EP0926453B1 - Heating apparatus for heating air and/or water - Google Patents

Description

The invention relates to a heater for heating air and / or water for Small rooms, especially for caravans, mobile homes, boats or the like according to the preamble of claim 1.

The applicant produces such heaters and in caravans or mobile homes used. An air heater is also part of EP 0 544 853 B1 a heat exchanger insert known, in which the during the Combustion chamber combustion takes place producing hot combustion gases experience heat dissipation and the actual heating process by releasing it this heat energy via the essentially radially arranged ribs of the Heat exchanger use takes place. Heating water is pure with these Air heaters not provided.

On the part of the applicant such heating devices with a water boiler provided, which around the heat exchanger insert on its outer circumference is arranged. The heat exchanger insert from the hot ones Combustion gases absorb heat energy via the fins in the essentially directly to the inside of the kettle, which uses the heat exchanger surrounds, transmitted.

Especially during the cold season it is necessary that those in caravans and mobile homes used on the one hand for heating are and on the other hand serve to produce hot water. Especially during permanent heating is often required during this cold season. At the permanent heating is, however, permanent heat energy from the Heat exchanger use given to the kettle, so the danger there is that the water in the kettle begins to boil.

In addition, there is such a heater for heating air and / or water the problem that the internal dimensions of the kettle with relative high accuracy on the external dimensions of the relatively complicated profiled and complicated heat exchanger insert to be matched have to. On the one hand, this results in relatively high production costs, and on the other hand, it leads through the combustion gases as they flow over the Uneven surface of the heat exchanger insert Heat transfer from the combustion gas to the heat exchanger insert to one uneven heating of what is to be heated in the kettle Water. The result of this is that when a tap is opened, it is always with differently heated water can be expected. In addition to the risk of Scalding also has the problem of permanently supplying it changed from cold water to achieve a desired mixing temperature must become.

Furthermore, the heater should also be easy to use in summer Generate only heated water. Another problem with the heaters for heating air and / or water according to the state of the Technology is that due to the small distance between the Inside of the water boiler and the outside of the heat exchanger insert in the frequently occurring situation that the caravans, campers etc. go wrong stand, a "diameter problem" occurs because namely in such a situation individual areas of the inside of the kettle directly on the outer surface of the heat exchanger while other areas are at a greater distance to the heat exchanger than when it was originally in the design state is provided.

The invention is therefore based on the object of the disadvantages described overcome and a heater for heating air and / or water too create, in which the heat transfer from a heat exchanger insert a kettle can be optimized in such a targeted manner that an essentially constant one Temperature in the kettle can be achieved and boiling of the water avoided and in which the manufacturing cost of the kettle in terms its accuracy of the dimensions to be observed can be reduced.

This object is achieved by a heater with the features according to claim 1 solved. Appropriate developments are in the dependent claims Are defined.

In particular, the heater according to the invention, which is used for heating Air and / or water is used in small spaces, where in particular caravans, mobile homes, boats or the like, preferably the Represent areas of application. The heater has a boiler, which in one Combustion chamber is arranged, which is designed in the form of a flame tube, a boiler room surrounding the combustion chamber, a Heat exchanger insert, which surrounds the boiler room and which one Has inner jacket, and a water boiler, which the heat exchanger insert surrounds. The kettle and thus the heater are one surround an outer shell forming a housing. The inner jacket of the Heat exchanger insert separates the boiler room, through which the hot ones Combustion gases are directed from the combustion chamber after leaving the combustion chamber Heat exchanger surfaces of the heat exchanger insert, which the Are facing the inside of the kettle. According to the invention Kettle on the inside, which the heat exchanger insert facing areas on which the heat transfer from Use of heat exchanger to the kettle through different in between defined gap geometry can be determined. By means of the gap geometry between the Outside of the heat exchanger insert and inside of the water boiler, which face each other is the heat transfer as such as well the type of heat transfer so determined that an equilibrium situation of the water in the kettle is achievable. Under equilibrium in this context the temperature of the water is as constant as possible understood essentially in the entire kettle.

The gap geometry of the individual areas determining the heat transfer is designed so that, depending on the required heat transfer also under Taking into account the nominal load that can be achieved with the heater, the Gap geometry gap thicknesses of 0 mm, in which the inside of the Kettle directly on the outer surface of the heat exchanger insert is present, up to gap thicknesses of finite dimensions. Furthermore, it is possible that the gap geometry continuous transitions between the individual heat transfer areas or sharply defined transitions. The gap geometry with respect to the Longitudinal axis of the combustion chamber to be constant or variably designed column exhibit. By in the respective heat transfer areas Different defined gap geometry is the heat transfer from Heat exchanger use to the kettle directly influenced so that a constant water temperature in the kettle is reached and that the boiler is not overheated during continuous heating, i.e. that no boiling of water occurs in the kettle.

According to an embodiment of the invention, the kettle in Area of the burner of the flame tube, i.e. the lower part of the Heater, a first heat transfer area in which the inside of the kettle with close tolerance, i.e. high manufacturing accuracy, in essentially rests on the surface of the heat exchanger insert. Thereby, that the inside of the kettle in this heat transfer area the outer surface of the heat exchanger insert, dominates in this first heat transfer area the heat conduction. Even if a very small one Gap between the outer surface of the heat exchanger insert and the Inner surface of the kettle in this first heat transfer area should be present, this very narrow gap is still not large enough that convection and radiation play a major role in the heat transfer, in such a case, heat conduction is also dominant. Of the kettle also has at least in the area where the combustion gases exit from the flame tube, i.e. the upper area of the heater, one second heat transfer area, the gap geometry as a gap between the outer surface of the heat exchanger insert and the inside the kettle is formed so that in this second Convection and heat radiation dominate the heat transfer area. The means that between the inside surface of the kettle and the External surface of the heat exchanger insert in this second heat transfer area intended gap is large enough that the heat conduction of convection and heat radiation is dominated.

Depending on the operating condition of the heater and depending on what can be achieved Heat transfer are the first heat transfer area and the second heat transfer area trained different lengths. The term "long" refers the extension in the longitudinal direction of the combustion chamber or Flame tube.

An advantage of such a design of the water boiler according to the invention exists among other things also in that the high manufacturing accuracy in terms of tight Manufacturing tolerances are limited to the first heat transfer area thereby reducing the overall manufacturing cost of the kettle. in the In case of direct contact between the inside surface of the kettle and the outer surface of the heat exchanger insert in the first Heat transfer area is already a sufficient stability of the tilt Kettle in front of the heat exchanger use. For the sake of one The kettle exhibits increased rigidity either in the transition area between the first heat transfer area and the second Heat transfer area or within the first heat transfer area or an additional one within the second heat transfer area Bead on. The kettle is for reasons of required food safety preferably made of stainless steel and has a wall thickness of preferably 1 mm on.

According to a further exemplary embodiment, between the region of the Burner and the area of the exit of the combustion gases from the Flame tube, i.e. between the first heat transfer area and the second Heat transfer area, a third heat transfer area is provided in which the gap geometry is defined by a gap which is larger than the gap of the first heat transfer area and is smaller than the gap of the second heat transfer area. The number of defined provided Heat transfer areas, i.e. the areas of different gap geometries, has a direct influence on the uniformity of the temperature distribution of water in the kettle. It also takes into account the different Gap geometry the different heat transfer conditions as a result of different temperature and flow conditions, which due to the Flow of the combustion gases along the boiler room in the course of the flow from the upper part of the heater to the lower part of the heater on the Occur outside of the combustion chamber.

According to a further exemplary embodiment, the heat transfer areas are contrasted by shoulders or by beads or by these limited. The beads or shoulders can also be within the respective Heat transfer areas can be provided for increased stability and To ensure strength, in particular buckling stiffness, of the kettle.

The flame tube is preferably substantially cylindrical and are the boiler room, the heat exchanger insert with its inner jacket, the Kettle and the outer jacket of the heater arranged coaxially. According to a further embodiment, the heat exchanger insert is in the essentially cylindrical, so that its inner jacket is cylindrical is trained. The inner jacket carries radial, opposite one another attached inner and outer ribs, with on the outer edges of the outer ribs in each case an at least unilaterally projecting transverse web is formed. This Crosspieces on the outer ribs are not connected to one another and with their outer surfaces essentially follow the inside of the kettle. Such a heat exchanger insert can be designed, for example, as described in the applicant's EP 0 544 853 B1.

According to a further exemplary embodiment, the individual heat transfer regions have each have a constant gap geometry. Under constant Gap geometry is the radial expansion of the gap in the direction of Understand the longitudinal axis of the combustion chamber of the heater.

The gap of the first heat transfer region preferably measures 0 to 1.5 mm and the gap of the second heat transfer area 3 to 4 mm. Different heating conditions and different heat exchanger inserts than that described, however, may require gaps that differ significantly from the deviate as an example.

Fig.1

einen Axialschnitt durch das Heizgerät gemäß der Erfindung;

Fig. 2

einen Axialschnitt durch den Wasserkessel gemäß der Erfindung; und

Fig. 3

ein Segment des bei dem erfindungsgemäßen Heizgerät verwendeten Wärmeübertragereinsatzes.

Further advantages, features and possible applications of the invention will now be explained in detail using an exemplary embodiment with reference to the accompanying drawings. Show it:

Fig.1

an axial section through the heater according to the invention;

Fig. 2

an axial section through the kettle according to the invention; and

Fig. 3

a segment of the heat exchanger insert used in the heater according to the invention.

1 shows an axial section through a heater according to the invention. Inside the heater, a burner 1 is provided, which within a Flame tube 2 designed as combustion chamber 3 is arranged. The flame tube 2 is essentially cylindrical and extends inside the Heat exchanger insert 5 from the burner upwards, where it is with its upper Exit shortly before the heat exchanger insert 5 or its Inner jacket 6 ends Dekel 24 covering cap-shaped. The top cap 24 is preferably welded on. Through this top cap 24 in Flame tube 2 ascending combustion gases 23 deflected into a boiler room 4. The heating chamber 4 is between the inner jacket 6 of the heat exchanger insert 5 and the outer surface of the flame tube 2 is formed. The combustion gases 23 then flow in the boiler room in a coaxial direction with respect to the flame tube 2 towards the burner side of the heat exchanger insert, from where from the combustion gases 23 via an exhaust gas connection 25, for example into the Free to be dissipated.

The heat exchanger insert 5 has radially extending into the boiler room Inner ribs 17, which can have radially different dimensions, and radially outwardly extending outer ribs 18 from the inner jacket 6. In the longitudinal spaces between the outer ribs 18 of the heat exchanger insert 5 flows air, which by heat transfer from the heat exchanger insert 5 due to heat emission from the combustion gases 23 on the one hand absorbs heat energy and on the other hand, depending on the gap geometry, Dissipates thermal energy from the kettle 7. The along the outer ribs of the heat exchanger insert 5 flowing air flows in cocurrent to the Combustion gases 23 in the boiler room 4. The air enters the burner for example, also acted upon by a fan in the between the External ribs 18 formed a space and directly at the other end of the heater out of this room again.

The radial direction arranged over the circumference, from the inner jacket 6 of the heat exchanger insert 5 outwardly extending outer ribs 18 have on their outer edges transverse webs 19 which are on both sides of the Extend ribs. To increase the heat exchanger surface are on the Ribs between the crosspieces 19 and the inner jacket 6 further transverse processes formed on the outer ribs 18. Of course, it is also possible that the inner ribs 17 have such transverse processes or crosspieces. The after outside facing of the crossbars 19 forms the maximum Outer diameter or the outer surface of the cylindrical Heat exchanger insert 5. In the heat transfer area 9, in which the Cross webs 19 rest substantially on the inside of the water boiler 7 or have a small gap to it, the crossbars form the surfaces over which is the heat transfer that is essentially realized as heat conduction. In the heat transfer area 10, in which between the crosspieces 19 and the gap of the inner diameter of the water boiler 7 is provided, form the Crosspieces 19 additionally heat transfer surfaces, for example Radiation is realized. By providing the gap 14 carries in the area of Outer ribs, i.e. between the inner jacket 6 of the heat exchanger insert 5 and the water boiler 7, flowing air, depending on the heating condition, either to ensure the heat transfer to the kettle or Dissipate thermal energy from the kettle to boil the water in the Avoid kettle 7.

The number of outer fins of the heat exchanger insert is such that the airflow flowing over it is fanned out and thus in connection with the desired gap geometry of the selected gap geometry Heat transfer processes from the heat exchanger insert 5 to or from the Kettle 7 realized.

Fig. 2 shows an axial section through the water boiler 7 for the heater according to the invention. The kettle 7 has a first Heat transfer area 9, the diameter of which is dimensioned so that it with close tolerance to the outer diameter or to the outer surface 12 of the Heat exchanger insert 5 fits so that the crosspieces 19 on the inner surface of the kettle 7 or just have tight tolerances narrow gap is present. The precisely fitting manufacture of the water boiler 5 is so only limited to the first heat transfer area 9, which therefore increases significantly reduces the manufacturing costs of the water boiler 7, since the other heat transfer areas do not require such tight manufacturing tolerances. At the bottom of the water boiler 7, which in the area of the burner 1 of the Heater is arranged, a centering collar 20 is provided, which for Put on a plate (not labeled) and thus to fix the Kettle 7 in the housing of the heater is used.

The first heat transfer area 9 is delimited by a bead 16 which serves at the same time to increase the rigidity of the water boiler 7. From the bead 16 extends up to a shoulder 15, a third heat transfer area 11, whose inside diameter is chosen so that a gap between the inside of the Kettle 7 and the outer surface 12, which by the crosspieces 19 of the Heat exchanger element 5 are formed, which is> 0. Preferably, the inner diameter is chosen so that in the Heat transfer area 11 heat conduction, convection and radiation available are, preferably with almost equal shares.

In the upper area of the water boiler 7, which in the area of the upper end of the Flame tube 2 is located, extends from a shoulder 15 to a fixing collar (not shown) a second heat transfer area 10, the Inner diameter is greater than that by the outer surface 12 of the Heat exchanger insert 5 formed outer diameter, so that between the Outer surface 12 of the crosspieces 19 and the inner surface of the kettle 7 there is a gap 14 with a defined gap width. The gap 14 has such a dimension that convection and radiation dominate because the heat conduction is small over the air layer in the gap compared to the heat energy transmitted by radiation and convection. Of the water boiler 7 also has fasteners 21, 22.

The kettle 7 for the heater according to the invention can be selected Gap geometry also operated without water, for example in summer , in which case the heater is only for heating purposes without Water heating is used.

Fig. 3 shows a radial section of a cross-sectional view of the in the invention Heater used heat exchanger insert 5, the basic structure already described in connection with FIGS. 1 and 2 and which is in detail the execution according to EP 0 544 853 B1 Applicant complies.

Claims (9)

1. Heating apparatus for heating air and/or water for small spaces, in particular for caravans, mobile homes, boats or similar, which comprises a burner (1) in a combustion chamber (3) formed as a fire tube (2), a heating chamber (4) surrounding the combustion chamber, a heat exchanger insert (5), which encloses the heating chamber (4) and has an inner jacket (6), and a water boiler (7) surrounding the heat exchanger insert (5), wherein an outer jacket (8) enclosing the water boiler (7) is provided,
   characterised in that,
   at its inside which faces the heat exchanger insert (5), the water boiler (7) comprises regions (9, 11, 10) of different, defined gap geometry which determine the heat transfer from the heat exchanger insert (5) to the water boiler (7).
2. Heating apparatus according to Claim 1, characterised in that, in the region of the burner (1) of the fire tube (2), the water boiler (7) comprises a first heat transfer region (9) in which the gap geometry is formed such that the inside of the water boiler (7) lies with a close tolerance substantially against the outer surface (12) of the heat exchanger insert (5), and in which heat conduction therefore dominates, and that the water boiler (7) comprises, at least in the region of the exit (13) of the combustion gases from the fire tube (2), a second heat transfer region (10) in which the gap geometry is formed such that a gap (14) is provided between the outer surface of the heat exchanger insert (5) and the inside of the water boiler (7), so that convection and heat radiation dominate in the second heat transfer region (10).
3. Heating apparatus according to Claim 2, characterised in that, between the region of the burner (1) and the region of the exit (13) of the combustion gases from the fire tube (2), the water boiler (7) comprises a third heat transfer region (11) in which the gap geometry is defined by a gap which is larger than the gap of the first heat transfer region (9) and smaller than the gap (14) of the second heat transfer region (10).
4. Heating apparatus according to Claim 2 or 3, characterised in that the heat transfer regions (9, 11, 10) are offset relative to one another by means of shoulders (15) .
5. Heating apparatus according to Claim 2 or 3, characterised in that the heat transfer regions are delimited by beads (16).
6. Heating apparatus according to any one of Claims 1 to 5, characterised in that the fire tube (2) is substantially cylindrical, and the heating chamber (4), the heat exchanger insert (5) with its inner jacket (6), the water boiler (7) and the outer jacket (8) are disposed coaxially therewith.
7. Heating apparatus according to any one of Claims 1 to 6, characterised in that the heat exchanger insert (5) comprises radial, attached inner ribs (17) and outer ribs (18), which lie opposite one another, at the substantially cylindrical inner jacket (6), wherein a cross-bar (19), which projects at least on one side, is in each case formed at the outer edges of the outer ribs (18), and the crossbars (19) are not connected together and, with their outer faces, face the inside of the water boiler (7) substantially in succession.
8. Heating apparatus according to any one of Claims 1 to 7, characterised in that the heat transfer regions (9, 11, 10) each have a constant gap geometry.
9. Heating apparatus according to Claim 8, characterised in that the gap of the first heat transfer region is 0 to 1.5 mm and the gap (14) of the second heat transfer region is 3 to 4 mm.

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