JPH11337180A - Electric water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable hot water delivery by boiling at least a part of hot water to a set temperature in a short time out of a fixed quantity of hot water without enlarging the capacity of a heater, even in the case of boiling a fixed quantity of hot water at the upper part within a hot water storage tank. SOLUTION: This water heater is provided with a hot water storage tank 11 where a water supply pipe line 12 is connected to the bottom and also a hot water supply pipe line 13 is connected to the top. In this case, a plurality of heaters 17 and 18 which boil the hot water in the upper part within a hot water storage tank 11 in order from the upper layer, dividing it into the shape of plural layers, are arranged at the upper part within the hot water storage tank 11. One heater 17 is curved to come close to the upper part within the hot water storage tank 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electric water heater.

[0002]

2. Description of the Related Art Conventionally, in an electric water heater, the amount of hot water is limited (runs out) depending on the capacity of a hot water storage tank.
Although there are problems such as taking up the installation space, it has been considered difficult to simultaneously solve these problems because the capacity of the hot water storage tank and the installation space are physically opposite to each other.

Conventionally, the selection of the capacity of a hot water storage tank has been determined in accordance with the amount of hot water to be used the most throughout the year from the viewpoint of preventing running out of hot water. Therefore, in normal use, the capacity of the hot water storage tank was excessive.

[0004] Therefore, the concept of selecting the capacity of the hot water storage tank has been changed from an annual maximum to a winter average method, and the capacity of the hot water storage tank has been reduced to a capacity corresponding to the average amount of hot water used in winter. It is considered that additional use of hot water that exceeds the amount of hot water will result in additional firing. That is, an electric water heater that is space-saving and does not run out of hot water has been considered.

In order to realize an electric water heater that is space-saving and does not run out of hot water, it is essential to add a reheating function. For example, as shown in FIG. The heater 2
And a predetermined amount (required amount) of hot water in the hot water storage tank 1 is heated to the set temperature, thereby making it possible to prevent the hot water from being completely drained.

The heater 2 is disposed substantially horizontally at a height corresponding to a fixed amount of hot water with respect to the hot water storage tank 1, and reaches a height above the hot water storage tank 1 as shown in FIG. When energization of the heater 2 is started in the state where the water W is filled with the supplied water W, as shown in FIG. It is boiled in layers while raising the temperature at a substantially uniform temperature, and finally, as shown in FIG.
As shown in the figure, a certain amount of hot water H is boiled up.

[0007]

By the way, in an electric water heater that is space-saving and does not run out of hot water, even when the hot water is almost exhausted, the high-temperature hot water H is quickly boiled by additional heating in order to maintain the hot water supply function. It is necessary to be able to handle hot water.

However, it takes time to boil the hot water H for a certain amount in the upper part of the hot water storage tank 1, and during the boiling, a certain amount of hot water rises at a substantially uniform temperature as a whole. While the water is being boiled in a layered manner, if there is hot water on the way to boiling, the low-to-medium-temperature hot water M on the way to boiling that has not reached the high-temperature hot water H is discharged. Therefore, it is difficult to immediately discharge the required high-temperature hot water H, and the hot water supply function is impaired, and it is difficult to realize an electric water heater that is space-saving and does not run out of hot water.

The present invention has been made in view of such a point, and even when a certain amount of hot water in the upper part of the hot water storage tank is boiled, at least one of a certain amount of hot water and hot water without increasing the heater capacity. It is an object of the present invention to provide an electric water heater that is capable of boiling a portion of hot water to a set temperature in a short time so that it can cope with hot water.

[0010]

According to a first aspect of the present invention, there is provided an electric water heater in which a water supply pipe is connected to a lower part and a hot water supply pipe is connected to an upper part, and an upper part in the hot water storage tank. And a plurality of heaters that divide the hot water in the hot water storage tank into a plurality of layers and boil the water in order from the upper layer. In this way, even when a certain amount of hot water in the hot water storage tank is heated by dividing the upper hot water in the hot water storage tank into a plurality of layers and boiling the water in order from the upper layer by the plurality of heaters, the heater capacity is increased. Without doing this, at least a part of the fixed amount of hot water is boiled to the set temperature in a short time so that hot water can be discharged. And by having such a reheating function,
An electric water heater that does not run out of water in a small space can be realized.

According to a second aspect of the present invention, in the electric water heater according to the first aspect, at least one heater is bent so as to approach an upper portion in the hot water storage tank. This makes it possible to divide the hot water in the upper portion of the hot water storage tank into a plurality of layers and boil the water in order from the upper layer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

The electric water heater employs a hot water storage system of a first-stop push-up type and has a hot water storage tank 11.
The lower part of 11 is connected to a water supply pipe 12 connected to a water pipe via a pressure reducing valve (not shown), and the upper part of the hot water storage tank 11 is, for example, a bathroom, a kitchen and a washroom. Hot water supply pipeline connected to hot water taps installed
13 is connected.

In the lower part of the hot water storage tank 11, two lower heaters 14 capable of boiling the entire amount of hot water in the hot water storage tank 11 are provided. These lower heaters 14 are connected to the hot water storage tank 11 through openings 15 formed in the side surfaces of the hot water storage tank 11.
It is inserted into 11 and is fixed to lid 16 closing opening 15.

In the upper part of the hot water storage tank 11, two upper heaters 17 and 18 are arranged as a plurality of heaters capable of boiling a certain amount of hot water in the upper part of the hot water storage tank 11.
The upper heater 17 is bent substantially upward at a right angle so as to approach the upper part of the hot water storage tank 11 at the middle part, and the vertical part 17a is disposed substantially at the center of the hot water storage tank 11. I have. The other upper heater 18 is one upper heater
It is arranged almost horizontally at a height lower than 17. The upper heaters 17 and 18 are inserted into the hot water storage tank 11 through an opening 19 formed on a side surface of the hot water storage tank 11 and are fixed to a lid 20 that closes the opening 19.

A temperature detecting sensor 21 for detecting boiling is mounted on a side surface of the hot water storage tank 11 at a height between the upper end of the hot water storage tank 11 and the other upper heater 18.
A temperature detection sensor 22 for detecting boiling and remaining hot water is attached at the height of the hot water storage tank, and a plurality of temperature detection sensors 23 for detecting the remaining hot water at an intermediate height of the hot water storage tank 11 are provided. A temperature detection sensor 24 for detecting temperature and boiling is mounted.

In a specific time zone at night using, for example, a late-night power system or a time-based lighting system, the lower heater 14 is energized to boil up the entire amount of hot water in the hot water storage tank 11 or the set amount of hot water. Store hot water. The boiling water or the stored hot water for the set amount of hot water is detected by the temperature detection sensors 23 and 24.

At the time of hot water supply, when the hot water tap and the like at the end of the hot water supply pipe 13 are opened, the tap water is guided to the lower portion of the hot water storage tank 11 by the supply pressure of the tap water guided to the water supply pipe 12. Hot water in the tank 11 is pushed up, and the hot water in the upper portion of the hot water storage tank 11 is discharged from a hot water tap or the like through the hot water supply line 13.

Further, the hot water supply from the hot water storage tank 11 continues, the amount of remaining hot water in the hot water storage tank 11 decreases, and the hot water is almost exhausted.
When the temperature is detected by the temperature detection sensor 21 or the like, reheating is automatically performed mainly in a time period other than the specific time period in order to secure a certain amount (required amount) of hot and cold water.

In this reheating, for example, as shown in FIG. 2 (a), there is almost no remaining hot water remaining in the upper part of the hot water storage tank 11 and the upper heater is filled with the supplied water W. Electric power is supplied to both of 17 and 18, and a certain amount of hot water stored in the hot water storage tank 11 is stored.

At this time, both the upper heaters 17 and 18 boil simultaneously, but since the vertical portion 17a of one upper heater 17 is arranged in the upper part in the hot water storage tank 11, as shown in FIG. The hot water in the upper part of the hot water storage tank 11 is divided into two layers having different temperatures: an upper layer, for example, a layer of high-temperature hot water H at 90 ° C., and a lower layer, for example, a layer of low-medium-temperature hot water M at 45 ° C. It can be boiled in a stack.

When a time t1 has elapsed from the start of energization and the temperature detection sensor 21 installed at a height between the upper end of the hot water storage tank 11 and the upper heater 18 detects that the boiling temperature has reached the set temperature. Then, the energization of one upper heater 17 is stopped, and thereafter, the hot water storage is continued only by the other upper heater 18.

Further, a time t2 has elapsed since the start of energization,
As shown in FIG. 2C, when the temperature detection sensor 22 installed at the height of the upper heater 18 detects that the boiling temperature has reached the set temperature, the power supply to the other upper heater 18 is stopped. .

In this way, a certain amount of hot water in the upper part of the hot water storage tank 11 is stored by boiling to the set temperature.

Therefore, comparing the present example shown in FIG. 2 with the comparative example shown in FIG. 4 described in the conventional example on the assumption that the heater capacity is the same, when the time t2 elapses, FIG. 2 (c) and FIG.
As shown in (c), a certain amount of hot and cold water can be stored by boiling up to the set temperature, but at the time t1 before the time t2 elapses, the present example of FIG. While the high-temperature hot water H is boiled in the upper layer of the hot water, the comparative example in FIG. For this reason, in the present example, it is possible to cope with the tapping of the high-temperature hot water H after the lapse of the time t1.

As described above, the upper heaters 17 and 18 divide the upper hot water in the hot water storage tank 11 into two layers and boil them in order from the upper layer. At this time, without increasing the heater capacity, at least a part of the fixed amount of hot water can be boiled to the set temperature in a short time to cope with hot water.

Therefore, the concept of selecting the capacity of the hot water storage tank 11 has been changed from the annual maximum to the winter average method, and the capacity of the hot water storage tank 11 has been reduced to the capacity corresponding to the average amount of hot water used in winter. An electric water heater that is space-saving and does not run out of water can be realized by reliably reheating the amount of hot water that exceeds the amount of water in the tank 11.

The upper heaters 17 and 18 disposed above the hot water storage tank 11 are not limited to two heaters, and the shape of the upper heaters 17 and 18 may be further bent in an L-shape at the end of the vertical portion 17a of the upper heater 17. Alternatively, the upper hot water in the hot water storage tank 11 may be divided into a plurality of layers and boiled in order from the upper layer.

The lower heater 14 below the hot water storage tank 11
The above shows an electric water heater that performs boiling water storage in a specific time zone.However, a heating unit having a heater is arranged outside the hot water storage tank, and the water is heated while circulating hot water between this heating unit and the hot water storage tank. It may be applied to an electric water heater of a forced circulation boiling type for storing hot water.

[0030]

According to the electric water heater of the present invention, the upper portion of the hot water in the hot water storage tank is fixed by a plurality of heaters. Even when the hot water is boiled, at least a part of the fixed amount of hot water can be boiled to the set temperature in a short time without increasing the heater capacity, and the hot water can be handled.

According to the electric water heater of the second aspect, in addition to the effect of the electric water heater of the first aspect, at least one heater is bent so as to approach the upper part in the hot water storage tank. In addition, the hot water in the upper portion of the hot water storage tank can be divided into a plurality of layers and boiled in order from the upper layer.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an electric water heater according to an embodiment of the present invention.

2 (a) is an explanatory diagram before boiling, FIG. 2 (b) is an explanatory diagram during boiling, and FIG. 2 (c) is an explanatory diagram of completion of boiling.

FIG. 3 is an explanatory diagram showing the relationship between the energizing time of the heater and the boiling temperature.

4A and 4B show a conventional electric water heater, wherein FIG. 4A is an explanatory diagram before boiling, FIG. 4B is an explanatory diagram in the middle of boiling, and FIG. 4C is an explanatory diagram of completion of boiling.

[Explanation of symbols]

 11 Hot water storage tank 12 Water supply line 13 Hot water supply line 17, 18 Upper heater as heater

Claims (2)

[Claims] 1. A hot water storage tank having a lower portion connected to a hot water supply line and an upper portion connected to a hot water supply line, and a hot water tank disposed in an upper portion of the hot water storage tank and having a plurality of layers of hot water in the upper portion of the hot water storage tank. An electric water heater comprising: a plurality of heaters, each of which is heated in order from an upper layer. 2. The electric water heater according to claim 1, wherein at least one heater is bent so as to approach an upper part in the hot water storage tank.