JPH1122995A - Air heat exchanger - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To reduce the size and production cost of an air heat exchanger having heat transfer tubes arranged in multiple rows. SOLUTION: A plurality of fins 1, 1,... And a plurality of fins 1, 1,. Heat transfer tube 2,
A plurality of heat exchanger units X ₁ to
The air heat exchangers Z _{1 to} Z ₅ are configured by arranging X ₃ with a predetermined gap L in the flow direction of the air flow. With this configuration, in the heat exchanger units X ₂ and X ₃ on the downstream side of the air flow, the development of the temperature boundary layer formed around the heat transfer tubes 2, 2,. As a result, the heat transfer performance is improved, and the air heat exchangers Z _{1 to} Z ₅ are further downsized. In addition, since the gap L functions as a drop discharge path for condensed water, the drainage of the fins 1 is improved, and the heat transfer performance is accordingly improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of an air heat exchanger.

[0002]

2. Description of the Related Art In a so-called cross fin type air heat exchanger, a plurality of fins whose plate surface directions are substantially parallel to a flow direction of an air flow are arranged opposite to each other at a predetermined interval, and each of the fins is arranged at a predetermined interval. A plurality of heat transfer tubes are arranged in a plurality of rows so as to penetrate in the thickness direction and before and after in the flow direction of the air flow.

[0003]

However, as described above, in an air heat exchanger having a configuration in which a plurality of heat transfer tubes are arranged in multiple rows before and after in the flow direction of the air flow, the following will be described. There was a problem.

[0004] In general, in an air heat exchanger, the heat transfer performance tends to increase as the number of heat transfer tubes increases, but when the number of heat transfer tubes increases, the number of heat transfer tubes increases. , 4 rows or more), since the heat transfer performance in the leeward row of pipes is significantly reduced due to the development of the temperature boundary layer formed around the heat transfer pipes, even if the number of pipe rows of heat transfer tubes is increased, Has a problem that the heat transfer performance is not improved (that is, the heat transfer performance is saturated).

(B) When the air heat exchanger is applied to, for example, an air handling unit, the number of rows of heat transfer tubes in the air heat exchanger may be appropriately changed in accordance with the refrigeration capacity of the equipment. Required. In this case, a conventional general air heat exchanger has an integral structure including a plurality of fins and a plurality of heat transfer tubes. It is necessary to prepare a large number of molds having different numbers of tube rows as molds, resulting in high manufacturing costs.

(C) The condensed water condensed on the surface of the fin due to the operation of the air heat exchanger is caused to flow downward along the fin surface by its own weight, and at the same time, by the air flow flowing between the fins. Receives the effect of being swept downwind. In this case, the conventional air heat exchanger has an integral structure and the fins are continuous from the leading edge to the trailing edge. The condensed water has a stronger effect of being swept to the leeward side by the airflow than the effect of flowing down by its own weight, and is scattered outside from the trailing edge side of the fin. Accordingly, from the viewpoint of preventing the condensed water from scattering to the outside, the passing wind speed of the air flow must be suppressed to a certain level or less, and as a result, there is a certain limit to the improvement of the heat transfer performance.

(D) If the number of rows of heat transfer tubes in the air heat exchanger is increased, a work space around the heat transfer tubes cannot be widened. Therefore, when brazing piping components to the air heat exchanger, Is difficult to perform using an automatic brazing machine. As a result, the number of man-hours in the brazing operation increases, and the manufacturing cost increases accordingly.

Accordingly, the present invention provides an air heat exchanger in which heat transfer tubes are arranged in multiple rows in the flow direction of the air flow, thereby realizing a compact heat exchanger by improving heat transfer performance, and realizing a low manufacturing cost. This is done for the purpose of, for example.

[0009]

Means for Solving the Problems In the present invention, the following configuration is adopted as specific means for solving such problems.

According to the first aspect of the present invention, a plurality of fins 1, 1,... Arranged so as to be opposed to each other at a predetermined interval in the plate thickness direction and to allow an air flow to flow substantially parallel to the plate surface.
And a plurality of heat transfer tubes 2, 2,... Penetrating in the thickness direction of the plurality of fins 1, 1,. the formed plurality of heat exchanger unit X ₁ to X _3, are characterized by being integrated successively arranged with a predetermined gap 4 and these back and forth in the flow direction of the air flow.

[0011] In a second aspect of the present invention, in the air heat exchanger according to the first invention, the width dimension "L" of the gap (4), the fin of the heat exchanger unit X ₁ to X ₃ 1 is “Lw” and the number of rows of the heat transfer tubes 2, 2,... Is “N”, “L ≧ Lw”
/ N ”.

In a third aspect of the present invention, the first or second aspect
In the air heat exchanger according to the invention, the heat transfer tubes 2, 2 in the plurality of heat exchanger unit X ₁ to X _3, · ·
Is characterized in that the number of tube rows is two or three.

[0013]

According to the present invention, the following effects can be obtained by adopting such a configuration.

The air heat exchanger according to the first invention of the present application is provided with a plurality of fins 1 arranged so as to face each other at a predetermined interval in a plate thickness direction and to allow an air flow to flow substantially parallel to the plate surface. , And the plurality of fins 1,
A plurality of heat exchanger units each including a plurality of heat transfer tubes 2, 2,... Penetrating in the thickness direction thereof and arranged in multiple rows in the air flow direction. X _{1 to} X ₃ are
A predetermined gap 4 is sequentially arranged before and after in the flow direction of the air flow, and these are integrated.

Therefore, according to the air heat exchanger of the present invention, the following specific effects can be obtained.

A) The plurality of heat exchanger units X
_{Since 1 to} X ₃ are arranged with the gap 4, the heat exchanger tubes in the downstream row of the heat exchanger units X ₁ and X ₂ on the upstream side of the air flow facing the gap 4 and the heat exchange on the downstream side of the air flow. The continuity in the flow direction of the air flow is interrupted between the heat exchanger tubes of the upstream units in the unit units X ₂ and X ₃ , and the development of unsteady vortices is promoted between these two units, and especially the downstream of the air flow. In the heat exchanger units X ₂ , X ₃ on the side, the development of the temperature boundary layer formed around the heat transfer tubes 2, 2,... Is suppressed as much as possible, and the heat transfer performance is enhanced. As a result, when the enhanced heat transfer performance of the entire air heat exchanger Z ₁ to Z _5, which was the same for example required heat transfer performance,
The heat transfer area of the air heat exchangers Z _{1 to} Z ₅ can be reduced by the heat transfer performance of the heat exchanger units X ₂ and X ₃ on the downstream side of the air flow, and the size can be reduced. It is possible.

B) The condensed water condensed on the surfaces of the fins 1, 1,... With the operation of the air heat exchangers Z _{1 to} Z ₅ is caused to flow downward along the fin surfaces by their own weight. At the same time, the air flow flowing between the fins causes the air to flow downwindward. In this case, the air heat exchangers Z _{1 to} Z ₅ are connected to a plurality of heat exchanger units X ₁ to
Since the X ₃ is constituted by arranged with the gap 4 between and one behind the flow direction of the air flow cross, for example, increasing the passage velocity of air flow in the fin 1 part,
When the action of the condensed water adhering to the surface of the fin 1 flowing downstream on the fin 1 by its own weight is greater than the action of the condensed water flowing downstream by the air flow, especially the upper part of the fin 1 Water (that is, a portion where the distance to the lower end of the fin 1 where the condensed water is dropped is long) before the dripping from the lower end of the fin 1 and the heat exchanger unit and other Scattered toward the gap 4 between the heat exchanger units, most of which are freely dropped and discharged as it is, and another part passes through the gap 4 and is further diverted to the other heat exchanger. It reaches the unit side, is collected by the fins 1 of the heat exchanger unit, and flows down along the surface of the fins 1 and is discharged downward.

Therefore, according to the air heat exchanger of the present invention, drainage of condensed water on the fin surface is improved by providing the gap 4 between the heat exchanger units X ₁ to X _3. In addition, since the condensed water is prevented from being scattered to the downstream side of the air heat exchanger, it is possible to set a higher wind speed of the air flow in the fin 1,
As a result, the heat transfer performance of the air heat exchangers Z _{1 to} Z ₅ is further improved, and the air heat exchangers Z _{1 to} Z ₅ are further downsized.

According to the air heat exchanger according to the second invention of the present application, the width dimension “L” of the gap 4 is set to the width of the fin 1 in the air flow direction in the heat exchanger units X _{1 to} X ₃ . When the dimension is “Lw” and the number of the heat transfer tubes 2, 2,... Is “N”, by setting “L ≧ Lw / N”, the airflow due to the gap 4 is reduced. The effect of promoting the development of the unsteady vortex and the effect of accelerating the drainage of condensed water become more reliable, and the effects described above can be obtained more stably.

According to the air heat exchanger according to the third invention of the present application, the number of the heat transfer tubes 2, 2,... In the plurality of heat exchanger units X _{1 to} X ₃ is two or three. Because the number of heat transfer tubes is two or more, the total number of heat transfer tubes is two or more by appropriately combining a heat exchanger unit with two rows and a heat exchanger unit with three rows. Can easily be obtained. That is, in the case of manufacturing various types of air heat exchangers, the common use of the fins 1 as a part thereof is promoted, and thus the number of fin manufacturing molds is reduced and the number of fins in stock is reduced. The reduction enables a further reduction in the manufacturing cost of the air heat exchanger.

Further, since the air heat exchangers Z _{1 to} Z ₅ are constituted by the heat exchanger units X _{1 to} X ₃ having two or three rows of heat transfer tubes, for example, the air heat exchangers When the piping parts are brazed to the air heat exchangers Z _{1 to} Z _{3 in} the manufacturing process of Z _{1 to} Z ₃ , for example, compared to the case of an air heat exchanger having an integral structure having several rows of pipes, Work space around the heat transfer tube can be widened. As a result, the workability can be improved by using an automatic brazing machine for this brazing operation, and the manufacturing cost of the air heat exchanger can be further reduced accordingly.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air heat exchanger according to the present invention will be specifically described below based on a preferred embodiment.

First Embodiment FIG. 1A shows an air heat exchanger Z1 according to a _first embodiment of the present invention. This air heat exchanger Z ₁
It comprises two heat exchanger units X ₁ and X ₂ described below.

[0024] The heat exchanger unit X ₁ is a fin 1 of rectangular band plate shape with a predetermined interval in the thickness direction with arranging plural, respective fins 1,1, in its thickness direction .. A plurality of penetrating heat transfer tubes 2 are attached. And each of these heat transfer tubes 2, 2, ...
With respect to the fin 1, a tube row 21 is arranged at predetermined intervals in the vertical direction near the front edge 1a of the fin 1, and a tube row 22 is arranged at predetermined intervals in the vertical direction near the rear edge 1b of the fin 1. as such, disposed in two front and rear rows, constitutes a heat exchanger unit X ₁ with tube rows number in the second column.

The heat exchanger unit X ₂ has the same structure as the heat exchanger unit X ₁ .
It omitted by hence the description of the heat exchanger unit X _1.

[0026] The above pair of heat exchanger unit X _1, X ₂ having such a structure, are arranged one behind at a gap 4 having a width "L" in the flow direction of the air flow, and the heat transfer across a common tube plate of the heat pipe axis direction constitutes the air heat exchanger Z ₁ with the pipe number of columns of four rows as a whole by integrating them joined by (not shown).

The width "L" of the gap 4 is "Lw" in the air flow direction of the fin 1, and "N" is the number of rows of the heat transfer tubes 2, 2,... In the case, “L ≧ Lw
/ N ”, and in the case of this embodiment, since“ N = 2 ”, the width dimension“ L ”of the gap 4 is set in the range of“ L ≧ Lw / 2 ”.

Further, in this embodiment, each of the tube rows 21 and 22 of the fin 1 is
2, a plurality of slits 3, 3,... Extending in a direction orthogonal to the direction of air flow are formed at a portion corresponding to the middle of each heat transfer tube 2, 2,.

The above-described configuration air heat exchanger Z ₁ according to this embodiment with the structure thereof, an air heat exchanger of the conventional integrated type in which the tube columns and four columns as shown in FIG. 1 (b) Bowl Z
It corresponds to ₁₀ . Therefore, at the time of explaining the operational effect of the air heat exchanger Z ₁ in the following, as appropriate, referring to the air heat exchanger Z ₁₀ shown in FIG. 1 (b).
In FIG. 1B, reference numeral 11 denotes a fin, 12 denotes a heat transfer tube, and 13 denotes a slit.

[0030] Next, the function and effect will be described in the air heat exchanger Z _1.

In the air heat exchanger Z _{1 according} to the present embodiment, the air heat exchanger Z ₁ has the heat exchanger units X ₁ and X ₂ arranged with a gap 4 in the flow direction of the air flow. Because it is configured by integrating these,
The heat exchanger unit X ₁ on the upstream side of the airflow facing the gap 4
Each heat transfer tube 2, 2 belonging to the tube rows 22 in a ..., each heat transfer tubes 2, 2 belonging to the tube rows 21 in the heat exchanger unit X ₂ of the air flow downstream side, between the .. the air The continuity in the flow direction of the flow is broken. Therefore, they are between both the development of unsteady vortex is promoted, the heat transfer tubes 2, 2, development of a temperature boundary layer formed around the ... especially in the heat exchanger unit X ₂ of the air flow downstream side Is suppressed as much as possible, and only the heat transfer performance is improved.

[0032] Incidentally, in FIG. 6, FIG. 1 in an air heat exchanger Z ₁ according to this embodiment shown in (b), upstream of the heat exchanger unit that faces the air flow the flow direction across the gap 4 the tube rows 22 of X _1, shows an analysis diagram of the flow conditions of the air flow between the heat exchanger unit X ₂ rows of tubes 21 on the downstream side. Further, in FIG. 7, the airflow flow conditions between the air stream upstream of the conventional air heat exchanger Z ₁₀ and second row of tube rows and the third row of tube rows as shown in FIG. 1 (b) FIG.

Comparing these two analysis diagrams, in the air heat exchanger Z _{1 according} to the present embodiment, the unsteady vortex develops, whereby the temperature boundary layer formed around the heat transfer tube 2 develops. whereas is suppressed, unsteady vortices little development in the conventional air heat exchanger Z _10, it is understood that the temperature boundary layer is developed around the heat transfer tube 12.

[0034] Therefore, even air heat exchanger having a tube rows number of heat transfer tubes of the same four columns, in the air heat exchanger Z ₁ of this embodiment, the heat transfer performance in the air flow downstream side portion heat transfer performance as only whole air heat exchanger high partial is made higher than the conventional air heat exchanger Z _10. As a result, in the air heat exchanger Z ₁ according to this embodiment, for example, necessary heat transfer performance air heat exchanger of the conventional structure Z ₁₀
If the same as the one in which it is possible to achieve the compact to reduce the heat transfer area than the air heat exchanger Z ₁₀ of the follower come.

Furthermore, the air heat exchanger Z _1, for example when used as an evaporator of an air conditioning apparatus, the fins 1,1 along with its operation, although the condensed water adheres to the surface of ..., the condensed The water is caused to flow downward along the fin surface by its own weight, and at the same time, is subjected to the action of being swept to the leeward side by the air flow flowing between the fins. In this case, since the air heat exchanger Z ₁ is constituted by a pair of heat exchanger unit X _1, X ₂ behind the arranged with the gap 4 between and one behind the flow direction of the air flow cross, For example, by increasing the wind speed of the air flow passing through the fin 1 portion, the condensed water adhering to the surface of the fin 1 is pushed downstream by the air flow rather than flowing down on the fin 1 by its own weight. If so it is larger, condensed water attached to the fin 1 of the heat exchanger unit X ₁ is located in the air flow upstream side, the fin 1
Before dripping from the lower end of the
Most of them are scattered to the side, and most of them are freely dropped and discharged. The collection, another portion, leads to the heat exchanger unit X ₂ side located downstream than 4 between further該隙through the the clearance 4, the fins 1 of the heat exchanger unit X ₂ The fins 1 are discharged downward along the surface of the fin 1.

Therefore, the air heat exchanger Z _{1 of} this embodiment is used.
According to this, by providing the gap 4 between each of the heat exchanger units X ₁ and X ₂ , the drainage of condensed water on the fin surface is improved, and the air flow to the downstream side of the air heat exchanger Z ₁ is improved. Since the scattering of the condensed water is prevented, the passing wind speed of the air flow in the fin 1 can be set higher,
As a result, more are further improved heat transfer performance in the air heat exchanger Z _1, and by extension in which compactness of the air heat exchanger Z ₁ is further promoted.

Further, in the air heat exchanger Z _{1 according} to this embodiment, since each of the heat exchanger units X ₁ and X ₂ having the same configuration with the number of tube rows being _two , this is constituted.
For example, when brazing the piping components in the air heat exchanger Z ₁ in the process of manufacturing the air heat exchanger Z _1, for example, compared with the air heat exchanger Z ₁₀ integral as shown in FIG. 1 (b) Thus, a work space around the heat transfer tube 2 can be widened. As a result, the brazing operation using an automatic brazing machine can increase the workability, in which the more it is possible to reduce manufacturing costs of the air heat exchanger Z _1.

Further, as a plurality of heat exchanger units constituting the air heat exchanger, a heat exchanger unit having two rows of tubes as in the above-described embodiment, and a three-row heat exchanger unit as shown in an embodiment described later. Prepare a heat exchanger unit with the number of tube rows,
By appropriately combining these, an air heat exchanger having an arbitrary number of pipe rows as a whole can be easily obtained. This means that, when manufacturing various types of air heat exchangers having different numbers of tube rows, the fins 1 as parts thereof can be shared. The number of types and the number of fins can be reduced, and the manufacturing cost of the air heat exchanger can be further reduced.

Second Embodiment FIG. 2A shows an air heat exchanger Z2 according to a _second embodiment of the present invention. This air heat exchanger Z ₂
The first embodiment air heat exchanger Z ₁ according to the form, two heat exchanger units X ₁ having a tube rows 21, 22 of the two rows,
While constituted the this in X _2, the two rows of tube rows 21,
A heat exchanger unit X ₁ with 22, three rows of tube rows 23,
A heat exchanger unit X ₂ with 24, 25, one behind the flow direction of the air flow and disposed with a gap 4 having a width dimension "L", an air heat exchanger having a tube rows number of overall five columns Container Z ₂
It is what constituted.

The air heat exchanger Z having such a configuration
_2, its structure corresponds to the conventional integral type air heat exchanger Z ₂₀ having a tube rows of five columns as shown in FIG. 2 (b).

The air heat exchanger Z according to this embodiment
Also in _2, which the same effects as the air heat exchanger Z ₁ according to the first embodiment are obtained if,
Therefore, description of the operation and effect here is omitted.

Third Embodiment FIG. 3A shows an air heat exchanger Z3 according to a _third embodiment of the present invention. This air heat exchanger Z ₃
Are those having the air heat exchanger Z ₂ and reverse configuration according to the second embodiment, the heat exchanger unit X ₁ with three rows of tubes 23, 24 and 25 into the air flow upstream side, of the two the heat exchanger unit X ₂ with a tube rows 21 and 22 in the air flow downstream side, is constituted by arranging respectively.

The above-mentioned air heat exchanger Z having such a configuration
_3, its structure corresponds to the conventional integral type air heat exchanger Z ₃₀ having a tubular columns of five rows, as shown in FIG. 3 (b).

The air heat exchanger Z according to this embodiment
Also in _3, which same effects as the air heat exchanger Z ₁ according to the first embodiment are obtained if,
Therefore, description of the operation and effect here is omitted.

Fourth Embodiment FIG. 4A shows an air heat exchanger Z4 according to a _fourth embodiment of the present invention. This air heat exchanger Z ₄
Air heat exchanger Z ₁ according to the first embodiment, two heat exchanger units X ₁ having two rows of tubes 21 and 22,
While constituted the this in X _2, the two rows of tubes 21,
The three heat exchanger units X ₁ , X ₂ , and X ₃ each having 22 are arranged in front and rear in the air flow direction with a gap 4 having a width dimension “L” therebetween, and the total number of tube rows is six. it is obtained by constituting the air heat exchanger Z ₄ with.

The air heat exchanger Z having such a configuration
_4, its structure, and corresponds to FIG. 4 conventional air heat exchanger Z ₄₀ integral with the tube number of columns 6 rows as shown in (b).

The air heat exchanger Z according to this embodiment
Also in _4, which similar effects as the air heat exchanger Z ₁ according to the first embodiment are obtained if,
Therefore, description of the operation and effect here is omitted.

Fifth Embodiment FIG. 5A shows an air heat exchanger Z5 according to a _fifth embodiment of the present invention. This air heat exchanger Z ₅
The fourth embodiment air heat exchanger Z ₄ according to the embodiment of the three heat exchanger units X ₁ having a tube rows 21, 22 of the two rows,
While this was composed of X ₂ and X ₃ , three tube rows 2
Two heat exchanger units X ₁ , X _{2 having 3} , 24, 25
The in which respectively at a gap 4 having a width dimension "L" and arranged one behind the airflow flowing direction, constitutes an air heat exchanger Z ₅ with tube rows number of overall 6 columns.

The above-mentioned air heat exchanger Z having such a configuration
_5, its structure, and corresponds to FIG. 5 conventional air heat exchanger Z ₅₀ integral with the tube number of columns 6 rows as shown in (b).

The air heat exchanger Z according to this embodiment
Also in _5, which similar effects as the air heat exchanger Z ₁ according to the first embodiment are obtained if,
Therefore, description of the operation and effect here is omitted.

[Brief description of the drawings]

FIG. 1 is a sectional view of an air heat exchanger according to a first embodiment of the present invention.

FIG. 2 is a sectional view of an air heat exchanger according to a second embodiment of the present invention.

FIG. 3 is a cross-sectional view of an air heat exchanger according to a third embodiment of the present invention.

FIG. 4 is a sectional view of an air heat exchanger according to a fourth embodiment of the present invention.

FIG. 5 is a sectional view of an air heat exchanger according to a fifth embodiment of the present invention.

FIG. 6 is an analysis diagram of an air flow in an air heat exchanger.

FIG. 7 is an analysis diagram of an air flow in an air heat exchanger.

[Explanation of symbols]

1 is a fin, 2 is a heat transfer tube, 3 is a slit, 4 is a gap, Z
₁ to Z ₅ are air heat exchanger, X ₁ to X ₃ is a heat exchanger unit.

Claims (3)

[Claims] 1. A plurality of fins (1), (1), ..., which are arranged to face each other at a predetermined interval in a thickness direction and allow an air flow to flow substantially parallel to the plate surface. A plurality of heat transfer tubes (2), (2),... Piercing the fins (1), (1),. A plurality of heat exchanger units (X ₁ ) to (X ₃ ) are sequentially arranged with a predetermined gap (4) before and after in the flow direction of the air flow, and these are integrated. An air heat exchanger characterized by becoming. 2. The width dimension “L” of the gap (4) in the air flow direction of the fins (1) in the heat exchanger units (X ₁ ) to (X ₃ ). To “Lw”, the heat transfer tubes (2), (2),
·························· L = Lw / N ”when the number of tube rows is“ N ”. 3. The heat exchanger units (X ₁ ) to (X ₃ ) according to claim 1 or 2, wherein the plurality of heat exchanger units (X ₁ ) to (X ₃ ) have two rows of heat transfer tubes (2), (2),. Or an air heat exchanger characterized by having three rows.