Controlling convective flow in a valve

Abstract

A flow disrupter is configured for use in a valve. These configurations are well-suited for applications that subject the valve to extreme temperature gradients that can cause convective flow to develop in their elongate structure and, in turn, increase thermal heat loss and disrupt operator processes. The proposed design introduces obstacles into the elongate structure. These obstacles may create transient seals that inhibit convective flow. In one implementation, this feature may reduce heat loss because it creates localized, smaller circulation zones within the elongate structure.

Description

CONTROLLING CONVECTIVE FLOW TN A VALVECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Serial No. 63 / 643,855, filed on May 7, 2024, and entitled “MULTISTAGE CONVECTION BRAKING.” The content of this application is incorporated herein by reference in its entirety.BACKGROUND

[0002] Flow controls play a significant role in many industrial settings. Power plants and industrial process facilities, for example, use different types of flow controls to manage flow of material, typically fluids, throughout vast networks of pipes, tanks, generators, and other equipment. Often these devices may find use in applications with harsh or extreme operating conditions, including both very high and very low process temperatures.SUMMARY

[0003] This disclosure describes improvements to flow controls for use under these extreme conditions. Of particular interest are embodiments of structure that can change characteristics of fluid flow that may occur inside parts of the device. This flow may result from conditions that expose the flow control to extreme temperature gradients. For example, the flow control may integrate into a “cold box” system found in facilities that produce liquid or liquified products, like liquified natural gas (LNG). The cold box houses equipment, like heat exchangers and cryogenic equipment, that cools natural gas to its liquified form. In these applications, the flow control may handle fluids at temperatures as low as -200 °C. These “cryogenic” applications may be prone to convection currents or convective flow within the structure of the flow control. This convective flow may disrupt operator’s processes because it increases thermal or heat loss from the device. The proposed design may avoid, or eliminate, these losses because it may localize any convective flows to smaller areas of the flow control. This feature may reduce thermal loss, thus alleviating operator concerns and providing flow controls that ensure stable processes.DRAWINGS

[0004] This specification refers to the following drawings:

[0005] FIG. 1 depicts a schematic diagram of an elevation view of the cross-section of an exemplary embodiment of a flow disrupter;

[0006] FIG. 2 depicts a schematic diagram of a detail view of the flow disrupter of FIG. 1;

[0007] FIG. 3 depicts a schematic diagram of an elevation view of the cross-section of the flow disrupter of FIG. 1;

[0008] FIG. 4 depicts an elevation view of an example of the flow disrupter of FIG. 1;

[0009] FIG. 5 depicts an elevation view of an example of the flow disrupter of FIG. 1;

[0010] FIG. 6 depicts an elevation view of an example of a flow disruptive feature for use on the flow disrupter of FIG. 1;

[0011] FIG. 7 depicts an elevation view of an example of a flow disruptive feature for use on the flow disrupter of FIG. 1;

[0012] FIG. 8 depicts an elevation view of an example of a flow disruptive feature for use on the flow disrupter of FIG. 1;

[0013] FIG. 9 depicts an elevation view of an example of a flow disruptive feature for use on the flow disrupter of FIG. 1; and

[0014] FIG. 10 depicts an elevation view of the cross-section of an example of a flow control that includes the flow disrupter of FIG. 1.

[0015] These drawings and any description herein represent examples that may disclose or explain the invention. The examples include the best mode and enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The drawings are not to scale unless the discussion indicates otherwise. Elements in the examples may appear in one or more of the several views or in combinations ofthe several views. The drawings may use like reference characters to designate identical or corresponding elements. Methods are exemplary only and may be modified by, for example, reordering, adding, removing, and / or altering individual steps or stages. The specification may identify such stages, as well as any parts, components, elements, or functions, in the singular with the word “a” or “an;” however, this should not exclude plural of any such designation, unless the specification explicitly recites or explains such exclusion. Likewise, any references to “one embodiment” or “one implementation” does not exclude the existence of additional embodiments or implementations that also incorporate the recited features.DESCRIPTION

[0016] The discussion now turns to describe features of the examples shown in the drawings noted above. These examples embody a flow disrupter 100 that may be configured to inhibit movement of fluid due to convective flow or currents. These configurations may form “transient” seals with other parts of the valve to prevent flow of fluid. The benefit of this design is to slow or retard convection currents that can develop in the valve. However, as noted herein, configurations of the flow disruptor 100 may permit the transient seals to “break” or “open” in response to fluid conditions, like “overpressure” that may occur due to the convection currents in the device. This feature allows the fluid to flow to avoid damage to the valve. Other examples, embodiments, and configurations are contemplated within this disclosure.

[0017] FIG. 1 depicts an example of structure for the flow disrupter 100. This example is part of a flow control 10, for example, a cryogenic or “cold box” valve that may find use on a cold box B. The flow control 10 may have an elongate structure 12, shown here to include a valve portion 14, an actuator portion 16, and a tube portion 18 disposed therebetween. The elongate structure 12 serves to minimize heat transfer that may result from a temperature gradient that exists between (extreme) cold temperatures (Ti) of fluid that flows through the valve portion 14 and ambient temperatures (T2) at the actuator portion 16. As noted herein, though, the elongate structure 12 often does not eliminate effects of this temperature gradient completely and, thus, convective flow F may still develop within the tube portion 18. This convective flow F may increase heat losses that may adversely affect operator’s processes in the cold box B.

[0018] The flow disrupter 100 may be configured to interfere with or disrupt the convective flow F. These configurations may include disruptive sections D that reside in a gap G found between the tube portion 18 and a plug extender 20. The disruptive sections D may include “flow disruptive” features that modulate convective flow F in the gap G for this purpose. The features may integrate into one or both of the tube portion 18 and the plug extender 20.

[0019] FIG. 2 depicts an example of the flow disrupter 100. This example includes flow disruptive features Di, D2, shown here as projections and recesses (or cavities) in parts 18, 20. These features may change dynamics of the convective flow F, for example, by inducing turbulence (or similar flow dynamic) to slow a rate of flow (or velocity) or to disrupt continuity of the convective flow F. In one implementation, the projections may extend from the plug extender 20 into the gap G. The recesses may form in the tube portion 18. However, this disclosure contemplates other configurations for these features, for example, that locate the projections on the tube portion 18 and the recesses on the plug extender 20.

[0020] FIG. 3 depicts an example of the flow disrupter 100. This example may include a sleeve 102 that resides in the gap G. The sleeve 102 may have a cylindrical body 104 with a central bore 106, preferably with a diameter that fits or slides over the plug extender 20. The cylindrical body 104 may have an outer surface 108 with disruptive sections 110 that may slow or prevent the convective flow F to reduce heat losses in the valve 10. In use, circulation zones Z may form between adjacent disruptive sections 110. The circulation zones Z may contain convective flow F within smaller areas of the tube portion 18, which is useful to reduce heat losses because the convective flow F is not able to flow along the entire length of the tube portion 18.

[0021] The flow disruptive features may extend from the sleeve 102 into the gap G for this purpose. In one implementation, the flow disruptive features may embody protrusions 112 that have a body 114 that circumscribes the sleeve 102. The body 114 may terminate at a tip 116. Construction of the body 114 may allow the protrusions 112 to flex or bend, for example, in response to conditions of convective flow F that may develop in the gap G. The construction may adopt designs of various shapes, dimensions, configurations, and the like. These designs may benefit from additive manufacturing (ADM) techniques, like 3-D printing. The techniques may utilize materials like plastics or polymers (including PTFE); although, this disclosure considersthat other materials (including metal(s) or metal alloys) may prevail that conform to an operator’s specifications or objectives or other design considerations.

[0022] FIG. 4 depicts an example of the flow disrupter 100. The plug extender 20 may have a shoulder 22 on one end and a groove 24 on the other. As also shown, a retaining member 26 may fit into the groove 24. Examples of the retaining member include snap rings, polymeric rings, O-rings, among others. These devices (and the shoulder 22) may operate as “stops” to prevent longitudinal movement of the sleeve 102 relative to plug extender 20. The body 114 of the protrusions 112 may locate the tip 116 in contact with an inner surface of the tube portion 18. This feature may create a seal P that may prevent or retard the convective flow F, as contemplated herein. Notably, though, the body 114 may be configured so as not to interfere with movement of the plug retainer 20 as part of normal operation of the flow control 10.

[0023] FIG. 5 depicts another example of the flow disrupter 100. The sleeve 102 may embody a single, unitary structure with a length that extends from the shoulder 22 (FIG. 2) to the groove 24 (FIG. 2) on the plug extender 20 (FIG. 2). However, in one implementation, the sleeve 102 may be shorter than the plug extender 20 or may comprise separate parts or segments 118. Construction of the sleeve 102 may arrange the segments 118 in a stack 120, which may extend longitudinally along the plug extender 20 (FIG. 2).

[0024] FIGS. 6, 7, 8, and 9 depict examples of geometry for the flow disruptive features. This geometry may include a “t-shape” 122, shown in FIG. 6, where the body 114 extends perpendicularly away from the sleeve 102. The geometry in FIG. 7 adopts an “r-shape” 124 with radius R that causes the body 114 to curve or bend in one direction or the other relative to the sleeve 102. As best shown in FIG. 8, the geometry may adopt a “k-shape” 126 with a surface that extends at an angle a relative to the sleeve 102. FIG. 9 depicts another example of the sleeve 102 that incorporates flow disruptive features on an inner surface and an outer surface of the sleeve 102. This example is useful to create the seal P with both the tube portion 18 and the plug retainer 20.

[0025] FIG. 10 depicts an example of additional structure for the flow control 10. A bonnet 30 may couple the tube portion 18 with the actuator 16 that can generate a load L. A valve stem32 may extend from the actuator 16 through the bonnet 30 into the tube portion 18. The valve stem 32 is useful to transfer the load L to the end of the plug extender 20 that has the groove 24. The other end of the plug extender 20 may couple with a closure member 34. In use, this arrangement may leverage the load L from the actuator 16 to regulate a position of the closure member 34 relative to a seat 36.

[0026] The flow control 10 may be configured for use in cryogenic applications. These configurations may include globe valves, gate valves, and ball valves. Construction of many of the parts may leverage cast or machined metals. The actuator 16 may embody pneumatic or electronic devices. The valve stem 32 may embody an elongate cylindrical rod that controls the position of the closure member 34, which in turn maintains process parameters, like pressure, temperature, or flow rate, at desired levels. The closure member 34 may embody a cylindrical “plug”, that may form a metal-to-metal seal when in contact with the seat 36. The metal-to-metal seal is effective in harsh conditions, for example, in processes that move caustic or hazardous materials or materials at very low (or very high) temperatures or pressures.

[0027] The parts 34, 36 may reside in a casing portion 38 that may be configured with flanges at openings In, Out. These flanges may connect the device in-line with conduit 40 to transfer system fluid 42 in a production facility 44, and particularly one that is configured for low or very-low temperature processes or applications. These configurations may include the cold box B that houses process equipment. System fluid 42 may comprise fluids including gases, liquids, or liquid / gas mixes. In one implementation, the system fluid may comprise natural gas. The conduit 40 may include pipes or pipelines that may connect to the cold box B, as well as to other equipment, like pumps or boilers that are part of the operator’s process line. The pipes may also connect to tanks or reservoirs. In many facilities, this equipment forms process lines or like complex process networks that can liquify, separate, or re-gasify the natural gas.

[0028] In use, the flow control 10 may receive and process signals from a control network 46 (or “distributed control system” or “DCS”). Operators rely on the DCS 46 to maintain operation of devices on their process lines, for example, to ensure that system fluid 42 flows in accordance with a process or meets certain process parameters. For example, the DCS 46 may generate a control signal S to convey operating parameters (like set point) that describe or define operationof the control valve for this purpose. The flow control 10 may include a controller 48 that employs electrical and computing components, like processors and memory storage (with data and executable instructions), to process the control signal S and set the position of the closure member 34 relative to the seat 36.

[0029] Considering the foregoing, the improvements herein can negate the impact of convective flow on heat losses in flow controls. Operators may find this feature beneficial on process lines that induce extreme temperature gradients across their valves, for example, process liens that employ cold boxes or like cryogenic technology.

[0030] The examples below may include certain elements or clauses that may be combined with other elements and clauses to describe embodiments contemplated within the scope and spirit of this disclosure. This disclosure may include and contemplate other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

CLAIMSWhat is claimed is:

1. A valve, comprising: a tube portion; a plug extender disposed in the tube portion; and a sleeve disposed over the plug extender, the sleeve comprising a disruptive section that creates a seal with the tube portion.

2. The valve of claim 1, further comprising: a flow disruptive feature disposed in disruptive section, the flow disruptive feature in contact with both the sleeve and the tube portion to create the seal.

3. The valve of claim 1, further comprising: a flow disruptive feature disposed in the disruptive section, the flow disruptive feature extending perpendicular to the sleeve and the tube portion away to create the seal.

4. The valve of claim 1, further comprising: a protrusion disposed in the disruptive section, the protrusion having an end in contact with the tube portion to create the seal, wherein the protrusion is configured to flex in response to pressure on one side.

5. The valve of claim 1, further comprising: an r-shape protrusion disposed in the disruptive section, the protrusion forming a r-shape.

6. The valve of claim 1, further comprising:a k-shape protrusion disposed in the disruptive section.

7. The valve of claim 1, further comprising: a plurality of protrusions disposed in the disruptive section, each of the protrusions spaced apart form an adjacent protrusion in a longitudinal direction along the sleeve, wherein the plurality of protrusions contact the tube portion to create the seal.

8. The valve of claim 1, wherein the sleeve extends longitudinal from a first end to a second end of the plug extender.

9. The valve of claim 1, wherein the sleeve contacts a shoulder on the plug extender.

10. The valve of claim 1, further comprising: a retaining member coupled to the plug extender proximate a first end of the sleeve.

11. A valve, comprising: a tube portion; a plug extender disposed in the tube portion; and flow disruptive features disposed between the tube portion and the plug extender.

12. The valve of claim 11, wherein the flow disruptive features are integral to the plug extender.

13. The valve of claim 11, wherein the flow disruptive features are integral to the tube portion.

14. The valve of claim 11, wherein the flow disruptive features are integral to both the tube portion and the plug extender.

15. The valve of claim 11, wherein the flow disruptive features comprises recess and projections that align with one another.

16. A method, comprising: on a valve, locating flow disrupting features in a gap between a plug extender and a tube portion of the valve to change flow of fluid therebetween.

17. The method of claim 16, further comprising: providing a plurality of protrusions that circumscribe the plug extender, the plurality of protrusions disposed in the gap.

18. The method of claim 16, further comprising: providing a plurality of recesses that circumscribe the plug extender, the plurality of recess disposed in the gap.

19. The method of claim 16, further comprising: providing a sleeve with a plurality of protrusions that circumscribe the plug extender, the plurality of protrusions disposed in the gap to create a seal that prevents flow of fluid.

20. The method of claim 16, further comprising:providing a sleeve between the tube portion and the plug extender, the sleeve forming one or more seals with the tube portion.

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