DE102017211927A1 - Intercooler for an internal combustion engine - Google Patents

Abstract

The invention relates to a charge air cooler (1) for an internal combustion engine (2), with an air inlet box (3), an air outlet box (4) and a heat exchanger block (5) arranged therebetween, wherein an air outlet channel (6) is provided in the air outlet box (4).
Essential to the invention is
- That the air outlet channel (6) at least slightly increases from the heat exchanger block (5) to the outside,
- That in the air outlet channel (6) a swirl generator (7) with a helicoidal body (8) and a surrounding jacket tube (9) is arranged, wherein between the helicoidal body (8) and the jacket tube (9) there is a radial distance a.

Description

The present invention relates to an intercooler for an internal combustion engine according to the preamble of claim 1. The invention also relates to an internal combustion engine with such a charge air cooler.

Generic intercoolers are well known and are used in particular in supercharged internal combustion engines to compress the entering into the engine ambient air and to be able to achieve an increase in performance over it. The compression of the charge air, which takes place for example by means of an exhaust gas turbocharger, can lead to an increase in the temperature of the charge air, which is why a charge air cooler is used to cool the heated charge air and increase its density. When the charge air cools down, however, the dew point can be undershot and condensate (condensate water) precipitated, which then collects in the intercooler. At low mass flows of charge air to be supplied, a continuous discharge of condensate collecting in the intercooler can not be reliably ensured, while at a high mass flow following in time, the risk that the condensed water entrained by the high mass flow and transported abruptly in a combustion chamber of the internal combustion engine is, whereby a so-called "water hammer" in the internal combustion engine is to be feared, which can permanently damage them and has high repair costs.

For this reason, several methods are already known to avoid such a water hammer.

From the DE 10 2013 111 448 A1 For example, a method and apparatus for performing proactive condensate drainage of a charge air cooler is known. In response to accumulated condensate in the charge air cooler and corresponding operating conditions of an internal combustion engine, the air flow to the intake manifold is boosted, allowing condensate to be purged from the charge air cooler.

From the DE 10 2012 219 796 A1 a device for supplying charge air for an internal combustion engine is known, comprising a charge air cooler, a condensate collecting region and a connecting pipe for connecting the charge air cooler with a charge air inlet of the internal combustion engine, the device comprising a suction tube, which with a first end in the condensate collecting region and with an opposite second end is disposed in an injection portion of the connecting pipe for supplying fluid from the condensate collecting area in the injection portion.

In order generally to be able to counteract a water hammer in the internal combustion engine and, associated therewith, damage or dropouts thereof, on the one hand attempts can be made to avoid or at least reduce the formation of condensate. In addition, a discharge of separated condensate from the intercooler can be supported. Additionally or alternatively, it is also conceivable to prevent a sudden water hammer by entrainment of a accumulated amount of condensate by a periodic flushing. A cycle for rinsing can take place, for example, as a function of a condensate level.

A disadvantage of the known from the prior art methods and devices is that they often require a complex control, which may not only error-prone, but also expensive. In addition, known from the prior art devices and methods usually do not allow continuous condensate separation or emptying.

The present invention therefore deals with the problem of providing for an intercooler of the generic type an improved or at least one alternative embodiment, which overcomes the disadvantages known from the prior art.

This problem is solved according to the invention by the subject matter of independent claim 1. Advantageous embodiments are the subject of the dependent claims.

The present invention is based on the general idea of arranging a swirl separator in an air outlet duct of a charge air cooler, which enables a continuous separation of condensate from the charge air flow, in particular at high mass flows, but ensures a continuous discharge of condensate at low mass flows. The intercooler according to the invention for an internal combustion engine has in a known manner an air inlet box, an air outlet box and a heat exchanger block arranged therebetween, wherein in the air outlet box, an air outlet channel is provided in the manner of leading to the internal combustion engine outlet nozzle. The air outlet duct rises to the outside, that is from the heat exchanger block in the direction of the internal combustion engine, at least slightly and houses a swirl generator with a helical body with a surrounding tubular casing, wherein between the Helicoid body and the jacket tube is a radial distance a. This radial distance allows a back flow of condensate deposited over the helicoid body back into the air outlet box. The helicoid body, which is designed in the manner of a helical surface, thus deflects the charge air flowing out of the intercooler into a swirling flow, the swirling forces or centrifugal forces acting on the charge air being dependent on the flow velocity. At low mass flows, that is, at the same time low flow velocity, there is little or no condensation on the jacket surrounding the helicoid body, so that at low or medium mass flows due to the cooling of the compressed charge air accumulating condensate continuously the combustion process in the Internal combustion engine is supplied. If the power demanded of the internal combustion engine increases abruptly, the mass flow flowing through the intercooler also increases and thus the centrifugal forces acting on the mass flow in the helicoid body. Due to the increased flow velocity, more condensate is now deposited on the jacket tube surrounding the helicoid body, whereby due to both the inclination of the jacket tube toward the heat exchanger block and the radial distance between the helicoid body and the jacket tube, an annular channel is created which allows backflow of separated condensate into the Air outlet box allows. There it can theoretically be collected until it can be taken up and removed again at lower power of the internal combustion engine and thus also lower mass flow. With the intercooler according to the invention it is thus possible for the first time to allow a simple and control-free and continuous removal of accumulating in the intercooler condensate, without this a sudden discharge of water and thus a so-called "water hammer" in the internal combustion engine must be feared. In contrast to known from the prior art methods and devices, the intercooler according to the invention is without any moving parts and without any control and is thus not only extremely reliable, but also cost. About a slope of the helical surface of the helicoid body or via a setting of the radial distance a between the helicoid body and the surrounding jacket tube, can be comparatively easy influence on the dissipated at certain mass flows or to be recycled condensate.

Suitably, the helicoid body is formed as a one-piece plastic injection molded part. As a result, production of the helicoid body according to the invention is not only of high quality, but also cost-effective. In the simplest case, in which only a single helicoid body is arranged in the air outlet nozzle of the intercooler, the surrounding jacket tube can be formed by the air outlet box or the air outlet pipe itself.

Expediently, a first screw thread surface is arranged on the outside of the casing tube, which is surrounded radially on the outside by a second casing tube, wherein a radial distance b exists between the first screw thread surface and the second casing tube. For cost-effective production, the jacket tube and the first screw thread surface can be produced as a one-piece plastic injection-molded part in this case. In this case, therefore, the swirl generator not only has an internal helicoid body, but also has a coaxially arranged first helical gear surface, ie a second helicoid body, which can also be used for condensate separation. On the existing between the first screw gear surface and the second casing radial distance b, in turn, an annular channel for the return of separated condensate can be created.

In an advantageous development of the solution according to the invention, a collar for fixing or for positioning the jacket tube on the second jacket tube is arranged on the longitudinal side of the jacket tube. In this case, therefore, the jacket tube can be easily inserted into the second jacket tube for mounting, wherein on the jacket tube arranged on the collar at the same time between the first screw groove surface and the second jacket tube remaining annular gap (radial distance b) is defined. Of course, the collar is interrupted in the circumferential direction to allow a return of separated condensate.

In a further advantageous embodiment of the solution according to the invention, a second screw thread surface is arranged on the outside of the second casing tube, in particular integrally with this produced as a cost plastic injection molded part, wherein the second screw gear surface is surrounded by a third outer casing and wherein between the second screw gear surface and the third casing tube a radial distance c exists. In this embodiment, one thus obtains a three-part swirl generator with internal helicoid body, outer second screw gear surface or second casing pipe and arranged therebetween first screw gear surface and second casing pipe.

The present invention is further based on the general idea, a Internal combustion engine with an exhaust gas turbocharger and this downstream intercooler to equip according to one of the preceding paragraphs, wherein the bottom side in the air outlet box of the intercooler, a condensate collecting space is arranged, which is connected via a condensate line and a Venturi geometry with a charge air line. In this case, thus, a supply of condensate separated in the intercooler is not carried out exclusively via the air outlet channel of the intercooler, but also depending on the performance of a suction of condensate from the condensate collection chamber of the charge air cooler, which also achieves a demand-related removal of condensate and in particular the risk of sudden water hammer can be reliably avoided.

Other important features and advantages of the invention will become apparent from the dependent claims, from the drawings and from the associated figure description with reference to the drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination given, but also in other combinations or in isolation, without departing from the scope of the present invention.

Preferred embodiments of the invention are illustrated in the drawings and will be described in more detail in the following description, wherein like reference numerals refer to the same or similar or functionally identical components.

• 1 einen erfindungsgemäßen Ladeluftkühler in montiertem Zustand in einer Seitenansicht,
• 2 einen Luftaustrittskasten mit einem erfindungsgemäßen Drallerzeuger mit einem Helikoidkörper,
• 3 eine Schnittdarstellung durch den erfindungsgemäßen Ladeluftkühler im Bereich eines Luftaustrittskanals,
• 4 eine Detaildarstellung A aus 3,
• 5 eine Frontalansicht auf den erfindungsgemäßen Ladeluftkühler.

Show, each schematically

• 1 an intercooler according to the invention in the assembled state in a side view,
• 2 an air outlet box with a swirl generator according to the invention with a helicoid body,
• 3 a sectional view through the charge air cooler according to the invention in the region of an air outlet channel,
• 4 a detailed view A from 3 .
• 5 a frontal view of the charge air cooler according to the invention.

According to the 1 has an inventive intercooler 1 for an internal combustion engine 2 an air inlet box 3 , an air outlet box 4 and a heat transfer block disposed therebetween 5 on. In the air outlet box 4 is an air outlet channel 6 provided (compare also the 2-5 ). According to the invention is now in the air outlet duct 6 a swirl generator 7 arranged, in its simplest form a helicoid body 8th with a surrounding jacket tube 9 having. Between the helicoid body 8th and the jacket tube 9 is a radial distance a arranged (see 4 ), so that between the helicoid body 8th and the surrounding jacket pipe 9 an annulus 10 remains over which due to the slope of the air outlet duct 6 by centrifugal forces separated condensate back into a condensate collecting space 11 of the air outlet box 4 can flow. With the swirl generator according to the invention 7 can thus in a structurally simple and also cost-effective manner a continuous condensate removal from the intercooler 1 if necessary. In particular, by the charge air cooler according to the invention 1 a so-called "water hammer" in the internal combustion engine 2 reliably prevented, in which due to a sudden increase in power demand to the internal combustion engine 2 in the intercooler 1 separated and collected condensate suddenly entrained and the internal combustion engine 2 is supplied. In the charge air cooler according to the invention 1 on the other hand, with a low mass flow of charge air 12 , For example, recirculated exhaust, deposited little to no condensate, since the necessary centrifugal forces for the separation of condensate are not sufficient. In this case, thus, in the charge air flow 12 entrained condensate a combustion process in the internal combustion engine 2 fed and burned there. In this case, condensate originating from a previous dew point undershoot can also be discharged slowly. At a previous dew point and thus precipitated condensate and a sudden increase in power of the internal combustion engine 2 and thus with a suddenly increasing mass flow of the charge air 12 , causes the swirl generator 7 However, a deposition of condensate due to centrifugal forces, whereby a water hammer can be reliably prevented. By the swirl generator according to the invention 7 Thus, a continuous and needs-based condensate separation can take place, entirely without costly control technology or moving parts, whereby the condensate separation in the charge air cooler according to the invention is extremely reliable and cost-effective.

In general, it must be ensured that the radial distance a is not too great, since otherwise an undesired annular bypass channel is created, which causes a forced flow through the charge air 12 through the individual helical turns of the helicoid body 8th bypass. On the other hand, if the radial distance a is too small, condensate separated due to the centrifugal forces can no longer be returned to the air outlet box 4 and the condensate collection room 11 respectively.

The helicoid body 8th surrounding jacket pipe 9 can in a merely one-piece design of the swirl generator 7 also a wall 13 of the air outlet duct 6 be.

The helicoid body 8th can also be formed as a one-piece plastic injection molded part and thereby not only high quality, but also cost-effectively manufactured.

In a further advantageous embodiment of the solution according to the invention is on the outside of the jacket tube 9 a first spiral surface 14 arranged, preferably even in one piece with the jacket tube 9 trained (compare 4 ), the first helical gear area 14 from a second casing pipe 15 is surrounded and being between the first helical gear surface 14 and the second casing pipe 15 a radial distance b exists. The first screw gear surface 14 and the helicoid body 8th are arranged coaxially with each other. As the case 4 can be seen, is a pitch h at the first screw gear surface 14 larger than the helicoid body 8th , wherein about a slope or pitch h in the helicoid body 8th or at the first screw gear surface 14 a degree of separation of condensate can be determined, as well as by an appropriate selection of the radial distances a and b.

The jacket tube 9 and the first helical gear area 14 can also be designed as a cost-effective and production technology easy to manufacture, one-piece plastic injection molded part.

Looking at the 2 , so you can see that the longitudinal end of the jacket tube 9 a collar 16 is arranged, over which the casing pipe 9 and therefore also the first screw thread surface 14 on the second casing pipe 15 fixed or positioned, that is, can be held.

Outside on the second casing pipe 15 can be a second helical surface 17 (see 2-4 ) arranged radially outward from a third casing pipe 18 is surrounded, wherein between the second helical gear surface 17 to the third casing pipe 18 a radial distance c exists. The third casing 18 is now in the present case at the same time the wall 13 of the air outlet duct 6 ,

In addition, the second casing can 15 a collar 16 ' or webs 16 ' for fixing and / or positioning of the second jacket tube 15 on the third casing pipe 18 or on the wall 13 of the air outlet duct 6 exhibit. Of course, both are the collar 16 and possibly the collar 16 ' or the webs 16 ' interrupted in the circumferential direction to allow backflow of condensate. The collar 16 or the collar 16 ' or the webs 16 ' have openings 22 on, over which a return of which acts as a swirl wall jacket tube 9 , second casing pipe 15 , third casing pipe 18 or wall 13 can be done (compare in particular the 5 ).

The second casing pipe 15 and the second helical gear area 17 can in turn be designed as cost-effective and at the same time high quality, one-piece plastic injection molded part.

Looking again at the 1 so you can see that as well as in 3 bottom side in the air outlet box 4 the aforementioned condensate collecting space 11 is arranged. This condensate collecting room 11 can do this via a condensate line 19 with a venturi geometry 20 a charge air line 21 be connected, which also causes a regular and in particular power-dependent suction of condensate from the condensate collection room 11 can be done.

Such equipped internal combustion engine 2 can be a demand-based and continuous discharge of in the intercooler 1 allow separated condensate and thereby prevent in particular a risky water hammer.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102013111448 A1 [0004]
• DE 102012219796 A1 [0005]

Claims (10)

Intercooler (1) for an internal combustion engine (2), with an air inlet box (3), an air outlet box (4) and a heat transfer block (5) arranged therebetween, wherein in the air outlet box (4) an air outlet channel (6) is provided, characterized the air outlet channel (6) rises at least slightly outwards from the heat exchanger block (5), that a swirl generator (7) with a helicoid body (8) and a jacket tube (9) surrounding it is arranged in the air outlet channel (6), wherein between the Helicoid body (8) and the jacket tube (9) has a radial distance a. Intercooler after Claim 1 , characterized in that the helicoidal body (8) is formed as a one-piece plastic injection molded part. Intercooler after Claim 1 or 2 , characterized in that on the outside of the jacket tube (9) a first screw thread surface (14) is arranged which is surrounded radially on the outside by a second jacket tube (15), wherein between the first screw thread surface (14) and the second jacket tube (15) Radial distance b exists. Intercooler after Claim 3 , characterized in that the jacket tube (9) and the first screw gear surface (14) are formed as a one-piece plastic injection molded part. Intercooler after Claim 3 or 4 , characterized in that on the longitudinal side of the jacket tube (9) a collar (16) for fixing and / or positioning of the jacket tube (9) on the second jacket tube (15) is arranged. Intercooler after one of the Claims 3 to 5 , characterized in that on the outside of the second jacket tube (15) a second screw thread surface (17) is arranged which is surrounded radially on the outside by a third jacket tube (18), wherein between the second screw thread surface (17) and the third jacket tube (18) a radial distance c exists. Intercooler after Claim 6 , characterized in that the second casing tube (15) and the second screw gear surface (17) are formed as a one-piece plastic injection molded part. Intercooler after Claim 6 or 7 , characterized in that the longitudinal end of the second jacket tube (15) a collar (16 ') for fixing and / or positioning of the second jacket tube (15) on the third jacket tube (18) is arranged. Intercooler according to one of the preceding claims, characterized in that on the bottom side in the air outlet box (4) a condensate collecting space (11) is arranged. Internal combustion engine (2) with a charge air cooler (1) according to Claim 9 , wherein the condensate collecting space (11) via a condensate line (19) and a Venturigeometrie (20) is connected to a charge air line (21).

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