CN101738100A

CN101738100A - Heat converter for heating automobile

Info

Publication number: CN101738100A
Application number: CN200910221258A
Authority: CN
Inventors: 米夏埃尔·科尔; 托马斯·施特劳斯
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2008-11-18
Filing date: 2009-11-05
Publication date: 2010-06-16
Also published as: EP2187157A3; EP2187157B1; DE102008058100A1; EP2187157A2

Abstract

The present invention relates to a heat converter (1) for heating an automobile. The heat converter has a plurality of flow passages, the first side of the flow passages is flowed through by a heat transport fluid, the second side is flowed and circulated by air, wherein, the heat transport fluid and the air current are intersect and form a converted circulation, and the heat transport fluid flows and turns back at least two times in an in opposite direction of the flowing of air. The present invention is characterized in that a flow passage is made of a set of sheets (2), wherein, each sheet (2) has two half-sheets (2a, 2b) and at least three flow paths that can be flowed through.

Description

Heat exchanger for automobile heating

Technical Field

The invention relates to a heat exchanger for heating a motor vehicle.

Background

Heat exchangers for heating motor vehicles, also referred to as heaters or heating systems, are nowadays usually brazed metal heat exchangers. Known heaters have a heater core, also referred to as a core, which is composed of tubes and fins, preferably flat tubes and corrugated fins. The tubes are tapped into the header and brazed to the bottom of the header. The heated coolant from the engine cooling circuit passes through a tube in the warmer. The fins in the core are circulated by ambient air which absorbs heat from the coolant and is delivered into the passenger compartment. The primary requirement for the warmer is to achieve as uniform a distribution of the temperature at the air outlet side as possible over the entire air outlet plane, i.e. in the height and width directions.

In DE 19752139 a1, the applicant proposes that the coolant passing through the warmer is deflected "in the depth direction", i.e. in the direction of the air flow or in the opposite direction. This makes the temperature distribution on the air outlet side as uniform as possible. In order to deflect the coolant to a certain depth, a so-called longitudinal partition is arranged in the collecting tank of the heating device, which distributes the coolant flow first over the entire width and then through only one tube row. After deflection in the deflection box, the coolant then passes through a second tube row over its entire width.

It is known, for example, as disclosed in EP 0777585B 1, to baffle coolant in a radiator several times, for example three times, in the depth direction, so that the coolant passes through the radiator along four flow paths. Here, the air flow and the cooling liquid flow form cross convection, thereby improving heating efficiency.

When the principle of multiple deflection in cross-convection is implemented on modern heaters as described in the applicant's documents presented above, it causes problems, especially when two or more longitudinal partition walls are arranged in the header and are sealingly brazed to the tubes, tube sheets and header walls. It is also to be taken into account that the compartments divided by the longitudinal partition walls are not completely sealed from one another, so that leakage can occur. This would reduce the efficiency of the warmer, particularly in the case of a small volume flow of cooling liquid.

Disclosure of Invention

It is an object of the present invention to provide a heat exchanger, the manufacturing process of which is easy to control and the manufacturing costs of which are relatively low. Another object of the invention is to provide a gas flow exiting from the heater with a temperature profile on the air outlet side that is as uniform as possible, even in the case of small volumetric flows of the heat transfer fluid.

The object of the invention is achieved by a heat exchanger having the following features. Preferred embodiments are described below.

According to the invention, the heat exchanger, also referred to herein as a radiator, is of plate construction, i.e. the flow channels are formed by a plate stack, while one plate has two half-plates connected to one another, which can be traversed by a heat transfer fluid, preferably a coolant, in a multi-flow manner. It is known that plate structures are used in particular in oil coolers for motor vehicles. The two half-plates each have an upright edge with a fold, which is connected to the folds of the other plate in a material-locking manner, in particular by means of a braze joint. The advantage of the plate construction is that the plates can be assembled relatively easily into a plate package and have simple, mostly flat, brazing surfaces which are firmly brazed and which are pressure and liquid-tight. In this way, the manufacturing process of the warmer of plate structure according to the invention is easy to control, in particular without leakage.

In a preferred embodiment, the plates have partitions in their interior to form the flow channels, and in a further preferred embodiment, deflection regions are arranged at the ends of the partitions, so that adjacent flow channels in a plate are connected to one another and deflect the heat transfer fluid, in particular the coolant, in the depth direction.

In another preferred embodiment, the plates have inlets and outlets which are dish-shaped and are connected liquid-tightly to corresponding inlets and openings of adjacent plates. The inlets and openings of a plurality of plates arranged next to one another together form a flow channel which connects the plates to one another, i.e. on the coolant side, the plates communicate via a collecting channel both on the inlet side and on the outlet side. The collecting ducts are thus similar to the chambers in the collecting tank, which is divided by a longitudinal partition. The construction according to the invention, however, has the advantage that the sheets can be easily and firmly brazed to each other through a dish-shaped opening with a continuous flange.

Depending on the location of the coolant inlet and/or outlet, the collecting ducts can be arranged on one or both sides of the plate package.

According to a particularly preferred embodiment of the invention, two adjacent flow channels are connected to one another by an external deflecting duct. Through the deflection ducts, the heat transfer fluid flows out of the plate stack, is stirred sufficiently and then enters the adjacent collecting ducts and is distributed from there to the parallel flow channels of the plates. The temperature on the air outlet side is homogenized by this external deflection.

According to another preferred embodiment, the flow cross section of the deflecting ducts is smaller than the sum of the flow cross sections of the flow channels in the plate. The flow cross-section of the deflecting channel is preferably equal to 20 to 40% of the sum of the flow cross-sections of the individual flow channels. This results in a so-called throttling of the coolant, i.e. a certain stagnation effect due to the reduction of the cross-section, which facilitates a sufficient stirring of the coolant, i.e. a uniform coolant temperature distribution.

According to a particularly preferred embodiment, the heater according to the invention has four flow paths, wherein the first and third deflection flows of the heat transfer fluid occur in the plate and in the deflection region, and the second deflection occurs outside the plate via deflection ducts. The coolant temperature profile, which is still asymmetrical after the first two throughflows, becomes uniform after the coolant has been deflected in the deflection line, so that a uniform air outlet-side temperature profile is obtained on the air outlet side after the third and fourth throughflows of the coolant.

According to a preferred embodiment, the baffle channel is arranged inside the first lateral part, preferably formed in a lateral part, which closes off the plate package on one side to the outside.

According to a further preferred embodiment, a second side part is provided, which has an inlet and an outlet and closes the second side of the plate package to the outside.

According to a preferred embodiment, the warmer according to the invention has only three different parts, namely three different plate types. The first plate type has an inlet and an outlet, partition walls and a baffled region. The second plate type is a first side member having a baffle channel. The third plate type is a second side member and has an inlet and an outlet.

In a further preferred embodiment, second surfaces, in particular corrugated fins, are arranged between the plates, which are used to increase the air-side heat exchange surface, i.e. to improve the air-side heat exchange.

Drawings

Embodiments of the invention are described in detail below with reference to the drawings, while other features and/or advantages can be derived from the description and/or drawings. Wherein,

FIG. 1 is a perspective view of a warmer of plate-and-fin construction according to the invention, without side members;

FIG. 2 is a perspective view of a warmer according to the present invention with side members;

FIG. 3 is a cross-sectional view of the warmer;

FIG. 4 is a top view of the warmer;

in fig. 5 is a side part of the warmer as a connector;

FIG. 6 is a view of an individual half plate;

FIG. 7 is a perspective view of an individual half plate;

FIG. 8 is a perspective view of a panel made up of two half panels;

FIG. 9 is a cross-sectional view of one half plate;

FIG. 10 is a cross-sectional view of one plate (two half plates);

FIG. 10a is an enlarged view of a portion of FIG. 10;

fig. 11 is a cross-sectional view through the dish region of the plate.

Detailed Description

Fig. 1 shows a heating device 1 according to the invention, which is of plate-and-fin design, i.e. the heating device 1 is formed by a plurality of plates 2, which form flow channels for a heat transfer fluid, preferably a coolant, in a cooling circuit of an internal combustion engine of a motor vehicle. The plate 2 has dish-shaped openings 3, 4, 5, 6 in its upper region, which together with the adjacent dish-shaped openings (also referred to simply as dishes 3, 4, 5, 6)

form collecting ducts

7, 8, 9, 10. The term "collecting line" used here only encompasses the term "distribution line". The plate 2 also has

non-through partition walls

11, 12 and a centrally through partition wall 13. All the plates 2 are made of aluminium and brazed to each other as will be explained further below. The flow path of the cooling liquid is schematically indicated by arrows K1 to K9 indicating the flow. The

partitions

11, 12, which are not pierced, form flow-deflecting

zones

14, 15, through which the cooling liquid can be deflected in the depth direction, the air flowing between the plates 2 and passing through the warmer 1, which are indicated by the two arrows L1, L2. In order to improve the heat exchange, a second surface (not shown) in the form of a corrugated fin is arranged between the plates 2, said corrugated fin being brazed to the plates. The heated air, not shown, is delivered into the passenger compartment of the vehicle. The coolant enters the collecting channel 7 of the warmer 1 as indicated by the arrow K1 and is distributed into the cavities of the plates 2 and then flows downwards in the plates as indicated by the arrow K2. At the end of the partition 11, the coolant is deflected in the depth direction, as indicated by the arrow K3, i.e. in the direction opposite to the gas flow direction L1, L2, and flows upwards as indicated by the arrow K4. The arrows K2, K3, K4 apply to each plate 2 in the entire set of plates. The coolant then collects in the collecting channel 8, from where it flows out of the plate package consisting of the plates 2 through a not shown channel according to the arrow K5 and into the adjacent collecting channel 9. The coolant is distributed again there into the plates 2 and flows downwards as indicated by the arrow K6, is then deflected in depth as indicated by the arrow K7, flows upwards again as indicated by the arrow K8 and is collected in the collecting line 10 and finally flows out of the heater 1 as indicated by the arrow K9.

Fig. 2 is a perspective view of the warmer 1 with a side part 16 in which a baffle duct 17 is formed. The deflecting line 17 is connected to the collecting lines 8, 9 (see fig. 1) via two dish-shaped openings 4, 5, not shown in fig. 2, and deflects the coolant as indicated by the arrow K5 in fig. 1. The coolant is deflected in the plates 2 as indicated by arrows K3, K7 and outside the plates as indicated by arrow K5 through deflection ducts 17. The flow cross-section in the deflection ducts 17 is preferably smaller than the sum of the flow channel cross-sections of the individual plates 2, so that the cooling liquid flowing in the deflection ducts 17 is throttled by the reduction of the cross-section. As a result of the reduction in the cross section, a certain stagnation effect is produced, with the result that the coolant flowing out of the collecting channel 8 is mixed sufficiently, i.e. the coolant temperature is distributed uniformly. The flow cross-section of the baffle ducts 17 is preferably 20% to 40% of the sum of the flow channel cross-sections in the individual plates 2. By means of this "external deflection", a temperature profile on the air outlet side is obtained which is as uniform as possible, i.e. on the side of the arrows L1, L2 representing the outgoing air (see fig. 1).

FIG. 3Is a sectional view of the warmer 1 with arrows showing the flow of the cooling liquid and air. The cooling liquid flowing in is indicated by the arrow K_EThe coolant flowing out is indicated by the arrow K_AIndicated, and the air entering the warmer 1 is indicated by L_EAnd (4) showing. The flow channels in each plate 2 perpendicular to the plane of the drawing correspond to the arrows K2, K4, K6, K8 in fig. 1, and are indicated by the rows R1, R2, R3, R4 in fig. 3. The coolant thus flows downward in the row R1 according to the two arrow symbols (crosses), upward in the row R2 according to the arrow symbols (dots), downward in the row R3 and upward again in the R4. Between rows R2 and R3, the cooling liquid flows through baffle 17 in the direction of flow L, as indicated by arrow U (arrow K5 in FIG. 1), along the direction of flow L_EDeflecting in the opposite direction. The flow of air and coolant is known as cross-convection and has a higher heating efficiency, as described in the prior art. The section in fig. 3 passes through the common mid-plane of the collecting

ducts

7, 8, 9, 10 formed by the dishes 3, 4, 5, 6 formed on each plate 2. Each plate 2 consists of two half-

plates

2a, 2b, each having a

dish

3a, 3b, 4a, 4b, 5a, 5b, 6a, 6 b.

Fig. 4 is a top view of the warmer 1, in which the plate 2, consisting of half-

plates

2a, 2b respectively, is visible, the first side part 16 with the baffle duct 17 and the second side part 18-which together form a plate pack.

Fig. 5 shows a second side part 18, which has an inlet 18a and an outlet 18b, which are concentric with the collecting channels 7 and 10. Thus, the second side member 18 serves as a connecting member for inflow and outflow of the coolant.

In fig. 6, a single half-plate 2a is shown with two

non-through partition walls

11a, 12a and one through partition wall 13 a. In the upper region of the plate 2a,

dishes

3a, 4a, 5a, 6a are arranged, which are also indicated by arrows for the inflow and outflow of fluid. The total depth of the plate 2 is denoted by T and the depth of the individual flow channels is denoted by b1, b2, b3, b4, respectively, wherein in the illustrated embodiment all flow channels have the same depth, i.e. b 1-b 2-b 3-b 4. However, it is also advantageous to use different depths for the flow channels, i.e. b3 and b4 are greater than b1 and b 2. It is also advantageous if the viscosity of the coolant increases with intensive cooling. b4 is preferably twice as large as b 1. The height of the flow-deflecting

areas

14a, 15a is denoted by h1, where h1 ═ b 1. The height of the plate 2a is designated by h, wherein according to a preferred embodiment h is 100 to 400mm, and the structural or overall depth T is 10 to 120mm, preferably 25 to 80 mm.

Figure 7 is a perspective "view of one half-panel 2 a. The

partitions

11a and 12a that do not penetrate and the partition 13a that penetrates are formed by press-fitting grooves.

Figure 8 is a perspective "view of a panel 2 consisting of two half-

panels

2a, 2 b. The two half-

plates

2a, 2b are welded to each other in a sealed manner along the entire circumference and along the

partition walls

11a, 12a, 13 a.

Fig. 9 is a sectional view of the half-plate 2a, in which the

partitions

11a, 12a, 13a formed by trapezoidal recesses can be seen.

Fig. 10 is a sectional view of a plate 2 consisting of half-

plates

2a, 2 b. The plate 2 has a continuous, brazed-in flange 19, so that it is sealed to the outside. The

partitions

11, 12, 13 are formed by brazing the two

half plates

2a, 2b, so that the flow channels are formed.

Fig. 10a is an enlarged view of a portion E shown in fig. 10. The flow path width B1 (clear width), dish height B3, and material thickness s are indicated in the figure. The flow path width B1 is preferably 0.5 to 2.5mm and the dish height B3 is 1.5 to 5.0 mm. This dimension is equal to half the width of the corrugated fin arranged between the plates 2. The material thickness s is 0.15 to 0.5mm, which is suitable for aluminum materials.

Fig. 11 is a cross-section through the dish-shaped areas 3, 4, 5, 6 of the panel 2, which determine the maximum height of the panel 2, indicated by B4 in the figure. B4 is preferably 3.8 to 13.5 mm.

According to the illustrated and described embodiment, the entire warmer 1 can be made of only three different parts: these are plates 2 consisting of half-

plates

2a, 2b, a first lateral part 16 with baffle ducts 17 and a second lateral part with inlet and outlet ports 18a, 18 b. The number of parts is small, which reduces the manufacturing cost. Furthermore, the soldering process can be better controlled, since all surfaces to be soldered (successive folds, partitions, pans) are flat, thus ensuring that a soldering seal is achieved. The structure can be used for manufacturing a warmer capable of deflecting for multiple times.

In order to increase the heating efficiency, swirl plates, not shown, can be arranged in the plate 2, which are likewise brazed to the plate.

Claims

1. Heat exchanger (1) for heating motor vehicles, comprising a plurality of flow channels through which a heat transfer fluid flows on a first side and through which air flows on a second side, wherein the heat transfer fluid flow and the air flow form a cross-convection and the heat transfer fluid flow is deflected at least twice in the direction opposite to the air flow direction, characterized in that the flow channels are formed by a set of plates (2), wherein the plates (2) have two half-plates (2a, 2b) and have at least three flow paths through which air can flow.

2. A heat exchanger according to claim 1, characterised in that partition walls (11, 12, 13) are arranged in the plates (2) to form flow channels.

3. The heat exchanger according to claim 2, characterized in that baffle zones (14, 15) are formed at the ends of the partition walls (11, 12), which baffle zones connect adjacent flow channels.

4. A heat exchanger according to claim 1, 2 or 3, characterized in that the plates (2) have dish-like inlet and outlet openings (3, 4, 5, 6) which are liquid-tightly connected to the inlet and outlet openings (3, 4, 5, 6) of the adjacent plate (2).

5. A heat exchanger according to claim 4, characterized in that the dish-shaped inlet and outlet openings (3, 4, 5, 6) form flow channels (7, 8, 9, 10).

6. A heat exchanger according to claim 4 or 5, characterised in that the inlet and outlet openings (3, 4, 5, 6) or flow channels (7, 8, 9, 10) are arranged on one or both sides of the plate (2).

7. Heat exchanger according to claim 5 or 6, characterized in that two adjacent collecting ducts (8, 9) are connected to each other by an external baffle duct (17).

8. Heat exchanger according to claim 7, characterised in that the flow cross-section of the baffle ducts (17) is smaller than the sum of the flow cross-sections of the flow channels in the plate (2), preferably equal to 20 to 40% of the sum of the flow cross-sections of the flow channels.

9. Heat exchanger according to any of the preceding claims, characterized in that the first and third deflection (K3, K7) of the heat transfer fluid occur inside the plates (2) and in the deflection zones (14, 15), while the second deflection (K5) takes place outside the plates (2) by means of deflection ducts (17).

10. Heat exchanger according to claim 7, 8 or 9, characterised in that the baffle duct (17) is arranged inside a first side member (16) which closes one side of the plate package to the outside.

11. Heat exchanger according to any of the preceding claims, wherein the heat exchanger (1) has a second side member (18) with inlet and outlet openings (18a, 18 b).

12. Heat exchanger according to any of the preceding claims, characterized in that the heat exchanger consists of three different parts (2, 16, 18).

13. A heat exchanger according to any one of the preceding claims, characterised in that a second surface, preferably corrugated fins, is arranged between the plates (2).

14. A heat exchanger according to any of the preceding claims, characterized in that a whirl plate is arranged in the plate (2).