JP2010229992A - Solar heat utilizing power generation system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solar heat utilizing power generation system that can practically and sufficiently generate electricity even at a location where a large installation area is difficult to be secured such as an urban area. <P>SOLUTION: The system includes: a plurality of pillar-shaped chimneys 2 each having a hollow part 22 through which air passes and heating the air passing through the hollow part 22 by a thick part 21 heated by the radiation of solar light; a coupling pipe 3 having a plurality of holes 31 formed at a wall surface which are coupled to the respective hollow parts 22 of the chimneys 2, and into which air flows from one of openings 32 thereof; and a generator 4 for generating power by the air flow passing through the coupling pipe 3. By heating the thick parts 21 of the chimneys 2 by solar heat, ascending air flows are generated in the chimneys 2. Then, the air flow flowing in from the air flow-in openings 32 rotates blades 41 of a turbine to generate power. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a solar thermal power generation system that generates power using air heated by solar heat.

  In recent years, as a part of global warming countermeasures represented by CO2 gas reduction, interest in power generation systems using natural energy is increasing. In addition to solar power generation using solar panels, solar thermal power generation and wind power generation are attracting attention as the use of natural energy. However, with regard to wind power generation, large windmills have been introduced only in areas with limited wind conditions where a steady wind blows constantly at a certain speed or higher.

  On the other hand, as a power generation system using solar heat and wind power, a system called “solar chimney” that forcibly generates wind power using solar heat has been proposed in the early 1980s (see Non-Patent Document 1). FIG. 6 shows a schematic configuration of the solar chimney.

  The solar chimney 10 includes a circular transparent cover 11 that covers the ground surface 15 through the air layer A, and a chimney 12 connected to the center of the transparent cover 11. A turbine blade 13 is disposed near the entrance of the chimney 12, and a generator 14 is installed on the ground to generate power by the rotation of the turbine blade 13.

  The ground surface 15 is warmed by sunlight, and the heat is transmitted to the air layer A under the transparent cover 11 by heat conduction and radiation. The heated and lightened air layer A rises in the chimney 12 provided in the center of the transparent cover 11, and the blades 13 of the turbine are rotated by the rising air flow at that time to generate electricity.

R. Richards: Electrical Review, Vol.210, No.15, April, 1982, pp.26-27

  The above-described solar chimney 10 has few consumable parts and has the advantage of being able to generate power permanently once it is installed. On the other hand, in order to obtain a practically sufficient amount of power generation, the transparent cover 11 that is a heat receiving part. Need to have a diameter of about 200 m and a height of the chimney 12 of 100 m or more. However, such a power generation system that requires a large installation area is not practical in urban areas where land is small.

  The present invention has been made in view of such problems, and it is an object of the present invention to provide a solar thermal power generation system capable of obtaining a practically sufficient power generation amount even in a place where it is difficult to secure a large installation area such as an urban area. And

To achieve the above object, a solar thermal power generation system according to the present invention is a solar thermal power generation system that generates power using air heated by solar heat,
A plurality of column-shaped chimneys that have a hollow part through which air passes and that heat the air that passes through the hollow part by a thick part heated by irradiation with sunlight,
A plurality of holes connected to each of the hollow portions of the plurality of chimneys on the wall surface, and a connection pipe into which air flows from one opening;
And a generator that generates power by an air flow passing through the inside of the connecting pipe.

  Here, you may cover the outer peripheral surface irradiated with sunlight among the thick parts of the said chimney with a material with high heat absorption. Moreover, you may cover the outer peripheral surface on the opposite side to the side irradiated with sunlight among the thick part of the said chimney with a material with high heat insulation. Moreover, you may comprise a part of thick part of the said chimney with a material with high thermal storage property. Moreover, you may install a concave mirror in the vicinity of the side opposite to the side irradiated with the sunlight of the said chimney.

  In the solar thermal power generation system according to the present invention, as the generator, a turbine generator configured by a turbine blade attached to a rotary shaft and a generator main body that generates power by rotation of the rotary shaft is used. Preferably, the turbine blades are installed in the vicinity of the air inlet that is one opening of the connecting pipe, and the generator body is installed in the other opening of the connecting pipe.

  Here, between the air inlet and the blades of the turbine, a cone-like structure in which the diameter of the air inlet is smaller than the diameter of the air outlet may be installed. A plurality of the cone-like structures may be installed along the air flow path of the connecting pipe. A plurality of turbine blades may be provided, and the plurality of turbine blades may be attached to the rotary shaft at equal intervals. Further, the turbine blades may be arranged such that the one disposed on the upstream side of the air flow has a smaller radial length.

  In the solar thermal power generation system according to the present invention, as the generator, a generator that generates power by vibrating a long piezoelectric element by an air flow, the long piezoelectric element having an air flow in the longitudinal direction is used. You may install in the state orthogonal to a flow path. In this case, a plurality of the piezoelectric elements may be provided, and the plurality of piezoelectric elements may be installed along the air flow path.

  The solar heat-generating power generation system according to the present invention does not require a heat receiving part having a large area as in the above-mentioned solar chimney because the chimney itself is heated by solar heat to generate an updraft inside the chimney. As a result, it is possible to achieve a compact power generation system that can be placed along the walls of single-family houses in narrow spaces such as urban areas, apartment buildings, and office buildings. Natural energy can be used.

It is sectional drawing which shows the structure of the solar thermal power generation system concerning Embodiment 1 of this invention. It is sectional drawing of the chimney which improved heat absorption and heat storage. It is sectional drawing of the air flow inlet vicinity of the connection pipe which employ | adopted the method of improving the utilization efficiency of an air flow. It is a figure which shows the whole structure of the generator used for Embodiment 2 of this invention. It is a perspective view which shows the use condition of the piezoelectric element of FIG. It is a figure which shows schematic structure of the solar chimney which is the conventional solar thermal power generation system.

  Hereinafter, a solar thermal power generation system according to an embodiment of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 shows a configuration of a solar thermal power generation system (hereinafter abbreviated as “power generation system”) according to the first embodiment of the present invention. The power generation system 1 includes a plurality of columnar chimneys 2, a connection pipe 3 having a plurality of holes connected to each of the hollow portions of the chimney 2 on the wall surface, and a turbine generator that generates power by an air flow in the connection pipe 3. 4.

  The chimney 2 is composed of a thick part 21 and a hollow part 22 formed at the center, and air warmed by the thick part 21 is discharged from the upper part to the outside air through the hollow part 22. The plurality of chimneys 2 are arranged in a straight line in a vertical direction and at a predetermined interval, and are installed on a wall 5 facing south or southeast of a building or the like using a metal fitting or the like. A cover or the like (not shown) is installed on the upper part of the chimney 2 to prevent rainwater from flowing in. However, it is preferable that the chimney 2 be opened so as not to prevent the warmed air flow from rising.

  A plurality of holes 31 are formed in the tube wall of the connecting tube 3, and each of the holes 31 is connected to the hollow portion 22 of the chimney 2. An air inlet 32 is provided in one opening of the connecting pipe 3, and the other opening 33 is closed by a generator 42. The air inflow port 32 is processed into a truncated cone shape whose diameter decreases toward the tip.

  The turbine generator 4 includes a turbine blade 41 disposed in the vicinity of the air inlet 32 of the connection pipe 3, a generator main body 42 installed in the other opening 33 of the connection pipe 3, and rotation of the turbine blade 41. Is constituted by a rotating shaft 43 that transmits the power to the generator main body 42. Although not shown, the rotating shaft 43 is fixed to the inner wall of the connecting pipe 3 at a plurality of locations via bearings.

  Next, the operation of the power generation system 1 will be described. Solar heat is accumulated in the thick part 21 by irradiating the outer peripheral surface of the thick part 21 of the chimney 2 with sunlight. The air passing through the hollow portion 22 of the chimney 2 is warmed by the solar heat accumulated in the thick portion 21 by heat conduction and radiation, and ascends the hollow portion 22.

  When an ascending air current is generated in the chimney 2, the pressure near the hole 31 of the connecting pipe 3 is lowered, and air flows from the air inlet 32 of the connecting pipe 3 to generate an air flow. The ascending airflow per chimney 2 is not so strong, but since the number of chimneys is large, the pressure drop due to each chimney is totaled, and the air pressure in the vicinity of the air inlet 32 of the connecting pipe 3 is considerably reduced, and the high speed Air flow. Turbine blades 41 installed in the vicinity of the air inlet 32 of the connecting pipe 3 are rotated by this air flow, and power is generated by the generator main body 42.

  As described above, the power generation system 1 according to the present embodiment generates a rising air current inside the chimney by heating the chimney itself with solar heat, and as a result, a compact power generation system with a small installation area can be realized. Therefore, if this power generation system 1 is arranged along the wall surface of a single-family house in a narrow area such as an urban area, an apartment house, or an office building, it can be sufficiently installed even in an urban area where the land is small. Become.

  For example, if the power generation system 1 according to the present embodiment is installed on the south surface of a building having a height of 50 m or more and the chimney is arranged so as to remove the window, the lighting of the building is not hindered. By using this, a high-performance power generation system can be realized.

  Next, a method for increasing the power generation amount of the turbine generator 4 will be described. As a method for increasing the power generation amount of the power generator 4, a method of generating a stronger updraft by increasing the heating efficiency of air in the chimney 2, and a connecting pipe There is a method for increasing the utilization efficiency of the airflow generated in the interior 3. First, a method for increasing the heating efficiency of air in the chimney 2 will be described.

  Although it is possible to use a metal pipe including a copper pipe for the chimney 2, it is preferable to use a pipe made of vinyl chloride because it is easily available and is excellent in terms of price. And in order to improve the heat absorption property and heat storage property of a vinyl chloride pipe | tube, ie, in order to improve the heating efficiency of the air in the chimney 2, many measures are taken. In FIG. 2, the cross section of the chimney which improved the heat absorption of the thick part 21 of the chimney 2 and heat storage is shown.

  FIG. 2A shows a case where the black paint 23 is applied to the surface irradiated with sunlight among the outer peripheral surface of the thick portion 21. By covering the outer peripheral surface of the thick portion 21 with a black paint which is a highly endothermic material, the endothermic property of the chimney 2 can be enhanced.

  FIG. 2B shows a material 24 having a high heat insulating property applied to the surface opposite to the surface irradiated with sunlight in the outer peripheral surface of the thick portion 21. By covering the outer peripheral surface of the thick part 21 with a highly heat-insulating material 24, the heat accumulated in the thick part 21 can be prevented from diffusing into the outside air by radiation or conduction, and the heat storage of the chimney 2 Can increase the sex.

  Fig. 2 (c) is a PVC pipe containing at least the upper part of the thick part 21 of the chimney 2 made of a material having excellent heat storage, for example, concrete itself, or a sandstone or concrete component as an aggregate. It is configured. Although the vinyl chloride pipe is excellent in terms of price, it is not always satisfactory in terms of heat storage. Therefore, by constituting a part of the thick portion 21 with the material 25 having excellent heat storage, the heat storage of the chimney 2 is achieved. Can be increased.

  FIG. 2D shows a concave mirror 26 disposed in the vicinity of the chimney 2 on the side opposite to the sunlight irradiation surface. The heat absorption of the chimney 2 can be enhanced by irradiating the surface of the thick portion 21 that is not normally irradiated with sunlight with the concave mirror 26.

  In addition, in FIG. 2 (a)-FIG.2 (d), although the countermeasure which raises the heating efficiency of the air in a chimney was shown separately, the heating efficiency of the air in the chimney 2 is further improved by combining these countermeasures. Can do.

  Next, a method for increasing the utilization efficiency of the airflow generated in the connecting pipe 3 will be described. FIG. 3 shows the shape of the connection pipe 3 in the vicinity of the air inlet 32 and the arrangement of the turbine blades 42.

  FIG. 3A is a cross-sectional view of the connecting pipe 3 shown in FIG. Since the diameter of the connecting pipe 3 is widened toward the downstream side of the air flow and the flow velocity of the air flow is maximized in the vicinity of the air inlet 32, the turbine blade 41 is rotated using the air flow. The number of rotations of 4 also increases.

  FIG. 3B is a modification of the structure shown in FIG. In FIG. 3 (a), the diameter in the vicinity of one opening of the connecting pipe 3 is changed. In FIG. 3B, the diameter of the opening of the connecting pipe 3 is not changed. Instead, a cone-like structure 44 is installed near the air inlet 32 so that the diameter of the air inlet is smaller than the diameter of the air outlet. Yes. The diameter of the connecting pipe 3 is constant, and it is not necessary to process the connecting pipe 3 because a separately prepared cone-like structure 44 only needs to be arranged near the air inlet 32. As a result, the cost for manufacturing the connecting pipe 3 can be reduced.

  In FIG. 3C, two cone-shaped structures 44 shown in FIG. 3B are arranged in series along the flow path of the air flow, and in correspondence with this, the rotating shaft 43 is connected to the turbine shaft. Two blades 41 are attached. By providing turbine blades corresponding to each of the two cone-like structures 44, the utilization efficiency of the airflow can be increased. Although the figure shows a set of two cone-like structures and turbine blades, the set may be a plurality of sets of three or more sets.

  FIG. 3D is a modification of the structure shown in FIG. In FIG. 3B, one turbine blade 41 corresponding to the cone structure 44 is provided. By attaching a plurality of turbine blades 41 in series to the rotating shaft 43, it is possible to increase the efficiency of the air flow and increase the rotational speed of the generator 4.

  FIG. 3E is a modification of the structure shown in FIG. Among the turbine blades 41 attached in series to the rotating shaft 43, the angle of the adjacent turbine blades is shifted by 90 degrees, so that the utilization efficiency of the airflow flowing along the rotating shaft 43 is increased, and the generator 4 The number of rotations can be increased.

  FIG. 3F is a modification of the structure shown in FIG. In FIG. 3 (d), a plurality of turbine blades 41 of the same size are attached in series to the rotary shaft 43. In FIG. 3 (f), a plurality of turbine blades 41 of different sizes are attached to the rotary shaft. The use efficiency of the airflow is enhanced by arranging the blades in series with the airflow inlet 43 and the smaller blades closer to the air inlet 32.

<Experimental example>
In order to confirm the effect of the power generation system 1 according to the present embodiment, the following miniature model was created. As the chimney 2, 12 high impact resistant pipes (dark blue) having a length of 4 m and an inner diameter of 13 mm made of vinyl chloride were used. The connecting pipe 3 was prepared by connecting 11 cheeses made of 13A (nominal diameter 13 mm) made of vinyl chloride and one elbow 13A, and the air inlet 32 was reduced in diameter to 6.5 mm.

  The 12 prepared chimneys 2 and the connecting pipe 3 were connected as shown in FIG. A small anemometer (manufactured by Keyence Corporation, FD-A10) was connected to the air inlet 32 of the connecting pipe 3, and the wind speed was calculated from the passing air volume. Moreover, the inner wall surface temperature of the thick part 21 of the chimney 2 was measured using a K thermocouple.

  The chimney 2 and the connecting pipe 3 assembled as described above were leaned against the south surface of the building having an outside air temperature of 14 ° C., and the chimney 2 was warmed by sunlight in fine weather. The tube inner wall surface temperature of the thick part 21 of the chimney 2 was 29 ° C., and the calculated wind speed of the air inlet 32 was 1 m / s. As a result of the experiment, it was confirmed that even in the miniature model, sufficient wind speed was obtained at the solar radiation level in winter, and in the practical system, the wind speed necessary for rotating the blades of the turbine was obtained.

(Embodiment 2)
In the first embodiment, power is generated by a turbine generator. A turbine generator is suitable for a large-scale power generation system because of its complicated structure and relatively expensive, but it is not suitable for a power generation system using a wall of a small building. In this embodiment, a power generation system that generates power with a relatively small generator using a piezoelectric element will be described.

  In the present embodiment, the generator 4a using the piezoelectric element 6 shown in FIG. 4 is installed in the vicinity of the air inlet 32 of FIG. The configuration other than the generator 4a is the same as that of the power generation system of the first embodiment. Hereinafter, the configuration and operation of the generator 4a using the piezoelectric element 6 will be described with reference to FIG. 4 and FIG.

  FIG. 4 shows an example of the configuration of the generator 4 a using the piezoelectric element 6, and FIG. 5 shows the usage state of the piezoelectric element 6. In FIG. 4, a long piezoelectric element 6 is provided so as to sandwich a cylindrical core material layer 61 having an elliptical cross section made of a highly elastic material, and the front and back surfaces of the core material layer 61. A pair of electrostrictive layers 62 made of a material and having a flat cross section, and an electrode 63 for taking out electric power from the electrostrictive layer 62 are configured.

  The piezoelectric element 6 generates electric power by using an electromotive force generated when the electrostrictive layer 62 is deformed. Electric power can be extracted from the electrostrictive layer 62 by vibrating the piezoelectric element 6 by an air flow.

FIG. 5 shows the usage state of the piezoelectric element 6. The piezoelectric element 6 is preferably installed in the air flow channel by the support base 64 in a state where the longitudinal direction is orthogonal to the air flow, and wind is applied from a specific direction orthogonal to the longitudinal direction of the piezoelectric element 6. As the specific direction, when the angle of attack of the wind with respect to the longitudinal direction of the major axis of the cross section is θ, the lift coefficient depending on this is C _L (θ), and the drag coefficient is C _D (θ), dC _L ( A direction that satisfies θ) / dθ + C _D (θ) <0 is preferable.
Here, if the angle of attack θ of the wind is too small, it is difficult for lift to occur when the piezoelectric element receives the wind, and conversely, if θ is increased, the drag in the direction opposite to the lift increases and galloping occurs. Since it becomes difficult to generate the phenomenon, it is preferably within a range of 10 to 20 degrees from the above formula. The piezoelectric element 6 vibrates as indicated by a two-dot chain line by the air flow, and the electrostrictive layer 62 generates power.

  The AC power generated in the electrostrictive layer 62 and taken out by the electrode 63 is sent to the rectifier circuit 8 by the electric wire 7 as shown in FIG. 4, converted into direct current by the rectifier circuit 8, and then stored in the storage battery 9. Note that the storage battery 9 is not an essential component of the generator 4a, and the electric power rectified by the rectifier circuit 8 may be supplied to the load as it is.

  In the piezoelectric element 6 shown in FIG. 4, as the electrostrictive polymer material used for the electrostrictive layer 62, a conductive elastomer mainly composed of acrylic rubber or silicon rubber, polyaniline, polypyrrole, polythiophene or the like is used. There are molecules. It is preferable to use a dielectric elastomer type in view of the magnitude of the current-stretching response speed and the high efficiency of converting displacement into electric power.

  The highly elastic material used for the core material layer 61 is not particularly limited as long as elasticity is maintained even when repeatedly deformed. In order to generate vibrations even under a slight wind, for example, glass fiber reinforced resin or polypropylene that is super-stretched and made highly elastic is preferable.

  As described above, the generator 4a using the piezoelectric element 6 is smaller than the turbine generator 4 shown in FIG. Therefore, by installing a plurality of piezoelectric elements 6 in the vicinity of the air inlet 32 in FIG. 1 along the air flow, efficient power generation is possible.

  The power generation system according to the present invention is suitable for power generation in urban areas where a sufficient installation area cannot be ensured, and once installed, power generation can be made permanently, so that its utility value is high.

DESCRIPTION OF SYMBOLS 1 Solar power generation system 2 Chimney 3 Connecting pipe 4 Turbine generator 4a Generator using a piezoelectric element 5 Wall 6 Piezoelectric element 7 Electric wire 8 Rectification circuit 9 Storage battery 21 Thick part 22 Hollow part 31 Hole 32 Air inlet 41 Turbine Blade 42 Generator body 43 Rotating shaft 61 Core material layer 62 Electrostrictive layer 63 Electrode

Claims (12)

A solar thermal power generation system that generates power using air heated by solar heat,
A plurality of column-shaped chimneys that have a hollow part through which air passes and that heat the air that passes through the hollow part by a thick part heated by irradiation with sunlight,
A plurality of holes connected to each of the hollow portions of the plurality of chimneys on the wall surface, and a connection pipe into which air flows from one opening;
A solar power generation system comprising: a generator that generates power by an air flow passing through the connection pipe.   2. The solar thermal power generation system according to claim 1, wherein an outer peripheral surface irradiated with sunlight is covered with a highly endothermic material among the thick part of the chimney.   2. The solar thermal power generation system according to claim 1, wherein an outer peripheral surface of the thick part of the chimney opposite to the side irradiated with sunlight is covered with a highly heat-insulating material.   2. The solar thermal power generation system according to claim 1, wherein a part of the thick part of the chimney is made of a material having a high heat storage property.   2. The solar thermal power generation system according to claim 1, wherein a concave mirror is installed in the vicinity of the side opposite to the side irradiated with sunlight of the chimney. As the generator, a turbine generator composed of a turbine blade attached to a rotating shaft and a generator main body that generates electric power by rotation of the rotating shaft,
The turbine blade is installed in the vicinity of an air inlet that is one opening of the connecting pipe, and the generator main body is installed in the other opening of the connecting pipe. A solar thermal power generation system according to the above.   The solar thermal power generation system according to claim 6, wherein a cone-like structure having a diameter of the air inlet smaller than that of the air outlet is installed between the air inlet and the blade of the turbine. .   8. The solar thermal power generation system according to claim 7, wherein a plurality of the cone-like structures are installed along an air flow path of the connecting pipe.   The solar thermal power generation system according to claim 6, wherein a plurality of blades of the turbine are provided, and the blades of the plurality of turbines are attached to the rotating shaft at equal intervals.   10. The solar thermal power generation system according to claim 9, wherein the blades of the turbine have a shorter radial length as they are arranged on the upstream side of the air flow. As the generator, a generator that generates power by vibrating a long piezoelectric element by an air flow,
6. The solar thermal power generation system according to claim 1, wherein the long piezoelectric element is installed in a state in which a longitudinal direction is orthogonal to a flow path of an air flow.   The solar thermal power generation system according to claim 11, wherein a plurality of the piezoelectric elements are provided, and the plurality of piezoelectric elements are installed along an air flow path.

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