Hitachi, Ltd.

Babcock-hitachi Kabushiki Kaisha

Masahide Nomura

Hiroshi Matsumoto

Tadayoshi Saito

Hisanori Miyagaki

Makoto Shimoda

Akira Sugano

Eiji Toyama

Yoshio Sato

Hiroshi Yokoyama

Seiitsu Nigawara

Akira Kaji

Nobuyuki Yokokawa

Susumu Takahashi

Kenji Baba

Nobuo Kurihara

Yasunori Katayama

Junzo Kawakami

Atsushi Morihara

Shigeyoshi Kawano

Katsuhito Shimizu

Nobuyuki Hokari

Jinichi Tomuro

Tooru Kimura

Hiroshi Hanaoka

Atsushi Takita

Katsunori Ouchi

Haruya Tobita

Kohji Tachibana

Eiji Tohyama

Masakazu Kondoh

Yasunori Yamamoto

A power plant has two fluidized beds, one of the fluidized beds being used for generating main steam and the other being used for generating reheated steam. Further, the power plant includes a control apparatus for controlling the main steam by adjusting the fuel flow for the main steam generating fluidized bed and the fuel flow for the reheated steam generating fluidized bed so that each of the main steam temperature and the reheated temperature is maintained at a respective predetermined value.

Fluidized bed power plant, and control apparatus and method thereof

A combined cycle power generating plant has a fluidized bed furnace and a heat exchanger disposed therein, a steam turbine which is driven by steam generated in the heat exchanger and a gas turbine which is driven by combustion gas generated in the fluidized bed furnace. If the output of the whole of the plant is increased, the pressure in the fluid bed furnace is increased by supplying water into the fluidized bed furnace and then the amount of steam generated in the heat exchanger is increased by elevating the height of the fluidized bed.

Fluidized bed combined cycle power generating plant with method to

A state diagnostic system for equipment is disclosed. The system is constructed of a neural network model for learning in advance one or more samples of information on vibrations, which are produced in a specific operation state of the equipment, in association with the corresponding operation state and obtaining an output signal corresponding to results of the learning when information on vibrations produced upon operation of the equipment is inputted; an input unit for inputting to the neural network model the information on the vibrations produced upon operation of the equipment; and an output unit for outputting the output signal from the neural network model as diagnostic results to a user. State diagnostic methods, learning system, preview/predict system, diagnosis training system, service life estimation assisting system, service life estimation assisting system, and maintenance assisting system are also disclosed.

Neural network state diagnostic system for equipment

A method for controlling a controlled system by a controller such that a controlled variable can be brought into conformity with a desired value. With respect to at least one of input/output variables for a combined controlling-controlled system, which includes in combination the controller and the controlled system, and input/output variables for the controlled system, information containing its characteristics is taken out from the combined controlling-controlled system. The information with the characteristics contained therein is inputted to a neural network which has been caused beforehand to learn a correlation between the information containing the characteristics and control parameters. From the neural network, one or more of the control parameters, said one or more control parameters corresponding to a corresponding number of inputs to the neural network, are outputted to the controller.

Process control method and system for performing control of a controlled

A process control system controls a large scale plant such as thermal power plant. This process control system includes a target setting unit for setting an operation target, a control unit for receiving a signal indicating the operation target and for outputting a controlled variable to operate the process, an evaluation unit for quantitatively evaluating operation characteristics corresponding to the operation target of the process operated on the basis of a signal indicating the controlled variable supplied from the control unit, a modification unit for extracting an optimum operation process qualitatively squaring or conforming with the evaluated value derived by the evaluation unit out of a modification rule predetermining operation unit in qualitative relation between the operation characteristics and the operation target of the process and for determining the modification rate of the control unit, a storage unit having a model of a neural network for storing a relation between the operation target and the modification rate derived by the modification unit as a connection state within a circuit, and a learning unit for making the model of the neural network learn the relation between the operation target and the modification rate.

Process control system and power plant process control system

A process controller having a setting section for giving a target value for a fixed period of time, a control section including a predicting section for predicting a process response for the fixed time period in accordance with a current value of a process control amount and a virtual value of an operation amount; a quantitating section for quantitating a difference between the target value and the result by the predicting section; a calculating section for calculating a basic signal of the operation amount in accordance with the quantitated result, and an optimizing section including a predicting section for predicting a process response for the fixed time period with a control amount and an initial operation amount of the process; another quantitating section for quantitating a difference between the prediction and the target value, a calculating section for calculating the operation amount in accordance with the second quantitated result; and a section for performing control in such a way that the quantitating result and a predetermined evaluation criterion are compared with each other to perform an evaluation. The calculated result of the operation amount is repeatedly applied to the predicting section until the evaluation criterion is satisfied, a correcting signal used for optimizing the operation amount is obtained from a value of the operation amount when the quantitated result satisfies the criterion, and the correcting signal is added to a basic signal of the control section, and the adding result is output to the process.

Process controller for controlling a process to a target state

A process control apparatus and a process control system for observing the waveform of the deviation between a set point which controls the process in a control loop and the process controlled variable transmitted from the process so that the operating parameters are adjusted in accordance with a predetermined adjustment rule by using the deviation based upon the absolute value of a wave for every half cycle of the wave. Therefore, even if the process controlled variable is influenced, the area of the wave cannot be changed significantly. As a result, the operating parameters can be adjusted correctly, causing the process controlled variable to quickly coincide with the set point.

Process control apparatus and method for adjustment of operating

A digital controlling device in which arithmetic operations are executed under control of a predetermined program on the basis of an input signal obtained from at least one detector in a section to be controlled to generate a driving signal, said driving signal being sent to actuating means in said controlling section. Said digital controlling device comprises a plurality of calculation specification tables for respectively describing therein an operation type for each arithmetic element, storage addresses of input/output data for said each arithmetic element, and storage addresses of operation parameters for the each arithmetic element; a calculation sequence table for describing therein the number of arithmetic blocks and addresses used for reading-out of associated said calculation specification tables corresponding to said arithmetic elements in an order that arithmetic operations are to be executed in said digital controlling device, said calculation sequence also being a total arithmetic element number at its leading address; data tables for respectively describing therein data in the corresponding address zones specified in said calculation specification tables; and a processing program section for executing said operation elements in said order described in said calculation sequence table and reading data necessary for said execution from said data tables on the basis of associated said calculation specification tables.

Digital controlling device

A system and method for the adaptive control of a process in which a feed forward control signal corresponding to a process demand is calculated according to a predetermined algebraic function, while a feedback correction signal is calculated on the basis of an error of a process feedback signal indicative of an error of a controlled variable from a predetermined setting, and the controlled variable of the process is controlled on the basis of the sum of these two signals. The adaptive control is such that, when a set point of the function deviates from the actual process demand, a value corresponding to the error appears in the feedback correction signal, and this value is used for automatically modifying the function itself to ensure the adaptive control of the process. A determination is made whether or not the process is in the steady state and when steady state operation is determined, the function of the feed forward control signal is modified.

System and method for adaptive control of process

A speed control device is constituted of an acceleration control device used for starting a turbine, a constant speed control device used for the constant speed operation of the turbine and a selection circuit for selecting that one of the outputs of the control devices which makes smaller the opening of an adjustable valve provided at the entrance of the turbine. The output of the selection circuit determines the opening of the valve. The speed control device is so designed that the speed regulation may affect only the loop gain of the constant speed control system. For this purpose, the speed regulation circuit is provided, for example, between the subtractor of the constant speed control device and the selection circuit.

Device for controlling speed of turbine

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Hitachi, Japan

Masahide Nomura