Fin structure of coil

Abstract

To provide a heat exchanger capable of improving heat exchange efficiency of a slit fin of a coil and preventing a free end from occurring at the slit fin.SOLUTION: In a slit fin structure, slit fins provided on a coil of a heat exchanger are made larger than a distance between adjacent main pipes in a direction of the number of stages of the main pipes of the coil, and a length of the slit fins at an end part in the direction of the number of stages is made shorter than the distance between adjacent main pipes by performing end processing so as to prevent many free ends from being present causing by cutting slits at the end part in the direction of the number of stages in the middle.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a fin structure for a coil of a heat exchanger, and more particularly to a fin structure for a heat exchanger which provides good heat exchange and facilitates handling during manufacture of the heat exchanger. [Background technology]

[0002] A so-called coil of a conventional heat exchanger has fins attached to the main tube of the coil, and is provided with slit fins with cuts and raised portions on the fin surface to enhance heat exchange performance, as shown in Fig. 1. This slit fin has gaps on the fin surface through which air passes, as shown in Patent Document 1, for example, and the slits in Patent Document 1 are usually formed continuously in the row direction (up and down) and row direction (left and right). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Design Registration No. 1137226 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional slit fins improve the heat transfer coefficient by updating the thermal boundary layer at the front edges of the cut-and-raised slits on the fin surface and suppressing the development of the thermal boundary layer, so the longer the vertical length of the slits in the slit fin, the higher the heat transfer coefficient. When arranging a slit between the main pipes of the coil, increasing the slit length brings the front edge of the slit, which has a high heat transfer coefficient, closer to the main pipe, which further improves the heat transfer coefficient. However, if the length of the slit between the main tubes of the coil becomes long, when creating a coil (heat exchanger) with a specified number of stages (specified height), as shown in Figure 3, the formed slit will be cut halfway at the end in the stage direction. The slits cut off during the process can cause the ends to come apart during the various steps of coil (heat exchanger) manufacturing, leading to problems such as fin irregularities and bending due to snagging, making handling difficult during coil manufacturing. In addition, there are problems such as increased pressure loss due to fin irregularities and bending that can lead to noise pollution.

[0005] This invention seeks to solve the inconveniences associated with increasing the heat exchange rate of the conventional slit fins, and aims to provide a slit fin for a heat exchanger which is provided on a coil of a heat exchanger and which is made larger (Figure 5: X3) than the distance between adjacent main pipes in the row direction (Figure 5: X2) in order to improve heat exchange efficiency, thereby preventing the slit fins at the ends in the row direction from being cut off midway to leave many free ends, and preventing the slit fins from becoming distorted or curved during the manufacture of the coil. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a slit fin structure in which slit fins are provided on a heat exchanger coil and are made larger than the distance between adjacent main pipes in the row direction of the coil's main pipes, and the length of the slit fins at the ends in the row direction is made shorter than the distance between adjacent main pipes so that the slits at the ends in the row direction are not cut midway and there are not many free ends. Effect of the Invention

[0007] The slit fins provided on the coil which is the heat exchanger of the present invention can increase the thermal conductivity as the vertical length of the slits is longer, and the distance between the main pipes in FIG. 5 is set to X3. Furthermore, if the length of the slits in the fins of the main tube of the coil becomes long, as shown in Figure 3, when creating a coil (heat exchanger) with a specified number of stages (specified height), the formed slits will be cut halfway at the end in the stage direction. The slits that are cut off during this process tend to become disjointed as they pass through each step of the coil (heat exchanger) manufacturing process, causing problems such as bending of the fins and making them difficult to handle during manufacturing. In addition, any irregularities in the bending of the slit fins can cause turbulence in the air flow, resulting in high pressure loss, or can lead to abnormal noise due to fin vibration. This invention is a slit fin in which the distance between the slit fins is greater (Figure 5: X3) than the distance between the main pipes (Figure 5: X1) in order to increase the heat exchange rate, and the length of the slit fins at the ends of the upper and lower main pipes in the row direction is made shorter than the distance between adjacent main pipes (Figure 5: X2) so that the slit fins at the ends in the row direction of the upper and lower main pipes are cut off halfway so that there are not many free ends.As a result, the heat exchange efficiency is improved overall by lengthening the slit length of the many slit fins between the main pipes (Figure 5: X3).In order to make only the slit fins at the ends in the row direction short (Figure 5: X2), the slit fins are simply cut immediately after the main pipe at the end, so this is a coil fin structure in which the reduction in thermal conductivity is negligible, and the heat exchange efficiency is improved overall.

[0008] In this way, when making a coil (heat exchanger) with a predetermined number of stages (predetermined height), the slits formed at the ends in the direction of the number of stages to be cut are not cut off halfway, and the slits cut off halfway do not come apart (free ends) at the ends in each process of manufacturing the coil (heat exchanger), and there is no bending of the fins or fin disorder due to being caught, making it easy to handle during coil manufacturing. Also, since there is no disorder of the slit fins, there is less possibility of an increase in pressure loss or noise generation. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of the overall appearance of a heat exchanger according to a first embodiment; [Diagram 2] FIG. 2 is a perspective view of an enlarged portion of the slit fin of FIG. [Diagram 3]FIG. 3(a) is an enlarged partial side view of the side surface of the slit fin, and FIG. 3(b) is an enlarged partial plan view of the end of the slit fin. [Figure 4] A photograph of an enlarged side view of the untreated end of Figure 3. [Diagram 5] FIG. 5(a) is an enlarged partial side view of the side surface of the slit fin according to the first embodiment of the present invention; FIG. 5(b) is an enlarged partial plan view of the end of the slit fin; [Figure 6] A photograph of an enlarged side view of the coil end fins in Example 1 of the present invention, where the disorder of the fins has been eliminated [Figure 7] A process diagram of the slit fin processing process (two-stage feed) of Example 1; [Figure 8] In this explanatory diagram, which explains the process of pressing using a two-stage die in Example 1, dies A and B are prepared as a pair, and when pressing areas other than the ends, only die A is used for pressing, and die B is not used. Near the ends, die A is not used for pressing, and only die B is used for pressing. [Figure 9] FIG. 9(a) is an overall plan view of the first embodiment in which the number of slit fin coil stages is 20, and FIG. 9(b) is an overall plan view of the first embodiment in which the number of slit fin coil stages is 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present invention relates to a slit fin structure in which the slit fin is provided on a heat exchanger coil and is made larger than the distance between adjacent main pipes in the row direction, and the length of the slit fin at the end of the row direction is made shorter than the distance between adjacent main pipes (X1 in Figure 5) so that the slits at the end of the fin in the row direction are not cut midway and there are not many free ends. Preferred embodiments of the present invention will be described with reference to the drawings.

[0011] Figure 1 shows a heat exchanger 1 using fins 3 of the present invention, and Figure 2 is a partially enlarged view of the fin 3. Figures 3 and 4 show slit fins 32 in which the length of the slit fins 32 at the ends in the row direction is longer than the distance between adjacent main tubes, and Figures 5 to 9 show embodiments in which the length of the slit fins 32 at the ends in the row direction is shorter than the distance between adjacent main tubes. 1 and 2 showing the basic configuration, in Fig. 1, in a heat exchanger 1, a coil 2 is provided in a frame 21, a header 22 is provided on one side of the coil 2, a main pipe 25 of the coil is connected to this header 22, and the main pipe 25 is folded back to the header 22 at the other side with a U-bend 26. The header 22 has header portions on the chilled / hot water inlet 221 side and the chilled / hot water outlet 222 side, and a chilled / hot water inlet portion 23 and a chilled / hot water outlet portion 24 are provided on the chilled / hot water inlet 221 side and the chilled / hot water outlet 222 side of this header portion, and are connected to the coil 2.

[0012] As shown in Fig. 2, the main pipe 25 is inserted into the main pipe through hole 31 so as to contact and penetrate the fin 3. The fin 3 is composed of a long side slit fin 321 arranged as long as possible longer than the distance between adjacent main pipes 25, and a short side slit fin 322 arranged shorter than the distance between adjacent main pipes. In this embodiment, if the long side slit fin 321 is too long, it will bend or warp. Therefore, as shown in Figs. 2, 3, and 5, it is originally longer (Fig. 5: X3) than the distance between adjacent main pipes 25 (Fig. 5: X2). However, if there is no support or rib in the middle, warping will occur. Therefore, in this embodiment, it is divided into two sides, upper and lower, to reduce the occurrence of warping. In this way, the heat exchange efficiency is improved by the amount that the area where the air flow hits the slit is expanded. However, if the slit portion of the long-side slit fin 321 overlaps with the cut surface 33 of the fin 3, it will be cut off at the cut surface 33 midway through the slit fin 32 of the fin 3, as shown in the ellipse A part of Figure 3, and will become like an octopus tenon. As a result, it will become curved as shown in part C of the photograph in Figure 4, the function of the fin will be hindered, pressure loss will increase, or noise will be generated.

[0013] In order to eliminate the above-mentioned inconveniences, as shown in Figure 5, the ends of the long side slit fins 321 at the ends are arranged so that the length of the slit fins 32 at the ends in the row direction is shorter than the distance between adjacent coil main pipe through holes 31 (Figure 5: X1) so that the ends do not overlap the cut surface 33, and the ends are treated to be short side slit fins 322 (Figure 5: X2).Therefore, even if the fin 3 is cut at the cut surface 33 at the end, no free ends are created as shown in the elliptical part B in Figure 5, and the slit fins 32 are not cut in the middle as shown in the photograph in Figure 6, and the ends of the slit fins 32 do not become free ends. This state is shown in the photograph of FIG. 6, which is completely different from the untreated state at the end of the slit 32 in FIG. 4, and is easier to handle.

[0014] [Manufacturing process] Next, an example of the processing steps for the slit fin 32 of Example 1 will be described. The slit fin 32 of Example 1 will be described using a two-stage processing step, as shown in FIG. 7, instead of a one-stage processing step, in order to increase the processing speed. In FIG. 7, plate-shaped fin material 5 for unprocessed slit fins is sent from a supply device 51. First, the main pipe through hole 31 is processed in the main pipe through hole processing (pierce burring / reflare processing) 52 process. Next, every time the fin material 5 moves two stages, in the slit processing 53 (press machine) process, when the fin material 5 is pressed, a die A (531) for pressing the normal long side slits 321 and a die B for pressing the short side slits 322 for end processing are selected and pressed to perform the slit processing 53. 8, in this die selection slitting process 53, a pair of slitting dies A and B are prepared, and usually only the long side slitting die A531 is selected to press the fin material 5. Then, when the slit fin 32 approaches the end, the die B532 for short side slits on the end surface is selected in the slitting process 53, the fin material 5 is pressed with the die B532 for short side slits on the end surface, and the slit fin 32 is cut at a predetermined position in the longitudinal direction by the slit fin cutting process 54 at the cut surface 33 in the central part of the slit fin 32 pressed with the die B532 for short side slits on the end surface, and the product slit fin 32 is discharged from the feed mechanism 55. That is, die A: 531 is a die that forms long side slits 321, and die B: 532 is a die that forms short side slits 322, but in the slit processing 53 (press machine) process, die B: 532 is selected for the ends, and die A is selected for all others. Of course, in Example 1, a two-stage processing process is performed, but a one-stage press process may also be used. The overall plan views of the slit fins 32 thus processed are shown, with FIG. 9(a) being an overall plan view of Example 1 having 20 slit fin coil stages, and FIG. 9(b) being an overall plan view of Example 1 having 10 slit fin coil stages. Each has had its ends processed, and there are no free ends at the ends of the slit fins 32.

[0015] As described above, according to the embodiment of the present invention, the slit fins provided on the coil, which is the heat exchanger of the present invention, can increase the heat transfer coefficient as the vertical length of the slits is longer. Furthermore, when the length of the slits between the main pipes (tubes) of the coil is increased, as shown in FIG. 2, when a coil (heat exchanger) with a predetermined number of stages (predetermined height) is produced, the formed slits are cut halfway at the ends in the stage direction. However, as the manufacturing process goes through each of the manufacturing steps, the ends of the slits that are cut halfway become disjointed, which is inconvenient as it causes handling difficulties in manufacturing, such as bending of the fins. Furthermore, the existence of free ends of the slit fins can cause abnormal noise due to vibration of the fins. However, as the distance between the main pipes increases, The distance between the slit fins is greater (Fig. 5: X3) than (Fig. 5: X1), and the slit fins at the ends of the upper and lower main pipes in the row direction are cut off halfway so that there are not many free ends.Only the length of the slit fins at the ends in the row direction is shorter than the distance between adjacent main pipes (Fig. 5: X2).As a result, the slit length of the many slit fins between the main pipes can be made longer overall (Fig. 5: X3), improving the heat transfer coefficient.Only the slit fins at the ends in the row direction are short (Fig. 5: X2) and the slit fins are simply cut immediately after the main pipes at the ends, so the heat exchange efficiency is improved compared to conventional slit fins, and the coil fin structure results in a negligible decrease in heat transfer coefficient due to end processing. In this way, when making a coil (heat exchanger) with a specified number of stages (specified height), the formed slits are not cut off at the ends of the slit fins in the stage direction, and the parts of the slits that are cut off do not come apart (free ends) at the ends in each process of manufacturing the coil (heat exchanger), there is no bending of the fins due to getting caught, and the fins are not disturbed, and handling during coil manufacturing is the same as with conventional methods, making it easy to handle. Also, because there are no free ends of the slit fins, there is no possibility of increased pressure loss or noise generation. [Explanation of symbols]

[0016] 1...heat exchanger, 2... Coil, 21... Coil frame, 22 Header, 221 Cold / hot water inlet header, 222 Cold / hot water outlet header, 23... Cold / hot water inlet, 24... Cold / hot water outlet 25··Main pipe, 26··U-bend, 3 fin, 31 through hole for coil main pipe, 32 slit fin, 321...Long side slit (fin), 322...Short side slit (fin), 33...Cutting surface 5. Fin material, 52 ·· Through hole processing for main pipe, 53 ·· Slit processing (selective die press processing), 531: Mold A (long side slit), 532: Mold B (short side slit), 54...Slit fin cutting process, 55...Feed mechanism (slit fin)

Claims

[Claim 1] A fin structure of a coil, characterized in that the slit fins provided on the coil of a heat exchanger are made larger than the distance between adjacent main tubes in the row direction of the coil, and the length of the slit fins at the ends in the row direction is made shorter than the distance between adjacent main tubes so that the slits at the ends in the row direction are not cut midway and there are not many free ends.

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