JP2000314561A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent drum cracks due to fatigue breaking by executing local heat insulation by a ceramic fiber or the like on an inner surface of the drum only for the circumferential pipe of closest approach to a finned pipe in a heat exchanger, having a circumferential pipe wound at the outer periphery of the drum obtained by bending a plate material in a prismatic state. SOLUTION: This heat exchanger for an instantaneous water heater, a water heater or the like comprises a prismatic drum 11, having flanges 12, 13 provided at a combustion equipment side and an exhaust chamber side at both ends, a circumferential pipe 21 wound on the periphery of the drum 11, and a plurality of rows of finned pipes 23 arranged to pass through the drum 11. In this case, a heat insulator such as a ceramic fiber 41 or the like is charged in an inner surface of the drum to the pipe 21 nearest the pipes 23. Thus, the behavior of the pipe 21 due to thermal expansion and thermal contraction is suppressed, repeating load applied to the brazed end of the drum 11 to the fins 31 of the pipe 23 is reduced, and drum cracks due to fatigue breakdown is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum formed by bending a plate material into a rectangular tube shape, a group of heat absorbing fins arranged in a large number, and a fin pipe having a plurality of rows fixed to the fin group. The present invention relates to a heat exchanger comprising a peripheral pipe wound around the outer periphery of the drum, and a U-shaped pipe connecting the ends of the fin pipes and the ends of the peripheral pipes in series.

[0002]

2. Description of the Related Art Conventional heat exchangers, such as instantaneous water heaters and water heaters, have fin pipes, fins, fins, drums, drums, drums, peripheral pipes, U-shaped pipes, etc. attached by brazing or welding. Things.

[0003]

SUMMARY OF THE INVENTION In a conventional heat exchanger,
Since the fins and the heat transfer tubes repeat thermal expansion and thermal contraction due to repeated burner combustion and stoppage, the restrained portion by brazing or welding may cause fatigue failure due to repeated load. In particular, the brazed ends of the fin and the drum are different in the thermal expansion and thermal contraction behavior of the fin itself and the thermal expansion and thermal contraction behavior of the drum and the peripheral pipe. May cause cracking.

[0004]

Means for Solving the Problems and Their Functions and Effects To achieve the above object, a first aspect of the present invention is to provide a drum formed by bending a plate material into a rectangular tube shape, a heat absorbing fin group having a large number of aligned fins, A fin pipe penetrating and fixing a plurality of rows to the fin group, a peripheral pipe wound around the outer periphery of the drum, and a U-shaped pipe connecting the ends of the fin pipes and the ends of the peripheral pipes in series In the heat exchanger consisting of only the peripheral pipe closest to the fin pipe,
By applying local heat insulation to the inner surface of the drum using ceramic fibers or the like, the load on the fin and the brazed end of the drum can be reduced to thereby prevent the drum from cracking due to fatigue fracture.

[0005] A second aspect of the present invention is to provide a drum formed by bending a plate material into a rectangular tube shape, a plurality of heat absorbing fins arranged in a large number, and a two-system water pipe arranged in a pair above and below the fins. A fin pipe fixedly penetrating through the rows, two peripheral pipes wound around the outer periphery of the drum, and a U connecting in series between the ends of the fin pipes and the ends of the peripheral pipes
In a one-can two-circuit heat exchanger consisting of U-shaped pipes, only the peripheral pipe group closest to the fin pipe is locally insulated with ceramic fiber or the like on the inner surface of the drum, so that the brazed ends of the fin and drum By reducing the repeated load applied to the portion, it is possible to prevent the drum from being cracked due to fatigue fracture.

[0006]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 and 2 show a configuration diagram applied to a heat exchanger exclusively for hot water supply which is an embodiment of the present invention. As shown in the figure, the heat exchanger is a rectangular drum 1
1, combustion device side flange 12, exhaust chamber side flange 13,
A peripheral pipe 21 wound around the outer periphery of the drum, a plurality of rows of heat-absorbing fins 31, a plurality of fin pipes 23 penetrated and fixed, a U-shaped pipe 25 connecting the ends of each fin pipe, a fin pipe outlet pipe 26, and heat insulating material such as ceramic fiber 41 is inserted into the inner surface of the drum only for the peripheral pipe closest to the fin pipe.

FIG. 3 and FIG. 4 are diagrams showing a configuration applied to a one-can two-channel heat exchanger according to an embodiment of the present invention. As shown in the figure, the heat exchanger has a rectangular cylindrical drum 11, a combustion device side flange 12, an exhaust chamber side flange 13, a peripheral pipe 21 wound around the outer periphery of the drum, and a bath circulation system peripheral pipe 22,
The fin pipes 23 and the circulating fin pipes 2 are fixedly penetrated in a plurality of rows with respect to the heat absorbing fins 32 arranged in a large number.
4. U-shaped pipe 25 connecting the ends of each fin pipe,
A heat insulating material such as a ceramic fiber 41 is charged into the inner surface of the drum only for the peripheral pipe group which is constituted by the fin pipe outlet pipe 26 and is closest to the fin pipe.

The behavior of the peripheral pipe due to thermal expansion and thermal contraction can be suppressed by inserting a heat insulating material such as a ceramic fiber inside the drum only for the peripheral pipe closest to the fin pipe. Therefore, it is possible to reduce the repetitive load applied to the brazing ends of the fins and the drum, and to provide a heat exchanger that does not cause drum cracking due to fatigue failure.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a heat exchanger exclusively for hot water supply according to an embodiment of the present invention.

Fig. 2 Ceramic fiber installed in a heat exchanger dedicated to hot water supply

FIG. 3 is an overall perspective view of a one-can two-channel heat exchanger according to an embodiment of the present invention.

Fig. 4 State of loading ceramic fiber into one-can two-channel heat exchanger

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Drum 12 ... Combustion device side flange 13 ... Exhaust chamber side flange 21 ... Peripheral pipe (hot water supply) 22 ... Peripheral pipe (fill) 23 ... Fin pipe (hot water) 24 ... Fin pipe (fill) 25 ... U-shaped pipe 26 ... Fin pipe outlet pipe 31 Heat-absorbing fins (for hot water supply only) 32 Heat-absorbing fins (for one can, two water channels) 41 Heat insulation material (ceramic fiber)

Claims (2)

[Claims] 1. A drum formed by bending a plate material into a rectangular tube shape, a group of heat absorbing fins arranged in a large number, a fin pipe penetrating and fixing a plurality of rows to the group of fins, and a winding around the outer periphery of the drum. In a heat exchanger composed of a U-shaped pipe connected in series between end portions of the fin pipes and the end portions of the fin pipes, only the peripheral pipe closest to the fin pipe has a drum inner surface portion. A heat exchanger characterized by having local insulation made of ceramic fiber or the like. 2. A drum formed by bending a plate material into a rectangular tube shape, a plurality of heat absorbing fin groups arranged in a large number, and two lines of water pipes arranged in a pair of upper and lower sides with respect to the fin group, and fixed in a plurality of rows. 1-circuit 2-circuit type comprising a fin pipe which has been wound, two sets of peripheral pipes wound around the outer periphery of the drum, and a U-shaped pipe which connects the ends of the fin pipes and the ends of the peripheral pipes in series. A heat exchanger characterized in that only a peripheral pipe group closest to a fin pipe is locally insulated by a ceramic fiber or the like on a drum inner surface portion.