JP5277036B2 - Temperature control device for sludge incinerator and temperature control method for sludge incinerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a temperature control device of a sludge incinerator and a temperature control method of the sludge incinerator capable of stably controlling a temperature to keep a temperature of a freeboard section at a high temperature while keeping a temperature of a sand layer section at a constant temperature. <P>SOLUTION: Model prediction control is performed in a state that temperatures of the freeboard intermediate section 3 and a freeboard upper section 4 have different target values under constraint conditions that the temperature of the freeboard intermediate section 3, the temperature freeboard upper section 4, a flow rate of fuel 12 supplied to a lower section 5 of a sand layer section, an air volume of flowing air 16 supplied to the lower section 5 of the sand layer, and air volumes of the air 17, 18 supplied to the freeboard intermediate section 3 and the freeboard upper section 4 are control input, a flow rate of the fuel 12, the air volume of flowing air 16, and air volumes of supplied air 17, 18 are control output, and the flow rate of the fuel 12 and/or the air volume of flowing air 16, and the air volumes of the supplied air 17, 18 are kept within prescribed ranges. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  This invention has a sand layer part and a free board part, burns the sludge supplied to the sand layer part, and further burns in the free board part. Temperature control device for fluidized bed sludge incinerator and sludge incinerator This relates to a temperature control method.

  Conventionally, fluidized bed incinerators are frequently used as incinerators that efficiently and reliably burn incinerated materials such as sludge in a short time. In this fluidized bed incinerator, fluidized / combustion air is blown into a fluidized bed through a nozzle to cause the sandy layer constituting the fluidized bed to flow, utilizing the excellent heat transfer characteristics of the sanded layer and the sand. It has a free board which is a combustion chamber for crushing and gasifying the incinerated material and burning the generated gas.

Japanese Patent Laid-Open No. 10-233201

By the way, in order to cope with recent environmental problems, it is desired to reduce greenhouse gases such as N ₂ O discharged from the sludge incinerator. In order to reduce the greenhouse gas, it is effective to increase the temperature of the free board portion and increase the degree of complete combustion. For example, the greenhouse gas is reduced by about 70% by raising the temperature of the free board portion from 800 ° C. to 850 ° C. On the other hand, the temperature of the sand layer portion needs to be maintained at a certain temperature or higher so that combustion is maintained, and therefore it is necessary to increase the fuel.

  Here, since the conventional PID control can be controlled only for a single target value, a plurality of target values for maintaining the temperature of the freeboard portion at a high temperature while maintaining the temperature of the sand layer portion at a constant temperature. If there is, temperature control is performed by cascade control, etc., but in this case, the flow rate of fuel interferes with the flow rate of flowing air, and excessive supply of fuel due to excessive supply of flowing air occurs, or the temperature of the sand layer part There is a case where the combustion stop due to the lowering may occur, and the stable combustion control may not be performed.

  The present invention has been made in view of the above, and can stably perform temperature control for maintaining the temperature of the freeboard portion at a target high temperature while maintaining the temperature of the sand layer portion at a target constant temperature. An object of the present invention is to provide a temperature control device for a sludge incinerator and a temperature control method for a sludge incinerator.

  In order to solve the above-described problems and achieve the object, a temperature control device for a sludge incinerator according to the present invention has a sand layer part and a free board part, and burns sludge supplied to the sand layer part, A temperature control device for a fluidized bed sludge incinerator that further combusts in the freeboard section, the temperature of the sand layer section, the temperature of the freeboard section, and the flow rate of fuel supplied to the lower part of the sand layer section, The flow rate of the flowing air supplied to the sand layer portion and the air volume supplied to the freeboard middle portion and the upper portion of the freeboard are used as control inputs, and the flow rate of the fuel and the flow rates of the flowing air and the supply air are And the temperature of the sand layer portion and the freeboard portion are different from each other under the constraint condition that the flow rate of the fuel and / or the flow rate of the flowing air and the supply air are within a predetermined range. And performing model predictive control as a target value.

  Further, in the temperature control device for a sludge incinerator according to the present invention, in the above invention, the constraint condition is that a theoretical flow rate of air necessary for the combustion of the sludge and a theoretical air volume of air necessary for the combustion of the fuel are determined. The air ratio of the flowing air supplied from the lower part of the sand layer and the air supplied from the middle part of the free board is set within a predetermined range with respect to the total theoretical air volume.

  The temperature control device for a sludge incinerator according to the present invention is the above-described invention, wherein the value of the evaluation function indicating the prediction result of the flow rate of the fuel and the flow rate of the flowing air, which is the control output, is a minimum when it is less than a predetermined value. Model predictive control is performed so that

  Moreover, in the temperature control device for a sludge incinerator according to the present invention, in the above invention, when the minimum value of the evaluation function is obtained under the constraint condition, the element of the evaluation function is outside the constraint condition, A penalty function in which an allowable error is given to the upper and lower limits of the predetermined range of the constraint condition to widen the predetermined range of the constraint condition, the expanded constraint condition is used as a modified constraint condition, and the square of the allowable error is multiplied by a predetermined weight A function obtained by adding to the evaluation function is a modified evaluation function, and the minimum value of the modified evaluation function is obtained under the modification constraint condition.

  Further, in the temperature control device for a sludge incinerator according to the present invention, in the above invention, the temperature of the sand layer part and / or the temperature of the free board part is a plurality of temperatures, and each different temperature is targeted. Model predictive control is performed as a value.

  Further, the temperature control method of the sludge incinerator according to the present invention comprises a fluidized bed type having a sand layer part and a free board part, burning the sludge supplied to the sand layer part, and further combusting in the free board part. A temperature control method for a sludge incinerator, wherein the temperature of the sand layer part, the temperature of the free board part, the flow rate of fuel supplied to the lower part of the sand layer part, and the flow rate of fluidized air supplied to the sand layer part And the flow rate of the fuel and the flow rate of the flowing air and the supply air as control outputs, and the flow rate of the fuel and / or Model predictive control is performed by setting each temperature of the sand layer portion and the free board portion as different target values under a constraint condition in which the air volume of the flowing air and supply air falls within a predetermined range. And features.

  Further, in the temperature control method for a sludge incinerator according to the present invention, in the above invention, the constraint condition is that a theoretical flow rate of air necessary for the combustion of the sludge and a theoretical flow rate of air necessary for the combustion of the fuel are determined. An air ratio that is a ratio of an actual air flow rate to a total theoretical flow rate is set within a predetermined range.

  Also, in the temperature control method for a sludge incinerator according to the present invention, in the above invention, the value of the evaluation function indicating the prediction result of the flow rate of the fuel and the flow rate of the flowing air and supply air as the control output is a predetermined value. The model predictive control is performed so as to be minimized below.

  Further, in the temperature control method for a sludge incinerator according to the present invention, in the above invention, when the minimum value of the evaluation function is obtained under the constraint condition, the element of the evaluation function is outside the constraint condition, A penalty function in which an allowable error is given to the upper and lower limits of the predetermined range of the constraint condition to widen the predetermined range of the constraint condition, the expanded constraint condition is used as a modified constraint condition, and the square of the allowable error is multiplied by a predetermined weight A function obtained by adding to the evaluation function is a modified evaluation function, and the minimum value of the modified evaluation function is obtained under the modification constraint condition.

  Further, in the temperature control method for a sludge incinerator according to the present invention, in the above invention, the temperature of the sand layer part and / or the temperature of the free board part is a plurality of temperatures, and each different temperature is targeted. Model predictive control is performed as a value.

  According to this invention, the temperature of the sand layer portion, the temperature of the free board portion, the flow rate of the fuel supplied to the lower portion of the sand layer portion, the air volume of the flowing air supplied to the sand layer portion, the middle portion of the free board, and The flow rate of air supplied to the upper part of the freeboard is used as a control input, the flow rate of fuel and the flow rate of flowing air and supply air are used as control outputs, and the flow rate of fuel and / or the flow rate of flowing air and supply air are predetermined. Since the model predictive control is performed with the temperature of the sand layer part and the free board part as different target values under the constraint conditions that fall within the range, the temperature of the sand layer part is maintained at a constant temperature. Temperature control to maintain the temperature of the board part independently at a high temperature can be performed stably, and the flow rate of fuel and the flow rate of flowing air can be reduced due to constraints. Since it is, it is possible to further suppress the generation of greenhouse gases in addition to the high temperature of the freeboard section.

FIG. 1 is a schematic diagram showing a schematic configuration of a sludge combustion system including a control device according to Embodiment 1 of the present invention. FIG. 2 is a block diagram showing model prediction calculation processing in the control device. FIG. 3 is an explanatory diagram for explaining the optimum value calculation of the evaluation function in the model prediction calculation process. FIG. 4 is a diagram illustrating a measurement result by model predictive control. FIG. 5 is a diagram comparing the case where model predictive control is applied and the case where combined control of a plurality of PID controls is applied. FIG. 6 is a flowchart showing an optimization function processing procedure for evaluation function according to Embodiment 2 of the present invention.

  Hereinafter, a temperature control device for a sludge incinerator and a temperature control method for a sludge incinerator, which are embodiments for carrying out the present invention, will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a schematic diagram showing a schematic configuration of a sludge combustion system including a control device according to Embodiment 1 of the present invention. As shown in FIG. 1, the sludge combustion system 1 has a sludge incinerator 2. The sludge incinerator 2 has a substantially cylindrical shape, and in the furnace is a sand layer portion 5 that forms a fluidized bed, a freeboard middle portion 3 that is an upper space of the sand layer portion 5, and an upper space of the freeboard middle portion 3. And a free board upper part 4.

  The sludge 10 is supplied to the freeboard middle part 3 through the sludge flow rate detector 20 and the sludge supply part 11. Fuel 12 is supplied to the sand layer portion 5 through a valve 41, a fuel flow rate detector 21, and a fuel supply portion 13. The opening degree of the valve 41 is controlled by the fuel flow rate regulator 31 so that the fuel flow rate detected by the fuel flow rate detector 21 becomes the control amount instructed from the control device C.

  Primary air 16, secondary air 17, and tertiary air 18 are supplied to the sand layer portion 5, the freeboard middle portion 3, and the freeboard upper portion 4, respectively. The fluid blower 14 supplies the fluid air 15 to the heat exchanger 19 via the fluid air detector 15 that detects the air volume of the fluid air 15. The heat exchanger 19 heats the flowing flowing air 15 to a predetermined temperature and branches and outputs it to the valves 42, 43 and 44. The primary air temperature controller 32 controls the valve 42 based on the detection result of the primary air flow rate detector 22 so as to supply the controlled air C 16 instructed by the controller C to the sand layer 5. Opening control is performed. Further, the secondary air temperature controller 33 is based on the detection result of the secondary air flow rate detector 23 so as to supply the secondary air 17 of the control amount instructed from the control device C to the freeboard middle part 3. The opening degree of the valve 43 is controlled. Further, the tertiary air temperature regulator 34 is based on the detection result of the tertiary air flow rate detector 24 so as to supply the controlled air tertiary air 18 instructed by the control device C to the freeboard upper part 4. The opening degree of the valve 44 is controlled. A valve 51 is provided on the upstream side of the flow blower 14. The flowing air regulator 50 controls the opening degree of the valve 51 so as to supply the controlled amount of flowing air 15 instructed from the control device C based on the detection result of the flowing air detector 25. Here, the flow air regulator 50 may control the opening degree of the valve 51 so that the flow rate is not a control amount from the control device C but a predetermined constant flow air flow rate. This is because the primary air 16, the secondary air 17, and the tertiary air 18 can be adjusted by the primary air volume regulator 32, the secondary air volume regulator 33, and the tertiary air volume regulator 34, respectively. Because.

  Here, in the free board middle part 3, a thermocouple group 26 composed of five thermocouples is distributed as a plurality of temperature detection parts. In addition, a thermocouple group 27 composed of five thermocouples as a plurality of temperature detection units is dispersedly arranged on the free board upper portion 4.

  In the sludge incinerator 2, the sludge 10 supplied to the freeboard middle part 3 in the freeboard middle part 3 is supplied with the fuel 12 and the primary air 16 supplied from the sand layer part 5 and the secondary supplied to the freeboard middle part 3. It burns with air 17. Furthermore, in the free board upper part 4, the incompletely burned part in the free board middle part 3 is completely burned using the tertiary air 18. The gas burned by the free board upper part 4 is discharged out of the furnace as the exhaust gas 28.

  Here, the control device C includes a sludge flow rate detector 20, a fuel flow rate detector 21, a primary air flow rate detector 22, a secondary air flow rate detector 23, a tertiary air flow rate detector 24, and a flowing air detector 25. , Sludge flow rate, fuel flow rate, primary air flow rate, secondary air flow rate, tertiary air flow rate, and flowing air flow rate are input, and the sand layer temperature and free board temperature are input from thermocouple groups 26 and 27, respectively. Then, the control device C supplies the fuel flow rate controller 31, the primary air flow rate adjuster 32, the secondary air flow rate adjuster 33, and the tertiary air flow rate adjuster 34 to the fuel flow rate and the primary air flow rate as control amounts, respectively. Outputs secondary air volume and tertiary air volume.

  The control device C is configured so that the input sand layer temperature and freeboard temperature are maintained at the set temperatures, and the fuel flow rate, the primary air flow rate, the secondary air flow rate, and the tertiary air flow rate are reduced. Predictive control is performed, and control values for each flow rate and air volume are output to the fuel flow rate detector 21, the primary air flow rate detector 22, the secondary air flow rate detector 23, and the tertiary air flow rate detector 24, respectively. The fuel flow rate detector 21, the primary air flow rate detector 22, the secondary air flow rate detector 23, and the tertiary air flow rate detector 24 perform food back control by PID control based on the input control values. Do it separately.

  The control device C includes a model prediction calculation unit 100 as shown in FIG. 2, and the model prediction calculation unit 100 performs model prediction control. Note that model predictive control is control that predicts future outputs and states based on a system model, solves an optimal control problem at fixed time intervals, and determines an input at that time. Moreover, the multi-input / multi-output control peculiar to the modern control is enabled, and the interference of the control amount does not occur. In particular, this model predictive control is attracting attention as a control method capable of handling the constraint conditions because the constraint conditions can be easily described. When this sludge incinerator 2 is controlled, the supply amounts of fuel and air are unknown control amounts that greatly depend on the size of the furnace, etc. As a constraint condition, the supply amounts of fuel and air are applied, and the supply amounts of fuel 12 and air are predicted and controlled while maintaining a plurality of temperature target values of the freeboard middle part 3 and the freeboard upper part 4 at a constant temperature. Can do.

  The model prediction calculation unit 100 generates a dynamic model of the sludge combustion system 1 in advance. Since it is difficult to construct a precise physical model, a step response model is generated here. The step response model is expressed by time and value until the step response when the step input is saturated. In this embodiment, the five sand layer temperatures detected by the thermocouple group 26, the five free board temperature detected by the thermocouple group 27, the air volume of the primary air 16, the air volume of the secondary air 17, 3 A step response model for the air volume of the next air and the flow rate of the fuel 12 is generated.

Further, the model prediction calculation unit 100 describes the air ratio constraint condition in the step response model. As described above, the control amounts of the fuel and air are unknown, and the constraint condition of the air ratio is described in the step response model when controlling the fuel and air. Here, the air ratio is the ratio of the minimum required theoretical air amount A for completely burning the fuel to the actually supplied air amount B. For example, the air ratio AFR is:
AFR = fair / (ηcake · fcake + ηfuel · ffuel)
As shown. Here, ηcake is a sludge theoretical air ratio necessary for complete combustion of sludge, fcake is a sludge flow rate, ηfuel is a fuel theoretical air ratio necessary for complete combustion of fuel, and ffuel is , The fuel flow rate. In the air ratio AFR, a constraint condition that falls within the range between the upper limit air ratio rmax and the lower limit air ratio rmin is described.

  The model prediction calculation unit 100 performs model prediction calculation based on this model. In order to perform this model prediction calculation, as shown in FIG. 2, first, five sand layer temperatures, five free board units The temperature setting temperature value 101 is input. Further, the constraint condition 102 which is the condition value of the above-described constraint condition is input. For example, the upper limit value and the lower limit value of the air ratio described above. For example, the upper limit value of the freeboard section upper temperature may be input as a constraint condition. Further, the calculation condition 103 is input. The calculation conditions are set scales and calculation parameters necessary for actual calculation, such as a calculation period (sampling period) and a prediction period.

  The model prediction calculation unit 100 to which such setting processing has been performed acquires the current temperature 110 from the thermocouple groups 26 and 27, performs prediction calculation for maintaining the temperature set value 101 for the current temperature, and fuel. The current manipulated variable 120 of the flow rate of air and the air flow rate of air are input within the range where the constraint condition is input and the manipulated variable 130 for the next time of the flow rate of fuel and the air flow rate of air is output.

  In addition, solid content of sludge is calculated | required by solid content = sludge flow volume x (1-water content), and a combustion content can be known from the composition analysis result of this solid content. Since this combustion component is involved in the calculation of the “required combustion air volume from sludge” related to the air volume, a step response model of the sludge flow rate is generated and incorporated into the model predictive control. Can be suppressed.

  As shown in FIG. 3, the outline of the model prediction calculation is as follows. The known parameter 201 and the current input / output value 202 at the current time (time k) are set as initial values, and the set parameter 203 is used for every predetermined sampling time (k + 1, k + 2, ..., k + N: N is an integer), a state equation representing the predicted input value 200 and the predicted output value 204 is obtained, and an evaluation function J is generated using the predicted output value 204, and an optimal solution for this evaluation function J is obtained. That is, the optimum value calculation for obtaining the minimum value is performed. This optimum value calculation satisfies the constraint condition 102 such as the air ratio, finds the minimum value of each element including the distance of the control error between the temperature setting value 101 and the predicted temperature value, and calculates the predicted input value 200 at this time as Output as a time operation amount 130.

  As a result, temperature control values such as the sand layer temperature and freeboard temperature are controlled so as to be maintained at a plurality of target values, and the fuel flow rate and air flow rate are within a predetermined range and stable control can be performed. it can.

  FIG. 4 is a time chart showing measurement results when model predictive control is applied to an actual sludge combustion system. The operating conditions of the measurement target system are as follows: sludge supply rate is 80 kg / h, water load indicated by water supply rate W is 14 kg / h (corresponding to a water content of 3%), and the target value T2S of the freeboard middle temperature T2 is 850. The target value for the sand layer temperature T1 is 700 ° C.

  In FIG. 4, when the water supply amount W is added, the fuel flow rate G and the secondary air flow rate F2 increase with this water load, but the sand layer temperature T1, the freeboard middle temperature T2, which are different target values, Each of the freeboard upper temperature T3 is maintained at the target value regardless of the water load. On the other hand, the fuel flow rate G is controlled to be equal to or lower than the fuel flow rate upper limit value GU, and the primary air flow rate F1 is also limited to be equal to or lower than the primary air upper limit value F1U.

  FIG. 5 is a diagram comparing the measurement results of control responsiveness between the model predictive control used in Embodiment 1 of the present invention and the combination control of a plurality of PID controls. FIG. 5 shows the control response characteristics of the sand layer temperature when the water supply is stopped. In the case of the conventional PID control, the recovery time or convergence time from when the water supply is stopped until the sand layer temperature reaches the target value is 70 minutes, but in this Embodiment 1, the recovery time is 43 minutes. Yes. Moreover, the deviation of the target value after the water supply is stopped is also smaller than that of the conventional PID control.

  In the first embodiment, a model to which an air ratio constraint is added is generated, model predictive control is performed based on the model, and a plurality of temperatures including a high freeboard temperature are stabilized as independent target values. Can control. In addition, since the fuel flow rate and air flow rate are controlled to satisfy the constraints, there is no interference between the fuel flow rate and air flow rate, and in addition to high-temperature freeboard temperature control, the fuel flow rate and air flow rate are reduced. As a result, the greenhouse gas can be suppressed and reduced.

(Embodiment 2)
In the model predictive control according to the first embodiment, the calculation is performed with a constraint condition. However, when a severe constraint condition is given, the optimization calculation result of the evaluation function becomes impossible or there is no solution within the constraint condition. The optimization calculation may stop.

Therefore, in this second embodiment, the penalty function f is added to the evaluation function J of the first embodiment.
f = ρε ²
To perform optimization. Here, ε is a tolerance value, and ρ is a weight value.

In the optimization calculation of the first embodiment, the following calculation is performed on the evaluation function J. That is, the minimum value of the evaluation function J is calculated under the constraint condition that the element y (τ) is within the range between the upper limit value ymax and the lower limit value ymin.
min (J) subject to ymin ≦ y (τ) ≦ ymax
On the other hand, in the second embodiment, the following calculation is performed using the penalty function f = ρε ² . That is,
min (J + ρε ² ) subject to ymin−ε ≦ y (τ) ≦ ymax + ε
It is. This is because the upper limit value and the lower limit value are expanded by an allowable error ε, the minimum value of the evaluation function (J + ρε ² ) is substantially larger than the minimum value of only the evaluation function J, and a penalty function is added. Even when the minimum value is obtained, the minimum value is not selected. As a result, the calculation of the evaluation function does not stop.

  In particular, when the system is started up, if the constraints are severe, the evaluation function may not be optimized. If the evaluation function cannot be optimized, the system startup time will increase. End up. In the second embodiment, continuous system control can be maintained by introducing the penalty function described above, and the system startup time can be shortened.

  Here, with reference to the flowchart shown in FIG. 6, the evaluation function optimization calculation processing procedure according to the second embodiment will be described. First, an optimization calculation for only the evaluation function J is performed without adding a penalty function (step S101). Thereafter, it is determined whether or not the result of the optimization calculation is out of a constraint condition such as no solution (step S102).

If it is outside the constraint (step S102, Yes), the introduced penalty function f = ρε ² described above, spread the upper and lower limits of constraint only allowable error ε min, the evaluation function J in the penalty function f = Ρε ^{2 is} added (step S103), and an optimization calculation is performed (step S104).

  Thereafter, the process proceeds to step S105, or if it is not outside the constraint condition (step S102, No), the process proceeds to step S105 to determine whether or not there is a next optimization operation (step S105). If there is an optimization operation (step S105, Yes), the process proceeds to step S101 and the above-described processing is repeated. If there is no next optimization operation (step S105, No), this processing ends.

  In the second embodiment, since the above-described penalty function is introduced so that the optimization calculation can be continuously performed, the robustness of the control can be improved. In particular, when the system tends to become unstable, such as when the system is started up, it is preferable to introduce a penalty function to perform the optimization calculation.

  In addition, the temperature control apparatus and temperature control method which were mentioned above are applicable other than a sludge incinerator. For example, it can be applied to a control system or the like in which blower pressure control and water treatment DO control may interfere with each other, corresponding to the above-described fuel flow control and air flow control. By applying the model predictive control described above to this control system, each control can be stably performed.

DESCRIPTION OF SYMBOLS 1 Sludge combustion system 2 Sludge incinerator 3 Free board middle part 4 Free board upper part 5 Sand layer part 10 Sludge 11 Sludge supply part 12 Fuel 13 Fuel supply part 14 Fluid blower 15 Fluid air 16 Primary air 17 Secondary air 18 Tertiary air 19 Heat exchanger 20 Sludge flow rate detector 21 Fuel flow rate detector 22 Primary air flow rate detector 23 Secondary air flow rate detector 24 Tertiary air flow rate detector 25 Fluid air flow rate detector 26, 27 Thermocouple group 28 Exhaust gas 31 Fuel Flow rate regulator 32 Primary air flow rate regulator 33 Secondary air flow rate regulator 34 Tertiary air flow rate regulator 41-44, 51 Valve 50 Flowing air flow rate regulator 100 Model prediction calculation unit C Controller

Claims (10)

A temperature control device for a fluidized bed type sludge incinerator having a sand layer part and a free board part, burning sludge supplied to the sand layer part and further burning in the free board part,
The temperature of the sand layer part, the temperature of the free board part, the flow rate of the fuel supplied to the sand layer part, the air volume of the flowing air supplied to the lower part of the sand layer part, the middle part of the free board, and the free board The flow rate of the air supplied to the upper part is used as a control input, the flow rate of the fuel and the flow rate of the flowing air and the supply air are used as control outputs, and the flow rate of the fuel and / or the flow rate of the flowing air and the supply air are within a predetermined range. constraints under conditions to fit within, the temperature control apparatus of the sludge incineration furnace and performing model predictive control each temperature of the sand layer portion and the free board section as different target values.   The constraint condition is a predetermined range of an air ratio that is a ratio of an actual air volume of the supplied air to a total theoretical air volume of the theoretical air volume of the supplied air necessary for the combustion of the sludge and the theoretical air volume of the supplied air necessary for the combustion of the fuel. The temperature control device for a sludge incinerator according to claim 1, wherein the temperature control device is inside.   2. The model predictive control is performed so that a value of an evaluation function indicating a prediction result of the flow rate of the fuel and the flow rate of the flowing air and the supply air as the control output is minimized below a predetermined value. Or the temperature control apparatus of the sludge incinerator of 2.   When determining the minimum value of the evaluation function under the constraint condition, if the element of the evaluation function is outside the constraint condition, an allowable error is given to the upper and lower limits of the predetermined range of the constraint condition to determine the predetermined value of the constraint condition A range is expanded, the expanded constraint is set as a modified constraint, a penalty function obtained by multiplying the square of the allowable error by a predetermined weight is added to the evaluation function as a modified evaluation function, and The temperature control device for a sludge incinerator according to claim 3, wherein a minimum value of the modified evaluation function is obtained.   The temperature of the sand layer part and / or the temperature of the free board part is a plurality of temperatures, respectively, and model predictive control is performed with each different temperature as a target value. The temperature control apparatus of the sludge incinerator as described in one. A temperature control method of a fluidized bed sludge incinerator having a sand layer part and a free board part, burning sludge supplied to the sand layer part, and further burning in the free board part,
The temperature of the sand layer part, the temperature of the free board part, the flow rate of fuel supplied to the lower part of the sand layer part, the air volume of the flowing air supplied to the lower part of the sand layer part, the middle part of the free board, and the free board The flow rate of the air supplied to the upper part of the board is used as a control input, the flow rate of the fuel and the flow rate of the flowing air and the supply air are used as control outputs, and the flow rate of the fuel and / or the flow rate of the flowing air and the supply air are predetermined. constraints conditions fall within the range, the temperature controlling method of the sludge incineration furnace and performing model predictive control each temperature of the sand layer portion and the free board section as different target values.   The constraint condition is a predetermined range of an air ratio that is a ratio of an actual air volume of the supplied air to a total theoretical air volume of the theoretical air volume of the supplied air necessary for the combustion of the sludge and the theoretical air volume of the supplied air necessary for the combustion of the fuel. The temperature control method for a sludge incinerator according to claim 6, wherein the temperature control method is used.   7. The model predictive control is performed so that a value of an evaluation function indicating a prediction result of the flow rate of the fuel and the flow rate of the flowing air and supply air as the control output is minimized below a predetermined value. Or the temperature control method of the sludge incinerator of 7.   When determining the minimum value of the evaluation function under the constraint condition, if the element of the evaluation function is outside the constraint condition, an allowable error is given to the upper and lower limits of the predetermined range of the constraint condition to determine the predetermined value of the constraint condition A range is expanded, the expanded constraint is set as a modified constraint, a penalty function obtained by multiplying the square of the allowable error by a predetermined weight is added to the evaluation function as a modified evaluation function, and 9. The temperature control method for a sludge incinerator according to claim 8, wherein a minimum value of the modified evaluation function is obtained.   The temperature of the sand layer part and / or the temperature of the free board part is a plurality of temperatures, respectively, and model predictive control is performed with each different temperature as a target value. The temperature control method of the sludge incinerator as described in one.

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