Heat exchanger, such as a charge air cooler

Abstract

A heat exchanger, such as a water cooled charge air cooler, is disclosed for cooling of charge air with the aid of coolant. In at least one embodiment, the heat exchanger includes charge air tubes and coolant turbulators made of corrugated sheet metal interposed between the air tubes. The turbulators define coolant channels and including at least one turbulating device provided therein. According to at least one embodiment of the invention, at least one channel includes at least one continuously shaped side wall which is non-apertured along its entire length and thus promotes coolant flow along the channel by inhibiting cross flow of coolant to a neighbouring channel.

Claims

1. Heat exchanger for cooling of charge air with the aid of coolant, said heat exchanger comprising: charge air tubes; and coolant turbulators made of corrugated sheet metal interposed between said air tubes, the turbulators defining coolant channels and including turbulating devices provided therein, at least one of the coolant channels including at least one continuously shaped side wall which is non-apertured along its entire length and thus promotes coolant flow along said at least one channel by inhibiting cross flow of coolant to a neighbouring one of the coolant channels, wherein all the coolant channels include a first continuously shaped side wall, which is non-apertured, and a second opposing side wall, which is provided with turbulence creating apertures, and wherein a width of the channels is defined by the first continuously shaped side wall and an adjacent second opposing side wall.

2. Heat exchanger according to claim 1, wherein the turbulence creating apertures form interruptions in top and bottom walls of the channels.

3. Heat exchanger according to claim 1, wherein the heat exchanger is a water cooled charge air cooler for cooling of charge air.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention is described in detail in below with reference to the schematic drawings.

(2) In the drawings:

(3) FIG. 1 is an isometric view of a heat exchanger with parts thereof broken away for clarity;

(4) FIG. 2 is an isometric view of a turbulator for a first embodiment of the invention;

(5) FIG. 3 is a partial cross section view of the turbulator in FIG. 2;

(6) FIG. 4 is an isometric view of a turbulator for a second embodiment of the invention;

(7) FIG. 5 is a partial cross section view of the turbulator in FIG. 4;

(8) FIG. 6 is an isometric view of a third and preferred embodiment of the invention; and

(9) FIG. 7 is a partial cross section view of the turbulator in FIG. 6.

DESCRIPTION OF TWO EMBODIMENTS

(10) The heat exchanger 1 of FIG. 1 is a so called WCCAC (Water Cooled Charge Air Cooler) provided for cooling of charge air to an internal combustion engine (not shown) by means of a coolant, mainly comprising water. The coolant is circulated by a pump of said engine and dissipates accumulated heat through a radiator, which also provides cooling for said engine.

(11) The charge air is led into and out of the heat exchanger 1 by means of two opposing cowlings 2, 3, and inside of the heat exchanger 1 the charge air flows through air tubes 4. The air tubes 4 are of a flat design and extend in parallel through said heat exchanger 1 in four groups of five air tubes 4 each. In each group flat sides of the air tubes 4 in the group face each other or casing walls of the heat exchanger 1. Across the flat sides of the air tubes 4 and brazed thereto there are a plurality of coolant turbulators 5. These are preferably made of aluminium sheet metal. As indicated by means of four arrows 6, 7, the coolant turbulators define an altogether serpentine flow path through the heat exchanger from a coolant inlet 8 to a coolant outlet 9. They do it by being corrugated, the corrugation ridges and valley extending transversely of the air tubes 4, and have a design described in detail below.

(12) In FIGS. 2 and 3 parts of a turbulator 10 for a first embodiment of a heat exchanger 1 according to the invention is shown. The turbulator 10 is made of a aluminium sheet which has been stamped into a corrugated pattern which comprises two different kinds of channels.

(13) The first kind is designated 11 and has flat top and bottom walls 12, 13 and vertical side walls 14. The side walls 14 have turbulence creating apertures 15 therein, made by offset stamping/cutting in a known way and resulting in a non-continuous side wall shape. The apertures 15 allow cross flow of coolant between the channels 11 and would, if all channels across the turbulator 10 were of that kind, result in a coolant flow pattern exemplified by the arrows 6 in FIG. 1. Such a flow pattern causes cross flow, which is detrimental to efficiency.

(14) In order to remedy this, amongst the first kind of apertured channels 11 are arranged a second kind of channels, which are designated 16. The channels 16 too have flat top and bottom walls 17, 18 and vertical side walls 19. However, these side walls 19 are continuously shaped ones, which are all straight and lack apertures. In that way they hinder cross flow of coolant to neighbouring channels 11 and confine coolant flow through the heat exchanger 1 to narrower, more straight-lined flow paths as illustrated by the arrows 7 in FIG. 1.

(15) It is obvious that the second kind of closed channels 16 do not transfer heat as effectively as the first kind of open channels 11. Thus, it is preferred to arrange less closed channels 16 than open channels 11. Should the heat exchanger 1 be a narrow one, one closed channel 16 amongst a plurality of open channels 11 could well suffice. However, a wider heat exchanger 1 requires more closed channels 16 than that to straighten the coolant flow through the heat exchanger. Hence, in a wider heat exchanger several closed channels 16, each surrounded by open ones, are recommended, preferably with a regular spacing, such as one at least every tenth channel.

(16) In FIGS. 4 and 5 parts of a turbulator 20 for a second embodiment of a heat exchanger 1 according to the invention is shown. The turbulator 20 too is made of a aluminium sheet which has been stamped into a corrugated pattern, but it comprises but kind of channels.

(17) These channels are designated 21 and have flat top and bottom walls 22, 23 and vertical side walls 24. The side walls 24 are parallel to each other and follow a meander shaped outline, causing some degree of turbulence when coolant passes there through although there are no apertures at all in the side walls 24. The turbulence is further enhanced by means of inverted dimples 25, which are stamped into the aluminium sheet and protrude into the channels 21 along the entire length of these with a certain spacing. Preferably as shown in the drawings the spacing is such, that there is one inverted dimple 25 at each meander turn of a channel 21.

(18) It is obvious that a heat exchanger 1 according to the second embodiment with turbulators 20 only having wavy, closed channels 21 gives rise to an even lower flow resistance than the heat exchanger 1 according to the first embodiment, because it inhibits coolant cross flow even more. However, without the extra turbulence created by the inverted dimples 25 and relying only on the turbulence created by means of the non-apertured, continuous meander shaped side walls 24 alone, one has to upgrade size of the heat exchanger 1 in order to achieve a comparable cooling effect.

(19) In FIGS. 6 and 7 parts of a turbulator 30 for a third embodiment of a heat exchanger 1 according to the invention is shown. The turbulator 30 too is made of a aluminium sheet which has been stamped into a corrugated pattern, and like the second embodiment it comprises but one kind of channels.

(20) These channels designated are 31 and comprise vertical side walls 32, 33 and top and bottom walls 34, 35. The side walls 32, 33 are parallel to each other, but are of two different kinds. Thus, the first kind of side walls 32 resemble the closed ones 19 of the first embodiment of the invention, whereas the second kind of side walls 33 resemble the apertured ones 14 of the first embodiment of the invention. This leads to channels 31 promoting both coolant flow by means of the first kind side walls 32, which are non-apertured and smooth, and heat exchange by means of the second kind of side walls 33 with apertures 36 therein.

(21) Preferably, in the third embodiment said apertures 36 form interruptions in the top and bottom walls 34, 35 of the channels 31 as well. This is highly beneficial when it comes to production by stamping and differs from previous solutions, where both channel side walls used to be apertured.

(22) It is apparent, that the embodiments described can be combined in different ways within the scope of the invention.