KR100194446B1 - Combustion control method and apparatus for waste incinerator - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control method and apparatus for a waste incinerator, which can suppress fluctuations in O ₂ concentration in an incinerator and to reduce CO concentration and NO _x concentration in combustion flue gas. 1) is equipped with a boiler (5) at the incinerator outlet (4), the furnace temperature sensor 13 for measuring the furnace temperature, the O ₂ concentration sensor 18 for measuring the exhaust gas O ₂ concentration, NO _x to detect the concentration _x concentration sensor 22, CO concentration sensor 24 for measuring CO concentration, and their output is a furnace thermometer 14, furnace exhaust O ₂ concentration meter 19, furnace exhaust NO _x concentration meter 23, These are respectively input to the furnace exhaust CO concentration meter 25, and these measured values are supplied to the secondary combustion air amount control means 20 of the computer 21, and the force regulating mechanism 11 is opened and closed based on the secondary air amount control value. the second combustion air amount control is operated and controlled so that a constant furnace temperature and the exhaust O ₂ concentration as the peripheral System is measured by the amount of steam in the boiler (5) to the steam flow meter 12, and first combustion air control means 16 influential adjustment mechanism 9 to open and close control for controlling the amount of heat generated and the O ₂ concentration, CO concentration by, NO _x concentration is controlled.

Description

Combustion control method and apparatus for waste incinerator

1 is an overview diagram showing a combustion control method and apparatus thereof for a waste incinerator according to the present invention.

2 is a control block diagram of a combustion control method according to the present invention.

3 is a control block diagram of a combustion control method by purge control according to the present invention.

4 is a diagram showing a relationship between an incinerator internal temperature and secondary combustion air amount according to the present invention.

5 is a diagram showing the relationship between the concentration of O ₂ in the exhaust gas and the amount of secondary combustion air according to the present invention.

6 is a diagram showing the relationship between the CO concentration in the exhaust gas and the secondary combustion air amount according to the present invention.

7 is a diagram showing a relationship between NO _x concentration and secondary combustion air amount in exhaust gas according to the present invention.

8 is a diagram showing an input unit and an output unit of fuzzy control according to the present invention.

9 is a diagram showing a membership function according to the present invention.

10 is a view showing a control result of CO concentration and NO _x concentration by a combustion control apparatus of a conventional waste incinerator.

11 is a view showing control results of CO concentration and NO _x concentration by the combustion control apparatus of the waste incinerator according to the present invention.

12 is a view showing a calculation method of a control unit of secondary combustion air amount according to the present invention.

13 is an overview diagram showing a combustion control method and a device of a conventional waste incinerator.

* Explanation of symbols for main parts of the drawings

1: Incinerator 1a ~ 1c: Iron This

2: garbage inlet 3: ash dropping hole

4: incinerator exit 5: boiler

5a: heat exchanger 6: chimney

7 inlet port 9,11 flow control mechanism

10: fan 17: computer

14 incinerator thermometer 15 cooling air control means

16: combustion air volume control means

The present invention relates to a combustion control method of a waste incinerator and an apparatus thereof.

The metal-type waste incinerator is an incinerator which is widely used in urban cleaning factories, and many steam turbine power generation facilities are installed in order to effectively recover the enormous thermal energy generated by waste incineration and to conserve resources and save energy. In this power generation by waste incineration, it is necessary to maintain stable combustion, that is, the heat generation in the incinerator, in order to perform stable power generation.

In this type of iron-type garbage incinerator, the basic operation method is the constant efficiency incineration in which a certain amount of waste is incinerated at a predetermined time. The method of controlling the calorific value of the incinerator uniformly detects the amount of waste input to the waste incinerator and the amount of heat generated by the waste incinerator, that is, the amount of state according to the combustion load (for example, the amount of steam), and the waste of the waste incinerator is stabilized. It controls the amount of combustion air sent to this.

FIG. 12 shows a conventional crab-type garbage incinerator and its combustion control system. In the same drawing, the waste incinerator 1 includes a fine grain type 1a to 1c, a waste inlet 2, a ash drop 3, an incinerator outlet 4 to discharge exhaust gas, a chimney 6, and a secondary An inlet 7 for air (cooling air) is provided, and a boiler 5 for steam generation provided with a heat exchanger 5a is provided at an incinerator outlet 4 for exhaust gas discharge.

The waste incinerator 1 has a combustion air supply system for supplying cooling air to the iron parts 1a to 1c and a cooling supply system for supplying cooling air into the incinerator. The combustion air supply system includes a combustion air damper, etc., from the fan 8. It is a supply system which is sent to the metal parts 1a-1c through the flow regulating mechanism 9 of this. The cooling air supply system is a supply system that is directly sent from the inlet 7 to the incinerator through the flow control mechanism 11 such as a damper from the fan 10. The opening / closing control of these flow regulating mechanisms 9 and 11 is controlled by the computer 17.

The flow rate regulating mechanism 9 is controlled based on the control output value (operation amount) from the combustion air amount control means 16. The amount of steam generated from the boiler 5 is measured by the steam flow meter 12, the measured value is input to the combustion air control means 16, and arithmetic processing is performed. When the steam flow rate exceeds the target value, the flow rate adjusting mechanism ( The combustion air flow rate in step 9) is narrowed to suppress the calorific value in the incinerator, and the temperature in the incinerator is also reduced. In addition, when the increase flow rate is the target value, the combustion air flow rate of the flow regulating mechanism 9 is increased to increase the calorific value in the incinerator, and the temperature in the incinerator increases with this.

The flow rate regulating mechanism 11 is controlled based on the control output value (operation amount) from the cooling air control means 15. It is insufficient to control the incinerator temperature only by the combustion air supply system, and in order to stabilize the incinerator temperature further, the incinerator temperature is measured by the incinerator thermometer 14, and the measured value is transferred to the cooling air control means 15. The input and arithmetic processing are performed, and the opening degree of the flow regulating mechanism 11 is adjusted on the basis of the output (cooling air control value) so that the temperature in the incinerator is constant.

Conventional iron-type waste incinerator includes a control means for controlling the amount of evaporation generated from the boiler by manipulating the amount of combustion air supplied from the bottom of the iron, and a control means for controlling the temperature in the incinerator by supplying cooling air directly into the incinerator; have. However, it is difficult to constantly control the temperature change in the incinerator caused by the change in the incinerator situation, such as the change in the calorific value of the waste or the distribution state of the waste layer on the soot.

In addition, there is a problem that it is difficult to suppress the amount of harmful substances discharged from the waste incinerator, such as carbon monoxide (CO) or nitrogen oxides (NO _x ) as low as possible.

It is an object of the present invention to provide a combustion incinerator combustion control method and apparatus capable of controlling fluctuations in O ₂ concentration in an incinerator and controlling CO concentration and NO _x concentration in combustion flue gas. .

In order to achieve the above object, the present invention provides a combustion control apparatus of a waste incinerator.

Primary combustion air supply means for supplying primary combustion air to the waste incinerator;

Secondary combustion air supply means for supplying secondary combustion air to the waste incinerator;

Control means for manipulating the amount of primary combustion air supplied from the primary combustion air supply means to the waste incinerator according to the combustion load;

First measuring means for measuring the temperature in the waste incinerator;

Second measuring means for measuring the concentration of O _{2 in} the combustion flue gas of the waste incinerator;

Third measuring means for measuring the concentration of CO in the combustion flue gas of the waste incinerator;

Fourth measuring means for measuring the concentration of NO _{x in} the combustion flue gas of the waste incinerator;

Nonlinear control means for manipulating the secondary combustion air amount in accordance with the measured value by said fourth measuring means from said first measuring means.

In addition, a combustion control method for a waste incinerator comprising the following steps of the present invention is provided.

Operating the primary combustion air amount according to the calorific value of the amount of waste put into the waste incinerator at a given time;

Measuring the incinerator temperature, O ₂ concentration, CO concentration and NO _x concentration in the combustion flue gas of the waste incinerator;

A step of operating secondary combustion air amount by nonlinear control means based on the measured value of the said measuring process.

The primary combustion air amount is operated by feedforward control or feedback control.

The present invention also provides a combustion control method for a waste incinerator comprising the following steps.

Preparing a primary combustion air supply means for supplying primary combustion air to a waste incinerator and a secondary combustion air supply means for supplying secondary combustion air;

Operating the primary combustion air amount supplied from the primary combustion air supply means to the waste incinerator according to the combustion load;

Measuring the incinerator temperature, O ₂ concentration, CO concentration and NO _x concentration in the combustion flue gas of the waste incinerator;

-A step of manipulating the secondary combustion air amount supplied by the nonlinear control means based on a function having the measured value of the measuring step as a parameter.

Next, the outline of the present invention will be described. A primary combustion air supply system for supplying primary combustion air to the soot grains of a waste incinerator, a secondary combustion air supply system for supplying secondary combustion air in a furnace, and their control system are provided. the air control system and on the basis of the state amount in accordance with the combustion load control the amount of heat generated by combustion and become subordinate substantially stabilize the temperature in the incinerator, the addition of the second combustion to the air operation in a non-linear control means for the furnace temperature within the combustion gas O ₂ The concentration, CO concentration, and NO _x concentration are controlled to be settled within a predetermined range.

In the present invention, the relationship between the incinerator temperature and the secondary combustion air amount is divided into two regions, in which the incinerator temperature is positively correlated with the secondary combustion air amount and a negative correlation characteristic, as shown in FIG. The maximum value (for example, the amount of secondary combustion air is 4000 to 5000 Nm ³ / h). In the region having a positive correlation characteristic, the secondary combustion air and the furnace temperature are positive because unburned fraction of the exhaust gas generated by the primary combustion is secondary combustion, and secondary combustion is activated as the amount of secondary combustion air increases. On the other hand, if the unburned fraction in the flue-gas from primary combustion burns out, the secondary combustion air further functions as a cooling air and thus becomes negative. Moreover, as shown in FIG. 5, the concentration of O ₂ in the combustion flue gas has a positive correlation with the amount of secondary combustion air. As shown in FIG. 6, as the CO concentration decreases the amount of secondary combustion air, oxygen in the incinerator is insufficient to increase the CO concentration. The NO _x concentration in the combustion flue gas has a positive correlation with the secondary combustion air amount as shown in FIG.

From this point of view, the O ₂ concentration, CO concentration, and NO _x concentration in the incinerator and flue gas are measured, and the non-linear control (e.g., purge control) is performed according to the incinerator temperature and flue gas characteristics for the secondary combustion air. By operating the secondary combustion air volume more seamlessly, the temperature in the incinerator and the O ₂ concentration in the furnace are controlled in a stable state, and the CO concentration and the NO _x concentration in the exhaust gas are also controlled to be lower than a predetermined value. In other words, the temperature of the incinerator is followed and controlled by the feedback control or the feedforward control to the predetermined control target value, and the O ₂ concentration, the CO concentration, and the NO _x concentration are significantly correlated with the secondary combustion air amount. Non-linear control of the amount of combustion air makes the response characteristic good, and the O ₂ concentration, CO concentration, and NO _x concentration can be controlled seamlessly by the control target value. In addition, this nonlinear control is realized by the increase / decrease control or purge control for each condition using the O ₂ concentration, CO concentration, and NO _x concentration in the incinerator temperature and exhaust gas as measured values and the secondary combustion air amount as the manipulated value. Fuzzy control is most suitable for control.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings. 1 is a view showing an embodiment of a waste incinerator and a combustion control method according to the present invention. The same figure shows the iron-type waste incinerator (1), which includes the iron-fired waste (1a to 1c), waste inlet (2), ash dropping hole (3), incinerator outlet (4) and combustion furnace outlet (4). It is provided with a steam generating boiler 5, a chimney 6 for discharging combustion exhaust gas out of the incinerator, and a suction port 7 through which secondary combustion air is supplied.

The waste introduced into the waste incinerator 1 from the waste inlet 2 is incinerated by the primary combustion air flying under the soot grains 1a to 1c through the combustion and combustion stages, and as ash from the ash dropping hole 3 as ash. Is discharged out. Secondary combustion air is supplied from the inlet 7 into the incinerator to control the temperature of the incinerator, the O ₂ concentration, the CO concentration, and the NO _x concentration in the exhaust gas.

The combustion exhaust gas generated by the combustion is led from the incinerator outlet 4 to the chimney 6 and discharged out of the incinerator. At that time, the high temperature combustion flue gas heats the heat exchanger 5a to boil the water in the boiler 5 and uses the steam for heat supply, power generation, and the like.

This waste incinerator 1 has two systems of combustion air supply system, primary combustion air and secondary combustion air, and the primary combustion air supply system is made of iron through the flow control mechanism 9 such as a damper from the fan 8. The secondary combustion air supply system is a system for blowing secondary combustion air from the fan 10 directly into the incinerator from the inlet 7 through a flow control mechanism 11 such as a damper from the fan 10. .

The primary and secondary combustion air open and close the flow regulating mechanisms 9 and 11 by means of control values from the primary combustion air control means 16 and the secondary combustion air control means 20 by the computer 21. The flow rate is set. The primary combustion air control system is a control system which measures the steam flow rate of the boiler 5 by the steam flowmeter 12, calculates the measured value by the primary combustion air control means 16, and controls the opening and closing of the flow rate regulating mechanism 9. In addition, the secondary combustion air control system detects the incinerator temperature by the incinerator temperature sensor 13, and further includes an O ₂ concentration sensor 18, a NO _x concentration 22, and a CO concentration sensor installed in the incinerator outlet 4. 24) respectively detect O ₂ concentration, CO concentration and NO _x concentration in the flue-gas, respectively, and output their incinerator thermometer (14), incinerator exhaust O ₂ concentration meter (19), incinerator exhaust NO _x concentration meter (23) The input to the incinerator discharge CO concentration meter 25 is inputted to the secondary combustion air control means 20 to calculate and process the flow rate regulating mechanism 11 on the basis of these measured values.

Next, the control system of the primary combustion air control means 16 and the secondary combustion air control means 20 will be described with reference to the control blocks in FIGS. 2 and 3. FIG. 2 is a secondary combustion air conditioner with primary combustion air control means for stabilizing the amount of steam, secondary combustion air control for suppressing incinerator temperature, incinerator O ₂ concentration stabilization and incinerator exhaust NO _x concentration, and CO concentration. The control system is a combination of air control means, and FIG. 3 shows a case where secondary air control means for the same purpose are used as a purge control system.

Referring to the primary combustion air control means 16 based on FIG. 2, the primary combustion air amount is the primary combustion air amount control unit A1 according to the steam amount deviation between the steam amount target value and the steam amount obtained from the combustion process A2 of the waste incinerator. ), Proportional and integral control by feedforward to feedback is carried out, and the amount of steam is controlled by operating the primary combustion air intake to the combustion process A2 of the waste incinerator by the primary combustion air control output value.

In the primary combustion air amount control unit A1, the primary combustion air control output value F1 is calculated based on the calculation formula shown in Expression (1).

(However, F1 is the primary combustion air control output value, STMset is the steam target value, STMnow is the steam flow measurement value. PB is the non-reggae, Ti is the adjustment parameter indicating the load gain, and s is the Laplace operator.)

The opening degree of the flow regulating mechanism 9 which controls the amount of primary combustion air is controlled by the primary combustion air control output value F1 calculated by the formula (1), and the amount of primary combustion air supplied to the incinerator is controlled.

In the secondary combustion air control means 20, the incinerator temperature deviation value from the combustion process A2 of the waste incinerator and the incinerator temperature target value, the incinerator temperature deviation value, the incinerator discharge O ₂ concentration and the incinerator discharge O ₂ concentration are set. By the comparison of the values, the incinerator discharge NO _x concentration and the incinerator discharge NO _x concentration setting value, and the comparison between the CO concentration value and the CO concentration setting value, the secondary combustion air volume control unit (A3) is increased or decreased on a condition-by-condition basis. The incinerator temperature, incinerator exhaust O ₂ concentration, NO _x concentration and CO concentration of the combustion process A2 of the waste incinerator are controlled by the control output values.

Next, the control method of the secondary combustion air amount control unit A3 will be described in more detail. 2 is a conditional increase / decrease control. Before the description, the relationship between incinerator temperature, O ₂ concentration, CO concentration, NO _x concentration and secondary combustion air amount will be described in detail with reference to FIGS.

Secondary combustion air has a secondary combustion zone that functions as secondary combustion air and a cooling zone that serves as cooling air, as is apparent from FIG. The secondary combustion zone is less than 4000 Nm ³ / h, and this combustion zone is a zone in which the temperature in the incinerator rises due to the activation of secondary combustion. In addition, in the region of 4000 to 5000 Nm ³ / h, the temperature rise in the incinerator caused by the secondary combustion air reaches the maximum region with the increase of the secondary combustion air amount. In addition, there is a cooling zone in which the temperature in the incinerator decreases when the amount of secondary combustion air increases to, for example, 5000 Nm ³ / h or more.

In addition, as shown in FIG. 5, the relationship between O ₂ concentration in exhaust gas and secondary combustion air amount is increased, and as the secondary combustion air amount increases, the O ₂ concentration in exhaust gas increases, and a positive correlation between secondary combustion air amount and O ₂ concentration is shown. Relationship exists.

As shown in FIG. 6, the relationship between the CO concentration in the exhaust gas and the secondary combustion air amount decreases as the secondary combustion air amount increases, and there is a negative correlation between the CO concentration in the exhaust gas and the secondary combustion air amount and the CO concentration.

In addition, as shown in FIG. 7, the relationship between NO _x concentration in exhaust gas and secondary combustion air amount increases as the secondary combustion air amount increases, and there is a positive correlation between the NO _x concentration in exhaust gas and the secondary combustion air amount and NO _x concentration. exist.

By using this phenomenon, the secondary combustion air amount control unit A3 controls the secondary combustion air amount. The secondary combustion air amount control unit A3 determines whether the temperature deviation in the incinerator is negative or positive as a predetermined deviation value, and the secondary combustion air amount is in the combustion zone (for example, the function value is set to less than 4000 Nm ³ / h), and the boundary zone ( for example, set to 4000~5000Nm ³ / h) or the cooling zone (for example, determines whether the function value to set to 5000Nm ³ / h or more) to reduce not increase the second combustion air amount from the results of those two conditions is determined Increasing / decrease control by condition

Also, it is determined whether NO _x concentration and CO concentration exceed the upper limit, and if the NO _x concentration exceeds the upper limit, the secondary combustion air is reduced by a certain amount, and if the CO concentration exceeds the upper limit, the secondary combustion air is adjusted to increase a certain amount. Control to suppress the increase of NO _x concentration and CO concentration.

A method of controlling the secondary combustion air amount of the secondary combustion air amount control unit A3 will be described in detail below based on Table 1. FIG. The secondary combustion air amount is calculated and detected in sequence under the conditions of (1) to (10), and when the conditions of (8) to (10) are satisfied, the control indicated by the arrow (→) is executed in sequence.

In addition, the control method shown in Table 1 (1) to (6) is for the temperature variation in the furnace, the control to increase or decrease the secondary combustion air amount, and the control to adjust the increment or decrement amount of the secondary combustion air amount by one cycle. It is a process. (7) shows a control process of developing and maintaining secondary combustion air amount. (8) shows the control of the oxygen concentration, (9) shows the control process for the NO concentration upper limit set value, and (10) for the CO concentration upper limit set value. It is assumed that these controls can be set individually.

Next, the calculation method of the control part (secondary combustion air control means 20) of secondary combustion air quantity is demonstrated based on the flowchart of FIG. The measured values from the control object are sampled at regular intervals, and the secondary combustion air amount is controlled based on those measured values. 12 (a) to 12 (d) show a specific control method of the secondary combustion air amount shown in Table 1, and these control methods (1) to (10) shown in Table 1 are shown in (1). It is shown as (10).

FIG. 12 (a) shows a control method for calculating the control methods (1) to (7) of Table 1, and FIG. 12 (b) shows the control method (8) of Table 1, and FIG. 12 (c) shows Table 1 Control method (9) and FIG. 12 (d) show control method (10) of Table 1. As shown in FIG. 12 (a) to 12 (d) start the control from start1, start2, start3 and start4 and judge whether or not each condition is satisfied according to the flow chart and adjust the final secondary combustion air amount for each control item. The values of the parameters z1 to z4 are determined. The secondary combustion air output value is the current value of the secondary combustion air output value from the previous value (P2 (k-1)) and the adjustment parameters (z1 to z4) of the secondary combustion air output value as shown in the following formula (secondary combustion air control amount in a certain cycle). (F2 (k)) is calculated.

The adjustment parameters z1 to z4 are calculated based on the flowcharts of FIGS. 12 (a) to 12 (d). In FIGS. 12 (a) to 12 (d), Te denotes a temperature deviation in an incinerator, F2 _now denotes a secondary combustion air amount, O2 denotes an oxygen concentration, and NO _x denotes a NO _x concentration. C ₁ and C ₂ are adjustment parameters for determining the amount of secondary combustion air in the combustion zone, boundary zone, and cooling zone. O _x 1 is an adjustment parameter for determining the upper limit set value of oxygen concentration, O _x 2 is an adjustment parameter for determining the lower limit set value of oxygen concentration, NO _x 1 is an adjustment parameter for determining an upper limit set value of NO _x concentration. And CO is an adjustment parameter for determining the upper limit set value of the CO concentration. y1 to y10 are adjustment parameters for increasing and decreasing secondary combustion air amount.

Referring to FIG. 12A, first, in step S1, when the incinerator temperature deviation Te is determined by the control condition Te 0 and satisfies the control condition Te 0, the flow proceeds to step S2. In step S2, when the secondary combustion air amount satisfies the control condition (F2 _now? C ₂ ), the adjustment parameter z1 is set to y1. If the control condition F2 _now? C ₂ of step S2 is not satisfied, the process proceeds to step S3 and the control condition F2 _now? C ₁ is determined. When the control condition F2 _now ≤ C ₁ is satisfied, the adjustment parameter z1 is set to y3, and when the control condition F2 _now ≤ C ₁ is set, the adjustment parameter z1 is set to y7. If the control condition Te 0 of step S1 is not satisfied, the flow advances to step S4. If the control condition F2 _now ≥ C ₂ of step S4 is satisfied, the adjustment parameter z1 is set to y2, and if the control condition F2 _now ≥ C ₂ is not satisfied, the flow advances to step S5. In step S5, when the control condition F2 _now ≤ C ₁ is determined and satisfied, the adjustment parameter z1 is set to y4, and when the control condition F2 _now ≤ C ₁ is not satisfied, the process proceeds to step S6. In step S6, the control condition (O2 ≥ O _x 1) is determined. When the control condition is satisfied, the adjustment parameter z1 is set to y5. When the control condition is not satisfied, the adjustment parameter z1 is set. Let y6 be.

12 (b) is a flowchart showing the control of the secondary combustion air amount by the oxygen concentration. Is adjusted if the O2 of the oxygen concentration measuring a predetermined period determined by the control condition (O2O _x 2) for determining whether or not a temperature lower than the minimum set value of the oxygen concentration (O _x 2), and satisfy the control conditions The parameter z2 is set to y8, and the adjustment parameter z2 that is not satisfied is set to zero. FIG. 12 (c) is a flowchart showing the control of the secondary combustion air amount by the NO _x concentration. Determined by the NO _x concentration (NO _x 1) the control condition (NO _x NO _x 1) for determining whether or not a higher concentration than the upper limit set value for the NO _x concentration (NO _x 1) measuring a predetermined period, and the control When the condition is satisfied, the adjustment parameter z3 is set to y9, and when the condition is not satisfied, the adjustment parameter z3 is set to 0. FIG. 12 (d) is a flowchart showing control of the secondary combustion air amount in accordance with the CO concentration. It is determined by the control condition COCO1 that determines whether the CO concentration measured at a predetermined cycle is lower than the lower limit set value NO _x 1 of the CO concentration, and when the control condition is satisfied, the adjustment parameter z4. Is y10, and if not satisfied, the adjustment parameter z4 is zero.

The secondary combustion air output value F2 (k) is calculated by substituting the value of the adjustment parameters z1 to z4 calculated in accordance with the flowchart of FIG.

Next, another embodiment of the present invention will be described. In this embodiment, the secondary combustion air amount control A3 is purge control and will be described based on the control block in FIG. The loop of fuzzy control is shown in Table 2.

FIG. 8 shows the loops 1 to 10 in Table 2, and the calculation of these loops 1 to 10 is performed based on the total health membership function shown in FIG. The inference result (secondary combustion air volume control value) of the entirety of the loops is output by integrating the back dry part inference result of each of the loops obtained by the secondary combustion air volume control means 20. Based on this control output value, the flow regulating mechanism 9 is adjusted to control the secondary combustion air amount. The integration of fuzzy inference results for each loop is used for general methods of fuzzy computation, for example, for min-max or product-sum.

If the results of the calculations in the loops (1) to (10) in Table 2 do not satisfy the conditions, the output is set to 0. The calculation results for each of the loops (1) to (10) are based on the sum of those calculation results. The secondary combustion air amount is adjusted by calculating the change in secondary combustion air amount. The calculations from these loops (1) to (10) are obtained continuously.

In addition, the calculated value of the change in the amount of secondary combustion air in the directions opposite to each other in the loops 4 and 8 is calculated. Therefore, the secondary output air amount is manipulated to increase or decrease the secondary combustion air amount by the addition value or to maintain the development.

The calculation method of the control unit of the secondary combustion air in the case of applying the specific fuzzy control is shown by using the front part membership function of FIG. First of all, it is calculated about the fit of the health unit. The measured value Te of the incinerator temperature deviation is a suitability for the condition that the temperature variation in the incinerator is negative in the unit function function of the same degree (a). Similarly, the goodness of fit is "a" for "0" and the goodness of fit for "plus" is a ("0"). At the incinerator exit (O) concentration, the measured value is O2, and the goodness-of-fit for the condition "high" is b ("0"), and the goodness-of-fit for the "red" is b (" 1 ") and the goodness of fit for" low "are b (" 0 "). For the current value of secondary combustion air volume, in the preliminary part membership function of the same degree (c), the measured value is F2, the suitability for the condition "small" is c, the suitability for the "middle" is c, and for the "large" The goodness of fit is c ("0"). Regarding the incinerator exit (NO) concentration, in the preliminary unit membership function of the same degree (d), the measured value is NO, the suitability for the "high" condition is d, and the suitability for the "red" is d. For the incinerator exit (CO) concentration, in the pre-membership function of the same degree (e), the measured value is CO, the goodness-of-fit for the "high" condition is e ("0"), and the goodness-of-fit for the "red" is e (" 1 ″).

Now, the fitness (X) is calculated by the formula (3) in the rule ① of FIG. Rule 1 is also good because the temperature deviation in the incinerator is negative and the present value of the secondary combustion air is large.

Similarly, the goodness-of-fit (X to X) for the rules ② to ⑩ is calculated by the following formulas (4) to (12) by the calculation formula.

Next, in the latter part membership function, the secondary combustion air amount change (Y _{1 to} Y ₁₀ ) is determined in order to perform inference. Inference is carried out by the following equation (13) to obtain the inference result (Z).

Finally, the current value F2 (k) of the secondary combustion air output value is obtained from the inference result Z and the secondary combustion air output value F2 (k-1).

FIG. 11 shows an example of control test results by the control method of the waste incinerator according to the present invention, and FIG. 10 shows the result by the proportional control method of the conventional waste incinerator.

As apparent from these drawings, the application of the present invention resulted in a reduction of approximately 30 ppm of NO _x concentration averaging value in the flue gas from 100 ppm level to 70 ppm level. On the other hand, in the CO concentration, the peak of the CO concentration is mainly caused by the temperature decrease in the incinerator, and the temperature change in the incinerator is suppressed by about 25%, so that the temperature decrease in the furnace is less likely to occur, and in the present invention, the CO concentration peak is suppressed and is flat. Could do as a character. In addition, about 30% in can be reduced enough so satisfactory results for the variation of the O ₂ concentration was obtained.

In this embodiment, the temperature deviation in the incinerator is used as an input to the control system of the secondary combustion air amount. When the boiler is provided in the waste incinerator, the steam flow rate variation may be used instead of the temperature variation in the incinerator.

As described above, according to the present invention, the secondary combustion air amount is nonlinearly controlled, in particular, the secondary combustion air amount is conditionally amplified or purged controlled, thereby stabilizing the temperature in the incinerator and the O ₂ concentration in the incinerator, and also the CO concentration and NO in the exhaust gas. _By controlling the concentration of _x to a predetermined value, it is possible to control harmful components in the flue gas below a predetermined value, and at the same time, it is possible to extend the life of the waste incinerator. In addition, since the temperature in the incinerator can be stabilized, the amount of steam in the boiler can be stabilized and the energy can be effectively used.

In addition, when the temperature in the incinerator is too low, secondary combustion is difficult to occur even though there is sufficient oxygen concentration in the incinerator, and the CO concentration of the exhaust gas is increased, and the concentration of O ₂ in the flue gas correlated with the secondary combustion air volume. If it is possible to detect the secondary combustion air amount in the cooling zone, the secondary combustion air amount can be reduced to increase the temperature in the incinerator to prevent the increase of the CO concentration in the exhaust gas.

According to the present invention, the fluctuation range of the O ₂ concentration in the flue gas is suppressed, and when the CO concentration and the NO _x concentration increase, the secondary combustion air is adjusted in the direction of eliminating the temperature rise in response to the increase in the O ₂ concentration. There is an advantage that it is possible to prevent the increase of the exhaust CO concentration due to incomplete combustion due to the decrease or the increase of the exhaust NO _x concentration due to the increase of the O ₂ concentration.

In addition, even if there is a fluctuation in the amount of waste heat input to the waste incinerator, there is an advantage in that combustion with good combustion efficiency is always possible because the temperature in the incinerator and the O ₂ concentration in the flue gas are controlled in a stable state. Therefore, since the calorific value is stable in the cowl-type garbage incinerator including a boiler for power generation, it has an effect of improving power generation efficiency.

Claims (8)

The primary combustion air supply means for supplying the primary combustion air to the waste incinerator, the secondary combustion air supply means for supplying the secondary combustion air to the waste incinerator, and the primary combustion air quantity supplied to the waste incinerator from the primary combustion air supply means for the combustion load Therefore, the control means for operation, the first measuring means for measuring the temperature in the waste incinerator, the second measuring means for measuring the O ₂ concentration in the combustion flue gas of the waste incinerator, and the CO concentration in the combustion flue gas of the waste incinerator are measured. The third measurement means, the fourth measurement means for measuring the NO _x concentration in the combustion flue gas of the waste incinerator, and the non-linear control for manipulating the secondary combustion air amount according to the measured value by the fourth measurement means from the first measurement means. A combustion control apparatus for a waste incinerator, comprising a means. The combustion control apparatus according to claim 1, wherein the nonlinear control means comprises a purge control means. A process of manipulating the primary combustion air volume according to the calorific value of the amount of waste put into the waste incinerator at a given time, measuring the in-house temperature of the waste incinerator, O ₂ concentration in the combustion flue gas, CO concentration, and NO _x concentration; And a step of manipulating the secondary combustion air amount by nonlinear control means based on the measured value of said measuring step. 4. The combustion control method according to claim 3, wherein the primary combustion air amount is operated by feedforward control. 4. The combustion control method according to claim 3, wherein the primary combustion air amount is operated by feedback control. 4. The combustion control method according to claim 3, wherein the nonlinear control means comprises a purge control means. Preparing the primary combustion air supply means for supplying the primary combustion air to the waste incinerator and the secondary combustion air supply means for supplying the secondary combustion air, and the amount of primary combustion air supplied to the waste incinerator from the primary combustion air supply means Therefore, the secondary combustion air amount is determined by nonlinear control means based on the operating process, the furnace temperature of the waste incinerator, the O ₂ concentration in the combustion flue gas, the CO concentration, and the NO _x concentration, and the measured values of the measurement process. Combustion control method of a waste incinerator, characterized in that consisting of a step of operating. 8. A combustion control method according to claim 7, wherein said nonlinear control means comprises a purge control means.