JPH10220982A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger in which a temperature distribution at the surface of the heat exchanger can be reduced and a heat exchanging performance can be improved while some disadvantages such as a reduction in an assembling work efficiency and an increased aeration resistance are being prevented. SOLUTION: A heat exchanger having an inlet tank 4 and a plurality of tubes 2 communicated with and connected to the inlet tank 4 to feed refrigerant of double gas-liquid phases through an expansion valve is constructed such that a partition plate 15 for defining an inner area of the inlet tank 4 into at least two chambers 16, 17 for a refrigerant feeding side and a refrigerant discharging side and allowing a communication between both chambers is arranged in the inlet tank 4, and the communication allowing part of the partition plate 15 is formed at the lower part of a cross sectional direction of the inlet tank 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger using a refrigerant used in, for example, a vehicle air conditioner.

[0002]

2. Description of the Related Art Conventionally, a heat exchanger as shown in FIG. 1 has been known for use in, for example, a vehicle air conditioner. FIG. 1 showing the appearance of this heat exchanger is commonly used in the following description of the present invention. In FIG. 1, the heat exchanger 1 has a plurality of tubes 2 having a fluid passage formed therein, and fins 3 disposed between the tubes 2. The plurality of tubes 2 allow an inlet tank 4 that controls fluid distribution and an outlet tank 5 that controls fluid collection to communicate with each other.

[0003] An expansion valve 6 is connected to the heat exchanger 1, and a refrigerant introduced from the outside is decompressed and expanded by the expansion valve 6 and distributed to each tube 2 in an inlet tank 4. After passing through the tube 2 and gathering in the outlet tank 5, it is discharged to the outside via the expansion valve 6. FIG. 9 shows the flow of the refrigerant. Then, heat exchange is performed between the refrigerant circulating in the heat exchanger 1 and the heat exchange air passing in the heat exchanger 1.

The refrigerant decompressed by the expansion valve 6 is in a gas-liquid mixed state, that is, a gas-liquid two-phase refrigerant. For this reason, due to the inertia forces of the gas phase and the liquid phase, the gas refrigerant flows into the tube 2 communicating with the upstream side of the inlet tank 4,
A large amount of liquid refrigerant may flow into the tubes 2 communicating with the downstream side, and as a result, a temperature distribution may occur between the tubes 2 and the heat exchange performance may be reduced.

[0005] In order to solve the above-mentioned problems, proposals have been made, for example, in Japanese Patent Application Laid-Open No. Hei 7-103610. In this proposal, a gas refrigerant tank in which the refrigerant decompressed by the expansion valve is gas-liquid separated by gas-liquid separation means, and the separated gas refrigerant and liquid refrigerant are communicated with each tube.
By evenly distributing the liquid to each tube through the liquid refrigerant tank, the temperature of each tube is made uniform, and the heat exchange performance is improved by reducing the temperature distribution on the heat exchanger surface. It has become so.

[0006]

However, in the above proposal, the tubes are stacked, and the gas refrigerant tank and the liquid refrigerant tank are formed integrally with the laminate in the laminate. If the tube is to be made of two press-formed plates joined to each other, asymmetric plates must be joined.

For this reason, an increase in the number of press dies is inevitable. Further, since the left and right asymmetric plates are joined to each other, the assembling work efficiency may be reduced.
Further, in one aspect of the above proposal, a configuration is adopted in which a gas refrigerant tank and a liquid refrigerant tank are provided at both ends in the tube longitudinal direction. In this configuration, it is necessary to reduce the ventilation area and increase the ventilation resistance. May be invited.

The object of the present invention is to reduce the efficiency of assembly work,
An object of the present invention is to provide a heat exchanger that can reduce the temperature distribution on the surface of the heat exchanger and improve heat exchange performance without causing adverse effects such as an increase in ventilation resistance and a decrease in a heat transfer area.

[0009]

In order to solve the above-mentioned problems, a heat exchanger according to the present invention has an inlet tank and a plurality of tubes communicating with and connected to the inlet tank. In the heat exchanger for introducing a gas-liquid two-phase refrigerant through a valve, the inlet tank is divided into at least two chambers, a refrigerant introduction side and a refrigerant counter-introduction side, and the two chambers communicate with each other. And a communication permitting portion of the partition plate is formed at a lower portion in a cross-sectional direction of the inlet tank.

The number of tubes (hereinafter simply referred to as gas tubes) connected to the refrigerant introduction side chamber of the inlet tank is determined by the number of tubes (hereinafter simply referred to as "tubes") connected to the refrigerant non-introduction side chamber of the inlet tank. Liquid tube). More preferably, the number of gas tubes is in the range of 10-30% of the total number of tubes. A gas refrigerant is mainly introduced into a tube communicating with a refrigerant introduction side chamber of the inlet tank, and a liquid refrigerant is mainly introduced into a tube communicating with the refrigerant non-introduction side chamber.

In the above-described heat exchanger, the gas-liquid two-phase refrigerant introduced into the heat exchanger is substantially separated into a gas refrigerant and a liquid refrigerant in a chamber on the refrigerant introduction side of the inlet tank. You. The gas refrigerant having a low specific gravity is introduced into a gas tube that communicates with the chamber on the refrigerant introduction side. On the other hand, the liquid refrigerant having a higher specific gravity than the gas refrigerant is sent to the refrigerant non-introduction-side chamber through the communication permitting portion formed at the lower portion of the partition plate in the transverse direction of the inlet tank, and is sent to the anti-introduction-side chamber. It is introduced into the fluid tube that is in communication. At this time, in the gas tube, the mist-like liquid refrigerant included in the gas refrigerant evaporates, and heat exchange is performed with the heat exchange air passing through the heat exchanger. On the other hand, the liquid refrigerant, which is substantially gas-liquid separated and flows into the chamber on the opposite side of the introduction, has an extremely small dryness, and is therefore evenly distributed to the respective liquid tubes. In other words, the separated gas refrigerant and liquid refrigerant are passed through separate gas tubes and liquid tubes, respectively, and the gas refrigerant is effectively used for heat exchange, while the liquid refrigerant having a large proportion of the gas-liquid two-phase refrigerant. Is evenly distributed to each liquid tube, so that the temperature of each liquid tube is equalized, so that the temperature distribution on the surface of the heat exchanger is reduced, and efficient heat exchange can be realized.

Further, in the gas-liquid two-phase refrigerant which is decompressed by the expansion valve and introduced into the heat exchanger, the ratio of the gas refrigerant is smaller than that of the liquid refrigerant. If you set less than the number of liquid tubes,
The object of the present invention can be achieved more effectively. The number of gas tubes is desirably set in the range of 10 to 30% of the total number of tubes.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. First, the external configuration of the heat exchanger 1 is substantially the same as the conventional configuration shown in FIG. In the present invention, the inside of the heat exchanger 1 is configured, for example, as shown in FIGS.

FIGS. 2 to 7 show a heat exchanger 1 according to a first embodiment of the present invention. The heat exchanger 1 has a core portion 7 formed by alternately stacking the tubes 2 and the fins 3, and side plates 8 and 9 are provided at both ends of the core portion 7 in the stacking direction. .

On the side plate 8 side of the core part 7, a flat tank 10 for introducing and discharging the refrigerant into the heat exchanger 1 is provided. The interior of the flat tank 10 is divided into an inlet channel 11 through which the gas-liquid two-phase refrigerant decompressed by the expansion valve 6 is introduced, and an outlet channel 12 through which the refrigerant is led out. An inlet pipe 13 and an outlet pipe 14 communicate with the inlet channel 11 and the outlet channel 12, respectively.
The expansion valve 6 is connected to 3 and 14.

A partition plate 15 is provided inside the inlet tank 4. Due to the partition plate 15, the inside of the inlet tank 4 is
It is divided into a chamber 16 on the refrigerant introduction side and a chamber 17 on the side opposite to the refrigerant introduction side. Further, the partition plate 15 is provided with a communication permitting portion 18 that permits communication between the chamber 16 and the chamber 17. In the present embodiment, the communication permitting portion 18 is formed by a gap between the chord portion of the partition plate 15 having a circular part as a chord portion and the inner wall of the inlet tank 4. This communication permitting part 18
Are formed at the lower portion in the cross-sectional direction of the inlet tank 4 when viewed in the up-down direction. In addition, as shown in FIGS. 6 and 7, a hole 24 may be formed in the partition plate 15, and the hole 24 may be used as the communication permission portion 18. In this case, the number, shape, and the like of the holes 24 are not particularly limited.

The chamber 16 on the refrigerant introduction side and the chamber 1 on the side opposite to the refrigerant introduction side
Numeral 7 is connected to the outlet tank 5 by the corresponding gas tube 21 and liquid tube 22. That is, the tube 2 includes the gas tube 21 and the liquid tube 22. As shown in FIG. 4, the tube 2 is formed by joining forming plates 23 formed by press-forming plate members to form a flow path inside. In this embodiment, 15 tubes 2
Of them (about 13% of the total number of tubes) are configured as gas tubes 21.

In the heat exchanger 1 according to this embodiment,
The gas-liquid two-phase refrigerant flows into the chamber 1 of the inlet tank 4 through the expansion valve 6.
When introduced into 6, the gas refrigerant having a low density rises due to the difference in density between the gas phase and the liquid phase, and the liquid refrigerant having a high density
The refrigerant flows down to the lower part of the chamber 16, that is, the tank 4, and the gas-liquid two-phase refrigerant is substantially separated into the gas refrigerant and the liquid refrigerant. In the present embodiment, the communication permitting portion 18 is provided at the lower portion of the partition plate 15 in the cross-sectional direction of the inlet tank 4, so that the separated liquid refrigerant gathers on the lower side due to a difference in specific gravity, and the communication permitting portion is provided. It flows into the chamber 17 via 18.

The gas refrigerant separated in the chamber 16 is
Due to the difference in specific gravity, they gather on the upper side and pass through the gas tube 21 and flow into the outlet pipe 5. However, since the gas refrigerant contains a mist-like liquid refrigerant, the mist-like liquid refrigerant is contained in the gas tube 21. Liquid refrigerant evaporates and heat exchanger 1
Heat is exchanged with the heat exchange air passing through the inside. On the other hand, since the liquid refrigerant flowing into the chamber 17 is substantially separated from the gas refrigerant in the chamber 16 as described above, its dryness is extremely small. Therefore, the liquid refrigerant can be evenly distributed into each liquid tube 22,
The amount of liquid refrigerant flowing through each liquid tube 22 is made uniform, and the temperature distribution of each tube 22 is reduced. That is, in the gas-liquid two-phase refrigerant, the ratio of the liquid refrigerant is overwhelmingly higher than that of the gas refrigerant, so that the liquid refrigerant is evenly distributed and the temperature of each liquid tube 22 is equalized, so that the heat is increased. The temperature distribution on the surface of the exchanger 1 is reduced, and efficient heat exchange is achieved.

Therefore, if the number of gas tubes 21 is smaller than the number of liquid tubes 22, the object of the present invention can be achieved more effectively, but the number of gas tubes 22 is 10 to 30 of the total number of tubes. % Is preferably set. The number of gas tubes 21 can be easily changed by moving the position of the partition plate 15 in the inlet tank 4.

FIG. 8 shows a heat exchanger according to a second embodiment of the present invention. In the present embodiment, a plurality of (two in FIG. 8) partition plates 25, 26 are provided in the inlet tank 4.
Is provided. Further, the inside of the inlet tank 4 is partitioned by a partition plate 26 into a chamber 16 on the refrigerant introduction side and a chamber 17 on the side opposite to the refrigerant introduction side.
It is divided into and. Furthermore, the chamber 16 on the refrigerant introduction side is
The partitioning plate 25 partitions the first chamber 27 and the second chamber 28. Moreover, the number of tubes 2 in the heat exchanger of the present embodiment is larger than that of the heat exchanger 1 of the first embodiment.

In this embodiment, the gas-liquid two-phase refrigerant is separated into the gas refrigerant and the liquid refrigerant in multiple stages by the first chamber 27 and the second chamber 28 constituting the chamber 16, so that the gas The dryness of the liquid refrigerant introduced into the chamber 17 can be further improved while effectively using the refrigerant for heat exchange. Therefore, the temperature distribution over the surface of the heat exchanger is reduced more,
Efficient heat exchange can be achieved. That is, for a heat exchanger having a relatively large number of tubes 2, by providing a plurality of partition plates as in the present embodiment, the object of the present invention can be more effectively achieved.

Also in this embodiment, the number of gas tubes 21 is in the range of 10 to 30% of the total tubes 2.

In the first and second embodiments, since the tube 2 can be formed by joining the symmetrical forming plates 23 to each other, the number of press dies is prevented from increasing, and the assembling is easy. Can be secured. In addition, since the external shape of the heat exchanger 1 is not changed at all, there is no possibility of causing adverse effects such as an increase in airflow resistance and a decrease in the heat transfer area.

[0025]

As described above, when the heat exchanger of the present invention is used, the temperature distribution on the surface of the heat exchanger can be reduced without causing adverse effects such as a reduction in assembly work efficiency and an increase in ventilation resistance. As a result, more efficient heat exchange becomes possible, so that the performance of the heat exchanger can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat exchanger according to an embodiment of the present invention (however, it is also used for explanation of the prior art).

FIG. 2 is a cross-sectional view of the heat exchanger according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a flow of a refrigerant in a heat exchanger corresponding to the structure of FIG. 2;

FIG. 4 is a plan view of a forming plate constituting a tube of the heat exchanger of FIG. 2;

FIG. 5 is an enlarged cross-sectional view of an inlet tank of the heat exchanger of FIG. 2;

FIG. 6 is an enlarged cross-sectional view of an inlet tank provided with a partition plate different from that of FIG. 5;

FIG. 7 is an enlarged cross-sectional view of an inlet tank provided with a partition plate different from that of FIG. 6;

FIG. 8 is a cross-sectional view of a heat exchanger according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram showing a flow of a fluid in a conventional heat exchanger.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchanger 2 Tube 3 Fin 4 Inlet tank 5 Outlet tank 6 Expansion valve 7 Core part 8, 9 Side plate 10 Flat tank 11 Inlet flow path 12 Outlet flow path 13 Inlet pipe 14 Outlet pipe 15 Partition plate 16 Refrigerant introduction side Chamber 17 Refrigerant anti-introduction side chamber 18 Communication permitting part 21 Gas tube 22 Liquid tube 23 Forming plate 25, 26 Partition plate 27 First chamber 28 Second chamber

Claims (3)

[Claims] 1. A heat exchanger having an inlet tank, a plurality of tubes connected to and connected to the inlet tank, and introducing a gas-liquid two-phase refrigerant to the inlet tank through an expansion valve.
In the inlet tank, a partition plate for partitioning the inside of the inlet tank into at least two chambers on a refrigerant introduction side and a refrigerant non-introduction side and allowing communication between the two chambers is provided, and the communication permitting portion of the partition plate is connected to the inlet. A heat exchanger formed at a lower portion in a cross-sectional direction of a tank. 2. The heat exchanger according to claim 1, wherein the number of tubes communicating with the refrigerant introduction side chamber of the inlet tank is smaller than the number of tubes communicating with the refrigerant non-introduction side chamber. 3. A gas refrigerant is mainly introduced into a tube communicating with a refrigerant introduction side chamber of the inlet tank, and a liquid refrigerant is mainly introduced into a tube communicating with the refrigerant non-introduction side chamber. 1 or 2 heat exchangers.