JP2018009731A - Core structure of heat exchanger - Google Patents

Abstract

[Problem] To provide a core structure for a heat exchanger in which the durability of the fin ends and the durability of the flat tube ends are interrelated. [Solution] In the core structure of a heat exchanger 1 formed by alternately stacking a plurality of flat tubes 3 through which liquid flows and a plurality of fins 4 around which cooling air flows, both ends 4a of each fin 4 in the core 2 on the side through which the cooling air flows are folded, the upstream end 3a of the flat tube 3 at the upstream end of the air flow in the core 2 and the downstream end 3a of the flat tube 3 at the downstream end of the air flow are overlapped, the plate thickness T1 of the fins 4 is formed to be 0.08 mm to 0.13 mm, and the plate thickness T2 of the flat tubes 3 is formed to be 0.25 mm to 0.35 mm. [Selected Figure] Figure 2

Description

  The present invention relates to a core structure of a heat exchanger mounted on an automobile or the like, and more particularly to a core structure in which the durability of fin ends and the durability of flat tube ends that are reduced in thickness have a mutual relationship. .

  In general, a core portion in a heat exchanger such as a radiator for engine cooling water includes a flat tube made of an aluminum material or a copper material and a corrugated fin. Usually, the core part is alternately laminated with a plurality of flat tubes through which liquid flows, and fins through which cooling air circulates, and the cooling air is introduced from one end of the laminate disposed in the core part. It is discharged from the other end.

  In recent years, there has been a demand for reduction in the thickness of core material, particularly fins and flat tubes, for light weight and cost reduction. However, as the plate thickness of these members is reduced, the physical durability is also reduced accordingly. For example, in a heat exchanger such as an automobile radiator, external air is sucked from the direction of travel of the automobile as cooling air, but solid matter such as fine stones and dust is mixed in such external air. There are also many. When external air containing fine solids is introduced into the heat exchanger, it repeatedly collides with the fins and flat tubes that constitute the core part, particularly the fins and flat tubes arranged on the cooling air introduction side. The end portion having a reduced thickness is particularly susceptible to deformation and damage.

  In order to solve such problems, conventionally, methods have been proposed in which the end portions of fins and flat tubes positioned on the cooling air introduction side of the core portion are physically reinforced to increase the durability of these end portions. For example, in Patent Document 1 and Patent Document 2, the flat tube is reinforced by folding the end portion of the flat tube into a double layer. In Patent Document 3, the tube is reinforced by folding the end portion of the fin into a double. Further, in Patent Document 4, the ends of the flat tube are folded and doubled to reinforce, and the ends of the fins are doubled and doubled to reinforce both.

Japanese Patent Laid-Open No. 11-183073 WO 03/052337 A1 publication Japanese Patent No. 446750 Japanese Utility Model Publication No. 56-124781

  The life time of the heat exchanger, that is, the time when the replacement is required due to the performance deterioration or damage of the end or the like is the time when any one of the performance deterioration of the fin and the flat tube falls below a predetermined standard. Usually, the time when it is judged that the performance has fallen below the standard is, for example, in the case of fins, when the deterioration of the heat radiation performance due to the buckling of the fin end due to solid collision etc. becomes about 90% of the specified value, The case is when a defect such as a liquid leakage phenomenon due to a solid collision occurs.

  When only one of the fins or flat tubes that reinforce the end in the longitudinal direction and improve the durability against solid collision and friction is used for the core, the durability on the reinforced member side is improved. However, the life of the core part can be avoided, but the possibility that the solid material that first collided with the reinforced member will strongly bounce and collide with the unreinforced member side will increase. There is also a possibility that the lifespan is shortened and the heat exchanger is replaced earlier as a result.

  On the other hand, when both the fins and the ends of the flat tubes are reinforced to improve durability and these members are used in combination, the above-described problem that one of the lifespans of the fins and the like is lowered is avoided. However, the structure of the fin and the flat tube are different from each other, and the reinforcing characteristics of the members themselves are also different from each other, so that a difference in life is likely to occur between them. Therefore, it is necessary to replace the heat exchanger when either the fin or the flat tube reaches the end of its life, and members that have not yet reached the end of their life are also discarded. As a result, there is a problem that the waste of members increases and the cost is likely to increase.

  An object of the present invention is to solve such a problem, and to provide a core structure of a heat exchanger that can improve the life of the heat exchanger and avoid unnecessary cost increases.

That is, the first invention of the present invention is a heat exchanger (1) formed by alternately laminating a plurality of flat tubes (3) through which liquid flows and a plurality of fins (4) through which cooling air flows. ) Core part structure,
Each fin (4) of the core part (2) is bent at both ends (4a) on the cooling air flow side, and upstream of the flat tube (3) at the upstream end of the air flow of the core part (2). And the downstream end (3a) of the flat tube (3) at the downstream end of the air flow are overlapped, and the plate thickness T1 of the fin (4) is formed to be 0.08 mm to 0.13 mm. The thickness T2 of the flat tube (3) is 0.25 mm to 0.35 mm (Claim 1).

According to a second aspect of the present invention, in the first aspect,
The fin (4) has a plate thickness T1 = 0.08 mm to 0.095 mm, and the flat tube (3) has a plate thickness T2 = 0.25 mm to 0.28 mm. 2).

According to a third aspect of the present invention, in the first aspect,
The fin (4) has a plate thickness T1 of 0.095 mm to 0.115 mm, and the flat tube (3) has a plate thickness T2 of 0.28 mm to 0.32 mm. 3).

According to a fourth aspect of the present invention, in the first aspect,
The fin (4) is formed to have a plate thickness T1 = 0.115 mm to 0.13 mm, and the flat tube (3) is formed to have a plate thickness T2 of 0.32 mm to 0.35 mm. 4).

  In the present invention, as described above, when the fins with the end portions overlapped and the flat tube with the end portions bent are used in combination, the range of the plate thickness T1 of the fins and the plate thickness T2 of the flat tube, and the plate thicknesses. If the ratio is within the above range, the lifetimes of the two substantially overlap each other, so that the exchange time of the heat exchanger is optimal. Therefore, the problem of waste and cost increase due to disposal of members that have not yet reached the end of their service life can be solved.

The fragmentary perspective view which shows 1st Embodiment of the core part structure of this invention. The top view of the core part structure shown in FIG. The elements on larger scale of the core part structure shown in FIG. Explanatory drawing of the manufacturing process of the fin in the core part structure shown in FIG. The partial top view which shows the example of a structure different from the flat tube shown in FIG. The partial top view which shows the example of a structure further different from the flat tube shown in FIG. The figure which shows the example of the fin structure different from the fin structure shown in FIG. The figure which shows the example of the fin structure different from the fin structure shown in FIG. The figure which shows the example of the fin structure different from the fin structure shown in FIG. The figure which shows the example of the fin structure different from the fin structure shown in FIG. The figure which shows the example of the fin structure different from the fin structure shown in FIG. The figure which shows the lifetime measurement value of the fin obtained by experiment. The figure which shows the lifetime measurement value of the flat tube obtained by experiment.

  Next, an embodiment of the core structure in the heat exchanger of the present invention will be described with reference to the drawings. FIG. 1 is a partial perspective view showing a first embodiment of the core structure of the present invention. The core part 2 constituting the heat exchanger 1 is formed by alternately laminating flat tubes 3 through which liquid flows and fins 4 through which cooling air flows. In addition, the fin 4 of this embodiment is a rectangular wave longitudinal wave fin. The materials of the flat tubes 3 and the fins 4 constituting the core portion 2 are both aluminum alloys that are generally used in heat exchangers.

  2A is a partially enlarged plan view of the core portion 2 shown in FIG. 1, and FIG. 2B is an enlarged view of a portion B in FIG. 2A. 3A is a partially enlarged perspective view of the core portion 2 shown in FIG. 1, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A. 2A is also a view taken along the line II-II in FIG. 3B.

  Next, a detailed description will be given mainly based on FIG. 2A, cooling air is introduced into the core portion 2 from the direction of arrow H, that is, from the left side of FIG. 2A, and passes through the circulation space of the fins 4 constituting the laminated body. It discharges from the edge part (not shown) of the laminated body. In the present invention, the end 3a of each flat tube 3 and the end 4a of each fin 4 arranged on the cooling air introduction side are respectively end portions 3a, 4a, That is, it means each end 3a, 4a in the position where the introduced cooling air is first in contact with the laminate.

  As shown in FIG. 2 (B), the end portions 3a of the flat tubes 3 arranged on the cooling air introduction side overlap each other with a pair of side wall ends extending to the end portions in parallel to each other (a pair of opposing pairs). By folding the side wall end portions inward and in surface contact with each other, the thickness of the end portion 3a where the cooling air collides is increased and reinforced.

  In this embodiment, as shown in FIG. 2B, the end portion 3a of the flat tube 3 has a three-layer structure by overlapping the end portions of the side walls, but can also have a general two-layer structure. . In addition, the durability of the part improves more by making the superposition | stacking of the edge part 3a into three layers.

  On the other hand, as shown in FIG. 2 (B), the end 4a of each fin 4 arranged on the cooling air introduction side folds the plate of the end 4a (the end is folded back and overlapped). As a result, the plate thickness of the end 4a where the cooling air collides increases and is reinforced. In this example, edge folds are formed at both ends 4a of each fin 4 in the air flow direction. This is because the downstream side edge of each fin 4 may be damaged by sand dust due to the air flow rising by the blower fan or the like.

  FIG. 4 is a diagram for explaining the processing steps of the fins constituting the core structure shown in FIG. 1, and FIG. 4 (A) is a partial perspective view showing the plate material 5 for the fins 4, and FIG. FIG. 5 is a partial perspective view showing a state in which the fin 4 is completed by processing the plate material 5. In this embodiment, for example, in order to process the flat plate material 5 made of an aluminum alloy into the fins 4, first, as shown in FIG. 4A, the end portions 4 a of the fins 4 are bent to form the edge folded portions 5 a. Then, it is processed into a corrugated fin shape as shown in FIG. By this method, it is possible to manufacture the fin 4 having the end portions 4a that are bent at both sides.

  5 and 6 are partial plan views showing examples of a flat tube having an internal structure different from that of the flat tube 3 shown in FIG. In the example of FIG. 5, the inside of the flat tube 3 is reinforced at a predetermined interval in the axial direction. Specifically, a plurality of reinforcing bridges 3b are formed by repeatedly bending a pair of plate materials forming the elongated side wall of the flat tube 3 inward at a plurality of locations in the middle. Further, a reinforcing rib 3c protruding in an arc shape is formed in the middle of each reinforcing bridge 3b. These reinforcing bridges 3b and reinforcing ribs 3c provide reinforcement other than the ends of the flat tube 3.

  On the other hand, in the example of FIG. 6, the reinforcing bridge 3b and the reinforcing rib 3c as shown in FIG. 5 are not provided, and a structure having a relatively short structure such as the flat tube 3 shown in FIG. And has a simple shape with a relatively long length. Such a form has an advantage that the structure is simple and the manufacturing cost is low.

  7 to 11 are diagrams showing examples of fin structures different from the fin structure shown in FIG. These fins including the fins of FIG. 1 are often used mainly for heat exchangers for civil engineering machinery used in places where there is dust, but also for mobile vehicles such as automobiles that run on dusty roads. Preferably used. In these drawings, the same parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and redundant description is omitted.

  7A is a partial perspective view of the flat tube 3 and the fins 4, and FIG. 7B is a cross-sectional view taken along line BB of FIG. 7A. 7 is a sine wave longitudinal wave fin, the folded shape is a sine wave, and the fin surface has a longitudinal wave structure.

  8A is a partial perspective view of the flat tube 3 and the fins 4, and FIG. 8B is a cross-sectional view taken along line BB in FIG. 8A. The fin 4 shown in FIG. 8 is a rectangular wave inclined wave fin, the folded shape is a rectangular wave, and the fin surface has an inclined wave structure. The fin 4 shown in FIG. 9 is a modification of the fin 4 shown in FIG. 8 and is called a sine wave inclined wave fin having a sine wave folded shape and an inclined wave structure on the fin surface.

  10A is a partial perspective view of the flat tube 3 and the fins 4, and FIG. 10B is a cross-sectional view taken along the line BB of FIG. 10A. The fin 4 shown in FIG. 10 is a rectangular wave flat surface fin, the folded shape is a rectangular wave, and the fin surface is a flat surface. The fin 4 in FIG. 11 is a modification of the fin 4 in FIG. 10 and is called a sine wave flat surface fin in which the folded shape is a sine wave and the fin surface is a flat surface.

  Each of the fins 4 in FIGS. 7 to 11 having the above-described various structures can be used for the core structure of the present invention by bending the end thereof in the same manner as the fins 4 in FIG.

  12 and 13 show the correlation between the lifespan of the fin 4 and the flat tube 3 constituting the core structure of the present invention, that is, the plate thickness T1 of the fin 4 itself that is bent at the end 4a, and the end 3a. It is the result of experimenting the interrelationship of the lifetime when the plate thickness T2 of the overlapped flat tube 3 itself is changed. Note that the fins 4 and the flat tubes 3 used in these experiments are both aluminum alloys generally used in heat exchangers, and the shapes of the main bodies thereof are the same as those shown in FIGS. However, the end 3a of the flat tube 3 has a structure in which two layers are stacked (for example, a structure like the end 3a of the flat tube 3 shown in FIG. 5).

  FIG. 12 is a diagram showing the relationship between the change in the plate thickness of the fin 4 and the lifetime. The plate thickness of the fin 4 itself is three types of 0.08 mm, 0.10 mm, and 0.13 mm, and the end portions of the fin 4 are 0.16 mm, 0.20 mm, and 0.26 mm by bending the edges. The life of the fins 4, that is, the time when replacement is necessary is the time when the heat dissipation performance is reduced from the specified value to 90%. The experiment was conducted by the sandblast method, which can obtain results in a short time. For reference, a life test of the fin 4 having a plate thickness of 0.10 mm and not bending the end 4a was also performed.

  The material of the sand used for sandblasting (solid particles that collide with the object by jetting) is polyplus PP8-16, and the particle size is in the range of 2.36 mm to 1.18 mm. The spray angle of the sand with respect to the axial direction of the end 4a of the fin 4 is 45 degrees, and the spray distance is 372 mm. In FIG. 12, the vertical axis represents the heat dissipation performance (%), and the horizontal axis represents the sandblast durability time (sandblasting time) (Hr).

  FIG. 13 is a diagram showing the relationship between the change in the thickness of the flat tube 3 and the life. The flat tube 3 has three thicknesses of 0.25 mm, 0.3 mm, and 0.35 mm, and the respective end portions are overlapped to be 0.5 mm, 0.6 mm, and 0.7 mm. The life of the flat tube 3, that is, the time when replacement is necessary is a time when liquid leakage occurs due to deformation or breakage of the end 3 a of the flat tube 3. The liquid leakage experiment is performed by a hydraulic method which is usually performed. For reference, a life test of the flat tube 3 having a plate thickness of 0.3 mm and without overlapping the end portions 3a was also performed.

  The material and particle size of the sand used for sandblasting in FIG. 13 are the same as in the experiment of FIG. The sand injection angle with respect to the axial direction of the end 3a of the flat tube 3 is 0 degree (same as the axial direction), and the injection distance is 300 mm. In FIG. 13, the vertical axis represents the plate thickness (mm) of the tube fitting portion (or overlapping portion), and the horizontal axis represents the leakage time (sandblasting time) (Hr) due to sandblasting.

  12 and 13, if the plate thickness T1 of the fin 4 is in the range of 0.08 mm to 0.13 mm and the plate thickness T2 of the flat tube 3 is in the range of 0.25 mm to 0.35 mm, It became clear that the lifetimes of the flat tubes 3 overlap each other.

  For example, when the plate thickness T1 of the fin 4 is 0.08 mm, the sandblast durability time is about 2 hours, and when the flat tube 3 has T2 of 0.5 mm, the sandblast leakage time is about 2 hours. Accordingly, the lifetimes of the two substantially overlap each other, and a combination of these plate thicknesses T1 and T2 is a desirable example.

  Further, when the fin plate thickness T1 is 0.10 mm, the sandblast durability time is about 2.5 hours, and when the flat tube plate thickness T2 is 0.6 mm, the sandblast leakage time is about 2.5 hours. . Therefore, the lifetimes of the two overlap each other, and a combination of these plate thicknesses T1 and T2 is also a desirable example.

  Further, when the plate thickness T1 of the fin is 0.13 mm, the sandblast durability time is about 3 hours, and when the plate thickness T2 of the flat tube is 0.7 mm, the leakage time by sandblasting is about 3 hours. Accordingly, the lifetimes of the two are overlapped with each other, and a combination of these plate thicknesses T1 and T2 is also a desirable example.

  The core part structure of the present invention can be used as a core part structure of a heat exchanger mounted on an automobile or the like.

DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Core part 3 Flat tube 3a End part 3b Reinforcement bridge 3c Reinforcement rib 4 Fin 4a End part 5 Plate material 5a Edge folding part T1 Plate thickness T2 Plate thickness

Claims (4)

In the core part structure of the heat exchanger (1) formed by alternately laminating a plurality of flat tubes (3) through which liquid circulates and a plurality of fins (4) through which cooling air circulates,
Each fin (4) of the core part (2) is bent at both ends (4a) on the cooling air flow side, and upstream of the flat tube (3) at the upstream end of the air flow of the core part (2). And the downstream end (3a) of the flat tube (3) at the downstream end of the air flow are overlapped, and the plate thickness T1 of the fin (4) is formed to be 0.08 mm to 0.13 mm. The core part structure of the heat exchanger is characterized in that the flat tube (3) has a thickness T2 of 0.25 mm to 0.35 mm.   The plate thickness T1 of the fin (4) is formed to 0.08 mm to 0.095 mm, and the plate thickness T2 of the flat tube (3) is formed to 0.25 mm to 0.28 mm. The core part structure of the heat exchanger as described in 2.   The plate thickness T1 of the fin (4) is formed to 0.095 mm to 0.115 mm, and the plate thickness T2 of the flat tube (3) is formed to 0.28 mm to 0.32 mm. The core part structure of the heat exchanger as described in 2.   The plate thickness T1 of the fin (4) is formed to be 0.115 mm to 0.13 mm, and the plate thickness T2 of the flat tube (3) is formed to be 0.32 mm to 0.35 mm. The core part structure of the heat exchanger as described in 2.

Images