JP2935074B2 - Heat exchanger for heating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger used for, for example, a water heater.

[0002] In this specification, the term "aluminum" shall include aluminum alloys in addition to pure aluminum.

[0003]

2. Description of the Related Art Conventionally, as this type of heat exchanger for heating,
Inside the upper part of the combustion cylinder, a heat exchange part comprising a parallel plate fin and a strong heating water pipe penetrating the plate fin is provided, and a heat source such as a burner is arranged inside the lower part of the combustion cylinder. It is already known that the preheating water pipe connected to the strong heating water pipe is wound around and joined to the outer peripheral surface of the outer wall of the combustion drum.

[0004]

However, in the conventional heat exchanger, the combustion cylinder, the fins, and the water pipe are all made of copper or a copper alloy, which increases the weight of the heat exchanger and reduces the cost. Was expensive.

In order to reduce the weight, it was conventionally considered that the combustion cylinder of the heat exchanger was made of aluminum and the preheating water pipe wound therearound was made of water-resistant stainless steel. In this case, the combustion cylinder that contacts the preheating water pipe is kept at a relatively low temperature, while the combustion cylinder that does not contact the preheating water pipe becomes extremely hot, causing a difference in the thermal expansion of both parts. , By repeating thermal stress,
Cracks are likely to occur in the non-contact part of the water pipe of the combustion drum,
There was a problem that the durability was poor.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and it is difficult for cracks to occur in the non-contact portion of the water pipe of the combustion cylinder, so that it has excellent durability and is lightweight,
In addition, it is an object of the present invention to provide a heat exchanger for heating that is very inexpensive to manufacture.

[0007]

The heat exchanger for heating according to the present invention comprises a parallel plate-like aluminum plate fin and a stainless steel strong heating penetrating the plate fin inside the upper part of a stainless steel combustion cylinder. A heat exchange part comprising a water pipe for use is provided, a heat source such as a burner is arranged inside the lower part of the combustion cylinder, and a stainless steel connected to the water pipe for strong heating on a peripheral surface of an outer wall of the combustion cylinder. A steel preheating water pipe is wrapped around, and the preheating water pipe and the outer wall of the combustion cylinder are joined to each other via a joining piece made of aluminum brazing sheet. The gist is an exchanger.

[0008]

According to the above heat exchanger, since the combustion cylinder is made of stainless steel, the combustion cylinder has extremely high strength, and cracks are unlikely to occur in the non-contact portion of the combustion cylinder even when thermal stress is repeated. . Further, since both the water pipe for strong heating and the water pipe for preheating are made of stainless steel, they have water resistance. Further, since the parallel plate fins are made of aluminum, the weight of the heat exchanger is reduced as a whole.

Further, the preheating water pipe wound around the outer peripheral surface of the combustion cylinder and the outer wall of the combustion cylinder are joined to each other via a joining piece made of an aluminum brazing sheet. Therefore, the joining operation is very simple compared to the case where stainless steels are welded together.

[0010]

Next, an embodiment of the present invention will be described with reference to the drawings.

Referring first to FIG. 1, a heating heat exchanger (1) according to the present invention is used as a water heater, and is provided, for example, with an aluminum blade inside a combustion cylinder (10) made of stainless steel. A heat exchange section (5) consisting of a parallel sheet fin (2) made of a jing sheet and a meandering stainless steel meandering water pipe (3) penetrating the plate fin (2) is provided. A burner (11) using city gas as a fuel gas is disposed at a lower end portion in the combustion drum (10).

On the other hand, on the peripheral surface of the outer wall (10a) of the combustion cylinder (10),
A stainless steel preheating water pipe (4) having a circular cross section connected to the strong heating water pipe (3) is wound.

As shown in detail in FIGS. 2 and 3, in the first embodiment of the present invention, the outer wall (10a) of the combustion cylinder (10) is fitted with a preheating water pipe in contact with a preheating water pipe. A recess (7) is provided. A preheating water pipe (4) is inserted into this fitting recess (7).
A preheating water pipe, which is also fitted via a joint piece (6) made of aluminum brazing sheet, which is also arc-shaped in cross section
(4) and the outer wall (10a) of the combustion drum (10) are joined to each other via a joining piece (6). Here, the joining piece (6) is made of an aluminum brazing sheet in which brazing material layers (6b) and (6b) are provided on both front and back surfaces of an aluminum core plate (6a).

The meandering strong heating water pipe (3) is
The ends of a plurality of hairpin tubes are connected via U-shaped bends.

The heating heat exchanger (1) is provided with a parallel plate fin (2) made of aluminum brazing sheet and a stainless steel made of stainless steel inside a combustion cylinder (10) made of stainless steel. Heat exchange part consisting of a meandering strong heating water pipe (3)
(5), and a joining piece made of aluminum brazing sheet is attached to the outer surface (10a) of the combustion cylinder (10).
A preheating water pipe (4) made of stainless steel is wound through (6), and the end of the preheating water pipe (4) is connected to the end of the strong heating water pipe (3) to heat the pipe. After all the components of the heat exchanger (1) are set, they are manufactured by, for example, collective brazing by a vacuum brazing method.

In the above heat exchanger, the burner (11)
When the water is ignited, the water is preheated while passing through the stainless steel preheating water pipe (4) wound around the outer surface of the combustion cylinder outer wall (10a), and the water is further heated inside the upper part of the combustion cylinder (10). Parallel aluminum plate fins in the heat exchange section (5)
(2) Stainless steel meandering strong heating water pipe penetrating
It is strongly heated to (3).

At this time, the portion of the combustion cylinder (10) in contact with the preheating water pipe (4) is kept at a relatively low temperature, while the combustion cylinder (10) not in contact with the preheating water pipe (4). Although the part gets hot, the combustion cylinder (10) is made of stainless steel,
The strength is extremely high, and even when thermal stress is repeated, cracks are less likely to occur in the non-contact portion of the water pipe of the combustion drum (10), and the durability is excellent.

FIG. 4 shows a second embodiment of the present invention. Here, the difference from the first embodiment is that
The preheating water passage pipe (4) made of stainless steel is not a circular cross section but a modified pipe having a flat portion (8) on the combustion drum (10) side. Along with this, aluminum bra
The joint sheet (6) made of a jing sheet is flat, and the flat part (8) of the preheating water pipe (4) is flattened by the combustion cylinder (10) through the flat joint piece (6). It is joined to the outer wall (10a). As a result, the preheating water pipe (4) is formed into a deformed pipe, resulting in the combustion cylinder (1).
Example 1 was applied to the portion of the outer wall (10a) of the
There is an advantage that there is no need to provide a fitting concave portion (7) having a circular cross section as in the case of (1).

Since the other points of the second embodiment are the same as those of the first embodiment, the same parts are denoted by the same reference numerals in the drawings.

[0020]

According to the heat exchanger for heating of the present invention, as described above, a parallel aluminum plate fin and a stainless steel piercing through the plate fin are provided inside the upper part of the stainless steel combustion cylinder. A heat exchange part comprising a water pipe for strong heating is provided, and a heat source such as a burner is arranged inside the lower part of the combustion cylinder, and connected to the water pipe for strong heating on the outer peripheral surface of the combustion cylinder. The preheated water pipe made of stainless steel is wound around the pipe and the outer wall of the combustion cylinder is joined to each other via aluminum brazing sheet joint pieces. According to the heating heat exchanger of the present invention, since the combustion cylinder is made of stainless steel, the strength is extremely high. Therefore, even when thermal stress is repeated, cracks are generated in the non-contact portion of the combustion cylinder with the water pipe. Unfortunately, the heat exchanger It is excellent in durability. Further, since both the water pipe for strong heating and the water pipe for preheating are made of stainless steel, they have water resistance.

Further, since the parallel plate fins are made of aluminum and the combustion drum and the water pipe are both made of stainless steel, the weight of the heat exchanger can be reduced as compared with a conventional copper heat exchanger. Can play.

In addition, the preheating water pipe wound around the outer surface of the outer wall of the combustion cylinder and the outer wall of the combustion cylinder are collectively connected via a joining piece made of aluminum brazing sheet, for example, by a vacuum brazing method. Since the joining is performed by brazing, the joining operation is very simple and the production cost of the heat exchanger for heating is reduced as compared with the case where the stainless steels are directly welded.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view of a heating heat exchanger according to the present invention.

FIG. 2 is an enlarged sectional view showing a main part of the first embodiment of the present invention, in which the outer wall of the combustion drum and the preheating water pipe are separated before being joined.

FIG. 3 is an enlarged cross-sectional view of a main part showing a state after joining of an outer wall of a combustion drum and a water pipe for preheating.

FIG. 4 is an enlarged sectional view of a main part showing a state after joining an outer wall of a combustion drum and a preheating water pipe according to a second embodiment of the present invention, and corresponds to FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat exchanger for heating 2 Plate fin 3 Water pipe for strong heating made of stainless steel 4 Water pipe for preheating made of stainless steel 5 Heat exchange part 6 Joint piece made of aluminum brazing sheet 10 Combustion cylinder 10a Outer wall of combustion cylinder 11 burner

Claims (1)

(57) [Claims] 1. A parallel aluminum plate fin (2) and a stainless steel strong heating water pipe (3) penetrating the plate fin (2) are provided inside the upper part of a stainless steel combustion cylinder (10). ), And a heat source such as a burner (11) is arranged inside the lower part of the combustion cylinder (10), and the outer peripheral surface (10a) of the combustion cylinder (10) is provided. The stainless steel preheating water pipe connected to the strong heating water pipe (3)
(4) is wound around the preheated water pipe (4) and the combustion drum (1
A heat exchanger for heating, wherein the outer wall (10a) of (0) is joined to each other via a joining piece (6) made of aluminum brazing sheet.