JPH0886583A - Heat exchanger - Google Patents

Abstract

PURPOSE: To improve the heat exchanging efficiency by reducing the uneven flow of refrigerant in a heat exchanger. CONSTITUTION: This heat exchanger 1 comprises a refrigerant tube 4 provided through a plurality of fins 3. The tube 4 is partitioned to a plurality of sets S1-S3 formed of a plurality of parallel tubes 6, 7. The tuber 6, 7 of the sets S1, S2 communicate with each other at the ends, and communicate with the ends of the tubes 6, 7 of the other sets S2, S3 at a single passage 2P.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for refrigeration and air conditioning, which has a refrigerant pipe provided through a plurality of fins.

[0002]

2. Description of the Related Art Conventionally, heat exchangers used in evaporators or condensers for refrigeration and air conditioning are, for example, Japanese Utility Model Sho 60-26.
No. 301 publication (F28F1 / 32) and Jitsuko Sho 60-26
As disclosed in Japanese Patent Publication No. 303 (F28F1 / 32), a plurality of fins are arranged at a predetermined interval, a plurality of refrigerant pipes are provided through the fins, and end portions of the respective refrigerant pipes are arranged. A connecting pipe (bend pipe) bent into a curved shape is connected to form a meandering coolant passage.

For the purpose of reducing the flow resistance of the refrigerant passing through the refrigerant pipe, improving heat exchange efficiency and space efficiency, and the like, conventionally, a plurality of refrigerant pipes of this type heat exchanger are provided at the inlet. It was divided into parallel pipes and re-joined at the outlet.

An example of the piping configuration of the conventional heat exchanger 100 according to FIG. 4 is shown. In each drawing, each refrigerant pipe 101
Actually, as described above, 102 and 102 are formed by connecting a plurality of refrigerant pipes and connecting pipes so as to form a meandering refrigerant passage. Shown with a tube.

That is, the heat exchanger 100 is provided with a plurality of fins 103, ... Arranged at a predetermined interval and, for example, two refrigerant pipes 101, 102 penetrating the fins 103. The heat exchanger 100
A distribution pipe 104 is connected to the ends of both the refrigerant pipes 101 and 102 located on the inlet side of the heat exchanger 100, and a merging pipe 106 is connected to the ends of the refrigerant pipes 101 and 102 located on the outlet side of the heat exchanger 100. Are connected.

The refrigerant flowing into the heat exchanger 100 as shown by the arrow in the figure is divided into two parts by the distribution pipe 104, passes through the refrigerant pipes 101 and 102, and radiates heat (used as a condenser). In some cases), or after absorbing heat (when used as an evaporator), they merge at the merge pipe 106 and exit.

FIG. 5 shows another example of the piping structure of the conventional heat exchanger 100. In this case, the refrigerant pipes 101, 10
2 is configured to be slightly shorter than that in FIG. 4, and one refrigerant pipe 107 having the fins 103 is connected even after exiting the joining pipe 106.

[0008]

However, the amount of the refrigerant and the liquid / gas ratio of the refrigerant divided into the refrigerant pipes 101 and 102 are determined by the difference in the channel resistance between the refrigerant pipes 101 and 102 and the heat exchanger. 100 is likely to be non-uniform (unbalanced) due to differences in the degree of contact with the wind. This non-uniformity is especially noticeable in the case of evaporators with high pressure loss,
Further, it is likely to occur even when a non-azeotropic mixed refrigerant is used.

Such non-uniformity of the flow rate of the refrigerant occurs,
When almost no refrigerant flows through one of the refrigerant pipes 101 or 102, the heat exchanger 100 functions only half of that. That is, the entire heat exchanger 100 cannot be effectively used, and the heat exchange efficiency is reduced.

In order to deal with this, both refrigerant pipes 10
A method of establishing a pressure balance by connecting the intermediate portions of Nos. 1 and 102 with a pressure equalizing pipe may be considered, but in any case, since the refrigerant hardly flows through the pressure equalizing pipe, non-uniformity of the refrigerant flow rate or the like cannot be effectively resolved. was there.

The present invention has been made to solve the above-mentioned conventional technical problems, and an object of the present invention is to improve the heat exchange efficiency by reducing the uneven flow of the refrigerant in the heat exchanger. To do.

[0012]

A heat exchanger according to a first aspect of the present invention comprises a refrigerant pipe penetrating a plurality of fins, each of the refrigerant pipes being a plurality of parallel pipes. In addition to dividing into multiple sets composed of piping,
The parallel pipes of this set are connected to each other at their ends, and are connected to the ends of the parallel pipes of the other set through a single passage.

A heat exchanger according to a second aspect of the present invention is provided with a refrigerant pipe penetrating a plurality of fins, the plurality of refrigerant pipes being arranged in parallel with each other. It has a set and a connecting pipe connected to the end of each refrigerant pipe of both sets between these sets, and this connecting pipe has a single passage which connects both sets.

In the heat exchanger according to a third aspect of the present invention, in the above, the diameters of the passages communicating with each other are narrowed.

[0015]

According to the invention of claim 1, the refrigerant pipes constituting the heat exchanger are divided into a plurality of sets each composed of a plurality of parallel pipes, and the parallel pipes of this set are mutually connected at the ends. Since they are communicated and communicated with the ends of the parallel pipes of another set through a single passage, even if there is unevenness in the flow rate of the refrigerant in the parallel pipes of a certain set, after leaving the set. Since they are once merged and then flow into another set, the nonuniform refrigerant flow rate is resolved at this point. Therefore, nonuniformity of the flow rate of the refrigerant is less likely to occur in the entire heat exchanger, and the performance of the heat exchanger can be fully exerted to improve the heat exchange efficiency.

According to the second aspect of the invention, a plurality of sets of a plurality of refrigerant pipes arranged in parallel with each other,
Between these sets, with a connecting pipe connected to the end of each refrigerant pipe of both sets, this connecting pipe was provided with a single passage that communicates both sets, so in the unlikely event of a refrigerant pipe of one set Even if the non-uniformity of the refrigerant flow rate or the like occurs, the non-uniformity of the refrigerant flow rate or the like is resolved at this point because the non-uniformity of the refrigerant flow rate is merged once by the connecting pipe and then flows into another set.
Therefore, nonuniformity of the flow rate of the refrigerant is less likely to occur in the entire heat exchanger, and the performance of the heat exchanger can be fully exhibited to improve the heat exchange efficiency.

Further, according to the invention of claim 3, in addition to these, since the diameter of the passages for communicating the assembly is narrowed, the temperature difference between the inlet and the outlet of the heat exchanger can be reduced. When it is used as an evaporator, it is possible to suppress or eliminate the formation of frost at the inlet.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a piping configuration diagram of a heat exchanger 1 of the present invention, FIG. 2 is a front view of the heat exchanger 1, and FIG. 3 is a perspective view of a connecting pipe 2. That is, the heat exchanger 1 is composed of a plurality of fins 3 arranged at a predetermined interval and a refrigerant pipe 4 penetrating the fins 3. Reference numeral 4 denotes a set S of a plurality (three in the embodiment) of parallel pipes 6 and 7 each composed of, for example, two refrigerant pipes.
It is divided into 1, S2, and S3.

A connecting pipe 2 is attached between each set S1, S2, S3 and connected in series with each other. As shown in FIG. 3, this connecting pipe 2 is provided with, for example, two inlets 2I, 2I and two outlets 2E, 2E, and a single passage 2P connecting these inlets 2I, 2I and outlets 2E, 2E. The diameter of the passage 2P is narrower than the diameter of other pipes.

Then, one ends of the parallel pipes 6 and 7 forming the set S1 are connected to the inlets 2I and 2I of the connecting pipe 2 respectively, and the outlets 2E and 2E of the parallel pipes 6 and 7 forming the set S2 are connected. Connect to the other end. Similarly, one ends of the parallel pipes 6 and 7 forming the set S2 are connected to the inlets 2I and 2I of the connecting pipe 2 respectively, and the outlets 2E and
2E is connected to the other ends of the parallel pipes 6 and 7 forming the set S3, respectively. Further, the same branch pipe 11 as that described above is connected to the other ends of the parallel pipes 6 and 7 forming the set S1, and the merging pipe 12 is connected to one end of the parallel pipes 6 and 7 forming the set S3.

As a result, the parallel pipes 6 and 7 of each set S1 to S3 are connected in parallel to each other, and between each set S1 and S2, and between S2 and S3, a single passage 2P having a connection 2 is provided. Will be communicated with each other.

The heat exchanger 1 having such a configuration is used as an evaporator of a refrigerant circuit (not shown), and for example, R-12 is provided in the refrigerant circuit.
5 (25 wt%), R-32 (23 wt%) and R-1
A non-azeotropic mixed refrigerant composed of 34a (52 wt%) is filled. The mixed refrigerant discharged from the compressor (not shown) and condensed in the condenser is decompressed by the decompression device, and then flows into the heat exchanger 1 as a two-phase flow as indicated by an arrow in the figure. The refrigerant that has flowed into the heat exchanger 1 is split into two in the diversion pipe 11, enters the parallel pipes 6 and 7 of the set S1, and is first evaporated from R-32 and R-125 having a low boiling point therein. It exerts an endothermic action (cooling action).

The refrigerants that have passed through the parallel pipes 6 and 7 of the set S1 once merge at the connection pipe 2, and then split into two again and then enter the parallel pipes 6 and 7 of the set S2. Then, the refrigerants that have passed through the parallel pipes 6 and 7 of the set S2 merge again in the connection pipe 2, and then split into two again, and then enter the parallel pipes 6 and 7 of the set S3. R-134a
(After starting to evaporate), they merge at the merging pipe 12 and exit. The state of the refrigerant flowing through the heat exchanger 1 will be described. R-32 and R- having a low boiling point are provided near the inlet of the refrigerant.
The gas ratio of 125 is large, and R-134 is near the outlet.
The ratio of the gas of a becomes large. Further, the refrigerant flowing through the heat exchanger 1 is throttled when passing through the passage 2P of the connecting pipe 2.

Here, a non-azeotropic mixed refrigerant is used as the refrigerant, and due to the deviation of the wind flowing around the heat exchanger 1, etc., the refrigerant is evenly distributed in the parallel pipes 6 and 7 in each of the sets S1 to S3. Is not split, and the non-uniform refrigerant flow rate and non-uniform liquid / gas ratio are likely to occur. However, in the present invention, for example, even if non-uniformity of the refrigerant flow rate or the like occurs in the parallel pipes 6 and 7 of the set S1, the refrigerant exiting the set S1 is once merged in the connection pipe 2 and then to the set S2. It will flow in. Therefore, the non-uniformity of the refrigerant flow rate and the liquid / gas ratio generated in the set S1 is caused by the passage 2P of the connecting pipe 2.
Since it is mixed and eliminated at the time of flowing into the heat exchanger 1, non-uniformity of the refrigerant flow rate or the like hardly occurs in the whole set S1 to S3 of the heat exchanger 1, and the performance of the heat exchanger 1 is sufficiently exhibited to perform heat exchange. Efficiency is improved.

In particular, since the refrigerant is throttled in the passage 2P of the connecting pipe 2, the temperature difference between the inlet and the outlet of the heat exchanger 1 can be reduced, and the occurrence of frost at the inlet can be suppressed or eliminated. It becomes possible to do.

Although each set S1 to S3 is composed of two parallel pipes 6 and 7 in the embodiment, it may be composed of more parallel pipes. Further, the number of sets is not limited to three, and the heat exchanger may be divided into a large number of sets of two or four or more. Furthermore, although the present invention is applied to the evaporator of the refrigerant circuit in the embodiment, the present invention is not limited to this, and the present invention is also effective to a condenser.

[0027]

As described above in detail, according to the invention of claim 1, the refrigerant pipes constituting the heat exchanger are divided into a plurality of sets each composed of a plurality of parallel pipes, and the parallel pipes of this set are divided. Since they are communicated with each other at their ends and the ends of the parallel pipes of other sets are communicated with each other through a single passage, the flow rate of the refrigerant and the liquid / gas ratio may not be uniform in the parallel pipes of a certain set. Even if they occur, they are once merged after leaving the set and then flow into another set, so that the nonuniformity of the refrigerant flow rate and the like is resolved at this point. Therefore, nonuniformity of the flow rate of the refrigerant is less likely to occur in the entire heat exchanger, and the performance of the heat exchanger can be fully exerted to improve the heat exchange efficiency.

According to the second aspect of the invention, a plurality of sets of a plurality of refrigerant pipes arranged in parallel with each other,
Between these sets, with a connecting pipe connected to the end of each refrigerant pipe of both sets, this connecting pipe was provided with a single passage that communicates both sets, so in the unlikely event of a refrigerant pipe of one set Even if the non-uniformity of the refrigerant flow rate or the like occurs, the non-uniformity of the refrigerant flow rate or the like is resolved at this point because the non-uniformity of the refrigerant flow rate is merged once by the connecting pipe and then flows into another set.
Therefore, nonuniformity of the flow rate of the refrigerant is less likely to occur in the entire heat exchanger, and the performance of the heat exchanger can be fully exhibited to improve the heat exchange efficiency.

Further, according to the invention of claim 3, in addition to these, since the diameter of the passages for communicating the assembly is narrowed, it is possible to reduce the temperature difference between the inlet and the outlet of the heat exchanger. When it is used as an evaporator, it is possible to suppress or eliminate the formation of frost at the inlet.

[Brief description of drawings]

FIG. 1 is a piping configuration diagram of a heat exchanger of the present invention.

FIG. 2 is a front view of the heat exchanger of the present invention.

FIG. 3 is a perspective view of a connection pipe.

FIG. 4 is a piping configuration diagram of a conventional heat exchanger.

FIG. 5 is a piping configuration diagram of another conventional heat exchanger.

[Explanation of symbols]

 1 Heat Exchanger 2 Connection Pipe 2P Passage 3 Fin 4 Refrigerant Pipe 6, 7 Parallel Pipe S1-S3 Assembly

Front Page Continuation (72) Inventor Takahide Kakinuma 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Koji Sato 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd.

Claims (3)

[Claims] 1. A heat exchanger comprising a refrigerant pipe provided through a plurality of fins, wherein the refrigerant pipe is divided into a plurality of sets each composed of a plurality of parallel pipes, and 2. The heat exchanger characterized in that the parallel pipes of the above are communicated with each other at their ends, and are communicated with the ends of the parallel pipes of another set through a single passage. 2. A heat exchanger provided with a refrigerant pipe penetrating a plurality of fins, comprising a plurality of sets of refrigerant pipes arranged in parallel with each other, and both sets between these sets. And a connection pipe connected to the end of each refrigerant pipe, the connection pipe having a single passage communicating the both sets. 3. The heat exchanger according to claim 1, wherein the diameter of the passages for communicating the assembly with each other is reduced.