JP2002122351A - Hot water storage device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a hot water reserving apparatus useful for reheating of water in a bathtub and reduce costs for heating. SOLUTION: The hot water reserving apparatus comprises a hot water reserving device 3 having two hot water reserving regions, and a hot water delivery device for recirculating hot water 2 in one of the hot water reserving regions after the hot water 2 has been used as a heat source of a heat exchanger 7 to restore the water again and giving priority to the water 2 used as the heat source of the heat exchanger 7 in supplying hot water while separately reserving hot water having a high temperature. Costs required for supplying heat to the heat exchanger 7 are reduced by reserving the heated hot water 2 in a hot water reservoir 3 to supply the water 2 by a required quantity at the time of use and using the hot water 2 as a heat supply medium to the heat exchanger 7. Costs required for equipment can also be reduced by utilizing the hot water reserving apparatus 1 also as a heat supply device. In the case the heat exchanger 7 is a heat exchanger of the bathtub, the water in the bathtub can be reheated by supplying heat by using the hot water 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a hot water storage device. More specifically, the present invention relates to an improvement in the configuration of a hot water storage device for supplying heated hot water.

[0002]

2. Description of the Related Art Some bathtubs in general households use an electric heater to heat a bath water whose temperature has dropped to a desired temperature. Such an electric heater is
It is suitable for heating hot water to several degrees Celsius or keeping it warm.

[0003]

However, in general, an electric heater for heating bath water has a smaller calorific value than a gas kettle or the like, and has insufficient capacity to reheat, for example, a cold bath water of the previous day. For this reason, the hot water is often replaced without reheating, which increases the fuel cost.

[0004] Therefore, an object of the present invention is to provide a hot water storage device which is useful for reheating of bath water and can reduce the cost required for heating.

[0005]

Means for Solving the Problems To achieve the above object, the present inventors paid attention to the configuration of a hot water storage device that has been widely used in homes and the like. The hot water storage device is generally installed to supply hot water, and hot water (or hot water) is secured in a tank so that hot water at a desired temperature can be used at all times. Heating when making hot water or keeping hot water is performed by converting electricity or gas into heat energy.

The hot water storage device according to the first aspect of the present invention focuses on the use and functions of such a hot water storage device, and includes a hot water storage facility having two hot water storage regions and a hot water storage device having one of the hot water storage regions. After using it as a heating source, reflux it and store it again,
At the time of hot water supply, there is provided a hot water supply facility which supplies hot water used as a heat source for the heat exchanger preferentially and separately secures high-temperature hot water.

[0007] The hot water storage device of the present invention can use the stored hot water as a heat supply source, and thus functions as a device capable of supplying heat together with the hot water supply. In this case, by storing a sufficient amount of hot water, a sufficient amount of heat for heating can be ensured, and bathtub hot water and the like can be heated to a desired temperature in a short time. In addition, when functioning as a heat supply device, the hot water storage device also functions as a heat storage tank, and it is possible to store heat using nighttime electric power.
The cost for supplying heat to the heat exchanger can also be reduced. Furthermore, since the hot water storage device can also be used as a heat supply device, the cost of equipment can be reduced.

Further, the hot water supplied with the heat does not completely lose the stored heat, and has a little more heat than the state before the heat storage. Therefore, the hot water storage device of the present invention collects such hot water in a hot water storage tank without discarding it, and uses it in preference to unheated water when supplying hot water. For this reason, it is possible to effectively use the heat of the hot water, reduce the loss of heat amount when heating again, and improve the thermal efficiency.

According to a second aspect of the present invention, in the hot water storage device according to the first aspect, at least two hot water storage tanks independent of each other are provided in the hot water storage facility. In such a hot water storage device, it is possible to separate hot water storage tanks that are mainly used for the case where the hot water supply function is exhibited and the case where the heat supply function is exhibited.

[0010] The third aspect of the present invention is the first or second aspect.
In the hot water storage device described above, the heat exchanger reheats the hot water in the bathtub. According to this, instead of the conventional heater, it is possible to use the heat of the hot water stored for hot water supply to reheat the temperature to a temperature suitable for the bathtub hot water.

According to a fourth aspect of the present invention, in the hot water storage device according to any one of the first to third aspects, the heating source of the hot water is CO.
_{This is a two} heat pump. CO ₂ as refrigerant
The pressure of the refrigerant is higher than that of the conventional refrigerant, and the performance as a hot water supply heat pump is improved by achieving a supercritical cycle in which the high pressure side exceeds a critical point. For this reason, it is possible to heat up to a high temperature of about 90 ° C. at a time as compared with the case where another heat pump is employed. Further, CO ₂ has almost the same refrigerant performance as a conventional refrigerant (CFC), but has a very low risk of depletion of the ozone layer.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on an example of an embodiment shown in the drawings.

FIG. 1 shows an embodiment of the present invention. The hot water storage device 1 of the present invention has a hot water supply function of storing a heated hot water 2 in a hot water storage tank 3 and supplying a required amount of the hot water 2 at the time of use, and a hot water supply device that uses the hot water 2 as a heat supply medium to a heat exchanger 7. It also has a thermal function. Hereinafter, a description will be given of a general hot water storage device 1 intended for use at home provided with a function as a heat supply device.

A hot water storage device 1 is provided with a hot water storage facility 3 having two hot water storage areas, and one of the hot water in the hot water storage area is used as a heat source of a heat exchanger 7 and then refluxed to store hot water again. And a hot water supply facility for separately securing high-temperature hot water 2 while preferentially supplying hot water used as a heat source. Hot water storage equipment 3 is constituted by hot water tanks independent of each other, and a required amount of tap water is supplied from branch water supply pipes 8.

The hot water supply equipment supplies hot water at an appropriate temperature to the hot water supply port 1.
And water supply pipes 8 and 8 for connecting the water supply source to the hot water storage facility 3 and supplying water at a predetermined water pressure.
An upper water supply valve 16, a hot water supply pipe 14 connecting the hot water storage facility 3 to the hot water supply port 10, a hot water storage facility 3 for storing hot water, and valves 11a and 11b provided on pipes connecting the hot water storage tanks 3a and 3b to the hot water supply pipe 14, The water supply pipe 8a directly connects the water supply pipe 8 and the water supply pipe 14 without passing through the hot water storage facility 3, a valve 11c provided in the middle of the water supply pipe 8a, a hot water supply temperature controller (not shown), and the like.

The hot water storage facility 3 is a hot water storage tank connected to a water supply source (water supply port 9) by a water supply pipe 8. In the hot water storage device 1 of the present embodiment, a two-tank system including two hot water storage tanks 3a and 3b is used, and at least one of them is also used as a heat storage tank. For example, in the case of the hot water storage device 1 shown in FIG.
The side indicated by is used for heat supply, and the side indicated by 3b is responsible for a normal hot water supply function. In addition, each hot water tank 3
Valves 11a and 11b are provided for each of
Opening 1 supplies water to hot water storage facility 3 while opening valve 1
Water supply can be stopped by closing 1. Hot water tank 3
a and 3b are arranged in parallel as shown, and further, a water supply pipe 8a is arranged in parallel. The water supply pipe 8a can make the hot water 2 in the hot water supply port 10 an appropriate temperature by mixing cold water (raw water from the water supply port 9) directly from the hot water supply port 10 and further mixing the hot water 2 in the hot water supply pipe 14 with an appropriate amount. Is provided.

One hot water storage tank 3 for storing hot water 2 for heat supply
The heat exchanger 7 is connected to a by a heating pipe 17. Then, the hot water 2 from the hot water storage tank 3a is diverted to the heating pipe 17, and heat is exchanged from the hot water 2 on the high temperature side to the low temperature heat medium on the heat exchanger 7 side. A pump 13 is provided in the middle of the pipe to the heat exchanger 7. On the other hand, the heat exchanger 7
A heating object 4 is provided by a pipe 18 provided with a pump 19 in the middle.
Is connected to

Further, an outlet of the hot water 2 in the heat exchanger 7 is connected to a water supply pipe 8 for supplying water to the hot water storage tank 3a. Therefore, the hot water 2 whose temperature has been lowered by the heat exchange in the heat exchanger 7 is guided again to the hot water storage tank 3. At this time, the temperature of the hot water 2 is lower than that at the time of storing the hot water, but if the temperature is not lower than that of the water supplied from the water supply port 9, the difference in heat can be recovered by the hot water storage facility 3.

The hot water storage device 1 includes a heater for heating the hot water 2. In the present embodiment, the heat pump 6 is adopted as a heater, and the heat pump 6 is arranged in parallel with the hot water storage facility 3 and the pump 12 for controlling the flow of the hot water 2 to the heat pump 6 is provided. Or, when reheating hot water 2 in hot water storage facility 3, raw water (or hot water 2)
Through the heat pump 6. For example, hot water tank 3b
When heating the raw water inside, the valve 11 b is opened, and the raw water is sent to the heat pump 6 by the pump 12. Therefore, the hot water 2 in the hot water tank 3b flows out of the lower part of the tank, and after being heated by the heat pump 6, flows again into the hot water tank 3b from the upper part of the tank. The heating of the hot water 2 in the hot water storage tank 3a on the other side is performed in the same manner.

As the heat pump 6, a CO ₂ heat pump using CO ₂ as a refrigerant is employed.
According to this, it is possible to heat up to about 90 ° C. at a time, and it is possible to heat more quickly than when other heat pumps are employed. Although not described in detail in this specification, CO ₂ as a refrigerant has a higher pressure than a conventional refrigerant (fluorocarbon), and achieves a supercritical cycle in which the high pressure side exceeds a critical point, thereby improving the performance as a hot water supply heat pump 6. obtain. Further, CO ₂ has higher refrigerant performance than conventional refrigerants, and there is no danger of destroying the ozone layer.

In the case of heating as described above, a high-temperature layer and a low-temperature layer of the hot water 2 are generated in the hot water storage tank 3b during the heating, and a temperature stratification is generally formed between these layers. Therefore, the heated hot water 2 can be stored in a state of being separated into two hot water storage areas of a high-temperature layer and a low-temperature layer. Even if the water in the tank is not entirely heated, the heated water in the upper layer can be stored. Only 2 can be taken out. In this case, the contact area between the upper layer side and the lower layer side is narrowed by adopting the vertically long hot water storage tank 3,
It becomes possible to maintain the thermal stratification by reducing the transfer of heat at the boundary.

When the hot water 2 whose temperature has been lowered due to heat deprived by the heat exchanger 7 is returned to the hot water storage tank 3a, the above-mentioned temperature stratification in the hot water storage tank 3a becomes unstable, and the temperature in the tank becomes uneven. In some cases. Therefore, when hot water is supplied, it is preferable to preferentially discharge the non-uniform hot water 2 in the tank, to effectively utilize heat, and to maintain the temperature in the tank and the operation cycle of the heat pump 6. In this case, hot water 2 is stored in hot water tank 3
The hot water 2 in the hot water storage tank 3a is reserved when the hot water 2 in the hot water storage tank 3a runs out, or is used when the temperature of the hot water 2 supplied by the hot water storage tank 3a is low.

Next, a second embodiment of the present invention will be described.

The second embodiment is of a one-tank type, and as shown in FIG.
Only one c is provided. The hot water storage device 1 is provided with an intermediate water intake pipe 8c for heating the heat exchanger 7 in addition to the water supply pipe 8a. In the present embodiment, the intermediate intake pipe 8
A three-way valve 5 is provided in the middle of c to form a three-pronged structure, a pipe 8b is attached, and each of the pipes 8b and 8c is attached to the upper part of the hot water storage tank 3 and an intermediate position on the side. The pipes 8b and 8c are provided with valves 11d and 11e, respectively. In addition, water supply piping 8
Another three-way valve 15 is provided at the connection between the water supply pipe 14 and the hot water supply pipe 14. For this reason, the hot water 2 is drawn out from the middle layer of the hot water storage tank 3 as shown in the figure by the action of the three-way valves 5 and 15 and the pumps 12 and 13, or is drawn out from the upper layer of the hot water storage tank 3 as shown in FIG. It can be guided to the exchanger 7 side. Further, the heating of the heat exchanger 7 is completed, and the cooled hot water 2 is returned to the hot water storage tank 3 again to recover waste heat in the same manner as in the first embodiment. Here, the lower temperature of the hot water 2 is returned to the lower side of the hot water tank 3c, so that the lower layer becomes a low temperature region.
By using c, the hot water 2 in the low temperature region can be extracted and used preferentially for hot water supply.

In both the first and second embodiments, it is preferable that pipes such as the water supply pipe 8 and the hot water supply pipe 14 constitute a closed loop so as to eliminate the introduction of outside air.
According to this, hot water can be supplied by using the water supply pressure, with little risk of corrosion of the piping.

[0026]

Preferred embodiments of the present invention will be described below.

The hot water storage device 1 has two hot water storage tanks 3a and 3b as shown in FIG. Hot water storage device 1 is a hot water supply device at home and is also a heating device for heating heat exchanger 7. Tap water is used as hot water 2, water supplied from water supply port 9 is stored in hot water storage tank 3, and heated. Use hot water. Heating uses a CO ₂ heat pump 6 to store heat required for heat supply at night, mainly by using electric power at night. Heating object 4
Are a heating floor and a bath tub, and are heat exchangers 7a and 7 respectively.
b.

The hot water storage device 1 as a hot water supply device includes a hot water supply port 1
Supply hot water from 0. The hot water supply port 10 is a faucet provided at two places as shown in the figure, and supplies hot water for washing, cooking and the like, and supplies hot water of an appropriate temperature to a bathtub. The hot water supply function is to mix hot water 2 and raw water so as to supply, for example, 65 ° C. water.

At the stage of supplying hot water to the hot water storage facility 3 and storing hot water, the corresponding valve 1 of one hot water storage tank (for example, 3a side)
1a and the water supply valve 16 are opened, and tap water is fed into the hot water storage tank 3a using the water supply pressure. At this time, the air in the hot water storage tank 3a is discharged through the hot water supply pipe 14. When water is stored in the hot water storage tank 3a, the water supply valve 16 is closed to stop water supply. Water is also supplied to the hot water storage tank 3b.

Next, the water in the hot water storage facility 3 is heated to make hot water. For example, when heating the water in the hot water tank 3a, the valve 11a is opened, and the water is circulated between the hot water tank 3a and the heat pump 6 by the pump 12 as shown in FIG. At this time, the water in the hot water storage tank 3a flows out from the lower layer side and the pump 1
2 and is sent to the heat pump 6 where it is heated and becomes hot water. In the case of the present embodiment, since the CO ₂ heat pump 6 is used as a heating source, for example, even tap water at 10 ° C. can be heated up to about 90 ° C. at a stretch.

The heated hot water passes through the valve 11a and is returned to the hot water storage tank 3a to form a high temperature upper layer. At this time, a temperature stratification occurs between the high-temperature upper layer and the low-temperature lower layer, and heat transfer is small. The temperature stratification descends with the supply of water, and eventually reaches the lower end, so that the entire hot water storage tank 3a becomes hot water 2.
When the entire amount of water in the hot water storage tank 3a is heated to make the hot water 2, the internal water on the other hot water storage tank 3b side is similarly heated.

As described above, if all (or a part of) the water in the hot water storage facility 3 is the hot water 2, hot water can be always supplied from the hot water supply port 10. In this case, as shown in FIG. 5, a desired amount of hot water supply temperature can be obtained by directly feeding an appropriate amount of unheated water supply water that has passed through the water supply pipe 8a to the hot water supply pipe 14. Hot water at a desired temperature is used for washing and cooking, and is also supplied to a bathtub. Hot water storage device 1 of the present embodiment
In this case, when hot water is supplied, hot water on the hot water tank 3b side is mainly used, but hot water on the other hot water tank 3a side can also be used.

On the other hand, when the hot water storage device 1 functions as a heating device, the hot water 2 in the hot water storage tank 3a is sent to the heat exchanger 7 as shown in FIG. Hot water 2 is circulated through heating pipe 17.
It depends on the function of the pump 13 provided above. Here, the hot water storage device 1 is used to perform floor heating and reheating of hot water stretched in the bathtub. Heating is performed by exchanging heat in the heat exchangers 7a and 7b arranged at two places of the heating pipe 17, and raising the temperature of the heating medium for floor heating and the hot water in the bathtub, respectively.

Here, in the hot water storage device 1 of this embodiment, the heat exchanger 7a on the floor heating side and the heat exchanger 7b for the bathtub are arranged in series on the heating pipe 17, but the floor heating and the reheating are separated. I'm trying to do it. That is, when floor heating is performed, heat exchange is performed only on the floor heating side, and reheating is not performed. In this embodiment, the heating medium for floor heating whose temperature has been reduced from 70 ° C. to about 60 ° C. by heating the floor is heated with the hot water 2 and again heated to about 70 ° C. At this time, the hot water 2 loses heat and its temperature drops to about 70 ° C.
And recover waste heat.

When reheating is performed, floor heating is not performed, and heat is exchanged with the heat exchanger 7b on the other side as shown in FIG. 7 to reheat the hot water in the bathtub. At this time, the bath water at about 15 ° C. is reheated to about 40 ° C. Also, the hot water 2 in the heating pipe 17 loses heat and lowers the temperature to about 30 ° C. This hot water 2 recovers waste heat by returning to the hot water storage tank 3. Here, at the time of heating, the hot water 2 of the hot water storage tank 3a is mainly used preferentially, but the hot water 2 of the hot water storage tank 3b can also be used.
In this case, as shown by the imaginary line in FIG. 7, a three-way valve or a pipe may be provided as needed.

When hot water is supplied thereafter, the hot water 2 in the hot water tank 3a is used preferentially in principle. In this case, hot water tank 3
This leads to preferential use of the waste heat recovered in step a), resulting in effective use of heat. When the hot water supply temperature is not enough, the hot water 2 on the hot water storage tank 3b side is appropriately supplied. Thus, hot water storage tank 3a
As a result of preferentially using hot water 2 on the side, hot water 2 in hot water storage tank 3a
When the water disappears and is replaced with the raw water, the hot water 2 in the other hot water storage tank 3b may be used this time.

In the case where heating is also performed by the hot water storage device 1 as described above, it is preferable to appropriately provide an empty heating prevention device. Such an empty heating prevention device is, for example, a sensor capable of detecting that there is no heat medium for floor heating or hot tub.

The above embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. In the present embodiment, an example has been described in which the hot tub 2 is used to heat the bathtub or to heat the floor, but the use of heat is not limited to these, and for example, it can be used for heating a bathroom.

The number of heat exchangers 7 is not limited to two, and the arrangement is not limited to the serial arrangement. The number of the heat exchangers 7 may be changed according to the number of the heating targets 4, or a plurality of heat exchangers 7 may be provided for a single heating target 4 according to a heating mode.

In the above-described embodiment, the heat exchanger 7 is provided between the hot water tank 3 and the object 4 to be heated. However, the heat exchanger 7 can be provided (enclosed) in the hot water tank 3 for example. It is.

Further, in the present embodiment, the hot water 2 having heated the heat exchanger 7 is returned to the hot water storage tank 3 to recover heat as long as it has heat. It can also be used directly. For example, in the above embodiment,
The hot water 2 cooled for the reheating is mixed with the hot water in the hot water tank 3 and adjusted to an appropriate temperature, and can be used as shower water without returning to the hot water tank 3.

Further, another heater may be employed in place of the heat pump 6 employed in the present embodiment. For example, instead of connecting the heat pump 6 to the hot water tank 3, an electric water heater may be built in the hot water tank 3. In this case, the electric water heater may heat the hot water 2 in the hot water storage tank 3 on the upper layer side, or may heat the hot water 2 as a whole.

[0043]

As is apparent from the above description, the hot water storage apparatus according to the first aspect has a hot water storage facility having two hot water storage areas and a hot water storage apparatus having one of the hot water storage areas as a heat source for a heat exchanger. The system is equipped with a hot water supply system that recirculates and stores hot water, and when hot water is supplied, preferentially supplies hot water used as a heat source for the heat exchanger and separately secures high-temperature hot water. And can heat bath water to a desired temperature in a short time. Further, when functioning as a heat supply device, a necessary amount of heat can be stored in advance, a necessary amount of heat can be taken out when necessary, and the cost for supplying heat to the heat exchanger can be reduced. Furthermore, since the hot water storage device can also be used as a heat supply device, the cost of equipment can be reduced.

In addition, the hot water supplied with heat is collected in a hot water storage tank without being discarded unnecessarily, and when hot water is supplied, it is used in preference to unheated water. Can be used effectively, and the heat loss when heating again can be reduced to increase the thermal efficiency.

Further, according to the hot water storage device of claim 2,
Since at least two independent hot water storage tanks are provided in the hot water storage equipment, it is possible to separate the hot water storage tanks mainly used when the hot water supply function is exhibited and when the heat supply function is exhibited,
It is easy to recover the cold water after heating.

Further, according to the hot water storage device of the third aspect,
Because the heat exchanger reheats the hot water in the bathtub,
Instead of the conventional heater, the heat of hot water stored for hot water supply can be used to reheat the water to a temperature suitable for bath water.

According to the hot water storage device of the present invention, the heating source of the hot water is a CO ₂ heat pump, and the performance as a hot water supply heat pump is improved as compared with the conventional refrigerant. It is possible to heat to a high temperature of about 90 ° C. at a time. Further, CO ₂ has almost the same refrigerant performance as a conventional refrigerant (CFC), but has a very low risk of depletion of the ozone layer.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a hot water storage apparatus according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a hot water storage device showing a second embodiment of the present invention.

FIG. 3 is a diagram showing an embodiment in which the hot water storage device of the present invention is used for reheating of a bathtub and floor heating.

FIG. 4 is a diagram showing a state in which water in a hot water storage tank is heated.

FIG. 5 is a diagram showing how hot water in a hot water storage tank is supplied.

FIG. 6 is a diagram showing a state in which floor heating is performed using hot water in a hot water storage tank.

FIG. 7 is a diagram showing a state of reheating using hot water in a hot water storage tank.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hot water storage apparatus 2 Hot water 3 Hot water storage equipment 6 Heat pump 7 Heat exchanger

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Michiyuki Saikawa 2-6-1 Nagasaka, Yokosuka City, Kanagawa Prefecture Inside the Yokosuka Research Institute, Central Electricity Research Institute (72) Katsumi Hashimoto 2-6 Nagasaka, Yokosuka City, Kanagawa Prefecture -1 Within the Yokosuka Research Laboratories, Central Research Institute of Electric Power Industry (72) Inventor Tomoaki Kobayakawa 1-3-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo Inside Tokyo Electric Power Company (72) Inventor Kazutoshi Kusakari 1, Uchisai-cho, Chiyoda-ku, Tokyo No. 1-3 Tokyo Electric Power Company (72) Inventor Koji Yoshitake 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation (72) Inventor Tetsuo Kaneda 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Shares F term in the company DENSO (reference) 3L025 AD09

Claims (4)

[Claims] 1. A hot water storage facility having two hot water storage areas, and one of the hot water in the hot water storage areas is used as a heat source of a heat exchanger, and then refluxed and stored again, and hot water used as a heat source for the heat exchanger at the time of hot water supply. And a hot water supply facility for separately securing high-temperature hot water while supplying the hot water preferentially. 2. The hot water storage device according to claim 1, wherein at least two hot water storage tanks independent of each other are provided in the hot water storage facility. 3. The hot water storage device according to claim 1, wherein the heat exchanger is for reheating the hot water in the bathtub. 4. The hot water storage device according to claim 1, wherein a heating source of the hot water is a CO ₂ heat pump.