JP3485699B2 - 1 can 2 water heat exchanger - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tube plate at both ends, a number of fins arranged in parallel between the two tube plates, and a figure eight formed on each fin. The first and second heat transfer tubes, which are inserted so as to be in contact with each other in the shape of a hole, have a fin insertion portion related to a one-can-two water heat exchanger connected by brazing. 2. Description of the Related Art In a typical fin-and-tube heat exchanger, one heat transfer tube is inserted through a circular insertion hole formed in each fin. In the heat exchanger for hot water supply equipment for burning hot water and reheating the bath by burning the water, an 8-shaped insertion hole is formed in each fin, and the 8-shaped insertion hole is used for hot water supply and reheating. In some cases, the heat transfer tubes are inserted through a pipe in contact with each other. This type is called a one-can two-water heat exchanger. [0003] The fin spacing is regulated by forming a burring portion around the circular insertion hole through which the one heat transfer tube is inserted, and a rod-shaped brazing material is inserted above each insertion hole. By drilling a small hole and melting the rod-shaped brazing material in the heating furnace to flow down the left and right outer peripheral surfaces of the heat transfer tube, the gap between the burring portion and the heat transfer tube penetrating through the burring portion is joined. This is described in Japanese Utility Model Laid-Open No. 1-136282 and Japanese Patent Laid-Open No. 4-493.
No. 4 discloses this. [0004] Compared with the case of a circular insertion hole, when the shape of the insertion hole is a figure of eight, the length of the portion to be joined by the brazing material is much longer. I see
It is difficult to turn the melted brazing material in the middle part where the figure eight line intersects well and to braze the part sufficiently. For this reason, a gap may be formed due to poor brazing. Since such a gap is a heat insulating layer of air, it deteriorates the efficiency of the heat exchanger. Therefore, a problem to be solved by the present invention is to make the heat transfer tube of the one-can-two water heat exchanger and the fin adhere closely without any gap. SUMMARY OF THE INVENTION The present invention provides a tube plate at both ends, a number of fins juxtaposed between the tube plates, and a figure-eight insertion hole formed in each fin. The first and second heat transfer tubes are inserted so as to be in contact with each other, and the fin insertion portions of the heat transfer tubes are connected to each other by brazing in a one-can two-water heat exchanger. The figure of figure 8 is formed by the vertical line portions connecting the terminals of the arc portions, and a burring portion is formed around the hole corresponding to the upper arc portion and the lower arc portion, and a symmetrical position in contact with the upper burring portion. The three surfaces of the triangular space formed on both sides of the contact points of the two heat transfer tubes provided in the figure-shaped insertion hole are formed by drilling small holes for inserting a rod-shaped brazing material into the holes.
The rod-shaped brazing material inserted into the space comes into contact with the outer surface. In FIG. 1, reference numeral 1 denotes a tube plate on both sides, 2 denotes a plurality of fins arranged between the tube plates 1 and 1 on both sides, and 3 denotes a figure-eight insertion hole. In the illustrated example, nine insertion holes 3 are formed in one fin 2. The figure-eight shape is formed by an upper arc portion, a lower arc portion, and a vertical line portion connecting terminals of both arc portions. As clarified in FIG. 2, burring portions 4 and 5 are formed on the periphery of the hole corresponding to the upper and lower arc portions, and the upper burring portion 4 contacts the upper burring portion 4 at symmetrical positions. Small holes 6, 6 are drilled. As shown in FIG. 3, the bar-shaped brazing members 7, 7 are inserted into the small holes 6, 6, respectively. In FIG. 3, the additional heat pipe 8 as the first heat transfer pipe and the hot water supply pipe 9 as the second heat transfer pipe are inserted into the insertion hole 3 in a state where they are in contact with each other. Triangular spaces 10, 10 are formed on both sides of the contact of the two heat transfer tubes. The triangular space 10 is configured to be surrounded by the outer surface of the first heat transfer tube 8, the outer surface of the second heat transfer tube 9, and the end face on the middle portion side of the insertion hole 3 corresponding to the above-described vertical line. When the bar-shaped brazing members 11, 11 are inserted into the triangular spaces 10, 10, the outer surfaces of the bar-shaped brazing members 11, 11 come into contact with the three surfaces forming the triangular space 10. Accordingly, a heating furnace (not shown) in the state of FIG.
When the bar-shaped brazing materials 7 and 11 are melted by heating, the bar-shaped brazing material 7 melted on the outer surface side of the upper burring portion 4 is also heated.
Through the small hole 6 drilled in contact with the upper burring portion 4, it is guided to the inner surface side of the upper burring portion 4, and is formed by the outer surface of the first heat transfer tube 8 and the inner surface of the upper burring portion 4. The gap is suddenly drawn and filled, and the surplus flows into the triangular space 10 to be filled. On the other hand, the melted rod material 11 fills the triangular space 10 and, at the same time, is drawn into the gap formed between the outer surface of the second heat transfer tube 9 and the inner surface of the lower burring portion 9 to fill the gap. . As described above, according to the present invention, the figure-eight shape of the insertion hole is formed by the upper arc portion, the lower arc portion, and the vertical line portion connecting the ends of both arc portions. Therefore, when the first and second heat transfer tubes are inserted into the insertion holes, a triangular space is automatically formed, and the insertion holes for the bar-shaped brazing material are inserted. It is not necessary to pierce, and processing can be facilitated. In addition, since the rod-shaped brazing material comes into contact with the three surfaces forming the triangular space, heat can be sufficiently transmitted to the bar-shaped brazing material to shorten the melting time. Also, the four bar-shaped brazing materials share the upper right part, upper left part, lower right part, and lower left part of the figure-eight joint part to be brazed, respectively, and perform the joining, thereby securely filling the triangular space. Thus, a space between the heat transfer tubes and the fins can be obtained without forming any gaps in the space, so that a one-can-two water heat exchanger that is sufficiently closely adhered can be obtained. [0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a fin plan shape in an embodiment of a one-can two-water heat exchanger according to the present invention. FIG. 2 is a perspective view of the fin of FIG. 1; FIG. 3 is a cross-sectional view of a part of the fin of FIG. 1 when a heat transfer tube and a bar-shaped brazing material are mounted. [Description of Signs] 1... Tube sheet 2... Fin 3... 8-shaped insertion hole 4... Burring part 5... Burring part 6. Heat tube 9 Second heat transfer tube 10 Triangular space 11 Rod material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F24H 1/00 303 F24H 9/00 F28F 1/32

Claims (1)

(57) Claims 1. Tube plates at both ends, a large number of fins juxtaposed between the two tube plates, and a figure-eight insertion hole formed in each fin so as to be in contact with each other. The first and second heat transfer tubes are inserted into the heat transfer tubes, and the fin insertion portions of the heat transfer tubes are connected by brazing in a one-can two-water heat exchanger. The figure 8 is formed by the vertical line connecting the terminals of
A burring portion is formed on the periphery of the hole corresponding to the upper arc portion and the lower arc portion, and a small hole for inserting a bar-shaped brazing material is formed at a symmetrical position in contact with the upper burring portion.
The three surfaces of the triangular space formed on both sides of the contact point of the two heat transfer tubes provided in the V-shaped insertion hole are brought into contact with the outer surface of the rod-shaped brazing material inserted into the space. 1-can 2 water heat exchanger.