CN116601450A - tubes for heat exchangers - Google Patents

Abstract

The present invention relates to a tube for a heat exchanger. The tube includes at least one fusible portion formed on at least one coupling edge of the tube for assembly with at least one wall of the heat exchanger. Furthermore, the fusible parts are aligned parallel with respect to the general plane (P1) of the tube. The tube further includes a base portion located adjacent the coupling edge and a tip portion defined adjacent a wall of the heat exchanger. The tip portion of the fusible part is adapted to fracture by the difference in expansion and contraction between the tube and the wall.

Description

tubes for heat exchangers

technical field

The present invention relates to a heat exchanger. In particular, the invention relates to a heat exchanger having tubes brazed to the wall of the heat exchanger housing.

Background technique

Generally, heat exchangers are provided in vehicles for various operations. In particular, the charge air cooler is arranged in the intake circuit of the engine. Typically, the engine may receive air from the atmosphere, and the atmospheric pressure decreases as the height of the vehicle changes, ie when the vehicle is driven in elevated areas such as mountainous terrain. In this case, the fuel economy and thermal efficiency of the engine will be reduced because the engine will receive an invalid volume/pressure of air. To overcome these problems, air (referred to here as "charge air") is pressurized by a mechanical or electric compressor known as a supercharger or turbocharger. In a forced induction engine, power output becomes a function of the amount of air delivered to the cylinders. The most common method is to introduce a compressor to recover energy from the exhaust manifold through an expansion turbine, which pressurizes the air delivered to the engine, or to deliver a portion of the engine power to drive a supercharger, usually through Wheel set.

Additionally, pressurizing air causes its temperature to increase significantly. Therefore, the density of air decreases with increasing temperature because hot air is less dense than cold air. Like many other areas of industry, the automotive industry uses heat exchangers to ensure optimum temperature operating conditions for the engine. Therefore, the charge air cooler is arranged upstream of the engine and downstream of the turbocharger/supercharger. The charge air cooler dissipates heat from the charge air flowing from the turbocharger. The charge air cooler is equipped with a tube bank forming a heat exchange bundle between the first fluid and the second heat transfer fluid, and the heat exchange bundle is housed in the casing.

The tubes in the charge air cooler can be made of aluminum, as this saves a lot of weight, and aluminum alloys also have good heat and corrosion resistance. Due to the complexity and permitted small size of the charge air cooler, the components of the charge air cooler are assembled by brazing. Furthermore, the tubes are usually brazed to the shell of the charge air cooler, ie joined by adding liquid metal to the metal parts to be joined. Since the tubes are brazed over their entire surface in contact with the housing wall, the added metal thus forms a continuous line and the assembly lacks flexibility. It is well known that charge air coolers are subjected to high and varying stresses during operating modes, such as thermomechanical stresses and chemical reactions with a more or less aggressive environment.

In particular, sudden and significant temperature changes can cause thermal shock, for example when opening a valve equipped with a sensor that measures engine temperature and allows cold engine cooling water to enter the warmer engine intake system. These thermal shocks lead to an expansion/contraction phenomenon of the tubes of the heat exchanger called heat flux. However, the lack of flexibility of the tube creates significant stresses, which can lead to rupture zones in the tube. It can then be observed that these fractured areas lead to leakage of the heat transfer fluid.

In some prior art heat exchange tubes may include frangible tabs between the tube and housing that break during thermal cycling. However, the frangible protrusions tend to form unpredictable shapes and configurations which in most cases lead to collisions between the casing and the tube, especially during expansion of the tube. Such collisions can lead to mechanical stress and eventually failure of the charge air cooler due to leaks.

Therefore, there is still a need for a heat exchanger tube with an original design that ensures greater tube flexibility and allows avoiding collisions between the remaining elements of the fragile fuse element.

Contents of the invention

The present invention therefore aims to compensate for the disadvantages of the prior art and to meet the above-mentioned limitations by proposing a tube for heat exchangers, the design and mode of operation of which is simple, reliable and economical, which makes it possible to limit or even avoid the A rupture zone associated with thermal shock occurs in the tube, as well as a collision between the remaining elements of the frangible fuse element.

Another object of the present invention is a tube for a heat exchanger that provides support on opposite walls of the housing for assembly by brazing with complementary tubes to form a tube for heat transfer fluid Circulating conduit.

The invention also aims to provide a heat exchanger comprising at least one such tube for the exchanger, thereby providing enhanced reliability. To this end, the invention relates to a tube for a heat exchanger, said tube comprising a joining edge with another tube.

According to the invention, said edge comprises at least one fusible portion for assembling the joint edge with at least one housing wall, said at least one fusible portion being configured to pass through said tube and its intended assembly therein Differential expansion/contraction between the at least one housing wall on the upper part is separated from the rest of the joint edge.

In this specification, some elements or parameters may be referred to, such as a first element and a second element. In this case, unless otherwise stated, such references are used only to distinguish and name similar but not identical elements. No concept of priority should be inferred from this index, as these terms may be interchanged without departing from the invention. Furthermore, such indexing does not imply any order of installation or use of the elements of the invention.

In view of the above circumstances, the present invention relates to a tube for a heat exchanger. The tube includes at least one fusible portion formed on at least one joining edge of the tube for assembly with at least one wall of the heat exchanger. Furthermore, the fusible portion is aligned parallel to the general plane (P1) of the tube. The tube also includes a base portion near the coupling edge and a tip portion near the wall of the heat exchanger. The tip portion of the fusible portion is adapted to be completely separated from the wall by a difference in expansion and contraction between the tube and the wall.

In one embodiment, the tube further comprises at least one notch on a corner region of the tube, in particular between the coupling edge and the base portion of the fusible part.

In one example, the tip portion of the fusible portion extends beyond the coupling edge of the tube.

In addition, fusible portions are formed at corners of the joint edges of the pipes.

In one embodiment, the tip portion of the fusible portion is narrower than the base portion to facilitate separation of the tube from the wall.

Furthermore, the joining edge is formed so as to delimit a tube formed by two plates assembled to each other with their respective facing faces.

Furthermore, the coupling edge serves to delimit a duct for the circulation of the heat transfer fluid inside the tube.

In one embodiment, the fusible portion has a trapezoidal shape, wherein the width of the tip portion is smaller than the width of the base portion.

Additionally, the fusible portion includes a beveled edge connecting the tip portion and the base portion.

In another embodiment, the fusible portion is triangular.

Preferably, the thickness of the fusible portion is half the thickness of the tube, wherein the thickness is measured in a direction perpendicular to the general plane (P1) of the tube.

Alternatively, the thickness of the fusible portion is greater than half the thickness of the tube, wherein the thickness is measured in a direction perpendicular to the general plane (P1) of the tube.

Alternatively, the thickness of the fusible portion is less than half the thickness of the tube, wherein the thickness is measured in a direction perpendicular to the general plane (P1) of the tube.

Description of drawings

Other characteristics, details and advantages of the invention can be inferred from the description of the invention below. A more complete appreciation of the present invention and its many attendant advantages will be readily obtained, and become more comprehensible, by reference to the following detailed description when considered in conjunction with the accompanying drawings, in which:

Figure 1 shows a perspective view of a heat exchanger according to an embodiment of the invention;

Figure 2 shows a side view of a heat exchanger according to the prior art with the tube and shell assembly shown in detail;

Figure 3 shows a perspective view of the individual tubes used in the heat exchanger of Figure 1;

Figure 4 shows a perspective view of a corner portion of the tube shown in Figure 3;

Figure 5 shows a top view of the fusible portion in Figure 3 formed on the joint edge of the pipe; and

Fig. 6 shows a front view of the fusible portion in Fig. 3 formed on the coupling edge of the pipe.

Detailed ways

It must be noted that the accompanying drawings disclose the invention in sufficient detail to help, if necessary, to better define the invention. However, the present invention should not be limited to the embodiments disclosed in the specification.

The present invention may disclose a heat exchanger tube having at least one fusible portion disposed in the heat exchanger. Generally, a heat exchanger may include a tube bundle disposed between two manifolds and forming a fluid passage. These tubes may be brazed to the inner wall of the heat exchanger housing. During heat exchanger operation, the tubes may undergo various thermal cycles. As a result, thermal stresses may act on the tube, which may lead to fracture zones in the tube. Furthermore, such fractured/cracked areas can lead to leaks of the heat transfer fluid. In order to avoid this problem, protrusions are provided at the joining edges of the tubes of the heat exchanger. Such protrusions may be fusible parts adapted to break when there are differential expansions and contractions between the tube and the corresponding wall of the heat exchanger.

Fig. 1 shows a perspective view of a heat exchanger 100 according to an embodiment of the present invention. The heat exchanger 100 may include three walls forming a housing 150 . The three walls are a first wall 110, a second wall 120, and a third wall 130, wherein the first wall 110 and the second wall 120 are aligned in parallel and spaced from each other, and the third wall 130 can be opposite to the first wall 110. Vertically aligned with the second wall 120 such that opposite edges of the third wall 130 are in contact with the first wall 110 and the second wall 120 .

The heat exchanger 100 may further include a manifold 140 . The manifold 140 may be positioned parallel to the third wall 130 and perpendicular to the first and second walls 110, 120 such that, similar to the third wall 130, opposite edges of the manifold 140 are aligned with the first wall. 110 and the second wall 120 are in contact.

Walls 110, 120, 130 and manifold 140 may be joined together, such as by brazing, such that walls 110, 120, 130 and manifold 140 form a substantially rectangular fluid-tight housing 150 that defines a A first fluid circuit for fluid such as charge air. Housing 150 may also receive an inlet and an outlet (not shown) for the first fluid on its open end. Exemplary first fluid flow directions from inlet to outlet are indicated in FIG. 1 by F _in and F _out , respectively.

Furthermore, a second fluid circuit for a second fluid may be formed, inter alia, by a manifold 140, which may comprise an inlet tap 142 and an outlet tap 144 for conveying or collecting a second fluid, such as coolant. Exemplary second fluid flow directions from the inlet to the outlet are indicated in FIG. 1 by W _in and W _out , respectively. The second fluid circuit also includes at least one tube 102 located within the housing 150 . In this example, the term "inside" means that the tube 102 does not protrude beyond the space defined by the housing 150 . Tubes 102 are aligned substantially parallel with respect to first wall 110 and second wall 120 , and substantially perpendicular to manifold 150 and third wall 130 .

Additionally, tube 102 extends from manifold 140 to third wall 130 but is only fluidly connected to manifold 140 . The tube 102 is formed such that there can be at least one U-turn on the path through which the second fluid flows. Generally, manifold 140 is configured to deliver and/or collect the second fluid into tube 102 through two parallel channels formed therein. Preferably, the channels in the manifold 150 are formed as an integral element with eg a divider, however other ways of providing a channel for the second fluid are also contemplated.

Typically, heat exchanger 100 may include multiple tubes 102 to increase its efficiency. The tubes 102 are stacked one after the other in a parallel fashion and perpendicular to the manifold 140 so that the second fluid is distributed as evenly as possible. The second fluid can be communicated through the inlet W _in , and it is directed to the corresponding channel of the manifold 140 of the supply tube 102 . Next, the second fluid flows back through the U-shaped tube 102 to the manifold 150 and is collected through the second fluid outlet W _out .

To increase heat exchange efficiency, the stack of tubes 102 may be interleaved with so-called turbulators or fins 160 . The number of turbulators or fins 160 interleaved between the tubes 102 corresponds to the free space around the tubes 102 . In other words, the turbulators or fins 160 fill the space within the housing 140 not occupied by other subcomponents in order to maximize heat exchange efficiency and reduce bypassing of the tube 102 by the first fluid. In this example, heat exchanger 100 is a charge air cooler. In this case, the first fluid is charge air and the second fluid is a heat transfer fluid, namely: coolant or water or a water-glycol mixture.

Figure 2 shows a heat exchanger 100 with a plurality of tubes 102 according to the prior art. Turbulators or fins 160 have been omitted for clarity. Heat exchanger 100 may be oriented horizontally. The horizontal orientation of the heat exchanger 100 refers to the horizontal direction of the stack of tubes 1 thereof. Alternatively, the heat exchanger 100 may be oriented at any angle relative to the horizontal as long as the first and second fluids are efficiently conveyed to provide effective heat exchange therebetween. As shown in FIG. 2, each tube 102 may be formed from two half-plates fabricated in the same process, one half-plate being essentially a mirror image of the other half-plate, to define the space for the heat transfer fluid to pass through. Paths for circulation between these half-plates. Alternatively, tube 102 may be a folded tube.

FIG. 2 also shows a detailed section “ S1 ” of the tube 102 and housing 140 assembly. According to the prior art, the individual tubes 102 are stacked and spaced apart from each other, thereby providing good efficiency of the overall heat exchanger 100 . During the operating mode of the heat exchanger 100 , the tubes 102 expand and contract depending on the temperature of the first and second fluids and their temperature differences in different parts of the heat exchanger 100 . Furthermore, different subcomponents of the heat exchanger 100 may expand or contract differently, since heat is generally not evenly distributed across all subcomponents.

The tube 102 may initially (ie: in the pre-operational mode) be secured to both the manifold 140 and the third wall 130 , however the tube 102 may also be secured to the manifold 140 only. Since the tube 102 is directly connected to the housing 150, the tube 102 may lack flexibility and thus the tube may become damaged and cause leakage of the second fluid. In order to avoid this problem, fusible parts are introduced in the tube 102 . The schematic and geometry of the fusible portion is depicted in the figure below.

3 and 4 show isometric views of the freestanding tube 102 and one of the corner regions of the tube 102 in FIG. 1 . In one embodiment, each tube 102 may have a substantially rectangular shape such that a general plane P1 may be defined. In this example, the general plane (P1) of the tube 102 is defined along the contact area of the two half-plates. In other words, the general plane ( P1 ) of the tubes 102 runs parallel and lies between the half-plates of the particular tube 102 . In other words, the general plane (P1) may pass through the middle part of the tube 102, so that the conduit for the first fluid is divided into two equal halves in its two parts.

As shown in Figure 3, the tube 102 may also include a coupling edge 104 for coupling the two half-plates. As mentioned above, the joint edge 104 may define a tube 104 formed from two plates that are assembled to each other by their respective facing faces, and the joint edge 104 may define a tube 104 for the second fluid (i.e., the tube 102). The conduit for the circulation of the heat transfer fluid inside. The coupling edge 104 may comprise at least one fusible portion 202 for assembling the coupling edge 104 with at least one wall of the heat exchanger 100 , in particular the third wall 130 of the housing 150 . Additionally, tube 102 may include a fluid inlet 106 and a fluid outlet 108 , as shown in FIG. 3 . Each of fluid inlet 106 and fluid outlet 108 may include a collar portion configured to provide a fluid-tight connection between tube 102 and manifold 140 of heat exchanger 100 .

Therefore, in a preferred embodiment of the invention, during the operating mode of the heat exchanger 100, one end of the tube 102 is fixed to the housing 150, while the other end should be a free end, allowing expansion of the tube 102 within the housing 150 or shrink.

FIG. 4 shows in detail a portion of the same tube 102 as shown in FIG. 3 . In particular, FIG. 4 shows one of the corner regions of the tube 102 having a fusible portion 202 . The fusible portion 202 is aligned parallel with respect to the general plane “ P1 ” of the tube 102 . The fusible portion 202 includes a base portion 204 located near the joining edge 104 and a tip portion 206 located/defined near a wall of the heat exchanger 100 , in particular the third wall 130 . In one embodiment, the tip portion 206 of the fusible portion 202 is in contact with the third wall 130 . In another embodiment, the tip portion 206 of the fusible portion 202 may be formed with a gap defined between the tip portion 206 and the third wall 130 . The tip portion 206 is adapted to be completely separated from the third wall 130 of the heat exchanger 100 by a difference in expansion and contraction between the tube 102 and the third wall 130 of the heat exchanger 100 .

5 and 6 show top and front views of the fusible portion 202 of FIG. 3 formed on the coupling edge 104 of the tube 102 . As shown in FIG. 5 , the tip portion 206 is in contact with the third wall 130 of the housing 150 . When the tube 102 expands or contracts due to thermal cycles, the fusible portion 202 can be broken or completely separated from the third wall 130, especially the tip portion 206 in contact with the third wall 130 can be broken, thereby preventing the tube 102 from contacting the third wall. 120 and prevent damage to the tube 102. The tube 102 also comprises at least one notch 208 on a corner region of the tube 102 , in particular the notch 208 is located between the joining edge 104 of the tube 102 and the base portion 204 of the fusible part 202 . In this embodiment, the tip portion 206 of the fusible portion 202 is narrower than the base portion 204 of the fusible portion 202 to facilitate separation of the tube 102 from the third wall 130 . The fusible portion 202 is formed at the corner of the coupling edge 104 of the tube 102 . Furthermore, the tip portion 206 of the fusible portion 202 extends beyond the coupling edge 104 of the tube 104 so that the tube 102 can separate from the wall of the housing 150 . Since the tip portion 206 of the fusible portion 202 extends beyond the coupling edge 104 of the tube 102, the fusible portion 202, and especially the tip portion 206, can break when the tube 102 undergoes differential expansion or contraction due to various thermal cycles.

As shown in FIG. 5 , the fusible portion 202 is trapezoidal in shape, wherein the tip portion 206 of the fusible portion 202 is narrower than the base portion 204 . Furthermore, the width of the tip portion 206 is smaller than the width of the base portion 204 such that the tip portion 206 can be easily separated from the third wall 130 by a difference in expansion or contraction between the tube 102 and the housing 150 . Furthermore, the fusible portion 202 includes a beveled edge 210 connecting the tip portion 206 and the base portion 204 of the fusible portion 202 . In one example, the tip portion 206 of the fusible portion 202 is brazed to the housing 150 , in particular to the third wall 130 . In another example, the tip portion 206 is just in contact with the housing 150 , in particular the third wall 130 . In another embodiment, the fusible portion 202 is triangular in shape.

As noted above, tip portion 206 may be configured to be separated from fusible portion 202 by a difference in expansion or contraction between tube 102 and at least one wall (eg, third wall 130 ) in which tip portion 206 will be assembled. at least one wall. During the first thermal cycle, the stress exerted between the tube 102 and the housing 150 allows the notch 208 to separate the tip portion 206 from the fusible portion 202 so that the tip portion 206 can break. Thus, with the tip portion 206 brazed together with the housing 150 , the base portion 204 of the fusible portion 292 is integral with the tube 102 , while the tip portion 206 is integral with the housing 150 , in particular with the third wall 130 into one.

Preferably, the thickness of the fusible portion 202 may be half the thickness of the tube 102 , wherein the thickness is measured in a direction perpendicular to the general plane ( P1 ) of the tube 102 . In other words, each fusible portion 202 protruding from one corner region of the tube 102 has the same thickness as the half-plate of the tube 102 from which the fusible portion 202 protrudes. Alternatively, the fusible portion 202 protruding from one corner region of the tube 102 is thicker than the half-plate of the tube 102 from which the fusible portion 202 protrudes. Alternatively, the fusible portion 202 protruding from one corner region of the tube 102 is thinner than the half-plate of the tube 102 from which the fusible portion 202 protrudes.

Since the notch 208 is provided between the coupling edge 104 of the tube 102 and the base portion 204 of the fusible portion 202, the tip portion 206 can be easily connected to the fusible portion 202 when there is differential expansion and contraction between the tube 102 and the housing 150. Section 202 is separated. In other words, the notches 208 allow the tip portion 206 to be separated from the base portion 204 in such a way that the tubes 102 do not collide with the housing 150 or the contact between these elements is very gentle during the operating mode of the heat exchanger 100 . This allows to significantly increase the thermal resistance of the entire heat exchanger 100 . To achieve a similar effect, a person skilled in the art can increase the dimensions of the housing 150, for example in a direction parallel to the general plane (P1) of the tube 102, so that the tube can expand and contract freely, however this will create several problems, such as Increase the packaging, reduce the thermal efficiency of the heat exchanger, etc.

In any case, the invention cannot and should not be limited to the embodiments specifically described herein, as other embodiments are possible. The invention shall extend to any equivalent means and to any technically operative combination of means.

Claims (13)

1. A tube (102) for a heat exchanger (100), comprising at least one fusible portion (202) formed on at least one joint edge (104) of said tube (102), said fusible part (202) for assembling with at least one wall (130) of said heat exchanger (100), characterized in that, The fusible portion (202) is aligned parallel with respect to the general plane (P1) of the tube (102), wherein the fusible portion (202) comprises a base portion near the coupling edge (104) (204) and a tip portion (206) located near the wall (130) of the heat exchanger (100), wherein the tip portion (206) of the fusible portion (202) is adapted to pass through the tube (102 ) and the difference in expansion and contraction between the wall (130) and completely separated from the wall (130). 2. The tube (102) according to claim 1, further comprising at least one notch (208) on a corner region of the tube (102), in particular said notch (208) is located between said coupling edge (104) and a base portion (204) of said fusible portion (202). 3. The tube (102) according to any one of the preceding claims, wherein the tip portion (206) of the fusible portion (202) extends beyond the coupling edge (104) of the tube (102). 4. The tube (102) according to any one of the preceding claims, wherein the fusible portion (202) is formed at a corner of a coupling edge (104) of the tube (102). 5. The tube (102) according to any one of the preceding claims, wherein the tip portion (206) of the fusible portion (202) is narrower than the base portion (204) to facilitate The tube (102) is separated from the wall (130). 6. The tube (102) according to any one of the preceding claims, wherein the joining edge (104) is formed to delimit the tube (102) formed by two plates with their The respective opposing faces are assembled to each other. 7. The tube (102) according to any one of the preceding claims, wherein the coupling edge (104) is adapted to delimit a duct for the circulation of a heat transfer fluid inside the tube (102) . 8. The tube (102) according to any one of the preceding claims, wherein the fusible portion (202) is trapezoidal in shape, wherein the tip portion (206) has a smaller width than the base portion (204) ) width. 9. The tube (102) of claim 8, said fusible portion (202) further comprising a beveled edge (210) connecting said tip portion (206) with said base portion (204). 10. The tube (102) according to any one of claims 1 to 7, wherein the fusible portion (202) is triangular in shape. 11. The tube (102) according to any one of the preceding claims, wherein the thickness of the fusible portion (202) is half the thickness of the tube (102), wherein the thickness is in the vertical Measured in the direction of the general plane (P1) of said pipe (102). 12. The tube (102) according to any one of the preceding claims, wherein the fusible portion (202) is thicker than half the thickness of the tube (102), wherein the thickness is in vertical Measured in the direction of the general plane (P1) of said pipe (102). 13. The tube (102) according to any one of the preceding claims, wherein the fusible portion (202) is thinner than half the thickness of the tube (102), wherein the thickness is in the vertical Measured in the direction of the general plane (P1) of said pipe (102).