JPH01193511A - Operation control method in waste incineration plant - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for controlling the operation of a waste incineration plant, and more particularly to a method for controlling the operation of a plant that incinerates municipal waste and utilizes its residual heat.

[Conventional technology] An incinerator for incinerating municipal waste, etc., and its residual heat (
In a waste incineration plant equipped with residual heat utilization equipment such as a boiler that utilizes combustion heat, it is necessary to control the operation of the incinerator in order to make it a stable heat supply source.

Conventionally, this type of operation control method detects the burnout point of garbage in an incinerator that incinerates garbage while sequentially transferring it, and adjusts the moving speed of garbage to keep it at a constant position. The aim was to obtain stable combustion conditions.

[Problems to be Solved by the Invention] However, in the above method, all of the transferred amount of waste is incinerated in the same way, regardless of the properties of the waste, so it is not necessarily necessary to maintain the generated amount of heat at the desired amount. I couldn't do that.

In other words, there is generally a negative correlation between the appearance and specific gravity of garbage, such that the larger the lower heat value ωflu of the garbage, the smaller it is, so it is not possible to adjust the calorific value by limiting the amount of garbage. It is possible to some extent.

However, the correlation differs depending on the proportion of moisture, organic matter, etc. contained in the garbage, and in some cases it may be a positive correlation. If the engine is operated to burn out garbage with contradictory properties in the same way, the amount of heat generated will naturally be a value that is significantly different from what was predicted. Also,
Even if the correlation between the lower calorific value and the apparent specific gravity is constant, if the amount transferred increases or decreases, the amount of heat supplied will vary accordingly.

On the other hand, in an incinerator, incineration residue (incineration ash) after incineration
In order to reduce the loss by burning to a predetermined value or less, it is necessary to appropriately supply combustion air to achieve as complete combustion as possible.

That is, in order to control the amount of heat, it is necessary to control the amount of combustion air with priority given to R, so it is difficult to simultaneously set the burn loss to an appropriate value.

However, as shown in FIG. 3, there is a negative correlation between the heat generation iHu and the optimum air ratio ε related to the ablation loss.

For example, it is a well-known fact that for low-quality garbage (minimum heat generation), increase the air volume by 1 mm, and for high-quality garbage (maximum heat generation), reduce the air-to-air ratio to maintain the amount of heat lost by burning. . In this way, keeping the amount of heat supplied to the residual heat utilization equipment constant and maintaining the burn loss within a specified value are different approaches to the control system.

Therefore, the present invention aims to keep the amount of heat supplied to the residual heat utilization equipment constant regardless of the properties of the waste, and to reduce the amount of heat ignited from the incinerated ash.
We provide an operation control method that can maintain the
It was invented.

[Means and effects for solving the v1 problem] The present invention provides an incinerator that combusts urban waste by appropriately supplying combustion air while transporting municipal waste, and residual heat utilization equipment for effectively utilizing the combustion heat. In the method of controlling the operation of a waste incineration plant having By incorporating the latest operating information at that time into the correlation formula between moving speed and heat amount obtained from actual results and finding a new correlation formula, we can ensure that the garbage that is incinerated immediately afterward generates the desired amount of heat. The air ratio is calculated by the amount of combustion air supplied above and the detected amount of heat by a control device that has a learning function that calculates the travel speed required for combustion by back calculating from the above correlation formula. Then, the transfer operation is performed by increasing or decreasing the above-mentioned back-calculated moving speed in order to obtain the air ratio necessary for combustion of the waste.

This method makes it possible to keep the amount of heat generated by the waste constant. Furthermore, by adjusting the moving speed of the garbage so as to maintain the air ratio at a certain constant value, the loss of incinerated ash by burning can be controlled to a predetermined value.

[Example] Embodiments of the present invention will be described below with reference to the accompanying drawings.

First, the configuration of an embodiment of a waste incineration plant to which the operation control method for a waste incineration plant according to the present invention is applied will be described.

As shown in FIG. 1, this waste incineration plant is mainly composed of an incinerator 1 and a boiler 2 which is equipment for utilizing residual heat. In this embodiment, the incinerator 1 uses a rotary stoker type incinerator, and includes a furnace body 3 that performs main combustion, a post-combustion stoker 4 provided at the end of the furnace body 3, and a rotary stoker type incinerator. It has a furnace 5 which is provided in an upwardly erected manner.

The furnace body 3 is formed as a cylindrical body held slightly tilted from the horizontal, and is equipped with a hopper 6 and a feed button 7 at one end to prevent rotation around an axis and the feed button 7.
By extrusion, the municipal waste S from the hopper 6 is sequentially transferred in the axial direction. Further, a wind box 8 is provided at the bottom of the furnace body 3 along the transfer direction to supply combustion air to the waste S in the furnace.

Then, the supply button 7, the furnace body 3. And in the wind box 8,
Detectors 9, 10 for detecting respective driving states.
11 are provided.

The post-combustion stoker 4 is formed as an endless conveyor, receives the incinerated ash A from the furnace main body 3 on its upper surface, and while further transporting it, burns the unburned matter remaining in the incinerated J311iA to reduce the amount of ash by burning. The ash is turned into small, so-called clean ash and is discharged outside the furnace.

For combustion, air is supplied by a wind box 12 provided similarly to that of the furnace main body 3, and in this embodiment, a detector 13 is used to also detect the amount of air. has been established.

The furnace 5 uses air from an air nozzle (not shown) to combust unburned gas and unburned carbon whose combustion has not been completed within the furnace body 3, and discharges waste gas from the combustion to the outside of the furnace. ing.

The boiler 2 is provided on the discharge side of the furnace 5 and is adapted to recover the thermal energy of the high-temperature gas in the form of steam. In other words, the heat generated by incineration is supplied to the boiler 2. A heat quantity detector 14 according to the present invention is provided in this boiler 2 to detect the quantity of heat supplied.

This incineration plant includes a supply button 7, a furnace body 3. In order to appropriately control the drive of the afterburning stoker 4, a known operation control device @15 is provided, and based on information obtained by a data detection means (not shown) provided at a predetermined position, For stable combustion,
The combustion air tank and the like are appropriately controlled via the controller 23 and air supply means 24.

In particular, according to the invention, the extrusion speed of the dust feed button 7 detected by the detector 9.10.14.

Stroke length, interval, and rotation speed of the furnace body 3.

From the amount of heat input to the boiler 14, the calculation unit 16
．． 17 performs appropriate calculations, and the feeding button driving means 21 and the furnace body rotating means 22 are adjusted via the general operator 18 and each controller 19, 20.

Further, information from the detectors 11 and 13 for detecting the amount of air is input to the general calculator 18.

Next, one embodiment of the present invention will be described as the effect of the above configuration.

The furnace body 3 incinerates the waste S from the hopper 6 while being sequentially transferred by intermittent strokes of the dust feeder 7 and rotation around the axis. This incineration is controlled by combustion conditions.
For example, by detecting the temperature of the exhaust gas inside the furnace body 3, the amount of air supplied is adjusted to achieve proper combustion.

Then, as shown in FIG. 2, the transfer state and the heat generation state of the garbage S are detected, and the transfer operation is performed to achieve the desired amount of heat generation HO.

The transfer state is calculated based on the stroke of the feed button 7 and the rotation speed of the furnace body 3 using the moving speed W of the waste as an index. The heat generation state is calculated from the heat amount H supplied to the boiler 2 as a lower heat value Hu specific to the waste.

Then, this moving speed W and the lower heating port H of the garbage at that time
u and the general computing unit 1 by an arbitrary number from past operation data.
8 as data and calculate the correlation formula. This is expressed as follows.

■ W = f t (llu) ・=Refer to Figure 2 (A) ■ Formula is the moving speed W and local heat generation lH at a certain time.
It represents the relationship with u, and also represents the properties of the waste S.

Next, the desired amount of heat HO is input into the general calculation 518, and the moving speed Wo is calculated backwards.

HO-+HuO ■ ft (t1uo) = WO, , see Fig. 2 (B) On the other hand, the air ratio ε is calculated from the detected air amount and the transfer state 1 heat generation state at that time, and the desired air ratio ε is calculated. A comparison calculation is performed with the optimum air ratio ε0 that results in a loss of heat by burning. If there is a difference 73e between these values, the corresponding moving speed IW is calculated and added to the moving speed Wo obtained by formula (2) for fine adjustment. For example, the air ratio ε at that time is the optimal air ratio ε0
If the sword is smaller than , the moving speed Wo is divided into its domain.

(Wo + 711w=Wp) From then on, the operation of the feed button 7 and the furnace body 3 is adjusted so as to achieve this moving speed Wp by reversing the procedure used to obtain the data.

In this way, the system is operated with a control device that has a learning function that constantly rewrites and controls the optimal data content (phase-opening method) without using fixed data, so it can handle garbage of all types. The operation can be controlled so that a predetermined amount of heat is stably generated over a long period of time. Furthermore, the calculation of the lower heat generation tooth is performed by detecting the amount of heat supplied to the boiler, and is extremely practical because it uses the moving speed of the garbage, which is directly related to the amount of combustion, as an index.

In general, reduce the loss of incinerated ash by a predetermined amount (for example, 3% or less)
Since the moving speed is corrected to control the air ratio so that the amount of heat generated is always constant and at the same time it is possible to create a high-performance incinerator that produces clean incinerated ash.

Although a rotary stoker type incinerator is illustrated as the incinerator of the waste incineration plant to which the present invention is applied, other incinerators, such as a moving bed type stoker type incinerator, may be used. In this case, the transfer state data is the transfer speed. Further, the feeding device may be of a rotary type, and the stroke of the bushing is equivalent to its rotational speed. In any case, it is sufficient if the state of transport of waste can be expressed using an appropriate index.

However, as a matter of course, the present invention is applicable to an incineration plant in which the air supply etc. are controlled so that the transported waste is always properly combusted.

[Effects of the Invention] In summary, according to the present invention, the following excellent effects are achieved.

(1) By detecting the moving speed and amount of heat of the waste to be transferred, and calculating a new correlation equation by incorporating the latest operating information at that time into the correlation equation between the moving speed and the amount of heat, waste is incinerated immediately after that. The transfer operation is performed by calculating backward from the correlation equation the speed of movement necessary for the garbage to be combusted to generate the desired amount of heat, so the desired amount of heat is always achieved regardless of the nature of the garbage. can be obtained, and the incinerator can be used as a stable heat supply source.

(2) Calculate the air ratio based on the amount of combustion air supplied and the amount of heat supplied, and perform transfer operation by increasing or decreasing the back-calculated moving speed to achieve the air ratio necessary for combustion of the garbage. This makes it possible to reduce the amount of incinerated ash to a desired value, contributing to the maintenance of a high-performance incinerator.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of a waste incineration plant to which the operation control method for a waste incineration plant according to the present invention is applied, and Fig. 2 illustrates the operation of Fig. 1 which is an embodiment of the present invention. 3 are relationship diagrams between the air ratio and the lower calorific value for explaining the problems of the conventional operation control method in a waste incineration plant. In the diagram, 1 is an incinerator, 2 is a boiler that is equipment for utilizing residual heat, and 15
is an operation control device. Figure 1

Claims (1)

[Claims] 1. A waste incineration plant is equipped with an incinerator that incinerates municipal waste by appropriately supplying air for combustion while transporting municipal waste, and residual heat utilization equipment for effectively utilizing the combustion heat. In a method of controlling operation to maintain a constant amount of heat, by detecting the moving speed of the waste to be transferred and the amount of heat, a correlation equation between the moving speed and the amount of heat obtained from past operation results is expressed as: By incorporating the latest operating information at that time and finding a new correlation formula, the moving speed required for the garbage to be incinerated immediately after to be combusted to generate the desired amount of heat can be calculated using the above correlation. In addition to calculating backwards from the formula, the air ratio is calculated from the amount of garbage supplied, the amount of combustion air supplied above, and the detected amount of heat, and the air ratio is determined to be the air ratio necessary for combustion of the garbage. An operation control method for a waste incineration plant, characterized in that the transfer operation is performed by increasing or decreasing the back-calculated movement speed.