Title:
COMBINED HEATING/WARM WATER SYSTEM FOR MOBILE APPLICATIONS
Kind Code:
A1


Abstract:
Combined heating/warm water system (10) for mobile applications, having a warm water accumulator (12) with a recess (14), and a burner (16) which is arranged in the recess (14) of the warm water accumulator (16) for the combustion of fluid and gaseous fuels, wherein the burner (16) is coupled thermally to the warm water accumulator (12) and has a combustion air supplying device (18), wherein the combustion air supplying device (18) has an air guiding apparatus (28) having an air inlet opening (20), a first air outlet opening (22) and a second air outlet opening (24), and the first air outlet opening (22) is arranged in such a way that the combustion air feeding device (18) can be cooled and the second air outlet opening (24) is arranged in such a way that combustion air can be fed to the burner (16).



Inventors:
Fiumidinisi, Alessandro (Pero, IT)
Application Number:
12/281483
Publication Date:
01/08/2009
Filing Date:
12/19/2006
Assignee:
Webasto AG (Stockdorf, DD)
Primary Class:
International Classes:
F24D3/08
View Patent Images:



Foreign References:
WO2007031344A12007-03-22
EP09264531999-06-30
Other References:
Brandtner, EP 0926453 English machine translation, 10/22/1998.
Primary Examiner:
DECKER, PHILLIP
Attorney, Agent or Firm:
FITCH EVEN TABIN & FLANNERY, LLP (120 SOUTH LASALLE STREET SUITE 2100, CHICAGO, IL, 60603-3406, US)
Claims:
1. A combined heating/warm water system for mobile applications, with a warm water accumulator with a recess, and a burner, arranged in the recess of the warm water accumulator, for the combustion of liquid or gaseous fuels, the burner being thermally coupled to the warm water accumulator and having a combustion air supply assembly, the combustion air supply assembly having an air guide device with an air inlet port, a first air outlet port and a second air outlet port, and the first air outlet port being arranged such that the combustion air supply assembly can be cooled, and the second air outlet port being arranged such that combustion air can be supplied to the burner.

2. The combined heating/warm water system of claim 1, characterized in that the combustion air supply assembly has a cooling air fan.

3. The combined heating/warm water system of claim 2, characterized in that the combustion air supply assembly has a combustion air fan and a combustion air duct, and in that the combustion air duct is arranged such that the combustion air can be supplied to the burner, with the cooling air fan being bypassed.

4. The combined heating/warm water system of claim 2, characterized in that the combustion air supply assembly has a combustion air fan, and in that the combustion air fan and the cooling air fan can be driven by a common drive device.

5. The combined heating/warm water system of claim 1, characterized in that the combustion air supply assembly has a shielding element which is arranged on a side of the combustion air supply assembly which faces the warm water accumulator and by means of which the thermal coupling between the combustion air supply assembly and the warm water accumulator can be reduced.

6. The combined heating/warm water system of claim 5, characterized in that the shielding element consists of aluminum.

7. The combined heating/warm water system of claim 5, characterized in that the shielding element consists of a magnesium/aluminum alloy.

Description:

The invention relates to a combined heating/warm water system for mobile applications.

Such a combined heating/warm water system for mobile applications is known, for example, from DE 297 22 802 U1. A burner is arranged in a recess of a warm water accumulator, the warm water accumulator being essentially hollow-cylindrical, and the burner being essentially cylindrical. The burner and the warm water accumulator are thermally coupled to one another. Consequently, by means of one burner, energy can be provided both for the heating system and for the warm water system.

It is desirable to improve further combined heating/warm water systems of this type, in order to use them under the confined conditions of space, such as occur, for example, in motor vehicles, in particular in mobile homes or other camping vehicles, and also in watercraft.

The object of the invention is to provide a combined heating/warm water system for mobile applications, which is operationally reliable, is easily adaptable to predetermined conditions of space and can be produced cost-effectively.

The object is achieved by means of the features of the independent patent claims. Advantageous developments of the invention are characterized in the subclaims.

The combined heating/warm water system for mobile applications is distinguished by a warm water accumulator with a recess, and a burner, arranged in the recess of the warm water accumulator, for the combustion of liquid or gaseous fuels, the burner being thermally coupled to the warm water accumulator and having a combustion air supply assembly, the combustion air supply assembly having an air guide device with an air inlet port, a first air outlet port and a second air outlet port, and the first air outlet port being arranged such that the combustion air supply assembly can be cooled, and the second air outlet port being arranged such that combustion air can be supplied to the burner.

The air guide device makes it possible, by means of a first airflow between the air inlet port and the first air outlet port, to route air through the combustion air supply assembly such that the latter can be cooled. By means of a second airflow between the air inlet port and the second air outlet port, combustion air can be supplied to the burner.

It can consequently be ensured that a cooling of the combustion air supply assembly is possible even when the heating/warm water system is at a standstill, as long as air can flow from the air inlet port to the first air outlet port via the combustion air supply assembly.

In an advantageous refinement of the invention, the combustion air supply assembly has a cooling air fan. Active cooling of the combustion air supply assembly is consequently possible even when the heating/warm water system is at a standstill. An overheating of the combustion air supply assembly can therefore be effectively counteracted.

In a further advantageous embodiment of the invention, the combustion air supply assembly has a combustion air fan and a combustion air duct, and the combustion air duct is arranged such that the combustion air can be supplied to the burner, with the cooling air fan being bypassed.

This makes it possible to supply the combustion air directly to the burner from the surroundings via the air inlet port, without this combustion air previously being warmed by parts of the combustion air supply assembly.

In a further advantageous embodiment of the invention, the combustion air supply assembly has a combustion air fan, and the combustion air fan and the cooling air fan can be driven by a common drive device.

It is consequently possible to save a drive device for one of the fans and thus keep the outlay for the structural elements for the combustion air supply assembly low. Furthermore, it is possible to keep the energy demand for the combustion air supply assembly low.

In a further particularly advantageous embodiment of the invention, the combustion air supply assembly has a shielding element which is arranged on a side of the combustion air supply assembly which faces the warm water accumulator and by means of which the thermal coupling between the combustion air supply assembly and the warm water accumulator can be reduced.

It is consequently possible to reduce the heat flow from the warm water accumulator to the combustion air supply assembly by means of a component acting passively.

In a particularly preferred embodiment of the invention, the shielding element consists of aluminum. In a further particularly preferred embodiment of the invention, the shielding element consists of a magnesium/aluminum alloy. The advantage of this is that aluminum and magnesium/aluminum alloys make it possible to have a low weight of the shielding element. Furthermore, the shielding element may be manufactured as a casting and be connected in a simple way to other components consisting of aluminum or aluminum alloys.

Exemplary embodiments of the invention are explained below by means of the diagrammatic drawings.

In the figures:

FIG. 1 shows a diagrammatic view of a first embodiment of the combined heating/warm water system for mobile applications in a longitudinal section,

FIG. 2 shows a diagrammatic view of a second embodiment of the combined heating/warm water system for mobile applications in a longitudinal section,

FIG. 3 shows a cross section through the combined heating/warm water system along the line III-III of FIG. 1, and

FIG. 4 shows a cross section through the combined heating/warm water system along the line IV-IV of FIG. 1.

The figures show a combined heating/warm water system 10 for mobile applications, with a warm water accumulator 12 which has a recess 14. The warm water accumulator 12 is preferably designed as a hollow cylinder, but may also have a different geometry. A burner 16 is arranged in the recess 14 of the warm water accumulator 12. The burner 16 has at its center a combustion chamber 42 and a fuel gas duct 44 is arranged coaxially around the latter. The fuel gas can be discharged into the surroundings via the fuel gas duct 44 and a fuel gas outlet port 46.

Further, a heat exchanger 17 with heat exchanger fins 17a is arranged in the recess 14 of the warm water accumulator 12 between the burner 16 and the warm water accumulator 12 and coaxially to these, by means of which heat exchanger the burner 16 is thermally coupled to the warm water accumulator 12. The heat exchanger 17 preferably consists of aluminum or of an aluminum alloy. A heating medium can enter the recess 14 of the warm water accumulator 12 via a heating medium inlet port 48 and pass via the heat exchanger 17 having the heat exchanger fins 17a to a heating medium outlet port 50. The heating medium is preferably air, but may also be water, if appropriate in combination with an anti-freeze agent.

The burner 16 has a combustion air supply assembly 18 and a fuel supply assembly 19. The combustion air supply assembly 18 has an air guide device 28. The air guide device 28 has an air inlet port 20, a first air outlet port 22 and a second air outlet port 24. A cooling air fan 30 is arranged, near at least some of the air inlet ports 20, in the air guide device 28. By means of the cooling air fan 30, supply air 36 can be introduced into the air guide device 28 from outside.

Further, the combustion air supply assembly 18 has a combustion air fan 27, by means of which combustion air 37 can be supplied to the burner 16 via a combustion air duct 26. The combustion air 37 may in this case be introduced into the combustion air supply assembly 18 preferably either directly via the air inlet port 20 (FIG. 1) or via the air inlet port 20 and the cooling air fan 30 (FIG. 2).

A further part of the airstream which is introduced into the air guide device 28 by the cooling air fan 30 circulates as cooling air 38 preferably around the combustion air duct 26 and passes again into the surroundings as outgoing air 39 via the first air outlet port 22.

The combustion air fan 27 and the cooling air fan 30 are preferably arranged on a common shaft 31 which can preferably be driven by a common drive device 32. However, the combustion air fan 27 and cooling air fan 30 may also be driven by separate drive devices.

Further, the combustion air supply assembly 18 has a shielding element 34. This is arranged on a side of the combustion air supply assembly 18 which faces the warm water accumulator 12 and the heat exchanger 17. The shielding element 34 preferably consists of aluminum or of a magnesium/aluminum alloy. In the shielding element 34, designed as a robust component, in particular, heat which is emitted on that side of the warm water accumulator 12 and of the heat exchanger 17 which faces the combustion air supply assembly 18 can be absorbed. It is consequently possible to cushion peak heat quantities occurring in the warm water accumulator 12 and heat exchanger 17 such that the heat energy cannot pass directly to the remaining regions of the combustion air supply assembly 18.

The functioning of the combined heating/warm water system 10 will be illustrated in detail below:

Supply air 36 is introduced via the air inlet port 20 into the combustion air supply assembly 18 and is distributed there in the direction of the first air outlet port 22 and the second air outlet port 24. The combustion air 37 passing through the second air outlet port 24 of the combustion air supply assembly 18 is supplied to the combustion chamber 42 by means of the combustion air fan 27. Via the fuel supply assembly 19, preferably liquid fuel, such as is also used for driving the vehicle, is supplied to the combustion chamber 42 and is burnt there by means of the combustion air 37. Instead of liquid fuel, however, gaseous fuel may also be used. The fuel gas occurring is routed outward as exhaust gas 40 via the fuel gas duct 44 and the fuel gas outlet port 46.

At the heating medium inlet port 48, a heating 16 medium, preferably air, enters the recess 14 of the heat accumulator 12 between the heat accumulator 12 and the burner 14. The heating medium is heated in the recess 14 of the warm water accumulator 12, particularly in the region of the heat exchanger 17 having the heat exchanger fins 17a, and emerges from the recess 14 at the heating medium outlet port 50. The heating medium may be supplied then by means of a heating medium conduction system, not illustrated any further, to a heat consumer, preferably an air heating system or water heating system of a camping vehicle, a mobile home or a watercraft.

The part of the supply air 36 which is supplied to the first air outlet port 22 flows as cooling air 38, in particular, around the combustion air duct 26 and the shielding element 34 and can thus cool these.

When the combined heating/warm water system 10 is inoperative and the warm water of the warm water accumulator 12 is at a high temperature, heat can be transmitted from the warm water accumulator 12 to the heat exchanger 17 having the heat exchanger fins 17a. Heat can then be discharged from the warm water accumulator 12 and from the heat exchanger 17. By means of the shielding element 34, it is possible to limit the heat flow from the warm water accumulator 12 and the heat exchanger 17 to the combustion air supply assembly 18. In particular, the shielding element 34 may be used as a buffer element for the heat energy flowing from the heat exchanger 17 to the combustion air supply assembly 18.

Should the temperature in the region of the combustion air supply assembly 18 be too high, the cooling air fan 30 can be put into operation by a suitable control arrangement and supply air 36 can be routed via the air inlet port 20 to the first air outlet port 22, the cooling air 38 being capable of cooling the combustion air supply assembly 18. It is consequently possible by means of the cooling air fan 30 and the air guide device 28 effectively to protect parts of the combustion air supply assembly 18 which are sensitive to high temperatures against excessively high heat load.