JPS6130114Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a heat exchanger for water heaters such as gas water heaters, and includes a drum section located upstream of a fin block that forms a combustion chamber and performs heat exchange in that section. The purpose is to prevent local temperature rise, remove thermal stress, and make the drum easier to process.

The most common drum shape of a conventional heat exchanger for water heaters is that shown in FIG. That is, this drum consists of a fin block section 1 on which a fin block is placed, and a drum body section 2 around which a pipe 3 for water passage is wound. At this time, the water passage pipe 3 through which the water passes is, for example, a drum pipe band 4.
It is fixed to the drum main body part 2 by etc.
Further, in order to improve the close contact between the drum body 2 and the water pipe 3, rounded portions 5 are provided at the four corners of the drum body 2.

However, such a structure has the following drawbacks. That is, the shapes of the fin block portion 1 and the drum body portion 2 are different, and therefore a shoulder portion 6 is necessarily required between the two.
If there is such a shoulder portion 6, the high temperature combustion gas 8 generated by the burner 7 will come into direct contact with that portion, and the temperature will become extremely high, resulting in high temperature deterioration. A further drawback is that the necessity of providing such a shoulder portion 6 makes machining of the drum difficult. Furthermore, since the drum pipe 3 and the drum body part 2 are in contact at the R part 5, thermal stress is applied to the pipe 3 at this part due to temperature.
There were also cases where the pipes were separated from the flat surface of the drum body.

The present invention eliminates the above drawbacks and will be explained below with reference to the accompanying drawings. Fig. 2 shows an embodiment of the present invention, in which the drum 9 is made up of a single plate bent at 90 degrees at each of its four corners, and a pipe 10 for water passage is wound around the drum 9. It is attached. The pipe 10 has a bent portion 12 at an angular bent portion 11 of the drum 9 so as not to come into contact with the drum 9. Although the fin block is not shown,
It is designed to be inserted into the upper part 13 of the drum,
Its outer shape is similar to that of the drum 9.

As described above, in the heat exchanger of this embodiment, since the drum 9 is constructed in the same shape as the fin block, it can have a continuous shape (linear shape) from the upper end 15 to the lower end 14, unlike the conventional drum. The visible shoulder area has been removed, and the high-temperature combustion gas no longer comes into direct contact with the engine, and the high-temperature area is no longer present. Furthermore, since there is no shoulder in the drum 9, the shape is simple and processing becomes very easy.

Furthermore, since the pipe 10 wound around the drum is provided with a curved part 12 so that it does not come into contact with the drum 9 at the angular curved part 11 of the drum 9, thermal stress is applied to this part and the pipe 10 10 will be separated and the heat exchange efficiency will not decrease. A similar effect can be obtained, for example, by removing the angular curved portion 11 of the drum to provide a curved portion, as shown in FIG. It can also be obtained by providing a recess 13 so that the pipe part does not come into contact with the drum.

As described above, the heat exchanger for a water heater of the present invention has a drum that forms a combustion chamber and has a water pipe wound around its outer surface, and a fin block for heat exchange that have the same external shape. As a result, there is no shoulder on the drum, and as a result, the combustion gases do not come into direct contact with the drum, making the drum cooler, which also prevents thermal deterioration due to combustion gases or damage due to thermal stress. , durability can be increased and workability is also facilitated. In addition, the water pipe is shaped so that it does not come into contact with the drum at the curved portion of the drum, so even if thermal stress is applied to this portion, the thermal stress can be absorbed by this portion. There is no possibility that the water passage pipe will separate from the drum due to thermal stress and the heat exchange efficiency will decrease.

[Brief explanation of the drawing]

Figure 1a is a front view of a conventional water heater heat exchanger.
Fig. 1b is a sectional view taken along the line A-A' in Fig. 1, Figs. FIG. 4 is a plan view of main parts showing another embodiment of the drum portion. 9...Drum, 10...Pipe.

Claims (1)

[Scope of utility model registration request] It is equipped with a drum that forms a combustion chamber and has a water passage pipe wound around its outer surface, and a heat exchange fin block installed on the top of the drum.
A heat exchanger for a water heater, characterized in that the outer shape of the drum and the fin block are the same, and the pipe for water passage is shaped so that it does not come into contact with the drum at a curved portion of the drum.