JPS5844174B2 - bath kettle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bathtub heated by combustion gas from a kerosene or gas stove, which incorporates a water-gas heat exchanger having two independent thread paths on the water side.

Examples of the use of a heat exchanger that generally heats two independent water lines include household hot water heaters, hot water heaters, and bathtubs.

That is, by circulating water in two independent thread paths and heating it with combustion gas, for example, in the case of an air path, hot water for hot water and hot water for bathtubs are obtained and used for their respective purposes.

Such a heat exchanger having two independent water channels is
Water does not necessarily circulate in both at the same time, and at least one of the circulating water may be stationary.

In this case, if the two yarn paths are far apart, the water temperature in the stationary one will become extremely high, which will increase the pressure in the flow path and cause the water to boil, making proper operation impossible. Become.

Conventionally, a heat exchanger with two thread paths consists of two sets: a heat exchanger and burner unit for heating the water stored in the bathtub, and a heat exchanger and burner unit for heating the hot water. There is an independent two-circuit bath kettle.

Since this bathtub has two heat exchangers and two burner units inside, it has a drawback that the external dimensions are large and the cost is high.

To solve this drawback, there is a 1.2-circuit bathtub.

That is, since the rising hot water layer flow path and the rising hot water layer flow path are combined into one heat exchanger, only one burner unit is required, so that the external dimensions can be reduced and costs can be reduced.

Figures 1 and 2 show a specific example of a bathtub heat exchanger, with pipe pieces 1a and 1b having a U-shaped cross section.
are brazed to form a flow path 2 with a rectangular cross section, which forms six rows of flow paths 21, 22, 23°, 24, 25, 26, and both ends are connected to the mixing chambers 3 and 4. A pipe 5°6 is connected to the bathtub water inlet/outlet to form a boiling water flow path.

Furthermore, circular tubes 91, 92, 93, . 6...
Two U-shaped pipes 10 (not shown) are connected in series to form an upstream shower flow path.

However, in a heat exchanger with this type of structure, the wakashi hot water flow path and the rising hot water shower flow path are provided separately and heated by a common burner unit, so as mentioned above, one flow path is stationary. Then, the water in the flow path is always in a high-temperature boiling state, and the pressure in the flow path increases, making it impossible to operate properly.

In order to prevent such a situation, water is drained from the stationary flow path, or both flow paths are thermally connected with heat radiating fins.

In the former case, in addition to the heat exchanger, an attached equipment called a water drainage mechanism is required, and in the latter case, the stationary flow path is cooled by flowing water via heat radiation fins, which results in poor fin efficiency. The number of fins increases or the area of the fins increases, making the heat exchanger larger.

Further, even if a large number of fins are provided, cooling is not sufficient, and water is removed in this case as well.

Furthermore, since the pipe 1 of the boiling water layer has a rectangular shape, the manufacturing process is complicated and it is difficult to fit it closely with the fins.

In addition, the hot water pipe is inserted eccentrically into the boiling water pipe to form one arcuate contact surface, thereby forming two flow paths, the hot water flow path and the boiling water flow path, within the outer pipe. A bathtub using a double heat exchange pipe is also known.

However, because the inner tube of this type of heat exchange pipe is arranged eccentrically, it is difficult to position the outer tube and the inner tube, which inevitably results in poor adhesion at the part that forms the arcuate contact surface. It has manufacturing defects.

To compensate for this drawback, conventionally, after inserting the outer tube into the inner tube, one step of welding, such as brazing, was performed to further improve the adhesion between the inner and outer tubes. Although improvements have been made, the drawback is that the manufacturing process is complicated.

In order to solve the above-mentioned drawbacks, the present invention provides a plurality of heat exchange pipes each consisting of an inner tube inserted concentrically into a circular heat exchanger tube and forming at least two arcuate contact surfaces along the axial direction of the outer tube. By arranging them in an inclined manner and forming heat transfer channels in parallel to form a boiling water flow path, a bath kettle using a heat exchanger that is easy to manufacture and has high performance is provided.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 3 is a partially cutaway perspective view of a specific example of a heat exchanger applied to the present invention, and FIG. 4 is a cross-sectional view showing the main part of FIG. 3 horizontally cut along X-Y. It is.

That is, to explain the structure and function using an example of use as a heat exchanger for a bath, 100, 101, and 102 are heat transfer tubes inserted into a large number of plate-shaped heat radiation fins 103, and inside the heat transfer tubes ioo, io1, and 102, respectively. By partitioning the radial direction of the heat transfer tubes approximately in the center and arranging them concentrically, arcuate contact surfaces A and B are formed to form boiling water flow paths 104 and 10.
Inner tubes 106, 107, 108 having a diameter of 5 are inserted.

The ends of the inner tubes have a circular shape, and the inner tubes 106, 107, and 108 are connected in series by a circular U-shaped tube 109, and this yarn path is used as an ascending hot water flow path.

One end and the other end of the heat exchanger tubes 100, 101, 102 are connected in a row through mixing chambers 110, 111, respectively.

5 and 6 show an embodiment of the present invention, and a heat exchanger 501 in which the heat exchanger shown in FIG. Combustion chamber 51
A combustion device, that is, a burner 512 is provided at the bottom of the combustion chamber 511.

Furthermore, an exhaust duct 520 is connected to the upper part of the combustion chamber 511 and communicates with the outside of the main body 500.

The heat exchanger 501 is installed so that the heat exchanger tube is inclined from the horizontal in the longitudinal direction (angle of inclination θ = 10 to 30 degrees), so that the inlet side pipe 112 of the boiling water flow path, the mixing chamber 110, the outlet side pipe 113, and the mixing The water in the bathtub can be heated by increasing the height of the chamber 111 by 100 to 200 degrees in the vertical direction and circulating water by natural convection.

After the fuel flows from the gas population 530 to the governor 515
After being set at a constant pressure, the pressure is supplied to the switching cock 514.

Then, by twisting the switching lever 509, gas is supplied from the pilot nozzle 518 through the switching cock 514 and the pilot passage 519, and is ignited by an ignition device (not shown).

By detecting the heat of the pilot flame and switching the switching cock 514 with the switching lever 509, the shower hot water 5 is connected in parallel to the boiling water layer gas flow path 516 leading to the main burner 512 and the boiling water layer gas flow path 516. The main burner 51
The gas is passed through a main flow path provided with a shower hot water supply gas flow path 51γ that leads to the main flow path 51γ.

In addition, the shower hot water flowing in from the water inlet 531 passes through the automatic water pressure valve 513, passes through the shower hot water supply flow path 506, is connected to the inlet side pipe 112 of the heat exchanger inlet, and flows out of the bathtub from the heat exchanger outlet side pipe 113. The hot water is taken out and supplied to the shower 507.

Next, the operation of the heat exchanger of the present invention will be explained.

That is, during boiling water operation, water flows through the boiling water flow path (outer pipe) 104 and 105, and when water flow through the upstream shower flow path (inner pipe) 114 is stopped, the temperature of the still water is the same as that of the boiling water flow. Road 104,
It is constantly lower than the water temperature at 105.

On the other hand, in upstream hot water operation, when the boiling water channel (outer pipe) is empty and does not contain water, the inner pipes 106, 107° 108 are brought into contact with a portion of the outer pipes 100, 101, 102,
6, 107, 108 with water flowing through the outer pipes 100, 101,
In order to cool the outer tube 102, the temperature of the outer tubes 100, 101, and 102 is at most 150°C.

At this temperature, there is no danger that the material (deoxidized copper) of the radiation fins 103 and the outer tube will be oxidized or corroded, resulting in a shortened lifespan (sufficiently safe).

Furthermore, in upstream hot water operation, if there is water in the boiling water flow path, a portion of the heat transferred from the combustion gas via the heat radiation fins 103 passes through the outer pipe 100° 10L 102 pipe wall to the outer pipe water. The remaining water will be transmitted to the inner pipe water through the contact parts A and B of the inner and outer pipes, but in the present invention, the outer pipe flow paths 104 and 105 are made into parallel flow paths and the inner pipe flow path 114 is made into a series flow path. If the flow rate of the inner pipe water is made larger than that of the outer pipe water, the thermal resistance of the inner pipe water and the thermal resistance of the outer pipe water will be much smaller than the latter, so that the thermal resistance will be transferred to the outer pipe water. It is possible to reduce the amount of heat.

In the present invention, if a part of the inner tube and outer tube are brought into contact and the contact thermal resistance is about 1Xl0-3h℃/Kcal and the hot water is operated for 15 minutes, the total heat exchange amount is 10,000 Kcal as shown in Figure 7.
If it is less than 1 2 /h, the proportion of heat transferred to the heat transfer tube water can be sufficiently reduced, and the rise in water temperature in the bathtub can be suppressed to about 1.5° C. or less, which is sufficiently safe for practical use.

Furthermore, the heat exchanger tubes and the heat radiation fins are cooled by the outer tube water, and therefore have a sufficiently low temperature.

In addition, Figure 7 shows a bathtub water volume of 0.2 m” with 3 pipes, 1=
The characteristics are when the outer tube is 300 mvt, the inner tube is 30 mvt, and the outer tube is 23 = 23 mm.The inner tube is 30 mm.

As explained above, according to the heat exchanger according to the present invention, sufficient and safe thermal performance can be obtained by using the pipes inserted into the circular tube in a radially divided manner. Since the outer tube is circular, it has a good density with the heat dissipation fins, and the area of the heat dissipation fins is only needed for one unit, reducing costs. Also, since the heat transfer tube and the inner tube are arranged concentrically, manufacturing is easy. The special brazing method used to improve the adhesion between the heat exchanger tube and the inner tube has the advantage that it does not require any process and is highly productive, making it suitable for mass production.

Furthermore, tilting the heat exchanger in the longitudinal direction makes it easier to drain the water in the heat exchanger when the operation is stopped than with conventional heat exchangers, and the amount of water remaining in the heat exchanger is small (this reduces freezing and prevents freezing). It has an advantageous configuration.

Furthermore, since the water capacity in the heat exchanger is small, there is an advantage that the start-up time at startup is short.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway perspective view of a conventional bath heat exchanger, Fig. 2 is a vertical sectional view of the main part of Fig. 1, and Fig. 3 is a heat exchanger used in the present invention. FIG. 4 is a longitudinal cross-sectional view of the main part of FIG. 3, FIG. 5 is a schematic diagram showing an embodiment of the present invention, and FIG. FIG. 7, a side view taken along the line A-B, is a characteristic diagram showing the temperature rise of bathtub water with respect to changes in the amount of heat according to the present invention. In addition, 100, 101.102 are outer tubes, 103 is a heat radiation fin, 104, 105 is an outer tube flow path, 106° 107.10
8 is the inner pipe, 109 is the U-shaped pipe, 110° 111 is the mixing chamber,
112 and 113 are pipes, and 114 is an inner pipe flow path.

Claims (1)

[Claims] 1 comprises a combustion device and a heat exchanger disposed obliquely in the longitudinal direction on the upper part of the combustion device, the heat exchanger has a plurality of heat exchanger tubes arranged in parallel, and a heat exchanger arranged on the outer circumferential surface of each heat exchanger tube. The heat dissipation fin has at least two channels formed by an inner tube inserted concentrically into the tube and forming at least two arcuate contact surfaces along the axial direction of the heat transfer tube, and This bath kettle is characterized in that both ends of the heat pipes are connected to respective mixing chambers and are connected in parallel to the bathtub as a boiling water flow path, and inner pipes are connected in series to form an upstream hot water flow path.