JPH11264688A - Multistage heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heat exchange efficiency by superposing respective heat exchangers such that the gap between the heat exchanging fin and header pipe of one of adjacent heat exchanging units is covered with the header pipe of the other heat exchanging unit thereby preventing the gap from serving as an air passage. SOLUTION: Heat exchanging units U1 , U2 have identical dimensions and shape and when the gap 5 between the heat exchanging fin 3 and header pipe 1 on one side of the heat exchanging unit U1 is covered with the header pipe 1 of the heat exchanging unit U2 , the gap 5 between the heat exchanging fin 3 and header pipe 1 on the other side of the heat exchanging unit U2 is covered simultaneously with the header pipe 1 of the heat exchanging unit U1 . Since the gap 5 between the heat exchanging fin 3 and header pipe 1 of the heat exchanging unit U1 or U2 is covered with the header pipe 1 or the heat exchanging fin 3 of adjacent the heat exchanging unit U2 or U1 without fail, mutual conducting part is eliminated and the air touch the heat exchanging fin 3 without fail.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multistage heat exchanger, and more particularly, to a heat exchanger (parallel flow heat exchanger) to which a header pipe, a heat exchange tube, and a heat exchange fin are brazed. ) Is a multi-stage heat exchanger combining two or more units.

[0002]

2. Description of the Related Art Conventionally, a so-called parallel flow (PF) type heat exchanger has been known as a heat exchanger used in an air conditioner for automobiles or homes. As shown in FIG. 7, this PF type heat exchanger includes a pair of header pipes 1, 1 and a plurality of flat heat exchange tubes 2, 2,. It mainly comprises a heat exchange fin 3 disposed between the exchange tubes 2 and 2.

In order to assemble the heat exchange tube 2 to the header pipe 1, a flat heat exchange tube insertion hole 4 is formed in the header pipe 1 as shown in FIG. 2 and are brazed together with the heat exchange fins 3. 9A, 9B, and 9C show a front view, a plan view, and a side view of the PF type heat exchanger after brazing. However, in the PF type heat exchanger, the heat exchange fins 3 are stopped before the header pipe 1 because of stability in production, that is, it is necessary to prevent the heat exchange fins 3 from melting during brazing. As shown in FIG. 10, the header pipe 1 and the heat exchange fins 3 are arranged so as to leave a gap D between them without leaving them in contact with each other.

[0004]

However, the header pipe, the heat exchange tube, and the heat-exchange fin brazed with P
In the F-type heat exchanger, since the gap 5 is left between the header pipe 1 and the heat exchange fins 3 as described above, when the heat exchanger is used, air is filled in the gap. As a result, the heat exchange rate is reduced, which is a negative factor in the performance of the heat exchanger.
Accordingly, even when two or more PF type heat exchanger units having this configuration are combined as shown in FIG. 11 to form a target multi-stage heat exchanger, the respective heat exchanger units U1 and U2 are simply the same. If they are merely combined in a positional relationship, air passes through the gap 5 between the heat exchanger units U1 and U2, and the heat exchange rate decreases as in the case of a single PF type heat exchanger unit. And acts as a negative factor in the performance of the heat exchangers in the multistage combination.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a multi-stage heat exchanger combining two or more PF type heat exchanger units each having a gap between a header pipe and a heat exchange fin. It is an object of the present invention to provide a multi-stage heat exchanger in which the gap is prevented from forming a passage through which air passes, thereby improving the heat exchange rate.

[0006]

Means for Solving the Problems In order to achieve the above object, the present invention is configured as follows.

According to a first aspect of the present invention, there are provided a pair of header pipes, a plurality of flat heat exchange tubes connected between the header pipes, and heat exchange fins disposed between the heat exchange tubes. A heat exchanger unit is constituted by heat exchange fins arranged with a gap left between the header pipe and the heat exchanger unit. In a multistage heat exchanger in which two or more heat exchanger units are combined in multiple stages. The heat exchanger units are stacked so that the gap between the heat exchange fins and the header pipe in one of the adjacent heat exchanger units is covered by the header pipe of the other heat exchanger unit. And

The heat exchanger units of the multi-stage heat exchanger may be of the same size and shape (claim 2). In this case, the specific arrangement of each heat exchanger unit is
The arrangement is staggered or stepped.

However, as the other heat exchanger unit of the multistage heat exchanger, a heat exchanger unit having a shorter header pipe interval than the header pipe interval of the one heat exchanger unit is used, and the one heat exchange unit is used. The header pipe of the other heat exchanger unit may be located so as to cover the gap between the header pipes of the heat exchanger unit.

In another aspect of the present invention, a pair of header pipes, a plurality of flat heat exchange pipes connected between the header pipes, and a heat exchange fin disposed between the heat exchange pipes are provided. And a heat exchanger unit comprising a heat exchange fin disposed with a gap left between the header pipe and the heat pipe, and a multistage heat exchanger in which two or more heat exchanger units are combined in multiple stages. In the first aspect, the heat exchanger unit has a first length having a header pipe interval of a predetermined length.
, And a second heat exchanger unit having a shorter header pipe interval than the first heat exchanger unit, wherein the first heat exchanger unit and the second heat exchanger unit are provided. Are alternately superimposed and arranged in two or more stages, and a gap between the heat exchange fins and the header pipe in the first heat exchanger unit is formed between the adjacent heat exchanger units. The first heat exchanger unit and the second heat exchanger unit are overlapped so as to cover a header pipe of the heat exchanger unit (claim 4).

As described above, the present invention relates to a multistage heat exchanger in which two or more so-called parallel flow (PF) heat exchanger units are combined, and a header pipe of each of the leeward and leeward heat exchanger units. The gaps are arranged so as to be shifted from each other in the direction, so that the gap does not communicate from the windward side to the leeward side, thereby preventing the air from passing through the heat exchanger.

Further, since the header pipes can be prevented from interfering with each other in the horizontal direction by displacing the positional relationship, the depth of the multistage heat exchanger combining two or more heat exchanger units can be reduced. It is possible to make it thin. This means that the gap between the first heat exchanger unit and the second heat exchanger unit becomes shorter, and the air that has exchanged heat in the first heat exchanger unit is immediately replaced by the second heat exchanger unit. As a result of being sucked by the unit, wasteful heat exchange with the outside air is prevented, which contributes to improving the performance of the heat exchange rate of the multi-stage heat exchanger.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 shows a multi-stage heat exchanger according to a first embodiment of the present invention, wherein (a) is a front view, (b) is a plan view,
(C) is a side view. This multistage heat exchanger uses two PF type heat exchanger units U1 and U2 having the same dimensions and shape, and is configured by combining them in multiple stages. The configuration itself of each PF type heat exchanger unit U1, U2 is the same as the conventional one,
, A plurality of flat heat exchange tubes 2, 2... Connected between the header pipes 1, 1, and heat exchange fins disposed between the heat exchange tubes 2, 2 and The heat exchange fins 3 are arranged with a gap 5 therebetween, and are brazed together. The arrangement of the heat exchange fins 3 is stopped before the header pipe 1, and as shown in FIG. 2, the header pipe 1 and the heat exchange fins 3 are not in contact with each other and a distance D is opened between them. 5 is left.

However, unlike the related art, the heat exchanger units U1 and U2 are superimposed on each other, and are arranged so as to be shifted toward the outside of the header pipe 1, that is, in the width direction of the heat exchanger unit. The heat exchanger units U1 and U2 are different from the related art in that they are arranged so as to be shifted from each other on the side where the header pipe 1 exists. The shift amount is set such that the gap 5 between the heat exchange fin 3 and the header pipe 1 in one of the adjacent heat exchanger units U1 and U2 is covered by the header pipe 1 of the other heat exchanger unit U2. Stipulated. In other words, the heat exchanger unit U2 is such that its header pipe 1 remains within the radius of the header pipe 1 of the heat exchanger unit U1 when viewed in the depth direction of the multistage heat exchanger, that is, the header pipes 1 Are also shifted in the depth direction so as to partially overlap. In the case of this embodiment, the amount of the shift in the depth direction is largely shifted until the header pipe 1 of the heat exchanger unit U2 comes into contact with the side of the heat exchange fin 3 of the heat exchanger unit U1. The shift position in the width direction of the heat exchanger unit U2 with respect to the heat exchanger unit U1 may be stopped so that the heat exchanger unit U1 is short of contact with the side of the heat exchange fin 3 of the exchanger unit U1.

In the case of this embodiment, the heat exchanger unit U
1 and U2 have the same dimensions and shape, so the heat exchange fins 3 on one side (the left end side in FIG. 1) of the heat exchanger unit U1.
And when the gap 5 between the header pipes 1 is covered by the header pipe 1 (left end side in FIG. 1) of the heat exchanger unit U2, at the same time, on the other side (right end side in FIG. 1) of the heat exchanger unit U2. The gap 5 between the heat exchange fins 3 and the header pipe 1 is covered with the header pipe 1 (the right end side in FIG. 1) of the heat exchanger unit U1. FIG. 2 shows an overlapping state on the right end side of FIG. As can be seen from FIG. 2, the heat exchanger unit U1, in which the header pipe 1 is located inside the adjacent heat exchanger unit U2, has the heat exchange fins 3 and the header pipe 1.
The fin 3 for exchange of the heat exchanger unit U2 is located on the gap 5 between them.

Therefore, the gap 5 between the heat exchange fin 3 and the header pipe 1 in the heat exchanger unit U1 or U2 is always covered by the header pipe 1 or the exchange fin 3 of the adjacent heat exchanger unit U2 or U1. As a result, there is no formation of a communicating portion that communicates with each other from the windward side to the leeward side. That is, the air is prevented from passing through the heat exchanger, and the air always comes into contact with the replacement fins 3 and exits the multi-stage heat exchanger. The heat exchange rate is improved as compared with the exchanger.

FIG. 3 shows the relationship between the displacement of the heat exchanger units U1 and U2 and the depth of the multi-stage heat exchanger. As shown in FIG. 3A, the heat exchanger units U1, U2
Is the header pipe 1 of the heat exchanger unit U2,
Since the width direction position is shifted so as to remain within the radius of the header pipe 1 of the heat exchanger unit U1, the header pipes 1 are mutually moved in the overlapping direction of the heat exchanger units U1 and U2 (vertical direction in FIG. 3). The overlapped portion (length L3) is formed, and the depth length L2 of the multi-stage heat exchanger is reduced accordingly. That is, as compared with the depth L1 of the conventional multi-stage heat exchanger stacked directly above shown in FIG.
The depth length L2 of the multi-stage heat exchanger is L2 = L1-L3
Only thinner.

This is because the gap (interval distance L) between the first heat exchanger unit U1 and the second heat exchanger unit U2 is reduced, and the heat exchange unit U1 The exchanged air is immediately sucked into the second heat exchanger unit U2, so that wasteful heat exchange with the outside air is prevented, and the performance of the multi-stage heat exchanger is improved.

In the above-described embodiment, two heat exchanger units U1 and U2 are used. However, three or more heat exchanger units are used, and they are displaced in a staggered or substantially staggered manner by one header pipe. They can also be arranged in steps.

Second Embodiment FIGS. 4A and 4B show a second embodiment of the multistage heat exchanger of the present invention, wherein FIG. 4A is a front view, and FIG.
Is a plan view. In the second embodiment, two types of heat exchanger units Ua and Ub having different header pipe intervals are used. That is, a first heat exchanger unit Ua having a header pipe interval of a predetermined length, and a second heat exchanger unit Ub having a shorter header pipe interval than the first heat exchanger unit Ua are prepared. The first heat exchanger unit Ua and the second heat exchanger unit Ub are alternately overlapped and arranged in two stages, and the first heat exchanger unit Ua is disposed between adjacent heat exchanger units. The gap 5 between the heat exchange fins 3 and the header pipe 1 in the first embodiment is connected to the header pipe 1 of the second heat exchanger unit Ub.
, The first heat exchanger unit Ua and the second heat exchanger unit Ub are overlapped to constitute a multi-stage heat exchanger.

In the above description, the case where the first heat exchanger unit Ua and the second heat exchange unit Ub are overlapped in two stages has been described. However, the first heat exchanger unit Ua and the second heat exchanger unit Ua And the heat exchanger units Ub are alternately superposed and arranged in two or more stages. For example, FIG.
As shown in (a) and (b), the first heat exchanger unit Ua and the second heat exchanger unit Ub can be alternately overlapped and arranged in three stages.

The functions and effects of the embodiment of FIGS. 4 and 5 are the same as those of the embodiment of FIG. That is, a configuration in which the arrangement of the heat exchanger units Ua and Ub is shifted in the outer direction of the header pipe 1, that is, in the width direction of the heat exchanger unit, by an amount equal to or less than one header pipe 1 as described above. , The windward heat exchanger unit Ua
The air taken in at step (1) is arranged to pass through the heat exchange fins without blowing out through the gaps 5 in the heat exchanger units Ua and Ub. As a result, the intake air exchanges heat at the heat exchange fins and blows out from the heat exchanger on the leeward side, thereby improving the heat exchange rate of the multistage heat exchanger.

The heat exchanger units Ua and Ub to be combined in the embodiment of FIG. 4 may be the same type of heat exchanger such as a condenser and a different type of heat exchanger such as a condenser and a radiator. It may be a vessel. In FIG. 6A, in the adjacent first heat exchanger unit Ua and second heat exchanger unit Ub, the first heat exchanger unit Ua on the leeward side is largely configured as a radiator, and the leeward side is used. 2 shows a case where the second heat exchanger unit Ub is configured to be small as a condenser. FIG.
(B) shows a case where the leeward first heat exchanger unit Ua is configured as a small radiator, and the leeward second heat exchanger unit Ub is configured as a condenser.

[0024]

Next, experimental results of the multistage heat exchanger of the present invention will be described. It was confirmed that when the test piece of the multi-stage heat exchanger in the first embodiment was configured as follows and the communicating portion of the gap 5 was eliminated, the heat exchange rate, which is the performance of the multi-stage heat exchanger, was improved. <Heat Exchanger Unit of Specimen> Effective width of heat exchanger units U1 and U2: 300 mm, number of heat exchange tubes: 20, pitch of heat exchange tubes: 9.83 mm, heat exchange tubes: 1.93 mm (thickness) T) × 18.8 mm (width w), outer diameter of header pipe 1: φ22.2 mm, number of heat exchange fins: 21, height of heat exchange fins: 7.92 mm (height h) × 0.1
(Thickness t), Heat exchange fin pitch: 1.4 mm.

The number of heat exchange fins 3 is 21 and the number of heat exchange tubes more than 20 is
This is because the heat exchange fins 3 are also provided outside the fins.

The amount of displacement of the heat exchanger units U1 and U2 is determined by the distance L between the heat exchanger units U1 and U2.
(See FIG. 3) was set to 1.7 mm. <Measurement conditions> The performance (heat exchange rate) measurement conditions were as follows.

Superheat degree: 25 ° C., supercool degree: 5 ° C., average condensing pressure: 15 kg / cm 2 G, suction air temperature: 35 ° C., suction air velocity: 4.5 m / sec, refrigerant: R134a Table 1 shows the results. . Table 1 shows how the heat exchange rate of the multistage heat exchanger improves when the distance L between the first and second heat exchanger units is reduced. The heat exchange rate is, for comparison, the distance L (L = 3.4 m) between the multi-stage heat exchangers of the conventional configuration (FIG. 3B).
The heat exchange rate at the time of m) was shown as an index of 100.

[0028]

[Table 1] As a result of the above experiment, the amount of displacement of the heat exchanger units U1 and U2 in the width direction increases, and as the distance L between the heat exchanger units decreases, the heat exchange rate may increase. I understand. In this embodiment, the distance L between the heat exchanger units (see FIG. 3) is 1.7 mm, and the distance L between the conventional heat exchanger units is 3.4 m.
Compared with the case of m, the heat exchange rate is improved to 100.5%.

[0029]

As described above, according to the first to fourth aspects of the present invention, in a multistage heat exchanger in which two or more parallel flow (PF) heat exchanger units are combined, a windward side is provided. By arranging the heat exchanger units on the leeward side in a positional relationship in the width direction where the header pipe is present, the gap is prevented from communicating from the leeward side to the leeward side, so that air exchanges heat. It is possible to prevent the vessel from passing through.

Also, by displacing the heat exchanger units in a positional relationship in the width direction, it is possible to prevent the header pipes from interfering with each other in the horizontal direction. It is possible to reduce the depth of the multistage heat exchanger combining the above. This means that the gap between the first heat exchanger unit and the second heat exchanger unit becomes shorter, and the air that has exchanged heat in the first heat exchanger unit is immediately replaced by the second heat exchanger unit. As a result of being sucked in the heat exchanger unit, wasteful heat exchange with the outside air is prevented, which contributes to the improvement of the heat exchange rate of the multi-stage heat exchanger.

[Brief description of the drawings]

FIG. 1 shows a multi-stage heat exchanger according to a first embodiment of the present invention, wherein (a) is a front view, (b) is a plan view, and (c) is a side view.

FIG. 2 shows the first and second units in the first embodiment of the present invention.
It is the figure which showed the relative positional relationship of the 1st heat exchanger unit.

3A and 3B are diagrams showing a change in the depth length of the multi-stage heat exchanger, wherein FIG. 3A is a diagram showing the case of the multi-stage heat exchanger according to the first embodiment of the present invention, and FIG. FIG. 3 is a view showing a case of a conventional multi-stage heat exchanger.

4A and 4B show a multi-stage heat exchanger according to a second embodiment of the present invention, wherein FIG. 4A is a front view and FIG. 4B is a plan view.

FIGS. 5A and 5B show a modified example of the multistage heat exchanger according to the third embodiment of the present invention, wherein FIG. 5A is a front view thereof and FIG.
Is a plan view.

FIGS. 6A and 6B show an application example of the second embodiment of the present invention, in which the radiator and the capacitor adjacent to each other have a larger radiator on the leeward side and FIG. FIG. 3 is a diagram showing a case where the condensate of the above is increased.

FIG. 7 is a front view showing a conventional PF type heat exchanger.

FIG. 8 is a perspective view showing a connection state between a conventional header pipe and a heat exchange pipe.

FIG. 9 shows a conventional PF type heat exchanger, in which (a)
Is a front view, (b) is a plan view, and (c) is a side view.

FIG. 10 is a view showing a part of a conventional PF type heat exchanger.

FIG. 11 shows a conventional multi-stage heat exchanger.
(A) is a front view, (b) is a plan view, and (c) is a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Header pipe 2 Flat heat exchange tube 3 Heat exchange fin 4 Heat exchange tube insertion hole 5 Clearance D Clearance distance U1, U2 Heat exchanger unit Ua, Ub First heat exchanger unit

Claims (4)

[Claims] 1. A pair of header pipes, a plurality of flat heat exchange pipes connected between the header pipes, and heat exchange fins disposed between the heat exchange pipes. In a multi-stage heat exchanger in which two or more heat exchanger units are combined in a multi-stage configuration with heat exchange fins arranged with a gap between them, adjacent heat exchanger units Characterized in that the heat exchanger units are overlapped so that the gap between the heat exchange fins and the header pipe on one side is covered by the header pipe of the other heat exchanger unit. . 2. The multi-stage heat exchanger according to claim 1, wherein the heat exchanger units of the multi-stage heat exchanger have the same dimensions and shape. 3. A heat exchanger unit having a header pipe interval shorter than a header pipe interval of the one heat exchanger unit as the other heat exchanger unit of the multistage heat exchanger. 2. The multistage heat exchanger according to claim 1, wherein the header pipe of the other heat exchanger unit is located so as to cover the gap between the header pipes of the heat exchanger unit. 4. A pair of header pipes, a plurality of flat heat exchange pipes connected between the header pipes, and heat exchange fins disposed between the heat exchange pipes. A heat exchanger unit is constituted by heat exchange fins arranged with a gap therebetween, and in a multistage heat exchanger in which two or more heat exchanger units are combined in multiple stages, A first heat exchanger unit having a header pipe interval of a predetermined length, and a second heat exchanger unit having a shorter header pipe interval than the first heat exchanger unit; The heat exchanger unit and the second heat exchanger unit are alternately superimposed and arranged in two or more stages, and the adjacent heat exchanger units are connected with the heat exchange fins in the first heat exchanger unit. H Wherein the first heat exchanger unit and the second heat exchanger unit are overlapped so that a gap between the first heat exchanger unit and the header pipe of the second heat exchanger unit covers a gap between the first heat exchanger unit and the second heat exchanger unit. Heat exchanger.