US 7,624,082 B2Granted

Correlation of plant states for feedback control of combustion

AssigneePowitec Intelligent Technologies GmbH

InventorsFranz Wintrich, Volker Stephan

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Abstract

Material (G) is converted by a combustion process in a plant (1) while air (L) is supplied. The state of the system in the plant (1) is described by state variables (x, y) and is regulated at least by one control loop (3, 5, 7, 9). Groups of states (Z) are defined for at least one pair of correlated state variables (x, y), with the groups being comparable as regards changes (dx/dt, dy/dt) of the correlated state variables (x, y). Each group of comparable states (Z) is characterized, as regards their transition functions, by parameters (Kp, Tn, Tv) of a standard controller. In the event of changes in the state of the system in the plant (1), the closest groups of comparable states (Z) are selected, and their transition functions, characterized by the parameters (Kp, Tn, Tv), are used for the purposes of regulation the system.

Claims20

Dependent claims

A method for regulating a combustion process in a plant, wherein material is converted by way of the combustion process while at least oxygen is supplied to the combustion process, and a state of a system in the plant is at least partially described with state variables, the method comprising:

regulating the system at least by way of a control loop, with the regulating of the system including
(a) identifying at least one pair of the state variables that are correlated with respect to one another;
(b) defining groups of comparable states for at least one pair of the state variables that are correlated with respect to one another, so that for each of at least some of the groups of comparable states
(1) the group of comparable states are comparable with respect to changes in the correlated state variables that correspond to the group of comparable states, and
(2) transition functions of the group of comparable states are characterized by parameters of a controller, wherein the parameters are adapted to data of actual states;
(c) selecting, in response to change from an initial state to a subsequent state of the system, one or more of the groups of comparable states that are closest to the subsequent state;
and
(d) using the transition functions of the selected one or more of the groups of comparable states in the regulating of the combustion process.

5 more elements

A plant apparatus comprising:

a control loop that includes
(a) a furnace for converting material by way of a combustion process which is supplied with at least oxygen,
(b) at least one adjusting device for adjusting how the combustion process is being supplied,
(c) a controller for regulating the combustion process by controlling at least the adjusting device, and
(d) at least one sensor for measuring one or more state variables, wherein
(1) a state of a system in the plant is at least partially described with the state variables,
(2) at least one pair of the state variables are correlated with respect to one another, and
(3) there are groups of comparable states for at least one pair of the state variables that are correlated with respect to one another, and for each of at least some of the groups of comparable states
(i) the group of comparable states are comparable with respect to changes in the correlated state variables that correspond to the group of comparable states, and
(ii) transition functions of the group of comparable states are characterized by parameters of a controller, and the parameters are adapted to data of actual states;
and
a computer for optimizing the regulating of the combustion process that is carried out by the controller, wherein the computer is configured for at least
(a) selecting, in response to change from an initial state to a subsequent state of the system, one or more of the groups of comparable states that are closest to the subsequent state, and
(b) using the transition functions of the selected one or more of the groups of comparable states in the regulating of the combustion process.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/904,427Filed 27 Sep 2007
Priority: EP 0602067230 Sep 2006
Published: US 2008/0081302 A13 Apr 2008
Granted: 24 Nov 2009
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

F23G 5/50
Incineration of waste ; Incinerator constructions; Details, accessories or control therefor: control or safety arrangements
F23N 5/203
With a time program acting through electrical means, e.g. using time-delay relays: using electronic means
F23N 2223/36
Signal processing; Details thereof: pID signal processing
F23N 2223/52
Signal processing; Details thereof: fuzzy logic