EP3953584B1

EP3953584B1 - Compressor valve assembly

Info

Publication number: EP3953584B1
Application number: EP19725600.1A
Authority: EP
Inventors: Joel T. Sanford
Original assignee: Siemens Energy Inc
Current assignee: Siemens Energy Inc
Priority date: 2019-05-09
Filing date: 2019-05-09
Publication date: 2023-11-29
Anticipated expiration: 2039-05-09
Also published as: EP3953584A1; WO2020226657A1; US20220186720A1; CN113811689A; CN113811689B

Description

TECHNICAL FIELD OF THE INVENTION

This invention relates generally to a compressor valve assembly, in particular, a compressor valve assembly for a reciprocating compressor.

DESCRIPTION OF THE RELATED ART

A reciprocating compressor is a positive displacement compressor. In a reciprocating compressor, a fluid to be compressed enters a chamber via an inlet and exits the chamber through an outlet. The compression is a cyclical process in which the fluid is compressed by a reciprocating movement of a piston head. A plurality of compressor valve assemblies may be arranged around the chamber. The compressor valve assemblies are switched between a close state and an open state due to a pressure difference across the compressor valve assemblies which is caused by the reciprocating movements of the piston head.
In a reciprocating compressor, performance and reliability of a compressor valve assembly are key to a performance of the reciprocating compressor. There is a continuing need for a more efficient and reliable compressor valve assembly for a reciprocating compressor. See FR2131709 A5 disclosing a valve for a compressor having an outflow structure with only one guide pin for each outflow passage.

SUMMARY OF THE INVENTION

Briefly described, aspects of the present invention relate to a compressor valve assembly, a guard for a compressor valve assembly and a method for operating a compressor valve assembly.
According to the invention, a guard for a compressor valve assembly according to claim 1 is presented.
According to the invention a method for operating a compressor valve assembly according to claim 9 is presented.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the application are explained in further detail with respect to the accompanying drawings. In the drawings:

FIG. 1 is a schematic cross section view of a reciprocating compressor in which a compressor valve assembly according to embodiments of the present invention is incorporated;
FIG. 2 is a schematic cut away perspective view of a conventional compressor valve assembly;
FIG. 3 is a schematic partial cross section view of the conventional compressor valve assembly shown in FIG. 2; and
FIGs. 4 to 7 are schematic partial cross section views of a compressor valve assembly for a reciprocating compressor according to various embodiments of the present invention.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures.

DETAILED DESCRIPTION OF THE INVENTION

A detailed description related to aspects of the present invention is described hereafter with respect to the accompanying figures.
FIG. 1 illustrates a schematic cross section view of a reciprocating compressor 10. The reciprocating compressor 10 includes a crankshaft 11 connected to a driving rod 12. The driving rod 12 is connected to a piston rod 14 by a crosshead 13. The piston rod 14 is connected to a piston head 15. The piston head 15 is at least partially disposed within a piston chamber 16. The piston head 15 may be driven by the piston rod 14 and the driving rod 12 and moves within the piston chamber 16 in a reciprocating manner as indicated by the dual arrows. A plurality of compressor valve assemblies 200 according to embodiments of the present invention may be disposed around the piston chamber 16. The compressor valve assemblies 200 may be switched between an open state and a closed state due to the reciprocating movements of the piston head 15 to control fluid to be compressed enter the chamber 16 and exit from the chamber 16.
FIG. 2 illustrates a schematic cutaway perspective view of a conventional compressor valve assembly 100 that may be used in a reciprocating compressor 10. FIG. 3 is a schematic partial cross section view of the conventional compressor valve assembly 100 shown in FIG. 2. With reference to FIGs. 2 and 3, the valve assembly 100 includes a seat 110 and a guard 120. The seat 110 and the guard 120 are attached to each other by any suitable means, such as a threaded stud and nut or a cap screw 111. A plurality of inlet holes 112 are arranged in the seat 110. Each inlet hole 112 includes an exit edge 112a disposed at bottom of the inlet hole 112. A plurality of outlet holes 122 are arranged in the guard 120. Fluid flow 300 may flow into the valve assembly 100 through the inlet holes 112 and discharge from the valve assembly 100 through the outlet holes 122.
The valve assembly 100 includes a plurality of guide pockets 124 disposed in the guard 120. The valve assembly 100 also includes a plurality of springs 126 and seal elements 130 disposed in the guard 120. Each spring 126 and seal element 130 are disposed in each respective guide pocket 124. The seal element 130 has an upside-down U shape having a socket 132 to receive the spring 126. The seal element 130 has a seal head 134 disposed on one end of the seal element 130. The seal head 134 may include an edge 134a disposed at a perimeter of the seal head 134. Each seal element 130 corresponds to each inlet hole 112.
During operation of the valve assembly 100, when the springs 126 extend, the springs 126 exert a force to the seal elements 130 that moves the seal heads 134 of the seal elements 130 toward the inlet holes 112 until the edges 134a of the seal heads 134 come in contact against the exit edges 112a of the inlet holes 112. The inlet holes 112 are thus sealed to prevent the fluid flow 300 into the valve assembly 100. The seal heads 134 of the seal elements 130 may recede into the guide pockets 124 when the springs 126 are compressed. The inlet holes 112 are thus opened to allow the fluid flow 300 into the valve assembly 100. The fluid flow 300 may enter the valve assembly 100 through the inlet holes 112, impinge the seal elements 130 and exit the valve assembly 100 through the outlet holes 122 as shown by the flow lines 300. The outlet holes 122 may be arranged between the guide pockets 124.
As shown in FIGs. 2 and 3, the conventional valve assembly 100 uses guide pockets 124 which are disposed externally from the springs 126 and the seal elements 130 to externally guide the springs 126 and the seal elements 130. The use of external guide pockets 124 may limit numbers of the springs 126 and the seal elements 130 to be installed in the valve assembly 100 which limits an efficiency of the valve assembly 100. The use of external guide pockets 124 also limit flow area of the valve assembly 100 which limits tolerance to dirt and debris.
FIG. 4 illustrates a schematic partial cross section view of a compressor valve assembly 200 that are incorporated in the reciprocating compressor 10 according to an embodiment of the present invention. The valve assembly 200 includes a seat 210 and a guard 220. The seat 210 and the guard 220 are attached to each other by any suitable means. A plurality of inlet holes 212 are arranged in the seat 210. The inlet hole 212 includes an exit edge 212a disposed at bottom of the inlet hole 212. The exit edge 212a of the inlet hole 212 may have any suitable shapes for sealing effectiveness. For example, the exit edge 212a of the inlet hole 212 may be a rounded shape, or a chamfered shape, etc. The valve assembly 200 includes a plurality of springs 226 disposed in the guard 220. The springs 226 may reside on the bottom 220a of the guard 220. The valve assembly 200 includes a plurality of guide pins 224 disposed in the guard 220. The guide pins 224 are attached to the bottom 220a of the guard 220 and extend out internally from the springs 226. The guide pins 224 may be attached to the bottom 220a of the guard 220 by any suitable means, such as threaded or press fit. The guide pins 224 may be replaceable from the guard 220 for any needs. For example, the guide pins 224 may be replaced for maintenance need, or for adapting a design requirement of the valve assembly 200. The guide pin 224 may have a cylindrical shape. The guide pin 224 may include a venting hole 225 (shown in FIG. 5) to prevent trapping gas in between the guide pin 224 and the seal element 230. The guide pins 224 may include any suitable materials, such as metal or high strength thermo-plastic.
The valve assembly 200 includes a plurality of seal elements 230 disposed in the guard 220. The seal elements 230 are attached to the guide pins 224. A detailed view of the seal element 230 is also illustrated in FIG. 4. As shown in FIG. 4 and the detailed view of the seal element 230, the seal element 230 may have an upside-down U-shape having a socket 232. The socket 232 defines an opening to receive the guide pin 224. The socket 232 may be disposed at a center of the seal element 230. The socket 232 may have a cylindrical shape. The socket 232 includes an inner side 232a in contact with the guide pin 224, an outer side 232b opposite to the inner side 232a, and an opening end 232c. The seal element 230 includes a seal head 234 disposed on one end of the socket 232 opposite to the opening end 232c. The seal head 234 may include an edge 234a disposed at a perimeter of the seal head 234. The edge 234a of the seal head 234 may have a shape corresponding to an exit edge 212a of the inlet hole 212 for sealing effectiveness. For example, the edge 234a of the seal head 234 may have a rounded shape, or chamfered shape, etc. The seal element 230 includes a spring landing area 236. The spring landing area 236 resides on top of the spring 226. A plurality of outlet passages 222 are disposed between the seal elements 230. Each seal element 230 corresponds to each inlet hole 212.
During operation of the valve assembly 200, the spring 226 exerts a force to the seal element 230 when the spring 226 extends. The seal head 234 of the seal element 230 then moves toward the inlet hole 212 along the guide pin 224 until the edge 234a of the seal head 234 comes in contact with the exit edge 212a of the inlet hole 212. The inlet hole 212 are thus sealed to prevent the fluid flow 300 into the valve assembly 200. When the spring 226 is compressed, the seal head 234 of the seal element 230 moves away from the inlet hole 212 along the guide pin 224. The inlet holes 212 are thus opened to allow the fluid flow 300 into the valve assembly 200. The fluid flow 300 may enter the valve assembly 200 through the inlet holes 212, impinge the seal head 234 of the seal elements 230 and exit the valve assembly 200 through the outlet holes 122 as shown by the flow lines 300.
In the exemplary embodiment as shown in FIG. 4, the spring landing area 236 is an area at the opening end 232c of the socket 232 opposite to the end of the seal head 234. The spring 226 is disposed in the guard 220. The guide pin 224 is attached to the bottom 220a of the guard 220 and extends out from the spring 226 internally. The guide pin 224 is inserted into the socket 232 of the seal element 230 to attach the seal element 230. The socket 232 of the seal element 230 is disposed above the spring 226. The spring landing area 236 resides on top of the spring 226. The outer side 232b of the socket 232 may have a chamfered surface 238. The chamfered surface 238 is chamfered from the spring landing area 236 at the opening end 232c.
FIG. 5 illustrates a schematic partial cross section view of a compressor valve assembly 200 according to another embodiment of the present invention that may be used in the reciprocating compressor 10. A detailed view of a seal element 230 of the compressor valve assembly 200 is also illustrated in FIG. 5. As shown in FIG. 5 and the detailed view of the seal element 230, the spring 226 is disposed in the guard 220. The guide pin 224 is attached to the bottom 220a of the guard 220 and extends out from the spring 226 internally. The guide pin 224 is inserted into the socket 232 of the spring element 230 to attach the seal element 230. A portion of the socket 232 of the seal element 230 is disposed between the guide pin 224 and the spring 226. The spring landing area 236 is an area disposed at the outer side 232b of the socket 232 at a distance from the opening end 232c and extending outwardly from the outer side 232b. The spring landing area 236 resides on top of the spring 226. In the exemplary embodiment as shown in FIG. 5, the spring 226 may have a large diameter such that the portion of the socket 232 may be inserted into the spring 226. An overall height of the valve assembly 200 may thus be reduced. Efficiency of the valve assembly 200 may be improved. The guide pin 224 may have a cylindrical shape. The guide pin 224 may include a venting hole 225 to prevent trapping gas in between the guide pin 224 and the seal element 230. The guide pin 224 may have a landing area where the spring 226 and the seal element 230 may reside on. It is understood that the spring 226 and the seal element 230 may reside on the bottom 220a of the guard 220.
FIGs. 6 and 7 illustrate schematic partial cross section views of a compressor valve assembly 200 according to embodiments of the present invention. As shown in FIGs. 6 and 7, an insert 214 may be attached to the exit edge 212a of the inlet hole 212. The insert 214 may be attached to the exit edge 212a of the inlet hole 212 by any suitable means, such as threaded or press fit. The insert 214 may be replaceable from the exit edge 212a of the inlet hole 212. The insert 214 may have a perimeter corresponding to the inlet hole 212, such as a ring. The insert 214 may include a structure to mate a shape of the exit edge 212a of the inlet hole 212. The insert 214 may include any suitable materials, such as metal or high strength thermo-plastic.
As mentioned above, during operation of the valve assembly 200, the edge 234a of the seal head 234 cyclically comes in contact with the exit edge 212a of the inlet hole 212. The edge 212a of the inlet hole 212 may be deformed which may deteriorate seal effectiveness of the valve assembly 200. Restoring the seal effectiveness of the valve assembly 200 may include recondition the exit edge 212a of the inlet hole 212. Such process may be time consuming and costly. According to the exemplary embodiments as shown in FIGs. 6 and 7, by attaching a replaceable insert 214 at the exit edge 212a of the inlet hole 212, the edge 234a of the seal element 234 cyclically comes in contact with the insert 214. A deformed insert 214 may be replaced with an undeformed insert 214 to restore the seal effectiveness of the valve assembly 200. Such process eliminates reconditioning of the exit edge 212a of the inlet hole 212 during operation of the valve assembly 200, and thus reduce the operation cost and provides an easy maintenance.
According to an aspect, the proposed compressor valve assembly 200 for a reciprocating compressor 10 utilizes guide pins 224 which are disposed internally from the springs 226 and in the seal elements 230 to internally guide the springs 226 and the seal elements 230. By using the internal guidance, the guide pockets 124 of the conventional valve assembly 100 which externally guide the springs 126 and the seal elements 130 are eliminated. The number of the springs 226 and the seal elements 230 to be installed in the proposed compressor valve assembly 200 may be increased due to the elimination of the guide pockets 124. Efficiency of the proposed compressor valve assembly 200 is thus improved due to the increased number of the springs 226 and the seal elements 230.
According to an aspect, the proposed compressor valve assembly 200 for a reciprocating compressor 10 increases flow area due to the elimination of the guide pockets 124. The increased flow area of the proposed compressor valve assembly 200 increases tolerance to dirt and debris of the proposed compressor valve assembly 200.
According to an aspect, the guide pins 224 of the proposed compressor valve assembly 200 for a reciprocating compressor 10 are replaceable. The replaceable guide pins 224 may reduce an operation cost of the valve assembly 200 and provides an easy maintenance. The proposed compressor valve assembly 200 for a reciprocating compressor 10 may also include replaceable inserts 214 attached to exit edges 212a of inlet holes 212. The replaceable inserts 214 also reduces an operation cost of the valve assembly 200 and provides an easy maintenance.

Reference List:

10:: Reciprocating Compressor
11:: Crankshaft
12:: Driving Rod
13:: Crosshead
14:: Piston Rod
15:: Piston Head
16:: Piston Chamber
100:: Conventional Compressor Valve Assembly
110:: Seat
111:: Cap Screw
112:: Inlet Hole
112a:: Exit Edge of Inlet Hole
120:: Guard
122:: Outlet Holes
124:: Guide Pocket
126:: Spring
130:: Seal Element
132:: Socket
134:: Seal Head
134a:: Edge of Seal Head
200:: Inventive Compressor Valve Assembly
210:: Seat
212:: Inlet Hole
212a:: Exit Edge of Inlet Hole
214:: Insert
220:: Guard
220a:: Bottom of Guard
222:: Outlet Passage
224:: Guide Pin
225:: Venting Hole
226:: Spring
230:: Seal Element
232:: Socket
232a:: Inner Side of Socket
232b:: Outer Side of Socket
232c:: Opening End of Socket
234:: Seal Head
234a:: Edge of Seal Head
236:: Spring Landing Area
238:: Chamfered Surface
300:: Fluid Flow

Claims

A guard (220) for a compressor valve assembly (200) comprising:
a plurality of springs (226);

a plurality of guide pins (224) attached to the bottom (220a) of the guard (220) and extending out the springs (226) internally;

a plurality of seal elements (230) attached to the guide pins (224),

wherein the seal elements (230) comprise a socket (232) defining an opening (232c) to receive a guide pin (224),

wherein the seal elements (230) comprise a seal head (234) disposed on one end of the socket,

wherein the seal elements (230) comprise a spring landing area (236) residing on top of a spring (226), and

wherein the guide pins (224) are configured to guide a movement of the seal elements (230) along the guide pins (224) such that the seal heads (234) of the seal elements (230) move toward inlet holes (212) of a seat (210) of the compressor valve assembly (200) when the springs (226) extend and move away from the inlet holes (212) when the springs (226) are compressed during an operation of the compressor valve assembly (200),

the guard (220) further comprising a plurality of outlet passages (222) disposed between the seal elements (230).
The guard as claimed in claim 1, wherein the spring landing area (236) comprises an area at an opening end (232c) of the socket (232) opposite to the one end of the seal head (234) of the seal elements (230).
The guard as claimed in claim 1, wherein a portion of the socket (232) is disposed between the guide pins (224) and the springs (226).
The guard as claimed in claim 3, wherein the spring landing area (236) comprises an area at an outer side (232b) of the socket (232) at a distance from an opening end (232c) of the socket (232) and extending outwardly from the outer side (232b) of the socket (232).
The guard as claimed in claim 1, wherein the guide pins (224) are replaceable from the guard (220).
A compressor valve assembly (200) comprising:
a seat (210) comprising a plurality of inlet holes (212); and

a guard (220) attached to the seat (210),

wherein the guard (220) is a guard (220) according to any of the claims 1 to 5.
The compressor valve assembly as claimed in claim 6, further comprising an insert (214) attached to an exit edge (212a) of the inlet holes (212).
The compressor valve assembly as claimed in claim 7, wherein the insert (214) is to be replaceable from the exit edge (212a) of the inlet holes (212).
A method for operating a compressor valve assembly (200), wherein the compressor valve assembly (200) comprises a seat (210) and a guard (220) attached to each other, wherein the seat (210) comprises a plurality of inlet holes (212), the method comprising:
disposing a plurality of springs (226) in the guard (220);

attaching a plurality of guide pins (224) to the bottom (220a) of the guard (220) and extending out the springs (226) internally; and

attaching a plurality of seal elements (230) to the guide pins (224),

wherein the seal elements (230) comprise a socket (232) defining an opening to receive a guide pin (224),

wherein the seal elements (230) comprise a seal head (234) disposed on one end of the socket (232),

wherein the seal elements (230) comprise a spring landing area (236) residing on top of a spring (226), and

wherein the guide pins (224) are configured to guide a movement of the seal elements (230) along the guide pins (224) such that the seal heads (234) of the seal elements (230) moves toward inlet holes (212) of the compressor valve assembly (200) when the springs (226) extends and move away from the inlet holes (212) when the springs (226) are compressed during an operation of the compressor valve assembly (200),

the guard (220) further comprising a plurality of outlet passages (222) disposed between the seal elements (230),

wherein a fluid flow (300) enters the compressor valve assembly (200) through the inlet holes (212), impinges the seal heads (234) of the seal elements (230) and exits the compressor valve assembly (200) through the outlet passages (222).
The method as claimed in claim 9, wherein the spring landing area (236) comprises an area at an opening end (232c) of the socket (232) opposite to the one end of the seal head (234) of the seal elements (230).
The method as claimed in claim 9, wherein a portion of the socket (232) is disposed between the guide pins (224) and the springs (226).
The method as claimed in claim 11, wherein the spring landing area (236) comprises an area at an outer side (232b) of the socket (232) at a distance from an opening end (232c) of the socket (232) and extending outwardly from the outer side (232b) of the socket (232).
The method as claimed in claim 9, wherein the guide pins (224) are configured to be replaceable from the guard (220).
The method as claimed in claim 9, further comprising attaching an insert (214) to an exit edge (212a) of the inlet holes (212).
The method as claimed in claim 14, wherein the insert (214) is replaceable from the exit edge (212a) of the inlet holes (212).