JP6334513B2 - Rotary valve and associated method for reciprocating compressors - Google Patents

Description

  Embodiments of the presently disclosed subject matter relate to an apparatus and method for controlling fluid suction and discharge in a compression chamber of a reciprocating compressor, generally using a single actuator. More particularly, it relates to an apparatus or method for operating a rotary valve configured to open or close a suction flow path to a compression chamber and a discharge flow path from the compression chamber.

  Compressors can be classified as positive displacement compressors (eg, reciprocating compressors, screw compressors or vane compressors) or dynamic compressors (eg, centrifugal compressors or axial flow compressors). For positive displacement compressors, compression is achieved by taking a gas and then reducing the volume of the gas. For dynamic compressors, the gas is compressed by transferring kinetic energy from a rotating element, typically an impeller, to the gas being compressed by the compressor.

  FIG. 1 is an explanatory diagram of a conventional double chamber reciprocating compressor 10. The fluid compression is performed inside the main body 20 having a generally cylindrical shape. The fluid to be compressed (eg, natural gas) is input into the body 20 via the inlet 30 and suction valves 32 and 34, and after compression, the fluid is output via the outlet 40 and discharge valves 42 and 44. . Compression is a periodic process in which fluid is compressed due to movement of the piston 50 between the head end 26 and the crank end 28 within the body 20. The piston 50 divides the body 20 into two compression chambers 22 and 24 that operate in different phases of the compression cycle, and when the volume of the compression chamber 24 is at its maximum value, the volume of the compression chamber 22 is at its minimum value and vice versa. Is the same.

Suction valves 32 and 34 are configured to open so that incoming fluid (having a _first pressure P ₁ ) can enter compression chambers 22 and 24, respectively. Discharge valves 42 and 44 are configured to open so that outflowing compressed fluid (having _second pressure P ₂ (> P ₁ )) can be output from compression chambers 22 and 24, respectively. The piston 50 moves due to the energy transmitted from the crankshaft 60 through the crosshead 70 and the piston rod 80. Valves 32, 34, 42, and 44 are shown on the side wall of the body 20, but can also be located on the head end 26 and crank end 28 of the body 20.

  Traditionally, the suction and discharge valves used in reciprocating compressors are between a closed state and an open state due to the differential pressure across the valve (ie, on one side of the movable part of the valve). Automatic valve that is switched between the pressure and the pressure on the other side of the moving part. An automatic valve has the disadvantage that the automatic valve considerably increases the compression volume of the compression chamber, and this compression volume (eg 25) is a volume that cannot be used effectively in the compression cycle. The compression efficiency decreases as the compression volume increases.

  The actuating rotary valve minimizes the portion of the compression volume of the compression chamber due to the valve and increases the flow area. 2A and 2B show a conventional rotary valve 200 that opens or closes a flow path that may be disposed between the inlet 30 and the compression chamber 22. It is contemplated that the rotary valve 200 can be used in place of any of the valves 32, 34, 42, and 44. The rotary valve 200 includes a valve seat (or stator) 210 and a rotor 220. The valve seat 210 and the rotor 220 are coaxial disks whose openings extend in the same size fan shape around the mandrel 230. The rotor 220 is actuated around a mandrel 230 from a first position (FIG. 2A) where the rotor opening 222 overlaps the valve seat opening 212 and the rotor opening 222 and valve seat opening 212 (dashed line). Can be rotated to a second position (FIG. 2B) that spans different sectors. When the rotor 220 is in the first position, the rotary valve 200 is in an open state, allowing fluid to flow through the valve. When the rotor 220 is in the second position, the rotary valve 200 is in a closed state, thus preventing fluid from flowing through the valve.

  The use of rotary valves is difficult even if it is suitable for compressors used in the oil and gas industries. Compressors used in the oil and gas industries must meet industry-specific requirements, for example, taking into account that compressed fluids are often corrosive and flammable. The American Petroleum Institute (API), an organization that establishes recognized industry standards for equipment used in the oil and gas industry, has published document API 618 that lists a complete set of minimum requirements for reciprocating compressors.

  Considering that valves used in oil and gas compressors generally have an operating time of about 5 ms to operate a rotary valve for such a compressor (relative to available space) An actuator with a large volume is required. Due to the potential explosion hazard, the electric valve actuators (which can give the required operating time) are placed out of contact with the flammable gas and the motion generated by these actuators It is preferably transmitted mechanically to the movable part of the valve in contact with the valve. The space required to arrange the actuator and the mechanism for transmitting the displacement generated by the actuator to the movable part of the valve is not always available. Further, the crank end side of the double reciprocating compressor usually has less space than the head end side.

  Therefore, it would be desirable to provide an alternative solution for automatic valves for reciprocating compressors used in the oil and gas industry that meets requirements and allows for limited space.

US Patent Application Publication No. 2010/092311

  When a rotary valve is used in a reciprocating compressor, there is an advantage that both a suction flow path and a discharge flow path are controlled by a single actuator. The rotary valve may be attached to the head end and the crank end of the double reciprocating compressor. The two rotary valves in the double reciprocating compressor may be operated using the same actuator.

  According to an exemplary embodiment, the reciprocating compressor is (1) a compression configured to compress fluid that enters the compression chamber via the suction port and is compressed and then discharged from the compression chamber via the discharge port. A chamber, (2) an actuator configured to provide an angular displacement, and (3) receiving the angular displacement and controlling whether the inlet and outlet are opened or closed according to the angular displacement. And a structured rotary valve. The rotary valve rotates due to angular displacement, and a first opening that allows the suction fluid flow to enter the compression chamber when the first opening overlaps the suction opening, and a second opening And a rotatable disk configured to have a second opening that allows the discharged fluid flow to exit the compression chamber when the portion overlaps the discharge port.

  According to another exemplary embodiment, the double reciprocating compressor is (1) divided into two compression chambers, each compression chamber entering the compression chamber via a suction port and from the compression chamber via a discharge port. And (2) a piston configured to move along the body and thereby vary the volume of the two compression chambers; and (3) angular displacement. And (4) whether the suction port and the discharge of each chamber are opened or closed in accordance with the angular displacement while being disposed at the opposite end of the main body and receiving the angular displacement. And two rotary valves configured to control. Each rotary valve rotates due to angular displacement and (A) a first opening that allows a suction fluid flow to enter a respective compression chamber when the first opening overlaps the suction opening. And (B) a second opening that allows the discharge fluid flow to exit the respective compression chamber when the second opening overlaps the discharge opening. Includes discs. The angular actuation of at least one of the two rotary valves is caused by angular displacement.

  According to another exemplary embodiment, a suction opening that is usable at one end of the compression chamber and configured to allow a suction fluid flow to enter the compression chamber, and a discharge fluid flow is provided in the compression chamber. A rotary valve having an end plate having a discharge opening configured to allow exiting. The rotary valve is a rotatable disk having a first opening and a second opening arranged at different angular positions, and when the first opening overlaps the suction opening, the suction fluid flow Includes a rotatable disk that can pass through the rotatable disk and that allows the discharge fluid flow to pass through the rotatable disk when the second opening overlaps the discharge opening.

  According to another exemplary embodiment, a method is proposed for retrofitting a reciprocating compressor having two automatic valves located on the end plate of the compression chamber of the initial reciprocating compressor. The method includes (1) removing the movable part of the valve and leaving the valve seat in place, each valve seat having an opening facing the interior of the compression chamber; and (2) providing angular displacement. And (3) mounting a rotatable disk having two openings at different angular positions outside the end of the compression chamber, and one of the openings of the rotatable disk. One overlies the opening of one of the valve seats at a first angular position, and the other one of the openings of the rotatable disc has a first angular position at the other one of the valve seats. And overlapping at a different second angular position. The method comprises (4) connecting the rotatable disk to an actuator, wherein the rotatable disk is caused by an angular displacement so that one of the openings of the rotatable disk and one of the valve seats respectively. The method further includes allowing the fluid flow to pass through or through the rotatable disk to or from the compression chamber so that it can rotate to an overlapping position.

  The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments.

It is the schematic of the conventional double chamber reciprocating compressor. A conventional operating rotary valve is shown in an open state. A conventional actuating rotary valve is shown in a closed state. 1 is a schematic diagram of a single chamber reciprocating compressor according to an exemplary embodiment. FIG. FIG. 6 is an illustration of a rotatable disk of a rotary valve according to an exemplary embodiment. 1 is a schematic view of a double chamber reciprocating compressor according to one exemplary embodiment. FIG. 1 is a schematic view of a double chamber reciprocating compressor according to one exemplary embodiment. FIG. 2 is a flow diagram of a method for retrofitting a reciprocating compressor according to an exemplary embodiment.

  In the following description of the exemplary embodiments, reference is made to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed in relation to reciprocating compressor terminology and structure used in the oil and gas industries for simplicity. However, the embodiments discussed herein are not limited to these compressors and may be applied to other systems that require power supply at low cost and small footprint.

  Reference throughout this specification to "one embodiment" or "one embodiment" refers to a particular feature, structure, or characteristic described in connection with one embodiment is at least one embodiment of the disclosed subject matter. It is included in. Accordingly, the appearances of the phrases “in one embodiment” or “in one embodiment” in various places throughout the specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

  As discussed in connection with the background art, one technical problem associated with the use of actuated valves in reciprocating compressors is that actuators that can provide angular displacement in a very short time (ie, about 5 ms) are relatively The volume is large and electric. Due to the flammability of the fluid in the oil and gas industry, the actuator should not contact the fluid and the actuation motion must be transferred to the moving part of the valve that is in contact with the fluid in this case. The space required to install the actuator and the transmission for each valve is not available very close to the reciprocating compressor valve. Some embodiments described below use a single actuator to control (ie, open and close) the two flow paths to or from the compression chamber. Moreover, in some embodiments, the same actuator controls a total of four flow paths to and from the two compression chambers of the double reciprocating compressor.

  According to one exemplary embodiment shown in FIG. 3, the single chamber reciprocating compressor 300 receives fluid via the inlet 320, compresses the fluid, and then discharges fluid from the compression chamber 310 via the outlet 330. The compression chamber 310 is configured to discharge the gas. Whether or not the fluid flow path from the suction port 320 to the compression chamber 310 and the fluid flow path from the compression chamber 310 to the discharge port 330 are opened depends on the angular displacement provided by the actuator 350 and rotates. It depends on the position of 340 openings. The rotatable disk 340 is a rotary valve switching (motion) component that controls whether fluid flows from and toward the compression chamber 310. The opening of the rotatable disc 340 is configured to align with the inlet 320 and outlet 330 at a certain angular position. The suction port 320 and the discharge port 330 are formed in the head end 360 of the compression chamber 310. Cover 365 separates the periphery from the volume in which rotatable disk 340 is located.

  Fluid compression is performed periodically along the axis 375 due to the back and forth movement of the piston 370 in relation to the timely opening or closing of the inlet 320 and outlet 330 by the rotatable disk 340.

  A front view of the rotatable disk 340 is shown in FIG. The rotatable disc 340 has a first opening 342 through which fluid flow enters the compression chamber 310 through the first opening 342 when the first opening 342 overlaps the inlet 320. The rotatable disc 340 also has a second opening 344 through which fluid flow exits the compression chamber 310 through the second opening 344 when the second opening 344 overlaps the outlet 330.

  The angular displacement of the rotatable disk 340 is transmitted from the actuator 350 via a gear mechanism. The angular displacement may be a continuous (unidirectional) rotation or an alternating rotation (clockwise and counterclockwise). The actuator 350 is preferably placed outside the fluid to avoid the risk of explosion (considering that the fluid is probably flammable). The gear mechanism includes a valve stem 380 that passes through the cover 365. A gear 382 is attached to the end of the valve stem 380 and meshes with the rotatable disc 340 between the rotatable disc 340 and the cover 365 within the volume filled with fluid (ie, the teeth 382A of the gear 382 are Engaging the teeth 340A of the rotatable disc 340). Another gear 384 is attached to the other end of the valve stem 380. One end of the actuator mandrel 390 is attached to the actuator 350 and the other end is attached to a gear 392 that meshes with the gear 384 (ie, the teeth 384A of the gear 384 engage the teeth 392A of the gear 392). The valve stem 380 may have a collar 386 and a bush 388 on both sides of the cover 365 to increase its stability during operation.

  In FIG. 3, the actuator 350 and the gear mechanism are shown as being located near the inlet 320. However, in other embodiments, the actuator 350 and gear mechanism may be located at different locations near the outlet 330 or around the compression chamber 310. The relative dimensional relationship between the components should not be inferred from FIG. 3 or from other exemplary embodiments shown in the figures.

  Double chamber (or operating) reciprocating compressors are used more frequently in the oil and gas industries than single chamber (or operating) reciprocating compressors. FIG. 5 illustrates a double chamber reciprocating compressor 500 according to another exemplary embodiment. The fluid is compressed between the head end plate 530 and the crank end plate 540 due to the back and forth movement of the piston 510 provided inside the main body 520. The piston 510 divides the body 520 into two compression chambers 522 and 524 that operate in different phases, and when the volume of the compression chamber 524 is at its maximum value, the volume of the compression chamber 522 is at its minimum value and vice versa. It is. The piston 510 moves back and forth due to energy received, for example, from a crankshaft (not shown) via a crosshead (not shown) and a piston rod 512.

  A suction port 532 and a discharge port 534 communicating with the compression chamber 522 are formed through the head end plate 530. Similarly, a suction port 542 and a discharge port 544 that communicate with the compression chamber 524 are formed through the crank end plate 540. Outside the body 520, rotatable disks 550 and 560 are disposed at the head end and the crank end, respectively. The rotatable disks 550 and 560 are configured to rotate due to angular displacement received from actuators 570 and 580, respectively. Each of the rotatable disks 550 and 560 has a first opening that allows fluid flow to enter the respective compression chamber 522 or 524 when the first opening overlaps the inlet 532 or 542, respectively. . Further, each of the rotatable disks 550 and 560 has a second opening that allows fluid flow to exit the respective compression chamber 522 or 524 when the second opening overlaps the outlet 534 or 544, respectively. Part. The structure of the rotatable disks 550 and 560 may be similar to the rotatable disk 340 shown in FIG. Some details on the crank end side (ie around the rotatable disc 560) have been omitted to clarify important details.

  Gear assemblies 575 and 585 are configured to transmit angular displacement from actuators 570 and 580, respectively, to rotatable disks 550 and 560, respectively. Covers 555 and 565 separate the fluid volume from the surroundings. A detailed description of each of the components of the gear assembly is omitted because the gear assembly is similar to the gear assembly described for the single chamber reciprocating compressor 300.

  In FIG. 5, the double chamber reciprocating compressor 500 is shown as having rotary valves 550 and 560 (defined by a rotatable disk) at both its head end and crank end, but an alternative embodiment is It is also possible to have a rotary valve only at one end of the head end or crank end and another type of valve at the other end of the compression chamber.

  FIG. 6 shows a double chamber reciprocating compressor 600 with rotary valves at both the head end and crank end. The rotatable disks 550 and 560 of the double chamber reciprocating compressor 600 are actuated by the same single actuator 590 instead of the two actuators 570 and 580 of FIG. The description of the components of the double chamber reciprocating compressor 600 similar to those of the double chamber reciprocating compressor 500 will not be repeated.

  Existing reciprocating compressors with automatic valves can be retrofitted to use actuated rotary valve (s). A method 700 for retrofitting a reciprocating compressor having two automatic valves located on the end plate of the compression chamber of the original reciprocating compressor is shown in FIG. The method 700 includes, at S710, removing a moving part of the automatic valve, leaving the valve seat of the automatic valve in place, each valve seat having an opening directed toward the interior of the compression chamber. The valve seat of the suction port valve may serve as a suction port, and the valve seat of the discharge valve may serve as a discharge port.

  The method 700 includes providing an actuator configured and connected to provide an angular displacement at S720, and mounting a rotatable disk having two openings at different angular positions outside the end of the compression chamber at S730. And further including.

  The method 700 also connects, at S740, the rotatable disk to the actuator, such that one of the disk openings overlaps one of the valve seat openings due to angular displacement. And allowing fluid flow to pass through or through the rotatable disk toward or from the compression chamber.

  The method 700 may further include mounting a gear mechanism for transmitting angular displacement from the actuator to the rotatable disk. The gear mechanism may be configured to penetrate the cover of the reciprocating compressor that separates the fluid-filled volume from the surroundings where the actuator is located.

  The back-and-forth reciprocating compressor is a double-chamber reciprocating compressor having two compression chambers back to back on the main body, and is initially placed on the opposite end of the main body from the end where the two automatic valves are arranged If there are two other automatic valves being used, the method 700 may further include the step of replacing the other two automatic valves with other rotary valves. Thus, the method 700 (1) removes moving parts from the other two valves, leaving the valve seats of the other two valves in place, with each valve seat facing toward the interior of the other compression chamber. A step having an opening; (2) mounting another rotatable disc having two other openings at different angular positions outside the opposite end; and (3) another rotatable. A position where the disk is connected to the actuator, and one of the other rotatable disk openings overlaps one of the other two openings due to the angular displacement of the other rotatable disk And allowing fluid flow to pass through other rotatable discs to and from other compression chambers.

  The disclosed exemplary embodiments provide a reciprocating compressor having at least one rotary valve and a method of retrofitting at least one rotary valve to an existing reciprocating compressor. It should be understood that this description is not intended to limit the invention. Rather, the exemplary embodiments are intended to embrace alterations, modifications, and equivalents that fall within the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the exemplary embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one of ordinary skill in the art appreciates that various embodiments can be practiced without such specific details.

  Although the features and elements of the exemplary embodiments are described in specific combinations in the embodiments, each feature or element may be without other features and elements of the embodiment or others disclosed herein. It can be used alone, in various combinations with or without the features and elements.

  This written description uses the examples of the disclosed subject matter to include any apparatus or system made and used by those skilled in the art and any embodied method. To be able to do the same thing. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Double chamber reciprocating compressor 20 Main body 22 Compression chamber 24 Compression chamber 25 Compression volume 26 Head end 28 Crank end 30 Inlet 32 Suction valve 34 Suction valve 40 Outlet 42 Discharge valve 44 Discharge valve 50 Piston 60 Crankshaft 70 Crosshead 80 piston rod 200 rotary valve 210 valve seat 212 valve seat opening 220 rotor 222 rotor opening 230 mandrel 300 single chamber reciprocating compressor 310 compression chamber 320 suction port 330 discharge port 340 rotatable disk, rotary valve 340A teeth 342 First opening 344 Second opening 350 Actuator 360 Head end 365 Cover 370 Piston 375 Axis 380 Valve stem 382 Gear 382A Tooth 384 Gear 384A Tooth 386 Color 388 Bush 390 Actuator stem 392 Gear 392A Tooth 5 00 Double chamber reciprocating compressor 510 Piston 512 Piston rod 520 Main body 522 Compression chamber 524 Compression chamber 530 Head end plate 532 Suction port 534 Discharge port 540 Crank end plate 542 Suction port 544 Discharge port 550 Rotatable disk, rotary valve 555 Cover 560 Rotating disc, rotary valve 565 Cover 570 Actuator 575 Gear assembly 580 Actuator 585 Gear assembly 590 Actuator 600 Double chamber reciprocating compressor

Claims (9)

The compression chamber is configured to compress the fluid that has entered the compression chamber through the suction port, and after the fluid is compressed, the compression chamber is discharged from the compression chamber through the discharge port;
An actuator configured to provide angular displacement;
In response to the angular displacement, the suction port and the discharge port are configured to control whether to open or close in accordance with the angular displacement, and configured to rotate due to the angular displacement. The first opening and the second opening allow the suction fluid flow to enter the compression chamber when the first opening overlaps the suction port. A rotary valve having the second opening that allows a discharge fluid flow to exit the compression chamber when overlapping a discharge port;
A gear mechanism configured to transmit the angular displacement from the actuator disposed outside the compression chamber to the outer peripheral surface of the rotatable disk of the rotary valve;
With
The actuator is disposed radially outside the compression chamber and the rotary valve;
Reciprocating compressor. The gear mechanism is
An actuator mandrel connected to the actuator;
At least two gears including a first gear mounted to the actuator mandrel and rotating with the actuator mandrel; and a second gear for transmitting the angular displacement to the rotatable disk of the rotary valve;
The reciprocating compressor according to claim 1, comprising: The actuator is further disposed on the outside of the cover, and the rotary valve is further disposed on the inside of the cover;
The gear mechanism is
A valve stem having the second gear at one end and configured to penetrate the cover;
A third gear connected to the other end of the valve stem and meshing with the first gear;
Further comprising
The reciprocating compressor according to claim 1 or 2. The valve stem is configured to have a first collar between the cover and the second gear, and a second collar between the cover and the third gear;
The gear mechanism further includes a first bush disposed between the first collar and the cover, and a second bush disposed between the second collar and the cover.
The reciprocating compressor according to any one of claims 1 to 3.   The reciprocating compressor is a double reciprocating compressor having two compression chambers, the rotary valve is disposed on a head end or a crank end of the reciprocating compressor, and the compression chamber is one of the two compression chambers. The reciprocating compressor according to any one of claims 1 to 4, which is one side.   In response to an angular actuation applied to a second rotatable disk configured to rotate due to angular actuation of the other one of the two compression chambers and the outlet. Configured to control whether to open or close, and (A) when another first opening overlaps the suction port, a suction fluid flow is directed to the other one of the two compression chambers. When the other first opening that allows entry and (B) the other second opening overlaps the discharge port, the discharge fluid flow is the other one of the two compression chambers. The reciprocating compressor according to any one of claims 1 to 5, further comprising a second rotary valve having the other second opening that allows the two to be removed.   At least one gear mechanism configured to transmit the angular displacement from the actuator to cause actuation of the angle of the rotatable disk of at least one of the rotary valve and the second rotary valve; The reciprocating compressor according to any one of claims 1 to 6, further comprising: The compression chamber configured to compress the fluid that has entered the compression chamber through the suction port and to be discharged from the compression chamber through the discharge port after compression,
An actuator configured to provide angular displacement;
A rotary valve that receives the angular displacement on the outer peripheral surface;
With
An end plate having a suction opening configured to allow suction fluid flow to enter the compression chamber; and a rotary valve to allow discharge fluid flow to exit the compression chamber. A rotary valve usable at one end of a compression chamber having a configured discharge opening,
Comprising a rotatable disk configured to have a first opening and a second opening that are rotated and arranged at different angular positions, wherein the first opening overlaps the suction opening , When the suction fluid flow passes through the rotatable disk and the second opening overlaps the discharge opening, the discharge fluid flow passes through the rotatable disk;
The actuator is disposed radially outside the compression chamber and the rotary valve;
Reciprocating compressor. A method of retrofitting the reciprocating compressor with two automatic valves initially disposed on the end plate of the compression chamber of the reciprocating compressor,
Removing the movable part of the valve, leaving the valve seat in place, each valve seat having an opening directed towards the interior of the compression chamber;
Providing an actuator configured to provide angular displacement;
A rotatable disc having two openings at different angular positions is mounted outside the end of the compression chamber, and one of the openings of the rotatable disc is in the first angular position at the valve seat. The other of the valve seats at a second angular position different from the position of the first angle, wherein the other one of the openings of the rotatable disk overlaps the one of the openings. Overlapping one of the openings;
Connecting the rotatable disk to the actuator, allowing the rotatable disk to rotate on an outer peripheral surface that receives an angular displacement transmitted from the actuator; and
Including
The actuator is disposed radially outside the compression chamber and the rotary valve;
Method.