JP2020186838A - Waste incinerator, and control method of refuse feeding device of waste incinerator - Google Patents

Abstract

To provide a waste incinerator capable of improving quantitative feeding performance of waste.SOLUTION: A waste incinerator 1 includes a refuse feeding device 6, and a control device 21 for controlling the refuse feeding device 6. The refuse feeding device 6 has an upper refuse feeder 7 and a lower refuse feeder 8 which are vertically disposed on a receiving floor 23. The control device 21 controls the upper refuse feeder 7 and the lower refuse feeder 8 on the basis of at least one of a moisture content of waste W in a hopper 5 detected by a moisture sensor 19, hydraulic pressures of hydraulic cylinders 7b, 8b of the upper refuse feeder 7 and/or the lower refuse feeder 8 detected by pressure sensors 17, 18, and a property of the waste W on the receiving floor 23 acquired on the basis of a thermal image of the waste W on the receiving floor 23 picked up by a thermal image pick-up device 22.SELECTED DRAWING: Figure 1

Description

The present invention relates to a waste incinerator that incinerates waste such as municipal waste and a method for controlling a dust supply device of the waste incinerator.

The waste incinerator is provided with a hopper into which the waste is put and a furnace for burning the waste. At the bottom of the hopper, a dust supply device is provided to push the waste put into the hopper into the furnace. At the bottom of the furnace, a grate that supplies combustion air to the waste and transports the waste is provided. The waste extruded by the dust feeder is supplied onto the grate of the furnace.

In order to continuously and stably burn waste, it is important to supply a fixed amount of waste to the furnace. That is, it is ideal to supply a constant calorific value of waste onto the grate at a constant speed. In order to improve the quantitative supply of waste, Patent Document 1 states that the dust supply device is composed of two upper and lower dust dispensers, and the upper dust dispenser and the lower dust dispenser are based on the combustion status of the waste in the furnace. A technology relating to a waste incinerator that controls a dust dispenser is disclosed.

Japanese Unexamined Patent Publication No. 2000-28121

By the way, since there are various types of waste put into the hopper, the properties of the waste vary. For example, a waste containing a large amount of water (low calorific value) may be charged into the hopper, or a waste having a low water content may be charged into the hopper. Moisture-rich waste may be consolidated in the hopper and firmly adhered. In this case, even if the waste is pushed out by the dust supply device, it does not fall on the grate, but accumulates on the receiving floor (hanging on the shelf), and a large amount of waste falls on the grate at one time (suspended on the shelf). Phenomena such as (dropping) are likely to occur.

This shelving phenomenon and the drop-off phenomenon can be dealt with by simply controlling the upper dust dispenser and the lower dust dispenser based on the combustion state of the waste in the furnace, as in the technique disclosed in Patent Document 1. I can't. This is because, in the technique disclosed in Patent Document 1, the upper dust dispenser and the lower dust dispenser are sometimes controlled based on the combustion state in the furnace after the shelving phenomenon or the falling phenomenon occurs. This is because there is a time lag in the ever-changing situation, and control is delayed. For this reason, there is a problem that it becomes difficult to ensure the quantitative supply of waste.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a waste incinerator and a method for controlling a dust supply device of a waste incinerator, which can improve the quantitative supply of waste. And.

In order to solve the above problems, one aspect of the present invention includes a dust supply device that pushes out the waste put into the hopper and supplies it onto the grate, and a control device that controls the dust supply device. In the lattice type incinerator, the dust supply device has an upper dust supply machine and a lower dust supply machine arranged vertically on the receiving floor, and the control device is a waste in the hopper detected by a moisture sensor. The receiver acquired based on the water content, the hydraulic pressure of the hydraulic cylinder of the upper dust dispenser and / or the lower dust dispenser detected by the pressure sensor, and the thermal image of the waste on the floor imaged by the thermal image imaging device. A waste incinerator that controls the upper dust dispenser and the lower dust dispenser based on at least one of the properties of waste on the floor.

Another aspect of the present invention is a method of controlling a dust supply device of a waste incinerator that pushes out the waste charged into the hopper and supplies it onto the grate, in which the dust supply devices are arranged vertically on the receiving floor. The water content of the waste in the hopper detected by the moisture sensor, the upper dust dispenser and / or the hydraulic cylinder of the lower dust dispenser detected by the pressure sensor. Based on at least one of the properties of the waste on the floor obtained based on the thermal image of the waste on the floor taken by the hydraulic and thermal image imaging device, the upper dust dispenser and the lower It is a control method of the dust supply device of the waste incinerator that controls the dust dispenser.

According to the waste incinerator of the present invention, the water content of the waste in the hopper, the oil pressure of the hydraulic cylinder of the upper dust dispenser and / or the lower dust dispenser, and the heat of the waste on the floor imaged by the thermal image capturing apparatus. Since the upper dust dispenser and the lower dust dispenser are controlled based on at least one of the properties of the waste on the floor acquired based on the image, the waste shelf suspension phenomenon and the drop-off phenomenon occur. Can be prevented. Therefore, the quantitative supply of waste can be improved.

It is a vertical sectional view (including a functional block diagram of a control device) of the waste incinerator of one Embodiment of this invention. FIG. 2A is a diagram showing the forward end position, the backward end position, and the stroke width of the upper dust dispenser and the lower dust dispenser in the normal operation mode, and FIG. 2B is a diagram showing the upper dust dispenser in the loosening operation mode. It is a figure which shows the forward end position, the backward end position, and the stroke width of the lower dust dispenser. It is a flowchart which shows the flow of the process of determining the property of waste. It is a figure which shows the thermal image schematically.

Hereinafter, the waste incinerator according to the embodiment of the present invention will be described in detail with reference to the accompanying drawings. However, the waste incinerator of the present invention can be embodied in various forms, and is not limited to the embodiments described in the specification. The present embodiment is provided with the intention of allowing those skilled in the art to fully understand the invention by adequately disclosing the specification.

FIG. 1 shows a vertical sectional view of a waste incinerator 1 according to an embodiment of the present invention. The waste incinerator 1 of the present embodiment is provided at the bottom of the furnace main body 2 in which the main combustion chamber 3 and the secondary combustion chamber 4 are formed, the hopper 5 into which the waste W is charged, and the bottom of the hopper 5. , The dust supply device 6 that supplies the waste W to the furnace body 2, the exhaust unit 9 that discharges the exhaust gas generated by the combustion of the waste W in the furnace body 2, and the ash content after the combustion of the waste W are discharged. It has an ash discharge unit 10.

A grate 11 is provided at the bottom of the main combustion chamber 3. The grate 11 includes a movable grate and a fixed grate. The waste W on the grate 11 is dried, burned, and post-combusted while being sent forward by the reciprocating motion of the movable grate.

The grate 11 is classified into a dry grate 11a, a combustion grate 11b, and a post-combustion grate 11c in order from the upstream side. In the dry grate 11a, the waste W is mainly dried and ignited. In the combustion grate 11b, the combustible gas generated by the thermal decomposition of the waste W and the thermal decomposition and the fixed carbon content (char) are mainly burned. In the post-combustion grate 11c, the fixed carbon component (char) left unburned in the combustion stage is burned, and the waste W is completely burned. The ash content on the post-combustion grate 11c is discharged from the ash content discharge unit 10.

Air for primary combustion is sent into the air boxes 12a, 12b, and 12c of the dry grate 11a, the combustion grate 11b, and the post-combustion grate 11c, respectively, by the air supply pipe 13. A pressure feed blower 15 is connected to the air supply tube 13 via a damper 14. The primary combustion air is supplied to the furnace body 2 via the grate 11. The amount of primary combustion air is adjusted by the damper 14.

A secondary combustion chamber 4 is provided on the downstream side of the combustion gas of the main combustion chamber 3. In the secondary combustion chamber 4, unburned gas is secondarily burned. The exhaust gas after the secondary combustion is discharged from the exhaust unit 9. A waste heat boiler (not shown) is provided in the secondary combustion chamber 4. The exhaust gas after the secondary combustion is recovered by the waste heat boiler. The steam generated by the heat recovered by the waste heat boiler is used for power generation by the generator.

A dust supply device 6 is provided on the receiving floor 23. The dust supply device 6 includes an upper dust supply machine 7 and a lower dust supply machine 8 arranged vertically on the receiving floor 23. The lower dust dispenser 8 includes a lower pusher 8a provided so as to be able to move forward and backward on the receiving floor 23, and a hydraulic cylinder 8b for moving the lower pusher 8a forward and backward. The upper dust feeder 7 includes an upper pusher 7a provided so as to be able to advance and retreat on the lower pusher 8a, and a hydraulic cylinder 7b for advancing and retreating the upper pusher 7a.

Flood control is supplied to the hydraulic cylinders 7b and 8b of the upper dust dispenser 7 and the lower dust dispenser 8 from a hydraulic pump (not shown) via a switching valve. By controlling the switching valve by the control device 21, the upper dust dispenser 7 and the lower dust dispenser 8 are controlled. The upper dust dispenser 7 and the lower dust dispenser 8 are independently controlled by the control device 21, and they do not operate integrally, but operate independently.

The forward end position, moving speed, stroke width, and backward end position of the upper dust dispenser 7 and the lower dust dispenser 8 are set independently for each of the upper dust dispenser 7 and the lower dust dispenser 8. In this embodiment, as shown in FIG. 2A, the dimension of the upper dust dispenser 7 (upper pusher 7a) in the furnace length direction is shorter than that of the lower dust dispenser 8. The forward end position and the backward end position of the upper dust dispenser 7 are behind that of the lower dust dispenser 8. The stroke width L1 of the upper dust dispenser 7 is larger than the stroke width L2 of the lower dust dispenser 8. The operating speed of the upper dust dispenser 7 is slower than that of the lower dust dispenser 8. As a result, the waste W near the drop on the head wall 16 is loosened, the waste W falls smoothly, and the quantitative supply of the waste W is improved. Further, by setting the forward end position of the upper dust supply machine 7 to be rearward of that of the lower dust supply machine 8, the waste W on the lower dust supply machine 8 (lower pusher 8a) is separated by the upper dust supply machine 7. It can be pushed forward of the lower dust dispenser 8.

As shown in FIG. 1, pressure sensors 17 and 18 are attached to the hydraulic cylinders 7b and 8b of the upper dust dispenser 7 and the lower dust dispenser 8. The pressure sensors 17 and 18 detect the oil pressure of the hydraulic cylinders 7b and 8b and send the information of the oil pressure to the control device 21. By detecting the oil pressure of the hydraulic cylinders 7b and 8b by the pressure sensors 17 and 18, it is possible to know the degree of adhesion of the waste W in front of the upper dust dispenser 7 and the lower dust dispenser 8.

A moisture sensor 19 is provided on the wall of the hopper 5. The moisture sensor 19 detects the moisture content of the waste W in the hopper 5 and sends the information on the moisture content of the detected waste W to the control device 21. Various methods can be adopted for the moisture sensor 19, for example, a transmission type microwave intensity method, a contact type capacitance method, a transmission type capacitance method, and an infrared intensity method can be adopted. In addition, the waste W containing a large amount of water tends to stick in the hopper 5. Therefore, by detecting the moisture content of the waste W in the hopper 5 with the moisture sensor 19, it is possible to know the degree of adhesion of the waste W in the hopper 5.

A level meter 20 is provided above the waste W charged into the hopper 5. The level meter 20 detects the height of the waste W and sends the information on the height of the detected waste W to the control device 21. In addition, there is a time lag before the waste W at the position of the moisture sensor 19 (moisture measurement position) reaches the dust supply device 6. Therefore, the control device 21 calculates the descending speed of the waste W based on the height of the waste W, and calculates the time lag until the waste W reaches the dust supply device 6 from the moisture measurement position.

An infrared camera 22 as a thermal image imaging device is provided on the side wall of the furnace body 2 on the ash discharge portion 10 side. The infrared camera 22 captures a thermal image of the waste W deposited on the receiving floor 23. The infrared camera 22 acquires a thermal image by detecting infrared rays having a specific wavelength.

As shown in the functional block diagram of the control device 21 of FIG. 1, the control device 21 includes an image processing unit 31, a property determination unit 32, and a control unit 33.

The image processing unit 31 performs image processing such as smoothing on the thermal image input from the infrared camera 22 at regular time intervals.

The property determination unit 32 determines the property of the waste W on the receiving floor 23 based on the thermal image processed by the image processing unit 31. The properties include, for example, the layer thickness of the waste W on the receiving floor 23, the amount of protrusion of the waste W on the receiving floor 23 from the head wall 16, the moisture content of the waste W on the receiving floor 23, and the disposal on the receiving floor 23. Types of material W (waste W with a lot of plastic, waste W with a lot of paper waste) and the like. By acquiring the properties of the waste W on the receiving floor 23, it is possible to know the degree of adhesion of the waste W on the receiving floor 23. The property determination unit 32 may include an identification unit 32a constructed by machine learning of the learning unit 32b.

FIG. 3 is a flowchart showing a flow of processing for acquiring the properties of the waste W. First, the infrared camera 22 acquires a thermal image of the waste W on the receiving floor 23. The thermal image is input to the property determination unit 32 via the image processing unit 31 (S1). FIG. 4 schematically shows a thermal image. The property determination unit 32 acquires a feature amount (for example, the brightness value of each pixel of the thermal image) from the thermal image of the waste W on the receiving floor 23 (S2). Next, the property determination unit 32 determines the properties of the waste W, for example, the layer thickness of the waste W on the receiving floor 23, the amount of protrusion of the waste W from the head wall 16, and the moisture content of the waste W, based on the feature amount. , The type of waste W and the like are determined (S3).

As shown in FIG. 1, the control unit 33 and the dust feeder 7 are based on at least one of the input from the moisture sensor 19, the input from the pressure sensors 17 and 18, and the input from the property determination unit 32. Controls the lower dust dispenser 8. That is, the control unit 33 has the upper dust dispenser 7 and the lower dust dispenser based on any one of the input from the moisture sensor 19, the input from the pressure sensors 17 and 18, and the input from the property determination unit 32. 8 may be controlled, or the upper dust dispenser 7 and the lower dust dispenser are based on two inputs, an input from the moisture sensor 19, an input from the pressure sensors 17 and 18, and an input from the property determination unit 32. 8 may be controlled, and the upper dust dispenser 7 and the lower dust dispenser are based on the input from the moisture sensor 19, the input from the pressure sensors 17 and 18, and the input from the property determination unit 32. 8 may be controlled.

Specifically, when the moisture content of the waste W in the hopper 5 detected by the moisture sensor 19 fluctuates (for example, when the moisture content in the hopper 5 is higher than a predetermined threshold value), the control unit 33 feeds the waste W. The command values of the operation parameters of the dust machine 7 and the lower dust supply machine 8 are changed. As described above, there is a time lag until the waste W reaches the dust supply device 6 from the moisture measurement position. The control unit 33 changes the designated values of the upper dust dispenser 7 and the lower dust dispenser 8 in consideration of this time lag.

Similarly, when the oil pressure of the hydraulic cylinders 7b and 8b detected by the pressure sensors 17 and 18 fluctuates (for example, when the oil pressure of the hydraulic cylinders 7b and 8b is higher than a predetermined threshold value), the control unit 33 supplies the feed. The command values of the operation parameters of the dust machine 7 and the lower dust supply machine 8 are changed. Further, when the properties of the waste W on the receiving floor 23 acquired by the control unit 33 based on the thermal image captured by the infrared camera 22 fluctuate (for example, the layer thickness of the waste W is greater than a predetermined threshold value). (When it is high), the command values of the operation parameters of the upper dust dispenser 7 and the lower dust dispenser 8 are changed.

Actually, the control device 21 also includes another control unit that adjusts the command values of the operation parameters of the upper dust dispenser 7 and the lower dust dispenser 8 based on other inputs. Further, the control unit 33 opens the operation parameters of the grate 11 (speed of the movable grate, etc.) and the operation parameters of the damper 14 (opening of the damper 14) based on the input of the layer thickness of the waste W on the grate 11. Adjust the command value of (degree, etc.).

The functional block of the control device 21 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip or the like), or may be realized by software. In the latter case, the control device 21 includes a computer that executes a program that is software that realizes each function.

When the control unit 33 changes the command values of the upper dust dispenser 7 and the lower dust dispenser 8, the operation modes of the upper dust dispenser 7 and the lower dust dispenser 8 are changed from the normal operation mode shown in FIG. 2A. The mode is switched to the loosening operation mode shown in 2 (b). In the loosening operation mode, the lower dust dispenser 8 is put out in front of the upper dust dispenser 7, and the movement of the lower dust dispenser 8 is made finer. That is, the stroke width of the lower dust dispenser 8 is reduced from L2 to L3, and the number of round trips per unit time is increased. The forward end position of the lower dust dispenser 8 and the speed of the lower dust dispenser 8 are the same as in the normal operation mode. The upper dust dispenser 7 operates in the same manner as in the normal operation mode. As a result, the stuck waste W can be loosened.

Contrary to the above, in the loosening operation mode, the stroke width of the upper dust dispenser 7 may be reduced and the number of round trips per unit time may be increased. Further, the stroke widths of both the upper dust feeder 7 and the lower dust dispenser 8 may be reduced, and the number of round trips per unit time may be increased.

The configuration of the waste incinerator of the present embodiment has been described above. The waste incinerator of the present invention is not limited to being embodied in the above embodiment, and can be embodied in other embodiments without changing the gist of the present invention.

For example, in the above-described embodiment, the example in which the two-stage dust dispenser is arranged vertically on the receiving floor 23 has been described, but the dust dispenser having three or more stages vertically may be arranged on the receiving floor 23. Further, the upper dust dispenser 7 and the lower dust dispenser 8 may be arranged in two or more rows in the width direction of the floor receiving 23.

1 ... Waste incinerator 5 ... Hopper 6 ... Dust supply device 7 ... Upper dust dispenser 7b, 8b ... Hydraulic cylinder 8 ... Lower dust dispenser 11 ... Grate 17, 18 ... Pressure sensor 19 ... Moisture sensor 21 ... Control device 22 ... Infrared camera (thermal image imaging device)
23 ... Floor W ... Waste

Claims (5)

In a grate-type incinerator including a dust supply device that pushes out the waste put into the hopper and supplies it onto the grate, and a control device that controls the dust supply device.
The dust supply device has an upper dust supply machine and a lower dust supply machine arranged vertically on the receiving floor.
The control device is captured by the moisture content of the waste in the hopper detected by the moisture sensor, the oil pressure of the hydraulic cylinder of the upper dust dispenser and / or the lower dust dispenser detected by the pressure sensor, and the thermal image imaging device. Waste incineration that controls the upper dust dispenser and the lower dust dispenser based on at least one of the properties of the waste on the floor obtained based on the thermal image of the waste on the floor. Furnace. The waste incinerator according to claim 1, wherein the forward end position of the stroke of the upper dust dispenser is behind the forward end position of the stroke of the lower dust dispenser. The retracted end position of the stroke of the upper dust dispenser is behind the retracted end position of the stroke of the lower dust dispenser.
The waste incinerator according to claim 2, wherein the stroke width of the upper dust dispenser is longer than the stroke width of the lower dust dispenser. The control device has at least one of the upper dust dispenser and the lower dust dispenser when at least one of the moisture content of the waste in the hopper, the oil pressure of the hydraulic cylinder, and the properties of the waste on the receiving floor fluctuates. The waste incinerator according to any one of claims 1 to 3, wherein one stroke width is reduced and the number of round trips per unit time is increased. In the control method of the dust supply device of the waste incinerator that pushes out the waste put into the hopper and supplies it on the grate.
The dust supply device has an upper dust supply machine and a lower dust supply machine arranged vertically on the receiving floor.
Moisture of waste in the hopper detected by the moisture sensor, hydraulic pressure of the hydraulic cylinder of the upper dust dispenser and / or the lower dust dispenser detected by the pressure sensor, and on the floor imaged by the thermal image imaging device. A dust supply device of a waste incinerator that controls the upper dust dispenser and the lower dust dispenser based on at least one of the properties of the waste on the floor obtained based on the thermal image of the waste. Control method.

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