Re-evaluating valve fit and functionality on production line

Abstract

The control system is configured to monitor operation of a flow control, such as a control valve. These configurations may use continuous or real-time data to assess the degree of fit or functionality of the device under operating conditions. This feature may alert an operator of a problem or problem about one or more devices or the entire production line. These problems may, for example, indicate that the size of the valve is incorrect for actual operating conditions. Thus, the engineer may find that the valve is too large (or too large) or too small (or too small) because the design process for the layout of the production line depends on the design load reflecting future maxima (plus certain safety factors), rather than the actual working conditions that may exist once the device is put into use on site.

Description

Background Art

[0001] Flow controls play a vital role in many industrial facilities. For example, power plants and industrial process facilities use different types of flow controls to manage the flow of materials (usually fluids) throughout a vast network of pipes, tanks, generators, and other equipment. During the design phase, engineers develop and lay out the structure of the production line or other distribution network at these facilities. The design process typically utilizes software to select flow controls, such as control valves. Engineers provide or input data into the software, including flow rate, pressure, material properties, and other system-related parameters. The software then identifies the appropriate size (or configuration) of valves that theoretically achieve the specific parameters on the production line. However, the "design" data may not reflect the actual operating parameters because these parameters are not known until the production line is created and the valves have been in use for some time.

[0002] Industrial plant control software can often perform diagnostics in "real time" to accommodate this lack of data during the design phase. These systems can collect information describing control valve performance, such as data defining travel or position, air usage, packing friction, etc. From this data, the system can generate values ​​to map or trend performance. By comparing these values ​​to expected thresholds (such as expected position), the system can potentially identify abnormal operations that are precursors to more damaging, problematic operations. Summary of the invention

[0003] The subject matter of the present disclosure relates to improvements in device and process diagnostics. Of particular interest herein are embodiments that can evaluate flow control devices (such as control valves) used as part of a production line. These embodiments may include systems that provide real-time analysis of control valves using data collected from the devices by the control system and data describing actual operating conditions on the production line. The use of such "operating data" can compensate for inconsistencies or incorrect assumptions made during the design phase because it takes into account the fit and function of the control valve under the actual conditions it faces in use. Thus, the system presented herein can identify various problems, such as valve undersizing or oversizing, valve cavitation, or similar performance anomalies or problems, which may not be noticed by operators and maintenance personnel using only data describing performance specific to each device. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] This specification refers to the following drawings:

[0005] Figure 1 A schematic diagram showing an embodiment of a valve control system is shown;

[0006] Figure 2 A flow chart illustrating an embodiment of a method for operating a valve control system; and

[0007] Figure 3 A flow chart of an embodiment of a method for operating a valve control system is shown.

[0008] These figures and any descriptions herein represent examples that can disclose or explain the present invention. These examples include the best mode and also enable any person skilled in the art to practice the present invention, including making and using any device or system and performing any combined method. Unless otherwise stated in the discussion, the drawings are not drawn to scale. The elements in the examples may appear in one or more of the several views or in a combination of several views. The drawings may use similar reference numerals to represent the same or corresponding elements. The method is exemplary only and may be modified by, for example, reordering, adding, deleting and / or changing the various steps or stages. This specification may use the singular form of the word "one" or "a kind" to identify such a stage and any part, component, element or function; however, this should not exclude any plural form of such a name unless the specification explicitly states or explains such exclusion. Similarly, any reference to "one embodiment" or "a specific implementation" does not exclude the existence of other embodiments or specific implementations that also combine the features.

[0009] describe

[0010] Features of the embodiments shown in the above-described figures will now be discussed. These embodiments use device-level diagnostics as part of a production line management system. These systems provide operators or facility personnel (such as technicians or engineers) with tools to understand or evaluate their assets in operation on a production line. These tools can be used to troubleshoot problems, predict potential failures, and proactively schedule maintenance. As a result, operators can better avoid long and costly downtime that could affect production. Other embodiments are contemplated within the scope and spirit of the present disclosure.

[0011] Figure 1 A schematic diagram of an example of a control system 100 is shown. The example is part of a distribution network 102, which is generally designed to transport material 104 through a network of conduits 106. A flow control 108 can be connected in series with the conduits 106. The flow control 108 can include a valve body 110 that houses a seat 112 and a closure member 114 that can be moved to a position relative to the seat 112 to regulate the flow of the material 104. A valve stem 116 can connect the closure member 114 to an actuator 118. The flow control 108 can also have a valve positioner 120 with operating hardware 122. In one specific implementation, the control system 100 can include a feedback loop 124 that provides data to a system controller 126 that generates a control signal C.

[0012] Broadly, the control system 100 can be configured to evaluate device performance. These configurations can process data that defines the actual operating conditions of the device. This data can occur in real time, or the process can periodically collect data and store the data in a repository for later processing. These features update the device analysis completed when the facility is laid out or designed. When the device is operated under conditions that may be different from, and usually are different from, those available at the layout or design stage, the result is a new value that better describes the fitness or function of the device.

[0013] Distribution network 102 can be configured to transmit or move resources. These configurations can be embodied as a huge infrastructure. Material 104 can include a gas, a liquid, or a mixture of a liquid or a gas. Conduit 106 can include a pipe or pipeline that is usually connected to a pump, a boiler, etc. The pipe can also be connected to a tank or a reservoir. In many facilities, the equipment forms a complex network.

[0014] The flow control unit 108 can be configured to regulate the flow of material 104 through the conduits 106 in these complex networks. These configurations can include control valves and similar devices. The valve body 110 in such devices is typically made of cast metal or forgings. The structure can form flanges at the openings I, O. Adjacent pipes 106 can be connected to these flanges to allow material 104 to flow through the device, for example, through the openings in the support 112. The closing member 114 can be embodied as a metal disk or a metal plug. The valve stem 116 can be embodied as an elongated cylinder or rod connected to the plug at one end. The other end of the rod can be connected to a pneumatic or electric manipulator embodied as an actuator 118.

[0015] The valve positioner 120 can be configured to process and generate signals. These configurations can control the position or "set point" of the flow control unit 108. For example, the operating hardware 122 can use electrical components and computing components (e.g., processors, memory, executable instructions, etc.). These components can also include electric-pneumatic devices. These devices can jointly process the input control signal C to generate an output actuator control signal S2 to the actuator 118 and an appropriate pressure (or other parameter) for controlling the valve 108 to supply the material 104 downstream according to the process parameters.

[0016] The feedback loop 124 can be configured to provide data that informs operating parameters on the production line. These configurations can measure various operating parameters or conditions present on, at, or near the flow control unit 108. Sensors or similar data collection mechanisms can be located throughout the pipeline or conduit, as well as on the valve. These sensors can provide device-specific information. In one example, the sensor can be embodied as a mechanical linkage that couples the valve stem 116 to a rotatable disk on the valve positioner 120. The disk can rotate in response to the mechanical linkage. This feature changes the position of the magnet relative to the flux sensor, which in turn indicates the position of the closing member 114. Other sensors may include pressure sensors, temperature sensors, humidity sensors, flow sensors, etc.

[0017] The system controller 126 may be configured to control devices on a production line. These configurations may be part of a larger control network (or "distributed control system" or "DCS"). The DCS maintains the operation of all devices on the production line to ensure that materials flow according to, for example, a specified process. In use, the system controller 124 may generate a control signal C to each of these devices. This electronic signal may define an operating parameter, such as a set point for a valve. As described above, the valve positioner 120 may convert this signal into an appropriate pressure for the actuator control signal S2 that it transmits to the actuator 118.

[0018] Figure 2 A flow chart showing an example of steps of a method 200 for operating a system controller 126 or a valve positioner is shown. The steps may correspond to executable instructions (such as a computer or software program) that configure the system controller 100 for certain operations. The instructions may, for example, process data to derive values ​​that define the operation of the flow control 108. The operations may set the flow control 108 to provide material to the process at the desired parameters. In one specific implementation, the method 200 may include, at stage 202, receiving inputs or feedback, and at stage 204, calculating performance parameters of one or more target valves based on the inputs. The method 200 may also include, at stage 206, identifying a relationship between a performance parameter and the value of one or more target valves. The method 200 may also include, at stage 208, generating an output based on the relationship.

[0019] At stage 202, the system controller 126 may receive certain inputs. These inputs may include valve position or pressure of the control signal S2. This information may also reflect data about the production line itself. This data may include parameters of the material 104, including pressure or temperature upstream and downstream of the valve. In one specific implementation, this data may also represent environmental conditions, such as temperature, relative humidity, and pressure at or around the device. As noted, this data may identify the operating conditions of the device on the production line. However, the present disclosure does contemplate that certain data may reflect "alternative" data, or data that may be selected or provided by an operator, particularly in situations where real-time data is not available or feasible.

[0020] At stage 204, the system controller 126 may calculate a performance parameter. The result may represent one of a variety of values ​​that characterize the target device when it is operating under current or "actual" operating conditions. In one specific implementation, the value may describe the valve size, for example, its flow coefficient (Cv) or similar metric. These values ​​may also describe other "key performance indicators" or "KPIs" as needed. KPIs may define noise, cavitation, valve travel or position, or fluid characteristics (such as speed, flow rate, or Mach number), etc. The algorithms and mathematical models used to achieve the KPIs may conform to industry standards. However, it is beneficial to use data that reflects actual operating conditions on the production line because the "actual" KPIs can represent a better and more accurate analysis of the performance of the target valve.

[0021] At stage 206, the system controller 126 may compare the "actual" KPI to certain thresholds. The relationship between these two values ​​may indicate a problem or potential problem with a device, production line, or process. The target device may be too large (oversized) or too small (undersized) for the process. Any of these defects may cause noise that exceeds system specifications or industry standards. Undersized valves may "starve" the process of process fluids due to their limited flow capacity. These valves may also have a higher pressure drop and in some cases lead to accumulation of upstream pressure. This accumulation produces back pressure that may damage pumps or other upstream equipment. Oversized valves may cost more and have a larger size (and weight). Devices that are larger than required are generally more difficult to control, resulting in instability in the process because the DCS must "find" the appropriate set value of the device to meet the process parameters. It is also common for the plug (or disc) in an oversized valve to operate in a position close to the seat. This position can result in higher fluid velocities, which can produce cavitation, noise, corrosion, or other operational defects that may damage components and potentially cause device failure.

[0022] At stage 208, the system controller 126 may generate an indicator. This relationship may indicate that the one or more target valves are not "suitable" for actual operating conditions on the production line. The indicator may alert the operator to this problem. In one specific implementation, the alert may provide information to the operator regarding changes in valve configuration (e.g., changes in valve trim that may remedy any of the size issues described above). The information may also identify an appropriate valve size or model that the operator may use to replace the target valve. The indicator may also provide the operator with a warning of the possibility of cavitation, noise, back pressure, etc. These warnings may be parsed on a user interface or as a message (such as an email or text message) on a connected device.

[0023] Figure 3 A flow chart of another example of method 200 is shown. This example may include, at stage 210, identifying a flow regime for the current operating conditions. The flow regime may include, for example, a "subcritical" flow regime, which may occur when the downstream pressure (P2) of the device is less than or equal to half of the upstream pressure (P1). This subcritical state may cause method 200 to continue to apply subcritical theory to calculate performance parameters at stage 212. Alternatively, the flow regime may correspond to a "critical" or "choked" flow regime in which the downstream pressure (P2) on the device is greater than half of the upstream pressure (P1). This state may limit or set an upper limit on the flow rate because any increase in pressure drop at a constant inlet pressure will not result in any increase in flow through the device. For choked flow, method 200 may continue to apply choked flow theory to calculate performance parameters at stage 214.

[0024] The flow coefficient of the liquid (C v ) can correspond to the corresponding flow state. For example, for subcritical flow, this value can be determined according to the following formula (1):

[0025]

[0026] Where q is the flow rate, P1 is the upstream pressure in absolute units, P2 is the downstream pressure in absolute units, G f is the specific gravity (of the liquid), N1 is a constant that depends on the flow and pressure units, and Fp is the pipe geometry factor. Choked flow can affect the flow coefficient according to the following formula (2):

[0027]

[0028] Where P v is the vapor pressure of the fluid at temperature T, F LP is the combined recovery factor and pipe geometry factor, and F F is the critical pressure of the liquid.

[0029] Operators can use these values ​​to differentiate valves on their production line. For example, an indicator can alert the operator to the “actual” flow coefficient (C v ) deviate from the flow control elements initially calculated during the design phase. The method 200 may also maintain a record of these values ​​to present to the operator as a reference for changes that may occur on the production line (such as changes in pressure or flow rate) that may not otherwise be visible from conventional data analysis.

[0030] Both "subcritical" and "choked" flow regimes may produce cavitation. This phenomenon may increase noise and cause damage to the flow control unit 108 and any adjacent or associated pipes 106 or equipment connected thereto. In one specific implementation, the method 200 may include the step of quantifying the cavitation value or "σ index" for both states. An indicator may correspond to an alarm to notify the operator that the σ index is higher than the use σ, thereby helping the operator avoid cavitation-induced problems on the device.

[0031] The method 200 may also include the step of quantifying other parameters. These parameters may include the percentage of opening of the valve in two states. This value defines the position of the closure member 114 relative to the support 112, which describes the contact between the closure member 114 and the support 112, preferably related to the closed position (or 0% open). These parameters may also include the step of calculating the velocity or flow rate of the material 104 when passing through the valve body 110.

[0032] In view of the foregoing, the improvements herein can help facilities maintain efficient production processes. The proposed design provides an online evaluation of valves through data reflecting operating conditions along with analysis. This feature can identify adverse effects that may occur to line valves in response to, for example, operator changes to process parameters necessary to accommodate different raw materials or other production anomalies. In one specific implementation, the design may discover fit and function issues with certain valves because the new parameters may fall outside the original "design" criteria for the valve. These issues may go undetected for some time until the valve itself fails or begins to fail before its final design for the product is known.

[0033] The examples below include certain elements or clauses, one or more of which can be combined with other elements and clauses, describing embodiments contemplated within the scope and essence of the present disclosure. The scope may include and contemplate other examples that would occur to those skilled in the art. If such other examples have structural elements that are indistinguishable from the literal language of the claims, or if they include equivalent structural elements that are indistinguishable from the literal language of the claims, these other examples are intended to fall within the scope of the claims.

Claims

1. A method, comprising: receiving data about the valve, the data reflecting the working condition of the valve on the production line; calculating valve parameters of the valve based on the data; comparing the valve parameter to a known threshold level; as well as An output is generated based on a relationship between the valve parameter and the known threshold level. The method according to claim 1 , wherein the valve parameter is a flow coefficient.

3. The method of claim 1, wherein the output identifies a fitness of the valve on the production line in relation to the operating condition.

4. The method of claim 1, wherein the output relates the size of the valve on the production line to the operating conditions.

5. The method of claim 1, wherein the output relates a percentage of opening of the valve on the production line to the operating condition.

6. The method according to claim 1, further comprising: The cavitation index of the valve is quantified.

7. The method according to claim 1, further comprising: identifying a flow regime of the valve based on the data; as well as A specific calculation theory corresponding to the flow regime is applied.

8. The method of claim 1, wherein the valve parameters are based on choked flow calculation theory.

9. The method of claim 1, wherein the valve parameters are based on subcritical flow calculation theory.

10. The method of claim 1, wherein the valve parameter describes a flow rate through the valve.

11. A control system, comprising: Controller; and a feedback loop that provides data to the controller describing the operating condition of the valve on the production line, The controller is configured to process the data according to the following operations: calculating valve parameters of the valve based on the data; comparing the valve parameter to a known threshold level; and An output is generated based on a relationship between the valve parameter and the known threshold level.

12. The control system of claim 11, wherein the valve parameter is a flow coefficient.

13. The method of claim 11, wherein the output identifies a fitness of the valve on the production line in relation to the operating condition.

14. The method of claim 11, wherein the output relates the size of the valve on the production line to the operating conditions.

15. The method of claim 11, wherein the output relates a percentage of opening of the valve on the production line to the operating condition.

16. The method according to claim 11, further comprising: The cavitation index of the valve is quantified.

17. The method according to claim 11, further comprising: identifying a flow regime of the valve based on the data; as well as A specific calculation theory corresponding to the flow regime is applied.

18. The method of claim 11, wherein the valve parameters are based on choked flow calculation theory.

19. The method of claim 11, wherein the valve parameters are based on subcritical flow calculation theory.

20. The method of claim 11, wherein the valve parameter describes a flow rate through the valve.

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