GB2453234A

GB2453234A - Heat exchanger

Info

Publication number: GB2453234A
Application number: GB0817426A
Authority: GB
Inventors: Ryuji Kitano
Original assignee: Toshiba Carrier Corp
Current assignee: Toshiba Carrier Corp
Priority date: 2007-09-27
Filing date: 2008-09-23
Publication date: 2009-04-01
Anticipated expiration: 2028-09-23
Also published as: GB2453234B; GB0817426D0; JP5128221B2; CN101398239B; IT1391519B1; ITPD20080272A1; JP2009085438A; CN101398239A

Abstract

A heat exchanger (3, fig 1) comprises a plurality of parallel spaced fins 20 which air passes over and between the spaces, a plurality of pipes 'P' passing through the fins 20 and communicating a heat exchange medium (fluid) inside, a plurality of cut and raised sections 22-24 provided on one side of the fins 20 and having a longest dimension (length) between the pipes 'P' and arranged orthogonal to a direction of flow of the air, and the longest dimension (length) of at least one of the cut and raised sections 22 - 24 having an undulating shape with a concave portion 22b in between two convex portions 22a, 22c. The heat exchanger (3) is used in an indoor ceiling mounted air conditioner (A), whereby air is drawn through an inlet (12) via a blower (6), with the air being blown over the heat exchanger (3) and passed out into a room (R) via an outlet (13). The undulating cut and raised sections 22 - 24 may be flat (castellated) or arcuated, and arranged in three lines (columns). The central line (column) of cut and raised sections (33, fig 5) may not have a concave portion so that its height is the same height as the concave cut and raised sections (32b, 34b) of the other two lines (columns) of cut and raised sections.

Description

TITLE OF THE INVENTION

HEAT EXCHANGER AND AIR CONDITIONER

BACKGROUND OF THE INVENTION

This invention relates to a heat exchanger and an air conditioner incorporating the heat exchanger, and more particularly to the heat exchanger and the air conditioner incorporating the heat exchanger that can improve heat transfer performance.

In order to improve heat transfer performance, an indoor heat exchanger or the like of an air conditioner is provided with cut-and-erected sections. The cut-and-erected sections are provided on fins of the heat exchanger in such a manner that the cut-and-erected sections are arranged between heat exchanger pipes adjacently arranged in a direction orthogonal to a direction of flow of heat exchanging air.

For example, an indoor heat exchanger in which three lines of cut-and-erected sections are provided on a fin in a direction of flow of heat exchanging air is disclosed. In such a heat exchanger, heights of a cut-and-erected section on a windward side and a downwind side are formed taller than a height of a central portion of the cut-and-erected section. (For example, Jpn. Pat. Appin. KOKAI Publication No. 2005-345021) According to the above-described indoor heat exchanger, there has been the following problem.

Variations in height of the cut-and-erected section which is provided on the fin is advantageous in agitating airflow in an airflow direction for improving heat transfer efficiency. On the other hand, however, there is a disadvantage in which ventilation resistance increases substantially, and heat transfer performance cannot be fully improved.

BRIEF SUMMARY OF THE INVENTION

The present invention is made in consideration of above-described problem. Accordingly, it is desired to provide a heat exchanger and an air conditioner incorporating the heat exchanger that are effective in agitating airflow and able to improve heat transfer performance, without substantially increasing ventilation resistance.

In order to resolve the above-described problem, the heat exchanger and the air conditioner of the present invention have the following configuration.

A heat exchanger comprising: a plurality of fins parallely provided with predetermined spaces for circulating heat exchanging air along the spaces; a plurality of heat exchanger pipes provided passing through the plurality of fins for conducting a heat exchange medium thereinside; and a plurality of cut-and-erected sections provided on the plurality of fins in such a manner that the plurality of cut-and-erected sections are arranged between the plurality of heat exchanger pipes that are adjacently provided in a 1036275v1 direction orthogonal to a direction of flow of the heat exchanging air; wherein the plurality of cut-and-erected sections project from only one surface side of the fins, and the cut-and-erected sections are arranged in more than three lines in the direction of flow of the heat exchanging air, while having a longer direction of the cut-and-erected sections orthogonal to the direction of flow of the heat exchanging air, and at least one line of the cut-and-erected sections has a concave portion in which a height of one part of the longer direction is lower than heights of both side ends.

1 0 An air conditioner comprising: a unit body being a chassis incorporating an air inlet and air outlet; a heat exchanger being contained in the unit body; and an air blower for blowing air to the heat exchanger.

According to the present invention, effectiveness in agitating 1 5 airflow can be obtained for improving heat transfer performance, without substantially increasing ventilation resistance.

Additional advantages of the invention will be set forth in the description which follows, and will be clear from the description. The desired effects and advantages of the invention may be realized and obtained by means of instrumentalities and combinations particularly pointed out hereinafter.

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BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated

in and constitute a part of the specification,

illustrate embodiments of the invention, and together

with the general description given above and the

detailed description of the embodiments given below, serve to explain the principles of the invention.

FIG. 1 is a longitudinal sectional view showing an indoor heat exchanger and an indoor unit of an air conditioner incorporating the indoor heat exchanger according to the first embodiment of the present invention.

FIG. 2 is a perspective view showing the indoor heat exchanger.

FIG. 3 is a plan view showing a main section of a fin which is incorporated in the indoor heat exchanger.

FIG. 4 is a side view of the main section of the fin.

FIG. 5 is a plan view showing a main section of a fin incorporated in an indoor heat exchanger according to the second embodiment of the present invention.

FIG. 6 is a cross-sectional view of the fin taken along line I-I in FIG. 5.

FIG. 7 is a cross-sectional view of the fin taken along line Il-Il in FIG. 5.

FIG. S is a diagram for explaining advantage of the fin.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a diagram showing an indoor heat exchanger 3 and an indoor unit A of an air conditioner which incorporates the indoor heat exchanger 3 according to the first embodiment of the present invention. FIG. 2 is a perspective view showing the indoor heat exchanger 3. This indoor unit A is, for example, a ceiling mounted type (also called as a ceiling cassette type) An opening section for installation 9 is provided on a ceiling board 8 of a room to be air-conditioned R, and a chassis section 10, which comprises a unit body of the indoor unit A, is mounted in a back of the ceiling in a projecting manner. A dress panel 11 for closing a lower surface opening section of the chassis section 10 is exposed from the ceiling board 8 to the room to be air-conditioned R. An air inlet 12 is provided in a central portion of the dress panel 11. Also, air outlets 13 are provided in both side portions and front and back portions (directions not shown in the drawing) of the dress panel 11. Furthermore, a filter 14 is fitted into a position facing to the air inlet 12 of the chassis section 10, and a drain pan 15 is arranged in a space between the air inlet 12 and the air outlets 13.

In other words, the drain pan 15 is formed along a periphery of the filter 14 in a rectangular frame-shape. The indoor heat exchanger 3 is arranged on the drain pan 15. This indoor heat exchanger 3 is formed in a bending manner into a rectangular shape in which one part is lacking in a plane view.

A heat insulating material 16 is attached to an inner periphery wall except the lower surface opening section of the chassis section 10, so as to cover the whole inner periphery wall. An upper end section of the indoor heat exchanger 3 is closely attached to the heat insulating material 16, which is attached to a ceiling plane lOa of the chassis section 10, and a lower end surface of the indoor heat exchanger 3 is on the drain pan 15.

Also, an indoor air blower 6 is attached to a central portion of the ceiling plane lOa of the chassis section 10. This indoor air blower 6 comprises a fan motor 6m having its rotational axis in a downward direction, and a turbo fan 6f which is fitted onto the rotational axis of the fan motor 6m. The indoor air blower 6 is surrounded by the indoor heat exchanger 3, since the indoor heat exchanger 3 has a substantially rectangular shape. The heat exchanger of the present invention may be applied to an outdoor unit of an air conditioner.

The indoor heat exchanger 3 is a fin-tube type, in which a plurality of fins 20 parallelly provided with a narrow spaces therebetween and heat exchanger tubes P are provided passing through the plurality of fins 20.

Each of the fins 20 has a vertically long reed shape, and one column of heat exchanger tubes P are provided passing through the plurality of fins 20 with a predetermined pitch in a vertical direction.

The plurality of fins 20 formed in the above manner are arranged side by side in two lines, and the two lines of the fins 20 are bended together. In this case, since the indoor heat exchanger 3 is substantially rectangular shaped, there are three points to be bended. Heat exchanger tube insertion openings are provided in the fins 20 along the vertical direction with a predetermined pitch. A size of an inner diameter of the heat exchanger tube insertion opening is formed slightly larger than a size of an outer diameter of the heat exchanger tube P. The heat exchanger tube P is made to pass through the heat exchanger tube insertion opening and then subjected to a tube expansion process, thereby tightly fitting the heat exchanger tube P with respect to the fins 20.

As shown in FIG. 3, the fin 20 includes a plate- like base section 21, and three lines of cut-and-erected sections 22-24 provided on the base section 21.

The cut-and-erected sections 22-24 are parallelly provided in a direction of flow of heat exchanging air.

Also, all of the cut-and-erected sections 22-24 are arranged in such a manner that a longer direction thereof is orthogonal to the direction of flow of the heat exchanging air, and the cut-and-erected sections 22-24 project from only one surface side of the fin 20, which is the base section 21 of the fin 20.

These cut-and-erected sections 22-24 respectively have the following portions along a longer direction: a convex portion 22a, a concave portion 22b, and a convex portion 22c; a convex portion 23a, a concave portion 23b, and a convex portion 23c; and a convex portion 24a, a concave portion 24b, and a convex portion 24c.

The height of the concave portion 22b from the base section 21 is lower than the heights of the convex portions 22a and 22c at the boLh side ends. Similarly, the heights of the concave portions 23b and 24b from the base section 21 are respectively lower than the heights of the convex portions 23a, 23c, and 24a, 24c at the both side ends.

The cut-and-erected section 23 has the concave portion 23b whose height from the base section 21 is lower than the heights of the convex portions 23a and 23c at the both side ends. The cut-and-erected section 24 has the concave portion 24b whose height from the base section 21 is lower than the heights of the convex portions 24a and 24c at the both side ends. Although it is preferable to arrange the concave portions 22b, 23b, and 24b at the center between the heat exchanger tubes P, the concave portions 22b, 23b, and 24b need not necessarily be arranged at the center.

As shown in FIG. 4, a distance Li between the base section 21 and the convex portions 22a, 22c, 23a, 23c, and 24a, 24c, is formed larger than a distance L2 between the convex portion 22a, 22c, 23a, 23c, and 24a, 24c of the fin 20 and a base section 21 of an adjacent fin 20A. Also, a distance L3 between the concave portions 22b, 23b, 24b and the base section 21 is formed smaller than a distance L4 between the concave porLions 22b, 23b, 24b and the base section 21 of the adjacent fin 20A.

The indoor unit 1 of the air conditioner configured in the above manner operates as follows.

When an operation of the air conditioner is started, a cooling medium is circulated through the heat exchanger tubes P for conditioning a temperature of the fins 20.

On the other hand, indoor air of the room to be air-conditioned R is taken into the chassis section 10 from the air inlet 12 via the filter 14, in accordance with rotation of the indoor air blower 6. The taken-in indoor air passes through the indoor heat exchanger 3 as heat exchanging air, and goes out from the air outlet 13 to the room to be air-conditioned R. During the above operation, heat is exchanged in the indoor heat exchanger 3. Since heat exchanging air (fluid) tends to flow in a direction of less resistance, the fins 20 of the indoor heat exchanger 3 -10 -are formed in such a manner that the cut-and-erected sections have concave shapes wherein concave portions 22b, 23b, 24b are provided, when viewed from a direction of flow of the heat exchanging air. These concave portions 22b, 23b, 24b make differences in height within the cut-and-erected sections, and air therefore tends to flow downward (toward the base section 21) at the convex portions 22a, 22c, 23a, 23c, and 24a, 24c which are high, and air tends to flow upward (toward a base section 21 of an adjacent fin 20A) at the concave portions 22b, 23b, 24b which are small. Thus, the heat exchanging air that passes through the cut-and-erected sections 22-24 is distributed in a view from the direction of flow of the heat exchanging air.

On the other hand, at the base section 21 which is flat and located after the cut-and-erected sections 22-24, the heat exchanging air distributed at the cut-and-erected sections 22-24 are flown to a direction in which the distribution is homogenized, thereby agitating the heat exchanging air. With this process, air temperature is homogenized and heat transfer performance in the indoor heat exchanger 3 is improved.

Furthermore, increase of ventilation resistance can be prevented since an opening space is not reduced. The concave portions 22b, 23b, 24b need not necessarily be flat, and they may be arcuated in a cross-sectional -11 -view.

As described above, according to the heat exchanger 3 and the indoor unit A of the air conditioner incorporating the heat exchanger 3 of the present embodiment, agitating action can be obtained without substantially increasing ventilation resistance and heat transfer performance can be thereby improved.

FIG. 5 is a plan view showing a main section of a fin 30 incorporated in an indoor heat exchanger 3A according to the second embodiment of the present invention. FIG. 6 is a cross-sectional view of the fin taken along line I-I in FIG. 5. FIG. 7 is a cross-sectional view of the fin 30 taken along line Il-Il in FIG. 5. Some of the functional parts shown in FIGS. 5-7 are same as those shown in FIGS. 1-4, and the same signs are therefore given to those same functional parts. Detailed explanations thereof are therefore omitted.

As shown in FIG. 5, the fin 30 has a plate-like base section 31 and three lines of cut-and-erected sections 32-34 provided on the base section 31. The cut-and-erected sections 32-34 are parallelly provided in a direction of flow of heat exchanging air. Also, all of the cut-and-erected sections 32-34 are arranged in such a manner that a longer direction thereof is orthogonal to the direction of flow of the heat exchanging air, and the cut-and-erected sections 32-34 -12 -project from only one surface side of the fin 30, which is the base section 31 of the fin 30.

These cut-and-erected sections 32-34 respectively have the following portions along a longer direction: a convex portion 32a, a concave portion 32b, and a convex portion 32c; a convex portion 33a, a concave portion 33b, and a convex portion 33c; and a convex portion 34a, a concave portion 34b, and a convex portion 34c.

The height of the concave portion 32b from the base section 31 is lower than the heights of the convex portions 32a and 32c at the both side ends. Similarly, the height of the concave portion 34b from the base section 31 is lower than the height of the convex portion 34a and 34c at the both side ends.

As shown in FIGS. 6 and 7, the cut-and-erected sections 32 and 34 having the concave portions 32b and 34b, and the cut-and-erected portion 33 not having a concave portion are alternately provided in the direction of flow of the heat exchanging air. The cut-and-erected section 32 having the concave portion 32b is provided on the most windward side of the fin 30.

Also, the maximum protrusion height H2 of the cut-and-erected section 33 not having a concave portion from the base section 31, and the maximum protrusion height Hi of the concave portions 32b and 24b from the base section 31 are designed to be the same.

When the heat exchanger 3A configured in the above -13 -manner is employed, the heat exchanging air circulates in the same manner as in the above-explained heat exchanger 3. In the FIGS. 6 and 7, arrows S indicate that flow rate of the heat exchanging air is low, and arrows T indicate that flow rate of the heat exchanging air is high.

When the heat exchanging air is introduced into the heat exchanger 3A, the flow of the heat exchanging air in the direction of flow of the heat exchanging air changes, and heat transfer performance thereby improves. That is to say, a part of the heat exchanging air that passes through the cut-and-erected section 22 gets to a side surface of the cut-and-erected section 23. Therefore, the part of the heat exchanging air is agitated in the orthogonal direction with respect to the direction of airflow.

Furthermore, since the maximum protrusion height H2 of the cut-and-erected section 33 not having a concave portion from the base section 31 and the maximum protrusion height Hi of the concave portions 32b and 24b from the base section 31 are designed to be the same, resistance at the central portion of the cut-and-erected sections 32-34 becomes low. Therefore, this configuration makes it easier for the heat exchanging air to flow toward the heat exchanger tube P in the second line as shown in FIG. 8. Also, it is possible to further improve the heat transfer performance by making a width of the cut-and-erected section 32 at the most windward side wider than a width of the cut-and-erected portion 34 at the downwind side.

As described above, according to the indoor heat exchanger 3A and the indoor unit A of the air conditioner incorporating the indoor heat exchanger 3A of the present embodiment, it is possible to improve heat transfer performance without substantially increasing the ventilation resistance.

Note that the present invention is not limited to the above- 1 0 described embodiments, aiid structural requirements can be modified and materialized within a range which does not deviate from the gist of the present invention.

Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is 1 5 not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the general inventive concept as defined by the appended claims.

1 036275v1

Claims

-. 15 -WHAT IS CLAIMED IS: 1. A heat exchanger comprising: a plurality of fins parallelly provided with predetermined spaces for circulating heat exchanging air along the spaces; a plurality of heat exchanger pipes provided passing through the plurality of fins for conducting a heat exchange medium thereinside; and a plurality of cut-and-erected sections provided on the plurality of fins in such a manner that the plurality of cut-and-erected sections are arranged between the plurality of heat exchanger pipes that are adjacently provided in a direction orthogonal to a direction of flow of the heat exchanging air; wherein the plurality of cut-and-erected sections project from only one surface side of the fins, and the cut-and-erected sections are arranged in more than three lines in the direction of flow of the heat exchanging air, while having a longer direction of the cut-and-erected sections orthogonal to the direction of flow of the heat exchanging air, and at least one line of the cut-and-erected sections has a concave portion in which a height of one part of the longer direction is lower than heights of both side ends.
2. The heat exchanger according to claim 1, -16 -wherein the cut-and-erected section having the concave portion and the cut-and- erected sections without a concave portion are alternately provided along the direction of flow of the heat exchanging air, the cut-and-erected section having the concave portIon is arranged on a most windward side, and a maximum height of a protrusion of the cut-and-erected section without a concave portion from a base section of the fins and a maximum height of a protrusion of the concave portion from the fin are equal.
3. The heat exchanger according to claim 1, wherein a distance between the both side ends of the cut-and-erected section having the concave portion and a base section of the fin is greater than a distance between the both side ends of the cut-and-erected section having the concave portion and a base section of an adjacent fin, and a distance between the concave portion and the base section of the fin is smaller than a distance between the concave portion and the base section of the adjacent fin.
4. An air conditioner comprising: a unit body being a chassis incorporating an air inlet and air outlet; -17 -a heat exchanger being contained in the unit body; an air blower for blowing air to the heat exchanger; a plurality of fins parallelly provided with predetermined spaces for circulating heat exchanging air along the spaces; a plurality of heat exchanger pipes provided passing through the plurality of fins for conducting a heat exchange medium thereinside; and a plurality of cut-and-erected sections provided on the plurality of fins in such a manner that the plurality of cut-and-erected sections are arranged between Lhe plurality of heat exchanger pipes that are adjacently provided in a direction orthogonal to a direction of flow of the heat exchanging air; wherein the plurality of cut-and-erected sections project from only one surface side of the fins, and the cut-and-erected sections are arranged in more than three lines in the direction of flow of the heat exchanging air, while having a longer direction of the cut-and-erected sections orthogonal to the direction of flow of the heat exchanging air, and at least one line of the cut-and-erected sections has a concave portion in which a height of one part of the longer direction is lower than heights of both side ends.
5. A heat exchanger and/or air conditioner, substantially as hereinbefore described with reference to the accompanying drawings.

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