EP0680586A1

EP0680586A1 - Heating boiler

Info

Publication number: EP0680586A1
Application number: EP94904968A
Authority: EP
Inventors: Hans Dr. Viessmann
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-01-29
Filing date: 1994-01-25
Publication date: 1995-11-08
Also published as: DE4302479A1; RU2101622C1; WO1994017338A1; CN1094495A; AU5878994A

Abstract

A heating boiler for the combustion of liquid or gaseous fuels consists of at least one intermediate member (3) arranged between two terminal members (1, 2), through which a heat transfer medium can flow. All members are made of light metal castings and are assembled together in a tight manner into a block (B) which forms a boiler body provided with flow and return connection pieces (4, 5) and having a furnace (10), heating air drafts and a combustion gas collecting chamber (12) with discharge pipes (9), in which at least the heat transfer surfaces located behind the furnace (10) are provided with heat transfer surface extensions (7). In each plate-shaped member (1, 2, 3) the cavity through which the heat transfer medium can flow consists of a pipe (6) or pipe system (6') formed, on casting, in the light metal body and whose flow and return connection pieces (4, 5) project out of each light metal body. These flow and return connection pieces (4, 5) are connected to flow and return collectors (4, 5) arranged outside of the block (B). The intermediate member (3) with an opening (10') which forms the furnace (10) is provided on both sides with a marginal connection projection (9) which extends around its circumference and whose ends are designed as gas-sealing surfaces (8'). Both terminal members (1, 2) are provided with similar projections on their side which faces the intermediate member.

Description

boiler

The invention relates to a boiler for the combustion of liquid or gaseous fuels, consisting of at least one intermediate member arranged between two flowable end members and also flowable through the heat transfer medium, all members being made of cast metal and forming one with the supply and return connections Provided block forming a combustion chamber, heating gas flues and an exhaust gas chamber with a flue pipe having boiler body are sealed together.

Such boilers, which are also known as sectional boilers, are known. The limbs of such boilers generally consist of gray cast iron hollow bodies and require the use of appropriate cores for their shaping, which, apart from disposal problems for the core molding sand, is associated with considerable manufacturing outlay. In addition, the links must be nippled against each other in order to be able to assemble them into a boiler housing block. In order to protect the links on the hot gas side against any acidic condensate and make them resistant, the gray cast iron links on the hot gas side must also be provided with suitable resistant coatings, which is not unproblematic, because this can only be put into practice if a self-contained coating can be produced with the gray cast iron, which creates a permanently solid connection.

In addition to the manufacture of such boilers or heat exchangers from gray cast iron, it is known from DE-A-36 22 260 to manufacture such boilers from aluminum alloys using the die-casting process, which is cheaper and also has the advantage of cheaper heat transfer. The principle of the well-known link structure vcn -.- eiz esse-u. -.-. ε-τ sicn a oei -ιeiocr-. r-icr-xc activated, us-- it is τ enor'ierlic, • → .z. e a iiieα oil - ocic-ler-. to vεrsc-.iv.'ei e, u: .. .- «. s uiese -.-. oeicie: - Dcr-Cie.- a :; r-.o ---- i.iCcr er zu form, which then nipples with appropriate hollow bodies and must be assembled into a boiler.

Compared to gray cast iron, light metal or light metal alloys such as aluminum or aluminum alloys also have the advantage that they are resistant to condensate from desulfurized natural gas, but not to the heating water as a heat transfer medium, which generally becomes basic, which sooner or later always leads to erosion on the water side of such light metal boilers. In addition, high demands are to be made of the light metal casting, since the finished casting or the light metal members must be free of pores, ie high demands must be made of the light metal, and light metal or Aluminum scrap can be used.

The invention is therefore based on a boiler of the generic type, the task of creating a boiler that is corrosion-resistant on both the heating gas and water side and for which it does not matter whether and to what extent the cast light metal body is porous or not, combined with the proviso that the casting can be cast without a core, and that the boiler, although formed from links, does not require the links to be nipped between them.

This object is achieved with a boiler of the type mentioned at the outset according to the invention in that the cavity in each plate-shaped member through which the heat transfer medium can flow is formed from a pipe or pipe system cast into the light metal body, the front and return connections of each The light metal body protrude and are connected to flow and return collectors arranged outside the block, and that the at least one intermediate member provided with an opening forming the combustion chamber is provided on both sides and the two end members are provided with peripheral edge connecting webs towards the intermediate member connection side and their ends in Form of gas sealing surfaces are formed. The pipe system used with the cast-in pipe, which extends in a serpentine shape through the light metal body, or Q, which is used in more detail below, is a steel pipe that is commonly used in boiler construction and ensures good watertightness against corrosion on the The water side is sufficiently resistant and, in this respect, is a prerequisite for the use of non-qualitative light metal which is resistant to condensate on the heating gas side. In order to meet the requirement for coreless shaping of the links, the flow and return connections are also not formed in the form of channels in the light metal bodies forming the links, but the ends of the tube or the tube system simply protrude laterally from the links and are on outer flow and return collectors connected.

To form the combustion chamber, the intermediate elements have corresponding recesses or openings, which then form the combustion chamber when several individual elements are joined together. The end members on the one hand have corresponding openings for the burner intervention and on the other hand the heating gas discharge connection. These recesses and openings also do not require the use of cores when casting.

In order to be able to cast light metal on all sides of the pipe or the pipe system in the case of coreless casting, the pipe or the pipe system is also provided with a necessary number of spacers made of light metal, with which the pipe or pipe system is inserted into the casting mold. Aluminum or light metal alloys are known to have a larger coefficient of expansion than iron. As a result, it is of great importance to design the boiler in such a way that the cast-in pipes or pipe systems expand similarly to the aluminum, in order to avoid the pipe system being unduly stressed by tensile stresses and, for example, welding seams on the pipe system . For this purpose, the tubes are advantageously provided with grooves at certain intervals, which are not very deep (for example, only corresponding to the material thickness of the tube) but relatively wide should be. When the pipes are cast around, the liquid aluminum also fills these beads, so that the light metal body, when it expands, cannot slide over the pipe system due to the engagement in the beads. Given the large number of beads that are rolled into the tubes, the change in length in the beads need only be minimal.

As far as the peripheral edge connecting webs are concerned, these naturally only extend where an external seal or seal is required. The height of these peripheral edge connecting webs is dimensioned such that the transmission area enlargements end below the plane in which the upper edge of the webs extends.

The boiler according to the invention is provided in particular as a boiler that can be operated with an atmospheric burner, but there is nothing to prevent it from being operated with a forced draft burner.

The boiler according to the invention and advantageous further developments are explained in more detail below with the aid of exemplary embodiments.

It shows

Figure 1 is an intermediate member of the boiler in side view.

Figure 2 shows a section through the intermediate member along line II-II in Fig. 1.

3 shows an intermediate member of the boiler in a side view with a slightly different embodiment of the pipe system;

3A, B in section special embodiments of the pipes forming the pipe system; 4 shows a section through the intermediate link along line IV-IV in Fig. 3.

Fig. 5 is a side view of the boiler, assembled from links according to Figures 1 and 3.

Figure 6 is an intermediate member of the boiler in side view with a meandering tube.

7 shows a side view of a further embodiment of the boiler;

8 a perspective and schematic view of a special embodiment of the boiler;

8A, B,

C, D on average the formation of the individual members belonging to the embodiment according to FIG. 8;

Fig. 9 with bypass channels intermediate members and

Fig.lθA, B an intermediate belonging to the embodiment of FIG. 7.

The boiler consists of at least one intermediate member 3 arranged between two end members 1, 2 through which flow can pass, and also through which the heat transfer medium can flow, all members being made of cast metal and forming a combustion chamber 10 and a gas outlet provided with the supply and return connections 4, 5 9 comprising boiler body-forming block B are joined together in a sealed manner. For such a boiler formed from a plurality of links 1 to 3, it is now essential that the links 1 to 3 are formed from core-free shaped light metal and in each link 1 to 3 the flowable cavity consists of a tube 6 or cast into the light metal body Pipe system 6 'is formed, the flow and return connections 4, 5 from each light metal body protrude and are connected to the flow and return collectors 4 ', 5'.

The at least one intermediate link 3 is on both sides and the two end links 1, 2 are provided toward the intermediate link connection side S on their large flank surfaces F with heat transfer surface enlargements 7 at least in the area of the gas extraction section AS and with peripheral edge connecting webs 8.

1 shows an intermediate member 3 in a side view and with a pipe system 6 ', the individual pipes of the pipe system being shown only in dashed lines but partially cross-hatched for clarification. The intermediate link according to FIGS. 3, 4 only differs from that according to FIG. 1 in that the pipe system 6 ', which is also partially cross-hatched, has a different arrangement structure of the individual pipes.

6, a meandering tube 6 is cast in the intermediate member 3.

All of the embodiments according to FIGS. 1, 3 and 6 are intended for boilers with an atmospheric burner (not shown), the intermediate members 3 shown having openings 10 'corresponding to the desired cross section of the combustion chamber 10. Since the heating gases flow upwards through the gas extraction section AS, the peripheral edge connecting webs 8 (see FIG. 3) open upwards, an exhaust gas collection chamber 12 with exhaust gas extractor 9 being arranged over the entire block B (see FIG. 5).

The individual tubes forming the cross-hatched tube system 6 'in FIGS. 1, 3 are expedient and, as shown in section in FIG. 3A, B, are oval-shaped in cross-section, their broad sides BS against the flank surfaces F of the links 1 to 3 in Light metal body are arranged oriented in order to "get in the way" of the largest possible heat transfer surface in the direction of heat application. Furthermore, the pipes 6 "for the pipe system are provided with beads 11 which are arranged at certain intervals from one another, but which are only recessed towards the water side, for example, by a wall thickness, which is sufficient to sufficiently differentiate the different material components from each other with thermal expansion Anchoring, which results from the fact that the liquid light metal naturally fills the beads 11 from the outside as well during casting. This anchoring expands the light metal body and the integrated pipe system together largely evenly when exposed to heat. Such different thermal expansions move only in the hundredths of a millimeter range, and these anchors have the purpose of essentially keeping the weld seams of the pipe system free of tensile loads which could otherwise lead to weld cracks on the pipe system.

The heat transfer surface enlargements 7, which are represented continuously and, for example, as knobs 7 ', are automatically created when the casting mold (mold) is designed accordingly, and likewise the condensate collection and discharge webs 11, which are used to ensure that any condensate that arises from the side is discharged. so that the condensate cannot drip onto the burner (not shown).

The pipes 6 or 6 "of the cast-in pipe system 6 'are, insofar as it is not a matter of vertically oriented pipe sections (see FIG. 1), arranged in a correspondingly increasing manner, as shown, to one or the other side SS , so that possibly forming steam bubbles can flow off.

As can be seen from FIG. 4, with a view to the high temperature load, the knobs 7 'in this area in the inflow area A above the combustion chamber 10 are dimensioned to be lower than those in the subsequent area F ^ of the gas exhaust section AS. In the exemplary embodiment according to FIG. 7, the links 1 to 3 are arranged upside down, so that the combustion chamber 10 which is then intended for a forced-air burner (not shown) is located at the top of the block, that is to say the gas is drawn down here into an exhaust gas collection chamber arranged there 12. The circulating webs 8 also extend in the upper horizontal transverse region and are kept correspondingly thick (see FIGS. 10A, B), in order to optionally pour in several pipe strands next to one another and to dissipate the amount of heat transferred there to a sufficient extent can.

The same also applies to a special embodiment according to FIG. 8, in which the combustion chamber 10 for a forced-air burner is arranged essentially horizontally, which is followed by the extraction section AS, oriented vertically downwards at the end of the combustion chamber 10. The combustion chamber 10 extends across the entire upper part, and the extraction section AS is located in the downward leg 16 of the generally rectangular block B. The shape of the combustion chamber or the combustion chamber 10 can, as shown in FIG. 8 indicated by dashed lines, at the end distant from the burner, with a corresponding shaping of the links 1 to 3, can also be arcuate. The members belonging to this embodiment are illustrated in detail in FIGS. 8A to D. FIG. 8A shows the two end links 1 ', 2' and FIG. 8B the intermediate links 3 'of the pipe systems cast with the respective ones, FIG. 8C being a section along line I-I in FIG. 8B. The intermediate link according to FIG. 8D differs from that according to FIG. 8B in that a lockable bypass channel 13 is present here. Otherwise, the same reference numerals for corresponding elements are used in these embodiments as before, so that these links need no additional explanation.

Incidentally, since the individual links are produced by the casting process, at least one of the links can be easily provided with a closable bypass channel 13, which is formed by a pipe made of condensate-resistant material which is also cast in. The opened bypass duct 13 then ensures speaking raising the flue gas temperature (see Fig. 9), if the boiler is not to be operated as a condensing boiler These vertical channels parallel to the heating gas flues are required in order to allow uncooled heating gases to flow through these channels into the exhaust gas collection chamber in order to raise the exhaust gas temperature.

In the embodiment of the links 1 to 3 in the sense of FIGS. 1, 3 and 6, which are intended for an atmospheric burner, the entire block B (see FIG. 6) is provided at the bottom with a condensate collecting trough 14.

In order to be able to join the individual members 1 to 3 to form a gas-tight block B with the insertion of sealing compound on the sealing surfaces 8 'of the peripheral edge connecting webs 8, these are provided with suitable and, if one does not want to provide correspondingly long tension anchors between the end members 1, 2 screwable clamping eyes 15, which are only shown on the intermediate link in Fig. 3. Incidentally, grooves 8 ″ (see FIG. 4) are pierced into the gas sealing surfaces 8 ′ at the ends of the peripheral edge webs 8 in order to be able to better fit suitable sealing means between the links 1 to 3.

1, 3, 6, 7 and 10A, B, the burner-side end member 1 has one with respect to the opening 10 'or the end members 1, 2 for the assembly of Heizkessel¬ blocks with intermediate members Intermediate members 3 have a smaller opening 10 ", as indicated by dash-dotted lines in FIG. 3, and the other end member 2 has no such opening, since this end member 2 forms the rear wall 2" of the combustion chamber or the combustion chamber. Since this rear wall 2 "is subjected to a great deal of heat, the water-carrying pipe system is also arranged there in the region of the rear wall 2 ', in fact the same or similar to the end members 1', 2 'shown in FIG on the whole block B according to FIG. 8 there form the side flank of block B.

Claims

Claims:

1. Boiler for the combustion of liquid or gaseous fuels, consisting of at least one intermediate member (3) 'arranged between two end members (1, 2) through which the heat transfer medium can flow and also through which intermediate members (3)' are made, all members being made of cast light metal and forming one with the Flow and return connections (4, 5) are provided, a combustion chamber (10), heating gas flues and an exhaust gas chamber (12) with exhaust pipe (9) having boiler body-forming block (B) are joined together sealed, in which at least the heat transfer surfaces behind the combustion chamber (10) are provided with heat transfer surface enlargements (7), characterized in that in each plate-shaped member (1, 2, 3) the cavity through which the heat transfer medium flows can be obtained from a tube (6) cast into the light metal body ) or pipe system (6 ') is formed, the flow and return connections (4, 5) from j protrude from the light metal body and are connected to flow and return plugs (4 ', 5') arranged on the outside of the block (B), and that the at least one intermediate member (3.) provided with an opening (10 ') forming the combustion chamber (10) ) on both sides and the two end links (1, 2) towards the intermediate link connection side (8) with peripheral edge connection webs (8) and the ends of which are designed in the form of gas sealing surfaces (8 ').

2. Boiler according to claim 1, characterized in that the at least one intermediate member (3), seen in Seitenan¬ view, is formed from a plate-shaped body, the upper half of which forms the Nachschalt- heat exchange surface, and in the lower half of the combustion chamber (10) forming opening (10 ') is arranged.

3. Boiler according to "nspruch 1, characterized in that the at least one intermediate member (3) seen in side view, is formed from a plate-shaped body, the lower half of which forms the Nachschaltwärme- exchange surface, and in the upper half of the combustion chamber (10th ) forming opening (10 ') is arranged.

4. Boiler according to claim 1, characterized in that the at least one intermediate link (3) and the two end links (1, 2), seen in side view, are formed from essentially rectangular bodies, the secondary heat exchange surfaces in the downward-pointing leg ( 16) the carcasses are arranged and the firebox (10) is arranged in the upper part of the intermediate member (3) and between the two end members (1, 2).

5. Boiler according to one of claims 1 to 4, characterized in that the tube (6) or the tube system (6 ') forming tubes (8 ") are oval in cross section and with their broad sides (B) against the flank surfaces (F) the links (1 to 3) are arranged oriented in the light metal body.

6. Boiler according to one of claims 1 to 5, d a d u r c h g e k e n n z e i c h n e t that the pipe (6) or the pipe system (6 ') forming pipes (6 ") with spaced Sickun¬ gene (11) are provided.

7. Boiler according to one of claims 1 to 6, characterized in that the heat transfer area enlargements (7), such as knobs, ribs or the like. In the Anstron area (A) are dimensioned lower than in the subsequent area (F * ^) of the gas extraction section (AS ).

8. Boiler according to one of claims 1 to 7, characterized in that the light metal body of the links (1 to 3) on nen flank surfaces acted upon by heating gases (F) with an inclination towards one or the other narrow side (SS) of the members oriented Condensate collection and drainage ridges (11 ') are provided.

9. Boiler according to one of claims 1 to 8, d a d u r c h g e k e n n z e i c h n e t that the intermediate members (3) are provided with closable bypass channels (13).

10. Boiler according to one of claims 1 to 9, characterized in that when the gas discharge section (AS) is arranged behind and / or under the combustion chamber (10) at least the circumferential edge connecting webs (8) which limit the fire chamber (10) upwards are reinforced and a plurality of water-carrying pipes (6 ") are cast in them.

11. Boiler according to one of claims 1 to 10, d a d u r c h g e k e n n z e i c h n e t that the peripheral edge connecting webs (8) are slightly larger than the heat transfer area enlargements (7).