JPH1068552A - Energy conversion method and energy conversion device, solar light composite utilization system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To convert the optical energy of solar light to heat energy with high efficiency. SOLUTION: Solar light 11 is collected with high density. A light absorption member 18 is arranged to introduce the solar light 11 thus condensed with high density directly into a heating medium e.g. an optical boiler 13 buried in water, thereby converting the optical energy of the solar light 11 to heat energy by means of the light absorption member 18. The heat energy is given to the water 14 and heated, thereby outputting a high temperature and high pressure gas from the optical boiler. More specifically, steam is output, which makes it possible to execute more direct heat energy conversion and convert optical energy to heat energy with higher efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an energy conversion method and an energy conversion device for sunlight, and a combined solar light utilization system using the energy conversion device.

[0002]

2. Description of the Related Art There are various energy supply sources, and as a future energy source, effective use of light energy of sunlight, which is clean energy, has been particularly spotlighted.

For example, a solar combined use system has been considered in which light energy of sunlight is converted into heat energy, steam is obtained, and a turbine generator is driven to obtain electric power and other resources. The outline will be described with reference to FIG. First, an optical boiler 4 mainly including a pressure vessel 3 into which water 2 is circulated by a water supply pump 1 is provided. The container housing 3a of the pressure container 3 is formed of a material having a high light transmittance and a strength sufficient to withstand pressure, and is formed in a cylindrical shape in cross section, and around the pressure container 3 (generally, the entire circumference). In addition, a plurality of concave mirrors (or plane mirrors) 6 for condensing the sunlight 5 on the surface of the container housing 3a as efficiently as possible are provided. Container housing 3 by concave mirror 6
The light energy of sunlight condensed on the surface of a is converted into thermal energy on the surface of the container housing 3a, and propagates through the container housing 3a to heat the water 2 in the container housing 3a. That is, by applying the heat energy to the water 2 having a temperature close to the normal temperature, the water is output from the pressure vessel 3 to a turbine generator (not shown) as a high pressure and a high temperature steam (steam). Drive. After the steam used to drive the turbine generator has cooled,
Water is supplied again into the pressure vessel 3 by the water supply pump 1.

According to this, steam can be output from the optical boiler 4 using the light energy of sunlight.

[0005]

In this type of apparatus, it is desirable to keep the pressure vessel 3 warm to suppress heat radiation in order to increase the efficiency of generating steam in the optical boiler 4.
According to the conventional method as exemplified in (1), the surface (light receiving surface) of the pressure vessel 3 cannot be kept warm from its principle. In particular, as the number of concave mirrors 6 is increased in order to increase the amount of light energy to be used, the area that cannot be kept warm and remains exposed increases, and the loss due to heat dissipation increases. That is, the efficiency of converting light energy of sunlight into heat energy is low.

Further, since a portion where sunlight is condensed by the concave mirror 6 has a temperature difference that becomes higher than other portions, a partial heat distortion occurs in the pressure vessel 3 and the pressure vessel 3 It also contributes to shortening the life.

[0007]

According to the first aspect of the present invention, there is provided an energy conversion method, wherein sunlight is concentrated at a high density, and the sunlight is concentrated at a high density by a light absorbing member in a heating medium. The light energy of sunlight is directly introduced into the buried optical boiler and converted into light energy by the light absorbing member,
The optical boiler outputs a high-pressure and high-temperature gas that has heated the heating medium. Therefore, sunlight is directly introduced into the optical boiler, the light energy is absorbed by the light absorbing member and converted into heat energy, and the heating medium in which the light absorbing member is embedded is heated. Is performed more directly and the optical boiler can be kept warm, so that light energy can be converted into heat energy with high efficiency. Further, since the light boiler itself is not irradiated with sunlight, there is no occurrence of partial thermal distortion. Here, the heating medium may be a liquid such as water (fresh water) or seawater, or may be a gas such as air, N ₂ , or Ar. If water is used as the heating medium, high-pressure and high-temperature steam can be output from the optical boiler. If the heating medium is air or a gas such as N ₂ or Ar, a high-pressure and high-temperature gas can be output from the optical boiler.

According to a second aspect of the present invention, there is provided an energy conversion apparatus for condensing sunlight at a high density, and a light guide transmission for transmitting the sunlight condensed by the light condensing means to a target location. Means, an optical boiler that outputs a high-pressure, high-temperature gas, and a light absorbing member embedded in a heating medium that is a source of the gas in the optical boiler, and an optical output end of the light guide transmission means is provided. Light-to-heat energy conversion means directly connected to the heating medium in the optical boiler. Here, as the light condensing means, any means having a light condensing function may be used, but an inexpensive and lightweight Fresnel lens flat plate made of an acrylic resin is preferable for condensing low-energy sunlight with a wide-area lens. . In order to increase the light-collecting efficiency of the light-collecting means, it is preferable to provide a mechanism for tracking the sun. However, for example, a tracking mechanism is not necessarily required under conditions such as when a time zone to be used is specified. If the light condensing means is provided with a sun tracking mechanism, the light guiding transmission means should have flexibility at least on the incident side so as to receive light following the tracking property, and have high efficiency. In order to secure transmission in the wavelength range, means having a low attenuation rate in the wavelength region of sunlight is preferable. Specifically, an optical fiber cable is preferable. Or, not limited to optical fiber cables, for example,
A light guide tube may be used in which the inner surface of a metal pipe is subjected to a treatment such as gold plating to guide the light from the light condensing means side to the optical boiler side without attenuating the light. When a suitable combination of a Fresnel lens plate and an optical fiber cable is used, the capacity of the pair alone is technically or economically limited, so that the solar light energy to be used can be increased or the installation space can be increased. Depending on the required output, a plurality of pairs of one Fresnel lens flat plate and one optical fiber cable are preferably provided. The light absorbing member embedded in the optical boiler may be a member that exhibits a high absorptivity in the wavelength region of sunlight. The light output end of the light guide transmission means may be directly connected to the heating medium in the optical boiler, but is preferably connected in a sealed state via a sealing member having a high light transmittance. “Direct” means that such a sealing member or the like may be interposed. Also,
The heating medium may be a liquid such as water (pure water, fresh water of seawater, or sewage that is not so bad), seawater itself, or a gas such as air, N ₂ , or Ar.

Therefore, according to the present invention, in realizing the energy conversion method according to the first aspect, the energy conversion method can be easily achieved by utilizing existing parts and manufacturing techniques.

According to a third aspect of the present invention, there is provided a solar combined use system, wherein the heating medium is water, and the water for introducing fresh water from seawater into an optical boiler of the energy conversion apparatus. An introduction unit; and a turbine generator driven by high-pressure and high-temperature steam output from the optical boiler. Therefore, for example, by extracting power based on the output of the turbine generator and returning the steam used to drive the turbine generator to water, it becomes possible to use the water as cold water for drinking water and air conditioners, and to combine sunlight and seawater. It is possible to construct a combined use system of power generation, desalination and cooling using Therefore, for example, a system that can efficiently use sunlight and seawater, which are abundant resources, in a remote area where the sea is near and water source facilities and electric power facilities are scarce, particularly in an island near the equator having a low latitude.

[0011]

FIG. 1 shows a first embodiment of the present invention.
It will be described based on. First, an energy conversion device and a conversion method according to the present embodiment will be described with reference to FIG. First, there is provided a Fresnel lens flat plate 12 made of an acrylic resin, which is a light collecting means for condensing sunlight 11 having a low energy of about 1 kW / m ² at a high density. In addition, the optical boiler 1
3 is fixedly installed. The optical boiler 13 is formed mainly of a pressure vessel 15 having a shape capable of storing water 14 as a heating medium. An optical fiber cable 16 serving as a light guide transmission means is interposed between the Fresnel lens plate 12 and the optical boiler 13. The optical fiber cable 16 is flexible and has a low attenuation rate in the wavelength region of sunlight 11, and both the light input end 16a and the light output end 16b at both ends are highly smoothed. . Such an optical fiber cable 16
Specifically, a 7-core optical fiber having a diameter of 1 mm is used. The optical input end 16a of the optical fiber cable 16
Is disposed at the focal position of the Fresnel lens flat plate 12.

Here, the condensing efficiency of the Fresnel lens flat plate 12 is increased, and when the position of the sun is changed, the Fresnel lens flat plate 12 condenses the sunlight 11 to another place to generate a high temperature. The sun is always tracked by a well-known sun tracking mechanism so as not to cause the sun. As such a sun tracking mechanism, for example, a combined use method of a solar trajectory calculation by a built-in computer and a sun position sensor adopted in “Solar Collection and Delivery System SUNDELIA” sold by NK Plant Construction Co., Ltd. may be used. The light input end 16a utilizes the flexibility of the optical fiber cable 16 and always follows the focal position of the Fresnel lens plate 12 even if the focal position of the Fresnel lens plate 12 fluctuates so as to track the sun by the sun tracking mechanism. It is attached to be.

On the other hand, a cable introduction hole 15a is formed on a side surface of the pressure vessel 15, and a pressure seal glass 17 for sealing an inner wall of the pressure vessel 15 including the cable introduction hole 15a is attached. The pressure seal glass 17 is made of a material having a high light transmittance and a strength enough to withstand the high pressure inside. The optical output end 16b of the optical fiber cable 16 is introduced into the cable introduction hole 15a, and is fixed so as to be in close contact with the outer surface of the pressure seal glass 17. As a result, the light output end 16b is
4 are directly connected.

A light absorbing member 18 is incorporated in the pressure vessel 15 so as to be buried in the water 14.
The light absorbing member 18 and the light boiler 13 constitute a light-to-heat energy converting means 19. The light absorbing member 18 may have a suitable shape, but a member having a surface property that is surface-treated so as to have a high absorptivity in the wavelength region of the sunlight 11 is used.

Further, an output pipe 20 for outputting steam, which is a kind of high pressure and high temperature gas, is connected to the upper end of the pressure vessel 15. An inlet pipe 21 for introducing water 14 is connected to a lower end of the pressure vessel 15, and is connected to a water tank 23 via a water supply pump 22.

In such a configuration, normal-temperature water 14 in a water tank 23 is appropriately introduced into the pressure vessel 15 by a water supply pump 22. On the other hand, the sunlight 11, which is substantially parallel light, is condensed by the Fresnel lens flat plate 12 at its focal position, that is, at the light input end 16a of the optical fiber cable 16, and enters the optical fiber cable 16 in a very large light energy density state. Introduce. The light guided through the optical fiber cable 16 is radiated again at an optical output end 16b thereof at an angle substantially equal to the incident angle. At this time, the light output terminal 16
Since b is in close contact with the surface of the pressure seal glass 17 having a high transmittance, light emitted from the light output end 16b passes through the pressure seal glass 17 with almost no attenuation by the pressure seal glass 17. , Into the water 14 in the pressure vessel 15. Here, the light absorbing member 1 is placed in the pressure vessel 15.
Since the light 8 is provided, the light emitted from the light output end 16b is converted into heat energy by being absorbed by the light absorbing member 18. Therefore, the water 14 at a temperature close to room temperature in the pressure vessel 15 in which the light absorbing member 18 is buried directly receives the heat energy given from the light absorbing member 18, and becomes high-temperature steam at a high pressure. Are output to the outside from the output pipe 20. An example of the utilization form of the steam will be described later, but it does not matter essentially how it is used.

Therefore, according to the present embodiment, the sunlight 1
1 is directly introduced into the optical boiler 13 and its light energy is absorbed by a light absorbing member 18 to convert it into heat energy.
Is directly applied with heat energy and heated, so that the conversion to heat energy is performed more directly and the light boiler 1
3 can also be kept warm, so that light energy can be converted to heat energy with high efficiency. Also, since the light boiler 13 itself is not irradiated with the sunlight 11, there is no occurrence of partial thermal distortion. Even in terms of configuration, the components such as the Fresnel lens flat plate 12, the optical fiber cable 16, and the light absorbing member 18 can be easily achieved by using existing parts and manufacturing techniques.

Next, a second embodiment of the present invention will be described with reference to FIG. Parts performing the same functions as the parts shown in FIG. 1 are denoted by the same reference numerals, and description thereof is omitted (the same applies to the following embodiments). In the present embodiment, a configuration example of a solar combined use system 24 for power generation, fresh water, and cooling using an energy conversion device 23 based on the above-described principle configuration will be described. The energy conversion device 23 in the combined solar light utilization system 24 of the present embodiment is configured using a plurality of Fresnel lens flat plates 12. More specifically, n × n frennel lens flat plates 12 are arranged in a matrix in a matrix, as employed in the above-mentioned “sunlight collection and delivery system SUNDELIA”, and the whole is tracked by the sun tracking mechanism. What is necessary is just to comprise. A light-shielding plate 25 is provided on the front surface of each of the Fresnel lens flat plates 12 so as to be openable and closable in consideration of the non-use of the solar combined use system 24 and the like. Also, one optical fiber cable 16 is provided for each Fresnel lens flat plate 12 (the pressure seal glass 17 is not shown in FIG. 2). The optical boiler 13 is provided with a safety valve 26.

The solar combined use system 24 of the present embodiment is a system that effectively uses seawater 27, which is also abundant resource, in addition to the solar light 11, which is abundant resource. Boiler 1 with water 14
A water introduction means 28 for introducing into the pipe 3 is provided for the introduction pipe 21. The water introducing means 28 includes a seawater pumping pump 29 for pumping seawater 27 from the sea, a water storage tank 30 for temporarily storing the pumped seawater 27, and the seawater 27 stored in the water storage tank 30 to the optical boiler 13 side. A water supply pump 31 (corresponding to the water supply pump 22) for feeding the water, a dialysis device 32 for heating the seawater 27 pumped and fed by the water supply pump 31 to remove salt from the seawater 27, and convert the water to fresh water. It consists of. In the present embodiment, the introduction pipe 21 between the dialysis device 32 and the optical boiler 13 is used.
A cooler 33 for returning the seawater 27 heated by the dialysis device 32 to a normal temperature and a condenser 34 are interposed therebetween.

On the other hand, a turbine generator 35 driven by high-pressure steam output from the output pipe 20 is connected to the output pipe 20 side of the optical boiler 13. Electric power is extracted from the output of the turbine generator 35. Further, a recovery pipe 36 for sending high-pressure steam used for driving the turbine generator 35 to the condenser 34 in a low-pressure steam state is provided. Therefore, the steam which has been used to drive the turbine generator 35 and has a low pressure is cooled through the condenser 34 and is condensed into hot water. An absorption refrigerator 37 is provided on the output path of the condensed high-temperature water.
A water storage tank 38 for temporarily storing water (fresh water) 14 which has been returned to room temperature by passing through the absorption refrigerator 37 is provided. The water supply facility 3 is provided to the water storage tank 38 by a pump or the like for supplying the water 14 to a required location as tap water.
9 are provided. On the other hand, 1
An air conditioning pipe 42 including a pump 41 for supplying warm water of about 5 to 20 ° C. to the absorption refrigerator 37 is provided, and cold water cooled to about 5 ° C. by the absorption refrigerator 37 is supplied to the air conditioning machine 40. It is configured as follows.

Therefore, according to the solar combined use system 24 of the present embodiment, the power is taken out based on the output of the turbine generator 35, and the steam used for driving the turbine generator 35 is returned to the water, so that the drinking water can be used. It is also possible to generate cold water for cooling by using the cooling means (absorption refrigerator 37) for returning to drinking water, and it is possible to generate abundant resources such as sunlight and seawater. It is possible to construct a combined use system of power generation, fresh water generation, and cooling that efficiently uses Therefore, for example, it is a suitable facility in a remote area where the sea is near and water source facilities and electric power facilities are scarce, particularly in an island near the equator with low latitude.

A third embodiment of the present invention will be described with reference to FIG. In the present embodiment, a configuration example of a solar combined use system 51 for power generation and use of residual heat using the energy conversion device 23 based on the above-described principle configuration will be described. Solar combined use system 51 of the present embodiment
In the energy conversion device 23, a gas 52 is used instead of the water 14 as a heating medium. This gas is, for example, N ₂ gas or Ar gas, and a compressor 54 is provided to compress the gas 52 introduced from a gas cylinder (not shown) through the initial gas inlet 53 as high pressure gas. The high-pressure gas compressed by the compressor 54 is introduced into the optical boiler 13 through the introduction pipe 21. Further, a gas turbine 55 driven by high-pressure and high-temperature gas output from the output pipe 20 of the optical boiler 13 is provided. The gas turbine 55 is connected to a generator 56 that rotates by its rotational energy to generate electric power. Electric power is extracted from the generator 56. The compressor 54, the gas turbine 55, and the generator 56
Is driven by another driving source such as a motor (not shown) at an initial time when the operation is started. Alternatively, the generator 56 is used as an electric motor via a control circuit by receiving power supply from an existing power supply. In addition, a residual heat utilization device 58 is provided in a path of a recovery pipe 57 for re-supplying the high-pressure and high-temperature gas used for driving the gas turbine 55 to the compressor 54 again. As a result, sufficient residual heat of the high-pressure and high-temperature gas is supplied to the residual heat utilization device 58.
Used in some form. This residual heat utilization device 5
At 8, the gas which has been cooled to a considerably low temperature (or normal temperature) by utilizing the residual heat is re-supplied to the compressor 54. here,
After a certain period of time has passed since the start of operation, when the gas pressure in the system reached the required value during operation, the valve at the initial gas inlet 53 was closed, and thereafter, the sealed gas was removed from the piping system of the system. By circulating air, power is supplied and the system functions as a system that utilizes residual heat.

The energy conversion device 23 or the combined solar light utilization system 24, 51 according to the present embodiment is merely an example, and is similarly applied to various modified examples and applied examples. it can. For example, in the case of constructing a system that does not intend to produce fresh water or the like with respect to the solar combined use system 24 shown in FIG. 2, filtering processing that simply removes dust without desalinating the seawater 27 is performed. The seawater 27 may be introduced into the optical boiler 13 as it is to serve as a heating medium. Also, the optical boiler 13
The high-pressure and high-temperature steam or gas output from is not limited to the drive of the turbine generator 35 or the gas turbine 55, but may be directly applied to the industrial machine as it is.

[0024]

According to the first aspect of the present invention, the sunlight is condensed at a high density, and this sunlight is condensed at a high density in an optical boiler in which a light absorbing member is embedded in a heating medium. To convert the light energy of sunlight into heat energy by the light absorbing member, and to output a high-pressure and high-temperature gas that heats the heating medium from the light boiler, so that the light energy is converted into heat energy. Can be carried out more directly, and the light boiler can be kept warm, so that light energy can be converted to heat energy with high efficiency, and at the same time, the light boiler itself is not irradiated with sunlight. Therefore, there is no inconvenience of causing partial thermal strain.

According to the second aspect of the present invention, the light condensing means for condensing the sunlight at a high density, and the light guide transmitting means for transmitting the sunlight condensed by the light condensing means to a target location. A light boiler for outputting a high-pressure and high-temperature gas, and a light absorbing member embedded in a heating medium serving as a source of the gas in the light boiler. Since the light-to-heat energy conversion means is directly connected to the heating medium in the boiler, existing parts and manufacturing techniques are used to realize the energy conversion method according to claim 1. It can be easily achieved.

According to a third aspect of the present invention, there is provided the energy conversion apparatus according to the second aspect, wherein the heating medium is water, and water introduction means for introducing seawater desalinated water into an optical boiler of the energy conversion apparatus. And a turbine generator driven by high-pressure and high-temperature steam output from the optical boiler, so that, for example, electric power is extracted based on the output of the turbine generator, and steam used for driving the turbine generator is extracted. By returning it to water, it can be used as drinking water or cooling water for cooling, and it is possible to build a combined use system of power generation, fresh water, and cooling using abundant resources of sunlight and seawater, for example, the sea The system will be highly useful in remote areas where water and power facilities are scarce and nearby, especially islands near the equator with low latitude.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a basic configuration of an energy conversion device according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram showing a combined solar light utilization system according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a combined solar light utilization system according to a third embodiment of the present invention.

FIG. 4 is a schematic view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Sunlight 12 Condensing means 13 Optical boiler 14 Heating medium, water 16 Light guide transmission means 16b Light output end 18 Light absorption member 19 Light-heat energy conversion means 23 Energy conversion device 28 Water introduction means 35 Turbine generator 52 Heating medium

Claims (3)

[Claims] 1. A method for concentrating sunlight at a high density, and introducing the sunlight condensed at a high density directly into an optical boiler in which a light absorbing member is buried in a heating medium, thereby obtaining light energy of the sunlight. Is converted into thermal energy by the light absorbing member, and a high-pressure and high-temperature gas that heats the heating medium is output from the optical boiler. 2. A light condensing means for condensing sunlight at a high density, a light guiding transmission means for transmitting the sunlight condensed by the light condensing means to a target location, and outputting a high pressure and high temperature gas. An optical boiler and a light absorbing member buried in a heating medium serving as a source of the gas in the optical boiler, and an optical output end of the light guide transmission unit is provided in the heating medium in the optical boiler. An energy conversion device comprising: light-heat energy conversion means directly connected. 3. An energy conversion device according to claim 2, wherein the heating medium is water, water introduction means for introducing seawater desalinated into the optical boiler of the energy conversion device, and an output from the optical boiler. And a turbine generator driven by high-temperature and high-pressure steam.