JP2828412B2 - Hot water storage type electric water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage type electric water heater which has a plurality of hot water storage tanks and can be installed on a small site.

[0002]

2. Description of the Related Art To increase the capacity of a hot water storage type electric water heater using one hot water storage tank, the diameter or height of the hot water tank must be increased. However, if the hot water tank is enlarged in this way, it cannot be installed in a place where the width dimension and the height dimension are limited. Therefore, as shown in Japanese Utility Model Laid-Open Publication No. 63-196047, a relatively large capacity that can be installed even in a place where the width dimension and the height dimension are short by arranging a plurality of hot water tanks and arranging them in parallel. An electric water heater was proposed.
In the electric water heater described in the publication, a hot water supply port of one hot water tank is connected to a water supply port of the other hot water tank by a connecting pipe, and the hot water tanks are connected in series.

[0003]

However, when a plurality of hot water tanks are connected in series using a connecting pipe, the following problems occur.

(A) When hot water tanks are connected in series, the piping path becomes long, and a large-diameter hot water tank and a small-diameter connecting pipe are alternately arranged between a water supply pipe and a hot water supply pipe. Therefore, there is a problem that the hot water supply pressure is reduced.

(B) The connecting pipe connecting the hot water supply port of one hot water tank and the water supply port of the other hot water tank has L-shaped bent portions at the upper and lower sides, and the upper bent portion and one end are connected to each other. When air accumulates between the hot water tank and the hot water supply port, the water flow is hindered by this air layer, and the hot water cannot be supplied at the pressure (0.6 kg / cm ² ) of the water reduced by the pressure reducing valve. There is. To prevent this, an air vent valve may be provided near the bent portion above the connecting pipe, but in this case, there is a problem that the number of parts increases.

Therefore, a technique has been proposed in which a plurality of hot water storage tanks are arranged in parallel and each hot water storage tank is connected in parallel, as in a hot water storage type water heater disclosed in Japanese Utility Model Laid-Open No. 51-163564. However, in the conventionally proposed technology, the hot water storage tanks are simply connected in parallel, and there has been no study on the effective use of the hot water in the hot water storage tanks connected in parallel. For this reason, the fluid resistance of each flow path from the water supply pipe to the hot water supply pipe through each hot water storage tank was varied. The low fluid resistance in the flow path from the water supply pipe to the hot water supply pipe through the hot water storage tank means that the amount of hot water supplied from the hot water storage tank in the flow path to the hot water supply pipe is large.
Conversely, a high fluid resistance in the flow channel means that the amount of hot water supplied to the hot water supply pipe from the hot water storage tank in the flow channel is small. In other words, the hot water in each hot water storage tank is used in inverse proportion to the fluid resistance of the flow path from the water supply pipe to the hot water supply pipe through the hot water storage tank. For this reason, hot water is lost in order from the hot water storage tank located in the flow path with a small fluid resistance, and thereafter water flows out of the hot water storage tank where the hot water has been lost, and water is mixed with the hot water discharged from the hot water storage tank where the hot water remains. To be supplied to the hot water supply pipe. Therefore, there was a problem that hot water in each hot water storage tank could not be used effectively.

[0007] An object of the present invention is to provide a hot water storage type electric water heater in which, even when a plurality of hot water storage tanks are arranged in parallel, the hot water supply pressure does not decrease and the hot water in each hot water storage tank can be used effectively. Is to provide.

It is another object of the present invention to provide a hot water storage type electric water heater which does not require the use of an air vent valve.

[0009]

SUMMARY OF THE INVENTION The present invention relates to a hot water storage type electric water heater having a plurality of hot water storage tanks having a water supply port at a lower part and a hot water supply port at an upper part arranged in parallel. To achieve.

[0010] In the present invention, the water supply ports of the plurality of hot water storage tanks are connected to each other via the first connecting pipe. The hot water supply ports of the plurality of hot water storage tanks are connected to each other via the second connecting pipe. Water is supplied to one end of the first connecting pipe.
Connecting the tubes and the first of the two ends of the second connecting tube.
One end on the side where the other end of the connecting pipe is located
Connect the hot water supply pipe . In particular, in the present invention, the fluid resistance of each flow path from the water supply pipe to the hot water supply pipe through each hot water storage tank is made substantially equal.

Although an electric heater may be provided in each hot water storage tank and each hot water storage tank may be heated at the same time, the electric heater may be provided in one hot water storage tank or in the first connection pipe, and the first and second electric heaters may be provided. Each hot water storage tank may be filled with hot water by convection of the hot water into each hot water storage tank through the second connection pipe. In this case, it is preferable that the inner diameter of the first and second connecting pipes be larger than the inner diameter of the water supply pipe or the hot water supply pipe. Further, the tank bodies of the plurality of hot water storage tanks may be connected to each other by a third connection pipe, and an auxiliary electric heater may be provided in an upper counter flow path passing through the third connection pipe.

[0012]

When a plurality of hot water storage tanks are connected in parallel using the first and second connecting pipes, the hot water supply pressure does not decrease as compared with a case where a plurality of hot water storage tanks are connected in series. Further, since there is no need to connect the connecting pipe from above to below, there is no possibility that air is accumulated in the connecting pipe and hot water supply becomes impossible. In particular, in the present invention, since the fluid resistance of each flow path from the water supply pipe to the hot water supply pipe through each hot water storage tank is substantially equal, even when a plurality of hot water storage tanks are connected in parallel, Can be made substantially equal, and the hot water in each hot water storage tank can be used effectively.

If the electric heater is arranged in one hot water storage tank or in the first connection pipe, and hot water is convected in each hot water storage tank through the first and second connection pipes, the inside of each hot water storage tank can be improved. Can be filled with warm water, and the efficiency of use of the tank can be increased. In addition, since only one electric heater needs to be periodically inspected, inspection and electric wiring are facilitated. In addition, since the processing cost of the hot water storage tank is reduced and the cost of the electric heater is reduced, the price of the water heater can be significantly reduced.

Further, if a short counter flow path is formed above the plurality of hot water storage tanks using the third connecting pipe and the auxiliary electric heater, even when the plurality of hot water storage tanks are connected in parallel,
Easy reheating or instant water heating is possible.

Further, when the upper portions of the inner wall surfaces of the second connecting pipe and the hot water supply pipe are made to coincide with each other, it is possible to prevent air from being trapped between the second connecting pipe and the hot water feeding pipe.

[0016]

FIG. 1 shows a schematic configuration of an embodiment of the present invention. In the figure, reference numerals 1 and 2 denote cylindrical first and second cylindrical members which are arranged upright in an outer case (not shown).
These hot water storage tanks 1 and 2 are provided with water supply ports 1a and 2a at the lower part and hot water supply ports 1b and 2b at the upper part, respectively. The water supply ports 1a and 2a of the hot water storage tanks 1 and 2 are connected to each other by a first connection pipe 3, and the water supply ports 1b and 2b are connected to a second connection pipe 4
Are connected to each other. A water supply pipe 5 such as a water pipe is provided at an end of the first connecting pipe 3 located on the first hot water storage tank 1 side.
And a hot water supply pipe 6 is connected to an end of the second connecting pipe 4 located on the second hot water storage tank 2 side. Electric heaters 7 and 8 are provided below the inside of the hot water storage tanks 1 and 2, respectively.

In the above embodiment, the first and second hot water storage tanks 1 and 2 have the same inner diameter and height, and the first and second connecting pipes 3 and 4 have the same inner diameter and length. Therefore, the fluid resistance of the flow path A from the outlet of the water supply pipe 5 to the inlet of the hot water supply pipe 6 through the hot water storage tank 1 and the connection pipe 4, and the connection pipe 3 and the hot water storage tank 2 from the outlet of the water supply pipe 5.
And the fluid resistance of the flow path B up to the inlet of the hot water supply pipe 6 is substantially equal. Therefore, even when two hot water storage tanks are connected in parallel, the amount of hot water supplied from each hot water storage tank becomes substantially equal, and the hot water in each hot water storage tank can be used effectively.

In the present embodiment, the electric heaters 7 and 8 are heated by midnight power to heat the water in both hot water storage tanks 1 and 2 to a predetermined temperature. When hot water is supplied from the hot water supply pipe 6,
Water is supplied from the water supply pipe 5 as much as the hot water is supplied.

FIG. 2 shows a second embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 1 except that two hot water storage tanks are connected in parallel, but differs in that one electric heater heats water in the two hot water storage tanks. In the embodiment of FIG. 1, the electric heaters 7 and 8 in each of the hot water storage tanks 1 and 2 are simultaneously energized and heated.
And the part below 8 cannot be heated. Therefore, the utilization rate of the hot water storage tank cannot be 100%. In addition, when the electric heater is provided in each hot water storage tank, there is a problem that processing of the hot water storage tank becomes troublesome and processing cost increases. Also, as the number of electric heaters increases, maintenance becomes more troublesome, and an extra inspection space for inspecting the electric heaters provided in each hot water storage tank is required.

The embodiment of FIG. 2 improves the disadvantages of the embodiment of FIG. 1 as described above. In FIG. 2, the same members as those of the embodiment of FIG. To 10
Are added. In this embodiment, the first hot water storage tank 11 is not provided with an electric heater.
And the inner diameter of the second connecting pipes 13 and 14
And it is made larger than the inner diameter of the hot water supply pipe 6. More specifically, the inner diameter of the connecting pipe is about 2.5 times that of the water supply pipe.
It should be noted that the upper portions of the inner wall surfaces of the connecting pipe 14 and the hot water supply pipe 6 are made to coincide with each other (to be flush with each other) to prevent air from being trapped between the connecting pipe 14 and the hot water feeding pipe. The other points are the same as those of the embodiment of FIG. 1, and the fluid resistance of each flow path from the outlet of the water supply pipe 5 to the inlet of the hot water supply pipe 6 is substantially the same.

In the present embodiment, when the electric heater 18 is energized to perform heating, the heated water starts convection along the path indicated by the dashed arrow. As a result, the cold water in the first hot water storage tank 11 passes through the first connection pipe 13 from the water supply port 11a and the second water.
Flows into the hot water storage tank 12 and is heated. According to this embodiment, the entire inside of both hot water storage tanks 11 and 12 can be filled with warm water having a substantially uniform temperature. According to an experiment, when a 4.4 kw electric heater is energized by midnight power for about 7 hours when the temperature of the supply water is 10 ° C. and heated, the temperature of the water near the water supply port of the first hot water storage tank 11 and the temperature of the second The temperature difference from the hot water temperature near the hot water supply port of hot water storage tank 12 was about 3 to 4 ° C.
For comparison, the first and second connection pipes 13 and 14
As a result, the same experiment as above was performed using pipes having the same inner diameter as the water supply pipe 5 and the hot water supply pipe 6, and the temperature difference was 10 to 1
It was about 5 ° C. From this result, it is preferable to increase the inner diameter of the connecting pipes 13 and 14 as much as possible in order to sufficiently perform the convection between the hot water storage tanks.

When the electric heater is provided only in one of the hot water storage tanks, the wiring of the electric heater is simple, and the cost for the electric heater can be reduced.
By the way, even if the wattage doubles, the price of the electric heater does not double. Therefore, according to the present embodiment, it is possible to reduce the price of the electric water heater as compared with the related art.

FIG. 3 shows a modification of the embodiment of FIG. This embodiment is obtained by adding a reheating function and an instantaneous water heating function to the water heater of the embodiment of FIG. In the present embodiment, the tank body of the first hot water storage tank 21 and the tank body of the second hot water storage tank 2 are connected by a third connection pipe 20. In the present embodiment, the mounting position of the third connecting pipe 20 is set to a position about 1/4 from above the tank main body, but this mounting position can be appropriately determined. The auxiliary electric heater 19 is arranged above the connection position of the third connection pipe 20. Use hot water when the temperature of the hot water heated by energizing the electric heater 18 with late-night power is reduced due to a decrease in environmental temperature or the passage of time, or before the hot water temperature in the hot water storage tank is heated to a desired temperature. In this case, the auxiliary electric heater 19 may be energized. When the auxiliary electric heater 19 is energized, the heated hot water convects through the upper convection flow path shown by the dashed line in the drawing, and the first and second hot water storage tanks 21 positioned above the auxiliary electric heater 19 and The warm water heated by the auxiliary electric heater 19 accumulates in the inside 22.

When heating using only the electric heater 18 without using the auxiliary electric heater 19, convection occurs not only through the second connecting pipe 14 but also through the third connecting pipe 20, but substantially. There is no effect.

According to the present embodiment, by adding the additional heating or the instant water heating function, the usability is further improved as compared with the second embodiment.

FIG. 4 shows a schematic configuration of another embodiment of the present invention. In this embodiment, the hot water storage tanks 3 connected in parallel
The electric heater 38 and the auxiliary electric heater 39 are arranged inside the first and second connecting pipes 33 and 34 without disposing the electric heater inside 1 and 32. In the case where an electric heater is arranged in one hot water storage tank and all the hot water tanks are filled with hot water at a predetermined temperature by using convection as in the embodiment of FIGS. Even if the temperature is good, the temperature difference in the hot water storage tank cannot be completely eliminated. If the electric heater 38 is arranged at least in the first connecting pipe 33 as in the embodiment of FIG. 4, the position of the electric heater can be arranged lower than in the embodiments of FIGS. Therefore, the temperature difference between both hot water storage tanks can be almost eliminated. When the electric heater is arranged inside the connecting pipe as in the present embodiment, the connecting pipe 3 is smaller than the connecting pipes 13 and 14 used in the embodiment of FIGS.
It is preferable to increase the inner diameter dimensions of 3 and 34. Incidentally, in this embodiment, a pipe having a larger diameter than the connecting pipes 13 and 14 used in the embodiment of FIGS. 2 and 3 is used. The auxiliary electric heater 39 heats the hot water in the connection pipe 34 and raises the temperature of the upper hot water of the hot water storage tanks 31 and 32, thereby exhibiting a reheating function.

According to this embodiment, the temperature difference in the hot water storage tank can be further reduced. Further, since the processing for disposing the electric heater in the hot water storage tank becomes unnecessary, the cost for the hot water storage tank can be significantly reduced. In addition, there is an advantage that an auxiliary electric heater can be easily added.

Although each of the above embodiments has two hot water storage tanks, the present invention can of course be applied to a case where two or more hot water storage tanks are connected in parallel. In the above embodiment, the hot water storage tanks and the connecting pipes have the same shape in order to make the fluid resistance of each flow path from the water supply pipe to the hot water supply pipe through each hot water storage tank substantially equal.
However, in order to make the fluid resistance of the flow path substantially equal, each hot water storage tank and the connecting pipe do not necessarily have to have the same shape. For example, when the inner diameter of one hot water storage tank is small, a part of the connecting pipe is And the fluid resistance of the flow path can be made substantially equal.

[0029]

According to the present invention, a plurality of hot water storage tanks are connected in parallel using the first and second connecting pipes.
Compared to a case where a plurality of hot water storage tanks are connected in series, the hot water supply pressure does not decrease and there is no need to pipe the connecting pipe from above to below, so that air is accumulated in the connecting pipe and hot water supply is not possible. Nothing is possible. In particular, according to the present invention, since the fluid resistance of each flow path from the water supply pipe to the hot water supply pipe through each hot water storage tank is made substantially equal, even when a plurality of hot water storage tanks are connected in parallel, each hot water storage tank The amount of hot water supplied from the hot water can be made substantially equal, and the hot water in each hot water storage tank can be used effectively.

When the upper portions of the inner wall surfaces of the second connection pipe and the hot water supply pipe are made to coincide with each other, it is possible to prevent the formation of air pockets between the second connection pipe and the hot water supply pipe.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of another embodiment of the present invention.

FIG. 3 is a diagram showing a schematic configuration of another embodiment of the present invention.

FIG. 4 is a diagram showing a schematic configuration of another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water storage tank 2 Hot water storage tank 3 First connection pipe 4 Second connection pipe 5 Water supply pipe 6 Hot water supply pipe 7 Electric heater 8 Electric heater 11 Hot water storage tank 12 Hot water storage tank 13 First connection pipe 14 Second connection pipe 18 Electricity Heater 19 Auxiliary electric heater 21 Hot water storage tank 22 Hot water storage tank 31 Hot water storage tank 32 Hot water storage tank 33 First connecting pipe 34 Second connecting pipe 38 Electric heater 39 Auxiliary electric heater

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junichi Nishimura 1150 Kyushu Transformer Co., Ltd., 2150 Shioido, Fukuma-cho, Munakata-gun, Fukuoka No. 2150 No. 1 in Kyushu Transformer Co., Ltd. (72) Noriyoshi Nakayama Inventor No. 2150 Shioido, Fukuma-cho, Munakata-gun, Fukuoka Prefecture No. 1 No. 1 in Kyushu Transformer Co., Ltd. (56) References JP-A-1-106856 (JP) , A) (58) Field surveyed (Int.Cl. ⁶ , DB name) F24H 1/18

Claims (4)

(57) [Claims] 1. A hot water storage type electric water heater comprising a plurality of hot water storage tanks having a water supply port at a lower portion and a water supply port at an upper portion, wherein the water supply ports (1a, 2a) of the plurality of hot water storage tanks are provided. First
And the hot water supply ports (1b, 2b) of the plurality of hot water storage tanks are connected to each other through a second connection pipe (3).
And a water supply pipe (5) at one end of the first connection pipe (3).
Are connected and at two ends of the second connecting pipe (4) .
The side where the other end of the first connecting pipe (3) is located
A hot water supply pipe (6) is connected to one end of the hot water supply pipe (5). The fluid resistance of each flow path from the water supply pipe (5) to the hot water supply pipe (6) through each of the hot water storage tanks (1, 2) is reduced. A hot water storage type electric water heater characterized by being substantially equal. 2. A hot water storage type electric water heater according to claim 1, wherein an electric heater (38) is arranged in said first connecting pipe (33). 3. The water supply pipe according to claim 1, wherein an inner diameter of the first and second connection pipes is larger than an inner diameter of the water supply pipe or the hot water supply pipe. Hot water storage type electric water heater. 4. The inner wall surface of each of the second connection pipe (4) and the hot water supply pipe (6) coincides with each other at an upper portion so as to prevent air from being trapped between the two pipes. Hot water storage type electric water heater.