JP3689503B2 - Burner combustion control method for asphalt plant - Google Patents

Description

という意味を表わす。
【００２７】
これは「もし骨材供給量Ｍが非常に多く、かつ排ガス温度Ｔが非常に低いならば」（前件部）、「初期燃焼待ち時間ｔを非常に短くせよ」（後件部）というルールを示している。
【００２８】
このファジィ推論規則からも分かるように、骨材供給量が多くなれば初期燃焼待ち時間は短くなる略反比例関係にあり、また排ガス温度が高ければ初期燃焼待ち時間は長くなる略比例関係にある。即ち、骨材供給量が多くなればドラム内に多量の骨材が投入されてくるので、早めにバーナの燃焼量を上げる必要があり、また排ガス温度が高ければドライヤ内部の雰囲気温度が高いということなので燃焼量を遅めに上げても良いということである。
【００２９】
図６は、定性的に決定された初期燃焼待ち時間ｔを定量的な値に変換するためのメンバーシップ関数である。図中のｔ（ｉ）（ｉ＝１〜５）はメンバーシップ関数の形を規定する定数であって骨材検出用センサ１１による骨材の検出から初期燃焼を開始するまでの待ち時間を示すもので適宜決定する。ＰＢ、ＰＭ、ＰＳ、ＺＲ、ＮＳ、ＮＭ、ＮＢは初期燃焼待ち時間ｔを定性的に表わすためのメンバーシップ関数に与えた名称であり、前述と同様の意味を表わしている。また、図中の縦軸はメンバーシップ値である。
【００３０】
このメンバーシップ関数を用いて先に推論された初期燃焼待ち時間ｔが定性的にどのメンバーシップ関数に属するかが決定される。初期燃焼待ち時間ｔが複数の推論規則により規定された場合には各メンバーシップ値に応じた加重平均をもって初期燃焼待ち時間ｔとする。
【００３１】
そして初期燃焼待ち時間ｔが決定されると、骨材供給開始から初期燃焼待ち時間ｔの経過後、バーナ６の燃料バルブ１５を駆動するコントロールモータ１６を作動させて燃焼量を増加させて初期燃焼を行うのである。
【００３２】
このように、ドライヤ１への骨材供給開始時に骨材供給量と排ガス温度を把握し、あらかじめ設定した骨材供給量及び排ガス温度と初期燃焼待ち時間の関係から初期燃焼待ち時間を決定するようにしたので、最適の初期燃焼待ち時間となり、無駄にバーナ燃焼させることなくて燃費を削減できる。
【００３３】
なお、本発明の実施例では、初期燃焼待ち時間をファジィー推論を用いて決定したが何らこれに限定するものではなく、骨材供給量及び排ガス温度と初期燃焼待ち時間の関係をあらかじめ適宜設定しておけば良く、この関係は骨材供給量が多くなれば初期燃焼待ち時間は短くなる略反比例関係とし、また排ガス温度が高ければ初期燃焼待ち時間は長くなる略比例関係として適宜設定する。
【００３４】
また、骨材供給量及び排ガス温度から初期燃焼待ち時間を決定するようにしたが、骨材供給量のみから初期燃焼待ち時間を決定することも可能であり、また排ガス温度のみから初期燃焼待ち時間を決定することも可能である。
【００３５】
【発明の効果】
以上のように、本発明に係るアスファルトプラントのバーナ燃焼制御方法にあっては、ドライヤへの骨材供給が開始されると、ドライヤへの骨材供給量とドライヤより導出される排ガスの温度を検出し、あらかじめ設定した骨材供給量及び排ガス温度と初期燃焼待ち時間の関係から初期燃焼待ち時間を決定し、該初期燃焼待ち時間経過後に初期燃焼を開始するようにしたので、運転開始時のバーナの初期燃焼の開始待ち時間を最適に決定して燃費を極力抑えることができる。
【図面の簡単な説明】
【図１】本発明の一実施例に適用されるドライヤの全体構成を示す図である。
【図２】初期燃焼過程を示す図である。
【図３】骨材供給量のランク評価用メンバーシップ関数を示す図である。
【図４】排ガス温度のランク評価用メンバーシップ関数を示す図である。
【図５】初期燃焼待ち時間の推論ルールの一例を示す図である。
【図６】初期燃焼待ち時間のメンバーシップ関数を示す図である。
【符号の説明】
１…ドライヤ ２…ドラム
５…骨材供給用ベルコン ６…バーナ
７…骨材用温度センサ ８…排ガス用温度センサ
９ａ、９ｂ、９ｃ…骨材ホッパ
１０ａ、１０ｂ、１０ｃ…切り出しフィーダ
１１…骨材検出用センサ １２…バーナ燃焼制御装置
１３…データ入力部 １５…燃料バルブ
１６…コントロールモータ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a combustion control method for a burner used in a dryer which is an aggregate heating device such as an asphalt plant, a recycle plant, and a drum mixing plant for producing an asphalt mixture which is a road pavement material.
[0002]
[Prior art]
The burning procedure of the burner when heating the aggregate with a dryer is to prepare for the aggregate supply while igniting the burner before starting the aggregate supply and making the combustion low. Next, when the supply of the aggregate is started, the supply of the aggregate is detected by a sensor arranged near the dryer inlet, and the amount of combustion is appropriately increased by this aggregate supply detection to increase the atmospheric temperature in the dryer, The aggregate that is gradually fed into the dryer is heated. Then, when the heated aggregate is discharged from the dryer outlet, it shifts to automatic combustion control that detects the heated aggregate temperature and controls the combustion amount based on the amount of difference from the set aggregate temperature. To go. The transition period of combustion that shifts from low combustion to automatic combustion control is called initial combustion.
[0003]
[Problems to be solved by the invention]
However, if the amount of combustion of the burner is increased at the same time that the aggregate is detected by the sensor disposed near the inlet of the dryer as described above, the aggregate begins to enter the dryer at the beginning of combustion, and the inside of the dryer This is a waste of fuel considering that the amount of accumulated aggregate is small and the aggregate retention time in the dryer is 3 to 5 minutes.
[0004]
Therefore, it is conceivable to delay the timing of shifting the burner from low combustion to high combustion, that is, the start timing of initial combustion, but the problem is how much it should be delayed.
[0005]
An object of the present invention is to provide a burner combustion control method for an asphalt plant that optimally determines the start waiting time of initial burner combustion at the start of operation and suppresses fuel consumption as much as possible.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention detects the aggregate supply amount to the dryer and the temperature of the exhaust gas derived from the dryer when the aggregate supply to the dryer is started, and sets the preset aggregate. The initial combustion waiting time is determined from the relationship between the supply amount and the exhaust gas temperature and the initial combustion waiting time, and the initial combustion is started after the initial combustion waiting time has elapsed.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
According to the burner combustion control method of the asphalt plant of the present invention, the aggregate supply amount and the exhaust gas temperature at the start of the aggregate supply to the dryer are detected, and the optimum initial combustion waiting time is determined from the aggregate supply amount and the exhaust gas temperature. Determine the time. The relationship between the exhaust gas temperature and aggregate supply amount and the initial combustion waiting time is set in advance, but this relationship is an approximately proportional relationship that the initial combustion waiting time becomes longer when the exhaust gas temperature is higher, and the aggregate supply amount is If it increases, the initial combustion waiting time is set to be approximately inversely proportional. When the initial combustion waiting time elapses, the combustion amount of the burner is increased and initial combustion is started.
[0008]
In this way, fuel consumption is achieved by detecting the aggregate supply amount and exhaust gas temperature at the start of initial combustion, and accurately determining the start timing of initial combustion by predicting heat exchange when aggregate is supplied into the dryer. Can be reduced.
[0009]
【Example】
Embodiments of the present invention will be described below with reference to the drawings.
[0010]
FIG. 1 shows an overall configuration of a dryer to which the present invention is applied. A dryer 1 in the figure supports a cylindrical drum 2 on a machine base 3 so as to be freely rotatable, and a drum driving motor (not shown). ) At a predetermined speed. Numerous scraping blades 4 are arranged inside the drum 2, and the aggregate fed by the aggregate supplying velcon 5 is scraped up by the scraping blades 4 and rolled in the drum 2 while being dropped into a curtain shape. While being flowed down, the aggregate is heated and heated at a desired temperature in contact with hot air sent from the burner 6.
[0011]
The dryer 1 is provided with an aggregate temperature sensor 7 for detecting the temperature of the heated aggregate discharged from the drum 2 and an exhaust gas temperature sensor 8 for detecting the temperature of the exhaust gas.
[0012]
Aggregate hoppers 9a, 9b, and 9c for storing aggregates according to particle diameter are disposed at the end of the aggregate supplying bell-con 5 and aggregates are disposed below the aggregate hoppers 9a, 9b, and 9c. Cutting feeders 10a, 10b, and 10c that cut out by a predetermined amount are arranged. And the aggregate detection sensor 11 for aggregate supply confirmation is arrange | positioned in the front-end | tip part of the aggregate supply belcon 5 facing the aggregate supply port of the drum 2. As shown in FIG.
[0013]
A signal from the sensor is input to the burner combustion control device 12, and the burner combustion control device 12 is connected to a data input unit 13 for setting and inputting the aggregate cutting amount of each aggregate hopper 9a, 9b, 9c. ing. The burner combustion control device 12 determines the burner control opening based on various signals and data, and the burner control signal is marked via a driver 14 to a drive control motor 16 for a fuel valve 15 that controls the combustion amount. It has become so.
[0014]
Reference numeral 17 denotes a combustion air damper which is interlocked with the control motor 16, and reference numeral 18 denotes a fuel gauge for measuring the flow rate of the fuel.
[0015]
Next, the determination of the initial combustion waiting time of the burner and the combustion control method will be described.
[0016]
As shown in FIG. 2, the burner combustion control is performed from the start of operation through burner ignition, low combustion, aggregate supply, aggregate detection, waiting for initial combustion, initial combustion, and automatic combustion control.
[0017]
Therefore, before the operation, first, various data such as the blending type and the shipping amount of the asphalt mixture to be shipped are input via the data input unit 13 of the burner combustion control device 12. In the burner combustion control device 12, the aggregate amount to be cut out from each aggregate hopper 9a, 9b, 9c is calculated from the inputted blending type, shipment amount and moisture content, and the cutting speed (ton / h) of the cutting feeders 10a, 10b, 10c is calculated. ) Is set.
[0018]
When the operation is started, the burner 6 is ignited to start low combustion. After a predetermined time has elapsed, the cutting feeders 10a, 10b, and 10c are driven to cut out various aggregates from the aggregate hoppers 9a, 9b, and 9c based on the cutting speed set in advance.
[0019]
When the aggregate cut out from the aggregate hoppers 9a, 9b, and 9c is conveyed to the aggregate supply port of the drum 2 by the aggregate supply bell-con 5, the bone disposed in the vicinity of the aggregate supply port of the drum 2 The aggregate detection sensor 11 detects the aggregate that has reached the aggregate supply port of the drum 2.
[0020]
When the aggregate detection sensor 11 detects the aggregate, the initial combustion waiting time until the initial combustion is started is determined from the relationship between the preset aggregate supply amount and the exhaust gas temperature. In the embodiment, the aggregate supply amount and the exhaust gas temperature are assumed as the antecedent part of the fuzzy inference rule, and the initial combustion waiting time is estimated by the fuzzy inference as the consequent part of the fuzzy inference rule.
[0021]
Explaining the reasoning method,
FIG. 3 is a membership function for qualitatively evaluating the aggregate supply amount M, and M (i) (i = 1 to 5) in the figure is a constant that defines the shape of the membership function. Determine as appropriate. PB, ZR, and NB are names given to the membership function in order to qualitatively evaluate the rank of the aggregate supply amount M, and have the following meanings together with PM, PS, NM, and NS described later.
[0022]
PB: Positive Big
PM: Positive Medium
PS: Positive Small
ZR: Zero
NS: Negative Small
NM: Negative Medium
NB: Negative Big
The vertical axis in FIG. 3 is a membership value, and the aggregate supply amount M is qualitatively evaluated.
[0023]
The aggregate supply amount M may be calculated from the cutting speeds of the cutting feeders 10a, 10b, and 10c of the aggregate hoppers 9a, 9b, and 9c, and a measuring conveyor is installed in the middle of the aggregate supply. The aggregate supply amount may be measured, or the aggregate amount deposited on the aggregate supply bell-con 5 may be calculated. Further, considering that the shipping interval is short and the previous aggregate is still retained in the dryer, the aggregate retention amount in the dryer may be taken into account as the aggregate supply amount.
[0024]
FIG. 4 is a membership function for qualitatively evaluating the exhaust gas temperature T. In the figure, T (i) (i = 1 to 5) is a constant that defines the shape of the membership function and is determined as appropriate. . PB, ZR, and NB are names given to the membership function in order to qualitatively evaluate the rank of the exhaust gas temperature T, and have the above-mentioned meanings. The vertical axis in the figure is the membership value.
[0025]
FIG. 5 shows fuzzy inference rules for qualitatively determining the initial combustion waiting time t from the qualitative relationship between the aggregate supply amount M and the exhaust gas temperature T until the start of initial combustion.
[0026]
For example,

Represents the meaning.
[0027]
This is the rule that "if the aggregate supply amount M is very large and the exhaust gas temperature T is very low" (the antecedent part), "make the initial combustion waiting time t very short" (the consequent part). Is shown.
[0028]
As can be seen from this fuzzy inference rule, the initial combustion waiting time becomes shorter when the aggregate supply amount increases, and the initial combustion waiting time becomes longer when the exhaust gas temperature is higher. That is, if the aggregate supply amount increases, a large amount of aggregate is introduced into the drum, so it is necessary to increase the burner combustion amount early, and if the exhaust gas temperature is high, the atmospheric temperature inside the dryer is high. This means that the amount of combustion may be increased later.
[0029]
FIG. 6 shows a membership function for converting the initial combustion waiting time t determined qualitatively into a quantitative value. In the figure, t (i) (i = 1 to 5) is a constant that defines the shape of the membership function, and indicates the waiting time from the detection of the aggregate by the aggregate detection sensor 11 to the start of the initial combustion. It decides with a thing suitably. PB, PM, PS, ZR, NS, NM, and NB are names given to the membership function for qualitatively representing the initial combustion waiting time t, and have the same meaning as described above. The vertical axis in the figure is the membership value.
[0030]
Using this membership function, it is determined to which membership function the initial combustion waiting time t previously inferred belongs qualitatively. When the initial combustion waiting time t is defined by a plurality of inference rules, a weighted average corresponding to each membership value is used as the initial combustion waiting time t.
[0031]
When the initial combustion waiting time t is determined, after the initial combustion waiting time t elapses from the start of the aggregate supply, the control motor 16 that drives the fuel valve 15 of the burner 6 is operated to increase the combustion amount, thereby initial combustion. Is done.
[0032]
As described above, the aggregate supply amount and the exhaust gas temperature are grasped when the aggregate supply to the dryer 1 is started, and the initial combustion waiting time is determined from the relationship between the preset aggregate supply amount and the exhaust gas temperature and the initial combustion waiting time. As a result, the optimal initial combustion waiting time is reached, and fuel consumption can be reduced without wasteful burner combustion.
[0033]
In the embodiment of the present invention, the initial combustion waiting time is determined using fuzzy reasoning, but the present invention is not limited to this. The relationship between the aggregate supply amount and the exhaust gas temperature and the initial combustion waiting time is appropriately set in advance. This relationship may be set appropriately as an approximately inversely proportional relationship in which the initial combustion waiting time becomes shorter as the aggregate supply amount increases, and as an approximately proportional relationship in which the initial combustion waiting time becomes longer when the exhaust gas temperature is higher.
[0034]
In addition, the initial combustion waiting time is determined from the aggregate supply amount and the exhaust gas temperature, but it is also possible to determine the initial combustion waiting time from only the aggregate supply amount, and the initial combustion waiting time can be determined only from the exhaust gas temperature. It is also possible to determine.
[0035]
【The invention's effect】
As described above, in the burner combustion control method for an asphalt plant according to the present invention, when the aggregate supply to the dryer is started, the aggregate supply amount to the dryer and the temperature of the exhaust gas derived from the dryer are set. The initial combustion waiting time is determined from the relationship between the detected aggregate supply amount and exhaust gas temperature and the initial combustion waiting time, and the initial combustion is started after the initial combustion waiting time has elapsed. The fuel consumption can be suppressed as much as possible by optimally determining the initial combustion start waiting time of the burner.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a dryer applied to an embodiment of the present invention.
FIG. 2 is a diagram showing an initial combustion process.
FIG. 3 is a diagram showing a membership function for rank evaluation of aggregate supply amount.
FIG. 4 is a diagram showing a membership function for rank evaluation of exhaust gas temperature.
FIG. 5 is a diagram showing an example of an inference rule for an initial combustion waiting time.
FIG. 6 is a diagram showing a membership function of an initial combustion waiting time.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Dryer 2 ... Drum 5 ... Belcon for aggregate supply 6 ... Burner 7 ... Aggregate temperature sensor 8 ... Exhaust gas temperature sensor 9a, 9b, 9c ... Aggregate hopper 10a, 10b, 10c ... Cutting feeder 11 ... Aggregate Sensor for detection 12 ... Burner combustion control device 13 ... Data input unit 15 ... Fuel valve 16 ... Control motor

Claims (1)

When the aggregate supply to the dryer is started, the aggregate supply amount to the dryer and the temperature of the exhaust gas derived from the dryer are detected. From the relationship between the preset aggregate supply amount and exhaust gas temperature and the initial combustion waiting time A burner combustion control method for an asphalt plant, wherein an initial combustion waiting time is determined, and initial combustion is started after the initial combustion waiting time elapses.

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