JPH06257893A - Heat exchanger - Google Patents

Abstract

PURPOSE:To suppress a height of frost, to eliminate bridging due to frost and to obviate obstruction of a gas stream by forming a cutout, etc., at an end disposed at a gas stream inlet side of a fin in a heat exchanger in which a refrigerant tube bent in a zigzag manner is connected with a plurality of fins. CONSTITUTION:A heat exchanger to be used for an evaporator, etc., for a refrigerator, a refrigerating display case, etc., comprises many fins 1 so disposed from a dense side to a sparse side toward an upstream side of a gas stream 11, and a zigzag refrigerant tube 5 inserted perpendicularly to the fins 1 and made of a straight tube part 7 and a bent tube part. Each fin 1 is formed at a plurality of positions with a long hole 3 in which the tube 5 is inserted in such a manner that both ends of the hole 3 are as reception holes 9 for receiving the part 7. A cutout 21 is formed at a part of the end of the fin 1 at an input side of the stream 11 thereby to grow frost 13 along edges 1A, 21A having long line lengths to suppress growth of the frost 13 in a height direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger used in an evaporator or the like of a refrigerator or a freezer showcase, and more particularly to the shape of a fin through which a meandering refrigerant tube is inserted.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 7, the above heat exchanger has a plurality of fins 1 arranged in parallel and a plurality of elongated holes 3 formed in the fins. It is formed by inserting the curved tube portion 8 (see FIG. 1) of the meandering refrigerant tube 5 bent into a U shape. Receiving holes 9 for receiving the straight pipe portion 7 of the refrigerant tube 5 are formed at both ends of the long hole 3,
By pressing the straight pipe portion 7 into the receiving hole 9, the refrigerant tube 5 and the fin 1 are firmly joined.

When the heat exchanger constructed as described above is used for an evaporator of a refrigerator or a freezer showcase, the outside air invades as the air flow 11, and as shown in FIG. Frost 13 is formed on the surface of the fin 1 located on the side and on the outer periphery of the refrigerant tube 5. The frost 13 is significantly increased at the air inlet side edge 1A of the fin 1, and as the frost 13 grows, the frost is connected to the adjacent fins 1 to form the bridge 15.

When the bridge 15 is formed here, the air flow 11 is obstructed (FIG. 8), and the function of the heat exchanger is significantly deteriorated.

In order to prevent such frost formation as much as possible, conventionally, fins 1 having different lengths are used so that the fins 1 are arranged in an array from sparse to dense from the air inflow to the outflow side. Alternatively, the width dimension of the fins 1 may be changed so that the airflow may pass beside the narrow fins 1 even when frost is formed.

[0006]

However, in any of the above-mentioned structures, there is a problem that frost formation cannot be sufficiently prevented.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a heat exchanger having a structure capable of preventing obstruction of air flow caused by frost formation. And

[0008]

In order to achieve the above object, the present invention is a heat exchanger in which a plurality of fins are joined to a meanderingly bent refrigerant tube, and the ends of the fins located on the air inflow side. It is characterized in that a notch or a hole is formed in the portion.

[0009]

[Function] Frost caused by water contained in the air flow is generated at the edges of the fins. By providing notches or holes in the fins, frost is formed not only by the original edges of the fins but also by the notches or holes. It also occurs at the edges that are exposed. As a result, the line length of the frosted edge can be increased, the frost grows along the length of the fin, so to speak, and the growth in the height direction is suppressed. Therefore, the height of frost does not increase, and the bridge phenomenon does not occur between the fins.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the fin 1 has three different lengths.
Different types are used alternately and are arranged so as to become denser and sparser toward the upstream side of the air flow 11. The fins 1 are arranged in parallel, and the refrigerant tubes 5 are inserted into the fins 1 at right angles. The refrigerant tube 5 has a straight pipe portion 7 and a curved pipe portion 8, meanders by the curved pipe portion 8, and the straight pipe portions 7 are parallel to each other. A side plate 17 is arranged on the outermost side of the plurality of fins 1.

FIG. 2 shows a plan view of a typical fin 1. The side plate 17 also has a similar plan view.

That is, elongated holes 3 into which the refrigerant tubes 5 are inserted are formed at a plurality of locations on the fin 1. The elongated hole 3 is for inserting the U-shaped bent tube portion 8 of the refrigerant tube 5. Since the central portion of the U-shape of the curved pipe portion 8 is crushed so that its cross section becomes an ellipse and has a small thickness, the refrigerant tube 5 can be easily inserted.
Both ends of the long hole 3 are receiving holes 9 for receiving the straight pipe portion 7 of the refrigerant tube 5. A locking piece (not shown) is formed at the edge of the receiving hole 9, and when the straight pipe portion 7 is received and press-fitted, the elastic force of the locking piece maintains the press-fitted state. . In addition, embossing by press molding is performed between the plurality of long holes 3 to form concave or convex ribs 19 to increase the strength of the fin 1.

According to this embodiment, however, the fin 1
A notch 21 is formed in a portion of the end portion of the above portion located on the inlet side of the air flow 11.

Next, the operation of this embodiment will be described.

When the heat exchanger of this embodiment is used in a refrigerator or an evaporator of a freezer showcase, the airflow 11 passing between the heat exchangers contains water. Then, referring to FIG. 3 and FIG. 4, the water content of the air flow 11 becomes frost 13,
Frost is formed on the edge 1A of the fin 1, and this frost 13 grows around this edge 1A.

According to the present embodiment, however, since there is not only the edge portion 1A at the end portion of the fin 1 but also the edge portion 21A formed by the notch 21, the line length of the edge portion becomes long, so that the frost is generated. 13 grows along the edges 1A and 21A having this long line length. Therefore, the frost 13 grows along the length direction of the fin 1, so to speak, and the growth in the height direction (the thickness direction of the fin 1) is suppressed. This is because, if the water content in the airflow 11 is constant, the frost 13 grows along the length of the fin 1 to a sufficient amount, and it is not necessary to grow in the height direction.

By suppressing the growth in the height direction,
The conventional bridge 15 phenomenon shown in FIG. 7 or 8 can be prevented, and a sufficient space can be secured between the fins 1 due to the air flow 11 as shown in FIG. Therefore, it is possible to eliminate or reduce the inconvenience that the airflow 11 is blocked by the bridge phenomenon and the performance of the heat exchanger is significantly reduced.

However, in this embodiment, the notch 21 is half of the slot 3. Usually, the fin 1 is manufactured by feeding out a coiled aluminum plate, forming the long holes 3 and the ribs 19 in the plate surface, and cutting the plate into a predetermined length. Therefore, the shape of the fin 1 in FIG. 2 is extremely convenient for forming the notch 21 at the end of the fin 1. That is, if the middle of the long hole 3 and the rib 19 is cut, the fin 1 having the notch 21 is automatically manufactured.

The cutouts 21 are also formed in the fins 1 and the side plates 17 having different lengths.

5 and 6 show another embodiment.

In this example, holes 23 are formed in the end portions of the fins 1 instead of the notches 21. Since the line length of the edge portion can be lengthened also by this hole 23, the frost 13 can grow along the length of the fin 1.

That is, as shown in FIG. 5, by forming a hole 23 at a position away from the edge 1A at the end of the fin 1, frost is generated on the edge 23A formed by the hole 23. As described above, this hole 2
The amount of frost 13 attached can be increased by the line length of 3.

As a result, as shown in FIG. 6, the frost 13 is
Not only the edge 1A at the end of the fin 1 but also the edge 2 of the hole 23
Since it grows to 3A, the bridge 15 phenomenon of the frost 13 can be prevented as in the above-described embodiment.

In the above, the notch 21 or the hole 23
Alternatively, the long hole 3 for inserting the refrigerant tube may be used, but a special notch or hole may be provided for increasing the line length of the edge portion where frost is formed. For example, it is needless to say that it is still effective in accordance with the above-mentioned point if a notch having a particularly long line length as a wavy shape, or a hole having a long line length at its edge portion is formed by meandering.

[0026]

As described above, according to the heat exchanger of the present invention, by providing the notch or the hole at the end portion of the fin located on the air inflow side, the line length of the edge portion where frost is easily formed is reduced. Since it can be lengthened, the height of frost can be suppressed, and the bridging phenomenon due to frost can be less likely to occur, it is possible to prevent the airflow from being obstructed by the bridging phenomenon. This can prevent the performance of the heat exchanger from being deteriorated.

[Brief description of drawings]

FIG. 1 is an overall view of a radiator according to an exemplary embodiment of the present invention.

FIG. 2 is a plan view of the fin of FIG.

FIG. 3 is an enlarged view of a portion III in FIG.

FIG. 4 is a side view of the end of FIG.

FIG. 5 shows another embodiment of the present invention and corresponds to FIG.

FIG. 6 is a side view of the end of FIG.

FIG. 7 shows a conventional example and is a diagram corresponding to FIG.

FIG. 8 is a side view of the tip of FIG.

[The code theory]

 1 Fin 3 Long Hole 5 Refrigerant Tube 7 Straight Pipe 8 Curved Pipe 9 Receiving Hole 19 Rib 21 Notch 23 Hole

Claims (1)

[Claims] 1. A heat exchanger in which a plurality of fins are joined to a meanderingly bent refrigerant tube, wherein a notch or a hole is provided at an end of the fin located on the air inflow side. vessel.