Cooler Block, Especially For A Charge Air Cooler/Coolant Cooler

Abstract

The invention relates to a soldered cooler block, especially for a charge air cooler/coolant cooler, which is constructed in a packet-type manner. Cooling channels (2) for a liquid coolant are arranged in said cooler block in a crossways manner in first layers and gas channels (1) for a gas which is to be cooled are arranged in a crossways manner in second layers. The cooling channels (2) are respectively formed by two wall areas (3) which are arranged at a distance and by intermediate strips and connection strips (4.5) comprising groove profiles.

Description

The invention relates to a cooler block, especially for a charge air cooler/coolant cooler of packet design according to the precharacterizing clause of patent claim 1. A cooler block of this type has been disclosed by the applicant in DE-A 196 51 625.

Charge air coolers of what is referred to as packet design are used in particular in large engines where the charge air is cooled by a liquid coolant. These charge air coolers are produced and brazed in a design made totally from aluminum, the cooler block of cuboidal design and the associated connecting branches for the charge air and the coolant being produced separately. The cooler block comprises a multiplicity of plates which are layered on one another and between which strips for forming flow passages and for spacing are arranged. The ready stacked block is then brazed in a brazing furnace. The flow passages for the charge air have corrugated fins or turbulence inserts in the interior, in order to improve the transfer of heat and to increase the internal compressive strength. The cooling passages have a smaller flow cross section than the charge air passages and are bounded by intermediate strips and outer terminating strips. The transfer of heat between coolant and charge air takes place in cross current, i.e. the coolant passages and charge air passages run perpendicularly to one another. A charge air cooler of this type has been disclosed by the applicant in DE-A 196 51 625 mentioned above. In the case of the known charge air cooler, the cooling passages for the liquid coolant have a rectangular cross section, since the intermediate strips arranged between the adjacent plates likewise have a rectangular cross section. A problem with these heat exchangers are the unsteady states, in particular on the charge air side, which, due to sharp changes in temperature with high temperature differences and temperature peaks, lead to the coolant overheating, i.e. to the boiling point being exceeded locally with steam bubbles being formed. It is absolutely to be avoided.

A similar heat exchanger of packet design, likewise a charge air cooler, has been disclosed by the applicant in DE-C 196 44 586. The difference in this case are the cooling passages which are formed by a plate-like extruded profile. The passage cross sections are rectangular or oval, but this is primarily for manufacturing reasons (extrusion).

It is the object of the present invention to improve a cooler block of the type mentioned at the beginning in such a manner that local overheating occurrences are avoided as far as possible.

This object is achieved by the features of patent claim 1. According to the invention, the intermediate and/or terminating regions of the cooling passages, which regions are designed in particular as strips, are provided on their coolant sides with a grooved profile. This grooved profile results in a rounding of the rectangular cross section on its narrow side.

Under some circumstances, local occurrences of overheating may occur in the corner regions of rectangular passage cross sections. Such overheating is advantageously largely avoided by the rounding according to the invention of the passage cross section by means of the grooved profile.

The grooved profile results, firstly, in evened-out flow conditions in the coolant passage and, secondly, in a thermal load alleviation at the critical corner regions. Furthermore, the introduction of heat from the hot gas into the coolant flowing in the cooling passage is distributed over a relatively large area. Local boiling with harmful formation of steam bubbles in the coolant is therefore also avoided.

A design is made possible by means of a stacking design according to an advantageous embodiment, with profiled bars being used, in which simple components, such as plates and strips, can be used.

An integral design of the cooling passages according to another embodiment brings about the advantage of a simple design with a low number of individual parts.

According to an advantageous refinement of the invention, the grooved profile has a parabolic cross section which is bounded on both sides by profiled strips which are brazed to the adjacent plate. This cross section constitutes a favorable compromise in terms of strength and flow.

According to another advantageous refinement of the invention, the grooved profile has a V-shaped cross section, i.e. a certain simplification in terms of manufacturing in comparison to the parabolic profile.

According to a further refinement of the invention, the profile of an intermediate strip is designed approximately as an H profile, i.e. with approximately U-shaped indentations on each coolant side.

An exemplary embodiment of the invention is illustrated in the drawing and is described in more detail below. In the drawing

FIG. 1 shows a cut-out of a charge air cooler,

FIG. 2 shows a terminating strip,

FIG. 3 shows an intermediate strip, and

FIG. 4 shows a detail X from FIG. 1.

FIG. 1 shows a cut-out of a cooler block (not illustrated at all) with charge air coolers 1 and cooling passages 2 which run transversely with respect thereto and are formed by plates 3 arranged parallel to one another. The charge air passages 1 have charge air flowing through them in the direction of the arrow LL and generally have corrugated fins which are not illustrated here but are known from the prior art. The outer cooling passages 2 are formed, on the one hand, by adjacent plates 3 and, on the other hand, by a respective terminating strip 4 and a respective intermediate strip 5. Further cooling passages 2 (not illustrated) which are arranged on the inside are only bounded by intermediate strips 5. The intermediate strips and the terminating strips are designed as profiled bars 4, 5 and respectively have on their coolant side, that is the side which is wetted by the coolant, a groove 7 and a groove 8, i.e. grooved profiles running in the longitudinal direction of the strips. The cooling passages 2 are therefore somewhat rounded on their narrow sides, as a result of which the wetted circumference of the passage cross section increases and an evened-out admission of heat from the charge air passages 1 takes place. The profiled bars 4, 5 are, as usual, brazed to the plates 3 and can preferably be produced as extruded profiles.

FIG. 2 shows an individual illustration of the terminating strip 4 which has the grooved profile 7 on just one side, i.e. the coolant side. The flat side 4a is brazed.

FIG. 3 shows an individual illustration of the intermediate strip 5 which has two grooved profiles 8 on opposite coolant sides. The flat side 5a is brazed.

FIG. 4 shows a detail X from FIG. 1, i.e. the profiled bar 5 (half of which is illustrated) with the approximately parabolic grooved profile 8 which is surrounded laterally by two rounded profiled strips 9, 10 which, for their part, are brazed to the plates 3.

Slight modifications of the grooved profile which is illustrated in the drawing and has approximately a parabolic cross section are possible, for example as a V profile or a H profile.

Claims

1. A cooler block, especially for a charge air cooler/coolant cooler of packet design, in which cooling passages for a liquid coolant are arranged in first layers, and gas passages for a gas to be cooled are arranged in second layers, in particular crosswise, the cooling passages in each case being formed by two spaced apart wall regions and by intermediate and/or terminating regions, characterized in that at least one intermediate and/or terminating region has, on its side which is wettable by the coolant, a grooved profile running in the longitudinal direction.

2. The cooler block as claimed in claim 1, characterized in that the first and second layers are formed by alternating stacking above one another of plates and intermediate and/or terminating strips, with at least one intermediate and/or terminating strip being designed as a profiled bar having a grooved profile running in the longitudinal direction.

3. The cooler block as claimed in claim 1, characterized in that wall regions and intermediate and/or terminating regions are formed integrally with one another, in particular as an extruded profile.

4. The cooler block as claimed in claim 1, wherein the grooved profile has an approximately parabolic cross section which is surrounded in particular by two profiled strips.

5. The cooler block as claimed in claim 1, wherein the grooved profile has a V-shaped cross section.

6. The cooler block as claimed in claim 1, wherein intermediate strips have an approximately H-shaped cross section.

7. The cooler block as claimed in claim 1, wherein corrugated fins are arranged in the gas passages.