EP0154690A2 - Regulation of a fluidised-bed combustion apparatus in a heating boiler - Google Patents

Regulation of a fluidised-bed combustion apparatus in a heating boiler Download PDF

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Publication number
EP0154690A2
EP0154690A2 EP84114617A EP84114617A EP0154690A2 EP 0154690 A2 EP0154690 A2 EP 0154690A2 EP 84114617 A EP84114617 A EP 84114617A EP 84114617 A EP84114617 A EP 84114617A EP 0154690 A2 EP0154690 A2 EP 0154690A2
Authority
EP
European Patent Office
Prior art keywords
temperature
fuel
fluidized bed
bed
supply
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.)
Withdrawn
Application number
EP84114617A
Other languages
German (de)
French (fr)
Other versions
EP0154690A3 (en
Inventor
Rolf Dr. Dipl. Ing. Noack
Hans Dipl. Ing. Freitag
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.)
Omnical GmbH
Original Assignee
Buderus AG
Omnical GmbH
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 Buderus AG, Omnical GmbH filed Critical Buderus AG
Publication of EP0154690A2 publication Critical patent/EP0154690A2/en
Publication of EP0154690A3 publication Critical patent/EP0154690A3/en
Withdrawn legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F23C10/18—Details; Accessories
    • F23C10/28—Control devices specially adapted for fluidised bed, combustion apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N1/00—Regulating fuel supply
    • F23N1/02—Regulating fuel supply conjointly with air supply
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2225/00—Measuring
    • F23N2225/08—Measuring temperature
    • F23N2225/16—Measuring temperature burner temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2233/00—Ventilators
    • F23N2233/06—Ventilators at the air intake
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23N—REGULATING OR CONTROLLING COMBUSTION
    • F23N2239/00—Fuels
    • F23N2239/02—Solid fuels

Definitions

  • the invention relates to a regulation according to the preamble of claim 1.
  • Fluidized bed firing swirls and burns fine-grained fuel. Such furnaces are particularly suitable for burning coal rich in ballast. In addition to the use in large-scale plants, fluidized bed furnaces are also becoming increasingly interesting for water heaters and heating boilers. The advantages of this type of firing can be put to excellent use here.
  • Precise control is essential for the functioning of the fluidized bed furnaces. Since it is a solid fuel firing, several aspects have to be considered. In addition to the usual criteria, such as setting and maintaining the correct bed temperature, there is also a dependency on the heat requirement when using fluidized bed firing in heating boilers.
  • the object of the invention was to set and maintain the correct bed temperature and also to take into account the heat demand from the boiler water.
  • the controlled variable is used to determine the bed temperature using temperature sensors in the fluidized bed. These ensure that the required bed temperature is set and maintained, including safety monitoring.
  • the required bed temperature is first achieved by switching on the forced draft burner. At a lower switching point, the actual fluidized bed combustion is switched over. An upper switching point is used to monitor the maximum bed temperature. The fuel supply is interrupted until a lower limit temperature is reached.
  • the flow temperature determined by a flow thermostat, serves as a further control variable. If heat is requested when the flow temperature falls below the target value, the induced draft and combustion air fan are switched on and the air control flap is opened. Then fuel is added. As a result, there is sufficient heat replenishment through the fluidized bed even if the fuel supply through the thermostats in the fluidized bed should be cut off. As soon as the target flow temperature is exceeded again, the fuel supply is shut off. The combustion air fan and suction run on first. To the air control flap is closed when it is switched off. The bed temperature is therefore not raised to the maximum temperature.
  • the mouth area of the fuel conveyor preferably a fuel feed screw, must be particularly protected against overheating with the risk of reignition.
  • an air valve is opened after the fuel supply is shut off and the mouth area is blown free of ash and coal residues. If a specified maximum temperature is nevertheless exceeded, the coal dosing screw under the bunker is stopped and lime or sand is added as a coolant on the short side.
  • the pressure in the fluidized bed is continuously monitored during the actual fluidized bed operation. Pressure overshoots and undershoots are signaled. Since the formation of ash changes the pressure in the fluidized bed, it is possible to control the ash extraction depending on the pressure.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)

Abstract

The fluidised-bed combustion apparatus in a heating boiler is, via temperature sensors in the fluidised bed with a number of operating points, a) brought to the required temperature by means of a blast burner, b) kept at temperature by supply of air and fuel, c) protected against overheating by fuel switch-off, and also, by means of a thermostat in the forward run, d) brought to increased output by supply of air and fuel in the event of the temperature falling below a set value and e) throttled in output by fuel and air switch-off in the event that the set temperature value is exceeded.

Description

Die Erfindung betrifft eine Regelung nach dem Oberbegriff des Patentanspruches 1.The invention relates to a regulation according to the preamble of claim 1.

Bei Wirbelschichtfeuerungen wird feinkörmiger Brennstoff verwirbelt und verbrannt. Solche Feuerungen sind besonders zum Verfeuern von balastreicher Kohle geeignet. Neben dem Einsatz in großtechnischen Anlagen werden Wirbelschichtfeuerungen auch immer stärker für Wassererhitzer wie Heizungskessel interessant. Hier lassen sich die Vorzüge dieser Feuerungsart hervorragend nutzen.Fluidized bed firing swirls and burns fine-grained fuel. Such furnaces are particularly suitable for burning coal rich in ballast. In addition to the use in large-scale plants, fluidized bed furnaces are also becoming increasingly interesting for water heaters and heating boilers. The advantages of this type of firing can be put to excellent use here.

Von wesentlicher Bedeutung für die Funktion der Wirbelschichtfeuerungen ist eine genaue Regelung. Da es sich um eine Feststoff-Feuerung handelt, müssen mehrere Gesichtspunkte berücksichtigt werden. Neben den üblichen Kriterien, wie dem Einstellen und Einhalten der richtigen Bett-Temperatur kommt bei der Verwendung der Wirbelschichtfeuerung in Heizungskesseln noch die Abhängigkeit von der Wärmeanforderung hinzu.Precise control is essential for the functioning of the fluidized bed furnaces. Since it is a solid fuel firing, several aspects have to be considered. In addition to the usual criteria, such as setting and maintaining the correct bed temperature, there is also a dependency on the heat requirement when using fluidized bed firing in heating boilers.

Der Erfindung lag die Aufgabe zugrunde, die richtige Bett-Temperatur einzustellen und einzuhalten und dabei zusätzlich die Wärmeanforderung durch das Kesselwasser zu berücksichtigen.The object of the invention was to set and maintain the correct bed temperature and also to take into account the heat demand from the boiler water.

Gemäß der Erfindung wird dieses erreicht durch die im Kennzeichen des Patentanspruches 1 genannten Maßnahmen.According to the invention, this is achieved by the measures mentioned in the characterizing part of claim 1.

Als Regelgröße dient auf der einen Seite die Bett-Temperatur ermittel durch Temperaturfühler im Wirbelbett. Diese sorgen für das Einstellen und Einhalten der erforderlichen Bett-Temperatur einschließlich einer Sicherheitsüberwachung. Durch Einschalten des Gebläsebrenners wird zunächst die erforderliche Bett-Temperatur erzielt. Bei einem unteren Schaltpunkt wird dann auf die eigentliche Wirbelschichtfeuerung umgeschaltet. Der Überwachung der maximalen Bett-Temperatur dient ein oberer Schaltpunkt. Bei diesem wird die Brennstoffzufuhr unterbrochen bis eine untere Grenztemperatur erreicht ist.On the one hand, the controlled variable is used to determine the bed temperature using temperature sensors in the fluidized bed. These ensure that the required bed temperature is set and maintained, including safety monitoring. The required bed temperature is first achieved by switching on the forced draft burner. At a lower switching point, the actual fluidized bed combustion is switched over. An upper switching point is used to monitor the maximum bed temperature. The fuel supply is interrupted until a lower limit temperature is reached.

Als weitere Regelgröße dient die Vorlauftemperatur ermittelt durch einen Vorlaufthermostaten. Wird bei unterschrittener Soll-Vorlauftemperatur Wärme angefordert, dann werden zunächst Saugzug und Verbrennungsluftventilator eingeschaltet und die Luftregelklappe geöffnet. Anschließend wird Brennstoff zugeführt. Dadurch erfolgt ein ausreichender Wärmenachschub durch das Wirbelbett selbst dann, wenn die Brennstoffzufuhr durch die Thermostate im Wirbelbett unterborchen sein sollte. Sobald die Soll-Vorlauftemperatur wieder überschritten wird, wird die Brennstoffzufuhr abgesperrt.Verbrennungsluftventilator und Saugzug laufen zunächst nach. Nach ihrer Abschaltung wird die Luftregelklappe geschlossen. Die Bett-Temperatur wird also nicht bis zur maximalen Temperatur hochgefahren.The flow temperature, determined by a flow thermostat, serves as a further control variable. If heat is requested when the flow temperature falls below the target value, the induced draft and combustion air fan are switched on and the air control flap is opened. Then fuel is added. As a result, there is sufficient heat replenishment through the fluidized bed even if the fuel supply through the thermostats in the fluidized bed should be cut off. As soon as the target flow temperature is exceeded again, the fuel supply is shut off. The combustion air fan and suction run on first. To the air control flap is closed when it is switched off. The bed temperature is therefore not raised to the maximum temperature.

Sollte während der Stillstandsphase, d.h. bei abgeschalteter Luft- und Brennstoffzufuhr, die maximale Bettemperatur überschritten werden, dann wird über einen Temperaturfühler im Wirbelbett die Luftzufuhr bis zum Erreichen der unteren Grenztemperatur freigegeben. Das erfolgt im konkreten Fall durch Einschalten von Saugzug und Verbrennungsluftventilator und Öffnen der Luftregelklappe. Es ist somit ein Schutz gegen Überhitzung vor, handen.Should during the standstill phase, i.e. If the air and fuel supply is switched off, the maximum bed temperature is exceeded, then the air supply is released via a temperature sensor in the fluidized bed until the lower limit temperature is reached. In this specific case, this is done by switching on the induced draft and combustion air fan and opening the air control flap. It is therefore a protection against overheating.

Der Mündungsbereich des Brennstoff-Förderers, vorzugsweise einer Brennstoffeintragschnecke, muß besonders gegen Überhitzung mit der Gefahr einer Rückzündung geschützt werden. Zu diesem Zweck wird nach dem Absperren der Brennstoffzufuhr ein Luftventil geöffnet und der Mündungsbereich von Asche und Kohleresten freigeblasen. Sollte dennoch eine festgelegte Höchsttemperatur überschritten werden, dann wird die Kohledosierschnecke unter dem Bunker angehalten und dafür kurzseitig Kalk oder Sand als Kühlmittel zugegeben.The mouth area of the fuel conveyor, preferably a fuel feed screw, must be particularly protected against overheating with the risk of reignition. For this purpose, an air valve is opened after the fuel supply is shut off and the mouth area is blown free of ash and coal residues. If a specified maximum temperature is nevertheless exceeded, the coal dosing screw under the bunker is stopped and lime or sand is added as a coolant on the short side.

Während des eigentlichen Wirbelschichtbetriebes wird der Druck im Wirbelbett kontinuierlich überwacht. Drucküber-und -unterschreitungen werden signalisiert. Da die Aschebildung den Druck im Wirbelbett verändert, besteht die Möglichkeit den Ascheabzug druckabhängig zu steuern.The pressure in the fluidized bed is continuously monitored during the actual fluidized bed operation. Pressure overshoots and undershoots are signaled. Since the formation of ash changes the pressure in the fluidized bed, it is possible to control the ash extraction depending on the pressure.

Claims (5)

1. Regelung einer Wirbelschichtfeuerung in einem Heizungskessel durch Veränderung der Luft- und Brennstoffzufuhr,
dadurch gekennzeichnet, daß über Temperaturfühler im Wirbelbett mit mehreren Schaltpunkten a) unterhalb einer erforderlichen Bett-Temperatur bei gedrosselter Luftzufuhr ein Gebläsebrenner eingeschaltet wird, b) ab der erforderlichen Bett-Temperatur der Gebläsebrenner abgeschaltet, die Luftzufuhr freigegeben und Brennstoff dem Wirbelbett zugeführt wird sowie c) bei Überschreiten einer maximalen Bett-Temperatur die Brennstoffzufuhr zum Wirbelbett bis zum Erreichen einer unteren Grenztemperatur abgesperrt wird.
und daß ferner über einen Thermostaten im Vorlauf d) bei Unterschreiten der Soll-Vorlauftemperatur die Luftzufuhr freigegeben und anschließend Brennstoff zugeführt wird sowie e) bei Überschreiten der Soll-Vorlauftemperatur die Brennstoffzufuhr wieder abgesperrt und mit Nachlauf die Luftzufuhr unterbrochen wird. 1. regulation of a fluidized bed combustion in a heating boiler by changing the air and fuel supply,
characterized in that via temperature sensors in the fluidized bed with several switching points a) a forced draft burner is switched on below a required bed temperature with restricted air supply, b) the fan burner is switched off from the required bed temperature, the air supply is released and fuel is fed to the fluidized bed and c) if a maximum bed temperature is exceeded, the fuel supply to the fluidized bed is shut off until a lower limit temperature is reached.
and that also via a thermostat in advance d) if the flow temperature falls below the target, the air supply is released and then fuel is supplied and e) if the desired flow temperature is exceeded, the fuel supply is shut off again and the air supply is interrupted with overrun. 2. Regelung nach Anspruch 1,
dadurch gekennzeichnet, daß über einen Temperaturfühler im Wirbelbett bei Überschreiten der maximalen Bett-Temperatur während der Stillstandsphase die Luftzufuhr bis zum Erreichen einer unteren Grenztemperatur freigegeben wird.2. Regulation according to claim 1,
characterized in that the air supply is released until a lower limit temperature is reached via a temperature sensor in the fluidized bed when the maximum bed temperature is exceeded during the standstill phase. 3. Regelung nach Anspruch 1,
dadurch gekennzeichnet, daß nach dem Absperren der Brennstoffzufuhr durch öffnen eines Ventiles der Mündungsbereich des Brennstoff-Förderers freigeblasen wird.3. Regulation according to claim 1,
characterized in that after the fuel supply has been shut off, the opening area of the fuel conveyor is blown free by opening a valve. 4. Regelung nach den Ansprüchen 1 bis 3,
dadurch gekennzeichnet, daß über einen Temperaturfühler an der Mündung des Brennstoff-Förderers bei Überschreiten einer festgelegten Höchsttemperatur kurzzeitig die Zufuhr von Kalk oder Sand als Kühlmittel eingeschaltet wird.4. Regulation according to claims 1 to 3,
characterized in that the supply of lime or sand as a coolant is briefly switched on via a temperature sensor at the mouth of the fuel conveyor when a predetermined maximum temperature is exceeded. 5. Regelung nach Anspruch 1,
dadurch gekennzeichnet, daß ab Erreichen der erforderlichen Bett-Temperatur der Differenzdruck des Wirbelbettes überwacht und oberhalb eines festgelegten Druckes der Ascheabzug eingeschaltet wird.5. Regulation according to claim 1,
characterized in that when the required bed temperature is reached, the differential pressure of the fluidized bed is monitored and the ash extraction is switched on above a predetermined pressure.
EP84114617A 1984-02-28 1984-12-01 Regulation of a fluidised-bed combustion apparatus in a heating boiler Withdrawn EP0154690A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3407132 1984-02-28
DE19843407132 DE3407132A1 (en) 1984-02-28 1984-02-28 CONTROL OF A FLUIDIZED BURN FIRING IN A HEATING BOILER

Publications (2)

Publication Number Publication Date
EP0154690A2 true EP0154690A2 (en) 1985-09-18
EP0154690A3 EP0154690A3 (en) 1986-03-19

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Application Number Title Priority Date Filing Date
EP84114617A Withdrawn EP0154690A3 (en) 1984-02-28 1984-12-01 Regulation of a fluidised-bed combustion apparatus in a heating boiler

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EP (1) EP0154690A3 (en)
DE (1) DE3407132A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106224947A (en) * 2016-08-04 2016-12-14 华北电力大学 The event-driven control system of Circulating Fluidized Bed Temperature based on feedback of status

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1526061A1 (en) * 1964-03-31 1969-09-25 Dorr Oliver Inc Process and device for the incineration of organic waste with a high moisture content
US3508506A (en) * 1968-06-13 1970-04-28 Us Interior Process and apparatus for reduction of unburned combustible in fly ash
JPS5541365A (en) * 1978-09-18 1980-03-24 Ishigaki Kiko Kk Method of and apparatus for removing foreign matter from fluidized furnace
EP0028458A2 (en) * 1979-10-03 1981-05-13 Sandfire (Proprietary) Limited Fluidised-bed boilers
US4295817A (en) * 1978-08-04 1981-10-20 The Energy Equipment Co. Ltd. Method and means for controlling the operation of fluidized bed combustion apparatus
US4416418A (en) * 1982-03-05 1983-11-22 Goodstine Stephen L Fluidized bed residential heating system

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DK155464C (en) * 1978-10-27 1989-08-21 Smidth & Co As F L WHIRL CHAMBER BRANCH SYSTEM

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1526061A1 (en) * 1964-03-31 1969-09-25 Dorr Oliver Inc Process and device for the incineration of organic waste with a high moisture content
US3508506A (en) * 1968-06-13 1970-04-28 Us Interior Process and apparatus for reduction of unburned combustible in fly ash
US4295817A (en) * 1978-08-04 1981-10-20 The Energy Equipment Co. Ltd. Method and means for controlling the operation of fluidized bed combustion apparatus
JPS5541365A (en) * 1978-09-18 1980-03-24 Ishigaki Kiko Kk Method of and apparatus for removing foreign matter from fluidized furnace
EP0028458A2 (en) * 1979-10-03 1981-05-13 Sandfire (Proprietary) Limited Fluidised-bed boilers
US4416418A (en) * 1982-03-05 1983-11-22 Goodstine Stephen L Fluidized bed residential heating system

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENTS ABSTRACTS OF JAPAN, Band 4, Nr. 80 (M-15)[562], 10. Juni 1980; & JP - A - 55 41365 (ISHIGAKI KIKOU K.K.) 24.03.1980 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106224947A (en) * 2016-08-04 2016-12-14 华北电力大学 The event-driven control system of Circulating Fluidized Bed Temperature based on feedback of status

Also Published As

Publication number Publication date
EP0154690A3 (en) 1986-03-19
DE3407132A1 (en) 1985-09-05

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