JPH07234016A - Hot water storage type warm water machine - Google Patents

Abstract

PURPOSE:To provide a hot water storage type warm water machine having a heat insulation structure which can be reduced in size. CONSTITUTION:The hot water storage type warm water machine comprises a hot water storage tank 1, a peripheral sheath 10B, an upper sheath 11B and a lower sheath 12B covering the tank 1, a peripheral heat shielding plate 13, and an upper heat shielding plate 14 and a lower heat shielding plate 15 provided between the tank 1 and the sheaths 10B, 11B, 12B, wherein intervals between the tank 1 and the plates 13, 14, 15 and the sheaths 10B, 11B, 12B are 10mm or less. Thus, air convection does not almost occur between the tank 1 and the sheaths 10B, 11B, 12B, thereby obtaining the machine having a small size and excellent heat insulation performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a heat retaining structure of a hot water storage type water heater.

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing a conventional hot water storage type electric water heater. In the figure, 1 is a hot water storage tank made of stainless steel, 2 is an electric heater, 3 is a water supply port, 4 is a hot water supply port, 5 is a tank leg, 6 is a controller, 7 is a heat insulating material (surrounding) made of glass wool material, and 8 is Thermal insulation (top), 9 thermal insulation (bottom), 10A exterior (peripheral), 11A exterior (top),
12A is an exterior (lower).

Next, the operation will be described. Tap water is supplied from the water supply port 3 to the hot water storage tank 1, and the controller 6
The hot water temperature setting is further received, and the electric heater 2 heats the hot water until the predetermined hot water temperature is obtained by using the late night electric power which is cheaper than the daytime electric power. When the temperature of the hot water reaches a predetermined value (about 60 to 90 degrees depending on the season), energization of the electric heater 2 is completed. Usually, hot water is boiled in the morning, and thereafter, it is kept warm by heat insulating materials 7, 8 and 9 made of glass wool so that the hot water does not cool.

[0004]

Since the conventional hot water storage type electric water heater is configured as described above, the main body cannot be downsized by the thickness of the heat insulating material of about 50 mm. Further, when the glass wool as the heat insulating material is attached to the main body, dust of the glass wool flies into the atmosphere and adheres to the skin of the worker to cause discomfort, which is not preferable in the working environment.

Here, as a method for obtaining a heat shield effect without using a heat insulating material made of glass wool, for example, Japanese Patent Laid-Open No. 53-53
-67156 and Japanese Patent Publication No. 4-34890,
There is disclosed a method of reducing the convection of air to obtain a heat shielding effect by making the thickness of the air layer less than the convection generation limit. However, Japanese Patent Application Laid-Open No. 53-67156 discloses the structure of a metal heat insulating material.
No. 90 discloses an adiabatic structure of an electronically controlled cooker, and neither of them is applied to a hot water storage type water heater that keeps hot water. Therefore, the structure cannot be directly used for a hot water storage type water heater which is relatively large and has pipes and the like around the hot water storage tank.

The present invention has been made in order to solve the above problems, and an object thereof is to obtain a hot water storage type hot water heater having a heat retaining structure which can be downsized.

[0007]

A first aspect of the present invention includes a tank for storing hot water, an exterior covering the tank, and a heat shield plate provided between the tank and the exterior. It is characterized in that the distance from the exterior is 10 mm or less.

A second aspect of the invention is to provide a plurality of heat shield plates at intervals of 10 mm or less.

A third aspect of the present invention is a hot water storage type water heater including a tank for storing hot water and an exterior covering the tank, wherein the distance between the exterior and the tank is 10 mm or less.

A fourth invention is a tank for storing hot water, an exterior covering the tank, a heat shield provided between the tank and the exterior, a gap between the tank and the heat shield, or a heat shield and the exterior. And a partition plate for partitioning at least one of the gaps between and in a direction intersecting with the heat shield plate.

A fifth aspect of the invention is provided with a tank for storing hot water, an exterior for covering the tank, and a partition plate for partitioning a space between the tank and the exterior in a direction intersecting with the tank.

According to a sixth aspect of the present invention, a partition plate for partitioning a space between the exterior and the tank is extended from the exterior so as not to contact the tank.

A seventh aspect of the invention comprises a tank for storing hot water and an exterior covering the tank, a heat insulating material is provided between the tank and the exterior, and no heat insulating material is provided between the tank and the exterior. The side gap is 10 mm or less.

An eighth aspect of the present invention is provided with a tank for storing hot water and an exterior covering the tank.
A heat insulating material is provided in the gap between the tank and the exterior below the tank, and a heat shield plate is provided in the gap between the tank and the exterior so that the gap between the tank and the exterior is 10 mm or less.

According to a ninth aspect of the present invention, a tank for storing hot water, an exterior covering the tank, a heat shield plate provided between the tank and the exterior, and a reinforcing ring for preventing negative pressure provided around the tank. And the gap between the heat shield plate and the exterior is 10 mm or less.

[0016]

In the hot water storage water heater according to the first aspect of the present invention, a heat shield for suppressing radiation is provided between the tank and the exterior, and the space between the tank, the heat shield and the exterior is 10 mm or less. Therefore, natural convection, which is a factor of radiating the heat of the tank to the exterior, can be suppressed, so that the heat retention performance is further improved and the body can be downsized.

In the second aspect of the present invention, the heat insulating plate for suppressing radiation is provided in plural at intervals of 10 mm or less for suppressing natural convection, so that the heat retaining performance can be further improved.

In the third aspect of the invention, since the space between the tank and the exterior is 10 mm or less, natural convection between the tank and the exterior can be suppressed, and the heat insulation effect can be maintained while the size is reduced and the cost is reduced. You can

In the fourth aspect of the present invention, a heat shield plate for suppressing radiation is provided between the tank and the exterior, and a partition plate is provided in the gap, whereby the space can be subdivided and convection is less likely to occur. , While suppressing the heat dissipation from the tank to the exterior while achieving miniaturization, heat retention performance is improved.

In the fifth aspect of the invention, since the partition plate is provided between the tank and the exterior to partition the space in the direction intersecting with the tank, natural convection in the space between the tank and the exterior can be prevented, and the heat insulation can be maintained. Performance can be improved and miniaturization can be achieved.

Further, in the sixth aspect of the invention, since the partition plate extended from the exterior is not in contact with the tank, it is possible to prevent the heat of the tank from being directly radiated to the outside, so that the heat insulating performance can be prevented. Is further improved.

In the seventh aspect of the present invention, the heat insulating function is provided by the heat insulating function of the heat insulating material provided between the tank and the exterior and the synergistic effect of the natural gap not occurring when the gap between the tank and the exterior is 10 mm or less. Further improve.

In the eighth aspect of the invention, since the heat insulating material is provided in the gap between the outer casing below the tank, the shape of the heat shield plate is not complicated due to the pipes and the like below the tank. The heat insulation performance is improved by providing a heat insulation material below the tank where there is room in the target space.

In the ninth aspect of the invention, since the reinforcing ring for preventing negative pressure maintains the predetermined distance, the reinforcing ring itself forms a space so as to prevent natural convection between the tank and the heat shield. Since it is subdivided and has a thickness of 10 mm or less to prevent natural convection between the heat shield plate and the exterior, which is the outside thereof, the heat retaining function works reliably, and the heat retaining performance can be improved and the size can be reduced.

[0025]

【Example】

Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view of a hot water storage type electric water heater showing a heat retaining method according to an embodiment of the present invention. In the figure, 1-6
Is the same as the conventional example. 10B is a peripheral exterior that surrounds the periphery of the tank 1, 11B is an upper exterior that covers the top of the tank 1, 12B is a lower exterior that covers the bottom of the tank 1,
The entire tank 1 is covered with a peripheral exterior 10B, an upper exterior 11B, and a lower exterior 12B. Further, 13 is provided between the tank 1 and the surrounding exterior 10B and surrounds the periphery of the tank 1, and 14 is provided between the tank 1 and the upper exterior 11B to cover the upper portion of the tank 1. The heat shield plate 15 is a lower heat shield plate that is provided between the tank 1 and the lower exterior 12B and covers the bottom of the tank 1, and is made of an inexpensive galvanized iron plate. Reference numeral 16 is a heat insulating packing that determines the distance between the tank 1 and the upper heat shield plate 14.

Next, the operation of the present invention will be described. It is the same as the conventional example until the boiling water is boiled, so the description is omitted.
The heat retaining function will be described. Tank 1 and surrounding heat shield 13
The space a1 between the air layer and the surrounding heat shield plate 1
Most of the distance a2 between the outer sheath 3 and the surrounding exterior 10B is 10 mm or less, and the distance a between the tank 1 and the upper heat shield plate a
3, the distance a4 between the upper heat shield plate 14 and the upper outer cover 11B, the distance a5 between the tank 1 and the lower heat shield plate 15, and the distance a6 between the lower heat shield plate 15 and the upper outer cover 12B are also 10 mm or less. . These intervals a1 to a6 hardly cause natural convection of air, which is a fluid therebetween, for the reason described later.

Here, since the shape of the tank is curved as shown in the figure, the space between the upper part and the lower part of the tank 1 is 10
mm or more, and some natural convection occurs. But,
Even if the distance is 10 mm or more, the distance is the same, and since the vertical direction is the short distance, the convection of air due to the rise of heat is hard to occur, and the lateral circumference of the tank 1 is long in the vertical direction. Since the gap is almost 10 mm or less, it does not affect the heat retention effect.

The thermal conductivity of air is 0.02 kcal / mh.
° C, the heat flow is suppressed at a value less than any solid. Therefore, the three elements of heat dissipation from the hot water tank,
Of conduction, radiation, and convection, conduction and convection are similar to glass wool, and only radiation is a problem. However, since a heat shield is used, radiation is blocked here, and the distance between the heat shield and the exterior is also within a close distance of 10 mm or less, so natural convection is suppressed and the surrounding, upper, and lower sides are suppressed. Each exterior 10B,
Almost no heat is transferred to 11B and 12B.

The reason why the above intervals a1 to a6 are set to 10 mm or less is as follows. That is, the Rayleigh number is used for free convection generated by heating a horizontal fluid layer from below, but it is well known that convection does not occur below a certain critical value. For example, according to the data described in the Heat Transfer Engineering Material Revision 3rd Edition of the Japan Society of Mechanical Engineers shown in FIG. 2, theoretically, if the Rayleigh number _Ra is 10 ³ or less, no convection occurs, and in reality, 1708. It has been experimentally confirmed that convection hardly occurs if it is below. Here, the Rayleigh number is expressed as the following equation. R _a = gβΔtD ³ / aν In the above equation, g is the acceleration of gravity, β is the coefficient of body expansion of air, Δt is the temperature difference between the upper and lower surfaces of the air layer, D is the distance between both surfaces, and a is the air layer. Is the thermal conductivity, and ν is the kinematic viscosity coefficient of air.

In the above equation, D is 0.01 m or less in order to reduce R _a to 1708 or less. It is preferable to set D to 0.008 m or less so that R _a is 1000 or less, but in the hot water storage water heater to which the present invention is applied, 0.01
The present inventors experimentally confirmed that there is no problem if m or less, that is, 10 mm or less.

If the heat shield plates 13, 14 and 15 are made of a galvanized steel sheet having an emissivity ε of about 0.2 and a stainless steel sheet having an ε of about 0.1 is used, the hot water tank 1 of the hot water tank 1 is replaced. The temperature drop is further improved (several 10%).
This is for the following reason. The amount of radiant heat transfer when reflection occurs between the radiating surfaces is expressed by the following equation. (Heat Transfer Engineering Exercise (Gakudonsha))

[0032]

[Equation 1]

In the above equation, ε ₁ is the emissivity of the tank (0.1), ε ₂ is the emissivity of the heat shield plate (about 0.2 for galvanized steel plate, about 0.1 for stainless steel plate), S ₁
Is the tank surface area, T ₁ is the tank temperature, and T ₂ is the heat shield plate temperature. According to this formula, the radiation dose of galvanized steel sheet is
It is 1.36 times the emissivity of stainless steel plate.

As described above, according to the configuration of the first embodiment, the heat radiation from the tank 1 is prevented, but the space between the tank 1, the heat shield plates 13, 14, 15 and the outer casings 10, 11, 12 is further increased. Since each is set to a close distance of 10 mm or less,
The main body can be downsized while maintaining heat retention performance.

Example 2. Next, a second embodiment of the present invention will be described. 2, parts that are the same as or correspond to those in FIG. 1 are given the same reference numerals, and descriptions thereof will be omitted. In the figure, reference numeral 17 denotes a heat shield plate added between the tank 1 and the heat shield plate 13. The tank 1, the heat shield plate 17, and the heat shield plate 1
7 and the heat shield plate 13, and the space between the heat shield plate 13 and the surrounding exterior 10B was also set to a close distance of 10 mm or less. Tank 1
Radiation from the tank 1 is achieved by adding the heat shield plate 17 to the periphery of the upper part, the side part, and the lower part, which has the widest area and the heat most easily escapes to the outside by radiation or convection. It is possible to shut off more reliably than in Example 1, and the heat retention performance is improved.

In Examples 1 and 2 above, the tank 1
Heat shield plates 13 to 15 and 17 for the upper, surrounding and lower parts of
However, due to the large surface area, it is easy to radiate heat in the peripheral portion of the cylindrical tank 1. Also, in a vertical type tank, natural convection causes a large amount of heat to move vertically. In the first and second embodiments, at least the tank 1 is provided because it is the peripheral portion of the tank 1.
A sufficient heat-retaining effect can be obtained by enclosing most of the periphery of the heat shield plates 13 and 17 and setting the gap distance to 10 mm or less.

At this time, the upper part of the tank 1 and the upper exterior 11B,
The space between the lower part of the tank 1 and the lower exterior 12B is 10 m.
It goes without saying that if the thickness is m or less, the heat retaining effect is better.

In the first and second embodiments, since the upper heat shield plate 14 and the lower heat shield plate 15 are flat plates, the distance from the tank 1 is 1 although the effect on the heat retention is small.
There was a part that became 0 mm or more, but this upper and lower heat shield plate 1
If the shapes of 4 and 15 are close to the curved shape of the tank 1 and the distance between the gaps is 10 mm or less in all parts, the heat retaining effect can be made more reliable.

Further, auxiliary members are provided inside the upper and lower heat shield plates 14 and 15, and the upper and lower heat shield plates 14 including the auxiliary members are provided.
By setting the shape inside 15 to be a shape close to the curved shape of the tank 1, the gap between the tank 1 and the upper and lower heat shield plates 14 and 15 may be adjusted to 10 mm or less. In that case, the auxiliary member has a function of reinforcing the upper and lower heat shield plates 14 and 15. Further, since the upper and lower heat shield plates 14 and 15 are made thicker by providing the auxiliary member, the heat insulating effect is also improved.

Example 3. In each of Examples 1 and 2, a heat shield plate is provided to prevent heat radiation and to prevent air convection. However, the heat shield plate is not used and the distance between the tank and the exterior is 10 mm or less. The warming effect can be obtained only by setting the distance to be close to and preventing convection of air. The third embodiment will be described with reference to FIG. In FIG.
The same or corresponding parts are designated by the same reference numerals, and the description thereof will be omitted. In the third embodiment, the spacing c1 between the periphery of the tank 1 and the surrounding exterior 10B, the spacing c2 between the upper portion of the tank 1 and the upper exterior 11B, and the spacing c3 between the lower portion of the tank 1 and the lower exterior 12B are set to 10 mm or less, respectively.

In the third embodiment, the tank 1 and the exterior 10
The space between B, 11B, and 12B is 10 mm or less to prevent convection, which has a heat retaining effect, and has a small capacity tank, a hot water storage water heater with a short hot water use cycle, a hot water storage water heater with a low set temperature, etc. Has a sufficient heat retention effect.
Further, since there is no heat shield plate, it can be made more compact, and the cost of the heat shield plate is less expensive, so that an inexpensive hot water storage type water heater can be obtained.

Also in FIG. 3, since the outer shapes of the upper and lower parts of the tank 1 are curved, the gap between the tank 1 and the exterior is not less than 10 mm in all parts, but 10 mm. A close distance is close to, and at least in most of the periphery of the tank 1 having a large surface area and where natural convection is likely to occur, if the gap interval is 10 mm or less, a sufficient heat retaining effect can be obtained.

Here, the upper exterior 11B and the lower exterior 12 are further added.
If the shape of B is not a flat plate shape as shown in FIG. 3 but a shape close to the curved shape of the tank 1 and the gaps are set to 10 mm or less in all parts, the heat retaining effect can be further ensured.

Further, an auxiliary member is provided inside the upper outer package 11B and the lower outer package 12B, and the outer package 11 including the auxiliary member is provided.
The shape of the inside of B and 12B may be a shape close to the outer shape of the tank 1, and the gap may be adjusted to be 10 mm or less. In this case, the auxiliary member also has a reinforcing effect.

Example 4. In each of the above-mentioned Examples 1 to 3,
Natural air convection was prevented by setting the distance of the air layer in the air gap formed with the exterior wall or the heat shield plate that surrounds the tank to 10 mm or less. FIG. 4 shows the fourth embodiment in which the occurrence of
Will be explained. 4, the same or corresponding portions as those in FIG. 1 are designated by the same reference numerals, and the description of those portions will be omitted.

In FIG. 4, the heat shield plates 14, 15, 18 are shown.
Is arranged between the hot water tank 1 and the exteriors 10B, 11B, 12B, and a plurality of partition plates 19, 20 are horizontally arranged from the heat shield plate 18 toward the hot water tank 1 side and the surrounding exterior 10B side. It extends to the vicinity of the exterior 10B. The partition plates 19 and 20 prevent natural convection from propagating to other parts. Therefore, since it is not necessary to consider the distance between the heat shield plate 18, the hot water tank 1, and the surrounding exterior 10B, the assembly can be performed very easily, and natural convection can be surely suppressed to improve the heat retention performance. Moreover, the size of the main body can be made smaller than that using the conventional heat insulating material of glass wool. Further, if the partition plates 19 and 20 are dimensioned so as not to contact the hot water tank 1 and the surrounding exterior 10B as shown in FIG. 4, the heat of the tank 1 will not be dissipated from the surrounding exterior 10B through the partition plates 19 and 20. Therefore, the heat retention performance is also good.

Further, in the fourth embodiment, the space between the upper part of the tank 1 and the upper heat shield plate 14 and the upper outer package 11B, and the space between the lower part of the tank 1, the lower heat shield plate 15 and the lower outer package 12B are set. If the thickness is 10 mm or less as in Example 1, the heat retention effect is improved.

Further, if the gap between the heat shield plate 18 having the partition plates 19 and 20 of Example 4 and the tank 1 and the surrounding exterior 10B is set to 10 mm or less, the heat retaining effect of Example 1 or more can be obtained. To be

Even when the upper heat shield plate 14 and the lower heat shield plate 15 are not provided, at least most of the periphery of the tank 1 is surrounded by the heat shield plate 18 having the partition plates 19 and 20 to prevent heat transfer. By preventing the occurrence of natural convection around the most frequent tank 1, a heat retaining effect can be obtained.

Further, in FIG. 4, partition plates 19 and 2 are provided.
Although 0 is provided on the heat shield plate 18, the partition plate 19 may be provided on the tank 1 side, and the partition plate 20 is the peripheral exterior 10B.
May be provided.

In FIG. 4, partition plates 19 and 20 are provided on both sides of the heat shield plate 18. However, the heat shield plate 18 is provided with a partition plate on either side, and no partition plate is provided. The space between the sides may be set to 10 mm or less to prevent natural convection by different methods on one surface and the other surface of the heat shield plate. Depending on the shape of the tank, it may be easier to manufacture the combination of providing the partition plate and setting the interval to 10 mm or less.

Example 5. In Example 4, the heat shield plate 1
Although the partition plates 19 and 20 are provided in FIG. 8, natural convection can be prevented by providing a partition plate in either the tank 1 or the exterior 10B without using the heat shield plate 18. The fifth embodiment will be described with reference to FIG. 5, parts that are the same as or correspond to those in FIG. 4 are given the same reference numerals,
Description of that part is omitted.

In FIG. 5, unlike FIG. 4, there is no heat shield plate, and a partition plate 22A extends horizontally from the surrounding exterior 21 to the hot water tank 1 side. Although this does not prevent heat loss due to radiation from the surroundings of the heat shield plate, the partition plate 22A
As a result, natural convection is reliably prevented, and heat is suppressed from propagating from the tank 1 to the outside due to natural convection.

Therefore, in the fifth embodiment, as in the third embodiment having no surrounding heat shield, a tank having a small capacity, a hot water storage type water heater having a short hot water use cycle, a hot water storage type water heater having a low set temperature, etc. In addition, a sufficient heat retaining effect can be obtained.
Furthermore, since there is no heat shield plate, it is possible to make the apparatus more compact than that of the fourth embodiment and lower the cost of materials and the cost of assembly, and there is an advantage that an inexpensive device can be provided.

Example 6. In the fifth embodiment, the partition plate 22A provided on the peripheral exterior 21 is in contact with the tank 1 to prevent heat loss due to natural convection between the tank 1 and the peripheral exterior 21. Partition plate 2
The structure is such that it is transmitted to the surrounding exterior by heat conduction or the like via 2A. A sixth embodiment in which this point is improved will be described with reference to FIG.

In FIG. 6, a partition plate 22B is provided inside the peripheral exterior 21, and the tank 1 of the partition plate 22B is provided.
The outer peripheral surface side is spaced apart by a small distance 23 of 2 to 3 mm so as to face the outer peripheral surface of the tank 1 so that the tank 1 and the partition plate 22B do not come into direct contact with each other. Therefore, the heat of the tank 1 is surely prevented from being transmitted through the partition plate 22B to be dissipated from the exterior 21 by heat conduction, and the heat retention performance is improved.

In FIG. 6, the partition plate 22B is provided on the inner side of the peripheral exterior 21.
By welding, welding, or integrally molding, the tank 1
It may be provided outside. However, it is easier to manufacture the partition plate 22 </ b> B provided on the peripheral exterior 21 as shown in FIG. 6 than the tank 1 side.

Example 7. As is apparent from the bottom part of the tank 1 of the conventional hot water storage type electric water heater shown in FIG. 9, the water supply port 3 extending from the lower part of the tank 1 is shown in the bottom part.
And a tank foot 5 for supporting the tank 1 from below are provided and have a complicated structure. In Examples 1 to 6 as shown in FIGS. 1 to 6, lower heat shields provided below the tank 1 It was necessary to make the plate 15 into a very complicated shape in order to avoid the water inlet 3, the tank foot 5, and the like. Further, since the bottom portion is provided with the water supply port 3 and the like, a certain amount of space is required.

Further, as described in Examples 1 to 6, in the hot water storage type electric water heater, it is most necessary to prevent heat radiation between the tank 1 and the surrounding exterior 10B or 21. In the embodiment, the gap interval is 10 m
Natural convection is prevented by setting the height to m or less and providing a partition plate.

Therefore, as a seventh embodiment, a hot water storage type electric water heater in which a heat insulating material is provided at the bottom portion of the tank 1 without changing the structure for preventing heat radiation around the tank 1 will be described. In FIG. 7, in the hot water storage type electric water heater of the first embodiment, a heat insulating material is provided at the bottom portion. Here, parts that are the same as or correspond to those in FIG. 1 are assigned the same reference numerals, and descriptions of those parts will be omitted. In FIG. 7, there is no heat shield below the tank 1, and a heat insulating material 24 is provided. The heat insulating material 24 is a deformable heat insulating material, such as glass wool, which can be re-moved after assembly, a heat insulating material that hardens after foaming such as foam material, a heat insulating material that solidifies from a fluid after pouring, a granular material. Is placed around the water supply port 3 and the like, and includes a heat insulating material that is hardened by heat fusion.

According to the seventh embodiment, it is possible to save the trouble of complicating the shape of the heat shield plate in order to avoid the water supply port 3 and the controller 6 located in the lower part of the hot water tank 1. Further, since there is a large space between the lower exterior 12B of the lower part of the tank 1 and the like due to the water supply port 3 and the like, the heat insulating performance is improved by using the heat insulating material. Further, since the heat shield plates 13 and 14 are provided around and above the tank 1 so that the distance between the tank 1 and the exteriors 10B and 11B is 10 mm or less, the water heater main body is miniaturized. It should be noted that the use of the heat insulating material causes some operational problems, but since the size of the heat insulating material is much smaller than that of the conventional example, this problem can be mitigated. As a result, the shape can be more easily introduced into mass production.

In FIG. 7, a deformable heat insulating material is provided below the tank 1 of the first embodiment, but other embodiments 2 to
Also in the case of No. 6, if the heat insulating material as shown in FIG. 7 is used below the tank 1, the same effect can be obtained.

Although the heat insulating material 24 is used in the lower space of the tank 1 in FIG. 7, the heat insulating material may be provided in the upper space of the tank 1 of the first to sixth embodiments. Well, in this case, the heat of the warm air flowing upward due to the convection of air is more effectively prevented from being radiated to the outside.

Furthermore, in the case where the heat shield plate is provided between the tank 1 and the surrounding exterior 10B as in the first, second, and fourth embodiments, the seventh embodiment is provided in the gap on one side of the heat shield plate. A heat insulating material similar to the above may be provided.

Example 8. Next, an eighth embodiment in which a reinforcing means for the tank 1 is provided in the seventh embodiment will be described with reference to FIG. 8, parts that are the same as or correspond to those in FIG. 7 are given the same reference numerals, and descriptions thereof will be omitted. In FIG. 8, a plurality of reinforcing rings 25 are provided in the tank 1 to prevent negative pressure deformation, and are provided so as to go around the entire circumference of the tank 1. This reinforcing ring 25 itself allows the tank 1
The heat shield plate 13 can be spaced apart. The outer peripheral end of the reinforcing ring 25 is brought close to the inside of the surrounding heat shield plate 13 in a non-contact state to prevent heat of the tank 1 from being transferred to the surrounding heat shield plate 13 by thermoelectricity. Since the gap between the heat shield plate 13 around the tank 1 is partitioned in the same manner as the partition plate 19 of FIG. 1, natural convection is suppressed and the heat retention performance is improved. Since a plurality of reinforcing rings 25 are provided around the tank 1, the space is subdivided and natural convection is suppressed more reliably.

In FIG. 8, the hot water storage type electric water heater of the seventh embodiment is provided with the reinforcing ring. However, in any of the first to sixth embodiments, natural convection can be suppressed. The heat retention performance can be further improved.

[0067]

As described above, according to the first aspect of the present invention, the heat shield plate is provided between the tank and the exterior, and the space between the tank, the heat shield plate and the exterior is 10 mm or less. , Natural convection, which is the main factor of radiating the heat of the tank to the exterior, does not occur, radiation is also cut by the heat shield, and each gap is an air layer with low thermal conductivity, so the heat retention performance is Almost the same as the heat insulating material of glass wool, it can be replaced. As a result, dust due to glass wool generated during conventional assembly is eliminated, the working environment is significantly improved, and the space between the tank and the exterior can be made thinner than when using a glass wool heat insulating material, and the main body can be downsized. .

According to the second invention, a plurality of heat shields for suppressing radiation are provided at intervals of 10 mm or less so as to suppress natural convection, so that the heat retaining performance can be further improved.

According to the third invention, the space between the tank and the exterior is set to 10 mm or less, so that natural convection between the tank and the exterior can be suppressed, and the size can be reduced and the cost can be reduced while maintaining the heat retaining effect. it can.

According to the fourth aspect of the present invention, a heat shield plate for suppressing radiation is provided between the tank and the exterior, and a gap between the tank, the heat shield plate and the exterior is provided in a direction intersecting the heat shield plate. By providing the partition plate, the space can be subdivided, and convection is less likely to occur, so that the heat retention performance is improved and the main body can be downsized.

According to the fifth aspect of the invention, since the partition plate is provided between the tank and the exterior in a direction intersecting with the tank, natural convection in the space between the tank and the exterior can be prevented, and the heat retention performance is improved. In addition, the size can be reduced.

According to the sixth aspect of the invention, since the partition plate extended from the exterior is not in contact with the tank, it is prevented that heat of the tank is directly picked up and transmitted through the partition plate by heat conduction to be radiated from the exterior. Therefore, the heat retention performance is improved.

According to the seventh aspect of the invention, since the heat insulating material is provided between the tank and the exterior, the heat insulating performance is further improved by the combination of the heat insulating material, and the portion using the heat shield plate is heat insulated from the tank. Since the distance between the plate and the exterior is 10 mm or less, the size of the main body can be reduced.

According to the eighth aspect of the invention, the heat insulating material is provided especially in the gap below the outer casing of the tank, and the heat shield plate is provided in the other gaps. Since the heat insulating material is used in the lower part of the tank having a relatively large space, the heat insulating performance is improved. Further, in the vicinity of the tank, the space between the tank, the heat shield plate, and the exterior is set to 10 mm or less at which natural convection does not occur, so that the heat retention performance is surely improved and the main body can be downsized.

According to the ninth aspect of the present invention, the reinforcement ring for preventing negative pressure is attached to the tank so as to maintain a predetermined distance from the heat shield plate. The space can be subdivided in to improve heat retention and reduce size.

[Brief description of drawings]

FIG. 1 is a sectional view of a hot water storage type electric water heater showing a first embodiment of the invention.

FIG. 2 is a sectional view of a hot water storage type electric water heater showing a second embodiment of the invention.

FIG. 3 is a sectional view of a hot water storage type electric water heater showing a third embodiment of the invention.

FIG. 4 is a cross-sectional view of a hot water storage type electric water heater showing a fourth embodiment of the invention.

FIG. 5 is a cross-sectional view of a hot water storage type electric water heater showing a fifth embodiment of the invention.

FIG. 6 is a sectional view of a hot water storage type electric water heater showing a sixth embodiment of the invention.

FIG. 7 is a cross-sectional view of a hot water storage type electric water heater showing a seventh embodiment of the invention.

FIG. 8 is a sectional view of a hot water storage type electric water heater showing an eighth embodiment of the invention.

FIG. 9 is a cross-sectional view of a conventional hot water storage type electric water heater.

[Explanation of symbols]

 1 Tank 2 Heater 10B Surrounding Exterior 11B Upper Exterior 12B Lower Exterior 13 Surrounding Heat Shield 14 Upper Heat Shield 15 Lower Heat Shield 17 Surround Heat Shield 18 Surround Heat Shield 19 Partition Board 21 Partition Exterior 21 Partition 22 24 Thermal insulation

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayoshi Okabe 800 Iwamatsu, Oshima-cho, Nitta-gun, Gunma Sanryo Electric Co., Ltd.Gunma Plant (72) In Masami Fukuhara Oshima-machi, Niita-gun, Gunma Prefecture Address 800 Sanryo Electric Co., Ltd. Gunma Factory

Claims (9)

[Claims] 1. A tank for storing hot water, an exterior covering the tank, and a heat shield plate provided between the tank and the exterior, and a space between the tank, the heat shield plate and the exterior. A hot water storage type water heater characterized in that each is 10 mm or less. 2. The hot water storage water heater according to claim 1, wherein a plurality of the heat shield plates are provided at intervals of 10 mm or less. 3. A tank for storing hot water, and an exterior covering the tank, wherein the distance between the tank and the exterior is 10 mm.
A hot water storage type water heater characterized in that: 4. A tank for storing hot water, an exterior covering the tank, a heat shield provided between the tank and the exterior, a gap between the tank and the heat shield, or the heat shield. A hot water storage water heater comprising: a partition plate that partitions at least one of the gaps with the exterior in a direction intersecting with the heat shield plate. 5. A hot water storage type hot water, comprising: a tank for storing hot water, an exterior covering the tank, and a partition plate for partitioning a space between the tank and the exterior in a direction intersecting with the tank. vessel. 6. The partition plate is extended from the exterior,
6. The tank is not in contact with the tank.
Hot water storage water heater as described. 7. A tank for storing hot water and an exterior covering the tank are provided, a heat insulating material is provided in a part between the tank and the exterior, and the heat insulating material between the tank and the exterior is provided. A hot water storage type water heater characterized in that a gap not provided is 10 mm or less. 8. The hot water storage type hot water according to claim 7, wherein the heat insulating material is provided in a gap between the exterior of the tank below the tank, and a heat shield plate is provided between the periphery of the tank and the exterior. vessel. 9. A tank for storing hot water, an exterior covering the tank, a heat shield plate provided between the tank and the exterior, and a reinforcing ring for preventing negative pressure provided around the tank. Provided, the distance between the heat shield plate and the exterior is 10 m
Hot water storage type water heater characterized by being m or less.