JPH0510566B2 - - Google Patents

Info

Publication number
JPH0510566B2
JPH0510566B2 JP60186628A JP18662885A JPH0510566B2 JP H0510566 B2 JPH0510566 B2 JP H0510566B2 JP 60186628 A JP60186628 A JP 60186628A JP 18662885 A JP18662885 A JP 18662885A JP H0510566 B2 JPH0510566 B2 JP H0510566B2
Authority
JP
Japan
Prior art keywords
air preheater
air
temperature
preheater
primary
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 - Lifetime
Application number
JP60186628A
Other languages
Japanese (ja)
Other versions
JPS6249118A (en
Inventor
Takao Ishihara
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Heavy Industries Ltd
Original Assignee
Mitsubishi Heavy Industries Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Mitsubishi Heavy Industries Ltd filed Critical Mitsubishi Heavy Industries Ltd
Priority to JP60186628A priority Critical patent/JPS6249118A/en
Publication of JPS6249118A publication Critical patent/JPS6249118A/en
Publication of JPH0510566B2 publication Critical patent/JPH0510566B2/ja
Granted legal-status Critical Current

Links

Classifications

    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00Combustion technologies with mitigation potential
    • Y02E20/34Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery

Landscapes

  • Air Supply (AREA)

Description

【発明の詳細な説明】 産業上の利用分野 本発明は、原動機製品のボイラに適用される空
気予熱システム、殊に1次及び2次の空気予熱器
が組込まれるシステムに関する。
DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air preheating system applied to a boiler of a motor product, in particular to a system in which primary and secondary air preheaters are incorporated.

従来の技術 従来、石炭−重油焚きボイラ等においては、ユ
ングストローム式又は鋼管式の空気予熱器が一般
的に使用されている。そして、よく知られている
ように、ユングストローム式空気予熱器は波形の
薄鋼板を組み合せて円筒内におさめて伝熱体と
し、これを回転させて燃焼ガスと空気とに交互に
接触させるようにした構造であり、また鋼管式空
気予熱器は鋼管の壁を介して燃焼ガスと空気との
間に熱交換を行わせるようにした構造である。
BACKGROUND ART Conventionally, a Ljungström type or steel pipe type air preheater has been generally used in coal-heavy oil fired boilers and the like. As is well known, the Ljungström air preheater is a heat transfer body made by combining corrugated thin steel plates and placing them in a cylinder, which is then rotated to bring it into alternate contact with combustion gas and air. The steel pipe air preheater has a structure in which heat exchange occurs between the combustion gas and the air through the wall of the steel pipe.

また、最近は、内部流体循環式の空気予熱器が
開発されている。この形式の空気予熱器は、例え
ば第2a〜2c図に示すように、燃焼ガス側セク
シヨン31、2次エアセクシヨン32、1次エア
セクシヨン33の3個の伝熱セクシヨンより構成
され、下側に燃焼ガス側セクシヨン31、上側に
2次エアセクシヨン32及び1次エアセクシヨン
33を配置し、各々の伝熱セクシヨンには、フイ
ン付鋼管または裸鋼管が配置され、各鋼管10
は、加熱側、冷却側毎に上下に配置されたヘツダ
ー36,37,38,39と連結されている。さ
らに、各ヘツダーは、第2c図に示すように、加
熱側セクシヨン下部ヘツダー36は、冷却側セク
シヨン下部ヘツダー38と降水管34で連絡され
ており、また、加熱側セクシヨン上部ヘツダー3
7と冷却側セクシヨン上部ヘツダー39は、上昇
管35で連絡されている。
Also, recently, an internal fluid circulation type air preheater has been developed. This type of air preheater is composed of three heat transfer sections: a combustion gas side section 31, a secondary air section 32, and a primary air section 33, as shown in FIGS. 2a to 2c, for example. A side section 31, a secondary air section 32 and a primary air section 33 are arranged on the upper side, and a finned steel pipe or a bare steel pipe is arranged in each heat transfer section.
are connected to headers 36, 37, 38, and 39 arranged above and below for each heating side and cooling side. Furthermore, as shown in FIG. 2c, the heating side section lower header 36 is connected to the cooling side section lower header 38 by a downcomer pipe 34, and the heating side section upper header 3
7 and the cooling side section upper header 39 are connected by a riser pipe 35.

各降水管34には、水面計44が設置されてお
り、降水管下部には、給水ライン41、及びドレ
ンライン45が設置される。一方、上昇管35の
上部には、ベントライン42及び安全弁43が設
置されている。通常、内部流体としては、水が使
用されるが、高温領域では、水以外の熱媒体も使
用される。
A water level gauge 44 is installed in each downdown pipe 34, and a water supply line 41 and a drain line 45 are installed at the bottom of the downdown pipe. On the other hand, a vent line 42 and a safety valve 43 are installed at the upper part of the riser pipe 35. Usually, water is used as the internal fluid, but in high-temperature regions, heat carriers other than water are also used.

しかして、このような閉ループにおいて、水
(又は熱媒)は、加熱側、冷却側で、蒸発、凝縮
を繰返し、自然循環系統を形成することにより、
加熱側で吸収された熱量は、冷却側で放出され、
燃焼ガスと空気が全く接触することなく、熱伝達
が可能となる。
In such a closed loop, water (or heat medium) repeats evaporation and condensation on the heating side and cooling side, forming a natural circulation system.
The amount of heat absorbed on the heating side is released on the cooling side,
Heat transfer is possible without any contact between combustion gas and air.

発明が解決しようとする問題点 以上述べた従来の空気予熱器においては、しか
し、次に述べるような問題があつた。
Problems to be Solved by the Invention The conventional air preheater described above, however, had the following problems.

ユングストローム式及び鋼管式の空気予熱器の
場合には、低温部のメタル温度Tmが入口空気温
度(大気温度)Taと排ガス温度Tgとの平均値、
すなわちTm=1/2(Tg−Ta)で決まるので、例 えばTa=20℃、石炭焚き時の目標Tmを低温腐
食防止のために70℃とすれば、Tg=120℃とな
り、Tgをこれ以下に下げられず、これがボイラ
効率のアツプ化の妨げとなつている。
In the case of Jungstrom type and steel pipe type air preheaters, the metal temperature Tm of the low temperature section is the average value of the inlet air temperature (atmospheric temperature) Ta and the exhaust gas temperature Tg,
In other words, it is determined by Tm = 1/2 (Tg - Ta), so for example, if Ta = 20℃ and the target Tm for coal firing is 70℃ to prevent low-temperature corrosion, then Tg = 120℃, and Tg must be lower than this. This is an impediment to increasing boiler efficiency.

一方、内部流体循環式の空気予熱器において
は、低温部の伝熱管をホウ硅酸ガラス等の耐蝕性
ガラス又はポリテトラフルオロエチレン等の耐蝕
性プラスチツクの材料で形成して、低温部の材質
温度を酸露点以下に下げることはできるが、しか
し、この場合にはガラス等の熱伝導率の悪さ、材
質的もろさ等の欠点がある。
On the other hand, in an internal fluid circulation type air preheater, the heat exchanger tube in the low temperature section is made of a corrosion-resistant glass such as borosilicate glass or a corrosion-resistant plastic material such as polytetrafluoroethylene, so that the material temperature of the low temperature section is It is possible to lower the temperature below the acid dew point, but in this case, there are disadvantages such as poor thermal conductivity of glass etc. and fragility of the material.

そこで、本発明は、このような従来の問題点を
解決するためになされたもので、空気予熱器低温
部での酸腐蝕及び空気予熱器の後流に続く電気集
塵器等の付属機器の酸腐蝕の防止を計りながら、
ボイラプラントとして石炭−重油の混焼条件に応
じて最高効率の運用を可能とすることを目的とす
る。
Therefore, the present invention was made to solve these conventional problems, and it prevents acid corrosion in the low-temperature section of the air preheater and the damage to attached equipment such as an electrostatic precipitator downstream of the air preheater. While trying to prevent acid corrosion,
The purpose is to enable maximum efficiency operation as a boiler plant depending on the co-firing conditions of coal and heavy oil.

問題点を解決するための手段 本発明は、空気予熱システムにおいて、燃焼ガ
ス流れの高温側に2次空気予熱器を配置するとと
もに、この2次空気予熱器の下流側に内部流体循
環式の1次空気予熱器を配置し、空気通路を空気
が1次空気予熱器及び2次空気予熱器の順に流れ
るように連結するとともに、1次空気予熱器の空
気入口部の上流側で分岐して、2次空気予熱器の
下流側に連通するバイパス通路を設け、このバイ
パス通路に1次空気予熱器の内部流体の温度と1
次空気予熱器から出る燃焼ガスの温度とに基づい
て作動する流量調整手段を配置したものである。
Means for Solving the Problems The present invention provides an air preheating system in which a secondary air preheater is disposed on the high temperature side of the combustion gas flow, and an internal fluid circulation type air preheater is disposed downstream of the secondary air preheater. A secondary air preheater is arranged, the air passage is connected so that air flows through the primary air preheater and the secondary air preheater in that order, and is branched on the upstream side of the air inlet of the primary air preheater, A bypass passage communicating with the downstream side of the secondary air preheater is provided, and the temperature of the internal fluid of the primary air preheater and the
A flow rate adjusting means is provided that operates based on the temperature of the combustion gas coming out of the secondary air preheater.

作 用 このような手段によれば、1次空気予熱器とし
て内部流体循環式のものを用いているので、その
伝熱管を形成する金属管の低温部メタル温度を酸
露点以上に保ちながら、燃焼ガス温度を最小限ま
で下げ、その分ボイラ効率の上昇が可能となる。
また、かかる金属管として一般に鋼管を使用でき
るので、熱伝導率の悪い等の欠点があるガラス等
の特殊材質からなる管の使用を避けることができ
る。
Effect According to this method, since an internal fluid circulation type is used as the primary air preheater, the temperature of the low-temperature part of the metal tube forming the heat transfer tube is maintained above the acid dew point while combustion is being carried out. It is possible to lower the gas temperature to the minimum and increase boiler efficiency accordingly.
Furthermore, since steel pipes can generally be used as such metal pipes, it is possible to avoid the use of pipes made of special materials such as glass, which have drawbacks such as poor thermal conductivity.

実施例 以下図面を参照して本発明の一実施例について
記述する。
Embodiment An embodiment of the present invention will be described below with reference to the drawings.

第1図は、本発明による空気予熱システムを組
み込んだボイラの一例を示す。
FIG. 1 shows an example of a boiler incorporating an air preheating system according to the invention.

この図において、押込通風機1より供給された
空気は、1次空気予熱器入口エア系統2を通して
内部流体循環式の1次空気予熱器3に供給され、
この部分で後述する燃焼ガスと熱交換を行い、加
熱される。この1次空気予熱器3は、燃焼ガス流
れの高温側に配置されているユングストローム式
又は鋼管式の2次空気予熱器4の下流側に配置さ
れている。
In this figure, air supplied from a forced draft fan 1 is supplied to an internal fluid circulation type primary air preheater 3 through a primary air preheater inlet air system 2.
This part exchanges heat with combustion gas, which will be described later, and is heated. This primary air preheater 3 is arranged downstream of a secondary air preheater 4 of the Ljungström or steel tube type, which is arranged on the high temperature side of the combustion gas flow.

1次空気予熱器3で加熱されて高温となつた空
気は、それから、2次空気予熱器4とミルテンパ
リングエア系統5とに分けられる。そして、2次
空気予熱器4で更に加熱された高温空気はホツト
エア系統6を通して流れ、その一部は2次エア供
給系統7を通して火炉8内に導入され、またその
残りはミル用の1次エアとしてミルテンパリング
エア系統5及びその流量調整ダンパ9を通して流
れてきた空気と混合した後1次エアフアン10に
よりミル11に供給される。
The air heated to a high temperature by the primary air preheater 3 is then divided into a secondary air preheater 4 and a mill tempering air system 5. The high-temperature air further heated by the secondary air preheater 4 flows through the hot air system 6, a part of which is introduced into the furnace 8 through the secondary air supply system 7, and the rest is used as the primary air for the mill. After being mixed with the air flowing through the mill tempering air system 5 and its flow rate adjusting damper 9, it is supplied to the mill 11 by the primary air fan 10.

また、1次空気予熱器3の空気入口部の上流側
すなわち入口エア系統2から分岐されたバイパス
通路12が2次空気予熱器4の下流側すなわちホ
ツトエア系統6に連通して設けられ、押込通風機
1からの供給空気の一部がこのバイパス通路12
及びバイパスエア流量調整ダンパ13を通してホ
ツトエア系統6内の高温空気と合流できるように
なつている。
Further, a bypass passage 12 branched from the air inlet section of the primary air preheater 3, that is, the inlet air system 2, is provided to communicate with the downstream side of the secondary air preheater 4, that is, the hot air system 6. A portion of the air supplied from the machine 1 flows through this bypass passage 12.
The high temperature air in the hot air system 6 can be merged with the high temperature air through the bypass air flow rate adjusting damper 13.

このバイパスエア流量調整ダンパ13は、1次
空気予熱器3の内部流体の温度を検出する温度計
14と1次空気予熱器3から出る燃焼ガスの温度
を検出する温度計15とからの各検出信号を受け
る制御器16によつて制御される。これにより、
1次空気予熱器3の低温部メタル温度又は燃焼ガ
スの温度が石炭−重油混焼比に応じて要求される
値となるように、エアバイパス量を制御すること
ができる。
This bypass air flow rate adjustment damper 13 receives each detection from a thermometer 14 that detects the temperature of the internal fluid of the primary air preheater 3 and a thermometer 15 that detects the temperature of the combustion gas coming out of the primary air preheater 3. It is controlled by a controller 16 which receives the signal. This results in
The amount of air bypass can be controlled so that the low-temperature part metal temperature of the primary air preheater 3 or the temperature of the combustion gas becomes a value required according to the coal-heavy oil co-combustion ratio.

一方、コールバンカ17からミル11に供給さ
れた石炭は、1次エアフアン10によりミル内に
導入された空気によつて粉砕、乾燥され、それか
ら微粉炭供給系統18を通してバーナより火炉8
内に投入され、燃焼される。その燃焼ガスは、対
流伝熱セクシヨン19を通過した後、節炭器出口
排ガス系統20を通して2次空気予熱器4、1次
空気予熱器3、電気集じん器21及び誘引通風機
22を通過して煙突23から大気に排出される。
On the other hand, the coal supplied from the coal bunker 17 to the mill 11 is pulverized and dried by air introduced into the mill by the primary air fan 10, and then passed through the pulverized coal supply system 18 to the burner to the furnace 8.
is thrown into the interior and burned. After passing through the convection heat transfer section 19, the combustion gas passes through the economizer outlet exhaust gas system 20, the secondary air preheater 4, the primary air preheater 3, the electrostatic precipitator 21 and the induced draft fan 22. and is discharged into the atmosphere from the chimney 23.

しかして、1次空気予熱器3として使用した内
部流体循環式の空気予熱器は、2次空気予熱器4
として使用したユングストローム式又は鋼管式の
空気予熱器に比較して、第3図(内部流体循環
式)及び第4図(ユングストローム式)に示すよ
うに、メタル温度の点で有利な点がある。すなわ
ち、内部流体循環式の空気予熱器では、その入口
空気温度Taとは直接関係なく、低温部の平均メ
タル温度Tm(内部流体温度+2〜3℃)を燃焼
ガスTg側に近づけて設計可能であるし、また運
転も可能なものである。
Therefore, the internal fluid circulation type air preheater used as the primary air preheater 3 is different from the secondary air preheater 4.
Compared to the Jungström type or steel pipe type air preheater used as be. In other words, with an internal fluid circulation type air preheater, it is possible to design the average metal temperature Tm (internal fluid temperature + 2 to 3°C) of the low temperature part to be closer to the combustion gas Tg side, regardless of the inlet air temperature Ta. Yes, it is possible to drive.

発明の効果 以上詳述したように、本発明によれば、1次空
気予熱器として伝熱管を金属管通常は鋼管で形成
し得る内部流体循環式のものを使用しているの
で、ガラス等の特殊材質の伝熱管を使用すること
なく、例えば石炭専焼時には酸露点50〜80℃に対
して、1次空気予熱器の低温部メタル温度を約90
℃にキープしながら、燃焼ガス温度を約100℃程
度まで下げることができる。したがつて、これに
より、1次及び2次の空気予熱器の両方をユング
ストローム式として燃焼ガス温度を120〜130℃と
した場合に比べ、ボウラ効率を約1.3〜1.5%上昇
することができる。
Effects of the Invention As detailed above, according to the present invention, since the heat exchanger tube as the primary air preheater is of an internal fluid circulation type that can be formed of a metal tube, usually a steel tube, Without using heat exchanger tubes made of special materials, for example, when burning coal exclusively, the temperature of the low temperature metal part of the primary air preheater can be kept at about 90℃, compared to the acid dew point of 50 to 80℃.
It is possible to lower the combustion gas temperature to approximately 100℃ while maintaining the temperature at ℃. Therefore, this makes it possible to increase the bowler efficiency by approximately 1.3 to 1.5% compared to when both the primary and secondary air preheaters are of the Jungström type and the combustion gas temperature is set at 120 to 130°C. .

また、この1次空気予熱器の低温部メタル温度
又は燃焼ガス温度は1次及び2次の空気予熱器を
バイパスする空気の量を変えることにより制御す
ることができる。しかがつて、例えば重油専焼時
には電気集じん器の酸腐蝕等をさけるために燃焼
ガス温度を石炭専焼時等に比べて大幅に上昇させ
る必要があるが、このようなことも該空気バイパ
ス方式によつて最も効果的にかつ簡単に行うこと
ができる。
Also, the low temperature metal temperature or combustion gas temperature of the primary air preheater can be controlled by changing the amount of air that bypasses the primary and secondary air preheaters. However, for example, when burning only heavy oil, it is necessary to raise the combustion gas temperature significantly compared to when burning only coal to avoid acid corrosion of the electrostatic precipitator, but this also applies to the air bypass method. Therefore, it can be done most effectively and easily.

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

第1図は本発明による空気予熱システムを組み
込んだボイラの一例を示す系統図、第2a図は本
発明にしたがつて1次空気予熱器として使用され
る内部流体循環式の空気予熱器の一例を示す正面
図、第2b図はその側面図、第2c図はその内部
流体流れ系統図、第3図及び第4図はそれぞれ内
部流体循環式及びユングストローム式の空気予熱
器における低温部の平均メタル温度と空気温度及
び燃焼ガス温度との関係を示す図である。 3……1次空気予熱器、4……2次空気予熱
器、8……火炉、11……ミル、12……バイパ
ス通路、13……バイパスエア流量調整ダンパ、
14,15……温度計、16……制御器。
FIG. 1 is a system diagram showing an example of a boiler incorporating an air preheating system according to the present invention, and FIG. 2a is an example of an internal fluid circulation type air preheater used as a primary air preheater according to the present invention. Figure 2b is a side view, Figure 2c is an internal fluid flow diagram, and Figures 3 and 4 are averages of low-temperature parts in internal fluid circulation type and Jungstrom type air preheaters, respectively. It is a figure showing the relationship between metal temperature, air temperature, and combustion gas temperature. 3...Primary air preheater, 4...Secondary air preheater, 8...Furnace, 11...Mill, 12...Bypass passage, 13...Bypass air flow rate adjustment damper,
14, 15...Thermometer, 16...Controller.

Claims (1)

【特許請求の範囲】[Claims] 1 燃焼ガス流れの高温側に2次空気予熱器を配
置するとともに、この2次空気予熱器の下流側に
内部流体循環式の1次空気予熱器を配置し、空気
通路を空気が1次空気予熱器及び2次空気予熱器
の順に流れるように連結するとともに、1次空気
予熱器の空気入口部の上流側で分岐して、2次空
気予熱器の下流側に連通するバイパス通路を設
け、このバイパス通路に1次空気予熱器の内部流
体の温度と1次空気予熱器から出る燃焼ガスの温
度とに基づいて作動する流量調整手段を配置して
なる空気予熱システム。
1. A secondary air preheater is placed on the high temperature side of the combustion gas flow, and an internal fluid circulation type primary air preheater is placed downstream of this secondary air preheater, so that the air passes through the air passage and is connected to the primary air. A bypass passage is provided that connects the preheater and the secondary air preheater in order to flow, and branches on the upstream side of the air inlet portion of the primary air preheater and communicates with the downstream side of the secondary air preheater, An air preheating system in which a flow rate adjusting means that operates based on the temperature of the internal fluid of the primary air preheater and the temperature of the combustion gas exiting from the primary air preheater is disposed in the bypass passage.
JP60186628A 1985-08-27 1985-08-27 Air preheating system Granted JPS6249118A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP60186628A JPS6249118A (en) 1985-08-27 1985-08-27 Air preheating system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP60186628A JPS6249118A (en) 1985-08-27 1985-08-27 Air preheating system

Publications (2)

Publication Number Publication Date
JPS6249118A JPS6249118A (en) 1987-03-03
JPH0510566B2 true JPH0510566B2 (en) 1993-02-10

Family

ID=16191905

Family Applications (1)

Application Number Title Priority Date Filing Date
JP60186628A Granted JPS6249118A (en) 1985-08-27 1985-08-27 Air preheating system

Country Status (1)

Country Link
JP (1) JPS6249118A (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4959156B2 (en) 2004-11-29 2012-06-20 三菱重工業株式会社 Heat recovery equipment
CN105090929B (en) * 2015-08-28 2017-04-19 山东英电环保科技有限公司 Hot primary air waste-heat utilization device used by being coupled with low-pressure economizer
CN110986077A (en) * 2019-12-26 2020-04-10 润电能源科学技术有限公司 Coal-fired unit heat utilizes system

Also Published As

Publication number Publication date
JPS6249118A (en) 1987-03-03

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