| EMERSON PROCESS MANAGEMENT POWER & WATER SOLUTIONS INC. Patent applications |
| Patent application number | Title | Published |
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| 20120040299 | DYNAMIC MATRIX CONTROL OF STEAM TEMPERATURE WITH PREVENTION OF SATURATED STEAM ENTRY INTO SUPERHEATER - A technique of controlling a steam generating boiler system using dynamic matrix control includes preventing saturated steam from entering a superheater section. A dynamic matrix control block uses a rate of change of a disturbance variable, a current output steam temperature, and an output steam setpoint as inputs to generate a control signal. A prevention block modifies the control signal based on a saturatec temperature and an intermediate steam temperature. In some embodiments, the control signal is modified based on a threshold and/or an adjustable function g(x). The modified control signal is used to control a field device that, at least in part, affects the intermediate steam and output steam of the boiler system. In some embodiments, the prevention block is included in the dynamic matrix control block. | 02-16-2012 |
| 20120040298 | Steam Temperature Control Using Dynamic Matrix Control - A technique of controlling a steam generating boiler system includes using a rate of change of disturbance variables to control operation of a portion of the boiler system, and in particular, to control a temperature of output steam to a turbine. The technique uses a primary dynamic matrix control (DMC) block to control a field device that, at least in part, affects the output steam temperature. The primary DMC block uses the rate of change of a disturbance variable, a current output steam temperature, and an output steam temperature setpoint as inputs to generate a control signal. A derivative DMC block may be included to provide a boost signal based on the rate of change of the disturbance variable and/or other desired weighting. The boost signal is combined the control output of the primary DMC block to more quickly control the output steam temperature towards its desired level. | 02-16-2012 |
| 20120036852 | DYNAMIC TUNING OF DYNAMIC MATRIX CONTROL OF STEAM TEMPERATURE - A technique of controlling a steam generating boiler system includes dynamically tuning a rate of change of a disturbance variable (DV) to control operation of a portion of the boiler system, and in particular, to control a temperature of output steam to a turbine. The rate of change of the DV is dynamically tuned based on a magnitude of an error or difference between an actual and a desired level of an output parameter, e.g., output steam temperature. In an embodiment, as the magnitude of the error increases, the rate of change of the DV is increased according to a function f(x). A dynamic matrix control block uses the dynamically-tuned rate of change of the DV, a current output parameter level, and an output parameter setpoint as inputs to generate a control signal to control a field device that, at least in part, affects the output parameter level. | 02-16-2012 |
| 20120010758 | OPTIMIZATION SYSTEM USING AN ITERATIVELY COUPLED EXPERT ENGINE - An energy management system uses an expert engine and a numerical solver to determine an optimal manner of using and controlling the various energy consumption, producing and storage equipment in a plant/communities in order to for example reduce energy costs within the plant, and is especially applicable to plants that require or that are capable of using and/or producing different types of energy at different times. The energy management system operates the various energy manufacturing and energy usage components of the plant to minimize the cost of energy over time, or at various different times, while still meeting certain constraints or requirements within the operational system, such as producing a certain amount of heat or cooling, a certain power level, a certain level of production, etc. In some cases, the energy management system may cause the operational equipment of the plant to produce unneeded energy that can be stored until a later time and then used, or that can be sold back to a public utility, for example, so as to reduce the overall cost of energy within the plant. | 01-12-2012 |
| 20110144772 | PROCESS CONTROL AND OPTIMIZATION TECHNIQUE USING IMMUNOLOGICAL CONCEPTS - 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. The technique responds to a significant change in the current process state by determining anew set of process control inputs to be provided to the process based on one or more of the stored process control states. | 06-16-2011 |
| 20110131017 | DECENTRALIZED INDUSTRIAL PROCESS SIMULATION SYSTEM - A high fidelity distributed plant simulation technique includes a plurality of separate simulation modules that may be stored and executed separately in different drops or computing devices. The simulation modules communicate directly with one another to perform accurate simulation of a plant, without requiring a centralized coordinator to coordinate the operation of the simulation system. In particular, numerous simulation modules are created, with each simulation module including a model of an associated plant element and these simulation modules are stored in different drops of a computer network to perform distributed simulation of a plant or a portion of a plant. At least some of the simulation modules, when executing, perform mass flow balances taking into account process variables associated with adjacent simulation modules to thereby assure pressure, temperature and flow balancing (i.e., conservation of mass flow) through the entire simulation system. In a dynamic situation, a transient mass storage relay technique is used to account for transient changes in mass flow through any non-storage devices being simulated by the simulation modules. Moreover, adjacent simulation modules located in different drops communicate directly with one another using a background processing task, which simplifies communications between adjacent simulation modules without the need for a central coordinator. | 06-02-2011 |
| 20110066298 | OPTIMIZED CONTROL OF POWER PLANTS HAVING AIR COOLED CONDENSERS - 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 of each kilowatt-hour of energy or other useful 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. As part of determining the optimal plant operating point, the numerical solver may determine the number of fans to run within the air cooled condensers of the plant and/or the speed of the fans to use in the air cooled condensers in conjunction with the amount of fuel to burn in the boiler, the desired temperature of the steam at the input of the steam turbine, etc., all required to produce a given amount of power (load demand) at the particular environmental conditions currently experienced at the plant. The expert system may modify these outputs by determining which fans to actually use at any particular time based on, for example, the availability of or the operational status of the fans, the wear of the fans and fan motors, etc. | 03-17-2011 |
| 20100087933 | TWO-STAGE MODEL PREDICTIVE CONTROL TECHNIQUE - A two-stage model predictive control (MPC) controller uses a process model and two separate MPC control modules, including a feedfoward MPC control module and a feedback MPC control module, to determine a set of control signals for use in controlling a process. The feedforward MPC control module uses the process model to determine a feedforward control component for each of a set of control signals and the feedback MPC control module uses the process model and one or more measured process outputs to determine a feedback control component for each of the set of control signals. The two-stage MPC controller combines the feedforward control components with the feedback control components to form the final control signals used to control the process. The two different control modules may receive separate and different inputs from the process to determine the feedforward control components and the feedback control components and may be tuned separately, to thereby enable a control operator or other user to perform more standardized and stabilized tuning within an MPC controller environment. | 04-08-2010 |
| 20090118873 | VARIABLE RATE FEEDFORWARD CONTROL BASED ON SET POINT RATE OF CHANGE - A method of controlling a power generating unit or other process equipment with a slow reaction time includes creating a feedforward control signal to selectively include a fast response rate component or a slow response rate component based on the average rate at which a load demand set point signal has changed during a particular previous period of time. The method then uses the developed feedforward control signal to control the power generating equipment or other slowly reacting process equipment. In particular, a control method switches between introducing a fast or a slow response component within a feedforward control signal based on whether the change in the load demand set point over a particular period of time in the past (e.g., an average rate of change of the load demand set point signal) is greater than or less than a predetermined threshold. This method is capable of providing a relatively fast control action even if the expected load demand set point change is in a small range. In addition, this method does not require knowledge of the final or target load demand set point during the time in which the load demand set point is ramping up to a final target value and is not dependent on the ramp size, i.e., the ultimate difference between the load demand set point at the beginning of the load demand set point change and the final or target value of the load demand set point, making it more versatile than prior art systems. | 05-07-2009 |
| 20090063113 | Dual Model Approach for Boiler Section Cleanliness Calculation - A method of controlling soot blowers near a heat exchange section includes generating models of both the ideal clean operating condition of the section and the dirty operating condition. The current operating condition of the section is used to calculate a reliability parameter that provides an indication of the reliability of the ideal and dirty models. If the reliability parameter indicates that the models are reliable, the models are used to help evaluate the cleanliness status of a particular heat exchange section and assist in making decisions on whether to blow the section or not, and whether to make any necessary adjustments to the operating sequence of the soot blowers. If the reliability parameter indicates that the models are unreliable, the models are regenerated using additional process data. | 03-05-2009 |
| 20090038304 | Hydraulic Isolating Manifold - An isolating manifold fluidly connected between a hydraulic valve and a hydraulic manifold operates to automatically isolate the valve from the hydraulic manifold as the valve is removed from the manifold, without requiring any particular blocking and bleeding procedures to be implemented on the valve or the manifold prior to the removal process. The isolating manifold includes an adaptor removably mounted onto a base with various pressure, control and tank fluid channels disposed in alignment through the adaptor and base portions to allow fluid to flow through each of the channels between the hydraulic manifold and the valve. During operation, the valve is mounted onto the adaptor while the base is mounted onto the hydraulic manifold. The valve may be removed from the hydraulic manifold by removing the adaptor from the base, during which process, the isolating manifold operates automatically to block the pressure and control ports of the hydraulic manifold and to bleed pressurized fluid from the pressure and control channels of the valve to a tank channel so as to automatically isolate the valve from the hydraulic manifold as the valve is removed from the hydraulic manifold. | 02-12-2009 |
| 20090012653 | USE OF STATISTICAL ANALYSIS IN POWER PLANT PERFORMANCE MONITORING - 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 into account more than just the cost of fuel. In particular, this method works well when the real costs of production are dependent on other variable costs besides the cost of fuel, such as environmental credits, equipment degradation and repair costs, as well as electrical energy trade market factors like ramp rate, LMP factors, and the ability to deliver contracted power levels and spot transactions. The power plant performance monitoring 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, in whatever state or operating level the plant is run. Because heat rate calculation applications are typically performed on-line, it is possible to analyze collected plant data in detail and to apply for example, principal component analysis (PCA) and linear and nonlinear regression analysis to the data, which enables the performance method to obtain a more accurate detection of the influence of the principal process parameters that affect heat rate deviation (efficiency), as well as to establish baseline or best-possible operational constraints to be used to control the plant in the future. This performance based control methodology will allow for near optimum performance of power plants by constantly allowing for refinement and best practices and control to be realized. | 01-08-2009 |
| 20080302102 | Steam Temperature Control in a Boiler System Using Reheater Variables - A technique of controlling a boiler system such as that used in a power generation plant includes using manipulated variables associated with or control inputs to a reheater section of the boiler system to control the operation of the furnace, and in particular to control the fuel/air mixture provided to the furnace or the fuel to feedwater ratio used in the furnace or boiler. In the case of a once-through boiler type of boiler system, using the burner tilt position, damper position or reheater spray amount to control the fuel/air mixture or the fuel to feedwater flow ratio of the system provides better unit operational efficiency. | 12-11-2008 |
| 20080288198 | Method and Apparatus for Generalized Performance Evaluation of Equipment Using Achievable Performance Derived from Statistics and Real-Time Data - 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. The statistical performance evaluation system may set desired upper and lower limits for performance parameters, and compare desired limits to the actual performance parameter values to determine the readjustment to be made to the operation of the device or process. | 11-20-2008 |
