JPS6023645Y2 - heat storage device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a heat storage device used, for example, in a solar heat utilization device.

Figure 1 is a piping diagram showing an overview of a solar heating system. In the figure, 1 is a solar collector, 2 is a water storage tank for heat medium fluid, and 3 is a heat supply pump. The amount of heat collected by the collector 1 is supplied to the water in the tank 2 via the heat supply side heat medium paths 4a and 4b of the tank 2.

5 is an evaporator consisting of a double tube, and the outer tube is used to store hot water in tank 2 (5
The temperature is preferably about 25°C.

) flows through the inner pipe, and a refrigerant such as fluorocarbon flows through the inner pipe.

Reference numeral 6 denotes a heat utilization side pump, which circulates water to be mixed with heat supply side water in the tank 2 in the direction of the arrow, and connects heat utilization side heat medium paths 7a and 7b.
The heat collected by the collector 1 is applied to the refrigerant through the collector 1.

8 is a refrigerant compressor, 9 is a condenser, and 10 is a pressure reduction mechanism, which together with the evaporator 5 forms a refrigerant circuit.

11 is a blower installed opposite to the condenser 9.

FIG. 2 is a cross-sectional view and a plan view showing a heat storage body 12 arranged in the tank 2. Reference numeral 13 is a latent heat storage material containing, for example, calcium chloride as a main component, which melts at a predetermined temperature, for example, 20°C. It stores heat through sensible heat and latent heat.

14 is a heat conductive container containing the inside of the heat storage material 13, which includes a cylindrical tube portion 14a, an end plate 14b with both ends of the tube portion 14a sealed,
A large number of fins 1 provided radially on 14b and 14a
4c.

15 is a heat storage body consisting of a heat storage material 13 and a container 14;
A large number of heat storage bodies 15 are arranged inside.

In this configuration, the amount of heat collected by the collector 1 is given to the refrigerant as the heat of evaporation of the refrigerant in the evaporator 5, and is compressed by the compressor 8, so that it becomes a high-temperature liquid in the condenser 9. This exchanges heat with the air, and the loosened air is sent to a predetermined position by the blower 11 and used for heating.

On the other hand, the water that has given heat to the refrigerant in the evaporator 5 has a low temperature and returns to the tank 2 through the heat medium path 7b.

When the sunshine hours are long, the water temperature in the tank 2 gradually rises even though the above operation is repeated, and the heat storage material 13
is in a molten state, and a large amount of heat is accumulated in the tank 2 together with the sensible heat of the water.

However, even though rapid heating is desired on early cloudy days with no sunlight and especially on low temperature days, the above configuration had the disadvantage that the heating capacity suddenly decreased after a relatively short period of time, for example, around 3 inches. .

As a result of a detailed investigation of this phenomenon, it was found that although the heat storage material 15 still has a large amount of heat and the center of the heat storage material 13 is still in a molten state, the water temperature in the tank 2 is close to O'C, resulting in heating. It was found that the performance deteriorated rapidly.

Furthermore, if the water temperature in the tank 2 falls below 5° C., there is a risk that local water freezing will occur in the above-mentioned device, and it is dangerous to continue operation beyond that point.

The above phenomenon is caused by the cold water returning from the heat medium path 7b taking sensible heat from the heat storage material 13 through the heat conductive container 14, and further removing the sensible heat from the heat storage material 13.
This occurs because the cold water is heated and solidified on the inner surface of the container 14.

This solidified layer generally has poor thermal conductivity, and some of its latent heat of solidification is also given to the molten heat storage material 13 in the center, so the amount of heat flowing from the center toward the container 14 is reduced. Even though the center is in a high-temperature molten state, the amount of heat given to the water through the container 14 is insufficient, and the amount of heat obtained from the condenser 9 rapidly decreases.

Furthermore, when it is desired to rapidly store heat in the tank 2, such as when the weather is cloudy and the sunshine hours are short, the above configuration has the disadvantage that it is difficult to melt the heat storage material 13 to the center.

In view of the above circumstances, the object of this invention is to obtain a heat storage device that effectively radiates or stores heat from the heat storage body.

Figures 3 and 4 show a water tank 2 showing an embodiment of this invention.
In the sectional view and piping diagram of the equipment, the same symbols as in the previous section indicate the same or equivalent parts.

In the figure, reference numeral 16 denotes a heat storage body placed in the rectangular tank 2, which is made of a box 17a and a large number of fins 17b provided on the outer surface of the box 17a. A heat conductive container 17, a heat storage material 13 using latent heat similar to a conventional product built in this container 17 in a watertight manner, and a serpentine tubular inner passage 18 made of aluminum, which is a heat conductive material, embedded in the heat storage material 13. and support legs 16a that facilitate water flow to both end openings 18a, 18b of the passage 18 opened at the bottom of the container 17.

2a is the heat insulating wall of the tank 2, 19a and 20a are the heat insulating walls 2 on the top surface
A pair of insulated pipes extending upward from near the left and right ends of a, 19
b, 20b are a pair of insulating pipes extending left and right from the lower part of the heat insulating walls 2a on both sides, the pipe 19a is connected to the three-way valve 21 connected to the heat medium path 7a on the heat utilization side, and the pipe 20a is connected to the heat supply side pipe. The pipes 19a, 19b and 20a, 20b form two first heat medium flow paths 19, 20 via the tank 2.

23 is a pipe connecting the three-way valves 21 and 22; 24a is an insulated pipe connected to the center of the passage 18 and extending above the tank 2;
It is connected to the piping 23 via a piping 25 which is connected so that the two converge.

There is a passage 1 between this pipe 25 and pipes 19b and 20b.
Two second heat medium flow paths 24, 24 are formed via 8.

Note that 26, 27, and 28 are temperature sensing elements arranged inside the pipes 19a, 20a, and 24a, respectively.

In the case of such a configuration, first, a case where heating is performed in the early morning when there is no sunlight will be explained.

It is assumed that the temperature inside tank 2 is now 23C due to the accumulation of solar heat from the previous day.

Therefore, the heat storage material 13 is in a molten state.

The element 26 that turns on the start switch of the device detects that the water temperature in the tank 2 is 23°C, and the three-way valve 21 is connected to the piping. a
, 19a are set so that they are in communication with each other, and then the pump 6 and compressor 8 are started.

In this case, the three-way valve 22 is in a fully closed state, and the pump 3 is stopped.

Therefore, the outside of the pipe 19b1 heat storage material 16, that is, the heat storage material 1
The gap between the outer surface of 6 and the inner surface of the heat insulating wall 2a, and the piping 1
Hot water at 23° C. is supplied to the evaporator 5 through one of the first heat medium flow paths 19 made up of the heat medium flow path 9a.

This hot water evaporates the refrigerant in the evaporator 5 to give heat,
The amount of heat is extracted from the condenser 9 by the blower 11 to start heating.

On the other hand, the water that has lost its calorific value returns to the tank 2 through the pipe 19b.

As described above, the temperature of the water in the tank 2 gradually decreases, and the sensible heat of the heat storage body 16 is extracted and used for heating.

When the temperature of the box body 17a reaches 20°C, the heat storage body 13 begins to solidify on the inner surface of the box body 17a while releasing solidification heat, and when this solidified layer becomes thick enough to form, the water temperature in the tank 2 rapidly decreases as in the conventional device. begins to decline.

The element 26 detects this drop in water temperature and operates the three-way valve 21 to connect the heat medium path 7a and the pipe 23.

In this case, the element 26, an electric circuit (not shown) connected to the element 26, and the three-way valve 21 form switching means for the first and second heat medium flow paths 19 and 24.

In the process of supplying water to the evaporator 5 through the first heat medium flow path 19 as described above, in the second heat medium flow path 24,
Of course, the water flow except for the part shared with the first heat medium flow path 19,
Since there is almost no exchange of heat between the heat storage material 13 and the water, the heat storage material 13 in contact with the passage 18 is in a molten state.

Therefore, when the three-way valve 21 is switched to the piping 23 side, water close to 23°C is supplied to the evaporator 5, unlike the conventional device.
Comfortable heating can be continued without reducing the heating capacity even if the heating capacity is only powdery.

In the water supply process from the second heat medium flow path 24, almost no water above the lower end of the fin 17b in FIG. The temperature of the solidified layer of the heat storage material 13 formed on the inner surface of the heat storage material 17a increases.

On the other hand, as the water supply continues, a solidified layer of the heat storage material 13 grows on the outer surface of the passage 18, gradually lowering the temperature of the supplied water, but the heat of solidification when the heat storage material 13 solidifies along the passage 18 is While giving heat to the water in the passage 18,
This promotes heat flow toward the box body 17a.

As the water supply process as described above continues, the water temperature detected by the element 26 becomes higher than the water temperature detected by the element 28.

When the water temperature difference reaches, for example, 5° C., the three-way valve 21 operates to connect the pipes 7a and 19a again, and water is again supplied to the evaporator 5 via the first heat medium flow path 19.

During this water supply period, the heat distribution changes in the heat storage body 16 as described above, and the water temperature detected by the element 28 becomes higher than the water temperature detected by the element 26.

When this water temperature difference reaches, for example, 3°C, the three-way valve 21 is turned off again. It operates so as to connect a and 23.

By repeating such an operation, the amount of heat accumulated in the tank 2 can be effectively used as the amount of heating heat without reducing the temperature of the water supplied to the evaporator 5 to, for example, 5° C. or lower.

Note that it is necessary to frequently switch the three-way valve 21 as the amount of heat in the heat storage material 13 decreases, but such control is performed by the element 2.
This can be easily done by using a microcomputer that inputs 6.28.

FIG. 5 shows the temporal change in the temperature of the water supply, showing that the device of the above embodiment, which has the same amount of heat in the tank 2, utilizes the amount of heat in the tank 2 more effectively than the conventional device. Figure A relates to the conventional device, and the bad days relate to the example device.

The solid line on bad days is the detected temperature of element 26, and the dotted line is the temperature detected by element 28.
Figure A shows the detected temperature when an element corresponding to element 26 is installed, where the solid line is during heating operation and the dashed-dotted line is when operation is stopped.

As can be seen in the figure, in contrast to the conventional device, which is able to provide heating for about 2 hours by stopping the operation several times for approximately m minutes, the device in the example is capable of continuous heating. This has the effect of reducing heating temperature ripple.

In the embodiment, as mentioned above, when the sunlight increases and the collector 1 becomes available for use while heating is performed only by the heat amount of the tank 2, for example, when the vane meter (not shown) detects, the three-way valve is activated. 21 is the pipe 7a.

19a and the three-way valve 22 are set so that they communicate with the pipes 4a and 20a, respectively, and the pump 3 starts operating.

In this state, the hot water collected by the collector 1 and the cold water released by the evaporator 5 are mixed in the tank 2, and water at an appropriate temperature is supplied to the evaporator 5, providing comfortable heating.

When the element 26 detects that the sunlight is getting stronger and the water supply temperature of the evaporator 5 approaches the dangerous temperature of the refrigerant circuit, for example 30°C, the three-way valve 22 is connected to the pipes 4a and 23 in response to a command from the microcomputer, for example. Switch to

That is, the first heat medium flow path 20 on the heat supply side has been switched to the second heat medium flow path 24.

Even in this state, if the temperature detected by the element 26 is 30°C, the pump 3 is stopped to protect the refrigerant circuit, but if the temperature detected by the element 26 decreases, the heat storage body 13 near the passage 18 is heated to 20°C. Since it is in a solidified state below °C, pump 3
continues driving.

In this case, the relatively high temperature water collected in collector 1 is transferred to passage 1.
8, the heat storage material 13 cools the pipe 19b.
Since the water is mixed with relatively low temperature water flowing in from the pipe 19a and flows out from the pipe 19a, the evaporator 5 is again supplied with water at an appropriate temperature.

This state continues until the heat storage material 13 near the passage 18 absorbs heat of fusion from the water and melts, and the temperature of the molten material approaches 30°C.

When the detected temperature of element 26 reaches 30°C, for example, element 2
7, and if the difference is larger than a predetermined value, the three-way valve 22 is switched so that the pipes 4a and 20a communicate with each other, and if the difference is smaller than the predetermined value, the pump 3 is stopped and the three-way valve 22 is completely closed. Closed.

The above is the operation when the sunlight is strong and the sunlight hours are long, but if there is little sunlight in the daytime and you want to accumulate as much heat as possible in the tank 2 during the evening sunlight, the pump 6 and compressor 8 should be stopped. , for example, at regular time intervals, the three-way valve 22 closes the pipe 20.
By controlling the heat storage material 13 by the computer so that the heat storage material 13 is alternately communicated with the heat medium path 4a, the entire heat storage material 13 can be melted and a large amount of heat can be stored in the tank 2 in a short time.

In the above embodiment, there was only one tank 2, but for example, two tanks A and B having the same shape as in FIG. B's first heat medium flow path 19, tank A
If hot water is taken out in a cycle such as the second heat medium flow path 24 in tank B, the second heat medium flow path 24 in tank B, the first heat medium flow path 19 in tank A, etc., the hot water can be used. It is also possible to make the ripple in hot water temperature very small.

Note that in the above embodiment, the first and second heat medium flow paths 19
, 24 are used by switching them alternately, but in the case of rapid heat radiation or heat storage, the flow path 20 or 19 and the flow path 24 may be used simultaneously in parallel.

Further, although the above embodiment deals with positive heat storage, that is, heat storage of hot water, this invention produces the same effect even in the case of negative heat storage, that is, use of cold water.

Further, tank 2 is not necessarily required.

Although the above-mentioned embodiments relate to solar heat utilization devices, similar effects can be obtained in various heat storage devices, such as those utilizing late-night electricity or factory wastewater.

Further, the heat medium flow path can provide the same effect on substances other than water salt, such as antifreeze and air.

As explained above, this device has a first heat medium flow path passing through the outside of a heat conductive container containing a heat storage material utilizing latent heat, and a second heat medium flow path passing through a heat transfer internal passageway passing through the heat storage material. road and
By providing the switching means for both the flow paths, it is possible to effectively utilize the amount of heat of the heat storage material.

[Brief explanation of drawings]

Fig. 1 is a piping diagram of a conventional device, Fig. 2 is a sectional view and a plan view of a conventional heat storage body, and Figs. 3 and 4 are a sectional view of a heat storage tank and piping of the device showing an embodiment of this invention. 5 are characteristic diagrams of the conventional device and the above embodiment. In the figure, 1 is a solar collector, 2 is a water tank, 4a, 4
b is a heat medium path on the heat supply side; 5. 8.9. 10 is a refrigerant circuit;
7a and 7b are heat medium paths on the heat utilization side; 13 is a heat storage material utilizing latent heat;
16 is a heat storage body, 17 is a heat conductive container, 18 is an internal passage, 1
9, 19a, 19b and 20, 20a, 20b are first heat medium flow paths, 21.degree. 22.26, 27, 28 are switching means, and 24, 24a are second heat medium flow paths. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (3)

[Scope of utility model registration request] (1) A heat storage tank connected to the heat supply side and the heat utilization side. A heat storage material using latent heat is built into a heat conductive container placed in this heat storage tank. A heat storage material provided with an internal passage, a first heat medium flow path formed so that a heat medium flow flows between the outer circumferential wall of the heat storage body and the inner wall of the heat storage tank, and a second heat medium flow path formed through the internal passage. The first heat medium flow path and the second heat medium flow path depend on the temperatures of the heat medium flow path and both heat medium flow paths.
A heat storage device equipped with a switching means for switching between a heat medium flow path and a heat medium flow path. (2) The heat storage device according to claim 1, wherein the first and second heat medium passages are connected to the heat utilization side heat medium passage through a switching means. (3) The heat storage according to claim 1 or 2 of the utility model registration claim, characterized in that the first and second heat medium flow paths are connected to the heat supply side heat medium path through a switching means. Device.