Abstract: Methods and apparatus to compensate first principle-based simulation models are disclosed. An example method to compensate a first-principle based simulation model includes applying one or more first test inputs to a process system to generate first output data, applying one or more second test inputs to a first principle model to generate second output data, generating an error model based on the first and second output data, applying input data to the first principle model to generate simulation model output data, and compensating the model data via the error model to generate compensated model output data.

Abstract: An at least partially automatic valve stem lubrication system including a source of grease lubricant, a pump and an at least partially automated control system, the control system structured and arranged such that lubricant is pumped onto a valve stem surface area as a function of the receipt of certain inputs.

Abstract: A process control system simulation technique performs real-time simulation of an actual process control network as that network is running within a process plant in a manner that is synchronized with the operation of the actual process control network. This real-time, synchronized simulation system includes a simulation process control network and a process model which are automatically updated periodically during the operation of the actual process control network to reflect changes made to the process control network, as well as to account for changes in the plant itself, i.e., changes which require an updated process model. The simulation system provides for more readily accessible and usable simulation activities, as the process control network and the process models used within the simulation system are synchronized with and up-to-date with respect to the current process operating conditions.

Abstract: Redundant metal-to-metal seals for use with internal valves are described. A plug having redundant sealing functionality for use with a poppet of an internal valve includes a tapered surface to sealingly engage a seat of the poppet. Additionally, the plug includes a seal adjacent the tapered surface and disposed in a groove defined by the plug to sealingly engage the seat.

Abstract: An integrated optimization and control technique performs process control and optimization using stochastic optimization similar to the manner in which biological immune systems work, and thus without the use of historical process models that must be created prior to placing the control and optimization routine in operation within a plant. An integrated optimization and control technique collects various indications of process control states during the on-line operation of the process, and attempts to optimize the process operation by developing a series of sets of process control inputs to be provided to the process, wherein the control inputs may be developed from the stored process control states using an objective function that defines a particular optimality criteria to be used in optimizing the operation of the process.

Abstract: An example loading regulator having an internal relief valve apparatus includes a body having a loading diaphragm disposed between a first casing and a second casing. The first casing and a first side of the loading diaphragm define a first chamber and the second casing and a second side of the loading diaphragm define a second chamber. A relief valve assembly is coupled to the loading diaphragm. The relief valve assembly includes a relief valve seat having an aperture that forms a passageway to fluidly couple the first chamber and the second chamber and a relief valve plug movably coupled to the relief valve seat. The relief valve seat is to move relative to the relief valve plug to a bleed position to allow the flow of fluid between the first chamber and the second chamber in response to an outlet pressure substantially greater than a pressure at which the loading regulator enters a lock-up condition.

Abstract: Valve stem and valve plug apparatus for use with fluid regulators are described herein. An example fluid regulator includes a flow control member having a body that includes a longitudinal bore between a first end and a second end and a valve stem is disposed in the bore of the flow control member. A connector slidably couples the valve stem and the flow control member such that the connector moves away from the flow control member to relieve the flow control member of a loading force imparted by a loading element of the fluid regulator when the flow control member sealingly engages a valve seat of the fluid regulator.

Abstract: An optimization and control system for a utility plant that uses fan based air cooled condensers controls the operation of the power generation system at the plant in conjunction with the operation of the air cooled condensers so as to run the power plant at an optimum operating point associated with minimizing or reducing the cost energy produced by the plant. The optimization and control system includes an optimizer having a numerical solver that determines values for a set of control variables associated with an optimal operating point of the plant and an expert system that oversees and modifies the control variable settings prior to providing these settings to a plant controller. The numerical solver uses an objective function and one or more models of plant equipment to determine the operating point of the plant that minimizes the cost per unit of useful energy generated by the plant.

Abstract: An example internal relief valve disclosed herein includes a relief valve seat coupled to a first end of the relief valve stem and to engage a first side of a sensing apparatus to prevent fluid flow between the first side of the sensing apparatus and a second side of the sensing apparatus when the internal relief valve is in a closed position. A bleed hole within a surface of the sensing apparatus and separate from the opening of the sensing apparatus is dimensioned to provide a controlled flow rate between the first side and the second side of the sensing apparatus when the internal relief valve is in an open position. A seal is disposed along a body of the relief valve stem upstream from the bleed hole and the valve seat to prevent fluid flow between the first side of the sensing apparatus and the second side of the sensing apparatus via the opening of the sensing apparatus when the relief valve is in the open position.

Abstract: The present invention relates generally to process control systems and devices and, more particularly, to an apparatus for and a method of implementing redundant controller synchronization for bump-less failover during normal and mismatch conditions at the redundant controllers. The redundant controllers are configured to transmit state information of the process control areas of the primary controller to the backup controller that is necessary for synchronizing the redundant controllers but is not typically transmitted to other devices during the performance of process control functions. Synchronization messages are transmitted from the primary controller to the backup controller each time one of the control areas executes to perform process control functions.

Abstract: A gas regulator includes an actuator, a regulator valve, and a secondary device. Downstream pressure feedback is provided to the actuator and the secondary device via a Pitot tube disposed within an outlet of the regulator valve. The Pitot tube has a first branch having an end connected to the actuator to place the actuator control cavity and diaphragm in fluid communication with downstream pressure within the outlet for maintaining the outlet pressure at an actuator setpoint pressure. The Pitot tube also has a second branch having an end connected to the secondary device to place the interior of the secondary device in fluid communication with downstream pressure within the outlet for responding to changes in the downstream pressure when the outlet pressure diverges from a predetermined normal operating pressure range.

Abstract: Example methods and apparatus to arbitrate valve position sensor redundancy are disclosed. A disclosed example method comprises measuring a first value representative of a position of a valve, measuring a second value representative of the position of the valve, computing a first estimated position of the valve, selecting one of the first and second values based on the first estimated position, and generating a first valve control signal for the valve based on the selected one of the first and second values.

Abstract: Methods and apparatus to charge accumulators are described. An example system to charge an accumulator apparatus includes a piston disposed within a housing to define a first chamber adjacent a first side of the piston and a second chamber adjacent a second side of the piston. A fill probe having a body and a passageway between a first end of the fill probe and a second end of the fill probe removably couples to the piston to fluidly couple to the passageway of the fill probe to the second chamber of the housing when the accumulator is in a charging condition. A valve is fluidly coupled to the piston to enable fluid flow to the second chamber of the housing via the piston when the fill probe is coupled to the piston.

Abstract: Fluid flow control members for use with valves are described herein. An example fluid flow control member for use with a valve includes a body having a first seating surface to control a flow of fluid through the valve. The body defines a second seating surface opposite the first seating surface to control a flow of fluid through the valve. Additionally, the body defines an aperture to receive a stem of the valve, and a bore surrounded by the first seating surface to receive at least one of a seal or a sliding member each of which have a first surface to be engaged by a second surface of a spring seat coupled to the stem to control a fluid flow through the valve.

Abstract: Apparatus to configure fluid regulators are described. In one example, a stem guide for use with a fluid regulator is described. The stem guide includes a body having an opening to slidably receive a valve stem and an outer surface having a plurality of circumferential seals that removably couple the body within a bore of a regulator casing and align the body with the regulator casing or a valve.

Abstract: A gas regulator includes an actuator, a regulator valve, and pressure loading device. The pressure loading device provides a pressure load to a surface of a diaphragm of the actuator to act against a downstream pressure being applied to the opposite surface of the diaphragm and being controlled by the regulator. As the downstream pressure varies and the diaphragm displaces to move a control element to regulate the downstream pressure, the pressure loading device maintains a specified load pressure. The regulator may further include a balanced trim applying a balancing force to offset a force of an upstream pressure on the control element.

Abstract: A technique of implementing performance monitoring in a power plant is appropriate to control operating parameters and factors connected with the efficiency of the energy production process in an energy marketplace that is more complex than in the past, and that takes variable costs besides the cost of fuel into account, e.g., environmental credits, equipment degradation and repair costs, electrical energy trade market factors like ramp rate, LMP (Locational Marginal Pricing) factors, the ability to deliver contracted power levels and spot transactions, etc. The technique applies a statistical analysis to collected power plant data to determine the factors that are best controlled or changed to affect (increase) the efficiency or other primary performance indication of the plant, as well as to establish baseline or best-possible operational constraints to be used to control the plant in the future.

Abstract: Field removable bonnet assemblies for use with valves are described herein. An example field removable bonnet assembly for use with internal valves includes a body that is to be removably coupled to the internal valve. The body defines a bore that is to receive a valve packing. Additionally, the field removable bonnet assembly includes a shaft having a cam assembly that is to rotatably engage a stem of the internal valve. The shaft is rotatably coupled to the body and the shaft is at least partially positioned within the bore. Further, the field removable bonnet assembly includes a removable adjuster that is externally accessible to enable an adjustment of the removable adjuster relative to the body to change a force exerted by the valve packing on the shaft. The removable adjuster is field removable to replace or repair the valve packing.

Abstract: A statistical performance evaluation system for a thermodynamic device and process uses the achievable performance derived from statistics and real-time data for the device or process to evaluate the current performance of the device or process, and to adjust the operations of the device or process accordingly, or provide feedback to an operator or other monitoring system for taking corrective actions to obtain performance approaching the optimum achievable performance. The achievable performance of the device or process is derived from data collected during operational periods when the best achievable performance is anticipated, such as after maintenance is performed, and supersedes the ideal or design performance specified by the manufacturer, which typically does not represent the actual operating conditions in the field, as the basis for evaluating the real-time performance of the device.

Abstract: Apparatus to regulate fluid flow are disclosed. The apparatus includes an example regulator valve and an example automatically-adjusting or self-adjusting amplifier valve to maintain fluid flow during low downstream demand fluid flow conditions, and to maintain the operational accuracy and stability of the regulator valve during higher downstream demand fluid flow conditions.