JP3669779B2 - Combustion control device for garbage incinerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention includes a stoker-type incineration treatment zone for carrying out an incineration treatment while transporting the waste introduced into the furnace by a dust supply mechanism, a combustion gas supply mechanism for supplying a combustion gas from below the incineration treatment zone, Combustion control device for a refuse incinerator comprising a heat exchanger for heating the combustion gas supplied by the combustion gas supply mechanism and a temperature control means for adjusting the heating temperature of the combustion gas by the heat exchanger About.
[0002]
[Prior art]
In a conventional combustion control apparatus for a garbage incinerator, in order to keep a good combustion state of garbage in the furnace, the heating temperature of the combustion gas by the heat exchanger is in the range of about 70 ° C. to 100 ° C. by the temperature control means. It was adjusted to enter.
However, depending on the quality, such as moisture content and calories, of the waste to be incinerated on the incineration zone, there is a risk that the drying will be insufficient and the combustion state will deteriorate, and the flue provided above the incineration zone will The inlet side gas temperature or the generated steam flow rate of the waste heat boiler provided in the flue is detected, and as a result of indirect determination of the combustion state based on the value, for example, if the combustion state is bad, the garbage quality is bad A weight detection mechanism is installed on the crane mechanism that adjusts the heating temperature of the combustion gas (for example, air) to a high temperature side to accelerate the drying of the garbage and the crane mechanism that transports the garbage to the garbage hopper. In addition, the apparent specific gravity of dust is obtained based on the weight of dust detected by the weight detection mechanism, and the heating temperature of the combustion gas is adjusted based on the value, judging the quality of dust before combustion.
[0003]
[Problems to be solved by the invention]
However, what detects the gas temperature on the inlet side of the flue or the generated steam flow rate of the waste heat boiler described above detects the amount of heat generated in the entire incineration treatment zone, and therefore is abnormal based on the detected value. When it is determined that the combustion is in a low-temperature combustion state, a large amount of low-calorie waste with a high water content has already been put into the furnace in large quantities, and it takes a considerable amount of time to recover this. On the contrary, when it is determined that the combustion state is abnormally high based on the detected value, the temperature of the grate constituting the incineration treatment zone becomes abnormally high and burnout occurs. There was a problem that it became a habit.
On the other hand, in the case of detecting the specific gravity of garbage, not only does the garbage become compacted in the garbage hopper, but it is not clear when the garbage conveyed to the garbage hopper is put into the furnace. There was a problem similar to that described above.
The object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to accurately detect the quality of garbage immediately after the start of combustion, thereby predicting the future combustion state and capable of continuously performing stable garbage combustion control. It is in providing a furnace combustion control device.
[0004]
[Means for Solving the Problems]
In order to achieve this object, the characteristic configuration of the combustion control device for a refuse incinerator according to the present invention includes a stoker-type incineration treatment zone for carrying out an incineration treatment while transporting the dust introduced into the furnace by a dust supply mechanism, and the incineration treatment A combustion gas supply mechanism for supplying combustion gas from below the belt, a heat exchanger for heating the combustion gas supplied by the combustion gas supply mechanism, and a heating temperature of the combustion gas by the heat exchanger. Temperature control means for adjusting, provided with infrared detection means for detecting the radiation temperature of the dust in the ignition start area in the incineration treatment zone, the temperature control means based on the dust surface temperature detected by the infrared detection means Thus, the heating temperature of the combustion gas is adjusted.
The temperature control means preferably adjusts the heating temperature of the combustion gas to the high temperature side when the detected dust surface temperature is lower than the low temperature side reference temperature for a predetermined time.
Furthermore, it is preferable that the temperature control means adjusts the heating temperature of the combustion gas to a low temperature side when the detected dust surface temperature is higher than the high temperature side reference temperature for a predetermined time.
[0005]
The operation will be described below.
There is no noticeable difference in the radiant temperature of the trash immediately after charging into the furnace due to the quality of the trash, and the radiant temperature of the trash after charging and before ignition can hold the trash even if the effect of moisture can be grasped. The amount of heat cannot be determined. For example, even if only the moisture content is detected, such as crushed dust with a large amount of heat even if it contains a lot of moisture, the subsequent combustion state cannot be controlled appropriately. According to the radiation temperature in the ignition start region, it is detected that the combustion temperature is high for high-calorie dust, and the combustion temperature is low for low-calorie dust, so that the subsequent combustion state can be estimated based on the value.
On the other hand, since the quality of the input garbage does not fluctuate so much in a short time, it becomes possible to adjust the heating temperature of the combustion gas in advance while predicting the subsequent combustion state. Thus, it is possible to maintain a good combustion state by avoiding a decrease in incineration amount due to a low-temperature combustion state and burning of a grate due to an abnormal high-temperature combustion state. Even when the quality of the thrown-in dust changes extremely, the radiation temperature detection area is not so far away from the dust supply port, so that the influence can be suppressed to a minimum.
Furthermore, when judging the quality of dust, the detected dust surface temperature is lower than the low-temperature reference temperature indicating low-calorie dust, or higher than the high-temperature reference temperature indicating high-calorie dust. If it is a short time, it is determined that it will not have a significant effect on the subsequent combustion state. It can be avoided.
[0006]
【The invention's effect】
Therefore, according to the present invention, by detecting the quality of the dust immediately after the start of combustion and upstream of the combustion center position, while avoiding inconvenience such as burning of the grate in advance, It has become possible to provide a combustion control apparatus for a garbage incinerator capable of continuously performing stable garbage combustion control.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention will be described below.
As shown in FIG. 1, the garbage incinerator includes a waste hopper 3 having a push-in mechanism 5 as a dust supply mechanism at the bottom, and a stoker type that incinerates the waste thrown in by the push-in mechanism 5. Incineration zones 6, 7, 8, an ash pit 4 for collecting ash that has been treated by the incineration zones 6, 7, 8, and a flue 2 formed in the space above the incineration zones 6, 7, 8 The waste heat boiler 16 and the exhaust gas treatment device 17 provided in the above are configured.
[0008]
The push-in mechanism 5 reciprocates a push-in action member (not shown) that pushes the dust thrown into the dust hopper 3 toward the dust supply port 1 by the hydraulic cylinder C1 so as to throw the dust into the furnace. It is configured.
The incineration treatment zones 6, 7, and 8 include a drying zone 6 that dries while feeding the dust introduced from the inlet 1, and a combustion zone 7 that burns while carrying the dust dried in the drying zone 6. In addition, a post combustion zone 8 for ashing the waste burned in the combustion zone 7 is connected through stepped portions d1 and d2, and each processing zone is a grate G arranged in a slanting vertical position. Is constituted by a stoker mechanism that reciprocally moves the cylinder in a slanting vertical direction with hydraulic cylinders C2, C3, and C4.
Under the incineration treatment zones 6, 7, and 8, a wind box 12 is provided separately, and a combustion gas supply mechanism A that supplies air as combustion gas by a blower 13 through a supply path 14 is provided. Each wind box 12 is provided with a damper D for adjusting the air supply amount. The supply path 14 is provided with a heat exchanger T that adjusts the temperature of the supply air using exhaust gas or generated steam, and is provided with temperature control means 30 that adjusts the heating temperature based on the quality of dust.
The residue ashed in the post-combustion zone 8 falls on the ash chute 10 and is accumulated in the ash pit 4 by a conveyor mechanism.
The waste heat boiler 16 generates steam by the thermal energy held in the combustion exhaust gas secondary-combusted in the flue 2 and drives a steam turbine connected to the generator 18. The exhaust gas that has passed through the waste heat boiler 16 is exhausted from a chimney (not shown) through an exhaust gas treatment device 17 such as a bag filter or a smoke washing device.
[0009]
In the above-mentioned waste incinerator, the amount of steam detected by a steam amount detection sensor (not shown) provided in the waste heat boiler 16 is generated in the waste heat boiler 16 in order to incinerate the target amount of waste. Waste transport control means for adjusting the amount of dust input by the push-in mechanism and the speed of transport of dust by the incineration treatment zones 6, 7, and 8 so that the target steam amount calculated and derived as the amount of steam to be generated 20 and a supply air amount control means (not shown) for adjusting the amount of air blown from each wind box 12 are provided.
Here, the target steam amount is the efficiency of the boiler due to the difference between the total heat quantity such as the average retained heat quantity of dust, the heat input quantity by combustion air, etc., and the total heat quantity such as the heat output quantity by exhaust gas and the loss heat quantity. The multiplied value is obtained as the amount of heat provided for steam generation, and the amount of steam generated by the amount of heat is calculated and obtained.
[0010]
On the downstream side wall of the rear combustion zone 8, there is provided a television camera 21 as an imaging means for detecting the combustion flame in the combustion zone 7, and an image of the combustion flame input by the television camera 21 is image processing means. The end position of gasification combustion, that is, the burnout position is detected by processing (not shown).
Based on the burnout position detected by the image processing means, the transport speed in the drying zone 6 or the combustion zone 7 by the dust transport control means 20, that is, the number of operations per unit time of the hydraulic cylinders C2 and C3 is determined. The first correcting means 20a for correcting is provided, and if the detected burnout position is on the downstream side of the allowable range, the number of operations per unit time is set so that the burnout position is on the upstream side in order to secure the target heat reduction amount. If the detected burnout position is on the upstream side of the allowable range, the number of operations per unit time is increased and corrected so that the burnout position is on the downstream side in order to avoid a decrease in the grate combustion rate.
[0011]
On the ceiling wall of the drying zone 6 is provided an infrared camera I as an infrared detection means facing the drying zone 6 to detect the radiation temperature of dust in the ignition start area in the incineration treatment zone.
More specifically, the infrared detecting means detects the radiation energy from the furnace corresponding to the black body radiation energy as shown in FIG. 2, and obtains the temperature. As shown in FIG. In order to avoid the infrared energy absorption band due to CO, CO ₂ , NOx, SOx, and H ₂ O in the flame ignited above, the infrared camera has a transmission wavelength of about 3.9 (3.6 to 4). A filter (not shown) of μm is attached, so that the radiant energy can be measured through the combustion flame in the dry zone 6.
The infrared camera I captures an image that passes through the filter and an image that does not pass through the filter, and an image processing means (not shown) detects a region where a temperature difference on the drying zone 6 in both images is detected. The region is determined to be an ignition region, and a region having a predetermined width immediately upstream is set as an ignition start region, and an average value of dust surface temperatures in an image through the filter in the region is obtained.
Based on the average value, there is provided second correction means 20b for correcting the amount of dust input by the push-in mechanism determined by the dust transport control means 20, that is, the number of operations per unit time of the hydraulic cylinder C1. When the temperature lower than the low temperature side reference temperature continues for a predetermined time, the number of operations per unit time of the hydraulic cylinder C1 is lowered stepwise in a range of 10 to 30% depending on the temperature and time. In this case, it is possible to reduce the amount of dust input and avoid the transition to the poor combustion state.On the other hand, when the state higher than the high-temperature side reference temperature continues for a predetermined time, the temperature and time are By increasing the number of operations per unit time of the hydraulic cylinder C1 upward in a range of 10 to 30%, the amount of dust input is increased and the dust is exhausted. To avoid the line.
[0012]
Further, the temperature control means 30 adjusts the temperature of the air by the heat exchanger T based on the average value, and the average value is the air temperature that is normally maintained at about 70 ° C. to 100 ° C. When the temperature lower than the low temperature side reference temperature continues for a predetermined time, the air temperature is increased from about 150 ° C. to 200 ° C. according to the degree, and the transition to the poor combustion state is promoted by promoting the drying / combustion of garbage. On the other hand, when the state where the average value is higher than the high temperature side reference temperature continues for a predetermined time, the air temperature is lowered to room temperature to prevent burning of the grate due to high temperature combustion. Here, the air temperature may be adjusted only for the drying zone 6 or may be adjusted including the combustion zone 7.
[0013]
As described above, the combustion control device of the refuse incinerator is combusted from the stoker type incineration treatment zone in which the dust introduced into the furnace is conveyed by the dust supply mechanism 5 and from below the incineration treatment zone. Combustion gas supply mechanism A for supplying the combustion gas, heat exchanger T for heating the combustion gas supplied by the combustion gas supply mechanism A, and adjusting the heating temperature of the combustion gas by the heat exchanger T And an infrared detector I for detecting the radiation temperature of the dust in the ignition start area in the incineration treatment zone, and the temperature controller 30 is detected by the infrared detector I. The heating temperature of the combustion gas is adjusted based on the temperature.
[0014]
A part or all of the function realizing means such as the dust conveyance control means, infrared detection means, temperature control means, correction means, etc., described above, uses various computers such as microcomputers, memory circuits, and other known peripheral circuit techniques. It is composed.
[0015]
Another embodiment will be described below.
In the above-described embodiment, the infrared detecting means is provided with a filter having a wavelength of 3.9 μm and is configured to be used with an infrared camera that is switched between a mounted state and a non-mounted state. The wavelength is not limited to a 9 μm filter, and any wavelength can be used as long as it can avoid the infrared energy absorption band due to the gas interposed between the object to be measured and the radiation temperature measuring instrument 1, and an infrared ray equipped with a filter having a wavelength of 3.9 μm Two infrared cameras, that is, a camera and an infrared camera not equipped with the filter, may be provided to shoot separately. Furthermore, the infrared detection means is not limited to the infrared camera, and can be configured using a known infrared detection element as appropriate. For example, a spot type infrared sensor is provided so as to face the inside of the furnace from a measurement hole formed in the ceiling wall of the drying zone 6, and the dust surface temperature on the drying zone 6 has a spot diameter of several tens mm to several hundreds mm. A plurality of locations may be measured.
[0016]
The low-temperature side reference temperature is preferably about 900 ° C., and the high-temperature side reference temperature is preferably about 1000 ° C., but is not limited to this value, and is appropriately determined based on the average quality of the garbage treated in each garbage incinerator. Just do it. In addition, the predetermined time at that time is preferably about 15 to 30 minutes, but can be appropriately determined according to the scale of the furnace.
[0017]
In the above-described embodiment, the second correction unit 20b corrects the amount of dust input by the push-in mechanism determined by the dust transport control unit 20, that is, the number of operations per unit time of the hydraulic cylinder C1. As described above, the target processing amount may be corrected. In other words, if the temperature lower than the low temperature side reference temperature continues for a predetermined time, the target processing amount is corrected downward in the range of a maximum of 10% depending on the degree, thereby reducing the amount of dust input and causing a poor combustion state. While avoiding the transition, if the temperature higher than the high temperature side reference temperature continues for a predetermined time, the amount of dust input is increased by correcting the target processing amount upward within a range of up to 10% depending on the degree. To avoid going out of garbage.
[0018]
In addition, although the code | symbol is written in order to make contrast with drawing convenient for the term of a claim, this invention is not limited to the structure of an accompanying drawing by this entry.
[Brief description of the drawings]
[Fig. 1] Schematic configuration diagram of a garbage incinerator [Fig. 2] Wavelength characteristic diagram of black body radiation energy [Fig. 3] Characteristic diagram of atmospheric transmittance [Explanation of symbols]
5 Dust supply mechanism 30 Temperature control means I Infrared detection means T Correction means I Heat exchanger

Claims (3)

A stoker-type incineration treatment zone for carrying out incineration treatment while transporting the dust introduced into the furnace by the dust supply mechanism (5), and a combustion gas supply mechanism for supplying combustion gas from below the incineration treatment zone (A) A heat exchanger (T) for heating the combustion gas supplied by the combustion gas supply mechanism (A), and a temperature control means for adjusting the heating temperature of the combustion gas by the heat exchanger (T) ( 30) a combustion control device for a garbage incinerator,
Infrared detection means (I) for detecting the emission temperature of dust in the ignition start area in the incineration treatment zone is provided, and the temperature control means (30) is burned based on the dust surface temperature detected by the infrared detection means (I) Combustion control device for a garbage incinerator configured to adjust the heating temperature of the industrial gas. The temperature control means (30) adjusts the heating temperature of the combustion gas to a high temperature side when the detected dust surface temperature is lower than a low temperature side reference temperature for a predetermined time. Combustion control device for the refuse incinerator described. The temperature control means (30) adjusts the heating temperature of the combustion gas to a low temperature side when the detected dust surface temperature is higher than the high temperature side reference temperature for a predetermined time. Or the combustion control apparatus of the refuse incinerator of 2.

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