JPS6080020A - Burning control of refuse incinerator - Google Patents

Abstract

PURPOSE:To maintain automatically the steady burning even in case of a lower quality material refuse incineration by a method wherein a low level heating value of a refuse is estimated and an air quantity is changed according to the estimated value. CONSTITUTION:A LHV estimating device 4 estimates and calculates the LHV (low level heating value) of a refuse 11 with a heat balance method and the like based on the determined value for a boiler vaporizing quantity 1, a burning air quantity 2 and a burning air temperature 3 and the like. The estimated value LHV5 is inputted to a function, then an O2 target setting value 7 is calculated based on the LHV. Meanwhile, a normal O2 constant control device 8 compares the O2 measurements 9 with the O2 target setting valve 7 inputted in cascade manner, then an air quantity adjusting signal 10 is outputted so that the deviation is made to be zero. Thereby, the LHV changing is estimated moment by moment, when the LHV is low, the operation is maintained under higher level of the O2 target setting value, the amount of the air is introduced larger than the amount of the air which corresponds to the load, thus, the drying of refuse is accelerated by the diffusion effect, accordingly, the steady burning is maintained.

Description

【発明の詳細な説明】 となるよう、操作員が手動にて操作したり、最近では自
動的に空気量を調節する装置を付加して、へ一定運転す
るプラントが増えて来ている。ところがごみ質は時々刻
々変化し、水分の多い低質ごみの場合は炉内での乾燥が
不十分となり、燃焼が不安定となる事があり、このよう
な時には、空気量を若干条目にする運転方法を操作員の
判断で実施しているが、常時監視の必要があったり、ま
た経験も必要である等の不具合があり、従って自動化の
要望が出ていた。DETAILED DESCRIPTION OF THE INVENTION In order to achieve this, an increasing number of plants are operated manually by an operator or, recently, by adding a device that automatically adjusts the amount of air. However, the quality of waste changes from moment to moment, and low-quality waste with a high moisture content may not be sufficiently dried in the furnace, resulting in unstable combustion. The method is implemented at the discretion of the operator, but there are drawbacks such as the need for constant monitoring and the need for experience, so there have been requests for automation.

本発明は前記従来の要望にこたえて提案されたもので、
低質ごみにおいても安定した燃焼を自動的に維持するご
み焼却炉用燃焼制御方法を提供することを目的とするも
ので、ごみ焼却炉における燃焼空気量を調節する方法に
おいて、ごみの低位発熱量を推定し、その値に従って空
気量を変更するごみ焼却炉燃焼制御方法に係り、焼却炉
の運転データよりＬＨＶ　（低位発熱量）を推定し、予
じめ設定した低位発熱量対Ｏ２目標設定値の関数に従っ
て、低ＬＨＶ時は〇一定制御装置の目標設定値をカスケ
ード的に上昇することを特徴とするものである。The present invention has been proposed in response to the above-mentioned conventional demands.
The purpose of this project is to provide a combustion control method for waste incinerators that automatically maintains stable combustion even with low-quality waste. The method involves estimating the LHV (lower heating value) from the incinerator operating data and changing the air volume according to the estimated value. According to the function, when the LHV is low, the target setting value of the constant control device is increased in a cascade manner.

以下本発明の実施例を図面について説明すると、第１図
は本発明の実施例を示し、Ｌ）ＩＶ推定装置４は、排熱
回収用のボイラ蒸発量１、燃焼空気量２、燃焼空気温度
３等の実測値をもとに熱収支法等を用いてごみ１１のＬ
ＨＶ　（低位発熱量）を推定計算する。推定ＬＨＶ５の
値は、関数に入力され、ＬＨＶに相当するＯＬ目標設定
値７を算出する。An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 shows an embodiment of the present invention, and the L) IV estimating device 4 includes a boiler evaporation amount 1 for exhaust heat recovery, a combustion air amount 2, and a combustion air temperature. The L of garbage 11 is determined using the heat balance method etc. based on the actual measured values of 3 etc.
Estimate and calculate HV (lower heating value). The value of the estimated LHV5 is input to a function to calculate the OL target set value 7 corresponding to the LHV.

関数の形は、例えば第２図に示すように設定する。The form of the function is set, for example, as shown in FIG.

ここでごみＬＨＶの推定方法を第３図についである。Here, the method for estimating the waste LHV is shown in Fig. 3.

また給水１２、蒸気１３についてはＷ６＝Ｗ４と仮定し
、エンタルピーも等しく、一定とすると、（Ｑ４−Ｑ６
）は蒸気量から算出できる。一方排ガス温度は、ボイラ
１４のバイパスガス量を調節する事により一定に制御さ
れ、エンタルピー一定となり、排ガス１５０量Ｗ５＝Ｗ
ｌ　＋Ｗ２より０５がめられる。また灰１６の量Ｗ３お
よび比熱を一定と仮定すると、Ｑ３がめられる。更にご
み１１の比熱を一定とすると、Ｑｌがめられる。Assuming that W6=W4 for the water supply 12 and steam 13, and assuming that the enthalpies are also equal and constant, (Q4-Q6
) can be calculated from the amount of steam. On the other hand, the exhaust gas temperature is controlled to be constant by adjusting the amount of bypass gas in the boiler 14, and the enthalpy is constant, and the amount of exhaust gas 150 W5=W
05 is determined from l +W2. Further, assuming that the amount W3 of the ash 16 and the specific heat are constant, Q3 is obtained. Furthermore, assuming that the specific heat of the dust 11 is constant, Ql can be determined.

以上よりボイラ蒸発量、燃焼空気１７量、燃焼空気温度
、ごみ量が実測できれば、ＬＨＶがめられる。なお、１
８は炉を示す。From the above, if the amount of boiler evaporation, amount of combustion air, temperature of combustion air, and amount of waste can be measured, LHV can be determined. In addition, 1
8 indicates a furnace.

一方通常の０２一定制御装置８はＯＬ測定値９と、カス
ケード的に入力されたＯ目標設定値７を比較し、偏差が
零となるよう燃焼空気量調節信号１゜を出力する。これ
によって時々刻々変化するＬＨＶを推定し、低い場合は
ＯＬ目標設定値を高目に運転する事によって、負荷に見
合った空気量より多口の空気が注入され、拡散効果によ
るごみの乾燥が促進され、安定燃焼が維持される。なお
、ごみのＬＨＶが低いという事と、ごみの水分が多いと
いう事は同じと考えてよい。On the other hand, the normal 02 constant control device 8 compares the OL measurement value 9 with the 0 target setting value 7 input in a cascade manner, and outputs a combustion air amount adjustment signal of 1° so that the deviation becomes zero. This estimates the LHV, which changes from moment to moment, and if it is low, the OL target set value is set higher, so more air is injected than the amount of air commensurate with the load, and the drying of the garbage is promoted due to the diffusion effect. and stable combustion is maintained. Note that it can be considered that the fact that the LHV of the garbage is low is the same as the fact that the garbage has a high moisture content.

【図面の簡単な説明】[Brief explanation of drawings]

第１図は本発明方法の１例を説明するブロック図、第２
図は本発明におけるＬＨＶと０との関係を示す線図、第
３図はＬＨＶの推定方法の説明図である。 図の主要部分の説明 １−・ボイラ蒸発量　２・−燃焼空気量３−燃焼空気温
度　４・−ＬＨＶ推定装置５−推定Ｌ　ＨＶ　７−ＯＬ
目標設定値８・−０Ｌ一定制御装置 ９−０測定値　１１−ごみFIG. 1 is a block diagram explaining one example of the method of the present invention, and FIG.
The figure is a diagram showing the relationship between LHV and 0 in the present invention, and FIG. 3 is an explanatory diagram of the LHV estimation method. Explanation of main parts of the diagram 1- Boiler evaporation amount 2- Combustion air amount 3- Combustion air temperature 4- LHV estimation device 5- Estimated L HV 7-OL
Target setting value 8 -0L constant control device 9-0 measurement value 11-garbage

Claims (1)

【特許請求の範囲】[Claims] ごみ焼却炉における燃焼空気量を調節する方法において
、ごみの低位発熱量を推定し、その値に従って空気量を
変更することを特徴とするごみ焼却炉燃焼制御方法。A method for controlling combustion in a waste incinerator, the method comprising estimating the lower calorific value of waste and changing the air amount in accordance with the estimated value.