Heat exchanger having a heat transfer block with a screen arranged thereon

Abstract

A gas-cooled heat exchanger, in particular a direct intercooler, for cooling of a fluid which flows through the heat exchanger, with a heat transfer block featuring a plurality of flow channels, with a first collection chamber and a second collection chamber. The collection chambers are fluidically connected with one another via the flow channels and the outside of the heat transfer block can be perfused by gas. In the direction of the perfusion, a screen is arranged in front of the heat transfer block for the prevention of flow in certain areas around the flow channels of the screen. One of the collection chambers features a vent for discharge of condensate of the fluid which can be sealed from or released into the surrounding area of the heat exchanger.

Claims

1. A gas-cooled heat exchanger for cooling of a fluid flowing through the heat exchanger, the heat exchanger comprising: a heat transfer block having a plurality of flow channels, an outside of the heat transfer block being perfused by a gas; a first collection chamber; a second collection chamber positioned downstream of the first collection chamber, the first and second collection chambers being fluidly connected with one another via the flow channels, a screen being arranged on the heat transfer block in a direction of the perfusion in front of the heat transfer block for prevention of flow of the gas around at least one of the flow channels; a vent being arranged in the second collection chamber for discharge of condensate of the fluid into the surrounding area of the heat exchanger, a first mounting device provided on the first collection chamber and a second mounting device provided on the second collection chamber, and a retaining rod having a first end fixed to the first mounting device and a second end fixed to the second mounting device, wherein the screen is angled along a length thereof, such that the screen has a vertex, a first sloped surface and a second sloped surface, the first sloped surface and the second sloped surface extending from opposing sides of the vertex in a direction towards the heat transfer block, and wherein the distal ends of the first sloped surface and the second sloped surface are positioned closer to the heat transfer block than the vertex, and wherein an inner surface of the vertex of the screen is positioned on the retaining rod.

2. The heat exchanger according to claim 1, wherein the second collection chamber is situated downstream from the heat transfer block in a flow direction of the fluid.

3. The heat exchanger according to claim 1, wherein the vent is arranged at a lower end of the second collection chamber and is spaced at a distance from a lowest positioned flow channel of the heat transfer block.

4. The heat exchanger according to claim 1, wherein the vent is a check valve, wherein a fluid stream is releasable from the second collection chamber into the surrounding area through the vent.

5. The heat exchanger according to claim 1, wherein the second collection chamber has a funnel-shaped inner contour that forms a slope in a direction towards the vent.

6. The heat exchanger according to claim 1, wherein the vent is controllable as a function of a pressure difference between pressure in the second collection chamber in which the vent is located and pressure outside of the second collection chamber, wherein a pressure sensor is provided to sense the pressure in the second collection chamber and a pressure sensor is provided to sense the pressure outside of the second collection chamber.

7. The heat exchanger according to claim 1, wherein the screen covers at least a lowest positioned flow channel of the heat transfer block or the lowest positioned flow channel and a flow channel positioned directly above the lowest positioned flow channel.

8. The heat exchanger according to claim 1, wherein the screen reduces a cooling performance of the heat exchanger by between 40% and 95%.

9. The heat exchanger according to claim 1, wherein the screen is fused or clipped or bonded or screwed together or clamped with the heat exchanger.

10. The heat exchanger according to claim 1, wherein the gas-cooled heat exchanger is a direct intercooler.

11. The heat exchanger according to claim 1, wherein the first sloped surface is sloped towards the heat transfer block in an upward direction and the second sloped surface is sloped towards the heat transfer block in a downward direction.

12. The heat exchanger according to claim 6, wherein the vent is a check valve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

(2) FIG. 1 is a perspective, partial view of a heat exchanger, wherein the lower section of the heat transfer block is covered by a screen; and

(3) FIG. 2 is a sectional view of the heat exchanger, wherein a section of the heat transfer block and a section of the collection chamber are shown, wherein the collection chamber displays a vent at the lower end section.

DETAILED DESCRIPTION

(4) FIG. 1 shows a perspective, partial view of a heat exchanger 1. The heat exchanger 1 features a heat transfer block 2 which is formed by a plurality of tubes that are not shown and are arranged parallel to one another, and by corrugated fin elements arranged between them. The ends of the tubes of the heat transfer block 2 are each incorporated into a collection chamber 3. In FIG. 1, only one of these collection chambers is shown. In their interior, the tubes form the flow channels 9 of the heat transfer block 2.

(5) The collection chamber 3 features a retaining element 7 with which the collection chamber 3 can be fastened inside a vehicle to surrounding structural elements. The collection chamber 3 further features a mounting device 6 to which a retaining element 5 formed by a rod can be affixed. The retaining element 5 serves to fasten the screen 4 which at least partially covers the heat transfer block 2.

(6) The screen 4 is hereby designed in such a way that a certain number of tubes of the heat transfer block 2 are covered throughout the entire width of the heat exchanger 1. The screen 4 hereby specifically extends from the shown collection chamber 3 to the collection chamber not shown which is located at the opposite end section of the heat transfer block 2.

(7) The screen 4 serves to shield the heat transfer block 2 from air flow which surrounds the heat exchanger. For this purpose, the screen 4 is preferably arranged on the side of the heat exchanger 1 that is fed by gas flowing around the heat exchanger 1. In this way, the gas flowing towards the heat exchanger 1 is diverted upwards and downwards, wherein particularly the tubes arranged above the screen 4 and the area below the heat exchanger 1 are surrounded by the flowing gas.

(8) According to the invention, a fluid flows through the heat exchanger 1. At the heat transfer block 2, a heat transfer occurs between the fluid flowing through the heat exchanger 1 and the gas flowing through the heat exchanger 1. This particularly serves to cool the fluid flowing through the heat exchanger 1.

(9) In the area of the heat transfer block 2 covered by the screen 4, a lesser cooling of the fluid flowing in the covered tubes of the heat transfer block 2 takes place. This way, the tendency towards formation of condensate inside the covered tubes is greatly reduced. Particularly in contrast to the tubes arranged above the screen 4, which are completely surrounded by the flowing gas, the formation of condensate under certain operating conditions in the heat exchanger 1 is much greater than in the tubes covered by the screen 4.

(10) The fluid flowing in the heat exchanger 1 is distributed to the tubes of the heat transfer block 2 in one of the collection chambers 3 and is collected from these tubes in the respective, other collection chambers and is discharged from the heat exchanger 1.

(11) Preferably, the heat exchanger 1 is an intercooler which is used to cool air flow, which is in turn fed to the combustion engine via a turbo charger or a compressor.

(12) In the embodiment in FIG. 1, the screen 4 is triangular and rests with its vertex on the rod of the retaining device 5. This results in sloped surfaces of the screen 4 above the retaining device 5 and below the retaining device 5 which promote the discharge of the air stream flowing upwards or downwards to the screen 4. In the embodiment in FIG. 1, the screen 4 features an angled contour as a cross-section.

(13) In alternative embodiments, the screen 4 can also be formed as a level, plate-shaped component arranged in front of a certain number of tubes. The screen can also be combined with the heat exchanger in one piece or connected to the heat exchanger via methods such as welding, bonding, clamping or clipping. The screen 4 is preferably formed from a metallic material so that it can be easily connected to the heat transfer block.

(14) In a further, preferred embodiment, the screen can be formed from synthetic material which particularly simplifies its production and the screen can be designed in an especially cost-effective manner. The screen can preferably be produced in an extrusion process which allows for simple manufacturing within the framework of a mass production.

(15) In a further, preferred embodiment, the screen can also contain a number of openings which allow at least a partial surround-flow of the covered tubes of the heat transfer block. It is also possible that the screen only extends over a portion of the heat transfer block. A screen partitioned into several, individual parts can also be provided so that for example only the tube end sections facing the collection chambers are covered.

(16) The basic objective of the screen 4 is to reduce the air flow directed at the covered tubes by a certain amount in order to reduce the cooling performance in the covered tubes. Hereby, the cooling performance should preferably be reduced by 40% and 95% as compared to the uncovered tubes.

(17) The reduction of cooling performance in the covered tubes particularly prevents the formation of condensate. This ensures that at no point in time, freezing and the resulting blocking of the covered tubes of the heat transfer block 2 occurs. This allows for an air flow to be transported at any time through at least the heat exchanger 1 through the tubes covered by the screen 4.

(18) FIG. 2 shows a cross-section of the heat exchanger 1. The cross-section illustrates that the tubes which each form a flow channel 9 are arranged parallel on top of one another inside the heat transfer block 2. Corrugated fin elements 10 are arranged between the individual flow channels 9 which are meant to improve particularly the heat transfer between the gas flowing around the heat transfer block 2 and the fluid flowing through the flow channels 9. The ends of the flow channels 9 are each incorporated into the tube sheet 8 to which a cover-shaped wall 11 is connected which forms the collection chamber 3 between the tube sheet 8 and the wall 11. The flow channels 9 thus all unilaterally flow to the inner volume of the illustrated collection chamber 3. FIG. 2 shows collection chamber 3 on the outlet side.

(19) In the wall 11 of collection chamber 3, a vent 12 is arranged which features a vent inlet side 13 and a vent outlet side 14. The vent inlet side 13 points towards the inner volume of the collection chamber 13 whereas the vent outlet side 14 is directed towards the surrounding area. The vent 12 is formed in such a way that a fluid stream can only flow from inside the collection chamber 3 out into the surrounding area. The vent 12 particularly serves to discharge condensate which can form within the heat exchanger 1. For this purpose, the vent 12 is pressure controlled and can be opened or closed by a pressure difference formed inside the heat exchanger 1 and outside the heat exchanger 1. Preferably, the vent 12 is designed in such a way that it only opens when the combustion engine is operated with a predefined, minimum load.

(20) FIG. 2 shows that the top edge of the vent inlet side 13 is arranged below a contour line 15 which is also arranged below the bottom edge of the lowest flow channel 9. This ensures that the inlet to the vent 12 lies below the lowest point of the lowest flow channel 9 at all times. This serves to better discharge the resulting condensate from the collection chamber 3. If the vent 12 is situated higher, the condensate could flow back into the lower flow channel 9 which could again result in a freezing or blocking of the lower flow channel 9.

(21) In an alternative embodiment, the collection chamber can feature a funnel-shaped inner contour in the region of the lower end section which can particularly enable an influx of the condensate collected in the collection chamber towards the vent. This would allow for further improved removal of the condensate from the collection chamber.

(22) The embodiments shown in FIGS. 1 and 2 are examples and their purpose is to illustrate the concept of the invention. Particularly in respect of the detailed design of the heat exchanger 1 or the design of the collection chambers 3, FIGS. 1 and 2 have no restrictions. The arrangement or design of the screen 4 in FIG. 1 is also exemplary. In alternative embodiments, other screens can also be used. The main purpose of screen 4 is the at least partial covering of a predefined number of tubes of the heat transfer block 2 at the lower end section of the heat transfer block 2.

(23) The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.