JP2002349827A - Method for controlling dust feeding amount in incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a dust feeding amount controlling method to properly control an amount of refuse fed in a furnace F by a refuse feeding means 11, in an incinerator 10 to incinerate and dispose of refuse in the furnace F. SOLUTION: A process wherein the refuse feeding efficiency of the refuse feeding means 11 is calculated; a process wherein from the calculated refuse feeding efficiency, a heating value per a unit amount of refuse, and a target heating amount in the furnace F, a reference operation speed of the refuse feeding means 11 is calculated; and a process wherein the operation speed of the refuse feeding means 11 is set to an operation speed where a given additional amount is added to a reference operation speed are executed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the amount of dust supplied to the furnace by the dust supply means in an incinerator for incinerating dust in a furnace.

[0002]

2. Description of the Related Art Conventionally, a refuse incineration system is provided with a dust supply mechanism as dust supply means for supplying refuse to the furnace, and detects the temperature at the exit of the furnace and the oxygen concentration of the exhaust gas discharged from the furnace, and so on. In some cases, the calorific value is calculated, and the operation speed of the dust supply mechanism is adjusted so that the calorific value is stabilized near the target calorific value, thereby controlling the amount of dust supplied to the furnace. That is, based on the moving average of the calorific value calculated within a predetermined time of 2 to 3 hours and the moving average of the weight of dust input to the dust supply mechanism by the crane or the like within the same predetermined time, the heat generation per unit weight of the dust is calculated. The amount of so-called dust is estimated, the target incineration amount per unit time of the dust is determined from the dust quality and the target calorific value. From the operation speed of the dust supply mechanism, the dust supply efficiency, which is the weight of the dust with respect to the operation speed of the dust supply mechanism, is obtained. The target incineration amount and the supply amount are set so that the supply amount of the dust by the dust supply mechanism becomes the target incineration amount. The operation speed of the dust supply mechanism is set based on the dust efficiency.

[0003]

However, in the control of the amount of refuse supplied to the conventional refuse incineration equipment, the quality of the refuse actually supplied by the dust supply mechanism and the amount of heat generated in the furnace as calculated above are controlled. Between the garbage quality estimated from
An error may occur, causing the following problem. For example, when the moisture content and bulk density of the refuse change rapidly, the calorific value of the refuse supplied into the furnace changes rapidly. Even if feedback control of the supply amount of garbage is performed, the response may be delayed.

Further, dust is usually thrown into the hopper by a crane at a cycle of about 15 to 20 minutes. If a bridge occurs in which the thrown dust does not fall in the hopper and the hopper level does not decrease, There is a case that the garbage input cycle becomes longer. In addition, when the crane is operated manually, if the input of dust by the operator of the crane is delayed for some reason, the input cycle of the dust into the hopper becomes longer, The cycle becomes shorter.
For this reason, the actual dust supply efficiency of the dust supply mechanism fluctuates, and the control of the operation speed of the dust supply mechanism based on the calorific value of the dust supplied into the furnace may not catch up, and the dust may run out.

Accordingly, the present invention has been made in view of the above circumstances,
It is an object of the present invention to realize a dust supply amount control method capable of appropriately controlling a supply amount of the dust into the furnace by a dust feeding unit in an incinerator for incinerating dust in a furnace.

[0006]

According to a first aspect of the present invention, there is provided a dust supply amount control method according to the first aspect of the present invention, wherein in the incinerator for incinerating garbage in a furnace, the dust is supplied by the dust supply means. A dust supply amount control method for controlling a supply amount of the dust to the inside, wherein a dust supply efficiency calculating step of calculating a dust supply efficiency which is a supply amount of the dust with respect to an operation speed of the dust supply means; A dust supply efficiency calculated in the dust efficiency calculation step, a calorific value per unit amount of the dust, and a target calorific value in the furnace, a reference operation speed calculation step of calculating a reference operation speed of the dust supply means, And an operation speed setting step of setting the operation speed of the dust supply means to an operation speed obtained by adding a predetermined additional amount to the reference operation speed calculated in the reference operation speed calculation step.

According to the dust supply amount control method of this configuration, first, in the dust supply efficiency calculation step, the operation speed of the dust supply means within a predetermined unit time and the operation speed of the dust supply unit within the predetermined unit time are also determined. The above-mentioned dust-supplying efficiency of the dust-supplying means is calculated from the amount of refuse supplied to the furnace by the dusting means, and then, in the reference operation speed calculating step, the operating speed of the dust-supplying means for achieving the target heating value in the furnace. Is calculated. In the dust supply control method of the present invention, in the operation speed setting step, the operation speed of the dust supply means is a value obtained by adding a predetermined additional amount to the reference operation speed, preferably,
An additional amount of about 5 to 15% of the reference operation speed is set to a value obtained by adding to the reference operation speed. in this way,
By setting the operation speed of the dust supply means to a value slightly larger than the value that achieves the target calorific value in the furnace, the supply of dust to the furnace is slightly excessive within the range of the capability of the furnace. Even if the quality of refuse supplied to the furnace suddenly decreases or the dust supply efficiency of the dust supply means drops sharply, the furnace does not run out of refuse and always keeps the target heating value in the furnace. can do.

[0010] According to a second aspect of the present invention, in addition to the configuration of the dust supply amount control method of the first aspect, the dust supply amount control method according to the present invention further comprises the addition of the additional amount to the reference operation speed. The ratio is set to be smaller as the calorific value per unit amount of the dust is larger.

According to the dust supply amount control method of this configuration, for example, the moving average value of the amount of dust introduced into the dust supply means by a crane or the like within a predetermined time in the past is the same as that in the past. The heating value per unit amount of garbage supplied to the furnace, which can be automatically calculated from the moving average value of the heating value generated in the furnace within the time, or the unit amount of garbage manually input In the dust supply amount control method of the present invention, even if the operation speed of the dust supply unit is set to be slightly excessive, exhaust gas is received by receiving the heat generation amount and setting the additional amount to be smaller as the received heat generation amount is larger. Excessive rise in the calorific value in the furnace can be suppressed so as not to exceed the upper limit capacity of the processing equipment or the like.

[Structure 3] In the dust supply amount control method according to the present invention, in addition to the structure of the dust supply amount control method according to the above structure 1 or 2, the dust supply efficiency calculating step may be carried out. Calculating the dust supply efficiency from the operation speed of the dust supply unit within a predetermined time and the amount of dust input to the dust supply unit within the predetermined time.

[Effects] As in the present configuration, in the dust supply efficiency calculating step, the operation speed of the dust supply means set in the operation speed setting step is determined by calculating the dust supply efficiency. It is possible to easily calculate the dust-supply efficiency of the dust-supply unit from the moving average value and the like within a predetermined time with the amount of dust that is measured by a crane or the like that throws the dust.

[Structure 4] According to a fourth aspect of the present invention, in addition to the configuration of the dust supply amount control method of any one of the first to third aspects, the dust supply amount control method according to the present invention further comprises the operation speed setting method. In the step, when the operation speed of the dust supply unit is set, the operation speed of the dust supply unit is temporarily reduced by a predetermined amount when the heat generation amount in the furnace becomes equal to or more than the target heat generation amount. It is characterized by.

[Operation and Effect] According to the dust supply amount control method of this configuration, in the operation speed setting step, the operation speed of the dust supply means is usually set to be slightly excessive with respect to the reference operation speed. However, when the calorific value in the furnace exceeds the target calorific value, it is considered that if the operation speed of the dust supply means is set to an excessive degree, there is a risk that a calorific value exceeding the capacity of the furnace may occur, and By temporarily setting the operating speed to a value that is sharply reduced by, for example, about 50% or more with respect to the normal operating speed, the generation of the heat generation that deviates from the furnace capability as described above is suppressed. be able to.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for controlling the amount of dust supplied to a refuse incinerator according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, a refuse incineration facility to which the dust supply amount control method of the present invention can be applied includes a flue D from a secondary combustion chamber 13 of a refuse incinerator 10, Waste heat boiler 15 that collects the heat of the waste, that is, the heat generated by incineration of the refuse incinerated on the grate, and generates steam, and a bag filter 16 that removes dust from the exhaust gas
And an exhaust gas treatment device 17 for detoxifying the exhaust gas after dust removal, and an induction blower 18 for sending the exhaust gas after the detoxification toward the chimney. The refuse incinerator 10 is provided with a combustion control mechanism 20 for controlling the amount of combustion in the furnace under predetermined conditions. The combustion control mechanism 20 has a temperature detection end 7a at the outlet of the furnace F. Furnace outlet temperature detecting means 7 for detecting the temperature of the flue gas at the furnace outlet, and a detecting end 8a for the flue D on the inlet side of the bag filter 16 for detecting the temperature of the exhaust gas. The apparatus is provided with a detecting means 8 and an oxygen concentration detecting means 6 for arranging an oxygen detecting end 6a in the flue D on the outlet side of the bag filter 16 to detect the oxygen concentration in the exhaust gas. The steam generated by the waste heat boiler 15 is
It is used as a drive source of a power generation device 50 that generates power by rotating a turbine.

The refuse incinerator 10 includes a dust supply mechanism 11 for introducing refuse into the furnace F, a primary air supply mechanism 12 for supplying primary air into the furnace F, and a A secondary combustion chamber 13 that forms a secondary combustion space S for secondary combustion of combustion gas generated by the incineration of garbage; and a secondary air supply mechanism 14 that supplies secondary air into the secondary combustion chamber 13 Are provided. The combustion control mechanism 20 includes:
The amount of refuse supplied into the furnace F by the dust supply mechanism 11 is
Dust supply amount control means 25 is provided for setting and controlling a target heat generation amount with respect to the combustion heat generation amount.

The combustion control mechanism 20 is provided with an oxygen concentration detecting means 6 for detecting the oxygen concentration in the exhaust gas at the outlet of the secondary combustion space S in the flue D downstream of the secondary combustion space S. I have. Further, the combustion control mechanism 20 determines the oxygen concentration in the exhaust gas detected by the oxygen concentration detecting means 6 and the total amount of combustion air supplied by the primary air supply mechanism 12 and the secondary air supply mechanism 14. The combustion heating value calculating means 21 for calculating and deriving the combustion heating value of the refuse charged into the furnace F is provided. Further, the combustion heating value calculated in this manner is supplied by a crane (not shown) or the like. A dust heating value estimating means 22 for estimating a heating value per unit weight of the dust supplied to the furnace F as dust quality based on the weight of the dust input to the dust mechanism 11.

The combustion control mechanism 20 then controls the dust supply mechanism 11 based on the heat generation amount of dust per unit weight estimated in this way and a preset target incineration amount of dust.
Then, the primary air supply mechanism 12 and the secondary air supply mechanism 14 are adjusted.

The dust supply amount control means 25 includes a dust supply mechanism 1.
1 is provided with a dust supply efficiency calculating means 26 for executing a dust supply efficiency calculating step of calculating a dust supply efficiency which is a supply amount of dust with respect to the operation speed of 1;
The dusting efficiency is determined based on the moving average value of the operating speed of the dust supply mechanism 11 within a predetermined time of 3 hours and the moving average value of the weight of dust input from the crane or the like to the dust supply mechanism 11 within the predetermined time period. Is calculated.

The dust supply amount control means 25 includes a reference operation speed calculation means 27.
Is calculated from the dust-supply efficiency calculated by the dust-supply efficiency calculating means 26, the heat value per unit weight of dust estimated by the dust heat value estimating means 22, and the preset target incineration amount of dust. A reference operation speed for calculating a reference operation speed of the dust supply mechanism 11 capable of supplying dust generating the target heat generation amount to the furnace F based on the target heat generation amount per unit time in the furnace F based on the target heat generation amount per unit time. Execute the calculation process.

The dust supply control means 25 includes an operation speed setting means 28 for setting the operation speed of the dust supply mechanism 11 based on the reference operation speed calculated as described above. The operation speed of the dust supply mechanism 11 is a value obtained by adding a predetermined additional amount to the reference operation speed calculated by the reference operation speed calculation means 27, preferably, a ratio of about 5 to 15% of the reference operation speed. An operation speed setting step of setting the amount to a value obtained by adding the amount to the reference operation speed is performed, and the operation speed of the dust supply mechanism 11 is slightly larger than the value estimated to be able to achieve the target heating value in the furnace F. When the value is set to a value, even if a sudden decrease in dust supply efficiency or a decrease in dust quality occurs, it is possible to prevent the furnace F from running out of dust.

Further, as shown in FIG. 2, the operating speed setting means 28 first determines that the heat value per unit weight of dust estimated by the dust heat value estimating means 22 is equal to or smaller than a reference dust heat value as a design standard. At this time, the rate of addition of the additional amount to the reference operation speed, which is the ratio of the additional amount to the reference operation speed, is maintained at about 10%, and the heat generation amount per unit weight of the dust is equal to or more than the reference heat generation amount and is set in advance. When the heat generation amount is less than the high-quality garbage, the additional rate is set in the range of 10% to 5% so that the heat generation amount per unit weight of the garbage becomes smaller as the heat generation amount becomes larger. If the calorific value of the
The above addition rate is maintained at 5%. In this way, the operation speed setting means 28 sets the excessive degree of the operation speed of the dust supply mechanism 11 low when high-quality dust having a large heat value per unit weight is put into the furnace F, This suppresses an excessive increase in the calorific value in the furnace F.

Further, the operating speed setting means 28 normally sets the operating speed to be slightly excessive with respect to the reference operating speed. However, when the calorific value in the furnace F exceeds the target calorific value, If the operating speed of the dust mechanism 11 is maintained at an excessive level, there is a danger that a heating value exceeding the upper limit of the capacity of the furnace F may be generated. For example, the speed is set to a value reduced by about 50% or more with respect to the speed, and further, the temporary reduction of the operating speed is performed in a pulsed manner until the speed returns to an appropriate state.

In the garbage incineration system configured as described above, the dust supply mechanism 11 is used to confirm the stability of the calorific value.
As a result of measuring the amount of water vapor generated from the waste heat boiler 15 by setting the above-mentioned addition rate of the operation speed of the furnace to 15%, the amount of water vapor was within ± 5% at a frequency of 90% or more, and the heat generation of the furnace F It can be seen that the amount is stable.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a garbage incineration facility.

FIG. 2 is a graph showing the relationship between the amount of heat generated by dust and a set additional rate;

[Explanation of symbols]

 Reference Signs List 10 incinerator 11 dust supply mechanism (dust supply means) 20 combustion control mechanism 25 dust supply amount control means 26 dust supply efficiency calculation means 27 standard operation speed calculation means 28 operation speed setting means F furnace

Claims (4)

[Claims] 1. An incinerator for incinerating garbage in a furnace, comprising: a dust supply amount control method for controlling a supply amount of the refuse into the furnace by a dust supply unit; A dust supply efficiency calculating step of calculating a dust supply efficiency that is a supply amount of the dust with respect to, a dust supply efficiency calculated in the dust supply efficiency calculation step, a calorific value per unit amount of the dust, and A reference operation speed calculation step of calculating a reference operation speed of the dust supply unit from the target heat generation amount, and a predetermined addition of the operation speed of the dust supply unit to the reference operation speed calculated in the reference operation speed calculation step. An operation speed setting step of setting an operation speed to which the amount has been added. 2. The dust supply amount control method according to claim 1, wherein a ratio of the additional amount to the reference operation speed is set smaller as a heat generation amount per unit amount of the dust is larger. 3. The dust-supply efficiency calculating step includes calculating the dust-supply efficiency from an operation speed of the dust-supply means within a predetermined time and an amount of dust input to the dust-supply means within the same predetermined time. The dust supply amount control method according to claim 1, wherein the dust supply amount is controlled. 4. An operation speed setting step for setting the operation speed of the dust supply unit, wherein the operation speed of the dust supply unit is temporarily set when a heat generation amount in the furnace becomes equal to or more than the target heat generation amount. The dust supply amount control method according to any one of claims 1 to 3, wherein the predetermined amount is reduced.