A heat recovery steam generator (HRSG) may be described as an energy recovery heat exchanger. The HRSG may recover heat from a stream of hot gas. The HRSG produces steam which may be used in a process, such as cogeneration. The steam may also be used to drive components in a plant that includes the HRSG. An example of a component includes a turbine.
The HRSG may include many components and systems, many of which are under automated control or partially automated control. Different types of models may be used to control operation of the HRSG. The accuracy of such models may also impact control of other operations related to a plant that includes the HRSG.
Features of the present disclosure are illustrated by way of examples shown in the following figures. In the following figures, like numerals indicate like elements, in which:
For simplicity and illustrative purposes, the present disclosure is described by referring mainly to examples thereof. In the following description, details are set forth in order to provide an understanding of the present disclosure. It will be readily apparent however, that the present disclosure may be practiced without limitation to these details. In other instances, methods and structures apparent to one of ordinary skill in the art have not been described in detail so as not to unnecessarily obscure the present disclosure.
Throughout the present disclosure, the terms “a” and “an” are intended to denote at least one of a particular element. As used herein, the term “includes” means includes but not limited to, the term “including” means including but not limited to. The term “based on” means based at least in part on.
According to of the present disclosure, a heat recovery steam generator (HRSG) adaptive control apparatus and methods for HRSG adaptive control are disclosed herein. The apparatus and methods disclosed herein may provide for adaptive tuning of an HRSG transient dynamic model. For example, the adaptive tuning may be based on an analysis of HRSG design operation data from a steady state model of the HRSG and plant operation data for a plant that includes the HRSG. The apparatus and methods disclosed herein may tune the HRSG transient dynamic model to match a steady state operational point of the HRSG steady state model. The tuned HRSG transient dynamic model may be implemented, for example, for HRSG operation control, HRSG fault detection, plant operation control, operator training simulation, and other such applications related to an HRSG or a plant including the HRSG.
An HRSG steady state model may be described as a computerized model of components of the HRSG. Examples of the HRSG components may include a superheater, an economizer, an evaporator, etc. According to an example, the HRSG steady state model may include and/or be executed to provide various types of data such as HRSG mechanical design data and HRSG design operation data. HRSG mechanical design data may include data that describes physical dimensions of components of the HRSG, and a number of sub-components of the HRSG. For example, the physical dimensions may include tube diameters for a superheater of the HRSG. The number of sub-components of the HRSG may include, for example, a number of tubes of the superheater. The HRSG design operation data may be described as performance data that is indicative of operational characteristics of the HRSG. The HRSG design operation data may include different temperatures associated with the HRSG components based on different input conditions. The HRSG design operation data may include other data such as steam flow rate, pressure associated with a component of the HRSG, etc.
An HRSG transient dynamic model may be described as a computerized model that represents transient behavior of the components of the HRSG. For example, an HRSG transient dynamic model may be used to predict a rate of change for different temperatures associated with the HRSG components based on different input conditions. The HRSG transient dynamic model may be used to predict other data such as rate of change for the steam flow rate, rate of change for the pressure associated with a component of the HRSG, etc.
Plant operation data may be described as data associated with operation of a plant that includes the HRSG. Examples of plant operation data may include different temperatures associated with the HRSG components based on different input conditions, steam flow rate, pressure associated with a component of the HRSG, etc.
The steady-state operational point may be described as an operational point of the HRSG for which an attribute of a component of the HRSG for the steady state model matches the attribute of the component of the HRSG for the transient dynamic model. For example, the steady-state operational point may represent a temperature of superheater outlet steam or gas temperature of the HRSG at a steady-state operational condition of the HRSG.
For the apparatus and methods disclosed herein, the steady-state HRSG mechanical design data and the HRSG design operation data from a steady state model of the HRSG, and/or from an actual reference plant, may be collected by a simulation layer data transformer. The simulation layer data transformer may apply a data transformation to the mechanical design data and HRSG design operation data to support the development of an HRSG transient dynamic model. The simulation layer data transformer may generate model parameters for the HRSG transient dynamic model. The model parameters may be populated for HRSG components such as a superheater, an economizer, an evaporator, etc. Examples of the model parameters may include tube bundle metal mass, heat transfer surface areas based on metal physical properties, tube geometries and spatial alignment, etc. The HRSG transient dynamic model may be generated by application of the model parameters to a predetermined HRSG transient dynamic model.
A model simulator may execute the HRSG transient dynamic model to generate simulation results. The model simulator may be designated as an HRSG transient dynamic model based simulator. The model simulator may receive tuning parameters to generate an HRSG tuned transient dynamic model. The tuning parameters received by the model simulator may be described as calibrated tuning parameters that are established, for example, based on past experience, prior to calibration by a model tuner.
The model tuner may dynamically calibrate the tuning parameters for the HRSG tuned transient dynamic model to match a steady-state operational point and a simulation performance for the HRSG transient dynamic model. The model tuner may be designated as an HRSG transient dynamic model tuner. The tuning parameters may include the heat transfer coefficient, friction factor, ambient losses, and other turnable factors. In this regard, the model tuner may apply a convergence criterion and a weight to dynamically calibrate the heat transfer coefficient and other tunable factors of the HRSG transient dynamic model to match the steady-state operational point and simulation performance.
The model tuner may use an integrative moving window technique to calibrate the tuning parameters. The integrative moving window technique may be described as a window of time during which plant operation data is collected for use by the model tuner. Thus the HRSG transient dynamic model may be tuned for the particular window of time.
The HRSG transient dynamic model may represent a transient dynamic model of a heat exchanger including an HRSG or a complete HRSG. For example, the HRSG transient dynamic model may represent a transient dynamic model of a superheater, an evaporator, etc., or the complete HRSG. Therefore, if the apparatus and methods disclosed herein are to control a superheater, a predetermined transient dynamic model of a superheater may be parameterized by a simulation layer data transformer to generate model parameters for the transient dynamic model of the superheater. Otherwise, if the apparatus and methods disclosed herein are to control an HRSG, a predetermined transient dynamic model of an HRSG may be parameterized by the simulation layer data transformer to generate model parameters for the transient dynamic model of the HRSG.
The HRSG-transient dynamic model may be integrated with other transient dynamic models of systems other than the HRSG. The integration may provide a high-fidelity transient dynamic model of a complete combined-cycle power plant (CCPP) for control system validation, plant operability, etc.
The simulation layer data transformer 102 may generate, based on the HRSG mechanical design data 104 and the HRSG design operation data 108, model parameters 112 for an HRSG transient dynamic model 114 of the HRSG 110.
The model parameters 112 for the HRSG 110 may include, for example, gas-side surface area, steam and water-side surface area, total tube metal mass, tube metal mass excluding fin metal mass, etc., as determined by the simulation layer data transformer 102.
An HRSG transient dynamic model updater 116 may update the HRSG transient dynamic model 114 based on the model parameters 112. That is, the model parameters 112 may be applied to the HRSG transient dynamic model 114 to update the HRSG transient dynamic model 114. Alternatively, the HRSG transient dynamic model updater 116 may update a transient dynamic model of a component of the HRSG 110 based on the model parameters 112. For example, the component of the HRSG 110 may include an economizer, an evaporator, a superheater, a water preheater, etc. The HRSG transient dynamic model 114 may include a pre-determined HRSG transient dynamic model for the HRSG 110.
A model tuner 118 may calibrate the HRSG transient dynamic model 114 relative to a particular operating point of the HRSG steady state model 106. The data associated with the particular operating point of the HRSG steady state model 106 may be determined from the HRSG design operation data 108 and plant operation data 120. The calibration of the HRSG transient dynamic model 114 may be implemented to determine a tuning parameter 122 for the HMG transient dynamic model 114. The tuning parameter 122 may include, for example, a heat transfer coefficient, a friction factor, ambient losses, and other tunable factors. As disclosed herein, the tuning parameter 122 may be applied to the HRSG transient dynamic model 114 to tune the HRSG transient dynamic model 114 such that the HRSG transient dynamic model 114 matches a steady state operational point of the HRSG steady state model 106. In this regard, tuning the MSG transient dynamic model 114 may be described as updating the HRSG transient dynamic model 114 based on application of the tuning parameter 122. The model tuner 118 may access the HRSG design operation data 108, the plant operation data 120, a convergence criterion 124, and a weight 126.
The plant operation data 120 may include real-time, and/or actual data from a plant 128. The plant operation data 120 may be used with the HMG design operation data 108, the convergence criterion 124, and the weight 126 to tune and calibrate the HRSG transient dynamic model 114.
The convergence criterion 124 may be received or otherwise determined for the HRSG 110. As disclosed herein with respect to
The weight 126 may be used to specify different weights for factors of the HRSG transient dynamic model 114 that are to be fine-tuned. For example, if a temperature associated with a superheater for the HRSG 110 is to be fine-tuned, then the weight 126 may be increased for the temperature associated with the superheater, compared to temperatures associated with other components of the HRSG 110.
With respect to the OR block 130, the plant operation data 120 may be superimposed onto the HRSG design operation data 108. For example, the HRSG design operation data 108 may be substituted with available plant operation data 120. Alternatively, the HRSG design operation data 108 for certain components may be substituted with corresponding plant operation data 120. In this regard, the OR block 130 may implement a higher accuracy representation of the HRSG transient dynamic model 114 based on selective superimposition of the plant operation data 120 onto the HRSG design operation data 108. For example, the OR block 130 may implement superimposition of the plant operation data 120 related to mass flow rate at inlets and outlets at every component of the HRSG 110 onto the corresponding HRSG design operation data 108. In this regard, the plant operation data 120 may provide for real-time updates to HRSG transient dynamic model 114.
In some examples, the elements of the apparatus 100 may be machine readable instructions stored on a non-transitory computer readable medium. In this regard, the apparatus 100 may include or be a non-transitory computer readable medium. In some examples, the elements of the apparatus 100 may be hardware or a combination of machine readable instructions and hardware.
Operation of the apparatus 100 is described with reference to
In operation, the model tuner 118 may minimize an error between HRSG transient dynamic model 114 and information that includes the steady state HRSG design operation data 108 and the steady state plant operation data 120. The model tuner 118 may minimize the error based on the convergence criterion 124. Further, the model tuner 118 may apply the weight 126 to a specified factor of the HRSG transient dynamic model 114 that is to be fine-tuned. Once the convergence criterion 124 is met, the model tuner 118 may generate the tuning parameter 122 for the HRSG transient dynamic model 114. The model tuner 118 may also generate a plurality of the tuning parameters that include, for example, a heat transfer coefficient, a friction factor, ambient losses, and other tunable factors.
The model tuner 118 may operate in an iterative manner to generate the tuning parameter 122. The iterative operation may continue until the model tuner 118 has met the convergence criterion 124. That is, for each iteration of the HRSG transient dynamic model 114, the model tuner 118 may generate an updated tuning parameter 122, which a model simulator 132 may apply to execute the HRSG transient dynamic model 114. If the convergence criterion 124 has not been met, then the model tuner 118 may determine an updated tuning parameter 122 based on an evaluation of the HRSG design operation data 108, the plant operation data 120, the convergence criterion 124, the weight 126, and simulation results 134 from execution of the HRSG transient dynamic model 114.
At block 302, if a normalized difference between information that includes the plant operation data 120 and the HRSG design operation data 108 specified as Y, and the simulation results 134 specified as Ŷ, is less than the convergence criterion 124 (i.e., if Norm{(Y−Ŷ)}<e), then the model tuner 118 may determine that the convergence criterion 124 is met. In response to a determination that the convergence criterion 124 is met, the model tuner 118 may generate the tuning parameter 122 based on the current values of the HRSG design operation data 108 and the plant operation data 120 as Y, the simulation results 134 as Ŷ, the convergence criterion 124 as e, and the weight 126 as W. The tuning parameter 122 and the indication of convergence may be forwarded to the model simulator 132. The model simulator 132 may generate an HRSG tuned transient dynamic model 136 as illustrated in
At block 304, the logic to the tuning functionality of the model tuner 118 may be enabled. For example, the logic to the tuning functionality may be enabled by selection of an ON state.
At block 306, an objective function may be implemented to minimize the difference between information including the plant operation data 120 and the HRSG design operation data 108, and the simulation results 134, where the weight 126 is applied to the difference between the information including the plant operation data 120 and the HRSG design operation data 108, and the simulation results 134 as follows: Min(Y−Ŷ)TW(Y−Ŷ)ƒ(t,U), where U is constrained between Umin and Umax (i.e., Const Umin≤U≤Umax). For block 306, U may represent constraints on the tuning parameter 122, where the tuning parameter 122 is to be tuned between Umin and Umax. U may represent a vector of a plurality of tuning parameters, where each of the plurality of tuning parameters includes a minimum value Umin and a maximum value Umax. For a single tuning parameter, U may represent a scalar. Thus, U may be constrained between Umin and Umax, irrespective of a value for U determined at block 306.
At block 308, a variety of techniques may be used for the HRSG transient dynamic model tuning for determination of an updated value of U. Examples of techniques that may be used for determination of an updated value of U includes multivariate optimization, and other such techniques.
At block 310, the updated U vector may be forwarded to the model simulator 132. The updated U vector may represent an updated tuning parameter (or tuning parameters) 122. The model simulator 132 may apply the tuning parameter 122 to the HRSG transient dynamic model 114. The results of application of the tuning parameter 122 to the HRSG transient dynamic model 114 may be forwarded as the simulation results Ŷ, which are accessed at block 300 for further iterations until the convergence criterion 124 is met at block 302.
Referring again to
The HRSG tuned transient dynamic model 136 may be implemented by a fault detector 140. For example, the fault detector 140 may implement the HRSG tuned transient dynamic model 136 to detect transmitter failure. For example, data related to pressure for a component of the HRSG 110 may be compared to actual plant data to determine whether a transmitter that detects the pressure at the plant 128 is providing an accurate reading. Based on the detected transmitter failure, the HRSG operation controller 138 may implement the HRSG tuned transient dynamic model 136 to prevent tripping of the plant 128 including the HRSG 110. An example of tripping of the plant 128 may include plant shut-down due to a pressure overload. In this regard, the HRSG tuned transient dynamic model 136 may provide for predictive maintenance of the plant 128 that includes the HRSG 110.
The HRSG tuned transient dynamic model 136 may be implemented for other operations related to the HRSG 110. For example, a plant operation controller (not shown) of the apparatus 100 may implement the HRSG tuned transient dynamic model 136 to control operation of the plant 128 including the HRSG 110. For example, the HRSG tuned transient dynamic model 136 may be used to tune various control loops of a plant transient dynamic model (not shown) to control operation of the plant 128 including the HRSG 110. With respect to tuning of the plant transient dynamic model, results from execution of the HRSG tuned transient dynamic model 136 may be used to provide operational feedback for the HRSG 110 for operational input to the plant transient dynamic model, in a similar manner as the plant operation data 120.
According to another example, the HRSG tuned transient dynamic model 136 may be implemented by an operator training simulator (not shown) of the apparatus 100 for providing training simulation of the HRSG 110 and/or the plant 128 that includes the HRSG 110. In this regard, faults may be injected into the HRSG tuned transient dynamic model 136 for training an operator, and/or ascertaining a reaction of the operator of the HRSG 110, and/or the plant 128 that includes the HRSG 110.
The processor 402 of
Referring to
At block 408, the method 400 may include accessing (e.g., by the model tuner 118) simulation results of the HRSG transient dynamic model 114 of the HRSG 110.
At block 410, the method 400 may include determining (e.g., by the model tuner 118) the tuning parameter 122 for the HRSG transient dynamic model 114 based on an analysis of the accessed information and the accessed simulation results 134.
At block 412, the method 400 may include updating (e.g., by the model simulator 132) the HRSG transient dynamic model 114 based on an application of the determined tuning parameter 122 to the HRSG transient dynamic model 114.
At block 414, the method 400 may include generating (e.g., by the model simulator 132) further simulation results 134 based on execution of the updated HRSG transient dynamic model.
At block 416, the method 400 may include determining (e.g., by the model tuner 118) whether the convergence criterion 124 is met based on an analysis of the accessed information and the generated further simulation results 134.
At block 418, in response to a determination that the convergence criterion 124 is met, the method 400 may include controlling (e.g., by the HRSG operation controller 138) operation of the HRSG 110 using the updated HRSG transient dynamic model (e.g., the HRSG tuned transient dynamic model 136).
According to examples, in response to a determination that the convergence criterion 124 is not met (e.g., block 304 of
According to examples, for the method 400, the HRSG design operation data 108 may include results of execution of a steady state model of the HRSG 110 (e.g., the HRSG steady state model 106).
According to examples, for the method 400, determining whether the convergence criterion 124 is met based on the analysis of the accessed information and the generated further simulation results 134 may further include determining whether the convergence criterion 124 is met based on an analysis of a difference (e.g., block 302 of
According to examples, the method 400 may further include accessing HRSG mechanical design data 104 for the HRSG 110 from the steady state model 106 of the HRSG 110. The method 400 may include determining model parameters 112 for the HRSG transient dynamic model 114 prior to the update of the HRSG transient dynamic model 114 based on an analysis of the accessed HRSG mechanical design data 104 and the HRSG design operation data 108. The method 400 may further include applying the determined model parameters 112 (e.g., by the HRSG transient dynamic model updater 116) to a predetermined HRSG transient dynamic model to generate the HRSG transient dynamic model 114 prior to the update of the HRSG transient dynamic model 114.
According to examples, the method 400 may further include substituting selected data for the HRSG design operation data 108 with data from the plant operation data 120. The selected data may represent data that is missing from the HRSG design operation data 108 and/or data that is identified for substitution with the data from the plant operation data 120.
According to examples, the method 400 may further include analyzing an operation of the HRSG 110 based on an application of load to the updated HRSG transient dynamic model 114, and performing fault detection operations (e.g., by the fault detector 140) based on results of the analysis of the operation of the HRSG 110.
According to examples, the method 400 may further include accessing the weight 126 to be applied to a factor of the HRSG transient dynamic model 114 prior to the update of the HRSG transient dynamic model 114. The weight 126 may be applied to the factor for fine tuning of the factor. The method 400 may include determining the tuning parameter 122 based on an analysis of the accessed information, the accessed weight 126, and the accessed simulation results 134 of the HRSG transient dynamic model 114 (e.g., by the model tuner 118) prior the update of the HRSG transient dynamic model 114.
Referring to
At block 504, the method 500 may include accessing (e.g., by the model tuner 118) simulation results 134 of the HRSG transient dynamic model 114 of the HRSG 110.
At block 506, the method 500 may include determining the tuning parameter 122 for the HRSG transient dynamic model 114 based on implementation of an objective function (e.g., block 306 of
At block 508, the method 500 may include updating (e.g., by the model simulator 132) the HRSG transient dynamic model 114 based on an application of the determined tuning parameter 122 to the HRSG transient dynamic model 114.
At block 510, the method 500 may include controlling (e.g., by the HRSG operation controller 138) operation of the HRSG 110 using the updated HRSG transient dynamic model.
Referring to
At block 608, the method 600 may include determining (e.g., by the simulation layer data transformer 102) model parameters 112 for the HRSG transient dynamic model 114 of the HRSG 110 based on an analysis of mechanical design data for the HRSG 110 from the steady state model 106 and the HRSG design operation data 108.
At block 610, the method 600 may include generating (e.g., by the HRSG transient dynamic model updater 116), based on the determined model parameters 112, the HRSG transient dynamic model 114.
At block 612, the method 600 may include accessing simulation results 134 of the HRSG transient dynamic model 114.
At block 614, the method 600 may include determining (e.g., by the model tuner 118) the tuning parameter 122 for the HRSG transient dynamic model 114 based on an analysis of the accessed information and accessed simulation results 134.
At block 616, the method 600 may include updating (e.g., by the model simulator 132) the HRSG transient dynamic model 114 based on an application of the determined tuning parameter 122 to the HRSG transient dynamic model 114. For the determined tuning parameter 122, operational performance of the updated HRSG transient dynamic model and the steady state model 106 at a steady state operation point may be generally identical. Generally identical means that the operational performance of the updated HRSG transient dynamic model and the steady state model 106 at a steady state operation point are approximately 95% (or another user defined percentage) identical.
At block 618, the method 600 may include controlling (e.g., by the HRSG operation controller 138) operation of the HRSG 110 using the updated HRSG transient dynamic model (e.g., the HRSG tuned transient dynamic model 136).
According to examples, for the method 600, determining the tuning parameter 122 for the HRSG transient dynamic model 114 may further include iteratively analyzing (e.g., as disclosed herein with respect to
What has been described and illustrated herein is an example along with some of its variations. The terms, descriptions and figures used herein are set forth by way of illustration only and are not meant as limitations. Many variations are possible within the spirit and scope of the subject matter, which is intended to be defined by the following claims—and their equivalents—in which all terms are meant in their broadest reasonable sense unless otherwise indicated.