CN100516760C

CN100516760C - Stacked-plate heat exchanger

Info

Publication number: CN100516760C
Application number: CNB2005800078039A
Authority: CN
Inventors: 延斯·里希特
Original assignee: Behr GmbH and Co KG
Current assignee: Mahle Behr GmbH and Co KG
Priority date: 2004-03-11
Filing date: 2005-03-04
Publication date: 2009-07-22
Anticipated expiration: 2025-03-04
Also published as: KR20060130207A; WO2005088223A1; CN1930440A; JP2007527984A; WO2005088223A8; JP4944009B2; EP1725824B1; EP1725824A1

Abstract

The invention relates to a stacked-plate heat exchanger, particularly an in-tank oil cooler, which is mounted in a coolant casing of a coolant cooler for vehicles. The heat exchanger comprises a number of stacked and interconnected, particularly soldered, elongated plates (71-77), each consisting of two plate halves and enclosing a hollow space though which a medium to be cooled, such as oil, passes in a longitudinal direction of the plates. In order to create a stacked-plate heat exchanger that can be economically produced, each of the plate halves have a multitude of grooves extending from one longitudinal side to the opposite longitudinal side of the plate half.

Description

Laminated plate heat exchanger

Technical Field

The invention relates to a laminated plate heat exchanger, in particular an internal oil cooler, for a motor vehicle, comprising a plurality of elongated plates which are arranged one above the other and are connected to one another, in particular brazed, each consisting of two identical half-plates turned 180 DEG relative to one another, and comprising a cavity through which a medium to be cooled, such as oil, flows in the longitudinal direction of the plates.

Background

German laid-open patent application DE 4308858C 2 discloses a laminated plate heat exchanger with plates stacked on top of each other and brazed to each other, consisting of two identical half-plates turned 180 ° relative to each other and comprising a cavity for the passage of the medium to be cooled. The half-sheet having been punched

For brazing the half plates to form a plate, and with connecting surfaces for brazing the plates to each other. The half plate pieces have punched portions in the form of truncated cones on the inner and outer surfaces. The half-plates are mirror-symmetrical with respect to their transverse and/or longitudinal axes. Frustoconical punch on the connecting surfaceAnd are arranged in a staggered manner. The positive punching part and the negative punching part are alternated mutually. The positive and negative punch parts are similar to pimples

In the installed state, the half-plates form a cavity through which a fluid, such as oil, flows. The protruding pimples in the cavity enable the oil to form a vortex, and the pimples play a role of a pull rod, so that the strength is improved.

Disclosure of Invention

The object of the invention is to provide a laminated plate heat exchanger, in particular an internal oil cooler, for a motor vehicle, with a plurality of elongated plates which are arranged one above the other and are connected, in particular brazed, to one another, each consisting of two identical half-plates turned 180 DEG relative to one another, and which comprise a cavity through which a medium to be cooled, for example oil, flows in the longitudinal direction of the plates. The heat exchanger has simple structure and low manufacturing cost. The laminated plate heat exchanger according to the invention also ensures that the medium to be cooled forms a good vortex in the cavity between the half plates.

The object of the invention is achieved in a heat exchanger of the laminated plate type, in particular an internal oil cooler, for a motor vehicle, having a plurality of elongated plates which are arranged one above the other and are connected to one another, in particular brazed, each consisting of two identical plate halves and comprising a cavity through which a medium to be cooled, such as oil, flows in the longitudinal direction of the plates, by each plate half having a plurality of grooves which extend straight from one longitudinal side of the plate half to the opposite longitudinal side. The plates are also known as flat tubes or plates. The grooves are oriented to ensure that the cooling fluid flows from one longitudinal side of the half-plate to the opposite longitudinal side. In the cavity, the grooves form a good vortex for the medium to be cooled.

A preferred embodiment of the laminated plate heat exchanger is characterized in that the long plate consists of two identical half plates turned 180 deg. in relation to each other. This greatly simplifies the manufacture of the laminated plate heat exchanger according to the invention.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the groove extends straight from one longitudinal side of the plate half to the opposite other longitudinal side. This ensures that the cooling liquid flows unhindered from one longitudinal side of the half-plate to the opposite longitudinal side.

Another preferred embodiment of the laminated plate heat exchanger is characterized in that the grooves are embossed on one side of each half plate. The groove is formed by a straight, long and narrow depression, which is pressed out, for example, on one side of the sheet. The manufacture of the half-slabs is simplified, since the grooves have to be pressed out only on one side.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the groove is bordered on the longitudinal sides by a circumferential edge. The circumferential edge serves to connect the two plate halves to one another, in particular by soldering. In this way, the cavity between the two half-plates is sealed from the surroundings.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the plate is formed by two half-plates attached to each other, the grooves of which project outwards. The grooves form flow paths for the medium to be cooled in the interior of the plate. Preferably, an inlet for the medium to be cooled is provided at one end of the plate and an outlet for the medium to be cooled is provided at the other end.

Another preferred embodiment of the laminated plate heat exchanger is characterized in that the two plates are attached to each other in raised areas formed by grooves and are joined to each other by brazing. In these raised areas, a cooling fluid, such as water, may flow from one longitudinal side of the half-plate to the opposite longitudinal side. In addition, the plate has a cup-shape in the edge region of the through-openingHere also the plates are brazed to each other.

A further preferred embodiment of the stacked plate heat exchanger is characterized in that the angle between the groove and the longitudinal axis of the respective plate half is 35 deg. to 55 deg., in particular 45 deg.. In this way it is ensured on the one hand that the medium to be cooled can pass from one end of the plate through the cavity inside the plate to the other end. On the other hand, according to the invention, the groove course also ensures that the cooling liquid between the plates can flow from one longitudinal side to the opposite longitudinal side.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the grooves of two half plates lying against each other are at an angle of 70 ° to 110 °, in particular 90 °, to each other. The flow paths formed for the medium to be cooled inside the plates thus have many changes in direction and turbulence. This has the advantage that the boundary layer which forms in the cavity during operation is continuously destroyed. This significantly reduces heat transfer compared to a flat tube without grooves. While the medium to be cooled undergoes many changes in direction when passing through the cavity. In contrast, the coolant flows almost unimpeded in a straight line in the groove between two plates lying against one another. An angle of 90 deg. causes the solder at the connection point of the two grooves to form a rounded meniscus. In this way, the influence on the flow along or across the main flow direction of the medium to be cooled is the same. The angle is preferably 80 ° to 100 °.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the depth of the groove is 0.8 to 1.5mm, in particular 1.15 mm. This depth is particularly advantageous within the scope of the invention. Particularly in the case of a fuel cooler, the depth of the groove is preferably 0.5mm to 1.5 mm.

A further preferred embodiment of the stacked plate heat exchanger is characterized in that the grooves in the plate halves are parallel to each other and at a distance of 3mm to 5mm, in particular 4mm, from each other. This spacing is particularly advantageous within the scope of the present invention.

Another preferred embodiment of the stacked plate heat exchanger is characterized in that the width of the half plates is about 20mm to 50 mm. This width is particularly advantageous within the scope of the invention. In commercial vehicles, the width of the half-panel is preferably about 20mm to 120 mm. Particularly preferred widths are 70mm to 80mm, especially 76 mm.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the hydraulic diameter has a value of 1.5mm to 2.5mm, in particular 1.8 mm. This hydraulic diameter value is particularly advantageous within the scope of the invention.

The hydraulic diameter between two adjacent plate halves in the main flow direction of the medium to be cooled represents the relationship between the cross section of the pipe through which the flow can pass and the heat exchange area. Hydraulic diameter is defined as four times the ratio of area ratio to area density. The area ratio is the ratio of the free duct cross-section to the area of the duct general end face in the duct between two adjacent half-plates. Areal density refers to the ratio of the area over which heat is transferred to the volume of the core. The hydraulic diameter remains as constant as possible over the entire main flow direction of the medium to be cooled. This allows the cavity between the two half-plates to be uniformly traversed.

A further preferred embodiment of the stacked plate heat exchanger is characterized in that the half plates are made of a metallic material, in particular aluminium or stainless steel (Edelstahl). The plates are preferably joined to each other by brazing. Stainless steel is preferably used for commercial vehicles.

Another preferred embodiment of the laminated plate heat exchanger is characterized in that at least one side of the half plates is coated with a brazing compound. This may simplify the manufacturing process of the laminated plate heat exchanger according to the invention.

Another preferred embodiment of the laminated plate heat exchanger is characterized in that the plate halves are provided with a pair of through holes as an inlet pipe and an outlet pipe, respectively. The medium to be cooled enters through the through-openings into a cavity which is located between the two half-plates forming the plate or flat tube. The plate may also be referred to as a plate and the half-plate may also be referred to as a half-plate.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the edge area of the through hole is convex. The raised width of the edge region of the through-hole is the same as the groove or corrugation. The two edge regions of the different half-plates, which lie against one another, seal the through-opening and seal the space between the two half-plates, which is connected to the through-opening, from the surroundings through which the coolant flows.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that an indentation is provided in the edge region of the through hole

The press-fit portion is used for reinforcing the half-chip in the through-hole region.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the pressed-in portions, seen in cross-section, have a wave-like shape with peaks and valleys in the inlet area. The peaks and valleys are essentially point contacts between two adjacent half-sheets.

A further preferred embodiment of the stacked plate heat exchanger is characterized in that several half plates in the inlet area are brazed essentially linearly together, both on their inner side and on their outer side, with adjacent half plates, respectively. This significantly increases the internal compressive strength of the tube formed by the two half-sheets.

A further preferred embodiment of the stacked plate heat exchanger is characterized in that the pressed-in portions extend in a serpentine shape at least partly around the through hole in a top view. This increases the contact area between the two half-plates.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that each two half plates are integrally connected to each other by means of a bent edge extending in the longitudinal or transverse direction for forming a pipe arrangement for the medium to be cooled. Since the two half-plates are joined together at the bending edges, they need only be brazed to one another on one side. This increases the cross-sectional area through which the medium to be cooled flows. Furthermore, the number of parts required is reduced by half, since only one part is required per line set.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the pipe means are formed by an elongated, in particular substantially rectangular, plate which is divided into two elongated halves by a bent edge, and the plate halves are folded together. The plate is preferably a metal stamping which is simple to manufacture and inexpensive to manufacture. In the folded state, the two half-sheets overlap each other.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the plate is provided with an edge which extends over the plate surface for a circle. The plate is preferably pressed in the edge surrounding the circumference, with the surface depth of the pressing in being equal to half the clear width of the pipe arrangement.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the edge surrounding the circumference is interrupted at the intersection with the bent edge. In the region of the bending edge, the plate has the same depth over the entire length of the bending edge. In this way, unnecessary damage to the material of the sheet in the region of the bending edges during folding can be avoided.

A further preferred embodiment of the laminated plate heat exchanger is characterized in that the two half plates in the folded state are brought to a close contact at the edges around the circumference. The half-plates are preferably brazed to each other at the edges around the circumference.

In a motor vehicle cooler with at least one water tank, the object of the invention mentioned above is achieved in that the previously described laminated plate heat exchanger is mounted in the water tank.

Drawings

Additional advantages, features and details of the present invention are provided in the following description and are illustrated in the accompanying drawings and examples. The features mentioned in the claims and the description, or any combination thereof, are of importance for the invention here. Wherein,

figure 1 is a perspective view of a half plate,

figure 2 is an end bottom view of the half plate shown in figure 1,

figure 3 is a cross-sectional view along line III-III in figure 2,

figure 4 is a perspective view of two half plates,

figure 5 is an enlarged view of a portion of figure 4,

fig. 6 is a perspective view of seven plates, which are assembled into a laminated plate heat exchanger according to the invention,

figure 7 is an enlarged perspective view of a connection piece of the stacked plate heat exchanger shown in figure 6,

figure 8 is a cross-sectional view of one end of the stacked plate heat exchanger shown in figure 6,

figure 9 is a side view of one end of the stacked plate heat exchanger shown in figure 6,

figure 10 is a perspective view of a tank with a built-in stacked plate heat exchanger,

in figure 11 is a cooler with a water tank as shown in figure 10,

FIG. 12 is a view of a solder having a meniscus formed in a cross section of a channel

Fig. 13 is a top view of the solder forming the meniscus, which in the figure is approximately circular,

figure 14 is a top view of a stacked plate heat exchanger according to another embodiment of the present invention,

figure 15 is a side view of the stacked plate heat exchanger shown in figure 14,

figure 16 is a cross-sectional view along line XVI-XVI in figure 14,

figure 17 is a cross-sectional view along line XVII-XVII in figure 14,

figure 18 is a cross-sectional view along line XVIII-XVIII in figure 14,

figure 19 is an enlarged view of part XIX of figure 14,

figure 20 is a top view of a line set according to the invention in an open state,

in figure 21 is the line set shown in figure 20 in a semi-closed condition,

fig. 22 is a top view of a stacked plate heat exchanger in a closed position, having a closed tube set as shown in fig. 20 and 21,

figure 23 is a side view of the stacked plate heat exchanger shown in figure 22,

fig. 24 is a sectional view taken along line XXIV-XXIV in fig. 22.

Detailed Description

Fig. 1 is a perspective view of a half plate 1. The half-sheet 1 is in the shape of a long aluminium plate having two

longitudinal sides

2 and 3 which are straight and parallel to each other. The ends 4 and 5 of the half-plate 1 are semicircular. Through

holes

8 and 9 are provided at the

ends

4 and 5. The

edge regions

10, 11 of the through-

holes

8, 9 are pressed into depressions, so that the

edge regions

10, 11 form projections on the underside of the half-plate 1.

A plurality of slots 12 are punched in the half-plate 1 between the through-

holes

8 and 9. The slot 12 extends straight from the longitudinal side 2 of the half-plate 1 to the opposite longitudinal side 3. The groove is in the form of an elongate recess which forms a protrusion on the underside of the half-plate 1. However, the grooves may not be straight, and may for example be wavy or zigzag.

Fig. 2 is a bottom view of the end 4 of the half-plate 1 shown in fig. 1. The edge region 10 and the ten grooves 21 to 30 project from the plane of the drawing. The ends of the grooves 21 to 30 are rounded and directed towards the

longitudinal sides

2, 3. The longitudinal axis of the half-panel 1 is identified by 31. The slots 21 to 30 are at an angle alpha of 45 deg. to the longitudinal axis 31.

In fig. 3, the half-plate 1 has a wave-shaped contour, viewed in cross-section. This wavy cross-sectional profile is formed by grooves pressed out on one side of the half-plate 1.

Fig. 4 is a perspective view of the two half-

plates

1 and 42. On the half-

plates

1 and 42, the half-plate sides having projections formed by the grooves face in opposite directions.

As can be seen from fig. 5, the half-plate 42 conforms to the shape of the half-plate 1. But in arrangement the half-panel 42 is turned 180 deg. with respect to the half-panel 1. The end 44 is provided with a through-hole 48, the edge region 50 of which protrudes from the plane of the drawing and the through-hole 48 is situated above the end through-hole 8 of the half plate 1, where the cup-shaped edge region 10 of the through-hole 8 is recessed in the plane of the drawing. Slots 52 are formed in the half-plate 42 and project from the plane of the drawing. The angle β between the groove 52 and the groove 12 recessed in the plane of the drawing is 90 °. The two half-

plates

1 and 42 are brazed to one another at the contact points of the grooves and at the

edge regions

2 and 3, so that a plate or a flat tube is formed.

In fig. 6, a plurality of plates 60 are brazed to each other. The through-hole of the plate 60 is closed at the underside by connecting

webs

61, 62. On the upper side of the plate 60,

connection pipes

67, 68 are fitted to the through holes at the ends. The medium to be cooled can enter the interior of the plate 60 through one of the connecting

pipes

67, 68. While the medium to be cooled can flow out of the plate 60 through the other of the connecting

pipes

67, 68.

Fig. 7 is an enlarged perspective view of the connecting piece 61. The connecting tab 61 is in the form of a disc 64 having a central raised portion 65 which is circular. The outer diameter of the circular raised portion 65 matches the inner diameter of the through hole in each plate.

As can be seen from fig. 8 and 9, the stacked plate heat exchanger shown in perspective in fig. 6 comprises seven plates 71 to 77, which are stacked on top of each other. In the interior of the plates 71 to 77, a multiplicity of essentially zigzag-shaped flow paths for the medium to be cooled are formed, which extend between the plates 71 to 77 from one side of the respective plate half, straight through the recess between each two grooves, to the opposite side of the plate half.

In fig. 10 is a water tank 78 into which the stacked plate heat exchanger shown in fig. 6 is fitted. The sheet 60 is disposed inside the water tank 78. The

connection pipes

67, 68 extend from the water tank 78.

In fig. 11, a water tank 78 shown in fig. 10 is mounted on one side of a cooling core 79. On the other side of cooling core 79 is another water tank 80. The two

water tanks

78 and 80 and the cooling core 79 together form a coolant cooler 81 of a motor vehicle (not shown).

In designing the profiles of the half-

plates

1 and 42, point contact should be made between the wavy profiles at the time of plate stacking. This causes the medium to be cooled flowing through the plate to change direction repeatedly. The two half-plates are brazed to each other at numerous contact points, thus ensuring pressure stability. The angle between the contour and the main flow direction of the medium to be cooled is 45 deg.. The hydraulic diameter is 1.8 mm. The angle between the press-in portion and the main flow direction is between 20 ° and 60 °. The hydraulic diameter may vary between 1.5mm and 2.5 mm.

The large area of the raised areas at the inlet and outlet regions enables the panel connections to form a seal, thereby eliminating the need for additional components. The half plates have horizontal brazing surfaces, which ensure a sufficient flow cross-section of the cooling liquid outside the cooler. The perimeter of the half-sheets is preferably slightly bent. This will improve the flatness of the sheet in the unwelded state. The bending angle is between 5 ° and 20 °, preferably 10 °. The half-plates are made of aluminum and are brazed by a wheel brazing process

Are connected with each other.

As can be seen from fig. 12, each two half plates are connected to each other by

solder

101, 102 and 103, 104 forming a meniscus. As can be seen in fig. 13, the solders 101 to 104 forming the meniscus are approximately circular in top view.

In figure 14 is a half-plate 1 of a stacked plate heat exchanger according to another embodiment of the invention. Here, the same reference numerals are used for the same components as in the embodiment shown in fig. 1. To avoid repetition, please refer to the previous description of fig. 1. The following only relates to the differences between the two embodiments.

In the half-plate 1 in fig. 14, the

edge regions

110, 111 of the through-

holes

8, 9 are provided with pressed-in portions. The edge region 111 of the end 5 of the half-plate 1 is provided with

serpentine impressions

115 and 116, which are connected by a connecting flange 117. The edge region 110 of the end 4 of the half-plate 1 is provided with

serpentine impressions

118 and 119, which are connected by a connecting flange 120. As described above and shown in fig. 14, to form a plate or flat tube, also referred to as a pipe system, the two half-plates 1 are brazed to one another at the contact points and

edge regions

2 and 3 of the groove 12 and at the pressed-in

portions

118, 119.

FIG. 15 is a side view of a cooler core comprising a plurality of flat tubes stacked on top of one another.

Fig. 16 is a sectional view taken along line XVI-XVI in fig. 14. As can be seen from the sectional view, the flat tubes of the stacked cooler core form a linear connection with one another in the region of the serpentine pressed-in

portions

115, 116 and in the pressed-in

portions

118, 119.

Fig. 17 is a sectional view taken along line XVII-XVII in fig. 14. As can be seen in the cross-sectional view, the serpentine indentation 116 increases the number of substantially linear contact surfaces. The serpentine indentation 116 is also referred to as a reinforcing flange. Here, it can be seen that the pressed-in portions at the plate ends are brazed to one another both on the inside and on the outside of the laminated heat exchanger.

Fig. 18 is a cross-sectional view along line XVIII-XVIII in fig. 14. Here it can be seen that the pressed-in portions 119 at the plate ends 4 are brazed to each other both on the inside and on the outside of the laminated plate heat exchanger.

Fig. 19 is a partial enlarged view of XIX in fig. 14. Here, the shape of the pressed-in

portions

118, 119 is such that the mutually overlapping plates are soldered to one another linearly both on the inside and on the outside. This will significantly improve the internal compressive strength of the tube formed by the two half-sheets. In fig. 19, the plate connection is serpentine.

In fig. 20, there is a conduit means 140, also referred to as a flattened tube or a short tube, in an open state. The flat tube 140 is formed from a plate 142 which is substantially rectangular and the corners of which are rounded. The plate 142 is a stamped part made of aluminum plate and has a bent edge 143, by means of which bent edge 143 the plate 142 is divided longitudinally into two halves 145, 146 of equal size, which are also referred to as half plates. The two half-plates 145, 146 are identical to the previous embodiment except for their integral structure. The plate 142 is surrounded on the outside by a circumferential edge 148, which serves to solder the two half-plates 145, 146 to one another in the folded or closed state. Within the circumferential edge 148, the half-plates 145, 146 have press-in grooves as described previously.

Figure 21 shows the tube 140 in a partially closed state.

Fig. 22 is a top view of the tube 140 in a closed state. The tubes 140 are the uppermost flat tubes of a stacked plate heat exchanger having a plurality of flat tubes stacked on one another.

Figure 23 is a side view of the stacked plate heat exchanger shown in figure 22. In addition to the flat tubes 140, the stacked plate heat exchanger can be seen in a side view to comprise further flat tubes 150 to 155, which are brazed to one another in a stacked arrangement.

Fig. 24 is a sectional view taken along line XXIV-XXIV in fig. 22. As can be seen in the cross-sectional view, the stacked plate heat exchanger is formed from folded

flat tubes

140, 150 to 155. Due to the integral structure of the flat tubes, the number of parts required for the construction of the stacked plate heat exchanger is reduced by half. The folded flat tube has the following advantages: the length of the braze joint used for sealing is reduced by nearly half.

Claims

1. Laminated plate heat exchanger for motor vehicles, mounted in a coolant tank of a coolant cooler, with a number of elongated plates (71-77) placed on top of each other and connected to each other, which plates each consist of two half-plates and comprise a cavity through which a medium to be cooled flows in the longitudinal direction of the plate, characterised in that each half-plate is provided with a number of grooves (21-30) extending from one longitudinal side (2) of the half-plate to the opposite longitudinal side (3); each half plate is integrally connected to each other by a longitudinally extending bent edge (143) to form a pipe arrangement (140) for a medium to be cooled.

2. The laminated plate heat exchanger of claim 1 wherein the elongated plate is comprised of two identical half plates turned 180 ° relative to each other.

3. The laminated plate heat exchanger of claim 1, wherein the slots extend straight from one longitudinal side of the plate half to the opposite longitudinal side.

4. The laminated plate heat exchanger according to claim 1, characterized in that the slots (21-30) are pressed out at one side of each half plate.

5. The laminated plate heat exchanger according to claim 1, characterized in that the slots (21-30) are bounded on the longitudinal sides by a circumferential edge.

6. The laminated plate heat exchanger according to claim 1, characterized in that the two plates (71, 72) are brought into close contact in the raised areas formed by the slots and brazed to each other.

7. The laminated plate heat exchanger according to claim 1, characterized in that the angle between the slots (21-30) and the longitudinal axis (31) of the respective half plate is 35 ° to 55 °.

8. The laminated plate heat exchanger according to claim 7, characterized in that the angle between the slots (21-30) and the longitudinal axis (31) of the respective half plate is 45 °.

9. The laminated plate heat exchanger according to claim 1, wherein the grooves (12, 52) of the two integrally connected half plates are at an angle of 70 ° to 110 ° to each other.

10. The laminated plate heat exchanger according to claim 9, characterized in that the grooves (12, 52) of the two integrally connected half plates are at an angle of 90 ° to each other.

11. The laminated plate heat exchanger according to claim 1, characterized in that the depth of the grooves (21-30) is 0.5mm to 1.5 mm.

12. The laminated plate heat exchanger according to claim 11, characterized in that the depth of the grooves (21-30) is 1.15 mm.

13. The laminated plate heat exchanger according to claim 1, characterized in that the slots (21-30) in the plate halves are parallel to each other and at a distance of 3mm to 5mm from each other.

14. The laminated plate heat exchanger according to claim 13, characterized in that the slots (21-30) in the plate halves are at a distance of 4mm from each other.

15. The laminated plate heat exchanger of claim 1, wherein the width of the half plates is 20mm to 120 mm.

16. The laminated plate heat exchanger of claim 15, wherein the width of the half plates is 20mm to 50 mm.

17. The laminated plate heat exchanger of claim 1, wherein four times the ratio of area ratio to area density has a value of 1.5mm to 2.5 mm.

18. The laminated plate heat exchanger of claim 17, wherein four times the ratio of area ratio to area density has a value of 1.8 mm.

19. The laminated plate heat exchanger according to one of the preceding claims, wherein the half plates are made of aluminium or stainless steel.

20. The laminated plate heat exchanger of the preceding claim 19, wherein at least one side of the half plates is coated with a brazing filler material.

21. The laminated plate heat exchanger according to any one of claims 1 to 18, wherein the half plates are provided with a pair of through holes (8, 9) as an inflow pipe and an outflow pipe, respectively.

22. The laminated plate heat exchanger according to claim 19, wherein the half plates are provided with a pair of through holes (8, 9) as an inflow pipe and an outflow pipe, respectively.

23. The laminated plate heat exchanger according to claim 20, wherein the half plates are provided with a pair of through holes (8, 9) as an inflow pipe and an outflow pipe, respectively.

24. The laminated plate heat exchanger according to claim 21, characterized in that the edge regions (10, 11; 110, 111) of the through-holes (8, 9) are convex.

25. The laminated plate heat exchanger according to claim 22, characterized in that the edge regions (10, 11; 110, 111) of the through-holes (8, 9) are convex.

26. The laminated plate heat exchanger according to claim 23, characterized in that the edge regions (10, 11; 110, 111) of the through-holes (8, 9) are convex.

27. The laminated plate heat exchanger as claimed in claim 21, characterized in that the edge regions (110, 111) of the through-holes (8, 9) are provided with pressed-in portions (115, 120).

28. The laminated plate heat exchanger as claimed in claim 24, characterized in that the edge regions (110, 111) of the through-holes (8, 9) are provided with pressed-in portions (115, 120).

29. The laminated plate heat exchanger of claim 27, wherein the pressed-in portions (115, 116, 118, 119) have a wave shape with peaks and valleys as seen in a cross-sectional view.

30. The laminated plate heat exchanger according to claim 29, characterized in that the pressed-in portions (115, 116, 118, 119) extend in a serpentine shape at least partially around the through-holes (8, 9) in a top view.

31. The laminated plate heat exchanger according to claim 1, wherein the pipe means (140) is formed by a rectangular plate (142) which is divided by a bent edge (143) into two elongated half-plates which are folded together.

32. The laminated plate heat exchanger of claim 31, wherein the plates (142) have a circumferential edge (148) raised above the surface of the plates.

33. The laminated plate heat exchanger of claim 32, wherein the circumferential edge (148) is interrupted at the intersection with the bent edge (143).

34. The laminated plate heat exchanger according to claim 32, wherein the two half plates (145, 146) in the folded state are fitted tightly around the peripheral edge (148).

35. Automotive cooler with at least one water tank, characterised in that a laminated plate heat exchanger according to one of the preceding claims is mounted in the water tank.