JPH0345895A - Heat exchanger - Google Patents

Abstract

PURPOSE:To improve heat transfer rate by disposing slit pairs in a zigzag state along thermally exchanging air conducting direction, and reversely directing the slit protruding direction of the adjacent slit pairs in rows perpendicular to the flow. CONSTITUTION:Slits 2 are disposed together with heat exchanging pipes 3 in a zigzag state, and each slit 2 is formed of three slit pairs 20 provided laterally at a predetermined interval. The pairs 20 are composed of a pair of slits 21, 22 of longitudinally cut and erected pieces in a direction perpendicular to thermally exchanging air conducting direction, and the protruding direction of the erecting direction of the slits 21, 22 it so divided as to be different at right and left sides. For example, the slit 21 of left side blank in a drawing of the pair 20 protrudes to the front face side of this paper of beforehand, and the slit 22 of right side protrudes to the rear face side of back face side. Accordingly, the position of a fin base 1a after the slits 21, 22 are provided indispensably becomes an opened through hole 23.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a heat exchanger used, for example, in an air conditioner having a refrigeration cycle circuit.

(Prior Art) For example, a heat exchanger as an indoor heat exchanger or an outdoor heat exchanger is used in an air conditioner that constitutes a refrigeration cycle circuit. This consists of a large number of fins arranged side by side with narrow gaps between them, and a plurality of heat exchange vibes passing through these fins. The fins constituting this type of heat exchanger are initially simply flat plates, and heat exchange air flows along the surface direction that is the gap between them.

By the way, with such fins, a temperature boundary layer gradually develops from the end where heat exchange air is introduced to the outlet side, and with this development, the heat transfer coefficient at that part of the fin decreases. This is a well-known fact. In other words, there was a problem in that effective heat exchange was not performed between the fins and the heat exchange air.

Therefore, recently, it has been considered to provide the fin with a plurality of pairs of slits, and it has become possible to improve the heat exchange efficiency to some extent. That is, these slit pairs are cut and raised integrally with the fin, and protrude in a direction perpendicular to the direction of conduction of heat exchange air and in opposite directions with respect to the remaining fin base. Therefore, the heat exchange air guided to the fins is first divided at the fin base forming the introduction end of the fin, and then at one side of the fin base by a slit cut and raised in one of the slit pairs. Furthermore, it is divided on the other side of the fin base by a slit cut and raised on the other side,
Finally, the fin is divided at the fin base that forms the lead-out side end of the fin. The slit pairs are arranged in multiple locations on the fins from the upstream side to the downstream side of the heat exchange air,
To uniformly divide heat exchange air regardless of the part of the fin.

Such division of the heat exchange air is a division of the temperature boundary layer and also serves to destroy it, so that the heat transfer coefficient can be improved.

(Problems to be Solved by the Invention) However, in all of the slit pairs provided in conventional fins, the protruding directions of the slits are aligned in the same direction. Therefore, considering the fins that are arranged side by side with a predetermined gap, heat exchange air flows from the upstream side to the downstream side where the slit density is low, that is, in the direction of the through holes in the fin base after the slit pairs are provided. Since the slits are guided along the slits, the mutual relationship between the upstream slit pair and the downstream slit pair is weak, making it difficult to expect a synergistic effect between them.

For this reason, we selected the protruding direction and position of the slit pair relative to the flow of heat exchange air from the upstream side to the downstream side to efficiently destroy the temperature boundary layer and further improve the heat transfer coefficient. There is a need for a heat exchanger that can

The present invention was made in view of the above-mentioned circumstances, and does not change the basic structure consisting of a large number of fins having a plurality of slit pairs and a heat exchange pipe passing through these fins.
It is an object of the present invention to provide a heat exchanger that can further improve the heat transfer coefficient by selecting the positions of the slit pairs and the protruding direction of adjacent slit pairs in each row orthogonal to the flow of heat exchange air. shall be.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides fins that are arranged side by side with a predetermined gap between them, heat exchange air is conducted in the plane direction along the gap between them, and the fins are provided with internal air flow. Penetrates the heat exchange pipe that conducts the fluid to be heat exchanged,
A slit pair consisting of a pair of slits is integrally cut and raised on the above fin, and the slits of this slit pair are perpendicular to the conduction direction of the heat exchange air and in opposite directions with respect to the remaining fin base. In the protruding one, the slit pairs are arranged in a staggered manner along the conduction direction of the heat exchange air, and in each row orthogonal to this flow, the slit protruding directions of the adjacent slit pairs are directed opposite to each other. This is a heat exchanger with special features.

(Function) The pair of slits on the upstream side acts to separate the temperature boundary layer, and the heat exchange air is bent along the direction of low slit density. Since the slit protrusion directions of the adjacent slit pairs in each row orthogonal to the flow of heat exchange air are opposite, the heat exchange air is guided in mutually opposite directions with respect to the fin surface, and between the adjacent fins, the slit pairs are guided in opposite directions. The heat-exchanging air collides with each other, causing turbulence and effectively destroying the temperature boundary layer. The heat is further guided to a pair of slits on the downstream side, where the temperature boundary layer is separated, thereby improving the heat transfer coefficient of the fin as a whole.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 schematically shows part of a heat exchanger. That is, in the figure, 1... is a large number of fins arranged in parallel with a predetermined gap. Heat exchange air is conducted along the surface direction along the gaps between all of these fins, as shown by arrows in the figure. Also, these fin...
In this case, slit portions 2, which will be described later, are provided at positions that are shifted from each other across the upstream and downstream sides of the heat exchange air, forming a so-called zigzag pattern. Furthermore, a heat exchange vibrator 3 is aligned with the slit portion 2 in the upper and downstream row directions and in the step direction, is perpendicular to the surface direction of the fins 1, and conducts the heat exchange fluid therein. ... penetrates and is fixed by any means. In other words, heat exchange vibe 3
The penetration positions of ... are so-called staggered.

Next, the slit portion 2 will be explained based on FIG. 2. Each slit part 2... is a heat exchange vibrator 3
As described above, they are arranged in a staggered manner with each other. Each slit portion 2 consists of, for example, three pairs of slits 20 provided at predetermined intervals in the width direction in the figure.

This pair of slits 20 is a pair of slits 2 that are cut and raised vertically in a direction perpendicular to the direction of conduction of heat exchange air.
1.22. each slit 21
．． The protrusion direction, which is the cutting direction of 22, is divided into two parts so that the left and right sides are different. For example, to explain in detail the slit portion 2 on the lower right side of the figure, the white slit 21 on the left side of the figure in each slit pair 20 protrudes toward the front side of the paper, and is shown by crossed hatching for convenience. The middle right slit 22 projects to the back side of the paper. The line indicating the boundary between the slits 21 and 22 cut and raised in each direction is the cutting line, and therefore the fin base 13 after these slits 21 and 22 are formed is inevitably open. It is a through hole 23.

In this way, the other slit sections 2 in the upstream row and the slit sections 2 in the downstream row also consist of three slit pairs 20, and each slit pair 20...
Similarly, it is constructed with a pair of slits 21 and 22 that are divided into two halves so that the protrusion direction, which is the cutting and raising direction, is different on the left and right sides. In the adjacent slit portions 2, 2 in the upstream and downstream rows, the slits 21.2
The rising directions of 2 are opposite to each other. That is, in the figure, the slit section 2 at the bottom of the right row and the heat exchange vibrator 3
Slit 21°22 of slit section 2 in the middle of the same row across
The protruding directions of the slit portions 2 are opposite to each other, and the protruding direction of the slit portion 2 on the uppermost stage that holds the heat exchanger vibrator 3 is opposite to that on the middle stage, and is the same as that on the lowermost stage. Similarly, the protruding direction of the slit portions 2 in the left row in the figure is the same as that in the right row. That is, the slit protruding directions of adjacent slit pairs 20, 20 in each row orthogonal to the flow of heat exchange air are opposite to each other.

The slit 21 in such a slit portion 2...
The protruding direction of 22 can also be explained from FIG. That is, the center of each stage represents the remaining fin base 1a provided with slits 21 and 22, and it can be seen that the fin base 1a is cut and raised so as to protrude from this surface in the vertical direction in the figure. Then, at the same location of the fins arranged in parallel with a predetermined gap in the vertical direction, slits 2 and 2 are arranged in the same direction.
Of course, 1.22 stands out.

Thus, the fins 1 having such slit portions 2 and the heat exchange vibe 3 constitute a heat exchanger and perform a heat exchange function. That is, ε conducts the fluid to be heat exchanged to the heat exchange vibe 3 and conducts heat exchange air between the fins 1. This heat exchange air is transferred to the fin 1 and heat exchange vibe 3.
There is heat transfer from the fins 1 to the heat exchange vibe 3, and a heat exchange effect with the fluid to be heat exchanged is obtained.

To explain the flow effect of heat exchange air, as shown in FIG. 3, each slit 21, 22 in a predetermined slit pair 20 protrudes from the fin base 1a.
The heat exchange air flows in a straight line in the direction of the through hole 23, which is the location where the slit density is low in the slit pair 20. Here, the heat exchange air flows through the through holes 23 from the lower surface of the fin 1 to the upper surface, and further through the through holes 23 from the lower surface to the upper surface of the adjacent slit pair 20 of the fin 1 on the upper surface of the fin 1. It will flow through.

In other upstream slit portions 2..., as shown in FIG. 4, if the protruding direction of the slits 21 and 22 is reversed, it is natural that the slits 21 and 22 should be directed from the upper surface to the lower surface of the fin 1, which is the opposite direction. It flows. In addition, since the upstream and downstream slit sections 2 are arranged in a staggered manner, the heat exchange air drawn out of the upstream slit section 2 has a slit density of the downstream slit section 2. It is spaced at a predetermined angle toward the through hole 23 of the slit pair 20, which is the lower direction. To explain, in the uppermost and lowermost slit sections 2 and 2 in the upstream diagram, the left slit 21 protrudes toward the front and the right slit 22 protrudes toward the back, from which the heat exchange air flows. The flow is represented by the white arrow as an airflow flowing from the front to the back of the paper. On the other hand, in the middle slit section 2, the left slit 22 protrudes to the back side, and the right slit 21 protrudes to the front side, so that the flow of heat exchange air is as shown by the intersecting hatched arrows in the paper. Expressed as airflow flowing from surface to surface. In any case, the temperature boundary layer is still divided by all the fin parts 2 in the upstream row.

Naturally, the fins (not shown) arranged in parallel with each other with a predetermined gap in front of the fins 1 also have slits protruding in the same direction at the same position, so that the heat exchange air flows in the same direction. Furthermore, the fins (not shown) arranged in parallel with a predetermined gap on the back side of the fin 1 also have slits protruding in the same direction at the same position, so that heat exchange air flows in the same direction. . From this, the airflow of heat exchange air from the front to the back of the paper in the fin 1 is combined with the airflow of heat exchange air from the front to the front of the paper in the fins on the back side, and the slit portion 2 on the downstream side. It collides just before it is introduced. Alternatively, the air flow from the front of the page to the front in the fin 1 is the air flow from the front to the back of the paper in the fin on the near side, and the slit portion 2 on the downstream side.
・Collides just before being introduced. In this way, in the slit portions 2 in the downstream row, the air flows coming out of the adjacent slit portions 2°2 in the upstream row collide with each other at the position just before the heat exchange air flows into the slit portions 2... in the downstream row. Thereafter, it is guided to the slit section 2. The collision of these heat exchange air streams with each other creates turbulence that further disrupts the temperature boundary layer that is developing on the fins 1. Then, the heat exchange air after colliding is guided to the slit section 2 on the downstream side, where the through holes 23 where the slit density is low are again guided depending on the rising direction of the slits 21 and 22. At the same time, the temperature boundary layer is further divided, and then the temperature boundary layer is guided in a predetermined direction. Therefore, the temperature boundary layer formed along the fins 1 as the heat exchange air is conducted is completely separated and destroyed, and the heat transfer coefficient of the fins 1 can be improved.

As shown in FIG. 5, the characteristics of the air side heat transfer coefficient with respect to the front wind speed are improved by approximately the same ratio over the entire range of wind speeds, compared to the conventional case in which the positions and rising directions of the slits are aligned. Furthermore, as shown in FIG. 6, the characteristics of the air side pressure loss with respect to the front wind speed are almost the same as in the conventional case. That is, the pressure loss of the present invention is the same as that of the conventional one, and the heat transfer coefficient can be improved.

Note that the configuration of each of the slit portions 2 is not limited to the above embodiment, and various modifications can be considered. In short, the pairs of slits are arranged in a staggered manner along the conduction direction of the heat exchange air, and the protruding directions of the slits at adjacent positions in each row orthogonal to this flow are directed in opposite directions to each other, so that the heat exchange air can be mutually Any configuration may be sufficient as long as it can guide the flow in the opposite direction.

[Effects of the Invention] As explained above, according to the present invention, the temperature boundary layer is divided by the pair of slits on the upstream side, and the heat exchange air exiting from the adjacent pair of slits on the upstream side is separated at the introduction position of the pair of slits on the downstream side. They collide with each other to further destroy the temperature boundary layer, and are further separated by a pair of slits on the downstream side. Therefore, it is possible to improve the heat transfer coefficient and to achieve an efficient heat exchange effect.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a perspective view schematically showing a part of a heat exchanger, FIG. 2 is a longitudinal sectional front view of the heat exchanger, and FIG. 3 is a view taken from FIG. 2 A-A Fig. 4 is a longitudinal cross-sectional view taken along the line;
FIG. 6 and FIG. 6 are characteristic diagrams comparing the characteristics of the present invention and the conventional characteristics. 1... Fin, 3... Heat exchange pipe, 20... Slit pair, 21.22... Slit.

Claims (1)

[Claims] A plurality of fins that are arranged in parallel with a predetermined gap and conduct heat exchange air in a plane direction along the mutual gaps, a heat exchange pipe that passes through these fins and conducts a fluid to be heat exchanged, and is integrated with the fins. A pair of slits that are cut and machined in a direction perpendicular to the direction of conduction of the heat exchange air and a plurality of pairs of slits that protrude in directions opposite to each other with respect to the remaining fin base. , the heat exchanger characterized in that the slit pairs are arranged in a staggered manner along the conduction direction of the heat exchange air, and in each row orthogonal to this flow, the slit protruding directions of the adjacent slit pairs are opposite to each other. vessel.