JPH0348424B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat storage hot water supply equipment, and more specifically,
The present invention relates to a heat storage hot water supply facility that stores heat held by a heat medium supplied from a solar heat collector or the like as hot water and supplies hot water as needed.

Heat-storage water heating equipment is known that can supply hot water using heat obtained from solar collectors or waste heat from heat pumps, and store excess heat as hot water to meet hot water demand and space heating demand. In this type of thermal storage hot water supply equipment, the hot water storage tank that stores the water to be heated is
It may be placed under the floor of a house because the area under the floor is less affected by changes in outside temperature.
Therefore, in order to secure a certain amount of heat storage capacity and provide stable hot water supply, it is necessary to secure a certain capacity of the hot water storage tank, for example, a capacity of around 400 liters is required even for general household use. The shape of the hot water storage tank placed under the floor has to be flat. In other words, a flat shape is advantageous for effectively utilizing the space under the floor.
In addition, it is difficult to dig into the soil under the floor and place a vertical hot water storage tank because it is a heavy construction work.

By the way, if the hot water storage tank is made flat, the height of the hot water storage tank will be low relative to the overall capacity of the hot water storage tank, and the temperature difference in the height direction of the heated water in the hot water storage tank will tend to be small. ,Also,
Heat exchange with the heat exchanger (radiator) occurs only in a part of the tank, which tends to create dead areas around the tank. Therefore, sufficient natural convection of the heated water within the tank due to the temperature difference in the height direction of the heated water could not be expected. Therefore, the heat exchange efficiency was low, and the entire capacity of the hot water storage tank could not be used effectively.

Furthermore, not only when a flat hot water storage tank is placed under the floor, heat exchange efficiency may be low due to insufficient natural convection within the hot water storage tank.

An object of the present invention is that even if the hot water storage tank has a flat shape, the overall convection of the heated water in the hot water storage tank is sufficient, so that the heat exchange efficiency is high. The objective is to provide heat storage hot water supply equipment with excellent capacity and hot water supply capacity.

Therefore, the present invention provides a heat exchanger having a heat medium flow path connected to an external heat source and through which a heat medium from the heat source passes, and a heated flow path capable of exchanging heat with the heat medium flow path. One end of the heated flow path is extended to the vicinity of the liquid level in the hot water storage tank and is open, and the other end of the heated flow path is The switching means is connected to the circulation flow path and the hot water supply flow path, and the switching means is provided to selectively communicate the heated flow path with the circulation flow path or the hot water supply flow path, and the switching means for the circulation flow path is connected to the circulation flow path and the hot water supply flow path. The end opposite to the switching means is opened to the bottom side of the hot water storage tank, and the end opposite to the switching means of the hot water supply flow path is configured to be connected to a water heater.

That is, during heat storage, hot water from the bottom side (low temperature side) of the hot water storage tank is supplied to the other end side of the inner pipe by the circulation means and forcedly circulated to the heat exchanger, so that the hot water is connected to the heat exchanger. The temperature difference is ensured to improve heat exchange efficiency, and the heated hot water is sequentially discharged near the liquid surface, and when hot water is being supplied, the heated water from the upper side (high temperature side) in the hot water storage tank is pumped by the hot water supply means. The water heater is supplied with the highest temperature heated water in the tank, and natural convection due to the rise of the heated water at the bottom can also be expected. When hot water is supplied, the heated water in the hot water storage tank is passed through the exchanger and, if necessary, heated again before being supplied to the water heater, thereby achieving the above object.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of the heat storage water heater according to the present invention. In the figure, a floor 2 of a building 1 such as a general residence is supported on a cloth foundation 3, and the space under the floor is covered with cloth. Several underfloor spaces 4 are defined by the foundation 3.

A hot water storage tank 5 is installed in one of the underfloor spaces 4. The hot water storage tank 5 is formed into a bag shape from a synthetic resin sheet or the like with insulation quilting pasted on the outer circumferential surface, and a cap 6 is attached to the opening of the hot water storage tank 5.
A lid body 7 is attached via. On the other hand, floor 2
has an opening 9 to which a lid 8 is removably attached.
The control equipment, piping, etc. of the hot water storage tank 5 can be maintained through this opening 9, and the tank 5 can be folded into a small size inside the underfloor space 4. It is now possible to store it.

A predetermined amount of heated water 11 is filled in the hot water storage tank 5, and the head pressure of the heated water 11 causes the hot water storage tank 5 to be expanded into a flat shape. In addition, the hot water storage tank 5, which has expanded into a flat shape,
It is placed on the floor subfloor 13 via a heat insulating mat 12. The hot water storage tank 5 is surrounded by the cloth foundation 3, but the hot water storage tank 5 and the cloth foundation 3 are
A heat insulating material 14 such as foamed beads is filled in the gap between the hot water storage tank 5 and the cloth foundation 3 through the heat insulating material 14.

Heated water 11 in the hot water storage tank 5 is supplied into the tank 5 through a water supply pipe 15 . The water supply pipe 15 is connected to a ball tap 16 attached to the upper end of the tank 5, and an introduction pipe 17 whose tip water supply port faces the bottom of the hot water storage tank 5 is connected to the ball tap 16, and water is supplied from the water supply pipe 15. The water to be heated 11 is supplied to the bottom side of the hot water storage tank 5 through the ball tap 16 and the introduction pipe 17, and the filled volume of the water to be heated 11 in the hot water storage tank 5 reaches a predetermined amount by the action of the ball tap 16. configured to be maintained.

A heat exchanger 21 is installed at the bottom of the hot water storage tank 5 via an anchor 20 or the like. In this case, if the heat exchanger 21 is made of steel, the anchor can be omitted. The heat exchanger 21 has a double tube structure, and a heat medium pipe 23 is connected to an outer case 22 which is a heat medium flow path, and is mounted on the roof of the building 1 through the heat medium pipe 23. A solar heat collector 24 as an external heat source is connected thereto. A heat medium circulation pump 25 is provided in the middle of the heat medium pipe 23, and this pump 25 circulates the solar heat collector 2.
4 and the outer case 22 of the heat exchanger 21, a heat medium is appropriately circulated therebetween.

On the other hand, the inner tube 2 which is the heated flow path of the heat exchanger 21
6 has one end open to the heated water 11 in the hot water storage tank 5, and the heated water 11 flows through the inside of the heated water 11. It is configured to perform heat exchange. Note that the inner tube 26 may be designed to have a spiral shape or meander so that the contact area (contact time) between the heated water 11 and the heat medium is secured to a predetermined amount or more. .

A vertical communication pipe 19 is connected to the other end of the inner tube 26 . The tip of this vertical communication pipe 19 is opened near the liquid level of the water to be heated 11, and the pipe 1
9, the heated water 11 on the upper side in the hot water storage tank 5 is sucked into the inner pipe 26, or the pipe 19
The heated water 11 in the inner pipe 26 is discharged to the upper side of the tank 5 from the inner pipe 26 .

Further, a first port 31A of a first three-way switching valve 31 and a first port 32A of a second three-way switching valve 32, which are switching means, are connected to the other end side of the inner pipe 26 via a circulation pipe 30. ing. The second port 31B of the first three-way switching valve 31 is connected to the circulation pipe 3
The third port 31C is connected to the hot water pump 34, which is a forced water supply means, through the pump pipe 3.
5 to the pumping pipe 36. The lower end opening of the pumping pipe 36 is arranged on the bottom side of the hot water storage tank 5, and the pumping pipe 36 and the pumping pipe 35 constitute a circulation flow path, and the heated water 11 on the bottom side inside the hot water storage tank 5
is being pumped up. Further, the first three-way switching valve 31 is equipped with a valve switching motor 37, which controls the first port 31A and the second port 3 during hot water supply (operation).
1B, and a valve switching operation is performed so that the second port 31B and the third port 31C are communicated during heat storage (operation).

On the other hand, the second port 32B of the second three-way switching valve 32 is connected to the thermowax valve 41 via the hot water supply pipe 38, which is a flow path for hot water supply, and the third port 32C is connected to the hot water supply via the circulation pipe 33. It is connected to the pump 34. Further, the second three-way switching valve 32 is equipped with a valve switching motor 39, and when the valve switching operation is performed by this valve switching motor 39, the first port 32A and the third port are connected to each other during heat storage (operation). The port 32C is communicated with the second port 32B and the third port 3 during hot water supply (operation).
2C.

The hot water supply pipe 38 is branched into two at the thermowax valve 41, and one of the hot water supply pipes 38 is interposed with a proportionally controlled water heater 42. After the bifurcated hot water pipe 38 is connected again, the water heater 4 such as a shower or a hot water faucet is connected.
Connected to 3.

Note that the three-way switching valves 31, 32, the hot water supply pump 34, and the pumping pipe 36 constitute a circulation means for forcibly circulating the heated water on the bottom side of the hot water storage tank 5 to the heat exchanger 21 during heat storage, and When hot water is supplied by the three-way switching valves 31, 32 and the hot water supply pump 34, the heated water 1 in the upper side of the hot water storage tank 5 is heated.
1 to the water heater 43 is configured.

Next, the operating method of this embodiment will be explained with reference to FIGS. 2 and 3.

FIG. 2 shows the paths of the heat medium and heated water during heat storage operation. During heat storage, the first
In the case of the switching valve 31, the second port 31B and the third port
The valve is switched to communicate with the port 31C, and in the case of the second three-way switching valve 32, the valve is switched so that the first port 32A and the third port 32C are communicated with each other. As a result, the low-temperature heated water 11 on the bottom side of the hot water storage tank 5 is pumped up from the lower end opening of the pumping pipe 36, and this pumped heated water 11 is transferred to the two switching valves 31, 32 and the hot water pump 34. The heat exchanger 21 is supplied to the other end of the inner tube 26 of the heat exchanger 21 via the circulation pipe 30. The water to be heated 11 supplied to the inner pipe 26 is heated by exchanging heat with the high-temperature heat medium circulating in the outer case 22, and then passed through the upper and lower connecting pipes 19 to the upper side of the hot water storage tank 5 (at the liquid level). side). On this occasion,
The heated water 11 that exchanges heat with the high-temperature heat medium in the heat exchanger 21 is the low-temperature water at the bottom side of the hot water storage tank 5 pumped up by the pumping pipe 36, so the heated water 11 that exchanges heat with the high-temperature heat medium is the heated water that exchanges heat with each other. 11 and the heat medium is large, resulting in high heat exchange efficiency.

FIG. 3 shows a route during hot water supply operation, and in this case, in the case of the first three-way switching valve 31, the first port 31A and the second port 31B communicate with each other, and the second three-way switching valve 31 communicates with the first port 31A and the second port 31B. In the case of the switching valve 32, the second port 32B and the third port 32C are communicated. During hot water supply, the high-temperature heated water 11 in the upper part of the hot water storage tank 5 is sucked into the inner pipe 26 of the heat exchanger 21 via the upper and lower connecting pipes 19, and then the two three-way switching valves 31, 32 The water is then supplied to the thermowax valve 41 via the hot water pump 34.
That is, the heated water 11 at the highest temperature part in the hot water storage tank 5 is supplied to the thermowax valve 41; It passes through the heat exchanger 21, receives the heat of the heat medium, and is further heated.

If the temperature of the heated water 11 supplied to the thermowax valve 41 is lower than a predetermined value, the heated water 11 is supplied to the water heater 4 via a proportional control type water heater 42.
If the temperature is already higher than a predetermined value, the water is supplied directly to the water heater 43 without passing through the proportional water heater 42.

In addition, when the water to be heated 11 in the water heater 43 is consumed in the water heater 43 and the liquid level in the hot water storage tank 5 falls, the ball tap 16 is opened and new water to be heated 11 is stored through the introduction pipe 17. The hot water is supplied near the bottom of the tank 5, and the liquid level within the hot water storage tank 5 is always kept constant.

According to this embodiment, during the heat storage operation, the heated water 1 at the lowest temperature in the hot water storage tank 5 is
1 is supplied to the heat exchanger 21, the heat exchange efficiency in the heat exchanger 21 is high. It also has the effect of having a high heat storage capacity. In particular, in this embodiment, heat exchange is performed by forced circulation by the hot water supply pump 34, so rather than partial heat exchange within the hot water storage tank 5, heat exchange is performed throughout the entire hot water storage tank 5 by circulating flow. ) can perform heat exchange. Furthermore, heated water 1 heated by heat exchange
1 is discharged near the liquid level, and the upper part of the hot water storage tank 5 is heated to a high temperature, and the high temperature part is extracted from the bottom and expanded toward the bottom by forced circulation, so that the entire inside of the hot water storage tank 5 becomes hot. The temperature will be raised to further improve heat storage efficiency.

Furthermore, even during hot water supply operation, the heated water 11 in the upper part of the tank 5, which is the highest temperature part of the hot water storage tank 5, is supplied to the water heater 43. (Heated water 1
1) is obtained, and the hot water supply capacity is also excellent.

Furthermore, a hot water storage tank 5 that is supplied to the water heater 43
The heated water 11 on the upper side further receives heat from the heat medium in the heat exchanger 21, and then is transferred to the water heater 4.
3, and from this point of view as well, the hot water supply capacity can be excellent.

In addition, by arranging the heat exchanger 21 in the hot water storage tank 5, the heat of the heat medium radiated from the outer case 22 can be recovered by the heated water 11 around the heat exchanger 21. Therefore, in this respect as well, the heat storage capacity and hot water supply capacity can be improved.
In addition, as the heated water whose temperature has been raised due to heat radiation from the outer case 22 rises, the hot water storage tank 5
This has the effect of inviting natural convection within the interior. That is, by installing the heat exchanger 21 on the bottom side of the hot water storage tank 5, not only forced circulation but also natural circulation can be expected, and from this point of view as well, the heat storage capacity and hot water supply capacity are improved.

Furthermore, for example, when the heat exchanger 21 is installed on the outside of the hot water storage tank 5, a heat insulating material, a heat retention mechanism, etc. are required to prevent the heat held by the heat medium from being radiated to the outer circumferential side of the outer case 22. If the heat exchanger 21 is placed inside the hot water tank 5, there is no need for a heat insulator or the like, which is extremely convenient.

In addition, a flexible hot water storage tank 5 is arranged in the underfloor space 4 defined by the cloth foundation 3, and the cloth foundation 3 is effectively utilized to form a heat insulating layer in the underfloor space 4 and to expand the hot water storage tank 5. We are having them undergo shape restorative surgery, etc.
It has the effect of being easy to construct without requiring extensive construction. In addition, by arranging the heat transfer pipe 23 outside the building 1 and communicating with the hot water storage tank 5 only by penetrating the fabric foundation 3, damage caused by an accidental leakage is limited to the outdoors. Also, repairs are easy.

In addition, when implementing hot water supply, the heat exchanger 21
The heated water 11 on the upper side of the hot water storage tank 5 is simply transferred to the water heater 4 without passing the heat medium from the heat collector 24 to the water heater 4.
3 may be supplied. However, if the temperature of the heat medium is higher than the water to be heated 11, the temperature of the water to be heated 11 can be further increased as described above by passing this heat medium through the heat exchanger 21.

Further, heat radiation from the lid 7 may be particularly prevented by attaching a heat insulating material to the lid 7 or placing foam beads or the like on the lid 7. In addition, heat exchanger 2
1 is a double-tube structure, but the present invention is not limited to this. For example, the heat medium flow path is formed in a spiral shape to form a single circular tube structure, and the center of this circular tube structure is located inside the inner tube. The heated water 11 corresponds to the pipe 26.
Alternatively, the water to be heated 11 may be passed through the outer case 22 as an inner pipe, and a heat medium similar to the inner pipe 26 in the above embodiment may be disposed at the center thereof. It may have a structure in which a heat medium is circulated through the passage, or it may have a triple-pipe structure.

In addition, although the heat medium circulated in the heat exchanger 21 is the heat medium whose temperature has been raised by the solar heat collector 24, it is possible to use instead of the solar heat collector 24, or
Any heat collection source can be used, such as one that connects the exhaust heat side of a heat pump with the solar heat collector 24 and also uses the exhaust heat of the heat pump, or one that uses geothermal heat, domestic waste heat, etc., and is specified in the above case. It is not something that will be done. Further, a coil or the like may be arranged in the hot water storage tank 5 in addition to the heat exchanger 21, and a heater or the like may be operated by the heat collected by the coil or the like in the hot water storage tank 5.

In addition, the hot water storage tank 5 is not limited to a flexible, flat-shaped tank that is placed under the floor, but may also be a tank that is placed somewhere other than under the floor, is vertically long, or is a rigid tank that maintains a certain shape. It's okay. Furthermore, the proportional water heater 42 is not necessarily required.

As described above, according to the present invention, it is possible to provide a heat storage hot water supply facility with high heat exchange efficiency and excellent heat storage capacity and hot water supply capacity.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the heat storage hot water supply device according to the present invention, and FIGS. 2 and 3 show the paths of the heat medium and heated water during the heat storage operation and hot water supply operation of the embodiment, respectively. FIG. 1...Building, 2...Floor, 3...Fabric foundation, 4...
... Underfloor space, 5... Hot water tank, 11... Heated water, 12... Insulating mat, 13... Subfloor surface,
14...Insulation material, 15...Water supply pipe, 16...
Ball tap, 17...Introduction pipe, 19...Upper and lower connecting pipe, 20...Anchor, 21...Heat exchanger, 22...Outer case serving as a heat medium flow path, 23...
... Heat medium pipe, 24 ... Solar collector which is an external heat source, 25 ... Heat medium circulation pump, 26 ... Inner pipe which is a heated flow path, 30 ... Circulation pipe, 3
1, 32...First and second three-way switching valves serving as switching means, 31A, 32A...First port, 31B,
32B...2nd port, 31C, 32C...3rd port
Port, 33...Circulation pipe, 34...Hot water pump serving as forced water supply means, 35, 36...Pumping pipe and pumping pipe serving as circulation flow path, 38
... Hot water pipe which is a flow path for hot water supply, 41 ... Thermowax valve, 42 ... Proportional control type water heater,
43...Water heater.

Claims (1)

[Claims] 1. A heat exchanger having a heat medium flow path connected to an external heat source and through which a heat medium from the heat source passes, and a heated flow path capable of exchanging heat with the heat medium flow path. It is installed at the bottom of the hot water storage tank, one end of the heated flow path is extended to near the liquid level in the hot water storage tank and is open, and the other end of the heated flow path is connected to a switching means and a forced water supply means. The switching means is connected to the circulation channel and the hot water supply channel through the channel, and the switching means is provided to selectively communicate the heated channel and the circulation channel or the hot water supply channel, and the switching means is connected to the circulation channel and the hot water supply channel through A thermal storage hot water supply facility characterized in that an end opposite to the switching means is open to the bottom side of the hot water storage tank, and an end of the hot water supply flow path opposite to the switching means is connected to a water heater. 2. Claim 1, wherein the heated flow path of the heat exchanger is disposed to penetrate into the heat medium flow path, so that the heat exchanger has a double structure. Thermal storage hot water equipment described in .