DD295904A5

DD295904A5 - BOILER

Info

Publication number: DD295904A5
Application number: DD90342042A
Authority: DD
Inventors: Joerg Fuellemann; Heinrich Boner
Original assignee: ��@��@��k��
Priority date: 1989-06-26
Filing date: 1990-06-25
Publication date: 1991-11-14
Also published as: EP0406173A2; EP0406173B1; PL164910B1; EP0406173A3; CA2033988A1; CZ281126B6; PL285725A1; HU209911B; HUT58410A; ATE75024T1; CS306290A3; AU5832890A; DE59000086D1; HU904743D0; WO1991000481A1

Abstract

A heating boiler comprises a heat-exchange chamber (13) surrounded by a heating jacket (15). Another water jacket (27) arranged concentrically with the latter extends, at the rear of the heating boiler, over approximately half the length of the heating jacket (15). A concentric core body (43) is located inside the water jacket (27). Helical flue gas channels (54, 56) each provided with an outlet (33, 37, respectively), are arranged in the spaces (53, 55, respectively. A flue gas flap (39) is located in the opening region of the outlets (33, 37). In the central position illustrated, the flue gases can escape virtually unhindered from both flue gas channels. This corresponds to full-load operation of the burner (11). At minimal load, the outlet (33) is closed by the flue gas flap. In both cases, however, the flue gas temperature is the same. This prevents the temperature in every part of the heating boiler from descending below the dew point.

Description

Anwendungsgebiet der ErfindungField of application of the invention

Die Erfindung bezieht sich auf einen Heizkessel, insbesondere zur Verwendung mit einem mehrstufigen oder modulierenden Brenner, mit einem Wärmetauschraum, einem diesen umgebenden Wassermantel, der eine Außenwandung an eine Innenwandung aufweist, und einem im Wärmetauschraum angeordneten weiteren Wassermantel, der sich über einen Teil der Länge des Wärmetauschraums erstreckt und so einen Zwischenraum bildet und einen Innenraum ummantelt.The invention relates to a heating boiler, in particular for use with a multi-stage or modulating burner, with a heat exchange space, a surrounding water jacket having an outer wall to an inner wall, and arranged in the heat exchange space further water jacket, extending over part of the length extends the heat exchange space and so forms a gap and an interior sheathed.

Charakteristik des bekannten Standes der TechnikCharacteristic of the known state of the art

Die französische Patentschrift 2,154,347 beschreibt einen Heizkessel, bei welchem zwei zylindrische Wassermäntel konzentrisch zueinander angeordnet sind. Dabei bildet der vom inneren Wassermantel ummantelte Innenraum den Brennerraum währenddem der Zwischenraum zwischen den Wassermänteln als Rauchgaskanal dient. In diesem Rauchgaskanal befindet sich ein schraubenförmiger Einsatz. Dieser Heizkessel ist relativ kompliziert im Aufbau. Die Fertigung ist daher relativ teuer, und die Servicearbeiten sind schwierig auszuführen und zeitaufwendig. Besonders nachteilig ist die Gefahr von Kaltstellen, bei denen bei reduzierter Brennerleistung eine Kondensation von Schadstoffen aus den Rauchgasen erfolgen kann, was dann zu Korrosionsproblemen führt. Dieser Heizkessel eignet sich daher schlecht zum Betrieb mit einem mehrstufigen Brenner. Auch sieht der vorbekannte Heizkessel keine Mittel zur Warmwasserbereitung, d. h. zur sogenannten Brauchwasserbereitung vor.French patent specification 2,154,347 describes a heating boiler in which two cylindrical water jackets are arranged concentrically with each other. In this case, the inner water jacket sheathed interior forms the burner chamber while the space between the water jackets serves as a flue gas channel. In this flue gas duct is a helical insert. This boiler is relatively complicated in construction. The manufacturing is therefore relatively expensive, and the service work is difficult to carry out and time consuming. Particularly disadvantageous is the risk of cold spots where condensation of pollutants from the flue gases can occur at reduced burner output, which then leads to corrosion problems. This boiler is therefore not suitable for operation with a multi-stage burner. Also, the prior art boiler sees no means for water heating, d. H. for so-called dhw production.

Es ist wichtig, daß die Leistung von Heizkessel und Brenner aufeinander abgestimmt sind. Es waren somit bisher im unteren Leistungsbereich in Abstufungen von etwa 5 KW verschiedene Kesselgrößen notwendig.It is important that the performance of boiler and burner are matched. So far, in the lower power range in gradations of about 5 KW different boiler sizes were necessary.

Ziel der ErfindungObject of the invention

Das Ziel der Erfindung besteht darin, die Herstellungskosten gattungsgemäßer Heizkessel zu reduzieren und seine Einsatzmöglichkeiten zu erhöhen.The aim of the invention is to reduce the production costs of generic boilers and to increase its capabilities.

Darlegung des Wesens der ErfindungExplanation of the essence of the invention

Es ist daher Aufgabe der vorliegenden Erfindung einen konstruktiv einfachen und preiswerten Heizkessel mit hohem thermischen Wirkungsgrad zu schaffen. Der Heizkessel sollte sich auch zur Verwendung mit einem mehrstufigen oder modulierenden Brenner eignen, ohne daß die Gefahr von Korrosion besteht. Weiter sollte der Heizkessel geringe Stillstandsverluste aufweisen und sich möglichst auch zur Aufbereitung von Warmwasser eignen.It is therefore an object of the present invention to provide a structurally simple and inexpensive boiler with high thermal efficiency. The boiler should also be suitable for use with a multi-stage or modulating burner without the risk of corrosion. Furthermore, the boiler should have low standstill losses and should also be suitable for the treatment of hot water.

Erfindungsgemäß wird diese Aufgabe bei einem Heizkessel der eingangs erwähnten Art dadurch gelöst, daß zusätzlich zu dem aus dem Zwischenraum führenden Auslaß ein aus dem Innenraum führender Auslaß für Rauchgase vorgesehen ist und daß Mittel zur Regelung eines Rauchgasstromes aus dem Auslaß des Zwischenraums und/oder zur Regelung eines Rauchgasstromes aus dem Auslaß des Innenraums vorgesehen sind. Wenn die Mittel zur Regelung der Rauchgasströme einen Rauchgasstrom sowohl aus dem Zwischenraum als auch aus dem Innenraum zulassen, kann der Heizkessel mit Vollast gefahren werden. Die Rauchgase können dann sowohl durch den Zwischenraum zwischen beiden Wassermänteln als auch durch den Innenraum des weiteren Wassermantels strömen und dabei soviel Wärme an diese Wassermäntel übertragen, daß sie den Heizkessel mit einer relativ niedrigen Abgastemperatur verlassen. Wird jedoch der Heizkessel nur mit Teillast gefahren, die beispielsweise 30% der Vollast betragen kann, so wird der Auslaß aus dem Zwischenraum verschlossen, so daß die Rauchgase nur noch durch den Innenraum strömen können. Es besteht dann keine Gefahr, daß sie sich zu stark abkühlen und im hinteren Teil des Kessels Kondensationsprobleme auftreten. Der Heizkessel eignet sich daher gut für die Verwendung mit einem zweistufigen Brenner. Es wäre aber auch möglich, einen modulierenden Brenner zu verwenden, der stufenlos von Minimallast zu Vollast geregelt werden kann. In diesem Falle ist es zweckmäßig, einen Motorantrieb für die Rauchgasklappe zu wählen, damit auch diese stufenlos geregelt werden kann. Es ist also möglich, die Größe des durch den Zwischenraum fließenden Rauchgasstroms zu regeln. Die vorliegende Erfindung hat auch den Vorteil, daß die gleiche Kesselgröße für einen relativ großen Leistungsbereich anwendbar ist. Bei der Verwendung des Heizkessels mit einstufigem Brenner kann die gleiche Kesselgröße für einen relativ großen Leistungsbereich verwendet werden. Es müssen somit wesentlich weniger verschiedene Heizkesselgrößen gefertigt und an Lager gehalten werden als dies bisher notwendig war. Dies ermöglicht eine erhebliche Reduzierung der Produktions- und Lagerhaltungskosten. Bei der Installation eines Heizkessels mit einem einstufigen Brenner genügt es, die Mittel zur Regelung der Rauchgasströme entsprechend der Brennerleistung bzw. der optimalen Abgastemperatur von Hand einzustellen.According to the invention this object is achieved in a boiler of the type mentioned in that in addition to the leading out of the gap outlet from the interior leading outlet for flue gases is provided and that means for controlling a flue gas flow from the outlet of the gap and / or for control a flue gas stream are provided from the outlet of the interior. If the means for controlling the flue gas flows allow a flue gas flow from both the interspace and from the interior, the boiler can be run at full load. The flue gases can then flow through both the space between the two water jackets and through the interior of the other water jacket while transfering so much heat to these water jackets that they leave the boiler with a relatively low exhaust gas temperature. However, if the boiler is driven only at partial load, which may for example be 30% of full load, the outlet is closed from the gap, so that the flue gases can only flow through the interior. There is then no danger that they cool down too much and condensation problems occur in the rear of the boiler. The boiler is therefore well suited for use with a two-stage burner. But it would also be possible to use a modulating burner that can be steplessly controlled from minimum load to full load. In this case, it is expedient to choose a motor drive for the flue damper, so that they can be controlled continuously. It is thus possible to control the size of the flue gas flow flowing through the gap. The present invention also has the advantage that the same size of vessel is applicable for a relatively large power range. When using the single-stage burner, the same size boiler can be used for a relatively large power range. It must therefore be made much less different boiler sizes and kept in stock than was previously necessary. This allows a significant reduction in production and storage costs. When installing a boiler with a single-stage burner, it is sufficient to set the means for controlling the flue gas flows according to the burner output and the optimal exhaust gas temperature by hand.

Zweckmäßigerweise ist als Mittel zur Regelung des Rauchgasstroms eine Rauchgasklappe vorgesehen. Dabei kann vorgesehen werden, daß die Auslässe in ein gemeinsames Rauchrohr münden und daß die Rauchgasklappe so angeordnet ist, daß sie beim Schließen des aus dem Zwischenraum führenden Auslasses den aus dem Innenraum führenden Auslaß öffnet. Für maximale Brennerleistung kann die Rauchgasklappe somit in eine Mittelstellung gebracht werden und für minimale Brennerleistung wird der Auslaß aus dem Zwischenraum verschlossen. In der Mittelstellung hat die Rauchgasklappe praktisch keine Drosselwirkung für die beiden Auslässe, Mit einem Motorantrieb ist es aber auch möglich, die Rauchgasklappe in eine Stellung zu bringen, in welcher sie auf einen der Auslässe eine Drosselwirkung ausübt.Conveniently, a flue gas flap is provided as means for controlling the flue gas flow. It can be provided that the outlets open into a common flue pipe and that the flue damper is arranged so that it opens when closing the leading out of the gap outlet leading out of the interior outlet. For maximum burner output, the flue damper can thus be brought into a middle position and for minimum burner output, the outlet is closed from the intermediate space. In the center position, the flue damper has virtually no throttling effect for the two outlets, With a motor drive, but it is also possible to bring the flue damper in a position in which it exerts a throttling effect on one of the outlets.

Vorteilhaft ist der den Wärmetauschraum umgebende Wassermantel ein Doppelmantel mit einem inneren und einem äußeren Mantelraum, die durch eine Mittelwandung voneinander getrennt sind. Bei dieser Ausgestaltung wird bei der Inbetriebnahme des Heizkessels das Wasser im inneren Mantelraum rascher erwärmt als das Wasser im äußeren Mantelraum. Infolgedessen besteht bei Kaltstart lediglich für eine sehr geringe Zeit eine Gefahr von Kondensatbildung. Ferner kann das im Betrieb des Heizkessels zurückströmende relativ kühle Rücklaufwasser die innere Wandung nicht beaufschlagen. Vielmehr wirkt das im inneren Mantelraum enthaltene Wasser als Puffer gegen eine übermäßige Auskühlung der Innenwandung. Dies ist von besonderem Vorteil bei Niedertemperaturheizungen, wo die Rücklauftemperatur relativ tief ist. Infolgedessen besteht keine Gefahr der Bildung von unerwünschten Kondensaten, welche Korrosion zur Folge haben können. Ein weiterer gewichtiger Vorteil der beschriebenen Ausführung besteht darin, daß Stillstandverluste stark reduziert werden. Das Wasser im inneren Mantelraum wirkt bei Stillstand des Brenners als Isolation für den äußeren Mantelraum.Advantageously, the water jacket surrounding the heat exchange space is a double jacket with an inner and an outer jacket space, which are separated from each other by a middle wall. In this embodiment, the water in the inner shell space is heated more quickly than the water in the outer shell space during commissioning of the boiler. As a result, there is a risk of condensation during a cold start only for a very short time. Furthermore, the relatively cool return water flowing back during operation of the boiler can not act on the inner wall. Rather, the water contained in the inner shell space acts as a buffer against excessive cooling of the inner wall. This is of particular advantage in low temperature heaters where the return temperature is relatively low. As a result, there is no danger of formation of undesirable condensates, which can result in corrosion. Another significant advantage of the described embodiment is that standstill losses are greatly reduced. The water in the inner shell space acts as an insulation for the outer shell space when the burner is at a standstill.

Es hat sich als besonders vorteilhaft erwiesen, den Abstand zwischen der Innenwandung und der Mittelwandung des Doppelmantels relativ gering zu halten, vorzugsweise 10 bis 15 mm. Dadurch wird einmal Temperaturschichtung des Wassers im inneren Mantelraum vermieden. Es erfolgt also eine gute Temperaturverteilung. Ferner werden Siedegeräusche vermieden. Der Wasserinhalt des inneren Mantelraums ist relativ klein. Dies hat den Vorteil, daß im Betrieb eine rasche Aufheizung des Wassers im inneren Mantelraum erfolgt, wodurch einerseits Korrosionsprobleme vermieden werden und andererseits bei Bedarf dieses Wasser zur raschen Aufladung eines Boilers benutzt werden kann. Dieser Boiler kann daher relativ klein dimensioniert werden, weil er bei großem Warmwasserbedarf praktisch wie ein Durchlauferhitzer Warmwasser abgeben kann. Da der Wasserinhalt des inneren Mantelraums klein ist, geht durch die Abkühlung dieses Wassers nach der Aufladung des Boilers relativ wenig Wärme durch Stillstandsverlust verloren. Die Warmwasseraufbereitung erfolgt daher auch im Sommer mit einem sehr hohen Gesamtwirkungsgrad. Dies ist in markantem Gegensatz zu bekannten Heizkesseln, deren Gesamtwirkungsgrad im Sommer notorisch tief ist, so daß allgemein Elektroaufheizung für den Sommer vorgeschlagen wird. Zweckmäßigerweise ist der Abstand zwischen der Mittelwandung und der Außenwandung des Doppelmantels wesentlich größer als der Abstand zwischen der Innenwandung und der Mittelwandung. Dadurch ergibt sich ein ausreichendes Volumen für das beispielsweise für eine Raumheizung benötigte Kesselwasser.It has proven to be particularly advantageous to keep the distance between the inner wall and the middle wall of the double jacket relatively low, preferably 10 to 15 mm. As a result, once temperature stratification of the water in the inner shell space is avoided. So there is a good temperature distribution. Furthermore, Siedigeräusche be avoided. The water content of the inner shell space is relatively small. This has the advantage that during operation a rapid heating of the water takes place in the inner shell space, whereby on the one hand corrosion problems are avoided and on the other hand, if necessary, this water can be used for rapid charging of a boiler. This boiler can therefore be relatively small dimensions, because it can deliver hot water in a large hot water demand practically as a water heater. Since the water content of the inner jacket space is small, the cooling of this water after charging the boiler relatively little heat is lost by loss of standstill. The hot water treatment is therefore also in the summer with a very high overall efficiency. This is in marked contrast to known boilers, whose overall efficiency is notoriously low in summer, so that electric heating is generally proposed for the summer. Conveniently, the distance between the middle wall and the outer wall of the double jacket is substantially greater than the distance between the inner wall and the middle wall. This results in a sufficient volume for the boiler water required for example for a space heating.

Die Ausführung des Heizkessels erfolgt vorteilhaft so, daß der weitere Wassermantel etwa halb so lang ist wie der erstgenannte Wassermantel. So entsteht brennerseitig ein Brennraum mit großem Durchmesser, der sich speziell für moderne Vergasungsbrenner mit stark expandierender Flamme eignet. Stark expandierende Flammen haben eine günstige Flammentemperatur, bei welcher die Bildung von Stickoxiden sehr gering ist.The design of the boiler is advantageously carried out so that the further water jacket is about half as long as the former water jacket. On the burner side, this creates a combustion chamber with a large diameter, which is especially suitable for modern gasification burners with a strongly expanding flame. Highly expanding flames have a favorable flame temperature at which the formation of nitrogen oxides is very low.

Der weitere Wassermantel ist vorteilhaft an der Rückwand des Wärmetauschraums befestigt. Dies ergibt eine einfache Konstruktion des Heizkessels, bei dem das Innere gut zugänglich ist, um Reinigungsarbeiten durchzuführen.The further water jacket is advantageously attached to the rear wall of the heat exchange chamber. This results in a simple construction of the boiler, in which the interior is easily accessible to perform cleaning work.

Vorteilhaft wird in dem vom weiteren Wassermantel umschlossenen Innenraum ein Kernkörper unter Bildung eines Zwischenraums angeordnet. Dieser Zwischenraum erlaubt eine die Wärmeübertragung fördernde Führung der Rauchgase. Vorteilhaft werden die verschiedenen Komponenten des Heizkessels zylindrisch ausgeführt. Dies ermöglicht eine rationelle und preisgünstige Fertigung des Heizkessels, insbesondere wenn die verschiedenen Elemente koaxial zueinander angeordnet werden. Der Heizkessel kann beispielsweise als geschweißte Stahlkonstruktion realisiert werden. Auch kann der weitere Wassermantel und der Kernkörper von einem etwa schraubenförmigen Rauchgaskanal umgeben sein. Solche Rauchgaskanäle stellen einen relativ langen Weg für die Rauchgase dar, so daß ein optimaler Wärmeaustausch erfolgt. Alle Wärmeaustauschflächen werden gleichmäßig von den Rauchgasen bestrichen. Dies hat auch den Vorteil, daß die Gefahr einer Kondenswasserbildung aus den Rauchgasen noch weiter reduziert wird. Die Dimensionierung der Rauchgaskanäle erfolgt zweckmäßigerweise so, daß der Heizkessel mit einem Überdruck im Brennraum von etwa 0,5 bis 6mm Quecksilbersäule arbeitet, vorzugsweise 2 mm. Dies setzt die Verwendung von Mitteln zur Erzeugung des Überdrucks voraus, z, B. eines Gebläsebrenners. Eine solche Kombination arbeitet sehr geräuscharm. Die Rauchgaskanäle können durch einen Einsatz aus einem schraubenförmig gewundenen Blechstreifen gebildet werden. Dies ermöglicht eine äußerst billige Ausführung der Rauchgaskanäle. Weiter hat diese Ausführung den Vorteil, daß zur Reinigung des Heizkessels der aus einem schraubenförmig gewundenen Blechstreifen gebildeter Einsatz einfach herausgezogen werden kann.Advantageously, in the interior space enclosed by the further water jacket, a core body is arranged to form a gap. This space allows a heat transfer promoting guidance of the flue gases. Advantageously, the various components of the boiler are cylindrical. This allows a rational and inexpensive manufacture of the boiler, especially when the different elements are arranged coaxially with each other. The boiler can be realized, for example, as a welded steel construction. Also, the further water jacket and the core body may be surrounded by an approximately helical flue gas channel. Such flue gas ducts represent a relatively long way for the flue gases, so that an optimal heat exchange takes place. All heat exchange surfaces are evenly coated by the flue gases. This also has the advantage that the risk of condensation forming from the flue gases is further reduced. The dimensioning of the flue gas ducts is advantageously carried out so that the boiler works with an overpressure in the combustion chamber of about 0.5 to 6mm mercury column, preferably 2 mm. This requires the use of means for generating the overpressure, eg, a forced draft burner. Such a combination works very quietly. The flue gas ducts can be formed by a use of a helically wound metal strip. This allows a very cheap execution of the flue gas ducts. Next, this embodiment has the advantage that for cleaning the boiler formed from a helically wound metal strip insert can be easily pulled out.

Vorteilhaft nimmt der Querschnitt der Rauchgaskanäle von vorn nach hinten ab. Weil die Rauchgase sich auf dem Weg nach hinten abkühlen, nimmt ihr Volumen ab, so daß hinten der Querschnitt kleiner als vorn dimensioniert werden kann. Diese Verminderung des Querschnitts hat den Vorteil, das die Länge des Rauchgaskanals größer gemacht werden kann. Von besonderem Vorteil ist, daß durch den Rauchgaskanal eine starke Geräuschdämpfung erfolgt. Der sich ändernde Querschnitt verhindert nämlich die Bildung von resonanten Schwingungen. Die progressive Verminderung des Querschnitts kann beispielsweise dadurch erreicht werden, daß die Steigung des schraubenförmig gewundenen Blechstreifens von vorn nach hinten abnimmt. Da ein schraubenförmig gewundener Blechstreifen relativ wenig stabil ist, sind zweckmäßigerweise die Windungen des Blechstreifens mit Distanzhaltern miteinander verbunden. Dadurch kann der gewünschte Abstand zwischen je zwei Windungen festgelegt werden.Advantageously, the cross-section of the flue gas ducts decreases from the front to the rear. Because the flue gases cool down on the way back, their volume decreases so that the cross-section at the rear can be made smaller than the front. This reduction in cross-section has the advantage that the length of the flue gas duct can be made larger. It is particularly advantageous that a strong noise reduction takes place through the flue gas duct. The changing cross section prevents the formation of resonant vibrations. The progressive reduction of the cross section can be achieved, for example, that the slope of the helically wound metal strip decreases from front to back. Since a helically wound metal strip is relatively less stable, the turns of the metal strip are expediently connected to spacers. As a result, the desired distance between each two turns can be determined.

Vorteilhaft ist der Kernkörper hohl. Dabei können beispielsweise im Mantel Öffnungen vorgesehen werden. Der Hohlraum im Kernkörper wirkt vibrationsdämmpfend. Insbesondere kann das Gasvolumen im Kernkörper Druckunterschiede aufnehmen, welche durch den sogenannten Anfahrtsschock beim Zünden der Flamme entstehen. Der Kernkörper wirkt somit als Schalldämpfer. Besonders gute Schalldämpfeigenschaften werden erzielt, wenn der Hohlraum locker mit Mineralfasern, z. B. Steinwolle, gefüllt ist. Durch diese Füllung wird auch ein unerwünschter Wärmetransfer weitgehend verhindert.Advantageously, the core body is hollow. In this case, for example, openings can be provided in the jacket. The cavity in the core body acts vibration damping. In particular, the gas volume in the core body can absorb pressure differences which arise due to the so-called approach shock when the flame is ignited. The core body thus acts as a muffler. Particularly good soundproofing properties are achieved when the cavity is loose with mineral fibers, eg. B. rock wool, is filled. This filling also largely prevents unwanted heat transfer.

Vorteilhaft ist der weitere Wassermantel mit dem inneren Mantelraum des Doppelmantels in Serie geschaltet. Dadurch wird bewirkt, daß heißes Wasser aus dem inneren Mantelraum in den weiteren Wassermantel strömt, so daß dieser rasch über den Taupunktbereich gebracht wird, wo keine Kondensation mehr erfolgen kann. Zweckmäßigerweise ist zwischen dem weiteren Wassermantel und dem inneren Mantelraum eine Pumpe angeordnet. Dadurch wird eine gute Zirkulation erreicht, welche ihrerseits eine gute Temperaturverteilung bewirkt. Da das Wasservolumen relativ klein ist und daher rasch umgewälzt werden kann, wird die Wärme rasch abgeführt und Siedegeräusche werden vermieden. Es kann noch ein Ventil vorgesehen werden, um die Ladung eines Boilers zu bewirken.Advantageously, the further water jacket is connected in series with the inner jacket space of the double jacket. This causes hot water to flow from the inner shell space into the further water jacket so that it is quickly brought over the dew point range where condensation can no longer occur. Conveniently, a pump is arranged between the further water jacket and the inner jacket space. As a result, a good circulation is achieved, which in turn causes a good temperature distribution. Since the volume of water is relatively small and therefore can be circulated quickly, the heat is dissipated quickly and Siedigeräusche be avoided. It can still be provided a valve to effect the charge of a boiler.

Zweckmäßigerweise sind der Vorlauf und der Rücklauf des Heizkreises an den äußeren Mantelraum des Doppelmantels angeschlossen. Dabei ist es vorteilhaft, wenn der Vorlauf an einem Ende des Doppelmantels und der Rücklauf am anderen Ende des Doppelmantels angeschlossen sind.Appropriately, the flow and the return of the heating circuit are connected to the outer shell space of the double jacket. It is advantageous if the flow is connected to one end of the double jacket and the return at the other end of the double jacket.

Die Erfindung betrifft auch einen Heizkessel mit einem Wärmetauschraum und einem diesen umgebenden Wassermantel, der eine Außenwandung und eine Innenwandung aufweist. Erfindungsgemäß ist dieser Heizkesel dadurch gekennzeichnet, daß der Wassermantel ein Doppelmantel ist, der einen inneren und einen äußeren Mantelraum aufweist, die durch eine Mittelwandung voneinander getrennt sind. Dieser Heizkessel stellt eine Vereinfachung des zuvor beschriebenen Heizkessels dar. Wesentlich ist dabei, daß für beide Arten von Heizkesseln größtenteils die gleichen Bauteile verwendet werden können. Es erweist sich dabei als vorteilhaft, im Mantelraum einen Kernkörper unter Bildung eines Zwischenraums anzuordnen. Dies bringt wiederum die Vorteile einer günstigen Rauchgasführung, wobei auch ein schraubenförmiger Rauchgaskanal verwendbar ist, wie dies vorher beschrieben wurde.The invention also relates to a heating boiler with a heat exchange space and a surrounding water jacket, which has an outer wall and an inner wall. According to the invention this Heizkesel is characterized in that the water jacket is a double jacket having an inner and an outer shell space, which are separated by a middle wall. This boiler is a simplification of the boiler described above. It is essential that for both types of boilers largely the same components can be used. It proves to be advantageous to arrange a core body in the shell space to form a gap. This in turn brings the benefits of a favorable flue gas duct, whereby a helical flue gas duct is used, as previously described.

Ausführungsbeispielembodiment

Die Erfindung wird nun unter Bezugnahme auf die Zeichnung beschrieben. Es zeigtThe invention will now be described with reference to the drawings. It shows

Fig. 1: schematisch einen Heizkessel und seine Verwendung in einer Heizanlage mit einem zweistufigen oder einem modulierenden Brenner undFig. 1: schematically a boiler and its use in a heating system with a two-stage or a modulating burner and

Fig. 2: eine vereinfachte Ausführung des Heizkessels, die sich insbesondere für eine Heizanlage mit einem einstufigen Brenner eignet.Fig. 2: a simplified embodiment of the boiler, which is particularly suitable for a heating system with a single-stage burner.

Die Heizanlage von Fig. 1 zeigt einen Heizkessel 10, der von einem mehrstufigen, z.B. zweistufigen, odereinem modulierenden Brenner 11 befeuert wird. Der Wärmetauschraum 13 ist von einem Wassermantel 15 umgeben. Der Wassermantel 15 ist als Doppelmantel mit einem inneren Mantelraum 17 und einem äußeren Mantelraum 19 ausgebildet. Der innere Mantelraum 17 ist vom äußeren Mantelraum 19 durch eine Mittelwandung 21 getrennt. Der Abstand zwischen der Innenwandung 23 und der Mittelwandung 21 ist relativ gering, z.B. 10 bis 15 mm. Bei einem Heizkessel mit 25 KW Leistung wird das Wasservolumen im inneren Mantelraum auf etwa fünf Liter gehalten. Der Abstand zwischen der Mittelwandung 21 undderAußenwandung25istje nach Bedarf wesentlich größer als der Abstand zwischen der Innenwandung 23 und der Mittelwandung 21. Da die Schadstoffemissionen beim Start und beim Aufstellen am größten sind, müssen kurze Brennerlaufzeiten vermieden werden. Dementsprechend ist das Wasservolumen des äußeren Mantelraums zu bemessen. Das relativ kleine Wasservolumen des inneren Mantelraums 17 kann rasch auf Betriebstemperatur gebracht werden. Konzentrisch zum vorzugsweise zylindrischen Doppelmantel 15 ist ein weiterer zylindrischer Wassermantel 27 angeordnet. Der innere Mantelraum 17 ist mit dem Wassermantel 27 übereine Leitung 28 in Serie geschaltet, um Kondenswasserbildung und Korrosionsprobleme zu vermeiden.The heating system of Fig. 1 shows a heating boiler 10 which is of a multi-stage, e.g. two-stage, or a modulating burner 11 is fired. The heat exchange chamber 13 is surrounded by a water jacket 15. The water jacket 15 is formed as a double jacket with an inner jacket space 17 and an outer jacket space 19. The inner jacket space 17 is separated from the outer jacket space 19 by a middle wall 21. The distance between the inner wall 23 and the middle wall 21 is relatively small, e.g. 10 to 15 mm. In a boiler with 25 KW power, the volume of water in the inner shell space is maintained at about five liters. The distance between the center wall 21 and the outer wall 25 is substantially greater than the distance between the inner wall 23 and the middle wall 21, as needed. Since pollutant emissions are greatest at take-off and deployment, short burner run times must be avoided. Accordingly, the water volume of the outer shell space is to be measured. The relatively small volume of water of the inner jacket space 17 can be quickly brought to operating temperature. Concentric with the preferably cylindrical double jacket 15, a further cylindrical water jacket 27 is arranged. The inner jacket space 17 is connected in series with the water jacket 27 via a line 28 to prevent condensation and corrosion problems.

Der Wassermantel 27 ist an der Rückwand 29 des Wärmeaustauschraums 13 befestigt und erstreckt sich nur über einen Teil der Länge, z.B. der Hälfte, des Wärmeaustauschraums 13. Der vordere Teil 31 des Wärmeaustauschraumes 13 stellt daher einen Brennraum mit relativ großem Durchmesser dar, der sich speziell für moderne Vergasungsbrenner mit stark expandierender Flamme eignet. Der Zwischenraum zwischen dem Doppelmantel 15 und dem weiteren Wassermantel 27 besitzt hinten einen Rauchgasauslaß 33, der durch eine Rauchgasklappe 39 verschließbar ist. Der vom weiteren Wassermantel 27 umgebene Innenraum 35 besitzt einen Rauchgasauslaß 37. Dem Antrieb der Rauchgasklappe 39 dient ein Solenoid oder ein Motor 41, Bei der Verwendung des Heizkessels mit einem einstufigen Brenner ist ein Antrieb überflüssig. Die Rauchgasklappe wird dann manuell in die Lage gebracht, in welcher die Abgastemperatur den optimalen Wert aufweist. Konzentrisch zum weiteren Wassermantel 27 ist ein hohlzylinderförmiger Kernkörper 43 angeordnet. Dieser ist vorn durch eine Platte 45 aus feuerfestem Material verschlossen. Bei einem Zerstäuberbrenner dient die Platte 45 als Verbrennungshilfe. An der heißen Oberfläche können etwaige auftreffende Öltröpfchen verdampfen, worauf das entstehende Gas praktisch ohne Bildung von Schadstoffen verbrennt.The water jacket 27 is attached to the rear wall 29 of the heat exchange space 13 and extends only over part of the length, e.g. The front part 31 of the heat exchange space 13 therefore constitutes a relatively large diameter combustion chamber, which is particularly suitable for modern gasification burners with a strongly expanding flame. The space between the double jacket 15 and the other water jacket 27 has a rear flue gas outlet 33 which is closed by a flue 39. Surrounded by the other water jacket 27 interior 35 has a flue gas outlet 37. The drive of the flue damper 39 is a solenoid or a motor 41, When using the boiler with a single-stage burner is a drive superfluous. The flue damper is then manually brought into the position in which the exhaust gas temperature has the optimum value. Concentric with the further water jacket 27, a hollow cylindrical core body 43 is arranged. This is closed at the front by a plate 45 made of refractory material. In a Zerstäuberbrenner the plate 45 serves as a combustion aid. On the hot surface any impinging oil droplets can evaporate, whereupon the resulting gas burns virtually without the formation of pollutants.

Auch der hintere Teil ist vorteilhaft durch eine Scheibe 47 abgeschlossen. Im Mantel 49 befindet sich eine Vielzahl von Öffnungen 51. Im Hohlraum 50 befindet sich eine Füllung 52 aus Steinwolle oder dergleichen. Dadurch wird eine Schalldämpfung erreicht und ein unerwünschter Wärmetransfer zum Auslaß 33 weitgehend verhindert. Sowohl im Zwischenraum 53 als auch im 1The rear part is advantageously completed by a disc 47. In the shell 49 is a plurality of openings 51. In the cavity 50 is a filling 52 made of rock wool or the like. As a result, a sound attenuation is achieved and an undesirable heat transfer to the outlet 33 largely prevented. Both in the intermediate space 53 and in the first

Zwischenraum 55 ist ein schraubenförmiger Rauchgaskanal 54 bzw. 56 ausgebildet. Diese Rauchgaskanäle 54,56 bestehen aus einem schraubenförmig gewundenen Blechstreifen, welcher die Form eines Einsatzes hat. Die Steigung des schraubenförmig gewundenen Blechstreifens nimmt von vorn nach hinten ab, so daß auch der Querschnitt des Rauchgaskanals von vorn nach hinten abnimmt. Die Windungen des Blechstreifens sind mit Distanzhaltern,z.B. Stäbe (nicht eingezeichnet), miteinander verbunden.Interspace 55 is a helical flue gas channel 54 and 56, respectively. These flue gas channels 54,56 consist of a helically wound metal strip, which has the form of an insert. The pitch of the helically wound metal strip decreases from the front to the back, so that the cross section of the flue gas duct decreases from front to back. The turns of the metal strip are with spacers, z. Rods (not shown) connected to each other.

Aus der Figur 1 ist auch die Verwendung des Heizkessels 10 in einer Heizanlage ersichtlich. Vom vorderen Ende des äußeren Mantelraums 19 führt der Vorlauf 59 zu einem Mischventil 61 und von dort über die Umwälzpumpe 63 zu den Verbrauchern 65.From Figure 1, the use of the boiler 10 is visible in a heating system. From the front end of the outer jacket space 19, the flow 59 leads to a mixing valve 61 and from there via the circulation pump 63 to the consumers 65.

Der Rücklauf 67 wird am hinteren Ende des Heizkessels des äußeren Mantelraums 19 zugeführt. Ein Bypass 70 führt vom Rücklauf 67 zum Mischventil 61.The return 67 is supplied to the rear end of the boiler of the outer jacket space 19. A bypass 70 leads from the return 67 to the mixing valve 61.

Vom weiteren Wassermantel 27 führt eine Vorlaufleitung 71 zur Wärmetauscherschlange 73 des Boilers 75. Die Rücklaufleitung 77 von der Wärmetauscherschlange 73 führt über das Ventil 79 und die Pumpe 81 zum inneren Mantelraum 17. Von der Vorlaufleitung 71 ist ein Bypass 83 zum Ventil 79 vorgesehen.From the further water jacket 27, a feed line 71 leads to the heat exchanger coil 73 of the boiler 75. The return line 77 from the heat exchanger coil 73 leads via the valve 79 and the pump 81 to the inner jacket space 17. From the flow line 71, a bypass 83 is provided to the valve 79.

Mit der Bezugsziffer 85 ist schematisch eine Steuereinrichtung dargestellt, welche die Heizungsanlage steuert.The reference numeral 85, a control device is shown schematically, which controls the heating system.

Die vereinfachte Ausführungsform des Heizkessels gemäß Fig. 2 unterscheidet sich von jener der Fig. 1 dadurch, daß ein weiterer Wassermantel und ein weiterer Rauchgasauslaß mit einer Rauchgasklappe fehlt. Dafür hat der Kernkörper 43 einen größeren Durchmesser. Dieser Durchmesser entspricht dem Durchmesser des weiteren Wassermantels 27 von Fig. 1. Der Heizkessel von Fig. 2 kann daher praktisch mit den gleichen Teilen gebaut werden wie der Heizkessel von Fig. 1, was sich günstig auf die Produktionskosten und die Ersatzteilhaltung auswirkt. Da der weitere Wassermantel 27 von Fig. 1 weggelassen wurde, führt bei der Ausführungsform von Fig.2 die Vorlaufleitung 71 vom inneren Mantelraum 17 zur Wärmetauscherschlange 73. Im übrigen ist die Heizanlage gleich ausgestaltet wie in Fig. 1, so daß auf die diesbezügliche Beschreibung verwiesen werden kann.The simplified embodiment of the boiler according to FIG. 2 differs from that of FIG. 1 in that a further water jacket and a further flue gas outlet with a flue gas flap is missing. For this, the core body 43 has a larger diameter. This diameter corresponds to the diameter of the further water jacket 27 of Fig. 1. The boiler of Fig. 2 can therefore be built with practically the same parts as the boiler of Fig. 1, which has a favorable effect on the production costs and spare parts inventory. 1, the feed line 71 leads from the inner jacket space 17 to the heat exchanger coil 73 in the embodiment of FIG can be referenced.

Es sind verschiedene Änderungen möglich, ohne vom Erfindungsgedanken abzuweichen. So ist beispielsweise auch eine Kesselkonstruktion mit vertikaler Bauweise möglich.Various changes are possible without departing from the spirit. For example, a boiler construction with a vertical construction is possible.

Zur Wirkungsweise der Heizanlage von Fig. 1 wird noch folgendes bemerkt:For the operation of the heating system of Fig. 1, the following is noted:

Bei der Kesselaufladung läuft der Brenner mit Vollast. Relativ kühles Wasser wird von der Pumpe 81 in den inneren Mantelraum 17 gepumpt und über den ganzen Mantelraum ziemlich rasch und gleichmäßig verteilt. Es findet eine rasche Vorerhitzung statt, worauf das Wasser in den inneren Wassermantel 27 strömt, dort weiter erhitzt wird und zurückzur Wärmetauschschlange 73 des Boilers 75 fließt. Im Boiler 75 wird Wärmetausch das Brauchwasser erhitzt. Wenn die Steuerung 85 Wärmeerzeugung für die Raumheizung verlangt, läuft die Pumpe 81 auch, wenn der Boiler 75 nicht aufgeladen werden muß. Da aber das im inneren Wassermantel erhitzte Wasser über den Bypass 83 strömt, gelangt es ohne merklichen Wärmeverlust in den inneren Mantelraum 17. Von dort wird die Wärme, welche aus dem inneren Mantelraum 17 stammt oder aus dem Wärmetauschraum 13 direkt auf die Innenwandung 23 übertragen wird, über die Mittelwandung 21 auf den äußeren Mantelraum 19 übertragen, in welchem wegen des Betriebs der Umwälzpumpe 63 Zirkulation herrscht, welche den Wärmeaustausch begünstigt.When charging the boiler, the burner runs at full load. Relatively cool water is pumped by the pump 81 into the inner shell space 17 and distributed quite rapidly and evenly over the entire shell space. There is a rapid preheat, after which the water flows into the inner water jacket 27, where it is heated further and flows back to the heat exchange coil 73 of the boiler 75. In the boiler 75 heat exchange, the hot water is heated. If the controller 85 requires heat generation for space heating, the pump 81 will also run if the boiler 75 does not need to be recharged. However, since the water heated in the inner water jacket flows over the bypass 83, it passes without noticeable heat loss into the inner shell space 17. From there, the heat which originates from the inner shell space 17 or is transferred from the heat exchange chamber 13 directly to the inner wall 23 , transferred via the middle wall 21 on the outer jacket space 19, in which there is circulation due to the operation of the circulation pump 63, which favors the heat exchange.

Claims

claims:

1. A boiler, in particular for use with a multi-stage or modulating burner, with a heat exchange chamber (13), a surrounding water jacket (15) having an outer wall (25) and an inner wall (23), and one in the heat exchange chamber (13) arranged further water jacket (27) which extends over part of the length of the heat exchange chamber (13) and so forms a gap (53) and an interior space, and from the space (53) leading outlet (33) for flue gases, characterized characterized in that in addition to the leading out of the space outlet from the interior leading outlet (37) is provided for flue gases and that means are provided for controlling a flue gas flow from the outlet of the interspace and / or for controlling a flue gas flow from the outlet of the interior ,

2. Heating boiler according to claim 1, characterized in that a flue gas flap is provided as a means for controlling the flue gas flow.

3. A boiler according to claim 2, characterized in that the outlets open into a common flue pipe and that the flue gas flap is arranged so that it opens when closing the leading out of the gap outlet leading out of the interior outlet.

4. Heating boiler according to one of claims 1 to 4, characterized in that a motor drive for the flue gas flap are provided.

5. Heating boiler according to one of claims 1 to 4, characterized in that the heat exchange space (13) surrounding the water jacket (15) has a double jacket with an inner and an outer shell space (17,19) by a central wall (21) from each other are separated.

6. Heating boiler according to claim 5, characterized in that the distance between the inner wall (23) and the middle wall (21) of the double jacket (15) is relatively low, preferably 10 to 15mm.

7. Heating boiler according to claim 6, characterized in that the distance between the middle wall (21) and the outer wall (25) of the double jacket (15) is substantially greater than the distance between the inner wall (23) and the middle wall (21).

8. Heating boiler according to one of claims 1 to 7, characterized in that the further water jacket (27) is about half as long as the former water jacket (15).

9. Heating boiler according to one of claims 1 to 8, characterized in that the further water jacket (27) is fixed to the rear wall of the heat exchange chamber (13).

10. Heating boiler according to one of claims 1 to 9, characterized in that in the further water jacket (27) enclosed interior (50), a core body (43) to form a gap (53) is arranged.

11. Heating boiler according to one of claims 1 to 10, characterized in that the heat exchange chamber (13) is cylindrical.

12. Heating boiler according to one of claims 1 to 11, characterized in that the further water jacket (27) is cylindrical.

13. Heating boiler according to one of claims 1 to 12, characterized in that the core body (43) is cylindrical.

14. Heating boiler according to one of claims 1 to 13, characterized in that the further water jacket (27) is arranged coaxially in the heat exchange chamber (13).

15. Heating boiler according to one of claims 1 to 14, characterized in that the core body (43) is arranged coaxially in the further water jacket (27).

16. Heating boiler according to one of claims 1 to 15, characterized in that the further water jacket (27) by an approximately helical flue gas duct (54) is surrounded.

17. Heating boiler according to one of claims 1 to 16, characterized in that the core body (43) by an approximately helical flue gas channel (56) is surrounded.

18. A heating boiler according to claim 16 or 17, characterized in that the respective helical flue gas duct (54, 56) is formed by an insert of a helically wound metal strip.

19. Heating boiler according to one of claims 16 to 18, characterized in that the cross section of the respective flue gas duct (54, 56) decreases from front to rear.

20. Heating boiler according to one of claims 16 to 19, characterized in that the pitch of the helically wound metal strip decreases from front to back.

21. Heating boiler according to one of claims 18 to 20, characterized in that the turns of the sheet metal strip with spacers are interconnected.

22. Heating boiler according to one of claims 10 to 21, characterized in that the core body (43) has a cavity (50).

23. Heating boiler according to claim 22, characterized in that the core body (43) has openings (51).

24. Heating boiler according to claim 22 or 23, characterized in that the cavity (50) with mineral fibers, for. B. rock wool (52), is filled.

25. Heating boiler according to one of claims 5 to 24, characterized in that the further water jacket (27) with the inner jacket space (17) of the double jacket (15) is connected in series.

26. Heating system with a boiler according to one of claims 1 to 25, characterized in that between the further water jacket (27) and the inner jacket space (17) a pump (81) is arranged.

27. Heating system according to claim 26 with a boiler, characterized in that a valve (79) for charging a boiler (75) with the pump (81) is provided.

28. Heating system according to one of claims 25 to 27, characterized in that the course (59) and the return (67) of the heating circuit (65) to the outer jacket space (19) of the double jacket (15) are connected.

29. Heating system according to claim 28, characterized in that the flow (59) at one end of the double jacket (15) below and the return (67) at the other end of the double jacket (15) is connected at the top.

A heating boiler having a heat exchange space (13) and a water jacket (15) surrounding it, having an outer wall (25) and an inner wall (23), characterized in that the water jacket (15) is a double jacket comprising an inner and an outer shell Mantle space (17,19), which are separated by a middle wall (21).

31. A heating boiler according to claim 30, characterized in that in the heat exchange space a core body (43) to form a gap (54,13) is arranged.

32. Heating boiler according to claim 31, characterized in that the distance between the inner wall and the middle wall of the double jacket is relatively low, preferably 10 to 15mm.

33. A heating boiler according to claim 32, characterized in that the distance between the middle wall (21) and the outer wall (25) is substantially larger, preferably three to ten times, than the distance between the inner wall (23) and the middle wall (21). ,

34. Heating boiler according to one of claims 31 to 33, characterized in that the core body (43) is about half as long as the water jacket (15).

35. Heating boiler according to one of claims 31 to 34, characterized in that the core body (43) is cylindrical.

36. Heating boiler according to claim 35, characterized in that the core body (43) is arranged coaxially in the water jacket (15).

37. Heating boiler according to claim 36, characterized in that the core body (43) by an approximately helical flue gas duct (54) is surrounded.

38. A heating boiler according to claim 37, characterized in that the schraubenform ige flue gas channel (54) is formed by an insert of a helically wound metal strip.

39. Heating boiler according to one of claims 37 to 38, characterized in that the cross section of the flue gas duct (54) decreases from front to rear.

40. Heating boiler according to claim 38 or 39, characterized in that the pitch of the helically wound metal strip decreases from front to back.

41. Heating boiler according to one of claims 38 to 40, characterized in that the turns of the metal strip are connected to spacers with each other.

42. Heating boiler according to one of claims 31 to 41, characterized in that the core body (43) has a cavity (50).

43. Heating boiler according to claim 42, characterized in that the core body (43) in its jacket openings (51).

44. Heating boiler according to claim 42 or 43, characterized in that the cavity (50) with mineral fibers, for. B. rock wool (52), is filled.

45. Heating system with a boiler according to one of claims 30 to 44 with a boiler (75), characterized in that a portion of the inner jacket space (17) with another portion of the inner jacket space (17) via a pump (81) is connected ,

46. Heating system according to claim 45, characterized in that the lower portion of the inner jacket space (17) via the pump (81) with the upper portion of the inner jacket space (17) is connected.

47. Heating system according to claim 46 with a boiler, characterized in that a valve (79) for charging the boiler (75) with the pump (81) is provided.

48. Heating system according to one of claims 45 to 47, characterized in that the flow (59) and the return (67) of the heating circuit (65) to the outer jacket space (19) of the double jacket (15) are connected.

49. Heating system according to claim 48, characterized in that the flow (59) at one end of the double jacket (15) below and the return (67) at the other end of the double jacket (15) are connected at the top.

For this 2 sheets of drawings

Field of application of the invention

The invention relates to a heating boiler, in particular for use with a multi-stage or modulating burner, with a heat exchange space, a surrounding water jacket having an outer wall to an inner wall, and arranged in the heat exchange space further water jacket, extending over part of the length extends the heat exchange space and so forms a gap and an interior sheathed.

Characteristic of the known state of the art

French patent specification 2,154,347 describes a heating boiler in which two cylindrical water jackets are arranged concentrically with each other. In this case, the inner water jacket sheathed interior forms the burner chamber while the space between the water jackets serves as a flue gas channel. In this flue gas duct is a helical insert. This boiler is relatively complicated in construction. The manufacturing is therefore relatively expensive, and the service work is difficult to carry out and time consuming. Particularly disadvantageous is the risk of cold spots where condensation of pollutants from the flue gases can occur at reduced burner output, which then leads to corrosion problems. This boiler is therefore not suitable for operation with a multi-stage burner. Also, the prior art boiler sees no means for water heating, i. for so-called dhw production. It is important that the performance of boiler and burner are matched. So far, different boiler sizes were necessary in the lower power range in increments of about 5KW.

Object of the invention

The aim of the invention is to reduce the production costs of generic boilers and to increase its capabilities.

Explanation of the essence of the invention

It is therefore an object of the present invention to provide a structurally simple and inexpensive boiler with high thermal efficiency. The boiler should also be suitable for use with a multi-stage or modulating burner without the risk of corrosion. Furthermore, the boiler should have low standstill losses and should also be suitable for the treatment of hot water. According to the invention this object is achieved in a boiler of the type mentioned in that in addition to the leading out of the gap outlet from the interior leading outlet for flue gases is provided and that means for controlling a flue gas flow from the outlet of the gap and / or for control a flue gas stream are provided from the outlet of the interior. If the means for controlling the flue gas flows allow a flue gas flow from both the interspace and from the interior, the boiler can be run at full load. The flue gases can then flow through both the space between the two water jackets and through the interior of the other water jacket while transfering so much heat to these water jackets that they leave the boiler with a relatively low exhaust gas temperature. However, if the boiler is driven only at partial load, which may for example be 30% of full load, the outlet is closed from the gap, so that the flue gases can only flow through the interior. There is then no danger that they cool down too much and condensation problems occur in the rear of the boiler. The boiler is therefore well suited for use with a two-stage burner. But it would also be possible to use a modulating burner that can be steplessly controlled from minimum load to full load. In this case, it is expedient to choose a motor drive for the flue damper, so

This can also be controlled steplessly. It is thus possible to control the size of the flue gas flow flowing through the gap. The present invention also has the advantage that the same size of vessel is applicable for a relatively large power range. When using the single-stage burner, the same size boiler can be used for a relatively large power range. It must therefore be made much less different boiler sizes and kept in stock than was previously necessary. This allows a significant reduction in production and storage costs. When installing a boiler with a single-stage burner, it is sufficient to set the means for controlling the flue gas flows according to the burner output and the optimal exhaust gas temperature by hand.

Conveniently, a flue gas flap is provided as means for controlling the flue gas flow. It can be provided that the outlets open into a common flue pipe and that the flue damper is arranged so that it opens when closing the leading out of the gap outlet leading out of the interior outlet. For maximum burner output, the flue damper can thus be brought into a middle position and for minimum burner output, the outlet is closed from the intermediate space. In the middle position, the flue damper has virtually no throttle effect for the two outlets. With a motor drive, it is also possible to bring the flue damper in a position in which it exerts on one of the outlets a throttle effect.

Advantageously, the water jacket surrounding the heat exchange space is a double jacket with an inner and an outer jacket space, which are separated from each other by a middle wall. In this embodiment, the water in the inner shell space is heated more quickly than the water in the outer shell space during commissioning of the boiler. As a result, there is a risk of condensation during a cold start only for a very short time. Furthermore, the relatively cool return water flowing back during operation of the boiler can not act on the inner wall. Rather, the water contained in the inner shell space acts as a buffer against excessive cooling of the inner wall. This is of particular advantage in low temperature heaters where the return temperature is relatively low. As a result, there is no danger of formation of undesirable condensates, which can result in corrosion. Another significant advantage of the described embodiment is that standstill losses are greatly reduced. The water in the inner shell space acts as an insulation for the outer shell space when the burner is at a standstill.

It has proven to be particularly advantageous to keep the distance between the inner wall and the middle wall of the double jacket relatively low, preferably 10 to 15 mm. As a result, once temperature stratification of the water in the inner shell space is avoided. So there is a good temperature distribution. Furthermore, Siedigeräusche be avoided. The water content of the inner shell space is relatively small. This has the advantage that during operation a rapid heating of the water takes place in the inner shell space, whereby on the one hand corrosion problems are avoided and on the other hand, if necessary, this water can be used for rapid charging of a boiler. This boiler can therefore be relatively small dimensions, because it can deliver hot water in a large hot water demand practically as a water heater. Since the water content of the inner jacket space is small, the cooling of this water after charging the boiler relatively little heat is lost by loss of standstill. The hot water treatment is therefore also in the summer with a very high overall efficiency. This is in marked contrast to known boilers, whose overall efficiency is notoriously low in summer, so that electric heating is generally proposed for the summer. Conveniently, the distance between the middle wall and the outer wall of the double jacket is substantially greater than the distance between the inner wall and the middle wall. This results in a sufficient volume for the boiler water required for example for a space heating.

The design of the boiler is advantageously carried out so that the further water jacket is about half as long as the former water jacket. On the burner side, this creates a combustion chamber with a large diameter, which is especially suitable for modern gasification burners with a strongly expanding flame. Highly expanding flames have a favorable flame temperature at which the formation of nitrogen oxides is very low.

The further water jacket is advantageously attached to the rear wall of the heat exchange chamber. This results in a simple construction of the boiler, in which the interior is easily accessible to perform cleaning work. Advantageously, in the interior space enclosed by the further water jacket, a core body is arranged to form a gap. This space allows a heat transfer promoting guidance of the flue gases. Advantageously, the various components of the boiler are cylindrical. This allows a rational and inexpensive manufacture of the boiler, especially when the different elements are arranged coaxially with each other. The boiler can be realized, for example, as a welded steel construction. Also, the further water jacket and the core body may be surrounded by an approximately helical flue gas channel. Such flue gas ducts represent a relatively long way for the flue gases, so that an optimal heat exchange takes place. All heat exchange surfaces are evenly coated by the flue gases. This also has the advantage that the risk of condensation forming from the flue gases is further reduced. The dimensioning of the flue gas ducts is advantageously carried out so that the boiler works with an overpressure in the combustion chamber of about 0.5 to 6mm mercury column, preferably 2mm. This implies the use of means for generating the overpressure, e.g. a fan burner. Such a combination works very quietly. The flue gas ducts can be formed by a use of a helically wound metal strip. This allows a very cheap execution of the flue gas ducts. Next, this embodiment has the advantage that for cleaning the boiler formed from a helically wound metal strip insert can be easily pulled out.

Advantageously, the cross-section of the flue gas ducts decreases from the front to the rear. Because the flue gases cool down on the way back, their volume decreases, so that at the rear the cross-section can be made smaller than the front. This reduction in cross-section has the advantage that the length of the flue gas duct can be made larger. It is particularly advantageous that a strong noise reduction takes place through the flue gas duct. The changing cross section prevents the formation of resonant vibrations. The progressive reduction of the cross section can be achieved, for example, that the slope of the helically wound metal strip decreases from front to back. Since a helically wound metal strip is relatively less stable, the turns of the metal strip are expediently connected to spacers. As a result, the desired distance between each two turns can be determined.

Advantageously, the core body is hollow. In this case, for example, openings can be provided in the jacket. The cavity in the core body acts vibration damping. In particular, the gas volume in the core body can absorb pressure differences which arise due to the so-called approach shock when the flame is ignited. The core body thus acts as a muffler. Particularly good soundproofing properties are achieved when the cavity is loose with mineral fibers, eg. B. rock wool, is filled. This filling also largely prevents unwanted heat transfer. Advantageously, the further water jacket is connected in series with the inner jacket space of the double jacket. This causes hot water to flow from the inner shell space into the further water jacket so that it is quickly brought over the dew point range where condensation can no longer occur. Conveniently, a pump is arranged between the further water jacket and the inner jacket space. As a result, a good circulation is achieved, which in turn causes a good temperature distribution. Since the volume of water is relatively small and therefore can be circulated quickly, the heat is dissipated quickly and Siedigeräusche be avoided. It can still be provided a valve to effect the charge of a boiler.

Appropriately, the flow and the return of the heating circuit are connected to the outer shell space of the double jacket. It is advantageous if the flow is connected to one end of the double jacket and the return at the other end of the double jacket.

The invention also relates to a heating boiler with a heat exchange space and a surrounding water jacket, which has an outer wall and an inner wall. According to the invention this Heizkesel is characterized in that the water jacket is a double jacket having an inner and an outer shell space, which are separated by a middle wall. This boiler is a simplification of the boiler described above. It is essential that for both types of boilers largely the same components can be used. It proves to be advantageous to arrange a core body in the shell space to form a gap. This in turn brings the benefits of a favorable flue gas duct, whereby a helical flue gas duct is used, as previously described.

embodiment

The invention will now be described with reference to the drawings. It shows

Fig. 1: schematically a boiler and its use in a heating system with a two-stage or a

modulating burner and
Fig. 2: a simplified embodiment of the boiler, which is particularly suitable for a heating system with a single-stage burner.

The heating system of Fig. 1 shows a heating boiler 10 which is of a multi-stage, e.g. two-stage, or a modulating burner 11 is fired. The heat exchange chamber 13 is surrounded by a water jacket 15. The water jacket 15 is formed as a double jacket with an inner jacket space 17 and an outer jacket space 19. The inner jacket space 17 is separated from the outer jacket space 19 by a middle wall 21. The distance between the inner wall 23 and the middle wall 21 is relatively small, e.g. 10 to 15mm. In a boiler with 25KW power, the volume of water in the inner shell space is kept at about five liters. The distance between the middle wall 21 and the outer wall 25 is substantially larger than the distance between the inner wall 23 and the middle wall 21 as needed. Since the pollutant emissions at startup and when setting up are greatest, short burner run times must be avoided. Accordingly, the water volume of the outer shell space is to be measured. The relatively small volume of water of the inner jacket space 17 can be quickly brought to operating temperature. Concentric with the preferably cylindrical double jacket 15, a further cylindrical water jacket 27 is arranged. The inner shell space 17 is connected to the water jacket 27 via a line 28 in series to prevent condensation and corrosion problems. The water jacket 27 is attached to the rear wall 29 of the heat exchange rough ms 13 and extends only over part of the length, e.g. The front part 31 of the heat exchange space 13 therefore constitutes a relatively large diameter combustion chamber, which is particularly suitable for modern gasification burners with a strongly expanding flame. The space between the double jacket 15 and the other water jacket 27 has a rear flue gas outlet 33 which is closed by a flue 39. The interior space 35 surrounded by the further water jacket 27 has a flue gas outlet 37. The drive of the flue gas flap 39 is a solenoid or a motor 41. When using the boiler with a single-stage burner drive is superfluous. The flue damper is then manually brought into the position in which the exhaust gas temperature has the optimum value. Concentric with the further water jacket 27, a hollow cylindrical core body 43 is arranged. This is closed at the front by a plate 45 made of refractory material. In a Zerstäuberbrenner the plate 45 serves as a combustion aid. On the hot surface, any impinging droplets can evaporate, whereupon the resulting gas burns practically without formation of pollutants. The rear part is advantageously completed by a disc 47. In the shell 49 is a plurality of openings 51. In the cavity 50 is a filling 52 made of rock wool or the like. As a result, a sound attenuation is achieved and an undesirable heat transfer to the outlet 33 largely prevented. Both in the intermediate space 53 and in the intermediate space 55, a helical flue gas channel 54 and 56 is formed. These flue gas ducts 54, 56 consist of a helically wound sheet metal strip, which has the form of an insert. The pitch of the helically wound metal strip decreases from the front to the back, so that the cross section of the flue gas duct decreases from front to back. The turns of the metal strip are spacers, z. B. bars (not shown), interconnected.

From Figure 1, the use of the boiler 10 is visible in a heating system. From the front end of the outer jacket space 19, the feed 59 leads to a mixing valve 61 and from there via the circulation pump 63 to the consumers 65. The return 67 is fed to the rear end of the boiler of the outer jacket space 19. A bypass 70 leads from the return 67 to the mixing valve 61.

From the further water jacket 27, a feed line 71 leads to the heat exchanger coil 73 of the boiler 75. The return line 77 from the heat exchanger coil 73 leads via the valve 79 and the pump 81 to the inner jacket space 17. From the flow line 71, a bypass 83 is provided to the valve 79.

The reference numeral 85, a control device is shown schematically, which controls the heating system.

The simplified embodiment of the boiler according to FIG. 2 differs from that of FIG. 1 in that a further water jacket and a further flue gas outlet with a flue gas flap is missing. For this, the core body 43 has a larger diameter. This diameter corresponds to the diameter of the further water jacket 27 of Fig. 1. The boiler of Fig. 2 can therefore be built with practically the same parts as the boiler of Fig. 1, which has a favorable effect on the production costs and spare parts inventory. Since the other water jacket 27 has been omitted from Fig. 1, leads in the embodiment of Fig. 2, the supply line 71 from the inner jacket space 17 to the heat exchanger coil 73. Moreover, the heating system is designed the same as in Fig. 1, so that to the relevant description can be referenced.

Various changes are possible without departing from the spirit. For example, a boiler construction with a vertical construction is possible.

For the operation of the heating system of Fig. 1, the following is noted:

When charging the boiler, the burner runs at full load. Relatively cool water is pumped by the pump 81 into the inner shell space 17 and distributed quite rapidly and evenly over the entire shell space. There is a rapid preheat, after which the water flows into the inner water jacket 27, where it is heated further and flows back to the heat exchange coil 73 of the boiler 75. In the boiler 75 heat exchange, the hot water is heated. If the controller 85 requires heat generation for space heating, the pump 81 will also run if the boiler 75 does not need to be recharged. However, since the water heated in the inner water jacket flows via the bypass 83, it passes without appreciable heat loss into the inner shell space

17. From there, the heat which originates from the inner jacket space 17 or is transferred from the heat exchange chamber 13 directly to the inner wall 23 is transmitted via the middle wall 21 to the outer jacket space 19, in which there is circulation due to the operation of the circulation pump 63, which favors the heat exchange.