EP0509298A1 - High pressure feedwater preheater - Google Patents

High pressure feedwater preheater Download PDF

Info

Publication number
EP0509298A1
EP0509298A1 EP92105389A EP92105389A EP0509298A1 EP 0509298 A1 EP0509298 A1 EP 0509298A1 EP 92105389 A EP92105389 A EP 92105389A EP 92105389 A EP92105389 A EP 92105389A EP 0509298 A1 EP0509298 A1 EP 0509298A1
Authority
EP
European Patent Office
Prior art keywords
zone
steam
desuperheating
chamber
condensation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP92105389A
Other languages
German (de)
French (fr)
Other versions
EP0509298B1 (en
Inventor
Mustafa Dr. Youssef
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.)
Alstom SA
Original Assignee
ABB Asea Brown Boveri Ltd
Asea Brown Boveri AB
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 ABB Asea Brown Boveri Ltd, Asea Brown Boveri AB filed Critical ABB Asea Brown Boveri Ltd
Publication of EP0509298A1 publication Critical patent/EP0509298A1/en
Application granted granted Critical
Publication of EP0509298B1 publication Critical patent/EP0509298B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22D—PREHEATING, OR ACCUMULATING PREHEATED, FEED-WATER FOR STEAM GENERATION; FEED-WATER SUPPLY FOR STEAM GENERATION; CONTROLLING WATER LEVEL FOR STEAM GENERATION; AUXILIARY DEVICES FOR PROMOTING WATER CIRCULATION WITHIN STEAM BOILERS
    • F22D1/00—Feed-water heaters, i.e. economisers or like preheaters
    • F22D1/32—Feed-water heaters, i.e. economisers or like preheaters arranged to be heated by steam, e.g. bled from turbines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D9/00—Heat-exchange apparatus having stationary plate-like or laminated conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall

Definitions

  • the invention relates to a regenerative high-pressure feed water preheater of the standing type with a U-shaped tube bundle, with a built-in desuperheating zone, with an integrated, flooded undercooling zone and with a water chamber underneath, the desuperheating zone and the undercooling zone each being shielded from the condensation zone by a cover.
  • the subcooler's flood level forms a pressure reserve, which makes it difficult to re-evaporate the condensate.
  • the flooding is ensured by appropriate design of the condensate drain regulation and the level control range.
  • the highest regulated condensate level must be below the end baffle of the desuperheater so that no condensate can flow back into the desuperheating zone.
  • the correct dimensioning of the desuperheating zone is also extremely important.
  • the superheated bleed steam is led to the feed water at a certain speed in countercurrent or cross-countercurrent.
  • the heat transfer to the pipe on the steam side takes place by convective means.
  • the desuperheating zone is too large, the condensation can already start at a point where the pipe outer wall reaches the local saturation temperature.
  • the laws of condensation apply to the steam-side heat transfer to the pipe and erosion-corrosion is to be expected. For reasons of operational safety, this condition must be avoided over the entire load range of the device.
  • the desuperheating zone may be dimensioned incorrectly. This applies in particular to the case where, for example, the supercooling zone has to be enlarged in order to lower the condensate outlet temperature and thus also the steam flow.
  • Such a design usually leads to a subcooling zone, which is divided into several chambers by means of baffles and thus has a greater height in the longitudinal direction of the apparatus.
  • the invention is based on the object of providing measures for a three-zone feedwater preheater of the type mentioned at the outset by which the occurrence of condensation nuclei in the desuperheating zone is reliably avoided.
  • this is achieved in that a chamber not flowed through by the steam is arranged around the tube bundle in the desuperheating zone.
  • both the cover and the bottom of the chamber are formed from tube support plates. According to the harassment of the desuperheating zone, only the supporting plates involved have to be covered with a simple sheet metal to form the chamber.
  • the high-pressure feed water preheater of the standing type is clad with an outer jacket 1, at the lower end of which a steam inlet opening 2 and a condensate outlet opening 3 are arranged opposite each other.
  • a desuperheating zone 4 is provided in the left part of the apparatus. This is provided up to the condensation zone 5 with a cover 6 in the form of an end baffle. The inside of the desuperheating zone 4 is harassed by means of steam baffles 7, 7 'and 7' ', which at the same time perform the function as pipe support plates.
  • the upper end of the desuperheating zone 4 opens into a steam distribution shaft 8 which is delimited by end walls 17.
  • This shaft runs centrally between one U-shaped tube bundle, the two legs of which form a right cold tube bundle part 9 and a left warm tube bundle part 10.
  • the shaft is arranged in such a way that its opposite longitudinal openings act as a steam outlet.
  • These longitudinal openings are provided with perforated cover plates 12, which have steam outlet openings 11 in the shaft plane on the one hand and steaming holes 13 in the plane of the pipe-covered zone on the other hand.
  • a ventilation duct 15 is recessed, in which a ventilation tube 14 is guided.
  • Pipe supports 16 are arranged in the condensation zone 5 in such a way that the condensate can trickle downwards.
  • a harassed hypothermia zone 18 is provided in the right part of the apparatus.
  • the baffles 19 acting as tube support plates divide the supercooling zone into several chambers and force the condensate to cross-flow to the feed water which flows in the tubes of the tube bundle.
  • This supercooling zone is likewise provided with a cover 20 in the form of an end baffle towards the condensation zone 5.
  • a control element 21 is arranged in the condensate drain line, not shown, with which the drain flow is regulated. Above the end baffle 20, the level of flooding of the condensate is indicated at 22. 29 denotes the level control range.
  • the cold tube bundle part 9 opens out at the bottom of the preheater via a tube plate 26 into a collecting chamber 27, through which the feed water flows into the tubes from the bottom up. After heating, the feed water is discharged from the apparatus via the collecting chamber 28, into which the warm leg 10 of the Rorbund bundle opens.
  • a thermally inactive zone is created in it.
  • the easiest way to do this is to provide a steam-free chamber 23 around the warm tube bundle part 10 within the desuperheating zone.
  • the steam guide plates 7 'and 7' ' can be used for this. These plates, which are anyway welded on one side to the partition 30 between the heating zone and the supercooling zone, form the cover and the bottom of the chamber 23.
  • this sheet 24 can have an almost semi-cylindrical or polygonal shape.
  • the support plates 7 'and 7''could strike the outer jacket 25 of the desuperheater as well, with a corresponding adaptation of the sheet 24 in the semi-cylindrical interior of the heating zone.
  • Superheated steam enters the desuperheating zone 4 through the steam inlet opening 2, flows around the steam baffle 7 arranged therein and the chamber 23 and passes directly into the steam distribution shaft 8, which is flowed through from bottom to top .
  • the steam enters the annular space of the condensation zone 5 directly from the mutually opposite steam outlet openings 11 in the cover plates 12 and is distributed therein. At a comparatively low speed, it hits the condensation surface of the tube bundles 9, 10 in the direction of the arrow in FIG. 2 and flows radially through the bundle from the outside inwards.
  • the condensate flows downward and collects above the supercooling zone, the level of the condensate covering the subcooler being adjusted to the desired level. Air and non-condensable gases are drawn off through the ventilation tubes 14 within the tube bundles 9 and 10 after the condensation has been completed.
  • the feed water in the tubes is preheated in a three-stage process, first in the supercooling zone 18, then in the condensation zone 5 and finally in the desuperheating zone 4.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Air Supply (AREA)
  • Instantaneous Water Boilers, Portable Hot-Water Supply Apparatuses, And Control Of Portable Hot-Water Supply Apparatuses (AREA)
  • Chimneys And Flues (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Feeding And Controlling Fuel (AREA)

Abstract

In a regenerative high-pressure feedwater preheater of upright construction with a U-shaped tube bank (9, 10), with built-in heat removal zone (4), with integrated, submerged undercooling zone (18) and with a water chamber (27, 28) lying below, the heat removal zone and the undercooling zone are each shielded with a cover (6 and 20 respectively) against the condensation zone. In the heat removal zone (4), a chamber (23), which is not flowed through by vapour, is arranged around the tube bank (10). <IMAGE>

Description

Technisches GebietTechnical field

Die Erfindung betrifft einen regenerativen Hochdruck-Speisewasservorwärmer der stehenden Bauart mit U-förmigem Rohrbündel, mit eingebauter Enthitzungszone, mit integrierter, überfluteter Unterkühlungszone und mit untenliegender Wasserkammer, wobei die Enthitzungszone und die Unterkühlungszone mit je einer Abdeckung gegen die Kondensationszone abgeschirmt sind.The invention relates to a regenerative high-pressure feed water preheater of the standing type with a U-shaped tube bundle, with a built-in desuperheating zone, with an integrated, flooded undercooling zone and with a water chamber underneath, the desuperheating zone and the undercooling zone each being shielded from the condensation zone by a cover.

Stand der TechnikState of the art

Ein solcher Vorwarmer ist bekannt aus dem Fachartikel "The effect of condensate reheat on mean temperature difference in feedwater heater subcooling zones", publiziert in der Literaturstelle "Transactions of the ASME", Oktober 1957, Seiten 1494-1500, Fig. 3a.Such a preheater is known from the technical article "The effect of condensate reheat on mean temperature difference in feedwater heater subcooling zones", published in the reference "Transactions of the ASME", October 1957, pages 1494-1500, Fig. 3a.

Bei derartigen Vorwärmern mit integrierter und überfluteter Unterkühlungszone kann in keinem Betriebsfall Dampf aus der Kondensationszone in die Unterkühlungszone gelangen. Dennoch müssen die wärmeübertragenden Zonen mit grösster Sorgfalt gestaltet werden, denn auch äussere und innere Leckagen sind zu minimieren. So wird durch entsprechend dicke Abschlussschikanen des Unterkühlers, durch kleine strömungsbedingte Druckverluste in der Eintrittspartie und durch kleine Ringspalte das Eindringen von Kondensatströmen in die Unterkühlungszone klein gehalten. Innere Leckagen werden minimiert durch dicht an den Unterkühlermantel angeschweisste Schikanen und durch kleine Ringspalte an den Rohrdurchführungen.With such preheaters with an integrated and flooded subcooling zone, steam can never pass from the condensation zone into the subcooling zone. Nevertheless, the heat transfer zones must be designed with the greatest of care, because external and internal leakages must also be minimized. The subcooler has correspondingly thick end baffles, small flow-related pressure losses in the inlet section and small annular gaps keep condensate flows from entering the subcooling zone. Internal leaks are minimized by baffles welded close to the subcooler jacket and by small annular gaps on the pipe penetrations.

Bei dieser Art von Vorwärmern bildet die Überflutungshöhe des Unterkühlers eine Druckreserve, die das Wiederverdampfen des Kondensates erschwert. Die Überflutung wird durch eine entsprechende Auslegung der Kondensat-Abflussregulierung und des Niveau-Regelbereiches sichergestellt. Hierbei muss sich das höchste geregelte Kondenatniveau unterhalb der Abschlussschikane des Enthitzers befinden, damit kein Kondensat in die Enthitzungszone zurückströmen kann.With this type of preheater, the subcooler's flood level forms a pressure reserve, which makes it difficult to re-evaporate the condensate. The flooding is ensured by appropriate design of the condensate drain regulation and the level control range. The highest regulated condensate level must be below the end baffle of the desuperheater so that no condensate can flow back into the desuperheating zone.

Andererseits kommt der richtigen Dimensionierung der Enthitzungszone ebenfalls grösste Bedeutung zu. Der überhitzte Anzapfdampf wird im Enthitzer mit einer bestimmten Geschwindigkeit im Gegenstrom oder im Kreuzgegenstrom zum Speisewasser geführt. Solange die Aussenwandungen der vom überhitzten Dampf beaufschlagten Rohre trocken ist, erfolgt der dampfseitige Wärmeübergang zum Rohr auf konvektivem Wege. Bei zu gross dimensionierter Enthitzungszone kann die Kondensation bereits an einer Stelle einsetzen, bei welcher die Rohraussenwand die örtliche Sättigungstemperatur erreicht. In diesem Fall gelten für den dampfseitigen Wärmeübergang zum Rohr die Gesetze der Kondensation und es ist mit Erosion-Korrosion zu rechnen. Aus Gründen der Betriebsicherheit muss dieser Zustand über dem ganzen Lastbereich des Apparates vermieden werden.On the other hand, the correct dimensioning of the desuperheating zone is also extremely important. The superheated bleed steam is led to the feed water at a certain speed in countercurrent or cross-countercurrent. As long as the outer walls of the pipes exposed to the superheated steam are dry, the heat transfer to the pipe on the steam side takes place by convective means. If the desuperheating zone is too large, the condensation can already start at a point where the pipe outer wall reaches the local saturation temperature. In this case, the laws of condensation apply to the steam-side heat transfer to the pipe and erosion-corrosion is to be expected. For reasons of operational safety, this condition must be avoided over the entire load range of the device.

Bedingt durch die oben erwähnte notwendige Höhendifferenz zwischen Abschlussschikane der Enthitzungszone und höchstmöglichem Überflutungsniveau oberhalb der Unterkühlungszone kann es folglich zu einer Fehldimensionierung der Enthitzungszone kommen. Dies gilt insbesondere für den Fall, dass beispielsweise die Unterkühlungszone vergrössert werden muss, um die Kondensataustrittstemperatur und damit auch den Dampfstrom zu senken. Eine solche Auslegung führt in der Regel zu einer Unterkühlungszone, die mittels Schikanen in mehrere Kammern unterteilt ist und somit eine grössere Höhe in Längsrichtung des Apparates aufweist.Due to the above-mentioned necessary height difference between the final chicane of the desuperheating zone and the highest possible level of flooding above the hypothermia zone, the desuperheating zone may be dimensioned incorrectly. This applies in particular to the case where, for example, the supercooling zone has to be enlarged in order to lower the condensate outlet temperature and thus also the steam flow. Such a design usually leads to a subcooling zone, which is divided into several chambers by means of baffles and thus has a greater height in the longitudinal direction of the apparatus.

Darstellung der ErfindungPresentation of the invention

Der Erfindung liegt nunmehr die Aufgabe zugrunde, bei einem Dreizonen-Speisewasservorwärmer der eingangs genannten Art Massnahmen zu schaffen, durch welche das Auftreten von Kondensationskernen in der Enthitzungszone mit Sicherheit vermieden wird.The invention is based on the object of providing measures for a three-zone feedwater preheater of the type mentioned at the outset by which the occurrence of condensation nuclei in the desuperheating zone is reliably avoided.

Erfindungsgemäss wird dies dadurch ereicht, dass in der Enthitzungszone eine nicht vom Dampf durchströmte Kammer um das Rohrbündel herum angeordnet ist.According to the invention, this is achieved in that a chamber not flowed through by the steam is arranged around the tube bundle in the desuperheating zone.

Die Vorteile der Erfindung sind insbesondere in der Einfachheit der neuen Massnahme zu sehen. Dem Konstrukteur bleibt es überlassen, das derart geschaffene strömungstechnisch und damit auch wärmetechnisch inaktive Volumen beliebig in die Enthitzungszone zu integrieren, gegebenenfalls in mehrere Kammern zu unterteilen.The advantages of the invention can be seen in particular in the simplicity of the new measure. It is up to the designer to integrate the fluidically inactive and thus also thermally inactive volume created in this way into the desuperheating zone, if necessary to subdivide it into several chambers.

Es ist besonders zweckmässig, wenn sowohl der Deckel als der Boden der Kammer aus Rohr-Stützplatten gebildet sind. Entsprechend der Schikanierung der Enthitzungszone müssen dann zur Bildung der Kammer nur noch die beteiligten Stützplatten mit einem einfachen Blech ummantelt werden.It is particularly expedient if both the cover and the bottom of the chamber are formed from tube support plates. According to the harassment of the desuperheating zone, only the supporting plates involved have to be covered with a simple sheet metal to form the chamber.

Kurze Beschreibung der ZeichnungBrief description of the drawing

In der Zeichnung ist ein Ausführungsbeispiel der Erfindung schematisch dargestellt.In the drawing, an embodiment of the invention is shown schematically.

Es zeigen:

Fig.1
einen Teillängsschnitt durch einen Speisewasservorwärmer;
Fig.2
einen Querschnitt entlang der Schnittlinie 2-2 in Fig.1
Fig.3
einen Querschnitt entlang der Schnittlinie 3-3 in Fig.1
Es sind nur die für das Verständnis der Erfindung wesentlichen Elemente gezeigte. Die Strömungsrichtung der Arbeitsmittel ist mit Pfeilen bezeichnet.Show it:
Fig. 1
a partial longitudinal section through a feed water preheater;
Fig. 2
a cross section along the section line 2-2 in Fig.1
Fig. 3
a cross section along the section line 3-3 in Fig.1
Only the elements that are essential for understanding the invention are shown. The direction of flow of the work equipment is indicated by arrows.

Weg zur Ausführung der ErfindungWay of carrying out the invention

Der Hochdruck-Speisewasservorwärmer der stehenden Bauart ist mit einem Aussenmantel 1 umkleidet, an dessen unterem Ende einander gegenüberliegend je eine Dampfeinlassöffnung 2 und eine Kondensatauslassöffnung 3 angeordnet sind. Im linken Teil des Apparates ist eine Enthitzungszone 4 vorgesehen. Diese ist nach oben zur Kondensationszone 5 hin mit einer Abdeckung 6 in Form einer Abschlussschikane versehen. Das Innere der Enthitzungszone 4 ist schikaniert mittels Dampfleitblechen 7, 7' und 7'', welche gleichzeitig die Funktion als Rohrstützplatten ausüben.The high-pressure feed water preheater of the standing type is clad with an outer jacket 1, at the lower end of which a steam inlet opening 2 and a condensate outlet opening 3 are arranged opposite each other. A desuperheating zone 4 is provided in the left part of the apparatus. This is provided up to the condensation zone 5 with a cover 6 in the form of an end baffle. The inside of the desuperheating zone 4 is harassed by means of steam baffles 7, 7 'and 7' ', which at the same time perform the function as pipe support plates.

Das obere Ende der Enthitzungszone 4 mündet in einen Dampfverteilungsschacht 8, welcher durch Abschlusswände 17 begrenzt ist. Dieser Schacht verläuft zentral zwischen einem U-förmigen Rohrbündel, dessen beide Schenkel einen rechten kalten Rohrbündelteil 9 und einen linken warmen Rohrbündelteil 10 bilden. Der Schacht ist so angeordnet, dass seine einander gegenüberliegenden Längsöffnungen als Dampfaustritt wirken. Diese Längsöffnungen sind mit gelochten Abdeckblechen 12 versehen, welche einerseits in der Schachtebene Dampfaustrittsöffnungen 11 und andererseits in der Ebene der berohrten Zone Bedampfungslöcher 13 aufweisen. Im zentralen Raum in den Rohrbündelteilen 9 und 10 ist je ein Entlüftungskanal 15 ausgespart, in welchem ein Entlüftungsrohr 14 geführt ist. In der Kondensationszone 5 sind Rohrabstützungen 16 so angeordnet, dass das anfallende Kondensat nach unten rieseln kann.The upper end of the desuperheating zone 4 opens into a steam distribution shaft 8 which is delimited by end walls 17. This shaft runs centrally between one U-shaped tube bundle, the two legs of which form a right cold tube bundle part 9 and a left warm tube bundle part 10. The shaft is arranged in such a way that its opposite longitudinal openings act as a steam outlet. These longitudinal openings are provided with perforated cover plates 12, which have steam outlet openings 11 in the shaft plane on the one hand and steaming holes 13 in the plane of the pipe-covered zone on the other hand. In the central space in the tube bundle parts 9 and 10, a ventilation duct 15 is recessed, in which a ventilation tube 14 is guided. Pipe supports 16 are arranged in the condensation zone 5 in such a way that the condensate can trickle downwards.

Im rechten Teil des Apparates ist eine schikanierte Unterkühlungszone 18 vorgesehen. Die als Rohrstützplatten wirkenden Schikanen 19 unterteilen die Unterkühlungszone in mehrere Kammern und zwingen das Kondensat zu einer Kreuz-Gegenströmung zum Speisewasser, welches in den Rohren des Rohrbündels strömt. Diese Unterkühlungszone ist nach oben zur Kondensationszone 5 hin ebenfalls mit einer Abdeckung 20 in Form einer Abschlussschikane versehen. In der nicht dargestellten Kondensatabflussleitung ist ein Regelorgan 21 angeordnet, mit dem der Abflussstrom reguliert wird. Oberhalb der Abschlussschikane 20 ist das Überflutungsniveau des Kondensates mit 22 angegeben. 29 bezeichnet den Niveau-Regelbereich.A harassed hypothermia zone 18 is provided in the right part of the apparatus. The baffles 19 acting as tube support plates divide the supercooling zone into several chambers and force the condensate to cross-flow to the feed water which flows in the tubes of the tube bundle. This supercooling zone is likewise provided with a cover 20 in the form of an end baffle towards the condensation zone 5. A control element 21 is arranged in the condensate drain line, not shown, with which the drain flow is regulated. Above the end baffle 20, the level of flooding of the condensate is indicated at 22. 29 denotes the level control range.

Das kalte Rohrbündelteil 9 mündet an der Unterseite des Vorwärmers über einen Rohrboden 26 in eine Sammelkammer 27, durch welche das Speisewasser von unten nach oben in die Rohre hineinströmt. Nach der Aufheizung wird das Speisewasser über die Sammelkammer 28, in welche der warme Schenkel 10 des Rorbündels mündet, aus dem Apparat abgeführt.The cold tube bundle part 9 opens out at the bottom of the preheater via a tube plate 26 into a collecting chamber 27, through which the feed water flows into the tubes from the bottom up. After heating, the feed water is discharged from the apparatus via the collecting chamber 28, into which the warm leg 10 of the Rorbund bundle opens.

Soweit sind Drei-Zonen-Speisewasservorwärmer bekannt. Es kann nunmehr vorkommen, dass gemäss Spezifikationen des Betreibers die Kondensataustrittstemperatur auf ein besonders tiefes Niveu gesenkt werden muss, damit unter anderem die angesaugte Dampfmenge reduziert werden kann. Eine Senkung der Kondensataustrittstemperatur führt zu einer Vergrösserung der Wärmeaustauschfläche in der Unterkühlungszone. Bei gegebenem Aussendurchmesser des Apparates bedeutet dies eine Vergrösserung der Unterkühlungszone in Längsrichtung des Apparates, also in der Höhe. Um nun die Bedingung zu erfüllen, dass das höchstmögliche Überflutungsniveau auf jeden Fall unterhalb der Abschlussschikane im Enthitzer liegen muss, führt dies zwangsläufig auch zu einer Anhebung dieser Abschlussschikane und damit zu einer unerwünschten Vergrösserung der Wärmeaustauschfläche in der Enthitzungszone, sofern nicht Gegenmassnahmen getroffen werden.So far, three-zone feed water preheaters are known. It can now happen that, according to the operator's specifications, the condensate outlet temperature drops to a particularly high level deep level must be lowered so that, among other things, the amount of steam drawn in can be reduced. Lowering the condensate outlet temperature leads to an increase in the heat exchange area in the supercooling zone. Given the outer diameter of the apparatus, this means an enlargement of the supercooling zone in the longitudinal direction of the apparatus, that is to say in height. In order to meet the condition that the highest possible level of flooding must in any case be below the final chicane in the desuperheater, this inevitably leads to an increase in this final chicane and thus to an undesirable increase in the heat exchange area in the desuperheating zone, unless countermeasures are taken.

Hier setzt nun die Erfindung ein: Um die Wärmeaustauschfläche in der Enthitzungszone trotz erhöhtem Gesamtvolumen auf ein erträgliches Mass zu reduzieren, wird darin eine wärmetechnisch inaktive Zone geschaffen. Am einfachsten geschieht dies dadurch, dass innerhalb der Enthitzungszone eine vom Dampf nichtdurchströmte Kammer 23 um das warme Rohrbündelteil 10 vorgesehen wird. Gemäss dargestelltem Ausführungsbeispiel können hierzu die Dampfleitbleche 7' und 7'' benutzt werden. Diese an einer Seite ohnehin mit der Trennwand 30 zwischen Enthitzungszone und Unterkühlungszone verschweissten Platten bilden dabei den Deckel und den Boden der Kammer 23. Sie werden mit einem einfachen Blech 24 ummmantelt, wodurch ein geschlossener, nicht vom Dampf beaufschlagter Raum entsteht. Entsprechend der Aussenkontur der Platten 7' und 7'' kann dieses Blech 24 von nahezu halbzylindrischer oder aber von mehreckiger Form sein.This is where the invention comes in: In order to reduce the heat exchange surface in the desuperheating zone to a tolerable level despite the increased total volume, a thermally inactive zone is created in it. The easiest way to do this is to provide a steam-free chamber 23 around the warm tube bundle part 10 within the desuperheating zone. According to the illustrated embodiment, the steam guide plates 7 'and 7' 'can be used for this. These plates, which are anyway welded on one side to the partition 30 between the heating zone and the supercooling zone, form the cover and the bottom of the chamber 23. Corresponding to the outer contour of the plates 7 'and 7' ', this sheet 24 can have an almost semi-cylindrical or polygonal shape.

Es versteht sich, dass beispielsweise bei mehrfach schikanierter Enthitzungszone die Stützplatten 7' und 7'' genau so gut am Aussenmantel 25 des Enthitzers anschlagen könnten mit entsprechender Anpassung des Bleches 24 im halbzylindrischen Innenraum der Enthitzungszone.It goes without saying that, for example, in the case of a heating zone which has been harassed several times, the support plates 7 'and 7''could strike the outer jacket 25 of the desuperheater as well, with a corresponding adaptation of the sheet 24 in the semi-cylindrical interior of the heating zone.

Die Betriebsweise des 3-Zonen-Apparates wird nachstehend erläutert: Durch die Dampfeinlassöffnung 2 tritt überhitzter Dampf in die Enthitzungszone 4 ein, umströmt das darin angeordnete Dampfleitblech 7 sowie die Kammer 23 und gelangt unmittelbar in den Dampfverteilumngsschacht 8, welcher von unten nach oben durchströmt wird. Aus den einander gegenüberliegenden Dampfaustrittsöffnungen 11 in den Abdeckblechen 12 tritt der Dampf unmittelbar in den Ringraum der Kondensationszone 5 ein und verteilt sich darin. Mit vergleichsweiser geringer Geschwindigkeit trifft er gemäss Pfeilrichtung in Fig.2 auf die Kondensationsfläche der Rohrbündel 9, 10 und durchströmt die Bündel radial von aussen nach innen. Nach Wärmeabgabe und Kondensation des Heizdampfes fliesst das Kondensat abwärts und sammelt sich oberhalb der Unterkühlungszone, wobei das Niveau des den Unterkühler überfutenden Kondensates auf das jeweils gewünschte Mass eingeregelt ist. Durch die Entlüftungsrohre 14 innerhalb der Rohrbündel 9 und 10 werden Luft und nichtkondensierbare Gase nach abgeschlossenener Kondensation abgezogen.The mode of operation of the 3-zone apparatus is explained below: Superheated steam enters the desuperheating zone 4 through the steam inlet opening 2, flows around the steam baffle 7 arranged therein and the chamber 23 and passes directly into the steam distribution shaft 8, which is flowed through from bottom to top . The steam enters the annular space of the condensation zone 5 directly from the mutually opposite steam outlet openings 11 in the cover plates 12 and is distributed therein. At a comparatively low speed, it hits the condensation surface of the tube bundles 9, 10 in the direction of the arrow in FIG. 2 and flows radially through the bundle from the outside inwards. After the heat has been given off and the heating steam has condensed, the condensate flows downward and collects above the supercooling zone, the level of the condensate covering the subcooler being adjusted to the desired level. Air and non-condensable gases are drawn off through the ventilation tubes 14 within the tube bundles 9 and 10 after the condensation has been completed.

Das Speisewasser in den Rohren wird in einem dreistufigen Vorgang zunächst in der Unterkühlungszone 18, danach in der Kondensationszone 5 und schliesslich in der Enthitzungszone 4 vorgewärmt.The feed water in the tubes is preheated in a three-stage process, first in the supercooling zone 18, then in the condensation zone 5 and finally in the desuperheating zone 4.

BezugszeichenlisteReference symbol list

11
AussenmantelOuter jacket
22nd
DampfeinlassöffnungSteam inlet opening
33rd
KondensatauslassöffnungCondensate outlet
44th
EnthitzungszoneDesuperheating zone
55
KondensationszoneCondensation zone
66
Abdeckungcover
7,7',7''7.7 ', 7' '
DampfleitblechSteam baffle
88th
DampfverteilungsschachtSteam distribution shaft
99
kaltes Rohrbündelteilcold tube bundle part
1010th
warmes Rohrbündelteilwarm tube bundle part
1111
DampfaustrittsöffnungSteam outlet opening
1212
AbdeckblechCover plate
1313
BedampfungslochVaporization hole
1414
EntlüftungsrohrVent pipe
1515
EntlüftungskanalVentilation duct
1616
RohrabstützungPipe support
1717th
AbschlusswandEnd wall
1818th
UnterkühlungszoneHypothermia zone
1919th
Schikanechicane
2020th
Abdeckungcover
2121
RegelorganGoverning body
2222
ÜberflutungsniveauFlood level
2323
Kammerchamber
2424th
Blechsheet
2525th
AussenmantelOuter jacket
2626
RohrbodenTube sheet
2727th
SammelkammerCollection chamber
2828
SammelkammerCollection chamber
2929
Niveau-RegelbereichLevel control range
3030th
Trennwandpartition wall

Claims (2)

Regenerativer Hochdruck-Speisewasservorwärmer der stehenden Bauart mit U-förmigem Rohrbündel (9, 10), mit eingebauter Enthitzungszone (4), mit integrierter, überfluteter Unterkühlungszone (18) und mit untenliegender Wasserkammer (27, 28), wobei die Enthitzungszone und die Unterkühlungszone mit je einer Abdeckung (6 respektiv 20) gegen die Kondensationszone abgeschirmt sind,
dadurch gekennzeichnet,
dass in der Enthitzungszone (4) eine nicht vom Dampf durchströmte Kammer (23) um das Rohrbündel (10) herum angeordnet ist.Regenerative high-pressure feed water preheater of the upright type with a U-shaped tube bundle (9, 10), with built-in desuperheating zone (4), with integrated, flooded undercooling zone (18) and with the water chamber (27, 28) underneath, with the desuperheating zone and the undercooling zone one cover (6 or 20) are shielded against the condensation zone,
characterized,
that in the desuperheating zone (4) a chamber (23) not flowed through by the steam is arranged around the tube bundle (10). Regenerativer Hochdruck-Speisewasservorwärmer nach Anspruch 1, dadurch gekennzeichnet, dass sowohl der Deckel als auch der Boden der Kammer (23) aus Rohr-Stützplatten (7', 7'') gebidet sind, welche mit einem Blech (24) ummantelt sind.Regenerative high-pressure feed water preheater according to claim 1, characterized in that both the lid and the bottom of the chamber (23) are bididet from tube support plates (7 ', 7' '), which are coated with a sheet (24).
EP92105389A 1991-04-15 1992-03-28 High pressure feedwater preheater Expired - Lifetime EP0509298B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CH1117/91A CH682692A5 (en) 1991-04-15 1991-04-15 High-pressure feedwater.
CH1117/91 1991-04-15

Publications (2)

Publication Number Publication Date
EP0509298A1 true EP0509298A1 (en) 1992-10-21
EP0509298B1 EP0509298B1 (en) 1995-05-24

Family

ID=4202889

Family Applications (1)

Application Number Title Priority Date Filing Date
EP92105389A Expired - Lifetime EP0509298B1 (en) 1991-04-15 1992-03-28 High pressure feedwater preheater

Country Status (6)

Country Link
EP (1) EP0509298B1 (en)
KR (1) KR100205274B1 (en)
AT (1) ATE123129T1 (en)
AU (1) AU654536B2 (en)
CH (1) CH682692A5 (en)
DE (1) DE59202292D1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106288322A (en) * 2016-10-18 2017-01-04 东方电气集团东方锅炉股份有限公司 A kind of nothing reducing low-pressure heater device diameters is indulged and is plunderred heat exchange superheat section structure

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2489645C1 (en) * 2011-12-27 2013-08-10 Открытое акционерное общество "Российский концерн по производству электрической и тепловой энергии на атомных станциях" (ОАО "Концерн Росэнергоатом") Steam and water heater

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB828680A (en) * 1957-03-20 1960-02-24 Foster Wheeler Ltd Improvements in heat exchangers

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB828680A (en) * 1957-03-20 1960-02-24 Foster Wheeler Ltd Improvements in heat exchangers

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106288322A (en) * 2016-10-18 2017-01-04 东方电气集团东方锅炉股份有限公司 A kind of nothing reducing low-pressure heater device diameters is indulged and is plunderred heat exchange superheat section structure
CN106288322B (en) * 2016-10-18 2022-01-04 东方电气集团东方锅炉股份有限公司 Longitudinal-grazing-free heat exchange superheat section structure for reducing diameter of low-pressure heater equipment

Also Published As

Publication number Publication date
KR100205274B1 (en) 1999-07-01
CH682692A5 (en) 1993-10-29
AU654536B2 (en) 1994-11-10
DE59202292D1 (en) 1995-06-29
EP0509298B1 (en) 1995-05-24
ATE123129T1 (en) 1995-06-15
AU1404792A (en) 1992-10-22
KR920020178A (en) 1992-11-20

Similar Documents

Publication Publication Date Title
DE2430208C3 (en) Nuclear power plant with steam generator and reheater for partially expanded steam
DE19645322B4 (en) Combined power plant with a forced once-through steam generator as a gas turbine cooling air cooler
CH632331A5 (en) METHOD FOR STARTING A FORCED STEAM GENERATOR.
DE2263461A1 (en) BOILER CIRCUIT FOR A FORCED CIRCULATION GENERATOR WITH VARIABLE PRESSURE
DE19545308A1 (en) Convective counterflow heat transmitter
DE1132932B (en) Method and device for utilizing the heat released during the nuclear reaction in a steam generator which is arranged outside the reactor and heated by a steam-water mixture
DE1426698A1 (en) Device for starting up a circulation steam generator
EP0509298B1 (en) High pressure feedwater preheater
EP0123986B1 (en) Feed-water heater
DE2249581A1 (en) HEAT EXCHANGER
EP0325758A1 (en) Steam condenser
CH634646A5 (en) HEAT EXCHANGER FOR COOLING PROCESS GASES UNDER HIGH PRESSURE AND HIGH TEMPERATURE.
DE2441324C2 (en) Feed water preheater with a desuperheater
CH628410A5 (en) Feed water preheater.
EP0919707A1 (en) Cooling-air cooling unit for gas turbines
DE2844077C2 (en)
DE3121297C2 (en) Device for regulating the temperature of a corrosive gas, in particular synthesis gas
WO1983002658A1 (en) Method and device for operating a high pressure steam boiler
DE2813808C2 (en)
DE2842039A1 (en) STEAM GENERATOR
DE2813614C2 (en) Indirectly heated steam generator
EP0097989B1 (en) High pressure feedwater heater disposed upright in a header construction with a desuperheater and a steam-water separator
DE1021377B (en) Device to protect the reheater in high pressure steam power plants
DE3121346C2 (en)
DE19513204A1 (en) Apparatus for heating and degassing water

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): AT CH DE FR IT LI NL

17P Request for examination filed

Effective date: 19930326

17Q First examination report despatched

Effective date: 19941025

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AT CH DE FR IT LI NL

REF Corresponds to:

Ref document number: 123129

Country of ref document: AT

Date of ref document: 19950615

Kind code of ref document: T

REF Corresponds to:

Ref document number: 59202292

Country of ref document: DE

Date of ref document: 19950629

ITF It: translation for a ep patent filed

Owner name: DE DOMINICIS & MAYER S.R.L.

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

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

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LI

Effective date: 19960331

Ref country code: CH

Effective date: 19960331

26N No opposition filed
REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

NLS Nl: assignments of ep-patents

Owner name: ALSTOM

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

Ref country code: NL

Payment date: 20020228

Year of fee payment: 11

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

Ref country code: AT

Payment date: 20020307

Year of fee payment: 11

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

Ref country code: DE

Payment date: 20020309

Year of fee payment: 11

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

Ref country code: FR

Payment date: 20020315

Year of fee payment: 11

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF THE APPLICANT RENOUNCES

Effective date: 20021213

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20030328

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031001

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20031127

NLV4 Nl: lapsed or anulled due to non-payment of the annual fee

Effective date: 20031001

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES;WARNING: LAPSES OF ITALIAN PATENTS WITH EFFECTIVE DATE BEFORE 2007 MAY HAVE OCCURRED AT ANY TIME BEFORE 2007. THE CORRECT EFFECTIVE DATE MAY BE DIFFERENT FROM THE ONE RECORDED.

Effective date: 20050328