed within the scope of the disclosure contemplated by the inventors.

Claims

1. A method for measuring the speed of a piston, the method comprising: include: passing a piston in the chamber past at least one sensor; inducing an electrical characteristic in the at least one sensor via the piston; measuring a change in the electrical characteristic over time in the at least one sensor; as well as A velocity of the piston is calculated based on the change in the electrical characteristic in the at least one sensor.

2. The method according to claim 1, in, Measuring the change in the electrical characteristic includes monitoring at least one of current or voltage.

3. The method according to claim 1, in, Calculating the velocity of the piston includes calculating the velocity of the piston based on a magnitude of the change in the electrical characteristic in the at least one sensor.

4. The method according to claim 1, in, Calculating the speed of the piston includes calculating the speed of the piston based on a rate of change of the electrical characteristic detected in the at least one sensor.

5. The method according to any one of claims 1 to 4, further comprising: include: The piston is passed by the at least one sensor, the at least one sensor comprising a first coil and a second coil, wherein the first coil and the second coil are axially aligned and spaced apart a first distance.

6. The method according to claim 5, further comprising: include: inducing a current in the second coil; measuring the change of the electrical characteristics in the second coil over time; as well as The speed of the piston is calculated based on the difference between the change in the electrical characteristic over time in the first coil and the change in the electrical characteristic over time in the second coil.

7. The method according to any one of claims 1 to 4, further comprising: include: Using a first sensor to detect the piston; measuring a voltage level in the first sensor; Detecting the piston with a second sensor; measuring a voltage level in the second sensor; as well as The voltage level in the first sensor is compared to the voltage level in the second sensor to determine whether the piston has passed both the first sensor and the second sensor.

8. The method according to any one of claims 1 to 4, further comprising: include: measuring a change in voltage over time in the at least one sensor in response to passage of the piston; calculating the speed using the change in the voltage over time; if the speed exceeds a threshold speed level, measuring another change in voltage over time in the at least one sensor in response to passage of the piston; as well as Another speed is calculated using the another change in the voltage over time.

9. The method according to any one of claims 1 to 4, further comprising: include: monitoring a position of the piston in the chamber and a position of a second piston in a second chamber; changing a position of a valve in response to the position of the second piston; During a dwell phase, stopping the flow of fluid from the second chamber while maintaining the flow of fluid into the chamber; as well as After the residence period, the flow of the fluid from the chamber is redirected to the second chamber.

10. The method according to claim 9, further comprising: include: The dwell period is varied in response to the position of the piston or the position of the second piston.

11. The method according to claim 9, further comprising: include: A period difference of approximately 180 degrees between the first piston and the second piston is maintained.

12. The method according to claim 9, further comprising: include: monitoring one or more of a velocity or an acceleration of the piston or the second piston; as well as The dwell period is varied in response to the one or more of a velocity or an acceleration of the piston or the second piston.

13. A device for detecting the characteristics of a piston, the device include: at least one sensor positioned proximate the chamber; as well as a piston comprising one or more sensing features disposed about a surface of the piston, wherein the piston is configured to travel within the chamber; Wherein the at least one sensor is configured to generate a signal based on the proximity of the one or more detection features.

14. The device according to claim 13, in, The at least one sensor includes at least two coils spaced a first distance apart along an axis of the chamber.

15. The apparatus of claim 14, further comprising a third coil arranged around the chamber and at a second distance from one of the at least two coils.

16. The device according to any one of claims 13 to 15, in, The one or more sensing features include one or more magnetic members configured to induce an electric current in the at least one sensor.

17. The device according to claim 16, in, The one or more magnetic members are arranged such that the same magnetic pole of each of the one or more magnetic members faces radially outward.

18. The device according to claim 17, in, The one or more magnetic members are embedded in the surface of the piston.

19. The device according to any one of claims 13 to 15, in, The at least one sensor is configured to detect whether the piston at least partially passes the at least one sensor.

20. The device according to any one of claims 13 to 15, in, The at least one sensor is configured to detect a velocity of the piston.

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