JP2001091101A - Heat exchanger for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heating capability by restraining frosting onto fins generating in a heating operation at the time of a low outdoor temperature in a heat exchanger used for an outdoor unit of an air conditioner. SOLUTION: A plurality of fins 1 are laminated, and each of fins has a plurality of assembling holes 5 provided with circular collar parts 5a and comprises bending parts 6 or a flat part on the windward side at a border of a fin middle part to an air flow to have heat exchange, and providing cut- and-raised parts 7 in slit shapes or the cut-and-raised parts 7 in louver shapes on the leeward side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for an air conditioner, and more particularly, to a fin structure of a heat exchanger for an outdoor unit.

[0002]

2. Description of the Related Art As shown in FIG. 1, for example, a heat exchanger for an outdoor unit of an air conditioner has a plurality of fins 1 stacked in parallel at predetermined intervals and a plurality of hairpins perpendicular to the fins. A heat transfer tube 2 and a connecting tube 3 and the like connecting the open ends of the heat transfer tubes 2 in order, for example, as shown in FIG. A so-called corrugate in which a plurality of assembly holes 5 having collar portions 5a are provided at predetermined intervals, and corrugated protrusions 6 are provided on the windward and leeward sides of the fin center with respect to the flow of air for heat exchange. A so-called slit fin in which a plurality of so-called fins are laminated and a plurality of slit-shaped cut-and-raised portions 7 are provided at predetermined intervals on the fin surface with respect to the flow of air for heat exchange as shown in FIG. Or a stack of Not, but there is one provided with a raised flat fin or louver-like cut with the fin surface to a flat left.

[0003]

By the way, in an air conditioner having an outdoor unit equipped with a heat exchanger using slit fins 1B as shown in FIG. Low-temperature outside air hits the windward tip portion 1a earlier than the other portions of the fin 1, and cuts and raises 7a.
The low-temperature outside air hits the front edge (windward tip) 7a of the front edge of the cut-and-raised portion 7 earlier than other portions. Therefore, the front edge 1a of the fin 1 and the front edge 7a of the cut-and-raised portion 7 have a lower temperature than other portions, and frost occurs as shown in FIG. 4C. The air flow of the air significantly decreases, and thereby the heating capacity sharply decreases, and the comfort is greatly impaired. Therefore, the heat exchanger using the slit fins 1B is not suitable for the heating operation at a low outside air temperature. There is a problem.

On the other hand, in a heat exchanger using a corrugated fin 1A or a flat fin as shown in FIG. 3, since air passages are formed at substantially equal intervals from the windward to the leeward of the fin 1, the fin 1 Windward (leading edge 1
Even if frost occurs as shown in FIG. 3C in FIG. 3A, the space between the fins is not closed by the frost layer 8 in a short time as in the above-mentioned slit fins 1B, and the heating capacity is reduced. Although it does not drop sharply, this type of heat exchanger has a smaller heat transfer coefficient to the air (outside air) originally flowing between the fins than the heat exchanger using the above-mentioned slit fins 1B. Has disadvantages.

Accordingly, in the present invention, the advantage of each of the heat exchangers is utilized to make it difficult for clogging between the fins due to frost formation to occur, and particularly to an air conditioner capable of improving the heating capacity at a low outside air temperature. The purpose is to provide a heat exchanger for the machine.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and comprises a plurality of collar portions provided with a plurality of collar portions in the vertical direction at the center of the plate surface and stacked in parallel at predetermined intervals. Fins, a plurality of heat transfer tubes fitted into the collar portion so as to be orthogonal to the fins, and a connecting tube connecting the open ends of the heat transfer tubes, with the center of the fin plate surface as a boundary. A slit-shaped or louver-shaped cut-and-raised portion is provided on the leeward side of the flow of the air for heat exchange.

The windward side is bent at the center of the plate surface of the fin.

Further, the cut-and-raised portion is provided in the same direction as the protrusion.

Further, the height of the cut-and-raised portion is set to be lower than one half of the lamination interval of the fins.

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 shows a basic configuration of a heat exchanger used for an air conditioner.
Is a plurality of fins stacked in parallel at a predetermined interval, 2 is a plurality of hairpin-shaped heat transfer tubes orthogonal to the fins 1, 3
Reference numerals 4 denote connecting pipes connecting the open ends of the heat transfer tubes 2 in order, and 4 denotes support plates disposed on both sides of the fin group formed by lamination.

FIG. 2 is an enlarged view of a part of the fin 1. The fin 1 has a plurality of mounting holes provided with a cylindrical collar portion 5a for inserting the heat transfer tube 2 and expanding and fixing the tube. 5 are provided at predetermined intervals, and a bent portion 6 having a gentle slope is provided on the windward side of the center of the fin 1 with respect to the heat exchange airflow indicated by the arrow. A slit-shaped cut-and-raised portion 7 is provided, and many sheets are laminated as shown in FIGS. 1 and 3 (c). Note that the cut-and-raised portion 7 is provided on the front side of the fin 1 in the same direction as the bent portion 6, and the height of the cut-and-raised portion 7 is smaller than half the stacking interval of the fins 1.

With such a fin 1, there is only the bent portion 6 on the windward side where frost is likely to occur, and air passages at substantially equal intervals are formed between the fins. Even if the front edge 1a is frosted as shown in FIG. 3 (c), the fin layer 8 does not block the fins, and the fin 1 has no fear of frosting. Since there is a cut-and-raised portion 7 effective for improving heat transfer to the flowing air, heat transfer is promoted, and as a result, heat exchange performance is improved.

In this embodiment, a bent portion 6 is formed on the windward side of the center of the fin 1 and a slit-like cut-and-raised portion 7 is provided on the leeward side.
The configuration is not necessarily limited to this. For example, a configuration in which a bent portion 6 is formed on the windward side of the fin 1 and a louver-shaped cut-and-raised portion is provided on the leeward side, and the windward side of the fin 1 is flat. A configuration in which a slit-like or louver-like cut-and-raised portion is provided on the leeward side may be used.

[0014]

According to the heat exchanger using the fins described above, frost formation on the fins can be minimized even in the heating operation at a low outside air temperature, and The space between the fins is not closed in a short time, the heating operation is stable, and a higher heat transfer rate is obtained, so that not only the heating capacity but also the cooling capacity is improved.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a heat exchanger according to the present invention and a conventional example.

FIG. 2 shows an embodiment of a fin according to the present invention;
(A) is an enlarged view of the main part of the fin front, and (b) is (a)
FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, and FIG.

3A and 3B show a conventional example, in which FIG. 3A is an enlarged view of a main part of the front of the fin, FIG. 3B is a sectional view taken along the line AA of FIG. 3A, and FIG. It is sectional drawing which shows a lamination state.

4A and 4B show another conventional example, in which FIG. 4A is an enlarged view of a main part of the front of the fin, and FIG.
FIG. 3C is a cross-sectional view showing a state in which the fins are stacked.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fin 2 Heat transfer tube 3 Connecting tube 4 Support plate 5 Assembly hole 5a Collar part 6 Bend part 7 Cut and raised 8 Frost layer

Claims (4)

[Claims] A plurality of fins provided in a vertical direction at a center of a plate surface, and a plurality of fins stacked in parallel at predetermined intervals;
A plurality of heat transfer tubes inserted into the collar portion so as to be orthogonal to the fins; and a connecting tube connecting the open ends of the heat transfer tubes. A heat exchanger for an air conditioner, characterized in that a slit-shaped or louver-shaped cut-and-raised portion is provided on the leeward side of the flow of air. 2. The heat exchanger for an air conditioner according to claim 1, wherein the windward side is bent at the center of the plate surface of the fin. 3. The heat exchanger for an air conditioner according to claim 1, wherein the cut-and-raised portion is provided in the same direction as the protrusion. 4. The heat exchanger for an air conditioner according to claim 1, wherein the height of the cut-and-raised portion is smaller than one half of the interval between the fins.