JPH0585837B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a cross-fin heat exchanger in which a flat fin substrate is provided with slit fins or louver-shaped fins, and particularly relates to a cross-fin type heat exchanger in which a flat fin substrate is provided with slit fins or louver-shaped fins. Regarding improvement measures.

(Prior Art) Conventionally, as disclosed in, for example, Japanese Unexamined Patent Publication No. 61-21358, as shown in FIG. Insertion holes b, ... are provided in rows in the longitudinal direction of the board in the fin board a, and a large number of slit fins c, ... are provided in the longitudinal direction of the board between each adjacent insertion hole b, b, and the slit fins c at both ends are By providing strip-shaped fin substrate parts e, e that cross the slit fin c in the center, the insertion holes b, . . .
The purpose is to improve the heat conduction characteristics between the heat medium pipe inserted through the fin board a and both ends of the fin board a, thereby improving the heat transfer coefficient of the fin board a, that is, the heat exchange efficiency between the fin board a and the airflow. is a known technique.

(Problems to be Solved by the Invention) On the other hand, when looking at the heat conduction characteristics within the fin substrate a, the above-mentioned conventional structure has the following problems.

That is, during heating operation, for example, in the fin board a, the vicinity of the side end on the upstream side of the airflow is quickly cooled due to heat exchange with the airflow, while on the downstream side of the airflow, the airflow after heat exchange mainly flows, so that the airflow is relatively cool. Not cooled. In that case, in the above-mentioned conventional device, the slit fins c, . divided by. Therefore, the temperature of the fin board a on the downstream side of the airflow cannot be effectively conducted to the upstream side, and the fin board a
As a result, the overall heat transfer coefficient of the fin substrate a becomes insufficiently improved.

The present invention has been made in view of the above, and its purpose is to improve the heat conduction characteristics between the upstream side and the downstream side of the airflow in the fin substrate when louver-shaped fins or slit fins are provided on the fin substrate. The purpose of this improvement is to make the temperature distribution within the fin substrate relatively uniform, thereby improving the overall heat transfer coefficient of the fin substrate.

(Means for solving the problem) In order to achieve the above object, the solving means of the present invention is as follows:
A fin board section that crosses the fins in the width direction of the board is provided at the intermediate part between insertion holes adjacent to each other in the longitudinal direction of the fin board, and the fins are arranged to allow airflow to flow through the fins to prevent a decrease in air resistance in the fin board section. It should be installed on the downstream side.

Specifically, as shown in FIGS. 1 and 2, a plurality of heating mediums are placed in the longitudinal direction of a substantially rectangular flat fin substrate 2 arranged so that the width direction of the substrate coincides with the direction of air flow. Insertion holes 3 for inserting tubes 1 are provided in a row, and a number of slit fins 5 are formed by cutting and raising two long sides parallel to the longitudinal direction of the board into a bridge shape on the fin board 2, or one long side is cut and raised. A cross-fin heat exchanger is assumed in which a large number of deformed louver-shaped fins are provided in parallel to each other along the width direction of the substrate.

Then, the slit fins 5 or louvered fins are inserted into the insertion holes 3, 3 adjacent to each other in the longitudinal direction of the board.
In the center part 2a in the width direction of the substrate between them, a band-shaped fin board part 7 extending across the slit fins 5 or the louvered fins in the width direction of the board is left, and the airflow is lower than the center part 2a in the width direction of the board. On the downstream side in the flow direction, it is provided so as to face the band-shaped fin substrate section 7 .

(Function) With the above configuration, in the present invention, when used in a condenser during heating operation, for example, the central part 2a of the fin board 2 in the board width direction is provided with an air flow direction that crosses each slit fin 5 or louvered fin. Since the strip-shaped fin substrate portion 7 extending in the board width direction is formed, heat exchange is performed on the airflow upstream side of the fin board 2, and when the fin board 2 is cooled by the heat exchange, the central portion of the fin board 2 in the board width direction is Heat conduction occurs from the downstream side of the airflow, which is in a relatively high temperature state, to the upstream side through the fin board portion 7 of 2a. That is, on the upstream side, heat conduction occurs not only between the heat medium pipes 1 inserted through the insertion holes 3, but also with the high temperature part of the fin board 2, and the cooling heat is quickly diffused. The temperature distribution within the fin substrate 2 is made relatively uniform.

On the other hand, a slit fin 5 or a louver-shaped fin is provided on the airflow downstream side of the central portion 2a in the substrate width direction so as to face the fin substrate portion 7, so that the air resistance in the fin substrate portion 7 may be lowered. This effectively prevents airflow from penetrating.

As a result of the above, the overall heat transfer coefficient of the entire fin substrate 2 is improved.

(Example) Examples of the present invention will be described below in Figures 1 to 5.
The explanation will be based on the drawings in the figures.

1 to 3 show a first embodiment of the present invention,
Reference numeral 2 denotes a fin board disposed in a heat exchanger of an air conditioner. The fin board 2 is formed into a substantially rectangular flat plate shape, and is installed so that the width direction of the board coincides with the air flow direction. In the fin board 2, insertion holes 3 for inserting the coil 1 of the heat exchanger, which is a heat medium pipe, are arranged in a line in the longitudinal direction of the fin board 2 so that the center position is on the center line l in the width direction of the board. A large number of flat slits 4, etc. are bored in the longitudinal direction of the board in the fin board 2 excluding the insertion holes 3, and the upper and lower short sides 5c and 5d are connected to the fin board 2 to form the slits 4. Slit fins 5, . . . are provided by cutting and raising the two long sides 5a, 5b into a bridge shape.

The slit fins 5, . . . are four pairs of slit fins 5, which are arranged adjacent to each other in the width direction of the substrate.
..., and a single slit fin 5 on the center line l, and the paired slit fins 5, 5
As shown in FIG. 3, on the airflow upstream side of the center line l, the airflow upstream side of the pair of slit fins 5, 5 is on the upper side in the figure with respect to the fin board 2 surface, and the airflow downstream side is on the upper side in the figure. Each has a bridge-like cut at the bottom. In addition, on the downstream side of the airflow from the center line l,
It is formed so as to have a reverse relationship with the above-mentioned upstream side, that is, to be symmetrical on both sides with respect to a vertical plane including the center line l in FIG. Note that the slit fin 5 on the center line l is cut upward in FIG.

Here, as a feature of the present invention, in the center part 2a in the board width direction between the insertion holes 3, 3 which are adjacent to each other in the board longitudinal direction, the slit fin 5 on the center line l in the board width direction and each of the slit fins on both sides thereof are A band-shaped fin substrate portion 7 extending across the pair of slit fins 5, .
It is formed so as to leave a

Each of the slit fins 5 on both side ends is divided into three parts in the longitudinal direction of the board so as to leave two side end fin board parts 8, . . . that cross the slit fin 5 in the board width direction. 5 is arranged to face the band-shaped fin substrate section 7. In other words, a decrease in air resistance in the fin board portion 7 is prevented.

Therefore, in the above embodiment, the slit fins 5, ... are formed at the center part 7 in the board width direction, and the strip-shaped fin board part 7 is formed which connects the slit fins 5 in the board width direction. The heat conduction characteristics of the fin board 2 are improved, and heat on the downstream side of the airflow of the fin board 2 is quickly conducted to the upstream side. That is, as in the above-mentioned conventional one, the central part 2 of the fin substrate 2 is
A slit fin 5 is provided near a in the width direction of the board.
... is formed, heat conduction in the substrate width direction is blocked, so even if heat is exchanged on the upstream side of the airflow of the fin substrate 2, the amount of heat exchanged on the downstream side is relatively small. Therefore, for example, in an indoor heat exchanger during heating operation, the central portion 2 of the fin board 2
The upstream side of the airflow near a is cooled by heat exchange with the airflow, but the downstream side is in a relatively high temperature state. As a result, sufficient heat exchange is not performed over the entire board, and the overall heat transfer coefficient of the fin board 2 is insufficiently improved.

In contrast, in the embodiment described above, when the center portion 2a of the fin board 2 in the board width direction is cooled by heat exchange on the upstream side of the airflow, heat conduction occurs from the downstream side of the airflow, which is in a relatively high temperature state, to the upstream side. That is, on the upstream side, not only the coil 1 inserted through the insertion holes 3, but also the widthwise central portion 2 of the fin board 2
Heat is also conducted from a relatively high-temperature portion located downstream of point a in the air flow direction, and cooling heat is rapidly diffused. Therefore, the heat transfer coefficient of the entire fin substrate 2 increases.

FIG. 5 shows the temperature distribution in the board width direction of the fin board 2 during heating operation and the average air temperature of the airflow for the conventional method and the first embodiment, and also as a comparative example. Values compared with a structure having a strip-shaped fin substrate portion 7 extending across the entire width direction of the substrate as shown in FIG. shows. In the figure, the solid line is the value of the first embodiment, the broken line is the value of the conventional one, and the one-dot chain line is the value of the comparative example shown in FIG.

Here, when comparing the temperatures of the fin substrate 2, on the upstream side of the airflow, the temperature of the fin substrate according to the present invention is higher than that of the conventional one. That is, it can be seen that the temperature distribution within the fin substrate 2 is made relatively uniform due to the thermal conductivity from the downstream side of the airflow. Also,
In the comparative example shown in FIG. 6, the thermal conductivity within the fin substrate 2 is good, so the temperature on the upstream side of the airflow of the fin substrate 2 is even higher than that of the inventive example.

On the other hand, when looking at the average temperature of the air that exchanged heat with the fin board 2, there is not much difference between the conventional type and the comparative example, and the average air temperature of the type of the present invention is considerably higher than that of both. ing.
That is, in the conventional type, the temperature of the fin substrate 2 is uneven due to the division of heat conduction in the central portion 2a, and in the comparative example, even though the temperature distribution of the fin substrate 2 is uniform, the fin substrate portion 7 The overall heat transfer coefficient decreases due to the penetration of the air flow in each case. In contrast, in the present invention, the temperature distribution of the fin substrate 2 is made relatively uniform, and the penetration of the air flow to the fin substrate portion 7 is effectively prevented, so that the air flow between the fin substrate 2 and the air flow is effectively prevented. The overall heat transfer coefficient is improved, resulting in
This improves heat exchange efficiency.

In the first embodiment, the slit fins 5, 5 are provided on the upstream and downstream sides of the airflow of the central portion 2a in the substrate width direction, but the slit fins 5 may be provided only on the downstream side. FIG. 4 shows a second embodiment having such a configuration. In this embodiment, the slit fins 5, . On the upstream side of the airflow, a band-shaped fin substrate portion 7 extends across the slit fin 5 in the width direction of the substrate. Other configurations are as described in the first section above.
This is similar to the example.

Therefore, in this embodiment as well, since the slit fins 5 are formed to face each other on the downstream side of the strip-like fin substrate section 7 in the air flow direction, a decrease in the air resistance of the strip-like fin substrate section 7 is effectively prevented. has been done. In other words, the strip-shaped fin substrate portion 7
This effectively prevents the airflow from penetrating through, and therefore the same effect as in the first embodiment can be achieved.

Further, although the embodiment is omitted, instead of the slit fins 5, a large number of louver-shaped fins, each of which is deformed by cutting one long side upright, are provided in the longitudinal direction of the substrate.
The louver-shaped fins are provided so that a strip-shaped fin substrate portion 7 extending across the louver-shaped fins in the substrate width direction remains in the center portion 2a in the substrate width direction between adjacent insertion holes 3, 3, and On the downstream side in the air flow direction of the widthwise central portion 2a, it may be provided so as to face the band-shaped fin substrate portion 7. It is easily understood that even in that case, the same effects as those of the first and second embodiments can be achieved.

Furthermore, in the above embodiment, an example was explained in which the insertion holes 3,... are arranged in one row, but the present invention is also applicable to a structure having a plurality of rows of insertion holes 3,..., for example, a fin substrate 2.
It is also possible to apply the above embodiment to a structure in which a plurality of rows of insertion holes 3, . . . are provided in a staggered arrangement in the longitudinal direction.

(Effects of the Invention) As explained above, according to the present invention, in a fin board provided with a large number of slit fins or louver-shaped fins, the slit fins are inserted across the slit fins in the central part of the board width direction between the insertion holes. In addition to leaving a strip-shaped fin substrate extending in the widthwise direction of the board, a slit fin or a louver-shaped fin was provided to face the strip-shaped fin substrate on the airflow downstream side of the center in the width direction of the board. This improves the heat conduction characteristics from the downstream side of the airflow to the upstream side of the airflow in the fin board, making the temperature distribution within the board relatively uniform, and effectively preventing the airflow from penetrating due to the decrease in air resistance in the band-shaped fin board part. Therefore, it is possible to improve the overall heat transfer coefficient of the fin substrate.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention.
The figures are a plan view of the fin board according to the first embodiment, and a plan view of the fin board according to the first embodiment.
The figure is a sectional view taken along the - line in Fig. 1, Fig. 3 is a sectional view taken along the - line in Fig. 1, Fig. 4 is a plan view of the fin board according to the second embodiment, and Fig. 5 is a sectional view of the central part of the fin board. FIG. 3 is a characteristic diagram showing the distribution state of substrate temperature and average air temperature in the substrate width direction. FIG. 6 is a plan view of a fin board according to a comparative example. FIG. 7 is a plan view showing the structure of a conventional fin board. 1...Coil (heat medium tube) 2...Fin board, 2
a...Central portion, 3...Through hole, 5...Slit fin, 7...Fin board portion.

Claims (1)

[Claims] 1 A fin substrate 2 having a substantially rectangular flat plate shape arranged so that the width direction of the substrate coincides with the air flow direction is provided with insertion holes 3 for inserting a plurality of heat medium pipes 1 in a row in the longitudinal direction of the substrate, and A large number of slit fins 5 are formed by cutting two long sides parallel to the longitudinal direction of the substrate 2 into a bridge shape, or louver-shaped fins formed by cutting one long side and deforming them in an upright manner are arranged parallel to each other along the width direction of the substrate. In the cross-fin type heat exchanger provided in large numbers in
In the center part 2a in the board width direction between the boards, a band-shaped fin board part 7 extending across the slit fins 5 or the louvered fins in the board width direction is left, and the airflow is lower than in the board width direction center part 2a. A heat exchanger characterized in that it is provided so as to face the band-shaped fin substrate section 7 on the downstream side in the flow direction.