JPS5815805Y2 - Heat exchanger for gas instant water heater - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a heat exchanger for a gas instantaneous water heater.

Conventional Structure and Problems Conventionally, a heat exchanger for a gas instantaneous water heater was disclosed in Japanese Utility Model Publication No. 49-5974.

A conventional example is shown in FIG. 1 and will be described in detail below.

In this conventional example, while water is supplied from the water supply port 1 and hot water comes out to the hot water supply port 3, gas is burned in the combustion chamber 16 by the burner 14, and heat is exchanged between the drum part 4 and the fin part 2. The fin portion 2 is provided with a plurality of fins 5, and when combustion gas flows between the fin portion 2 and the fins 5, heat is exchanged by convection heat transfer.

Furthermore, when combustion occurs in the combustion chamber 16, the combustion gas contains CO2 plus 20 and force components, and when these become high-temperature gases, they emit radiant heat with a wavelength of λCO2 - λH20, and heat transfer to the fin portion 2 is caused by convection. Heat is transferred to the drum section 4 by radiation only.

In other words, since the combustion gas has a draft force, the fin portion 2
The principal component force flowing toward the drum part 4 is strong, and there is almost no component in the direction perpendicular to the drum part 4, so no convection effect occurs.

Therefore, if the amount of heat exchanged in the entire heat exchanger is 100%, about 15 of the heat is exchanged in the drum section 4, and the remaining 8
5% is heat exchanged in the fin section 2.

On the other hand, if we compare the weight ratios of the heat exchangers, they are about 50% each, and how we can receive a large amount of heat in the drum section 4 of the heat exchanger depends on whether we can reduce the cost of materials.

Purpose of the Invention The present invention is intended to improve the above-mentioned drawbacks of the conventional heat exchanger, and aims to reduce the cost by reducing the number of constituent materials of the heat exchanger.

Structure of the invention In order to achieve the above object, the present invention uses a plurality of plate-shaped fins with a circular cutout in the center of the lower surface in a heat exchanger for a gas instantaneous water heater, and exchanges heat with the sides of these fins. A drum part is formed to surround the chamber, a fin part is formed as a water pipe through which hot water passes through these fins, and a burner is placed in the combustion chamber formed by the notches of the plurality of fins. This heat exchanger for a gas instantaneous water heater has a structure in which a drum part and a fin part are integrated with a plurality of fin plates.

Description of examples An embodiment of the present invention will be described below with reference to the drawings.

The fin 13 has a top surface shape as shown in FIG.
A plurality of fins 13 having the bent side portions 18 are used.

Therefore, when the gas burned in the burner 15 and the combustion chamber 17 flows between the fins 13 and the fin pipe 8, convection heat transfer occurs.
Enable radiant heat transfer.

On the other hand, since radiant heat is transmitted in wavelengths, the waves within the fins 13 collide with the fins 13 many times and are attenuated, thereby achieving effective radiant heat transfer.

Since effective attenuation cannot be achieved with a mere flat surface, the drum portion 1 is formed by arranging a plurality of fins 13 arranged at regular intervals.
Convection within the heat exchanger 1 is caused by the effective arrangement of the fin pipes 8, so that the rising combustion gas is properly diffused, and the entire heat exchanger is If configured with 9, this effect can be greatly utilized,
The heat exchange distribution between the drum section 11 and the fin section 9 becomes uniform due to convection heat transfer.

Therefore, since the heat exchange characteristics per unit weight are improved, the raw material cost can be reduced by reducing the amount of raw materials.

For example, the combustion amount of a No. 5 map water heater is 9,600 kcal/
h and the thermal efficiency is 80 factors.

Therefore, the amount of heat received by the heat exchanger is 7680 kcal/h.

The content of this amount of heat received is shown in Figure 6.According to actual measurements, the amount of heat received by the drum section is 15% of the total amount of heat received, so 11
It is 52kcal/h.

The amount of heat received by the fin portion is 6228 kcal/h.

On the other hand, the material weight of the drum portion is 548 grams, and the material weight of the fin portion is 673 grams.

Therefore, the drum part has 2.1 kcal/h per unit weight.
Obtain the amount of heat received.

The fin portion receives a heat amount of 9.7 kcal/h per unit weight.

This difference in the amount of heat received per unit weight reduces the material cost when the drum section is eliminated and the heat exchanger is formed only with the fin section.

In other words, the amount of heat received per unit weight of the fin part is 9.7 kea
l/h, so the amount of heat received is 7680 kcal/h.
The weight of the fin part material to obtain h is 792 gm.

Therefore, the weight of a conventional heat exchanger having a drum part and a fin part is 1221 grams, whereas the weight of a heat exchanger formed with the fin part of the present invention is 792 grams.

Compared to conventional heat exchangers, material cost is 429 grams lower.

Effects of the Invention As mentioned above, the present invention uses a plurality of plate-shaped fins with a Yamabushi-shaped cutout in the center of the lower surface, and forms a drum part on the side of these fins to surround a heat exchange chamber. The heat per unit weight is It is possible to improve the exchange characteristics and reduce the cost, and because there is no difference in the amount of heat received per material weight between the drum part and the fin part as in the past, a uniform heat exchange distribution can be achieved. This has the effect of improving the durability of the heat exchanger against strain and the like.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional example, Fig. 2 is a schematic diagram of an embodiment of the present invention, Fig. 3 is a plan view of Fig. 2, Fig. 4 is a side view of Fig. 2, and Fig. 5 is a schematic diagram of an embodiment of the present invention. The figure is a top view of the fin used in one embodiment of the present invention, and FIG. 6 is an explanatory diagram showing the conventional heat exchange distribution ratio at each part. 9...Fin part, 11...Drum part, 13...Fin, 15...Burner,
17... Combustion chamber.

Claims (1)

[Scope of utility model registration request] A plurality of plate-shaped fins with a mountain-shaped notch at the center of the lower surface are used, and the sides of the fins form a drum part for surrounding the heat exchange chamber, and hot water passes through the fins to circulate. A burner is arranged in a combustion chamber formed by a cutout of the plurality of fins, and the drum part and the fin part are integrated by the plurality of fins, and the drum part is integrated with the fin part. A heat exchanger for gas instantaneous water heaters that penetrates a fin pipe.