WO2008122258A1 - Heat exchanger for a combined heating/warm water system for mobile applications and combined heating/warm water system for mobile applications - Google Patents

Abstract

The invention relates to a heat exchanger (18) for a combined heating/warm water system (10) for mobile applications and a combined heating/warm water system (10) for mobile applications. The heat exchanger (18) for a combined heating/warm water system (10) for mobile applications has a pipe jacket (20) comprising a first center axis (M1) and an interior space (22) for accommodating a combustion pipe (16) for the combustion of liquid or gaseous fuels with a second center axis (M2), outer ribs (26a, 26b, 26c) which are arranged on an outer side (24) of the pipe jacket (20) and extend radially therefrom and inner ribs (30) which are arranged between the combustion pipe (16) and an inner side (28) of the pipe jacket and extend radially therefrom, characterized in that the second center axis (M2) is arranged at a distance from the first center axis (M1).

Description

 description

Heat exchanger for a combined heating / hot water system for mobile applications and combined heating / hot water system for mobile applications

The invention relates to a heat exchanger for a combined heating / hot water system for mobile applications and Combined heating / hot water system for mobile applications.

A combined heating / hot water system for mobile applications is known for example from DE 297 22 802 U1. A burner is arranged in a recess of a hot water tank, wherein the hot water tank is substantially hollow cylindrical and the burner is substantially cylindrical. The burner and the hot water tank are thermally coupled with each other. This can be provided by means of a burner energy for both the heating system and for the hot water system.

It is desirable to further improve such combined heating / warm water systems in order to use them in the limited space conditions, such as in motor vehicles, especially in motorhomes or other camping vehicles and in watercraft.

The object of the invention is to provide a heat exchanger for a combined heating / hot water system for mobile applications and an arrangement for a combined heating / hot water system for mobile applications, which is reliable, well adapted to given space conditions and cost can be produced.

The object is solved by the features of the independent claims. Advantageous developments of the invention are characterized in the subclaims. According to a first aspect, the invention is characterized by a heat exchanger for a combined heating / hot water system for mobile applications, with a pipe jacket having a first central axis and an interior, which is adapted for receiving a combustion tube for the combustion of liquid or gaseous fuels a second central axis, arranged on an outer side of the tubular jacket, radially extending outer ribs, and between the combustion tube and an inner side of the tubular jacket extending in the radial direction inner ribs, wherein the second central axis is spaced from the first central axis.

This has the advantage that a targeted formation of a fuel pipe asymmetrically arranged with respect to the tubular jacket of the heat exchanger and thus a compensation of an asymmetrical heat emission of the combustion tube is possible. This is particularly advantageous in the case of a horizontal arrangement of the heat exchanger, since in this case an unbalanced heat output of the combustion tube can often be present.

In an advantageous embodiment, the outer ribs each have a respective same angular distance with respect to the first central axis and the inner ribs each have a respective same angular distance with respect to the second central axis. This is advantageous because an equi-angular fin arrangement allows a uniform distribution of the heat energy over the circumference of the heat exchanger both in the interior and outside of the tubular jacket.

In a further advantageous embodiment, the heat exchanger has a first outer rib, a second outer rib and further outer ribs, and the first and second outer rib have projections in the radial direction, wherein the first and the second outer rib have a greater extent in the radial direction than the others External ribs, and the first and second outer rib are formed for abutment with a arranged outside of the heat exchanger lateral surface. This embodiment of a heat exchanger, which can also be used independently of a spacing of the center axes, has the advantage that a defined positioning of the heat exchanger against over the lateral surface is possible. This is especially true in the case of a horizontal arrangement of the heat exchanger.

In a further advantageous embodiment, the first and the second outer rib with respect to the first central axis at an angular distance of a maximum of 120 ° to each other. This makes it possible to achieve a stable positioning of the heat exchanger relative to the lateral surface, in particular in the case of a horizontal arrangement of the heat exchanger.

In a further advantageous embodiment, the outer ribs each have a transverse web. This good heat transfer properties of the heat exchanger can be achieved.

In a further advantageous embodiment, the transverse webs are arranged at distal ends of the outer ribs. This is particularly advantageous, since such a good heat transfer from the heat exchanger to the outside is possible.

In a further advantageous embodiment, the heat exchanger has a first group of outer ribs and a second group of outer ribs, and the outer ribs of the first group have a first length and the transverse ribs of the first group of outer ribs have a first width, and the outer ribs of the second Group have a second length and the transverse webs of the second group of outer ribs on a second width, wherein the first length is smaller than the second length and optionally the first width is greater than the second width. This is particularly advantageous, since so the inner transverse webs can transmit a larger amount of heat to the outside than the outer transverse webs.

In a further advantageous embodiment, at least two adjacent transverse webs of the outer ribs are arranged and formed such that their outer sides are arranged in a common plane. This allows precise positioning of the heat exchanger on a flat surface. In a further advantageous embodiment, a spring is arranged at the distal ends of the outer ribs and / or at the transverse webs, which spring is designed such that the heat exchanger can be supported on a cylindrical outer surface arranged outside the heat exchanger, for example. This has the advantage that such a stable positioning of the heat exchanger relative to the lateral surface is possible. In particular, such a secure attachment for mobile operation is given.

In a further advantageous embodiment, the heat exchanger is designed as an extruded profile. For a simple production of the heat exchanger is possible.

According to a second aspect, the invention is characterized by a combined heating / hot water system for mobile applications, with a hot water tank with a recess, and arranged in the recess of the hot water storage combustion pipe for the combustion of liquid o- and gaseous fuels, wherein the combustion tube thermally is coupled to the hot water tank, wherein between the hot water tank and the combustion tube, a heat exchanger according to the first aspect is arranged, which is designed for the thermal coupling of the combustion tube with the hot water tank.

In an advantageous embodiment of the second aspect of the invention, the heat exchanger is designed for the release of heat energy to air, which can be introduced into an air heating system. This is particularly advantageous because such a dual function of the heat exchanger for transferring heat to the hot water tank and / or the air heating can be used.

In a further advantageous embodiment of the second aspect of the invention, the first center axis of the tubular jacket of the heat exchanger is arranged horizontally. The heat energy of the likewise horizontally arranged combustion tube can be transferred so well on the heat exchanger to the air heater and / or the hot water tank. The advantages of the embodiments of the first aspect of the invention are correspondingly applicable to the embodiments of the second aspect of the invention.

Embodiments of the invention are explained in more detail below with reference to the schematic drawings.

Show it:

1 shows a schematic view of a heat exchanger of a first embodiment in a cross section,

FIG. 1A shows a detail of the heat exchanger in a section IA of FIG. 1,

FIG. 2 shows a schematic view of a combined heating / hot water system for mobile applications in a longitudinal section,

FIG. 3 shows a cross section through the combined heating / water system along the line IH-IH 'of FIG. 2 with a heat exchanger in a further embodiment,

4 shows a cross section through the combined heating / hot water system with a heat exchanger in a further embodiment,

Figure 5 shows a cross section through the combined heating / hot water system with a heat exchanger in a further embodiment, and

6 shows a cross section through the combined heating / hot water system with a heat exchanger in a further embodiment.

Elements of the same construction or function are provided across the figures with the same reference numerals. Figure 1 shows a first embodiment of a heat exchanger 18 for a combined heating / hot water system 10 for mobile applications (Figure 2). The heat exchanger 18 is preferably made of aluminum or an aluminum alloy. The heat exchanger 18 has a tubular jacket 20, which is cylindrical in the illustrated embodiment and has a first central axis M1, which is arranged in an interior 22 of the heat exchanger 18. The tube jacket 20 has an outer side 24 and an inner side 28. On the outer side 24 of the tube jacket 20 outer ribs 26a, 26b, 26c are arranged, which extend in the radial direction with respect to the first central axis M1 and are formed wave-shaped here with respect to a good heat transfer , The tube jacket 20 may have a shape deviating from a cylindrical shape, for example an oval or angular cross section, if this is expedient in the respective application. The outer ribs 26a, 26b, 26c then stand, for example, perpendicular to the outer side 24 of the tubular jacket 20.

The interior 22 is designed to receive a preferably cylindrical combustion tube 16 (see FIG. 2) with a second center axis M2, which can serve for the combustion of liquid or gaseous fuel. On the inner side 28 of the tubular jacket 20 inner ribs 30 are arranged, which extend in the radial direction with respect to the second central axis M2. The inner ribs 30 extend between the combustion tube 16 and the inner side 28 of the tubular jacket 20. Due to the spacing of the second central axis M2 relative to the first central axis M1, the lengths of the individual inner ribs 30 are different. In particular, the inner fins 30 are shorter where the combustion tube 16 is near the inner side 28 of the tube jacket 20 than where the combustion tube 16 is remote from the inner side 28 of the tube jacket 20. As a result of the spacing of the second center axis M2 from the first center axis M1, the course of the inner ribs 30 deviates from the profile of the outer ribs 26a, 26b, 26c, that is to say that even if there are an equal number of outer ribs 26a, 26b, 26c and inner ribs 30 these are not radially opposite each other, but arranged offset from one another. The outer ribs 26a, 26b, 26c each have a respective same angular distance ALPHA_A with respect to the first center axis M1. The inner ribs 30 each have a respective same angular distance ALPHAJ with respect to the second central axis M2. A first outer rib 26a and a second outer rib 26b each have a projection 32 in the radial direction. Thus, the first and second outer ribs 26a, 26b have a greater extent in the radial direction than further outer ribs 26c. If the heat exchanger 18, as shown here, arranged in a cylindrical recess 14, so are the projections 32 of the first and second outer rib 26a, 26b on the cylindrical lateral surface 34, so that the heat exchanger 18 relative to the lateral surface 34 in a well-defined Position is. This means that, when the first center axis M1 of the heat exchanger 18 is arranged horizontally, ie the heat exchanger 18 itself is also arranged horizontally, the heat exchanger 18 is securely and defined against the lateral surface 34 is positioned (see Figure 1A).

The first and second outer ribs 26a, 26b with the projections 32 have an angular distance ALPHA_A_12 of less than 120 ° with respect to the first center axis M1. Thus, a stable positioning of the heat exchanger 18 relative to the lateral surface 34 is possible, in particular in the case of a horizontal arrangement of the heat exchanger 18, i. a horizontal orientation of the first center axis M1. It is particularly preferred if the angular distance ALPHA_A_12 is between 60 ° and 90 °.

The outer ribs 26a, 26b, 26c of the heat exchanger 18 each have a transverse web 38, which allows a good heat transfer from the heat exchanger 18 to the lateral surface 34. In the embodiment shown here, the transverse webs 38 are arranged at distal ends 27 of the outer ribs 26a, 26b, 26c.

The transverse webs 38 are arranged and formed on three of the further outer ribs 26c (see FIG. 1, top) such that outer sides 39 of the transverse webs 38 lie in a common plane E. Thus, the heat exchanger 18 in the course of Manufacturing process preferably be safely parked on a flat surface.

Furthermore, at least one of the transverse webs 38 has a greater distance from the cylindrical lateral surface 34 than the remaining transverse webs 38. It is thus possible to arrange a spring 40 between this transverse web 38 and the lateral surface 34, such that the heat exchanger 18 adjoins the Jacket surface 34 can be supported so as to achieve an accurate positioning of the heat exchanger 18 relative to the lateral surface 34 together with the projections 32. This is especially important in mobile applications when the system may be subject to shock.

Preferably, the heat exchanger 18 is formed as an extruded profile, since this allows a particularly simple production of the heat exchanger 18.

Figure 2 shows the combined heating / hot water system 10 for mobile applications with a hot water tank 12 having a recess 14. The hot water tank 12 is preferably formed as a hollow cylinder, but may also have a different geometry. In the recess 14 of the hot water tank 12, the preferably cylindrical combustion tube 16 is arranged. The cylindrical combustion tube 16 has at its center a combustion chamber 42 and coaxially around it a fuel gas passage 44 is arranged. About the fuel gas passage 44 and a fuel gas outlet opening 46, the fuel gas can be discharged to the environment. The fuel gas channel 44 is formed by an outer wall of the combustion tube 16 and a wall 17 within the combustion tube 16

In the recess 14 of the hot water tank 12, the heat exchanger 18 with the outer ribs 26a, 26b, 26c and the inner ribs 30 is arranged between the cylindrical combustion tube 16 and the hot water tank 12 coaxially by means of which the combustion tube 16 is thermally coupled to the hot water tank 12. Via a heating medium inlet opening 48, a heating medium can enter into the recess 14 of the hot water storage tank 12 and via the heating medium Heat exchanger 18 with the ribs 26 a, 26 b, 26 c, 30 reach a Heizmediumein- opening 50. The heating medium is preferably air, but may also be water, optionally in combination with an antifreeze.

A horizontal arrangement is particularly favorable. The design of the heat exchanger 18 according to FIGS. 1 and 2 is optimized with regard to the horizontal arrangement, for which purpose several features contribute in each case, but in particular in the case of cumulative realization. The two projections 32 on the outer ribs 26a, 26b secure the fixed positioning in the recess 14. The generally relatively heavy heat exchanger 18 can thus not swing, as may be the case with a purely frontal attachment. The opposite spring 40 presses the two projections 32 against the lateral surface 34, so that vibrations of the heating / warm water system 10 do not adversely affect. At the same time tolerances can be compensated, so that a cost-effective production is possible. A different position of the center axes M1, M2 of the combustion tube 16 and tube jacket 20 of the heat exchanger 18 takes into account the flow behavior of hot gases in particular in the horizontal position and ensures optimized heat distribution in the heat exchanger 18th

The combustion tube 16 has a fuel supply device 19. By means of a fan, not shown, the combustion tube 16 via an air inlet opening 36 combustion air 52 can be supplied.

FIGS. 3 to 6 show alternative embodiments of the combined heating / hot water system 10, in particular of the heat exchanger 18.

FIG. 3 shows an embodiment of the combined heating / hot water system with a further embodiment of the heat exchanger 18 without transverse webs. In addition, the heat exchanger 18 here has straight outer ribs 26 a, 26 b, 26 c and straight inner ribs 30. FIG. 4 shows the heating / hot water system 10 with a further embodiment of the heat exchanger 18, in which case the heat exchanger 18 has transverse webs 38 at the distal ends 27 of the outer ribs 26a, 26b, 26c of the heat exchanger 18. The outer ribs 26a, 26b, 26c and the inner ribs 30 of the heat exchanger 18 are each formed straight. The distance of the transverse webs 38 to the lateral surface 34 is here almost all outer ribs 26 a, 26 b, 26 c the same. But you can also choose an unbalanced distance.

FIG. 5 shows the heating / hot water system 10 with a further embodiment of the heat exchanger 18, in which the transverse webs 38 are not arranged at the distal ends 27 of the outer ribs 26a, 26b, 26c of the heat exchanger 18, but radial with respect to the first center M1 are offset inwards. In this case, the distal ends 27 of the outer ribs 26a, 26b, 26c of the heat exchanger 18 can play a comparable function with respect to a defined positioning of the heat exchanger 18 with respect to a jacket surface formed as an inner jacket of the hot water tank 12 as the projections 32 of the outer ribs 26a, 26b , 26c of the embodiment of the heat exchanger 18 according to FIG. 1.

FIG. 6 shows the heating / hot water system with a further embodiment of the heat exchanger 18, the heat exchanger 18 having a first group of outer ribs 26a, 26b, 26c having a first length L_1. The transverse webs 38 of the first group of outer ribs 26a, 26b, 26c have a first width EM. The heat exchanger 18 further has a second group of outer ribs 26a, 26b, 26c having a second length L_2. The transverse webs 38 of the second group of outer ribs 26a, 26b, 26c have a second width B_2. The first length L_1 is smaller than the second length L_2 and the first width B_1 is greater than the second width B_2. It can thus be achieved that transverse webs 38 of the first width B_1 can have a greater distance from the inner jacket of the hot water storage 12 than transverse webs 38 of the second width B_2 of the second group of outer ribs 26a, 26b, 26c. The transverse webs 38 of the first group of outer ribs 26a, 26b, 26c can thus have a have the same good heat transfer as the transverse webs 38 of the second group of outer ribs 26a, 26b, 26c.

The following briefly illustrates the function of the combined heating / hot water system 10:

Combustion air 52 is supplied via the air inlet opening 36 of the combustion chamber 42. Via the fuel supply device 19 is preferably liquid fuel, as it is also used to drive the vehicle, the combustion chamber 42 and burned there by means of the combustion air 52. However, gaseous fuel can also be used instead of the liquid fuel. The resulting fuel gas is passed via the fuel gas channel 44 and the fuel gas outlet opening 46 as exhaust gas 54 to the outside.

At the Heizmediumeintrittsöffnung 48 enters a heating medium, preferably air, in the recess 14 of the hot water tank 12 between the hot water tank 12 and the combustion tube 16 a. The heating medium is heated in the recess 14 of the hot water tank 12, in particular in the region of the heat exchanger 18 with the ribs 26a, 26b, 26c, 30, and emerges from the recess 14 at the heating medium outlet opening 50. The heating medium can then be supplied to a heat consumer, preferably an air heater or a water heater of a camping vehicle, a mobile home or a watercraft, by means of a heating medium control system (not shown).

Further embodiments, in particular of heat exchangers are possible and are at the discretion of the expert. In particular, features of various embodiments of heat exchangers can be combined.

Claims

claims 1. Heat exchanger (18) for a combined heating / hot water system (10) for mobile applications, with a tube jacket (20) having a first center axis (M1) and an interior space (22) adapted to receive a combustion tube (16) for combustion of liquid or gaseous fuels having a second center axis (M2), - On an outer side (24) of the tubular jacket (20) arranged in the radial direction extending outer ribs (26 a, 26 b, 26 c), and - between the combustion tube (16) and an inner side (28) of the tubular jacket (20) extending in the radial direction inner ribs (30), wherein the second central axis (M2) with respect to the first central axis (M1) is spaced. 2. Heat exchanger (18) according to claim 1, wherein the tubular jacket (20) and the combustion tube (16) are cylindrical, and the outer ribs (26 a, 26 b, 26 c) each have a same angular distance (ALPHA_A) with respect to the first central axis (M1). and the inner ribs (30) each have a respective same angular distance (ALPHAJ) with respect to the second central axis (M2). 3. Heat exchanger (18) according to claim 1 or 2, wherein the heat exchanger has a first outer rib (26 a), a second outer rib (26 b) and further outer ribs (26 c), and the first and second outer ribs (26 a, 26 b) projections (32 ) in the radial direction, wherein the first and second outer ribs (26a, 26b) have a greater extent in the radial direction than the further outer ribs (26c), and the first and second outer ribs (26a, 26b) are formed to abut a jacket surface (34) arranged outside the heat exchanger (18). 4. Heat exchanger (18) according to claim 3, wherein the first and the second outer rib (26a, 26b) with respect to the first central axis (M1) at an angular distance (ALPHA_A_12) of 120 ° maximum. 5. Heat exchanger (18) according to any one of the preceding claims, wherein the outer ribs (26 a, 26 b, 26 c) each have a transverse web (38). 6. Heat exchanger (18) according to claim 5, wherein the transverse webs (38) at distal ends (27) of the outer ribs (26 a, 26 b, 26 c) are arranged. 7. Heat exchanger (18) according to claim 6, wherein the heat exchanger (18) has a first group of outer ribs (26 a, 26 b, 26 c) and a second group of outer ribs (26 a, 26 b, 26 c), and the outer ribs (26 a, 26 b , 26c) of the first group have a first length (L_1) and the transverse webs of the first group of outer ribs (26a, 26b, 26c) have a first width (EM), and the outer ribs (26a, 26b, 26c) of the second group have a second width Length (L_2) and the transverse webs of the second group of outer ribs (26a, 26b, 26c) have a second width (B_2), wherein the first length (L_1) is smaller than the second length (L_2). 8. Heat exchanger (18) according to claim 7, wherein the first width (B_1) is greater than the second width (B_2). 9. heat exchanger (18) according to claim 6, wherein at least two adjacent transverse webs (38) of the outer ribs (26 a, 26 b, 26 c) are arranged and formed so that their outer sides (39) in a common plane (E) are arranged. 10. Heat exchanger (18) according to any one of claims 5 to 9, wherein at the distal ends (27) of the outer ribs (26a, 26b, 26c) and / or on the transverse webs (38), a spring (40) is arranged, which is formed in that the heat exchanger (18) can be supported on a lateral surface (34) arranged outside the heat exchanger (18). 11. Heat exchanger (18) according to one of the preceding claims, wherein the heat exchanger (18) is designed as an extruded profile. 12. Combined heating / hot water system (10) for mobile applications, with - A hot water tank (12) with a recess (14), and - A in the recess (14) of the hot water tank (16) arranged combustion tube (16) for the combustion of liquid or gaseous fuels, wherein the cylindrical combustion tube (16) is thermally coupled to the hot water tank (12), wherein between the hot water tank (12) and the combustion tube (16) a heat exchanger (18) is arranged according to one of the preceding claims, which is designed for the thermal coupling of the combustion tube (16) with the hot water tank (12). 13. Combined heating / hot water system (10) according to claim 12, wherein the heat exchanger (18) is designed for the release of heat energy to air, which can be introduced into an air heating system. 14. Combined heating / hot water system (10) according to claim 12 or 13, wherein the first center axis (M1) of the tubular jacket (20) of the heat exchanger (18) is arranged horizontally.