JP6107686B2 - Fin-tube heat exchanger, method for producing the same, and air conditioner - Google Patents

Description

  The present invention relates to a finned tube heat exchanger, a manufacturing method thereof, and an air conditioner.

  The finned tube heat exchanger has a structure in which a plurality of plate fins that are overlapped with each other at a predetermined distance are in close contact with each other around a plurality of heat transfer tubes through which a heat transfer fluid flows. In order to improve heat exchange efficiency, flat tubes may be used for heat transfer tubes. In order to improve the adhesion between plate fins and flat tubes without deformation of the plate fins, reinforcing structures such as ribs are formed on the plate fin surfaces. (For example, Patent Document 1).

Japanese Utility Model Publication No. 5-90173

  However, in such a fin tube type heat exchanger, it is necessary to form a reinforcing structure such as a rib on the plate fin as described above in order to prevent fin deformation when the flat tube is inserted. This rib hinders ventilation between the plate fins, increasing ventilation resistance and reducing heat exchange efficiency.

  Further, it is important in manufacturing that the distance between the fins (hereinafter referred to as fin pitch) is ensured to be equal to the designed fin pitch. In a heat exchanger using a flat tube, a method is used in which fins are shaped such as protrusions to ensure the fin pitch, but this method impairs ventilation between the fins and reduces the heat exchanger performance. There was a problem. If the product itself does not have protrusions to secure the fin pitch, insert a spacer jig between the huge number of fins and the fins to secure the fin pitch and secure the fin and flat tube in the manufacturing process. After fixing, it is necessary to remove the jig from the spacer jig, which greatly increases the working time. In order to manufacture products with different fin pitches, spacer jigs corresponding to each are required, so the number of spacer jigs increases, the setup time becomes longer, and the manufacturing cost of the jigs increases. There was a problem of becoming.

  The present invention has been made to solve such a problem, and in a finned tube heat exchanger having a heat transfer tube formed of a flat tube, the plate fin interval is uniformly controlled without using a spacer jig. An object of the present invention is to obtain a fin-tube heat exchanger that can prevent deformation of the plate fin accompanying the attachment of the heat transfer tube without forming ribs or the like on the plate fin.

  The finned tube heat exchanger of the present invention includes a plurality of circular tube insertion round holes, a plurality of flat tube insertion U-shaped openings, and adjacent heat dissipation plate fins formed around the circular tube insertion round holes. A laminated plate fin composed of a plurality of heat radiating plate fins obtained by laminating a heat radiating plate fin having a surface facing the surface, and a plurality of flat tubes of the laminated plate fins. A plurality of flat tubes penetrating in the laminating direction with respect to the insertion U-shaped opening; and a plurality of circular tubes penetrating in the laminating direction with respect to the plurality of circular tube insertion round holes of the laminated plate fins. The gap between the heat dissipating plate fins of the laminated fin plate is larger than ½ of the short diameter of the flat tube inserting round hole and smaller than the radius of the circular tube inserting round hole.

  The finned tube heat exchanger of the present invention uses a flat tube and a circular tube as heat transfer tubes and uses them at the same time, thereby improving the heat exchange efficiency by using the flat tube and by using the circular tube. A finned tube heat exchanger with excellent heat exchange efficiency at low cost that can reduce the manufacturing cost by reducing the number of jigs used in production and the working time, and improve the heat exchange efficiency by improving the ventilation resistance. Can be obtained.

It is the schematic of the finned-tube type heat exchanger which concerns on Embodiment 1 of this invention. It is a schematic diagram which shows a part of aluminum plate fin of the heat exchanger which concerns on Embodiment 1 of this invention. It is an expanded sectional schematic diagram of the fin plate which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the structure of the heat exchanger which concerns on Embodiment 1 of this invention. It is a top view which shows the plate fin before the cutting | disconnection in the middle of a shaping | molding sequentially in the progressive press apparatus which concerns on Embodiment 1 of this invention. It is a flowchart which shows the structure of the heat exchanger manufacturing process which concerns on Embodiment 1 of this invention.

  In the description of the embodiments and the respective drawings, the portions denoted by the same reference numerals indicate the same or corresponding portions.

Embodiment 1 FIG.
<Configuration of heat exchanger>
FIG. 1 shows a schematic diagram of a finned tube heat exchanger 100 according to Embodiment 1 of the present invention. In this figure, the structure of the plate fin 1 and the circular tube 3 and the flat tube 2 which are heat-transfer tubes is shown, and other configurations, for example, cut-and-raised slits and tube connections between heat-transfer tubes are omitted.

  In FIG. 1, the number of the plate fins 1 is 11, and the number of the heat transfer tubes including the flat tubes 2 and the circular tubes 3 is nine. However, for the convenience of drawing, it is drawn in such a configuration. The finned tube heat exchanger 100 generally uses more plate fins 1 and heat transfer tubes than those depicted in FIG.

  FIG. 2 is a schematic diagram showing a part of one plate fin 1 of the finned tube heat exchanger 100 according to Embodiment 1 of the present invention shown in FIG. The plate fin 1 is made of aluminum, and a circular hole 5 into which the circular tube 3 is inserted is arranged at a ratio of three locations of the U-shaped opening 4 for inserting the flat tube 2. Yes. That is, the ratio of the round hole 5 into which the circular tube 3 is inserted is 25% with respect to the four heat transfer tubes. A cut-and-raised slit 12 for improving heat exchange efficiency is formed between the round hole 5 into which the flat tube 2 and the circular tube 3 as heat transfer tubes are inserted, and the U-shaped opening 4.

  FIG. 3 is an enlarged schematic cross-sectional view showing a cross-section of the broken line portion indicated by AA in FIG. 2, and a fin collar portion 6 formed around the circular hole 5 for insertion of the circular tube 3 according to the first embodiment. The flange part 7 by the starting process formed in the circumference | surroundings of the U-shaped opening 4 for inserting the flat tube 2 is shown in detail. Further, in order to clarify the arrangement of the adjacent heat dissipating plate fins 1, the adjacent and opposing heat dissipating plate fins 1 are indicated by broken lines.

  FIG. 4 is a schematic diagram showing a partial cross-sectional structure of the finned tube heat exchanger 100 according to Embodiment 1 of the present invention shown in FIG. 1, and the heat dissipation plate shown in FIGS. 2 and 3. A structure in which a plurality of fins 1 are stacked is shown.

  Here, referring mainly to FIG. 3, the radius (a) of the circular tube insertion round hole 5, the short diameter (b) of the flat tube insertion opening 4, and the heat dissipation plate, which are important components of the present invention. The gap (c) between the laminated plate fins on which the fins 1 are laminated will be described.

  The interval (c) between the laminated plate fins is formed by folding the periphery of the circular tube insertion round hole 5 at two places to form a fin collar portion 6 having a spacer function for maintaining the interval (c). Accordingly, the interval (c) between the heat dissipating plate fins 1 needs to be shorter than the radius (a) of the circular tube insertion round hole 5. Further, it is necessary that the distance (c) between the heat dissipating plate fins 1 is larger than ½ of the short diameter (b) of the flat tube insertion opening 4. Therefore, it cannot be said that the flange portion 7 bent around the flat tube insertion opening 4 by one bend is sufficient to maintain the space between the heat dissipating plate fins.

  Since the radius (a) of the circular hole 5 for insertion of the circular tube 3 is larger than half of the short diameter (b) of the U-shaped opening 4, by bending it at two places by burring, It can be set as the structure which has a flat part in which a part of fin collar part 6 opposes the surface of the plate fin 1 which adjoins. Therefore, the height of the fin collar portion 6 is stable, and the interval (c) between the plate fins 1 can be maintained accurately and stably. In this embodiment, two places around the circular tube insertion round hole 5 are bent. However, if the structure has a flat portion facing the surface of the adjacent plate fin 1, it is bent at three or more places. The fin collar portion 6 may be formed.

  On the other hand, since the flange portion 7 formed around the U-shaped opening 4 by the start-up process is formed by one bending, it does not have a surface facing the surface of the adjacent plate fin 1 and is adjacent. It is difficult to stably maintain the distance (c) from the plate fin 1.

  Furthermore, the fin collar portion 6 has a structure facing the surface of the adjacent plate fin 1 and at the same time has a convex shape toward the center of the round hole 5, so that the circular tube 3 is formed in the round hole 5. Since the fin collar portion 6 and the circular tube 3 can be stably brought into contact with each other over a large area when the is inserted, high heat exchange efficiency can be obtained.

<Progressive press process for plate fins>
The manufacturing method using the progressive press process of the plate fin 1 is described using FIG. The plate fin 1 is generally a metal thin plate wound in a hoop shape having a thickness of 0.1 to 0.2 mm, and the round hole 5, the U-shaped opening 4 and the like are sequentially formed using a progressive press device. In the present embodiment, an aluminum thin plate 10 having a thickness of 0.1 mm is used.

  FIG. 5 shows a state in the middle of manufacturing the plate fin 1 using the progressive press performed in the first embodiment of the present invention. The aluminum thin plate 10 in FIG. Sequential movement in the left direction, and drilling and the like are performed gradually from the left to the right.

  The production of the plate fin 1 using the progressive press is performed with the plurality of plate fins 1 being connected to the aluminum thin plate 10, and a round hole for inserting the peripheral pilot hole 11 and the circular pipe 3. 5 is intermittently conveyed. In the case of the present embodiment, the transport pitch 13 using the pilot holes 11 and the round holes 5 is an integral multiple of the arrangement pitch of the round holes 5. While being conveyed, a U-shaped opening 4 for inserting the flat tube 2 and a cut-and-raised slit 12 are formed, and finally cut into individual plate fins 1 along a cutting line 14.

<Manufacturing process of heat exchanger>
FIG. 6 shows a flow of the manufacturing process of the finned tube heat exchanger 100 from the process of manufacturing the plate fin 1 through the progressive press process to the brazing process. The manufacturing method of the finned-tube heat exchanger 100 of this Embodiment is demonstrated using this figure.

  First, the hoop-like aluminum thin plate 10 is processed and cut by a progressive press process to form the plate fins 1. The thickness of the aluminum thin plate 10 was 0.1 mm as described above. Since the transport using the pilot hole 11 and the round hole 5 has already been described, it is omitted here.

  A pilot hole 11, a round hole 5 for inserting the circular tube 3, a U-shaped opening 4 for inserting the flat tube 2, and a cut-and-raised slit 12 for increasing the heat exchange efficiency are formed and cut in the aluminum thin plate 10. Cut off at the position of the line 14 to obtain a molded strip-shaped plate fin 1.

  When storing the plate fins 1 manufactured so far, about several hundred plate fins 1 can be stacked and stored with two or more round holes 5 passing through the stack rods.

  After the storage, when proceeding to the next circular tube insertion step, the circular tube 3 is first inserted into the round hole 5 other than the round hole 5 through the stack rod in a state where the stack rod is passed. Subsequently, the stack rod is extracted, and the circular tube 3 is inserted into the extracted round hole 5.

  Next, the circular tube 3 is expanded while being inserted into the round hole 5. In the pipe expanding process, the outer shape of the circular pipe 3 is expanded and the fin collar portion 6 formed in the peripheral portion of the round hole 5 and the circular pipe 3 are brought into close contact with each other to improve heat exchange efficiency. There are a method of expanding by pressurizing with water pressure, and a method of expanding by inserting a tube expansion rod larger than the inner diameter of the tube into the tube 3. In the present embodiment, tube expansion was performed by a method using the latter tube expansion rod, which has a relatively simple process.

  By expanding the tube, the circular tube 3 and the plate fin 1 are in close contact with each other, so that the transfer and storage can be easily performed in a state where the process is completed. Further, in the process of inserting the flat tube 2 into the U-shaped opening 4, the circular tube 3 and the plate fin 1 are already firmly fixed by expanding the tube, so that unnecessary distortion is applied to the U-shaped opening 4 when the flat tube 3 is inserted. It does not occur and the flat tube 2 can be inserted with high adhesion. Further, in the brazing operation, similarly, since the circular tube 3 and the plate fin 1 are fixed, the brazing step can be performed only by fixing the circular tube 3 with a jig or the like.

  In general, since a plurality of flow paths are formed independently in the flat tube 2, the step of increasing the inner diameter of the flat tube 2 by expanding the tube after being inserted into the U-shaped opening 4 cannot be used. Then, push it into the U-shaped opening 4 and insert it.

  The length of the plate fin 1 varies depending on the performance and ability of an air conditioner using a heat exchanger, etc., but in order for the present invention to be effective, two or more round holes 5 are provided. Preferably, four or more places are appropriate. When plate fins 1 are manufactured and a plurality of plates are fixed together with a stack rod, if there are two round holes 5, one round hole 5 is used for inserting the stack rod, and the remaining one The circular tube 3 can be inserted and fixed through a tube expanding process.

  Further, by using the two round holes 5 for inserting the stack rod, and inserting the circular tube 3 into the remaining round holes 5 and fixing them through the pipe expanding process, the pipe can be expanded more stably. After that, even if the stack rod is removed, since the circular tube 3 and the plate fin 1 are firmly fixed, the subsequent steps can be performed smoothly.

  In the pressing process of the conventional flat tube heat exchanger, the width of the aluminum thin plate 10 is widened to manufacture a large number of plate fins 1 at the same time, thereby improving the production efficiency. In the case of FIG. 3, 12 rows of plate fins are manufactured simultaneously. When a thin plate having such a wide width is used, the pilot hole 11 cannot transmit a sufficient conveying force that can resist frictional resistance or the like to the aluminum thin plate 10 only at both ends of the thin plate. It was necessary to form the pilot hole 11.

  Since the pilot hole 11 is usually formed in a part different from the plate fin 1, the part has to be discarded as a waste material after cutting, and the material yield is reduced. On the contrary, when the pilot hole 11 is provided in the plate fin 1 in consideration of the material yield, a slit cannot be formed in the portion where the pilot hole 11 is formed, and there is a problem that the heat exchange characteristic is deteriorated. .

  However, as shown in the present embodiment, the pilot hole 11 is formed in the plate fin 1 and can be used at the time of conveyance, and can be used as the round hole 5 for inserting the circular tube 3 after cutting. It is possible to obtain a finned tube heat exchanger that is not reduced and has no reduction in heat exchange efficiency.

  By using the plate fin 1 of the present embodiment, burring is performed on the round hole 5 for inserting the circular tube 3, and the fin collar portion 6 bent twice is formed around the round hole 5. Therefore, the fin collar portion 6 has a spacer function, and the plate fin interval c can be maintained uniformly.

  Therefore, it is not necessary to form a protrusion for securing the plate fin interval c as a spacer in another portion of the plate fin 1, and a cut and raised slit can be formed instead. Therefore, heat exchange efficiency is increased. It has the feature of being able to.

  When the flat tube 2 is inserted, the plate fin 1 is already reinforced by the circular tube 3, and it is not necessary to reinforce the plate fin 1 by a rib or the like. Therefore, more cut and raised slits 12 and the like can be formed on the plate fin 1, and the heat exchange efficiency can be increased.

  Since a stack rod can be easily inserted into the circular hole 5 for inserting the circular tube 3 formed in the plate fin 1 for storage, transportation, etc., it is necessary to manufacture a special storage jig or the like. In addition, dedicated equipment can be reduced and capital investment can be suppressed.

  In the present embodiment, one flat tube 2 is used for one circular tube 3 and three flat tubes 2 are used. Therefore, the ratio of the circular tube 3 was 25%. The ratio of the circular tube 3 is preferably 15 to 30%, and good characteristics can be obtained.

  If the ratio of the circular tube 3 is less than 15%, the effect of the circular tube 3 is small, and there may be a problem that the plate fin interval c cannot be stably maintained. On the other hand, when it exceeds 30%, the effect of the flat tube 2 is reduced, and problems such as a decrease in heat exchange efficiency may occur.

  In a heat exchanger, the heat transfer tube used may be bent into a U shape. In such a case, the same kind of heat transfer tubes are continuously attached. That is, in the present embodiment, one circular tube 3 and three flat tubes 2 are alternately arranged. However, even in a structure in which two or more circular tubes 3 are continuously arranged, the flat tubes 3 are flat. If the ratio of the installation of the tube 2 and the circular tube 3 is in the above range, good characteristics can be obtained.

  Moreover, when arrange | positioning the circular tube 3, when the circular tube 3 is arrange | positioned at equal intervals, the structure of the fin tube type heat exchanger 100 is stable and preferable. However, the circular tubes 3 are not only arranged at equal intervals, but also may have excellent heat exchange characteristics in relation to the plate fin interval c because of the unequal intervals. If the ratio of the flat tube 2 can be maintained in the above range, good characteristics can be obtained.

  The application of the finned tube heat exchanger 100 of the present invention is not particularly limited, and can be used as various heat exchangers. In particular, by using it as a heat exchanger for an air conditioner, it is possible to take advantage of the features of the finned tube heat exchanger of the present invention, which are excellent in heat exchange efficiency and low in cost.

1 plate fin, 2 flat tube, 3 circular tube, 4 U-shaped opening, 5 round hole, 6 fin collar part, 7 flange part, 10 aluminum thin plate, 11 pilot hole, 12 cut and raised slit, 13 transport pitch, 14 cutting Wire, 100 fin tube heat exchanger.

Claims (11)

A fin collar portion having a plurality of circular tube insertion round holes and a plurality of flat tube insertion U-shaped openings and a surface formed around the circular tube insertion round hole and facing the adjacent heat radiating plate fin surface A laminated plate fin comprising a plurality of heat radiating plate fins laminated with the heat radiating plate fins via the fin collar portion, and
A plurality of flat tubes respectively penetrating in the laminating direction with respect to the plurality of flat tube insertion U-shaped openings of the laminated plate fins;
A plurality of circular tubes penetrating in the stacking direction with respect to the plurality of circular tube insertion round holes of the laminated plate fin,
The gap between the heat radiating plate fins of the laminated plate fin is larger than ½ of the short diameter of the flat tube insertion U-shaped opening and smaller than the radius of the circular tube insertion round hole. Finned tube heat exchanger. The fin tube type heat exchanger according to claim 1, wherein the fin collar portion has at least two bent portions. The fin tube type heat exchanger according to claim 1 or 2, wherein a shape of the fin collar portion is convex in a central direction of the round hole for inserting the circular tube. The ratio of the said circular tube with respect to the total number of the said circular tube inserted in the said laminated plate fin and the said flat tube is 10% or more and 30% or less, The any one of Claims 1-3 characterized by the above-mentioned. The finned tube heat exchanger described in 1. An air conditioner using the finned tube heat exchanger according to any one of claims 1 to 4. Forming a U-shaped opening for the flat tubes inserted into the thermal plate fin release,
A circular hole for circular tube insertion having a diameter larger than the short diameter of the flat tube insertion U-shaped opening is formed in the heat radiating plate fin by burring, and adjacent to the circular hole for circular tube insertion. Forming a fin collar portion having a surface facing the plate fin surface for use;
A plurality of the heat radiating plate fins are laminated with a gap larger than ½ of the short axis of the flat tube insertion U-shaped opening and smaller than the radius of the circular tube insertion round hole to form a laminated plate fin. Process,
The Bian Tairakan the flat tubes inserted for U-shaped opening, a circular tube to said circular tube insertion round hole, a step of inserting,
A method for manufacturing a finned tube heat exchanger. The method of manufacturing a finned tube heat exchanger according to claim 6, wherein the shape of the fin collar portion is formed by bending at least two places. The method of manufacturing a finned tube heat exchanger according to claim 6 or 7, wherein a shape of the fin collar portion is formed in a convex shape in a central direction of the round hole for inserting the circular tube. The ratio of the circular pipe to the total number of the circular pipe and the flat pipe inserted into the laminated plate fin is 10% or more and 30% or less, any one of claims 6 to 8. The manufacturing method of the finned-tube type heat exchanger as described in 2. Forming a U-shaped opening for the flat tubes inserted into the thermal plate fin release,
A circular hole for circular tube insertion having a diameter larger than the short diameter of the flat tube insertion U-shaped opening is formed in the heat radiating plate fin by burring, and adjacent to the circular hole for circular tube insertion. Forming a fin collar portion having a surface facing the plate fin surface for use;
A plurality of the heat radiating plate fins are laminated with a gap larger than ½ of the short axis of the flat tube insertion U-shaped opening and smaller than the radius of the circular tube insertion round hole to form a laminated plate fin. Process,
The Bian Tairakan the flat tubes inserted for U-shaped opening, a circular tube to said circular tube insertion round hole, and a step of inserting,
A method for manufacturing a fin-tube heat exchanger, wherein the circular hole for inserting a circular tube of the heat radiating plate fin is used as a pilot hole for conveyance in a fin press process. Forming a U-shaped opening for the flat tubes inserted into the thermal plate fin release,
A circular hole for circular tube insertion having a diameter larger than the short diameter of the flat tube insertion U-shaped opening is formed in the heat radiating plate fin by burring, and adjacent to the circular hole for circular tube insertion. Forming a fin collar portion having a surface facing the plate fin surface for use;
A plurality of the heat radiating plate fins are laminated with a gap larger than ½ of the short axis of the flat tube insertion U-shaped opening and smaller than the radius of the circular tube insertion round hole to form a laminated plate fin. Process,
The Bian Tairakan the flat tubes inserted for U-shaped opening, a circular tube to said circular tube insertion round hole, and a step of inserting,
A finned tube heat exchanger, wherein the flat tube is inserted and brazed while supporting the circular tube after the circular tube is inserted into the circular hole for inserting the circular tube into the heat dissipating plate fin. Manufacturing method.

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