JPS6329153A - Solar heat collecting method - Google Patents

Abstract

PURPOSE:To reduce a power consumption expense for collecting a heat in water within a container and reduce a cost by a method wherein an interior of a heat-insulating sealed container is pressurized to a negative pressure to cause a water surface within the container to be lifted above a water surface out of the container and a solar heat is absorbed in the water surface layer part out of the container. CONSTITUTION:A lower end of heat-insulating sealed container 1 is immersed at a shallow part below a water surface of a pond 5, a suction port 15 arranged at an upper central part the container 1 is connected to a suction port of a vacuum pump 18, a suction end part of a hot water feeding pipe 19 is installed in the water in the container and a discharging end of a cold water return pipe 20 is arranged in the water in the pond 5. The container is made to have a negative pressure by an operation of the vacuum pump 18 and the water surface 2 within the container is lifted above the water surface 3 within the pond 5, thereafter the operation of the vacuum pump 18 is terminated and left in this condition, a solar heat absorbed at the water surface layer of the pond 5 is collected in the water in the container due to a natural convection phenomenon and the hot water of which temperature is increased is sent to a location where hot water is used through the hot water feeding pipe 19.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention utilizes solar heat as a variety of heat sources such as power generation, various industrial heat source supplies, consumer hot water supply, industrial hot water supply, air conditioning, seawater desalination, and snow melting. This article relates to solar heat collection methods that can be used when

[Prior art]

Traditionally, solar energy is absorbed through the water surface.

As shown in FIG. 6, a typical method for storing heat is to inject highly concentrated salt water into an artificial or natural pond 5 built on the ground 4 to form a bottom heat storage layer 6. Above the heat storage layer B, salt water whose concentration is gradually lowered from the bottom side upwards is divided into layers and injected in about 50 stages to form a salt water concentration gradient layer (intermediate non-convection layer) 7, and the salt water Clean water is poured onto the concentration gradient layer 7 to form an upper clean water layer 8, and the concentration of the bottom heat storage layer 6 is approximately 20 to 25%.
In addition to collecting and storing all of the solar heat in the bottom heat storage layer 6, the salt water concentration gradient layer 7 suppresses convection and exhibits non-convection heat insulation to prevent heat radiation from the bottom heat storage layer 6. Furthermore, the dust and dirt floating on the water surface are purified by the upper clean water layer 8, solar heat is incident and absorbed into the bottom heat storage layer 6, and hot water is supplied from the bottom heat storage layer 6 through the hot water supply pipe 9 to utilize the heat. A heat collection method is mentioned in which cold water is returned to the bottom heat storage layer 6 through a return pipe 10.

[Problem that the invention seeks to solve]

The conventional solar heat collection method has the following problems.

(1) It is expensive because it requires a large amount of salt;
Moreover, it is complicated because it is necessary to dissolve the salt.

(2) The work of forming a large number of different concentration layers when providing the salt water concentration gradient layer 7 is extremely complicated, and the maintenance and management of the salt water concentration gradient state of the salt water concentration gradient layer 7 is also extremely time consuming.

(6) It is necessary to provide layers other than the bottom heat storage layer within the container or provide partitions, and the amount of water is significantly large, resulting in high construction costs and water supply costs.

(4) Since the heat storage layer is at the bottom, the amount of solar heat absorbed is small.

(5) Since the bottom heat storage layer and other layers are exposed to sunlight, they are prone to the growth of bacteria and algae, and therefore require chemicals for sterilization and prevention of algae growth, which increases costs.

(6) It is vulnerable to wind and rain, and the stable state of the salt water concentration gradient layer is likely to collapse.

(7) If the salt water in the bottom heat storage layer B is directly circulated to supply heat, the salt water concentration gradient layer 7 is likely to be disturbed.

[Purpose and structure of the invention]

The purpose of this invention is to provide a method for collecting solar heat that can advantageously solve the above-mentioned problems. By immersing the water shallowly under the water surface irradiated by sunlight and creating a negative pressure inside the insulated closed container 1, the water level 2 inside the insulated closed container 1 is raised above the water level 6 outside the insulated closed container 1. By continuously maintaining this state, the solar heat absorbed by the water surface layer outside the insulated hermetic container 1 is collected into the water inside the insulated hermetic container 1 by natural convection. It is a method of collecting solar heat.

〔Example〕

Next, the present invention will be explained in detail using illustrated examples.

FIG. 1 shows a first embodiment of the present invention, in which an artificial pond 5 is built on the ground 4, and an insulated airtight container 1 consisting of a cylindrical portion and a hemispherical portion connected to the upper end thereof. is composed of a container body 11 made of metal or plastic and a heat insulating material 12 such as foamed urethane provided integrally on the outer surface of the container body 11. The upper ends of the supporting legs 13 are fixed at intervals in the circumferential direction of the lower end of the closed container, and each supporting leg 16
The lower end portion is fixed to a foundation 14 provided at the bottom of the pond 5, and the lower end portion of the heat-insulating sealed container 1 is shallowly submerged below the water surface 6 of the pond 5.

A suction port 15 provided at the center of the upper part of the heat-insulating airtight container 1
is connected to the suction port of the vacuum pump 18 via an air suction pipe 17 having an on-off valve 16, and the suction end of the hot water supply pipe 19 is placed in the water inside the insulated sealed container 1, and the discharge end of the cold water return pipe 20 The end portion is placed underwater in the pond 5.
,.

After the inside of the insulated airtight container 1 is made negative pressure by the direct air pump 18 and the water level 2 in the insulated airtight container 1 is raised above the water level 3 in the pond 5, the on-off valve 16 is closed and the vacuum pump is turned off. 18 is stopped and left in this state.

In this way, solar heat is absorbed by the water surface layer of the pond 5, and the absorbed solar heat is collected into the water in the heat-insulating closed container 1 by natural convection. The high-temperature water heated in the heat-insulating sealed container 1 is sent to a hot water usage area through a hot water supply pipe 19, and the cold water after being used in the heat cave is returned to the pond 5 through a cold water return pipe 20.

FIG. 2 shows a second embodiment of the present invention, in which a buoyancy tank 21 is attached to the lower outer periphery of a hemispherical heat-insulating sealed container 1 with an open bottom. The anchor 2 is constructed at a shipyard, towed to the installation site at sea, and anchored 2 from the seabed ground 24.
6 and mooring lobe 2'2 on the sea surface.

A suction port 15 provided at the center of the upper part of the heat-insulating sealed container 1 is connected to the direct air bong 1 through an air suction pipe 17 having an on-off valve 16.
8, and the suction end of the hot water supply pipe 19 is arranged above the water in the insulated closed container 1, and the discharge end of the cold water return pipe 20 is arranged below the water in the insulated closed container 1. It is located in

In the case of the second embodiment as well, after the inside of the insulated hermetic container 1 is made negative pressure by the vacuum pump 18 and the water level 2 inside the insulated hermetic container 1 is raised above the water level 6 outside the insulated hermetic container 1, The on-off valve 16 is closed, the operation of the direct air pump 18 is stopped,
When left in this state, heat is collected and hot water and water are supplied in the same manner as in the first embodiment.

In the case of the second embodiment, a buoyancy tank 21 is attached around the insulated closed container 1, and the insulated closed container 1 floats, so that the insulated closed container 1 can be used as a mobile device, and It can also automatically respond to changes in water level.

When carrying out the present invention, the heat-insulating sealed container 1 can be installed in a natural sea, pond, lake, puddle, etc., or can be used by being floated and moored. Further, the first shape of the heat-insulating sealed container is ideally hemispherical, but it may be any other arbitrary shape. Furthermore, the heat insulating airtight container 1 may be installed so as to be movable up and down, or
Alternatively, a lid that can be opened and closed is provided at the lower end opening of the insulating airtight container 1, so that when sunlight is not irradiated, the insulating airtight container 1f,
It may be moved downward or the lid may be closed to shut off the water inside the insulated hermetic container 1 and the water outside the insulated hermetic container 1, thereby preventing the water inside the insulating hermetic container 1 from radiating heat.

In order to recover the heat accumulated in the water in the insulated hermetic container 1, a heat exchanger may be provided in the insulated hermetic container 1, and a water surface 6 around the insulated hermetic container 1 may be provided on the outer periphery of the insulated hermetic container 1. A covering light-transmitting film or light-transmitting glass may be attached to prevent heat radiation from the water surface around the heat-insulating closed container 1.

An air ejector or other means may be used instead of a vacuum bong as a means of creating a negative pressure inside the insulated hermetic container 1. Also, when performing small-scale heat collection, the bottom of the insulated hermetic container 1 may be placed in a pond. Temporarily seat it on the bottom of the insulated sealed container 1, and fill it with water inside the insulated sealed container 1.
t- You may pull it up. Furthermore, the structure of the heat insulating wall portion of the heat insulating closed container 1 may be any structure other than the above.

〔Effect of the invention〕

According to this invention, the lower part of the insulating sealed container 1, which is open at the bottom, is immersed shallowly under the water surface irradiated with sunlight, and the inside of the insulating sealed container 1 is made to have a negative pressure. By raising the water level 2 above the water level 6 outside the insulated hermetic container 1 and continuously maintaining this state, the solar heat absorbed by the surface layer of the water outside the insulated hermetic container 1 can be absorbed by natural convection. Due to this phenomenon, heat is collected in the water in the heat-insulating closed container 1, so that the following effects can be obtained.

(1) Since the power required to collect heat is only the power needed to fully raise the water level in the heat-insulating sealed container 1, the power cost can be extremely reduced and costs can be lowered.

(2) There is no need for salt water production, water quality control, flow control, pollution/clarification control, and naturally available seawater or fresh water can be used as is, reducing costs.
It has wide applicability and can easily collect heat.

(3) It is possible to collect and store the heat of the water in the surface layer, which is at its highest temperature in its natural state, using natural convection.
Heat collection efficiency can be improved by simple means.

(4) The natural water surface can be used without partitioning, and when constructing an artificial pond, a shallow pond is sufficient, so construction costs can be reduced.

(5) There are no technical problems regardless of whether the scale is large or small, and it can be easily put into practical use.

(6) Since the size of the heat-insulating sealed container 1 is only required for the heat storage capacity, the manufacturing cost of the heat collection equipment can be reduced.

By creating a negative pressure in the upper part of the insulated hermetic container 1, a large amount of water in the insulated hermetic container 1 can be maintained at a higher level than the water surface 6 outside the insulated hermetic container 1.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional side view showing a first embodiment of the present invention, and a second embodiment of the present invention is shown in FIG.
The figure is a longitudinal sectional side view showing a second embodiment of the present invention. FIG. 6 is a longitudinal sectional side view showing a conventional solar heat collection facility. In the figure, 1 is an insulated airtight container, 2 and 3 are water surfaces, and 5
is the pond, 11 is the container body, 12 is the insulation material, 13 is the support leg, 1
4 is a foundation, 15 is a suction port, 16 is an on-off valve, 17 is an air suction pipe, 18 is a direct air pump, 19 is a hot water supply pipe, 20 is a cold water return pipe, 21 is a buoyancy tank, 22 is a mooring rope, 26 is an anchor It is.

Claims (1)

[Claims] By immersing the lower part of the insulated sealed container 1, which is open at the bottom, shallowly under the water surface irradiated by sunlight and create a negative pressure inside the insulated sealed container 1, the water surface 2 in the insulated sealed container 1 is insulated. By raising the water level above the water level 3 outside the hermetic container 1 and continuously maintaining this state, the solar heat absorbed by the water surface layer outside the insulating hermetic container 1 is absorbed by the natural convection phenomenon. A solar heat collection method characterized by collecting heat into water within a room.