Closed circulation type land-based aquaculture system

Abstract

[Problem] To provide a closed circulation type land-based aquaculture system that has a lower environmental load than conventional breeding systems. [Solution] A closed circulation type land-based aqu

Description

Closed-loop land-based aquaculture system

[0001] The present disclosure relates to a closed recirculating land-based aquaculture system.

[0002] As the global population grows, demand for food is increasing, and a stable supply of highly productive marine resources is required from the perspective of realizing a sustainable society. Regarding productivity, the feed conversion ratio (FCR), defined as the amount of feed required to gain 1 kg of weight, is 10-15 for cattle, 3-4 for pigs, and 1.4-2.2 for chickens, while it is 1.3-1.7 for shrimp and other crustaceans and around 1.1 for fish. Furthermore, the amount of water required to gain 1 kg of weight is over 20,000 liters for cattle, approximately 6,000 liters for pigs, and 4,500 liters for chickens, whereas when raised in closed-loop land-based aquaculture, shrimp and other crustaceans require only 315 liters.

[0003] Although aquatic resources are more productive than terrestrial animal food resources, using natural water sources such as the sea, rivers, and lakes for aquaculture limits the locations where aquaculture facilities can be set up. Therefore, closed-loop land-based aquaculture has been seen as promising in recent years. Closed-loop land-based aquaculture allows aquaculture facilities to be set up even in locations far from natural water sources, making it particularly advantageous for inland areas.

[0004] Examples of conventional technologies relating to such closed circulation land-based aquaculture include Patent Documents 1 and 2.

[0005] The temperature-controlled aquaculture greenhouse for artificial aquaculture disclosed in Patent Document 1 has a tank installed inside the greenhouse, and when the temperature inside the greenhouse becomes high, the temperature is regulated by ventilation and the water is changed automatically. The water change in the tank in Patent Document 1 is performed by operating a pump installed inside the tank to drain the water from the tank, and the drained water is supplied from outside.

[0006] The land-based aquaculture system disclosed in Patent Document 2 includes a plurality of tanks arranged on land, a top plate that covers at least a portion of the space between the plurality of tanks and abuts against at least one of the tanks that form the space, and a partition wall that is provided in the space covered by the top plate and abuts against at least one of the tanks that form the space. In the tanks disclosed in Patent Document 2, the temperature of the tanks is adjusted by, for example, removing a window provided in the top plate or the partition wall.

[0007] Patent No. 6784879 Patent No. 5274884

[0008] In the aquaculture systems described in Patent Documents 1 and 2, the tanks are placed in a greenhouse or a closed space, and temperature is regulated by ventilation, etc. as needed. In this way, in conventional aquaculture systems, attempts have been made to regulate temperature while using as little electricity as possible.

[0009] On the other hand, in the system of Patent Document 1, water is changed by draining the water in the tank and supplying water from outside, which requires a large amount of water.In addition, the system of Patent Document 2 does not mention water management, so it is recognized that water purification is also handled by water replacement in this system.

[0010] When installing an aquaculture system on land, it is necessary to use a circulating system for the rearing water in order to reduce the amount of water used. However, when using a circulating system for the rearing water, electrical energy is required to drive the circulation pump for constantly circulating the water and the aeration pump for adjusting the dissolved oxygen, and electricity or heavy oil or kerosene is used to adjust the water temperature, resulting in a large amount of energy consumption and CO2 emissions. ２ From the perspective of emissions, it cannot be said that the environmental impact is low.

[0011] An object of the present invention is to provide a closed circulation land-based aquaculture system that imposes a lower environmental impact than conventional rearing systems.

[0012] The closed-circulation land-based aquaculture system of the present invention, which is provided to solve the above-mentioned problems, is a closed-circulation land-based aquaculture system comprising a breeding tank that holds breeding water and grows aquatic products, an insulating member that covers at least a portion of the breeding tank, a filtration tank that purifies the water quality of the breeding tank, a circulation pump that delivers the breeding water from the filtration tank to the breeding tank, a distributor that connects electricity generated by renewable energy or grid power to an aquaculture system load including the circulation pump, and a control device that controls at least the circulation pump, wherein the breeding tank and the filtration tank are arranged adjacent to each other, and the circulation pump is installed below the water level of the lower of the breeding tank or the filtration tank, and delivers water from the filtration tank into the breeding tank.

[0013] In the closed circulation land-based aquaculture system of the present invention, the circulation pump is installed below the water level of either the rearing tank or the filtration tank, whichever is lower, and the water in the filtration tank is delivered to the rearing tank, enabling circulation within the rearing tank with less power. This makes it possible to provide a closed circulation land-based aquaculture system with a lower environmental impact than conventional rearing systems.

[0014] In the closed circulation land-based aquaculture system of the present invention, the renewable energy may be a solar power generation panel, and the system may further include a converter that converts the voltage of the electricity generated by the solar power generation panel, and a storage battery that is connected to the solar power generation panel via the converter and stores the electricity generated by the solar power generation panel, and the circulation pump may be a DC pump.

[0015] By installing these solar panels, a closed-circulation land-based aquaculture system can be installed even in places without grid power. Also, by using a DC pump for the circulation pump, power consumption can be reduced compared to an AC pump, and water from the filter tank can be delivered to the breeding tank with low power consumption.

[0016] The closed-circulation land-based aquaculture system of the present invention may further include a temperature sensor that measures the temperature of the breeding water, and a solar water heater that stores solar heat in a heat medium and transfers the heat from the heat medium to the breeding water, wherein the control device generates a first control signal to start transferring heat from the heat medium in the solar water heater to the breeding water when information indicating that the breeding water is below a predetermined first temperature is input from the temperature sensor, and generates a second control signal to stop transferring heat from the heat medium in the solar water heater to the breeding water when information indicating that the breeding water has reached a predetermined second temperature is input from the temperature sensor. With this configuration, the temperature in the breeding aquarium can be controlled to a constant temperature by the solar water heater.

[0017] Furthermore, the closed-circulation land-based aquaculture system of the present invention may further include a boiler capable of heating the rearing water, and the control device may operate the boiler to generate a third control signal for heating the rearing water when the second control signal is not generated even after a predetermined first time has elapsed since the generation of the first control signal. With this configuration, even when temperature control by the solar water heater is not possible due to weather, the boiler can control the temperature in the rearing aquarium to a constant temperature.

[0018] The closed circulation land-based aquaculture system of the present invention may further include a wind power generation facility connected to the distributor. With this configuration, more power can be obtained in windy installation locations.

[0019] Furthermore, the closed circulation land-based aquaculture system of the present invention may further include a water quality sensor that measures the water quality of the breeding water, and the control device may generate a fifth control signal to start the operation of the circulation pump or increase the discharge rate per unit time of the circulation pump when information indicating that the breeding water has reached a first water quality level is input from the water quality sensor, and generate a sixth control signal to stop the operation of the circulation pump or decrease the discharge rate per unit time of the circulation pump when information indicating that the breeding water has reached a second water quality level is input from the water quality sensor. With this configuration, the water quality in the breeding aquarium can also be maintained constant.

[0020] Furthermore, the closed-circulation land-based aquaculture system of the present invention may further include an aeration device that aerates the breeding water, wherein the fifth control signal includes a signal to start operation of the aeration device and the sixth control signal includes a signal to stop operation of the aeration device. With this configuration, the water quality in the breeding aquarium tank can be maintained more constant.

[0021] The present invention provides a closed circulation land-based aquaculture system that imposes a lower environmental impact than conventional rearing systems.

[0022] 1 is an explanatory diagram of a closed circulation land-based aquaculture system according to an embodiment of the present invention, in which (A) is a diagram seen from diagonally front and (B) is a diagram seen from diagonally rear. FIG. 2 is an explanatory diagram of a closed circulation land-based aquaculture system according to this embodiment. FIG. 3 is a block diagram explaining the functions of a control device.

[0023] The present disclosure will be described below with reference to the drawings. Figures 1(A) and 1(B) are explanatory diagrams of a closed-loop land-based aquaculture system according to one embodiment of the present invention, with (A) showing the exterior of the system as seen obliquely from the front and (B) as seen obliquely from the rear.

[0024] The closed circulation land-based aquaculture system 100 according to one embodiment of the present invention includes a container 110 that uses a known modular house or a shipping container, and the interior of the container 110 serves as a rearing space 100U. The container 110 has dimensions of 4899 mm in length, 2230 mm in width, and 2694 mm in height, so the footprint (occupied area) of the closed circulation land-based aquaculture system 100 according to this embodiment is 9.99 m. ２ (3.02 tsubo) and 10m ２ is less than.

[0025] For this reason, the closed-circulation land-based aquaculture system 100 according to this embodiment can be installed in a parking space large enough for one car. Therefore, the closed-circulation land-based aquaculture system 100 according to this embodiment can be installed in densely populated areas where closed-circulation land-based aquaculture systems have not been installed before, such as outdoor parking lots in commercial areas or vacant lots in residential areas. By installing the closed-circulation land-based aquaculture system 100 in such areas where people live, it is possible to provide fresh marine resources safely and at low cost.

[0026] In the closed-circulation land-based aquaculture system 100 according to this embodiment, a photovoltaic power generation panel 200, a solar water heater 210 that stores solar heat in a heat medium (e.g., water, antifreeze, etc.) and can transfer the heat of the heat medium to the rearing water in the rearing space 100U, and a wind power generation facility 230 are mounted on the ceiling 111 of the container 110. Note that the photovoltaic power generation panel 200, the solar water heater 210, and the wind power generation facility 230 are not essential components of the closed-circulation land-based aquaculture system 100.

[0027] Furthermore, in order to utilize renewable energy, the closed circulation land-based aquaculture system 100 is equipped with a storage battery 240 that stores the electricity generated by the solar power generation panel 200 and the wind power generation facility 230 as needed. This allows the electricity required to operate the closed circulation land-based aquaculture system 100 to be procured without relying on an external power grid. In other words, the CO2 derived from the energy ２ Emissions can be reduced to zero.

[0028] As a non-limiting example, if the solar power generation panel 200 and the wind power generation facility 230 can generate 7.2 kWh of electricity per day, the aquaculture system load can be stably operated. In one example, the footprint of the storage battery 240 installed outside the container 110 is 0.25 m ２ The following is the result.

[0029] As described above, the closed-circulation land-based aquaculture system 100 according to this embodiment can operate without an external power supply, and therefore can be installed in temporary housing areas in disaster areas or in evacuation centers (refugee camps). It is extremely difficult to obtain fresh marine resources in unsteady environments such as temporary housing areas, but installing the closed-circulation land-based aquaculture system 100 makes it possible to continuously provide fresh marine resources.

[0030] 2 is an explanatory diagram of a closed circulation land-based aquaculture system according to this embodiment. As shown in FIG. 2, the closed circulation land-based aquaculture system 100 according to this embodiment includes a breeding tank 300 in a breeding space 100U for holding breeding water and cultivating aquatic products. As a non-limiting example, the breeding tank 300 shown in FIG. 2 is 12.5 m ３ Approximately (W3.6m x D1.9m x H1.2m) ３ It can stably hold approximately 7 tons of water for breeding.

[0031] In the breeding space 100U, a filter tank 310 that purifies the water in the breeding aquarium 300 is provided adjacent to the breeding aquarium 300. A water conveying section 350 that supplies breeding water from the breeding aquarium 300 to the filter tank 310 is provided between the breeding aquarium 300 and the filter tank 310. A circulation pump 340 is disposed at the bottom of the filter tank 310, and a water conveying pipe 330 that delivers breeding water discharged from the circulation pump 340 to the breeding aquarium 300 connects the bottom of the filter tank 310 to the bottom of the breeding aquarium 300. In this way, the circulation pump 340 is provided below the water level WL1 in the breeding aquarium 300 and the water level WL2 in the filter tank 310.

[0032] In this embodiment, a DC pump is used as the circulation pump 340, and, as an example, the total head is 8 m or less and the discharge rate per unit time is 15,000 L / hour or less. DC pumps can reduce power consumption compared to AC pumps. As a non-limiting example, in the closed circulation land-based aquaculture system 100 according to this embodiment, the power consumption can be reduced to approximately 0.2 kW when circulating approximately 10 tons of culture water 50 times per day. If the circulation pump 340 is a DC pump, the voltage of the power generated by the solar power generation panel 200 can be converted by the converter 510 to directly drive the DC pump.

[0033] By disposing the circulation pump 340 at the bottom of the filtration tank 310 and discharging the culture water to the bottom of the culture tank 300 through the water conveyance section 350, it is possible to reduce the total head required for the circulation pump 340. Therefore, in the closed circulation land-based aquaculture system 100 according to this embodiment, it is possible to reduce the size of the circulation pump 340. The total head of the circulation pump 340 may be 10 m or less, 8 m or less, or 5 m or less.

[0034] The discharge volume per unit time of the circulation pump 340 is set based on the total volume of breeding water in the breeding aquarium 300 and the filtration tank 310, the flow rate of the breeding water moving through the filtration tank 310, and other factors. For example, if the discharge volume per unit time of the circulation pump 340 is 15,000 L / hour, the breeding water in the breeding aquarium 300 can be circulated once in 40 minutes. The discharge volume per unit time of the circulation pump 340 may be 20,000 L / hour or less, 15,000 L / hour or less, or 10,000 L / hour or less.

[0035] Inside the breeding tank 300, there are provided an agitation pump 301 for generating waves, a temperature sensor 302 for measuring the breeding water temperature, a water quality sensor 303 for measuring the breeding water quality, a heat exchanger 304 for transferring heat from the heat medium heated by the solar water heater 210 to the breeding water, and an aeration device 305.

[0036] The circulation pump 340 sprays breeding water from the water guide pipe 330, generating a water current at the bottom of the breeding aquarium 300. The aeration device 305 installed at the bottom of the breeding aquarium 300 creates an upward water current, and the water current created by the agitation pump 301 causes the breeding water to overflow from the water guide section 350 and flow into the filtration tank 310. Therefore, the water level WL1 in the breeding aquarium 300 is higher than the water level WL2 in the filtration tank 310.

[0037] As described above, in the closed-loop land-based aquaculture system 100 according to this embodiment, a vertically rotating circulating water current is formed, which flows from bottom to top in the breeding tank 300 and from top to bottom in the filtration tank 310. This circulating water current stirs up solid waste, such as leftover food, feces, and molted shells, that normally accumulate at the bottom of the breeding tank 300, and makes it easier for them to be carried to the filtration tank 310. The aeration device 305 installed on the bottom of the breeding tank 300 may also be placed near the wall of the breeding tank 300 on the filtration tank 310 side. The upward water current created by the aeration device 305 prevents solid waste contained in the breeding water that overflows from the breeding tank 300 into the filtration tank 310 from settling due to its own weight and returning to the breeding tank 300, thereby more stably transferring the solid waste to the filtration tank 310.

[0038] An insulating member 320 is provided to cover at least a portion of the breeding tank 300. In the closed circulation land-based aquaculture system 100 according to this embodiment, a box-shaped insulating member 320 is provided, and an aquarium unit consisting of the breeding tank 300 and the filtration tank 310 is placed inside the insulating member 320. This prevents the temperature of the breeding water in the aquarium unit from dropping.

[0039] As described above, the breeding tank 300 is provided with a heat exchanger 304, and heat from the heat medium heated by the solar water heater 210 can be transferred via this heat exchanger 304 to the breeding water in the breeding tank 300. As such, since the closed-circulation land-based aquaculture system 100 according to this embodiment is equipped with the solar water heater 210, it is not necessary to supply an energy source (electricity, fuel) for heating the breeding water in the breeding tank 300, and the running costs of the closed-circulation land-based aquaculture system 100 can be reduced.

[0040] If necessary, the closed-circulation land-based aquaculture system 100 may be provided with a boiler 410 in the heat medium circulation path connecting the solar water heater 210 and the heat exchanger 304. The boiler 410 can further heat the heat medium heated by the solar water heater 210 and supply it to the heat exchanger 304. A non-limiting example of the output of the boiler 410 is 50 kW.

[0041] The specific configurations of the temperature sensor 302 and the water quality sensor 303 are arbitrary, but it is necessary that they be able to output predetermined information to the control device 500 (information regarding the temperature of the rearing water in the case of the temperature sensor 302, and information regarding the water quality of the rearing water in the case of the water quality sensor 303).

[0042] A water purification device is provided in the filtration tank 310. The water purification device may have some or all of the following functions, and may also have other functions not listed below: Physical filtration (specific examples: settling tank, foam separator, screen filter, drum filter, etc.) Nitrification (specific examples: biological filtration, etc.) Denitrification

[0043] The closed circulation land-based aquaculture system 100 according to this embodiment may also have the following functions: Sterilization (specific examples: ultraviolet sterilization device, ozone sterilization device, etc.) Dissolved oxygen adjustment (specific examples: blower / aeration, oxygen dissolving device, etc.) Feeding device

[0044] The closed-circulation land-based aquaculture system 100 according to this embodiment includes a power supply control panel 400 that houses a converter 510 that converts the voltage of the power generated by the solar power generation panel 200. In the closed-circulation land-based aquaculture system 100 according to this embodiment, the power supply control panel 400 also includes a distributor 520 that connects the power generated by the solar power generation panel 200 or the wind power generation facility 230 or the power from the grid power supply 600 to aquaculture system loads such as the storage battery 240 or the circulation pump 340.

[0045] In Figure 2, as a specific example of an aquaculture system load, only the circulation pump 340 is shown with a power supply line connected to the distributor 520 of the power supply control panel 400. However, the aquaculture system load also includes the agitation pump 301, the aeration device 305, the boiler 410, the control device 500, etc., and the distributor 520 of the power supply control panel 400 and the power supply lines connecting these are not shown in Figure 2.

[0046] By providing such a distributor 520, it is possible to store surplus power generated by the solar power generation panel 200 or the wind power generation facility 230 in the storage battery 240 and operate autonomously without requiring power from the grid power supply 600, and it is also possible to store power from the grid power supply 600 in the storage battery 240 in preparation for situations where it is difficult to generate power stably in the closed-loop land-based aquaculture system 100, such as in bad weather. Of course, it is also possible to cover the entire load of the aquaculture system with power from the grid power supply 600. In other words, the provision of the distributor 520 increases the flexibility of system operation.

[0047] Next, the operation of the control device 500 included in the closed circulation land-based aquaculture system 100 according to this embodiment will be described. In FIG. 2, the control device 500 is shown as being disposed outside the power supply control panel 400, but the control device 500 may also be disposed inside the power supply control panel 400. FIG. 3 is a block diagram illustrating the function of the control device 500. As shown in FIG. 3, the control device 500 has four control units (a water heater start unit 501, a water heater stop unit 502, a boiler start unit 503, and a boiler stop unit 504) related to temperature control of the rearing water, and operates one of these control units based on information input from the temperature sensor 302 to generate a control signal to control the operation of the solar water heater 210 and the boiler 410.

[0048] When information indicating that the breeding water is at or below a predetermined first temperature T1 is input from the temperature sensor 302, the water heater start unit 501 generates a first control signal to start transferring heat from the heat medium of the solar water heater 210 to the breeding water. As a specific example, the first control signal starts the circulation of the heat medium from the solar water heater 210 to the heat exchanger 304, and the breeding water in the breeding aquarium 300 is heated via the heat exchanger 304.

[0049] When information indicating that the breeding water has reached a predetermined second temperature T2 is input from the temperature sensor 302, the water heater stop unit 502 generates a second control signal to stop the transfer of heat from the heat medium to the breeding water in the solar water heater 210. As a specific example, the second control signal stops the circulation of the heat medium from the solar water heater 210 to the heat exchanger 304, and stops the heating of the breeding water in the breeding aquarium 300 via the heat exchanger 304.

[0050] When the water heater starting unit 501 does not generate the second control signal even after a predetermined first time t1 has elapsed since generating the first control signal, the boiler starting unit 503 generates a third control signal to operate the boiler 410 to heat the rearing water. As a specific example, the third control signal causes the boiler 410 to start additional heating of the heat medium circulating through the heat exchanger 304.

[0051] When the boiler stop unit 504 receives information from the temperature sensor 302 indicating that the rearing water has reached the third temperature T3, it generates a fourth control signal to stop heating the rearing water by the boiler 410. As a specific example, the fourth control signal stops heating the heat medium by the boiler 410. From the perspective of preventing the rearing water temperature from rising excessively (overshooting) and minimizing the use of external energy, it may be preferable to set the third temperature T3 lower than the second temperature T2.

[0052] The closed-circulation land-based aquaculture system 100 according to this embodiment includes a thermal insulating member 320, making it difficult for heat to escape from the rearing water in the rearing tank 300. Therefore, the water temperature typically rises quickly when the water heater starter 501 generates the first control signal. By narrowly setting the temperature difference between the first temperature T1 and the second temperature T2 (e.g., 4°C), assuming a 10°C difference between the ambient air temperature and the rearing water temperature, the temperature change of the rearing water can be limited from 0.5°C / day to 1°C / day, thereby reducing the need for additional energy for temperature regulation (i.e., the operation of the boiler 410). Specifically, when the actual temperature is to be maintained between 20°C and 28°C, the temperature difference between the first temperature T1 and the second temperature T2 may be set to 22°C and 26°C, respectively.

[0053] As shown in Figure 3, the control device 500 has two control units (circulation start unit 505 and circulator stop unit 506) that control the circulation pump 340, and based on information input from the water quality sensor 303, it operates one of these control units to generate a control signal and control the operation of the circulation pump 340.

[0054] When information indicating that the rearing water has reached the first water quality level Q1 is input from the water quality sensor 303, the circulation start unit 505 generates a fifth control signal to at least one of start the operation of the circulation pump 340 and increase the discharge rate per unit time of the circulation pump 340. Increasing the discharge rate per unit time of the circulation pump 340 can be achieved by increasing the operating frequency of the circulation pump 340 or by operating it intermittently.

[0055] The circulation start unit 505 may generate a control signal that gradually increases the discharge rate per unit time of the circulation pump 340. Similarly to the circulation pump 340, the circulation start unit 505 may also generate control signals for other devices that form the circulation of the rearing water, such as the agitation pump 301 and the aeration device 305.

[0056] When information indicating that the rearing water has reached the second water quality level Q2 is input from the water quality sensor 303, the circulator stop unit 506 generates a sixth control signal for at least one of stopping the operation of the circulation pump 340 and reducing the discharge rate per unit time of the circulation pump 340. Similar to the circulation pump 340, the circulator stop unit 506 may also generate control signals for other devices that form the circulation of the rearing water, i.e., the agitation pump 301 and the aeration device 305.

[0057] The embodiments described herein are provided to facilitate understanding of the present disclosure, and are not intended to limit the present disclosure. Therefore, each element disclosed in the above embodiment is intended to include all design modifications and equivalents that fall within the technical scope of the present disclosure.

[0058] For example, a heat-insulating cover member may be provided to cover the top of the aquarium unit consisting of the breeding aquarium 300 and the filtration tank 310. Furthermore, although a DC pump is used as the circulation pump 340 in the above embodiment, an AC pump with low power consumption may also be used.

[0059] 100... Closed circulation land-based aquaculture system 100U... Rearing space 110... Container 111... Ceiling 200... Solar power generation panel 210... Solar water heater 230... Wind power generation equipment 240... Storage battery 300... Rearing tank 301... Mixing pump 302... Temperature sensor 303... Water quality sensor 304... Heat exchanger 305... Aeration device 310... Filtration tank 320... Heat insulating member 330... Water conveyance pipe 340... Circulation pump 350... Water conveyance section 400... Power supply control panel 410... Boiler 500... Control device 501... Water heater start section 502... Water heater stop section 503... Boiler start section 504... Boiler stop section 505... Circulation start section 506... Circulation stop section 510... Converter 520... Distributor 600... System power supply WL1...Water level WL2...Water level

Claims

1. A closed circulation type land-based aquaculture system comprising:a breeding water tank configured to retain breeding water and grow a marine product;a heat insulating member configured to cover at least a part of the breeding water tank;a filtration tank configured to purify a water quality of the breeding water tank;a circulation pump configured to supply the breeding water from the filtration tank to the breeding water tank;a distributor configured to connect an electric power by renewable energy or an electric power from a power system to a cultivation system load including the circulation pump; anda control unit configured to control at least the circulation pump, wherein the breeding water tank and the filtration tank are arranged adjacent one another, andwherein the circulation pump is located below a water level of either the breeding water tank or the filtration tank, whichever is lower, and water within the filtration tank is sent into the breeding water tank.

2. The closed circulation type land-based aquaculture system according to claim 1,wherein the renewable energy is a solar power generation panel,wherein the closed circulation type land-based aquaculture system further includes:a converter configured to convert voltage of electric power generated by the solar power generation panel; anda storage battery connected via the converter to the solar power generation panel and configured to store electric power generated by the solar power generation panel, andwherein the circulation pump is a DC pump.

3. The closed circulation type land-based aquaculture system according to claims 1 or 2, further comprising:a temperature sensor configured to measure a temperature of the breeding water; anda solar water heater configured to store solar heat in a heat medium and to transmit heat of the heat medium to the breeding water,wherein the control unit is configured togenerate a first control signal for starting transmission of heat of the heat medium in the solar water heater to the breeding water in a case where information indicating that the breeding water is equal to or below a predetermined first temperature is entered from the temperature sensor, andgenerate a second control signal for stopping transmission of heat of the heat medium in the solar water heater to the breeding water in a case where information indicating that the breeding water has reached a predetermined second temperature is entered from the temperature sensor.

4. The closed circulation type land-based aquaculture system according to claim 3, further comprising:a boiler configured to heat the breeding water, andwherein, if the control unit does not generate the second control signal after a predetermined first time has elapsed from the generation of the first control signal,the control unit generates a third control signal for operating the boiler and heating the breeding water.

5. The closed circulation type land-based aquaculture system according to any one of claims 1 to 4, further comprisinga wind power generating facility connected to the distributor.

6. The closed circulation type land-based aquaculture system according to any one of claims 1 to 5, further comprising:a water quality sensor for measuring a water quantity of the breeding water, andwherein the control unit is configured togenerate a fifth control signal for realizing at least either starting of operation of the circulation pump or increasing of a discharge rate per unit time of the circulation pup when information indicating that the breeding water has reached a first water quality level is entered from the water quality sensor, andgenerate a sixth control signal for realizing at least either stopping of operation of the circulation pump or reducing of a discharge rate per unit time of the circulation pump when information indicating that the breeding waterhas reached a second water quality level is entered from the water quality sensor.

7. The closed circulation type land-based aquaculture system according to claim 6, further comprising:an aeration device for performing aeration of the breeding water,wherein the fifth control signal includes a signal for starting operation of the aeration device, andwherein the sixth control signal includes a signal for stopping operation of the aeration device.INTERNATIONAL SEARCH REPORT International application No. PCT / JP2021 / 038326A. CLASSIFICATION OF SUBJECT MATTER A01K 63 / 04(2006.0l)i FI: A01K63 / 04 A According to International Patent Classification (IPC) or to both national classification and IPC B. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbols) A01K63 / 04 Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched Published examined utility model applications of Japan 1922-1996 Published unexamined utility model applications of Japan 1971-2021 Registered utility model specifications of Japan 1996-2021 Published registered utility model applications of Japan 1994-2021 Electronic data base consulted during the international search (name of data base and, where practicable, search terms used) C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. Y JP 2003-144003 A (MISHIMAYA KAISANTEN KK) 20 May 2003 (2003-05-20) paragraphs [0005]-[0007], [0018]-[0026], fig. 1, 2 1-7 Y JP 2019-068791 A (FUJINOEBI CO., LTD.) 09 May 2019 (2019-05-09) paragraph [0023] 1-7 Y JP 2014-068624 A (TANAKA, Kenzo) 21 April 2014 (2014-04-21) paragraphs [OO3O]-[OO5O], fig. 3 1-7 Y JP 2001-231339 A (KOYAMA, Takatoshi et al.) 28 August 2001 (2001-08-28) paragraphs [OOO3]-[OOO5], fig. 1 1-7 Y JP 2003-169565 A (SEKISUI HOUSE, LTD.) 17 June 2003 (2003-06-17) paragraphs [0008]-[0018], fig. 1, 2 2-7 Y JP 11-169011 A (KYUSHU MEDICAL KK) 29 June 1999 (1999-06-29) paragraph [0025] 3-7 | V1 Further documents are listed in the continuation of Box C. | / 1 See patent family annex. * Special categories of cited documents: ■‘A” document defining the general state of the art which is not considered to be of particular relevance earlier application or patent but published on or after the international filing date “L” document which may throw doubts on priority claim(s) or which is cited to establish the publication date of another citation or other special reason (as specified) “O” document referring to an oral disclosure, use, exhibition or other means “P” document published prior to the international filing date but later than the priority date claimed “T” later document published after the international filing date or priority date and not in conflict with the application but cited to understand the principle or theory underlying the invention “X” document of particular relevance; the claimed invention cannot be considered novel or cannot be considered to involve an inventive step when the document is taken alone “Y” document of particular relevance; the claimed invention cannot be considered to involve an inventive step when the document is combined with one or more other such documents, such combination being obvious to a person skilled in the ait document member of the same patent family Date of the actual completion of the international search Date of mailing of the international search report 21 December 2021 11 January 2022 Name and mailing address of the ISA / JP Authorized officer Japan Patent Office (ISA / JP) 3-4-3 Kasumigaseki, Chiyoda-ku, Tokyo 100-8915 Japan Telephone No.INTERNATIONAL SEARCH REPORT International application No. PCT / JP2021 / 038326C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. Y JP 2014-176339 A (KABUSHIKI KAISHA SAIJO SANGYO JOHO SHIEN CENTER) 25 September 2014 (2014-09-25) paragraphs [0027], [0048] 4-7 Y KR 10-2150497 Bl (KANEMITSU, Kaoru) 01 September 2020 (2020-09-01) paragraphs [0040], [0041] 5-7 Y JP 2018-033418 A (HITACHI, LTD.) 08 March 2018 (2018-03-08) paragraphs [0033]-[0037] 6-7 Y JP 3202317 U (TAIWAN ANJIE ELECTRONICS CO., LTD.) 28 January 2016 (2016-01-28) paragraphs [0027], [0028] 7 A JP 60-176526 A (INA SEITO KK) 10 September 1985 (1985-09-10) p. 3, lower left column, line 15 to lower right column, line 14 3INTERNATIONAL SEARCH REPORT Information on patent family membersInternational application No.PCT / JP2021 / 038326Patent document cited in search report Publication date (day / month / year) Patent family member)s) Publication date (day / month / year) JP 2003-144003 A 20 May 2003 (Family: none) JP 2019-068791 A 09 May 2019 (Family: none) JP 2014-068624 A 21 April 2014 (Family: none) JP 2001-231339 A 28 August 2001 (Family: none) JP 2003-169565 A 17 June 2003 (Family: none) JP 11-169011 A 29 June 1999 (Family: none) JP 2014-176339 A 25 September 2014 (Family: none) KR 10-2150497 Bl 01 September 2020 (Family: none) JP 2018-033418 A 08 March 2018 (Family: none) JP 3202317 U 28 January 2016 US 2017 / 0099812 Al paragraphs [0027], [0028] CN 205567491 U JP 60-176526 A 10 September 1985 (Family: none)

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