JPH02298796A - Heat exchanger core - Google Patents

Abstract

PURPOSE:To facilitate a bending of a core and to reduce a resistance of fluid by a method wherein a fin at one end is overlapped integrally between each of rows from a deformation part of the core and the other end fin is separated for each of the rows and contacted and fixed to a tube, respectively. CONSTITUTION:Tubes 1 and 2 are arranged in a thickness direction of a core. The tubes pass through several fins 3 and 4. The fin 3 is provided with tube insertion holes of circular form in two rows. Outside tube and the core part formed by the fin 4 are projected longer than that of the core. A reamer is placed within the tube to expand an outer diameter and then the tube is press fitted to the fin. A bending machining guide jig 6 is placed within the core, an external force is applied to the core as indicated by an arrow and bent. In this way, since only the fin at the bent portion is separated for every tube, its bending may easily be carried out and at the same time it is possible to reduce a fluid resistance with the integral fin 3.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a heat exchanger core used mainly as an outdoor unit of an air-conditioner/heater, in which multiple rows of tubes are arranged in the thickness direction of the core, and the outer surface of the core is This invention relates to a bent core type heat exchanger in which a large number of fins are provided to form a flat heat exchanger core, and the ends of the core are bent.

[Traditional technique].

A bent core type heat exchanger having multiple rows of tubes in the thickness direction of the core had a structure as shown in FIG. In this structure, as shown in FIGS. 5 and 6, flat cores are formed in each row in the thickness direction of the core, and one end of each core is connected by a side member 7, and a bending guide jig 6 is used. The pair of flat cores are curved simultaneously or for each tube row as shown in FIG. 6 by being guided by the tube. In such a heat exchanger core, a large number of fins 4 whose width is half the width of the entire core are arranged in parallel at small intervals, and the tube insertion holes are aligned with each other. Then, a large number of tubes 1 bent in advance into a U-shape are inserted into the tube holes in each row. The length of the core located on the inside is made smaller than the length of the core located on the outside. Then, the ends of both cores were pressed in the direction of the arrow, and each core was guided by a bending guide jig 6 to form a bend as shown in FIG.

In such a heat exchanger core, the thickness of the fins 4 is half the thickness of the core.

The reason for this is to absorb the difference in circumference caused by the difference in radius of curvature between the inner and outer sides when bending the core, and to prevent abnormal deformation of the fins.

[Problem to be Solved] However, in such a plurality of rows of bent cores, each fin 4 creates a discontinuous step in the thickness direction of the core at the separation line 5 of each row, increasing fluid resistance. This had the disadvantage of hindering the promotion of heat exchange.

Also, when this core is used as an evaporator for a heat pump type air conditioner or the like, strong frost formation occurs on the separation line 5.
This had the disadvantage of lowering thermal efficiency and availability.

[Means to solve the problem]

Therefore, as a result of various experiments, the present inventor observed the behavior of the fins of each part during bending in a bent core type heat exchanger in which multiple rows of tubes were arranged, and found that the effect of bending was constant. Focusing on the fact that this occurs only within a certain range, we developed a heat exchanger core with low ventilation resistance, and its configuration is as follows.

A flat core is formed by a large number of parallel tubes and a large number of fins interposed between each tube and fixed in contact with the tubes, and a part of the core is curved in the thickness direction. .

Here, the feature of the present invention is that the tube 1
．． 2 are arranged in multiple rows in the thickness direction of the core, and each fin 3 located on one end side of the deformed portion of the core is integrally formed in the thickness direction of the core and extends over each row. Fixed in contact with. At the same time, each fin 4 including the deformed portion and located on the other end side is separated for each row of tubes and fixed in contact only with the tubes of each row.

Therefore, according to the present heat exchanger core, the fins are formed integrally across multiple tubes in the parts other than the deformed part of the bent core, so there is resistance to the flow of the heat exchange medium through the fins. becomes smaller and can promote heat exchange.

In addition, when this heat exchanger core is used for heating as a heat exchanger for an outdoor unit of the cooling/heating heat pump type, the condensate that adheres to the fins can be smoothly removed, and the heat transfer efficiency and operating efficiency can be increased. .

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 is a schematic perspective view of the present heat exchanger core, FIG. 2 is an explanatory view showing the manufacturing process thereof, and FIG. 3 is an enlarged view of the main part of FIG. 2. This heat exchanger core is used as an outdoor unit of a heat pump type air conditioner and heater, and is of a type in which tubes are arranged in two rows in the thickness direction of the core, and the tubes penetrate through a large number of plate fins. That is, the fins 3 made of thin aluminum metal plates or copper metal plates each having a tube insertion hole are arranged in parallel with a slight gap from each other so that the tube insertion holes are aligned.

Two rows of circular tube insertion holes are bored in this fin 3. Next, the rightmost end of the parallel fins 3 has a width half the width of the fin 3, and one row of tube insertion holes are formed in each of the fins 3. Two rows of fins 4 with holes are arranged in parallel in the width direction. Then, the core portion formed by the tube and fins 4 located on the outside is made to protrude longer. In addition, the laminated fins 3
The side member 7 is located at the rightmost end.

Next, tubes 1 and 2, which have been formed in a U-shape in advance, are inserted into each row of the laminated fins from the right end side.

Next, an expansion jig is press-fitted into the left end openings of the tubes 1 and 2 to enlarge the outer diameters of the tubes, and the outer surfaces of the tubes 1 and 2 are crimped into the tube insertion holes of the respective plate fins.

This improves thermal conduction between the fins and the tube. Next, as shown in FIG. 2, the bending guide jig 6 is positioned on the inner surface of the core. Then, the tip of the core is bent by applying an external force as shown by the arrow to form the heat exchanger core shown in FIG. At this time, tube 1 located inside the bent part
Since the bending radii of the tube 2 and the tube 2 located on the outside are different, a difference in circumference occurs. However, since the tube 2 located on the outside is longer in advance and the fins 4 are also provided on the longer part, the ends of both tubes 1.2 are on the same plane after bending. The one end openings of the tubes 1.2 are successively connected to each other by U-bend pipes (not shown) to form a meandering refrigerant flow path inside the core.

A fan 8 is disposed on the inner surface of the core as shown in FIG. 1, and a four-way valve, an expansion valve, and a compressor (not shown) are provided to constitute an outdoor unit. A refrigerant circulation path is then formed between the tube of the core of the indoor unit and the tube of the main core. As this refrigerant, fluorocarbon or the like, which flows in a gas-liquid two-phase state, is used. In addition to driving the fan 8, the heat exchanger core is used as a condenser in the summer via a four-way valve. In winter, the four-way valve is switched and the core is used as an evaporator. In this case, especially in the conventional heat exchanger core, as shown in FIG. 4, the separation line 5 between the two rows of tubes exists at the center in the width direction of the core, and each fin is formed discontinuously in the width direction. Ru.

Therefore, frost tends to form at the joint, resulting in a longer defrosting time and lower heating efficiency. However, in the heat exchanger core of the present invention, as shown in FIG. 1, the separation line 5 is only a part of the core and most of it is formed by the integral fins 3, so there is little frost formation, so the thawing time is It becomes shorter and heating efficiency increases.

At the same time, there are fewer joint lines and less resistance to airflow caused by the fan 8. Therefore, air circulation is promoted and heat exchange is promoted.

〔Effect of the invention〕

The heat exchanger core of the present invention is of a so-called bent core type in which a core is assembled into a flat plate shape and then a part of the core is curved in the thickness direction, and only the fins that are affected by the bending are attached to each tube. Since the fins are separated from each other, bending is facilitated, and abnormal deformation of the fins due to the bending process can be prevented. In addition, since the fins in the portions that do not affect the bending process are integrally formed, the flow resistance of the heat exchange medium passing through the fins in those portions can be reduced and heat exchange can be promoted. That is, in the case of the bent core type shown in FIG. 4, which is separated for each tube row, mismatched portions of the fins occur at the boundaries, resulting in an increase in fluid resistance. However, the heat exchanger core of the present invention can minimize the increase in fluid resistance and facilitate its heat exchange.

[Brief explanation of the drawing]

Fig. 1 is a schematic perspective view of the heat exchanger core of the present invention, Fig. 2 is a plan view explaining the manufacturing process, Fig. 3 is an enlarged view of the main part of the same plan view, and Fig. 4 is a conventional heat exchanger core. Perspective schematic diagram of the core, No. 5
FIG. 6 is a plan view showing the manufacturing process, respectively. 1.2...Tube 3,4...Fin 5...
・Separation line 6...Bending guide jig 7...
・Side member 8... Hwang's agent Patent attorney Kubo 1) Takumi No. 4 Figure 5 Figure 6

Claims (2)

[Claims] (1) A core is constructed in a flat plate shape by a large number of parallel tubes and a large number of fins interposed between each tube (1) and fixed in contact with the tube, and a part of the core is curved in the thickness direction. In the deformed tube, the tube (1
)(2) are arranged in plural rows in the thickness direction of the core, and each fin (
3) are integrally formed in the thickness direction of the core, straddle the respective rows and are fixed in contact with the tubes, and each fin (4) is located on the other end side including the deformed portion; A heat exchanger core characterized in that the tubes in each row are separated and fixed in contact only with the tubes in each row. (2) Each of the fins is of a plate type with tube insertion holes aligned with each other and arranged in parallel, and the tube is passed through the insertion holes of a large number of aligned fins. heat exchanger core.