JP2005061798A - Water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water heater having further improved water heating efficiency by accelerating heat exchange between the residual heat of exhaust gas passing through a smoke tube and water in a canned body. <P>SOLUTION: The water heater 10 comprises a heat exchanger arranged at the upper part of a burner 13 and an exhaust chamber 16A. The heat exchanger includes the canned body 11 and the smoke tube 17 forming a passage for exhaust gas for heat exchange with water in the canned body. On the upper face side of a top wall 11A of the canned body forming part of the exhaust chamber, a coating surface P is formed with frosting black heat resistant paint. The coating surface P accelerates the absorption of the residual heat of the exhaust gas exhausted into the exhaust chamber 16A to improve the water heating efficiency. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hot water heater, and more particularly, to a hot water heater capable of increasing the efficiency of hot water supply by effectively utilizing the residual heat of exhaust gas after passing through a smoke pipe.

  2. Description of the Related Art Conventionally, there has been known a water heater in which a heat exchanger is disposed on an upper portion of a burner, and water supplied into the heat exchanger is exchanged with combustion heat of the burner to supply hot water from a hot water supply pipe. This water heater is configured to include a burner and a heat exchanger provided on the upper portion of the burner. The heat exchanger includes a can body, a plurality of smoke pipes arranged in the can body, and a baffle that is housed in each smoke pipe and delays the passage time of exhaust gas in the smoke pipe to increase heat exchange efficiency. It is configured. Here, the smoke tube has a lower end opened to the combustion chamber side and an upper end located in a hole formed in the top wall of the can body so as to communicate with the upper exhaust chamber.

In the water heater described above, when the exhaust gas accompanying combustion of the burner passes through the smoke pipes, heat is exchanged with the water in the can accommodated around each smoke pipe, and the exhaust gas is still exhausted to the exhaust chamber. Normally, exhaust is performed while maintaining a high temperature. This leaves room for further use of the exhaust gas in the exhaust chamber for heat exchange.
However, it is the actual situation that known hot water heaters are constantly improving heat exchange efficiency around the smoke pipe.
Thus, as a result of intensive studies by the present inventors, it has been found that the residual heat of the exhaust gas in the exhaust chamber can be used more effectively by providing a heat exchange promoting portion on the top wall side of the can body made of a metal plate.
[Object of invention]

  The present invention has been devised based on the above knowledge, and its purpose is to further improve the hot water supply efficiency by promoting heat exchange between the residual heat of the exhaust gas that has passed through the smoke pipe and the water in the can body. It is to provide a water heater that can be used.

In order to achieve the above object, the present invention provides a water heater comprising a heat exchanger disposed at the top of a burner and an exhaust chamber provided above the top wall of the heat exchanger.
The heat exchanger includes a can body, and a smoke pipe which is disposed in the can body and forms a passage for exhaust gas accompanying combustion of the burner to exchange heat with water in the can body,
The heat exchange promoting part is formed on the top wall of the can that forms a part of the exhaust chamber.

  The heat exchange promoting portion in the present invention can be configured by providing a heat-resistant paint coating surface on the upper surface side of the top wall. In this case, a matte black paint is preferably employed as the heat resistant paint.

  According to the present invention, when the exhaust gas accompanying combustion of the burner passes through the smoke pipe, heat is exchanged with the water around the smoke pipe and the exhaust gas is exhausted to the exhaust chamber. When exhaust gas is exhausted to the upper surface side of the top wall forming a part of the exhaust chamber, it comes into contact with the top wall. At this time, the residual heat of the exhaust gas is accelerated by the heat exchange promoting portion, specifically, the top wall painted with matte black paint, and is efficiently exchanged with water in the can under the top wall. It will be. Therefore, according to the present invention, the hot water supply efficiency can be increased by more efficiently using the residual heat of the exhaust gas after passing through the smoke pipe.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a schematic configuration diagram of a water heater in the present embodiment. In this figure, a water heater 10 includes a can body 11 having a substantially cylindrical outer shape and forming a water containing space therein, a combustion chamber 12 provided on the bottom side of the can body 11, and the combustion chamber. 12 is disposed between the burner 13 arranged so as to form a flame from the side toward the side 12, the upper wall 12A of the combustion chamber 12 and the top wall 11A of the can body 11, and the lower end is in the combustion chamber 12. A plurality of smoke pipes 17 having upper ends opened to the exhaust chamber 16A of the silencer 16 disposed above the top wall 11A to form an exhaust gas passage, and disposed in these smoke pipes 17, A baffle 18 constituting a heat exchanger together with the can body 11 and the smoke pipe 17, and a water supply pipe 19 and a hot water supply pipe 20 provided on the outer peripheral wall portion of the can body 11 are configured.

  The baffle 18 is formed using a single elongated metal piece. The baffle 18 includes a main body piece 21 extending in a vertical direction within a substantially vertical plane, and a baffle plate that is continuous with the main body piece 21 and is alternately bent up and down in a direction substantially orthogonal to the surface of the main body piece 21. Thus, when the baffle 18 is arranged in the smoke pipe 17, the exhaust gas directed from the lower side to the upper side of the smoke pipe 17 flows along a substantially zigzag locus, and the exhaust gas in the smoke pipe 17 is The passage time is secured and heat exchange can be performed efficiently. In addition, the baffle 18 in this embodiment is accommodated in the smoke pipe 17 in the direction along the tangential direction of the virtual circle centering on the center of the can body 11 except for the central baffle 18.

  In the can 11, a coating surface P as a heat exchange promoting portion is provided on the upper surface side of the top wall 11 </ b> A, that is, the surface facing the exhaust chamber 16 </ b> A. The painted surface P is made of a matte heat-resistant black paint, and in this embodiment, a trade name “heat-resistant paint silicon resin paint heat-resistant temperature 600 ° C.” manufactured by Asahi Pen Co., Ltd. is adopted.

  In the above configuration, the high-temperature exhaust gas generated by the combustion of the burner 13 passes through the smoke pipe 17 and is discharged to the outside through the silencer 16. When the exhaust gas passes through the smoke pipe 17, it passes along a substantially zigzag locus due to the presence of the main body piece 21 and the baffle plate 22 connected thereto. Therefore, the exhaust gas does not flow linearly along the smoke pipe 17 but efficiently exchanges heat with the water around the smoke pipe 17 while ensuring a contact time with the inner wall surface of the smoke pipe 17.

  The exhaust gas that has passed through the smoke pipe 17 flows into the exhaust chamber 16A and comes into contact with the painted surface P. At this time, the painted surface P exhibits an endothermic effect as compared with the case where the coating is not performed, and therefore the water immediately below the top wall 12 is further heated by utilizing the residual heat of the exhaust gas in the exhaust chamber 16A. Will be exchanged.

  Therefore, according to such an embodiment, when performing heat exchange around the smoke pipe 17 and heat exchange from the top wall 12 surface, it is possible to promote an endothermic effect on the top wall 12 surface, It is possible to increase the efficiency of hot water supply compared to a conventional type hot water heater that is not coated.

  Below, in order to confirm the effect of this invention, Example 1 and the comparative example 1 in the case where the coating surface P is provided and the said coating surface P are not provided are shown.

[Example 1]
Water heater: Product name KG2-380VS, manufactured by Yamaha Living Tech
Fuel consumption 5 l / h
Hot water supply (flow rate) 17 l / h
Top wall painted surface: Asahi Pen Co., Ltd. [heat resistant paint silicon resin paint heat resistant temperature 600 ℃]
Coating method: Spray once coating Measuring instrument: “Precision flow meter model CFM-SO” manufactured by Tokyo Aviation Instruments Co., Ltd.

[Comparative Example 1]
Water heater: Product name KG2-380VS, manufactured by Yamaha Living Tech Co., Ltd.
Fuel consumption 5 l / h
Hot water supply (flow rate) 17 l / h
No top wall paint Measuring instrument: “Tokyo Air Meters Co., Ltd.“ Precision flow meter model CFM-SO ”

  The results when Example 1 and Comparative Example 1 were performed three times each are shown in Table 1 below.

As is apparent from Table 1, it is understood that the hot water supply apparatus of the present invention has a high hot water supply efficiency of about 0.8% on average. The continuous hot water supply efficiency is obtained by the following.
1) Continuous hot water supply output Adjust the amount of water flow so that the burner operates continuously with maximum fuel consumption when the difference between the hot water supply temperature and the water supply temperature is 35 ± 1 deg. Measure the flow rate of water flow when the difference between the hot water temperature and the hot water temperature is stable, and the difference between the hot water temperature and the hot water temperature.
Continuous hot water supply output = (T ₂ −T ₁ ) × Q × 4.186 / 1000 (MJ / h) (1)
Here, T ₁ : Water supply temperature (° C.) T ₂ : Hot water supply temperature (° C.) Q: Water flow rate (L / h)
2) Continuous hot water supply efficiency Calculated from the following equation from the fuel consumption (L / h) and the continuous hot water supply output.
Continuous hot water supply efficiency = continuous hot water supply output x 100 / (ν x 34.49) (%) (2)
Where ν: Fuel consumption (L / h) 34.49: Low calorific value per liter of kerosene (MJ / L)

The best configuration, method and the like for carrying out the present invention have been disclosed in the above description, but the present invention is not limited to this.
That is, the invention has been illustrated and described with particular reference to certain specific embodiments, but the embodiments described above are within the scope of the technical idea and scope of the invention. On the other hand, those skilled in the art can add various modifications.
Therefore, the configuration disclosed above is described as an example in order to facilitate understanding of the present invention, and does not limit the present invention.
For example, in the above-described embodiment, the heat exchange promoting portion is formed by painting the matte black paint on the top surface of the top wall of the can body. For example, even if a dark-colored paint other than black is used, the efficiency of hot water supply is increased. I can expect that.
Further, the painted surface P can be additionally provided on the inner peripheral surface of the smoke pipe 17 and the lower surface of the upper wall 12A of the combustion chamber 12.
Furthermore, it is also possible to provide an appropriate guide member or the like for causing the gas exhausted to the exhaust chamber 16A along the top wall 11A, so as to ensure a long contact time with the top wall and promote heat absorption by the top wall. is there.

  INDUSTRIAL APPLICABILITY The present invention can be mainly used as a water heater for a hot water supply system in a general household.

The schematic block diagram of the water heater based on this embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Hot water heater, 11 ... Can body (heat exchanger), 11A ... Top wall, 13 ... Burner, 16A ... Exhaust chamber, 17 ... Smoke tube (heat exchanger), 18 ... Baffle (heat exchanger), P ... Paint Surface (Heat Exchange Promotion Section)

Claims (3)

In a water heater provided with a heat exchanger arranged at the top of the burner and an exhaust chamber provided above the top wall of the heat exchanger,
The heat exchanger includes a can body, and a smoke pipe disposed in the can body and forming a passage for exhaust gas accompanying combustion of the burner to exchange heat with water in the can body,
2. A water heater according to claim 1, wherein a heat exchange promoting portion is formed on a top wall of a can forming a part of the exhaust chamber. The hot water heater according to claim 1, wherein the heat exchange promoting unit is configured by providing a heat-resistant paint coating surface on an upper surface side of the top wall. 3. The water heater according to claim 2, wherein the heat resistant paint is a matte black paint.

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