Patent application number | Description | Published |
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 |
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 |
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 |
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 |
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 |
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 |
20110010138 | METHODS AND APPARATUS TO COMPENSATE FIRST PRINCIPLE-BASED SIMULATION MODELS - 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. | 01-13-2011 |
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 |
20130204587 | ENHANCED SEQUENTIAL METHOD FOR SOLVING PRESSURE/FLOW NETWORK PARAMETERS IN A REAL-TIME DISTRIBUTED INDUSTRIAL PROCESS SIMULATION SYSTEM - A pressure and flow calculation technique can be used in a distributed process network simulation system that uses the sequential solving method to perform better or faster simulations of a process flow, especially with respect to process junction nodes at which flow either converges or diverges. The pressure and flow variable determination technique uses a grouped node identification technique that identifies a local set of nodes for each junction node of the process network to use when solving for the pressure at the junction node, a grouped node iteration technique that uses the grouped set of nodes at each junction node to perform iterative pressure calculations at the junction node, and a flow-based pressure calibration technique at each junction node to enable the system to perform highly accurate pressure and flow variable determination at each junction node in real-time. | 08-08-2013 |
20130211601 | HYBRID SEQUENTIAL AND SIMULTANEOUS PROCESS SIMULATION SYSTEM - A pressure and flow calculation technique that efficiently solves for pressures and flows within a process network uses both a simultaneous and a sequential solving method. The calculation technique first determines a flow conductance for each of the process network elements, linearizes pressure and flow relationships in each flow path by determining a linearized flow conductance for each process element and then determines a composite process network having a linearized, composite process component in each flow path to produce a simplified process network. A simultaneous solving method is then used to simultaneously solve for the pressures and flows at each of a set of junction nodes of the simplified process network and thereafter a sequential solving method is applied to determine the pressures and flows at the other nodes of the process network. | 08-15-2013 |
20140107993 | METHOD FOR DETERMINING AND TUNING PROCESS CHARACTERISTIC PARAMETERS USING A SIMULATION SYSTEM - A process characteristic parameter determination system uses a process model and a tuning module to accurately determine a value for a process characteristic parameter within a plant without measuring the process characteristic parameter directly, and may operate on-line or while the process is running to automatically determine a correct value of the process characteristic parameter at any time during on-going operation of the process. The process characteristic parameter value, which may be a heat transfer coefficient value for a heat exchanger, can then be used to enable the determination of a more accurate simulation result and/or to make other on-line process decisions, such as process control decisions, process operational mode decisions, process maintenance decisions such as implementing a soot blowing operation, etc. | 04-17-2014 |
Patent application number | Description | Published |
20120184072 | METHODS FOR MANUFACTURING SUPERJUNCTION SEMICONDUCTOR DEVICE HAVING A DIELECTRIC TERMINATION - A superjunction semiconductor device is provided having at least one column of a first conductivity type and at least one column of a second conductivity type extending from a first main surface of a semiconductor substrate toward a second main surface of the semiconductor substrate opposed to the first main surface. The at least one column of the second conductivity type has a first sidewall surface proximate the at least one column of the first conductivity type and a second sidewall surface opposed to the first sidewall surface. A termination structure is proximate the second sidewall surface of the at least one column of the second conductivity type. The termination structure includes a layer of dielectric of an effective thickness and consumes about 0% of the surface area of the first main surface. Methods for manufacturing superjunction semiconductor devices and for preventing surface breakdown are also provided. | 07-19-2012 |
20130221482 | METAL-INSULATOR-METAL CAPACITOR - A capacitor suitable for inclusion in a semiconductor device includes a substrate, a first metallization level, a capacitor dielectric, a capacitor plate, an interlevel dielectric layer, and a second metallization level. The first metallization level overlies the substrate and includes a first metallization plate overlying a capacitor region of the substrate. The capacitor dielectric overlies the first metallization plate and includes a dielectric material such as a silicon oxide or silicon nitride compound. The capacitor plate is an electrically conductive structure that overlies the capacitor dielectric. The interlevel dielectric overlies the capacitor plate. The second metallization layer overlies the interlevel dielectric layer and may include a second metallization plate and a routing element. The routing element may be electrically connected to the capacitor plate. The metallization plates may include a fingered structure that includes a plurality of elongated elements extending from a cross bar. | 08-29-2013 |
20130285201 | MIM CAPACITOR FORMATION METHOD AND STRUCTURE - Metal-insulator metal (MIM) capacitors are formed by providing a substrate having a first surface, forming thereon a first electrode having conductive and insulating regions wherein the conductive regions desirably have an area density D | 10-31-2013 |
20130292764 | Semiconductor Device with Drain-End Drift Diminution - A device includes a semiconductor substrate, source and drain regions in the semiconductor substrate, a channel region in the semiconductor substrate between the source and drain regions through which charge carriers flow during operation from the source region to the drain region, and a drift region in the semiconductor substrate, on which the drain region is disposed, and through which the charge carriers drift under an electric field arising from application of a bias voltage between the source and drain regions. A PN junction along the drift region includes a first section at the drain region and a second section not at the drain region. The drift region has a lateral profile that varies such that the first section of the PN junction is shallower than the second section of the PN junction. | 11-07-2013 |
20140264724 | DEEP TRENCH ISOLATION - An integrated semiconductor device includes a substrate of a first conductivity type, a buried layer located over the substrate, an isolated region located over a first portion of the buried layer, and an isolation trench located around the isolated region. A punch-through structure is located around at least a portion of the isolation trench. The punch-through structure includes a second portion of the buried layer, a first region located over the second portion of the buried layer, the first region having a second conductivity type, and a second region located over the first region, the second region having the first conductivity type. | 09-18-2014 |
20150050817 | METHOD OF PREVENTING VOLTAGE BREAKDOWN AT A SURFACE OF A SEMICONDUCTOR SUBSTRATE OF A SUPERJUNCTION SEMICONDUCTOR DEVICE - A superjunction semiconductor device is provided having at least one column of a first conductivity type and at least one column of a second conductivity type extending from a first main surface of a semiconductor substrate toward a second main surface of the semiconductor substrate opposed to the first main surface. The at least one column of the second conductivity type has a first sidewall surface proximate the at least one column of the first conductivity type and a second sidewall surface opposed to the first sidewall surface. A termination structure is proximate the second sidewall surface of the at least one column of the second conductivity type. The termination structure includes a layer of dielectric of an effective thickness and consumes about 0% of the surface area of the first main surface. Methods for manufacturing superjunction semiconductor devices and for preventing surface breakdown are also provided. | 02-19-2015 |