JP2000130745A - Operating method for heating furnace - Google Patents
Operating method for heating furnaceInfo
- Publication number
- JP2000130745A JP2000130745A JP10311002A JP31100298A JP2000130745A JP 2000130745 A JP2000130745 A JP 2000130745A JP 10311002 A JP10311002 A JP 10311002A JP 31100298 A JP31100298 A JP 31100298A JP 2000130745 A JP2000130745 A JP 2000130745A
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- combustion
- flue
- dilution amount
- heating furnace
- 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.)
- Granted
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
- Regulation And Control Of Combustion (AREA)
- Air Supply (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、蓄熱体を有して一
対のバーナーを交互燃焼させる蓄熱式燃焼装置を備えた
例えば連続式加熱炉の操業方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of operating, for example, a continuous heating furnace provided with a regenerative combustion device having a regenerator and alternately burning a pair of burners.
【０００２】[0002]
【従来の技術】従来の加熱炉の操業方法としては、例え
ば特開平８−１９９２３１号公報（以下、単に従来例と
称す）に記載されているものが知られている。この従来
例には、予熱帯、加熱帯及び均熱帯からなる加熱炉にお
いて、予熱帯で複数の蓄熱式バーナーにより燃焼と蓄熱
とを交互に繰り返して加熱し、蓄熱後の低温燃焼排ガス
を空気予熱器（エアレキュペレータ）入側の高温燃焼排
ガス中へ導入して燃焼排ガス温度を空気予熱器の溶損温
度未満に冷却しながら操業するようにした加熱炉の操業
方法が記載されている。2. Description of the Related Art As a conventional method of operating a heating furnace, for example, a method described in Japanese Patent Application Laid-Open No. 8-199231 (hereinafter simply referred to as a conventional example) is known. In this conventional example, in a heating furnace consisting of a pre-tropical zone, a heating zone, and a soaking zone, combustion and heat storage are alternately and repeatedly heated by a plurality of regenerative burners in the pre-tropical zone, and the low-temperature combustion exhaust gas after the heat storage is preheated by air. A method of operating a heating furnace is described, which is introduced into a high-temperature flue gas on the inlet side of a heater (air recuperator) and operates while cooling the flue gas temperature below a melting temperature of an air preheater.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記従
来例にあっては、従来の３０℃程度のエアに代えて蓄熱
燃焼装置からの蓄熱体を通過した２００℃程度の燃焼排
ガスを空気予熱器の入側にダイリューションするので、
エアレキュペレータの入側の高温燃焼排ガス温度をエア
レキュペレータ溶損温度以下に低下させるために、エア
流量に比較して多くの燃焼排ガス流量を必要とするた
め、エアレキュペレータ入側の排ガス流量が増大し、こ
れによって圧損が増大することになり、その結果、加熱
炉の燃焼負荷が大きい場合には煙道ドラフトが不足し、
操業に支障をきたすおそれがあるという未解決の課題が
ある。However, in the above conventional example, the flue gas of about 200 ° C. that has passed through the regenerator from the regenerative combustion device is replaced with air of about 30 ° C. in the conventional air preheater. Dilution on the entry side,
To reduce the temperature of the high-temperature flue gas at the inlet of the air recuperator below the melting temperature of the air recuperator, a larger amount of flue gas is required than the air flow. Increases, which leads to an increase in pressure loss. As a result, when the combustion load of the heating furnace is large, the flue draft is insufficient,
There is an unsolved problem that operation may be hindered.
【０００４】そこで、本発明は、上記従来例の未解決の
課題に着目してなされたものであり、煙道ドラフトと高
効率廃熱回収とを両立させた最適な加熱炉の操業方法を
提供することを目的としている。The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and provides an optimum heating furnace operating method that achieves both a flue draft and highly efficient waste heat recovery. It is intended to be.
【０００５】[0005]
【課題を解決するための手段】上記目的を達成するため
に、請求項１に係る加熱炉の操業方法は、炉壁に配設し
た所要対のバーナと、各バーナに接続された燃焼空気供
給用兼排ガス排出用管の途上にそれぞれ介装した所要対
の蓄熱体とを有する蓄熱式燃焼装置を燃焼室に配設した
加熱炉の操業方法において、前記加熱炉の燃焼負荷から
煙道ドラフト、煙道圧損、エアレキュペレータ溶損温度
を考慮し、前記蓄熱体から排出される排ガスを前記エア
レキュペレータの入側に供給する際の排ガスダイリュー
ション量の上下限値を決定し、決定した排ガスダイリュ
ーション量の上下限範囲内で燃料原単位が最小となる最
適排ガスダイリューション量を求め、求めた最適排ガス
ダイリューション量に基づいて排ガスダイリューション
量を制御すると共に、残りの排ガスをガスレキュペレー
タ出側の煙道に供給するようにしたことを特徴としてい
る。In order to achieve the above object, a method of operating a heating furnace according to the present invention is characterized in that a required pair of burners disposed on a furnace wall and a supply of combustion air connected to each burner are provided. A method for operating a heating furnace in which a regenerative combustion device having a required pair of regenerators interposed on the way of a combined exhaust gas discharge pipe is provided in a combustion chamber, wherein a flue draft from the combustion load of the heating furnace is provided. In consideration of the flue pressure loss and the melting temperature of the air recuperator, the upper and lower limits of the exhaust gas dilution amount when supplying the exhaust gas discharged from the heat storage body to the inlet side of the air recuperator were determined and determined. Calculate the optimal exhaust gas dilution amount that minimizes the unit fuel consumption within the upper and lower limits of the exhaust gas dilution amount, and control the exhaust gas dilution amount based on the obtained optimal exhaust gas dilution amount. It is characterized in that the remaining gas was then supplied to the flue gas recuperator outlet side.
【０００６】[0006]
【発明の実施の形態】以下、本発明の実施の形態を図面
に基づいて説明する。図１は本発明の一実施形態を示す
概略構成図であって、図中、１は例えばウォーキングビ
ーム２によって連続的に搬送されるフラットバー、ビー
ムブランク等の鋼材を連続的に加熱する連続式加熱炉で
あって、鋼材を左側から装入し、予熱帯３、第１加熱帯
４、第２加熱帯５及び均熱帯６を順次通過して加熱さ
れ、加熱を終了した鋼材が右側から抽出されて次工程に
搬送される。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention. In the drawing, reference numeral 1 denotes a continuous system for continuously heating steel materials such as a flat bar and a beam blank continuously conveyed by a walking beam 2, for example. A heating furnace, in which steel is charged from the left side, heated in order through the pre-tropical zone 3, the first heating zone 4, the second heating zone 5, and the solitary zone 6, and the heated steel product is extracted from the right side. And transported to the next step.
【０００７】そして、予熱帯３の入側における上部には
煙道７が配設され、この煙道７にエアレキュペレータ
（空気予熱器）８及びガスレキュペレータ（ガス予熱
器）９がその順に配設され、煙道の自由端に煙突１０が
配設されている。第１加熱帯４、第２加熱帯５及び均熱
帯６には、夫々燃焼バーナが配設されているが、第１加
熱帯４には、上部及び下部側に夫々少なくとも１組の蓄
熱式燃焼装置１１及び１２が配設されている。[0007] A flue 7 is disposed above the pretropical zone 3 on the entrance side, and an air recuperator (air preheater) 8 and a gas recuperator (gas preheater) 9 are provided on the flue 7. The chimney 10 is arranged at the free end of the flue. Each of the first heating zone 4, the second heating zone 5, and the soaking zone 6 is provided with a combustion burner, and the first heating zone 4 has at least one set of regenerative combustion at the upper and lower sides, respectively. Apparatuses 11 and 12 are provided.
【０００８】ここで、蓄熱式燃焼装置１１及び１２の夫
々は、第１加熱帯４の側壁に並設された一対のガスバー
ナ１３ａ，１３ｂを有する。これらガスバーナ１３ａ，
１３ｂの夫々は、その基部に燃料ガス供給口及び燃焼空
気給排口（共に図示せず）が設けられ、燃焼時には燃料
ガス供給口に供給される燃料ガスがガスノズルによって
加熱帯４側に噴射されると共に、ガスノズルの回りに燃
焼空気給排口に連通された空気ノズルから燃焼空気が噴
射されるが、非燃焼時には空気ノズルから第１加熱帯４
の加熱排ガスを吸引するように構成され、燃焼時には、
噴射される燃料ガスがガスノズルから噴射される燃料ガ
スと空気ノズルから噴射される燃焼空気との合流点近傍
に配設されたパイロットバーナ（図示せず）によって点
火される。Here, each of the regenerative combustion devices 11 and 12 has a pair of gas burners 13 a and 13 b provided side by side on the side wall of the first heating zone 4. These gas burners 13a,
Each of the fuel gas supply ports 13b has a fuel gas supply port and a combustion air supply / discharge port (both not shown) at its base, and fuel gas supplied to the fuel gas supply port is injected into the heating zone 4 side by a gas nozzle during combustion. At the same time, combustion air is injected from an air nozzle connected to a combustion air supply / discharge port around the gas nozzle.
It is configured to suck the heated exhaust gas of
The fuel gas to be injected is ignited by a pilot burner (not shown) provided near a junction of the fuel gas injected from the gas nozzle and the combustion air injected from the air nozzle.
【０００９】そして、ガスバーナ１３ａ，１３ｂの燃料
ガス供給口が個別の燃料遮断弁１４ａ，１４ｂを介し、
さらに共通のメイン遮断弁１５、流量調節弁１６を介し
て燃料ガスとしてのＭガスを供給するＭガス供給源１７
に接続されている。また、ガスバーナ１３ａ，１３ｂの
燃焼空気給排口が蓄熱体２０ａ，２０ｂの一端に接続さ
れ、この蓄熱体２０ａ，２０ｂの他端が分岐され、その
一方の分岐部が個別の空気遮断弁２２ａ，２２ｂを介
し、さらに共通の流量調節弁２３を介してエアブロア２
４に接続されていると共に、他方の分岐部が個別の排ガ
ス遮断弁２５ａ，２５ｂを介し、さらに共通の流量調節
弁２６を介して排ガス吸引ファン（ＩＤＦ）２７に接続
され、この排ガス吸引ファン２７で吸引された蓄熱式燃
焼装置１１，１２の蓄熱帯で熱交換した後の排ガスが流
量調節弁２８を介してエアレキュペレータ８の入側の煙
道７にエアレキュペレータ８の溶損を防止するためのダ
イリューション（希釈）媒体として供給されると共に、
残りの排ガスがガスレキュペレータ９の出側の煙道７に
排出される。The fuel gas supply ports of the gas burners 13a and 13b are connected via individual fuel cutoff valves 14a and 14b.
Further, an M gas supply source 17 for supplying M gas as a fuel gas via a common main shutoff valve 15 and a flow control valve 16
It is connected to the. Further, the combustion air supply / discharge ports of the gas burners 13a and 13b are connected to one ends of the heat storage bodies 20a and 20b, and the other ends of the heat storage bodies 20a and 20b are branched. 22b and further through a common flow control valve 23
4 and the other branch is connected to an exhaust gas suction fan (IDF) 27 through individual exhaust gas cutoff valves 25a and 25b and further through a common flow control valve 26. Exhaust gas that has been heat-exchanged in the regenerators of the regenerative combustion devices 11 and 12 sucked in at step A is prevented from being melted in the flue 7 on the inlet side of the air recuperator 8 via the flow control valve 28. As a dilution (dilution) medium for
The remaining exhaust gas is discharged to the flue 7 on the outlet side of the gas recuperator 9.
【００１０】また、蓄熱体２０ａ，２０ｂの夫々は、気
体流通炉に沿って蓄熱媒体として例えば直径２０ｍｍの
アルミナボールが９８０ｋｇ充填されており、このアル
ミナボールに第１加熱帯４から排出される高温（例えば
１３００℃程度）の排ガスと熱交換されて蓄熱され、こ
の顕熱がエアブロア２４から供給される低温の燃焼空気
と熱交換されて放熱される。Each of the heat storage bodies 20a and 20b is filled with, for example, 980 kg of alumina balls having a diameter of 20 mm as a heat storage medium along the gas flow furnace. The heat is exchanged with the exhaust gas (for example, about 1300 ° C.) and stored, and this sensible heat is exchanged with the low-temperature combustion air supplied from the air blower 24 and radiated.
【００１１】そして、各蓄熱式燃焼装置１１，１２の蓄
熱体２０ａ，２０ｂで熱交換された後の排ガスを煙道７
におけるエアレキュペレータ８の入側にダイリューショ
ン媒体として供給する際の排ガスダイリューション量Ｖ
１が以下に述べるように加熱炉の燃焼負荷から求めた最
適排ガスダイリューション量Ｖ１* に制御される。The exhaust gas after heat exchange in the heat storage bodies 20a and 20b of each of the heat storage type combustion devices 11 and 12 is discharged to the flue 7
Exhaust gas dilution V when supplying as dilution medium to the inlet side of air recuperator 8 at
1 is controlled to the optimum exhaust gas dilution amount V1 * obtained from the combustion load of the heating furnace as described below.
【００１２】まず、加熱炉の燃焼負荷に応じて、排ガス
ダイリューション量Ｖ１（Ｎｍ3 ／Ｈ）と煙道ドラフト
（ｍｍＡｑ）及び煙道圧損（ｍｍＡｑ）との関係は、図
２に示すよう、煙道ドラフトは排ガスダイリューション
量Ｖ１の変化にかかわらず一定であるが、煙道圧損は、
排ガスダイリューション量Ｖ１が増加するつれて増加す
るので、煙道圧損が煙道ドラフトに達したときの排ガス
ダイリューション量を排ガスダイリューション量上限値
Ｖ１U として決定する。First, the relationship between the exhaust gas dilution amount V1 (Nm 3 / H), the flue draft (mmAq) and the flue pressure loss (mmAq) according to the combustion load of the heating furnace is shown in FIG. , The flue draft is constant irrespective of the change in the exhaust gas dilution amount V1, but the flue pressure loss is
Since exhaust gas dilution amount V1 is increased with increasing the flue pressure loss is determined as the exhaust gas dilution amount upper limit value V1 U exhaust gas dilution amount when reaching the flue draft.
【００１３】一方、排ガスダイリューション量Ｖ１とエ
アレキュペレータ入側排ガス温度（℃）との関係は、図
３に示すように、エアレキュペレータ入側排ガス温度は
排ガスダイリューション量Ｖ１が増加するに応じて減少
することになるため、エアレキュペレータ溶損防止温度
ＴR （例えば８００℃）に達する排ガスダイリューショ
ン量Ｖ１を排ガスダイリューション量下限値Ｖ１L とし
て決定する。On the other hand, the relationship between the exhaust gas dilution amount V1 and the exhaust gas temperature (° C.) on the inlet side of the air recuperator is shown in FIG. since will be reduced in response to, for determining the exhaust gas dilution amount V1 reaching the air recuperator erosion prevention temperature T R (e.g. 800 ° C.) as the exhaust gas dilution amount lower limit value V1 L.
【００１４】そして、排ガスダイリューション量Ｖ１と
加熱炉燃料原単位（Ｍcal/t)の関係は、図４に示すよう
に、排ガスダイリューション量Ｖ１が１３５００（Ｎｍ
3 ／Ｈ）から増加すると加熱炉燃料原単位が減少し、排
ガスダイリューション量下限値Ｖ１L を越えた２２００
０（Ｎｍ3 ／Ｈ）で最小となった後に増加傾向に転じ排
ガスダイリューション量上限値Ｖ１U を越えてもなお増
加することになるため、操業最適条件としては、排ガス
ダイリューション量下限値Ｖ１L 及び排ガスダイリュー
ション量上限値Ｖ１U 間の範囲で加熱炉燃料原単位が最
小となる排ガスダイリューション量Ｖ１を最適排ガスダ
イリューション量Ｖ１* として決定する。As shown in FIG. 4, the relationship between the exhaust gas dilution amount V1 and the heating furnace fuel consumption unit (Mcal / t) is 13500 (Nm
3 / H) is the heating furnace fuel consumption rate to increase from decrease, beyond the exhaust gas dilution amount lower limit value V1 L 2200
0 (Nm 3 / H) to become the still increasing beyond exhaust gas dilution amount upper limit value V1 U turned increasing after reaching a minimum, as the operational optimum, exhaust gas dilution amount lower determining the value V1 L and exhaust gas dilution amount V1 of exhaust gas dilution amount upper limit value furnace fuel consumption rate in the range between V1 U is minimum as an optimum exhaust gas dilution volume V1 *.
【００１５】そして、決定された最適排ガスダイリュー
ション量Ｖ１* に一致するように流量制御弁２８を例え
ばプロセスコンピュータ等の制御装置でフィードバック
制御又はフィードフォワード制御することにより、煙道
７におけるエアレキュペレータ８の入側に供給する排ガ
スダイリューション量を最適値に制御し、残りの排ガス
をガスレキュペレータ９の出側の煙突１０側に排出す
る。The flow rate control valve 28 is feedback-controlled or fed-forward-controlled by a control device such as a process computer so as to correspond to the determined optimum exhaust gas dilution amount V1 * . The exhaust gas dilution amount supplied to the inlet of the pererator 8 is controlled to an optimum value, and the remaining exhaust gas is discharged to the chimney 10 on the outlet side of the gas recuperator 9.
【００１６】次に、上記実施形態の動作を説明する。連
続式加熱炉１の操業を開始する際に、所定の初期化処理
を行って炉内温度を予め設定された目標温度ＴT （例え
ば１３００℃）まで昇温する昇温処理を実行し、目標温
度ＴT に達したとき第１加熱帯４内に配設した燃焼空気
温度センサ（図示せず）の温度検出値に基づいて燃焼バ
ーナの切換えタイミングを決定して燃焼バーナの切換え
を行う定常切換制御処理を行う。Next, the operation of the above embodiment will be described. When the operation of the continuous heating furnace 1 is started, a predetermined initialization process is performed to perform a temperature raising process for raising the furnace temperature to a preset target temperature T T (for example, 1300 ° C.). When the temperature T T is reached, the combustion burner switching timing is determined based on the temperature detection value of a combustion air temperature sensor (not shown) disposed in the first heating zone 4 to perform the combustion burner switching. Perform control processing.
【００１７】このとき、一方のガスバーナ１３ａが燃焼
状態にあり、他方のバスバーナ１３ｂが非燃焼状態にあ
るものとすると、この状態では、燃焼状態のガスバーナ
１３ａに対しては、外気からエアブロア２４によって圧
送される冷風状態（例えば２０℃）の燃焼空気が流量調
節弁２３、空気遮断弁２２ａを介して蓄熱体２０ａに供
給され、この蓄熱体２０ａで蓄熱されたアルミナボール
と熱交換されて１０００℃以上に予熱された状態でガス
バーナ１３ａの燃焼空気給排口に供給され、ガスノズル
から噴射される燃料ガスと混合されて燃焼されて炉内を
加熱する。At this time, assuming that one gas burner 13a is in a combustion state and the other bus burner 13b is in a non-combustion state, in this state, the air is blown from the outside air to the combustion gas burner 13a by an air blower 24. The combustion air in a cool air state (for example, 20 ° C.) is supplied to the heat storage body 20a via the flow control valve 23 and the air cutoff valve 22a, and heat-exchanges with the alumina balls stored in the heat storage body 20a to be 1000 ° C. or more. The gas is supplied to the combustion air supply / discharge port of the gas burner 13a in a preheated state, mixed with fuel gas injected from a gas nozzle, burned, and heats the inside of the furnace.
【００１８】これと同時に、他方の非燃焼状態のガスバ
ーナ１３ｂでは、燃焼空気給排口が蓄熱体２０ｂ、排ガ
ス遮断弁２５ｂ、共通流量調節弁２６を介して排ガス吸
引ファン２７に連通され、この排ガス吸引ファン２７に
よって炉内の排ガスが吸引されて蓄熱体２０ｂを通って
排出され、蓄熱体２０ｂ内のアルミナボールと熱交換す
ることにより、蓄熱体２０ｂの蓄熱温度が徐々に上昇さ
れる。At the same time, in the other non-combustion gas burner 13b, the combustion air supply / discharge port is connected to an exhaust gas suction fan 27 via a heat storage unit 20b, an exhaust gas cutoff valve 25b, and a common flow control valve 26, and Exhaust gas in the furnace is sucked by the suction fan 27 and discharged through the heat storage body 20b, and exchanges heat with alumina balls in the heat storage body 20b, so that the heat storage temperature of the heat storage body 20b is gradually increased.
【００１９】このとき、ガスバーナ１３ａが燃焼状態
に、ガスバーナ１３ｂが非燃焼状態に夫々切換えられた
直後であるものとすると、燃焼状態のガスバーナ１３ａ
側の蓄熱体２０ａの温度は、図５で実線図示の特性曲線
Ｌa で示すように、蓄熱体２０ａの飽和温度例えば１２
００℃であり、一方、非燃焼状態のガスバーナ１３ｂの
蓄熱体２０ｂの温度は、一点鎖線図示の特性曲線Ｌb で
示すように、前回の燃焼時に放熱された設定下限温度Ｔ
L である１０００℃となっており、ガスバーナ１３ｂ側
の排ガス遮断弁２５ｂの出側の温度は、図５の特性曲線
Ｌc で示すように、露点温度（１７０℃前後）より高い
例えば１９０℃程度になっている。At this time, assuming that it is immediately after the gas burner 13a is switched to the combustion state and the gas burner 13b is switched to the non-combustion state, respectively, the combustion gas burner 13a is switched to the non-combustion state.
As shown by a characteristic curve La indicated by a solid line in FIG.
Was 00 ° C., while the temperature of the regenerator 20b of the gas burner 13b of the non-combustion state, as shown by the characteristic curve L b of a chain line shown, set the lower limit temperature T which is radiated to the previous combustion
L has a 1000 ° C. which is the temperature of the outlet side of the exhaust gas shutoff valve 25b of the gas burner 13b side, as shown by the characteristic curve L c of FIG. 5, a higher e.g. 190 ° C. about the dew point temperature (170 ° C. so) It has become.
【００２０】この状態でガスバーナ１３ａでの燃焼状態
が継続されると共に、ガスバーナ１３ｂでの排ガス回収
状態が継続されるが、ガスバーナ１３ａに供給される燃
焼空気の温度ＴDaは、図５の特性曲線Ｌa で示すよう
に、時間の経過と共に徐々に低下する一方、ガスバーナ
１３ｂ側の蓄熱体２０ｂの温度が図５の特性曲線Ｌb で
示すように徐々に上昇し、これに伴って排ガス遮断弁２
５ｂの出側温度も図５の特性曲線Ｌc に示すように、徐
々に上昇する。In this state, the combustion state in the gas burner 13a is continued and the exhaust gas recovery state in the gas burner 13b is continued. The temperature T Da of the combustion air supplied to the gas burner 13a is represented by the characteristic curve in FIG. as shown by L a, while gradually decreases with time, gas burner 13b temperature regenerator 20b of side rises gradually as shown by a characteristic curve L b in FIG. 5, the exhaust gas shutoff valves along with this 2
Delivery temperature of 5b also as shown in characteristic curve L c of FIG. 5 increases gradually.
【００２１】その時、時点ｔ1 でガスバーナ１３ａに供
給される燃焼空気温度ＴDaが下限設定温度ＴL に達する
と、これによってガスバーナ１３ａが非燃焼状態の排ガ
ス回収状態に切換えられると共に、他の非燃焼状態のガ
スバーナ１３ｂに高温の蓄熱体２０ｂで予熱された燃焼
空気を供給する燃焼準備状態に移行し、その後所定時間
経過した後ガスバーナ１３ｂを燃焼状態に切換える。At that time, when the temperature T Da of the combustion air supplied to the gas burner 13a at time t 1 reaches the lower limit set temperature TL , the gas burner 13a is switched to the non-combustion exhaust gas recovery state and the other non-combustion exhaust gas recovery state. A transition is made to a combustion preparation state in which the combustion air preheated by the high-temperature regenerator 20b is supplied to the gas burner 13b in the combustion state. After a lapse of a predetermined time, the gas burner 13b is switched to the combustion state.
【００２２】このように、ガスバーナ１３ｂが燃焼状態
に切換わると、時間の経過と共に図５の特性曲線Ｌb で
示すように、燃焼空気温度ＴDbが徐々に低下し、逆にガ
スバーナ１３ａで回収された排ガスによって蓄熱体２０
ａの温度が徐々に上昇され、これに応じて排ガス遮断弁
２５ａの出側の排ガス温度が特性曲線Ｌd で示すよう
に、徐々に上昇する。[0022] Thus, when the gas burner 13b is switched to the combustion state, as shown by the characteristic curve L b in FIG. 5 over time, the combustion air temperature T Db is gradually decreased, collected in a gas burner 13a conversely Heat storage body 20
a is the temperature is gradually elevated, the temperature of the exhaust gas outlet side of the exhaust gas shutoff valve 25a in response to this, as shown by the characteristic curve L d, and gradually rises.
【００２３】そして、このガスバーナ１３ｂの燃焼状態
が、燃焼空気温度ＴDbが下限設定温度ＴL 以下となるま
で継続され、燃焼空気温度ＴDbが加減設定温度ＴL 以下
となると、ガスバーナ１３ｂが燃焼状態から非燃焼状態
に、逆にガスバーナ１３ａが非燃焼状態から燃焼状態に
切換えられる。その後、燃焼状態のガスバーナ１３ｉ
（ｉ＝ａ，ｂ）に供給される燃焼空気温度ＴDiが下限設
定温度ＴL 以下となる毎に燃焼バーナの切換えが行われ
る。[0023] Then, the combustion state of the gas burner 13b is continued to the combustion air temperature T Db is lower than the lower limit set temperature T L, when the combustion air temperature T Db is less acceleration set temperature T L, a gas burner 13b combustion The gas burner 13a is switched from the non-combustion state to the combustion state from the state to the non-combustion state. After that, the gas burner 13i in the combustion state
Each time the combustion air temperature T Di supplied to (i = a, b) falls below the lower limit set temperature T L , the combustion burner is switched.
【００２４】このようにして、蓄熱式燃焼装置１１及び
１２の各バーナ１３ａ及び１３ｂが交互に切換燃焼され
ることにより、第１加熱帯４の炉温を設定温度に維持す
ることができるものであるが、この間に蓄熱式燃焼装置
１１及び１２の蓄熱体２０ａ又は２０ｂを通過して排ガ
ス吸引ファン２７によって吸引排出された排ガスは、前
述したように、最適排ガスダイリューション量Ｖ１* に
制御されて、煙道７におけるエアレキュペレータ８の入
側に導入されると共に、残りがガスレキュペレータ９の
出側に排出される。As described above, the burners 13a and 13b of the regenerative combustion devices 11 and 12 are alternately switched and burned, so that the furnace temperature of the first heating zone 4 can be maintained at the set temperature. However, during this time, the exhaust gas sucked and discharged by the exhaust gas suction fan 27 through the heat storage body 20a or 20b of the regenerative combustion devices 11 and 12 is controlled to the optimum exhaust gas dilution amount V1 * as described above. Thus, the gas is introduced into the flue 7 on the inlet side of the air recuperator 8, and the remainder is discharged on the outlet side of the gas recuperator 9.
【００２５】そして、最適排ガスダイリューション量Ｖ
１* は、前述したように、加熱炉の燃焼負荷から、先
ず、煙道ドラフト、煙道圧損及びエアレキュペレータ溶
損防止温度を考慮して、蓄熱式燃焼装置１１，１２の蓄
熱体２０ａ，２０ｂで熱交換後に排出される排ガスを煙
道７におけるエアレキュペレータ８の入側にダイリュー
ション媒体として供給する際の排ガスダイリューション
量の下限値Ｖ１L 及び上限値Ｖ１U を決定し、決定され
た排ガスダイリューション量の上下限値の範囲内で燃料
原単位が最小となる排ガスダイリューション量として求
められるので、この最適排ガスダイリューション量とな
るように流量調節弁２８で排ガスダイリューション量Ｖ
１を制御することにより、蓄熱式燃焼装置を使用した加
熱炉操業の最適化を図ることができる。The optimum exhaust gas dilution amount V
1 * , as described above, from the combustion load of the heating furnace, first, considering the flue draft, the flue pressure loss, and the air recuperator melting loss prevention temperature, the heat storage bodies 20a, 20a, the exhaust gas discharged after heat exchange to determine the lower limit value V1 L and an upper limit V1 U of the exhaust gas dilution amount when supplying a dilution medium to the inlet side of the air recuperator 8 in the flue 7 in 20b, Since it is determined as the exhaust gas dilution amount that minimizes the fuel consumption unit within the range of the upper and lower limits of the determined exhaust gas dilution amount, the exhaust gas is controlled by the flow control valve 28 so that the optimal exhaust gas dilution amount is obtained. Dilution amount V
By controlling 1, the operation of the heating furnace using the regenerative combustion device can be optimized.
【００２６】すなわち、操業条件として、鋼材の挿入温
度を４００℃、抽出温度を１１４４℃としたときに、排
ガスダイリューションの上限値Ｖ１U が２５０００Ｎｍ
3 ／Ｈ、下限値Ｖ１L が１７０００Ｎｍ3 ／Ｈ、最適値
Ｖ１* が２２０００Ｎｍ3 ／Ｈとなり、排ガスダイリュ
ーション量を流量調節弁２８で最適排ガスダイリューシ
ョン量Ｖ１* となるように制御することにより、加熱能
力限界は従来例では２５０t/H であったものが本発明で
は排ガスダイリューションにより、ダイリューションエ
アが不要になることで煙道の圧損が低減されて２８０t/
H に大幅に向上させることができ、燃料原単位が従来法
では２４０Ｍcal/t であったものが本発明では２１５Ｍ
cal/t に大幅に低減することができた。That is, as operating conditions, when the steel material insertion temperature is 400 ° C. and the extraction temperature is 1144 ° C., the upper limit value V1 U of the exhaust gas dilution is 25,000 Nm.
3 / H, the lower limit value V1 L is 17000 Nm 3 / H, the optimum value V1 * is 22000 Nm 3 / H, and the exhaust gas dilution amount is controlled by the flow control valve 28 so as to be the optimum exhaust gas dilution amount V1 * . Thus, the heating capacity limit was 250 t / H in the conventional example, but in the present invention, exhaust gas dilution eliminates the need for dilution air, thereby reducing the pressure loss of the flue to 280 t / H.
H can be greatly improved, and the unit fuel consumption is 240 Mcal / t in the conventional method, but is 215 Mcal / t in the present invention.
Cal / t was greatly reduced.
【００２７】なお、上記実施形態においては、第１加熱
帯４にのみ蓄熱式燃焼装置１１，１２を設けた場合につ
いて説明したが、これに限定されるものではなく、３組
以上の蓄熱式燃焼装置を設置するようにしてもよく、あ
るいは蓄熱式燃焼装置１１，１２に複数対のバーナー及
び蓄熱体を設けるようにしてもよく、また、第２加熱帯
５や均熱帯６にも蓄熱式燃焼装置を設けるようにしても
よく、さらには、各燃焼帯で蓄熱式燃焼装置と通常バー
ナーによる燃焼装置とを混在させるようにしてもよく、
要は蓄熱式燃焼装置の蓄熱体２０ａ，２０ｂを通過して
排出される排ガスを煙道７のエアレキュペレータ８の入
側にその排ガス温度を溶損防止温度に冷却するダイリュ
ーション媒体として供給する場合に、本発明を適用し得
るものである。In the above embodiment, the case where the regenerative combustion devices 11 and 12 are provided only in the first heating zone 4 has been described. However, the present invention is not limited to this. An apparatus may be installed, or a plurality of pairs of burners and regenerators may be provided in the regenerative combustion devices 11 and 12. A device may be provided, and further, a regenerative combustion device and a combustion device using a normal burner may be mixed in each combustion zone,
In short, the exhaust gas discharged through the heat storage bodies 20a and 20b of the regenerative combustion device is supplied to the flue gas inlet side of the air recuperator 8 as a dilution medium for cooling the exhaust gas temperature to the melting prevention temperature. In this case, the present invention can be applied.
【００２８】また、上記実施形態においては、第１及び
第２の加熱帯４及び５を有する場合について説明した
が、これに限定されるものではなく、加熱帯が１つ又は
３以上である場合であっても、各帯に配設した蓄熱式燃
焼装置の排ガスを排ガス吸引ファンで吸引した後、最適
排ガスダイリューション量Ｖ１* に制御することにより
最適な加熱炉操業を行うことができる。Further, in the above-described embodiment, the case where the first and second heating zones 4 and 5 are provided has been described. However, the present invention is not limited to this, and the case where one or three or more heating zones are provided. Even in this case, after exhaust gas from the regenerative combustion device disposed in each zone is sucked by the exhaust gas suction fan, the optimal heating furnace operation can be performed by controlling the exhaust gas dilution amount to V1 * .
【００２９】さらに、上記実施形態においては、蓄熱式
燃焼装置１１，１２に供給する燃料としてＭガスを使用
する場合について説明したが、これに限定されるもので
はなく、他の燃料ガスや重油等の液体燃料を使用するこ
とができる。さらにまた、上記実施形態においては蓄熱
式燃焼装置１１，１２におけるガスバーナ１３ａ，１３
ｂに対する燃焼空気の供給及び排ガスの排出を個別の空
気遮断弁２２ａ，２２ｂ及び排ガス遮断弁２５ａ，２５
ｂで行う場合について説明したが、これらに限らずエア
シリンダ等によって流路を切換える方向切換片や、特開
平１−２１９４１１号公報に開示されているように流体
力学的にコアンダ効果を利用して切換機構を構成するよ
うにしてもよい。Further, in the above embodiment, the case where M gas is used as the fuel to be supplied to the regenerative combustion devices 11 and 12 has been described. However, the present invention is not limited to this, and other fuel gas, heavy oil, etc. Liquid fuel can be used. Furthermore, in the above embodiment, the gas burners 13a, 13
b, the supply of combustion air and the discharge of exhaust gas are controlled by separate air shutoff valves 22a, 22b and exhaust gas shutoff valves 25a, 25.
However, the present invention is not limited to these, but is not limited to these. For example, a direction switching piece for switching a flow path by an air cylinder or the like, or a fluid dynamic utilizing the Coanda effect as disclosed in Japanese Patent Application Laid-Open No. 1-219411. A switching mechanism may be configured.
【００３０】[0030]
【発明の効果】以上説明したように、請求項１に係る発
明によれば、加熱炉の燃焼負荷から煙道ドラフト、煙道
圧損、エアレキュペレータ溶損温度を考慮し、前記蓄熱
体から排出される排ガスを前記エアレキュペレータの入
側に供給する際の排ガスダイリューション量の上下限値
を決定し、決定した排ガスダイリューション量の上下限
範囲内で燃料原単位が最小となる最適排ガスダイリュー
ション量を求め、求めた最適排ガスダイリューション量
に基づいて排ガスダイリューション量を制御すると共
に、残りの排ガスをガスレキュペレータ出側の煙道に供
給するようにしたので、煙道ドラフトと高効率廃熱回収
とを両立させた最適な加熱炉操業を実現することができ
るという効果が得られる。As described above, according to the first aspect of the present invention, the exhaust gas is discharged from the heat storage body in consideration of the flue draft, the flue pressure loss, and the air recuperator melting loss temperature from the combustion load of the heating furnace. Determine the upper and lower limits of the exhaust gas dilution amount when supplying the exhaust gas to be supplied to the inlet side of the air recuperator, and optimize the fuel consumption unit within the upper and lower limit range of the determined exhaust gas dilution amount. Since the amount of exhaust gas dilution was determined and the amount of exhaust gas dilution was controlled based on the determined optimal amount of exhaust gas dilution, the remaining exhaust gas was supplied to the flue at the outlet of the gas recuperator. The effect is obtained that it is possible to realize an optimum heating furnace operation that achieves both a flue draft and highly efficient waste heat recovery.
【図１】本発明の一実施形態を示す概略構成図である。FIG. 1 is a schematic configuration diagram showing an embodiment of the present invention.
【図２】排ガスダイリューション量と煙道ドラフト及び
圧損との関係を示す特性線図である。FIG. 2 is a characteristic diagram showing a relationship between an exhaust gas dilution amount, a flue draft, and a pressure loss.
【図３】排ガスダイリューション量とエアレキュペレー
タ入側排ガス温度との関係を示す特性線図である。FIG. 3 is a characteristic diagram illustrating a relationship between an exhaust gas dilution amount and an exhaust gas temperature on an inlet side of an air recuperator.
【図４】排ガスダイリューション量と加熱炉燃料原単位
との関係を示す特性線図である。FIG. 4 is a characteristic diagram illustrating a relationship between an exhaust gas dilution amount and a heating furnace fuel consumption rate.
【図５】燃焼バーナの切換えによる蓄熱体の前後の温度
変化及び排ガス温度変化を示すタイムチャートである。FIG. 5 is a time chart showing a change in temperature before and after the heat storage body and a change in exhaust gas temperature due to switching of the combustion burner.
１ 連続式加熱炉 ３ 予熱帯 ４ 第１加熱帯 ５ 第２加熱帯 ６ 均熱帯 ７ 煙道 ８ エアレキュペレータ ９ ガスレキュペレータ １１，１２ 蓄熱式燃焼装置 １３ａ，１３ｂ ガスバーナ ２０ａ，２０ｂ 蓄熱体 ２５ａ，２５ｂ 排ガス遮断弁 ２７ 排ガス吸引ファン ２８ 流量調節弁 REFERENCE SIGNS LIST 1 continuous heating furnace 3 pre-tropical zone 4 first heating zone 5 second heating zone 6 isotropy 7 flue 8 air recuperator 9 gas recuperator 11, 12 regenerative combustion device 13a, 13b gas burner 20a, 20b regenerator 25a , 25b Exhaust gas cutoff valve 27 Exhaust gas suction fan 28 Flow control valve
───────────────────────────────────────────────────── フロントページの続き Ｆターム(参考） 3K003 EA08 FB01 FB08 GA03 3K023 QA03 QB01 QB09 QB17 QC07 QC08 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K003 EA08 FB01 FB08 GA03 3K023 QA03 QB01 QB09 QB17 QC07 QC08
Claims (1)
ーナに接続された燃焼空気供給用兼排ガス排出用管の途
上にそれぞれ介装した所要対の蓄熱体とを有する蓄熱式
燃焼装置を燃焼室に配設した加熱炉の操業方法におい
て、前記加熱炉の燃焼負荷から煙道ドラフト、煙道圧
損、エアレキュペレータ溶損温度を考慮し、前記蓄熱体
から排出される排ガスを前記エアレキュペレータの入側
に供給する際の排ガスダイリューション量の上下限値を
決定し、決定した排ガスダイリューション量の上下限範
囲内で燃料原単位が最小となる最適排ガスダイリューシ
ョン量を求め、求めた最適排ガスダイリューション量に
基づいて排ガスダイリューション量を制御すると共に、
残りの排ガスをガスレキュペレータ出側の煙道に供給す
るようにしたことを特徴とする加熱炉の操業方法。1. A regenerative combustion system comprising: a required pair of burners disposed on a furnace wall; and a required pair of regenerators respectively interposed on a combustion air supply / exhaust gas discharge pipe connected to each burner. In a method of operating a heating furnace in which the apparatus is disposed in a combustion chamber, considering a flue draft, a flue pressure loss, and an air recuperator melting loss temperature from the combustion load of the heating furnace, the exhaust gas discharged from the heat storage body is subjected to the method. Determine the upper and lower limits of the exhaust gas dilution amount when supplying to the inlet of the air recuperator, and the optimal exhaust gas dilution amount that minimizes the unit fuel consumption within the determined upper and lower limits of the exhaust gas dilution amount And controlling the exhaust gas dilution amount based on the obtained optimal exhaust gas dilution amount,
A method for operating a heating furnace, characterized in that the remaining exhaust gas is supplied to a flue on the exit side of a gas recuperator.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31100298A JP3799841B2 (en) | 1998-10-30 | 1998-10-30 | Operating method of heating furnace |
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| Application Number | Priority Date | Filing Date | Title |
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| JP31100298A JP3799841B2 (en) | 1998-10-30 | 1998-10-30 | Operating method of heating furnace |
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| JP2000130745A true JP2000130745A (en) | 2000-05-12 |
| JP3799841B2 JP3799841B2 (en) | 2006-07-19 |
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| Application Number | Title | Priority Date | Filing Date |
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| JP31100298A Expired - Fee Related JP3799841B2 (en) | 1998-10-30 | 1998-10-30 | Operating method of heating furnace |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101020358B1 (en) | 2003-07-07 | 2011-03-08 | 재단법인 포항산업과학연구원 | Waste heat recovery Apparatus for reheating furnace |
| KR101420652B1 (en) | 2007-12-21 | 2014-07-21 | 재단법인 포항산업과학연구원 | Waste gas temperature control method for recuperator in reheating furnace system |
| WO2024189990A1 (en) * | 2023-03-14 | 2024-09-19 | Ｊｆｅスチール株式会社 | Heating furnace operation method and heating furnace |
-
1998
- 1998-10-30 JP JP31100298A patent/JP3799841B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101020358B1 (en) | 2003-07-07 | 2011-03-08 | 재단법인 포항산업과학연구원 | Waste heat recovery Apparatus for reheating furnace |
| KR101420652B1 (en) | 2007-12-21 | 2014-07-21 | 재단법인 포항산업과학연구원 | Waste gas temperature control method for recuperator in reheating furnace system |
| WO2024189990A1 (en) * | 2023-03-14 | 2024-09-19 | Ｊｆｅスチール株式会社 | Heating furnace operation method and heating furnace |
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| Publication number | Publication date |
|---|---|
| JP3799841B2 (en) | 2006-07-19 |
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