DE4229146C1 - Gas boiler - Google Patents

Description

The invention relates to a gas boiler consisting of a water-bearing housing, in which one with burner equipped combustion chamber and between this and the fume cupboard connecting piece of an exhaust gas collection chamber from the heat Post-flow heat exchanger through which media can flow with inflow and outflow connections for the me to be heated dium is arranged.

Boilers of the type mentioned are generally known and in use, so there is no particular one in this regard Written proof is required. Depends on the Output size and construction of such boilers have the secondary heat exchanger different con structures, for example in the form of several in parallel arranged pockets, around which the heating water flows be or in the form of one or more tubes formed, so-called lamella blocks, the lamella len form the outer fins of the pipes. With boilers the The first-mentioned type is used for hot water preparation usually in separate hot water tanks and at those of the second type, which are usually such smaller power acts in that the hot water pipes uses pipes through which the hot water to be heated is passed through the heating water has a high temperature must, but what ver with a strong calcification tendency  is bound. Regardless of whether with such Heizkes only heating water or hot water is heated is to produce such secondary heat exchanger in any case quite expensive and if it are bags, including their integration into the Kettle, since tight connections from pocket to pocket be put or the bags individually in appropriate Connection openings of the boiler housing are welded have to. Such an integration effort exists in Form of lamella blocks trained secondary heat are not exchanging, but at least sufficiently large To get heat transfer surfaces must do that Pipes with considerable effort with external fins be provided. In addition, the Nachschaltwär Metauscher even if the cross section is not circular Combustion chambers from the heating gases, seen in cross section, flow is essentially circular, which Circular, the secondary heat exchangers are not ideal correspond.

Taking into account today's tendency to increase Construction costs and land prices and the inevitably there win with associated living space reduction Heaters or boilers with low heat output too taking on importance, and the object of the invention is to create a boiler that supports these ten takes into account, be accordingly small and compact can be measured, in particular the Nachschaltwär  Meta exchanger not only easy and rational to manufacture, but with high concentration and optimal flow speed of the heat transfer surface also simply in the Boiler or the boiler housing can be integrated should.

This task is known with a gas boiler Kind according to the invention by the Main claim specified combination of features solved. Advantageous further developments result from the Un claims.

Spirally wound heat exchangers are, for example, after the DE-PS 9 25 721 known per se. To specifically in this regard further relevant known prior art is on referenced the following publications:

US-PS 2 085 256, DE-PS 95 873, DE-PS 2 88 039, DE-PS 1 01 612 and DE-OS 17 53 242. So cheap such spiral form-wound heat exchangers with regard to the flow management, their compactness and also the heat accumulation may be surprising, it can be determined len that such heat exchangers, as far as known, as Post-heat exchanger integrated in the boiler housing have not introduced it, presumably because it is extremely difficult, the sheets involved while maintaining their necessary distance other, d. that is, without any deformation at all to be able to wrap. Approaches to the feasibility of this shows  a proposal for boilers according to DE-OS 17 53 242, which, however, also proved to be impracticable has, and a proposal according to the aforementioned DE-PS 9 25 721, the subject of which on the one hand as secondary heat exchanger for boilers is not suitable because for the Heating gases cannot be flowed openly and also not from the heating gas can flow through in a straight line. Also arise exposed on the downstream side of this heat exchanger Sheet metal edges that would be subject to high thermal stress, and in addition, additional spacers (see also DE-PS 28 80 039) can be provided between the channels were apparently seen as a necessary requirement to wind in a spiral around such a structure to be able to. In addition, they are against the Winding axis directed edge bends with which the full width of the individual channels is specified for spi ral-shaped wrapping, because with full width inside white send, wavy discard, which inevitably the ver welding difficult.

The applicability of such spirally wound The heat exchanger for boilers stands and falls Consideration of the necessary and largely mechanical Series production with an education that is a complica allows for production without manufacture. Such Nachschaltwär However, according to the unpublished DE- 42 21 528 A1 is now available and is thus a we significant element in combination with the other characteristics  len to solve the tasks presented that the Boiler is assigned where it's easiest namely in the uncooled, i.e. not water-bearing Exhaust gas collection chamber, directly behind the combustion chamber opening, the opening cross-section and shape in the we substantially corresponds to the total cross-sectional area, d. that is, that of the spirally wound bag and that Flow cross-section for the heating gases. This gives what is still going on based on example representations will show a very compact small boiler with a Power in the order of 12 KW, for example because of its small size can be installed on a wall.

Advantageous embodiments of the heater according to the invention boilers consist of the following:

The flue gas fitted with the secondary heat exchanger Melkammer is sealed and the water-bearing housing releasably assigned, the connection between the housing and exhaust gas collection chamber produced by turnbuckles becomes. This allows the exhaust gas collection chamber to be turned on built "spiral plan" easily replaced if necessary if necessary and at abge The exhaust gas chamber is also the combustion chamber room easily accessible for inspection.

A production of the exhaust gas collection chamber with the plane spiral as a separate unit, however, this is incidentally be  notices, also possible without any problem, if no solution bare connection is provided, d. that is, the Ab gas collection chamber simply with the water-carrying housing welded.

Regarding the function of the secondary heat exchanger in Form a plane spiral are different options given. So the outlet connection of the secondary heat exchanger with the water-bearing interior of the housing be connected, the heating return inside the Plane spiral is connected to this. Here serves the Plane spiral as additional heating surface for heating the Heating water. In the same sense, it is also possible Lich, the plane spiral as a water heater for custom to use water. The secondary heat exchanger can, however also from two independently flowable Ta be formed, one of which with the water leading interior of the housing communicates and the other with process water supply and drainage connections is provided, the two pockets with respect to the axial gas flow direction arranged one behind the other are.

However, an embodiment is also possible in such a way that that with the water-bearing interior of the housing in Connected secondary heat exchanger double strand gig trained and between these two strands, with standing on both sides in a flat heat conducting contact,  a third line with the hot water supply and discharge conclusions is arranged. This is where the heat comes from transfer to the domestic water not directly through the Heating gases, but indirectly through the heating water, the the sides adjacent to the process water line on both sides Flows through strands. A further explanation in this regard form in which not even an additional day required for the passage of the domestic water is explained in more detail.

An embodiment is preferred such that the Exhaust gas collection chamber under the water-bearing housing is arranged with the combustion chamber in the form of an angular or arc piece and the burner with his Axis perpendicular or inclined to the winding axis of the Post-heat exchanger is arranged oriented. The Training of water-bearing housings with the associated combustion chamber in the form of an elbow or elbow is known per se, but wins here Context of special importance, since this Increase the compactness of the entire boiler even further position the burner relatively close to the spiral plane leaves. A flat surface does not come as a burner ger gas burner (radiant burner), but one preferred for use, the effective burner surface e.g. hemispherical or ellipsoidal shape, d. i.e., a bren ner not only against the water-cooled walls of the  Housing, but also directly against the switching spiral coil forming heat exchanger is effective.

The gas boiler according to the invention and further details The following are based on the graphic representation development of exemplary embodiments explained in more detail. It shows

Fig. 1 shows a longitudinal section through the gas boiler in a preferred embodiment;

Figure 2 shows a cross section through the gas boiler along line II-II in Fig. 1.

. Fig. 3 a of Figure 1 corresponding longitudinal section through the gas boiler with two superposed Nachschaltwärmetauschern;

Fig. 4-6 in section corresponding to Figure 1, other design forms of the water-carrying housing.

7 shows a section through the gas heating boiler having an atmospheric burner.

Fig. 8 is a perspective detail view of the plan spiral;

Fig. 9 shows a section through a special embodiment form of the plane spiral with hot water supply and

Fig. 10 shows a section through the preferred embodiment form of the plane spiral with hot water supply.

The gas boiler basically and in a known manner consists of a water-carrying housing 1 , in which a combustion chamber 3 equipped with a burner 2 and between this and the exhaust connection piece 4 of an exhaust gas collecting chamber 5 a secondary heat exchanger NT through which the heat exchange media can flow and with inflow and outflow connections 6 , 7 for the medium to be heated is arranged.

For such a gas boiler, it is now essential that the at least one post-heat exchanger NT is designed in the form of an axially gas-flowable pocket 9 which is spirally wound between two parallel planes E and whose cross-sectional width B is substantially greater in cross-sectional main axis HA parallel to the winding axis 15 and the Nachschaltwärmetauscher NT arranged in the uncooled exhaust gas collection chamber 5 and this is assigned as a separate unit to the water-carrying housing 1 , the total cross-section of the Nachschaltwärmetau shear NT flowed from the heat-carrying medium essentially corresponds to the opening cross section 8 of the open against the Nachschaltwärmetauscher NT and cross-sectional circular combustion chamber 3 .

Is shown in Fig. 1, the preferred embodiment in which the exhaust gas collecting chamber 5 is the water-carrying Ge housing 1 with the interposition of an annular seal 18 from releasably assigned, the two parts being held together by turnbuckles 16 .

In this embodiment, the plane spiral or to a in the sense of FIG. 2 to a spiral wrapped pocket 9 as NT to pass through the heating return, which is connected to the inflow connection 6 and after passage of the plane spiral from the center through a line piece 17th enters the interior 10 of the housing 1 and heats it through the outflow connection 7 (flow). If the spiral plan is to be used for the preparation of process water, the inflow connection 6 is the cold water connection, and the outflow connection 7 sits instead of the line piece 17 directly on the plan spiral and serves as a hot water discharge connection from the hot water either directly or via a process water buffer reservoir (not shown) can.

The same construction principle show the other Ausführungsbei games according to FIGS. 3 to 6, in which corresponding elements are provided with corresponding reference numerals. Here, however, the flue gas collecting chambers 5 , which are recognizable as separate structural units, are shown directly welded to the respective water-carrying housing 1 , which makes an outer pipe section 17 unnecessary, since here, as indicated by arrows, a direct connection between the spiral plane and the water-carrying interior 10 can be provided .

An embodiment such that the Nachschaltwärmetau NT shear from two independently flowable pockets 9 , 9 'is formed, one of which is connected to the water-bearing interior 10 of the housing 1 and the other 9 ' with hot water supply and drain connections 6 ', 7 ' is provided, the two pockets 9 , 9 'are arranged one behind the other with respect to the axial gas flow direction, is illustrated in Fig. 3. As shown by arrows, the lower pocket 9 is used for heating the returning heating water and the upper pocket 9 'for that of the process water.

A special embodiment of the plane spiral is shown in section in FIG. 9. Thereafter, the secondary heat exchanger NT connected to the water-carrying interior 10 of the housing 1 is double-stranded and between these two strands 11 , which is in flat thermal contact on both sides, is a third Line 12 with the hot water supply and discharge connections 6 ', 7 ' arranged. All three strands 11 , 12 are here wound together into a spiral. The heat transfer to the process water or the process water-carrying pocket does not take place directly through the heating gas, but rather through thermal contact of the pockets 9 'on both sides of the pocket 9' . In this embodiment, it is also possible, moreover, to wind the strands 11 , 12 separately and to insert the strand 11 in spiral form between the strands 12 , which are also already in spiral form, for which the strands 11 below may not have any beads, as shown.

In all of the exemplary embodiments except for that of FIG. 6, which represents an atmospheric gas heating boiler, the water-carrying housing 1 is, as it were, saddled onto the exhaust gas collection chamber 5 containing plan spirals, i.e. the exhaust gas collection chamber 5 is arranged under the water-carrying housing 1 , which also includes the combustion chamber 3 in the form of an elbow or elbow 13 , 13 'formed and the burner 2 with its axis 14 perpendicular or inclined to the winding axis 15 of the / after switching heat exchanger NT is arranged oriented. As burners, those with the shapes shown are used, the effective burner surface of which consists of metal mesh. In this way, the burner acts with its heat radiation not only directly against what was cooled walls of the housing 1 , but also against the spiral, and the boiler receives small Höhenab measurements. With a capacity for 7 to 12 KW, for example, the boilers shown in FIGS . 1 to 5 are only about 2-3 times as large as shown.

As for the spiral forming the post-heat exchanger NT itself, reference is made to FIG. 8, according to which the inner wall 20 bent upwards and downwards with respect to the winding axis 15 , the maximum width B of the water-carrying interior 25 accordingly Has edges 22 . The outer wall 23 has inwardly bent edges 24 with a maximum half the width B, which edges 24 grip over the edges 22 of the inner wall 20 or are flush with them and are fluid-tightly connected to them. In the gas-carrying, upstream and downstream interior 25 'facing Wellenprä conditions 27 both walls 20 , 23 are at a distance D to the edges 22 , 24 in the walls 20 , 23 essentially pa parallel to the winding axis 15 mutually supporting, arranged and formed, and the water-carrying inner space 25 is at both ends of the plane spiral except for the attached forward and return port openings. Such NT is shown in plan view according to FIG. 2, from which it can also be seen that the inner winding end of the spiral does not of course begin in the center of the spiral, but on a filler 26 , which can also be designed as a hollow body and the Rücklaufan circuit forms. A winding from the center is not allowed because the bending radii would be too small. In the illustrated embodiment according to FIG. 8, it is an NT with a relatively large height H, and in consideration of this, the inner wall 20 is provided with a central corrugation which extends perpendicular to the winding axis 15 and has the central width 27 ', the depth of which is width B. of the water-bearing interior 25 corresponds. This Wel lenembung 27 'supports the wall 23 in the middle and divides the water-bearing interior 25 , so that it flows through the Füllkör by 26 (return connection) from in two corresponding spi-shaped parallel flows and passes from the two openings into the water-bearing interior 10 of the boiler . The entering from the combustion chamber 3 of the boiler into the NT heating gases flow through the gas-carrying interior 25 'open to both sides parallel to the winding axis 15 . Through this design of the bag 9, it can be continuously wound and welded, then surrounded with an adapted cladding sheet 19 and thus inserted into the exhaust gas collecting chamber 5 , the cladding sheet 19 (see FIGS . 1 to 6) being advantageously installed in the exhaust gas collecting chamber 5 facilitated. The training and manufacture of the flat spirals are always the same, regardless of whether the flat spiral should be used to pass heating water or process water.

If the NT is also used to heat industrial water, as already described in relation to FIG. 9, this is in a preferred embodiment according to FIG. 10 in that the spirally wound pocket 9 is formed from two pocket parts 9 ', which with their against each other directed flanks 28 a service water channel 29 be limit, the two pocket parts 9 'in cross-sectional profile up to the upstream and downstream side Ver 30 edges are formed identical in shape.

The the hot water channel 29 delimiting edges 28 of the two pocket portions 9 ', as shown, provided at their edges with oppositely directed welded together upper and lower fasteners of the Brauchwas serkanales 29 forming Wulstprägungen 31st In the resulting gusset 31 'a weld seam is made of additional welding material (not shown).

Furthermore, in this embodiment, the gas-impinged flanks F of the two pocket parts 9 'with extending in the winding direction groove impressions 32 hen, wherein profile-matched spacer wires 33 are arranged between the groove impressions 32 of the adjacent flanks F.

The groove embossments 32 have a much smaller depth than the wave embossments 27 of the gas-impinging flanks F, because otherwise the heating gas passage would be prevented. Since the wave embossings 27 have a relatively small height of only about 3 to 4 mm with a sheet thickness of about 0.8 to 1 mm, the gas passage cross section of the entire spiral would be too small in this compact design, ie, one can in this way by the arrangement of the Spacer wires, without having to increase the height of the wave embossments, enlarge the gas passage cross-section accordingly. Apart from that, the spacer wires lead to an improved gas swirl.

As already described for Fig. 8 and at a height H of the pocket 9 or the pocket parts 9 'of about 110 to 130 mm, the winding axis-side flanks WF of the two pocket parts 9 ' are each in the middle and with one to this embodiment to the adjacent water-side wall W recessed and extending in the winding direction support embossing.

The closure edges 30 are, as shown, ausgebil det, that is, these are provided with short, outward bends 31 '', which are melted down after the merging of the walls involved in the winding at the same time without additional material, thereby avoiding exposed projecting connecting edges those that would be particularly disadvantageous on the gas inflow side. This embodiment is also preferred in all of the other embodiments of the NT described above.

Claims (17)

1.Gas boiler, consisting of a water-bearing housing ( 1 ) in which a burner ( 2 ) equipped combustion chamber ( 3 ) and between this and the Abzugsan connection piece ( 4 ) an exhaust gas collection chamber ( 5 ) a flow through the heat exchange media Nachschaltwär metauscher (NT ) with inlet and outlet connections ( 6 , 7 ) for the medium to be heated, characterized in that the at least one secondary heat exchanger (NT) is designed in the form of an axially gas-flowable pocket ( 9 ) wound spirally between two parallel planes (E) and whose in relation to their cross-sectional width (B) much larger cross-sectional main axis (HA) parallel to the winding axis ( 15 ) and the secondary heat exchanger (NT) arranged in the uncooled exhaust gas collection chamber ( 5 ) and this as a separate unit to the water-carrying housing ( 1 ) is assigned, the total cross section of the secondary flow flowing from the heat-supplying medium heat exchanger (NT) essentially corresponds to the opening cross section ( 8 ) which is open to the secondary heat exchanger (NT) and has a circular cross section of the combustion chamber ( 3 ). 2. A boiler according to claim 1, characterized in that the exhaust gas collecting chamber ( 5 ) with the secondary heat exchanger (NT) is assigned to the housing ( 1 ) in a releasably sealed manner. 3. Boiler according to claim 1 or 2, characterized in that the outflow connection ( 7 ) of the Nachschaltwärmetau shear (NT) with the water-carrying interior ( 10 ) of the housing ( 1 ) is connected. 4. Boiler according to one of claims 1 to 3, characterized in that the Nachschaltwärmetauscher (NT) from two independent from each other flowable pockets ( 9 , 9 ') is formed, one of which with the water-guiding interior ( 10 ) of the housing ( 1 ) is connected and the other ( 9 ') with process water supply and discharge connections ( 6 ', 7 ') is provided. 5. Boiler according to claim 4, characterized in that the two pockets ( 9 , 9 ') are arranged one behind the other in relation to the axial gas flow direction. 6. A boiler according to claim 4, characterized in that with the water-carrying interior ( 10 ) of the housing ( 1 ) in connection post-heat exchanger (NT) is double-stranded and between these two strands ( 11 ), with them on both sides in flat thermal contact , A third strand ( 12 ) with the hot water supply and discharge connections ( 6 ', 7 ') is arranged. 7. A boiler according to any one of claims 1 to 3, characterized in that the spirally wound pocket ( 9 ) is formed from two pocket parts ( 9 ') which, with their mutually facing flanks ( 28 ), limit a process water channel ( 29 ). 8. A boiler according to claim 7, characterized in that the two pocket parts ( 9 ') are formed in the cross-sectional profile fil up to the upstream and downstream side of the lock rims ( 30 ). 9. A boiler according to claim 8, characterized in that the service water channel ( 29 ) delimiting flanges ( 28 ) of the two pocket parts ( 9 ') at their edges with mutually directed and welded upper and lower closures of the service water channel ( 29 ) Bead embossments ( 31 ) are provided. 10. Boiler according to one of claims 7 to 9, characterized in that the gas-charged flanks (F) of the two Ta's parts ( 9 ') with extending in the winding direction he extending groove impressions ( 32 ) and inter mediate the groove impressions ( 32 ) of the adjacent Flan ken (F) profile-matched spacer wires ( 33 ) are arranged. 11. Boiler according to one of claims 7 to 10, characterized in that the winding-axis-side flanks (WF) of the two pocket parts ( 9 ') in the middle and with a wall up to the adjacent wall (W) and recessed in the winding direction extending support stampings ( 35 ) are provided. 12. Boiler according to one of claims 1 to 11, characterized in that the exhaust gas collecting chamber ( 5 ) under the water guide the housing ( 1 ) is arranged, the mer with the Brennkam mer ( 3 ) in the form of an elbow or elbow ( 13 , 13th ') Trained and the burner ( 2 ) with its axis ( 14 ) perpendicular or inclined to the winding axis ( 15 ) of the / the post-heat exchanger (NT) is oriented. 13. Boiler according to one of claims 2 to 12, characterized in that the water-carrying housing ( 1 ) sealed releasably associated exhaust gas collection chamber ( 8 ) with turnbuckles ( 16 ) on the housing ( 1 ) is attached. 14. Boiler according to one of claims 1 to 13, characterized in that the heating water leading Nachschaltwärmetauscher (NT) with the water-carrying interior ( 10 ) of the Ge housing ( 1 ) is connected by a limited bendable pipe section ( 17 ). 15. Boiler according to one of claims 1 to 14, characterized in that the at least one spirally wound after switching heat exchanger (NT) arranged in a cylindrical cladding sheet ( 19 ) and used with this in the Abgassam melkammer ( 5 ). 16. Boiler according to one of claims 1 to 15, characterized in that the burner ( 2 ) arranged in the combustion chamber ( 3 ) as a radiation burner has a spherical shape and a part (F) of the burner surface over the inflow cross section of the secondary heat exchanger (NT) is arranged. 17. Boiler according to one of claims 4 to 6 and 12 up to 16. characterized, that the pocket (s) carrying the heating water Light metal sheet, such as aluminum sheet, and the industrial items This leading pocket (s) is made of stainless steel sheet is (are).