Land cultivation plant

Abstract

To provide a land cultivation plant that can improve productivity with excellent energy efficiency.SOLUTION: A land cultivation plant 20 comprises: a hot water tank 21 which stores hot spring water SW, which is heated by heat of a heat source derived from ground heat or hot spring, as hot water HW; a mixer 22 which adjusts the water temperature of marine water MW by using the heat of the hot spring water SW; a cultivation vessels 23 which are arranged in the hot water tank 21 and cultivate subjects to be cultured; and an injection part 24 which injects the sea water MW whose temperature is adjusted by the mixer 22 into the cultivation vessels 23 as cultivating water AW. The mixer 22 mixes the hot spring water SW of hot spring having relatively high water temperature into the sea water MW to adjust the water temperature of the cultivating water AW.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a land-based aquaculture plant. [Background technology]

[0002] 2. Description of the Related Art Land-based aquaculture plants for cultivating marine products on land have been studied for some time now (see Patent Document 1). For example, it is being considered to cultivate the seaweed species, such as Uncaria arborescens, in land-based aquaculture plants. Uncaria arborescens can be used as cattle feed to suppress the generation of methane gas caused by cattle burps. For this reason, it is desirable to ensure a stable supply by carrying out land-based aquaculture near the areas where the cattle are raised (areas where feed is consumed). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-48268 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in land-based aquaculture, water temperature fluctuates more significantly due to seasons and weather than in marine aquaculture, which affects growth. For example, if the area where cattle are raised is in a cold region and a land-based aquaculture facility for seaweed that prefers relatively warm water temperatures, such as Undaria pinnatifida, is set up near the cattle raising area, a large amount of energy will be required to heat the seawater to ensure a water temperature suitable for growth. Thus, a large amount of energy is required to cultivate seaweed on land by recreating growing conditions similar to those found in the wild. Therefore, further improvements are needed to efficiently supply seaweed to consumer areas with stable quality and minimal environmental impact.

[0005] Therefore, an object of the present invention is to provide a land-based aquaculture plant that can improve productivity with good energy efficiency. [Means for solving the problem]

[0006] The land-based aquaculture plant of the present invention is characterized by comprising a temperature adjustment unit that adjusts the temperature of seawater using heat from a heat source derived from geothermal energy or a hot spring, a culture container for cultivating the culture targets, and an injection unit that injects the seawater, the temperature of which has been adjusted by the temperature adjustment unit, into the culture container. Effect of the Invention

[0007] According to the present invention, a land-based aquaculture plant is provided that can improve productivity with good energy efficiency. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic side view showing the overall configuration of a land-based aquaculture plant according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a top view illustrating the configuration of an insulated water tank of a land-based aquaculture plant. [Diagram 3] FIG. 3 is a perspective view illustrating the configuration of the culture container placed in the thermal insulation tank, as viewed from the direction of the arrow III in FIG. 2. [Figure 4] FIG. 1 is a schematic side view showing the overall configuration of a land-based aquaculture plant according to a second embodiment of the present invention. [Diagram 5] FIG. 11 is a side view showing the overall configuration of a hot spring plant in an onshore aquaculture plant according to a third embodiment. [Figure 6] FIG. 11 is a side view showing the overall configuration of a hot spring plant in a land-based aquaculture plant according to a fourth embodiment. [Figure 7] FIG. 11 is a side view showing the configuration of the main parts of the land-based aquaculture plant of embodiment 5. [Figure 8] FIG. 13 is a side view showing the overall configuration of a hot spring plant in a land-based aquaculture plant according to a sixth embodiment. [Figure 9] FIG. 13 is a side view showing variations of the culture container in the land-based culture plant of embodiment 7. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the following, in an embodiment of the present invention, a land-based aquaculture plant 10 for cultivating Porphyra japonica on land will be described with reference to the drawings as appropriate. In addition, the same components are given the same reference numerals, and duplicated descriptions will be omitted.

[0010] FIG. 1 shows a hot spring plant 1 having a land-based aquaculture plant 10 according to a first embodiment of the present invention. The hot spring plant 1 of embodiment 1 mainly comprises a hot spring 2 as a heat source, a horticultural center 3 for cultivating plants as a primary utilization facility that makes primary use of the hot spring water SW drawn from the hot spring 2, and a seafood farm 4 for raising seafood, also as a primary utilization facility. The hot spring plant 1 also has a land-based aquaculture plant 10 (described later) as a secondary utilization facility for utilizing the residual heat from the horticulture center 3 or the marine product breeding farm 4 for land-based aquaculture of algae.

[0011] First, the configurations of the horticultural center 3 and the marine product farm 4, which are the primary use facilities, will be described. The horticultural center 3 of the first embodiment draws in hot spring water SW, for example, at a temperature of about 90 degrees, from the source of the hot spring 2 as a heat source. The heat source may be derived from geothermal energy or a hot spring, and does not have to be hot spring water SW that flows directly from the source. The hot spring water SW drawn into the horticultural center 3 increases the cultivation temperature in the vinyl greenhouse of the horticultural center 3. This promotes the growth of the plants P cultivated in the vinyl greenhouse. Furthermore, the horticultural center 3 and the seafood farm 4 are connected by hot spring water piping 9a. For example, the hot spring water SW whose temperature has dropped to about 51° C. to 52° C. due to heat loss in the vinyl greenhouse is discharged from the horticulture center 3 and sent to the seafood farm 4 via the hot spring water piping 9a.

[0012] In the marine product farm 4, marine product seeds such as shellfish are farmed in a farming tank 7. In the marine product farm 4 of the first embodiment, the farming tank 7 is installed on land. However, the present invention is not limited to this, and instead of the farming tank 7, a fish cage or the like installed in an offshore farming facility using the sea surface may be used. In addition, an intake pipe ML is laid between the marine product farm 4 and the sea to take in seawater MW. An intake port M located in the sea is provided at the tip of the intake pipe ML. The seawater MW sucked up from the intake port M is sent to the marine product farm 4 via the intake pipe ML. For example, by placing the intake port M at a depth of about 200 m or more, it is possible to take in deep ocean water, the temperature of which is almost constant (about 9 degrees).

[0013] In the marine product rearing farm 4, the seawater MW is heated by heat exchange with the heat of the hot spring water SW sent from the horticultural center 3. For this purpose, the marine product rearing farm 4 is provided with a first heat exchanger 5 and a second heat exchanger 6 connected to the first heat exchanger 5 via a hot spring water pipe 9a. The seawater MW heated by the first heat exchanger 5 and the second heat exchanger 6 is sent to a rearing tank 7 and stored therein for rearing shellfish seedlings and the like.

[0014] A seawater conveying pipe 8c is connected to the breeding tank 7 of the embodiment 1. The seawater conveying pipe 8c discharges the seawater MW used for breeding shellfish in the breeding tank 7. The discharged seawater MW is sent to the land-based aquaculture plant 10 via the seawater conveying pipe 8c. In addition, a hot spring water supply pipe 9c is connected to the second heat exchanger 6 of the seafood farm 4. The hot spring water supply pipe 9c discharges the hot spring water SW that has given heat to the seawater MW in the seafood farm 4. The discharged hot spring water SW is then sent to the land-based aquaculture plant 10.

[0015] Next, the configuration of the land-based aquaculture plant 10, which is the secondary use facility of the first embodiment, will be described with reference to Figs. 1 to 3. The land-based aquaculture plant 10 of embodiment 1 includes an insulated water tank 21 that stores hot spring water SW discharged from a seafood farm 4 as insulated water HW, as shown in FIG. 1, and a plurality of aquaculture containers 23 arranged in the insulated water tank 21 and submerged in the insulated water HW. The land-based aquaculture plant 10 also includes a mixer 22 as a temperature adjustment unit that uses heat from the hot spring water SW to adjust the temperature of the seawater MW to make the aquaculture water AW at a temperature suitable for aquaculture, and an injection unit 24 that injects the aquaculture water AW whose temperature has been adjusted by the mixer 22 into each aquaculture container 23.

[0016] Of these, the thermal water tank 21 is a box-shaped pool with an open top. A horizontal hole 21a is formed in the side wall of the thermal water tank 21, penetrating the tank from inside to outside in a substantially horizontal manner. The tip of the hot spring water supply pipe 9c is inserted into the horizontal hole 21a toward the thermal water tank 21. At the tip of the hot spring water supply pipe 9c, a discharge port 9e is formed to allow the heat-retaining water HW to flow into the heat-retaining water tank 21. The vertical position of the discharge port 9e is set to be below the reference water level WL of the surface of the heat-retaining water HW (hereinafter, simply referred to as the water level). Then, hot spring water SW sent from the marine product farm 4 through the hot spring water supply pipe 9c is flowed into the thermal insulation tank 21. The hot spring water SW is temporarily stored as thermal insulation water HW in the thermal insulation tank 21. The surroundings of the aquaculture containers 23 stored in the thermal insulation tank 21 are kept at a desired temperature so that the surroundings are lower than the water level WL of the thermal insulation water HW.

[0017] As shown in FIG. 2, a total of ten culture containers 23 of the first embodiment are arranged in two rows in one thermal water tank 21 at predetermined intervals. As shown in Fig. 3, the culture container 23 of the first embodiment is made of a transparent resin and is a cylindrical container with a bottom and an upper opening. The culture container 23 is preferably made of a transparent polycarbonate such as Panlite (registered trademark). The culture container 23 made of a transparent resin can transmit the surrounding natural light and deliver the light to the cultured subject accommodated in the shallow water with a depth of about 10 m by adjusting the light to an amount suitable for growth.

[0018] A circular upper lid 23a is provided at each upper opening of the culture container 23. The upper lid 23a is attached so as to freely open and close the upper opening of the culture container 23. The upper lid 23a of the first embodiment is made of a transparent resin, similar to the culture container 23.

[0019] Furthermore, a round insertion hole 23c is formed at the center of the top lid 23a in the radial direction. An injection hose 26 is inserted vertically into the insertion hole 23c. The injection hose 26 slidably engages with the periphery of the insertion hole 23c and stops at a desired position. This allows the injection hose 26 to adjust the height position of an injection port 27 formed at an opening at the lower end in the vertical direction. For example, regardless of whether the vertical position of the top lid 23a is above or below the water level WL of the warm water HW, the vertical position of the injection port 27 can be set below the water level WL of the warm water HW.

[0020] 3, the culture container 23 of the first embodiment is made of a cylindrical transparent resin, and has a plurality of drainage holes 23d formed in the outer peripheral wall 23b. Each of the drainage holes 23d has a round hole shape that communicates with the outer peripheral wall 23b in the inward and outward directions, and is formed so as to be approximately equally spaced from the other adjacent drainage holes 23d over the entire surface. The size of each drainage hole 23d is set to a size that prevents the passage of culture objects such as seaweed contained inside the culture container 23, and yet allows the culture water AW inside to be drained outside the culture container 23.

[0021] In the land-based aquaculture plant 20 of the first embodiment, the aquaculture water AW pumped from the main pipe 25 above the thermal insulation tank 21 by the injection hose 26 of the injection section 24 is caused to flow down into each aquaculture container 23 from a relatively high position. Therefore, the water pressure of the culture water AW injected into the culture container 23 becomes higher than the water pressure of the warm water HW present around the culture container 23. Therefore, the culture water AW in the culture container 23 is drained in one direction from the drainage hole 23d toward the inside of the warm water tank 21. Therefore, the warm water HW does not flow back and infiltrate into the inside of the culture container 23 through the drainage hole 23d. Furthermore, a horizontal hole 21a into which the other end of the hot spring water supply pipe 9c is inserted is provided on the side wall surface of the thermal water tank 21. A discharge port 9e is formed on the other end of the hot spring water supply pipe 9c. In the first embodiment, the hot spring water supply pipe 9c conveys the hot spring water SW discharged from the second heat exchanger 6 of the seafood farm 4 and flows it into the thermal insulation tank 21 of the land-based aquaculture plant 10 from the outlet 9e at the other end.

[0022] In the heat-retaining water tank 21, the hot spring water SW is temporarily stored as the heat-retaining water HW. As shown in Fig. 1, in the heat-retaining water tank 21 of the first embodiment, the outlet 9e of the hot spring water supply pipe 9c inserted from the side wall surface is located below the water level WL of the heat-retaining water HW in the vertical direction. Therefore, the hot spring water SW flowing into the heat retention tank 21 from the discharge port 9e is discharged directly into the stored heat retention water HW and does not draw in air. Therefore, no air bubbles are generated in the heat retention water HW. Furthermore, the hot spring water pipe 9c is branched off by a branch pipe 9d within the land-based aquaculture plant 20 (see FIG. 1). The branch pipe 9d is connected to a mixer 22 serving as a temperature adjustment unit provided in the land-based aquaculture plant 10.

[0023] When the seawater MW in the rearing tank 7 sent from the marine product rearing farm 4 passes through the seawater conveyance pipe 8c, the water temperature is lowered due to heat loss by the outside air. For this reason, the land-based aquaculture plant 10 of the first embodiment reuses the hot spring water SW discharged from the horticulture center 3 and the marine product rearing farm 4 in the temperature adjustment unit to raise the water temperature of the aquaculture water AW. That is, the hot spring water SW, which is seawater MW heated by heat exchange in the first heat exchanger 5 and the second heat exchanger 6 of the seafood farm 4, is sent to the land-based aquaculture plant 10 via the hot spring water supply pipe 9c and reused as a heat source for the temperature adjustment section, thereby improving thermal efficiency.

[0024] The land-based aquaculture plant 10 of the first embodiment is provided with a mixer 22 as a temperature adjustment unit. The mixer 22 mixes the hot spring water SW sent from the marine product farm 4 with the seawater MW to raise the water temperature. This makes it possible to raise the temperature of the aquaculture water AW again after it has been lowered. The mixer 22 of the first embodiment is connected to a seawater supply pipe 8c drawn into the land-based aquaculture plant 10 and aquaculture water piping 8d connected to the thermal insulation tank 21. In the mixer 22, seawater MW and hot spring water SW are mixed in a desired ratio inside the sealed container to produce the culture water AW. Therefore, air is not mixed in when the seawater MW and the hot spring water SW are mixed, and no air bubbles are present in the culture water AW after mixing, in which the water temperature and components such as minerals have been adjusted. In the mixer 22 of the first embodiment, hot spring water SW is appropriately mixed with seawater MW sent from the marine product farm 4. The seawater MW mixed with the hot spring water SW is heated and the water temperature rises, and the seawater MW becomes culture water AW containing hot spring components.

[0025] The mixer 22 is connected to the injector 24 via a culture water piping 8d that sends the culture water AW. The mixer 22 may be a heat exchanger that exchanges heat from the hot spring water SW to warm the seawater MW. The injection section 24 of the first embodiment includes a main pipe 25 that delivers the culture water AW to above each culture container 23, and a plurality of injection hoses 26 that branch off from the main pipe 25 at predetermined intervals.

[0026] Of these, the main pipe 25 is laid between the two rows of the culture containers 23. The main pipe 25 pumps the culture water AW sent from the mixer 22 to above each of the culture containers 23. Each injection hose 26 is extended horizontally from the connection portion with the main pipe 25 to above the corresponding culture container 23 and is bent downward by approximately 90 degrees. The bent lower end is inserted into the culture container 23 from the center position of the upper lid 23a of the culture container 23. The insertion amount of the injection port 27 formed at the lower end of the injection hose 26 is adjusted so that it is located at the vertical middle position of the culture container 23 and the middle position in the diametrical direction. As a result, the injection position IN in the vertical direction by the injection hose 26 is set below the water level of the warm water HW in the warm water tank 21. Therefore, the culture water AW injected into each culture container 23 does not directly come into contact with air. This prevents air from being entrained at the injection port 27. Therefore, air bubbles are not generated due to entrainment of air when the culture water AW is mixed in the culture container 23.

[0027] Each culture container 23 contains a Porphyra niger as a culture target. The Porphyra niger is contained in an unfixed state in each culture container 23. In this way, the Porphyra niger is cultured while drifting with the flow of the culture water AW in the culture container 23.

[0028] The culture water AW injected into each culture container 23 creates a water flow that is not damaging to the algae. Therefore, the algae are stirred by the flow of the culture water AW while immersed in the culture water AW. Fresh culture water AW is constantly supplied to the algae, providing them with the nutrients necessary for growth to a desired harvestable size.

[0029] In the first embodiment, the upper lid 23a of the culture container 23 containing the algae closes the upper opening of the culture container 23. This reduces the amount of heat radiation, and the temperature of the culture water AW in the culture container 23 is less likely to drop. Furthermore, even if the algae in the culture container 23 floats upward due to stirring, it is held down by the upper lid 23a. Therefore, the algae will not exceed the water level WL of the thermal water HW and be exposed to the air above the thermal water tank 21. The seaweed is also stacked three-dimensionally in the vertical direction inside the culture container 23. This makes it possible to reduce the horizontal culture area required for culture while maintaining the same production volume of the cultured object. It also makes it possible to reproduce growth conditions similar to those of the algae that grow on rocky reefs with good wave exposure at a depth of about 10 m in land culture. Furthermore, there is no need to attach large amounts of seaweed to rocks as in the past, and the labor required for culture can be reduced.

[0030] In the land-based aquaculture plant 10 of the first embodiment, the aquaculture containers 23 are arranged in two rows and fixed on the bottom surface 21b of the insulated water tank 21. Note that each of the aquaculture containers 23 may be removably fixed as long as it is submerged in the aquaculture water AW of the insulated water tank 21 with its axial direction aligned in the up-down direction.

[0031] Hot spring water SW at a high water temperature is constantly supplied to the thermal insulation tank 21. Therefore, the thermal insulation water HW flowing into the thermal insulation tank 21 can keep each of the culture containers 23 warm with the same amount of heat from the surroundings regardless of the outside air temperature. Then, the thermal insulation water HW with a lowered water temperature is discharged to the outside through the overflow pipe 28.

[0032] The overflow pipe 28 in the first embodiment is provided penetrating the wall surface of the heat retention tank 21. A downflow port 29 is formed at the upper end of the overflow pipe 28. The up-down position of the downflow port 29 is set to be higher than the upper surface of each culture container 23. The heat retention water HW that flows into the heat retention tank 21 from the discharge port 9e is temporarily stored and then flows down from the downflow port 29 to be discharged to the outside. At this time, the heat retention water HW flows in the direction of the overflow pipe 28 and is discharged together with the culture water AW discharged from the drain hole 23d by so-called overflow.

[0033] For example, the inflow of hot spring water SW or seawater MW may cause the water level WL of the heat-retaining water HW in the heat-retaining water tank 21 to rise and exceed the vertical position of the downflow port 29. In this case, the heat-retaining water HW flows down from the downflow port 29 into the overflow pipe 28. The heat-retaining water HW that has flowed down inside the overflow pipe 28 is discharged outside the land-based aquaculture plant 10. Furthermore, when the water level WL of the warm water HW in the warm water tank 21 is below the vertical position of the outflow port 29 of the overflow pipe 28, the warm water HW is not discharged to the outside. This allows the water level WL of the warm water HW in the warm water tank 21 to be kept constant at a reference vertical position. Therefore, as long as the hot spring water SW or seawater MW continues to flow in, the heat retention water HW will not overflow from the upper edge of the heat retention tank 21. In addition, there is no risk that the culture containers 23 will be exposed above the surface of the heat retention water HW and exposed to the outside air. Therefore, the culture water AW in the culture container 23 in which the algae are stored is maintained at an appropriate water temperature. In addition, the entire culture container 23 is located in the warm water HW below the water level WL. Therefore, the algae stored in the culture container 23 are protected from contact with the cold outside air.

[0034] In this manner, in the land-based aquaculture plant 10 of the first embodiment, the seawater MW discharged from the marine product farm 4 is mixed with a portion of the hot spring water SW by the mixer 22 to become the aquaculture water AW. The temperature of the hot spring water SW mixed in the mixer 22 is higher than the temperature of the seawater MW. Therefore, the temperature of the seawater MW mixed with the hot spring water SW is raised, and the culture water AW becomes aquaculture water AW having seawater components to which the mineral components of the hot spring water SW have been added. The culture water AW distributed to each culture container 23 is then injected into the culture container 23 via the injection unit 24. As a result, the culture water AW in the culture container 23 is mixed with the culture water AW whose water temperature has been adjusted, and the water temperature becomes suitable for promoting the growth of the culture target.

[0035] Furthermore, the land-based aquaculture plant 10 of the first embodiment can make secondary use of the residual heat of the hot spring water SW from the seafood farm 4 included in the hot spring plant 1. Therefore, the land-based aquaculture plant 10 does not require a heating facility such as a boiler for heating the seawater MW. Therefore, the initial cost for installing the heating facility can be reduced.

[0036] In addition, there is no need for fossil fuels or other fuels to be burned in boilers, which reduces the running costs required for breeding. Furthermore, there is no longer any generation of gases such as carbon dioxide that are produced when fuel is burned, which reduces the environmental impact. The hot spring water SW having residual heat can be drawn from the marine product farm 4 through a hot spring water supply pipe 9c to the land-based aquaculture plant 10 and used as heat-retaining water HW. This allows for good energy efficiency and provides growth conditions suitable for cultivating the algae. Furthermore, the seawater MW that becomes the culture water AW is introduced into the land-based culture plant 10 through the seawater conveyance pipe 8c. Therefore, in the hot spring plant 1 of the first embodiment, it is not necessary to lay a separate water intake pipe ML in the sea for taking in the seawater MW exclusively for the land-based culture plant 10 of the algae.

[0037] In addition, the hot spring water SW discharged from the marine product farm 4 becomes the thermal insulation water HW and keeps the culture containers 23 warm from the surroundings. The volume of the culture water AW in one culture container 23 is small compared to the entire volume of the thermal insulation tank 21. Therefore, the amount of heat of the hot spring water SW required to raise the temperature of the seawater MW drawn in from the marine product farm 4 in the mixer 22 is small. Therefore, in the mixer 22, the amount of hot spring water SW mixed with the seawater MW to raise the water temperature can be reduced, thereby suppressing the variation from the salt content and mineral components of the seawater MW before mixing. In this way, the land-based aquaculture plant 10 of the first embodiment can approach the desired cultivation conditions such as water temperature suitable for promoting the growth of the cultured algae with good thermal efficiency. Furthermore, the land-based aquaculture plant 10 can maintain mineral components suitable for growth that are equal to or greater than those of the seawater MW in the natural environment.

[0038] In the land-based aquaculture plant 10 of the first embodiment, the hot spring water SW can be poured into the thermal insulation water tank 21. Therefore, the hot spring water SW having a temperature sufficient to keep the aquaculture container 23 warm is constantly supplied to the surroundings of the aquaculture container 23. Furthermore, the hot spring water SW, which has a relatively high temperature, is mixed with the seawater MW by the mixer 22, so that the temperature of the culture water AW can be easily adjusted. The land-based aquaculture plant 10 of the first embodiment keeps the adjusted culture water AW warm by running the same hot spring water SW through the thermal insulation tank 21 so that the temperature does not drop. Therefore, the land-based aquaculture plant 10 of the first embodiment can maintain water temperature conditions suitable for cultivating Porphyra japonica over a long culture period.

[0039] In addition, in the culture container 23, an appropriate water flow is generated by injecting the culture water AW from the inlet 27. This eliminates the need for mechanical stirring to generate a water flow, thereby reducing capital investment and the required energy. Furthermore, the position of the injection port 27 of the injection hose 26 is set at the radial middle position of each culture container 23, and the vertical injection position IN of the injection port 27 is set below the water level WL of the warm water HW stored in the warm water tank 21. Therefore, when the culture water AW is injected into the culture container 23 from the injection port 27, the seawater slamming against the water surface does not entrain air and generate air bubbles as in the conventional method.

[0040] The culture container 23 of the first embodiment is made of transparent resin and can guide natural light from the surroundings to the inside to a certain extent. Therefore, the dissolved oxygen concentration in the culture water AW is maintained by photosynthesis, and aeration equipment is not required. Therefore, there are no air bubbles for aeration. This eliminates physical contact between the air bubbles caused by each of these factors, and protects the cultivated objects, even the delicate algae, from damage.

[0041] In addition, the distances from the injection port 27 provided at the radial center position of each culture container 23 to each drainage hole 23d in the outer wall 23b are set to be approximately equal. As a result, water flow of approximately the same degree is generated all around, reducing the risk of the strength of the water flow being uneven within the culture container 23. For example, the inlet 27 is oriented downward toward the bottom surface, and the culture water AW having a relatively high water temperature is allowed to flow in from above downward. As a result, the culture water AW that has been injected rises due to the difference in specific gravity, and a vertical circulating flow can be generated within the culture container 23.

[0042] The culture water AW used for culture in the culture container 23 is drained from each drainage hole 23d to the outside of the culture container 23. In the heat retention tank 21, the running hot spring water SW joins with the drained culture water AW and flows toward the overflow pipe 28. This allows the culture water AW in the culture container 23 to be kept clean. The hot spring water SW and the aquaculture water AW flowing down from the outlet 29 of the overflow pipe 28 are discharged outside the land-based aquaculture plant 10. This keeps the inside of the heat-retaining tank 21 clean, reducing the frequency of maintenance.

[0043] Next, specific effects of the hot spring plant 1 of the embodiment 1 will be described with reference to the water temperatures of the hot spring water SW, seawater MW, and culture water AW. The water temperatures of the hot spring water SW, seawater MW, and culture water AW are not limited to those exemplified in the embodiment 1, and may be set according to the culture target to be cultured on land.

[0044] First, the seafood farm 4 draws seawater MW pumped up from the sea through the intake pipe ML into the first heat exchanger 5. At this time, if the hot spring plant 1 including the seafood farm 4 is installed in a cold region or when the outside air temperature is low, such as in winter, the temperature of the seawater MW that reaches the seafood farm 4 may be below 8 degrees. Therefore, the first heat exchanger 5 performs heat exchange using the heat of the hot spring water SW, which has a higher temperature than the seawater MW. The temperature of the hot spring water SW is, for example, about 51° C. to 52° C. As a result, the seawater MW passing through the first heat exchanger 5 is heated and sent to the seawater piping 8a with its temperature increased by about 1° C. to 3° C.

[0045] The seawater MW heated by the first heat exchanger 5 is sent to the breeding tank 7 or the second heat exchanger 6 via seawater piping 8a. The distribution ratio of the amount of seawater MW sent to the breeding tank 7 or the second heat exchanger 6 is adjusted so that the seawater MW stored in the breeding tank 7 has a temperature suitable for breeding.

[0046] On the other hand, the hot spring water SW in the first heat exchanger 5 is sent to the second heat exchanger 6 via the hot spring water pipe 9b. The second heat exchanger 6 is arranged near the breeding tank 7 in the same seafood breeding farm 4 as the first heat exchanger 5, and further heats the seawater MW to raise the water temperature by about 1 to 3 degrees, and then mixed with the seawater MW sent from the first heat exchanger 5 in the breeding tank 7. In the breeding tank 7, the mixing ratio of each seawater MW is adjusted to adjust the water temperature to a temperature suitable for breeding shellfish seedlings, for example, about 8 to 10 degrees. The seawater MW used to breed shellfish seedlings in the breeding tank 7 is discharged through the seawater supply pipe 8c.

[0047] The tip of the seawater conveying pipe 8c is connected to the mixer 22 of the land-based aquaculture plant 10. Then, when the seawater MW stored in the breeding tank 7 and used for cultivating shellfish seedlings is discharged from the breeding tank 7 through the seawater conveying pipe 8c, it is injected into the aquaculture container 23 via the mixer 22. At this time, in the land-based aquaculture plant 10 of embodiment 1, the hot spring water SW at approximately 40 to 50 degrees is mixed with the seawater MW by the mixer 22, and aquaculture water AW at approximately 18 to 22 degrees, which is suitable for use in cultivating algae, can be obtained. This allows the rearing water of the marine product rearing farm 4, which has already been heated by the first heat exchanger 5 and the second heat exchanger 6, to be reused as the aquaculture water AW of the land-based aquaculture plant 10 again.

[0048] Therefore, the land-based aquaculture plant 10 of the first embodiment does not require heating equipment such as a boiler that is conventionally used to heat the seawater MW, and therefore the initial cost for providing the heating equipment can be reduced. Moreover, there is no need for fuel such as fossil fuels to be burned in a boiler. This reduces the running costs required for rearing. Furthermore, there is no longer any generation of gases such as carbon dioxide that are generated when fuel is burned, reducing the environmental burden while improving productivity with good energy efficiency.

[0049] 4 shows a land-based aquaculture plant 20 according to the second embodiment. The same or equivalent parts as those in the land-based aquaculture plant 10 provided in the hot spring plant 1 according to the first embodiment are denoted by the same reference numerals, and the description will be omitted, and the following description will focus on the differences. In the land-based aquaculture plant 20 of embodiment 2 shown in FIG. 4, hot spring water SW introduced from the horticultural center 3 to the seafood breeding farm 4, or hot spring water SW branched off from the first heat exchanger 5 by the hot spring water supply pipe 9c, is drawn in. The land-based aquaculture plant 20 is equipped with a mixer 22 similar to that of the land-based aquaculture plant 10 of embodiment 1, which uses the heat from the drawn-in hot spring water SW to adjust the temperature of the seawater MW to produce aquaculture water AW with a temperature suitable for aquaculture.

[0050] The land-based aquaculture plant 20 of the second embodiment thus configured exhibits the following advantageous effects in addition to the advantageous effects of the land-based aquaculture plant 10 of the first embodiment. That is, the land-based aquaculture plant 20 adjusts the amount of hot spring water SW introduced from the first heat exchanger 5 of the seafood farm 4 or the amount of hot spring water SW introduced directly from the horticultural center 3. For example, the hot spring water SW sent from the first heat exchanger 5 or the gardening center 3 is maintained at a higher water temperature than the hot spring water SW sent from the second heat exchanger 6. Therefore, in the land-based aquaculture plant 20 of the second embodiment, the temperature of the culture water AW and the heat retention water HW can be adjusted to a water temperature condition of about 18 to 22 degrees Celsius suitable for the growth of the algae by changing the mixing ratio of each of the hot spring waters SW. Therefore, the land-based aquaculture plant 20 has even better energy efficiency.

[0051] In other words, the land-based aquaculture plant 20 of embodiment 2 can use hot spring water SW sent from the horticultural center 3, which has a higher water temperature, as a heat source compared to the hot spring water SW sent from the second heat exchanger 6 installed in the seafood farm 4 of embodiment 1. Therefore, in the land-based aquaculture plant 20 of the second embodiment, the ratio of the hot spring water SW sent from the horticulture center 3 is made larger than the hot spring water SW introduced from the first heat exchanger 5, so that the temperature of the culture water AW can be easily raised to a water temperature of about 18 to 22 degrees Celsius suitable for the growth of the algae. For example, all the hot spring water SW sent from the horticulture center 3 may be used as the heat source. The other configurations and effects are the same as those of the first embodiment, so the description will be omitted.

[0052] 5 shows a land-based aquaculture plant 30 according to embodiment 3. Note that the same or equivalent parts to those of the hot spring plant 1 according to embodiment 1 are given the same reference numerals and their explanations are omitted, and the following description will focus on the differences. The land-based aquaculture plant 30 shown in Figure 5 has a mixer 22 that adjusts the temperature of the aquaculture water AW as a temperature control unit, and a hot spring mixer 32 that adjusts the temperature of the hot spring water SW discharged from the seafood farm 4 as another temperature control unit. In the mixer 22 of the third embodiment, hot spring water SW having a temperature of, for example, about 90 degrees is drawn from the source of the hot spring 2. The mixer 22 mixes the hot spring water SW, which has a higher temperature than the seawater MW, with the seawater MW to warm the culture water AW.

[0053] In addition, hot spring water SW1 branched off from the hot spring water piping 9a connecting the horticultural center 3 and the seafood breeding farm 4, hot spring water SW2 branched off from the hot spring water piping 9b connecting the first heat exchanger 5 and the second heat exchanger 6, and hot spring water SW3 drained from the second heat exchanger 6 flow into the hot spring mixer 32 via their respective piping. Each pipe is provided with a flow rate control valve (not shown). When the hot spring waters SW1 to SW3, which have been adjusted to a predetermined flow rate by each flow rate control valve, flow into the hot spring mixer 32, they are mixed at a desired ratio to become hot spring water SW4 at a desired temperature. The hot spring water SW4 whose temperature has been adjusted in the hot spring mixer 32 is sent to the heat-insulated water tank 21 via a hot spring water supply pipe 9f that connects the hot spring mixer 32 and the heat-insulated water tank 21, thereby maintaining the heat-insulated water HW in the heat-insulated water tank 21 at the desired water temperature. Furthermore, if the desired amount of heat can be secured, an intake pipe ML2 for taking in seawater MW may be laid between the sea and the land-based aquaculture plant 30 so that the seawater MW is directly drawn into the mixer 22 of the land-based aquaculture plant 30.

[0054] The land-based aquaculture plant 30 of the third embodiment thus configured exhibits the following advantageous effects in addition to the advantageous effects of the land-based aquaculture plant 10 of the first embodiment. That is, the mixer 22 of the land-based aquaculture plant 30 mixes hot spring water SW, which has a relatively high temperature and is drawn directly from the source of the hot spring 2, with seawater MW to heat the aquaculture water AW.

[0055] Furthermore, the hot spring mixer 32 can adjust the hot spring waters SW1 to SW3 having different temperatures to produce hot spring water SW4 at a desired temperature by mixing them within the hot spring mixer 32. This further improves the energy efficiency of the land-based aquaculture plant 30 of embodiment 4. In addition, the temperatures of the culture water AW and the insulation water HW can be easily adjusted to water temperature conditions suitable for the growth of Porphyra japonica. The other configurations and effects are the same as those of the first embodiment, so the description will be omitted.

[0056] 6 shows a land-based aquaculture plant 40 according to embodiment 4. Note that the same or equivalent parts to those of the hot spring plant 1 according to embodiment 1 are given the same reference numerals and their explanations are omitted, and the following description will focus on the differences. In the land-based aquaculture plant 40 shown in Fig. 6, hot spring water SW is drawn directly from the source of the hot spring 2 as a heat source to the hot spring mixer 32 of the third embodiment. For example, by drawing hot spring water SW having a temperature of about 90 degrees, the temperature of the heat retention water HW can be easily increased.

[0057] The land-based aquaculture plant 40 of the fourth embodiment thus configured can improve thermal efficiency by utilizing the hot spring water SW as a heat source in addition to the effects of the land-based aquaculture plant 30 of the third embodiment. Therefore, even if the temperature of the seawater MW drawn into the mixer 22 is relatively low, the culture water AW can be easily heated to a water temperature condition suitable for the growth of the algae. For example, if the desired amount of heat can be secured, the seawater MW may be introduced directly from the water intake pipe ML2 laid between the sea and the land-based culture plant 40. The other configurations and effects are the same as those of the first embodiment, so the description will be omitted.

[0058] 7 shows a land-based aquaculture plant 50 according to embodiment 5. Note that the same or equivalent parts to those of the hot spring plant 1 according to embodiment 1 are given the same reference numerals and their explanations are omitted, and the following description will focus on the differences. In the fifth embodiment, in addition to the land-based aquaculture plant 10 (see FIG. 1) of the first embodiment, an in-plant heat exchanger 51 is further provided as one of the temperature adjustment units. The in-plant heat exchanger 51 exchanges heat with the hot spring water SW in the hot spring water supply pipe 9c in the land-based aquaculture plant 60, and warms the seawater MW sent from the seawater supply pipe 8c.

[0059] The land-based aquaculture plant 50 of the fifth embodiment thus configured can further heat the seawater MW by the in-plant heat exchanger 51 before the mixer 22 mixes the hot spring water SW. Therefore, even if the temperature of the seawater MW transported through the seawater transport pipe 8c laid outdoors in a cold region or the like drops, the temperature of the seawater MW can be increased again by the in-plant heat exchanger 51. Therefore, the land-based aquaculture plant 50 of the fifth embodiment can easily adjust the temperature of the culture water AW to a desired temperature. For example, in the mixer 22, the water temperature and the components of the culture water AW can be adjusted to provide suitable growth conditions for the growth of the algae, such as by reducing the ratio of the hot spring water SW to be mixed. This can further promote the growth of the algae. The other configurations and effects are the same as those of the first to fourth embodiments, and therefore the description thereof will be omitted.

[0060] 8 shows a hot spring plant 11 having a land-based aquaculture plant 60 and a hot spring bathing facility 61 according to a sixth embodiment. Note that the same or equivalent parts as those of the hot spring plant 1 according to the first embodiment are given the same reference numerals and their explanations are omitted, and the following description will focus on the configurations of the different parts. The hot spring plant 11 of the sixth embodiment is provided with a hot spring bathing facility 61 as a primary use facility for the primary use of the hot spring water SW drawn from the hot spring 2, instead of the horticultural center 3 and the marine product farm 4 of the first embodiment. The hot spring bathing facility 61 has a hot spring accommodation building 62 and a heat exchanger 63. The hot spring accommodation building 62 and the heat exchanger 63 each receive hot spring water SW from the source of the hot spring 2 as a heat source.

[0061] The hot spring accommodation building 62 is also provided with hot spring water piping 64 for discharging the hot spring water SW. The hot spring water piping 64 is connected to a heat exchanger 63. The heat exchanger 63 performs heat exchange using the heat of the hot spring water SW sent directly from the hot spring 2 or the heat of the waste hot water DW sent from the hot spring accommodation building 62 in a state where the water temperature is lower than that of the hot spring water SW as a heat source, and heats the seawater MW sent through the water intake pipe ML.

[0062] A seawater supply pipe 8c and a hot spring water supply pipe 9c are connected to the heat exchanger 63. Of these, the seawater MW discharged from the heat exchanger 63 is sent to the land-based aquaculture plant 60 via the seawater supply pipe 8c. Then, similar to the land-based aquaculture plant 10 of the first embodiment, the seawater MW is mixed with the hot spring water SW in the mixer 22 to become the aquaculture water AW. The culture water AW is injected into each culture container 23 from the injection section 24 and used for cultivating the algae.

[0063] In addition, the waste hot water DW discharged from the heat exchanger 63 is sent to the heat-retaining water tank 21 and the mixer 22 of the land-based aquaculture plant 60 via the hot spring water supply pipe 9c. In the sixth embodiment, the hot spring water SW may be sent directly from the hot spring 2 to the heat-retaining water tank 21 and the mixer 22 of the land-based aquaculture plant 60. Other configurations and effects are similar to those of the land-based aquaculture plants 10 to 50 of the first to fifth embodiments, and therefore will not be described.

[0064] 9 shows a land-based aquaculture plant 70 according to the seventh embodiment. The same or equivalent parts to those of the hot spring plant 1 according to the first embodiment are given the same reference numerals and will not be described. The following description will focus on the configuration of the different parts. In the land-based aquaculture plant 70 of the seventh embodiment, no drainage holes are formed in the outer peripheral wall of each culture container 123. A plurality of drainage holes 123d are formed in an upper lid 123a, which is one of the wall surfaces of each culture container 123. Each culture container 123 is disposed in the thermal insulation water tank 21 such that the vertical position of the upper lid 123a is above the water level WL of the thermal insulation water HW stored in the thermal insulation water tank 21.

[0065] The land-based aquaculture plant 70 of embodiment 7 configured as described above has the same effects as embodiments 1 to 6, and furthermore, the aquaculture water AW injected into the aquaculture container 123 is kept warm by the insulation water HW in the surrounding insulation tank 21, thereby maintaining the desired water temperature. The culture water AW used for culture in the culture container 123 is discharged from a drainage hole 123d formed in the upper cover 123a of the culture container 123 and overflows from the periphery of the culture container 123. Then, the culture water AW together with the heat-retaining water HW in the heat-retaining water tank 21 is discharged outside the land-based aquaculture plant 70. In addition, since no drainage holes are formed in the outer peripheral wall of each culture container 123, the thermal water in the thermal water tank 21 does not mix with the seawater in the culture container 123. Therefore, the state of the seawater in the culture container 123 is easy to manage. Other configurations and effects are similar to those of the land-based aquaculture plants 10 to 60 of the first to sixth embodiments, and therefore will not be described.

[0066] As described above, the land-based aquaculture plants 10 to 70 of each of embodiments 1 to 7 are equipped with a temperature adjustment unit (mixer 22, hot spring mixer 32 or in-plant heat exchanger 51) that adjusts the temperature of the seawater MW using heat from a heat source derived from geothermal energy or a hot spring, a culture container 23 or 123 for cultivating the culture targets, and an injection unit 24 that injects the seawater MW whose temperature has been adjusted by the temperature adjustment unit into the culture container 23, etc. Therefore, by using heat from a heat source derived from geothermal energy or hot springs, it is possible to obtain practically beneficial effects such as improving productivity with good energy efficiency.

[0067] Here, the problems with conventional land-based seaweed cultivation will be described. That is, seaweed grows naturally on rocky reefs about 10 meters deep where there is good exposure to the waves. For this reason, it is known that seaweed needs a moderate water flow and sunlight to grow. Therefore, seaweed is not suitable for land-based aquaculture in water tanks where there is no tide. For example, mechanical agitation to generate water currents can damage seaweed, as it is sensitive to physical contact. Seaweed can also be damaged by contact with air bubbles that are generated when seawater is slammed against the water surface and air bubbles from aeration. It is also possible to use a pump to circulate seawater, or to create waves by reciprocating a wave-making board on land, but a considerable amount of energy is required to mechanically create an appropriate water flow in this way. In addition, compared to marine aquaculture, land-based aquaculture has many restrictions on the amount of space available for cultivation. Moreover, it is not easy to attach large amounts of seaweed to rocks. Furthermore, seaweed such as Uncaria japonica can grow at different rates in different parts of the land. For this reason, it is difficult to harvest large amounts of seaweed in a uniform growth state. For seaweed to grow, it is best to have a certain amount of natural light. However, to reproduce a light close to natural light using artificial light such as LED lighting, additional electrical energy is required. In this way, a large amount of energy is required to reproduce on land the same growth conditions as in the wild, such as temperature, water flow, and lighting, for land-based aquaculture. In contrast to such conventional land-based aquaculture of seaweed, the land-based aquaculture plants 10 to 70 of the first to seventh embodiments can solve the various problems described above.

[0068] That is, the land-based aquaculture plants 10 to 70 of the first to seventh embodiments have a small environmental impact and efficiently supply seaweed with stable quality to consuming areas. 1, the land-based aquaculture plants 10-70 are provided with an insulation water tank 21 for storing insulation water HW heated by the heat of hot spring water SW, and a mixer 22 for adjusting the temperature of seawater MW using the heat of the introduced hot spring water SW or the hot spring water SW adjusted by a hot spring mixer 32. The land-based aquaculture plants 10-70 are also provided with a culture container 23 submerged in the insulation water tank 21, and an injection unit 24 for injecting the seawater MW, the temperature of which has been adjusted by the mixer 22, into the culture container 23 as aquaculture water AW.

[0069] The land-based aquaculture plant of this embodiment configured in this manner can heat the insulated water HW stored in the insulated water tank 21 using the heat from the hot spring water SW, and the aquaculture water AW which is injected into the aquaculture container 23 after the temperature of the seawater MW is adjusted in the mixer 22 or the hot spring mixer 32. Therefore, the culture containers 23 submerged in the heat-retaining water HW are efficiently kept warm from the surroundings in the heat-retaining water tank 21. In addition, the mixer 22 adjusts the temperature of the seawater MW injected into the culture containers 23, thereby making the culture water AW at a temperature suitable for culture with a small amount of heat. Therefore, compared to generating heat by burning fuel in a boiler or the like, the energy efficiency is good, making land-based aquaculture possible even in cold regions.

[0070] Furthermore, the culture target in the culture container 23 is agitated by the water flow of the seawater MW injected by the injection unit 24. This makes it possible to provide the culture target with a sufficient flow of seawater required for growth, thereby promoting growth.

[0071] The culture targets are entangled together by being stored in the culture containers 23, and uniform growth conditions can be obtained for each culture container 23. Furthermore, the culture targets do not scatter within the culture containers 23. This eliminates the need for attachment work to rocks, and reduces the amount of work. For example, if multiple culture containers 23 are submerged in one insulated water tank 21, it becomes easy to harvest large quantities of culture containers 23 that are in a uniform growth state above a certain level. Also, land-based culture plants 10 and the like can harvest and re-culture each culture container 23. This makes it easy to increase the production volume of cultured objects. Therefore, it is possible to enjoy the advantage of land-based aquaculture that is not easily affected by weather, and obtain a desired yield even in a limited land-based aquaculture space. In this way, the land-based aquaculture plant of the embodiment can improve productivity with good energy efficiency.

[0072] The subject of cultivation in the land-based cultivation plants 10 to 70 of the embodiment is algae. The land-based cultivation plants 10 and the like of the embodiment have good energy efficiency. For this reason, for example, algae, which requires a relatively warm growing environment, can be cultivated on land near cattle breeding areas, which are common in cold regions. Therefore, a stable supply can be secured with little environmental impact from renewable energy.

[0073] Furthermore, as shown in FIG. 1, the heat source in this embodiment is a hot spring, and the mixer 22 can adjust the water temperature of the aquaculture water AW by mixing seawater MW with hot spring water SW from the hot spring, or by heat exchange with the heat of the hot spring water SW. The mixer 22 adjusts the temperature of the culture water AW injected into the culture container 23 by mixing it with hot spring water SW, which has a relatively high temperature, so that the water temperature can easily be made suitable for cultivating the algae. This makes it possible to further improve the thermal efficiency and eliminates the need for heating equipment such as a boiler to heat the seawater MW, thereby reducing the initial cost for installing the heating equipment.

[0074] 3, the injection unit 24 includes an injection hose 26 having an injection port 27 formed therein to be inserted into the culture container 23. As shown in FIG. 1, the injection position IN of the injection port 27 in the vertical direction is located below the water level WL of the surface of the heat-retained water HW stored in the heat-retained water tank 21. 1 between the mixer 22 and the culture container 23. Therefore, air bubbles do not come into physical contact with the culture objects in the culture container 23, and the culture objects are not damaged even if they are delicate seaweed such as Porphyra japonica. Therefore, when the culture water AW is injected into the culture container 23 from the injection port 27, the seawater MW is not slammed against the water surface, as in the conventional case, and air is not mixed in. Therefore, air bubbles do not come into physical contact with the culture target, and even if the culture target is a delicate seaweed such as Porphyra japonica, it will not be damaged. Furthermore, when the culture water AW is injected into the culture container 23 through the inlet 27, a water current is generated. This eliminates the need to circulate seawater using a pump or to create waves by reciprocating a wave-making board or the like on land. This allows for a reduction in the energy required to drive the pump or the like.

[0075] As shown in FIG. 3, the culture container 23 is cylindrical and made of transparent resin, and has a drainage hole 23d in the outer peripheral wall 23b, which connects the inside and outside. Since the culture container 23 placed in the insulated water tank 21 has a cylindrical shape, the culture objects are stirred along the curved inner surface of the outer wall 23b, and the culture objects are moderately entangled with each other, thereby stabilizing their growth. Furthermore, seaweed can be stacked three-dimensionally in the vertical direction in the culture container 23. This makes it possible to increase production volume even with the same culture area.

[0076] Furthermore, the culture container 23 and the top cover 23a are made of transparent resin. This allows an appropriate amount of natural light to be evenly guided into the culture container 23. Naturally growing seaweeds are attached to rocky reefs with good wave exposure at a depth of about 10 m. In the land-based aquaculture plant 10 and the like of the embodiment, water flow and lighting suitable for the growth of seaweeds can be reproduced in the culture container 23. In addition, the growth status of the cultured objects can be checked from the outside, and even in the case of seaweed that has different growth rates in different parts, it is easy to determine when to harvest while still contained within the culture container 23. Then, the seawater MW used for the culture is drained from the culture container 23 into the thermal insulation tank 21 through the drain hole 23d. Therefore, the seawater MW in the culture container 23 is always kept clean.

[0077] Moreover, it is no longer necessary to attach large quantities of seaweed to rocks. Even with seaweed such as Porphyra nigricans, which varies in growth state, it is possible to harvest a large amount of seaweed of uniform size by checking the growth state and harvesting each of the culture containers 23. Therefore, in the embodiment, by establishing a land-based aquaculture plant 10 or the like near the area where cattle are raised, it is possible to achieve practically beneficial effects such as efficiently supplying cattle of stable quality to consumption areas.

[0078] The present invention is not limited to the above-described embodiment, and various modifications are possible. The above-described embodiment is exemplified to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all of the configurations described. In addition, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. In addition, it is possible to delete a part of the configuration of each embodiment, or to add or replace other configurations. Possible modifications of the above-described embodiment are, for example, as follows.

[0079] In the above embodiment, the land-based aquaculture plant has been described with reference to cultivating Porphyra nigricans as the aquaculture target. However, the present invention is not limited to this. For example, the aquaculture target may be other seaweeds such as red algae or seagrass. Furthermore, if it is a marine product, it may be other fish and shellfish, marine products, or organisms such as marine products that live in fresh water or brackish water. In other words, the cultured object is not limited to those that have been cultured or are suitable for land culture, but may be those that have not been cultured on land before. Furthermore, there are no particular limitations on the type, quantity, shape, or growth stage of the cultured object.

[0080] In addition, in the land-based aquaculture plants 10 to 70 of the first to seventh embodiments, for example, a total of ten culture containers 23 are arranged in two rows in one heat-retaining water tank 21 as shown in FIG. 2. However, the present invention is not particularly limited to this. For example, one row or multiple rows of three or more culture containers 23 may be arranged in one heat-retaining water tank 21. Furthermore, multiple culture containers 23 may be arranged in a staggered pattern. 3, the culture container 23 does not have to be made of transparent resin, and may be a translucent or colored container. The drainage hole 23d formed in the outer peripheral wall 23b does not have to be a round hole shape, and may be a polygonal shape or the like as long as it communicates with the inside and outside of the outer peripheral wall 23b and is large enough that seaweed contained inside the culture container 23 cannot pass through.

[0081] The number of the thermal water tanks 21 may be more than one, and the shape of the thermal water tanks 21 may be circular or elliptical, for example. In other words, the number, shape, and material of the thermal insulation tanks 21 and the culture containers 23 arranged in one thermal insulation tank 21 are not particularly limited.

[0082] Further, the land-based aquaculture plants 10 to 70 of the first to seventh embodiments perform land-based aquaculture of marine products by reusing the residual heat of the hot spring plants 1 and 11 that use the hot spring 2 as a heat source, but the present invention is not limited to this. For example, waste heat from a biomass power plant may be used as a heat source. Natural renewable energy such as from a geothermal power plant may also be effectively utilized. In other words, as long as the heat source derived from geothermal energy or hot springs is used to adjust the temperature of the seawater MW, there is no particular limitation on the type or form of the heat source.

[0083] Furthermore, in the heat-retaining water tank 21 of the first embodiment, a drainage overflow pipe 28 for draining the heat-retaining water HW is provided vertically as a drainage facility. The overflow pipe 28 may be any pipe that can keep the water level WL of the heat-retaining water HW stored in the heat-retaining water tank 21 constant at an appropriate reference position. For example, the drainage facility may be configured as a side overflow type, and the shape, number, and material are not particularly limited. [Explanation of symbols]

[0084] 2. Hot springs (heat source) 10. Land-based aquaculture plant 22 Mixer (temperature adjustment section) 23 Aquaculture container 24 Injection part

Claims

1. a temperature adjustment unit that adjusts the temperature of seawater using heat from a heat source derived from geothermal energy or hot springs; A culture container for cultivating the culture target; An injection unit that injects the seawater whose temperature has been adjusted by the temperature adjustment unit into the culture container; A land-based aquaculture plant comprising:

2. A heat-retaining water tank for storing the heat-retaining water heated by the heat of the heat source is further provided, 2. The land-based aquaculture plant according to claim 1, wherein the aquaculture container is disposed within the insulated water tank.

3. 3. The land-based aquaculture plant according to claim 1, wherein the aquaculture target is algae.

4. The heat source is a hot spring, 2. The land-based aquaculture plant according to claim 1, wherein the temperature adjustment unit adjusts the temperature by mixing the seawater with hot spring water from the hot spring or by heat exchange of the heat of the hot spring water.

5. The land-based aquaculture plant described in claim 2, characterized in that the injection section includes an injection hose having an injection inlet that is inserted into the aquaculture container, and the injection inlet is located below the water level of the insulated water stored in the insulated water tank.

6. 3. The land-based aquaculture plant according to claim 2, wherein the aquaculture container is cylindrical, made of transparent resin, and has a drainage hole in the wall thereof that connects the inside and outside.

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