JP2001330388A - Heat exchanger unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that it is very difficult to dispose a plurality of heat transfer tubes indistinguishable in outward appearance at prescribed positions correctly and surely when the heat transfer tubes different in an internal shape are present mixedly in an assembling process, and that the heat transfer performance thereof lowers considerably when they are disposed at incorrect position on the occasion of assembling a heat exchanger unit by using integral fins not being divided. SOLUTION: By dividing a fin group in the heat exchanger unit into a plurality of groups, finned heat exchangers can be made independent respectively for each of the heat transfer tubes in the same shape. Consequently, assembling processes can be made independent respectively and the mixed presence of the heat transfer tubes different in the shape of a groove can be avoided. It is also possible to constitute each finned heat exchanger according to the difference in length and to distinguish the heat transfer tubes from each other easily according to the outward appearance on the basis of the difference in length. Accordingly, it is possible to assemble the heat transfer tubes having several kinds of internal shapes in prescribed dispositions correctly and to obtain the heat exchanger unit being stable and having high performances.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger unit mainly used for an air conditioner or the like.

[0002]

2. Description of the Related Art A first conventional example of Japanese Patent Application Laid-Open No.
FIG. 9 shows a representative drawing of the '92 publication. FIG. 9 is a sectional view of the heat exchanger unit. The heat exchanger unit is fin 1
01 and the heat transfer tubes 102a,
b, 102c, and 102d.

At the time of condensation, the refrigerant flows in the pipe in the direction of arrow 103, and exchanges heat with the air flowing between the fins 101 outside the pipe. The heat transfer tubes 102a and 102d in which the refrigerant vapor and the liquid refrigerant in the single-phase region flow are smooth tubes having smooth inner wall surfaces. The heat transfer tubes 102b and 102c through which the two-phase refrigerant flows in which the refrigerant flows as a mixture of vapor and liquid are heat transfer tubes having a spiral groove having a trapezoidal cross section on the inner wall surface of the tube. The bottom width is the heat transfer tube 102 in the high dryness area.
The groove bottom width W2 of the heat transfer tube 102b in the low-dryness region is larger than the groove bottom width W1 of b.

[0004] Such a configuration produces the following effects. In the region where single-phase refrigerant vapor and liquid refrigerant flow,
By using a smooth tube having almost the same heat transfer performance as the grooved tube, an inexpensive heat exchanger unit can be obtained without lowering the heat exchange capacity and using a heat transfer tube with low processing cost. Further, by using a heat transfer tube having a small groove bottom width in a high dryness region and using a heat transfer tube having a large groove bottom width in a low dryness region, higher performance can be achieved.

Next, a second prior art example of Japanese Utility Model Laid-Open No. 62-29 is shown.
FIG. 10 shows a representative drawing of the '555 publication. FIG. 10 is a cross-sectional view of a main part of the heat exchanger unit. The heat exchanger unit includes a fin 111 and a heat transfer tube 11 penetrating at right angles thereto.
2a, 112b, and 112c.

[0006] The air flow flows in the direction of arrow W, and the heat exchanger units are composed of a plurality of rows from the windward side to the leeward side. The heat transfer tube 112a is a smooth tube having a smooth inner wall surface,
The heat transfer tube 112b is a grooved tube with a spiral groove having a spiral angle θ1 formed on the inner wall surface, and the heat transfer tube 112c is a grooved tube with a spiral groove having a spiral angle θ2 formed on the inner wall surface. The performance shows high heat transfer performance in the order of the heat transfer tubes 112a, 112b, and 112c. These heat transfer tubes 112a, 112b, 112 are arranged in the direction from the windward side to the leeward side.
c.

[0007] With such a configuration, the following effects are produced. Since the heat transfer performance of the heat transfer tubes 112a, 112b, and 112c is sequentially increased, their outer surface temperatures T
The values of a, Tb, and Tc decrease sequentially, and as a result, the temperature difference between the air temperature and the fin surface temperature becomes almost the same on the windward side and the leeward side. Therefore, the progress of frosting on the fins 111 is uniform, and the time until the occurrence of clogging due to frosting becomes longer. In other words, the reduction in the capacity during frost formation is reduced, the frequency of the defrosting operation is reduced, and the average heating capacity is improved.

[0008]

However, in the first and second prior art arrangements, since the integrated fins are not divided into any fins, when the heat exchanger unit is assembled, an inner surface is not used. A plurality of heat transfer tubes having different shapes are mixed in the assembly process. It is very difficult to reliably arrange heat transfer tubes, which cannot be distinguished by their appearance, without error. It is conceivable to add a device to make a distinction, but this requires an extra investment. Also, if the heat transfer tube is placed in the wrong position,
It is easy to presume that the heat transfer performance is significantly reduced. As described above, since the fins are not divided, a plurality of types of heat transfer tubes are mixed in the assembly process of the heat exchanger unit. However, there is a problem that the performance is significantly reduced.

The present invention solves such a conventional problem. By dividing a fin and combining a plurality of finned heat exchangers to constitute a heat exchanger unit, several types of tube inner surface shapes can be formed. Without mistaking the heat transfer tubes
An object is to provide a high-performance heat exchanger unit that can be assembled in a predetermined arrangement.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a group of fins arranged in parallel at a predetermined interval, through which a gas flows, and a row of fins penetrating the fins at substantially right angles. And a heat transfer tube group through which the fluid flows,
The fin group is divided into a plurality, and the inner surface shape in the heat transfer tube constituting at least one or more finned heat exchangers,
Other heat exchangers with fins are constituted by heat transfer tubes different from the inner surface shape inside the heat exchanger tubes, and each heat exchanger with fins has an independent configuration. Thus, a configuration having a different length for each finned heat exchanger is possible, and the heat transfer tubes can be easily distinguished by their different lengths. In addition, it is possible to make the assembly process independent for each heat exchanger with fins, avoid mixing heat transfer tubes having different groove shapes, and arrange heat transfer tubes having several types of tube inner surface shapes in a predetermined arrangement without mistake. Assembling is possible and a stable and high-performance heat exchanger unit can be obtained.

[0011]

According to the first aspect of the present invention, a plurality of fins are arranged in parallel at a predetermined interval, and a gas flows between the fins, and the fins penetrate through the fins at substantially right angles to form a row. A heat exchanger unit comprising a heat transfer tube group through which a fluid flows, wherein the fin group is divided into a plurality of heat transfer tubes each having a heat transfer tube of the same diameter. Is formed of a heat transfer tube having an inner surface shape different from the inner surface shape of the heat transfer tube forming another heat exchanger with fins. According to this configuration, it is possible to make the assembling process independent for each finned heat exchanger, and it is also possible to avoid mixing of heat transfer tubes having different groove shapes,
It is possible to assemble the heat transfer tubes having several types of tube inner surface shapes in a predetermined arrangement without mistake, and to obtain a stable and high-performance heat exchanger unit.

According to a second aspect of the present invention, a plurality of fins are arranged in parallel at a predetermined interval, and a gas flows between the fins, and the fins penetrate through the fins at a substantially right angle to form a line. A heat exchanger unit comprising a flowing heat transfer tube group, wherein the fin group is divided into a plurality of heat exchanger units, wherein at least one or more independent heat transfer tubes in the heat exchanger with fins have smooth inner surfaces. By using a smooth tube, the processing cost can be significantly reduced because the pipe is lightweight and does not require groove processing.

According to a third aspect of the present invention, at least one or more independent finned heat exchangers have a longitudinal length different from the lengths of the other finned heat exchangers, and Are different, the difference in groove shape can be easily distinguished, and a heat transfer tube having several types of tube inner surface shapes can be assembled in a predetermined arrangement without mistake, thereby obtaining a stable and high-performance heat exchanger unit. be able to.

According to a fourth aspect of the invention, at least one or more independent finned heat exchangers have a smaller tube diameter than those used in other finned heat exchangers, and use a smooth tube. Thus, the weight can be further reduced, and the cost can be significantly reduced.

According to a fifth aspect of the present invention, a finned heat exchanger using a smooth tube is disposed on the outflow side of the refrigerant flowing through the tube during condensation, so that the smooth tube is formed near the refrigerant outlet during condensation. Since the difference in the heat transfer performance of the grooved tubes is relatively small, a significant decrease in performance can be suppressed, and cost reduction can be achieved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing a basic structure of a heat exchanger unit according to the invention of Embodiment 1, FIG. 2 is a side view thereof, and FIG. 1 and 2, the heat exchanger unit 10 includes a finned heat exchanger 10a located on a gas inflow side W1 of an airflow indicated by an arrow W.
And the finned heat exchanger 10 located on the gas outflow side W2.
b. The finned heat exchanger 10a includes a plurality of fin groups 11a arranged side by side at predetermined intervals, and the fin groups 11a.
And a heat transfer tube group 12a which penetrates at substantially right angles and is arranged in a meandering manner. Further, the finned heat exchanger 10b includes a plurality of fin groups 11b arranged side by side at predetermined intervals, and the fin groups 1b.
Tube group 12 which is arranged in a meandering shape by penetrating through at approximately right angles 1b
b. The finned heat exchanger 10a and the finned heat exchanger 10b are separated from each other, and the heat transfer tube group 12a and the heat transfer tube group 12b are connected at a branch portion 13a. Next, description will be made with reference to FIG. In FIG. 3, a helical convex portion 14a and a groove 15a continuous in the longitudinal direction are formed on the inner wall surface 16a in the heat transfer tube group 12a, and the inner wall surface 16b in the heat transfer tube group 12b is formed in the longitudinal direction. A continuous spiral projection 14b and a groove 15b are formed. The number of the convex portions 14a of the heat transfer tube group 12a
The number of protrusions 14b is smaller than the number of protrusions 14b. In addition,
The airflow W flows through the fin groups 11a and 11b in the direction of the arrow, and exchanges heat with the fluid flowing inside the heat transfer tube groups 12a and 12b.

In the above configuration, when used as a condenser in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tubes flows in a gaseous state from the A1 side, and flows through the branch portion 13b above and below the heat transfer tube group 12b. The heat is exchanged with the airflow W to be in a liquid state through a gas-liquid two-phase state, and merge again at the branch portion 13a, flow into the heat transfer tubes of the heat transfer tube group 12a, and flow out to the A2 side.

When used as an evaporator in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tubes flows from the A2 side in a gas-liquid two-phase state, flows into the heat transfer tubes of the heat transfer tube group 12a, At the branch portion 13a, the flow is divided into upper and lower portions of the heat transfer tube group 12b, merges again at the branch portion 13b, and flows out to the A1 side while exchanging heat with the airflow W.

According to this configuration, since the number of convex portions of the heat transfer tube group 12a is smaller than the number of convex portions of the heat transfer tube group 12b, the heat exchanger unit 10 can be reduced in weight and cost.

In the heat exchanger unit 10, the finned heat exchanger 10a and the finned heat exchanger 10b are separated from each other only because the heat transfer tube group 12a and the heat transfer tube group 12b are connected at the branch portion 13a. As a result, the assembling process can be easily made independent for each heat exchanger with fins, the heat transfer tubes having different groove shapes in the same assembling process can be avoided, and the heat transfer tubes having several types of tube inner surface shapes can be avoided. Can be reliably assembled in a predetermined arrangement, and a heat exchanger unit having a predetermined heat exchange ability stably can be obtained.

FIG. 4 is an enlarged view of the inner shape of the heat transfer tube. In FIG. 4, θ is the peak angle of the convex portion 14 and G is the convex portion 1.
4 is the crest width, h is the height of the protrusion 14, and I is the groove bottom width of the groove 15. Although the difference in shape between the heat transfer tube group 14a and the heat transfer tube group 14b is indicated by the number of protrusions and the number of grooves, the weight of the heat transfer tubes can be reduced by the height h, the groove bottom width I, and the like.

(Embodiment 2) FIG. 5 is a sectional view of a main part of a basic structure of a heat exchanger unit. This heat exchanger unit differs from the first embodiment in that one of a plurality of finned heat exchangers has a smooth tube inner wall surface and the heat transfer tube diameter does not have to be the same. The portions having the same configuration and operation and effect are denoted by reference numerals, detailed description thereof will be omitted, and different portions will be mainly described.

Reference numeral 20a denotes a finned heat exchanger which includes a plurality of fin groups 21a arranged side by side at predetermined intervals,
tube group 22a which penetrates a at a substantially right angle and is arranged in a meandering manner
The inner wall surface shape 26a of the heat transfer tube group 22a is formed with a smooth surface. Reference numeral 20b denotes a finned heat exchanger, which includes a number of fin groups 21b arranged side by side at predetermined intervals.
The heat transfer tube group 22b penetrates the fin group 21b at a substantially right angle and is arranged in a meandering manner. The inner wall surface shape 26b of the heat transfer tube group 22b has a continuous spiral convex portion 24b and a groove portion 25b.
And formed.

In the above configuration, when used as a condenser in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tubes flows into the finned heat exchanger 20b in a gaseous state, and flows through the heat transfer tube group 22b. After flowing, it flows into the heat transfer tubes of the heat transfer tube group 22a in the finned heat exchanger 20a, and flows out of the liquid flow through a gas-liquid two-phase state by heat exchange with the airflow W.

When used as an evaporator in a refrigeration cycle of an air conditioner, the fluid flowing in the heat transfer tubes flows into the finned heat exchanger 20a in a two-phase state, and the heat transfer tube group 2
After flowing through 2a, it flows into the heat transfer tubes of the heat transfer tube group 22b in the finned heat exchanger 20b, exchanges heat with the airflow W, and flows out.

According to this configuration, the finned heat exchanger 2
The inner wall surface shape 26a of the heat transfer tube group 22a in Oa is constituted by a smooth tube whose surface is a flat surface, thereby making it possible to further reduce the weight and greatly reduce the processing cost because there is no groove processing step. it can.

In the heat exchanger unit, since the finned heat exchanger 20a and the finned heat exchanger 20b are separated from each other, the assembly process can be easily made independent for each finned heat exchanger. It is possible to avoid mixing of heat transfer tubes having different groove shapes in the same assembling process, and to assemble heat transfer tubes having several kinds of tube inner surface shapes in a predetermined arrangement without fail, and to stably obtain a predetermined heat exchange. A capable heat exchanger unit is obtained.

(Embodiment 3) FIG. 6 is a sectional view of a main part of a basic structure of a heat exchanger unit. This heat exchanger unit has one of a plurality of finned heat exchangers with a thin heat transfer tube diameter,
In addition, since the inner wall surface of the pipe is different from the first and second embodiments in that the inner wall surface is formed with a smooth surface, the same reference numerals are given to other portions having the same configuration and operation and effect, and detailed description is omitted. I will explain mainly.

Reference numeral 30a denotes a finned heat exchanger, which includes a plurality of fin groups 31a arranged side by side at predetermined intervals, and a fin group 31a.
heat transfer tube group 32a which penetrates a at a substantially right angle and is arranged in a meandering manner
Consists of Reference numeral 30b denotes a finned heat exchanger which includes a large number of fin groups 31b arranged side by side at predetermined intervals and a group of heat transfer tubes 32b penetrating the fin groups 31b at substantially right angles and arranged in a meandering manner.

In the above configuration, when used as a condenser in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tubes flows into the finned heat exchanger 30b in a gaseous state, and flows through the heat transfer tube group 32b. After flowing, the gas flows into the heat transfer tubes of the heat transfer tube group 32a in the finned heat exchanger 30a, and flows into a liquid state through a gas-liquid two-phase state due to heat exchange with the airflow W and flows out.

When used as an evaporator in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tubes flows into the finned heat exchanger 30a in a two-phase state, and the heat transfer tube group 3
After flowing through 2a, it flows into the heat transfer tubes of the heat transfer tube group 32b in the finned heat exchanger 30b, exchanges heat with the airflow W, and flows out.

According to this configuration, the finned heat exchanger 3
The inner surface shape 36a of the heat transfer tube group 32a in 0a is formed of a smooth tube having a flat surface. By using a smooth tube having a small diameter of the heat transfer tube, the weight can be further reduced, and the groove forming process can be performed. Since there is no such material, the processing cost can be greatly reduced.

Further, since the heat transfer tubes have different diameters, they can be distinguished by their appearance, and even if they are mixed in one assembly process, it is possible to assemble the heat transfer tubes having several types of inner surface shapes into a predetermined arrangement without fail. Thus, a heat exchanger unit having a predetermined heat exchange capacity can be obtained stably.

(Embodiment 4) FIG. 7 is a perspective view of a heat exchanger unit according to an embodiment 4 of the present invention after bending, FIG. 8 is a perspective view before bending, and FIG. 9 is a sectional view of a main part thereof. . 7, the heat exchanger unit 40 includes a finned heat exchanger 40a located on the gas inflow side W1 of the airflow indicated by the arrow W.
And the finned heat exchanger 40 located on the gas outlet side W2
b. The finned heat exchanger 40a includes a plurality of fin groups 41a arranged side by side at predetermined intervals, and the fin groups 41a.
And a heat transfer tube group 42a penetrating at substantially right angles and arranged in a meandering manner. The finned heat exchanger 40b includes a plurality of fin groups 41b arranged side by side at predetermined intervals, and the fin groups 4b.
Tube group 42 arranged in a meandering shape by penetrating substantially perpendicularly through 1b
b. The heat exchanger unit has a predetermined bending radius R
, And is bent at 90 degrees to improve the storability in outdoor air conditioners. FIG. 8 shows a state before the bending. In FIG. 8, the finned heat exchanger 40a
And the finned heat exchanger 40b are separated from each other, and the length of the heat transfer tube group 42a is longer than the length of the heat transfer tube group 42b by the step dL. As a result, it is possible to finish in a state where there is no step at both end surfaces as shown in FIG. Next, FIG.
In the inner wall surface 46a in the heat transfer tube group 42a, the inner wall surface shape 46a of the heat transfer tube group 42a is formed as a smooth surface, and the inner wall surface shape 46b of the heat transfer tube group 42b is a continuous spiral convex. It is formed by a portion 44b and a groove 45b. The airflow W flows through the fin group 41a and the fin group 41b in the direction of the arrow, and exchanges heat with the fluid flowing inside the heat transfer tube group 42a and the heat transfer tube group 42b.

According to this configuration, the finned heat exchanger 4
0a, the inner wall surface 46a of the heat transfer tube group 42a is formed of a smooth tube having a flat surface. By using the smooth tube, the weight can be reduced. Can also be significantly reduced.

The heat transfer tube 41a of the finned heat exchanger 40a and the heat transfer tube of the finned heat exchanger 40b have different inner wall shapes and different lengths, so that the same tube diameter is obtained. Therefore, even if the heat transfer tubes having different groove shapes are mixed in the same assembling process, it is possible to reliably assemble them in a predetermined arrangement, and to obtain a heat exchanger unit having a predetermined heat exchange ability stably.

(Embodiment 5) A description of Embodiment 5 will be given with reference to FIGS. 7 and 9 to 10. In FIG. 7, the heat exchanger unit 40 includes a finned heat exchanger 40a located on the gas inflow side W1 of the airflow indicated by the arrow W and a finned heat exchanger 40b located on the gas outflow side W2. The finned heat exchanger 40a is composed of a large number of fin groups 41a arranged side by side at predetermined intervals and a group of heat transfer tubes 42a penetrating the fin groups 41a at substantially right angles and arranged in a meandering manner. The finned heat exchanger 40b includes a large number of fin groups 41b arranged side by side at predetermined intervals and a group of heat transfer tubes 42b penetrating the fin groups 41b at substantially right angles and arranged in a meandering manner. In FIG. 9, the inner wall surface 46a in the heat transfer tube group 42a is formed of a smooth surface, and the inner wall surface shape 4 of the heat transfer tube group 42b is
6b is formed by a continuous spiral convex part 44b and a groove part 45b. The airflow W flows through the fin group 41a and the fin group 41b in the direction of the arrow, and exchanges heat with the fluid flowing inside the heat transfer tube group 42a and the heat transfer tube group 42b.

In the above configuration, when used as a condenser in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tubes is in a gaseous state and the finned heat exchanger 40 on the A1 side.
b, flows up and down by the branch portion 43b, flows through the heat transfer tube group 42b, flows into the heat transfer tube group 42a of the finned heat exchanger 40a, and merges again at the branch portion 43a.
Outflow to the two sides. The fluid flowing in the heat transfer tube undergoes a phase change from a gas phase state to a liquid state through a gas-liquid two-phase state due to heat exchange with the gas flow W on the way.

When used as an evaporator in a refrigeration cycle of an air conditioner, the fluid flowing through the heat transfer tube flows in the gas-liquid two-phase state from the A2 side, and is split up and down at the branch 43a. The heat passes through the heat transfer tubes of the group 42a, flows into the heat transfer tube group 42b, merges again at the branch portion 13b, and flows out to the A1 side. The fluid flowing in the heat transfer tube is in a gas-liquid two-phase state due to heat exchange with the airflow W on the way, but changes from a state of low dryness to a state of high dryness.

According to this configuration, the finned heat exchanger 4
0a, the inner wall surface 46a of the heat transfer tube group 42a is formed of a smooth tube having a flat surface. By using the smooth tube, the weight can be reduced. Can also be significantly reduced.

On the other hand, the use of a smooth tube causes a decrease in heat exchange capacity. The heat exchange capacity of the heat exchanger unit will be described with reference to FIG. FIG. 10 shows the relationship between the dryness of the fluid flowing in the heat transfer tube and the heat transfer coefficient. Curve E
Represents the heat transfer coefficient of the heat transfer tube group 42a having low heat transfer performance, and the curve F represents the heat transfer coefficient of the heat transfer tube group 42b having high heat transfer performance. FIG.
According to 0, although the heat transfer coefficient is low in the region where the dryness is small, the value of the heat transfer coefficient of the curve F sharply increases in the region where the dryness is large, and the degree of improvement of the heat transfer coefficient is the dryness. It can be seen that the region with the larger value is significantly larger. When used as a condenser in a refrigeration cycle of an air conditioner, the fluid flowing in the heat transfer tubes flows into the heat transfer tube group 42b having a high heat transfer performance in a gaseous state, and is transferred in a liquid state through a two-phase state. It flows out from the heat transfer tube group 42a having low thermal performance. By using the heat transfer tube group 42a on the side where the dryness is small, it is possible to reduce the cost while suppressing a decrease in the heat transfer performance.

[0043]

As is apparent from the above embodiment, the invention according to claim 1 is arranged in parallel at a predetermined interval, and a fin group through which gas flows and a fin group penetrating the fin group at a substantially right angle. A fin group is divided into a plurality of fin groups, and the heat exchanger unit comprises heat transfer tubes having the same pipe diameter.
One or more independent finned heat exchangers are composed of heat transfer tubes whose inner surface shape is different from the inner surface shape of the heat transfer tubes that make up other finned heat exchangers. The assembly process can be made independent for each vessel, the heat transfer tubes with different groove shapes can be avoided, and the heat transfer tubes with several types of tube inner surface shapes can be assembled in a predetermined arrangement without mistake, and stable. As a result, a high-performance heat exchanger unit is obtained.

According to a second aspect of the present invention, a plurality of fins are arranged in parallel at predetermined intervals, and a gas flows between the fins and the fins penetrate through the fins at substantially right angles to form a line. A heat exchanger unit comprising a flowing heat transfer tube group, wherein the fin group is divided into a plurality of heat exchanger units, wherein at least one or more independent heat transfer tubes in the heat exchanger with fins have smooth inner surfaces. By using a smooth tube, the processing cost can be significantly reduced because the pipe is lightweight and does not require groove processing.

According to a third aspect of the present invention, the length of the heat exchanger with at least one or more independent fins is different from the length of the other heat exchangers with fins, and the length of the heat transfer tube is different. Are different, the difference in groove shape can be easily distinguished, and a heat transfer tube having several types of tube inner surface shapes can be assembled in a predetermined arrangement without mistake, thereby obtaining a stable and high-performance heat exchanger unit. be able to.

According to a fourth aspect of the present invention, the diameter of at least one or more independent finned heat exchangers is smaller than the diameter of a tube used in another finned heat exchanger, and a smooth tube is used. Thus, the weight can be further reduced, and the cost can be significantly reduced.

According to a fifth aspect of the present invention, a finned heat exchanger using a smooth tube is disposed on the outflow side of the refrigerant flowing in the tube during condensation, so that the smooth tube is formed near the refrigerant outlet during condensation. Since the difference in the heat transfer performance of the grooved tubes is relatively small, a significant decrease in performance can be suppressed, and cost reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat exchanger unit showing a first embodiment of the present invention.

FIG. 2 is a side view of the heat exchanger unit of the embodiment.

FIG. 3 is a sectional view of a main part of the heat exchanger unit showing the embodiment.

FIG. 4 is an enlarged sectional view of the shape of the inner wall surface of the heat transfer tube.

FIG. 5 is a sectional view of a main part of a heat exchanger unit according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a heat exchanger unit according to a third embodiment of the present invention.

FIG. 7 is a perspective view of a heat exchanger unit according to a fourth embodiment of the present invention.

FIG. 8 is a perspective view of a heat exchanger unit showing the embodiment.

FIG. 9 is a sectional view of a main part of the heat exchanger unit showing the embodiment.

FIG. 10 is a characteristic diagram showing a relationship between a heat transfer coefficient and a dryness of a fluid flowing in a pipe.

FIG. 11 is a sectional view of a heat exchanger unit showing a first conventional example.

FIG. 12 is a sectional view of a heat exchanger unit showing a second conventional example.

[Explanation of symbols]

10, 40 heat exchanger unit 10a, 10b, 20a, 20b, 30a, 30b, 4
0a, 40b Finned heat exchangers 11a, 11b, 21a, 21b, 31a, 31b, 4
1a, 41b Fin group 12a, 12b, 22a, 22b, 32a, 32b, 4
2a, 42b Heat transfer tube group 13a, 13b, 43a, 43b Branch portion 14, 14a, 14b, 24a, 24b Convex portion in heat transfer tube 15, 15a, 15b, 25a, 25b Groove in heat transfer tube A1 Fluid in tube during condensation A2 Outlet side of pipe fluid during condensation W Airflow main flow direction W1 Airflow inflow side W2 Airflow outflow side

Claims (5)

[Claims] 1. A group of fins, which are arranged in parallel at a predetermined interval and through which gas flows, and a group of heat transfer tubes through which the fins penetrate at substantially right angles to form a row and through which a fluid flows. Prepared,
In the heat exchanger unit in which the fin group is divided into a plurality of parts and a plurality of finned heat exchangers configured by heat transfer tubes having the same pipe diameter are combined, at least one or more independent finned heat exchangers are configured. A heat exchanger unit comprising a heat transfer tube having an inner surface shape different from the inner surface shape of a heat transfer tube constituting another finned heat exchanger. 2. A group of fins arranged in parallel at a predetermined interval and through which a gas flows, and a group of heat transfer tubes through which the fins penetrate at substantially right angles to form a row and through which a fluid flows. Prepared,
In a heat exchanger unit in which a plurality of finned heat exchangers in which the fin group is divided into a plurality of parts are combined, at least one or more independent finned heat exchangers have smooth inner surfaces of heat transfer tubes. Heat exchanger unit. 3. The heat exchanger according to claim 1, wherein the longitudinal length of at least one or more independent finned heat exchangers is different from the length of the other finned heat exchangers. Heat exchanger unit. 4. The heat exchanger with at least one independent fin having a smaller diameter than a tube used in another heat exchanger with fins and using a smooth tube.
The heat exchanger unit according to claim 3. 5. A finned heat exchanger using a smooth tube,
The heat exchanger unit according to any one of claims 2 to 4, wherein the heat exchanger unit is disposed on the outflow side of the refrigerant flowing in the tube during condensation.