CN103384810A

CN103384810A - Brazable component and heat exchanger comprising same

Info

Publication number: CN103384810A
Application number: CN2011800653214A
Authority: CN
Inventors: G.德佩尔塞梅克; E.赫农; J.加西亚扎尔迪瓦
Original assignee: Valeo Systemes Thermiques SAS
Current assignee: Valeo Systemes Thermiques SAS
Priority date: 2010-11-19
Filing date: 2011-11-18
Publication date: 2013-11-06
Also published as: FR2967765A1; JP2017044468A; US20140096943A1; WO2012066115A1; FR2967765B1; EP2641047A1; JP2013543104A

Abstract

This invention relates to brazable components for the circulation of fluids in heat exchangers, particularly for motor vehicles. The core (4) of the component comprises an aluminum alloy. It also includes a pure aluminum protective layer (8) arranged to abut against the core (4).

Description

But soldering parts and the heat exchanger that comprises it

Technical field

The present invention relates to the field for the heat exchanger of motor vehicles, its intention is carried out heat exchange between two kinds of fluids, and more specifically, but not exclusively, relating to Al-alloy heat exchanger, it is used for the emission gases of the heat engine of cooling these vehicles.

Background technology

It is known being used for making the loop of exhaust gas recirculation (being called EGR, " exhaust gas recirculation ") of the heat engine of motor vehicles.Emission gases is recycled to the air inlet of engine within it, and there, they are by completing combustion.

Recirculation circuit extends between the exhausting loop of heat engine and air inlet loop, and substantially comprises the heat exchanger for cooling emission gases, because they are in high maximum temperature (400 ℃-900 ℃).It also comprises uncooled bypass passageways, be used for gas flow selectively is directed to by-passing valve in heat exchanger or bypass circulation, and is used for controlling the control valve of throughput of the gas flow of recirculation circuit.

These emission gases are particularly acid, and are condensed into acidic liquid, particularly when vehicle motor is cold.Because this acidic liquid comprises sulfate, nitrate, organic acid, chloride and/or hydrocarbon especially, these cause a large amount of infringements to heat exchanger by corrosion.Therefore usually note, the pH of condensate is less than 2, and the chloride value is 50ppm.In some vehicles, even notice the chloride of pH0.8 and 200ppm.

In addition, the assembling of the various parts of these interchangers is undertaken by soldering, thereby is coated with one deck solder before these elements.During soldering, the silicon of observing solder layer spreads towards the element core.This change of the component of core makes element be more vulnerable to corrosion.

Therefore need erosion-resisting exchanger part.

Document WO2006034876 is known, it proposes to form water-repellent layer on the surface in exchange loop, in order to remove as quickly as possible the condensation of acid water, and make it have no time to attack interchanger, but this scheme is not gratifying, because it can not prevent corrosion fully, and obviously reduce the heat-exchange capacity of interchanger.

Summary of the invention

The objective of the invention is to propose the parts for such interchanger, it can resist corrosion, and this corrosion for example causes due to the condensation of these gases, and described parts are simple especially and make cheap.

For this reason, but the present invention proposes a kind of parts of soldering, is used for fluid in the circulation of heat exchanger, and especially for motor vehicles, it comprises the aluminium alloy core, it is characterized in that, it further comprises the fine aluminium protective layer that is arranged as against core.

Therefore, after soldering, aluminum layer contacts with corrosive gas, and does not contact with the core of parts.Compare with the core of parts, aluminium lamination has the better opposing to corrosion, and its existence prevents that the silicon of solder from spreading towards core.No matter that parts are all resisted corrosion due to the circulation of emission gases, liquid (such as glycol water) or other fluid.

According to equal simple especially and embodiment feature easily when making and use:

Protective layer comprises that percentage by weight is more than or equal to 99.5% aluminium;

Core has first surface, is extended with equably protective layer on it;

Core has second surface, and facing to first surface, and parts comprise the second fine aluminium protective layer, and it is arranged against second surface;

Two protective layers have identical component;

Mechanical strength after the soldering of parts and the product of component thickness are more than or equal to 46800MPa. μ m;

The thickness that parts have is between 200 μ m to 530 μ m;

The thickness of protective layer is between 25 μ m to 80 μ m;

Protective layer is used for by parts being soldered to other parts and assembled between core and solder layer, and the ratio between the thickness of solder layer and the thickness of protective layer is between 0.3 to 1;

The thickness of solder layer be gross thickness 4% to 10% between;

These parts are pipe or plate.

The invention still further relates to a kind of interchanger; be used for especially motor vehicles; be used for carrying out heat exchange between the first fluid that circulates in the first loop and the second fluid that circulates in second servo loop; this second servo loop separates with the first loop; it is characterized in that; it comprises a plurality of aforesaid parts, and the surface of parts comprises the protective layer that belongs to the first loop.

First fluid comprises the emission gases of recirculation;

After soldering, the product of the thickness of the mechanical strength of parts and parts core is more than or equal to 46800MPa. μ m;

Parts are stacking plate or the pipe that is arranged in parallel.

Description of drawings

Characteristics and advantages of the present invention will manifest by provide preferred exemplary, following description with reference to accompanying drawing with non-limiting way in, in the accompanying drawings:

Fig. 1 a and 1b be pipe according to the present invention before soldering and a pair of partial cross section view afterwards, it only has aluminum layer on the outer surface;

Fig. 2 a and 2b are a pair of figure that is similar to Fig. 1, and wherein, aluminum layer and solder layer are arranged on the inner surface and outer surface of pipe;

Fig. 3 is the decomposition diagram according to interchanger of the present invention;

Fig. 4 is the view that is similar to Fig. 3, and interchanger is assembled;

Fig. 5 is the perspective view of plate according to the present invention before soldering, and aluminium lamination and solder layer are arranged on the inner surface and outer surface of plate;

Fig. 6 is the view that is similar to Fig. 5, after soldering;

Fig. 7 is the perspective view of plate according to the present invention before soldering, plate only have aluminum layer on a surface, have solder layer on every side.

The specific embodiment

Describe according to parts of the present invention referring now to Fig. 1 and 2.In this case, it is flat tube 1, is used as the part of heat exchange bundle 2 as shown in Figure 3.Pipe 1 comprises wall, wherein, is the square circle transverse to the cross section of its longitudinal axis, and wherein the part of two flat parts and two circles (for example semi-circular shape) replaces.The part of circle does not illustrate in the drawings.Two parallel-segment 3 of flat wall in the drawings as seen.

The thickness of the wall of pipe 1, that is, the thickness of section 3 is between 200 μ m to 530 μ m.

The wall of pipe 1 comprises core 4, and it is made by 3000 series alloys.

Pipe 1 inboard 5 is, in Fig. 1 and 2, and the space of extending between two sections 3.Each section 3 has towards the medial surface 6 of the inboard 5 of pipe 1, and faces toward the lateral surface 7 of medial surface 6.

At the sidepiece of lateral surface 7, core 4 comprises first surface, and fine aluminium protective layer 8 extends against this first surface.Fine aluminium is understood to have the aluminium alloy of high aluminium content, and its content is greater than set-point 99%.In this case, this is 1000 series alloys.Layer 8 has the thickness of 40 μ m, and in this case, has 99.5% aluminium percentage.

Before brazed tubes 1, protective layer 8 extends between core 4 and solder layer 10.The thickness of layer 10 is 30 μ m.Solder is used for manage 1 another parts that are soldered to bundle 2, for example is arranged between pipe 1 or at the separator of restrainting between 2 tube plate.Because soldering is known, and not theme of the present invention, in this case will be not the component of soldering or solder be described in detail, provide fusion temperature that solder has less than the fusion temperature of the parts of interchanger, in order to allow all parts to be fixed to each other.

At medial surface 6 sidepieces, core 4 comprises that another solder layer 10(is before soldering, against its surface).This layer 10 is used for brazed tubes 1, and the perturbation element (not shown) is arranged in pipe 1.

Usually, the thickness of parts, that is, the thickness of the thickness of the wall of pipe 1, layer 8, the thickness of solder layer 10 are selected in scope and with some relations by following:

Ratio between the thickness of the thickness of-solder layer 10 and aluminium lamination 8 is used for preventing that solder is towards core 4 migrations between 0.3 and 1;

The thickness of-solder layer 10 the thickness of pipe 1 wall 4% and 10% between;

The thickness of-protective layer 8 is between 25 μ m and 80 μ m;

The thickness of the wall of-pipe 1 is between 200 μ m and 530 μ m.

After interchanger 11 solderings (Fig. 3 and 4), the metal of solder layer 10 is towards will be by the zone migration of soldering, thereby in the outside in these zones, protective layer 8 is exposed.

Layer 8 form will with the coating of fluid contact, and act on as the sacrificing protection layer.Therefore, even if this layer 8 begins to be corroded, the core 4 of the wall of pipe 1 can not attacked.

On the pipe 1 of Fig. 1 a and 1b, therefore there is protective layer 8 in the outside of pipe 1, so that for outside corrosion protection pipe 1, this corrosion can occur under the effect of the fluid of process.

On pipe 1 in Fig. 2 a and 2b, the second surface of the core on the sidepiece of the medial surface 6 of pipe 1 is coated with the second protective layer 8.This second layer 8 extends between core 4 and another solder layer 10.Soldering occurs in the outside of pipe and the inboard of pipe, and for example, perturbation element is between pipe and in pipe.Due to the existence of protective layer 8 on pipe 1 outside and inboard, pipe 1 is protected for corrosion, occurs under the effect of the fluid that this corrosion can be flow through between pipe and in pipe.

After soldering, the mechanical strength of the wall of pipe 1 multiply by the thickness of core 4 greater than 46800MPa. μ m.

The example of the use of the pipe of Fig. 2 a and 2b is shown in Fig. 3 and 4.The interchanger 11 that illustrates comprises two row's flat tubes 1.Bundle is placed in housing 12.

Interchanger 11 comprises the loop for the EGR gas circulation, and this EGR gas and cooling agent carry out heat exchange.

Housing 12, it has the essentially rectangular cross section and in the sealing of one end thereof place, the bundle 2 of side containing pipe 1 within it, in this situation, pipe is U-shaped, that is, the entrance 13 of pipe 1 and outlet 14 are arranged on the same side at open end 15 places of housing 12.

The end of the bundle of pipe 1 is fixed to gripper shoe 16.Gripper shoe 16 has a plurality of openings 17, is used for installing respectively managing 1.

Housing 12 has for the access road 18 of EGR cooling agent and exit passageway (not shown), and in this case, the EGR cooling agent is the glycol water of engine cooling circuit.

EGR gas enters interchanger 11 by entrance 13, circulation in pipe 1, and they are cooled there, then return by exporting 15.Glycol water enters by access road 18, and submergence bundle 2 is also discharged by exit passageway.Exchange occurs between EGR gas and glycol water, in order to allow the EGR gas cooled.

The acidity of EGR gas can be approximately pH2, and in some cases, can reach 0.8 pH value, and holds until the chloride of 200ppm.Due to the possible condensation in the cyclic process in interchanger, the inboard experience of pipe etching condition, they are protected for these etching conditions by the existence of protective layer 8.

Glycol water is effect caustically also, and due to the protective layer 8 that is positioned at the outside, the outside of pipe is protected for this.

According to the alternative embodiment corresponding with Fig. 1 a and 1b, the only flow-induced corrosion ground effect of circulation outside pipe, thereby only outside protected seam 8 protections of pipe.

According to other alternative, protective layer only is arranged on the inboard of pipe, and solder layer is only in the outside of pipe.

Usually, protective layer is arranged at least one of interior or outer surface of pipe.

According to other alternative, do not have solder to be arranged on pipe inboard.

About managing 1 manufacturing, at first obtain core 4, it has the form of 3000 series alloys bands.Then, 1000 serial aluminium laminations 8 are sprayed on the outside equably (Fig. 1 a), or at the outside and inboard (Fig. 1 b).At last, solder layer is deposited on the outside and the outside, for example is immersed in solder bath by managing 1.Solder also can be injected, to manage 1 interior formation layer.Pipe 1 by with two border seals of flat core to them from forming with it.During the soldering of interchanger 11, pipe 1 is made into watertight.

According to alternative embodiment, the core 4 of pipe 1 is made by extruding.Then, 1000 serial aluminium laminations 8 are sprayed on the outside of pipe 1 equably, or on the outside and inboard.At last, solder layer is deposited on the outside and the inboard of pipe 1.

In both cases, perturbation element or turbulator can be arranged in manages 1 inboard, and the circulation of the fluid in its disturbance pipe is in order to improve heat transmission.

Other embodiment is described referring now to Fig. 5-8.For similar element, with using identical counting, increase by 100.According to parts of the present invention, in this case, be plate 101, it comprises core 104, two faces of core are coated with protective layer 108(Fig. 5 and 6).According to alternative, only surface of plate 101 is coated with protective layer (Fig. 7).

Identical with last embodiment, solder layer 110 is arranged on protective layer (one or more) 108.

After soldering (Fig. 6), protective layer 108 is exposed.

Interchanger 111 is plate heat exchanger.Plate 101 is stacked, one on another, thereby produce two fluid circuits, for example EGR gas return path and coolant circuit, this coolant circuit circulation has the glycol water of the cooling circuit of engine.In this case, these are plates 101 of Fig. 5 and 6, and it comprises protective layer in every side.

The stacking permission of plate 101 produces for EGR γ-ray emission loop and allows to produce the loop for glycol water.As in the embodiment that describes before, have the excessive risk condition of corrosion aspect, thereby protective layer 108 works in the protection for corrosion.

According to alternative embodiment (Fig. 7), plate 108 only comprises a baffle 108 on a side.In this case, plate 108 is orientated the protective layer 108 that makes two plates in succession as in the face of each other.Therefore this produce fluid circuit, and wherein, mask has the protective layer that replaces with the loop, and wherein, face does not have any specific protection.This layout is at corrosive fluid with only slightly be corrosive or the heat exchange that do not have between corrosive fluid is fit to.

About the manufacturing of plate 101, at first obtain core 104, it has the form of 3000 series alloys bands.Then 1000 serial aluminium laminations 108 are sprayed.At last, the deposition of solder layer 110.Alternatively, relief section can be manufactured on plate 101, particularly produces circulation canal (not shown) and projection 120 or pit, in order to increase exchange surface.

As an example; parts with thickness of 480 μ m comprise the core of the aluminium alloy 3916 of the thickness with 360 μ m, the protective layer of aluminium alloy 1050 of thickness with 48 μ m and two thickness with 36 μ m solder 4343 layer (one, each face) (namely; according to percentage; core is 75%, protective layer is 10%, and each solder layer is 7.5%).The mechanical strength of parts is 130MPa.

Other example is the parts with thickness of 400 μ m; it comprise the core of the aluminium alloy of the thickness with 300 μ m, the protective layer of aluminium alloy 1050 of thickness with 40 μ m and two thickness with 30 μ m solder 4343 layer (one, each face) (namely; according to percentage; core is 75%, protective layer is 10%, and each solder layer is 7.5%).The mechanical strength of parts is 156MPa.

The 3rd example is the parts with thickness of 400 μ m; it comprise the protective layer (one, each face) of the aluminium alloy 1050 of the core of the aluminium alloy of the thickness with 260 μ m, two thickness with 40 μ m and two thickness with 30 μ m solder 4343 layer (one, each face) (namely; according to percentage; core is 65%, each protective layer is 10%, and each solder layer is 7.5%).The mechanical strength of parts is 180MPa.

For each example, after soldering, the product of mechanical strength and core thickness is 46800Mpa. μ m.

As the alternative for described embodiment, parts, pipe or plate can obtain rolling multilayer sandwiched form.

Alternative embodiment contains various combinations, and it can be by only arranging protective layer on a face, protective layer is being set on each face, solder layer being set and on each face, solder layer being set on face only and obtain.

The optional existence of solder layer especially with pipe between separator or the demand that causes of the optional existence of the turbulator in pipe be associated.

According to other example, claimed parts (pipe or plate) comprise protective layer (one or more), and separator or perturbation element with solder layer are arranged in (or turbulator is arranged in pipe) between pipe or plate.

According to another embodiment, parts according to the present invention are the tube plates that comprise the aluminium alloy core, and it is for example by soldering and pipe assembling.This tube plate comprises the fine aluminium protective layer, and this protective layer is arranged on the surface of core at the sidepiece of pipe.

According to alternative, parts are gripper shoes 16 of interchanger 11.Pipe 1 and 16 of plates comprise protective layer.

According to other embodiment, heat exchanger according to the present invention comprises the first loop, and the first fluid that be cooled circulates therein, and glycol water for example, this first fluid are for example cooling by second fluid, and this second fluid is air for example.The pipe of interchanger or plate only comprise protective layer on the surface as the part in the first loop.

The invention is not restricted to the embodiment that institute describes and shows, and contain any alternative embodiment.

Claims

1. A brazeable component for the circulation of a fluid in a heat exchanger, in particular for a motor vehicle, comprising an aluminum alloy core (4, 104), characterized in that it further comprises an arrangement arranged against Lean on the pure aluminum protective layer (8,108) of the core (4,104).

2. The component as claimed in claim 1, characterized in that the protective layer (8, 108) comprises aluminum with a weight percentage greater than or equal to 99.5%.

3. A component according to claim 1 or 2, characterized in that the core has a first surface on which the protective layer (8, 108) extends uniformly.

4. The component according to the preceding claim, characterized in that the core has a second surface, opposite the first surface, and in that the component comprises a second protective layer (8, 108) of pure aluminum against which Second surface arrangement.

5. The component according to the preceding claim, characterized in that the two protective layers (8, 108) have the same composition.

6. The component according to any one of the preceding claims, characterized in that the product of the mechanical strength of the component after brazing and the thickness of the component is greater than or equal to 46800 MPa.μm.

7. A component as claimed in any one of the preceding claims, characterized in that it has a thickness of between 200 [mu]m and 530 [mu]m.

8. The component as claimed in any one of the preceding claims, characterized in that the thickness of the protective layer (8, 108) is between 25 μm and 80 μm.

9. A component according to any one of the preceding claims, characterized in that a protective layer (8, 108) is located between the core (4, 104) and the solder layer (10, 110) for passing The components are assembled by soldering to other components, the ratio between the thickness of the solder layer (10, 110) and the thickness of the protective layer (8, 108) being between 0.3 and 1.

10. The component according to claim 9, characterized in that the thickness of the solder layer (10, 110) is between 4% and 10% of the total thickness.

11. A component according to any one of claims 1 to 10, characterized in that the component is a tube (1).

12. A component according to any one of claims 1 to 10, characterized in that the component is a plate (101).

13. A heat exchanger, in particular for a motor vehicle, for exchanging heat between a first fluid circulating in a first circuit and a second fluid circulating in a second circuit, the second circuit being connected to the first A circuit separation, characterized in that it comprises a plurality of components (1, 101) according to any one of the preceding claims, the surface of said component (1, 101) comprising a protective layer belonging to the first circuit.

14. The exchanger of claim 13, wherein the first fluid comprises recirculated exhaust gas.

15. The exchanger according to claim 13 or 14, characterized in that, after brazing, the mechanical strength of the part (1, 101) is comparable to that of the core (4, 104) of the part (1, 101) The product of thickness is greater than or equal to 46800MPa.μm.

16. The exchanger according to any one of claims 13 to 15, characterized in that the part is a stacked plate (101).

17. The exchanger as claimed in any one of claims 13 to 15, characterized in that said components are tubes (1 ) arranged in parallel.

18. An exchanger as claimed in claim 17, wherein the tubes are divided by dividers.

19. The exchanger as claimed in claim 17 or 18, characterized in that the disturbance element is arranged inside the tube (1).