JPH1122941A - Method and apparatus for controlling feed amount of waste to waste incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control residual amount of waste on a combustion grate at an optimum condition. SOLUTION: This control method controls residual amount of waste in a waste incinerator for incinerating waste at a target residual amount of waste, by feeding onto a combustion grate waste 3 charged into the incinerator by a waste feeder 4 successively, and feeding combustion air to the combustion grate from below. Residual amount D1 of the waste on the grate and increase or decrease ΔD1 of residual amount of the waste on the grate are derived from pressure difference between pressures above and below the combustion grate periodically. When the residual amount of the waste exceeds the target residual amount but is still within a specified range and is in a decreasing trend, feed amount of the waste by the waste feeder is increased, and when the residual amount of the waste is smaller than the target residual amount and is within a specified range from the target residual amount and is in an increasing trend, the feed amount of the waste by the waste feeder is decreased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waste incinerator having a dust supply device and a combustion grate incorporated therein, and more particularly to a waste incinerator for controlling the amount of waste on a combustion grate to a target amount. The present invention relates to a dust amount control method and a dust amount control device.

[0002]

2. Description of the Related Art Waste incinerators in cities play an important role in treating various wastes discharged in daily city life. In recent years, interest in collecting enormous heat energy generated by incineration of waste as waste has increased, and a waste incinerator equipped with a boiler power generation facility has been put into practical use.

In a refuse incinerator provided with such a boiler power generation facility, refuse introduced into the hopper by a crane or the like is carried into the furnace by a dust supply device provided at the bottom of the hopper. The combustion grate in the furnace has a structure in which fixed parts and movable parts are alternately arranged with a certain inclination in the dirt feeding direction.

[0004] The refuse supplied to the furnace by this dust supply device is placed on a combustion grate. By moving the inclined combustion grate back and forth in the inclined direction, the refuse is moved on the combustion grate in the inclined direction. A wind box is provided below the combustion grate. Further, the air box is supplied with combustion air from a combustion air fan.

[0005] The refuse is efficiently burned by the combustion air blown up from below in the process of moving on the combustion grate in the inclined direction. The exhaust gas generated by the combustion of the refuse is guided to the chimney and discharged out of the furnace. During this discharging process, the heat of the exhaust gas is recovered by a steam generating boiler.

[0006] In the refuse incinerator having such a configuration, in order to stabilize the amount of generated steam which directly affects the stabilization of the amount of generated electric power or to stabilize the furnace outlet temperature, an automatic control for keeping the refuse combustion state constant. Combustion control has been implemented. Specifically, there are adjustment of the amount of combustion air supplied to the combustion grate, adjustment of the moving speed of the combustion grate, adjustment of the amount of refuse supplied, and the like.

As described above, in a refuse incinerator,
The refuse is intermittently put into the hopper at intervals of about ten minutes to several tens of minutes by a crane, and is continuously fed into the furnace by a dust supply device located at the bottom of the hopper.

Conventionally, when controlling the amount of refuse supplied, the relationship between the amount of steam generated by the boiler and the amount of combustion air supplied to the combustion grate, the amount of secondary air, and the amount of refuse supplied is determined in advance based on past results. In advance, every time the waste is introduced, the incineration amount corresponding to the required steam generation amount is calculated and set as the target incineration amount, and the waste supply amount is determined according to the target incineration amount.

In other words, if the actual amount of waste supplied is less than the target incineration amount, the interval of waste input by the crane is shortened to increase the amount of waste input, and the speed of the dust feeding device is increased to increase the amount of waste supply.

On the other hand, if the actual amount of waste supplied is greater than the target incineration amount, the waste incineration interval is lengthened to reduce the amount of waste input, and the dust supply speed is reduced to reduce the amount of waste supply. It was adjusted to approach the amount. In this case, the variation of the dust-feeding device speed is gradual, and the dust-feeding device speed can be regarded as constant in a short time interval.

[0011]

However, the properties of the refuse to be put into the hopper of the refuse incinerator are not constant, and the bulk density fluctuates greatly and the viscosity also changes greatly. Also, there is an effect of the weight of the dust in the hopper, and even if the speed of the dusting device is constant, the amount of dust to be fed into the furnace is not actually constant but varies slightly. As a result, the amount of waste (remaining amount) on the combustion grate also varies greatly.

[0012] If the remaining amount of the waste fluctuates, the elapsed time of the process of drying, igniting, and burning the waste on the combustion grate differs, the combustion state becomes unstable, and the furnace temperature fluctuates. As a result, there is a problem that the amount of steam generated by the final boiler varies.

For example, when the amount of residual garbage increases, the time required to reach ignition becomes longer even under the same combustion air amount and grate speed, and the combustion momentum decreases during that time. As it burns, the momentum of combustion will increase sharply. On the other hand, if the amount of the refuse remaining on the combustion grate is small, the refuse is reduced in a short time due to the combustion, and the power of the combustion is reduced. As a result, there is a problem that the intensity of combustion occurs and the temperature in the furnace and the amount of generated steam fluctuate greatly.

In order to solve such inconveniences, there has been proposed a method of adjusting the speed of a dust feeding device to keep the amount of waste (residence amount) on a grate constant (Japanese Patent Laid-Open No. Hei 4-2083).
No. 07 publication).

That is, in a drying grate having both a dust supply function and a dust drying function, the lower air pressure of combustion air supplied from below to the drying grate and the combustion air form a drying grate. By utilizing the fact that the pressure difference between the air pressure above the dry grate after passing and the air pressure on the upper side of the dry grate substantially corresponds to the residual amount of dust (residence) on the dry grate, the residual pressure on the dry grate is calculated from this pressure difference. Estimate the amount.

[0016] In a similar manner, the residual amount of dust on the combustion grate is estimated from the pressure difference above and below the combustion grate. Then, the reciprocating movement speed of the dry grate is corrected based on a combination of the estimated remaining amount of the refuse on the dry grate and the estimated remaining amount of the refuse on the combustion grate, and the refuse supply amount is adjusted to be constant.

However, merely controlling the feeder speed based on the above-described calculation for each input of the refuse does not prevent the fluctuation of the actual refuse supply amount, and the remaining amount of the refuse on the combustion grate is not stabilized.

In the method disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 4-208307, the speed of the dusting apparatus is controlled on the basis of the estimated amount of waste remaining on the combustion grate at the present time.

However, it takes a considerable amount of time for the refuse to move from the dry grate to the combustion grate,
Even if you change the reciprocating speed of the dry grate,
The residual amount of the refuse on the combustion grate does not change immediately, and the response characteristic of the residual refuse control on the combustion grate is poor.

As a result, the remaining amount of waste on the combustion grate is not stable, and as a result, the response width of the amount of waste combustion increases,
There was a problem that fluctuations in the furnace temperature and the amount of generated steam could not be sufficiently suppressed.

Further, the above-mentioned method has a problem that it cannot be applied unless the dust supply device is an incinerator having a structure also serving as a dry grate. The present invention has been made in view of such circumstances, based on the remaining amount of waste on the combustion grate and the increase or decrease of the corresponding waste amount, by controlling the amount of dust by the dust supply device, The response time delay of the change in the amount of waste on the combustion grate to the change in the amount of dust supplied by the dust supply device can be reduced, and the amount of waste on the combustion grate can be maintained within a certain range with high accuracy, stabilizing the amount of waste combustion. An object of the present invention is to provide a dust control method and a dust control device for a refuse incinerator capable of obtaining a stable steam generation amount as a result.

[0022]

According to the present invention, refuse introduced into a furnace is sequentially supplied onto a combustion grate by using a dust supply device, and combustion air is supplied to the combustion grate from below. Thus, in the incinerator for incinerating the refuse conveyed on the combustion grate, a method for controlling the amount of dust supplied to the incinerator for controlling the remaining amount of waste on the combustion grate to the target remaining amount and the supply of the waste incinerator Applied to dust control devices.

Then, in order to solve the above-mentioned problem,
In the method for controlling the amount of dust supplied to a refuse incinerator according to claim 1,
From a pressure difference between the lower air pressure and the upper air pressure of the combustion grate at regular intervals, the remaining amount of waste on the combustion grate and the increasing / decreasing tendency of the corresponding waste amount are determined. However, when the amount is within a predetermined range from the target remaining amount and the increase / decrease trend shows a decreasing trend, the amount of dust supplied by the dust supply device is increased, and the obtained remaining amount of waste is lower than the target remaining amount. When it is within the range and the increasing / decreasing tendency indicates an increasing tendency, the amount of dust supplied by the dust feeding device is reduced.

According to a second aspect of the present invention, there is provided a dust control apparatus for a refuse incinerator, wherein the residual amount of refuse on the combustion grate and the corresponding refuse are determined from the pressure difference between the lower air pressure and the upper air pressure of the combustion grate at regular intervals. A garbage remaining amount information calculating means for obtaining the increasing / decreasing tendency of the remaining amount; and feeding when the obtained garbage amount exceeds the target remaining amount but is within a predetermined range from the target remaining amount and the increasing / decreasing tendency shows a decreasing tendency. Increase the amount of dust supplied by the device, and reduce the amount of dust supplied by the dust supply device when the calculated remaining amount of waste is below the target remaining amount but within the specified range from the target remaining amount and the increasing / decreasing trend shows an increasing trend. And a dust amount control means.

In the method and apparatus for controlling the amount of dust in a refuse incinerator configured as described above, the remaining amount of refuse remaining on the combustion grate is set in a predetermined range including the target remaining amount. If the amount of dust exceeds the target amount, the amount of dust supplied by the dust supply device is reduced such that the amount of waste remaining approaches the target amount of waste.

On the other hand, if the amount of waste is significantly lower than a predetermined range including the target remaining amount, the amount of dust supplied by the dust supply device is set so that the amount of waste approaches the target amount. Will be increased.

That is, when the remaining amount of waste deviates from a predetermined range including the target remaining amount, as in the case of ordinary feedback proportional control, the amount of waste remaining is set in accordance with the deviation of the remaining amount of waste from the target remaining amount. If the remaining amount is larger than the target value, the amount of dust of the dust feeding device is increased, and if the remaining amount of waste is smaller than the target amount, the amount of dust of the dust feeding device is decreased. Therefore,
The amount of waste remaining on the combustion grate is controlled within a predetermined range within a short time.

In the present invention, in addition to the above-described control, when the remaining amount of dust is within the predetermined range, even if the remaining amount of dust is smaller than the target value, it is close to the target value. When the amount is increasing, the amount of dust supplied by the dust supply device is reduced earlier. Conversely, even if the remaining amount of waste is larger than the target value, it is close to the target value. Therefore, if the remaining amount of waste is decreasing, the amount of dust supplied by the dust supply device is increased earlier.

By adopting such a method,
The change in the amount of dust of the dust supply device cannot keep up with the fluctuation of the amount of waste on the combustion grate, and the amount of waste on the combustion grate is prevented from becoming too large or too small. That is, the overshoot phenomenon in the control of the amount of waste is suppressed, and the fluctuation range of the amount of waste on the combustion grate can be reduced.

According to a third aspect of the present invention, there is provided a dust control apparatus for a refuse incinerator, wherein the remaining amount of refuse on the combustion grate is sequentially calculated from the pressure difference between the lower side and the upper side of the combustion grate at regular intervals. An amount calculating means, a difference remaining amount calculating means for calculating a difference remaining amount between the current waste amount calculated in the current cycle and the previous garbage staying amount calculated in the immediately preceding cycle, a garbage amount and a difference A membership function indicating the relationship between the remaining amount and the target remaining amount, a rule indicating the relationship between the remaining amount of waste and the difference between the remaining amount and the amount of dust supplied by the dust supply device, Each time the difference remaining amount is calculated, there is provided a fuzzy operation processing means for calculating an optimum amount of supplied dust using a membership function and a rule.

[0031] In claim 4, the rule is
When the garbage remaining amount is slightly larger than the target remaining amount and the difference remaining amount indicates negative, the amount of dust supplied by the dust supply device is increased, and the garbage remaining amount is slightly smaller than the target remaining amount and the difference remaining amount indicates positive. The time is set so as to reduce the amount of dust supplied by the dust supply device.

In the dust amount control device for a refuse incinerator configured as described above, the optimum amount of dust in the dust device is fuzzy-calculated from the remaining amount of refuse on the combustion grate and the tendency of the refuse remaining amount to increase or decrease. We are looking for. Therefore, as compared with a case where the amount of dust supplied to the dust supply device is controlled only by the remaining amount of dust on the combustion grate, a factor given to the control is increased, and the control accuracy is improved.

[If-th] in the fuzzy operation
en], as described above, the relationship between the remaining amount of dust and the difference remaining amount and the amount of dust supplied by the dust supply device is described above, and the remaining amount of waste is slightly larger than the target remaining amount and the difference remaining amount. Is set to increase the amount of dust supplied by the dust-feeding device when the value indicates negative, and decrease the amount of dust supplied by the dust-feeding device when the remaining amount of waste is slightly less than the target remaining amount and the difference remaining amount is positive. Therefore, as described above, the overshoot phenomenon in the waste amount control is suppressed, and the fluctuation range of the waste amount on the combustion grate can be reduced.

[0034]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) FIG. 1 is a schematic configuration diagram of a refuse incinerator in which a dust amount control device employing a dust amount control method according to a first embodiment of the present invention is incorporated.

Hopper 2 for supplying refuse 3 into furnace 1
At the bottom of the hopper 2, a dusting device 4 for supplying the refuse 3 charged into the hopper 2 onto a combustion grate 5 in the furnace 1 is provided. The dust feeding device 4 pushes the refuse 3 of the hopper 2 into the furnace 1 by being reciprocated in the horizontal direction by the driving device 9.

The combustion grate 5 has a structure in which fixed parts and movable parts are alternately arranged with a certain inclination in the dirt feeding direction. Then, the combustion grate 5 pushes the refuse 3 placed on the upper side in the direction of the ash falling port 6 while agitating the refuse 3 placed on the upper side by the reciprocating motion of the movable part which pushes the refuse 3 obliquely upward and forward.

Below the combustion grate 5, four wind boxes 7a,
7b, 7c and 7d are provided. Further, combustion air is supplied from a common combustion air fan 8 to each of the wind boxes 7a, 7b, 7c, 7d.

The refuse 3 supplied to the combustion grate 5
Is efficiently burned by the combustion air blown from below the combustion grate 5 through the wind boxes 7a to 7d by the combustion air fan 8 into ash. Is discharged to On the other hand, the exhaust gas generated by the combustion of the refuse 3 is guided from the furnace outlet 10 to the chimney 11 and discharged out of the furnace. The heat of the exhaust gas is recovered by a steam generating boiler 12. The flow rate of the steam collected by the boiler 12 is measured by a steam flow meter 13.

Further, secondary air for promoting secondary combustion or cooling in the furnace is blown into the upper position in the furnace 1 from a blower fan 18 through a secondary air inlet 19. In each of the wind boxes 7a, 7b, 7c, 7d installed below the combustion grate 5, each pressure gauge 14 for measuring the air pressure under the combustion grate is provided.
a, 14b, 14c, and 14d are provided. Furthermore, each of the wind boxes 7a, 7b, 7c, 7d is provided with a respective damper (not shown) for adjusting the amount of combustion air supplied from the combustion air fan 8 into the own wind box.

Further, each of the wind boxes 7
flow meters 15 for measuring the flow rates of the combustion air supplied from the combustion air fan 8 to the wind boxes 7a, 7b, 7c, 7d in the supply paths of the respective combustion air to the a, 7b, 7c, 7d.
a, 15b, 15c, and 15d are attached.

A furnace pressure gauge 16 for measuring the pressure P _H in the furnace 1 is mounted at a position above the combustion grate 5 in the furnace 1. Each of the pressure gauges 14a, 14b, 14c,
Each air pressure P under combustion grate 5 measured at 14d
_La , P _Lb , P _Lc , P _Ld , the air pressure P _{H above the} combustion grate 5 measured by the in-furnace pressure gauge 16, and the respective flow meters 15
a, grate 5 measured at 15b, 15c, 15d
Air quantity Q _a , Q _b , Q _c , Q
_d is input to the dust amount control device 17.

The dust amount control device 17 is composed of a kind of information processing device such as a computer, and receives the lower air pressures P _La and P _{Ld of} the combustion grate 5, the upper air pressure P _H and the combustion air amount. Based on Q _{a to} Q _d , the current waste amount D ₁ of the waste 3 on the combustion grate 5 and the corresponding waste remaining amount D ₁
Is estimated and calculated, and the garbage remaining amount D ₁ at the current time and the increasing / decreasing tendency (difference remaining amount ΔD) are calculated.
From this, a dust feeder speed V ₀ corresponding to the amount of dust to be supplied to the combustion grate 5 in the dust feeder 4 is calculated and sent to the driving device 9 of the dust feeder 4.

The driving device 9 is provided with a dust amount control device 17.
The reciprocating movement of the dust feeding device 4 is controlled at the dust feeding device speed V ₀ input from. As a result, the refuse 3 stored in the popper 2 is supplied onto the combustion grate 5 in the furnace 1 by an amount corresponding to the dust feed speed V ₀ per unit time.

As shown in FIG. 2, in a dust amount control device 17 formed by a kind of information processing device, a previous value memory 20 and a speed calculation condition table 2 formed on a main storage portion are provided.
1, a measured value input unit 22 and a calculated speed output unit 23, each of which is constituted by an input / output interface.

Further, in the dust amount control device 17, for example, a waste remaining amount calculation unit 24, a difference calculation unit 25, an increase / decrease tendency determination unit 26 as a program module formed on an application program, a target value comparison unit Part 27,
An upper / lower limit comparing section 28 and a feeding device speed calculating section 29 are formed.

The measured value input section 22 inputs the analog lower air pressures P _La , to P _Ld , upper air pressure P _H and combustion air amounts Q _{a to} Q _d for, for example, 0.5 minutes (30 seconds). They crowded preparative prescribed period T ₀ equal to convert each digital value. Further, the four digitally converted lower air pressures P
_La, and calculates the lower air pressure P _L of the average of the to P _Ld. Also,
Calculating the digitally converted four combustion air quantity Q _a to Q average combustion air amount Q _d. Incidentally, the upper air pressure P _H of the digital used as is. The measurement value input unit 22 sends the lower air pressure P _L , upper air pressure P _H, and combustion air amount Q of the combustion grate 5 calculated at the specified period T ₀ to the waste remaining amount calculation unit 24.

The residual amount calculator 24 calculates the average residual amount D ₁ on the combustion grate 5 in the current cycle T ₀ using the equation (1). D ₁ = A (P _L −P _H ) / Q ⁿ (1) That is, the pressure difference (P _L −P _H ) between the lower air pressure P _L and the upper air pressure P _H of the combustion grate 5 is determined, and combustion is performed. The air quantity Q is divided by the nth power value. The magnitude of the pressure difference (P _L -P _H ) corresponds to the amount of dust D ₁ on the combustion grate 5 above the wind box upper portions 7a to 7d, and the pressure difference (P _L -P _H ) since it will change the size of the combustion air quantity Q, and the pressure difference per unit flow of the combustion air quantity by dividing the combustion air quantity Q ^n, excluding the effects of the variation of the combustion air quantity Q.

At this time, the combustion air amount Q and the pressure difference (P _L -P
_Since the relationship with _H ) is non-linear, a power exponent term n is added to the combustion air amount Q to eliminate the effect. The value of the exponent term n is obtained experimentally. further. A is also a coefficient obtained experimentally.

The garbage remaining amount calculating unit 24 calculates the present garbage remaining amount D ₁ calculated in the current cycle T ₀ by using the previous value memory 20, the difference calculating unit 25, the target value comparing unit 27, and the upper and lower limit comparing unit 2.
8. Send the data to the dust feeder speed calculator 29.

In the previous value memory 20, the previous waste remaining amount D calculated by the waste remaining amount calculator 24 in the previous cycle is stored.
I remember ₂ . Then, it calculates the difference remaining ΔD between the difference calculation unit 25 Wagomi remaining amount calculating unit last garbage remaining D ₂ read out from the previous value memory 20 from dust remaining D ₁ of the current input from the 24 And sends it to the increase / decrease tendency determination unit 26.

ΔD = D ₁ −D ₂ (2) The increasing / decreasing tendency determining unit 26 determines whether the input difference remaining amount ΔD is positive or negative, and in the case of [positive], the current dust remaining amount D ₁ is increasing. And the information of the increasing tendency and the difference remaining amount Δ
And D to the next feeding device speed calculating unit 29. On the other hand, in the case of [negative] is waste remaining D ₁ of the current is determined to be decreasing, and sends the information and the difference remaining amount ΔD of the decline to the next sheet dust system speed calculation unit 29.

When the above processing is completed, the previous value memory 20 writes the current waste amount D ₁ inputted from the waste amount calculation unit 24 as the previous waste amount D ₂ (D ₂ = D
₁ ).

Meanwhile, the target value in the comparison unit 27, the target remaining D ₀ of dust remaining the best combustion state is thus obtained which corresponds to a predetermined steam generation amount set in advance are stored.
Then, the target value comparison section 27 compares the magnitude of the dust remaining D ₁ of the current inputted to the target remaining amount D _0, the comparison result and the deviation (D ₁ -D ₀₎ and the next paper dust Device speed calculator 29
Send to

[0054] Further, the upper and lower limits in the comparison unit 28, the upper dust remaining Dmax and lower dust remaining Dmin in a predetermined range in the predetermined-determined dust remaining amount comprising about the target remaining D ₀ is stored ing. Then, the upper and lower limit comparing unit 28
Is the input garbage remaining amount D ₁ is the upper limit garbage remaining amount Dmax
And whether beyond, and it is determined whether dust remaining D ₁ of the current is less than the lower limit dust remaining Dmi, and sends the determination result to the next sheet dust system speed calculation unit 29.

In the speed condition table 21, as shown in FIG. 3, the current waste amount D ₁ , the difference remaining amount ΔD, the target remaining amount D ₀ , the upper limit waste amount Dmax and the lower limit waste amount in a predetermined range. D
every six combinations in min, calculation formula of the paper dust device speed V ₀ is stored in each combination. The six types of unions are as follows.

(1) Current waste amount D ₁ ≧ upper limit waste amount Dmax Dust feeding device speed V ₀ = K ₁ (D ₁ −D ₀ ) (3) (2) Target remaining amount D ₀ ≤ current time Remaining amount of waste D ₁ <upper limit of remaining amount of waste Dmax, ΔD> 0 Drainer speed V ₀ = K ₂ (D ₁ −D ₀ ) ΔD (4) (3) Target remaining amount D ₀ ≦ remaining amount of waste D ₁ <upper limit of remaining waste Dmax, ΔD <0 Dust feeding device speed V ₀ = K ₃ (D ₁ −Dmax) ΔD (5) (4) Lower limit of remaining amount of waste Dmin <remaining amount of waste D ₁ ≦ target Remaining amount D ₀ , ΔD> 0 Dust feeding device speed V ₀ = K ₄ (D ₁ −Dmin) ΔD (6) (5) Lower limit remaining amount Dmin <current waste remaining amount D ₁ ≦ target remaining amount D ₀ , ΔD <0 Dust feeding device speed V ₀ = K ₅ (D ₁ −D ₀ ) ΔD (7) (6) (6) Remaining waste amount D ₁ <lower limit waste remaining amount Dmin Dust feeding device speed V ₀ = K _{6 (D 1 -D 0) ... (} 8) the value der coefficients K ₁ ~K ₆ is determined empirically .

The dust-feeding unit speed calculating unit 29 includes a current waste remaining amount D ₁ inputted from the increase / decrease tendency determining unit 26, the target value comparing unit 27, the upper and lower limit comparing unit 28 and the waste remaining amount calculating unit 24.
Various conditions described above regarding it is judged whether corresponds to any of the above (1) to (6), identifies the calculation formula of the paper dust device speed V _0. Then, to calculate the sheet dust device velocity V ₀ with the corresponding calculation formula. The feeding device speed calculation unit 29
The calculated feeding device speed V ₀ is sent to the calculated speed output unit 23. The calculated speed output unit 23 outputs the dust feeding device speed V _0.
To the driving device 9 of the dust feeding device 4.

The driving device 9 controls the reciprocating movement of the dust feeding device 4 at the dust feeding device speed V ₀ input from the dust feeding amount control device 17. As a result, the refuse 3 stored in the hopper 2 is supplied onto the combustion grate 5 in the furnace 1 by an amount corresponding to the dusting apparatus speed V ₀ per unit time.

In the dust amount control device 17 of the refuse incinerator thus configured, the refuse remaining amount D _{1 of the} refuse 3 staying on the combustion grate 5 in the furnace 1 is equal to the target remaining amount D _0. In the case where the amount exceeds the upper limit dust remaining amount Dmax of the predetermined range provided including
It corresponds to the condition of (1), and the waste 3 by the dust feeding device 4 is calculated by using the equation (3) so that the waste remaining D ₁ approaches the target remaining D _0.
Because paper dust device velocity V ₀ indicating a supply amount per unit into the furnace 1 time is calculated, paper dust device speed V ₀ is lowered, the sheet dust amount is reduced.

On the other hand, when the remaining amount of dust D ₁ is significantly lower than the lower limit of remaining amount of dust Dmin in the predetermined range including the target remaining amount D ₀ , the speed calculation condition table 21
Corresponds to the conditions of (6), as dust remaining D ₁ approaches the target remaining D _0, since the sheet dust device speed V ₀ is calculated using the equation (8), paper dust device velocity V ₀ Is raised, and the amount of dust is increased.

As described above, the remaining amount of waste D ₁ is equal to the target remaining amount D _0.
Include if went wide dirt remaining Dmax and lower dust remaining Dmin over a predetermined range provided, as in the normal feedback proportional control, the target remaining D of dust remaining D ₁
Depending on the deviation (D ₁ -D ₀₎ from _0, paper dust device speed V ₀ is changed. Therefore, the amount of waste D ₁ on the combustion grate 5 is controlled within a predetermined range within a short time.

[0062] Also, since dust remaining D ₁ is in a state contained in a predetermined range, close to the target value D ₀ if dust remaining D ₁ is smaller than the target value D _0, dust remaining D ₁ Is increasing (ΔD> 0), which corresponds to the condition of (4) in the speed calculation condition table 21, and decreases earlier than the feeding device speed V ₀ of the feeding device 4.

[0063] Conversely, since even dust remaining D ₁ is close to the target value D ₀ be greater than the target value D _0, if the dust remaining D ₁ is decreasing ([Delta] D <0), the velocity calculation This corresponds to the condition (3) in the condition table 21, and increases ahead of the dust feeding device speed V ₀ of the dust feeding device 4.

By adopting such a method,
Change of the paper dust device velocity V ₀ which paper dust device 4 to change the dust remaining D ₁ of the on combustion grate 5 can not keep up, the combustion grate 5
It is possible to prevent the upper remaining amount D ₁ of the dust from becoming too large or too small, suppress the overshoot phenomenon in the remaining amount of the waste, and change the range of the remaining amount D ₁ of the dust on the combustion grate 5. Can be reduced.

Therefore, a stable combustion state is always maintained, and a stable steam generation amount can be obtained. In addition,
In the first embodiment, and a lower air pressure P _L and the combustion air amount Q of combustion grate 5 used for calculating the sheet dust device speed V ₀ and the average of the pressure and air volume in each windbox 7a to 7d. However, it is not always necessary to use the values from all the wind boxes 7a to 7d, and the measured values from the most effective wind boxes may be used, judging from the actual combustion state.

(Second Embodiment) FIG. 4 is a block diagram showing a schematic configuration of a dust amount control device for a waste incinerator according to a second embodiment of the present invention. The same parts as those in the dust amount control device 17 of the second embodiment shown in FIG. 2 are denoted by the same reference numerals, and detailed description of the overlapping parts will be omitted. The overall configuration of the refuse incinerator is the same as that shown in FIG.

The dust amount control device 17 of the second embodiment
“a” calculates the feeding device speed V ₀ for the feeding device 4 using a fuzzy calculation method. Therefore, in the dust amount control device 17a, a rule table 31 storing rules in the if-then format, a membership function memory 32 storing membership functions, a fuzzy arithmetic processing unit 33, a dust feeding device The speed calculation unit 34 is incorporated.

The garbage remaining amount calculator 24 calculates the current garbage remaining amount D ₁ in the current cycle T ₀ , sends it to the previous value memory 20 and the difference calculator 25, and calculates the calculated current garbage remaining amount D _1. To the fuzzy arithmetic processing unit 33. The difference detection unit 25 calculates the calculated difference remaining amount ΔD (= D ₁ −
D ₂ ) to the fuzzy arithmetic processing unit 33.

The rule table 31 contains if-then
Six rules (1) to (6) are stored in the form. The rules composed of the antecedent part (if part) and the consequent part (then) from (1) to (6) correspond to (6) to (1) in the speed calculation condition table 21 shown in FIG. ) Corresponds to each calculation condition. That is, the range in which the amount of waste D ₁ is “slightly small” or “slightly large” corresponds to the predetermined range.

Then, the antecedents (i) of (1) to (6)
f section) the feeding device speed V for the feeding device 4
₀ conclusions are listed. For example, (1)
_{When 1} is small (the membership function μLL (D ₁ )), the feeding device speed V ₀ is greatly increased (b1). (3) is slightly less garbage remaining D ₁ of the (membership function μL
If (D ₁ )) and the difference remaining amount ΔD is positive (membership function μp (ΔD)), the feeding device speed V ₀ is slightly reduced (b3).

In (4), when the remaining amount D ₁ of the waste is slightly large (membership function μH (D ₁ )), and the remaining amount of difference Δ
If D is negative (membership function μn (ΔD)),
It increased slightly the sheet dust device velocity V ₀ (b4) to. And
(6) often refuse remaining amount D ₁ of the (membership function μhh
(D ₁ )), the feeder speed V ₀ is greatly reduced (b
6) Yes.

The membership function memory 32 has a garbage remaining membership function memory 32a and a difference remaining membership function memory 32b. In the garbage remaining membership function memory 32a, FIG.
As shown in (a), each residual amount D ₁ of the antecedent (if) of each rule of (1) to (6) set in the rule table 31.
Each membership function μLL (D ₁ ), μL (D ₁ ),
The characteristics of μH (D ₁ ) and μHH ((D ₁ ) are stored on the horizontal axis as the amount of waste D _{1. The} fitness μ () takes a value in the range of 0 to 1.

The remaining difference membership function memory 32b
As shown in FIG. 6B, each membership function of each difference remaining amount ΔD of the antecedent part (if) of each rule of (1) to (6) set in the rule table 31 as shown in FIG. μn (ΔD), μ
The characteristic of p (ΔD) is stored on the horizontal axis as the residual dust amount ΔD. The fitness μ () takes a value in the range of 0 to 1.

The fuzzy arithmetic processing section 33 has a constant period T ₀
Every time the current residual amount D ₁ and the difference residual amount ΔD are input, the dust supply device is used by using the rules stored in the rule table 31 and the respective membership functions stored in the membership function memory 32. A normalized output value U corresponding to the speed V ₀ is calculated and sent to the next feeding device speed calculating unit 34.

Next, an example of the fuzzy calculation in the fuzzy calculation processing section 33 will be described. At present, various methods are used for fuzzy arithmetic, but in this embodiment, arithmetic is performed using a simple inference method that has relatively high inference accuracy and can execute arithmetic processing at high speed.

The conformity of each rule in the rule table 31 is defined as w _i (i = 1, 2, 3, 4, 5, 6), and each value of each consequent is defined as b _i
(I = 1,2,3,4,5,6), b _i is −1 or more,
A value equal to or less than 1 is entered, a negative value is entered into b3, b5, b6 which is a decrease, and a positive value is entered into b1, b2, b4 which is an increase.

Then, the fitness w _i of each rule of (1) to (6)
Can be calculated as follows. w ₁ = μLL (D ₁ ) w ₂ = μL (D ₁ ) × μn (ΔD) w ₃ = μL (D ₁ ) × μp (ΔD) w ₄ = μh (D ₁ ) × μn (ΔD) w ₅ = μh (D ₁ ) × μp (ΔD) w ₆ = μhh (D ₁ ) (9) Then, the normalized output value U is obtained by Expression (10).

[0078] _{U = [Σ (w i ×} b i)] / Σw i ... (10) i.e., the (10) equation is obtained by a weighted average value b _i of the consequent part in fitness w _u each rule And the output value U takes a value from −1 to 1.

The fuzzy arithmetic processing section 33 sends out the calculated standardized output value U to the feeder speed calculating section 34. In the dust feeder speed calculation unit 34, a speed reference value V _S of the dust feeder 4 is determined from the target incineration amount of the waste 3 and the amount of dust per reciprocation of the dust feeder 4 obtained as a result of the past certain time. Then, the actual feeder speed V ₀ is calculated by correcting the speed reference value V _S by the equation (11) using the calculated output value U.

V ₀ = V _S (1 + U) (11) The feeding device speed calculation unit 34 calculates the calculated feeding device speed V
_“0” is sent to the calculation result output unit 23. Calculation speed output unit 2
3 feeds the dust feeding device speed V ₀ to the driving device 9 of the dust feeding device 4.

The driving device 9 controls the reciprocating movement of the dust feeding device 4 at the dust feeding device speed V input from the dust feeding amount control device 17. As a result, the refuse 3 stored in the hopper 2 is supplied onto the combustion grate 5 in the furnace 1 by an amount corresponding to the dusting apparatus speed V ₀ per unit time.

In the dust control apparatus configured as described above and using fuzzy control, even if the residual amount D ₁ on the combustion grate 4 is slightly smaller than the target residual amount D ₀ , the residual amount D ₁ There when are increasing, a negative value is fit W ₃ rules greatest output value U is the corresponding (3). Therefore, (1 + U) in equation (11) is a value smaller than 1. As a result, the feeding device speed V ₀ becomes a value smaller than the speed reference value V _S and is reduced.

[0083] In addition, in the case refuse the remaining amount D ₁ is also slightly more than the target remaining D _0, the dust remaining D ₁ is decreasing,
Fitness W ₄ rules (4) becomes largest, thereby feeding dust device speed V ₀ is accelerated.

As described above, the amount of increase / decrease of the dust feeding device speed V ₀ is finely set in accordance with the size of the garbage remaining amount D ₁ and its increasing / decreasing tendency. These by the sheet dust device type of feedforward control of deceleration and acceleration in accelerating the feed dust device velocity V ₀ at 4 is realized, the dust remaining D ₁ of the on combustion grate 5 is stabilized. Therefore, almost the same effects as those of the first embodiment can be obtained.

FIG. 7 is an actual measurement diagram showing the time change of the temperature of the furnace outlet 10 of the furnace 1 and the steam generation amount of the boiler 12 in the refuse incinerator incorporating the apparatus of the embodiment. Boiler 12
It can be understood that the amount of generated steam is stable.

FIG. 8 shows the relationship between the standard deviation of the residual amount D ₁ of the refuse 3 on the combustion grate 5 and the standard deviation of the amount of generated steam of the boiler 12 in the refuse incinerator incorporating the apparatus of this embodiment. FIG. In this embodiment the apparatus shown in the figure, black triangles code, standard deviation of dust remaining D ₁ takes a small value, and taking the standard deviation is small the value of the steam generation amount.

On the other hand, when the control in the apparatus according to the present embodiment indicated by black circles in the figure is not performed, the standard deviation value of the residual amount D ₁ is large and the standard deviation value of the amount of generated steam is large. This demonstrates the effectiveness of the present invention.

The present invention is not limited to the above embodiments. In each embodiment, the feeding device speed V is controlled as a method of increasing or decreasing the amount of dust supplied by the dust feeding device 4.

However, as a method of increasing or decreasing the amount of dust,
For example, it is also possible to adopt a method of controlling the inclination angle by inclining the dust supply device 4 or controlling the degree of opening of the dust supply port of the hopper 2 with respect to the furnace 1.

[0090]

As described above, in the method and apparatus for controlling the amount of dust supplied to a refuse incinerator according to the present invention,
The amount of dust supplied by the dust supply device is controlled based on the amount of waste remaining on the combustion grate and the tendency of the amount of waste remaining to increase or decrease.

Therefore, it is possible to reduce the response time delay of the change in the amount of waste on the combustion grate with respect to the change in the amount of dust supplied by the dust supply device, and to maintain the amount of waste on the combustion grate within a certain range with high accuracy. The amount of combustion can be stabilized, and as a result, a stable amount of steam can be obtained. Further, since the temperature inside the furnace is also stabilized, the temperature at the furnace outlet is stabilized, and the temperature required for measures against dioxin can be constantly maintained.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a refuse incinerator incorporating a dust amount control device employing a dust amount control method according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a dust supply amount control device according to the first embodiment.

FIG. 3 is a diagram showing storage contents of a speed calculation condition table of the dust supply amount control device of the first embodiment.

FIG. 4 is a block diagram showing a schematic configuration of a dust supply amount control device according to a second embodiment of the present invention.

FIG. 5 is a diagram showing stored contents of a rule table of the dust supply amount control device according to the second embodiment.

FIG. 6 is a diagram showing a membership function of the dust amount control device according to the second embodiment.

FIG. 7 is an actual measurement diagram of a furnace outlet temperature and a steam generation amount in a refuse incinerator into which the apparatus of the present embodiment is incorporated.

FIG. 8 is an actual measurement diagram showing the relationship between the standard deviation value of the residual amount of waste and the standard deviation value of the amount of generated steam in a waste incinerator in which the apparatus of the present embodiment is incorporated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Furnace 2 ... Hopper 3 ... Garbage 4 ... Dust supply apparatus 5 ... Combustion grate 14a-14d ... Pressure gauge 16 ... Furnace pressure gauge 17, 17a ... Dust amount control apparatus 21 ... Speed calculation condition table 24 ... Garbage residue Amount calculation unit 29 ... Dust feeding device speed calculation unit 31 ... Rule table 32 ... Membership function storage unit 33 ... Fuzzy calculation processing unit

Claims (4)

[Claims] 1. A refuse charged into a furnace is sequentially supplied onto a combustion grate by using a dusting device, and combustion air is supplied from below to the combustion grate, whereby the combustion grate is supplied to the combustion grate. A method for controlling the amount of waste on the combustion grate in a waste incinerator that incinerates waste conveyed to a waste incinerator to control the remaining amount of waste on the combustion grate to a target remaining amount, comprising: The residual amount of waste on the combustion grate and the increase / decrease tendency of the corresponding residual amount of waste on the combustion grate are obtained from the pressure difference between the target air amount and the upper air pressure. When the increase / decrease trend indicates a decreasing trend, the amount of dust supplied by the dust supply device is increased, and the determined remaining amount of waste is lower than the target remaining amount but within a predetermined range from the target remaining amount and the When the increase / decrease trend indicates an increase A dust amount control method for a refuse incinerator, wherein the dust amount by the dust device is reduced. 2. The refuse introduced into the furnace is sequentially supplied to a combustion grate by using a dusting device, and combustion air is supplied from below to the combustion grate, whereby the combustion grate is supplied to the combustion grate. In a waste incinerator dust amount control device for controlling a residual amount of waste on the combustion grate in a waste incinerator for incinerating waste to be conveyed, a lower air pressure of the combustion grate at a constant cycle. Waste information calculation means for calculating the amount of waste remaining on the combustion grate and the increase / decrease tendency of the corresponding amount of waste on the combustion grate from the pressure difference between the upper air pressure and the upper air pressure; When the amount is within a predetermined range from the remaining amount and the increasing / decreasing tendency indicates a decreasing tendency, the amount of dust supplied by the dust supply device is increased, and the determined remaining amount of waste is lower than the target remaining amount. Within the range and the increase / decrease trend is increasing Paper dust amount control apparatus for waste incinerators equipped with a paper dust quantity control means for decreasing the feeding dust amount of the paper dust device when showing the direction. 3. The refuse introduced into the furnace is sequentially supplied onto a combustion grate by using a dust supply device, and combustion air is supplied to the combustion grate from below, whereby the combustion grate is supplied to the combustion grate. In the incinerator that incinerates the refuse conveyed, the amount of waste on the combustion grate in the incinerator for controlling the amount of waste on the combustion grate to a target remaining amount is controlled. A garbage remaining amount calculating means for sequentially calculating the garbage remaining amount on the combustion grate from the upper pressure difference, and a current garbage amount calculated in the current cycle and a previous garbage amount calculated in the immediately preceding cycle. A difference remaining amount calculating means for calculating the difference remaining amount of the garbage, a membership function indicating a relationship between the garbage remaining amount and the difference remaining amount and the target remaining amount, A rule indicating the relationship between the amount of dust and Remaining amount and each time the difference remaining is calculated, the paper dust quantity control device of incinerator and a fuzzy processing means for calculating an optimal supply dust amount by using the membership functions and rules. 4. The rule is that, when the remaining amount of waste is slightly larger than the target remaining amount and the difference remaining amount indicates negative, the amount of dust supplied by the dust supply device is increased, and 4. A dust amount control device for a refuse incinerator according to claim 3, wherein when the difference remaining amount is slightly smaller than a target remaining amount and the difference remaining amount is positive, the dust amount by the dust feeding device is reduced.