WO1996009499A1

WO1996009499A1 - Heating boiler

Info

Publication number: WO1996009499A1
Application number: PCT/EP1995/003700
Authority: WO
Inventors: Rudolf Justl
Original assignee: Rudolf Justl
Priority date: 1994-09-21
Filing date: 1995-09-20
Publication date: 1996-03-28
Also published as: DE19581074D2; DE19581074C1

Abstract

The invention concerns a heating boiler with a vertical heating space (1) in which a blower burner (2) which burns at the base¥is¥inserted. The boiler is formed by a pipe helix (3) which is tightly wound and is sealed outwardly in a heat-insulating manner. The heating space (1) is closed at the bottom by a deflector plate (5) which forms an annular gap (6) and via whose under-flue (17) the flue gases (20) flow into a heat exchanger (10). Cooled below the dew point, the flue gases (20) pass into a condensate collector (11) from which they are led into a preheater (12) for the air of combustion (28) and from there into the chimney. The fluid heating medium passes via a return line (21) into a distributor member (14') of the heat exchanger (10) and via fluid ducts (38) therein and guide ducts (35) in the two distributor members (14, 14') and via a connection line (29) into the pipe helix (3), which is flowed through in an upward direction, into the forward line (13) of the heating boiler.

Description

Condensing boiler

description

The invention relates to a condensing boiler for hot water heaters for operation with liquid or gaseous fuels according to the preamble of claim 1.

From EP-B1-0 275 401 it is known to build a condensing boiler with a small combustion chamber, which tightly encloses the horizontally burning flame of the burner, which is provided with regulated minimal cooling and which is directed downward connect to one or more heat exchangers, in which the major part of the heat content of the combustion gases is given off and these are cooled to below the dew point, the condensate formed being drained off into a condensate tray underneath.

In addition to the horizontal guidance of the flames and the resulting flow conditions of the flue gases, the disadvantage is the necessary regulation of the wall cooling in the combustion chamber, the failure of which, overheating or insufficient combustion results in an increased construction effort.

In a boiler such as is known from DE-Al-32 12 066, a simple coil is provided which forms a cylindrical combustion chamber in which the burner flame burns from top to bottom. The combustion gases are redirected upwards on a baffle plate, which closes the combustion chamber at the bottom, and in an area in which the pipe coils are wound at a distance. the, draft, from where they flow inwards through the spaces in the lower part of the coil, which forms a heat exchanger for the return of the heating, and are drained centrally into a chimney under the baffle plate. The fall train is surrounded on the outside by an insulating chamotte cylinder.

This boiler is not operated as a condensing boiler with condensation formation. In order to be able to dissipate the heat content of the flue gases, the coils are already flushed in the area of the combustion chamber, which increases the length of the dwell time of the flue gases in the combustion chamber. Furthermore, the insulation area of the boiler is significantly increased by the external draft. The lack of condensate reduces the efficiency of the boiler compared to a condensing boiler.

DE-Al-34 21 276 describes a condensing boiler in which the burner flame is formed horizontally in an underlying combustion chamber and in which the combustion gases heat the fireclay walls in front of a surrounding water jacket and are passed through an upper opening into a room above by delivering their heat content to a multi-layer coil of a heat exchanger. The condensate formed flows down through the furnace floor.

The arrangement of the heat exchanger above the combustion chamber will make it difficult to remove the condensate and, in particular, it will be difficult to avoid corrosion in the heat exchanger during the boiler shutdown because moisture inevitably remains in the heat exchanger room or in the combustion chamber and is difficult to remove is. The object of the invention is to provide a condensing boiler

Hot water heaters for operation with liquid or gas to create combustible fuels in the simplest possible construction and high efficiency, in which the condensate formation takes place only in an area in which no corrosion is possible and which is as simple as possible through the flow of both the flue gases and the liquid heat medium is excellent and has little need for regulation; In addition, the prescribed exhaust gas limit values should be observed.

This object is achieved in a boiler according to the preamble of claim 1 with its characteristic features.

The coiled tubing in the combustion chamber, which is sealed against the passage of the flue gases, results in a compact structure and avoids areas in which condensation can lead to corrosion.

The use of a baffle plate to bring the flue gases to the lower part of the tube coil serves the same purpose and additionally improves the heat absorption through increased convection.

The deflection plate, which is flown by the flue gases, forms a heat accumulator that protects against condensation, especially when it is at a standstill.

The closely installed heat exchanger enables a short flue gas path and thus reduces flow resistance and enables low NOX values for the flue gases. Particularly when using a very compact high-performance heat exchanger, the symmetrical attachment of the deflection plate and thus the symmetrical arrangement of a beam is advantageous because of the uniform exposure to the flue gases, with the deflection plate additionally being heated from below. Depending on the design of the heat exchanger and in order to provide space for its thermal expansion, an upstream draft for the flue gas duct is favorable.

The production of the deflection plate from a correspondingly stable material is advantageous for the period of use, while the production of a uniform annular gap is important for the uniform loading of the tube coil and also of the heat exchanger.

The provision of a depression in the deflection plate avoids disturbances due to soot formation and contamination, especially in the heat exchanger.

The sealed-off design of the coiled tubing creates a sealed combustion chamber in which the escape of smoke gases or the entry of false air is avoided; Ceramic wet fiber fleece is an ideal material for this because of its good mechanical adaptability during processing and because of its good sealing properties after solidification.

The guidance of the liquid heat medium in the coiled tubing from bottom to top, that is to say in countercurrent to the flue gases, results in a particularly good efficiency in the heat transfer.

The tube coil is placed in a very simple manner on refractory support plates, with the interposition of the aforementioned material for sealing.

The heat transfer to the heating medium in the coiled tubing is improved by using a correspondingly good heat-conducting and corrosion-resistant material, which is important for the length of use. A condensate collector made of plastic with an attached funnel, which extends over the entire cross section of the heat exchanger, for the discharge of the flue gases and the condensate draining off is inexpensive to manufacture, corrosion-resistant, easy to assemble and to seal well.

The use of a high-performance heat exchanger made of a particularly corrosion-resistant and temperature-resistant material with a large heat exchange surface and a high heat transfer coefficient at the same time enables the boiler to have a very compact design due to the small size of the heat exchanger.

For the attachment of the return and connecting lines for the liquid heating medium of the heat exchanger, the use of special distributing pieces made of cast material on the outlet surfaces of the liquid channels of the heat exchanger is a particularly simple solution and the use of powerful seals and by clamping together by means of anchor bolts results in a particularly reliable one Connection.

When installing the heat exchanger in the support plates of the boiler, it is important to have a seal to permanently prevent smoke gases from escaping through the insulation of the boiler.

The condensate drain is particularly easy to install in a prepared shaft in the support plates.

The utilization of the flue gases can be further improved by connecting an air preheater between the condensate collector and the flue, the condensate of which is also collected in the condensate collector and from there it is subjected to a common aftertreatment. It is part of the tight design of the firebox that the coiled tubing is covered at the top by a cover plate, with a fire-resistant sealing material, such as a nonwoven fiber interlayer, and is clamped together with anchor rods against the boiler frame, which are easy to detach and therefore easy to disassemble allow the boiler.

The modular design of the individual components of the boiler is advantageous for easy replacement of the individual components.

The invention is described with reference to the drawing of an exemplary embodiment.

Show it:

Fig. 1 shows a vertical section through the middle

Condensing boiler, return, connection u. Flow lines shown uncut, schematic;

Fig. 2 is an oblique view of the high heat exchanger with the connection points on the manifolds, schematized.

A condensing boiler has a standing, cylindrical combustion chamber 1, which is formed by a closely coiled tube coil 3 made of copper tube, into which a fan burner 2 is inserted, burning downward. The lower part 4 of the pipe coil 3 is made with a deflection plate 5 made of fire-resistant, ceramic material, in particular a ceramic fiber composite material, between the circumference 8 and the pipe coil 3 of a uniform annular gap 6 for the passage of the flue gases. is left. The deflection plate 5 stands with a plurality of spacers 7 on a support plate 16, and thereby forms a lower beam 17 to which a centrally arranged, downwardly directed train 9 connects.

The deflection plate 5 is provided with a large-area depression 41 which forms an edge towards the circumference 8 and which serves to catch any liquid fuel which may drip off and with which contamination or sooting, in particular of the heat exchanger 10, is avoided.

The pipe coil 3 is placed on the fixed, heat-insulating support plate 16 with the interposition of a sealing, fire-resistant heat-insulating layer 15 '. The lower beam 17 and the downward pull 9 are also lined with this thermal insulation layer 15 '; it consists of a ceramic fleece.

On the outside, the coiled tubing 3 is also sealed and insulated with a sealing, fire-resistant thermal insulation layer 15 made of the aforementioned material.

A heat exchanger 10, which is designed as a ceramic high-performance heat exchanger with a thin wall material made of very good heat-conducting and corrosion-resistant material, e.g. from Si-Sic.

This heat exchanger has a large number of channels for the liquid heating medium and for the flue gases, in which these are guided in co-current flow or in part also in counter-flow.

The heat exchanger 10 is sealed up and down between the support plates 16 of the boiler with insulation plates 19 'made of mineral fiber fleece. The supply line 33 'and the discharge line 33 of the liquid heating medium, in particular water, take place on opposite sides of the heat exchanger 10 arranged distributor pieces 14' and 14, which are connected to one another via anchor bolts 40 which pass through bores 39 ^' and in threaded bores 39 Distributors 14 'and 14 are screwed and thereby clamped together.

The distributor piece 14 'is screwed via the connection 33' to the return line 21 of the boiler and the other distributor piece 14 is screwed via the connection 33 to the connecting line 29 which is connected to the lower ends of the coiled tubing 3.

The liquid heating medium flows through the distributor channel 34 in the distributor piece 14 through the fluid channels 38 of the heat exchanger 10 and the deflection channels 35 in the distributor pieces 14 and 14 ', each of which is sealed with silicone seals inserted in sealing grooves 36. The flue gases 20 flow through flue gas channels 37 of the heat exchanger 10 and, cooled to below the dew point, pass through the flange funnel 18 into the condensate drain 11.

From the tubular condensate collector 11, the flue gases 20 flow through an air preheater 12 for the combustion air 28 of the fan burner 2 and from there into the chimney, while the combustion air 28 at the upper end of the air preheater 12 through the entry opening 42 between the inside - tube and the outer tube flows.

The condensate flowing out of the heat exchanger 10 and the chimney goes into the condensate collector 11 and, via a condensate drain 32, into an adsorption and ion exchange column (not shown). At the upper end of the coiled tubing 3, the flow line 13 is led to the outside. The pipe coil 3 is sealed against an overlying cover plate 23 of the combustion chamber 1 with an insulation sealing plate 19 made of mineral fiber fleece.

The cover plate 23 is overlaid by a cover plate 27 made of steel and clamped together with the latter against the heating frame 22 with the aid of anchor rods 26 and screw connections 31.

An opening 24 for the burner tube 25 of the forced-air burner 2 is provided in the cover plate 23 and the cover plate 27.

The external insulation 30 of the boiler is inserted between the cover plate 23 and the support plates 16.

Legend

1 firebox 2 forced draft burners

3 coils

4 lower part of the coiled tubing 3

5 deflection plate

6 annular gap between the deflection plate 5 and the lower part 4 of the coiled tubing 3

7 Spacer of the baffle plate 5

8 extent of the deflection plate 5

9 Train in front of the heat exchanger 10 10 heat exchanger 11 condensate collector

12 air preheaters

13 flow pipe 3

14 distributor piece for the removal of the heat transfer means from the heat exchanger 10 14 'distributor piece for the supply of the

Heat transfer medium to the heat exchanger 10

15 thermal insulation layer, sealing and fireproof, the coiled tubing 3

15 'thermal insulation layer, sealing and fireproof, the support plate 16

16 support plate, solid and heat-insulating, for the coiled tubing 3

17 Beam below the baffle plate 5

18 flange funnel of the condensate collector 11

19 Insulation and sealing plate of the combustion chamber 1 19 'Insulation and sealing plate of the

Heat exchanger 10

20 flue gases

21 Boiler return line

22 Boiler frame 23 Cover plate of the combustion chamber 1

24 opening in the cover plate 23 for the burner tube 25 25 Burner tube of the fan burner

26 anchor rods of the boiler frame 22

27 Steel cover plate for the cover plate 23

28 Combustion air 29 Connection line

30 external insulation

31 screw connections

32 condensate drain

33 Connection of the connecting line 29 33 'Connection of the return line 21

34 distribution channel in the distributor piece 14

35 deflection channel in the distributor piece 14

36 sealing groove in the distributor 14

37 flue gas channels 38 liquid channels

39 threaded holes for anchor bolts 40 39 'holes for anchor bolts 40

40 anchor bolts of the distributor pieces 14, 14 '

41 depression on the top of the baffle plate 5 42 inlet opening on the air preheater 12 for the

Combustion air 28

Claims

Expectations:

1. Condensing boiler with a standing combustion chamber, into which a forced draft burner, burning from top to bottom, is inserted and which is formed by a cooled wall, in particular consisting of at least one pipe coil, and is bounded at the bottom by a baffle plate and on that connects downward in the flow direction of the flue gases to a heat exchanger in which the flue gases are further cooled and discharged into the flue, characterized in that the combustion chamber (1) consists of at least one pipe coil, essentially close to one another horizontal pipe coil (3) is formed, in the lower area (4) of which the combustion chamber (1) is closed by a deflection plate (5), between its circumference (8) and the pipe coil (3) there is an annular gap (6 ) is left free, through which the flue gases (20) pass into the heat exchanger (10) and are cooled down to below the dew point and from which the condensate enters an underlying condensate mler (11) flows off.

2. condensing boiler according to claim 1, characterized in that after the annular gap (6) and before the heat exchanger (10), below the baffle plate (5), a beam (17) is provided.

3. condensing boiler according to claim 1 or 2, characterized gekenn¬ characterized in that after the beam (17) a directly the heat exchanger (10) upstream train (9), preferably coaxial to the baffle plate (5) is installed.

4. condensing boiler according to one of claims 1 to 3, da¬ characterized in that the baffle plate (5), which consists of fire-resistant material, in particular ceramic material and preferably a mineral fiber composite material, and in the top view, preferably circular, forming a uniform annular gap (6) towards the coiled tubing (3), is formed, is set up on several spacers (7), essentially coaxial to the cylindrical firebox (1), and leaves a beam (17) free.

5. condensing boiler according to one of claims 1 to 4, da¬ characterized in that in the baffle plate (5) at the top a, preferably large, recess (41) is incorporated, which forms a raised edge compared to its circumference (8).

6. condensing boiler according to claim 1, characterized in that the at least one coiled tubing (3), which delimits a cylindrical combustion chamber (1), at its upper end out of the boiler as a flow line (13) leads and at her the lower end, preferably via a connecting line (29) to a distributor (14 ') of the heat exchanger (10) for the removal of the heat transfer medium and on its outer circumference with a sealing, fireproof insulation layer (15), in particular ceramic wet fiber fleece is produced, is surrounded.

7. condensing boiler according to claim 1 or 6, characterized gekenn¬ characterized in that the coiled tubing (3) is seated on at least one, heat-insulating, heat-resistant support plate (16) against the combustion chamber (1) with a sealing, refractory heat-insulating layer (15 ' ), especially covered and sealed from ceramic wet fiber fleece.

8. condensing boiler according to claim 7, characterized in that with the sealing, fireproof thermal insulation layer (15 ') made of ceramic wet fiber fleece covers the heat-resistant support plate (16) in the region of the beam (17) and optionally the heat exchanger (10) pre-arranged train (9) the flue gases (20) is lined.

9. condensing boiler according to one of claims 1 or 6 to 8, characterized in that the coiled tubing (3) consists of a heat conducting material as well as possible, preferably from a thin-walled, scale and corrosion-resistant material, such as in particular made of chromium-nickel alloy steel or copper.

10. condensing boiler according to one of claims 1 to 9, da¬ characterized in that below the heat exchanger (10) a flange funnel (18) of the, preferably tubular, condensate collector (11) an¬ closes, the flange against the heat exchanger ( 10) is sealed and into which the condensate is discharged from the heat exchanger (10) and from the chimney.

11. condensing boiler according to one of claims 1 to 10, da¬ characterized in that the heat exchanger (10) is designed as a ceramic heat exchanger in which the flue gases (20) and the heat transfer medium, preferably water, in the same, cross, and / or countercurrent and the wall of which is made of a good heat-conducting material, preferably ceramic and in particular of Si / Sic, and is designed with a large heat exchange surface.

12. condensing boiler according to one of claims 1 to 11, da¬ characterized in that on the heat exchanger (10) for the liquid heat transfer medium laterally two manifolds (14,14 ') for removal and supply of the liquid heat transfer medium are tightly clamped together with the heat exchanger (10), the distributor piece (14) being connected to the coiled tubing (3) and the distributor piece (14 ') being connected to the return line (21) of the boiler.

13. Condensing boiler according to one of claims 1 to 12, characterized by the fact that the heat exchanger (10) is inserted sealingly in the support plates (16) and in particular with an insulation and sealing plate (19 '), preferably made of ceramic nonwoven fabric manufactured, sealed.

14. Condensing boiler according to one of claims 1 to 13, characterized in that the, in particular made of plastic, condensate collector (11) with the flange funnel (18) on the heat exchanger (10) with the interposition of an insulation and sealing plate ( 19 '), preferably made of ceramic nonwoven, is connected, the condensate collector (11) being inserted into a shaft of the support plates (16) which rest on the boiler frame (22) and having an air preheater (12) for the combustion air (28) of the forced draft burner (2) is connected.

15. condensing boiler according to one of claims 1 to 14, da¬ characterized in that the combustion chamber (1) upwards with a heat-insulating, fire-resistant cover plate

(23), which is sealed against the coiled tubing (3) with an insulation and sealing plate (19), preferably made of ceramic fiber fleece, and is overlaid by a cover plate (27) made of steel, into which an opening (24) for the burner tube (25) of the forced draft burner (2) and which is clamped together with the boiler frame (22) via anchor rods (26) and screw connections (31).

16. Condensing boiler according to one of claims 1 to 15, characterized in that the essential components of the boiler, in particular the coiled tubing (3), the deflection plate (5) of the heat exchanger (10) and the condensate collector (11) are designed as separate and releasably connectable structural units and, like the boiler frame (22), the support plates (16) and the cover plate (23) after removal of the cladding and loosening the screw connections (31) of the anchor rods (26) and required ¬ If the solution of the corresponding pipe connections can be removed and exchanged without any special effort.