JP2003262405A - Solar heat-using water heater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar heat-using water heater capable of efficiently producing hot water even if a heat collector can not be installed to face south. <P>SOLUTION: The solar heat water heater includes a solar heat collector 11 comprising an east side heat collector 11 and a west side heat collector 11b installed respectively on the eastward and westward surfaces of a roof, and a heat storage tank 12. Solar piping 13 having a heat exchanger part 16 to be introduced into the heat storage tank 12 is connected to the solar heat collector 11 to form a circulation path for a heat medium. A circulating pump 18 and a reservoir tank 19 are installed in the first main pipe 14 of the solar piping 13, and a motor-driven three-way valve 17 for selectively switching the circulation path to either the east side heat collector 11a or the west side heat collector 11b according to the temperatures of the heat collected by the east side heat collector 11a and the west side heat collector 11b is installed at the branch sections of the first branch pipes 14a and 14b of the first main pipe 14. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solar water heater that uses solar heat to generate hot water, and particularly to generate hot water efficiently even when a heat collector cannot be installed facing south. The present invention relates to a solar water heater.

[0002]

2. Description of the Related Art A solar water heater of this type is shown in FIG. This solar water heater 50
As shown in the figure, is equipped with a solar collector 51 installed on the roof surface of a house and the like, and a heat storage tank 52 in which clean water is stored. A circulation path for the heat medium is formed by the solar pipe 53 connecting the side and the outlet side. The solar pipe 53 forming the circulation path of the heat medium is partially introduced into the heat storage tank 52 and performs heat exchange between the clean water stored in the heat storage tank 52 and the heat medium. Circulating the heat medium between the solar collector 51 and the heat exchanging unit 54 by the circulation pump 55 installed in the solar pipe 53, the hot water is generated in the heat storage tank 52. It has become so.

[0003]

By the way, the solar collector 51 for collecting solar heat is preferably installed on a south facing roof surface or the like with good solar radiation conditions, but the roof surface of the house is not necessarily facing south. However, if the solar collector 51 cannot be installed on the south facing roof surface due to the installation space, etc., even if the house has a south facing roof surface. There is also.

As described above, when the solar collector 51 cannot be installed on the roof surface facing south, when the solar water heater 50 is installed, there is a time zone where solar radiation cannot be received. However, there is a problem in that the solar collector 51 must be installed on a roof surface facing east or west where heat collection efficiency is poor, and hot water cannot be efficiently generated.

Therefore, an object of the present invention is to provide a solar water heater that can efficiently generate hot water even when the heat collector cannot be installed facing south.

[0006]

In order to solve the above-mentioned problems, the invention according to claim 1 circulates a heat medium by a circulation pump so as to pass through a collector for collecting solar heat. Solar heat that introduces a heat exchange part formed in a part of the circulation path into the heat storage tank and circulates a heat medium between the heat collector and the heat exchange part to generate hot water in the heat storage tank. In the water heater used, multiple sets of the heat collectors are installed so that the heat collecting surfaces face different directions,
Hot water using solar heat, characterized in that a switching means for switching the circulation path is provided so that a heat medium is selectively supplied to any one of the plurality of collectors. To provide a container.

As described above, in this solar water heater, one of a plurality of heat collectors and a plurality of heat collectors installed so that the heat collecting surfaces face different directions. Since it has a switching means for switching the circulation path of the heat medium so that the heat medium can be selectively supplied to the heat collector, the heat collector can be installed, for example, on the south facing roof surface. Therefore, if two sets of heat collectors are installed on the east facing roof surface and the west facing roof surface respectively, in the morning when the east facing roof surface is exposed to sunlight, the heat collector installed on the east facing roof surface will be used. As the heat medium is supplied, the circulation route of the heat medium is switched by the switching means, so that the heat medium is supplied to the heat collector installed on the westward roof surface in the afternoon when the westward roof surface is exposed to the sunlight. By switching the circulation path of the heat medium by the switching means, It is possible to generate a rate well warm water.

Further, like the solar water heater of the invention according to claim 2, there is provided control means for controlling the switching operation of the switching means, and the control means is one of a plurality of sets of the heat collectors. If the circulation path is switched by the switching means so that the heat medium is supplied to the set of heat collectors having the highest heat temperature, the heat collector with good heat collection efficiency is automatically operated. Since the heat can be collected while selectively selecting the hot water, the hot water can be generated more efficiently. As the "heat collecting temperature" used here, the outlet temperature of the heat medium sent from the heat collector, the temperature of the heat collecting plate constituting the heat collector, or the air temperature in the heat collector is adopted. can do.

Further, as described above, when the circulation path is switched by the switching means so that the heat medium is supplied to the set of heat collectors having the highest heat collecting temperature, the heat collecting operation is not performed. The heat collector, i.e., the heat collector in which the heat medium is not circulated, does not radiate heat, so the collected heat is gradually accumulated even if the solar radiation is weak, and the heat collecting temperature is It may be higher than the heat collection temperature of the existing collector. In such a case, if the circulation path is immediately switched and the heat collection operation is started, the heat medium is circulated and heat is released, so that the heat collection temperature of the heat collector rapidly drops, and the heat collection is performed in a short time. The temperature will be reversed. Therefore, if the heat collecting temperatures of the heat collectors are simply compared and the circulation path is switched, the switching means frequently performs the switching operation, which causes a problem in durability of the switching means.

Therefore, like the solar water heater according to the third aspect of the present invention, the switching means switches the circulation path until a predetermined time elapses after the switching means switches the circulation path. If this is not done, the efficiency of generating hot water will be slightly reduced, but the switching means will not perform frequent switching operations, and therefore the deterioration in durability of the switching means can be minimized.

Further, when the heat medium is not circulated to all the heat collectors and the operation of the circulation pump is stopped, the heat collecting temperatures of the heat collectors are simply compared to determine the circulation path. Even if the circulation pump is switched, the switching means does not frequently perform the switching operation as in the operation of the circulation pump. Therefore, as in the solar water heater of the invention according to claim 4, the circulation pump stops operating. In this state, it is desirable that the switching means can switch the circulation path even after the switching means has switched the circulation path and before the elapse of the predetermined time. By adopting such a configuration, the operation of the circulation pump can be immediately restarted, so that the mechanical loss of the heat collecting operation can be minimized.

Further, as in the solar water heater of the present invention according to claim 5, the heat collecting operation is performed after the circulation path is switched by the switching means while the circulation pump is operating. When the heat collecting temperature of the heat collector is stable and the heat collecting temperature of the heat collector is lower than the heat collecting temperature of the heat collector that was performing the heat collecting operation immediately before the switching of the circulation path, If the switching of the circulation path is performed by the switching means even before the predetermined time has elapsed, the heat collection operation time of the heat collector in a state of poor heat collection efficiency is shortened. The effect that hot water can be generated efficiently is obtained.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments will be described below with reference to the drawings. As shown in FIG. 1, the solar water heater 1 includes a solar collector 11 and a closed heat storage tank 12.
And a water supply pipe 31 for supplying clean water to the lower end of the heat storage tank 12, and a hot water supply pipe 3 for delivering the stored warm water to the upper end.
2 is connected.

The solar heat collector 11 is composed of an east heat collector 11a installed on the east facing roof surface and a west heat collector 11b installed on the west facing roof surface. A circulation path for the heat medium is formed by the solar pipe 13 that connects the air outlet and the outlet side.

The solar pipe 13 is a forward main pipe 14 connected to a heat exchange section 16 introduced into the heat storage tank 12 and a branch from the forward main pipe 14 and an inlet side of the east side heat collector 11a and the west side heat collector 11b. Branch pipes 14a, 1 respectively connected to
4b, return branch pipes 15a and 15b connected to the outlet sides of the east side heat collector 11a and the west side heat collector 11b, respectively, and the return main pipes connected to the heat exchange section 16 by joining the return branch pipes 15a and 15b. 15, and the branch path of the outward branch pipes 14a and 14b in the outward main pipe 14 selectively has a circulation path of the heat medium to either the east side heat collector 11a or the west side heat collector 11b. An electric three-way valve 17 for switching is installed.

Further, the main pipe 1 in the solar pipe 13
4, a circulation pump 18 that circulates the heat medium between the solar heat collector 11 and the heat exchange unit 16, and a reserve tank 19 that stores the heat medium are installed, and the east side heat collector 1
The heat medium heated by either 1a or the west side heat collector 11b passes through the solar pipe 13 and the heat storage tank 1
The hot water is generated in the heat storage tank 12 by being guided to the inside of the heat storage tank 2 and exchanging heat with the water in the heat storage tank 12 in the heat exchange section 16.

The reserve tank 19 is provided with a reserve amount detecting means 19a for detecting whether or not the reserve amount of the heat medium stored in the reserve tank 19 is below a required minimum amount. When the detection means 19a detects that the amount of the heat medium held is less than the required minimum amount, the operation of the circulation pump 18 is forcibly stopped in order to prevent the idle operation of the circulation pump 18. There is.

The east side heat collector 11a and the west side heat collector 1
1b is a heat collecting temperature sensor 21 for detecting the outlet temperature (hereinafter referred to as heat collecting temperature) Tbe and Tbw of the heat medium.
a and 21b are installed respectively, and an in-tank temperature sensor 22 that detects a temperature (hereinafter, referred to as in-tank temperature) Tt of hot water stored in the heat storage tank 12 is installed in a lower portion of the heat storage tank 12. There is.

The solar heat water heater 1 is also provided with a controller 1a to which the holding amount detection signal from the holding amount detecting means 19a, the temperature detection signals from the heat collecting temperature sensors 21a and 21b and the in-tank temperature sensor 22 are input. Is mounted, and the controller 1a carries out start / stop control of the circulation pump 18 and switching control of the circulation path of the heat medium by the electric three-way valve 17 based on the holding amount detection signal and the temperature detection signal. ing.

The operation of the solar water heater 1 will be described below with reference to the operation state transition diagram shown in FIG. First, in the state where the power is turned off, the electric three-way valve 17 is switched to the east side route (outward branch pipe 14a) side, and the circulation pump 18 is in the operation state 1 in which the operation is stopped. When turned on, the operation is started from the operation state 1.

In the morning, the east side heat collector 11a receives solar radiation, so that the temperature of the heat medium in the east side heat collector 11a rises, and the heat collection temperature Tbe of the east side heat collector 11a changes to the tank. When the temperature becomes higher than the internal temperature Tt by 6 ° C. or more, hot water can be generated in the heat storage tank 12, so that the circulation pump 18 is activated and the east side heat collector 11a performs the heat collecting operation to the operating state 2. Transition.

As described above, when the solar radiation of the east side is weakened while the east side heat collector 11a is performing the heat collecting operation, the heat collection temperature Tbe of the east side heat collector 11a begins to gradually decrease. Heat collection temperature Tbe of the heater 11a and bath temperature Tt
When the difference between the temperature and the temperature decreases to 3 ° C. or less, almost no hot water can be generated in the heat storage tank 12, so the circulation pump 18 stops the operation and shifts to the operation state 1 in which the heat collecting operation is not performed. .

On the other hand, when the east side heat collector 11a is performing heat collecting operation and the altitude of the sun rises and the insolation gradually increases, the west side heat collector 11b also begins to gradually receive the sun's insolation. Therefore, the temperature of the heat medium in the western heat collector 11b gradually rises. At this time, the west side heat collector 11
Since the heat medium in b is not circulating, it is not radiated, and the heat collecting temperature Tbw of the west side heat collector 11b becomes higher than the heat collecting temperature Tbe of the east side heat collector 11a. , The heat collecting temperature Tbw is 3 ° C. higher than the heat collecting temperature Tbe
When the temperature is higher than the above, the electric three-way valve 17 is moved to the west side route (outgoing pipe 1
4b) side, and the west side heat collector 11b shifts to the operation state 3 in which heat collection operation is performed.

In this way, the heat collecting operation is performed on the east side heat collector 11a.
From the west side heat collector 11b, the west side heat collector 11b
Since the heat medium in b starts circulation and starts heat radiation, and the heat medium in the east side heat collector 11a stops circulation and does not radiate heat, the heat collection temperature Tbw of the west side heat collector 11b drops sharply. Heat collection temperature Tb of the east side heat collector 11a
e starts to rise, and the heat collection temperature Tbw of the west side heat collector 11b may be lower than the heat collection temperature Tbe of the east side heat collector 11a by 3 ° C. or more in a short time. However, once the heat collection operation is switched from the east side heat collector 11a to the west side heat collector 11b, the heat collection operation is again performed until the lapse of 15 minutes from that point.
It does not switch to the side.

On the contrary, in the afternoon, the west side heat collector 11b receives the solar radiation, so that the west side heat collector 11 is mainly used.
b will perform the heat collection operation, but similarly, the heat collection operation may switch from the west side heat collector 11b to the east side heat collector 11a. In such a case, the heat collection operation is similarly performed. Once the west heat collector 11b is switched to the east heat collector 11a, the heat collection operation is not switched to the west heat collector 11b side again until 15 minutes have elapsed from that point.

As described above, in the afternoon, the west side heat collector 11b mainly performs the heat collecting operation, and the west side heat collector 11b.
When the solar radiation of the sun weakens while the heat collecting operation is performed, the heat collecting temperature Tbw of the west side heat collector 11b begins to gradually decrease. Therefore, the heat collecting temperature Tbw of the west side heat collector 11b and the temperature in the tank When the difference from Tt decreases to 3 ° C. or less, almost no hot water can be generated in the heat storage tank 12, so the circulation pump 18 stops the operation and shifts to the operation state 4 in which the heat collecting operation is not performed. To do.

However, even when the circulation pump 18 is stopped, the solar radiation becomes strong after that, and the temperature of the heat medium in the west side heat collector 11b rises. When the heat collection temperature Tbw is higher than the temperature Tt in the tank by 6 ° C. or more, hot water can be generated in the heat storage tank 12, so that the circulation pump 18 is restarted and the west heat collector 11b collects heat. It will shift to the driving state 3 in which driving is performed.

Even in the operating state 1 or the operating state 4 in which the circulation pump 18 is stopped, the west side heat collector 11 is
The heat collection temperature Tbw of b is the heat collection temperature Tb of the east side heat collector 11a.
When it becomes higher than e by 3 ° C or more, the electric three-way valve 17 is switched to the west side route (outward branch pipe 14b) side, and conversely, the heat collecting temperature Tbe of the east side heat collector 11a is higher than that of the west side heat collector 11b. When the temperature is higher than the heat collecting temperature Tbw by 3 ° C. or more, the electric three-way valve 17 is switched to the east side route (outward branch pipe 14a) side.

However, in the operating states 1 and 4 in which the heat medium is not circulated and supplied to both the east side heat collector 11a and the west side heat collector 11b, the heat collection of the east side heat collector 11a and the west side heat collector 11b is performed. Even if the circulation paths are switched by simply comparing the temperatures Tbe and Tbw, the operating state 2 or the operating state 3 in which the heat medium is circulated and supplied to either the east side heat collector 11a or the west side heat collector 11b. As in the case, the electric three-way valve 17 does not frequently repeat the switching operation of the heat medium circulation path. Therefore, in the operating state 1 or the operating state 4 in which the circulation pump 18 is stopped, the circulation pump 18
Unlike the case of the operating state 2 or the operating state 3 in which the vehicle is operating, once the electric three-way valve 17 is switched to either the east side route or the west side route, if one minute elapses from that time point, the other side is immediately switched to the other side. It can be switched.

Also, normally, at the time of sunset, the electric three-way valve 1
7 has been switched to the west route, the circulation pump 18 has stopped operating, and the operating state 4 has been entered. However, the temperature difference between the heat collection temperature Tbw of the west heat collector 11b and the in-tank temperature Tt. If the temperature of 3 ° C or lower continues for 1 hour or more, the operating state 1 is automatically set in preparation for the heat collection operation in the next morning as described above.
It will shift to and wait.

As described above, in the solar water heater 1, the east side heat collector 11a and the west side heat collector 11b are installed on the eastward facing roof surface and the westward facing roof surface, respectively. Among the heat collectors 11b, the circulation path is automatically switched by the electric three-way valve 17 so that the heat medium is selectively circulated and supplied to the heat collector having the higher heat collection temperature. Even if it is not possible to install the container on the roof facing south with good heat collection conditions, hot water can be generated efficiently.

Further, in the solar water heater 1, as described above, in the operating state 2 and the operating state 3 in which the circulation pump 18 is operating, once the circulation path of the heat medium is switched by the electric three-way valve 17. However, the recirculation path is not re-switched until 15 minutes have elapsed from that point, so that the hot water generation efficiency is slightly reduced, but the electric three-way valve 17 frequently changes the heat medium circulation path. It is possible to minimize the deterioration of the durability of the electric three-way valve 17 without performing the switching operation.

Further, in the solar water heater 1, as described above, in the operating state 1 and the operating state 4 in which the circulation pump 18 is stopped, the electric three-way valve 17 is in either the east side route or the west side route. After switching to one side once,
After 1 minute has passed from the time of the switching, it is possible to switch to the other immediately. Therefore, the heat collection temperature Tbe or the heat collection temperature Tbw of the east side heat collector 11a or the west side heat collector 11b and the temperature in the tank When the temperature difference from Tt becomes 6 ° C. or more, the operation of the circulation pump 18 can be restarted within 1 minute, so that the mechanical loss of the heat collecting operation can be minimized.

In the above-described embodiment, when the circulation path of the heat medium is once switched by the electric three-way valve 17 in the operating states 2 and 3 in which the circulation pump 18 is operating, 15 minutes elapses from that point. Until then, the circulation path is not re-switched, but the invention is not limited to this. For example, the heat collection operation is performed after the heat medium circulation path is switched by the electric three-way valve 17. When the heat collecting temperature of the east side heat collector 11a or the west side heat collector 11b becomes stable (for example, 5 minutes from the time of switching the circulation path), the east side heat collector 11a or the west side heat collector 11
If the heat collection temperature of b is lower than the heat collection temperature of the west side heat collector 11b or the east side heat collector 11a that was performing the heat collection operation immediately before the switching of the circulation path, the circulation by the electric three-way valve 17 at that time. If the path is switched again, the heat collection operation time of the heat collector in a state where the heat collection efficiency is poor is shortened, so that the effect that hot water can be generated more efficiently can be obtained.

Further, in the above-described embodiment, in the operating state 1 and the operating state 4 in which the circulation pump 18 is stopped, the delay time for re-switching the circulation route after switching the circulation route is 1 minute. However, the present invention is not limited to this, and may be set to 15 minutes as in the case of operating state 2 and operating state 3 in which the circulation pump 18 is operating.

In the above embodiment, the heat collecting temperatures Tbe and Tb of the east side heat collector 11a or the west side heat collector 11b are collected.
When the temperature difference between w and the temperature Tt in the tank becomes 6 ° C or more, the circulation pump 18 is started, and when the temperature difference becomes 3 ° C or less,
The operation of the circulation pump 18 is stopped, and between the east side heat collector 11a and the west side heat collector 11b, the heat collection temperature of one is higher than the heat collection temperature of the other by 3 ° C. or more. Then, the circulation path is switched, but the invention is not limited to this. The temperature difference between the heat collection temperatures Tbe and Tbw and the temperature Tt in the tank when the circulation pump 18 is started and stopped, and the circulation path. Heat collection temperatures Tbe, T when switching between
The temperature difference between bw may be set appropriately.

In addition, in the above-mentioned embodiment, the delay time for re-switching the circulation path is set to 15 minutes and 1 minute, but the invention is not limited to this, and the solar collector 11 is not limited thereto. It may be appropriately set in consideration of the heat collection efficiency, the durability of the electric three-way valve 17, and the like.

Further, in the above-mentioned embodiment, the electric three-way valve 17 is used as the switching means for switching the circulation path of the heat medium, but the invention is not limited to this, and various switching means may be used. It goes without saying that you can do it.

In the above-described embodiment, the solar heat collector 11 is composed of two sets of heat collectors installed on the east facing roof surface and the west facing roof surface, respectively.
The present invention is not limited to this, and the heat collecting surface may be composed of three or more sets of heat collectors facing different directions.

Further, in the above-described embodiment, the controller 1a controls the electric three-way valve 17 based on the heat collection temperatures Tbe and Tbw of the east side heat collector 11a and the west side heat collector 11b, whereby the heat medium The circulation route is automatically switched, but the invention is not limited to this.
The user may manually switch the switching means such as a three-way valve.

[Brief description of drawings]

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

FIG. 2 is an operational state transition diagram for explaining an operational operation of the solar water heater using the same as above.

FIG. 3 is a schematic configuration diagram showing a conventional solar water heater.

[Explanation of symbols]

1 Solar water heater 1a controller (control means) 11 Solar collector (collector) 11a East side heat collector 11b West side heat collector 12 heat storage tank 13 Solar piping (circulation route) 14 Forward 14a, 14b Outgoing pipe 15 Return management 15a, 15b Return branch pipe 16 heat exchange section 17 Electric three-way valve (switching means) 18 Circulation pump 19 reserve tank 21a, 21b Heat collection temperature sensor 22 Tank temperature sensor Tbe, Tbw Heat collection temperature Tt bath temperature

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tetsuya Watanabe             93 Edo-cho, Chuo-ku, Kobe-shi, Hyogo Stock Association             Company Noritsu (72) Inventor Yoshihiko Tanaka             93 Edo-cho, Chuo-ku, Kobe-shi, Hyogo Stock Association             Company Noritsu

Claims (5)

[Claims] 1. A heat exchange section formed in a part of a circulation path for circulating a heat medium by a circulation pump so as to pass through a heat collector for collecting solar heat is introduced into a heat storage tank, and the heat collection is performed. In a solar-heated water heater that generates hot water in a heat storage tank by circulating a heat medium between a heat exchanger and the heat exchange unit, a plurality of sets of heat collectors whose heat collecting surfaces face different directions. And a switching means for switching the circulation path so that the heat medium is selectively supplied to any one of the plurality of sets of the heat collectors. A solar water heater. 2. A control means for controlling the switching operation of the switching means is provided, and the control means controls the heat collector to a set of the heat collectors having the highest heat collecting temperature among a plurality of sets of the heat collectors. The solar water heater according to claim 1, wherein the circulation path is switched by the switching means so that the medium is supplied. 3. The solar water heater according to claim 2, wherein the switching means does not switch the circulation path until a predetermined time elapses after the switching means switches the circulation path. . 4. In a state in which the circulation pump is not in operation, even after the switching means switches the circulation path and before the predetermined time elapses, the switching means changes the circulation path. The solar water heater according to claim 2 or 3, which can be switched. 5. With the circulation pump operating,
After switching the circulation path by the switching means, when the heat collection temperature of the heat collector performing the heat collection operation becomes stable, the heat collection temperature of the heat collector is immediately before switching of the circulation path. 3. When the temperature is lower than the heat collecting temperature of the heat collector that was performing the heat collecting operation, the switching of the circulation path is performed by the switching means even before the predetermined time has elapsed. The solar water heater as described in 3 or 4.