JP2000111163A - Gas hot water supply apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a compact low noise gas hot water supply apparatus in which thermal efficiency is enhanced while suppressing production of NOx by forming a water tube snaking repeatedly in a plane and disposing a planar surface combustion burner while sandwiching the snaking water tube from front and rear such that the combustion faces face each other. SOLUTION: The gas hot water supply apparatus comprises a water tube 1 snaking in a plane, a burner 2 for heating water flowing through the water tube, a gas supply pipe 3 for supplying fuel gas thereto, and interlocking channel change-over valve 4 and exhausting passage 5. Since combustion flame does not act directly onto the water tube 1, the water tube 1 can be disposed closely to the combustion face of a combustion burner and thermal efficiency is enhanced. Since a gas mixed with total quantity of required combustion air is supplied into the body of the burner 2, a secondary combustion air supply fan can be eliminated while reducing noise during use. The surface combustion burner enters into low temperature combustion state thus suppressing production of NOx.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas water heater, such as an instantaneous water heater, for producing hot water or hot water by applying combustion heat to flowing water.

[0002]

2. Description of the Related Art Conventionally, in a large-sized gas water heater capable of supplying a large amount of hot water, a plurality of crater portions are arranged in a row to form a burner, and a water pipe is disposed above the burner. And a gas mixture of the primary combustion air is ejected and burned, and the secondary combustion air is blown from below the burner by a fan.

[0003]

In the conventional gas water heater, since the blower fan is driven to obtain secondary combustion air, noise is generated during use and high temperature combustion occurs. Since NOx gas is easily generated and forced ventilation means such as a fan must be installed, there is a problem that the size of the water heater becomes large. In addition, since the heat of combustion in the burner is convectively transferred to the water pipe, there is a problem that the thermal efficiency cannot be sufficiently increased.

[0004] The present invention has been proposed in view of the above points, and an object of the present invention is to provide a gas water heater that is low noise, compact, can suppress the generation amount of NOx, and has high thermal efficiency. And

[0005]

According to the first aspect of the present invention, there is provided a gas water heater in which gas combustion heat is applied to flowing water flowing through a water pipe. Is formed in a meandering shape in a plane,
A surface combustion burner formed in a flat plate shape is sandwiched from the front and rear with the meandering water tube being sandwiched from the front and back, and the combustion surface thereof is arranged in a state where the combustion surfaces face each other. In a gas water heater in which the combustion heat of gas is made to act on flowing water, a surface combustion burner is formed in a cylindrical body whose combustion surface is an inner peripheral surface, and the surface combustion burner is formed into a cylindrical shape. The invention is characterized in that the water pipe is positioned in a coil shape in a space formed inside the inner peripheral surface, and in the invention according to claim 5, the heat of combustion of gas acts on flowing water flowing through the water pipe. In the gas water heater, the water pipe is formed in a flat box shape, and a flat surface burner formed in a flat plate shape with the flat box-shaped water tube sandwiched from front and rear is disposed in a state where the combustion surfaces thereof face each other. The feature is that There.

[0006]

According to the first aspect of the present invention, since the front and rear of the water pipe formed in a meandering shape in a plane are sandwiched between the flat surface combustion burners, the radiant transmission from the surface combustion burner is achieved. Heat can increase the thermal efficiency. Further, since the surface combustion burner can be arranged close to the water pipe, it can be formed thin as a water heater. In the case of surface burners,
Since the mixed air in which the entire amount of the combustion air is mixed is supplied into the burner body, the blowing fan for supplying the secondary combustion air can be omitted, and the noise during use can be reduced. .

On the other hand, according to the present invention, a water pipe formed in a coil shape is disposed in a space formed inside an inner peripheral surface of a surface combustion burner formed in a cylindrical shape. Therefore, the entire outer peripheral surface of the water tube coil is covered with the surface combustion burner, so that the thermal efficiency can be further improved. Therefore, in addition to the above-described operation of the opposed flat water heater, a water heater having a large hot water supply capacity can be formed in a small size.

Further, according to the present invention described in claim 5,
Since the surface combustion burner formed in a flat plate shape with the water box formed in a flat box shape sandwiching it is arranged in a state where the combustion surfaces face each other, the structure of the water tube can be formed simply and at low cost. However, since the combustion surface of the surface combustion burner formed in a flat shape and the surface of the water tube are arranged to face each other, the flat box type water tube can efficiently receive the radiant heat from the burner combustion surface, and have high thermal efficiency. Can be demonstrated.

In any case, when the combustion surface of the surface combustion burner is made of a metal fiber woven or knitted material, the gas flow resistance at the combustion surface is changed by changing the weaving density or knitting density. Can be easily adjusted.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of the present invention. FIG. 1 is a schematic front view of a water heater, and FIG. 2 is a sectional view taken along the line II-II. The water heater includes a water pipe (1) bent in a meandering shape in a plane, a burner (2) for heating water flowing in the water pipe (1), and a fuel gas supplied to the burner (2). Gas supply pipe (3), gas fuel supply pipe (3) and water pipe (1)
Interlocking flow path switching valve (4) and exhaust path installed in the middle of
It is formed in (5).

The burner (2) has a box-shaped casing (6) having one side formed in an opening, and a mat body (7) formed by weaving or knitting metal fibers in the opening. And a surface combustion burner having a combustion surface (8).

Then, a pair of surface combustion burners (2) is arranged with the combustion surfaces (8) facing each other, and the pair of combustion surfaces
(8) The meandering water pipe (1) is arranged in the space between the pipes. A large number of ring-shaped heat receiving fins (9) are provided upright on the peripheral surface of the water pipe (1).

FIGS. 3 and 4 show another embodiment of the water heater, in which the burner (2) is formed in a double cylindrical shape, and the entire inner peripheral wall thereof is formed in an opening. A water pipe formed into a combustion surface (8) by stretching a mat body (7) formed by weaving or knitting a metal fiber in a portion thereof, and a coil formed in a space formed inside the combustion surface (8). (1) is arranged. Although not shown in the drawing, ring-shaped heat receiving fins are also provided on the coiled water pipe (1).

In both of the above embodiments, the ring-shaped heat receiving fins (9) are set up on the peripheral surface of the water pipe (1). It may be formed in the shape of a ribbon standing upright so as to be parallel to.

FIG. 5 shows another embodiment of the water heater, which is a flat surface combustion burner (2) in which the water pipe (1) is formed in a flat box shape and the combustion surfaces (8) are arranged to face each other. The flat box-shaped water pipe (1) described above is placed between the combustion surfaces of the
It is arranged in a state close to (8). in this case,
As shown by the imaginary line in FIG. 5, a baffle plate (10) is arranged inside the flat box-shaped water pipe (1), and the length of the flow path in the water pipe (1) is increased so that the residence time is increased. It is also possible to do.

[0016]

According to the first aspect of the present invention, since the front and rear of the water pipe formed in a meandering shape in a plane is sandwiched between the surface combustion burners formed in a flat shape, the combustion flame directly acts on the water pipe. Therefore, the water pipe and the combustion surface of the surface combustion burner can be arranged close to each other.
Thereby, the thermal efficiency can be improved, and the water heater can be formed thin. When a surface combustion burner is used as a heat source, an air-fuel mixture in which the entire required amount of combustion air is mixed is supplied into the burner body. This can be omitted, noise during use can be reduced, and a quiet water heater can be provided.

On the other hand, in the invention described in claim 3, the water pipe formed in a coil shape is arranged in a space formed inside the inner peripheral surface of the surface combustion burner formed in a cylindrical shape. In addition to the effects of the flat plate-type water heater described above, a small-sized water heater having a large hot water supply capacity can be formed.

Further, in the invention described in claim 5, the water pipe is formed in a flat box shape, and the flat surface-shaped burner formed in a flat plate shape with the flat box-shaped water pipe sandwiched therebetween is disposed with the combustion surfaces facing each other. Therefore, the structure of the water pipe can be formed simply and at low cost. Since the combustion surface of the surface combustion burner formed in a flat shape and the water tube surface are arranged to face each other, the flat box type water tube can efficiently receive the radiant heat from the burner combustion surface and exhibit high thermal efficiency. be able to.

Further, since the surface combustion burner is brought into a low-temperature combustion state, it is possible to suppress the generation of NOx.

In any case, when the combustion surface of the surface combustion burner is made of metal fiber woven or knitted fabric, the gas flow resistance on the combustion surface can be reduced by changing the degree of opening on the surface. It can be easily adjusted, and the running water in the water pipe can be heated under optimal combustion conditions.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a water heater.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a schematic configuration diagram showing a main part in another embodiment of the water heater.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

FIG. 5 is a schematic configuration diagram showing a main part in still another embodiment.

FIG. 6 is a sectional view taken along line VI-VI of FIG. 5;

[Explanation of symbols]

 1 ... water pipe, 2 ... surface burning burner, 8 ... burning surface.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Makihiko Mori 3-21-8 Nishi-Shimbashi, Minato-ku, Tokyo Iwatani Industry Co., Ltd. Tokyo head office Iwatani Corporation Shiga Technology Center (72) Inventor Sadaki Nakamura 1095 Katsube-cho, Moriyama-shi, Shiga Prefecture Iwatani Corporation Shiga Technology Center (72) Inventor Tomohiro Miyamura 1095, Katsube-cho, Moriyama-shi, Shiga Stock 3L034 BA24 BA29 BB03 BB04

Claims (6)

[Claims] 1. A gas water heater in which combustion heat of gas is applied to flowing water flowing through a water pipe (1), wherein the water pipe (1) is formed by folding back in a plane in a meandering manner. A gas water heater characterized in that a plate-shaped surface combustion burner (2) is disposed in a state where its combustion surface (8) is opposed to the water pipe (1) formed in the shape of a tube from the front and back. 2. The gas water heater according to claim 1, wherein the combustion surface (8) of the surface combustion burner (2) is formed of a metal fiber fabric or a metal fiber knit. 3. A gas water heater in which gas combustion heat is applied to flowing water flowing through a water pipe (1), wherein the surface combustion burner (2) has a combustion surface (8) having an inner peripheral surface. A gas pipe characterized by having a water pipe (1) formed in a coil shape disposed in a space formed inside an inner peripheral surface of a surface combustion burner (2) formed in a cylindrical shape. Water heater. 4. The gas water heater according to claim 3, wherein the combustion surface (8) of the surface combustion burner (2) is formed of a metal fiber fabric or a metal fiber knit. 5. A gas water heater in which gas combustion heat is applied to flowing water flowing through a water pipe (1), wherein the water pipe (1) is formed in a flat box shape, and is formed in the flat box shape. A gas water heater characterized in that a surface combustion burner (2) formed in a flat plate shape with a water pipe (1) sandwiched from front and rear is disposed with its combustion surface (8) facing. 6. The gas water heater according to claim 5, wherein the combustion surface (8) of the surface combustion burner (2) is formed of a metal fiber fabric or a metal fiber knit.