JPH0682018B2 - Water heater - Google Patents

Description

TECHNICAL FIELD The present invention relates to a water heater used for hot water supply, heating, and the like.

2. Description of the Related Art A conventional water heater of this type, as shown in FIG. 3, has a can body 24 in which a water storage portion 23 is formed between a cylindrical inner body 21 and an inner body-shaped outer body 22, A baffle 25 located inside the inner case 21 was provided to promote heat exchange between the combustion gas generated in the combustion section 26 and the water in the water storage section 23.

Problems to be Solved by the Invention However, in such a structure, since the cross-sectional shape of the inner case 21 is linear, turbulent flow occurring when the combustion gas passes between the inner case 21 and the baffle 25 is small. Therefore, there is a problem that the heat exchange efficiency is low. Further, during combustion, the temperature of the inner case 21 is high because the inner surface of the inner case 21 is in contact with high-temperature combustion gas, while the temperature of the outer case 22 is lower than the temperature of the inner case 21, so that There has been a problem that thermal stress is generated due to the difference in thermal expansion between the outer case 22 and the vertical direction and the durability of the can 24 is reduced. In particular, when the enamel processing is applied to the surface on the water storage portion 23 side, that is, the outside of the inner case 21 and the inside of the outer case 22, the phenomenon that the enamel cracks due to the thermal stress occurs, and the durable life of the can body 24. However, there was a problem in that

In view of the above problems, the present invention provides a water heater that increases the turbulent flow of combustion gas to increase heat exchange efficiency and further reduce thermal stress in the inner and outer shells to improve the durability of the can body. To do.

Means for Solving the Problems Technical means of the present invention for solving the above problems include a can body having a water reservoir formed between a cylindrical inner cylinder and a cylindrical outer cylinder, and A burner attached to the can body facing a combustion chamber formed inside the barrel, and a baffle located above the combustion chamber for promoting heat exchange between combustion gas of the burner and water in the water storage section. The upper portion of the inner body has a plurality of small wavy portions having a corrugated cross-sectional shape, and the lower portion of the inner body has a cross-sectional shape substantially similar to the small wavy portion and larger than the small wavy portion. It has a large wavy portion.

Action The action of this technical means is as follows.

That is, since the cross-sectional shape of the inner case is corrugated, turbulent flow occurs when the combustion gas passes between the inner case and the baffle, and heat exchange efficiency can be improved. Since the small wavy portion is provided, the turbulent flow effect in this portion is further increased, and higher heat exchange efficiency can be obtained.

In addition, since the inner surface of the inner case is in contact with the hot combustion gas during combustion, the temperature of the inner case is higher than that of the outer case. Since it also extends in the horizontal direction, it is possible to absorb the thermal expansion in the vertical direction, and in particular, the large corrugated part is provided in the lower part of the inner body where the temperature becomes the highest, so the thermal expansion absorption effect in this part. Is further increased, and the difference in thermal expansion between the inner case and the outer case in the vertical direction can be almost eliminated.

Embodiment A water heater according to an embodiment of the present invention will be described below with reference to the accompanying drawings. In FIG. 1, 1 is a cylindrical inner body 2
It is a can body formed by forming a water storage part 4 between the outer cylinder 3 and the cylindrical outer case 3, and has a water supply port 5 and a hot water supply port 6. Reference numeral 7 is a baffle provided above the combustion chamber 8 inside the inner case 2, and has a plurality of baffle plates 9 provided vertically to the exhaust direction. Reference numeral 10 is a burner provided on the can body 1 facing the combustion chamber 8, and 11 is an exterior body surrounding the can body 1. In the upper part of the inner body 2, there are a plurality of small wavy portions 12 having a corrugated cross-section.
Further, in the lower part of the inner body 2, there are large wavy portions 13 whose cross-sectional shape is similar to the small wavy portion 12 and has a waveform larger than that of the small wavy portion 12. The small wavy portion 12 and the large wavy portion 13 are respectively formed. The inner diameter is maximized so that the tip of the baffle plate 9 is located in the valley 14.

Next, the operation of the configuration of this embodiment will be described. The combustion gas generated in the combustion chamber 8 by the combustion of the burner 10 passes between the inner case 2 and the baffle 7, exchanges heat with the water in the water storage section 4 of the can body 1, and is then exhausted upward. Can body 1
The water in the water storage section 4 of is heated by this operation to supply hot water.
It is supplied from the hot water supply port 6 as hot water used for heating or the like.

Turbulent flow occurs when the combustion gas passes between the inner case 2 and the baffle 7, but the cross section of the inner case 2 is corrugated, and in this embodiment, the baffle plate is formed in the valley 14 of the inner case 2. Since the tip of 9 is located, turbulent flow is increased in this portion, and as a result, the heat exchange efficiency between the combustion gas and the water in the water storage section 4 can be improved. Further, since the small corrugated portion 12 is provided on the upper portion of the inner case 2, the turbulent flow effect in this portion is further improved, and higher heat exchange efficiency can be obtained.

Further, since the inner surface of the inner case 2 is in contact with the high-temperature combustion gas, the temperature of the inner case 2 is very high, while the outer case 3 is in contact with only the water in the water storage section 4 and the outside air. The temperature is not so high compared to the inner case 2. When the inner case 2 has the same simple cylindrical shape as the outer case 3, the vertical thermal expansion of the inner case 2 is larger than the vertical thermal expansion of the outer case 3, but in the embodiment, the inner case 2 is expanded. By extending the corrugated portion 2 in the horizontal direction as well, it is possible to absorb the vertical thermal expansion of the inner case 2 and reduce the difference in the vertical thermal expansion between the inner case 2 and the outer case 3. Is. Further, since the large corrugated portion 13 is provided in the lower portion of the inner body 2 where the temperature is highest, the thermal expansion absorption effect in this portion is further improved, and the difference in thermal expansion between the inner body 2 and the outer body 3 is increased. Can be almost eliminated. As a result, it is possible to prevent the generation of thermal stress, which has been conventionally caused by the difference in thermal expansion between the inner case 2 and the outer case 3, and improve the durability of the can body 1. Even when the enamel processing is applied to the surface of the water storage section 4 side, that is, the outside of the inner case 2 and the inside of the outer case 3, respectively, there is almost no stress on the enamel so that the enamel can be kept in a perfect condition forever. The durability life of the can body 1 can be remarkably improved.

Next, another embodiment of the present invention will be described. The same members as those in the above embodiment are designated by the same reference numerals, and the description thereof will be omitted. FIG. 2 shows another embodiment. In this embodiment, a heat exchange coil 15 is provided above the water storage portion 4 formed between the inner body 2 and the outer body 3 of the can body 1. ing. The water in the heat exchange coil 15 is indirectly heated by the hot water in the water storage section 4 and is supplied as hot water for a purpose different from the hot water in the water storage section 4 (for example, bath circulating water). In this case, since the heat exchange coil 15 is located in the vicinity of the small wavy portion 12 of the inner case 2, the combustion gas and the heat exchange coil are passed through the hot water of the water storage portion 4.
The efficiency of heat exchange of water in 15 can be maximized,
Moreover, since the space for accommodating the heat exchange coil 15 can be secured even if the distance between the inner case 2 and the outer case 3 is reduced, the size of the can body 1 can be made compact.

EFFECTS OF THE INVENTION As is apparent from the above, the present invention provides a plurality of small wavy portions having a corrugated cross-sectional shape in the upper part of the inner body, and has a cross-sectional shape similar to the small wavy portion in the lower part and is smaller than the small wavy part. By providing a large wavy portion with a large waveform, it is possible to increase the turbulent flow that occurs when the combustion gas passes between the inner cylinder and the baffle, and to improve heat exchange efficiency. It is possible to absorb the expansion and prevent the generation of thermal stress caused by the difference in thermal expansion between the inner case and the outer case, thereby significantly improving the durability of the can body.

Further, by providing the inner body with the shaped portion, the vertical compression strength and the water pressure resistance strength of the can can be improved.

[Brief description of drawings]

1 is a vertical sectional view of a water heater according to an embodiment of the present invention, FIG. 2 is a vertical sectional view of a water heater according to another embodiment of the present invention, and FIG. 3 is a vertical sectional view showing a conventional water heater. Is. 1 ... Can body, 2 ... Inner body, 3 ... Outer body, 4 ... Water storage part,
7 ... Baffle, 8 ... Combustion chamber, 10 ... Burner, 12 ...
Small wavy section, 13 …… Large wavy section.

Claims (1)

[Claims] 1. A can body having a water storage portion formed between a cylindrical inner body and a cylindrical outer body, and a can body attached to the can body facing a combustion chamber formed inside the inner body. And a baffle located above the combustion chamber for promoting heat exchange between the combustion gas of the burner and the water in the water storage part, and a plurality of corrugated cross-sectional shapes are provided on the upper part of the inner body. A water heater having a small wavy portion, and a large wavy portion having a cross-sectional shape substantially similar to the small wavy portion and having a waveform larger than that of the small wavy portion at a lower portion of the inner shell.