EP1752710A2 - Assembly for stove with heat exchanger - Google Patents

Abstract

The system for tile ovens, stoves, or basic ovens (1) has a combustion chamber (11) with a rear wall and side walls, a hot gas flue (13), and a heat exchanger (2) through which flows a fluid for heat and/or hot water yield. The heat exchanger is installed between the rear wall and/or side wall or walls of the combustion chamber and/or the hot gas flue on one side, and the adjacent building walls on the other side. The heat exchanger is located in the region of great heat radiation in the direction of the heat radiation before an insulation of the building walls. An independent claim is included for a heat exchanger for the aforesaid arrangement which has a piping system (20) installed on heat conducting plates between return and feed connections.

Description

The invention relates to an arrangement for tiled stoves, in particular base ovens, which are individually constructed in front of at least one adjacent building wall, with a rear wall and side walls having combustion chamber, if necessary, a hot gas and a fluid flowed through the heat exchanger for hot and / or Heizwassergewinnung.

Increasingly, consumers demand that custom-built tiled stoves, fireplaces or stoves, in addition to the aesthetic effect of the fire and the comfortable heating of the room in question also provide a heat input for the rest of the building. Since the heat generated in such fireplaces, namely hot air and in particular radiant heat is poorly distributable to the entire building, solutions have been proposed to use fluid-flow heat exchanger for hot and / or Heizwassergewinnung. By way of example reference is made to fireplace inserts with attached heat exchanger from Ulrich Brunner GmbH, 84307 Eggenfelden. These known arrangements are characterized in that the heat exchanger on one side of the hot gases from the combustion chamber, either directly above the combustion chamber or in the subsequent Heizgaszug, is flown and on the other side a fluid circuit, usually water. With the known devices, it is possible to heat a hot water tank and / or supply the extracted from the Heizgaszug heat of the central heating.

From the GB 20 76 144 A a chimney is known which has a layer of water in its housing around the combustion chamber. Inlet and outlet pipes allow a circulation of the water heated by the chimney to a heat sink. In the water layer arranged around the combustion chamber there is thus a relatively large volume of water, which is critical for safety reasons in the event of excessive heating (overpressure). Furthermore, there is direct contact of the water layer to the combustion chamber forming the housing (sheet metal wall). The heat transfer is thus almost exclusively via heat conduction. Next likely by the considerable thermal stresses Dichtigkeits- and by the contact with the flue gases corrosion problems at the water layer receiving housing occur.

Furthermore, the shows GB 2 41 712 a heat exchanger in the firebox of a chimney, which is thus flows around directly from flue gases.

The disadvantage of such arrangements is thus that the heat exchanger is exposed by the extreme temperature stress from rest (room temperature) to the high combustion temperatures occurring considerable thermal and beyond by the chemically aggressive hot gases considerable corrosive loads. The heat exchanger must be designed to be correspondingly complex and of high quality.

From the DE 30 01 179 A1 a stove is known which has heat exchanger tubes in a separate luftumströmten space. In this case, an air flow forcedly supported by a blower is generated separately from the flue gases conducted therein, so that the heat exchanger tubes are heated by the warm air which is heated and flows along the combustion chamber or flue gas duct. Thus, the heat transfer takes place almost exclusively by convection. The disadvantage is that these elements are cooled by the positively driven air flow around the combustion chamber and Heizgaszug. What a cooling of the hot gases is achieved indirectly through the heat exchanger. What a Internal heat utilization over a longer Heizgaszug, as provided especially in Grundöfen, not sufficiently possible.

For modern kiln heating systems, in particular Grundöfen a strong cooling of the hot gases is just not desirable and technically harmful, since too low combustion chamber temperature only a poor, non-uniform combustion takes place, so the efficiency of the furnace is significantly deteriorated. In addition, in the proposed solutions due to the strong cooling of the furnace temperature of the CO content and soot levels above relevant statutory requirements, such as the Federal Immission Control Regulations, which would such ovens no approval would receive. Rather, as much heat as possible should be converted into particularly pleasant radiant heat in modern heating systems over a longer heating flue (basic furnace principle). However, a built-in Heizgaszug heat exchanger reduced in such furnaces, the Stahlungswärmeabgabe. The constructed for example for internal heat utilization in a basic furnace hot gas trains do not tolerate heat extraction from the flue gases through an additional heat exchanger. In addition to a reduction of the radiant heat emission and an insufficient train may occur in the flue, especially at an exhaust gas temperature of less than 180 ° C, which is defined as a minimum value in relevant regulations.

Furthermore, it has been shown in modern low-energy houses that the heating capacity of known Kaminheizsysteme is much too large, the fireplace operation thus quickly leads to an unpleasant overheating of the living spaces. The combination of a heat generated by the heat generated by its storage effect slowly with a heat exchanger, the "excess" amounts of heat to a heat sink (Zentralheizsystem or domestic hot water tank) is therefore the basic idea of the present invention.

The object of the invention is therefore, starting from the aforementioned prior art to provide an arrangement of a furnace with a heat exchanger, in which a heat removal is made possible by a heat exchanger, with strong thermal loads on the heat exchanger and further cooling of the hot gases can be avoided. The heat radiation output of the furnace in the installation room in the direction of the free space is not reduced.

This object is achieved with an arrangement according to claim 1.

Characterized in that the heat exchanger between the rear wall and / or side wall / walls of the combustion chamber and / or the Heizgaszug one hand and the adjacent building wall on the other hand without contact to the combustion chamber and the Heizgaszug is arranged, the heat exchanger is not affected by hot gases and has no connection to the furnace , Thus, the heat output of the furnace is hardly affected by the heat exchanger. The space between the building wall and combustion chamber or Heizgaszug, in which the heat exchanger is housed, does not allow air circulation with the environment, so that the heat exchanger receives the heat energy input almost exclusively as heat radiation, the same construction without heat exchanger in the adjacent building walls and / or insulation would have been introduced. Accordingly, the heating gas temperature remains essentially unaffected by the heat exchanger, as well as the usable for the residents radiant heat. Since the heat exchanger does not come into contact with the hot gases, the thermal load is considerably lower. A chemical load on the heat exchanger no longer takes place.

If the heat exchanger is arranged with its planar expansion in the region of high heat radiation substantially perpendicular to the radiation propagation and in the direction of heat radiation in front of the building wall, radiant heat energy is absorbed by the heat exchanger particularly effective, which would otherwise not be directly available to the residents.

Because heat insulation and / or a heat radiation-reflecting sheet-like element are provided between the heat exchanger and the building wall, the heat absorption in the building walls is considerably reduced. In particular, by a heat radiation reflective planar element, the utilization of the radiant heat can be further improved.

The heat energy absorbed by the heat exchanger is dissipated in that a heating circuit with circulation pump, supply and return line is arranged on the heat exchanger, wherein the supply line leads to a heat sink and the return of the fluid from the heat sink via the return line leads. Preferably, the heat sink is a buffer memory. From the buffer memory, if necessary, the heat energy for the home central heating on the existing circulation pipes and radiators, floor heating, wall heating, etc. are distributed in the house. Furthermore, the buffer memory can also be used for hot water production. By providing the buffer memory, for example, the amount of heat dissipated by the heat exchanger of an evening log fire can be used the next morning for heating the bath and / or shower water.

If a temperature sensor is arranged on the heat exchanger, preferably at the substantially highest point, which is operatively connected to a control unit, the circulation pump above a first limit temperature turns on, the circulation pump for the heat transfer fluid is only started at a first limit temperature, which is lower than the second limit temperature. That is, at the beginning of a fire, the heat transfer fluid in the heat exchanger is initially not circulated. Only after heating of the heat exchanger and the fluid contained therein, the exceeding of the first limit temperature is determined by the temperature sensor, whereby the circulation pump is started.

In order to avoid too low a feed temperature for the buffer storage and to support the heating of the fluid in the heat exchanger, a thermostatic valve is arranged in the heating circuit in the flow line between the heat exchanger and heat sink, which forms a flow connection to the return line via a connecting line below a presettable second limit temperature. It is thus provided via the thermostatic valve and the connecting line, an inner heating circuit, which circulates below the second limit temperature, the heat transfer fluid by means of circulating pump in the inner heating circuit. When the second limit temperature is exceeded, the thermostatic valve opens, so that then the buffer memory is loaded with heat energy.

To avoid overpressure in the circulation system, a safety valve in the heating circuit near the heat exchanger, preferably arranged in the return line, which opens at a preselectable limit pressure for safety reasons. The limiting pressure is for example 3 bar. The outlet of the safety valve can be connected directly to the sewer when using water as a heat transfer fluid. In the arrangement according to the invention, the circulating in the heating circuit with the heat exchanger water quantity can be limited to 3 liters, which according to relevant safety regulations, a complex thermal overload protection is unnecessary.

The heat exchanger consists of a piping system with a plurality of pipe loops between the return port and flow connection, wherein on the piping heat-conducting Wärmeleitplatten are arranged. The heat conducting plates absorb the radiant heat emitted by the furnace and conduct the heat to the piping system and the heat transfer fluid received therein. Preferably, the heat conducting plates of metallic material with a thermal conductivity over λ> 100 W / (m · K), in particular aluminum or copper are formed.

If the piping system is formed of copper pipes that are laid serpentine with vertical straight sections, the heat exchanger can be easily constructed by hand. Characterized in that the heat conducting plates are arranged substantially orthogonal to the copper pipe to the vertical straight sections, the heat conducting plates can be plugged onto the copper pipes without much effort. Preferably, a snug fit of the plugged Wärmeleitplatten on the copper tubes for effective heat conduction.

A particularly preferred dimensioning is obtained if the heat conducting plates are rectangularly formed of aluminum sheet, preferably with a size of about 100 mm x 50 mm, therein two parallel pipe sections of a pipe loop are intersectingly received, the heat conducting a thickness of 0.2 mm 2.0 mm, preferably about 0.5 mm and are arranged at a vertical distance of 3 mm to 20 mm, preferably about 7 mm from each other.

Hereinafter, an embodiment of the invention will be described in detail with reference to the accompanying drawings.

Fig. 1

eine Prinzipdarstellung der erfindungsgemäßen Anordnung und

Fig. 2

eine Ansicht eines Wärmetauschers für die Anordnung gemäß Fig. 1.

It shows:

Fig. 1

a schematic diagram of the inventive arrangement and

Fig. 2

a view of a heat exchanger for the arrangement of FIG. 1.

In Fig. 1 is shown in a schematic diagram of the interconnection of the arrangement according to the invention. The arrangement comprises an oven 1, for example a basic oven, which is individually constructed. The basic furnace has a combustion chamber 11 with a rear wall 12 and unspecified side walls. The combustion gases from the combustion chamber 11, are burned in the wood, wood pellets, briquettes or the like, are passed through a hot gas 13 to the chimney. Arrow X indicates the flow direction of the hot gases.

Behind the rear wall 12 and the hot gas flue 13 of the furnace 1, a heat exchanger 2 in front of a building wall provided with insulation materials, which is not shown in FIG. 1, arranged. Between the building wall and rear wall 12 or Heizgaszug 13, a gap is formed, which is closed in itself, so does not allow air circulation with the environment. The heat exchanger 2 is arranged without direct contact with the combustion chamber 11 or the Heizgaszug 13, to avoid an undesirably high heat loss of the combustion chamber and Heizgaszug and to keep the thermal stress of the heat exchanger low.

The structure of the heat exchanger 2 is shown in detail in FIG. The heat exchanger has a piping system 20 which consists of substantially vertically arranged straight pipe sections 21, which are joined together with pipe bend sections 22 to form a serpentine-shaped piping system 20. The pipe power system 20 connects a return port 23 to a flow port 24. Die straight pipe sections 21 are arranged parallel to each other substantially perpendicular. To increase the heat absorption by impinging heat radiation heat conducting plates 25 are provided, which are penetrated by the pipe sections 21.

In the illustrated embodiment, the heat conducting plates 25 are aligned substantially horizontally, that is orthogonal to the pipe sections 11 and are penetrated by two parallel juxtaposed pipe sections 21. In this case, a plurality of heat conducting plates 25 are arranged one above the other with a spacing of, for example, d = 7 mm over the height extent of the heat exchanger 2 along the pipe sections 21.

The heat exchanger 2 is part of a heat carrier circulation system 3, which is a heat transfer medium, for example water, between the heat carrier 2 and a heat sink 4 via a flow line 31 from the flow connection 24 of the heat exchanger 2 to the heat sink 4 and from the heat sink 4 via a return line 35 to the return port 23 of the Heat exchanger 2 leads. Further, in the return line 35 in the flow direction of the heat transfer medium circulation system 3 before the branch, in which the connecting line 34 opens, a backstop 351 inserted to prevent unwanted circulation of the heat transfer medium via the connecting line 34 into the heat sink 4. In the heat transfer circulation system 3, a circulation pump 32 is arranged in the flow line 31. The circulating pump 32 circulates the heat transfer medium in the system, preferably water.

On the heat exchanger 2 or in the flow line 31 near the heat exchanger 2, a temperature sensor 37 is provided with effective line 39 to a control unit 38. The control unit 38 controls the Circulation pump 32 via further active line 39 in dependence on the temperature measured by the temperature sensor 37.

Downstream of the circulation pump 32, a thermostatic valve 33 is provided in the flow line 31. At the thermostatic valve 33 branches off a connecting line 34 from the flow line 31, which forms a short inner heating circuit 30 falls below a second temperature limit, in which the heat transfer medium is not passed through the heat sink 4. The connecting line 34 opens into the return line 35 near the return connection 23 of the heat exchanger 2.

Further, in the region of the return line 35, a safety valve 36 is arranged, which opens at a presettable pressure of the heat transfer medium, in order to avoid an excessive overpressure in the heat transfer circulation system 3.

The heat sink 4 is preferably designed as a buffer memory, in which the registered heat transfer medium from the heat transfer system 3 layer is removable and can be accessed if necessary. For example, the building central heating with radiators, floor or Wandheizrohren and / or the hot water supply are connected to the buffer memory 4.

The operation of the arrangement according to the invention and of the heat exchanger will be described below.

At rest, ie without fire and residual heat, the system is almost at room temperature. The circulating or circulation pump 32 stands still, since the temperature sensor 37 to the control unit 38 of the pump 32, a temperature lower than the first limit temperature via effective line 39 reports. It is the same Thermostat valve 33 due to the low temperature set so that the inner heating circuit 30 is released.

Now, if the basic furnace 1 fueled with solid fuels, such as firewood, the temperature increases in the combustion chamber 11 and in the heating gas 13. After a while, sufficient radiant heat is produced, emanating from all heated surfaces and next to the aesthetic fire image in the combustion chamber 11, the comfortable Fireplace heat generated in the form of radiant heat. The radiant heat which is radiated from the rear walls of the combustion chamber and the Heizgaszuges, before it encounters the provided with insulating building walls, on the heat exchanger 2. In particular, the heat conducting plates 25 are heated by the incident radiant heat, which in the pipeline system 20th the heat exchanger 2 located heat transfer medium, preferably water, is heated.

The temperature in the piping system 20 of the heat exchanger 2 thus increases. The temperature sensor 37 arranged at the highest possible point near the heat exchanger 2 or in the heat exchanger 2 signals via its effective line 39 thus the rising temperatures to the control unit 38. When the first limit temperature is exceeded, the control unit 38 switches on the circulation pump 32, so that the heat transfer medium via the inner Heating circuit 30, ie flow connection 24, front part of the flow line 31 to the thermostatic valve 33, via connection line 34 to the downstream part of the return line 35 and via return port 23 back into the piping system 20 of the heat exchanger 2 passes.

In this inner, short circulation heating circuit 30, the temperature will continue to rise, so that then when the second limit temperature, the thermostatic valve 33 switches to the large heat transfer circulation circuit, so the carrier medium via the heat sink or

Buffer memory 4 is circulated. The thermostatic valve 33 thus blocks the connecting line 34. Now as long as heat is transported into the buffer memory until the fire is burned out and the residual heat is radiated from the components of the fireplace. In the buffer 4 heating or service water is thus heated by the entry of heat through a non-illustrated second heat exchanger, in which case only the radiation radiated from the fireplace to the rear is utilized.

LIST OF REFERENCE NUMBERS

1

Oven, basic oven

11

combustion chamber

12

rear wall

13

heating gas

2

heat exchangers

20

Piping

21

pipe section

22

Elbows section

23

Return connection

24

Flow connection

25

heat conduction

3

Heat transfer circulation system, heating circuit

30

inner heating circuit

31

supply line

32

circulating pump

33

thermostatic valve

34

connecting line

35

Return line

351

Backstop

36

safety valve

37

temperature sensor

38

control unit

39

active power

4

Heat sink, buffer tank

X

Flow direction of heating gas

Claims (9)

Arrangement of tiled stoves, in particular base stoves (1), which are individually constructed in front of at least one adjacent building wall, with a rear wall (12) and side walls having combustion chamber (11) possibly a hot gas flue (13) and a fluid flowed through the heat exchanger (2) for the Hot and / or Heizwassergewinnung, characterized in that the heat exchanger (2) between the rear wall (12) and / or side wall / walls of the combustion chamber (11) and / or the Heizgaszug (13) on the one hand and the adjacent building wall on the other hand without contact to Combustion chamber and the heating gas is arranged. Arrangement according to claim 1, characterized in that the heat exchanger (2) is arranged with its planar expansion in the region of high heat radiation substantially perpendicular to the radiation propagation and in the direction of heat radiation in front of the building wall. Arrangement according to claim 2, characterized in that between the heat exchanger (2) and building wall, a thermal insulation and / or a heat radiation-reflecting sheet-like element are provided. Arrangement according to claim 1, 2 or 3, characterized in that a heating circuit (3) with circulation pump (32), flow (31) and return line (35) on the heat exchanger (2) is arranged, wherein the supply line (32) to a Heat sink (4) leads and the Return (35) of the fluid from the heat sink (4) via the return line (35) leads. Arrangement according to one of the preceding claims, characterized in that a temperature sensor (37) is arranged on the heat exchanger (2), preferably at the substantially highest point, which operatively connected to a control unit (38) turns on the circulation pump (38) above a first limit temperature. Arrangement according to claim 3, 4 or 5, characterized in that in the heating circuit (3) in the flow line (31) between the heat exchanger (2) and heat sink (4) a thermostatic valve (33) is arranged, the below a presettable second limit temperature, a flow connection to the return line (35) via a connecting line (34). Arrangement according to one of the preceding claims, characterized in that a safety valve (36) in the heating circuit (3) near the heat exchanger (2), preferably in the return line (35) is arranged, which opens at a preselectable limit pressure. Arrangement according to one of the preceding claims, characterized in that the heat exchanger (2) return connection (23) and flow connection (24), wherein between the return (23) and flow connection (24) is a pipe system (20) is seen, at the heat-conducting Heat conducting plates (25) are arranged. Arrangement according to claim 8, characterized in that the heat conducting plates (25) of metallic material with a thermal conductivity over λ> 100 W / (m · K), in particular aluminum or copper are formed.

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