JP3364091B2 - Temperature control method for continuous annealing furnace - Google Patents
Temperature control method for continuous annealing furnaceInfo
- Publication number
- JP3364091B2 JP3364091B2 JP23060496A JP23060496A JP3364091B2 JP 3364091 B2 JP3364091 B2 JP 3364091B2 JP 23060496 A JP23060496 A JP 23060496A JP 23060496 A JP23060496 A JP 23060496A JP 3364091 B2 JP3364091 B2 JP 3364091B2
- Authority
- JP
- Japan
- Prior art keywords
- temperature
- furnace
- cooling
- continuous annealing
- burner
- 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.)
- Expired - Fee Related
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
Landscapes
- Air Supply (AREA)
- Combustion Of Fluid Fuel (AREA)
- Regulation And Control Of Combustion (AREA)
- Control Of Combustion (AREA)
- Gas Burners (AREA)
Description
【0001】[0001]
【発明の属する技術分野】本発明は、連続式焼鈍炉の温
度制御方法に関する。さらに詳しくは、鋼板などの被加
熱材を焼鈍する際に用いられる連続式焼鈍炉の温度制御
方法に関する。TECHNICAL FIELD The present invention relates to a temperature control method for a continuous annealing furnace. More specifically, the present invention relates to a temperature control method for a continuous annealing furnace used when annealing a material to be heated such as a steel plate.
【0002】[0002]
【従来の技術】近年、連続式焼鈍炉には、熱効率の向上
およびNOxガスの発生量の低減の観点から、蓄熱式ラ
ジアントチューブバーナが用いられている(特開平2−
254210号公報、特開平7−103435号公報な
ど)。2. Description of the Related Art In recent years, a heat storage type radiant tube burner has been used in a continuous annealing furnace from the viewpoint of improving thermal efficiency and reducing the amount of NO x gas generated (JP-A-2-
254210, JP-A-7-103435, etc.).
【0003】前記蓄熱式ラジアントチューブバーナによ
れば、図1に示されるように、ファン5から送入された
エアが、エア供給パイプ4aを介してバーナ1aに送入
され、燃料パイプ5aからの燃料ガスが該バーナ1aで
燃焼される。このとき、バーナ1aは加熱されるが、そ
の発熱を有効利用するために、発生した熱が蓄熱体2a
に蓄えられる。バーナ1aの燃焼ガスは、ラジアントチ
ューブ3内および蓄熱体2bを順次介してエア供給パイ
プ4bに送入され、排気パイプ6から排気される。この
ときにも、排気ガスの熱が蓄熱体2bに蓄えられ、その
熱が有効利用される。この操作を切替バルブ7で切替え
ることにより、バーナ1aおよび1bの燃焼が交互に行
なわれる。このように、蓄熱式ラジアントチューブバー
ナは、2本のバーナ1a、1bを交互に燃焼するもので
あり、排気ガスによってラジアントチューブ3を速やか
に加熱することができるため、高い燃焼効率がえられ、
大幅な省エネルギーを図ることができる。According to the heat storage type radiant tube burner, as shown in FIG. 1, the air sent from the fan 5 is sent to the burner 1a via the air supply pipe 4a, and the air from the fuel pipe 5a is sent. Fuel gas is burned in the burner 1a. At this time, the burner 1a is heated, but in order to effectively utilize the generated heat, the generated heat is generated by the heat storage body 2a.
Stored in. The combustion gas of the burner 1a is fed into the air supply pipe 4b through the inside of the radiant tube 3 and the heat storage body 2b, and is exhausted from the exhaust pipe 6. Also at this time, the heat of the exhaust gas is stored in the heat storage body 2b, and the heat is effectively used. By switching this operation with the switching valve 7, combustion of the burners 1a and 1b is alternately performed. As described above, the heat storage type radiant tube burner alternately burns the two burners 1a and 1b, and since the radiant tube 3 can be rapidly heated by the exhaust gas, high combustion efficiency can be obtained.
Significant energy savings can be achieved.
【0004】しかしながら、その反面、前記蓄熱式ラジ
アントチューブバーナは、蓄熱体2a、2bによって熱
をできるだけ外部に逃がさない構造を有していることに
より、燃焼後の連続式焼鈍炉の冷却に長大な時間を要す
るという欠点がある。On the other hand, however, the heat storage type radiant tube burner has a structure in which the heat is not released to the outside by the heat storage bodies 2a and 2b, so that it is very long for cooling the continuous annealing furnace after combustion. The drawback is that it takes time.
【0005】また、連続式焼鈍炉に鋼板を通板させてい
るときに鋼板の種類を切り替えたばあいには、その切り
替え後の鋼板に応じた炉温度に設定変更をする必要があ
り、切り替え前の鋼板に応じた炉温度よりも、切り替え
後の鋼板に応じた炉温度のほうが大幅に低い(たとえば
50℃以上低い)ばあいには、冷却に長時間を要するた
め、その冷却中に通板された部分は、品質不良となって
しまうという欠点がある。Further, when the type of the steel sheet is switched while the steel sheet is being passed through the continuous annealing furnace, it is necessary to change the setting to the furnace temperature according to the steel sheet after the switching. If the furnace temperature according to the steel plate after switching is significantly lower than the furnace temperature according to the previous steel plate (for example, 50 ° C. or more lower), it takes a long time to cool, so the cooling process is not performed during the cooling. The plated portion has a drawback that the quality is poor.
【0006】したがって、炉温度切り替え用コイル(以
下、調整コイルという)が必要とされ、冷却時間が長く
なればなるほど、その調整コイルを多数必要とするた
め、かかる調整コイル費用が増加し、燃料が浪費され、
生産量が低下するという欠点がある。Therefore, a furnace temperature switching coil (hereinafter referred to as an adjustment coil) is required, and the longer the cooling time, the larger the number of adjustment coils required. Wasted,
It has the drawback of reducing production.
【0007】また、たとえば、炉の修理時に炉温度を降
温させるばあいには、炉壁レンガを急冷によって損傷し
ないようにするために、最適な冷却速度が確保されるよ
うに炉温度を小刻みに設定変更し、降温していくが、従
来のラジアントチューブバーナを用いたばあいと対比し
て降温時間が2倍以上も必要とされ、これもまた生産性
を低下させる要因となっている。Further, for example, when lowering the furnace temperature at the time of repairing the furnace, the furnace temperature is divided into small pieces so as to ensure an optimum cooling rate in order to prevent damage to the bricks of the furnace wall by quenching. Although the setting is changed and the temperature is lowered, the cooling time is required to be more than twice as long as in the case where the conventional radiant tube burner is used, which also causes a decrease in productivity.
【0008】このように、炉温度の設定変更時および降
温時の双方に共通していえることは、小刻みな炉温度の
設定変更に対して、冷却時の応答性がわるいということ
である。As described above, what can be commonly said when changing the setting of the furnace temperature and when decreasing the temperature is that the response at the time of cooling is poor with respect to the setting change of the furnace temperature little by little.
【0009】そこで、冷却時の応答性を改善する方法と
して一般に考えられるのは、冷却時に燃焼を停止して相
当量の冷却エアを一気にラジアントチューブ内に吹き込
む方法である。Therefore, a method generally considered as a method of improving the response during cooling is to stop combustion during cooling and blow a considerable amount of cooling air into the radiant tube at once.
【0010】しかしながら、かかる冷却エアを吹き込む
方法を採用したばあいには、炉温度の設定変更時に、燃
焼を停止して再度、炉温度の設定変更が実施されると、
点火する手間が増え、制御性が悪化するおそれがあると
ともに、相当量の冷却エアを吹き込めば炉温度が低下し
すぎて炉温度にフレが生じるため、品質不良が発生する
おそれがある。また、降温時には、冷却速度が高すぎる
ばあい、炉壁レンガを損傷することがあり、また冷却時
間を長くしたばあいには生産性の悪化に繋がるため、最
適な冷却速度を確保する必要があるが、前記のように、
燃焼を停止して相当量の冷却エアを吹き込むだけでは、
最適な冷却速度を確保することが困難であるという欠点
がある。However, if such a method of blowing cooling air is adopted, when the setting of the furnace temperature is changed, if the combustion is stopped and the setting of the furnace temperature is changed again,
There is a risk that the time and effort required for ignition will increase and controllability will deteriorate, and if a considerable amount of cooling air is blown in, the furnace temperature will drop too much and the furnace temperature will fluctuate, which may result in poor quality. If the cooling rate is too high during cooling, the brick wall may be damaged, and if the cooling time is extended, productivity may deteriorate.Therefore, it is necessary to secure the optimal cooling rate. But as mentioned above,
Just by stopping the combustion and blowing a considerable amount of cooling air,
There is a drawback that it is difficult to secure the optimum cooling rate.
【0011】[0011]
【発明が解決しようとする課題】本発明は、前記従来技
術に鑑みてなされたものであり、連続式焼鈍炉の炉温度
の設定を変更する際に、所望の冷却時間で冷却させるこ
とができる連続式焼鈍炉の温度制御方法を提供すること
を目的とする。SUMMARY OF THE INVENTION The present invention has been made in view of the above prior art, and when changing the setting of the furnace temperature of the continuous annealing furnace, it can be cooled in a desired cooling time. An object is to provide a temperature control method for a continuous annealing furnace.
【0012】[0012]
【課題を解決するための手段】本発明は、その両端にそ
れぞれバーナが設けられ、前記バーナの周囲に通気性を
有する多孔質の蓄熱体が設けられてなる蓄熱式ラジアン
トチューブバーナを用いた連続式焼鈍炉の温度制御方法
であって、前記バーナをそれぞれ交互に燃焼させて被加
熱材を焼鈍させるバーナの燃焼操作による炉温制御を行
ない、炉の設定温度を低温に変更する際または炉の稼動
を停止するために炉温度を降温させる際に、前記バーナ
の燃焼操作を行ないながら、一方のバーナに接続された
エア供給パイプから強制冷却エアを供給し、ラジアント
チューブ内を介して他方のバーナに接続されたエア供給
パイプへ該強制冷却エアを通気させることによる冷却補
償を行ない、前記冷却補償において、あらかじめ連続式
焼鈍炉の加熱〜冷却の温度実績を調べておき、前記温度
実績にもとづいて所定時間に連続式焼鈍炉を所定温度に
冷却させるのに要する強制冷却エア量を決定し、前記強
制冷却エア量にもとづいて前記エア供給パイプへ強制冷
却エアを通気させることを特徴とする連続式焼鈍炉の温
度制御方法に関する。前記冷却補償における強制冷却エ
ア量を、前記温度実績と二次遅れ伝達関数にしたがう推
定モデル出力との偏差から決定するのが好ましい。 SUMMARY OF THE INVENTION The present invention is a continuous heat storage type radiant tube burner in which burners are provided at both ends of the burner, and a porous heat storage material having air permeability is provided around the burners. A method for controlling the temperature of a type annealing furnace, in which the furnace temperature is controlled by the burning operation of the burners for alternately burning the burners and annealing the material to be heated, when changing the set temperature of the furnace to a low temperature or When lowering the furnace temperature to stop the operation, while carrying out the combustion operation of the burner, forced cooling air is supplied from the air supply pipe connected to one burner, and the other burner is supplied through the inside of the radiant tube. Cooling supplement by ventilating the forced cooling air to the air supply pipe connected to
Compensation is made in advance for continuous cooling
Examine the temperature record of heating-cooling of the annealing furnace,
Based on actual results, the continuous annealing furnace was brought to the prescribed temperature in the prescribed time.
Determine the amount of forced cooling air required to cool the
Forced cooling to the air supply pipe based on the controlled cooling air volume
TECHNICAL FIELD The present invention relates to a temperature control method for a continuous annealing furnace, which is characterized by ventilating exhaust air . Forced cooling in the cooling compensation
(A) Estimate the quantity according to the actual temperature and the secondary delay transfer function.
It is preferable to determine from the deviation from the constant model output.
【0013】[0013]
【発明の実施の形態】本発明の連続式焼鈍炉の温度制御
方法は、前記したように、その両端にそれぞれバーナが
設けられ、前記バーナの周囲に通気性を有する多孔質の
蓄熱体が設けられてなる蓄熱式ラジアントチューブバー
ナを用いた連続式焼鈍炉の温度制御方法であって、前記
バーナをそれぞれ交互に燃焼させて被加熱材を焼鈍させ
るバーナの燃焼操作による炉温制御を行ない、炉の設定
温度を低温に変更する際または炉の稼動を停止するため
に炉温度を降温させる際に、前記バーナの燃焼操作を行
ないながら、一方のバーナに接続されたエア供給パイプ
から強制冷却エアを供給し、ラジアントチューブ内を介
して他方のバーナに接続されたエア供給パイプへ該強制
冷却エアを通気させることによる冷却補償を行ない、前
記冷却補償において、あらかじめ連続式焼鈍炉の加熱〜
冷却の温度実績を調べておき、前記温度実績にもとづい
て所定時間に連続式焼鈍炉を所定温度に冷却させるのに
要する強制冷却エア量を決定し、前記強制冷却エア量に
もとづいて前記エア供給パイプへ強制冷却エアを通気さ
せることを特徴とする。BEST MODE FOR CARRYING OUT THE INVENTION As described above, the temperature control method for a continuous annealing furnace of the present invention is provided with burners at both ends thereof, and a porous heat storage material having air permeability is provided around the burners. A method for controlling the temperature of a continuous annealing furnace using a heat storage type radiant tube burner consisting of, wherein the furnace temperature is controlled by the burning operation of the burner for alternately burning the burners to anneal the material to be heated, When changing the set temperature of to a low temperature or when lowering the furnace temperature to stop the operation of the furnace, while performing the combustion operation of the burner, the forced cooling air is supplied from the air supply pipe connected to one burner. The cooling compensation is performed by supplying the forced cooling air to the air supply pipe connected to the other burner through the radiant tube.
In the cooling compensation, heating the continuous annealing furnace in advance ~
Examine the cooling temperature record and based on the temperature record
To cool the continuous annealing furnace to a specified temperature in a specified time.
Determine the amount of forced cooling air required and add
Vent the forced cooling air to the air supply pipe.
It is characterized by making it.
【0014】このように、本発明の連続式焼鈍炉の温度
制御方法によれば、蓄熱式ラジアントチューブバーナの
一方のバーナに接続されたエア供給パイプから強制冷却
エアを供給し、ラジアントチューブ内を介して他方のバ
ーナに接続されたエア供給パイプへ該強制冷却エアを通
気させるという手段が採用されており、前記強制冷却エ
ア量を調節することにより、温度設定変更量に関係な
く、冷却時間を所望の冷却時間に調整することができ
る。As described above, according to the temperature control method for the continuous annealing furnace of the present invention, the forced cooling air is supplied from the air supply pipe connected to one burner of the heat storage type radiant tube burner, and the inside of the radiant tube is supplied. The means for ventilating the forced cooling air to the air supply pipe connected to the other burner via the means is adopted, and by adjusting the forced cooling air amount, the cooling time can be reduced regardless of the temperature setting change amount. The desired cooling time can be adjusted.
【0015】つぎに、図面を参照しながら、本発明の連
続式焼鈍炉の温度制御方法の一実施態様を説明する。Next, one embodiment of the temperature control method for a continuous annealing furnace of the present invention will be described with reference to the drawings.
【0016】図2は、本発明の連続式焼鈍炉の温度制御
方法に用いられる連続式焼鈍炉の一実施態様を示す概略
説明図である。FIG. 2 is a schematic explanatory view showing one embodiment of a continuous annealing furnace used in the temperature control method of the continuous annealing furnace of the present invention.
【0017】図2において、(a)は、連続式焼鈍炉の
概略平面図、(b)は、図2(a)の線A−A部におけ
る概略断面図である。In FIG. 2, (a) is a schematic plan view of the continuous annealing furnace, and (b) is a schematic sectional view taken along line AA of FIG. 2 (a).
【0018】図2において、連続式焼鈍炉11内の被加
熱材の通板部には、通板ロール12が配置されており、
該通板ロール12上にストリップなどの被加熱材(図示
せず)が通板する。通板ロール12、12のあいだにラ
ジアントチューブ3、3が上下2段に設けられており、
この上下のラジアントチューブ3、3のあいだを被加熱
材が通板する。In FIG. 2, a sheet passing roll 12 is arranged in the sheet passing portion of the material to be heated in the continuous annealing furnace 11.
A material to be heated (not shown) such as a strip is threaded onto the threading roll 12. Radiant tubes 3 and 3 are provided in upper and lower two stages between the threading rolls 12 and 12,
The material to be heated passes between the upper and lower radiant tubes 3, 3.
【0019】被加熱材を通板ロール12上に通板させた
際には、該被加熱材から抜熱が生じ、その抜熱とラジア
ントチューブ3による加熱とによって連続式焼鈍炉11
の炉温度が制御される。被加熱材を連続式焼鈍炉11内
で焼鈍させる際の炉温度は、被加熱材の種類などによっ
て異なるので一概には決定することができない。連続式
焼鈍炉11内で被加熱材を焼鈍させる際の炉温度は、ラ
ジアントチューブ3内に供給される燃料およびエアの供
給量、被加熱材の通板速度などを調整することにより、
適宜調節することができる。When the material to be heated is passed through the sheet passing roll 12, heat is removed from the material to be heated, and the heat is removed and the radiant tube 3 heats the continuous annealing furnace 11.
Furnace temperature is controlled. The furnace temperature at which the material to be heated is annealed in the continuous annealing furnace 11 varies depending on the type of material to be heated and cannot be unconditionally determined. The furnace temperature at the time of annealing the material to be heated in the continuous annealing furnace 11 is adjusted by adjusting the supply amount of fuel and air supplied into the radiant tube 3 and the strip speed of the material to be heated.
It can be adjusted appropriately.
【0020】ラジアントチューブ3には、バーナ1a、
1bが接続され、該バーナ1a、1bは、切替バルブ7
に接続されている。切替バルブ7は、燃焼ガス流量制御
装置(FIC)および燃焼エア流量制御装置を備えた燃
焼加熱制御装置14に接続されている。The radiant tube 3 has a burner 1a,
1b is connected, and the burners 1a and 1b are provided with a switching valve 7
It is connected to the. The switching valve 7 is connected to a combustion heating controller 14 including a combustion gas flow controller (FIC) and a combustion air flow controller.
【0021】連続式焼鈍炉11の炉温度は、たとえば熱
電対などの温度検出器13によって検出され、その結果
が温度実績測定装置に伝達される。The furnace temperature of the continuous annealing furnace 11 is detected by a temperature detector 13 such as a thermocouple, and the result is transmitted to a temperature performance measuring device.
【0022】つぎに、たとえば鋼板の種類を切り替える
ために連続式焼鈍炉11の設定温度を低温に変更する際
または炉の稼動を停止するために炉温度を降温させる際
に、本発明の連続式焼鈍炉の温度制御方法が有効とな
る。Next, for example, when the set temperature of the continuous annealing furnace 11 is changed to a low temperature in order to switch the type of steel sheet, or when the furnace temperature is lowered to stop the operation of the furnace, the continuous type of the present invention is used. The temperature control method of the annealing furnace becomes effective.
【0023】本発明の連続式焼鈍炉の温度制御方法の一
実施態様を図3に示されたブロック線図にもとづいて説
明する。An embodiment of the temperature control method for the continuous annealing furnace of the present invention will be described with reference to the block diagram shown in FIG.
【0024】図3において、包囲線Aで枠囲みされた部
分は、連続式焼鈍炉を稼働させているときの炉温度を制
御するための既設の炉温制御部であり、包囲線Bで枠囲
みされた部分は、連続式焼鈍炉を冷却させるときに強制
冷却エアを供給するための冷却補償部である。In FIG. 3 , a portion surrounded by a frame line A is an existing furnace temperature control unit for controlling the furnace temperature when the continuous annealing furnace is in operation, and a frame frame B is a frame. The enclosed portion is a cooling compensator for supplying forced cooling air when cooling the continuous annealing furnace.
【0025】炉温制御部において、21は炉温設定値
(SV)、22は温度制御装置(TIC)、23は温度
制御操作量(MV)、24は燃焼ガス流量制御装置(F
IC)、25は燃焼ガス流量制御バルブ、26は燃焼エ
ア流量制御装置(FIC)、27は燃焼エア流量制御バ
ルブである。In the furnace temperature control unit, 21 is a furnace temperature set value (SV), 22 is a temperature controller (TIC), 23 is a temperature control manipulated variable (MV), and 24 is a combustion gas flow rate controller (F).
IC), 25 is a combustion gas flow rate control valve, 26 is a combustion air flow rate control device (FIC), and 27 is a combustion air flow rate control valve.
【0026】まず、既設の炉温制御部においては、連続
式焼鈍炉内で被加熱材に焼鈍処理を施すばあい、蓄熱式
ラジアントチューブバーナを用い、その両端のバーナを
それぞれ交互に燃焼させる際には、炉温設定値21が設
定され、その炉温設定値21となるように、炉温度が温
度制御装置22で制御される。前記制御は、温度制御装
置22に接続された燃焼ガス流量制御装置24および燃
焼エア流量制御装置26を介して、それぞれ燃焼ガス流
量制御バルブ25および燃焼エア流量制御バルブ27
で、燃焼ガス流量および燃焼エア流量を調節することに
よって行なわれる。First, in the existing furnace temperature control unit, when the material to be heated is annealed in the continuous annealing furnace, a regenerative radiant tube burner is used and the burners at both ends are alternately burned. Is set to the furnace temperature set value 21, and the furnace temperature is controlled by the temperature control device 22 so that the furnace temperature set value 21 becomes the set value. The control is performed by a combustion gas flow rate control valve 25 and a combustion air flow rate control valve 27, respectively, via a combustion gas flow rate control device 24 and a combustion air flow rate control device 26 connected to the temperature control device 22.
By adjusting the combustion gas flow rate and the combustion air flow rate.
【0027】つぎに、前記したように、たとえば鋼板の
種類を切り替えるために連続式焼鈍炉11の設定温度を
低温に変更する際または炉の稼動を停止するために炉温
度を降温させる際には、本発明の連続式焼鈍炉の温度制
御方法が有効となる。Next, as described above, for example, when changing the set temperature of the continuous annealing furnace 11 to a low temperature in order to switch the type of steel sheet or when lowering the furnace temperature to stop the operation of the furnace. The temperature control method of the continuous annealing furnace of the present invention is effective.
【0028】本発明の連続式焼鈍炉の温度制御方法は、
具体的には、炉温制御部で炉温度の制御操作を行ないな
がら、冷却時には、既設の炉温制御部を助ける意味合い
で、併行して冷却補償部を作動させる。The temperature control method of the continuous annealing furnace of the present invention is as follows.
Specifically, while controlling the furnace temperature by the furnace temperature control unit, at the time of cooling, the cooling compensating unit is operated in parallel in order to help the existing furnace temperature control unit.
【0029】その理由としては、既設の炉温制御部だけ
では、冷却時に冷却時間が長くなり、所望の冷却時間が
えられないことや、冷却補償部のみでは、炉温度を一定
に保持することができず、炉温度が低下しすぎて、炉温
制御を大きく乱してしまうことがあげられる。The reason for this is that the cooling time required for cooling is long only with the existing furnace temperature control section, and the desired cooling time cannot be obtained, and the furnace temperature is kept constant only with the cooling compensation section. However, the temperature of the furnace is too low and the temperature control of the furnace is greatly disturbed.
【0030】したがって、任意の温度設定に対して、安
定的に炉温度を確保しようとすると、既設炉温制御部と
冷却補償部とを同時に作動させる必要がある。Therefore, in order to stably secure the furnace temperature with respect to an arbitrary temperature setting, it is necessary to operate the existing furnace temperature control section and the cooling compensation section at the same time.
【0031】また、蓄熱式ラジアントチューブバーナの
両端のバーナのトーチが消火しない範囲内で、バーナの
燃焼操作を行なうことが好ましい。このようにバーナの
トーチを消火させないのは、トーチを完全に消火させて
しまったばあい、連続式焼鈍炉の立上がり時にトーチに
点火させるのに長時間を要するからである。Further, it is preferable to carry out the burner combustion operation within a range in which the torches of the burners at both ends of the heat storage type radiant tube burner do not extinguish the fire. The reason why the torch of the burner is not extinguished is that it takes a long time to ignite the torch when the continuous annealing furnace is started up if the torch is completely extinguished.
【0032】また、冷却補償部での連続式焼鈍炉の冷却
操作は、一方のバーナに接続されたエア供給パイプから
強制冷却エアを供給し、ラジアントチューブ内を介して
他方のバーナに接続されたエア供給パイプへ該強制冷却
エアを通気させることにより、行なわれる。Further, in the cooling operation of the continuous annealing furnace in the cooling compensator, forced cooling air was supplied from the air supply pipe connected to one burner and connected to the other burner through the inside of the radiant tube. This is performed by ventilating the forced cooling air to the air supply pipe.
【0033】図3に示された冷却補償部において、28
は、冷却補償のための制御モデル(G(s)p)である。そ
の制御モデルとして、たとえば二次遅れ伝達関数で冷却
補償を行なうことができる。その二次遅れ伝達関数G
(s)pは、式(I):In the cooling compensator shown in FIG. 3, 28
Is a control model (G (s) p ) for cooling compensation. As the control model, for example, cooling compensation can be performed with a second-order lag transfer function. The secondary delay transfer function G
(s) p is the formula (I):
【0034】[0034]
【数1】 [Equation 1]
【0035】で表わされる。It is represented by
【0036】式(I)において、Kはゲイン定数、e
-TSはむだ時間推定伝達関数、Tp1およびTp2はそれぞ
れ炉温推定時定数、sはラプラス演算子を示す。In the formula (I), K is a gain constant, e
-TS is a dead time estimation transfer function, T p1 and T p2 are furnace temperature estimation time constants, and s is a Laplace operator.
【0037】つぎに、炉温度(温度実績)が温度検出器
によって検出され、その結果が温度実績測定装置(P
V)29に伝達される。その温度にもとづいて、二次遅
れ伝達関数G(s)pにしたがい、PI制御装置(PI)3
0で強制冷却エア量が決定され、リミッター(LM)3
1により必要エア量が燃焼エア流量制御装置26に伝達
され、燃焼エア流量制御バルブ27で燃焼エア流量が調
節される。Next, the furnace temperature (actual temperature) is detected by the temperature detector, and the result is measured by the actual temperature measuring device (P
V) 29. Based on the temperature, according to the second-order lag transfer function G (s) p , the PI controller (PI) 3
The forced cooling air amount is determined by 0, and the limiter (LM) 3
1, the required air amount is transmitted to the combustion air flow rate control device 26, and the combustion air flow rate control valve 27 adjusts the combustion air flow rate.
【0038】なお、本発明においては、式(I)で表わ
される二次遅れ伝達関数G(s)pの決定は、あらかじめ連
続式焼鈍炉の加熱〜冷却の温度実績、たとえば図4に示
される波形を有する温度実績(PV)を調べておくこと
によって行なわれる。G(s)pの応答は、既設の加熱時間
をほぼ合わせ、冷却時間が所望冷却時間T(B〜C間の
時間)となるように前記炉温推定時定数Tp1およびTp2
を設定する。制御精度をあまり必要としないときには、
Tp1およびTp2は同等の数値でもよく、制御精度を必要
とするときには、既設炉の応答波形に合わせるようにT
p1およびTp2の配分を変更してもよい。また、むだ時間
推定伝達関数e-TSについても、前記採取した実績波形
にもとづいて決定する。In the present invention, the determination of the second-order lag transfer function G (s) p represented by the formula (I) is previously shown in the actual temperature of heating to cooling of the continuous annealing furnace, for example, shown in FIG. This is done by examining the temperature performance (PV) with the waveform. Regarding the response of G (s) p, the furnace temperature estimated time constants T p1 and T p2 are set so that the existing heating time is almost matched and the cooling time becomes the desired cooling time T (time between B and C).
To set. When you do not need control accuracy,
T p1 and T p2 may have the same numerical value, and when control accuracy is required, T p should be adjusted to match the response waveform of the existing furnace.
The distribution of p1 and T p2 may be changed. The dead time estimation transfer function e −TS is also determined based on the acquired actual waveform.
【0039】図4においては、原点0から時間Aまでが
昇温曲線、時間Aから時間Bまでが定常状態、時間Bか
ら時間Dまでが冷却曲線となっている。In FIG. 4, the temperature rising curve is from the origin 0 to the time A, the steady state is from the time A to the time B, and the cooling curve is from the time B to the time D.
【0040】つぎに、時間Bで連続式焼鈍炉の加熱を終
了し、時間Cで所定温度に冷却されるようにするばあ
い、式(I)で表わされる二次遅れ伝達関数G(s)pにし
たがって温度推定曲線SV1が描かれる。Next, when the heating of the continuous annealing furnace is finished at time B and the temperature is cooled to a predetermined temperature at time C, the second-order lag transfer function G (s) represented by the formula (I) is given. A temperature estimation curve SV1 is drawn according to p .
【0041】したがって、加熱終了後、時間Cで所定温
度に冷却されるようにするためには、図4に示された斜
線部の面積で表わされるエネルギーを除去するのに必要
な冷却空気量(強制冷却エア量)をPI制御装置30で
決定し、燃焼エア流量制御バルブ27で強制冷却エア量
を調整し、エア供給パイプへ強制冷却エアを通気させれ
ばよい。ただし、リミッター31は、PI制御装置30
の出力の正の値のみを出力する(負の値は出力しない)
ように調整しておく。このように調整することで、炉温
設定値21が任意の値に変化したとしても、常に冷却時
には所望冷却時間Tを確保することができる。Therefore, in order to be cooled to a predetermined temperature at time C after the end of heating, the amount of cooling air required to remove the energy represented by the shaded area in FIG. 4 ( The amount of forced cooling air) may be determined by the PI controller 30, the amount of forced cooling air may be adjusted by the combustion air flow rate control valve 27, and forced cooling air may be ventilated into the air supply pipe. However, the limiter 31 is the PI control device 30.
Output only positive values (not negative values)
To make adjustments. By adjusting in this way, even if the furnace temperature set value 21 changes to an arbitrary value, the desired cooling time T can always be secured during cooling.
【0042】なお、式(I)で表わされる二次遅れ伝達
関数G(s)pにおいて、ゲイン定数Kは、K>1を満足す
るように設定しておくことが好ましい。このようにゲイ
ン定数Kを設定したばあい、加熱時〜定常時において、
リミッター31から強制冷却エアが出力するのを制御す
ることができる。In the second-order lag transfer function G (s) p represented by the formula (I), the gain constant K is preferably set so as to satisfy K> 1. When the gain constant K is set in this way, during heating to steady state,
It is possible to control the output of the forced cooling air from the limiter 31.
【0043】[0043]
【実施例】つぎに、本発明の連続式焼鈍炉の温度制御方
法を実施例にもとづいてさらに詳細に説明するが、本発
明はかかる実施例のみに限定されるものではない。EXAMPLES Next, the temperature control method of the continuous annealing furnace of the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.
【0044】実施例1
図1に示されるような蓄熱式ラジアントチューブバーナ
(チューブの外径178mm、第1直管の上端部から第
2直管の下端部までの幅1000mm、長さ2000m
m)を用いた。Example 1 A heat storage type radiant tube burner as shown in FIG. 1 (tube outer diameter 178 mm, width 1000 mm from upper end of first straight pipe to lower end of second straight pipe, length 2000 m)
m) was used.
【0045】まず、燃料パイプ5aから燃料ガス(コー
クス炉ガス)を、またエア供給パイプ4aからエアをバ
ーナ1aに空気比2.4で供給し、30秒間経過したの
ち、これと同様の操作を燃料パイプ5bおよびエア供給
パイプ4bから30秒間行なう操作を1サイクルとして
繰り返し、鋼板(温度400℃)を2m/secの速度
で通板させながら、鋼板を600℃にまで焼鈍させるバ
ーナ1a、1bの燃焼操作を行なった。First, fuel gas (coke oven gas) was supplied from the fuel pipe 5a and air was supplied from the air supply pipe 4a to the burner 1a at an air ratio of 2.4, and after 30 seconds had passed, the same operation was performed. The operation of performing 30 seconds from the fuel pipe 5b and the air supply pipe 4b is repeated as one cycle, and while the steel sheet (temperature 400 ° C) is passed at a speed of 2 m / sec, the burners 1a and 1b are annealed to 600 ° C. A burning operation was performed.
【0046】前記鋼板の通板後、焼鈍を終了する際に、
前記バーナの燃焼操作を行ないながら、式(I)で表わ
される二次遅れ伝達関数G(s)pにより、1000秒間で
冷却が完了(冷却温度:200℃以下)するように、P
I制御装置で強制冷却エア量を決定し、リミッターによ
り必要エア量を燃焼エア流量制御装置に伝達し、燃焼エ
ア流量制御バルブで燃焼エア流量を調節し、一方のエア
供給パイプから強制冷却エアを供給し、連続式焼鈍炉の
冷却を行なった。その結果を図5中のa〜bの曲線Aで
示す。After finishing the annealing of the steel sheet,
While performing the burning operation of the burner, by the second-order lag transfer function G (s) p represented by the formula (I), cooling is completed in 1000 seconds (cooling temperature: 200 ° C. or less), P
The I control unit determines the forced cooling air amount, the limiter transmits the required air amount to the combustion air flow rate control unit, the combustion air flow rate control valve adjusts the combustion air flow rate, and the forced cooling air is supplied from one air supply pipe. It was supplied and the continuous annealing furnace was cooled. The result is shown by curve A of a to b in FIG.
【0047】つぎに、再度、前記と同様にして鋼板を9
00℃にまで焼鈍させるバーナ1a、1bの燃焼操作を
行なった。Then, again, the steel plate
The burners 1a and 1b were annealed to anneal to 00 ° C.
【0048】前記鋼板の通板後、焼鈍を終了する際に、
前記バーナの燃焼操作を行ないながら、式(I)で表わ
される二次遅れ伝達関数G(s)pにより、再び1000秒
間で冷却が完了(冷却温度:400℃以下)するよう
に、PI制御装置で強制冷却エア量を決定し、リミッタ
ーで燃焼エア流量を調節し、一方のエア供給パイプから
強制冷却エアを供給し、連続式焼鈍炉の冷却を行なっ
た。その結果を図5中のc〜dの曲線Bで示す。After finishing the annealing of the steel sheet,
While performing the burning operation of the burner, the PI controller so that the cooling is completed again in 1000 seconds (cooling temperature: 400 ° C. or less) by the second-order lag transfer function G (s) p represented by the formula (I). The amount of forced cooling air was determined by, and the flow rate of combustion air was adjusted by a limiter, and forced cooling air was supplied from one air supply pipe to cool the continuous annealing furnace. The result is shown by a curve B of cd in FIG.
【0049】つぎに、比較のため、再度、前記と同様に
して鋼板を900℃にまで焼鈍させるバーナ1a、1b
の燃焼操作を行なった。Next, for comparison, the burners 1a and 1b for annealing the steel sheet to 900 ° C. are again carried out in the same manner as described above.
Burning operation was performed.
【0050】前記鋼板の通板後、焼鈍を終了する際に、
前記バーナの燃焼操作を行ないながら、強制冷却エアを
供給せずに、冷却温度が400℃以下となるまで放冷し
た。その結果を図5中のe〜fの曲線Cで示す。When the annealing is finished after passing the steel plate,
While performing the burning operation of the burner, it was allowed to cool to a cooling temperature of 400 ° C. or lower without supplying forced cooling air. The result is shown by a curve C of e to f in FIG.
【0051】図5の曲線Bおよび曲線Cに示された結果
から以下のことがわかる。すなわち、従来のように鋼板
の通板後、焼鈍を終了する際に、強制冷却エアを供給せ
ずに放置したばあいには、冷却温度400℃以下にまで
連続式焼鈍炉を冷却させるのに要する冷却時間が350
0秒間以上であるのに対し(図5の曲線C)、鋼板の焼
鈍を終了する際に、エア供給パイプ内に強制冷却エアを
通気させて連続式焼鈍炉を強制冷却させたばあいには、
冷却温度400℃以下にまで連続式焼鈍炉を冷却させる
のに要する冷却時間が1000秒間程度であることから
(図4の曲線B)、本発明の温度制御方法によれば、速
やかに連続式焼鈍炉の冷却を行なうことができ、かつ任
意の炉温設定値に対しても、ほぼ所望冷却時間どおりに
冷却時間を制御することができることがわかる。From the results shown by the curves B and C in FIG. 5, the following can be understood. That is, when the annealing is finished after passing the steel sheet as in the conventional case, if the continuous annealing furnace is cooled to a cooling temperature of 400 ° C. or less when left to stand without supplying forced cooling air. Cooling time required 350
While it is 0 seconds or more (curve C in FIG. 5), when the annealing of the steel sheet is finished, forced cooling air is passed through the air supply pipe to force the continuous annealing furnace to be cooled. ,
Since the cooling time required to cool the continuous annealing furnace to a cooling temperature of 400 ° C. or less is about 1000 seconds (curve B in FIG. 4), the temperature control method of the present invention enables rapid continuous annealing. It can be seen that the furnace can be cooled and the cooling time can be controlled almost in accordance with the desired cooling time even for an arbitrary set value of the furnace temperature.
【0052】また、図5の曲線Aおよび曲線Bの結果か
ら、以下のことがわかる。すなわち、本発明の冷却方法
において、所定温度に連続式焼鈍炉を冷却させるのに要
する強制冷却エア量をあらかじめ決定しておき、前記強
制冷却エア量にもとづいてエア供給パイプへ強制冷却エ
アを通気させ、所定時間に冷却が完了するように設定し
ておいたばあいには、所定時間の到達時に連続式焼鈍炉
の冷却を完了させることができる。したがって、炉温度
の切り替え温度差が大きいと、調整コイルが必要とさ
れ、冷却時間が長いと、調整コイルの本数が増加し、製
品の生産性が低下するという欠点があるが、前記のよう
に所定時間内での連続式焼鈍炉の冷却が可能であるなら
ば、調整コイルの本数を少なくすることができるので、
生産性を向上させることができるという利点がある。Further, from the results of the curves A and B of FIG. 5, the following can be understood. That is, in the cooling method of the present invention, the amount of forced cooling air required to cool the continuous annealing furnace to a predetermined temperature is determined in advance, and the forced cooling air is vented to the air supply pipe based on the amount of forced cooling air. When the cooling is set to be completed within a predetermined time, the cooling of the continuous annealing furnace can be completed when the predetermined time is reached. Therefore, if the switching temperature difference of the furnace temperature is large, the adjusting coil is required, and if the cooling time is long, the number of adjusting coils is increased and the productivity of the product is reduced, but as described above, If it is possible to cool the continuous annealing furnace within a predetermined time, the number of adjusting coils can be reduced,
There is an advantage that productivity can be improved.
【0053】[0053]
【発明の効果】以上説明したように、本発明の連続式焼
鈍炉の温度制御方法によれば、被加熱材の焼鈍を終了す
る際に、バーナの燃焼操作を行ないながら、エア供給パ
イプを利用してラジアントチューブ内に強制冷却エアを
通気させるという手段が採られているので、冷却に要す
る時間を大幅に短縮させることができるという効果が奏
される。As described above, according to the temperature control method of the continuous annealing furnace of the present invention, when the annealing of the material to be heated is finished, the air supply pipe is used while the burner is being burnt. Then, since the means of forcing forced cooling air into the radiant tube is adopted, there is an effect that the time required for cooling can be greatly shortened.
【0054】また、本発明の連続式焼鈍炉の温度制御方
法において、あらかじめ連続式焼鈍炉の加熱〜冷却の温
度実績を調べておき、前記温度実績にもとづいて所定温
度に連続式焼鈍炉を冷却させるのに要する強制冷却エア
量を決定し、前記強制冷却エア量にもとづいてエア供給
パイプへ強制冷却エアを通気させたばあいには、所定時
間に連続式焼鈍炉の冷却を終了させることができるとい
う効果が奏される。Further, in the temperature control method for the continuous annealing furnace of the present invention, the actual temperature of heating to cooling of the continuous annealing furnace is checked in advance, and the continuous annealing furnace is cooled to a predetermined temperature based on the actual temperature. The amount of forced cooling air required to do so is determined, and when the forced cooling air is ventilated to the air supply pipe based on the amount of forced cooling air, cooling of the continuous annealing furnace can be completed in a predetermined time. The effect of being able to be played is exhibited.
【図1】従来の連続式焼鈍炉の温度制御方法に用いられ
る蓄熱式ラジアントチューブバーナの一実施態様を示す
概略説明図である。FIG. 1 is a schematic explanatory view showing an embodiment of a heat storage type radiant tube burner used in a conventional temperature control method for a continuous annealing furnace.
【図2】本発明の連続式焼鈍炉の温度制御方法に用いら
れる連続式焼鈍炉の一実施態様を示す概略説明図であ
る。FIG. 2 is a schematic explanatory view showing an embodiment of a continuous annealing furnace used in the temperature control method for the continuous annealing furnace of the present invention.
【図3】本発明の連続式焼鈍炉の温度制御方法の一実施
態様を示すブロック線図である。FIG. 3 is a block diagram showing an embodiment of a temperature control method for a continuous annealing furnace of the present invention.
【図4】本発明の連続式焼鈍炉の温度制御方法における
加熱〜冷却曲線の概略説明図である。FIG. 4 is a schematic explanatory diagram of heating-cooling curves in the temperature control method for the continuous annealing furnace of the present invention.
【図5】本発明の連続式焼鈍炉の温度制御方法の実施例
における加熱〜冷却曲線である。FIG. 5 is a heating-cooling curve in an example of the temperature control method for the continuous annealing furnace of the present invention.
1a バーナ 1b バーナ 2a 蓄熱体 2b 蓄熱体 3 ラジアントチューブ 4a エア供給パイプ 4b エア供給パイプ 11 連続式焼鈍炉 1a burner 1b burner 2a Heat storage 2b Heat storage 3 radiant tubes 4a Air supply pipe 4b Air supply pipe 11 Continuous annealing furnace
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7,DB名) F23N 5/02 350 F23D 14/12 F23D 14/66 F23L 15/02 ─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. 7 , DB name) F23N 5/02 350 F23D 14/12 F23D 14/66 F23L 15/02
Claims (2)
前記バーナの周囲に通気性を有する多孔質の蓄熱体が設
けられてなる蓄熱式ラジアントチューブバーナを用いた
連続式焼鈍炉の温度制御方法であって、前記バーナをそ
れぞれ交互に燃焼させて被加熱材を焼鈍させるバーナの
燃焼操作による炉温制御を行ない、炉の設定温度を低温
に変更する際または炉の稼動を停止するために炉温度を
降温させる際に、前記バーナの燃焼操作を行ないなが
ら、一方のバーナに接続されたエア供給パイプから強制
冷却エアを供給し、ラジアントチューブ内を介して他方
のバーナに接続されたエア供給パイプへ該強制冷却エア
を通気させることによる冷却補償を行ない、前記冷却補
償において、あらかじめ連続式焼鈍炉の加熱〜冷却の温
度実績を調べておき、前記温度実績にもとづいて所定時
間に連続式焼鈍炉を所定温度に冷却させるのに要する強
制冷却エア量を決定し、前記強制冷却エア量にもとづい
て前記エア供給パイプへ強制冷却エアを通気させること
を特徴とする連続式焼鈍炉の温度制御方法。1. Burners are provided at both ends of the burner, respectively.
A method for controlling the temperature of a continuous annealing furnace using a heat storage radiant tube burner in which a porous heat storage material having air permeability is provided around the burner, and the burners are alternately burned to be heated. While controlling the furnace temperature by the burner burning operation to anneal the material, when changing the set temperature of the furnace to a low temperature or when lowering the furnace temperature to stop the operation of the furnace, while performing the burning operation of the burner , Forcibly cooling air is supplied from an air supply pipe connected to one of the burners, and cooling compensation is performed by ventilating the forced cooling air to the air supply pipe connected to the other burner through the inside of the radiant tube , The cooling supplement
In advance, the temperature from heating to cooling of the continuous annealing furnace
The actual temperature is checked, and at a specified time based on the actual temperature.
The strength required to cool the continuous annealing furnace to the specified temperature during
Determine the controlled cooling air amount and based on the forced cooling air amount
A forced cooling air is ventilated through the air supply pipe .
を、前記温度実績と二次遅れ伝達関数にしたがう推定モ
デル出力との偏差から決定する請求項1記載の連続式焼
鈍炉の温度制御方法。2. A forced cooling air amount in the cooling compensation.
Is an estimated model according to the actual temperature and the second-order lag transfer function.
The temperature control method for a continuous annealing furnace according to claim 1, wherein the temperature is determined from a deviation from the Dell output .
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23060496A JP3364091B2 (en) | 1996-08-30 | 1996-08-30 | Temperature control method for continuous annealing furnace |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP23060496A JP3364091B2 (en) | 1996-08-30 | 1996-08-30 | Temperature control method for continuous annealing furnace |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH1073242A JPH1073242A (en) | 1998-03-17 |
JP3364091B2 true JP3364091B2 (en) | 2003-01-08 |
Family
ID=16910362
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JP23060496A Expired - Fee Related JP3364091B2 (en) | 1996-08-30 | 1996-08-30 | Temperature control method for continuous annealing furnace |
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JP (1) | JP3364091B2 (en) |
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CN106642112A (en) * | 2016-12-16 | 2017-05-10 | 北京神雾环境能源科技集团股份有限公司 | Flat flame-crossover heat-accumulation type radiant tube combustion device |
CN106482100B (en) * | 2016-12-16 | 2019-02-01 | 神雾科技集团股份有限公司 | A kind of New Regenerative radiant tube combustion device |
-
1996
- 1996-08-30 JP JP23060496A patent/JP3364091B2/en not_active Expired - Fee Related
Also Published As
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