Fugitive Emissions Detection Using Valve Positioners

Abstract

A valve positioner configured to detect fugitive emissions on a valve is provided. The configuration may include a sensor located proximate to the device. The sensor may be connected to a control unit, preferably having operational hardware capable of processing the signal. This arrangement may be fixed to the structure of the valve. In one implementation, the sensor may be connected to a connection located on a circuit board. This feature allows for upgrades of the device, including during assembly or in the field, with minimal impact on design or performance.

Description

[Technical Field]

[0001] Flow control devices play a major role in many industrial facilities. For example, power plants and industrial processing facilities use different types of flow control devices to manage the flow of materials, typically fluids, throughout vast networks of pipes, tanks, generators, and other equipment. In some applications, such as those transporting hydrocarbons or fossil fuels, the performance of the flow control devices is subject to important regulatory or operating parameters to satisfy contractors, purchasers, or end users, including the allowable emissions that can be generated from the equipment. Summary of the Invention

[0002] The subject matter of this disclosure relates to improvements for addressing emissions in or around equipment on process lines. Of particular interest are embodiments that are sensitive to "fugitive" emissions. These embodiments can detect very small amounts of fluid that may emanate from components in or around flow control sections, typically valves. This feature can reduce costs and improve safety by eliminating the need for "manual" inspection of these devices, which often requires technicians to approach individual valves with handheld equipment. One advantage of the proposed approach is that it reduces labor costs because operators can extend scheduled maintenance cycles in lieu of warnings (or other indicators) of problems with their equipment. Another advantage is that it utilizes existing communications infrastructure at operator facilities. This feature can enable data, such as fugitive emission measurements, to be exchanged with a central control network for further analysis and diagnosis. [Brief explanation of the drawings]

[0003] This specification makes reference to the following drawings: [Figure 1] 1 shows a schematic diagram of an exemplary embodiment of valve control. [Figure 2]2 shows a schematic diagram of the controller of FIG. 1. [Figure 3] 2 illustrates an elevation view of one embodiment of the controller of FIG. 1. [Figure 4] 2 shows a perspective view of one embodiment of the controller of FIG. 1. [Figure 5] FIG. 1 shows a perspective view of one embodiment of a flow control section.

[0004] These drawings and any descriptions herein represent examples that may disclose or describe the invention. These examples, including the best mode, enable one skilled in the art to practice the invention, including making and using any device or system and performing any incorporated methods. The drawings are not to scale unless otherwise noted in the discussion. Elements in the examples may appear in more than one of the figures or in combinations of the figures. The figures may use like reference numerals to indicate identical or corresponding elements. Methods are merely illustrative and may be modified, for example, by reordering, adding, removing, and / or changing individual steps or stages. Although such stages, as well as any parts, components, elements, or functions, may be identified in the singular using the word "a" or "an," this should not, however, exclude a plural form of such designation unless the specification expressly states or explains such exclusion. Similarly, any reference to "one embodiment" or "an implementation" should not exclude the existence of additional embodiments or implementations that also incorporate the recited features. DETAILED DESCRIPTION OF THE INVENTION

[0005] Next, we will discuss features of each example shown in the above figures. These features address fluid leaks or emissions that may occur on process lines. Often, emissions are so small that they are difficult to detect or provide accurate measurements. However, over time, leaks can manifest in volumes that are much larger than standard or specifications. As described herein, the proposed design can address operator concerns about these "fugitive" emissions on process lines. The above design also proposes a cost-effective solution that can leverage existing computing hardware to provide operators with proactive notification of leaking gases (or other fluids) that may seep or escape from process equipment. Other embodiments are within the scope of this disclosure.

[0006] 1 shows a schematic diagram of an exemplary valve positioner 100. This embodiment is typically found in a distribution network 102 designed to transport material 104 throughout a network of conduits 106. The network 102 may include a flow control section 108 that is part of the network 102. The flow control section 108 may have an actuator 110 and a valve stem or shaft 112 that has an end that couples to a valve mechanism 114 that may include a closure member 116 and a seat 118. In one implementation, the valve positioner 100 may include a control unit 120 that couples to a sensor unit 122.

[0007] Broadly speaking, the valve positioner 100 can be configured to perform analysis or diagnostics. These configurations can embody devices that can alert operators to problems on process lines. These devices can detect fugitive emissions occurring near process equipment found in industrial environments. This feature can alert operators to the release of harmful fluids, such as chlorine gas. This feature can also reduce greenhouse gas emissions in hydrocarbon plants, as the device can alert operators to delay leaks occurring in valves or similar process equipment. Operators can then perform proactive maintenance to correct the problem, which will avoid any prolonged emissions from the equipment.

[0008] Distribution systems 102 may be configured to deliver or move these fluids. These configurations may embody vast infrastructures. Materials 104 may include gases, liquids, solids, mixtures of solids and liquids, or even mixtures of liquids and gases. Conduits 106 may include pipes or pipelines that are often connected to pumps, boilers, etc. Pipes may also connect to tanks or reservoirs. In many facilities, this equipment forms complex networks to carry out processes such as refining raw materials or manufacturing final products.

[0009] The flow control section 108 can be configured to regulate the flow of material 104 through the conduits 106 in this complex network. These configurations can include control valves and similar devices. The actuator 110 can use a pressurized fluid (such as air or natural gas) to generate a load. Often, the device can include a piston, spring(s), or flexible diaphragm for this purpose. The valve stem 112 can direct this load toward a closure member 116, which is typically a ball, plug, or disk. The load can counteract the pressure of the material 104 on the opposite side of the closure member 116. This feature can maintain the closure member 116 in a desired position relative to the seat 118. In one implementation, the desired position or "set point" can correspond to a flow parameter for the material 104 to meet process requirements or parameters.

[0010] The control unit 120 may be configured to process signals and generate signals. These components may be connected to a control network (or "distributed control system" or "DCS"), which maintains the operation of all devices on the process line to ensure that material flows according to the process. The DCS may generate control signals having operating parameters that describe or define the operation of the flow control section 108 for this purpose. The control unit 120 may include operating hardware such as electrical and computing components (e.g., processors, memory, executable instructions, etc.). These components may also include electro-pneumatic devices that operate on input pneumatic supply signals. These components ensure that the output actuator control signals to the actuators 112 are appropriate for the flow control section 108 to deliver material 104 downstream according to the process parameters.

[0011] The sensor unit 122 may be configured to detect fugitive emissions. These configurations may include devices sensitive to various fluids, often in limited or finite amounts or quantities. The devices may embody various types of detection technologies, including LIDAR detection technologies, infrared detection technologies, optical detection technologies, chemical detection technologies, etc. Technology may be prevalent to address the distance or spacing between the device and the emission source, e.g., packing material found on the flow control section 108. This technology may generate a signal that quantifies the amount of fluid in the vicinity of the device, or, for example, its presence or absence. This signal may be transmitted to the control unit 120. The operating hardware may be configured using software (or similar executable instructions) to process the signal as part of its analysis or diagnostic process.

[0012] FIG. 2 is an elevation view illustrating an example structure of the controller 100 of FIG. 1. The sensor unit 122 may include a sensor 124 sensitive to various types of emissions. In one implementation, an interface 126 may function to connect the sensor unit 124 to the control unit 120. The interface 126 may have an electrical conduit 128 having an end 130 for receiving the sensor 124. Another end 132 may mate with a connection 134 on the control unit 120. The ends 130, 132 may have appropriate threads or similar adapters for securing in a desired position. The conduit 128 itself may accept or be capable of accepting the wiring necessary to connect the sensor 124 with the electronics of the control unit 120. The present disclosure also contemplates the use of wireless technology (such as Bluetooth®) for this purpose.

[0013] 3 and 4 illustrate one example of the configuration of the control unit 120. The connection 134 may form part of a housing 136 that encloses and protects various parts, including the device's electronic or electro-pneumatic components. This housing 136 may include a manifold 138 having a manifold body 140, typically machined or formed metal, plastic, or composite. The manifold body 140 may include openings 142 for the entry or exit of a fluid, typically "instrument air" in the form of compressed air or sometimes pressurized natural gas (or, more generally, material 104). Threaded openings 144 may accept electrical connections, for example, threaded conduits such as those found on end 132 of conduit 128. These openings 144 may provide access for controlling components found on a circuit board 146. These components work in conjunction with a current-to-pressure converter 148 and a relay 150 to operate the flow control section 108. A cover 152 may mate with the manifold body 140 to enclose the electro-pneumatic components 148, 150. A separate cover 154 may enclose and protect the circuit board 146. The cover 154 may incorporate a display 156 and push-button input device 158, which act as the primary local user interface to allow an end user to interact with the controller 100. In one implementation, the gauges 160, 162 may provide an indication of flow conditions, such as pressure or flow rate, of the instrument air used by the valve positioner 100 to operate the valves 106 in the valve assembly 102.

[0014] FIG. 5 is a perspective view showing an exemplary structure of the flow control section 108. This example reflects the structure of a typical globe control valve. However, the present disclosure contemplates the use of the proposed design in any industrial valve apparatus, including rotary valves such as ball valves, butterfly valves, or globe valves. As shown, the valve body 110 may include a fluid coupling 164 forming a flow passage 166 with a flanged open end 168. The fluid coupling may enclose the valve mechanism 114 (thus, they are hidden in this view). This structure may be useful for regulating process fluids in industrial process lines typical of industries focused on chemical production, refinery production, and resource extraction. A superstructure 170 may be secured to the fluid coupling 164. The superstructure 170 may support a pneumatic actuator 172, which here is shown as having a bulbous housing 174, typically two pieces that clamp around their edges to confine a diaphragm (not shown) around its periphery. The control unit 120 can be mounted on a bracket 176, which itself is fixed to or incorporated as part of the superstructure 170. This arrangement can position the sensor unit 122 in close proximity to the fluid coupling 164, which can ultimately vent leaking gas, for example, from a packing 178 present in the valve body 110. The packing 178 can surround the valve stem 112. Also as shown, the control unit 120 can deliver instrument air at an appropriate pressure to a pneumatic actuator 172, which utilizes the pressurized fluid to generate a load. Often, this device can include a piston, spring (or springs), or flexible diaphragm for this purpose. The load can counteract the pressure of the material 104 on the opposite side of the closure member 116 to maintain the closure member 116 in a desired position relative to the seat 118. This desired position or "set point" may correspond to flow parameters for the material 104 to meet process requirements or parameters.

[0015] The following examples include particular elements or clauses to describe embodiments contemplated within the scope of this specification. These elements may be combined with other elements and clauses to similarly describe embodiments. This specification may include and contemplate other examples that occur to those skilled in the art. These other examples fall within the scope of the claims, for example, if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that differ insignificantly from the literal language of the claims.

Claims

1. A valve, An actuator; a valve positioner coupled to the actuator, the valve positioner having operating hardware for generating a pneumatic signal to the actuator; a sensor unit coupled to an open connector on the operational hardware, the sensor unit responsive to fugitive emissions; A valve comprising:

2. a valve body coupled to the actuator; The sensor unit is located adjacent to the valve body. The valve of claim 1.

3. a valve body coupled to the actuator; a packing material disposed within the valve body; Further provided with The valve of claim 1 , wherein the sensor unit is in proximity to the packing material.

4. a valve body coupled to the actuator; the sensor unit is sensitive to gas emissions originating from within the valve body; The valve of claim 1.

5. a valve stem coupled to the actuator; The sensor unit is located adjacent to the valve stem. The valve of claim 1.

6. The valve of claim 1 , wherein the sensor unit comprises an electrical conduit that connects to the valve positioner.

7. The valve of claim 1 , wherein the sensor unit comprises a wire harness that extends through the valve positioner to the opening connector.

8. A valve, a valve positioner comprising: operating hardware for generating a pneumatic signal; and a housing enclosing the operating hardware, the housing having an opening for access to the operating hardware; an electrical conduit connected to the opening; a wire harness extending through the electrical conduit and connecting to the operating hardware; a sensor connected to the wire harness; A valve comprising:

9. 9. The valve of claim 8, wherein the sensor is sensitive to natural gas.

10. 9. The valve of claim 8, wherein the electrical conduit is sized for placement of the sensor in proximity to a source of natural gas.

11. a valve body and a superstructure connected to the valve body; the valve positioner is on the superstructure; and the electrical conduit is sized to position the sensor in close proximity to the valve body; 9. The valve of claim 8.

12. a valve body; an upper structure connected to the valve body; an actuator disposed on the upper structure; and a valve stem connected to the actuator and extending into the valve body, the valve positioner is on the superstructure; and the electrical conduit is sized to position the sensor in close proximity to a valve stem; 9. The valve of claim 8.

13. a valve body having a packing material disposed therein; an upper structure connected to the valve body; an actuator disposed on the upper structure; a valve stem connected to the actuator and extending into the valve body; and a packing material disposed within the valve body and surrounding the valve stem, the valve positioner is on the superstructure; and the electrical conduit is sized to position the sensor in close proximity to the packing material; 9. The valve of claim 8.

14. 9. The valve of claim 8, wherein the electrical conduit includes a flexible portion.

15. 9. The valve of claim 8, wherein the electrical conduit comprises a threaded portion for connection with the opening in the housing.

16. A valve, An actuator; a valve stem coupled to the actuator; a valve body having an opening for receiving the valve stem; a sensor disposed proximate to the opening; a wire harness connected to the sensor; a valve positioner having a housing configured to receive the wire harness therein and to maintain the sensor in a position adjacent to the opening; A valve comprising:

17. 17. The valve of claim 16, wherein the valve positioner has operating hardware within the housing that processes signals from the sensor.

18. 17. The valve of claim 16, wherein the valve positioner has operating hardware within the housing that transmits data, including data related to signals from the sensors, to a location remote from the valve.

19. 17. The valve of claim 16, wherein the valve positioner has operating hardware within the housing that exchanges data with a control system, including data related to signals from the sensors.

20. 17. The valve of claim 16, wherein the valve positioner has operating hardware within the housing that generates a pneumatic signal to the actuator.

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