HEAT EXCHANGER FOR GASES, IN PARTICULAR ENGINE EXHAUST GASES

Abstract

The present invention relates to a heat exchanger for gases, in particular for the exhaust gases of an engine, which includes a plurality of gas circulation conduits and a casing for the exchange of heat between said gases and a coolant fluid that surrounds the gas circulation conduits housed inside the casing, wherein baffles are used to configure the passage of the coolant fluid between said gas circulation conduits, having at least one inlet baffle that directs the flow of coolant to the part and thus improving the operating conditions of the exchanger and making same more efficient.

Claims

1. A heat exchanger for engine exhaust gases, comprising: a heat-exchanger casing that delimits a circuit for the circulation of a coolant fluid; a plurality of gas conduits installed within said heat-exchanger casing; a gas inlet for gas circulation; and a coolant fluid inlet inside the casing, wherein the gas conduits each comprise an arrangement of baffles for distributing coolant on at least one of the outer faces thereof, said arrangement of baffles for distributing coolant comprising at least one inlet baffle located near the coolant inlet, said inlet baffle including a first portion and a second portion arranged in a substantially orthogonal position so as to guide the coolant inlet toward the gas inlet.

2. The heat exchanger for gases as claimed in claim 1, wherein the first portion of the inlet baffle is substantially perpendicular to a plane defined by the first edge or side of the gas conduits, without obstructing the coolant inlet, wherein the second portion is substantially parallel to the same plane defined by said first edge or side of the gas conduits, and wherein the second portion is arranged facing the gas inlet.

3. The heat exchanger for gases as claimed in claim 1, wherein said first and second portion of the inlet baffle form a single “L”-shaped piece.

4. The heat exchanger for gases as claimed in claim 1, wherein an end of the second portion of the inlet baffle, which is the end not adjoining the first portion, is located at a distance of between 6 mm and 12 mm from a second edge or end of the gas conduits facing the gas inlet.

5. The heat exchanger for gases as claimed in claim 1, wherein an end of the second portion of the inlet baffle, which is the end not adjoining the first portion, is located at a distance of between 3.5 mm and 8 mm from the first edge or side of the gas conduits.

6. The heat exchanger for gases as claimed in claim 1, wherein said arrangement of coolant distribution baffles comprises, in addition to the inlet baffle, a first plurality of baffles that define at least one first group of transversely arranged baffles in a staggered configuration, such that each baffle of said first group of transversely arranged baffles is situated at a different distance from the second edge or end of the gas conduits, thereby defining a coolant flow distribution along the entire extent of the second edge or end of the gas conduits adjacent to the gas inlet.

7. The heat exchanger for gases as claimed in claim 6, wherein a longitudinal axis of each baffle of the first transversely arranged group is arranged so as to form an angle of inclination of between 0° and 60° with respect to a longitudinal axis of the gas conduits.

8. The heat exchanger for gases as claimed in claim 1, wherein said arrangement of baffles comprises, in addition to the inlet baffle, a second plurality of baffles including one or more transversely distributed groups of staggered baffles, arranged on a first side of a central longitudinal axis of the gas conduits, and a third plurality of baffles comprising one or more transversely distributed groups of staggered baffles arranged on a second side of the central longitudinal axis of the gas conduits, and wherein the one or more groups of the second and third plurality of baffles are arranged at different distances from a second edge or end of the gas conduits adjacent to the gas inlet.

9. The heat exchanger for gases as claimed in claim 8, wherein a longitudinal axis of each of the baffles of the second and third plurality of baffles is arranged so as to form an angle of inclination of between 0° and 60° with respect to a longitudinal axis of the gas conduits.

10. The heat exchanger for gases as claimed in claim 1, wherein the baffles have a height that is at most substantially equal to half the separation distance between gas conduits, among which said baffles are located.

11. The heat exchanger for gases as claimed in claim 10, wherein the baffles do not come into contact with baffles located in the adjoining gas conduit in an opposing manner.

12. The heat exchanger for gases as claimed in claim 10, wherein the opposing baffles come into contact with each other, preventing the passage of coolant fluid between these opposing baffles of adjoining gas conduits.

13. The heat exchanger for gases as claimed in claim 1, wherein each of the gas conduits is formed by a pair of plates or by a tube, and wherein the inlet baffle and/or the first, second and/or third plurality of baffles are obtained by stamping or embossing on at least one external face of the conduit.

14. The heat exchanger for gases as claimed in claim 1, wherein the heat exchanger is a shell-and-tube heat exchanger.

15. The heat exchanger for gases as claimed in claim 1, wherein the second portion of the inlet baffle has a length that is at least equal to or greater than the width of the opening of the coolant inlet.

16. The heat exchanger for gases as claimed in claim 1, wherein the inlet baffle comprises at least a third portion for transition between the first portion and the second portion.

17. A process for manufacturing a heat exchanger as claimed in claim 1, comprising: stamping or embossing the arrangement of coolant distribution baffles in a gas conduit, said stamping or embossing being carried out on at least one plate or on at least one tube, forming part of said gas conduit.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0032] For a better understanding of what has been explained, drawings are attached in which, schematically and only as a non-limiting example, a practical case of embodiment is shown.

[0033] FIG. 1 is an exploded view of the heat exchanger for gases, in which the internal configuration thereof and the gas and coolant inlets can be seen.

[0034] FIG. 2 is a partial detail view of a cross section of a number of gas conduits showing the gas passage conduits and the spacing between adjoining baffles of two gas conduits.

[0035] FIG. 3 is a partial view of the inside of the refrigeration circuit in the area close to the gas and coolant inlet area, showing both inlet connections.

[0036] FIG. 4 is a partial view of a gas conduit from the outer face, where the detail of the inlet baffle can be seen.

[0037] FIG. 5 is a partial view of a gas conduit from the outer face, where the detail of the inlet baffle and the first plurality of baffles that define a first group of transversely arranged staggered baffles can be seen.

[0038] FIG. 6 is a partial sectional view of any baffle which has been formed by stamping the very plate that forms the conduit.

[0039] FIG. 7 is a partial view of a gas conduit from the outer face, where the detail of the inlet baffle and the first, second and third plurality of staggered baffles that define the corresponding transversely arranged groups of baffles can be seen.

DESCRIPTION OF A PREFERRED EMBODIMENT

[0040] In the following text, various embodiments of the heat exchanger for combustion gases with coolant fluid distribution baffles of the present invention are described, with reference to the figures indicated above.

[0041] In one embodiment of the invention, the heat exchanger (10) for engine gases for subsequent recirculation, commonly known as EGR, comprises a casing (11) that delimits a circuit for the circulation of a coolant fluid, laterally enveloping a plurality of gas conduits (12), formed by a pair of plates, which pass through said coolant circuit, with a gas inlet (13) for the circulation of gas through said conduits (12) until it exits at the other end. The coolant circuit formed in the volume between the casing (10) and the gas conduits (12) has a coolant inlet (14).

[0042] The combustion gases to be cooled, originating from the engine, are carried inside the gas conduits (12), with each one of said gas conduits (12) including an arrangement (100) of baffles for distribution of coolant, on both outer faces (15), between which the coolant fluid circulates.

[0043] At the coolant fluid inlet (14) in the casing (11), in each space between gas conduits (12) that creates the refrigeration circuit, an inlet baffle (101) is located. In each conduit, said inlet baffle (101) creates a distributor/guide (18) for the entry of the coolant into the casing (11) of the exchanger (10).

[0044] In the present embodiment, the inlet baffle (101) is preferably implemented by stamping, on each outer face (15) of each gas conduit (12), a relief that protrudes from the surface thereof toward the space created between gas conduits (12) inside the exchanger. The inlet baffle (101) is designed in an “L” shape, with a first portion (19) and a second portion (20) arranged starting from a first edge (21) or side of the gas conduits (12) (see FIG. 4). This inlet baffle (101) has been arranged so that, without obstructing the coolant inlet (14) itself, it guides the flow of coolant fluid toward the area of the circuit closest to the gas inlet (13), preventing the coolant fluid from being directed directly to more advanced areas of the gas conduits (12) of the exchanger (10).

[0045] The shape of the inlet baffle (101) can be substantially different from the “L” shape. However, the first portion (19) of the inlet baffle (101) will preferably be substantially perpendicular to a plane defined by a first edge (21) or side of the gas conduits (12) and the second portion (20) will be substantially parallel to the same plane defined by said first edge (21) of the gas conduits (12).

[0046] The dimensions of the inlet baffle (101) depend on the position of the coolant inlet (14) in the exchanger. However, in order to create an efficient distributor for guiding the coolant to the desired area, as seen in the figures, the end (23) of the second portion (20) of the inlet baffle (101), that is to say, the end not adjoining the first portion (19), is preferably located at a distance of between 6 and 12 mm from the end or second edge (22) of the gas conduits (12) that is closest to the gas inlet (13) of the exchanger. This end (23) of the second portion (20) is also located at a distance of between 3.5 and 8 mm from the first edge (21) or side of the gas conduits (12).

[0047] In the present embodiment, this configuration is implemented by means of a single-piece inlet baffle (101); that is to say, the two portions (19 and 20) are made continuously, although in alternative embodiments these portions may be adjoining and not joined, or may even have an intermediate connecting portion between the two.

[0048] The arrangement (100) of baffles for distribution of coolant in the gas conduit (12) comprises, in addition to the inlet baffle (101), a first plurality of baffles (102) that define at least a first group of transversely arranged staggered baffles (102). These baffles (102) are substantially aligned along an axis (E1) substantially transverse to the longitudinal passage of the coolant fluid and have a staggered configuration, such that each baffle (102) is located at a different distance from the second edge (22) or end of the gas conduits (12) closest to the gas inlet (13). For example, the furthest baffle (102) of the group may be located at a distance from the second edge (22) or end of the gas conduits (12) of between 12 mm and 110 mm (measured from the center of each baffle to a safety strip 0.5 mm from the second edge (22) or end of the gas conduits (12) adjacent to the gas inlet).

[0049] A longitudinal separation (d2) is provided between said baffles (102), designed so that a baffle (102) gets closer and closer to the second edge (22) or end of the gas conduit (12) adjacent to the gas inlet, thereby defining a coolant flow distribution along the entire extent of said second edge (22) or end of the gas conduits (12).

[0050] Each baffle (102) of the first transverse group has a length of between 1 mm and 9 mm and is arranged with respect to another baffle (101) with a transverse separation (d1) between said baffles (102), with the aim of occupying the maximum width of the gas conduit (12) and being able to distribute the coolant over the entire width indicated.

[0051] Each of the baffles (102) of the first transverse group has a longitudinal axis that is arranged so as to form an angle (A1) of inclination of between 0° and 60° with respect to a longitudinal axis (E2) of the gas conduits (12).

[0052] Moreover, the present embodiment of the heat exchanger (10) comprises a baffle arrangement (100) that includes, in addition to the inlet baffle (101) and the first plurality of baffles (102): [0053] a second plurality of baffles (103) comprising two transversely distributed groups of staggered baffles (103), arranged on a first side (L1) of the central longitudinal axis (E2) of the gas conduits (12); and [0054] a third plurality of baffles (104) comprising two transversely distributed groups of staggered baffles (104) arranged on the other side of said central longitudinal axis (E2), on the second side (L2) of said central longitudinal axis (E2) of the gas conduits (12).

[0055] Each of the groups of the second and third plurality of baffles (103 and 104) have their baffles (103 and 104) arranged at different distances from the second edge (22) or end of the gas conduits (12), so that the furthest baffle (103 and 104) in each group is at a distance ranging from 12 mm to 110 mm (measurements taken from the center of the baffle (103 and 104) to a safety strip at 0.5 mm from the second edge (22) or end of the gas conduits (12) adjacent to the gas inlet).

[0056] Likewise, each baffle (103 and 104) of the second and third plurality of baffles (103 and 104) is arranged so as to maintain a transverse separation (d1) with an adjacent baffle (103 and 104).

[0057] Preferably, the longitudinal axis of each of the baffles (103 and 104) of the second and third plurality of baffles (103 and 104) is arranged so as to form an angle (A2) of inclination of between 0° and 60° with respect to a central longitudinal axis (E2) of the gas conduits (12), considering that said range can be made both positively and negatively with respect to said central axis (E2).

[0058] All the baffles (101, 102, 103 and 104) indicated in this embodiment are stamped or embossed into the plates that form the gas conduits (12), and have a height (Rh), without coming into contact with the baffles (101, 102, 103 and 104) located on the face (15) of the adjoining conduit (12), so that they form a passage of minimum width for the coolant fluid between said baffles.

[0059] The manufacture of an exchanger as defined in the previous embodiments is based on a process comprising a step of stamping or embossing the arrangement (100) of baffles for distribution of coolant in the plates that form the gas conduit (12) or alternatively in the tube that forms same.

[0060] Although reference has been made to a specific embodiment of the invention, it is obvious for a person skilled in the art that the heat exchanger for gases, in particular engine exhaust gases, with coolant distribution baffles described is susceptible to numerous variations and modifications and that all the aforementioned details can be replaced by other technically equivalent ones, without departing from the scope of protection defined by the appended claims.