JP2804585B2 - Stacked heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) A laminated heat exchanger according to the present invention is incorporated in, for example, an air conditioner for automobiles and is used as an evaporator for cooling air. It is intended to reduce the amount of lubricating oil staying in such a heat exchanger.

(Prior Art) An air conditioner incorporates an evaporator that evaporates a refrigerant inside and cools air flowing outside.

Such a heat exchanger incorporated in an air conditioner and used as an evaporator has been conventionally laminated with a plurality of metal plates as described in, for example, JP-A-62-798. A so-called stacked heat exchanger is known.

As shown in FIG. 14, this laminated heat exchanger is configured by laminating a plurality of units 2 and 2 each of which is formed by combining two metal plates 1 and 1 in the middle. I have.

As shown in FIGS. 15 and 16, each metal plate 1, 1 has a flat portion 3 surrounding the entire circumference of each metal plate 1, 1 and a shallow U-shape formed inside the flat portion 3. One recess 4, deep second and third recesses 5 and 6 formed at both ends of the first recess 4, and through holes 7 and 8 formed at the center of the second and third recesses 5 and 6; Is provided. Further, a plurality of protrusions 9 are provided inside the first concave portion 4 so as to disturb the flow of the refrigerant inside the first concave portion 4.

The plurality of units 2 and 2 constituting the stacked heat exchanger include:
The U-shaped portion surrounded by the first concave portion 4 is constituted by two metal plates 1 each having the above-described shape, and abutting the flat portions 3 of the respective metal plates and combining them in the middle. The flat tube portion 12 through which the refrigerant flows, and a portion surrounded by the second and third concave portions 5 and 6 functions as a part of the inlet-side tank or the outlet-side tank.

As shown in FIG. 14, a plurality of the units 2 and 2 as described above are provided.
The outer surfaces of the third concave portions 5 and 6 are laminated by abutting each other,
An inlet pipe 10 is provided in one of a pair of spaces formed by the second and third concave portions 5 and 6, and an outlet pipe 11 is provided in the other space.
Each is connected.

In the state where the plurality of units 2 and 2 are stacked in this manner, the corrugated fins 13 and 13 are sandwiched between the flat tube portions 12 and 12 of the adjacent units 2 and 2 and the adjacent flat tube portions 1 and 2 are sandwiched.
The heat exchange between the air flowing between the flat tubes 2 and 12 and the refrigerant flowing inside the flat tube portions 12 and 12 is preferably performed.

Since the stacked heat exchanger is constructed and manufactured as described above, for example, when used as an evaporator, the inlet pipe 10
When the liquid refrigerant is sent into one of the spaces functioning as the inlet-side tank from the
While flowing through the flat tube portions 12, 12, the heat is exchanged with air flowing between the fins 13, 13 provided outside the flat tube portions 12, 12 to evaporate, and then the outlet side It is sent to the other space functioning as a tank and discharged through the outlet pipe 11.

By the way, in order to facilitate the manufacture of the stacked heat exchanger constructed and operated as described above, it is known that a unit formed by stacking two metal plates and a tank are separated from each other.
No. 27496.

That is, in the case of the conventional structure shown in FIGS. 14 to 16, since the tank is integrally formed at the end of each unit 2, 2, a deep portion is formed at the end of the metal plate 1, 1 constituting each unit 2, 2. Although the second and third concave portions 5 and 6 are formed, the pressing operation for forming the second and third concave portions 5 and 6 needs to be performed simultaneously with the formation of the shallow first concave portion 4. Therefore, a large force is required at the time of the press work, and the equipment for press-forming the metal plate 1 is increased in size, which inevitably increases the equipment cost.

In order to solve such a problem, a laminated heat exchanger having a structure started in the above-mentioned Japanese Patent Application Laid-Open No. 61-27496 is manufactured by a method as disclosed in, for example, Japanese Patent Application No. 63-324669. Things are being considered.

For example, in the case of a laminated heat exchanger manufactured by the method according to the prior invention, as shown in FIGS. 17 to 19, a metal plate 15 having a pair of protruding portions 14a and 14b formed at one edge at intervals.
A U-shaped recess 16 is formed on one side of the
The protrusions 14a and 14b are formed so as to be continued to the edge of the pair. A large number of protrusions 17, 17 are formed inside the concave portion 16,
The flow of the refrigerant flowing inside the return flow path formed by the concave portions 16 is disturbed, and heat exchange between the refrigerant and the metal plate 15 is efficiently performed.

The metal plate 15 having the concave portions 16 and the protrusions 17 and 17 is formed by passing a long metal plate between a pair of rolls to form the concave portions 16 and the protrusions 17 and 17. Since it can be made by cutting an appropriate portion of a long metal plate, a relatively simple manufacturing apparatus can be used.

Then, in the case of a laminated heat exchanger manufactured using such a metal plate 15, the metal plates 15, 15 are formed as a pair, and the concave portions 16, 16 are opposed to each other in a middle state. By overlapping and liquid-tightly joining each other, U-shaped folded flow path
Elements 20 and 20 each having a pair of joints 19a and 19b located at both ends of the flow path 18 and protruding from an edge thereof.

Then, the respective joints 19a, 1 of the plurality of elements 20, 20
9b is inserted into slit-shaped connection holes 23, 23 formed on the side surfaces of the first and second tanks 21, 22, respectively, and the outer peripheral surfaces of the joints 19a, 19b and the connection holes 23, 23 are formed. The inner peripheral edge and the inner peripheral edge are joined by liquid-tight brazing. Each of the tanks 21 and 22 is configured by combining a bottom plate 33 and a top plate 34 as shown in FIG. 17 and brazing them in a liquid-tight manner, and the connection holes 23 and 23 are formed in the bottom plate 33. It is formed on the bottom.

At the same time, fins (not shown) are provided between the adjacent elements 20, 20.

The inside of the first tank 21 is a partition wall fixed to an intermediate portion.
By partitioning by 24, it is divided into an entrance room 25 and an exit room 26,
A fluid inlet 27 is provided on the inlet chamber 25 side, and a fluid outlet 28 is provided on the outlet chamber 26 side.

In the case of the stacked heat exchanger of the separate tank type configured as described above, the first and second tanks 21, 22 and the plurality of elements 20, 20
The inside of the space formed by the return flow path 18 provided in
As shown in the figure, it can be divided into first, second, third and fourth chambers.

That is, the inlet chamber 25 existing in one half (left half in FIG. 18) of the first tank 21 and a part (left half in FIG. 18) of the elements 20, 20
A first chamber 29 comprising an upstream half of the first chamber 29 and a downstream optical section of the partial elements 20 and 20 and a half of the second tank 22 provided downstream of the first chamber 29. The second chamber 30 is provided on the downstream side (the right side in the drawing) of the second chamber 30 and includes the other half of the second tank 22 (the right half in the drawing). ) And the remaining half (the right half in the figure) of the elements 20, 20 and the upstream half of the element 20, and the other half of the first tank 21 provided downstream of the third chamber 31. (Right half of the figure) and the remaining elements 20, 20
And a fourth chamber 32 composed of the downstream half of the fourth chamber.

When a fluid such as a refrigerant is fed from the fluid inlet 27 into the stacked heat exchanger including the first to fourth chambers 29 to 32 as shown by an arrow a in FIG. Arrow b in the figure
As shown by the arrow, it flows through the first chamber 29, and the turn-back portion of the turn-back channel 18 of some of the elements 20, 20 flows as shown by the arrow c in FIG.

The fluid flowing in the second chamber 30 as shown by the arrow d, and flowing to the downstream end of the second chamber 30,
After flowing through the inside of the tank 22 in the direction of arrow e in FIG. 20 along the axial direction of the tank 22 and entering the third chamber 31, the return flow path of the remaining elements 20, 20 constituting the third chamber 31 18 flows as indicated by an arrow f in FIG.

Further, as shown by an arrow g in FIG.
It flows through the turn-back portions of the turn-back channels 18 of 0 and 20 and enters the fourth chamber 32, and flows inside the fourth chamber 32 as indicated by an arrow h.

The fluid that has flowed to the other half (the right half in FIG. 18) of the first tank 21 existing at the downstream end of the fourth chamber 32 then flows from the fluid outlet 28 into the same drawing. Flows out as shown by arrow i.

(Problems to be Solved by the Invention) However, in the case of the stacked heat exchanger of the separate tank type configured and operated as described above, there are still problems to be solved as described below.

That is, lubricating oil for lubricating the compressor is mixed into the refrigerant, which is a fluid flowing in the vapor compression refrigerator used as a cooling device, and this lubricating oil is used together with the refrigerant to function as an evaporator or a condenser. Also flows into the heat exchanger.

In particular, the lubricating oil sent together with the refrigerant into the laminated heat exchanger functioning as an evaporator, in this heat exchanger,
Separates as the refrigerant evaporates.

If the lubricating oil separated in the heat exchanger stays in the heat exchanger as it is, the amount of the lubricating oil sent to the compressor is insufficient, and adverse conditions such as the originally small amount of the lubricating oil overlap, In severe cases, the compressor may burn.

The stacked heat exchanger of the present invention solves the above-mentioned disadvantages.

(Means for Solving the Problems) The stacked heat exchanger of the present invention has a pair of protruding portions formed at one end edge at intervals at one end edge, similarly to the stacked heat exchanger of the separate tank type described above. A U-shaped recess is formed on one side of the metal plate, with both ends of the recess being continuous to the edges of the pair of protrusions. Are overlapped in the middle in a state where they face each other, and are joined in a liquid-tight manner to form a U-shaped folded flow path, and a pair of joints located at both ends of the flow path and protruding from the edge. And the junction of each of the plurality of elements is inserted into a slit-shaped connection hole formed on each of the side surfaces of the first and second tanks, and the outer peripheral surface of each junction and each connection hole are connected. The inner peripheral edge and the inner peripheral edge are joined to each other in a liquid-tight manner, and fins are provided between the adjacent elements. The first tank divided by the partition wall is provided with a fluid inlet on one side and a fluid outlet on the other side.

Further, in the stacked heat exchanger of the present invention, the refrigerant flows in the axial direction of the tank inside at least one of the first and second tanks, and the inside of the tank is the upstream part. A passage connecting the front and back of the weir plate to a part of the weir plate that corresponds to a part where lubricating oil mixed in the refrigerant is likely to stagnate. Is provided.

(Operation) The stacked heat exchanger of the present invention configured as described above exchanges heat between a fluid such as a refrigerant flowing inside the heat exchanger and a fluid such as air flowing outside the heat exchanger. The operation itself at the time of performing is the same as that of the heat exchanger according to the above-described invention.

However, in the case of the stacked heat exchanger of the present invention, the flow velocity of the fluid passing through the weir plate portion is increased by the weir plate provided inside at least one of the first and second tanks.

Since the passage communicating the front and back of the weir plate is provided at a portion corresponding to a portion where the lubricating oil mixed in the refrigerant is likely to stay, the lubricating oil is blown downstream by the flow of the fluid, The amount of lubricating oil staying in the heat exchanger can be reduced.

(Example) Next, the present invention will be described in more detail while describing the illustrated example.

FIGS. 1 to 4 show a first embodiment of the laminated heat exchanger of the present invention, and FIG. 1 shows a state in which a weir plate is provided inside a tank located at a lower end portion of the heat exchanger. FIG. 20 is a schematic longitudinal sectional view corresponding to the AA section in FIG. 20, and FIGS.
It is a perspective view which shows an example, respectively.

The structure of the laminated heat exchanger of the present invention is the same as that of the laminated heat exchanger of the separate tank type described above, except that a weir plate is assembled to a part of the tank. The characteristic part of will be described.

For example, in the downstream half of the second tank 22, inside the portion constituting the upstream end of the third chamber 31, weir plates 35, 35 as shown in FIGS. I have.

The weir plate 35 is made of the same material as the metal constituting the laminated heat exchanger, such as an aluminum alloy, and its outer peripheral shape matches the inner peripheral surface shape of the second tank 22, and The plate 35 can be fixed inside the second tank 22 without rattling.

A notch 36 as shown in FIG. 2 or FIG. 3 or a punched hole 37 as shown in FIG. On the way, the flow passage area of the portion where the weir plate 35 is fixed is reduced.

As described above, weir plates 35, 35 are provided on the downstream half of the second tank 22.
Fixed, by the laminated heat exchanger of the present invention, such as a refrigerant,
The operation itself when performing heat exchange between the fluid flowing inside the heat exchanger and the fluid flowing outside the heat exchanger, such as air, is the same as that of the heat exchanger according to the above-described prior invention. .

However, in the case of the stacked heat exchanger of the present invention, the second tank
This second tank is provided by dams 35, 35 provided inside 22.
It is possible to prevent the lubricating oil from staying in the inside 22.

That is, in the case of the laminated heat exchanger of the present invention, the flow path area of the refrigerant is notched by the notches 36 (the dam plate shown in FIGS. 2 to 3) by the dam plates 35 provided inside the second tank 22, for example. Or the area of the punched hole 37 is narrowed, so that the flow velocity of the fluid such as the refrigerant passing through the weir plates 35 becomes high.

The notch 36 or the punched hole 37 of the weir plate 35, 35
Is provided at a portion corresponding to a portion where the lubricating oil mixed in the fluid tends to stagnate (for example, a half portion on the downstream side of the second tank 22). The amount of lubricating oil that is blown off and stays in the heat exchanger can be reduced.

Also, by appropriately adjusting the opening area of the notch 36 or the punched hole 37 formed in each of the weir plates 35, 35, the return flow path 18 can be formed in the upstream part of each of the weir plates 35, 35 (see FIG. 17). The amount of the fluid sent into the inside and the amount of the fluid sent into the return channel 18 at the downstream portion of each of the weir plates 35 and 35 are substantially equal to each other,
Unevenness in the fluid flow rate is prevented between the plurality of return flow paths 18 provided in parallel with each other, and the performance of the heat exchanger can be maximized.

As described above, in the case of preventing the stagnation of the lubricating oil and preventing the deviation of the fluid flow rate, for example, a weir provided inside the portion constituting the third chamber 31 in the downstream half of the second tank 22 The number of the plates 35, 35 is set to be equal to or less than 1/2 of the number of the return flow paths 18 constituting the chamber 31. For example, the return flow path 18, which configures the third chamber 31 having the downstream half of the second tank 22 as the upstream end,
When the number 18 is six, the number of the weir plates 35 provided on the downstream half of the second tank 22 is one to three.

Also, as shown in FIG. 1, when a plurality of weir plates 35, 35 are fixed to the downstream half of the second tank 22,
Is smaller than the opening area of the upstream weir plate 35, so that the amount of fluid sent into the upstream return flow path 18 and the amount of refrigerant sent into the downstream return flow path 18 It is preferred that the amounts be substantially equal.

Since the lubricating oil mixed in the refrigerant, which is a fluid, is separated from the refrigerant along with the evaporation of the refrigerant, in the case of a laminated heat exchanger used as an evaporator, the lubricating oil is supplied to the second tank.
It is most likely to stay in the downstream half of 22. For this reason, the position where the weir plate 35 is provided is located at the downstream half of the second tank 22 in the third chamber 31.
The portion located at the upstream end of the first is most preferable, but when using a laminated heat exchanger as a condenser, etc., there is a large amount of uncondensed refrigerant, the upstream half of the first tank 21, the second half It may be provided at a portion located at the upstream end of the one room 29. Also, when used as an evaporator, a portion located at the downstream end of the second chamber 30 in the upstream half of the second tank 22 or the downstream half of the first tank 21 Room
By providing it at the portion located at the downstream end of 32, a certain effect can be expected.

Further, in the above-described first embodiment, the example in which the first and second tanks 21 and 22 are used in a state where they are positioned on the lower side has been described. Is not limited to the one in which the first and second tanks 21 and 22 are positioned on the lower side.

For example, as in the second embodiment shown in FIG. 5, when the second tank 22 is used in a state where the second tank 22 is positioned on the upper side, the sixth to fourth tanks 22 are disposed inside the downstream half of the second tank 22. As shown in FIG. 7, a notch is formed at the lower edge facing the bottom plate 33 (FIG. 17).
36, 36. The dams 35, 35 are fixed.

In addition, as shown in FIG. 8, when the first and second tanks 21 and 22 are used in a state where they are located on the side, the first and second tanks 21 and 22 have A dam plate 35 having a shape as shown in FIGS. 9 and 10 is fixed.

Further, the lubricating oil separated from the refrigerant in the heat exchanger is first,
In addition to staying on the bottom surfaces of the second tanks 21 and 22, the tanks often stay on the inner peripheral surfaces of the tanks 21 and 22.

In this way, in order to blow back the lubricating oil remaining in a state of being attached to the inner peripheral surfaces of the tanks 21 and 22, the notches 36 and 36 are provided at the peripheral edge as shown in FIGS. 11 to 13. Dam 35
Is fixed inside each of the tanks 21 and 22.

In the case of any of the embodiments, similarly to the case of the first embodiment, the installation position and the number of the weir plates 35, and the notches 36
It is needless to say that by appropriately adjusting the area of the refrigerant, it is possible to prevent the refrigerant flow from being biased.

(Effect of the Invention) The laminated heat exchanger of the present invention is configured and operates as described above, but the lubricating oil separated from the refrigerant in the heat exchanger is
It is possible to prevent stagnation in the heat exchanger as it is, thereby preventing shortage of lubricating oil sent to the compressor.

[Brief description of the drawings]

FIGS. 1 to 4 show a first embodiment of the laminated heat exchanger of the present invention, and FIG. 1 shows a state in which a weir plate is provided inside a tank located at a lower end portion of the heat exchanger. FIG. 20 is a schematic longitudinal sectional view corresponding to the AA section, FIG. 2 to FIG. 4 show three examples of the shape of the weir plate, respectively, perspective views, and FIG. FIG. 5 shows a state in which a weir plate is provided inside the tank located at the upper end of the heat exchanger.
FIGS. 6 and 7 are schematic longitudinal sectional views corresponding to section A, and FIGS. 6 and 7 show two examples of the shape of the weir plate, respectively, perspective views, and FIGS. 8 to 10 show the same third embodiment. Schematic side view of a heat exchanger,
9 to 10 show two examples of the shape of the weir plate, respectively, perspective views, and FIGS. 11 to 13 show a fourth embodiment of the same.
FIG. 12 to FIG. 12 show two examples of the shape of the weir plate.
FIG. 13 is a cross-sectional view showing a state in which the weir plate is fixed inside the tank, FIG. 14 is a front view of a conventional laminated heat exchanger, FIG. 15 is a side view of a metal plate constituting the heat exchanger, Figure 16 shows Figure 15.
FIG. 17 is a partially exploded perspective view of a laminated heat exchanger of a separate tank type which is an object of the present invention, FIG. 18 is a plan view showing the assembled state, and FIG. FIG. 20 is a schematic perspective view showing the flow of the refrigerant. 1: metal plate, 2: unit, 3: flat part, 4: first concave part, 5: second concave part, 6: third concave part, 7, 8: through hole, 9: ridge, 10: inlet pipe, 1
1: outlet tube, 12: flat tube portion, 13: fin, 14a, 14b: protrusion, 15: metal plate, 16: concave portion, 17: protrusion, 18: return channel,
19a, 19b: joint, 20: element, 21: first tank, 22: second tank, 23: connection hole, 24: partition, 25: inlet chamber, 26: outlet chamber, 27: fluid inlet, 28: fluid outlet, 29: first chamber, 30: second chamber, 31: third chamber, 32: fourth chamber, 33: bottom plate, 34:
Top plate, 35: dam plate, 36: notch, 37: punched hole.

Claims (1)

(57) [Claims] 1. A U-shaped concave portion is formed on one side of a metal plate having a pair of protruding portions formed at one end thereof at intervals from each other, and both ends of the concave portion are continuous with the edges of the pair of protruding portions. The U-shaped folded flow path is formed by forming these metal plates into a pair and overlapping them in the middle in a state where the concave portions are opposed to each other and liquid-tightly joining each other. And a pair of joints located at both ends of the flow path and protruding from the edge, and the joints of the plurality of elements are formed on the side surfaces of the first and second tanks, respectively. Inserted into the slit-shaped connection hole, the outer peripheral surface of each joint and the inner peripheral edge of each connection hole are liquid-tightly joined to each other, fins are provided between adjacent elements, and the intermediate part is partitioned by a partition. The first tank has a fluid inlet on one side and a fluid outlet on the other side. In the stacked heat exchanger constituted by providing each, the inside of at least one of the first and second tanks, the portion where the refrigerant flows in the axial direction of the tank, the inside of this tank upstream Along with fixing a weir plate partitioning into a side part and a downstream part, a part of this weir plate,
A laminated heat exchanger, wherein a passage communicating between the front and back of a weir plate is provided at a portion corresponding to a portion where lubricating oil mixed in a refrigerant is likely to stay.