JPS6152898B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to provide a thin heat exchanger with a large aspect ratio that can respond to the trend toward thinning in a heat exchanger in which the circulation inlet/outlet section forming the main body of an external bathtub is vertically up and down. Yes, (1) Excellent pot noise performance.

(2) Excellent thermal efficiency.

It is intended for such purposes.

In recent years, water heaters (including bathtubs) are moving from the traditional era of single-function bathtubs to the era of multifunctional water heaters and bathtubs. Furthermore, due to larger hot water supply and bath capacity and safety concerns, more and more equipment is being installed outdoors. On the other hand, there is a desire for equipment to save space. In other words, on the one hand, as water heaters and bathtubs become more complex, the size of the equipment increases and more installation space is required, while on the other hand, there is a desire for smaller and thinner equipment.

Heat exchangers for bathtubs play a central role in realizing space-saving composite equipment by making hot water heaters thinner, and below we will discuss their classification based on installation form and shape.

Bath pots can be roughly divided into outdoor type (CF or all-weather exhaust type) as shown in Figure 6 a, and type 7.
There is an indoor installation type (BF exhaust type) as shown in figure a. The relationship between this indoor/outdoor bathtub and the heat exchanger (particularly the circulation inlet/outlet section) will be described below.

(1) All heat exchangers used for outdoor installations have vertical circulation inlets and outlets. In addition, most of the shapes are close to rectangular as shown in FIG. 6b.

(2) Most heat exchangers used indoors have left and right upper and lower circulation inlets and outlets. Moreover, the shape is a thin type with a large aspect ratio, as shown in FIG. 7b.

As described above, there are no thin heat exchangers with a vertical circulation inlet/outlet and a large aspect ratio that are installed outdoors.

This is because, in the heat exchangers (1) and (2) above, the following challenges are faced in order to realize a thin heat exchanger with a vertical circulation inlet/outlet and a large aspect ratio that can be installed outdoors. .

(1) When the aspect ratio increases with respect to the vertical upper and lower circulation inlets and outlets, the flow of hot water tends to stagnate at both left and right ends in the heating width direction, which tends to cause partial boiling and deteriorates the kettle noise performance.

(2) As for the thermal efficiency, the flow rate of hot water tends to decrease gradually toward both the left and right ends in the heating width direction. Therefore, the amount of heat transferred between the center and both left and right ends tends to be uneven (the amount of heat transferred at both left and right ends is small).
Therefore, the total heat transfer amount decreases, and the thermal efficiency also tends to decrease. (However, this does not apply if the heat transfer area is increased, but the design becomes extremely uneconomical.) For the above reasons, it is recommended to use a thin heat exchanger with a vertical circulation inlet/outlet and a large aspect ratio in an external bathtub. In order to achieve this, it is not enough to simply design proportionally the conventional products from the viewpoints of ``kettle noise performance'' and ``thermal efficiency,'' and a great deal of ingenuity is required.

To this end, it is important to consider the following points.

(1) How to move the fluid flowing in from the circulation inlet to the heat exchange element in a low temperature state.

(2) How to move the fluid in the heat exchange collection section to the circulation outlet section.

(3) How to move the collected fluid at the circulation outlet to the bathtub.

(4) How to effectively utilize the heat radiation of combustion gas.

(5) To increase draft power without adversely affecting combustion performance (CO/CO ₂ %).

(6) The pitch (distance) of the circulation entrance and exit should be as small as possible to ensure ease of construction.

From the above, the present invention is an embodiment of the fin pipe heat transfer type as a heat exchange element,
By devising the above items and further devising the setting method of the heat exchange element and the circulation outlet, a thin heat exchanger with a vertically up-and-down circulation inlet and outlet and a large aspect ratio was realized.

The structure and function will be described below.

As shown in FIGS. 2 and 3, numeral 1 denotes a heat exchange element, which is composed of fin pipes 2 and fins 3, and a plurality of heat exchange elements are arranged in the heating width direction. The inlet section 4 of the heat exchange element 1 communicates with a heat exchange gathering section 6 having a circulation inlet section 5, and the inlet section 4 and the circulation inlet section 5 are set at opposing positions and at an upper position. Further, the outlet section 7 of the heat exchange element 1 communicates with a heat exchange gathering section 9 having a circulation outlet section 8, and the outlet section 7 and the circulation outlet section 8 are located on the same wall surface and set at the lower part.

Reference numeral 10 denotes water can portions located at both ends of the heat exchange gathering portions 6 and 9 in the heating width direction. This water can part 10 is located outside the heat exchange element 1 and is configured to abut on the plurality of fins 3 at the upper part. Furthermore, the water capacity of the water can part 10 is smaller in the lower part than in the upper part.

The above structure constitutes a heat exchanger, and the flow path circuit from the circulation inlet to the circulation outlet via the heat exchange element is arranged in series on a staircase.

In the above basic configuration, the heat exchanger collecting section 6 has a water can section 6' extending from the circulation inlet section 5 to a lower part.
It is said that Furthermore, the heat exchange gathering part 9 is also formed into a water can part 9' which extends below the position of the heat exchange element 1.

The water capacity of the extended water can part 9' is extremely small compared to the water capacity of the extended water can part 6'.

The extended water can portions 6', 9' and both end water can portions 10 constitute part or all of the combustion chamber 13.

Next, the top surface of the heat exchange gathering section 6 has no slope in the heating width direction, whereas the top surface of the heat exchange gathering section 9 has a slope of 1.
1 and 11', a slope is provided toward the circulation outlet section 8.

A plurality of burners 12 are provided.

In the above basic configuration, the heat exchange element 1 is sloped from the inlet 4 of the heat exchange assembly 6 to the outlet 7 of the heat exchange assembly 9 at an angle of 5 to 7 degrees. Furthermore, the circulation outlet section 8 is also sloped from the heat exchange gathering section 9 toward the bathtub (not shown).

For these angles, it is preferable that the pitch of the circulation inlet/outlet portions 8, 5 is as low as the value based on JIS (see Figure 4).
_B1 to _B3 dimensions) are set to fit within 100mm. The pitch (distance) between the circulation inlet section 5 and the circulation outlet section 8 is approximately equal to the distance between the burner 12 and the heat absorption fins 3 of the heat exchange element 1.

The flow and operation of hot water in the thin heat exchanger of the present invention, in which the circulation inlet and outlet sections are vertically vertical and have a large aspect ratio, will now be described.

The low-temperature hot water flowing in from the circulation inlet section 5 is distributed in the heating width direction within the heat exchange gathering section 6, and one side passes through the fin pipe section 2, which is the heat exchange element 1, and moves toward the circulation outlet section 8. The other low-temperature hot water passes through the water can portions 10 at both ends and moves toward the circulation outlet portion 8.

Due to heating by the burner 12, the low-temperature hot water flowing in from the inlet portion 4 of the heat exchange element 1 becomes high in temperature and moves to the heat exchange gathering portion 9 with a certain speed. Further, the water can portions at both ends also move toward the heat exchange gathering portion 9 with a certain speed.

At this time, the hot water near the outlet section 7 of the heat exchange element 1 becomes hotter than the temperature at the inlet section 4, and active convection occurs. The phenomenon is that small diameter bubbles are generated inside the fin pipe 2 of the heat exchange element 1 and convection occurs, but if the hot water becomes too hot, the amount of bubbles generated increases and the diameter becomes large. Then, due to the generation of bubbles and the bursting of the bubbles, convection becomes irregular and the hot water rapidly boils, so that the inner upper surface of the fin pipe 2 is filled with bubbles, and the hot water violently convects toward the heat exchange gathering part 9. Therefore, the low-temperature hot water flows into the inlet part 4 of the heat exchange element 1 via the circulation inlet part 5, and the bubbles disappear at once.
Accompanying this phenomenon is a rattling noise. Under this situation, the above phenomenon will normally be repeated at intervals of 5 to 8 seconds.

Therefore, as shown in FIG. 5, although the temperature of the hot water in the circulation inlet 5 rises with the heating time, at least the temperature of the hot water in the circulation inlet 5 remains the same at the inlet 4 of the heat exchange element 1.
The key is to move it to In this respect, if the circulation inlet/outlet is a horizontally elongated thin heat exchanger with a vertical up-and-down type and a large aspect ratio, a temperature difference is likely to occur between the center and both ends of the circulation inlet/outlet. In this respect, the present invention eliminates the above-mentioned drawback by making the water capacity of the heat exchange gathering section 6 on the side of the circulation inlet section 5 larger than that of the heat exchange gathering section 9.

Furthermore, a gradient is provided as a measure to increase the flow rate of hot water within the heat exchange element 1. This is to promote convection while generating bubbles as described above. In this case, the larger the slope, the better.
As shown in Fig. 4a, it is desirable that the pitch B of the circulation inlet/outlet part be as low as possible in accordance with JIS standards and in view of the installation of the bathtub, so as mentioned above, it is necessary to set the pitch B within 100 mm, which is a limitation. In addition, in order to set a large slope, the inlet section 4 of the heat exchange element 1 can be set downward, but due to the installation of the bathtub, the gap between the baseline and the circulation inlet section 4 (A ₁ to A ₃ dimensions) is Since it is desirable that the temperature be lower, the burner 12 and the heat exchange element 1 will be too close to each other (dimensions C ₁ to C ₃ in FIG. 4) as shown in FIG. 4c, leading to deterioration of combustion performance. Therefore, an appropriate angle is 5 to 7 degrees.

Next, as for the slope of the circulation outlet section 8, it is better to have a larger slope as described above. However, it is limited due to the above-mentioned dimensional restrictions. The angle is 2~
3 degrees is appropriate.

At this time, the slope of the heat exchange element 1 and the circulation outlet part 8
Concerning the gradient of , the rattling performance of the kettle improves when the former gradient is made larger. Therefore, under the above-mentioned size restrictions, the gradient distributed as in the embodiment is appropriate. By locating the inlet section 4 of the heat exchange element 1 at a higher position than the circulation inlet section 5, a sufficient distance between the burner 3 and the heat absorption fins 3 can be obtained, so that the draft force can be increased without adversely affecting combustion performance. can.

Furthermore, by making the B ₁ dimension and C ₁ dimension approximately equal as shown in FIG. 4a, it is possible to achieve both excellent combustion performance and workability without adversely affecting it.

In addition, the conditions for the circulation outlet section 8 of the heat exchange gathering section 9 are such that the convection at the center in the heating width direction becomes intense and obstructs the convection at both ends, making it easy for the above-mentioned partial boiling to occur near both ends. A slope is provided toward the circulation outlet section 8 in order to promote convection. This also serves to reduce the number of air bubbles near both ends.

As described above, by devising the heat exchange gathering parts 6 and 9, we have succeeded in realizing a heat exchanger in which the occurrence of the kettle noise phenomenon is reduced.

Next, let's talk about thermal efficiency.

By forming the combustion chamber section 13 with the heat exchange element 1, the extended water can section 6' of the heat exchange gathering section 6', the extended water can section 9' of the heat exchange gathering section 9, and the water can sections 10 at both ends, It is capable of absorbing high temperature gas radiation.

At this time, the water capacity of the extended water can part 9' is reduced to promote heat transfer, and the structure is such that the amount of heat transferred is added to that obtained by the upper heat exchange element 1.
Even in the case of 0, the lower water capacity is reduced in order to absorb high temperature gas radiation and promote heat transfer.

Regarding thermal efficiency, as the aspect ratio increases, the amount of heat transferred tends to be distributed between the center and both ends of the circulation inlet and outlet, and the amount of heat transferred at both ends is smaller than the center, so the total amount of heat transferred decreases and the thermal efficiency tends to decrease. However, by adopting the above structure as in the present invention, the amount of radiant heat transfer is increased, and a large amount of total heat transfer is obtained without reducing the amount of heat transfer at both ends, thereby improving thermal efficiency. Furthermore, as mentioned above, there are fewer stagnation areas in the convection of hot water and the flow velocity at the circulation inlet is faster, which leads to improved thermal efficiency.

Those that do not encourage ingenuity in Figure 5, those of the examples,
A typical example of the kettle noise performance chart is shown below, ignoring the dimensional regulations. The longer the heating time, the better the pot noise performance.

As described above, the flow path from the circulation inlet part to the circulation outlet part is a series circuit on a staircase, and the lower part of the heat exchange gathering part is an extended water can part, and water can parts are set at both ends. By making the slope between the element and the circulation outlet part larger for the heat exchange element than for the circulation outlet part, a horizontally elongated thin heat exchanger with a vertically up-and-down circulation inlet and outlet part has been realized, and the following effects can be obtained. It was done.

(1) In addition to increasing the water tank capacity of the heat exchange assembly section that has a circulation inlet, the heat exchange assembly section that has a circulation outlet has been designed to minimize the number of air bubbles and create a slope, thereby improving the kettle noise performance. I was able to figure it out. This made it possible to create a heat exchanger with a large aspect ratio.

(2) In the method of arranging the heat exchange element and the circulation outlet, by making the slope of the heat exchange element side larger than that of the circulation outlet, draft force is promoted (improves convection) and smooth melt flow is achieved. In this way, local boiling due to stagnation of hot water does not occur. This reduces the occurrence of hook noise.

The above (1) and (2) have made the installation management of the bathtub extremely simple.

(3) By setting the heat exchange collecting section as an extended water can section and setting its water capacity appropriately, a large amount of radiant heat transfer from the combustion gas could be absorbed, leading to improved thermal efficiency.

(4) By setting water cans at both ends and making the water capacity smaller at the bottom than at the top, it was possible to increase the amount of heat transferred at both ends, leading to improved thermal efficiency.

(5) Considering the appliance called a bath kettle, it is easy to increase the capacity by slightly changing the heat exchange element and the water cans at both ends, as in the present invention, and it is easy to adapt to series formation. .

A heat exchanger with the above-mentioned effects and extremely high practical value was realized.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of a heat exchanger showing an embodiment of the present invention, Fig. 2 is an external sketch of the same, Fig. 3 is a front sectional view of the main parts of the same, and Fig. 4 is a proposed embodiment of the same. Side views of a, b, and c, Figure 5 is the same kettle noise performance diagram as above, Figure 6 a is outdoor installation type (CF or all weather)
Figure 7a is an external sketch of the bath kettle used in the above, b is a diagram of the exterior of the heat exchanger used in the above, Figure 7 a is an external sketch of the indoor installation type (BF type) bath kettle, b is the heat exchanger used in the same. This is an external sketch. DESCRIPTION OF SYMBOLS 1...Heat exchange element, 2...Multiple fin pipes, 3...Multiple fins, 5...Circulation inlet part, 6...Heat exchange collecting part, 6'...Lower part of heat exchange collecting part Extension water can part, 8... Circulation outlet part, 9...
Heat exchange gathering part, 9'... Lower extension water can part of the heat exchange gathering part, 10... Water can parts at both ends, 11, 11'...
Slope part, 13... combustion chamber.

Claims (1)

[Claims] 1 A heat exchange body is constituted by a plurality of heat exchange gathering parts each having a heat exchange element and a circulation inlet/outlet and having an extended water can part at the bottom, and also forms all or part of a combustion chamber, and the heat exchanger element A thin bathtub in which the circulation outlet section is sloped in the flow direction of hot water, the slope of the heat exchange element is larger than that of the circulation outlet section, and the inlet section of the heat exchange element is arranged at a higher position than the circulation inlet section. Heat exchanger for pot.