JPH06337113A - Controller for heating furnace - Google Patents
Controller for heating furnaceInfo
- Publication number
- JPH06337113A JPH06337113A JP12724493A JP12724493A JPH06337113A JP H06337113 A JPH06337113 A JP H06337113A JP 12724493 A JP12724493 A JP 12724493A JP 12724493 A JP12724493 A JP 12724493A JP H06337113 A JPH06337113 A JP H06337113A
- Authority
- JP
- Japan
- Prior art keywords
- combustion
- temperature
- exhaust gas
- combustion air
- control system
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Links
Landscapes
- Regulation And Control Of Combustion (AREA)
- Control Of Combustion (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、加熱炉の燃焼排ガス熱
を熱交換器にて燃焼空気へ置換する系において、燃焼負
荷が高くなり炉設備（レキュペレータ、排ガスブロア
等）の破損の恐れがあるときに急速且つ自動的に負荷を
制限するようにした加熱炉の制御装置に関する。BACKGROUND OF THE INVENTION The present invention relates to a system in which the heat of combustion exhaust gas of a heating furnace is replaced by combustion air in a heat exchanger, the combustion load becomes high, and there is a risk of damage to the furnace equipment (recuperator, exhaust gas blower, etc.). BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a heating furnace that limits a load rapidly and automatically at a certain time.
【０００２】[0002]
【従来の技術】従来、加熱炉を制御するには、燃焼制御
系、燃焼空気制御系および排ガス温度制御系の３種のル
ープの制御系により行われている。図３はかかる加熱炉
の制御系のシステム構成例を示すものである。2. Description of the Related Art Conventionally, control of a heating furnace is performed by a control system of three types of loops, a combustion control system, a combustion air control system and an exhaust gas temperature control system. FIG. 3 shows an example of the system configuration of the control system of such a heating furnace.
【０００３】図３において、１は複数のバーナ２が縦列
配置された炉体であり、この炉体１の各バーナ２には燃
焼ガス供給系３および燃焼空気供給系４がそれぞれ接続
されている。また、炉体１には各バーナ２で燃焼した排
ガスを煙道を通して外部へ放出するための排ガス系５が
接続されている。In FIG. 3, reference numeral 1 denotes a furnace body in which a plurality of burners 2 are arranged in series, and a combustion gas supply system 3 and a combustion air supply system 4 are connected to each burner 2 of the furnace body 1. . Further, the furnace body 1 is connected to an exhaust gas system 5 for discharging the exhaust gas burned in each burner 2 to the outside through a flue.
【０００４】この場合、排ガス系５には燃焼排ガスを冷
却するためのレキュペレータ（熱交換器）６が設けら
れ、この熱交換器６にて燃焼排ガス熱が置換された燃焼
空気を燃焼空気供給系４に送り込むようになっている。
また、この熱交換器６の上流側の排ガス系５にはブロア
から冷気を供給する冷気供給系７が接続されている。In this case, the exhaust gas system 5 is provided with a recuperator (heat exchanger) 6 for cooling the combustion exhaust gas, and the combustion air in which the heat of the combustion exhaust gas is replaced by the heat exchanger 6 is supplied to the combustion air supply system. It is supposed to be sent to 4.
A cold air supply system 7 for supplying cold air from a blower is connected to the exhaust gas system 5 on the upstream side of the heat exchanger 6.
【０００５】一方、８はこのような加熱炉の燃焼制御系
で、この燃焼制御系８は上位コンピュータからの目標燃
焼要求指令により燃焼温度設定値および燃焼空気設定値
が設定される設定器９と、バーナ２の燃焼温度を検出す
る温度センサ１０の検出信号が入力される温度調節計１
１と、燃焼ガス供給系３に流れる燃焼ガス流量を検出す
るガス流量センサ１２の検出信号と温度調節計１１から
の温度制御信号または設定器９に設定された燃焼温度設
定値をもとに燃焼ガス供給系３に設けられた流量制御弁
１３の開度を制御するガス流量調節計１４と、前記設定
器９に設定された空気流量設定値または温度調節計１１
から出力される制御信号と燃焼空気供給系４に流れる空
気流量を検出する空気流量センサ１５の検出信号をもと
に空気供給系４に設けられた流量制御弁１６の開度を制
御する空気流量調節計１７とを備えている。On the other hand, 8 is a combustion control system for such a heating furnace, and this combustion control system 8 is a setter 9 for setting a combustion temperature set value and a combustion air set value according to a target combustion request command from a host computer. , A temperature controller 1 to which a detection signal of a temperature sensor 10 for detecting the combustion temperature of the burner 2 is input
1, the combustion signal based on the detection signal of the gas flow rate sensor 12 for detecting the flow rate of the combustion gas flowing in the combustion gas supply system 3 and the temperature control signal from the temperature controller 11 or the combustion temperature set value set in the setter 9. A gas flow rate controller 14 for controlling the opening of a flow rate control valve 13 provided in the gas supply system 3, and an air flow rate set value or temperature controller 11 set in the setting device 9.
Air flow rate for controlling the opening degree of the flow rate control valve 16 provided in the air supply system 4 based on the control signal output from And a controller 17.
【０００６】また、１８は燃焼空気温度制御系で、この
燃焼空気温度制御系１８は、燃焼空気供給系４に流れる
燃焼空気の温度を検出する燃焼空気温度センサ１９の検
出信号をもとに燃焼空気供給系４に設けられた燃焼空気
放散弁２０の開度を制御する燃焼空気温度調節計２１
と、燃焼空気放散弁２０を通して外部に放散される燃焼
空気放散量を検出する燃焼空気放散量センサ２２の検出
信号をもとに燃焼空気放散弁２０の開度を補正制御する
燃焼空気流量調節計２３とを備えている。Further, reference numeral 18 is a combustion air temperature control system, and the combustion air temperature control system 18 burns based on a detection signal of a combustion air temperature sensor 19 for detecting the temperature of the combustion air flowing into the combustion air supply system 4. Combustion air temperature controller 21 for controlling the opening of a combustion air diffusion valve 20 provided in the air supply system 4
And a combustion air flow controller for correcting and controlling the opening degree of the combustion air diffusion valve 20 based on a detection signal of a combustion air diffusion amount sensor 22 that detects the amount of combustion air that is diffused to the outside through the combustion air diffusion valve 20. And 23.
【０００７】さらに、２４は排ガス温度制御系で、この
排ガス温度制御系２４は熱交換器６の上流側の排ガス系
５を通して流れる排ガスの温度を検出する排ガス温度セ
ンサ２５の検出信号をもとに冷気供給系７に設けられた
希釈空気弁２６の開度を制御する希釈空気流量調節計２
７を備えている。Further, numeral 24 is an exhaust gas temperature control system, which is based on a detection signal of an exhaust gas temperature sensor 25 for detecting the temperature of the exhaust gas flowing through the exhaust gas system 5 upstream of the heat exchanger 6. Dilution air flow controller 2 for controlling the opening degree of dilution air valve 26 provided in cold air supply system 7
Equipped with 7.
【０００８】このように加熱炉の３種のループの制御系
は、それぞれ独立しており、燃焼負荷の結果により燃焼
空気温度制御および排ガス温度制御の制御量が決まると
いう関係を有している。As described above, the control systems of the three types of loops of the heating furnace are independent from each other, and the control amounts of the combustion air temperature control and the exhaust gas temperature control are determined by the result of the combustion load.
【０００９】[0009]
【発明が解決しようとする課題】しかし、上述した従来
の加熱炉の制御装置では、３種のループの制御系がそれ
ぞれ独立して制御しているため、燃焼が高負荷の場合に
は排ガス温度が上昇し、排ガス温度制御系２４により冷
気供給系７に設けられた希釈空気弁２６を全開に制御し
ても、冷却効果が得られないことがある。このため、排
ガス系４に設けられた排ガスブロアが熱破壊される恐れ
がある。However, in the above-mentioned conventional heating furnace control device, since the control systems of the three types of loops control independently, the exhaust gas temperature is high when the combustion is high load. However, even if the exhaust gas temperature control system 24 controls the dilution air valve 26 provided in the cold air supply system 7 to be fully opened, the cooling effect may not be obtained. Therefore, the exhaust gas blower provided in the exhaust gas system 4 may be thermally destroyed.
【００１０】また、排気ガス温度が高くなると熱交換器
６により、熱置換された燃焼空気の温度も高くなるた
め、この状態が継続されると燃焼空気温度制御系１８に
より放散弁２０を全開にしても、燃焼空気の温度を目標
値以下に制御されるまでに時間がかかる場合がある。When the exhaust gas temperature rises, the temperature of the combustion air that has been heat-exchanged by the heat exchanger 6 also rises. Therefore, if this state continues, the combustion air temperature control system 18 fully opens the diffusion valve 20. However, it may take time until the temperature of the combustion air is controlled to be equal to or lower than the target value.
【００１１】そこで、従来ではこのような状況になる前
に、プラント運転者による手動介入を行うことで燃焼負
荷を下げるようにしている。しかし、もしプラント運転
者による手動介入が行われない場合には、熱交換器６お
よび排ガスブロアが長時間高熱にさらされるため、熱破
損を招く恐れがある。Therefore, conventionally, before such a situation occurs, a plant operator manually intervenes to reduce the combustion load. However, if no manual intervention is performed by the plant operator, the heat exchanger 6 and the exhaust gas blower are exposed to high heat for a long time, which may cause thermal damage.
【００１２】本発明は上記のような事情に鑑みてなされ
たもので、燃焼負荷が高くなった場合にはオペレータに
頼ることなく早急に燃焼負荷が下がるように制御するこ
とにより、加熱炉の設備機器を熱破損することなく安全
に加熱炉の運転を行うことができる加熱炉の制御装置を
提供することを目的とする。The present invention has been made in view of the above situation, and when the combustion load becomes high, the heating load is controlled so that the combustion load is quickly reduced without depending on the operator. An object of the present invention is to provide a heating furnace control device capable of safely operating a heating furnace without causing damage to equipment.
【００１３】[0013]
【課題を解決するための手段】本発明は上記の目的を達
成するため、炉体に配置された複数のバーナに燃焼ガス
を供給する燃焼ガス供給系および燃焼空気を供給する燃
焼空気供給系をそれぞれ接続し、前記各バーナで燃焼し
た排ガスを冷気と熱交換する熱交換器を通して外部へ放
出する排ガス系を接続すると共にこの排ガス系の前記熱
交換器の上流側に冷気を供給する冷気供給系を接続し、
且つ前記熱交換器で熱置換された燃焼空気を前記燃焼空
気供給系に送込むと共にこの燃焼空気の一部を外部に放
散可能にした加熱炉において、前記バーナの燃焼温度を
検出し燃焼温度が目標燃焼要求量になるように前記燃焼
ガス供給系より前記各バーナに供給される燃焼ガス流量
および前記燃焼空気供給系より前記各バーナに供給され
る燃焼空気流量を制御する燃焼制御系と、前記燃焼空気
供給系に流れる燃焼空気の温度を検出しその温度検出値
をもとに外部に燃焼空気の一部を外部に放散して燃焼空
気温度を制御する燃焼空気温度制御系と、前記熱交換器
上流側の排ガス系を流れる排ガス温度を検出しその排ガ
ス温度検出値をもとに前記冷気供給系より排ガス系に供
給される冷気を制御する排ガス温度制御系とを備え、前
記排ガス制御系で検出された排ガス温度が第１の設定温
度以上のときその排ガス温度をもとに負荷降下のための
減少量を求めると共に、前記燃焼空気温度制御系で検出
された燃焼空気温度をもとに負荷降下のための減少量を
求めてこれら減少量の加算値により前記燃焼制御系の目
標燃焼要求量を補正する燃焼負荷低減処理手段を設けた
ものである。In order to achieve the above object, the present invention provides a combustion gas supply system for supplying combustion gas and a combustion air supply system for supplying combustion air to a plurality of burners arranged in a furnace body. A cold air supply system that is connected to each other and that connects an exhaust gas system that discharges the exhaust gas burned in each burner to the outside through a heat exchanger that exchanges heat with the cold air and that supplies the cool air to the upstream side of the heat exchanger of the exhaust gas system. Connect
And, in the heating furnace which sends the combustion air heat-exchanged in the heat exchanger to the combustion air supply system and allows a part of the combustion air to be diffused to the outside, the combustion temperature of the burner is detected and the combustion temperature is A combustion control system for controlling a flow rate of combustion gas supplied from the combustion gas supply system to each burner so as to achieve a target combustion demand amount and a flow rate of combustion air supplied to each burner from the combustion air supply system; The heat exchange with the combustion air temperature control system that detects the temperature of the combustion air flowing in the combustion air supply system and controls the combustion air temperature by releasing a part of the combustion air to the outside based on the detected temperature value. An exhaust gas temperature control system for controlling the cold air supplied to the exhaust gas system from the cold air supply system based on the detected exhaust gas temperature value of the exhaust gas temperature flowing through the exhaust gas system on the upstream side of the reactor; When the discharged exhaust gas temperature is equal to or higher than the first set temperature, the reduction amount for load drop is calculated based on the exhaust gas temperature, and the load is calculated based on the combustion air temperature detected by the combustion air temperature control system. Combustion load reduction processing means is provided for obtaining a reduction amount for the descent and correcting the target combustion demand amount of the combustion control system by the added value of these reduction amounts.
【００１４】また、燃焼負荷低減処理手段に対して上記
補正により前記排ガス制御系で検出された排ガス温度が
第１の設定温度より低い第２の設定温度以下となり、前
記燃焼空気温度制御系で検出された燃焼空気温度が第１
及び第２の設定温度より高い第３の設定温度以上のと
き、前記排ガス温度をもとに求められた負荷降下のため
の減少量を固定し、前記燃焼空気温度制御系で検出され
た燃焼空気温度をもとに負荷降下のための減少量を求め
て前記標燃焼要求量を補正する機能を持たせたものであ
る。Further, the exhaust gas temperature detected by the exhaust gas control system by the above correction for the combustion load reduction processing means becomes equal to or lower than the second set temperature lower than the first set temperature and detected by the combustion air temperature control system. The combustion air temperature
And a third set temperature higher than the second set temperature or higher, the amount of decrease for load drop determined based on the exhaust gas temperature is fixed, and the combustion air detected by the combustion air temperature control system is fixed. It is provided with a function of correcting the target combustion demand amount by obtaining a reduction amount for load drop based on the temperature.
【００１５】[0015]
【作用】このような構成の加熱炉の制御装置にあって
は、排ガス制御系で検出された排ガス温度が第１の設定
温度以上のときその排ガス温度をもとに求められた負荷
降下のための減少量と燃焼空気温度制御系で検出された
燃焼空気温度をもとに求められた負荷降下のための減少
量との加算値により燃焼制御系の目標燃焼要求量が補正
されるので、燃焼制御系により燃焼ガス供給系を通して
供給される燃焼ガス流量と燃焼空気供給系を通して供給
される燃焼空気流量が目標流量減少分だけ減少すること
になり燃焼負荷を低下させることができる。In the heating furnace control device having such a structure, when the exhaust gas temperature detected by the exhaust gas control system is equal to or higher than the first set temperature, the load drop calculated based on the exhaust gas temperature is caused. The target combustion request amount of the combustion control system is corrected by the addition value of the decrease amount for the load drop calculated based on the combustion air temperature detected by the combustion air temperature control system. By the control system, the flow rate of the combustion gas supplied through the combustion gas supply system and the flow rate of the combustion air supplied through the combustion air supply system are reduced by the target flow rate reduction amount, and the combustion load can be reduced.
【００１６】また、排ガス制御系で検出された排ガス温
度が第２の設定温度以下で燃焼空気温度制御系で検出さ
れた燃焼空気温度が第３の設定温度以上のとき排ガス温
度をもとに求められる負荷降下のための減少量が固定さ
れた状態で燃焼空気温度制御系で検出された燃焼空気温
度をもとに求められた負荷降下のための減少量により目
標燃焼要求量が補正されるので、燃焼空気の温度を第３
の設定温度以下に制御することができる。Further, when the exhaust gas temperature detected by the exhaust gas control system is equal to or lower than the second preset temperature and the combustion air temperature detected by the combustion air temperature control system is equal to or higher than the third preset temperature, it is determined based on the exhaust gas temperature. The target combustion demand is corrected by the reduction amount for load drop obtained based on the combustion air temperature detected by the combustion air temperature control system with the reduction amount for load reduction fixed. , The temperature of the combustion air third
It can be controlled below the set temperature of.
【００１７】[0017]
【実施例】以下本発明の一実施例を図面を参照して説明
する。図１は本発明による加熱炉の制御装置の構成例を
示す系統図で、図３と同一部分には同一符号を付して示
し、ここでは異なる点について述べる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a system diagram showing a configuration example of a heating furnace control device according to the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals, and different points will be described here.
【００１８】本実施例では、図１に示すように燃焼空気
温度制御系１８の燃焼空気温度調節計２１に入力される
燃焼空気温度センサ１９の検出信号と、排ガス温度制御
系２４の希釈空気流量調節計２７に入力される排ガス温
度センサ２５の検出信号とがそれぞれ与えられ、これら
燃焼空気温度検出信号および排ガス温度検出信号をもと
に燃焼制御系８の設定器９より出力される燃焼温度設定
値および燃焼空気設定値を補正する燃焼負荷低減処理回
路３０を設ける構成としたものである。In the present embodiment, as shown in FIG. 1, the detection signal of the combustion air temperature sensor 19 inputted to the combustion air temperature controller 21 of the combustion air temperature control system 18 and the flow rate of the dilution air of the exhaust gas temperature control system 24. The detection signal of the exhaust gas temperature sensor 25 input to the controller 27 is given respectively, and the combustion temperature setting output from the setter 9 of the combustion control system 8 based on the combustion air temperature detection signal and the exhaust gas temperature detection signal. A combustion load reduction processing circuit 30 for correcting the value and the combustion air set value is provided.
【００１９】この燃焼負荷低減処理回路３０は、図２に
示すように排ガス温度検出信号が入力されると、排ガス
温度から目標流量減少量に変換する排ガス温度／目標流
量減少量変換テーブル３１、燃焼空気温度検出信号が入
力されると燃焼空気温度から目標流量減少量に変換する
燃焼空気温度／目標流量減少量変換テーブル３２、これ
ら両変換テーブル３１および３２より出力される減少量
の何ずれかに排ガス温度と燃焼空気温度の判定条件によ
り切換える切換回路３３、この切換回路３３により排ガ
ス温度／目標流量減少量変換テーブル３１に切換られた
とき、排ガス温度／目標流量減少量変換テーブル３１よ
り出力される目標流量減少量に燃焼空気温度／目標流量
減少量変換テーブル３２より出力される目標流量減少量
を加算する加算器３４、この加算器３４により加算され
た燃焼空気温度／目標流量減少量変換テーブル３２の目
標流量減少量をある変化率で制限を加える燃焼空気側減
少量急変防止回路３５、設定器９に与えられる目標燃焼
要求量を加算器３４より出力される両変換テーブル３１
および３２の減少量の加算値により補正する減算器３６
から構成されている。When the exhaust gas temperature detection signal is input as shown in FIG. 2, the combustion load reduction processing circuit 30 converts an exhaust gas temperature into a target flow rate decrease amount, an exhaust gas temperature / target flow rate decrease amount conversion table 31, combustion. When the air temperature detection signal is input, the combustion air temperature / target flow rate decrease amount conversion table 32 for converting the combustion air temperature to the target flow rate decrease amount, and some of the decrease amounts output from both conversion tables 31 and 32 A switching circuit 33 that switches depending on the determination conditions of the exhaust gas temperature and the combustion air temperature. When the switching circuit 33 switches to the exhaust gas temperature / target flow rate decrease amount conversion table 31, the exhaust gas temperature / target flow rate decrease amount conversion table 31 outputs. Adder for adding the target flow rate decrease amount output from the combustion air temperature / target flow rate decrease amount conversion table 32 to the target flow rate decrease amount 4. The combustion air temperature / target flow rate decrease amount conversion table 32 added by the adder 34 is applied to the combustion air side decrease amount sudden change prevention circuit 35 that limits the target flow rate decrease amount at a certain change rate, and to the setter 9. Both conversion tables 31 that output the target combustion demand from the adder 34
And a subtracter 36 for correcting the addition value of the reduction amount of 32
It consists of
【００２０】ここで、切換回路３３は排ガス温度がｘ以
下で燃焼空気温度がｚ以上のとき排ガス温度／目標流量
減少量変換テーブル３１の出力をロックするスイッチ３
３−１と、排ガス温度がｘ以下で燃焼空気温度がｚ以上
のとき又は排ガス温度がｙ以上のとき燃焼空気温度／目
標流量減少量変換テーブル３２の出力を燃焼空気側減少
量急変防止回路３５を通して加算器３４に与える接点３
３−２を備えている。The switch circuit 33 locks the output of the exhaust gas temperature / target flow rate decrease conversion table 31 when the exhaust gas temperature is x or lower and the combustion air temperature is z or higher.
3-1 and when the exhaust gas temperature is x or lower and the combustion air temperature is z or higher, or when the exhaust gas temperature is y or higher, the output of the combustion air temperature / target flow rate decrease amount conversion table 32 is set to the combustion air side decrease amount sudden change prevention circuit 35. Contact 3 given to the adder 34 through
3-2 is provided.
【００２１】この場合、排ガス温度ｘ，ｙと燃焼空気温
度ｚとの関係は、ｘ＜ｙ＜ｚになっている。次に上記の
ように構成された加熱炉の制御装置の作用について述べ
る。In this case, the relationship between the exhaust gas temperatures x and y and the combustion air temperature z is x <y <z. Next, the operation of the heating furnace control device configured as described above will be described.
【００２２】いま、加熱炉が燃焼制御系８、燃焼空気温
度制御系１８および排ガス温度制御系２４によりそれぞ
れ制御されて運転されているものとする。このような状
態にあるとき、燃焼負荷が高くなると排ガス温度が上昇
し、排ガス温度制御系２４の希釈空気流量調節計２７に
より冷気供給系７に設けられた希釈空気弁２６の開度が
制御され、排ガス系５に冷気供給系７を通して冷気が送
込まれる。この場合、冷却効果が得られないと最終的に
は希釈空気弁２６が全開に制御される。Now, it is assumed that the heating furnace is controlled and operated by the combustion control system 8, the combustion air temperature control system 18 and the exhaust gas temperature control system 24, respectively. In such a state, the exhaust gas temperature rises when the combustion load increases, and the opening degree of the dilution air valve 26 provided in the cold air supply system 7 is controlled by the dilution air flow rate controller 27 of the exhaust gas temperature control system 24. Cold air is sent to the exhaust gas system 5 through the cold air supply system 7. In this case, if the cooling effect is not obtained, the dilution air valve 26 is finally controlled to be fully opened.
【００２３】さらに、排ガス系５を通して流れる燃焼排
ガスは熱交換器６で熱交換される。このとき熱交換器６
を通して流れる燃焼空気の温度が上昇し、燃焼空気温度
制御系１８の燃焼空気温度調節計２１および燃焼空気流
量調節計２３により燃焼空気放散弁２０の開度が制御さ
れ、外部に燃焼空気が放散される。これにより熱交換器
６の冷却効率が高められるが、それでも冷却効果が得ら
れないと最終的には燃焼空気放散弁２６が全開される。Further, the combustion exhaust gas flowing through the exhaust gas system 5 is heat-exchanged by the heat exchanger 6. At this time, the heat exchanger 6
The temperature of the combustion air flowing therethrough rises, the opening of the combustion air diffusion valve 20 is controlled by the combustion air temperature controller 21 and the combustion air flow controller 23 of the combustion air temperature control system 18, and the combustion air is diffused to the outside. It As a result, the cooling efficiency of the heat exchanger 6 is improved, but if the cooling effect is still not obtained, the combustion air diffusion valve 26 is finally fully opened.
【００２４】このような動作は希であるが、例え燃焼空
気放散弁２６が全開にならなくても結果的に冷却効果を
得るまでに時間がかかると、排ガスブロアおよび熱交換
器６が熱破損される恐れがある。Although such an operation is rare, even if the combustion air diffusion valve 26 is not fully opened, if it takes time to obtain a cooling effect, the exhaust gas blower and the heat exchanger 6 are damaged by heat. May be
【００２５】そこで、このような燃焼排ガス温度の制御
過程で排ガス温度がｙ℃以上になると図２に示す燃焼負
荷低減処理回路３０において、接点３３−２がオンする
ことで、排ガス温度／目標流量減少量変換テーブル３１
により求められた排ガス温度を変数とする負荷降下のた
めの減少量に燃焼空気温度／目標流量減少量変換テーブ
ル３２により求められた燃焼空気温度を変数とする負荷
降下のための減少量が加算器３４により加算され、その
合計値ｂ２を減算器３６により設定器８に与えられる設
定信号から減算して流量設定値を補正している。Therefore, when the exhaust gas temperature becomes y ° C. or higher in the process of controlling the combustion exhaust gas temperature, the contact point 33-2 is turned on in the combustion load reduction processing circuit 30 shown in FIG. Reduction amount conversion table 31
The amount of decrease for load drop with the exhaust gas temperature as a variable is added to the amount of decrease for load drop with the combustion air temperature as a variable with the combustion air temperature / target flow rate decrease conversion table 32. The flow rate setting value is corrected by subtracting the total value b2 added by 34 from the setting signal given to the setting device 8 by the subtractor 36.
【００２６】従って、燃焼制御系８により燃焼ガス供給
系３を通してバーナ２に流れる燃焼ガス流量と燃焼空気
供給系４を通してバーナ２に流れる空気流量が上記両変
換テーブル３１，３２で求められた目標流量減少量分だ
け減少するので、燃焼負荷が低下することになる。Therefore, the flow rate of the combustion gas flowing to the burner 2 through the combustion gas supply system 3 and the flow rate of the air flowing to the burner 2 through the combustion air supply system 4 by the combustion control system 8 are the target flow rates obtained by the conversion tables 31 and 32. Since the amount of reduction is reduced, the combustion load is reduced.
【００２７】この場合、燃焼空気温度側の目標流量減少
量を直接排ガス温度側の減少量に加算すると合計減少量
が急変する恐れがあるため、燃焼空気温度／目標流量減
少量変換テーブル３２の目標流量減少量ａ2 を燃焼空気
側減少量急変防止回路３５を通してある変化率で制限を
加えた減少流量ａ1 とすることにより、合計減少量の急
変を防止している。In this case, if the target flow rate reduction amount on the combustion air temperature side is directly added to the reduction amount on the exhaust gas temperature side, the total reduction amount may suddenly change. Therefore, the target of the combustion air temperature / target flow rate reduction amount conversion table 32 is set. The flow rate reduction amount a 2 is set to the reduction flow rate a 1 which is limited by a certain rate of change through the combustion air side reduction amount sudden change prevention circuit 35 to prevent a sudden change in the total reduction amount.
【００２８】これにより、燃焼ガスが燃焼する上で必要
な空気を確保することができる。、以上の処理により燃
焼負荷の低下により燃焼排ガス温度がｘ℃以下になる
が、このとき燃焼空気温度がｚ℃以上になっている場合
には、さらに燃焼負荷を下げる必要がある。つまり、燃
焼空気の温度をｚ℃以下に下げないと燃焼効率は高い状
態のままなので、排ガス温度が再度上昇して前の状態に
戻ってしまい、最終的には悪循環を繰返す恐れがある。As a result, it is possible to secure the air necessary for burning the combustion gas. By the above processing, the combustion exhaust gas temperature is reduced to x ° C. or lower due to the reduction of the combustion load, but if the combustion air temperature is z ° C. or higher at this time, it is necessary to further reduce the combustion load. That is, unless the temperature of the combustion air is reduced to z ° C. or lower, the combustion efficiency remains high, so the exhaust gas temperature rises again and returns to the previous state, which may eventually lead to a vicious circle.
【００２９】そこで、燃焼空気温度がｚ℃以上のときは
切換回路３３において、排ガス温度／目標流量減少量変
換テーブル３１の出力がスイッチ３３−１によりロック
され一定値として加算器３４に与えられ、燃焼空気温度
／目標流量減少量変換テーブル３２で求められた燃焼空
気温度を変数とする負荷降下のための減少量が加算器３
４に与えられてこれらが加算されるので、その合計値ｂ
２を減算器３６により設定器９に与えられる設定信号か
ら減算して流量設定値を補正することにより燃焼空気の
温度をｚ℃以下に制御することができる。Therefore, when the combustion air temperature is z ° C. or higher, in the switching circuit 33, the output of the exhaust gas temperature / target flow rate decrease conversion table 31 is locked by the switch 33-1 and given to the adder 34 as a constant value. The amount of decrease for load drop with the combustion air temperature obtained in the combustion air temperature / target flow rate decrease conversion table 32 as a variable is the adder 3
4 and these are added, the total value b
By subtracting 2 from the setting signal given to the setter 9 by the subtractor 36 to correct the flow rate set value, the temperature of the combustion air can be controlled to z ° C. or lower.
【００３０】このように加熱炉の燃焼負荷が高く、炉設
備保護を燃焼空気温度制御と排ガス温度制御だけで早急
に対処しきれない場合には、燃焼負荷降下機能で算出さ
れる減少量を燃焼要給量からの流量設定値に対する補正
量として燃焼制御系を制御することにより、早急で且つ
自動的な燃焼負荷降下を行うことができる。As described above, when the combustion load of the heating furnace is high and the protection of the furnace equipment cannot be quickly dealt with only by controlling the combustion air temperature and the exhaust gas temperature, the reduction amount calculated by the combustion load lowering function is burned. By controlling the combustion control system as a correction amount for the flow rate set value from the required supply amount, it is possible to quickly and automatically reduce the combustion load.
【００３１】従って、従来ではオペレータにより燃焼制
御系での燃焼負荷降下を手動で行っていたのに比べて、
早急に且つ自動的に燃焼負荷降下が行われるので、オペ
レータに対する負担を大幅に軽減できると共に、炉の運
転において、安全性を確保することができる。Therefore, as compared with the case where the operator conventionally manually lowers the combustion load in the combustion control system,
Since the combustion load is rapidly and automatically lowered, the burden on the operator can be significantly reduced, and safety can be ensured during the operation of the furnace.
【００３２】[0032]
【発明の効果】以上述べたように本発明によれば、燃焼
負荷が高くなった場合でもオペレータに頼ることなく早
急に燃焼負荷が下がるように制御されるので、加熱炉の
設備機器を熱破損することなく安全に加熱炉の運転を行
うことができる加熱炉の制御装置を提供できる。As described above, according to the present invention, even if the combustion load becomes high, it is controlled so that the combustion load can be quickly reduced without relying on the operator. Therefore, the equipment of the heating furnace is thermally damaged. It is possible to provide a heating furnace control device capable of safely operating the heating furnace without performing the above.
【図１】本発明による加熱炉の制御装置の一実施例を示
す系統構成図。FIG. 1 is a system configuration diagram showing an embodiment of a heating furnace control device according to the present invention.
【図２】同実施例における燃焼負荷低減処理回路の内部
構成を示す説明図。FIG. 2 is an explanatory diagram showing an internal configuration of a combustion load reduction processing circuit in the embodiment.
【図３】従来の加熱炉の制御装置の一例を示す系統構成
図。FIG. 3 is a system configuration diagram showing an example of a conventional heating furnace control device.
１……炉体、２……バーナ、３……燃焼ガス供給系、４
……燃焼空気供給系、５……排ガス系、６……熱交換
器、７……冷気供給系、８……燃焼制御系、９……設定
器、１０……温度センサ、１１……温度調節系、１２…
…ガス流量センサ、１３……流量制御弁、１４……ガス
流量調節系。１５……空気流量センサ、１６……流量制
御弁、１７……空気流量調節系、１８……燃焼空気温度
制御系、１９……燃焼空気温度センサ、２０……燃焼空
気放散弁、２１……燃焼空気温度調節系、２２……燃焼
空気放散量センサ、２３……燃焼空気流量調節系、２４
……排ガス温度制御系、２５……排ガス温度センサ、２
６……希釈空気弁、２７……希釈空気流量調節系、３０
……燃焼負荷低減処理回路、３１……排ガス温度／目標
流量減少量変換テーブル、３２……燃焼空気温度／目標
流量減少量変換テーブル、３３……切換回路、３４……
加算器、３５……燃焼空気側減少量急変防止回路、３６
……減算器。1 ... Furnace body, 2 ... Burner, 3 ... Combustion gas supply system, 4
... Combustion air supply system, 5 ... Exhaust gas system, 6 ... Heat exchanger, 7 ... Cold air supply system, 8 ... Combustion control system, 9 ... Setting device, 10 ... Temperature sensor, 11 ... Temperature Regulatory system, 12 ...
... Gas flow sensor, 13 ... Flow control valve, 14 ... Gas flow control system. 15 ... Air flow sensor, 16 ... Flow control valve, 17 ... Air flow control system, 18 ... Combustion air temperature control system, 19 ... Combustion air temperature sensor, 20 ... Combustion air diffusion valve, 21 ... Combustion air temperature control system, 22 ... Combustion air emission amount sensor, 23 ... Combustion air flow rate control system, 24
...... Exhaust gas temperature control system, 25 ...... Exhaust gas temperature sensor, 2
6 ... Diluting air valve, 27 ... Diluting air flow rate control system, 30
...... Combustion load reduction processing circuit, 31 ...... Exhaust gas temperature / target flow rate reduction amount conversion table, 32 ...... Combustion air temperature / target flow rate reduction amount conversion table, 33 ...... Switching circuit, 34 ......
Adder 35: Combustion air side reduction amount sudden change prevention circuit, 36
…… Subtractor.
Claims (3)
スを供給する燃焼ガス供給系および燃焼空気を供給する
燃焼空気供給系をそれぞれ接続し、前記各バーナで燃焼
した排ガスを冷気と熱交換する熱交換器を通して外部へ
放出する排ガス系を接続すると共にこの排ガス系の前記
熱交換器の上流側に冷気を供給する冷気供給系を接続
し、且つ前記熱交換器で熱置換された燃焼空気を前記燃
焼空気供給系に送込むと共にこの燃焼空気の一部を外部
に放散可能にした加熱炉において、前記バーナの燃焼温
度を検出し燃焼温度が目標燃焼要求量になるように前記
燃焼ガス供給系より前記各バーナに供給される燃焼ガス
流量および前記燃焼空気供給系より前記各バーナに供給
される燃焼空気流量を制御する燃焼制御系と、前記燃焼
空気供給系に流れる燃焼空気の温度を検出しその温度検
出値をもとに外部に燃焼空気の一部を外部に放散して燃
焼空気温度を制御する燃焼空気温度制御系と、前記熱交
換器上流側の排ガス系を流れる排ガス温度を検出しその
排ガス温度検出値をもとに前記冷気供給系より排ガス系
に供給される冷気を制御する排ガス温度制御系とを備
え、前記排ガス制御系で検出された排ガス温度が第１の
設定温度以上のときその排ガス温度をもとに負荷降下の
ための減少量を求めると共に、前記燃焼空気温度制御系
で検出された燃焼空気温度をもとに負荷降下のための減
少量を求めてこれら減少量の加算値により前記燃焼制御
系の目標燃焼要求量を補正する燃焼負荷低減処理手段を
設けたことを特徴とする加熱炉の制御装置。1. A combustion gas supply system for supplying combustion gas and a combustion air supply system for supplying combustion air are respectively connected to a plurality of burners arranged in a furnace body, and the exhaust gas burned by each burner is cooled with cold air and heat. The exhaust gas system which is discharged to the outside through the heat exchanger to be exchanged is connected, and the cold air supply system for supplying cold air is connected to the upstream side of the heat exchanger of this exhaust gas system, and the combustion heat-exchanged by the heat exchanger is connected. In a heating furnace in which air is sent to the combustion air supply system and a part of the combustion air can be diffused to the outside, the combustion gas is detected so that the combustion temperature of the burner is detected and the combustion temperature becomes a target combustion required amount. A combustion control system for controlling the flow rate of combustion gas supplied to each burner from a supply system and the flow rate of combustion air supplied to each burner from the combustion air supply system, and a fuel flowing to the combustion air supply system. A combustion air temperature control system that detects the temperature of the combustion air and controls the combustion air temperature by discharging a part of the combustion air to the outside based on the detected temperature value, and an exhaust gas system on the upstream side of the heat exchanger. An exhaust gas temperature control system for controlling the cool air supplied to the exhaust gas system from the cold air supply system based on the exhaust gas temperature detection value by detecting the exhaust gas temperature flowing through the exhaust gas temperature detected by the exhaust gas control system. When the temperature is equal to or higher than the first set temperature, the reduction amount for the load drop is calculated based on the exhaust gas temperature, and the reduction amount for the load drop is calculated based on the combustion air temperature detected by the combustion air temperature control system. And a combustion load reduction processing means for correcting the target combustion request amount of the combustion control system based on the addition value of these reduction amounts.
荷降下のための減少量をある変化率で制限を加えて前記
排ガス温度をもとに求められた負荷降下のための減少量
に加算する燃焼空気側減少量急変防止手段を設けたこと
を特徴とする請求項に記載の加熱炉の制御装置。2. The reduction amount for the load drop calculated based on the combustion air temperature is limited to a certain rate of change to obtain the reduction amount for the load decrease calculated based on the exhaust gas temperature. The control device for the heating furnace according to claim 1, further comprising a means for preventing a sudden change in the amount of decrease on the combustion air side to be added.
スを供給する燃焼ガス供給系および燃焼空気を供給する
燃焼空気供給系をそれぞれ接続し、前記各バーナで燃焼
した排ガスを冷気と熱交換する熱交換器を通して外部へ
放出する排ガス系を接続すると共にこの排ガス系の前記
熱交換器の上流側に冷気を供給する冷気供給系を接続
し、且つ前記熱交換器で熱置換された燃焼空気を前記燃
焼空気供給系に送込むと共にこの燃焼空気の一部を外部
に放散可能にした加熱炉において、前記バーナの燃焼温
度を検出し燃焼温度が目標燃焼要求量になるように前記
燃焼ガス供給系より前記各バーナに供給される燃焼ガス
流量および前記燃焼空気供給系より前記各バーナに供給
される燃焼空気流量を制御する燃焼制御系と、前記燃焼
空気供給系に流れる燃焼空気の温度を検出しその温度検
出値をもとに外部に燃焼空気の一部を外部に放散して燃
焼空気温度を制御する燃焼空気温度制御系と、前記熱交
換器上流側の排ガス系を流れる排ガス温度を検出しその
排ガス温度検出値をもとに前記冷気供給系より排ガス系
に供給される冷気を制御する排ガス温度制御系とを備
え、前記排ガス制御系で検出された排ガス温度が第１の
設定温度以上のときその排ガス温度をもとに負荷降下の
ための減少量を求めると共に、前記燃焼空気温度制御系
で検出された燃焼空気温度をもとに負荷降下のための減
少量を求めてこれら減少量の加算値により前記燃焼制御
系の目標燃焼要求量を補正し、また前記排ガス制御系で
検出された排ガス温度が前記第１の設定温度より低い第
２の設定温度以下で燃焼空気温度制御系で検出された燃
焼空気温度が前記第１及び第２の設定温度より高い第３
の設定温度以上になると前記排ガス温度をもとに求めら
れた負荷降下のための減少量を固定し、前記燃焼空気温
度制御系で検出された燃焼空気温度をもとに負荷降下の
ための減少量を求めて前記目標燃焼要求量を補正する燃
焼負荷低減処理手段を設けたことを特徴とする加熱炉の
制御装置。3. A combustion gas supply system for supplying combustion gas and a combustion air supply system for supplying combustion air are respectively connected to a plurality of burners arranged in the furnace body, and the exhaust gas burned by each burner is cooled with cold air and heat. The exhaust gas system which is discharged to the outside through the heat exchanger to be exchanged is connected, and the cold air supply system for supplying cold air is connected to the upstream side of the heat exchanger of this exhaust gas system, and the combustion heat-exchanged by the heat exchanger is connected. In a heating furnace in which air is sent to the combustion air supply system and a part of the combustion air can be diffused to the outside, the combustion gas is detected so that the combustion temperature of the burner is detected and the combustion temperature becomes a target combustion required amount. A combustion control system for controlling the flow rate of combustion gas supplied to each burner from a supply system and the flow rate of combustion air supplied to each burner from the combustion air supply system, and a fuel flowing to the combustion air supply system. A combustion air temperature control system that detects the temperature of the combustion air and controls the combustion air temperature by discharging a part of the combustion air to the outside based on the detected temperature value, and an exhaust gas system on the upstream side of the heat exchanger. An exhaust gas temperature control system for controlling the cool air supplied to the exhaust gas system from the cold air supply system based on the exhaust gas temperature detection value by detecting the exhaust gas temperature flowing through the exhaust gas temperature detected by the exhaust gas control system. When the temperature is equal to or higher than the first set temperature, the reduction amount for the load drop is calculated based on the exhaust gas temperature, and the reduction amount for the load drop is calculated based on the combustion air temperature detected by the combustion air temperature control system. Then, the target combustion demand of the combustion control system is corrected by the addition value of these reduction amounts, and when the exhaust gas temperature detected by the exhaust gas control system is lower than the second set temperature lower than the first set temperature. Combustion air temperature control system The issued combustion air temperature is first and second higher than the set temperature 3
When the temperature exceeds the set temperature, the amount of decrease for load drop determined based on the exhaust gas temperature is fixed, and the amount of decrease for load drop is determined based on the combustion air temperature detected by the combustion air temperature control system. A heating furnace control device comprising combustion load reduction processing means for determining the amount and correcting the target required combustion amount.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12724493A JPH06337113A (en) | 1993-05-28 | 1993-05-28 | Controller for heating furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP12724493A JPH06337113A (en) | 1993-05-28 | 1993-05-28 | Controller for heating furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06337113A true JPH06337113A (en) | 1994-12-06 |
Family
ID=14955271
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP12724493A Pending JPH06337113A (en) | 1993-05-28 | 1993-05-28 | Controller for heating furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06337113A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102889593A (en) * | 2012-08-06 | 2013-01-23 | 闻喜县白玉矿业有限公司 | Combustion system of magnesium reducing furnace |
| JP2013088101A (en) * | 2011-10-21 | 2013-05-13 | Nippon Steel & Sumitomo Metal Corp | Method of cooling air preheater in heating furnace |
| CN104100995A (en) * | 2014-07-14 | 2014-10-15 | 首钢总公司 | Heating furnace heat load distribution method and device |
| CN104197732A (en) * | 2014-09-19 | 2014-12-10 | 济南大学 | Regenerative gas heating furnace control system |
| CN104296548A (en) * | 2014-09-25 | 2015-01-21 | 苏州新长光热能科技有限公司 | Temperature cascade control system of casting holding furnace and control method of temperature cascade control system |
| CN106678865A (en) * | 2016-11-10 | 2017-05-17 | 安徽皖拓自动化有限公司 | Novel combustion control system of fire resistance testing for valves |
-
1993
- 1993-05-28 JP JP12724493A patent/JPH06337113A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013088101A (en) * | 2011-10-21 | 2013-05-13 | Nippon Steel & Sumitomo Metal Corp | Method of cooling air preheater in heating furnace |
| CN102889593A (en) * | 2012-08-06 | 2013-01-23 | 闻喜县白玉矿业有限公司 | Combustion system of magnesium reducing furnace |
| CN104100995A (en) * | 2014-07-14 | 2014-10-15 | 首钢总公司 | Heating furnace heat load distribution method and device |
| CN104197732A (en) * | 2014-09-19 | 2014-12-10 | 济南大学 | Regenerative gas heating furnace control system |
| CN104197732B (en) * | 2014-09-19 | 2016-04-06 | 济南大学 | A kind of regenerative gas heater control system |
| CN104296548A (en) * | 2014-09-25 | 2015-01-21 | 苏州新长光热能科技有限公司 | Temperature cascade control system of casting holding furnace and control method of temperature cascade control system |
| CN106678865A (en) * | 2016-11-10 | 2017-05-17 | 安徽皖拓自动化有限公司 | Novel combustion control system of fire resistance testing for valves |
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