JPS6319745Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) The present invention relates to a so-called cross-fin coil type heat exchanger, and more specifically to a heat exchanger in which louver-shaped inclined slit fins are formed on the inclined surface of corrugated fins. It is.

(Prior Art) Conventionally, in cross-fin coil type heat exchangers, various treatments have been applied to the fin surfaces in order to improve the heat transfer effect between the fins and a gaseous heat exchange fluid such as air. being done. For example, as shown in FIG. 3, a large number of so-called slit fins d each having a bridge-shaped fin portion b and a slit portion c formed by press working are formed on a flat or corrugated fin substrate a. The formed fin unit e is known.

(Problem to be solved by the invention) However, in this conventional device, since the surface of the slit fin d is formed parallel to the flow direction of the heat exchange fluid W, the slit fin d
turbulence of the heat exchange fluid W is not sufficiently promoted by The heat transfer performance is good at the slit fin d part because it is developed more than the slit fin a, but the heat transfer performance at the fin board a is poor, especially the heat transfer performance at the fin board a left between the slit fins d and d. It turned out to be bad. Furthermore, in the case where the height of the slit fin d is constant, the rear slit fin d is located downstream of the front slit fin d, so there is a drawback that the heat exchange efficiency of the rear slit fin d is reduced.

Therefore, in order to eliminate the above-mentioned drawbacks,
The present applicant first drilled a number of insertion holes for inserting heat medium tubes in multiple rows perpendicular to the direction of air flow in a fin board, and connected the centers of the insertion holes for each row with a center point. A large number of narrow slits are bored parallel to the line and substantially parallel to each other, leaving the periphery of the insertion hole, and both short sides and one long side on the side of the insertion hole are connected to the fin board. By forming a louver-shaped inclined slit fin that is deformed in an upright manner,
A cross fin coil is formed by configuring a fin unit, and a number of fin units are inserted into a heat medium pipe to form a cross fin coil, and the airflow is made to flow approximately at right angles to the slits and at an angle to the inclined slit fins. A large number of louver-shaped inclined slit fins are formed on most of the surface to reduce the area of the fin substrate portion with poor heat transfer performance as much as possible, and eliminate the influence of the downstream area of the front slit. A cross-fin coil type heat exchanger that uses the leading edge effect to suppress the development of a boundary layer and promotes turbulence in the heat exchange fluid, thereby dramatically improving the heat transfer effect. proposed an exchanger (Jet Application 1984-
(See specification No. 13580).

By the way, in such a proposal, the airflow flows straight between the fin units,
The slanted slit fins can promote turbulence due to the mixing effect with the flow that curves through the slit, but this mixing effect is mainly caused by the slanted slit fins on the upstream side changing the direction of the flowing flow. This is simply due to the collision of the flows, and it is desirable to make the flow more turbulent in order to improve the heat transfer effect.

In view of these points, the present invention was developed to take the above-mentioned proposal one step further.The entire fin board is made into a waveform, and the arrangement, shape, inclination relationship, etc. of the inclined slit fins with respect to the waveform fins are appropriately set. By doing so, while ensuring a dramatic improvement in the heat transfer effect by the louver-shaped inclined slit fin proposed above, in addition to fully exerting the mixing effect of the main flow and the branch flow of the heat exchange fluid, The purpose is to sufficiently promote the generation of turbulence due to direction change and the resulting mixing effect to further promote turbulence.

(Means for solving the problem) To achieve this purpose, the solution of the present invention is as follows:
As shown in FIGS. 1 and 2, a fin substrate 1
Insertion holes 3, 3... for insertion of the heat medium pipes 2 are provided in a plurality of rows perpendicular to the flow direction of the airflow W, and a center line connecting the centers of the insertion holes 3, 3... for each row. In a cross fin coil type heat exchanger in which a plurality of waveform fins 6 are arranged in parallel, the entire fin board 1 is formed into a continuous V-shaped waveform with the bending line l as the fin board 1 of the waveform fin 6. A large number of inclined slit fins 5, 5, . The configuration is such that the inclination angle α of the fin substrate 1 with respect to the inclined surface 1a is set larger than the inclination angle β of the inclined surface 1a of the fin substrate 1.

(Function) With the above configuration, in the present invention, in addition to dramatically improving the heat transfer effect by the louver-shaped inclined slit fins 5 as described above, a large number of inclined slit fins 5 are provided on each inclined surface 6a of the corrugated fins 6. ,V
The slit fins are bent parallel to the curved line of the V-shaped portion so that the fin direction is directed toward the inner surface of each V-shaped portion, and the inclination angle α of each inclined slit fin 5 with respect to the inclined surface 6a of the wavy fin 6 is set by the wavy fin. 6, the airflow W of the heat exchange fluid flowing through the fluid passage formed between the corrugated fins 6 is separated from the main stream by each inclined slit fin 5. On the upstream side of the bending line l of the V-shaped part, the main stream is largely bent toward the inner surface of the V-shaped part by each inclined slit fin 5, and on the downstream side, the main stream flows into the V-shaped part by each inclined slit fin 5. Since the flow flows toward the outer surface of the section with a large bend in the opposite direction to the upstream side, the main flow passing between the inclined slit fins 5 and the branch flow flowing between the corrugated fins 6 and 6 along the inclined surface 6a are sufficient. The main stream as a whole flows in a waveform that is opposite to the waveform of the corrugated fins 6, while the branch flow largely changes direction in a waveform that follows the waveform of the corrugated fins 6. By changing the flow rate, large turbulence is generated, and the main flow and the branch flow are mixed violently, and the turbulence of the heat exchange fluid is greatly promoted. 6 can be significantly improved. Note that when α=β, the airflow W is not branched into the main flow and the branched flow by each inclined slit fin 5 as described above, and only flows straight along each inclined slit fin 5, and there is no vortex or turbulence. Flow is difficult to occur.
Furthermore, when α<β, the airflow W is branched into a main flow and a branch flow by each inclined slit fin 5, but the main flow does not bend greatly and flows almost along the branch flow, and the waveform fins as a whole flow. The flow along the waveform becomes the main flow and is less turbulent.

In this case, if the insertion holes 3, 3, . The staggered arrangement of 2 eliminates the occurrence of bypass airflow around the heat medium pipes, and allows the flow between the waveform fins to flow on the curved line l (heat medium pipe row) of the waveform fins 6 where the flow is most accelerated. By changing the direction, the turbulence generated on the bending line l propagates to the downstream side of the heat medium pipe 2, and the heat transfer performance of the inclined slit fin 5 on the downstream side, where the transfer performance is relatively low, is reduced to that of the louvered inclined slit fin. This is preferable because the effect is improved in combination with the effect of No. 5 itself.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

1 and 2 show an air heat exchanger according to an embodiment of the present invention, in which 1 is a fin board in which the entire V-shape is bent, for example, twice in succession into a waveform; 1 has insertion holes 3, 3 on the bending line l of the V-shaped portion through which the heat medium pipe 2 can be inserted.
... are formed in multiple rows perpendicular to the flow direction of the airflow W in two rows in front and back in FIG. 1, and in a staggered arrangement between each row. Narrow slits 4, 4 parallel to the center line connecting the center of each row (i.e. bending line l)
... are bored in large numbers almost parallel to each other so as to surround the insertion hole 3, leaving only the very periphery thereof. Further, on each inclined surface 1a of the fin substrate 1, a large number of louver-shaped inclined slit fins 5, 5, . A large number of these corrugated fins 6 are inserted into and supported by the heat medium pipes 2, 2... with predetermined fin spacing through their insertion holes 3, 3... to form a cross fin coil 7, and the air flow W of the heat exchange fluid is The fin substrate 1 of the corrugated fin 6 is bent into a waveform at an angle with respect to the direction of flow of the airflow W.

The inclined slit fin 5 has both short sides 5a and 5b on the side of the insertion hole 3 integrally connected to the fin board 1, and one long side 5c (or 5d) connected to the inclined surface 1a of the fin board 1. The other long side 5d (or 5c) is bent and deformed to a predetermined inclination angle while the slit fins 5, 5 are positioned above, and a pair of opposing long sides 5c, 5d of the adjacent inclined slit fins 5, 5 form a single piece. The slit 4 is formed so as to constitute each opposing side edge (upper edge and lower edge in FIG. 2). Further, the inclined slit fin 5
is a line that faces forward with the long side 5d located on the leeward fin board 1 as a fold on the upstream side with respect to the center line (V-shaped bending line l) connecting the centers of the insertion holes 3, 3... of each row. On the downstream side, the long side 5c located on the windward fin board 1 is used as a crease, and the long side 5c on the windward fin board 1 is folded toward the rear, above the fin board surface (in Fig. 2, downward). Below)
It is upwardly inclined (that is, its tip side rises downward on the outer surface side of each V-shaped portion), and the fin direction is directed toward the inner surface side of each V-shaped portion with respect to the inclined surface 1a. The fin substrate 1 is bent and bent at an angle, and is formed to be inclined in a direction symmetrical to the inclined surface 1a (its inclination angle β) of the fin substrate 1 with respect to the flow direction of the airflow W. The angle of inclination α of the inclined slit fin 5 with respect to the inclined surface 1a of the fin substrate 1 is set to be larger than the angle of inclination β of the inclined surface 1a. Further, as a result, a mountain-shaped rib 8 having a direction opposite to the wave shape of the fin substrate 1 is formed on each ridge line of the wavy bend of the fin substrate 1, as shown in FIG. Note that 9 is a collar portion provided around the periphery of the insertion hole 3.

Therefore, in the embodiment described above, by providing a large number of slits 4 and inclined slit fins 5 on the fin board 1 except for the very periphery of the insertion hole 3, the corrugated fins 6 are fitted into and supported by the heat medium pipe 2. While ensuring the strength of It will improve.

Moreover, as shown in FIG. 2, the main flow Wa of the heat exchange fluid flowing through the fluid passages formed between the corrugated fins 6, 6 is located along the curved line l at each V-shaped portion of the corrugated fins 6. On the more upstream side, due to the inclined slit fins 5 rising in the opposite direction to the inclined surface 1a of the fin substrate 1, the water flows through the slits 4 in a large bend toward the inner surface of the V-shaped portion (upward in the figure), and flows toward the downstream side. Now, inclined slit fin 5.
As a result, the main flow flowing between the inclined slit fins 5 and 5 bends greatly in the direction opposite to the upstream side (downward in the figure) toward the outer surface of the V-shaped portion.
Wa and the branch flow Wb that runs straight between the corrugated fins 6 and 6 collide and mix, creating a vortex flow, and the main flow Wa as a whole becomes an upward flow and then a downward flow as shown in Fig. 2, and the waveform of the corrugated fin 6 While the current flows with a large change in direction with a wave shape in the opposite direction to that of the
Wb flows along the waveform of the corrugated fins 6, as shown in Figure 2, as a downward flow and then an upward flow, changing the direction greatly in the waveform, creating a large turbulent flow, and accompanying this, the main flow Wa and the branched flow Wb will mix vigorously, thereby significantly promoting the turbulence of the heat exchange fluid and significantly improving the heat transfer coefficient between the heat exchange fluid and the corrugated fins 6.

In particular, the inclined slit fin 5 has both short sides 5
a, 5b are integrally connected to the fin board 1, one long side 5c or 5d is positioned on the inclined surface 1a of the fin board 1, and the other long side 5d or 5c is deformed in an upright manner. , and since the pair of opposing long sides 5c and 5d of the adjacent inclined slit fins 5 and 5 are formed so as to constitute each opposing side edge of one slit 4, the fin width of the inclined slit fin 5 can be increased. without doing,
That is, the louver gap t of the inclined slit fins 5 can be made large without reducing the number of the inclined slit fins 5, and the turbulent flow due to the mixing effect of the main flow Wa and the branch flow Wb can be further promoted. .

Furthermore, since the inclined slit fin 5 is not located in the downstream area of the main stream Wa that passes between the inclined slit fin units 5, 5, the influence of the downstream area of the front inclined slit fin 5 is eliminated, and any of the inclined slit fins 5 works well. As a result, the heat transfer performance can be obtained, and the heat transfer effect can be further improved.

Furthermore, the rise of the inclined slit fin 5 exhibits the effect of cutting off the boundary layer, similar to the conventional slit fin shown in FIG. 3, thereby further improving the heat transfer coefficient.

Further, the fin board 1 has a wave-shaped curved ridge line parallel to the slits 4, 4... in the step direction, and insertion holes 3, 3... (heat medium pipes 2, 2...) are provided along the ridge line. As a result, the stiffness (strength) of the fin board 1 in the step direction is strengthened, and the fin board 1 is not deformed during pipe expansion, and when used as a wet coil, the ridge line of the bend allows the drain to flow down. It has the advantage of improving injuries. Moreover, since a mountain-shaped rib in the opposite direction to the wave shape of the fin substrate 1 is formed on the ridgeline of the bend of the fin substrate 1, the strength against bending in the longitudinal direction of the wavy fin 6 can be significantly increased. .

Furthermore, each inclined slit fin 5 is inclined such that its fin direction is directed toward the inner surface side of each V-shaped portion of the corrugated fin 6, and its fin substrate 1
The inclination angle α with respect to the inclined surface 1a is the inclined surface 1a.
is larger than the inclination angle β of the fin substrate 1 and is inclined upwardly in a direction symmetrical to the inclined surface 1a of the fin substrate 1 with respect to the flow direction of the airflow W. Bend line l of V-shaped part
On the upstream side, the flow velocity width of the airflow W tends to decrease and the flow velocity increases, and the fin surface boundary layer of the inclined slit fin 5 is difficult to develop and is thin, and its heat transfer performance is high. Conversely, as the flow velocity width tends to widen, the flow velocity slows down, and the fin surface boundary layer tends to develop and become thicker, resulting in poor heat transfer performance. When the flow direction between the corrugated fins 6 and 6 changes at
The slanted slit fin 5 on the downstream side propagates backward (downstream), and as a result, the transmission performance is relatively low.
The heat transfer performance can be improved together with the effect of the louver-shaped inclined slit fin 5 itself described above.

In addition, conventional louver fins of this type have been used in corrugated fins for automobile radiators, but in this corrugated fin, louver-shaped inclined slit fins are arranged in a row, so the inclined slit fins are arranged in a row. In contrast to the bypass airflow that occurs along the side fin substrates, in the present invention, by arranging the heat transfer medium tubes 2 in a staggered manner, bypass air flow does not occur around the heat transfer tubes 2, and the above effect is achieved. can be demonstrated even more efficiently.

Note that the width (width of the short side) of the inclined slit fin 5 is not necessarily constant, and it is preferable that it is not constant from the viewpoint of creating turbulent flow.

Further, the present invention is not limited to the above-mentioned embodiment, but also includes various other modifications. For example, in the above-mentioned embodiment, the heat medium pipes 2, 2...
(In other words, the insertion holes 3, 3...) were arranged in two rows, but
Needless to say, there may be three or more rows.

In addition, although only a circular tube is shown in the drawing as the heat transfer tube 2, if an elliptical tube or flat tube with a long axis in the flow direction is used, ventilation resistance can be kept low and good heat transfer performance can be obtained. Of course, that would be the case.

When the inclined slit fins 5 are bent so that the fin direction faces the inner surface of each V-shaped portion, it is possible to bend the inclined slit fins 5 so that the fin direction faces the inner surface of each V-shaped portion, as in the above-mentioned embodiment. , may be formed on the inner surface side of each V-shaped portion with its tip end raised upward.

(Effects of the invention) As described above, according to the invention, the insertion holes 3, 3, . A plurality of wavy fins 6 are arranged in parallel, with the entire fin board 1 formed in a continuous V-shape waveform, with the center line connecting the centers of the insertion holes 3, 3, and each row as a bending line l. In the cross-fin coil type heat exchanger, a large number of inclined slit fins 5, 5... are provided on each inclined surface 1a of the fin substrate 1 of the corrugated fins 6, parallel to the bent line l, and the fin direction is in each V-shaped portion. The inclined slit fins 5 are bent toward the inner surface, and the inclined angle α of each inclined slit fin 5 with respect to the inclined surface 1a of the fin substrate 1 is set to be larger than the inclined angle β of the inclined surface 1a of the fin substrate 1. By reducing the fin substrate portion with poor heat transfer performance as much as possible and increasing the inclined slit fin portion with good heat transfer performance,
In addition to being able to significantly improve heat transfer performance, the main flow flowing between the inclined slit fins 5, 5 flows in a wave shape opposite to that of the wave fins 6, whereas the main flow flows between the waveform fins 6, 6. Since the divided flow flows along the waveform of the corrugated fins 6, turbulence is caused by the mixing effect between the mainstream and the divided flow of the heat exchange fluid, the occurrence of turbulence due to the change in direction of the mainstream and the divided flow, and the resulting mixing effect. Therefore, it is possible to provide a heat exchanger with extremely excellent heat transfer effects.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
FIG. 1 is a partial side view, and FIG. 2 is a sectional view taken along the line A--A in FIG. 1. FIG. 3 is a partial perspective view showing a conventional example. DESCRIPTION OF SYMBOLS 1... Fin board, 1a... Inclined surface, 2... Heat medium pipe, 3... Insertion hole, 4... Slit, 5... Inclined slit fin, 6... Corrugated fin, 7... Cross fin coil, l ...Bending line, W...Air flow of heat exchange fluid, α...Inclination angle of inclined slit fin, β...Inclination angle of inclined surface.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) The fin board 1 is provided with insertion holes 3, 3, etc. for insertion of the heat transfer pipes 2 in a plurality of rows perpendicular to the flow direction of the airflow W, and the insertion holes A cross fin coil type in which a plurality of waveform fins 6 are arranged in parallel, each of which has a curved line l that connects the centers of 3, 3, and so on for each row, and the entire fin board 1 is formed into a continuous V-shaped waveform. In the heat exchanger, a large number of inclined slit fins 5, 5... are provided on each inclined surface 1a of the fin substrate 1 of the corrugated fins 6, and
The inclined slit fins 5 are bent parallel to the fins so that the direction of the fins is directed toward the inner surface of each V-shaped portion, and the inclination angle α of each inclined slit fin 5 with respect to the inclined surface 1a of the fin substrate 1 is set according to the inclination of the fin substrate 1. A heat exchanger characterized in that the inclination angle β of the surface 1a is set larger than that of the surface 1a. (2) The inclined slit fin 5 has both short sides 5a and 5b.
is integrally connected to the fin board 1, and while one long side (5c or 5d) is positioned on the inclined surface 1a of the fin board 1, the other long side (5d or 5c) is deformed in an upright manner. A pair of opposing long sides 5c and 5d of the adjacent inclined slit fins 5 and 5 form one slit 4.
The heat exchanger according to claim (1) of the utility model registration, wherein the heat exchanger is formed so as to constitute each opposing side edge of the heat exchanger. (3) Each insertion hole 3, 3... is provided in a staggered arrangement between each row, and each inclined slit fin 5, 5... is provided so as to surround the insertion hole 3, leaving the periphery intact. A heat exchanger according to claim (1) or (2) of patent registration.