EP0544615B1 - Verfahren zum Betrieb eines Zwangdurchlaufdampferzeugers mit Schwachlastumwälzung - Google Patents

Verfahren zum Betrieb eines Zwangdurchlaufdampferzeugers mit Schwachlastumwälzung Download PDF

Info

Publication number
EP0544615B1
EP0544615B1 EP92810857A EP92810857A EP0544615B1 EP 0544615 B1 EP0544615 B1 EP 0544615B1 EP 92810857 A EP92810857 A EP 92810857A EP 92810857 A EP92810857 A EP 92810857A EP 0544615 B1 EP0544615 B1 EP 0544615B1
Authority
EP
European Patent Office
Prior art keywords
separator
level
economizer
valve
water
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.)
Revoked
Application number
EP92810857A
Other languages
German (de)
English (en)
French (fr)
Other versions
EP0544615A1 (de
Inventor
Christoph Dr. Ruchti
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.)
ABB AG Germany
Original Assignee
ABB Management AG
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=4257083&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0544615(B1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by ABB Management AG filed Critical ABB Management AG
Publication of EP0544615A1 publication Critical patent/EP0544615A1/de
Application granted granted Critical
Publication of EP0544615B1 publication Critical patent/EP0544615B1/de
Anticipated expiration legal-status Critical
Revoked legal-status Critical Current

Links

Images

Classifications

    • 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
    • F22B35/10—Control systems for steam boilers for steam boilers of forced-flow type of once-through type
    • F22B35/101—Control systems for steam boilers for steam boilers of forced-flow type of once-through type operating with superimposed recirculation during starting or low load periods, e.g. composite boilers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B35/00—Control systems for steam boilers

Definitions

  • the invention relates to a method for operating a once-through steam generator with low-load circulation and the following elements: feed pump, feed line, economizer, evaporator, water separator and at least one superheater, and with a circulation line connected to the water outlet of the separator and a circulation pump between the feed pump and the economizer.
  • the amount of food supplied to the steam generator is set in the upper load range as a function of the steam temperature and in the lower load range as a function of the water level in the water separator, either by changing the speed of the feed pump or by adjusting the Flow cross-section of a feed valve.
  • a switchover device was provided in the signal flow behind the steam temperature controller or the water level controller.
  • the measured superheat at the inlet of the first superheater can be used as a criterion for the switchover (CH-PS 673 697).
  • This switchover can also take place due to a race between two always active controllers (DE-B 2 149 127).
  • the level controller can only bring about a reduction and the temperature controller can only increase the feed quantity.
  • a purely load-dependent switchover criterion is often used, e.g. the feed pressure of the feed pump (CH-PS 517 266). Switching the controller is This is not always an advantage, since major changes in the supply of working fluid to the economiser can occur when switching. This is due to the fact that the signal coming from the temperature controller and the signal coming from the water level controller are not of the same size when switching and do not have to have the same sign, depending on whether the water level in the separator was rising or falling or at what height he was just now.
  • the invention has for its object to improve an operating method for a once-through steam generator with the elements listed above so that switching in the aforementioned manner is omitted.
  • the amount of food is always set so that a desired flow through the economizer results.
  • This desired flow through the economiser is formed as a function of the steam temperature, whereby a minimum flow must never be undercut, so that operation with a wet separator takes place with a fixed, minimal flow through the economiser.
  • the water level in the water separator is not - as before - influenced by changing the quantity of food, but by the valve located behind the circulation pump in the direction of flow of the working fluid. In this way, the previous switching is avoided without giving up the great advantage of the solution according to CH-PS 673 697 in comparison with even earlier methods, for example according to CH-PS 517 266.
  • An otherwise conventional valve which is arranged in the circulation line between the water separator and the circulation pump and serves the level control in the separator, does not have to be throttled because of the level control, so that no vapor bubbles can occur at the mixing point of the circulation water with the feed water. In this way, no cavitation can occur in the circulation pump.
  • the once-through steam generator with low-load circulation has an economizer 1, an evaporator 2, a water separator 3 and a superheater 4, which are connected in series in the direction of the working fluid flow.
  • a feed pump 5 is provided, which is connected via a feed line 6 to the inlet of the economizer 1.
  • a measuring device 7 for the amount of water flowing through the economizer is arranged in the line 6 near the inlet of the economizer 1.
  • the quantity measuring device 7 is connected to a comparison point 9 via a signal line 8 connected, which is also connected via a signal line 16 to the output of a feed control device 11, which is designed as a status controller with an observer and is described in the applicant's patent application No.
  • the feed control device 11 receives a temperature measurement signal which represents the actual value of the steam temperature and is taken off by means of a measuring device 13 at the outlet of the superheater 4. Further superheaters can be provided downstream of the measuring device 13 before the steam is supplied to consumers, not shown. The measuring device 13 can also be arranged between the water separator 3 and the superheater 4. Via a signal line 14, the feed control device 11 receives a target value for the steam temperature and via a signal line 15 a signal which represents the minimum amount of working fluid which has to flow through the economizer 1.
  • the minimum quantity signal becomes effective when the quantity of working fluid flowing through the economizer 1 drops to the minimum quantity, which is approximately 30% of the full load, during a load reduction.
  • the comparison point 9 belongs to a controller 17, the output of which is connected via a signal line 18 to the feed pump 5, which forms the actuator of the feed control loop.
  • the controller 17 can e.g. be designed as a PI controller.
  • a circulation line 20 is connected to the water outlet of the water separator 3 and contains a check valve 21 and a shut-off valve 22 one after the other in the flow direction.
  • the line 20 opens at 19 downstream of the feed pump 5 into the feed line 6, which contains a circulation pump 23 and a level control valve 24 below this mouth 19.
  • the the circulation pump 23 and the section 6 'of the feed line 6 containing the level control valve 24 is therefore also flowed through by water from the separator 3 during operation with a wet separator in addition to the feed water.
  • a line 25 with a non-return flap 26 is provided parallel to the line section 6 'and a portion of the quantity of feed conveyed by the feed pump flows through when the steam generator is under high load.
  • an injection water line is designated, which leads in a known, not shown manner to the superheater 4 or to some downstream superheaters.
  • a line 30 with a drain valve 31 which leads to a feed water tank (not shown) of the steam generating system.
  • the line 30 can also lead into the condenser or a special tank of the system.
  • a level control device 33 which, like the feed control device 11, is designed as a state controller with an observer.
  • the level control device 33 receives a measurement signal via a signal line 34, which represents the actual value of the water level in the separator 3.
  • the setpoint for the water level is supplied to the level control device 33 via a signal line 35.
  • the shut-off valve 22 is subject to a control signal which comes from the level control device 33 via a signal line 20 and whose function is described below.
  • the drain valve 31 is subordinate to a level measurement signal, which is taken from the signal line 34 and passed over a signal line 32 and whose function is also explained further below.
  • the water level 7.7 m is the target water level for the level control device 33 during normal circulation operation of the steam generator system.
  • the water levels of 1 m and 3 m play a role in the transition from operation with a wet separator to operation with a dry separator and vice versa, while the water levels of 10.7 m and 14.2 m play a role in the first start-up phase of the steam generator.
  • the drain valve 31 opens under the influence of the level measurement signal in the line 32 until it is 100% open at the mark 14.2 m , as shown in Fig.2a in the middle by the line B.
  • the shut-off valve 22 goes from the opening cross-section 100% to the closed position 0% and when the water level mark 3 m is reached, it opens from 0% to 100%, as indicated by the two horizontal lines C in FIG. 2a.
  • the valve movements of the level control valve 24 at the water levels 1 m and 3 m are shown on the right in FIG. 2a by the two horizontal lines D, the dashed line showing the influence of the fully automatic control when operating with a wet separator.
  • the system described is operated as follows. In normal operation, ie above the minimum flow rate for the economizer 1, ie above approximately 30% of the full load, the feed quantity supplied to the forced-flow steam generator is conveyed by the feed pump 5 as a function of the steam temperature, which is measured by means of the measuring device 13. In the feed control device 11, this actual value of the temperature is compared with the setpoint value of the temperature supplied via the signal line 14 compared and processed to an output signal, which is fed as a setpoint for the flow rate in the economizer 1 via the signal line 16 to the comparison point 9. The measurement point for the flow rate is fed as an actual value to the comparison point 9 via the signal line 8.
  • a control signal is then generated in the controller 17 subordinate to the device 11, which adjusts the speed of the feed pump 5 via the signal line 18, namely with increasing steam temperature in the direction of a larger quantity of food and with decreasing steam temperature in the direction of a reduced one Amount of food.
  • superheated steam reaches the separator 3, so that no saturated water is returned to the economizer 1 via the circulation line 20.
  • the separator 3 is in dry operation, ie the water level in the separator is very low and the level control device 33 should actually keep the level control valve 24 in the fully closed position.
  • the circulation pump 23 is always to be flowed through in order to avoid that after a longer standstill of this pump temperature shocks occur in it when it resumes circulation operation.
  • the level control valve 24 remains fully open in the operating phase described and the circulating pump 23, which is switched off above 50% load, is flowed through by part of the feed quantity conveyed by the feed pump 5, while the remaining feed quantity is fed via line 25 to the economizer 1 flows.
  • An empty running of the separator 3 is prevented by the shut-off valve 22, which is then in the fully closed position, as is the drain valve 31.
  • the transition from dry to wet operation of the separator takes place as follows:
  • the level control valve 24 and the shut-off valve 22 have the position just described, i.e. they are in the ready position (area E in Fig. 2b) and the water level in the separator 3 is below 3 m.
  • the water level in separator 3 increases (see curve H in Fig. 2b).
  • the opening cross section of the level control valve 24 is reduced to 31% by a first sequence of control commands programmed into the level control device 33 (compare area F in FIG. 2b).
  • shut-off valve 22 is moved to the full opening area by the control commands (end of area F), whereupon they switch the level control device 33 into automatic control mode (area G in FIG. 2b), ie it adjusts the level control valve 24 so that the setpoint for the water level, which is 7.7 m, is maintained.
  • the level control device 33 reduces the opening cross section of the level control valve 24, so that the circulating quantity decreases in step with the inflow of saturated water into the separator 3 and the level in the separator remains constant .
  • the circulation volume is therefore automatically reduced to zero.
  • safe forced operation e.g. with a load of 50% of the At full load
  • the operating team switches off the circulation pump 23.
  • the control logic of the control device 33 then closes the shut-off valve 22 and opens the level control valve 24 completely, so that the circulation pump 23 passively receives a small flow that is sufficient for keeping it warm.
  • Fig. 2c forms a safety circuit that guarantees that steam is never circulated. If violent transients occur, it could happen that the level control device 33 reacts too slowly and that the level in the separator 3 temporarily drops below the mark of 1 m.
  • a second sequence of control commands is programmed into the control device 33.
  • the shut-off valve 22 closes immediately by these control commands (area I in FIG. 2c).
  • the level control device 33 leaves the automatic control mode and the control commands open the level control valve 24 to the maximum permitted value (area K in FIG. 2c). The system is thus ready to automatically take over the automatic control operation if the level in the separator 3 rises again.
  • the level control device 33 can then not regulate satisfactorily.
  • the level control device 33 according to FIG. 3 is modified in that it additionally receives an input signal PE and a pilot signal FF are applied.
  • the lines 25 and 30 and the check valve 21, the shut-off valve 22 and the drain valve 31 with the signal line 29 have been omitted for clarity.
  • the input signal PE is formed from the difference between the pressure PA in the separator 3 and the pressure PS on the delivery side of the feed pump 5.
  • An increase in the delivery pressure PS causes a change in the signal PE in the pre-circuit of the level control device 33, which immediately causes a corresponding increase in the opening cross section of the level control valve 24, even before the level in the separator 3 begins to rise.
  • the pilot signal FF is formed in a function generator 38 and a downstream multiplier 39. As the diagram in the function generator 38 shows, the signal is proportional to the minimum flow rate in the economizer 1 and is weighted in a multiplier 39 with the multiplier L.
  • the multiplier L is selected such that when the minimum flow rate through the economiser 1 increases, the level control valve 24 opens in a controlled manner as far as is necessary for the steady state with a constant level in the separator 3.
  • the feed control device 11 is also possible to design the feed control device 11 as a classic PID controller with limitation of its output signal and with a PI controller connected in cascade. Analogously, the same for the level control device 33.

Landscapes

  • 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)
EP92810857A 1991-11-28 1992-11-05 Verfahren zum Betrieb eines Zwangdurchlaufdampferzeugers mit Schwachlastumwälzung Revoked EP0544615B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH348891 1991-11-28
CH3488/91 1991-11-28

Publications (2)

Publication Number Publication Date
EP0544615A1 EP0544615A1 (de) 1993-06-02
EP0544615B1 true EP0544615B1 (de) 1996-05-08

Family

ID=4257083

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92810857A Revoked EP0544615B1 (de) 1991-11-28 1992-11-05 Verfahren zum Betrieb eines Zwangdurchlaufdampferzeugers mit Schwachlastumwälzung

Country Status (5)

Country Link
EP (1) EP0544615B1 (xx)
KR (1) KR100249721B1 (xx)
DE (1) DE59206231D1 (xx)
DK (1) DK0544615T3 (xx)
TW (1) TW212826B (xx)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110476014A (zh) * 2017-03-30 2019-11-19 西门子股份公司 在竖直的强制循环蒸汽发生器中的水冷却

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE19619836B4 (de) * 1996-05-17 2005-05-12 Alstom Einrichtung zur Speisewasser-Vorsteuerung eines Kühllufttemperaturreglers für einen Kühlluftkühler
EP2065641A3 (de) * 2007-11-28 2010-06-09 Siemens Aktiengesellschaft Verfahren zum Betrieben eines Durchlaufdampferzeugers sowie Zwangdurchlaufdampferzeuger
US20100251976A1 (en) * 2009-04-02 2010-10-07 Alstom Technology Ltd. Ejector driven steam generator start up system
DE102011006390A1 (de) 2011-03-30 2012-10-04 Siemens Aktiengesellschaft Verfahren zum Betreiben eines Durchlaufdampferzeugers und zur Durchführung des Verfahrens ausgelegter Dampferzeuger

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3194020A (en) * 1963-03-25 1965-07-13 Combustion Eng Method and apparatus relating to vapor generation
BE788957A (fr) * 1971-09-24 1973-03-19 Sulzer Ag Procede de reglage de l'alimentation d'un generateur de vapeur a circulation forcee
CH552173A (de) * 1972-05-16 1974-07-31 Sulzer Ag Vorrichtung zum regeln der speisewasserzufuhr eines mit gleitdruck betriebenen zwanglaufdampferzeugers.
CH552771A (de) * 1972-06-12 1974-08-15 Sulzer Ag Zwangdurchlaufdampferzeuger.

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110476014A (zh) * 2017-03-30 2019-11-19 西门子股份公司 在竖直的强制循环蒸汽发生器中的水冷却
CN110476014B (zh) * 2017-03-30 2021-08-03 西门子股份公司 在竖直的强制循环蒸汽发生器中的水冷却

Also Published As

Publication number Publication date
TW212826B (xx) 1993-09-11
DK0544615T3 (da) 1996-09-16
KR100249721B1 (ko) 2000-04-01
KR930010432A (ko) 1993-06-22
DE59206231D1 (de) 1996-06-13
EP0544615A1 (de) 1993-06-02

Similar Documents

Publication Publication Date Title
DE69728254T2 (de) Regelsystem für dynamische kompressoren zur verhinderung des wiederauftretens des pumpens
EP0013045B1 (de) Dampferzeugeranlage
DE3021375A1 (de) Regelanordnung fuer eine dampfturbine mit einen gleitenden oder konstanten druck aufweisenden kesseln
EP0544615B1 (de) Verfahren zum Betrieb eines Zwangdurchlaufdampferzeugers mit Schwachlastumwälzung
DE2544799A1 (de) Gasbeheizter dampferzeuger
DE2923288C2 (xx)
DE1127365B (de) Einrichtung zur Regelung eines Zwangdurchlauf-Dampferzeugers
CH663268A5 (de) Heizanlage an einem fernheizsystem.
EP0308596A1 (de) Verfahren zur Regelung der Speisewassermenge einer Dampferzeugeranlage
DE1237586B (de) Verfahren und Einrichtung fuer den Anfahr- und Teillastbetrieb von Zwangdurchlaufkesseln
DE702231C (de) Dampftemperaturregler fuer Zwangdurchlaufkessel
EP0622586B1 (de) Verfahren zum Betreiben einer Rohrleitung und Vorrichtung zur Durchführung des Verfahrens
DE2064705A1 (de) Verfahren zum Betrieb eines Zwang laufdampferzeugers im unteren Lastbe reich und Zwanglaufdampferzeuger zum Durchfuhren des Verfahrens
EP1004776A2 (de) Verfahren und Anlage zur Vermeidung von Kavitation in einer Sattwasser fördernden Pumpe
EP0507730B1 (de) Einrichtung zum lastabhängigen Regeln der Speisewassermenge eines Zwanglaufdampferzeugers
AT201627B (de) Dampfkraftanlage
DE565043C (de) Regelung der Speisung von Fluessigkeitserhitzern mit Zwangsumlauf des Arbeitsmittels
AT150128B (de) Dampferzeuger.
DE489649C (de) Verfahren zur Regelung von hintereinandergeschalteten Dampfmaschinen, insbesondere Normaldruckturbinen mit Vorschaltturbinen
DE675761C (de) Dampferzeuger
DE975395C (de) Im Zwangdurchlauf arbeitender Dampferzeuger
DE934172C (de) Einrichtung zur Verhinderung des Durchgehens einer Dampfturbine bei ploetzlicher Entlastung
DE1426701C (de) Anfahreinrichtung fur Zwangdurchlauf dampferzeuger
DE1576872C (de) Einrichtung fur die Speisewasserregelung von Zwangdurchlaufkesseln im unteren Teil lastbereich
DE1041973B (de) Dampfkraftanlage

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): BE DE DK

17P Request for examination filed

Effective date: 19930622

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ABB KESSELANLAGEN AG

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: ABB MANAGEMENT AG

17Q First examination report despatched

Effective date: 19950119

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): BE DE DK

REF Corresponds to:

Ref document number: 59206231

Country of ref document: DE

Date of ref document: 19960613

REG Reference to a national code

Ref country code: DK

Ref legal event code: T3

PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

26 Opposition filed

Opponent name: EVT ENERGIE UND VERFAHRENSTECHNIK GMBH

Effective date: 19970207

PLBF Reply of patent proprietor to notice(s) of opposition

Free format text: ORIGINAL CODE: EPIDOS OBSO

RAP2 Party data changed (patent owner data changed or rights of a patent transferred)

Owner name: ASEA BROWN BOVERI AG

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19971115

Year of fee payment: 6

RDAH Patent revoked

Free format text: ORIGINAL CODE: EPIDOS REVO

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DK

Payment date: 19981022

Year of fee payment: 7

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: BE

Payment date: 19981030

Year of fee payment: 7

RDAG Patent revoked

Free format text: ORIGINAL CODE: 0009271

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT REVOKED

27W Patent revoked

Effective date: 19980630