JP3850228B2 - Dust supply control method in incinerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dust supply amount control method for controlling the amount of dust supplied to the furnace by the dust supply means in an incinerator for incinerating waste in a furnace.
[0002]
[Prior art]
Conventionally, garbage incineration equipment has been equipped with a dust supply mechanism as dust supply means for supplying garbage to the furnace, and calculates the amount of heat generated in the furnace by detecting the outlet temperature of the furnace and detecting the oxygen concentration of exhaust gas discharged from the furnace. In some cases, the amount of dust supplied to the furnace is controlled by adjusting the operation speed of the dust supply mechanism so that the heat generation amount is stabilized near the target heat generation amount.
That is, the heat generation per unit weight of the garbage is calculated from 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 the dust input into the dust supply mechanism by a crane or the like within the predetermined time. Estimate the so-called waste quality, determine the target incineration amount per unit time of the waste from this waste quality and the target calorific value, and further, the weight of the dust introduced into the dust feed mechanism within the predetermined time and the dust feed mechanism The dust infusion efficiency, which is the weight of dust supplied with respect to the operating speed of the dust supply mechanism, is determined from the operating speed of the dust supply mechanism. Based on the dust efficiency, the operating speed of the dust supply mechanism is set.
[0003]
[Problems to be solved by the invention]
However, in the control of the amount of waste supplied from the conventional waste incineration facility, the amount of waste actually supplied by the dust supply mechanism and the amount of waste estimated from the calorific value in the furnace calculated as described above are used. In some cases, errors may occur, causing the following problems.
For example, when the moisture content or bulk density of garbage changes abruptly, the amount of heat generated by the garbage supplied into the furnace changes abruptly, but this causes a change in the furnace outlet temperature. Even if feedback control of the amount of dust supply is performed, the response may be delayed.
[0004]
In addition, trash is thrown into the hopper by a crane usually at a period of about 15 to 20 minutes. However, if a bridge that does not drop in the hopper and the hopper level does not drop is thrown in, the trash is thrown in. The period may be longer. In addition, when the crane is operated manually, if the crane operator throws in the trash for some reason, the trash throwing cycle into the hopper becomes longer. The cycle is shortened. For this reason, the dust supply efficiency of the actual dust supply mechanism fluctuates, the control of the operation speed of the dust supply mechanism based on the amount of heat generated by the dust supplied into the furnace cannot catch up, and there is a risk that the dust will run out.
[0005]
Therefore, in view of the above circumstances, the present invention is a dust supply amount control capable of appropriately controlling the amount of dust supplied to the furnace by dust supply means in an incinerator for incinerating garbage in the furnace. The aim is to realize the method.
[0006]
[Means for Solving the Problems]
[Configuration 1]
The dust supply amount control method according to the present invention is the dust supply control method for controlling the amount of dust supplied to the furnace by dust supply means in an incinerator for incineration of dust in the furnace as described in claim 1. A quantity control method,
A dust supply efficiency calculation step of calculating a dust supply efficiency which is a supply amount of the dust with respect to an operating speed of the dust supply means;
Reference operation speed calculation for calculating the reference operation speed of the dust supply means from the dust supply efficiency calculated in the dust supply efficiency calculation step, the heat generation amount per unit amount of the dust, and the target heat generation amount in the furnace Process,
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 set in advance to the reference operation speed calculated in the reference operation speed calculation step. Features.
[0007]
[Function and effect]
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 dust to the furnace by the dust supply means within the predetermined unit time are also shown. The dust supply efficiency of the dust supply means is calculated from the supply amount of the dust, and then, in the reference operation speed calculation step, the reference operation speed that is the operation speed of the dust supply means for achieving the target heat generation amount in the furnace is calculated. calculate.
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 set in advance to the reference operation speed, preferably the reference operation speed. Is set to a value obtained by adding an additional amount of about 5 to 15% to the reference operation speed. In this way, the operating speed of the dust supply means is set to a value slightly larger than the value that achieves the target calorific value in the furnace, and the supply of dust to the furnace is slightly overexposed within the range of the furnace capacity. Therefore, even if there is a sudden drop in the quality of garbage supplied to the furnace, or a sudden drop in the dust supply efficiency of the dust supply means, the furnace always keeps the target in place without causing waste in the furnace. A calorific value can be secured.
[0008]
[Configuration 2]
According to the dust supply amount control method of the present invention, as described in claim 2, in addition to the configuration of the dust supply amount control method of the configuration 1, the ratio of the additional amount to the reference operation speed is a unit of the dust. The larger the heat generation amount per unit, the smaller the setting.
[0009]
[Function and effect]
According to the dust supply amount control method of this configuration, for example, the moving average value of the amount of dust thrown into the dust supply means by a crane or the like within the past predetermined time, and also generated in the furnace within the past predetermined time. Receives the heat generation amount per unit amount of dust supplied into the furnace, which can be automatically determined from the moving average value of the generated heat generation amount, or the heat generation amount per unit amount of dust input manually By setting the additional amount to be smaller as the amount of generated heat is larger, the upper limit capacity of the exhaust gas treatment facility or the like can be increased even if the operating speed of the dust supply means is set slightly excessively in the dust supply amount control method of the present invention. An excessive increase in the amount of heat generated in the furnace can be suppressed so as not to exceed.
[0010]
[Configuration 3]
According to the dust supply amount control method of the present invention, as described in claim 3, in addition to the configuration of the dust supply amount control method of the above configuration 1 or 2, the dust supply efficiency calculation step includes the supply of dust within a predetermined time. It is a step of calculating the dust supply efficiency from the operating speed of the dust means and the amount of dust input to the dust supply means within the same predetermined time.
[0011]
[Function and effect]
As in this configuration, in the dust supply efficiency calculation step, the dust supply efficiency is calculated using the operation speed of the dust supply means set in the operation speed setting step and a crane or the like that throws dust into the dust supply means. The dust supply efficiency of the dust supply means can be easily calculated from the respective moving average values within a predetermined time with the amount of dust input.
[0012]
[Configuration 4]
The dust supply amount control method according to the present invention includes the dust supply means in the operation speed setting step in addition to the configuration of the dust supply amount control method of any one of the configurations 1 to 3, as described in claim 4. When the heat generation amount in the furnace is equal to or higher than the target heat generation amount, the operation speed of the dust supplying means is temporarily reduced by a predetermined amount.
[0013]
[Function and effect]
According to the dust supply amount control method of the present configuration, in the operation speed setting step, the operation speed of the dust supply means is usually set slightly excessively with respect to the reference operation speed. If the operating temperature of the dust supply means is excessively excessive, the operating speed of the dust supply means is temporarily By setting the value rapidly reduced, for example, by about 50% or more with respect to the normal operating speed, it is possible to suppress the generation of heat generation deviating from the furnace capacity as described above.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the method for controlling the amount of dust supply in the refuse incinerator of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the waste incineration equipment to which the dust supply amount control method of the present invention can be applied includes the exhaust gas from a secondary combustion chamber 13 of the waste incinerator 10 to a flue D that leads to a chimney 19. The waste heat boiler 15 that generates steam by collecting the heat of the waste, that is, the incineration generated heat of the garbage incinerated on the firebed, the bag filter 16 that removes dust from the exhaust gas, and the exhaust gas after dust removal is detoxified. An exhaust gas treatment device 17 and an induction blower 18 for sending the exhaust gas after detoxification treatment toward the chimney are arranged in order. The refuse incinerator 10 is provided with a combustion control mechanism 20 for controlling the amount of combustion in the furnace under a predetermined condition. The combustion control mechanism 20 includes a temperature detection end 7a at the outlet of the furnace F. An exhaust gas temperature for detecting the temperature of the exhaust gas by arranging the detection end 8a in the flue D on the inlet side of the bag filter 16 and the furnace outlet temperature detecting means 7 arranged to detect the temperature of the combustion exhaust gas at the furnace outlet. A detection means 8 and an oxygen concentration detection means 6 for detecting the oxygen concentration in the exhaust gas by disposing an oxygen detection end 6a in the flue D on the outlet side of the bag filter 16 are provided. The steam generated in the waste heat boiler 15 is used as a drive source for the power generation apparatus 50 that generates power by rotating the turbine.
[0015]
Further, the garbage incinerator 10 includes a dust supply mechanism 11 for introducing garbage into the furnace F, a primary air supply mechanism 12 for supplying primary air into the furnace F, and incineration of the garbage in the furnace F. There is provided a secondary combustion chamber 13 in which a secondary combustion space S for secondary combustion of combustion gas generated by the processing is formed, and a secondary air supply mechanism 14 for supplying secondary air into the secondary combustion chamber 13. It is. The combustion control mechanism 20 is provided with dust supply amount control means 25 for controlling the amount of dust supplied to the furnace F by the dust supply mechanism 11 by setting a target heat generation amount for the combustion heat generation amount. Yes.
[0016]
The combustion control mechanism 20 is provided with an oxygen concentration detection means 6 for detecting the oxygen concentration in the exhaust gas at the outlet of the secondary combustion space S in the flue D on the downstream side of the secondary combustion space S. Further, the combustion control mechanism 20 is based on the oxygen concentration in the exhaust gas detected by the oxygen concentration detection means 6 and the total amount of combustion air supplied by the primary air supply mechanism 12 and the secondary air supply mechanism 14. Is provided with combustion calorific value calculation means 21 for calculating and deriving the combustion calorific value of the waste introduced into the furnace F, and further supplied by a combustion calorific value calculated in this way and a crane (not shown). Waste heat generation amount estimation means 22 that estimates the heat generation amount per unit weight of the dust supplied to the furnace F as the waste quality based on the weight of the dust put into the dust mechanism 11 is provided.
[0017]
Then, the combustion control mechanism 20 uses the dust supply mechanism 11 and the primary air supply based on the heat generation amount of the dust per unit weight estimated in this way and the target incineration amount of the dust set in advance. The mechanism 12 and the secondary air supply mechanism 14 are adjusted.
[0018]
Further, the dust supply amount control means 25 includes a dust supply efficiency calculation means 26 for executing a dust supply efficiency calculation step of calculating dust supply efficiency which is the amount of dust supplied with respect to the operating speed of the dust supply mechanism 11. In addition, the dust supply efficiency calculating means 25 calculates the moving average value of the operation speed of the dust supply mechanism 11 within a predetermined time of 2 to 3 hours, and the input weight of dust from the crane or the like to the dust supply mechanism 11 within the predetermined time. The dust supply efficiency is calculated based on the moving average value.
[0019]
Further, the dust supply amount control means 25 includes a reference operation speed calculation means 27, and the reference operation speed calculation means 27 includes a dust supply efficiency calculated by the dust supply efficiency calculation means 26 and a dust heat generation amount estimation means 22. Based on the estimated heat generation amount per unit weight of the dust and the target heat generation amount per unit time in the furnace F, which is obtained from the preset target incineration amount of the dust, the target heat generation amount by the dust supply mechanism 11 A reference operation speed calculation step of calculating a reference operation speed of the dust supply mechanism 11 that can supply the waste that emits to the furnace F is executed.
[0020]
And the dust supply control means 25 is provided with the operation speed setting means 28 which sets the operation speed of the dust supply mechanism 11 based on the reference | standard operation speed calculated in this way, and the operation speed setting means 28 is the dust supply mechanism. 11 is the value obtained by adding a predetermined additional amount to the reference operating speed calculated by the reference operating speed calculating means 27, preferably, an additional amount of about 5 to 15% with respect to the reference operating speed. An operation speed setting step for setting the value added to the operation speed is executed, and the operation speed of the dust supply mechanism 11 is set to a value slightly larger than a value estimated to be able to achieve the target heat generation amount in the furnace F. Thus, even if there is a sudden drop in dust supply efficiency, a reduction in dust quality, or the like, it is possible to suppress the occurrence of waste in the furnace F.
[0021]
Further, as shown in FIG. 2, the operation speed setting means 28 first, when the heat generation amount per unit weight of the dust estimated by the dust heat generation amount estimation means 22 is equal to or less than the reference dust heat generation amount as a design standard, Maintaining an additional rate, which is a ratio of the additional amount to be added to the reference operation speed, with respect to the reference operation speed to about 10%, and a heat generation amount per unit weight of the dust is equal to or higher than the reference dust heat generation amount and set in advance. When the heat generation amount is less than or equal to the waste heat generation amount, the above-mentioned additional rate is set within the range of 10% to 5% so that the heat generation amount per unit weight of the dust becomes smaller, and further the heat generation amount per unit weight of the dust Is equal to or greater than the amount of heat generated from high-quality dust, the above-mentioned additional rate is maintained at 5%. As described above, the operation speed setting means 28 sets the excess of the operation speed of the dust supply mechanism 11 to be low when high-quality garbage having a large calorific value per unit weight is put into the furnace F, An excessive increase in the amount of heat generated in the furnace F is suppressed.
[0022]
Furthermore, the operation speed setting means 28 is normally set to be slightly excessive with respect to the reference operation speed. However, when the heat generation amount in the furnace F exceeds the target heat generation amount, the dust supply mechanism 11 is set. If the operating speed of the dust supply mechanism 11 is maintained excessively, the operating speed of the dust supply mechanism 11 is temporarily set to the normal operating speed because there is a risk that a heat generation amount exceeding the upper limit of the capacity of the furnace F may occur. For example, the value is set to a value reduced by about 50% or more, and the temporary operation speed is reduced in a pulse manner until the state returns to an appropriate state.
[0023]
In the waste incineration equipment configured as described above, the amount of water vapor generated from the waste heat boiler 15 with the additional rate of the operating speed of the dust supply mechanism 11 set to 15% in order to confirm the stability of the heat generation amount. As a result, the water vapor amount is within ± 5% at a frequency of 90% or more, and it can be seen that the heat generation amount of the furnace F is stable.
[Brief description of the drawings]
[Fig. 1] Schematic configuration diagram of garbage incineration equipment [Fig. 2] Graph diagram showing the relationship between the amount of heat generated by garbage and the set rate of addition
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 Reference operation speed calculation means 28 Operation speed setting means F Furnace

Claims (4)

In an incinerator for incinerating waste in a furnace, a dust supply amount control method for controlling the amount of dust supplied to the furnace by dust supply means,
A dust supply efficiency calculation step of calculating a dust supply efficiency which is a supply amount of the dust with respect to an operating speed of the dust supply means;
Reference operation speed calculation for calculating the reference operation speed of the dust supply means from the dust supply efficiency calculated in the dust supply efficiency calculation step, the heat generation amount per unit amount of the dust, and the target heat generation amount in the furnace Process,
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 set in advance to the reference operation speed calculated in the reference operation speed calculation step. Quantity control method.   2. The dust supply amount control method according to claim 1, wherein a ratio of the additional amount with respect to the reference operation speed is set to be smaller as a heat generation amount per unit amount of the dust is larger.   The dust supply efficiency calculation step is a step of calculating the dust supply efficiency from an operating speed of the dust supply means within a predetermined time and an amount of dust input to the dust supply means within a predetermined time. Item 3. A method for controlling the amount of dust supply according to Item 1 or 2.   In setting the operation speed of the dust supply means in the operation speed setting step, when the heat generation amount in the furnace is equal to or greater than the target heat generation amount, the operation speed of the dust supply means is temporarily set to a predetermined amount. The method for controlling the amount of dust supply according to any one of claims 1 to 3, wherein:

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