JP2696448B2 - Garbage incinerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refuse incinerator for spraying water into an incinerator to suppress generation of unburned components.

[0002]

2. Description of the Related Art Conventionally, in a refuse incinerator such as a refuse disposal facility for incinerating refuse such as municipal refuse and industrial waste, there is a shortage of combustion air (primary air) due to high calorie of refuse. Unburned components such as carbon oxides (CO) and hydrocarbons are apt to be generated, and when this unburned portion is discharged into the atmosphere together with exhaust gas, harmful substances such as dioxin are generated, resulting in air pollution.

Accordingly, the present applicant has filed Japanese Patent Application No. 2-31988.
As described in the specification and drawings of the application No. 8,
Atomized water is sprayed into the combustion chamber using air and steam,
It has been invented to promote complete combustion and induce a water gas reaction to suppress the generation of unburned components.

[0004]

As described above, when water is sprayed into the combustion chamber to suppress the generation of unburned components, the amount of spray water is set (adjusted) so as to maximize the effect of this suppression.
However, a specific configuration has not been invented. If the amount of spray water and the amount of primary air are each kept constant, for example, if the combustion state fluctuates due to a change in the furnace temperature accompanying a change in the quality of the refuse, the unburned portion increases as described below. Problem.

That is, when the spray water amount is kept constant, a. When the furnace temperature decreases, the amount of spray water becomes excessive and the furnace temperature further decreases, resulting in an incomplete combustion state and an increase in unburned matter. b. When the furnace temperature rises, the amount of spray water is insufficient, and thermal NOx and clinker are generated.

If the amount of primary air is kept constant, c, due to lack of the amount of primary air when the furnace temperature is high, the CO concentration increases, and the unburned portion increases. d, The CO concentration increases due to an excessive amount of primary air in a state where the furnace temperature is low, and the unburned content increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a refuse incinerator in which the amount of spray water and the amount of primary air are varied in accordance with the combustion conditions to enhance the effect of suppressing the generation of unburned water by spraying water. I do.

[0008]

In order to achieve the above object, in a refuse incinerator according to the present invention, the amount of water sprayed into the combustion chamber and the amount of water supplied to the combustion chamber are determined based on the furnace temperature and the amount of generated CO.
Determine the excess or deficiency of the next air amount by fuzzy inference calculation,
The water supply system for increasing or decreasing the amount of spray water in proportion to the furnace temperature.
Before the control signal and the amount of carbon monoxide generated increase
A control amount calculation unit for generating a primary air supply control signal for increasing or decreasing the primary air amount in proportion to the furnace temperature, and a supply for adjusting the water amount and the primary air supply amount based on the two supply control signals Control means.

[0009]

In the case of the refuse incinerator of the present invention constructed as described above, the excess and deficiency of the amount of spray water and the amount of primary air are determined by fuzzy inference from the furnace temperature indicating the combustion state and the amount of generated CO. Based on the determination, the amount of spray water and the amount of primary air are variably adjusted according to the combustion state so as to eliminate excess or deficiency. This variable adjustment, spraying water also changes the combustion conditions, the primary air amount is rather small, the generation of unburned, CO concentration is kept low <br/> have optimum values, generation of unburned and CO The effect of suppressing is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. As shown in the overall configuration of FIG. 2, the inside of the refuse incinerator is substantially formed by primary and secondary combustion chambers 1 and 2 and a gas discharge passage 3, and refuse 5 introduced from a charging hopper 4 is filled with an upper grate 6. To the grate 6 below.

During this movement, each grate 6 is removed from the air line 7.
The refuse 5 is dried and burned by the hot air of the primary air supplied through the wind box 8, and the ash after burning is deposited on the ash pit 9. Further, water for spraying in the water pipe 10 is supplied to the air pipe 11.
Of the front grate 6 near the hopper 4
Is sprayed into the primary combustion chamber 1 from a high-pressure spray nozzle 12 provided at the upper part of the fuel cell.

As will be described below, this spray promotes complete combustion and induces a water gas reaction.
The generation of unburned components is suppressed.

That is, when the refuse 5 is high calorie combustible refuse, a large amount of non-volatile components are generated in the front grate 6,
The non-volatile components burn and the furnace temperature rises. At this time, 1
If the amount of secondary air is insufficient, incomplete combustion of volatile components will occur and C
Unburned components such as O and hydrocarbons rise with the flame 13 and
It is released from the next combustion chamber 2 to the atmosphere via the gas discharge path 3,
Causes air pollution.

However, when an appropriate amount of water is sprayed from the nozzle 12, the unburned portion that has risen and the 1 that has risen from the grate 6 on the rear side have risen.
The secondary air is appropriately mixed with the jet to promote the combustion of unburned components. In addition, the sprayed water causes the following water gas reaction of Chemical Formula 1 to reduce the generation of unburned components.

[0015]

## STR1 ## _{C + H 2 O → CO +} H 2 C + 2H 2 O → CO 2 + 2H 2 CO + H 2 O → CO 2 + H 2

Further, the temperature around the front grate 6 is lowered by the sprayed water, and the furnace temperature is lowered and the NO.
The generation of x and clinker is also prevented.

The optimum values of the amount of spray water and the amount of primary air change according to the combustion conditions as described in the above items a to d. By adjusting the primary air amount to the opposite of the furnace temperature only when the CO concentration increases, the spray water amount and the primary air amount can be maintained at the optimum values.

Therefore, control valves 14 and 15 are provided in the air pipe 7 and the water pipe 10, and a temperature sensor 16 and a CO gas sensor 17 are provided in the secondary combustion chamber 2 and the gas discharge path 3, respectively. A control device 18 having a microcomputer structure for controlling the amount of spray water and the amount of primary air by adjusting the regulating valves 14 and 15 as supply control means based on the detected values of the furnace temperature and the CO concentration is provided.

As shown in FIG. 1, the control device 18 is formed by an input interface unit 19, a control amount calculating unit 20, and an output interface unit 21. The detected values of the furnace temperature and the CO concentration of the sensors 16 and 17 are constantly changed. It is taken into the control amount calculation unit 20 via the input interface unit 19.

The control amount calculation unit 20 determines whether the spray water amount and the primary air amount are over or under the optimum values by fuzzy inference calculation based on the furnace temperature and the CO concentration, and determines the spray water amount and the primary air amount that approach the optimum values. An air amount supply control signal (valve opening degree signal) is formed.

These two supply control signals are supplied to the respective regulating valves 14 and 15 via the output interface unit 21.
The valve openings of the two adjustment valves are variably set, and the amount of spray water and the amount of primary air are automatically adjusted to optimal values.

[0022] Next, the fuzzy inference of the control amount calculation unit 20
The specific processing of the calculation will be described. In this case, "IF
A control rule of the THEN type is used, and the membership functions of the furnace temperature and the CO concentration in the antecedent part of this rule are set in, for example, (a) and (b) of FIG. The membership function of the secondary air amount (increase / decrease amount) is set to, for example, (c) and (d) in FIG. Note that B, M, and S in FIGS. 3A to 3D are high (large), medium (medium), and low (small) function labels.

The control rules include, for example, the following. IF furnace temperature = S THEN water amount = S IF furnace temperature = M THEN water amount = M IF furnace temperature = B THEN water amount = B IF CO concentration = S THEN primary air amount = M IF CO concentration ≧ M and furnace temperature = M THEN Primary air amount = M IF CO concentration ≧ M and furnace temperature = S THEN Primary air amount = S IF CO concentration ≧ M and furnace temperature = B THEN Primary air amount = B

The control amount calculating section 20 obtains the furnace temperature and the CO concentration from the functions of the antecedents in FIGS. 3A and 3B based on the detected values of the furnace temperature and the CO concentration every moment. Furnace temperature, C
The calculation of the control rule based on the O concentration is executed, and it is determined from the functions of the consequent parts in FIGS.

Further, the valve opening of each of the regulating valves 14 and 15 is determined from the result of the determination of excess or deficiency. For example, a supply control signal of a voltage corresponding to the valve opening is formed to form the two regulating valves 14 and 1.
5, and the amount of spray water and the amount of primary air are automatically adjusted in accordance with combustion conditions by so-called fuzzy control.

Meanwhile, the CO concentration changes as shown in FIGS. 4 and 5 with respect to the amount of spray water and the furnace temperature. FIG. 4 is an example of actual measurement of a change in CO concentration with respect to the amount of sprayed water.
The solid lines a, b, and c connecting the circles, △, and さ れ are representative values of low, medium, and high furnace temperatures of 850.
The change characteristics at 900 ° C., 900 ° C., and 950 ° C. are shown.

FIG. 5 shows an example of the actual measurement of the change in the CO concentration with respect to the furnace temperature. The solid lines O, C, K and C connecting the circles, △, ▽ and □ indicate the spray water amount / spray air amount of 0, 0.1, 0. ., 0.3, and the broken line shows the characteristic curve when the amount of sprayed water is controlled by the automatic adjustment. 4 and 5
In the oxygen (O ₂₎ concentration in the furnace 6 to 8%.

By the automatic adjustment, when the furnace temperature is low, the amount of sprayed water is reduced, and the fall of the furnace temperature is prevented. Is promoted, the furnace temperature rises, and the generation of unburned components is suppressed. Further, when the furnace temperature is high, the amount of spray water increases, and the generation of thermal NOx and clinker due to the excessively high furnace temperature is suppressed, and at the same time, the water gas reaction of Chemical Formula 1 is promoted to improve combustion. And the generation of unburned components is suppressed.

In addition, when the amount of primary air is excessive when the furnace temperature is low and the amount of CO is increased, and when the amount of primary air is insufficient when the furnace temperature is high and the amount of CO is increased, the primary air amount is reduced. Is corrected to decrease and increase respectively, and the primary air amount is always an appropriate amount with a small amount of generated CO, and the effect based on the water spray is always kept at the best.

[0030]

Since the present invention is configured as described above, the following effects can be obtained. Furnace temperature, to determine the excess and deficiency of spray amount and primary air quantity of the fuzzy inference operation or we combustion chamber water based on the amount of generated carbon monoxide, the determine
Forming a supply control signal of the spray water quantity and the primary air amount control amount calculation unit based on the constant, the supply amount of the water and the primary air adjusted through the Rikyo supply control unit by the two supply control signal , Furnace temperature
Increase or decrease the amount of sprayed water in proportion to the
The primary air amount was increased / decreased in proportion to the furnace temperature when it was added, and the amount of spray water and the amount of primary air were varied according to the combustion situation.
By automatically adjusting each of them to optimal values, it is possible to extremely favorably suppress the generation of unburned components and carbon monoxide due to water spray.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control device of one embodiment of a refuse incinerator according to the present invention.

FIG. 2 is an overall configuration diagram of an incinerator provided with the control device of FIG. 1;

3 (a) to 3 (d) are explanatory diagrams of each membership function of the control amount calculation unit in FIG.

FIG. 4 is a characteristic diagram of a change in CO concentration with respect to a spray water amount in FIG. 1;

FIG. 5 is a characteristic diagram of a change in CO concentration with respect to a furnace temperature in FIG. 1;

[Explanation of symbols]

 1, 2 combustion chamber 5 refuse 14, 15 regulating valve 16 temperature sensor 17 gas sensor 18 control device 20 control amount calculation unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadashi Kono 5-3-28 Nishikujo, Konohana-ku, Osaka-shi Inside Tachibashi Shipbuilding Co., Ltd. (72) Inventor Masao Kinoshita 5-3-1 Nishikujo, Konohana-ku, Osaka-shi No. 28 Nippon Shipbuilding Co., Ltd. (72) Inventor Mamoru Kondo 5-3-28 Nishikujo, Konohana-ku, Osaka-shi Nitachi Shipbuilding Co., Ltd. (56) References JP-A 64-14515 (JP, A)

Claims (1)

(57) [Claims] 1. A waste incinerator for spraying water into a combustion chamber to suppress generation of unburned components, comprising: a furnace temperature, a generation amount of carbon monoxide, a water spray amount and a primary supply to the combustion chamber. Fuzzy reasoning performance of excess and deficiency of air volume
And increase or decrease the amount of spray water in proportion to the furnace temperature.
The water supply control signal and the amount of carbon monoxide generated
When the primary air volume increases in proportion to the furnace temperature
A refuse comprising: a control amount calculation unit for generating a supply control signal for increasing / decreasing primary air ; and supply control means for adjusting supply amounts of the water and the primary air based on the two supply control signals. Incinerator.