EP0808440B1 - Method and device for starting a once-through steam generator - Google Patents

Method and device for starting a once-through steam generator Download PDF

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Publication number
EP0808440B1
EP0808440B1 EP96900860A EP96900860A EP0808440B1 EP 0808440 B1 EP0808440 B1 EP 0808440B1 EP 96900860 A EP96900860 A EP 96900860A EP 96900860 A EP96900860 A EP 96900860A EP 0808440 B1 EP0808440 B1 EP 0808440B1
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EP
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Prior art keywords
throughput
evaporator
load
fuel
percentage
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EP96900860A
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German (de)
French (fr)
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EP0808440A1 (en
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Joachim Franke
Eberhard Wittchow
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Siemens AG
Siemens Corp
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Siemens AG
Siemens Corp
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B35/00—Control systems for steam boilers
    • F22B35/06—Control systems for steam boilers for steam boilers of forced-flow type
    • F22B35/14—Control systems for steam boilers for steam boilers of forced-flow type during the starting-up periods, i.e. during the periods between the lighting of the furnaces and the attainment of the normal operating temperature of the steam boilers

Definitions

  • the invention relates to a method for starting a Continuous steam generator with a number of burners for a fossil fuel combustion chamber, whose gastight surrounding wall is at least approximately vertical extending evaporator tubes is formed, which are penetrated from bottom to top on the medium side. she further relates to a device for performing the Procedure.
  • the flow of the evaporator is the Continuous steam generator - and often also one in the continuous steam generator arranged smoke gas heated preheater or Economizer - a circulating current is superimposed during startup, order by correspondingly high speeds in the Pipes to cool them safely.
  • The is from pass current and superimposed circulating current existing minimum current with vertically arranged pipes in the surrounding walls the combustion chamber between 25% and 50% of the full load flow. This means that the steam generator load when starting only be increased to at least 25% to 50% must, before the efficient continuous operation with its high steam outlet temperatures.
  • start-up process comprehensive efficiency Power plant especially by realizing high and highest steam conditions, there is therefore a reduction in start-up losses increased importance too.
  • start-up process Circulation circuit to be installed which is usually at least one circulation pump with appropriate accessories or comprises a drain heat exchanger with a high technical Effort and therefore high investment costs required.
  • the invention is therefore based on the object of a method and a device for operating a once-through steam generator to be indicated with low start-up losses. This is said to a device suitable for carrying out the method can be achieved with little technical effort.
  • this object is achieved according to the invention solved in that the evaporator throughput depending of the or each burner supplied per unit of time Fuel amount is set, the evaporator throughput proportional to the heat output in the combustion chamber is set.
  • the evaporator throughput i.e. the amount of the evaporator supplied per unit of time and this medium flowing through, with the procedure according to the invention within a narrow tolerance band.
  • the invention is based on the knowledge that a Continuous steam generator also with a rapidly increasing fire output can be approached because its proportionate thin-walled components have high rates of temperature change allow. Due to the low storage mass of the evaporator uses a rapid steam formation, which leads to Overheating heating surfaces provided generated steam be chilled well.
  • the conventional start-up procedure for continuous steam generators was based on the assumption that the evaporator tubes of highly heated combustion chamber can only be cooled well if the medium flow in the pipes is turbulent, which is a corresponding high mass flow density in the pipes even during of the start-up process.
  • the invention is based on the consideration that also very low mass flow densities and at the same time high heat flow densities a very good heat transfer from a pipe wall to the flow medium when there is a so-called Ring flow forms.
  • Recent studies on the inside Heat transfer in vertical pipes has surprisingly training even at very low mass flow densities of such a ring flow confirmed in the always a large proportion of water in a water-water / Steam mixture formed flow medium to the pipe wall is transported. This also leads to a below about 25% of the full load current, i.e. the evaporator throughput at 100% load, minimum current lies to the good mentioned Heat transfer.
  • the described thermal engineering phenomenon is used in the process to operate a continuous steam generator during the start-up was implemented particularly cheaply, if based on a minimum evaporator throughput of less than 15%, preferably less than 10%, e.g. 5% of Full load throughput the evaporator throughput only in one narrow range from the percentage, related to full load Furnace heat output deviates.
  • the evaporator throughput is expediently limited to 5% to 10% of full load throughput. This ensures a steady upward flow right from the start guaranteed in all evaporator tubes.
  • the evaporator throughput set that related to full load throughput percentage evaporator throughput within a certain Bandwidth equal to the percentage based on full load Firing heat output is.
  • the range extends preferably between 3 to 8% above and between 2 to 3% below the percentage increase over time Firing heat output. This condition is asymmetrical Bandwidth applies in particular to a heating output, which ensures stable combustion is.
  • the device for starting a continuous steam generator with a number of burners for a fossil Combustion chamber with fuel its gas-tight Surrounding wall made of at least approximately vertical arranged evaporator tubes is formed, the medium side can flow from bottom to top, is called Task solved by a controller module for setting the Amount of medium supplied to the evaporator per unit of time depending on the or each burner per unit of time amount of fuel supplied.
  • the manipulated variable determined by the controller block determines the evaporator throughput rate proportional to the determined from the amount of fuel Fire heat output.
  • the controller block is included connected to a feed water line leading into the evaporator switched actuator and with one in one connected to the or each burner leading fuel line second flow sensor.
  • a device is indeed from the document EP-A-0 308 596 for regulating the amount of feed water in a natural circulation steam generator system known in which a controller block a characterizing the amount of fuel filtered into the burner Measured value can be fed.
  • a controller block a characterizing the amount of fuel filtered into the burner Measured value can be fed.
  • a setpoint determined by the controller block for the amount of feed water depend on the heat output could.
  • the controlled variable is expediently the evaporator throughput, i.e. the amount of the evaporator on the medium side per unit of time fed feed water.
  • The is advantageous Controller module with one connected to the feed water line Flow sensor connected.
  • the vertical throttle cable of the steam generator 1 according to FIG. 1 with rectangular cross section is formed by a surrounding wall 2, at the bottom of the throttle cable into a funnel-shaped Floor 3 merges.
  • Evaporator tubes 4 of the surrounding wall 2 are gas-tightly connected on their long sides, e.g. welded.
  • the bottom 3 includes a not shown Discharge opening 3a for ashes.
  • the lower region of the surrounding wall 2 forms the one with Number of burners 5 provided combustion chamber 6 of the continuous steam generator 1.
  • the medium side i.e. of feed water or a water / water-steam mixture, parallel from bottom to top - or in the case of evaporator tube groups one behind the other - evaporator tubes flowed through 4 of the surrounding wall 2 are with their entry ends to an inlet header 8 and with its outlet ends connected to an outlet header 10.
  • the entry collector 8 and the outlet collector 10 are located outside the throttle cable and are e.g. each by an annular Tube formed.
  • the inlet header 8 is via a line 12 and one Collector 14 with the output of a high pressure preheater or Economizers 15 connected.
  • the heating surface of the economizer 15 is in a room above the combustion chamber 6 Surrounding wall 2 arranged.
  • the economizer 15 is on the input side via a collector 16 with a feed water tank 18 connected, in a manner not shown connected to a steam turbine via a condenser and is thus connected in their water-steam cycle.
  • the outlet header 10 is via a water-steam separation vessel 20 and a line 22 connected to a high pressure superheater 24, the inside the perimeter wall 2 between the economizer 15 and the combustion chamber 5 is arranged.
  • the high pressure superheater 24 is on the output side during operation via a collector 26 with a high-pressure part of the steam turbine connected.
  • Between the high pressure superheater 24 and the Economizer 15 is an intermediate superheater within the surrounding wall 2 28 provided, the collector 30, 32 between the high pressure part and a medium pressure part of the steam turbine is switched.
  • feed water line 17 In the feed water line 17 are in the direction of flow Feed water S from the feed water tank 18 in a row a motor-operated feed water pump 34 and a means Steam D heated heat exchanger 36 for preheating the feed water as well as a valve 38 and a flow sensor 40 switched.
  • the flow sensor 40 is used to determine the per unit time amount fed through the feed water line 17 Feed water S.
  • the per unit of time conducted via line 17 Amount of feed water S corresponds to that from the Evaporator tubes 4 feed water quantity supplied to existing evaporators and thus the evaporator throughput.
  • Another flow sensor 42 is in a fuel line 44 switched, the partial lines 46 in the burner 5 opens.
  • a valve 48 is provided in the fuel line 44 Setting of the or each burner 5 supplied per unit of time Amount of fuel B switched.
  • the flow sensors 40 and 42 are via signal lines 50 and 52, into which transducers 51 and 53 are connected, with one Controller block 54 connected.
  • the controller block 54 is over a line 56 is connected to the valve 38.
  • the controller block 54 can alternatively also be shown with a dashed line Line 56 'with the motor-operated feed water pump 34 be connected.
  • the controller block 54 and the flow sensor 40, 42 and that to adjust the amount of Feed water S serving valve 38 are part of a control device 58 for starting the once-through steam generator 1.
  • the feed water pump 34 can also be used even by changing their speed to adjust the Amount of the feed water fed through the feed water line 17 S can be used.
  • the control device 58 is used to adjust the evaporator throughput depending on the or each burner 5 amount of fuel supplied per unit of time during a start-up process.
  • the controller block 54 via the signal line 50 the measured by means of the flow sensor 40 current value of the amount of the evaporator, i.e. the Evaporator tubes 4, amount of the supplied per unit of time Feed water S supplied.
  • This the controller block 54 of the value supplied to the flow sensor 42 corresponds to the current one Evaporator throughput VD ( Figure 2).
  • the Controller block 54 the current value via the signal line 52 the combustion heat output FW (FIG. 2) in the combustion chamber 6 fed.
  • the Amount of the burners 5 via the fuel line 44 to current time supplied fuel B determined.
  • This Fuel throughput is converted into the converter 53 corresponding combustion heat output FW converted.
  • the controller block 54 becomes a comparison of the current combustion heat output FW and the current evaporator throughput VD determines a manipulated variable SG, which via line 56 or 56 'the valve 38 or the speed of the feed water pump 34 controls.
  • the evaporator throughput VD serves as a control variable.
  • a minimum throughput of less than 15% of the throughput at 100% load is preferably already set.
  • this minimum throughput is within a bandwidth BD of 5% to 10% of the throughput at 100% load, ie the maximum evaporator throughput VD.
  • This minimum throughput of 5% to 10% of the maximum evaporator throughput VD is set at the start of the start-up process.
  • the first burner 5 is ignited at a point in time t 1 , the heating output FW initially rising suddenly.
  • the combustion heat output FW initially increases gradually. From a furnace heat output FW of approximately 6% of the maximum furnace heat output, the furnace heat output FW increases continuously over time t. With the continuous increase in the combustion heat output FW, the evaporator throughput VD is also continuously increased.
  • the evaporator throughput VD is preferably set such that the percentage evaporator throughput VD related to the throughput at full load within the bandwidth BD of 5% to 10% of the throughput at full load is equal to the percentage firing heat output FW related to full load, ie 100% load .
  • the bandwidth BD, within which the evaporator throughput VD increases with the thermal output FW over time, is limited by an upper limit line OG and a lower limit line UG.
  • the evaporator throughput VD is preferably set to increase in time with the combustion heat output FW during the start-up process.
  • the bandwidth BD - as can be seen in FIG. 2 - is asymmetrical, a deviation of the percentage evaporator throughput VD from the percentage combustion heat output upwards by 3% to 8% and downwards by 2% to 3% of the throughput at 100% load is permissible is.
  • the bandwidth BD is 5% in the exemplary embodiment, so that a deviation A o from the thermal output FW upwards by 3% and a deviation A u from the thermal output FW downwards by 2% is permissible.
  • a minimum throughput of less than 15% i.e. also at a limitation of the evaporator throughput VD at the beginning of the Starting process to preferably 5% to 10% of the throughput at full load there is an even upward flow in all Evaporator tubes 4 guaranteed.
  • Start-up losses are kept particularly low because the most efficient in terms of efficiency even at low loads Continuous operation is achieved.
  • Circulation pumps or waste heat exchangers commonly used up to now can be omitted with this start-up procedure.
  • the water-steam separation vessel 20 shown in FIG Water can be pumped directly via a pump Return line 62, in which a valve 63 is connected, in the feed water tank 18 and thus in the water-steam cycle to be led back. Since there is also a return of the feed water S from the water-steam separation vessel 20 in the flow direction of the feed water S in front of the evaporator 4 or in front of the economizer 15 and thus behind the feed water tank 18 can be omitted, a particularly simple regulation of the start-up process reached.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Control Of Steam Boilers And Waste-Gas Boilers (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)

Description

Die Erfindung bezieht sich auf ein Verfahren zum Anfahren eines Durchlaufdampferzeugers mit einer eine Anzahl von Brennern für einen fossilen Brennstoff aufweisenden Brennkammer, deren gasdichte Umfassungswand aus mindestens annähernd vertikal verlaufend angeordneten Verdampferrohren gebildet ist, die mediumseitig von unten nach oben durchsetzt werden. Sie bezieht sich weiter auf eine Vorrichtung zur Durchführung des Verfahrens.The invention relates to a method for starting a Continuous steam generator with a number of burners for a fossil fuel combustion chamber, whose gastight surrounding wall is at least approximately vertical extending evaporator tubes is formed, which are penetrated from bottom to top on the medium side. she further relates to a device for performing the Procedure.

Während in einem Naturumlaufdampferzeuger ein im Umlauf geführtes Wasser-Wasserdampf-Gemisch nur teilweise verdampft, führt bei einem Durchlaufdampferzeuger die Beheizung von die gasdichten Umfassungswände einer Brennkammer bildenden vertikal angeordneten Verdampferrohren zu einer vollständigen Verdampfung des Strömungsmediums in den Verdampferrohren in einem Durchgang.While in a natural circulation steam generator a circulating one Water-steam mixture only partially evaporated, performs the heating of the in a continuous steam generator gas-tight surrounding walls of a combustion chamber forming vertically arranged evaporator tubes for complete evaporation of the flow medium in the evaporator tubes in one Continuity.

Üblicherweise wird dem Durchlauf strom des Verdampfers des Durchlaufdampferzeugers - und häufig auch einem im Durchlaufdampferzeuger angeordneten rauchgasbeheizten Vorwärmer oder Economizer - während des Anfahrens ein Umlaufstrom überlagert, um durch entsprechend hohe Geschwindigkeiten in den Rohren diese sicher zu kühlen. Dabei beträgt der aus Durchlauf strom und überlagertem Umlaufstrom bestehende Mindeststrom bei vertikal angeordneten Rohren in den Umfassungswänden der Brennkammer zwischen 25 % und 50 % des Volllaststroms. Dies bedeutet, daß beim Anfahrvorgang die Dampferzeugerlast erst auf mindestens 25 % bis 50 % gesteigert werden muß, bevor der wirkungsgradmäßig günstige Durchlaufbetrieb mit seinen hohen Dampfaustrittstemperaturen erreicht wird. Usually the flow of the evaporator is the Continuous steam generator - and often also one in the continuous steam generator arranged smoke gas heated preheater or Economizer - a circulating current is superimposed during startup, order by correspondingly high speeds in the Pipes to cool them safely. The is from pass current and superimposed circulating current existing minimum current with vertically arranged pipes in the surrounding walls the combustion chamber between 25% and 50% of the full load flow. This means that the steam generator load when starting only be increased to at least 25% to 50% must, before the efficient continuous operation with its high steam outlet temperatures.

Wie aus der europäischen Patentschrift 0 054 601 B1 bekannt ist, wird daher üblicherweise zum Anfahren und in einem unter einer bestimmten Grenzlast von 50 % der Vollast liegenden Lastbereich die Menge des von einer Speisepumpe zu fördernden Strömungsmediums vorzugsweise konstant gehalten. Dabei ist der Förderstrom der Speisepumpe gleich dem Verdampferdurchsatz. Bei dieser Betriebsweise sind die mit dem Zünden eines ersten Brenners des Durchlaufdampferzeugers beginnenden und mit Erreichen des Durchlaufbetriebs mit seinen hohen Dampftemperaturen endenden Anfahrzeiten sehr lang. Dies hat verhältnismäßig hohe Anfahrverluste zur Folge, da deren Höhe wesentlich von den Anfahrzeiten beeinflußt werden.As known from European patent 0 054 601 B1 is therefore usually used for starting off and in an under a certain limit load of 50% of the full load Load range is the amount of water to be pumped by a feed pump Flow medium preferably kept constant. It is the flow of the feed pump is equal to the evaporator throughput. In this mode of operation, the one with the ignition first burner of the once-through steam generator and when continuous operation with its high steam temperatures is reached approach times very long. This has been proportionate high start-up losses as their height is significant be influenced by the starting times.

Auch bei dem aus der europäischen Patentanmeldung 0 439 765 bekannten Dampferzeuger ist beim Anfahren im wesentlichen ein konstanter Speisewasserstrom vorgesehen. Gegen Ende des Anfahrvorgangs kann bei diesem Dampferzeuger aber auch eine Variation des Speisewasserstrom vorgesehen sein.Also in the case of the European patent application 0 439 765 known steam generator is essentially a when starting constant feed water flow is provided. Towards the end of the starting process can also be a variation with this steam generator of the feed water flow can be provided.

Im Zusammenhang mit den Bemühungen zur Steigerung des mittleren, auch den Anfahrvorgang umfassenden Wirkungsgrades einer Kraftwerksanlage, insbesondere durch Realisierung hoher und höchster Dampfzustände, kommt daher einer Reduzierung der Anfahrverluste erhöhte Bedeutung zu. Weiterhin ist bei einer derartigen Kraftwerksanlage zu beachten, daß der für den Anfahrvorgang zu installierende Umwälzkreislauf, der üblicherweise mindestens eine Umwälzpumpe mit entsprechendem Zubehör oder einen Ablaufwärmetauscher umfaßt, mit einem hohen technischen Aufwand verbunden ist und daher hohe Investitionskosten erfordert. Diese Investitionskosten nehmen mit der Realisierung hoher und höchster Dampfdrücke stark zu.In the context of efforts to increase the middle, also the start-up process comprehensive efficiency Power plant, especially by realizing high and highest steam conditions, there is therefore a reduction in start-up losses increased importance too. Furthermore, one Such power plant to note that the start-up process Circulation circuit to be installed, which is usually at least one circulation pump with appropriate accessories or comprises a drain heat exchanger with a high technical Effort and therefore high investment costs required. These investment costs increase with the Realization of high and highest vapor pressures strongly.

Der Erfindung liegt daher die Aufgabe zugrunde, ein Verfahren und eine Vorrichtung zum Betreiben eines Durchlaufdampferzeugers mit niedrigen Anfahrverlusten anzugeben. Dies soll bei einer zur Durchführung des Verfahrens geeigneten Vorrichtung mit geringem technischen Aufwand erreicht werden.The invention is therefore based on the object of a method and a device for operating a once-through steam generator to be indicated with low start-up losses. This is said to a device suitable for carrying out the method can be achieved with little technical effort.

Bezüglich des Verfahrens wird diese Aufgabe erfindungsgemäß dadurch gelöst, daß der Verdampferdurchsatz in Abhängigkeit von der dem oder jedem Brenner pro Zeiteinheit zugeführten Brennstoffmenge eingestellt wird, wobei der Verdampferdurchsatz proportional zur Feuerwärmeleistung in der Brennkammer eingestellt wird.With regard to the method, this object is achieved according to the invention solved in that the evaporator throughput depending of the or each burner supplied per unit of time Fuel amount is set, the evaporator throughput proportional to the heat output in the combustion chamber is set.

Mit anderen Worten: Da die auf Vollast, d.h. auf 100 % Last, bezogene prozentuale Feuerungswärmeleistung als Ziel- oder Sollwert (setpoint) für den prozentualen Verdampferdurchsatz gewählt wird, wird der Verdampferdurchsatz, d.h. die Menge des dem Verdampfer pro Zeiteinheit zugeführten und diesen durchströmenden Mediums, bei erfindungsgemäßem Vorgehen innerhalb eines engen Toleranzbandes eingestellt.In other words, since the full load, i.e. on 100% load, Relative percentage of thermal output as target or Setpoint for the evaporator throughput percentage is selected, the evaporator throughput, i.e. the amount of the evaporator supplied per unit of time and this medium flowing through, with the procedure according to the invention within a narrow tolerance band.

Die Erfindung geht dabei von der Erkenntnis aus, daß ein Durchlaufdampferzeuger auch mit einer schnell steigenden Feuerleistung angefahren werden kann, da seine verhältnismäßig dünnwandigen Bauteile große Temperaturänderungsgeschwindigkeiten zulassen. Aufgrund der geringen Speichermasse des Verdampfers setzt eine rasche Dampfbildung ein, wodurch zur Überhitzung erzeugten Dampfes vorgesehene Überhitzerheizflächen gut gekühlt werden.The invention is based on the knowledge that a Continuous steam generator also with a rapidly increasing fire output can be approached because its proportionate thin-walled components have high rates of temperature change allow. Due to the low storage mass of the evaporator uses a rapid steam formation, which leads to Overheating heating surfaces provided generated steam be chilled well.

Den herkömmlichen Anfahr-Verfahren für Durchlaufdampferzeuger lag dabei die Annahme zugrunde, daß die Verdampferrohre der hochbeheizten Brennkammer nur dann gut gekühlt werden, wenn die Mediumströmung in den Rohren turbulent ist, was eine entsprechend hohe Massenstromdichte in den Rohren auch während des Anfahrvorganges voraussetzt.The conventional start-up procedure for continuous steam generators was based on the assumption that the evaporator tubes of highly heated combustion chamber can only be cooled well if the medium flow in the pipes is turbulent, which is a corresponding high mass flow density in the pipes even during of the start-up process.

Die Erfindung geht nun von der Überlegung aus, daß auch bei sehr niedrigen Massenstromdichten und zugleich hohen Warmestromdichten ein sehr guter Wärmeübergang von einer Rohrwand an das Strömungsmedium vorhanden ist, wenn sich eine sogenannte Ringströmung ausbildet. Neuere Untersuchungen zum inneren Wärmeübergang in vertikalen Rohren haben überraschenderweise auch bei sehr niedrigen Massenstromdichten die Ausbildung einer derartigen Ringströmung bestätigt, bei der stets ein großer Wasseranteil im durch ein Wasser-Wasser/ Dampf-Gemisch gebildeten Strömungsmedium an die Rohrwand transportiert wird. Dies führt auch bei einem unterhalb von etwa 25 % des Vollaststromes, d.h. des Verdampferdurchsatzes bei 100 % Last, liegenden Mindeststrom zu dem erwähnten guten Wärmeübergang.The invention is based on the consideration that also very low mass flow densities and at the same time high heat flow densities a very good heat transfer from a pipe wall to the flow medium when there is a so-called Ring flow forms. Recent studies on the inside Heat transfer in vertical pipes has surprisingly training even at very low mass flow densities of such a ring flow confirmed in the always a large proportion of water in a water-water / Steam mixture formed flow medium to the pipe wall is transported. This also leads to a below about 25% of the full load current, i.e. the evaporator throughput at 100% load, minimum current lies to the good mentioned Heat transfer.

Das beschriebene wärmetechnische Phänomen wird bei dem Verfahren zum Betreiben eines Durchlaufdampferzeugers während des Anfahrens insbesondere dann besonders günstig umgesetzt, wenn ausgehend von einem Mindestdurchsatz des Verdampfers von weniger als 15 %, vorzugsweise weniger als 10 %, z.B. 5 % des Vollastdurchsatzes der Verdampferdurchsatz nur in einer schmalen Bandbreite von der prozentualen, auf Vollast bezogenen Feuerungswärmeleistung abweicht.The described thermal engineering phenomenon is used in the process to operate a continuous steam generator during the start-up was implemented particularly cheaply, if based on a minimum evaporator throughput of less than 15%, preferably less than 10%, e.g. 5% of Full load throughput the evaporator throughput only in one narrow range from the percentage, related to full load Furnace heat output deviates.

Zu Beginn des Anfahrvorgangs wird zweckmäßigerweise der Verdampferdurchsatz auf 5 % bis 10 % des Vollast-Durchsatzes begrenzt. Dadurch ist von Anfang an eine gleichmäßige Aufwärtsströmung in allen Verdampferrohren gewährleistet. Nach dem Zünden des ersten Brenners wird der Verdampferdurchsatz derart eingestellt, daß der auf den Vollast-Durchsatz bezogene prozentuale Verdampferdurchsatz innerhalb einer bestimmten Bandbreite gleich der auf Vollast bezogenen prozentualen Feuerungswärmeleistung ist. Dabei erstreckt sich die Bandbreite vorzugsweise zwischen 3 bis 8 % oberhalb und zwischen 2 bis 3 % unterhalb der über die Zeit ansteigenden, prozentualen Feuerungswärmeleistung. Diese Bedingung einer asymmetrischen Bandbreite gilt insbesondere für eine Feuerungswarmeleistung, bei der eine stabile Verbrennung sichergestellt ist.At the start of the start-up process, the evaporator throughput is expediently limited to 5% to 10% of full load throughput. This ensures a steady upward flow right from the start guaranteed in all evaporator tubes. After this Ignition of the first burner becomes the evaporator throughput set that related to full load throughput percentage evaporator throughput within a certain Bandwidth equal to the percentage based on full load Firing heat output is. The range extends preferably between 3 to 8% above and between 2 to 3% below the percentage increase over time Firing heat output. This condition is asymmetrical Bandwidth applies in particular to a heating output, which ensures stable combustion is.

Bezüglich der Vorrichtung zum Anfahren eines Durchlaufdampferzeugers mit einer eine Anzahl von Brennern für einen fossilen Brennstoff aufweisenden Brennkammer, deren gasdichte Umfassungswand aus mindestens annähernd vertikal verlaufend angeordneten Verdampferrohren gebildet ist, die mediumsseitig von unten nach oben durchströmbar sind, wird die genannte Aufgabe gelöst durch einen Reglerbaustein zur Einstellung der Menge des dem Verdampfer pro Zeiteinheit zugeführten Mediums in Abhängigkeit von der dem oder jedem Brenner pro Zeiteinheit zugeführten Brennstoffmenge. Dabei ist die durch eine vom Reglerbaustein ermittelte Stellgröße bestimmte Verdampferdurchsatzrate proportional zur aus der Brennstoffmenge ermittelten Feuerwärmeleistung. Der Reglerbaustein ist dabei verbunden mit einem in eine in den Verdampfer führende Speisewasserleitung geschalteten Stellglied und mit einem in eine an den oder jeden Brenner führenden Brennstoffleitung geschalteten zweiten Durchflußmeßfühler.Regarding the device for starting a continuous steam generator with a number of burners for a fossil Combustion chamber with fuel, its gas-tight Surrounding wall made of at least approximately vertical arranged evaporator tubes is formed, the medium side can flow from bottom to top, is called Task solved by a controller module for setting the Amount of medium supplied to the evaporator per unit of time depending on the or each burner per unit of time amount of fuel supplied. Here is the one The manipulated variable determined by the controller block determines the evaporator throughput rate proportional to the determined from the amount of fuel Fire heat output. The controller block is included connected to a feed water line leading into the evaporator switched actuator and with one in one connected to the or each burner leading fuel line second flow sensor.

Zwar ist aus der Druckschrift EP-A-0 308 596 eine Einrichtung zur Regelung der Speisewassermenge einer Naturumlauf-Dampferzeugeranlage bekannt, bei der einem Reglerbaustein ein eine den Brenner zugefilterte Brennstoffmenge charakterisierender Meßwert zuführbar ist. Aus dieser Druckschrift geht jedoch nicht hervor, wie ein vom Reglerbaustein ermittelter Sollwert für die Speisewassermenge von der Feuerwärmeleistung abhängen könnte.A device is indeed from the document EP-A-0 308 596 for regulating the amount of feed water in a natural circulation steam generator system known in which a controller block a characterizing the amount of fuel filtered into the burner Measured value can be fed. However, from this publication not like a setpoint determined by the controller block for the amount of feed water depend on the heat output could.

Die Regelgröße ist zweckmäßigerweise der Verdampferdurchsatz, d.h. die Menge der den Verdampfer mediumseitig pro Zeiteinheit zugeführten Speisewassers. Vorteilhafterweise ist der Reglerbaustein mit einem in die Speisewasserleitung geschalteten Durchflußmeßfühler verbunden.The controlled variable is expediently the evaporator throughput, i.e. the amount of the evaporator on the medium side per unit of time fed feed water. The is advantageous Controller module with one connected to the feed water line Flow sensor connected.

Die mit der Erfindung erzielten Vorteile bestehen insbesondere darin, daß durch einen mit der Feuerungswärmeleistung gleichmäßig ansteigenden Verdampferdurchsatz während eines Anfahrvorgangs eines Durchlaufdampferzeugers die Anfahrverluste sinken, da bereits bei niedriger Last ein wirkungsgradmäßig günstiger Durchlaufbetrieb erreicht wird. Dabei können vorteilhafterweise die Umwälzpumpen oder Ablaufwärmetauscher entfallen, so daß die Investitionskosten reduziert und die Anlagenverfügbarkeit erhöht sind. The advantages achieved with the invention are in particular in that through one with the combustion heat output steadily increasing evaporator throughput during a Starting process of a once-through steam generator the start-up losses decrease, since even at low load an efficiency favorable continuous operation is achieved. You can advantageously the circulation pumps or drain heat exchangers are eliminated so that the investment costs are reduced and the Plant availability is increased.

Da auch eine Rückführung von abgeschiedenem Wasser aus einer dem Verdampfer nachgeschalteten Wasser-Dampf-Trenneinrichtung in eine Stelle zwischen Speisepumpe und Verdampfer entfällt, ist bei einer Schaltung ohne Umwälzpumpe die Einstellung des Anfahrvorgangs wesentlich vereinfacht. Dadurch werden Schwankungen der Enthalpie bei Eintritt des Wasserstroms in den Verdampfer und damit auch Schwankungen des aus dem Verdampfer austretenden Wasserstroms vermieden.Since also a return of separated water from a the water-steam separator downstream of the evaporator in a place between the feed pump and the evaporator, is the setting of the in a circuit without circulation pump The start-up process is significantly simplified. This causes fluctuations the enthalpy when the water flow enters the Evaporator and therefore also fluctuations in the evaporator escaping water flow avoided.

Ein Ausführungsbeispiel der Erfindung wird anhand einer Zeichnung näher erläutert. Darin zeigen:

Figur 1
schematisch einen Durchlaufdampferzeuger mit vertikalem Gaszug und einer Anfahr-Regelvorrichtung, und
Figur 2
ein Anfahr-Diagramm für einen Verdampferdurchsatz und eine Feuerwärmeleistung.
An embodiment of the invention is explained in more detail with reference to a drawing. In it show:
Figure 1
schematically a continuous steam generator with a vertical throttle cable and a start-up control device, and
Figure 2
a start-up diagram for an evaporator throughput and a heat output.

Der vertikale Gaszug des Dampferzeugers 1 gemäß Figur 1 mit rechteckigem Querschnitt ist durch eine Umfassungswand 2 gebildet, die am Unterende des Gaszugs in einen trichterförmigen Boden 3 übergeht. Verdampferrohre 4 der Umfassungswand 2 sind an ihren Längsseiten gasdicht miteinander verbunden, z.B. verschweißt. Der Boden 3 umfaßt eine nicht naher dargestellte Austragsöffnung 3a für Asche.The vertical throttle cable of the steam generator 1 according to FIG. 1 with rectangular cross section is formed by a surrounding wall 2, at the bottom of the throttle cable into a funnel-shaped Floor 3 merges. Evaporator tubes 4 of the surrounding wall 2 are gas-tightly connected on their long sides, e.g. welded. The bottom 3 includes a not shown Discharge opening 3a for ashes.

Der untere Bereich der Umfassungswand 2 bildet die mit einer Anzahl von Brennern 5 versehene Brennkammer 6 des Durchlaufdampferzeugers 1.The lower region of the surrounding wall 2 forms the one with Number of burners 5 provided combustion chamber 6 of the continuous steam generator 1.

Die mediumseitig, d.h. von Speisewasser oder einem Wasser/Wasser-Dampf-Gemisch, von unten nach oben parallel - oder bei Verdampferrohrgruppen hintereinander - durchströmten Verdampferrohre 4 der Umfassungswand 2 sind mit ihren Eintrittsenden an einen Eintrittssammler 8 und mit ihren Austrittsenden an einen Austrittssammler 10 angeschlossen. Der Eintrittssammler 8 und der Austrittssammler 10 befinden sich außerhalb des Gaszugs und sind z.B. jeweils durch ein ringförmiges Rohr gebildet.The medium side, i.e. of feed water or a water / water-steam mixture, parallel from bottom to top - or in the case of evaporator tube groups one behind the other - evaporator tubes flowed through 4 of the surrounding wall 2 are with their entry ends to an inlet header 8 and with its outlet ends connected to an outlet header 10. The entry collector 8 and the outlet collector 10 are located outside the throttle cable and are e.g. each by an annular Tube formed.

Der Eintrittssammler 8 ist über eine Leitung 12 und einen Sammler 14 mit dem Ausgang eines Hochdruck-Vorwarmers oder Economizers 15 verbunden. Die Heizfläche des Economizers 15 ist in einem oberhalb der Brennkammer 6 liegenden Raum der Umfassungswand 2 angeordnet. Der Economizer 15 ist eingangsseitig über einen Sammler 16 mit einem Speisewasserbehälter 18 verbunden, der in nicht näher dargestellter Art und Weise über einen Kondensator mit einer Dampfturbine verbunden und somit in deren Wasser-Dampf-Kreislauf geschaltet ist. The inlet header 8 is via a line 12 and one Collector 14 with the output of a high pressure preheater or Economizers 15 connected. The heating surface of the economizer 15 is in a room above the combustion chamber 6 Surrounding wall 2 arranged. The economizer 15 is on the input side via a collector 16 with a feed water tank 18 connected, in a manner not shown connected to a steam turbine via a condenser and is thus connected in their water-steam cycle.

Der Austrittssammler 10 ist über ein Wasser-Dampf-Trenngefäß 20 und eine Leitung 22 mit einem Hochdruck-Überhitzer 24 verbunden, der innerhalb der Umfassungswand 2 zwischen dem Economizer 15 und der Brennkammer 5 angeordnet ist. Der Hochdruck-Überhitzer 24 ist während des Betriebs ausgangsseitig über einen Sammler 26 mit einem Hochdruckteil der Dampfturbine verbunden. Zwischen dem Hochdruck-Überhitzer 24 und dem Economizer 15 ist innerhalb der Umfassungswand 2 ein Zwischenüberhitzer 28 vorgesehen, der über Sammler 30, 32 zwischen dem Hochdruckteil und einem Mitteldruckteil der Dampfturbine geschaltet ist.The outlet header 10 is via a water-steam separation vessel 20 and a line 22 connected to a high pressure superheater 24, the inside the perimeter wall 2 between the economizer 15 and the combustion chamber 5 is arranged. The high pressure superheater 24 is on the output side during operation via a collector 26 with a high-pressure part of the steam turbine connected. Between the high pressure superheater 24 and the Economizer 15 is an intermediate superheater within the surrounding wall 2 28 provided, the collector 30, 32 between the high pressure part and a medium pressure part of the steam turbine is switched.

In die Speisewasserleitung 17 sind in Strömungsrichtung des Speisewassers S aus dem Speisewasserbehälter 18 hintereinander eine motorbetriebene Speisewasserpumpe 34 und ein mittels Dampf D beheizter Wärmetauscher 36 zur Speisewasservorwärmung sowie ein Ventil 38 und ein Durchflußmeßfühler 40 geschaltet. Der Durchflußmeßfühler 40 dient zur Ermittlung der pro Zeiteinheit über die Speisewasserleitung 17 geführten Menge an Speisewasser S. Die pro Zeiteinheit über die Leitung 17 geführte Menge des Speisewassers S entspricht der dem aus den Verdampferrohren 4 bestehenden Verdampfer zugeführten Speisewassermenge und somit dem Verdampferdurchsatz.In the feed water line 17 are in the direction of flow Feed water S from the feed water tank 18 in a row a motor-operated feed water pump 34 and a means Steam D heated heat exchanger 36 for preheating the feed water as well as a valve 38 and a flow sensor 40 switched. The flow sensor 40 is used to determine the per unit time amount fed through the feed water line 17 Feed water S. The per unit of time conducted via line 17 Amount of feed water S corresponds to that from the Evaporator tubes 4 feed water quantity supplied to existing evaporators and thus the evaporator throughput.

Ein weiterer Durchflußmeßfühler 42 ist in eine Brennstoffleitung 44 geschaltet, die über Teilleitungen 46 in die Brenner 5 mündet. In die Brennstoffleitung 44 ist ein Ventil 48 zur Einstellung der dem oder jedem Brenner 5 pro Zeiteinheit zugeführten Menge an Brennstoff B geschaltet.Another flow sensor 42 is in a fuel line 44 switched, the partial lines 46 in the burner 5 opens. A valve 48 is provided in the fuel line 44 Setting of the or each burner 5 supplied per unit of time Amount of fuel B switched.

Die Durchflußmeßfühler 40 und 42 sind über Signalleitungen 50 und 52, in die Wandler 51 bzw. 53 geschaltet sind, mit einem Reglerbaustein 54 verbunden. Der Reglerbaustein 54 ist über eine Leitung 56 mit dem Ventil 38 verbunden. Der Reglerbaustein 54 kann alternativ auch über eine gestrichelt dargestellte Leitung 56' mit der motorbetriebenen Speisewasserpumpe 34 verbunden sein. Der Reglerbaustein 54 und die Durchflußmeßfühler 40, 42 sowie das zur Einstellung der Menge des Speisewassers S dienende Ventil 38 sind Bestandteil einer Regelvorrichtung 58 zum Anfahren des Durchlaufdampferzeugers 1. Anstelle des Ventils 38 kann auch die Speisewasserpumpe 34 selbst durch Veränderung ihrer Drehzahl zur Einstellung der Menge des über die Speisewasserleitung 17 geführten Speisewassers S herangezogen werden.The flow sensors 40 and 42 are via signal lines 50 and 52, into which transducers 51 and 53 are connected, with one Controller block 54 connected. The controller block 54 is over a line 56 is connected to the valve 38. The controller block 54 can alternatively also be shown with a dashed line Line 56 'with the motor-operated feed water pump 34 be connected. The controller block 54 and the flow sensor 40, 42 and that to adjust the amount of Feed water S serving valve 38 are part of a control device 58 for starting the once-through steam generator 1. Instead of the valve 38, the feed water pump 34 can also be used even by changing their speed to adjust the Amount of the feed water fed through the feed water line 17 S can be used.

Die Regelvorrichtung 58 dient zur Einstellung des Verdampferdurchsatzes in Abhängigkeit von der dem oder jedem Brenner 5 pro Zeiteinheit zugeführten Brennstoffmenge während eines Anfahrvorgangs. Dazu wird dem Reglerbaustein 54 über die Signalleitung 50 der mittels des Durchflußmeßfühlers 40 gemessene aktuelle Wert der Menge des dem Verdampfer, d.h. den Verdampferrohren 4, pro Zeiteinheit zugeführten Menge des Speisewassers S zugeführt. Dieser dem Reglerbaustein 54 von dem Durchflußmeßfühler 42 zugeführte Wert entspricht dem aktuellen Verdampferdurchsatz VD (Figur 2). Außerdem wird dem Reglerbaustein 54 über die Signalleitung 52 der aktuelle Wert der Feuerungswärmeleistung FW (Figur 2) in der Brennkammer 6 zugeführt. Dazu wird mittels des Durchflußmeßfühlers 42 die Menge des den Brennern 5 über die Brennstoffleitung 44 zum aktuellen Zeitpunkt zugeführten Brennstoffs B ermittelt. Dieser Brennstoffdurchsatz wird mittels des Wandlers 53 in die entsprechende Feuerungswärmeleistung FW umgewandelt. Im Reglerbaustein 54 wird aus einem Vergleich der aktuellen Feuerungswärmeleistung FW und des aktuellen Verdampferdurchsatzes VD eine Stellgröße SG ermittelt, die über die Leitung 56 oder 56' das Ventil 38 bzw. die Drehzahl der Speisewasserpumpe 34 steuert. Dabei wird die Menge des über die Speisewasserleitung 17 geführten Speisewassers S und damit der Verdampferdurchsatz VD proportional zur Feuerungswärmeleistung FW in der Brennkammer 6 eingestellt, wobei der Verdampferdurchsatz VD als Regelgröße dient.The control device 58 is used to adjust the evaporator throughput depending on the or each burner 5 amount of fuel supplied per unit of time during a start-up process. For this purpose, the controller block 54 via the signal line 50 the measured by means of the flow sensor 40 current value of the amount of the evaporator, i.e. the Evaporator tubes 4, amount of the supplied per unit of time Feed water S supplied. This the controller block 54 of the value supplied to the flow sensor 42 corresponds to the current one Evaporator throughput VD (Figure 2). In addition, the Controller block 54 the current value via the signal line 52 the combustion heat output FW (FIG. 2) in the combustion chamber 6 fed. For this purpose, the Amount of the burners 5 via the fuel line 44 to current time supplied fuel B determined. This Fuel throughput is converted into the converter 53 corresponding combustion heat output FW converted. In the controller block 54 becomes a comparison of the current combustion heat output FW and the current evaporator throughput VD determines a manipulated variable SG, which via line 56 or 56 'the valve 38 or the speed of the feed water pump 34 controls. Thereby the amount of the feed water pipe 17 guided feed water S and thus the evaporator throughput VD proportional to the combustion heat output FW in the combustion chamber 6 set, the evaporator throughput VD serves as a control variable.

Der zeitabhängige Verlauf des Verdampferdurchsatzes VD und der Feuerungswärmeleistung FW ist in Figur 2 dargestellt. The time-dependent course of the evaporator throughput VD and the combustion heat output FW is shown in Figure 2.

Während die Abszisse die Zeitachse darstellt, sind auf der Ordinate Prozentzahlen aufgetragen, die auf den maximalen Verdampferdurchsatz (Verdampferdurchsatz bei 100 % Last) und auf die maximale Feuerungswärmeleistung (Feuerungswärmeleistung bei 100 % Last) bezogen sind.While the abscissa represents the time axis, are on the Ordinate percentages plotted on the maximum Evaporator throughput (evaporator throughput at 100% load) and to the maximum combustion heat output (combustion heat output at 100% load).

Zum Zeitpunkt t0, d.h. vor dem Zünden eines ersten Brenners 5, wird vorzugsweise bereits ein Mindestdurchsatz von weniger als 15 % des Durchsatzes bei 100 % Last (Vollastdurchsatz) eingestellt. Im Ausführungsbeispiel liegt dieser Mindestdurchsatz innerhalb einer Bandbreite BD von 5 % bis 10 % des Durchsatzes bei 100 % Last, d.h. des maximalen Verdampferdurchsatzes VD. Dieser Mindestdurchsatz von 5 % bis 10 % des maximalen Verdampferdurchsatzes VD wird zu Beginn des Anfahr-vorgangs eingestellt.At time t 0 , ie before the ignition of a first burner 5, a minimum throughput of less than 15% of the throughput at 100% load (full load throughput) is preferably already set. In the exemplary embodiment, this minimum throughput is within a bandwidth BD of 5% to 10% of the throughput at 100% load, ie the maximum evaporator throughput VD. This minimum throughput of 5% to 10% of the maximum evaporator throughput VD is set at the start of the start-up process.

Während des Vorgangs wird zu einem Zeitpunkt t1 der erste Brenner 5 gezündet, wobei die Feuerungswarmeleistung FW zunächst sprunghaft ansteigt. Durch Zünden eines zweiten Brenners 5 zum Zeitpunkt t2 und eines dritten Brenners 5 zum Zeitpunkt t3 steigt die Feuerungswärmeleistung FW zunächst stufenweise an. Ab einer Feuerungswärmeleistung FW von etwa 6 % der maximalen Feuerungswärmeleistung steigt die Feuerungswärmeleistung FW kontinuierlich über die Zeit t an. Mit dem kontinuierlichen Anstieg der Feuerungswärmeleistung FW wird auch der Verdampferdurchsatz VD kontinuierlich erhöht. Dabei wird der Verdampferdurchsatz VD vorzugsweise derart eingestellt, daß der auf den Durchsatz bei Vollast bezogene prozentuale Verdampferdurchsatz VD innerhalb der Bandbreite BD von 5 % bis 10 % des Durchsatzes bei Vollast gleich der auf Vollast, d.h. auf 100 % Last, bezogenen prozentualen Feuerungswärmeleistung FW ist. Die Bandbreite BD, innerhalb der der Verdampferdurchsatz VD mit der Feuerungswärmeleistung FW über die Zeit ansteigt, ist nach oben begrenzt durch eine obere Grenzlinie OG und nach unten durch eine untere Grenzlinie UG. During the process, the first burner 5 is ignited at a point in time t 1 , the heating output FW initially rising suddenly. By igniting a second burner 5 at time t 2 and a third burner 5 at time t 3 , the combustion heat output FW initially increases gradually. From a furnace heat output FW of approximately 6% of the maximum furnace heat output, the furnace heat output FW increases continuously over time t. With the continuous increase in the combustion heat output FW, the evaporator throughput VD is also continuously increased. The evaporator throughput VD is preferably set such that the percentage evaporator throughput VD related to the throughput at full load within the bandwidth BD of 5% to 10% of the throughput at full load is equal to the percentage firing heat output FW related to full load, ie 100% load . The bandwidth BD, within which the evaporator throughput VD increases with the thermal output FW over time, is limited by an upper limit line OG and a lower limit line UG.

Vorzugsweise wird der Verdampferdurchsatz VD während des Anfahrvorgangs gleichmäßig mit der Feuerungswärmeleistung FW zeitlich ansteigend eingestellt. Dabei ist die Bandbreite BD - wie aus der Figur 2 ersichtlich - asymmetrisch, wobei eine Abweichung des prozentualen Verdampferdurchsatzes VD von der prozentualen Feuerungswärmeleistung nach oben um 3 % bis 8 % und nach unten um 2 % bis 3 % des Durchsatzes bei 100 % Last zulässig ist. Die Bandbreite BD beträgt im Ausführungsbeispiel 5 %, so daß eine Abweichung Ao von der Feuerungswärmeleistung FW nach oben um 3 % und eine Abweichung Au von der Feuerungswärmeleistung FW nach unten um 2 % zulässig ist.The evaporator throughput VD is preferably set to increase in time with the combustion heat output FW during the start-up process. The bandwidth BD - as can be seen in FIG. 2 - is asymmetrical, a deviation of the percentage evaporator throughput VD from the percentage combustion heat output upwards by 3% to 8% and downwards by 2% to 3% of the throughput at 100% load is permissible is. The bandwidth BD is 5% in the exemplary embodiment, so that a deviation A o from the thermal output FW upwards by 3% and a deviation A u from the thermal output FW downwards by 2% is permissible.

Mittels der Regelvorrichtung 58 wird daher die Menge des dem Verdampfer 4 pro Zeiteinheit zugeführten Speisewassers S derart eingestellt, daß der Verdampferdurchsatz nur in einer schmalen Bandbreite von vorzugsweise 5 % bis 10 % von der prozentualen Feuerungswärmeleistung FW abweicht. Schon bei einem Mindestdurchsatz von weniger als 15 %, d.h. auch bei einer Begrenzung des Verdampferdurchsatzes VD zu Beginn des Anfahrvorgangs auf vorzugsweise 5 % bis 10 % des Durchsatzes bei Vollast wird eine gleichmäßige Aufwärtsströmung in allen Verdampferrohren 4 gewährleistet. Durch ein solches Anfahrverhalten werden Anfahrverluste besonders gering gehalten, da bereits bei niedriger Last der wirkungsgradmäßig günstige Durchlaufbetrieb erreicht wird.By means of the control device 58, the amount of the Evaporator 4 feed water S supplied per unit time set that the evaporator throughput only in one narrow bandwidth of preferably 5% to 10% of that percentage firing heat output FW deviates. Already at a minimum throughput of less than 15%, i.e. also at a limitation of the evaporator throughput VD at the beginning of the Starting process to preferably 5% to 10% of the throughput at full load there is an even upward flow in all Evaporator tubes 4 guaranteed. Through such a start-up behavior Start-up losses are kept particularly low because the most efficient in terms of efficiency even at low loads Continuous operation is achieved.

Bisher üblicherweise eingesetzte Umwälzpumpen oder Ablaufwärmetauscher können bei diesem Anfahr-Verfahren entfallen. In dem in Figur 1 dargestellten Wasser-Dampf-Trenngefäß 20 abgetrenntes Wasser kann ohne zusätzliche Pumpen direkt über eine Rückführleitung 62, in die ein Ventil 63 geschaltet ist, in den Speisewasserbehälter 18 und damit in den Wasser-Dampf-Kreislauf zurückgeführt werden. Da somit auch eine Rückführung des Speisewassers S aus dem Wasser-Dampf-Trenngefäß 20 in Strömungsrichtung des Speisewassers S vor den Verdampfer 4 oder vor den Economizer 15 und damit hinter den Speisewasserbehälter 18 entfallen kann, wird eine besonders einfache Regelung des Anfahr-Vorgangs erreicht.Circulation pumps or waste heat exchangers commonly used up to now can be omitted with this start-up procedure. In the water-steam separation vessel 20 shown in FIG Water can be pumped directly via a pump Return line 62, in which a valve 63 is connected, in the feed water tank 18 and thus in the water-steam cycle to be led back. Since there is also a return of the feed water S from the water-steam separation vessel 20 in the flow direction of the feed water S in front of the evaporator 4 or in front of the economizer 15 and thus behind the feed water tank 18 can be omitted, a particularly simple regulation of the start-up process reached.

Claims (7)

  1. Method for starting up a continuous-flow steam generator having a combustion chamber (6) which possesses a number of burners (5) for a fossil fuel (B) and the gas-tight containing wall (2) of which is formed from at least approximately vertically arranged evaporator tubes (4), through which the medium passes from the bottom upwards, characterized in that the evaporator throughput (VD) is set in dependence on the fuel quantity supplied to the or each burner (5) per unit time, the evaporator throughput (VD) being set in proportion to the firing heat capacity (FW) in the combustion chamber (6).
  2. Method according to Claim 1, characterized in that, at the commencement of the starting-up operation, a minimum throughput of the evaporator (4) of less than 15%, preferably less than 10%, of the throughput under 100% load (full-load throughput) is set.
  3. Method according to Claim 1 or 2, characterized in that the evaporator throughput (VD) is set so as to rise uniformly with the firing heat capacity (FW) in time.
  4. Method according to one of Claims 1 to 3, characterized in that the evaporator throughput (VD) is set in such a way that the percentage evaporator throughput (VD) related to the full-load throughput, within a bandwidth (BD), is equal to the percentage firing heat capacity (FW) related to full load.
  5. Method according to Claim 4, characterized in that the bandwidth (BD) is asymmetric, a deviation (Ao, Au) of the percentage evaporator throughput (VD) from the percentage firing heat capacity (FW) upwards by 3% to 8% and downwards by 2% to 3% of the full-load throughput being permissible.
  6. Apparatus for starting up a continuous-flow steam generator having a combustion chamber (6) which possesses a number of burners (5) for a fossil fuel (B) and the gas-tight containing wall (2) of which is formed from at least approximately vertically arranged evaporator tubes (4), having a controller module (54) for establishing a regulating variable (SG) determining the evaporator throughput (VD), the evaporator throughput (VD) determined by the regulating variable (SG) being proportional to the firing heat capacity (FW) established from the quantity of fuel (B) fed to the or each burner (5) per unit time, and the controller module (54) being connected to a regulating element (34, 38) connected into a feedwater conduit (17) leading to the evaporator (4) and to a throughflow-measuring sensor (42), connected into a fuel conduit (44) leading to the or each burner.
  7. Apparatus according to Claim 6, characterized in that the controller module (54) is connected to a throughflow-measuring sensor (40) connected into the feed-water conduit (17).
EP96900860A 1995-02-09 1996-01-29 Method and device for starting a once-through steam generator Expired - Lifetime EP0808440B1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE19504308A DE19504308C1 (en) 1995-02-09 1995-02-09 Method and device for starting a once-through steam generator
DE19504308 1995-02-09
PCT/DE1996/000115 WO1996024803A1 (en) 1995-02-09 1996-01-29 Method and device for starting a continuous steam generator

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EP0808440A1 EP0808440A1 (en) 1997-11-26
EP0808440B1 true EP0808440B1 (en) 1999-08-18

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EP (1) EP0808440B1 (en)
JP (1) JP3836139B2 (en)
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EP2065641A3 (en) * 2007-11-28 2010-06-09 Siemens Aktiengesellschaft Method for operating a continuous flow steam generator and once-through steam generator
EP2119880A1 (en) 2008-02-15 2009-11-18 Siemens Aktiengesellschaft Method for starting a steam producer
EP2180250A1 (en) * 2008-09-09 2010-04-28 Siemens Aktiengesellschaft Continuous-flow steam generator
EP2182278A1 (en) * 2008-09-09 2010-05-05 Siemens Aktiengesellschaft Continuous-flow steam generator
US9541282B2 (en) * 2014-03-10 2017-01-10 International Paper Company Boiler system controlling fuel to a furnace based on temperature of a structure in a superheater section
DE102014222682A1 (en) 2014-11-06 2016-05-12 Siemens Aktiengesellschaft Control method for operating a continuous steam generator
DE102017205382A1 (en) * 2017-03-30 2018-10-04 Siemens Aktiengesellschaft Water return in vertical forced-circulation steam generators
CN110006025A (en) * 2019-03-19 2019-07-12 广东美智智能科技有限公司 A kind of boiler pressure regulation method, equipment and storage medium based on PID
US20210341140A1 (en) 2020-05-01 2021-11-04 International Paper Company System and methods for controlling operation of a recovery boiler to reduce fouling

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DE59602799D1 (en) 1999-09-23
KR100427125B1 (en) 2004-08-02
IN186814B (en) 2001-11-17
CN1119554C (en) 2003-08-27
US5839396A (en) 1998-11-24
JPH10513543A (en) 1998-12-22
EP0808440A1 (en) 1997-11-26
DE19504308C1 (en) 1996-08-08
JP3836139B2 (en) 2006-10-18
CA2212517A1 (en) 1996-08-15
KR19980702020A (en) 1998-07-15
CA2212517C (en) 2001-04-10
WO1996024803A1 (en) 1996-08-15
CN1168172A (en) 1997-12-17

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