JPH09250816A - Hot water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectually achieve heat exchange and hence ensure a sufficient amount of effluent hot water even when the size of a heat exchanger is reduced to the utmost by parallely supply water to a main heat exchanger and an auxiliary heat exchanger. SOLUTION: A main heat exchanger 2 is disposed upstream a waste gas flow passage 7 above a burner 1 and an auxiliary treat exchanger 4 downstream the same so as to be overlapped vertically putting a drain pan 6 therebetween. The diameter of water pipes 3 constituting the auxiliary heat exchanger 4 is made finer than that of water pipes 5 of the main heat exchanger 2, whereby the water pipes 3 are densely disposed, and water is supplied parallely to the water pipes 3 and 5. Hereby, even when the diameter of the water pipe 3 constituting the auxiliary heat exchanger 4 is made finer, overall water supply resistance is prevented from being increased so that heat exchange is effectulally achieved and the satisfactory amount of effluent hot water is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water heater in which heat efficiency is improved by utilizing exhaust heat of combustion exhaust gas in a water heater or the like.

[0002]

2. Description of the Related Art Conventionally, there is a method of utilizing exhaust heat of combustion exhaust gas in order to improve the heat efficiency of a heat exchanger. For example, the one disclosed in Japanese Patent Publication No. 62-2671 discloses a gas burner and a true burner thereof. Two heat exchangers are provided upstream and downstream of the upper combustion exhaust gas passage, and water is passed in series from the auxiliary heat exchanger on the downstream side to the main heat exchanger on the upstream side.

[0003]

[Problems to be Solved by the Invention]
In order to reduce the size of the auxiliary heat exchanger and the overall size of the water heater without reducing the heat efficiency, the structure in which water is passed in series to the two heat exchangers as in the configuration described in Japanese Patent No. 2671 is used. , Reduce the diameter of the water pipes that make up the heat exchanger,
When these water pipes are arranged densely, for example, if the water pipe diameter of the main heat exchanger is 20 mm and the water pipe diameter of the auxiliary heat exchanger is 12 mm, the water resistance will decrease due to the thin water pipe diameter. There is a problem in that a sufficient amount of hot water is not obtained because of the increase.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide a water heater capable of efficiently exchanging heat and obtaining a sufficient amount of hot water discharged even if the heat exchanger is made as small as possible.

[0005]

To achieve the above object, a water heater according to a first aspect of the present invention is a water heater including a main heat exchanger, an auxiliary heat exchanger, and a burner. The feature is that water is passed in parallel to the vessel and the auxiliary heat exchanger. Further, in order to achieve the above object, the water heater according to claim 2 is the water heater according to claim 1, wherein at least one of a water pipe forming a main heat exchanger and a water pipe forming an auxiliary heat exchanger is used. The feature is that the diameter of the water pipe is thin.

In the water heater of the present invention, the feed water is passed from the branched water inlet circuit to the main heat exchanger and the auxiliary heat exchanger in parallel. Then, in each heat exchanger, hot and cold water heated by the high-temperature exhaust gas discharged from the burner exits from the heat exchanger and is then mixed again and discharged. Further, in the water heater according to claim 2, the water pipe diameter of at least one of the main heat exchanger and the auxiliary heat exchanger is reduced, and the heat exchangers are densely arranged to form the heat exchanger. It can be miniaturized. At this time, since water is passed through the two heat exchangers in parallel, the amount of hot water discharged does not decrease due to an increase in water passing resistance due to the thinning of the water pipe.

[0007]

1 is a side sectional view of a water heater according to a first embodiment of the present invention, and FIG. 2 is a side sectional view of a water heater according to a second embodiment.

In FIG. 1, the water heater according to the first embodiment has a main heat exchanger 2 on the upstream side of the exhaust gas passage 7 above the burner 1, an auxiliary heat exchanger 4 on the downstream side, and a drain receiver 6 sandwiched between them. Are arranged so that they overlap each other in the vertical direction. The diameter of the water pipe 3 that constitutes the auxiliary heat exchanger 4 is the water pipe 5 of the main heat exchanger.
The diameter of the water pipe 3 is 12 mm, and the water pipe 5 is 20 mm.
Since the water pipes 3 are densely arranged, the auxiliary heat exchanger can be downsized. The supply water is branched from a water inlet pipe (not shown) and is passed through the water pipe 3 and the water pipe 5 in parallel. The hot exhaust gas generated by the flame formed by the burner 1 mixes the hot and cold water heated in the two heat exchangers again, and the hot water is discharged from a hot water supply pipe (not shown).

In FIG. 2, in the water heater according to the second embodiment, a gap is formed between the main heat exchanger 2 and the auxiliary heat exchanger 4 by narrowing the exhaust gas passage 7, and the gap is sandwiched. The main heat exchanger 2 and the auxiliary heat exchanger 4 are arranged so as to overlap in the vertical direction and the horizontal direction. The high-temperature exhaust gas generated by the flame formed by the burner 1 rises in the exhaust gas passage 7 that gradually narrows while heating the main heat exchanger 2, and is collected. The auxiliary heat exchanger 4 located downstream of the exhaust gas passage 7 is heated and then exhausted. The supply water branched from a water inlet pipe (not shown) and passed through the water pipes 3 and 5 in parallel is heated by the high-temperature exhaust gas in the main heat exchanger 2, while in the auxiliary heat exchanger 4, the main heat exchanger is supplied. After being heated by the exhaust gas at 2, that is, after being heated by using exhaust heat, it is mixed again with the hot and cold water heated by the main heat exchanger 2 and tapped from a hot water supply pipe (not shown).

When water is heated using the exhaust heat in the auxiliary heat exchanger 4, the water in the exhaust gas is condensed to generate drain. This drain is strongly acidic, so drain drain 6
After being collected in (1), it is neutralized by the neutralizer 8. In the second embodiment, there is a gap between the main heat exchanger 2 and the auxiliary heat exchanger 4, and the drain receiver 6 is provided on the inner wall surface of the exhaust gas passage above the gap. The exhaust gas that has not been directly exposed to the exhaust gas and has reached the vicinity of the drain receiver 6 is heated in the two heat exchangers, as a result of which the temperature is somewhat lowered, the drain receiver 6 is heated,
It is possible to prevent heat from being lost due to evaporation of the drain, and to reduce thermal efficiency. Further, when the auxiliary heat exchanger 4 is provided according to the shape of the main heat exchanger 2 as shown in FIG. 2, it is possible to reduce the size of the entire water heater while ensuring the heat transfer area of the auxiliary heat exchanger 4 to the maximum. it can. The auxiliary heat exchanger 4 is
The shape does not have to match the shape of the main heat exchanger 2 unless the shape is such that it protrudes from the main heat exchanger 2 when combined with the main heat exchanger 2.

In both the first embodiment and the second embodiment, the main heat exchanger 2 has a larger amount of water flow than the auxiliary heat exchanger 4, and water is passed at a ratio of, for example, 2: 8. After being heated, they are mixed again and discharged from a hot water supply pipe (not shown), so that there is no influence of an increase in water flow resistance due to the thinning of the water pipe 3. Further, since the water pipes 3 of the auxiliary heat exchanger 4 are densely arranged, there is no reduction in thermal efficiency due to the reduction of the heat transfer area due to the reduced diameter.

Further, within a range where the amount of hot water discharged is not affected, both the water pipe 3 and the water pipe 5 are reduced in diameter so that, for example, both of them have a diameter of 1.
5 mm may be used, or contrary to the first and second embodiments, the water pipe 5 of the main heat exchanger 2 is made thinner than the water pipe 3 of the auxiliary heat exchanger 4, for example, the water pipe 3 is 20 mm and the water pipe 5 is 12 mm.
The water pipes 5 may be densely arranged. In addition,
In either case, the water inlet pipe and hot water supply pipe (not shown) are not thinned.

[0013]

The water heater according to the first aspect of the present invention having the above-described structure has the following effects. That is, in the water heater of the present invention, by passing water in parallel to the main heat exchanger and the auxiliary heat exchanger, even if the diameter of the water pipe constituting the heat exchanger is reduced, the overall water flow resistance does not increase. Since it does not exist, there is an effect that a sufficient amount of hot water can be obtained. Further, in the water heater according to claim 2, since the thin water pipes are densely arranged, the heat efficiency is prevented from being lowered due to the reduction of the heat transfer area, and the heat exchanger can be miniaturized. The effect is that it can be converted.

[Brief description of drawings]

FIG. 1 is a side sectional view of a water heater showing a first embodiment of the present invention.

FIG. 2 is a side sectional view of a water heater showing a second embodiment of the present invention.

[Explanation of symbols]

 1 burner 2 main heat exchanger 3 water pipe 4 auxiliary heat exchanger 5 water pipe 6 drain receiver 7 exhaust gas passage 8 neutralizer

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoji Kona, 93, Edo-machi, Chuo-ku, Kobe, Hyogo Prefecture, Noritsu Co., Ltd. (72) Hideo Ueda, 93, Edo-cho, Chuo-ku, Kobe, Hyogo Prefecture, Noritsu, Ltd.

Claims (2)

[Claims] 1. A water heater provided with a main heat exchanger, an auxiliary heat exchanger, and a burner, wherein water is passed in parallel to the main heat exchanger and the auxiliary heat exchanger. . 2. The water heater according to claim 1, wherein at least one of the water pipe constituting the main heat exchanger and the water pipe constituting the auxiliary heat exchanger has a thin water pipe diameter.