JP2024085829A - Vaporizer and solar power generation device - Google Patents

Abstract

To propose a vaporizer and a solar power generation device that are small but can efficiently collect heat.SOLUTION: A vaporizer comprises: a heat collection container having a cavity for storing liquid therein and having a constant inclination in a direction of gravity; a parabolic mirror arranged with its concave reflective surface facing a first surface side of the heat collection container; and a condenser lens that is arranged on a second surface side of the heat collection container opposite the first surface side, and condenses sunlight, which is blocked from entering the parabolic mirror by the heat collection container, onto the heat collection container.SELECTED DRAWING: Figure 12

Description

This disclosure relates to an evaporation device and a solar thermal power generation device.

Solar power generators, solar cookers, solar furnaces, and other devices that utilize solar heat are widely known. For example, the demand for solar cookers, such as solar cookers, has been increasing in recent years due to the popularity of outdoor leisure activities. In addition, solar power generators and solar furnaces have been attracting attention as a next-generation energy supply source due to rising energy prices, tight electricity demand, and efforts at the corporate and individual levels to achieve the SDGs (Sustainable Development Goals).

JP 2002-327962 A

However, conventional solar heat-utilizing devices sometimes fail to collect enough sunlight and produce the required amount of heat. To address this issue, it is possible to enlarge or add additional collectors to achieve the desired amount of heat, but conventional solar heat power generation devices, such as parabolic trough, linear Fresnel, and tower types, are not suitable for installation in an average home and are too large to be installed in an average home, so it is not realistic to make them even larger in order to produce more heat.

Therefore, this disclosure proposes an evaporation device and solar thermal power generation device that are small yet capable of efficiently collecting heat.

An evaporation device according to one embodiment of the present disclosure includes a heat collection vessel having a cavity for storing liquid therein and a constant inclination in the direction of gravity, a parabolic mirror arranged with a concave reflective surface facing a first surface side of the heat collection vessel, and a focusing lens arranged on a second surface side of the heat collection vessel opposite the first surface side, for focusing sunlight blocked from entering the parabolic mirror by the heat collection vessel onto the heat collection vessel.

In addition, a solar thermal power generation device according to one embodiment of the present disclosure includes the vaporizer and a generator that generates electricity using the steam generated in the heat collection vessel.

FIG. 2 is an external view of a heat collector according to an embodiment of the present disclosure. 2 is a vertical cross-sectional view including line A-A' of the solar collector shown in FIG. 1. 2 is a vertical cross-sectional view of the collector shown in FIG. 1 including line B-B' and perpendicular to line A-A'. 1 is an external view showing a schematic configuration example of a heat collector assembly according to an embodiment of the present disclosure. FIG. 2 is a side view of a pipe member according to an embodiment of the present disclosure. 6 is a cross-sectional view of the pipe member shown in FIG. 5 taken along the longitudinal direction. 1 is an external view showing a schematic configuration example of a joint member for connecting a pipe member to a heat collector according to an embodiment of the present disclosure. FIG. FIG. 2 is an exploded view of a light collection vessel according to an embodiment of the present disclosure. FIG. 2 is an assembled view of a light collection vessel according to an embodiment of the present disclosure. 1 is a block diagram showing an example of a functional configuration of a solar tracking device according to an embodiment of the present disclosure. FIG. 1 is an external view illustrating a schematic configuration example of a solar tracking device according to an embodiment of the present disclosure. 1 is an external view illustrating a schematic configuration example of a vaporization device according to an embodiment of the present disclosure. 1 is a diagram illustrating an example of a schematic configuration of a solar thermal power generation device according to an embodiment of the present disclosure. 1 is an external view showing a schematic configuration example of a water supply tank according to an embodiment of the present disclosure. 15 is a cross-sectional view showing an example of the internal structure of the water supply tank shown in FIG. 14. 1 is an external view showing a schematic configuration example of a steam turbine generator according to an embodiment of the present disclosure; FIG. 1 is an external view illustrating a schematic configuration example of a cooler according to an embodiment of the present disclosure.

In devices that use solar heat, such as solar thermal generators, solar cookers, and solar furnaces, there are cases where the amount of sunlight collected is insufficient and the required amount of heat cannot be obtained. For example, in a device that uses steam generated by heating a liquid, which is a heat medium, with solar heat, a configuration is conceivable in which sunlight is collected on the heat collection container using a reflector placed on the back side of the solar light incident surface to collect sunlight onto the heat collection container, thereby heating the liquid in the heat collection container. However, with such a configuration, there is an issue that the shadow of the heat collection container or the parts connected to it is cast on the reflector, reducing the heat collection efficiency.

One possible solution to this problem of not being able to obtain the required amount of heat is to enlarge or add more collectors to achieve the desired amount of heat. Conventional solar thermal power generation devices include parabolic trough, linear Fresnel, dish, and tower types, but these conventional solar thermal power generation devices have a structure that is not suitable for installation in an ordinary home, and have the problem of being too large for installation in an ordinary home. For example, in the case of parabolic trough and linear Fresnel types, a certain length is required for the collector mirror, while in the case of dish types, the collector mirror needs to be large, and in the case of tower types, the number of heliostats needs to be increased. In addition, for example, in the case of parabolic trough and linear Fresnel types, power loss from flowing the heat medium through long piping is an issue, and therefore it was necessary to use vacuum double tubes with low heat loss for the heat collection tube.

As a result, it was not realistic to further increase the size of conventional solar thermal power generation devices in order to increase the amount of heat they could generate as solar thermal power generation devices for general household use.

In addition, when using the vapor generated by heating a liquid heat transfer medium for power generation, etc., it is more efficient to store a certain amount of liquid in the collector, heat it, and then replenish the vaporized liquid. However, when trying to increase the heat collection efficiency by tracking sunlight in a compact device for general household use, there is a problem that the tilt of the collector causes the exhaust port to become clogged with liquid, resulting in damage to the collector.

In addition, when sufficient heat cannot be obtained, it is possible to use a liquid with a low boiling point as a heat transfer medium in order to achieve sufficient vaporization with a small amount of heat. However, many liquids with boiling points lower than those of water or seawater, for example, are flammable, expensive, and difficult to obtain, and there are issues such as the need to make the equipment larger and stronger to ensure safety, as well as high costs.

Furthermore, in order to achieve stable heat collection using sunlight, whose angle of incidence changes depending on the time of day and season, it is possible to consider a configuration that tracks the sunlight to increase heat collection efficiency. However, when configured in this way, there is a problem that the tilt of the housing can cause the exhaust port to be blocked by liquid, resulting in a decrease in heat utilization efficiency and damage to the device.

In the following exemplary embodiment, therefore, we propose an evaporation device and a solar thermal power generation device that are small but capable of efficiently collecting heat. For example, the evaporation device and the solar thermal power generation device illustrated in the following exemplary embodiment may include a heat collection vessel having an inlet and an outlet for a liquid that is a heat medium and a constant inclination with respect to the direction of gravity, a parabolic mirror that is arranged on the opposite side of the heat collection vessel to the direction of incidence of sunlight (also called the back side or first side) and focuses the incident sunlight on the heat collection vessel, a focusing lens that is arranged on the front side of the heat collection vessel with respect to the direction of incidence of sunlight (also called the front side or second side) and focuses the incident sunlight on the heat collection vessel, and a tracking device that tracks the parabolic mirror and the focusing lens so that they face the sun directly.

According to the embodiment exemplified below, it is possible to improve the efficiency of collecting solar heat, so that a sufficient amount of heat can be obtained even when the device is made compact. For example, the solar heat can be efficiently collected in the heat collection container by a collecting lens arranged on the front side of the heat collection container and a parabolic mirror arranged on the back side, so that a sufficient amount of heat can be obtained even when the device is made compact.

The vaporizer and solar thermal power generation device according to the embodiments of the present disclosure will be described in detail below with reference to the drawings.

In the following embodiments, examples are given in which water or seawater is used as the heat medium. Water and seawater are non-flammable, inexpensive, and easily available, making it possible to realize miniaturization and cost reduction of vaporizers and solar thermal power generation devices that use them as heat media. In addition, for example, when seawater is used as the heat medium, table salt and distilled hot water can also be obtained as by-products, providing a much higher effect than using existing solar thermal power generation and solar thermal water heaters. However, various media can be used, not limited to water and seawater, as long as they are liquid media with high safety.

In the following embodiment, a solar thermal power generation device using a steam turbine is exemplified, in which a heat medium is heated by solar heat to generate steam to drive a turbine to generate electricity, but the power generation method is not limited to this, and various power generation methods that use steam, such as a screw type, can be used.

(Heat collector 10)
1 to 3 are diagrams showing a schematic configuration example of a heat collector according to an embodiment of the present disclosure, in which Fig. 1 is an external view of the heat collector, Fig. 2 is a vertical cross-sectional view including line AA' of the heat collector, and Fig. 3 is a vertical cross-sectional view of a surface including line BB' of the heat collector and perpendicular to line AA'.

As shown in Figures 1 to 3, the heat collector 10 comprises a spherical heat collection vessel 11 having an internal cavity, and a cylindrical inlet pipe 12 and an outlet pipe 13 that protrude from the heat collection vessel 11 along a straight line A-A' that passes through the center of the heat collection vessel 11.

The internal space of each of the injection pipe 12 and the exhaust pipe 13 is continuous with the cavity inside the heat collection vessel 11. At least one of the injection pipe 12 and the exhaust pipe 13 may be formed integrally with the heat collection vessel 11, or may be formed separately from the heat collection vessel 11 and connected to the heat collection vessel 11 by screwing, welding, or the like.

The end of the injection tube 12 opposite the heat collection vessel 11 is an open injection port, through which a heat transfer medium such as water or seawater is injected. A certain amount of heat transfer medium is injected from the injection tube 12 and stored in the heat collection vessel 11, and is heated inside the heat collection vessel 11 where sunlight is collected, generating steam.

2 and 3, a guide member 15 is provided inside the heat collection container 11 to form a space connecting the cavity in the heat collection container 11 and the cavity in the exhaust pipe 13. The exhaust port 16 of the guide member 15 is located near the ceiling of the space inside the heat collection container 11. This makes it possible to efficiently exhaust steam generated in the heat collection container 11 from the exhaust pipe 13 while suppressing the outflow of the heat medium stored in the heat collection container 11 from the exhaust pipe 13. In addition, by locating the exhaust port 16 near the ceiling of the internal space, even if the heat collector 10 is tilted due to some factor such as attitude control, earthquake, or impact, the exhaust port 16 can be prevented from being blocked by the heat medium and the pressure inside the heat collection container 11 can be prevented from excessively increasing, so that it is also possible to suppress the occurrence of malfunctions such as damage to the heat collector 10.

The end of the exhaust pipe 13 opposite the heat collection vessel 11 is an open exhaust port. The steam generated from the heat medium is exhausted from the exhaust port of the exhaust pipe 13 and may be used, for example, for power generation.

In the above configuration, at least the heat collection vessel 11 may be made of a material with a high solar absorption rate or may be painted with a paint with a high solar absorption rate, thereby increasing the heat collection efficiency for solar heat. For example, there are commercially available paints with a light absorption rate of over 99%, and by painting the heat collection vessel 11 with such paint, it is possible to significantly improve the heat collection efficiency for solar heat.

By increasing the light absorption rate of the heat collection vessel 11, it becomes possible to increase the absorption of light other than that along the optical axis C, such as light that is reflected or scattered by surrounding objects and enters the heat collection vessel 11, light that avoids the focusing lens 60 and enters the heat collection vessel 11 directly, light that is obliquely incident on the parabolic mirror 40 and reflected toward the heat collection vessel 11, and light that is reflected or scattered by surrounding objects and then reflected by the parabolic mirror 40 and enters the heat collection vessel 11. This makes it possible to further increase the heat collection efficiency of the heat collection vessel 11.

In addition, at least the heat collection vessel 11 (and preferably the inlet pipe 12 and outlet pipe 13 as well) may be made of a material that is highly corrosion-resistant, strong, and has a high thermal conductivity, such as a seawater-resistant alloy (e.g., copper or stainless steel). This makes it possible to increase durability and heat collection efficiency even when, for example, seawater is used as the heat medium.

(Heat collector assembly 30)
Fig. 4 is an external view showing a schematic configuration example of a heat collector assembly according to the present embodiment. Fig. 5 and Fig. 6 are schematic configuration examples of pipe members connected to the heat collector according to the present embodiment. 5 is a side view of the pipe member according to the present embodiment, and FIG. 6 is a cross-sectional view of the pipe member shown in FIG. 5 cut along the longitudinal direction. 7 is an external view showing a schematic configuration example of a joint member for connecting the pipe member according to the present embodiment to the heat collector.

As shown in FIG. 4, a pipe member 20 for supplying a heat medium from the outside to the heat collector 10 is connected to the inlet pipe 12 of the heat collector 10, and a pipe member 20 for directing steam generated in the heat collection container 11 to the outside is connected to the outlet pipe 13.

As shown in Figs. 1 and 2, the inlet end of the injection pipe 12 and the outlet end of the exhaust pipe 13 each have a threaded portion (thread) 14. On the other hand, as shown in Fig. 5, the end of each pipe member 20 that is attached to the heat collector 10 has a threaded portion (thread) 24. The orientation of the threads (or grooves) of the threaded portion 14 and the threaded portion 24 (also called the thread orientation) may be the same or opposite.

As shown in FIG. 6, the inside of each pipe member 20 is hollow 21, allowing the flow of heat medium supplied from the outside or steam generated within the heat collector 10. A groove 22 may be provided near the end of the pipe member 20 opposite the threaded portion 24 to increase the fitting strength with a soft or hard pipe (see pipes 151 to 154 in FIG. 13) described below.

The pipe member 20 and the injection pipe 12 or the exhaust pipe 13 may be connected using a joint member 25, for example, as shown in FIG. 7. The joint member 25 may be, for example, a member called a joint nut, which has a threaded hole 26 at one end that screws into the threaded portion 14 of the injection pipe 12 or the exhaust pipe 13, and a threaded hole 26 at the other end that screws into the threaded portion 24 of the pipe member 20. However, this is not limited to this, and the pipe member 20 and the injection pipe 12 or the exhaust pipe 13 may be a single member, or may be welded to each other.

The pipe members 20 can also function as support members for the solar tracking device 90 (described later) to support the heat collector 10. For this reason, it is preferable that each pipe member 20 is made of a material (such as stainless steel) that is highly durable against heat and has sufficient rigidity to support the heat collector 10.

(Light collecting container 80)
8 and 9 are diagrams showing a schematic configuration example of a light collecting container that houses a heat collector according to this embodiment. Fig. 8 is an exploded view of the light collecting container according to this embodiment, and Fig. 9 is an assembled view of the light collecting container according to this embodiment.

As shown in Figures 8 and 9, the light collecting container 80 is composed of a parabolic mirror 40, a transparent cover 50, a collecting lens 60, and a rear cover 70.

The parabolic mirror 40 has a concave (or parabolic) reflecting surface 41 that reflects sunlight incident parallel or approximately parallel to the optical axis C so as to concentrate the sunlight on a focal point (hereinafter also referred to as the parabolic mirror focal point or the first focal point) set on the optical axis C. This parabolic mirror 40 may be housed and held in a housing made up of a transparent cover 50 and a rear cover 70. A heat collecting container 11 may be positioned at the parabolic mirror focal point when the parabolic mirror 40 is held in the housing.

The transparent cover 50 may be made of, for example, a material that transmits sunlight. Examples of materials that transmit sunlight include transparent materials that have a certain degree of durability against heat, such as glass, acrylic resin, and other plastics. In this case, by using a material with a large heat capacity or a double structure for the transparent cover 50, it is possible to suppress heat dissipation from the transparent cover 50 to the outside, thereby increasing the heat collection efficiency of the heat collection container 11 housed within the housing. Note that sunlight that has passed through the transparent cover 50 may be incident on the parabolic mirror 40.

The rear cover 70 may be a cover that holds the parabolic mirror 40 and covers the rear side of the heat collection vessel 11 (and the parabolic mirror 40). This rear cover 70 may be made of a material that absorbs sunlight, may be made of a material that reflects sunlight, or may be made of a material that transmits sunlight. In this case, by using a material with a large heat capacity or a double structure for the rear cover 70, it is possible to suppress heat dissipation from the rear cover 70 to the outside, and therefore it is possible to increase the heat collection efficiency of the heat collection vessel 11 housed within the housing.

The transparent cover 50 and the rear cover 70 may each have a hemispherical shape, and may be combined with each other to form a spherical housing with an internal cavity. Making the housing spherical makes it possible to reduce the surface area, which makes it possible to suppress heat dissipation from the housing surface. This makes it possible to increase the heat collection efficiency of the heat collection container 11 contained within the housing. However, this is not limited to this, and the shape of the housing may be modified in various ways, such as a cylinder, a polygonal prism, a cone, or a polygonal pyramid.

In addition, by surrounding the heat collection container 11 with a housing, it is possible to warm the air around the heat collection container 11, which provides a heat retention effect and makes it less susceptible to the effects of weather. This makes it possible to further increase the heat collection efficiency of the heat collection container 11. For example, even on a sunny day, a typical solar cooking device (solar cooker) may become unusable due to the effects of sub-zero temperatures and strong winds. However, by surrounding the heat collection container 11 with a housing made of a transparent cover 50 and a back cover 70 as in this embodiment, it is possible to suppress the decrease in heat collection efficiency due to such external factors.

In addition, in the case of the parabolic trough type, which is well known in solar thermal power generation devices, operation is stopped at wind speeds of approximately 15 m/s or more due to its structure, and in the case of the linear Fresnel type, operation is stopped at wind speeds of approximately 25 m/s or more. However, as in this embodiment, the surroundings of the heat collection vessel 11 are protected by a housing, so it is possible to reduce the impact of strong winds.

A focusing lens 60 is provided at the apex of the transparent cover 50, with its center located on the optical axis C and its focal point (hereinafter also referred to as the lens focal point or second focal point) located on the optical axis C. Here, the optical axis of the focusing lens 60 and the optical axis of the parabolic mirror 40 may coincide as the optical axis C. The apex of the transparent cover 50 may be a point on the transparent cover 50 that passes through the optical axis C when the focusing container 80 is directly facing the sun.

The focusing lens 60 may be an optical element capable of focusing incident light to a predetermined focal point, such as a spherical convex lens, a Fresnel lens, or a prism. When using a Fresnel lens or a prism, the shape of the cross section perpendicular to the optical axis is not limited to a circle, and may be variously modified, such as a rectangle, other polygons, or an ellipse. The focusing lens 60 may be formed integrally with the transparent cover 50, or may be a member fitted into a hole or recess provided in the transparent cover 50.

The heat collecting vessel 11 may be located at the lens focus. That is, the heat collector assembly 30 may be positioned by the transparent cover 50 and the rear cover 70 (specifically, the notches 54 and 74 described later) so that the heat collecting vessel 11 is close to or coincides with both the parabolic mirror focus and the lens focus. This makes it possible to provide a sufficient amount of heat to the heat collecting vessel 11 using the sunlight focused by the focusing lens 60 and the sunlight reflected and focused by the parabolic mirror 40, making it possible to obtain a sufficient amount of heat even when the device is made compact. Note that "close" may mean that each focus is out of the heat collecting vessel 11 within a range in which most (at least half) of the sunlight focused by the parabolic mirror 40/focusing lens 60 can be incident on the heat collecting vessel 11.

In addition, if a parabolic mirror 40 is placed on the back side of the heat collection vessel 11, a shadow of the heat collection vessel 11 will be formed on the parabolic mirror 40, which may reduce the amount of sunlight collected by the parabolic mirror 40. For example, if the heat collection vessel 11 is painted jet black, the shadow of the heat collection vessel 11 formed on the parabolic mirror 40 will become darker, which may reduce the amount of sunlight collected by the parabolic mirror 40.

Therefore, in this embodiment, the size and shape of the focusing lens 60 in a plane perpendicular to the optical axis C are made to match or approximately match the size and shape of the heat collection vessel 11 in a plane perpendicular to the optical axis C. For example, if the heat collection vessel 11 is spherical and the focusing lens 60 is a spherical convex lens, the diameter of the focusing lens 60 is made to be approximately the same as the diameter of the heat collection vessel 11. This makes it possible to focus the sunlight that is blocked by the heat collection vessel 11 and casts a shadow onto the heat collection vessel 11 using the focusing lens 60, and therefore makes it possible to compensate for the loss in light collection efficiency due to the shadow of the heat collection vessel 11 by focusing the light using the focusing lens 60. In addition, if the size of the condenser lens 60 is made larger than that of the heat collecting vessel 11, the shadow of the condenser lens 60 will be formed on the parabolic mirror 40. However, by making the size of the condenser lens 60 and the size of the heat collecting vessel 11 approximately the same, it is possible to suppress the shadow of the condenser lens 60 from being formed on the parabolic mirror 40, and it is also possible to suppress the decrease in the light collecting efficiency of the parabolic mirror 40 due to the shadow of the condenser lens 60 being formed. In addition, the shape of the heat collecting vessel 11 is not limited to a sphere, and various shapes such as a frontal body, a polyhedron, and a cylinder can be adopted. In this case, the same effect can be obtained by making the condenser lens 60 approximately match the shape of the heat collecting vessel 11.

The transparent cover 50 and the rear cover 70 may each be provided with semicircular notches 54 and 74 for forming a hole through which the pipe member 20 of the heat collector assembly 30 is inserted when the cover is assembled. The position of the heat collector container 11 when the pipe members 20 on both sides of the heat collector assembly 30 are inserted into the two holes formed by the notches 54 and 74 may be the center of the housing formed by combining the transparent cover 50 and the rear cover 70. The parabolic mirror focus and the lens focus may be set to the heat collector container 11 located at the center of the housing. By arranging the heat collector container 11 at the center of the housing, it is possible to prevent the heat collector container 11 from moving out of the lens focus and the parabolic mirror focus even when the light collector container 80 formed by combining the transparent cover 50 and the rear cover 70 is rotated in the up-down direction (also called the vertical direction) around the pipe member 20 as an axis.

The pipe member 20 may be part of a holding member for holding the heat collector assembly 30 (e.g., the heat collector vessel 11) against the solar tracking device 90 (specifically, the rotating table 92) described later. More specifically, the pipe member 20 and the inlet pipe 12 and outlet pipe 13 may be part of a holding member for maintaining the distance from the condenser lens 60 and the parabolic mirror 40 to the heat collector vessel 11. The pipe member 20 may be rotatably inserted into a hole formed by the notches 54 and 74 provided in the transparent cover 50 and the rear cover 70 so that the heat collector assembly 30 is not fixed to the housing formed by the transparent cover 50 and the rear cover 70.

When the housing and the heat collector assembly 30 are fixed, if the housing is rotated vertically using the solar tracking device 90 described below, the heat medium may flow into the exhaust port 16 in the heat collection container 11 depending on the angle. To avoid such a case, it is desirable to have a configuration in which the pipe member 20 is inserted into the hole so that the heat collector assembly 30 is not fixed to the housing, as in this embodiment. However, this description does not exclude a configuration in which the heat collector assembly 30 is fixed to the housing.

The end of the parabolic mirror 40 may be provided with a notch 44 to avoid contact with the pipe member 20. By avoiding contact between the parabolic mirror 40 and the pipe member 20, it is possible to suppress deformation of the parabolic mirror 40 due to heat, and therefore to suppress a decrease in the efficiency of light collection into the heat collection vessel 11.

Furthermore, the pipe member 20 may be provided with a groove for engaging with the hole formed by the notches 54 and 74. This makes it possible to prevent the holding position of the heat collection vessel 11 from shifting along the longitudinal direction of the pipe member 20.

The transparent cover 50 and the rear cover 70 may be assembled so as to be openable and closable, for example, using hinges 53. The hinges 53 may be attached, for example, to a flat surface 52 provided on the side of the transparent cover 50 and a flat surface 72 provided on the side of the rear cover 70. The opening and closing direction of the transparent cover 50 relative to the rear cover 70 may be upward opening, downward opening, or side opening (including diagonal opening) to the left or right, as exemplified in Figures 8 and 9. However, this is not limited thereto, and the housing may be formed by simply screwing the transparent cover 50 and the rear cover 70 together.

When the transparent cover 50 and the rear cover 70 can be opened and closed using the hinge 53, fasteners 51 and 71 for restricting the opening and closing of the transparent cover 50 and the rear cover 70 may be provided on the side opposite to the side where the hinge 53 is provided. The fasteners 51 and 71 may, for example, be provided with a structure (e.g., a convex portion and a concave portion) that engage with each other to restrict the opening and closing, or may have holes that overlap when the transparent cover 50 and the rear cover 70 are combined, and the holes may be screwed in to restrict the opening and closing.

(Solar light tracking device 90)
Fig. 10 is a block diagram showing an example of the functional configuration of the solar tracking device according to the present embodiment. Fig. 11 is an external view showing a schematic configuration example of the solar tracking device according to the present embodiment.

The solar tracking device 90 is a control device that controls the attitude of the light collecting container 80 so that the front of the light collecting container 80 (i.e., the direction of the optical axis C) tracks the direction of the sun. As shown in FIG. 10, the solar tracking device 90 may include, for example, a detection system 97 that detects the direction of the sun (e.g., azimuth and elevation angle) relative to the light collecting container 80, a drive system 99 that adjusts the horizontal rotation angle (also called the horizontal rotation angle) and vertical rotation angle (also called the vertical rotation angle or elevation angle) of the light collecting container 80 so that the front of the light collecting container 80 (the surface facing the transparent cover 50 in the direction of the optical axis C of the collecting lens 60 and the parabolic mirror 40) faces the direction of the sun detected by the detection system, and a control system (also called a control unit) 98 that controls the detection system and the adjustment system.

For example, the detection system 97 may include a pyranometer, and the direction in which the amount of energy measured by the pyranometer is maximum (i.e., the direction of the sun) may be constantly or periodically identified by a calculation unit (sun direction identification unit).

The detection system 97 may also include, for example, a GNSS receiver, estimate its own position based on a signal received by the GNSS (Global Navigation Satellite System) receiver, and input the result to the control system 98. Note that the estimation of the self-position based on the received signal may be performed in a calculation unit in the control system 98, which will be described later.

The detection system 97 may further include, for example, an orientation sensor that detects the horizontal and vertical rotation angles of the light collecting container 80, and may constantly or periodically detect the front direction to which the light collecting container 80 is currently facing (hereinafter also referred to as the orientation of the light collecting container 80). As the orientation sensor, for example, a rotary encoder, a gyro sensor, an acceleration sensor, or any other sensor capable of detecting the angle of the orientation of the light collecting container 80 relative to a predetermined direction (for example, the direction of gravity) may be used.

The control system 98 may, for example, include a calculation unit, and calculate rotation angle control amounts (horizontal rotation angle control amount and vertical rotation angle control amount) for orienting the light collecting container 80 toward the sun from the direction of the sun identified by the detection system 97 and the orientation of the light collecting container 80 detected by the detection system 97 in the calculation unit (horizontal rotation angle control amount calculation unit and vertical rotation angle control amount calculation unit), and generate a drive signal (motor drive signal) to be given to the drive system 99 in the calculation unit (motor drive signal generation unit) from the calculated horizontal and vertical rotation angle control amounts.

The calculation unit of the control system 98 may also calculate the orientation of the sun relative to the light collecting container 80 from the self-position information input from the detection system 97 and the current date and time, and calculate a rotation angle control amount for orienting the light collecting container 80 toward the sun from the calculated sun orientation to generate a drive signal. For example, when the amount of solar radiation is small and the sun direction cannot be identified by the pyranometer, or when it is determined that the accuracy of the identified sun direction is low, the control system 98 may calculate the rotation angle control amount based on the sun direction identified from the self-position estimated by the GNSS, instead of identifying the sun direction by the pyranometer.

The drive system 99 may include, for example, a horizontal drive motor that generates power to rotate the light collecting container 80 in the horizontal direction, a vertical drive motor that generates power to rotate it in the vertical direction, and a power transmission mechanism that transmits the power generated by each drive motor to the light collecting container 80 to change the orientation of the light collecting container 80.

A solar tracking device 90 having such a functional configuration may include a base 91, a rotating base 92, two support legs 93, and an elevation angle adjustment mechanism 95, as illustrated in FIG. 11.

The base 91 is the base of the solar tracking device 90, and houses some or all of the components that make up the detection system 97, the control system 98, and the drive system 99. In this description, the horizontal plane and the horizontal direction may refer to a plane parallel to the top surface of the base 91 and a direction within the horizontal plane, and the vertical direction may refer to a direction perpendicular to the horizontal plane.

The rotating platform 92 may include a rotating table that rotates in a horizontal direction (also called a first direction) relative to the main body. The rotation angle of this rotating table in a horizontal plane may be controlled by power generated by a horizontal drive motor in the drive system 99.

The two support legs 93 are members that protrude vertically upward from the rotating table 92, and support the heat collector assembly 30 and the light collecting container 80 relative to the rotating table 92. Each support leg 93 has a hole 94 at a position where the light collecting container 80 is held, and the end of the pipe member 20 in the heat collector assembly 30 opposite the light collecting container 80 is rotatably inserted into this hole 94 to support the heat collector assembly 30 and the light collecting container 80 relative to the rotating table 92. Therefore, by adjusting the rotation angle of the rotating table 92 in the horizontal plane, the horizontal orientation of the light collecting container 80 combined with the heat collector assembly 30 can be adjusted in the east-west direction.

The elevation angle adjustment mechanism 95 is a mechanism for adjusting the elevation angle of the light collecting container 80 based on the power generated by the vertical drive motor in the drive system 99. In the example shown in FIG. 11, the elevation angle adjustment mechanism 95 includes a gear or a tire that contacts the rear portion (rear cover 70) of the light collecting container 80 supported by the support legs 93, and the elevation angle (vertical rotation angle) of the light collecting container 80 may be controlled by transmitting the power (rotational force) generated by the vertical drive motor to the gear or tire via a power transmission mechanism. When a gear is used, a groove that meshes with the gear may be provided in the area of the rear cover 70 where the gear contacts.

However, the configuration for adjusting the elevation angle of the light collecting container 80 is not limited to this configuration, and may be modified in various ways, such as a configuration in which the elevation angle is controlled by adjusting the center of gravity position of the light collecting container 80, or a configuration in which a rotational force is applied to the pipe member 20 when the pipe member 20 is fixed to the light collecting container 80 to adjust the elevation angle of the light collecting container 80.

Also, the elevation angle adjustment mechanism 95 may be omitted. In that case, a mechanism that can automatically or manually adjust the inclination of the base 91 relative to the installation surface depending on the season (date) may be provided in the legs of the base 91, or may be provided separately as an accessory.

(Evaporation device 100)
By assembling the heat collector assembly 30, the light collecting container 80, and the solar tracking device 90 having the above-mentioned configuration, an evaporation device 100 that collects solar heat in the heat collecting container 11 and evaporates the heat medium is configured as shown in Fig. 12. Note that the evaporation device 100 according to this embodiment may or may not include the solar tracking device 90.

The vaporizer 100 shown in FIG. 12 tracks sunlight in the east-west direction by rotating the turntable 92 in the solar tracking device 90 in the horizontal direction, and tracks sunlight in the up-down direction by rotating the light collecting container 80 up and down using the elevation angle adjustment mechanism 95.

When the pipe member 20 is fixed to the hole 94 of the support leg 93, it is possible to prevent the vertical tilt of the heat collection vessel 11 from changing when the elevation angle of the light collection vessel 80 is adjusted. This reduces the possibility that the exhaust port 16 in the heat collection vessel 11 will be blocked by the heat medium, and it is possible to suppress the occurrence of problems such as a decrease in the heat utilization efficiency and damage to the heat collector 10.

Here, by configuring the pipe member 20 to be rotatably inserted into the hole formed by the notches 54 and 74 of the light collecting container 80, it is possible to adjust the elevation angle of the light collecting container 80 to track the sunlight in the vertical direction without changing the vertical inclination of the heat collecting container 11, which further improves the heat collection efficiency and makes it possible to obtain a sufficient amount of heat even when the device is made compact.

In addition, if the solar tracking device 90 rotates the light collecting container 80 in the vertical direction, and the distance between the heat collecting container 11 and the condensing lens 60 and/or the distance between the heat collecting container 11 and the parabolic mirror 40 changes, the lens focus of the condensing lens 60 and/or the parabolic mirror focus of the parabolic mirror 40 may deviate from the heat collecting container 11, and the heat collecting efficiency of the heat collector 10 may decrease. In response to such a possibility, in this embodiment, a spherical container is used for the heat collecting container 11, so that the distance between the heat collecting container 11 and the condensing lens 60 and the distance between the heat collecting container 11 and the parabolic mirror 40 do not change even when the light collecting container 80 rotates in the vertical direction. However, the shape of the heat collecting container 11 is not limited to a sphere, and may be variously modified, such as a cylindrical shape, an elliptical cylindrical shape, a polyhedral shape such as a regular hexahedron (including a column shape), a cone, an elliptical cone, a polygonal pyramid, or a coil shape wound with a pipe. In this case, it is more preferable that the shape of the side of the heat collection container 11 facing the sun (i.e., the side where sunlight is collected by the collecting lens 60) and the shape of the opposite side (i.e., the side where sunlight is collected by the parabolic mirror 40) are shapes (e.g., circular or sector-shaped) that do not change the above distance when the light collection container 80 is rotated up and down, since this makes it possible to stabilize the heat collection efficiency of the heat collection container 11.

(Solar power generation device 1000)
Next, a case where the energy obtained by the above-mentioned vaporization device 100 is used for power generation will be described. Fig. 13 is a diagram showing a schematic configuration example of a solar thermal power generation device according to this embodiment. Fig. 14 is an external view showing a schematic configuration example of a water supply tank according to this embodiment, and Fig. 15 is a cross-sectional view showing an example of the internal structure of the water supply tank shown in Fig. 14. Fig. 16 is an external view showing a schematic configuration example of a steam turbine type generator (hereinafter also referred to as a steam turbine type generator) according to this embodiment, and Fig. 17 is an external view showing a schematic configuration example of a cooler according to this embodiment.

As shown in FIG. 13, the solar thermal power generation system 1000 includes an evaporation device 100, a water supply tank 110, a steam turbine generator 120, a cooler 130, and a water storage tank (water pack) 140, which are connected via flexible pipes such as polyvinyl chloride pipes or rigid pipes such as metal pipes 151-154 so that the heat medium or its steam can be supplied from the upstream side to the downstream side. Note that the upstream side may be the water supply tank 110 side, and the downstream side may be the water storage tank 140 side.

As shown in Figures 13, 14 and 15, the water supply tank 110 includes a water pack 113 arranged at the top, a bellows-structured member 114 arranged at the bottom, an inlet 111 for injecting a heat transfer medium such as water or seawater into the water pack 113, and a supply port 112 for supplying the heat transfer medium in the water pack 113 to the outside. The supply port 112 is connected to a pipe member 20 connected to an injection pipe 12 in the vaporizer 100 via a tube 151.

The bellows-structured member 114 expands and contracts according to the amount of water in the water pack 113. This keeps the water level in the water pack 113 constant, and the heat medium in the water pack 113 is steadily supplied from the supply port 112 to the vaporizer 100 via the pipe 151. As a result, the heat medium in the heat collection vessel 11 in the vaporizer 100 is prevented from running out.

As shown in FIG. 13 and FIG. 16, the pipe member 20 connected to the exhaust pipe 13 in the vaporizer 100 is connected to the intake port 121 in the steam turbine generator 150 via a pipe 152. The steam turbine generator 120 has a turbine inside, and generates electricity by rotating the internal turbine with steam supplied from the vaporizer 100 via the pipe 152. The electricity generated in this way may be transmitted to the outside via a power transmission cable or a power outlet provided in the steam turbine generator 120. For example, the steam turbine generator 120 may be connected to an external storage battery via a power transmission cable and configured to store the generated electricity in the storage battery. The steam turbine generator 120 may also transmit the generated electricity directly to home appliances such as refrigerators and vacuum cleaners.

As shown in FIG. 13 and FIG. 17, the exhaust port 122 of the steam turbine generator 120 is connected to the intake port 131 of the cooler 130 via a pipe 153. The steam (which may include liquefied liquid) used for power generation in the steam turbine generator 120 is supplied to the cooler 130 from the exhaust port 122 via the pipe 153. The cooler 130 includes a cooling pipe 133 of sufficient length to cool the steam (which may include liquefied liquid) and one or more heat sinks 134 in contact with the cooling pipe 133 to release heat from the cooling pipe 133, and cools and liquefies the steam passing through the cooling pipe 133.

The cooler 130 may be equipped with a mechanism for adjusting the length of the cooling pipe in accordance with the air temperature. The cooler 130 may also be configured to perform active cooling using power such as a cooling fan.

The liquid cooled by the cooler 130 (for example, distilled water of hot water evaporated from steam) is discharged from the outlet 132. The outlet 132 may be connected to the water tank 140 via a pipe 154, for example. By storing the liquid cooled by the cooler 130 in the water tank 140, it is possible to reuse it. However, this is not limited to such a configuration, and the pipe 154 may be connected to the water supply tank 110 to return the cooled liquid to the water pack 113 of the water supply tank 110. In this way, by configuring the heat medium to circulate through the solar thermal power generation device 1000, it is possible to prevent the heat medium in the water supply tank 110 from drying up without the need for frequent water supply to the water supply tank 110, even if the solar thermal power generation device 1000 is installed in a season or region with long hours of sunshine, or in a season or region with high solar radiation. In addition, the liquid discharged from the cooler 130 is a harmless liquid, such as distilled water made from hot water whose steam has evaporated, and may therefore be directly discharged into a sewer pipe, etc.

By using the above configuration, it is possible to collect a sufficient amount of solar heat even when the device is compact, making it possible to realize solar thermal power generation using water, seawater, etc.

Furthermore, when seawater is used as the heat medium, the salinity increases as the water evaporates in the heat collection vessel 11 of the vaporization device 100, and eventually crystallizes. What happens inside this heat collection vessel 11 is a simplified version of what happens in salt fields, so when seawater is used as the heat medium, salt can be obtained as a by-product. For example, since the salinity of seawater is about 3.4%, it is possible to produce about 34 g of salt from 1 liter of seawater.

Although the embodiments and their modifications of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-mentioned embodiments or their modifications as they are, and various modifications are possible without departing from the gist of the present disclosure. In addition, components from different embodiments and modifications may be combined as appropriate.

Furthermore, the effects of the embodiments and their variations described in this specification are merely examples and are not limiting, and other effects may also be obtained.

REFERENCE SIGNS LIST 10 Heat collector 11 Heat collecting vessel 12 Inlet pipe 13 Outlet pipe 14, 24 Threaded portion 15 Guide member 16 Exhaust port 20 Pipe member 22 Groove 25 Joint member 26 Screw hole 30 Heat collector assembly 40 Parabolic mirror 41 Reflecting surface 44, 54, 74 Notch 50 Transparent cover 51, 71 Fastener 52, 72 Flat surface 53 Hinge 60 Condenser lens 70 Rear cover 80 Condenser vessel 90 Solar tracking device 91 Base 92 Rotating table 93 Support leg 94 Hole 95 Elevation angle adjustment mechanism 100 Vaporizer 110 Water supply tank 111 Inlet 112 Supply port 113 Water pack 114 Bellows structure member 120 Steam turbine generator 121 Intake port 122 Exhaust port 130 Cooler 131 Intake port 132 Exhaust port 133 Cooling pipe 134 Heat sink 140 Water tank 151 to 154 Pipe C Optical axis

Claims (6)

a heat collecting vessel having a cavity for storing liquid therein and having a constant inclination in the direction of gravity;
a parabolic mirror arranged with a concave reflecting surface facing the first surface side of the heat collecting container;
a collecting lens that is disposed on a second surface side of the heat collecting container opposite to the first surface side and collects sunlight that is blocked by the heat collecting container from being incident on the parabolic mirror onto the heat collecting container;
A vaporizer comprising: The solar tracking device further includes a solar tracking device that orients the condenser lens and the parabolic mirror in a direction directly facing the sun.
2. The vaporizer of claim 1. the heat collecting vessel has a shape capable of maintaining a distance between a focal point of the parabolic mirror and a focal point of the collecting lens,
The evaporation device according to claim 2 , wherein the solar tracking device orients the focusing lens and the parabolic mirror in the direction directly facing the sun while maintaining a positional relationship in which the focal point of the parabolic mirror and the focal point of the focusing lens are close to or coincident with the heat collection container. A transparent cover that is arranged to cover the second surface side of the heat collecting container and transmits sunlight;
a rear cover that is disposed so as to cover the first surface side of the heat collecting container and that constitutes a housing that houses the heat collecting container and the parabolic mirror together with the transparent cover;
The vaporizer according to any one of claims 1 to 3, further comprising: The heat collection vessel is made of a material having corrosion resistance equal to or higher than copper and thermal conductivity equal to or higher than aluminum,
The surface of the heat collection vessel is black.
The vaporizer according to any one of claims 1 to 3. The vaporizer according to claim 1 ;
a generator that generates electricity using steam generated in the heat collection vessel;
A solar thermal power generation device comprising:

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