JPS63197890A - Layered type heat exchanger - Google Patents

Abstract

PURPOSE:To simplify management over a forming of rib by a method wherein a group of ribs is comprised of a group of reinforcing ribs in which two pipe plates are adhered and abutted to each other and brazed and a group of heat exchanging ribs having less projecting amount than that of a group of reinforcing ribs are combined to each other. CONSTITUTION:A group of reinforcing ribs 2 having a shape mainly suitable for reinforcing operation and a group of heat exchanging ribs 3 having a shape to improve a maze passage forming effect without increasing a height of ribs and restricting it as much as possible and without increasing the flowing resistance of fluid are applied to make a group of complex type rib. Due to this fact, it is possible to improve heat exchanging performance while sufficiently restricting a pressure loss of the heat exchanging fluid to as little as possible and further management over a manufacturing step is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an assembly structure of a laminated heat exchanger such as an evaporator used in an air conditioner for an automobile.

[Prior Art] The general structure of the above-mentioned evaporator and its assembly method are as follows: The evaporator is formed by pasting together two press-formed "middle skin" tube plates, and is equipped with an inlet and outlet for refrigerant. The main body part is temporarily assembled by overlapping the flat tubes that function as replacement units and the corrugated fins for increasing the heat transfer area alternately so that the inlets and outlets of adjacent flat tubes communicate with each other. After the structure is fixed with a jig, it is heated in a brazing furnace that is maintained at a temperature higher than the melting temperature of the brazing filler metal that has been clad on the surface of the aluminum plate that is the constituent material of the evaporator.
At the same time, a method was adopted in which each component was joined by brazing.

As shown in FIG. 12, which is a plan view, and FIG. 13, which is a sectional view taken along line (C)-(C) in FIG. Since a large number of rib groups 1H protrude diagonally, when two tube plates are pasted together, the rib group of each tube plate 1 will be formed as shown in Fig. 12. By intersecting in an X-shape and brazing all the intersections, the pressure resistance of the flat tube is sufficiently increased, and the lip 1H group allows the refrigerant inlet tank part 1A and outlet tank part 1B to be connected to each other by brazing. By forming a labyrinth in the refrigerant flow path C connecting the two, it is possible to greatly improve heat exchange performance.

[Problems to be Solved by the Invention] The conventional evaporator described above has the following important problems that should be improved.

b) The pressure loss of the refrigerant is quite large because the shape of the maze is not appropriate.

(b) The pressure resistance of the flat tube against refrigerant pressure is mainly controlled by the brazing strength at the point where the opposing ribs collide. It is necessary to correctly match the thickness of 172. However, since the ribs are long and thin, maintaining a constant height over their entire length poses great technical difficulties.

(c) Since the contact between the opposing ribs is almost point contact, this is also one of the reasons why the strength of the brazed joint at the contact point tends to be insufficient.

SUMMARY OF THE INVENTION An object of the present invention is to provide a laminated heat exchanger having a structure that can substantially eliminate the above-mentioned problems and also simplify process control for forming ribs on tube plates.

[Means for Solving the Problems] In order to achieve the above-mentioned object distantly, the laminated heat exchanger according to the present invention is made up of a bonded body of two tube plates having a middle skin shape, and has a fluid inlet and outlet. A fluid flow path is formed between the inlet and outlet tank parts provided as ports, and a plurality of flat tubes each having a large number of opposing rib groups protruding inwardly on each tube plate are used to form a heat exchange gap. In a laminated heat exchanger that is created by laminating and combining the two pipe plates in an interposed state, the rib group is a reinforcing rib group that comes into contact with each other and is brazed together when the two pipe plates are bonded together. A combination structure is adopted in which this reinforcing rib group is combined with a heat exchange rib group whose protrusion is smaller than that of the reinforcing rib group.

[Operations and Effects of the Invention] In the flat tubes constituting the conventional laminated heat exchanger, the role of reinforcing the tubes and forming the labyrinth was carried out by a group of ribs having only one type of small jetty shape, but the present invention The laminated heat exchanger mainly consists of a group of reinforcing ribs with a shape suitable for reinforcement, and by keeping the rib height as low as possible without making it higher than necessary, it is possible to avoid increasing fluid flow resistance. By providing a so-called composite rib group, which is a combination with a heat exchange rib group with a shape that enhances the labyrinth formation effect, heat exchange performance is improved while keeping the pressure loss of the heat exchange fluid sufficiently low. Moreover, the manufacturing process management can be simplified.

[Example] The configuration of the present invention will be specifically described below based on an example shown in the drawings.

Figures 1 to 5 show an evaporator incorporated in an automobile air conditioner as an embodiment of the present invention, in which Figure 1 is a plan view showing the inner surface of the tube plate, and Figure 2 and Figure 3 are a sectional view taken along lines (a) and (a), and (b) and (b) in Figure 1, respectively, and Figure 4 is a partial plan view of the tube plate showing the arrangement of the beam group. FIG. 5 is a front view of the device.

As shown in FIG. 5, the general structure of the device is such that the main body portion is constructed by alternately stacking and combining a plurality of flat tubes A and fins 4 for improving heat exchange efficiency.

The low boiling point refrigerant Murotan 9 parts 1A provided at the upper end of each flat tube are communicated with each other to form a refrigerant distribution path E to each flat tube. Also, in this figure, the inlet tank section 1A
The refrigerant tank sections located behind the refrigerant tank are communicated with each other to form a refrigerant collection path. A refrigerant rotor 1-111 is connected to one end of the refrigerant distribution path, and a refrigerant outlet tube 12 is connected to one end of the refrigerant collection path. 13 and 14
1 is a joint for connecting each tube, and 15 and 16 are tube joints attached to the ends of each tube. Reference numeral 11 denotes side plates that protect both end surfaces of the evaporator body. In order to form a parallel heat exchange gap B by interposing the fins 4 between adjacent flat tubes A, the lower end of each flat tube A must have a thickness equal to the thickness of the refrigerant inlet (outlet) tank portion 1A. /
A spacer 1G with a height of 2 is provided protrudingly.

The two tube plates 1 constituting the flat tube A have the same shape, and in this embodiment, the thickness is 0.3 to 0, and the material of the button 1 is A 4004 on both surfaces of the aluminum plate made of A 3003. A material plate clad with a brazing filler metal such as the following is pressed and given the shape shown in FIGS. 1 to 3.

The tube plate 1 having a vertically elongated square plate shape has a peripheral flange portion 1E for brazing and bonding, and a central partition wall portion 1F for forming a U-shaped refrigerant flow path C in the flat tube A. The flat tube is bulged outward to a thickness similar to that of the middle part. At the upper end, there is an inlet tank part 1A and an outlet tank part 1 that serve as refrigerant inlet and outlet ports.
B is installed protrudingly, and each tank part has a cold! S outlet 1C or 1D is bored. As shown in FIG. 1, the refrigerant flow path C formed between the inlet tank part 1A and the outlet tank part 1B has a flat tube A formed with a small cylindrical projection with a flat top surface. Two groups of reinforcing ribs are protruded in a staggered arrangement using a punching method. The reinforcing rib 20 has three groups of heat exchange ribs in the shape of small bulges, which form a body with the rib 2, in order to form a labyrinth in the refrigerant flow path C and improve heat exchange performance. Projected radially.

As seen in FIG. 3, which shows a partial cross section of the flat tube A, the protrusion height hl of the reinforcing rib 2 is the thickness of the inside of the flat tube A, or in other words, the thickness of the cold W flow path C. It is correctly matched to 1/2 of Sato 1. Further, the protruding height h2 of the heat exchange rib 3 is set to be 172 or less of the dimension H, and in this embodiment, is set to approximately 1/2 of the height hl.

The height hl of the reinforcing rib 2 must be accurate in order to ensure a reliable brazing connection, but since the surface area of its top surface a is quite small, it is easy to ensure the precision of its machining dimensions. As shown in FIG. 4, which shows the planar arrangement of the rib group, the four heat exchange ribs 3 surrounding the reinforcing rib 2 are as follows:
In this embodiment, the angle θ of the radial interval is set to 90' as in -.
It is maintained at

Further, assuming that the mutual spacing between the reinforcing ribs 2 is set to 10 mm, the diameter of the top surface a of the reinforcing ribs 2 should ensure brazing joint strength to provide the required pressure resistance to the flat tube type. Therefore, it is appropriate to select 2 to 3 glIIIl. In this case, the length W of the heat exchange rib 3 is 5I
If it is set to IIm or more, the required heat exchange performance can be obtained.

"Rugate Fin 4 is a thin aluminum plate with approx.
It is made by bending it into a wavy shape with a pitch of 101. Moreover, the side plate 17 has a thickness of 0.6 to 1
．． The material is an aluminum plate such as A 3003, and the inner surface thereof is clad with a brazing material such as A 4004.

The outline of the method for assembling an evaporator consisting of such a combination of main components is as follows: First, the side plate 17 is installed on an assembly stand, then the corrugated fins 4, and then the middle Two pipe plates 1 superimposed on the translation, and again full gate fin 4,
Next, the two tube plates 1 are repeatedly stacked in this order, and finally the side plates 17 are stacked on top of each other, thereby completing the temporary assembly of the main body of the evaporator. The temporary assembly is made by pressing and fixing the laminated structure using a jig, placing it in a brazing furnace heated above the melting temperature of the brazing material, melting the brazing material, and then allowing it to cool. The joint assembly is completed in one go.

The refrigerant inlet/outlet levers 11 and 12 and their connecting joints 13 and 14 are either brazed to the main body portion at the same time in the above-mentioned brazing process, or are attached in a separate process.

Next, the operation of the above-mentioned evaporator will be explained with reference to the accompanying drawings. The high-temperature, high-pressure gas phase refrigerant compressed by the compressor of the air conditioner (not shown) is liquefied by condensation, and the pressure is reduced while passing through the decompression device, resulting in a gas-liquid two-phase state. , flows into the leftmost flat tube A constituting the evaporator.

As depicted in FIG. 1, the refrigerant that has flowed into the flat tube from the communication hole 1C provided in the refrigerant inlet tank portion 1A is blocked by the presence of the partition wall 1F and flows down inside the tube.
After passing through the missing part of the partition wall, it turns upward and follows a U-shaped flow path C toward the communication hole 1D of the outlet tank 1B.

Both sides of each flat tube A are in contact with a heat exchange gap B, and this gap has air conditioning equipment feed 1! Since a relatively small portion of the conditioned air is blown in through I1m (path shown), the low boiling point liquid phase refrigerant absorbs the latent heat of vaporization from the warm air while passing through the flat tube A and returns to the gas phase. The conditioned air is cooled to a desired temperature and then directed to the cold air outlet of the air conditioner.

As already explained with reference to FIG. 3, within the U-shaped refrigerant flow path C, reinforcing ribs 2 having the same thickness as this flow path are scattered, thereby creating a labyrinth-forming effect to some extent. Although the heat exchange capacity of the evaporator is increased by this, a plurality of heat exchange ribs 3 with a height that does not reach 1/2 of the thickness of the refrigerant flow path C are further provided so as to surround the reinforcing ribs 2.
By providing this, the labyrinth formation effect is further increased and the heat exchange capacity is greatly improved.

Moreover, the heat exchange ribs 3 have a height equal to 172 mm, which is the inner thickness of the flat tube A, as shown in FIG. Differently, the inner thickness H of the flat tube A is set to 174 or less. Therefore, the top surfaces of the heat exchange ribs 3 provided on each tube plate 1 forming the flat tube A are not brought into contact with each other, but are at least 172
The above voids remain. For this reason, the three groups of heat exchange ribs maximize the function of improving the heat exchange effect of the evaporator while sufficiently suppressing the negative effects that cause large pressure losses to the refrigerant flow. do.

6 to 8 are views of a second embodiment showing other examples of shapes of heat exchange ribs formed on the tube plate 1 constituting the above-mentioned evaporator.

The difference from the first embodiment is that of the refrigerant flow path C which is divided into two left and right sections with the partition wall 1F as a border, the heat exchange ribs 3B provided in the right section are replaced by the heat exchange ribs 3B provided in the left section. The radial direction thereof is shifted by 45 degrees with respect to the secondary rib 3A.

Therefore, by pasting together two tube plates 1 having such a shape, the heat exchange ribs 3 protruding from each tube plate 1 can be formed as shown in FIG.
A and 3B are different from the first embodiment in that they are shifted by 45 degrees from the positions facing each other. For this reason, not only the labyrinth formation effect is further enhanced, but also the effect of reducing pressure loss by reducing resistance to the coolant flow can be obtained at the same time.

FIG. 8 shows that the thickness of the flow path is reduced by twice the height h2 of the rib 3 in the first embodiment due to the protruding heat exchange ribs 3 provided in the refrigerant flow path. , in the second embodiment, the rib 3
This shows that the flow path thickness h4 becomes thicker and the flow path resistance is further reduced. Any angle other than 45° may be selected as the above-mentioned shift angle, if necessary.

FIG. 9 shows a third embodiment regarding the shape of the heat exchange ribs 3.

The difference from the first embodiment is that a rib-free portion G is interposed between the reinforcing rib 2 and the heat exchange rib 3, and the ribs are provided to protrude independently from each other. By appropriately selecting the width of the gap G where there are no ribs according to the design specifications of each evaporator, the pressure loss of the refrigerant can be kept sufficiently low, while at the same time the labyrinth formation effect can be enhanced to improve heat exchange performance. be able to.

In the above embodiment, the angle θ of the radiation interval between the three groups of heat exchange ribs is set to 90°, but by selecting this angle unevenly rather than uniformly or changing the angle θ, the ribs 3
You may increase or decrease the number of . Furthermore, there is still room for various design changes, such as making the shape of the ribs 3, especially the shape of the top surface, inclined with respect to the flat surface of the tube plate 1.

Further, the shape of the reinforcing rib 2 is not limited to a cylindrical shape, and can be selected from various shapes such as a truncated conical shape, an elliptical cylindrical shape, and a triangular prism shape.

Furthermore, the N relationship between the reinforcing ribs 2 and the heat exchange ribs 3 is as follows:
The arrangement of the embodiment may be further developed to be scattered at completely separate locations.

10 and 11 are partial plan views of tube plates of a fourth embodiment and a fifth embodiment, respectively, which differ from the above embodiments in the configuration of ribs.

In the fourth embodiment shown in FIG. 10, between two groups of reinforcing ribs arranged in a staggered manner, a direction perpendicular to the flow direction of the refrigerant is maintained, and a small jetty-shaped heat exchange rib 3 The groups are scattered at appropriate intervals.

The lengths of the heat exchange ribs 3 are made to vary depending on the location, depending on how they correspond to the gaps between the two groups of reinforcing ribs.

In the fourth embodiment shown in FIG. 11, in the gap between the reinforcing rib groups,
Three groups of small bulge-shaped heat exchange ribs are provided in a diagonal arrangement with respect to the flow direction of the refrigerant.

The structure of the laminated heat exchanger according to the present invention is that, in addition to the evaporator of the type in which the fluid inlet and outlet tank sections are provided only on the ends of the flat tubes shown in the embodiment, the stacked heat exchanger has inlet and outlet tank sections at both ends, respectively. The present invention can be applied to any type of evaporator, and of course is not limited to evaporators, but can be effectively incorporated into various other laminated heat exchangers having the same type of structure.

[Brief explanation of the drawing]

1 to 4 show an evaporator incorporated into an automatic heavy-duty air conditioner as an embodiment of the heat exchanger according to the present invention. Figure 1 is a plan view of the tube plate constituting the flat tube, and Figures 2 and 3 are sectional views taken along lines (A)-(A) in Figure 1 and (
FIG. 4 is a partially enlarged view showing the arrangement of reinforcing ribs and heat exchange ribs protruding from the tube plate, and FIG. 5 is a front view of the evaporator. 6 to 8 are views of a second embodiment showing other embodiments of the structure of the tube plate, in which FIG. 6 is a partial plan view, FIG. 7 is an explanatory diagram of the arrangement of ribs, and FIG. The figure is a partial cross-sectional view of a flat tube. FIG. 9 is an explanatory diagram of the rib arrangement situation as a third embodiment diagram showing still another example of how the ribs are arranged. FIG. 10 and FIG. 11 are partial cross-sectional views of tube plates of a fourth embodiment and a fifth embodiment, respectively, which are characterized by the way the ribs are arranged. FIGS. 12 to 14 show a conventional one-vaporator, each showing a plan view of a flat tube and a cross-sectional view (C)-(C) thereof,
It is a figure explaining the contact state of each rib of the tube plate of a and - set. In the figure 1... Pipe plate 2... Reinforcing rib 3
...Rib for heat exchange 4...Fin A...Flat tube B...Gap for heat exchange C...Fluid channel H...
Fluid channel thickness

Claims (1)

[Scope of Claims] 1) It is made up of a bonded body of two middle skin-like tube plates, and forms a fluid flow path between an inlet and an outlet tank section provided as a fluid inlet/outlet port, and In a laminated heat exchanger made by laminating and combining a plurality of flat tubes, each of which has a large number of opposing rib groups protruding inwardly on each tube plate, with a heat exchange gap in between. , the rib group is a combination of a reinforcing rib group that comes into contact with each other and is brazed together when the two pipe plates are bonded together, and a heat exchange rib group that protrudes smaller than the reinforcing rib group. A laminated heat exchanger characterized by being made of laminated sheets. 2) The reinforcing rib group has a height of 1/2 of the thickness of the fluid, and the heat exchange rib group has a height of 1/4 or less of the thickness of the fluid flow path. A stacked heat exchanger according to claim 1. 3) The reinforcing rib group is a small protrusion with a flat top surface, and the heat exchange rib group is a plurality of small bulge-like bodies arranged radially around the small protrusion. A laminated heat exchanger according to claim 1, characterized in that: 4) The reinforcing rib group is a small protrusion having a flat top surface, and the heat exchange rib group is a plurality of small bulge-like bodies formed between the reinforcing rib group. A stacked heat exchanger according to claim 1.