JPH0743089A - Heat exchanger - Google Patents

Abstract

PURPOSE:To prevent the deterioration of heat exchanging efficiency of a heat exchanger by preventing the leakage of exhaust gas through a gap between a tube plate and a heat transfer tube. CONSTITUTION:In a multitude of funs 3 except fins at both ends, heat transfer tubes 4 are penetrated through heat transfer tube penetrating holes 5 and fin collars 6 while the heat transfer tubes 4 are welded by welding members 10 penetrated through the notches 7 at the rims of the fins. In the fins 2 at both ends, only cylindrical fin collars 8 are provided at the rims of the penetrating holes for the heat transfer tubes to prevent the outflow of the welding members 10 to the side of a tube plate 1. Further, a projected piece 11, bent so as to have the shape of a chevron in the section thereof, is provided at the lower end of the fins 2 of both ends across the whole width of the fins to contact them elastically with the inner surface of the tube plate 1 and blockade a gap between the fin 2 and the inner surface of the tube plate 1 by the projected piece 11 whereby the inflow of exhaust gas can be prevented.

Description

Detailed Description of the Invention

[0001]

This invention relates to heat exchangers. Specifically, it relates to a heat exchanger used for a gas combustion appliance such as a water heater.

[0002]

2. Description of the Related Art FIG. 6 shows a partially broken sectional view of a conventional heat exchanger C (Japanese Utility Model Publication No. 62-22784). In this heat exchanger C, a large number of fins 52 and 53 are arranged substantially in parallel between a pair of opposed tube plates 51, and the fins 53 other than the fins 52 at both ends facing the tube plate 51 are provided. The fin collar 55 for preventing wax sagging is projected from the edge of the heat transfer tube insertion hole 54, and the cutout portion 56 communicating with the heat transfer tube insertion hole 54 is provided at the upper edge of the heat transfer tube insertion hole 54 and the fin collar 55. However, the fins 52 at both ends are provided with a fin collar 57 that is closed in a tubular shape without providing a cutout portion.

In assembling the heat exchanger C,
The heat transfer tubes 58 are inserted into the heat transfer tube insertion holes 54 of the fins 52 and 53, and the rod-shaped welding members 59 are inserted into the cutouts 56 of the fins 53 other than the both ends. There is.

As described above, the notches are not provided in the fins 52 at both ends so that the welding member 59 is not inserted. The welding member 59 flows to the tube sheet 51 so that the tube sheet 51 and the heat transfer tube 58 are separated from each other. When welded, the welded portion between the tube sheet 51 and the heat transfer tube 58 may be hardened due to repeated heating and cooling by the burner, and cracks may occur.
This is to prevent the welding member 59 from flowing out to the tube sheet 51 side by not providing the notch in 2 and prevent the tube sheet 51 and the heat transfer tube 58 from being welded. Further, since the tube plate 51 and the heat transfer tube 58 are not welded, a sealant is applied in order to block the gap between the heat transfer tube insertion hole 60 of the tube plate 51 and the heat transfer tube 58 to prevent exhaust leakage.

[0005]

However, there is a gap of about 3 to 5 mm between the fins at both ends and the tube sheet.
The pressure of the exhaust gas passing through this gap was the same as the pressure in the combustion space. For this reason, if the sealant between the tube sheet and the heat transfer tube is improperly applied or if the sealant deteriorates over time, the hot exhaust gas that has flowed into the gap between the fins on both ends and the tube sheet will not flow. There is a drawback that the heat exchange efficiency is reduced due to leakage from the gap between the heat transfer tube insertion hole of the plate and the heat transfer tube.

The present invention has been made in view of the drawbacks of the above-mentioned conventional examples, and an object thereof is to prevent exhaust leakage from the gap between the tube sheet and the heat transfer tube and to prevent heat from the heat exchanger. The purpose is to prevent a decrease in exchange efficiency.

[0007]

In the heat exchanger of the present invention, a large number of fins are arranged between a pair of tube plates, and the heat transfer tubes are inserted into the heat transfer tube insertion holes provided in the tube plates and the fins. In the exchanger, a projection piece is provided over substantially the entire width of the fin below the heat transfer tube insertion holes of the fins at both ends adjacent to the tube sheet, and the projection piece is brought into contact with the inner surface of the tube sheet. I am trying.

[0008]

According to the present invention, the fins at both ends are provided with the projecting pieces, and the projecting pieces are brought into contact with the inner surface of the tube sheet below the heat transfer tube. The gap can be closed, and exhaust gas can be prevented from flowing into the gap from below.

Therefore, it is possible to prevent the exhaust gas flowing into the gap between the fins at both ends and the tube sheet from leaking to the outside through the heat transfer tube insertion hole of the tube sheet. In particular, even if there is a poor seal between the tube plate and the heat transfer tube, it is possible to prevent exhaust gas from leaking through the gap between the tube plate and the heat transfer tube.

[0010]

1 is a partially exploded perspective view showing a heat exchanger A according to an embodiment of the present invention. In this heat exchanger A, a large number of fins 2 and 3 are arranged in parallel between a pair of tube sheets 1. Many fins 3 other than the fins 2 at both ends
2, has a fin collar 6 at the edge of a heat transfer tube insertion hole 5 through which a heat transfer tube 4 for passing cold water is inserted, and the heat transfer tube insertion hole for inserting a rod-shaped welding member 10 therein. A cutout portion 7 is provided which is continuous with the hole 5 and the fin collar 6. FIG. 3 shows a part of the fins 2 at both ends, and only a cylindrical fin collar 8 is provided at the edge of the heat transfer tube insertion hole 5 through which the heat transfer tube 4 is inserted, and a notch portion for inserting the welding member 10. Rather, the lower end portion is provided with a projecting piece 11 bent in a dogleg shape across the entire width. These fins 2 and 3 have a flange portion 12 in the direction opposite to the protruding direction of each fin collar 6 and 8. These fins 2, 3
Have the same plate thickness, and the pair of tube plates 1 have fins 2,
The heat transfer tube insertion holes 5 of the fins 2 and 3 and the heat transfer tube insertion holes 9 formed in the tube sheet 1 are formed to be slightly thicker than the outer diameter of the heat transfer tube 4. There is. Further, the tube plate 1 and the fins 2 and 3 are arranged between the pair of side plates 13, and the exhaust gas is exhausted from the lower side to the upper side while trapping the exhaust gas in the rectangular tubular exterior portion configured by the tube plate 1 and the side plate 13. It is designed to pass through.

Next, a method of assembling the heat exchanger A according to the present invention will be described with reference to FIG. A tube plate 1, a fin 2 having no cutout portion, and a fin 3 having a large number of cutout portions 7 are set in this order using a jig or the like, and then a heat transfer tube 4 is provided.
The straight pipe portion 4a of 4 is inserted into the heat transfer pipe insertion holes 9 and 5.
Next, the welding member 10 is inserted into the cutout portion 7 of the fin 3. After that, the straight tube portion 4 of the heat transfer tube 4 is inserted into the heat transfer tube insertion hole 9 of the remaining fins 2 and the remaining tube sheet 1 having no notch.
The fin 2 and the tube sheet 1 are set by inserting a.
At this time, the welding member 10 has a length to be accommodated between the fins 2 at both ends. Also, the protrusions 11 of the fins 2 at both ends
Is directed toward the tube sheet 1 side, and the projection 11 makes elastic contact with the inner surface of the tube sheet 1. Next, the bent tube portion 4b of the heat transfer tube 4 is connected to the straight tube portion 4a, and the flange portion 14 of the tube sheet 1 is temporarily fixed to the side plate 13 by welding or the like, and then welded in the furnace in the high temperature furnace. As a result, as shown in FIG. 4, the molten welding member 1
0 fills the inner surfaces of the heat transfer tube 4 and the fin collar 6 and the inner peripheral portion of the notch 7, and the heat transfer tube 4 is fixed to the fins 2 and 3 via the welding member 10. Reference numeral 15 is a burner, which is adapted to heat the cold water in the heat transfer tube 4 by this combustion hot air.

Since this heat exchanger A has the above-mentioned structure and is composed of the fins 2 having no notches at both ends, the molten welding member 10 is prevented from flowing out to the tube sheet 1 side. This can prevent the heat transfer tube 4 and the tube sheet 1 from being welded. Therefore, the repeated heating and cooling of the burner 15 prevents the welded portion between the tube sheet 1 and the heat transfer tube 4 from hardening and cracking. Moreover, even though the tube sheet 1 and the heat transfer tube 4 are not welded, the projecting pieces 11 provided at the lower end portions of the fins 2 at both ends are brought into contact with the inner surface of the tube sheet 1 to connect the fins 2 at both ends to the tube. Since the gap between the plate 1 and the plate 1 is closed below, the high temperature exhaust gas from the burner causes the fins 2 and the tube plate 1 to move.
It is possible to prevent it from flowing into the gap between the tube sheet 1 and the heat transfer tube 4, and as a result, it is possible to prevent exhaust gas leakage from the gap between the tube sheet 1 and the heat transfer tube 4. A sealant may be applied between the heat transfer tube insertion hole 9 of the tube sheet 1 and the heat transfer tube 4.

FIG. 5 is a partially cutaway sectional view showing a heat exchanger B according to another embodiment of the present invention. In this, the lower ends of the fins 2 at both ends are bent over the entire width toward the tube sheet 1 side, and the tips are brought into contact with the tube sheet 1.

The projection may have any cross-sectional shape as long as it can prevent the exhaust gas from flowing between the fins and the tube sheet, and is not limited to the one shown in the above embodiment. . Further, in the above-mentioned embodiment, the fin collars of the fins at both ends are projected to the same side as the projecting piece, that is, the tube sheet side. However, this fin collar interferes with the contact of the projecting piece with the inner surface of the tube sheet. If there is a risk of this, it may be projected to the side opposite to the projecting piece.

[0015]

According to the present invention, since the gap between the fins at both ends and the tube sheet can be closed by the protrusions provided at the fins at both ends, it is possible to prevent exhaust gas from flowing into the gap from below. It is possible to prevent the exhaust gas that has flowed into the gap between the fins at both ends and the tube sheet from leaking to the outside through the heat transfer tube insertion holes of the tube sheet. In particular, even if there is a poor seal between the tube plate and the heat transfer tube, it is possible to prevent exhaust gas from leaking through the gap between the tube plate and the heat transfer tube.

Moreover, the exhaust leakage can be prevented only by performing a simple process (for example, bending process) on the fins at both ends, the exhaust leakage can be effectively prevented at a low cost, and the heat exchange efficiency of the heat exchanger can be improved. Can be improved.

[Brief description of drawings]

FIG. 1 is a partially exploded perspective view showing a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a partially cutaway perspective view showing a fin collar and a notch portion, a heat transfer tube, and a welding member provided in the same fin.

FIG. 3 is a partially cutaway perspective view showing fins at both ends.

FIG. 4 is a partially broken sectional view showing the heat exchanger of the above.

FIG. 5 is a partially cutaway sectional view showing a heat exchanger according to another embodiment of the present invention.

FIG. 6 is a partially broken sectional view showing a heat exchanger according to a conventional example.

[Explanation of symbols]

 1 Tube Plate 2 Fins 3 Fins 4 Heat Transfer Tube 5 Heat Transfer Tube Insertion Hole 11 Projecting Piece

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Ikeda 32 Akashi-cho, Chuo-ku, Hyogo Prefecture Noritsu Co., Ltd. (72) Inventor Satoshi Kazumaki 32 Akashi-cho, Chuo-ku Kobe, Hyogo Prefecture Noritsu (72) Inventor Hidekazu Fukui 32 No. Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Prefecture Stock company Noritsu (72) Inventor Atsuhiro Morishita 32 Akashi-cho, Chuo-ku, Kobe City Hyogo (72) Inventor Yutaka Kawaguchi 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Within Noritsu Co., Ltd. (72) Eiji Kamiyoshi 32, Akashi-cho, Chuo-ku, Kobe-shi, Hyogo Within Noritsu, Inc.

Claims (1)

[Claims] 1. A heat exchanger in which a large number of fins are arranged between a pair of tube plates, and the heat transfer tubes are inserted through heat transfer tube insertion holes provided in the tube plates and fins. A heat exchanger characterized in that a projecting piece is provided below the heat transfer tube insertion hole of the fin over substantially the entire width of the fin, and the projecting piece is brought into contact with the inner surface of the tube sheet.