JP2015075311A - Solar heat utilization system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solar heat utilization system which is small in scale and has a simple structure, and which is not only able to perform heat exchange but also able to generate power.SOLUTION: A closed system is built by: a solar heat collector 2 for heating water by solar heat and generating steam; a condenser 3 for cooling the generated steam and retuning it to hot water having a water temperature near the boiling point; a reservoir 4; a decompressor 5 for performing decompression in the system; a heat exchanger 7 for performing heat exchange between the hot water near the boiling point flowing out of the condenser 3 and another medium; and a pipe 1 for connecting each of these configuration components. The water in the system is circulated by a buoyant force of the steam generated in the solar heat collector 2, and a water turbine power generation unit 6 is rotated by kinetic energy of the water circulating in the system and potential energy utilizing height difference from the condenser 3 to the heat exchanger 7 to generate power.

Description

  The present invention relates to a solar heat utilization system that performs power generation and heat exchange according to the principle of a thermosyphon utilizing solar heat.

  Systems that generate power using solar heat are known. As a known solar thermal power generation system, for example, a system in which sunlight is concentrated by a reflecting mirror or the like to heat a medium and generate power by a generator is known. Such a solar thermal power generation system heats a medium such as water, oil, or a molten salt to a high temperature such as 200 ° C. or more and drives the generator with the heat to generate electric power. Therefore, it is called binary power generation because it uses two types of media: a medium for propagating heat obtained from sunlight and a medium for driving the generator.

Such a solar thermal power generation system has a structure that heats the medium by concentrating sunlight, so that it is in a region where sunlight is strong and there is constant sunshine, that is, a region with low precipitation at low latitude, such as a desert, It is preferably constructed on a large site for collecting sunlight efficiently.
That is, the conventional solar thermal power generation system is large-scale, and for example, a small-scale one that can be installed in a general household has not been assumed.

On the other hand, as a small-scale device that obtains energy by using solar heat, there is a solar system or a solar water heater as disclosed in Patent Document 1, for example.
Solar water heaters use power such as pumps to move water to sunny places such as on the roof, heat the water with solar heat, exchange heat with hot water dropped after heating, and heating Solar heat is used in the form of water and hot water.

JP 2006-308234 A

As described above, there have been solar systems and solar water heaters using heat exchange as small-scale solar thermal energy utilization systems that can be used in ordinary homes. However, these have a demerit that energy can be used only in limited forms such as heating and hot water supply.
For this reason, there is a demand for not only heat exchange but also power generation using solar heat in a small-scale system that can be used even in ordinary homes.

In a small system, using solar heat to generate electricity, it is possible to generate electricity without strong sunshine or a large site, simplifying the structure of the generator, etc. There are multiple issues such as the need to reduce costs.
In light of the above, an object of the present invention is to provide a solar heat utilization system that is small in size and simple in structure and capable of generating electricity as well as heat exchange.

  The solar heat utilization system of the present invention includes a heat collector that heats and vaporizes a liquid by the heat of sunlight under reduced pressure, a condenser that condenses and vaporizes vapor vaporized in the heat collector, a water wheel, and the water wheel. A turbine directly connected to the rotating shaft of the turbine, and a water turbine power generation unit that rotates the water turbine by the liquid flowing out of the condenser and generates power by the rotation of the water turbine, and the liquid discharged from the water turbine power generation unit A heat exchanger that exchanges heat with the other medium, the heat collector, the condenser, the water turbine power generation unit, and the heat exchanger connected to each other to form a closed system, A pressure reducer for reducing the pressure in the closed system, and the liquid discharged from the heat exchanger flows into the condenser to cool the vapor for the condensation, and the condenser The liquid discharged from the And it flows into the heat sink.

  According to the present invention, heat exchange and power generation are possible.

FIG. 1 is a diagram showing the configuration of the solar heat utilization system of the present embodiment. FIG. 2 is a diagram illustrating an example of the configuration of the water turbine power generation unit of the solar heat utilization system of the present embodiment.

Hereinafter, embodiments of the solar heat utilization system of the present invention will be described.
A solar heat utilization system 100 shown in FIG. 1 is one of the preferred embodiments of the solar heat utilization system of the present invention.

<Configuration of solar heat utilization system 100>
As shown in FIG. 1, the solar heat utilization system 100 includes a pipe 1, a heat collector 2, a condenser 3, a liquid reservoir 4, a decompressor 5, a water turbine power generation unit 6, and a heat exchanger 7.
In the solar heat utilization system 100 shown in FIG. 1, the solar heat energy is collected and the liquid is heated and vaporized, the heat collector 2 for generating vapor, the condenser 3 for liquefying the vapor, and the reservoir 4 for storing the liquefied liquid. The turbine generator unit 6 for generating electricity by rotating the turbine with the flowing liquid and the heat exchanger 7 for exchanging heat with the liquid are connected to each other by the pipe 1 to construct a closed system. In the present embodiment, for example, tap water (hereinafter referred to as water) is assumed as a liquid that can be easily used by ordinary households.

The heat collector 2 collects solar heat and heats water.
The water heated by the heat collector 2 is water that is cooled by heat exchange in the heat exchanger 7 and flows in through the condenser 3 as described later.
The heat collector 2 has, for example, a heat collecting plate in which a plurality of copper pipes are bonded together, and when sufficient sunlight is applied to the heat collecting plate, the water flowing in the copper pipe is gradually warmed.
Here, as will be described later, the inside of the closed system of the solar heat utilization system 100 is depressurized by the decompressor 5, and is designed so that water is boiled and steam is generated by heating by the solar heat in the heat collector 2. Yes.

The condenser 3 has a double tube structure in which an inner tube 32 that is thinner than the outer tube 31 is passed inside the outer tube 31. Water vapor generated in the heat collector 2 is passed through the inner pipe 32, and water that has been cooled by the heat exchanger 7 is passed through the outer pipe 31. With such a double pipe structure, the water vapor passing through the inner pipe 32 is cooled and liquefied by the water in the outer pipe 31.
The water liquefied in the condenser 3 is warm water having a temperature in the vicinity of the boiling point lowered by the reduced pressure in the system. This hot water flows out through the pipe 1.

  The liquid reservoir 4 is a liquid storage container in which, for example, a copper plate or the like is bonded. In the liquid reservoir 4, water near the boiling point that has flowed out of the condenser 3 can be temporarily stored. Here, a heat insulating material may be provided around the liquid reservoir 4 so that the temperature of the water stored in the liquid reservoir 4 does not drop.

In addition, the liquid reservoir 4 is provided with a suction port 41 that communicates with a decompressor 5 including a vacuum chamber 51 and a vacuum pump 52. Valves that prevent backflow are provided between the suction port 41 and the vacuum chamber 51 and between the vacuum chamber 51 and the vacuum pump 52. As described above, the vacuum chamber 51 and the vacuum pump 52 are configured so that the pressure in the closed system of the solar heat utilization system 100 can be reduced.
It is preferable that the liquid reservoir 4 is not filled entirely with water, but a space is formed in the upper part. The space is preferably a vacuum. The suction port 41 is disposed so as to be in contact with this space, and is designed so that water does not touch the suction port 41.

  The decompressor 5 reduces the pressure in the closed system by the vacuum chamber 51 and the vacuum pump 52. As described above, the water heated in the heat collector 2 boils at a low temperature of less than 100 degrees Celsius due to the decompression by the decompressor 5. For this reason, the pressure in the closed system depressurized by the decompressor 5 is determined by how many times the water can be heated by solar heat in the heat collector 2.

The hot water flowing out of the condenser 3 passes through the water turbine power generation unit 6 through the pipe 1 and reaches the heat exchanger 7.
The water turbine power generation unit 6 is a unit in which a water turbine 62 and a rotor 64 having a magnet 63 are rotatably fixed in an insulating pipe 61 made of resin or the like, and power is generated by a coil 65 installed outside the insulating pipe 61.
An example of the configuration of the water turbine power generation unit 6 is shown in FIG.

FIG. 2A is a diagram illustrating an example of the structure of the rotor 64.
The rotor 64 has a structure in which a water wheel 62 is provided at an end of a cylinder, and a magnet 63 is attached near the center of the cylinder. Such a cylindrical rotor 64 is rotatably fixed in the insulating pipe 61. When water flows through the insulating pipe 61, water flows in from the cylindrical water wheel 62 side and flows out to the opposite side. At this time, since the water wheel is rotated by the flowing water, the entire rotor 64 is rotated.

  In the rotor 64, the magnet 63 is a two-pole permanent magnet attached so that the half circumference of the cylinder is the S pole and the remaining half circumference is the N pole. As shown in FIG. 2B, a plurality of coils 65 are installed outside the insulating pipe 61 close to the magnet 63. Accordingly, an induced electromotive force is generated in the coil 65 due to the rotation of the rotor 64 including the magnet 63. The electric power generated in the coil 65 is taken out to the outside by a conducting wire connected to the coil 65 and used.

  In addition, the water turbine power generation unit 6 of the solar heat utilization system 100 of the present embodiment performs power generation by electromagnetic induction by the magnet 63 and the coil 65 that are rotated in synchronization with the water wheel 62 by water as described above. . For this reason, the flow path of the solar heat utilization system 100 is basically constituted by the pipe 1 such as the copper pipe described above, but only in the vicinity of the water turbine power generation unit 6 by the insulation pipe 61 using an insulator such as resin. A road is constructed. Since the water passing through the water turbine power generation unit 6 is warm water having a water temperature near the boiling point as described above, the insulating pipe 61 is preferably made of a material resistant to high temperatures.

Hot water discharged from the water turbine power generation unit 6 flows into the heat exchanger 7 through the pipe 1.
The heat exchanger 7 has a double pipe structure in which an inner pipe 72 that is thinner than the outer pipe 71 is passed through the outer pipe 71. The hot water that has flowed out of the condenser 3 described above reaches the heat exchanger 7 while maintaining a high temperature in the vicinity of the boiling point after rotating a turbine power generation unit 6 described later through the pipe 1. This hot water passes through the inner pipe 72 of the heat exchanger 7. A cooling medium separately supplied from outside the closed system, for example, tap water (hereinafter referred to as cooling water) flows in the outer pipe 71, and heat exchange with hot water flowing in the inner pipe 72 is performed.
Here, since heat is transferred from the hot water in the solar heat utilization system 100 to the cooling water, this heat can be used for applications such as heating and hot water supply.

Heat exchange is performed in the heat exchanger 7, and the hot water flowing into the heat exchanger 7 is cooled to cold water when it flows out of the heat exchanger 7. The cold water flowing out from the heat exchanger 7 passes through the outer pipe 31 of the condenser 3 as shown in FIG. Here, the cold water passing through the outer tube 31 contacts the inner tube 32 and cools and liquefies the water vapor in the inner tube 32. That is, heat exchange is also performed in the condenser 3.
The cold water that has cooled the water vapor in the condenser 3 returns to the heat collector 2. The water returned to the heat collector 2 is heated again by solar heat, boils and vaporizes.
Thus, in the solar-heat utilization system 100 of this embodiment, the cycle which circulates the water in a closed system and performs heat exchange between the heat collector 2, the condenser 3, and the heat exchanger 7 is comprised.

<Specific examples of each configuration>
Hereinafter, specific examples of each configuration of the solar heat utilization system 100 described above will be described.
For example, the pipe 1 is composed of a copper tube having an outer diameter of 22.2 mm and an inner diameter of 20.0 mm, for example.
The water flowing from the outlet of the condenser 3 to the heat exchanger 7 via the liquid reservoir 4 and the water turbine power generation unit 6 is warm water having a water temperature near the boiling point as described above. In order to increase the efficiency of the heat exchange cycle in the solar heat utilization system 100, it is not preferable that the water temperature be lost while flowing through the pipe 1. For this reason, a heat insulating material or the like may be disposed around the pipe 1.

The heat collector 2 has a heat collecting plate formed by bonding, for example, eight copper pipes having a cross section of 10 mm × 10 mm and a length of 1920 mm. The size of the heat collecting plate was, for example, 1980 mm × 980 mm. The area of this heat collecting plate is 1.94 square meters.
When the heat collector 2 having such a configuration is installed southward at an angle of 50 degrees with a horizontal plane in Kanagawa Prefecture, for example, the water in the heat collector 2 is heated from about 60 degrees Celsius to about 80 degrees Celsius. I was able to.

The condenser 3 was configured by putting an inner tube of 22.2 mm into an outer tube having an outer diameter of 38.1 mm, for example.
The length of the condenser 3 is preferably such that the water vapor passing through the inner pipe 32 can be completely liquefied by the water in the outer pipe 31, and the water temperature after liquefaction is not lowered as much as possible. In this embodiment, it was set to 1110 mm, for example.

  As shown in FIG. 1, the condenser 3 is inclined at an angle of, for example, about 10 degrees from the horizontal plane including the pipes to the heat collector 2, and water vapor generated by the heat collector 2 passes through the inner pipe 32. It has a structure that rises without difficulty.

The liquid reservoir 4 has a size of, for example, an outer diameter of 104.8 mm, an inner diameter of 99.2 mm, and a length of about 500 mm.
The extent to which the inside of the closed system is decompressed by the decompression by the decompressor 5 is determined by how many times the water can be heated in the heat collector 2 as described above.
For example, when water can be heated to 80 degrees Celsius in the heat collector 2 as described above, the pressure is reduced to about 47 kPa (about 0.47 atmospheres) at which the boiling point of water becomes 80 degrees Celsius, for example. On the other hand, when water can be heated only up to 60 degrees Celsius in the heat collector 2 such as in an area where the amount of solar radiation is small, the pressure is reduced to about 20 kPa (about 0.2 atm) where the boiling point of water becomes 60 degrees Celsius.

  The heat exchanger 7 was configured by putting an inner tube of 22.2 mm into an outer tube having an outer diameter of 67.2 mm, for example. The length of the heat exchanger 7 is preferably long enough to sufficiently cool the inflowing hot water. In the present embodiment, for example, the length of the heat exchanger 7 is set to 1000 mm, for example.

In consideration of using the solar heat utilization system 100 of the present embodiment in a general household, for example, the heat collector 2, the condenser 3, the sump 4 and the decompressor 5 are installed at a high place such as on a roof. On the contrary, it is assumed that the heat exchanger 7 is installed near the ground or in a low place such as underground.
In the solar heat utilization system 100 of this embodiment, the height difference between the outlet of the condenser 3 and the inlet of the heat exchanger 7 is about 4000 mm. With such an arrangement, the flow velocity of water flowing out of the condenser 3 is accelerated by its potential energy before reaching the heat exchanger 7. Thereby, it is expected that the flow rate of water for rotating the water turbine 62 of the water turbine power generation unit 6 is increased and the power generation efficiency is increased.

<Operation Principle of Solar Heat Utilization System 100>
Next, the operation principle of the solar heat utilization system 100 will be described.
As described above, the heat collector 2, the condenser 3, the liquid reservoir 4, and the heat exchanger 7 are connected to each other by the pipe 1 to construct a closed system. A sufficient amount of tap water (water) is sealed as a liquid in the closed system.
The water in the closed system is decompressed by the decompressor 5, and the water heated by the heat collector 2 by the decompression is boiled to generate water vapor.

In the solar heat utilization system 100 of this embodiment, it is assumed that the heat collector 2 can heat water to about 80 degrees Celsius.
The water vapor generated in the heat collector 2 expands 1650 times in volume compared to water at 100 degrees and 1 atmosphere. For this reason, the water vapor flows out of the heat collector 2 and reaches the condenser 3 due to its expansion pressure. The expansion pressure of the water vapor is a driving force for circulating water in the closed system of the solar heat utilization system 100 of the present invention.
In the condenser 3, the water vapor is cooled and liquefied, and phase transitions to a water temperature near the boiling point, that is, hot water of about 80 degrees Celsius.

Hot water flowing out of the condenser 3 flows through the pipe 1 and flows into the heat exchanger 7.
Here, in the solar heat utilization system 100 of the present embodiment, a difference in height between the outlet of the condenser 3 and the inlet of the heat exchanger 7 is set to about 4000 mm. For this reason, water flows vigorously in the pipe 1 by the expansion pressure of the water vapor in the heat collector 2 and the energy of the fall due to the height difference.
A turbine power generation unit 6 is provided in the water dropping path between the outlet of the condenser 3 and the inlet of the heat exchanger 7, and the turbine 62 is rotated by the power of water to generate power.

Although the water which rotated the water wheel in the water turbine power generation unit 6 loses a part of its kinetic energy, the water temperature near its boiling point is not lost much.
Therefore, in the heat exchanger 7, heat exchange is performed by cooling the hot water near the boiling point flowing in the inner pipe 72 with the cooling water in the outer pipe 71. The water temperature in the system after cooling is, for example, about 25 degrees Celsius. The cooled water rises in the pipe 1 by the driving force resulting from the expansion pressure of the steam generated in the heat collector 2, passes through the outer pipe 31 of the condenser 3, and is heated again in the heat collector 2. The Here, when passing through the outer pipe 31 of the condenser 3, the water vapor in the inner pipe 32 of the condenser 3 is cooled and condensed into water.

As described above, the solar heat utilization system 100 of the present embodiment generates water vapor by evaporating water by solar heat in the heat collector 2 on the heating side, and liquefies the water vapor in the condenser 3 on the cooling side. Near the boiling point liquefied in the condenser 3 by using the expansion pressure of the steam generated in the heater 2 and the energy of the fall caused by the difference in height between the outlet of the condenser 3 and the inlet of the heat exchanger 7 as a driving force. Is a thermosiphon heat pipe that transports a large amount of heat by moving the hot water to the heat exchanger 7 on the cooling side and cooling the water near the boiling point with the cooling water in the heat exchanger 7. And the driving force used for the movement of water is converted into a rotational force by the water turbine power generation unit 6 to generate electric power.
That is, in the solar heat utilization system 100 of this embodiment, both solar energy can be used to obtain both thermal energy and electric energy from power generation through heat exchange.

Note that the operation principle described above is an ideal behavior of the solar heat utilization system 100 of the present embodiment, and an energy loss may actually occur.
Below, in the solar-heat utilization system of this invention, other embodiment for coping with an energy loss is described.

<Second Embodiment>
It is conceivable that the condenser 3 cannot condense all the water vapor generated in the heat collector 2.
In such a case, water vapor accumulates in, for example, the liquid reservoir 4 and the pressure in the solar heat utilization system 100 gradually increases. Along with this, the boiling point of water also rises, and sufficient water vapor is not generated in the heat collector 2, so that the expansion pressure of water vapor becomes insufficient and the driving force of water decreases, so that the power generation efficiency by the turbine power generation unit 6 Falls.

Alternatively, in the condenser 3, not only the water vapor is cooled and liquefied, but the water temperature is further deprived from the liquefied warm water, and the water temperature may be lowered.
In such a case, the efficiency of heat exchange in the heat exchanger 7 is lowered.

Such a disadvantage results from the fact that it is difficult for the condenser 3 to take away only latent heat, which is heat necessary for liquefying water vapor.
In order to deal with such disadvantages, for example, the length of the outer tube 31 of the condenser 3 may be changed as appropriate.
The solar heat collected in the heat collector 2 depends on the amount of solar radiation. For this reason, the amount of solar radiation is monitored, and the amount of heat obtained from the amount of solar radiation and the amount of water vapor obtained from the amount of heat are calculated as needed. And by adjusting the length of the outer tube 31 of the condenser 3 according to the amount of water vapor, it is possible to optimally condense so that all water vapor is liquefied as much as possible and heat is not taken away from the liquefied water as much as possible. it is conceivable that.

  As another countermeasure when the water vapor generated in the heat collector 2 cannot be completely condensed into water, the capacity of the liquid reservoir 4 is increased to disperse the pressure increase due to the inflowing water vapor, or the space portion of the liquid reservoir 4 is reduced. Water vapor may be returned to water by forcibly cooling, and an increase in water pressure in the closed system may be suppressed by preventing an increase in pressure.

<Third Embodiment>
As described above, a closed system is configured by the above-described components of the solar heat utilization system 100 and the pipe 1, but it is difficult to maintain the pressure in the system completely, and the water pressure in the system may gradually increase. It is done.
In such a case, when the water pressure in the system rises, the boiling point also rises, and a sufficient amount of water vapor cannot be obtained in the heat collector 2.

  As a coping method, for example, it is conceivable to monitor the pressure in the system and operate the decompressor 5 to perform decompression again when a predetermined threshold value is exceeded. In this way, the water pressure in the system can be kept low.

Next, the amount or efficiency of electric energy obtained by power generation in the solar heat utilization system 100 will be shown.
As described above, the solar heat utilization system 100 of the present embodiment is a thermosyphon utilizing solar heat. In the solar heat utilization system 100, assuming that the thermosyphon is operating in an equilibrium state, the energy to be considered is the heat energy taken in by the heat collector 2, the heat discharged from the solar heat utilization system 100 by the heat exchanger 7. Energy, electric energy generated in the water turbine power generation unit 6, and energy loss including the examples described in the second and third embodiments.

The thermal energy taken in by the heat collector 2 is Q _in , the thermal energy discharged from the solar heat utilization system 100 by the heat exchanger 7 is Q _ex , the electric energy generated in the water turbine power generation unit 6 is W, and the energy loss is L _oss .
The following formula 1 is obtained from the energy conservation law regarding the thermosyphon.

Based on Formula 1, the maximum electric energy W obtained from the solar heat utilization system 100 will be examined.
Assuming that the Carnot efficiency η in the solar heat utilization system 100 is given, the maximum theoretically obtained W is obtained when Q _ex is expressed by the following Equation 2.

  From the formulas 1 and 2, the maximum electric energy W is obtained by the following formula 3.

従って、

Therefore,

である。

It is.

Here, the operation temperature range of the solar heating system 100 of the present embodiment, the outlet temperature T _max of the heat collector 2 the maximum _temperature, the minimum temperature and the ambient temperature T _a. The Carnot efficiency in the solar heat utilization system 100 in this case is represented by the following formula 5.

集熱器２の出口温度Ｔ_ｍａｘを摂氏８０度、周囲温度Ｔ_ａを摂氏２５度とすると、数式５よりカルノー効率ηは約０．１５である。実験により得られたＱ_ｉｎの値が約１０００Ｗであったため、数式４により最大の電気エネルギーＷは１５０Ｗとなる。

Heat collector 2 outlet temperature _{T max} of 80 degrees Celsius, when the 25 degrees Celsius ambient temperature _{T a,} the Carnot efficiency η from Equation 5 is about 0.15. Since the value of Q _in obtained by the experiment was about 1000 W, the maximum electric energy W is 150 W according to Equation 4.

  That is, in the solar heat utilization system 100 of this embodiment, the theoretical maximum efficiency is about 15% and the theoretical maximum output is about 150 W.

  As described above, the solar heat utilization system 100 of this embodiment includes the heat collector 2 that heats water by solar heat to generate water vapor, and the condenser 3 that cools the generated water vapor and returns it to hot water having a water temperature near the boiling point. A sump 4, a decompressor 5 for reducing the pressure in the system, a heat exchanger 7 for exchanging heat between hot water near the boiling point flowing out of the condenser 3 and another medium, and each of these components A closed system is constructed by connecting the pipe 1 to the water, and the water in the system is circulated by the buoyancy of water vapor generated in the heat collector 2, and the kinetic energy of the water circulating in the system and the heat from the condenser 3 are circulated. The turbine power generation unit 6 is rotated by the potential energy using the height difference up to the exchanger 7 to generate power.

  Here, since the water in the closed system circulates due to the buoyancy of water vapor generated in the heat collector 2, as long as solar heat can be collected, other power for circulating the water in the system is unnecessary. In order to generate water vapor in the heat collector 2, the water pressure in the system is reduced by the pressure reducer 5, and this pressure reduction is expected to require several tens of watts of power. When power is generated by operating the solar heat utilization system 100, the pressure in the system may need to be adjusted again, but a large amount of power is not required. For this reason, the operation cost for the electric power generation of the solar heat utilization system 100 can be set to 0 or a value close thereto, which is economical.

That is, in the solar heat utilization system 100 of the present embodiment, if water can be heated up to about 80 degrees Celsius by solar heat, continuous power generation is possible, so the installation location is not so limited. As described above, it has been proven from experience that water can be heated to about 80 degrees Celsius by a heat collecting plate made by collecting copper pipes in Kanagawa Prefecture, for example, in the Kanto region of Japan. For this reason, there is no need for large concentrating facilities such as lenses and mirrors, and it is considered that power generation is possible at least in areas south of the Kanto region. The introduction cost that seems to be the biggest bottleneck can be reduced.
On the other hand, if a lens or mirror with a simple structure is introduced into the heat collector 2, solar heat sufficient for power generation in the solar heat utilization system 100 of the present embodiment can be collected even in the Tohoku and Hokkaido regions where the amount of solar radiation is relatively small. Seems to be able to. Moreover, since the solar heat utilization system 100 of this embodiment has an area of the heat collector 2 of at most 2 square meters and a thickness of the pipe 1 of at most 20 mm and is space-saving, it is a space-saving, so that the installation space has no room. Easy to install.

  Also, from the viewpoint of introduction costs, the solar heat utilization system 100 of this embodiment may be installed outdoors for the convenience of constructing a closed system, such as construction of introducing the pipe 1 indoors. Construction is not necessary. Furthermore, since the solar heat utilization system 100 of the present embodiment only heats water up to about 80 degrees Celsius, it is not necessary to prepare a special pipe for flowing the heated water, and a copper pipe of firewood may be used. The heat collector 2 can obtain sufficient performance with a simple structure such as gathering of copper pipes. For this reason, it is considered that the introduction cost can be suppressed to a level that can be sufficiently introduced even in ordinary households.

The present invention is not limited to the embodiment described above.
That is, those skilled in the art may make various changes and substitutions regarding the components of the above-described embodiments within the technical scope of the present invention or an equivalent scope thereof.

  The size of each component of the solar heat utilization system 100 and the thickness of the tube, the mounting angle of the heat collector 2, the heating temperature in the heat collector 2, the volume of the liquid reservoir 4, the pressure reduction by the pressure reducer 5 described in the embodiment described above. All the parameters such as the subsequent water pressure, the height difference from the condenser 3 to the heat exchanger 7 and the water temperature after cooling in the heat exchanger 7 are just preferred embodiments of the present invention. It is not limited to.

For example, if the thickness of the pipe is increased, the flow rate of water increases, so that the power generation efficiency can be increased.
In addition, if the water pressure after depressurization by the decompressor is lowered, a sufficient amount of water vapor can be obtained in the heat collector even at a time when only a small amount of solar radiation can be obtained or in the region, which is sufficient to drive the water in the closed system. Can be obtained.
Furthermore, in the embodiment described above, gravity due to the height difference from the condenser 3 to the heat exchanger 7 is also used as the driving force of water used for power generation, but as described above, in the present invention, Since the water in the closed system is circulated using the buoyancy of the generated water vapor as a driving force, even if there is no difference in height from the condenser to the heat exchanger, a sufficient flow rate of water can be obtained and power generation is possible It is.
Moreover, if the water temperature after cooling in the heat exchanger (the second predetermined temperature of the present invention) is lowered, the efficiency of heat exchange can be increased accordingly, and the power generation efficiency is also improved.

  100 ... Solar heat utilization system, 1 ... Pipe, 2 ... Heat collector, 3 ... Condenser, 31 ... Outer tube, 32 ... Inner tube, 4 ... Liquid reservoir, 41 ... suction port, 5 ... decompressor, 51 ... vacuum chamber, 52 ... vacuum pump, 6 ... turbine generator unit, 61 ... insulating pipe, 62 ... turbine, 63・ ・ ・ Magnet, 64 ... Rotor, 65 ... Coil, 7 ... Heat exchanger, 71 ... Outer tube, 72 ... Inner tube

Claims (3)

A heat collector that heats and vaporizes the liquid by the heat of sunlight under reduced pressure;
A condenser for condensing and liquefying the vaporized vapor in the heat collector;
A turbine and a generator directly connected to the rotating shaft of the turbine, the turbine being rotated by the liquid flowing out of the condenser, and generating electricity by rotating the turbine,
A heat exchanger for exchanging heat between the liquid discharged from the water turbine power generation unit and another medium;
A pipe constituting a closed system by connecting the heat collector, the condenser, the water turbine power generation unit, and the heat exchanger to each other;
A decompressor for decompressing the closed system;
Have
The liquid discharged from the heat exchanger flows into the condenser to cool the vapor for the condensation;
A solar heat utilization system configured such that the liquid discharged from the condenser flows into the heat collector. The outlet of the condenser is located higher than the inlet of the heat exchanger by a predetermined height difference,
The solar heat utilization system according to claim 1, wherein the water turbine of the water turbine power generation unit is disposed between an outlet of the condenser and an inlet of the heat exchanger. The solar heat utilization system according to claim 1 or 2, further comprising a reservoir for storing the liquid flowing out of the condenser and supplying the liquid to the turbine power generation unit.

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