Energy-saving double-cycle characteristic freshwater fish spawning pond system and use method thereof

Abstract

This invention relates to the field of freshwater fish aquaculture technology and discloses an energy-saving dual-cycle freshwater fish spawning pond system and its usage method. The system includes a spawning pond and a culture circulation treatment system connected to the spawning pond. The culture circulation treatment system includes a first circulation tailwater treatment system and a second circulation tailwater treatment system. The first circulation tailwater treatment system includes a side drainage pond connected to the side wall of the spawning pond and a first inlet pond. The second circulation tailwater treatment system includes a vortex egg collection pond connected to the bottom of the spawning pond. The vortex egg collection pond is connected to the spawning pond through a multi-stage sedimentation pond and a second inlet pond. An egg collection pond is connected to the bottom of the vortex egg collection pond. The vortex egg collection pond and the egg collection pond together form the spawning circulation treatment system. The spawning pond system of this invention adopts a dual-cycle treatment system, combining long-term high-density culture, spawning, and automatic egg collection functions. During the use of the spawning pond, water circulation is achieved through air lifting and water propulsion, resulting in high efficiency and low energy consumption.

Description

Technical Field

[0001] This invention relates to the field of freshwater fish farming technology, and more specifically to an energy-saving dual-circulation freshwater fish spawning pond system and its usage method. Background Technology

[0002] Spawning ponds are bodies of water where fish, shrimp, shellfish, and other aquatic organisms mate, spawn, hatch, and raise their young. They are vital sites for the survival and reproduction of aquatic life and play a significant role in replenishing fishery resources. Traditional spawning ponds only have spawning and egg collection functions. Their large-scale water exchange system, involving both drainage and irrigation, leads to water waste, and the lack of water treatment capabilities results in incomplete aquaculture functions. Consequently, traditional spawning ponds can only be used during the breeding season and are forced to remain idle at other times, leading to insufficient resource utilization. Summary of the Invention

[0003] In view of this, the present invention provides an energy-saving dual-circulation freshwater fish spawning pond system and its usage method, which is equipped with tailwater treatment and circulating water facilities, and has functions such as long-term high-density breeding, spawning and automatic egg collection. During the use of the spawning pond, water circulation is achieved by air lifting and water pushing, which has high working efficiency and low energy consumption.

[0004] To achieve the above objectives, the present invention provides an energy-saving dual-circulation freshwater fish spawning pond system, which includes a spawning pond and an aquaculture circulation treatment system connected to the spawning pond.

[0005] The aquaculture recycling system includes a first recycling tailwater treatment system and a second recycling tailwater treatment system. The first recycling tailwater treatment system includes a side drainage tank connected to the side wall of the spawning pond and a first inlet tank. A biological filter is connected between the side drainage tank and the first inlet tank. The second recycling tailwater treatment system includes a vortex egg collection tank connected to the bottom of the spawning pond. The vortex egg collection tank is connected to a second inlet tank through a multi-stage sedimentation tank. The outlet of the second inlet tank is connected to the spawning pond. An egg collection tank is connected to the bottom of the vortex egg collection tank. The vortex egg collection tank and the egg collection tank together form the spawning recycling system.

[0006] The bottom of the vortex egg collection tank, side drainage tank, sedimentation tank, biological filter, first inlet tank, second inlet tank and egg collection tank are all equipped with a bottom drain pipe.

[0007] During the breeding period, the connection between the vortex egg collection tank and the egg collection tank is disconnected, and the water in the spawning tank is circulated and filtered through the breeding circulation treatment system. During the spawning period, the connection between the vortex egg collection tank and the multi-stage sedimentation tank is disconnected, and the fish eggs in the spawning tank are collected through the spawning circulation treatment system.

[0008] Preferably, the side wall of the spawning pool is provided with a side drain outlet, which is connected to the side drainage pool through a connecting pipe.

[0009] Preferably, a ground source heat pump heating pipe is installed inside the biofilter, an oxygenation disc is installed at the bottom of the biofilter, and biological packing material is placed inside the biofilter, the volume of which is 50% of the volume of the biofilter.

[0010] Preferably, the bottom of the vortex egg collection pool is provided with an egg collection tube, the inlet end of which is connected to and communicates with the center of the bottom of the spawning pool, and the outlet end extends upward to the upper middle part of the vortex egg collection pool.

[0011] Preferably, the side wall of the vortex egg collection pool is provided with an overflow outlet for the egg collection pool that connects to the upstream of the multi-stage sedimentation pool.

[0012] Preferably, the multi-stage sedimentation tank is provided with several overflow baffles, which are used to separate the multi-stage sedimentation tank into several sedimentation chambers. The upper part of the water in the multi-stage sedimentation tank overflows into the second inlet tank through the downstream upper outlet, and the lower part of the water is discharged through the bottom drain pipe.

[0013] Preferably, several air-lift water inlets are provided between the first water inlet pool and the spawning pool, and between the second water inlet pool and the spawning pool. Ultraviolet sterilization tubes are provided in both the first water inlet pool and the second water inlet pool.

[0014] Preferably, the egg-collecting pool is equipped with a return water pump, which pumps water from the egg-collecting pool to the spawning pool to control the water level in the egg-collecting pool.

[0015] Preferably, the egg collection pool is equipped with an egg collection net box located below the outlet of the egg collection tube.

[0016] A method for using an energy-saving dual-circulation freshwater fish spawning pond system includes:

[0017] Preparation before parent stock is introduced into the pond: Start the blower and use the blower to aerate the water and push the water through the air lift inlet. If the water temperature is below 18℃, turn on the water source heat pump to heat the water and run it for 15 days to cultivate nitrifying bacteria in the biological filter and allow the biological packing material in the biological filter to form a biofilm.

[0018] Management of parent stock after introduction into the pool: Regularly test the ammonia nitrogen, nitrite, dissolved oxygen, temperature and pH in the water. Control the water exchange or air exchange rate through air pumps or level valves, and adjust the water level by installing a level control valve at the inlet.

[0019] Egg collection operation: During egg collection, fish eggs are discharged from the center of the bottom of the spawning pond through the egg collection tube into the vortex egg collection pond. The height of the egg collection tube is adjusted to 30cm below the top of the vortex egg collection pond. The overflow outlet of the egg collection pond leading to the multi-stage sedimentation pond is closed. The height of the egg collection tube is adjusted to 30cm-40cm below the top of the spawning pond. The outlet position of the egg collection tube is adjusted to guide the water to the egg collection net cage. The water level in the egg collection pond is controlled by pumping water into the spawning pond through a return water pump. The return water pump is electrically connected to a water level controller, and the water level is automatically regulated by the water level controller.

[0020] Water purification during aquaculture: During the aquaculture process, close the valves between the vortex egg collection pond and the egg collection pond. The upper clear water is discharged to the biological filter pond for purification through the side drain outlet, and then returned to the aquaculture pond for recycling. The bottom sewage flows to the vortex egg collection pond for preliminary sedimentation through the bottom drain pipe, and then overflows to the multi-stage sedimentation pond for purification. During the aquaculture process, biological filter brushes are hung in the multi-stage sedimentation pond to effectively settle uneaten feed and feces. If the water quality is found to be substandard, close the gate valve for overflow from the multi-stage sedimentation pond to the inlet. The bottom drainage of the multi-stage sedimentation pond is directly discharged to the outdoor ecological purification area for purification.

[0021] Water purification during spawning: Bottom drainage is achieved by opening the drain pipe switches at the bottom of the vortex egg collection tank, side drainage tank, sedimentation tank, biological filter, first water inlet tank, second water inlet tank, and egg collection tank. During the production process, drainage is carried out every 5-7 days. The discharged wastewater is discharged to the outdoor purification tank for purification treatment through the drainage ditch. Side drainage accounts for 90% of the total water exchange, and bottom drainage accounts for 10% of the total water exchange.

[0022] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the energy-saving dual-circulation freshwater fish spawning pond system disclosed in this invention are as follows:

[0023] (1) It has a dual-cycle treatment system consisting of an aquaculture cycle treatment system and an spawning cycle treatment system, which enables the spawning pond to have high-density aquaculture function during the idle period and can realize the recycling of aquaculture wastewater or discharge in compliance with standards.

[0024] (2) The use of an air-lift water inlet device to achieve water circulation can achieve an energy saving effect of 40% compared with the existing technology;

[0025] (3) The aquaculture circulation treatment system composed of the first circulation tailwater treatment system and the second circulation tailwater treatment system can circulate and filter the water in the spawning pond, which can reduce the water exchange rate and achieve a water saving effect of 80% compared with the traditional large-scale drainage and irrigation spawning pond.

[0026] (4) Automatic egg collection can be achieved through the egg-laying cycle system, which greatly saves labor costs and improves work efficiency;

[0027] (5) This invention does not require the use of easily damaged equipment or consumables such as microfiltration machines, and has the characteristics of stable operation, low cost and long service life. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the plan structure of the energy-saving dual-circulation freshwater fish spawning pond system of the present invention.

[0030] Figure 2 This is a vertical structural cross-sectional view of the vortex egg collection pool and egg receiving pool of the present invention.

[0031] Figure 3 This is a schematic diagram illustrating the working principle of the energy-saving dual-circulation freshwater fish spawning pond system of the present invention.

[0032] Explanation of reference numerals in the attached diagram: Spawning pond-1, Side drain outlet-3.1, Swirl-flow egg collection pond-2, Egg collection pipe-2.1, Egg collection pond overflow outlet-2.2, Side drain pond-3, Multi-stage sedimentation pond-4, Overflow baffle-4.1, Biological filter-5, First inlet pond-6.1, Second inlet pond-6.2, Air lift inlet-6.3, Egg collection pond-7, Egg collection net cage-7.2, Return water pump-7.3. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see the appendix Figure 1-3 This invention discloses an energy-saving dual-circulation freshwater fish spawning pond system and its usage method.

[0035] The energy-saving dual-circulation freshwater fish spawning pond system provided by this invention includes a spawning pond 1, a swirling egg collection pond 2, a side drainage pond 3, a multi-stage sedimentation pond 4, a biological filter 5, an inlet pond (including a first inlet pond 6.1 and a second inlet pond 6.2), and an egg collection pond 7, among other functional ponds (e.g., Figure 1 As shown), the functional pools are connected by pipes to form a dual-circulation water system (such as...). Figure 2 (As shown).

[0036] The spawning pond 1 is connected to an aquaculture recycling system;

[0037] The aquaculture recycling system includes a first recycling tailwater treatment system and a second recycling tailwater treatment system. The first recycling tailwater treatment system includes a side drainage tank 3 connected to the side wall of the spawning tank 1 and a first inlet tank 6.1. A biological filter 5 is connected between the side drainage tank 3 and the first inlet tank 6.1. The second recycling tailwater treatment system includes a vortex egg collection tank 2 connected to the bottom of the spawning tank 1. The vortex egg collection tank 2 is connected to the second inlet tank 6.2 through a multi-stage sedimentation tank 4. The outlet of the second inlet tank 6.2 is connected to the spawning tank 1. The bottom of the vortex egg collection tank 2 is connected to an egg collection tank 7. The vortex egg collection tank 2 and the egg collection tank 7 constitute the spawning recycling system.

[0038] The bottom of the vortex egg collection tank 2, the side drainage tank 3, the sedimentation tank 4, the biological filter tank 5, the first inlet tank 6.1, the second inlet tank 6.2, and the egg collection tank 7 is equipped with one or more bottom sewage pipes;

[0039] During the spawning period, the connection between the vortex egg collection tank 2 and the egg collection tank 7 is disconnected. The water in the spawning tank 1 is circulated and filtered through the aquaculture circulation treatment system. During the spawning period, the connection between the vortex egg collection tank 2 and the multi-stage sedimentation tank 4 is disconnected. The fish eggs in the spawning tank 1 are collected through the spawning circulation treatment system.

[0040] It should be noted that the spawning pond's circulating water system is entirely constructed of 24mm brick walls, and the structure of each functional pool is as follows:

[0041] Spawning Pool 1: It is cylindrical with a conical bottom, with a diameter of 8 meters and a total depth of 1.5 meters. The vertical depth of the cylinder is 1.3 meters and the depth of the conical bottom is 0.2 meters. The bottom center drains water through a PVC pipe to the vortex egg collection pool 2. The water source pool has pipes to add water to the spawning pool 1.

[0042] Swirl-flow egg collection pool 2: It is cylindrical with a conical bottom, with a diameter of 0.5 meters and a total depth of 1.5 meters. The cylindrical part is 1 meter deep vertically, and the conical bottom part is 0.5 meters deep. The side wall is equipped with an overflow outlet 2.2, which leads to the multi-stage sedimentation tank 4 through a pull-in pipe.

[0043] Side drainage tank 3: 1.5 meters deep. The spawning tank 1 and side drainage tank 3 are connected by a side drainage outlet 3.1, which is located 0.5 meters downward from the top of the spawning tank and is 0.5 meters wide. Side drainage tank 3 is connected to the upstream of the multi-stage sedimentation tank 4 through a pipe.

[0044] Multi-stage sedimentation tank 4: 1.5 meters deep and 1 meter wide, with several overflow baffles 4.1 in the middle dividing the multi-stage sedimentation tank 4 into multiple sedimentation chambers. The overflow baffles 4.1 are made of stainless steel. Taking one overflow baffle 4.1 as an example, the bottom of the overflow baffle 4.1 is fixed to the bottom, the two sides are fixed to the walls, and the top opening has a vertical depth of 0.5 meters, dividing the multi-stage sedimentation tank 4 into a sedimentation tank with two-stage sedimentation function. The upper opening of the downstream of the multi-stage sedimentation tank 4 can overflow to the nearby second inlet tank 6.2, while the bottom of the downstream can directly drain into the drainage ditch.

[0045] Biological filter 5: 1.5 meters deep, requiring 20%-30% of the total water volume of spawning tank 1. It has two stainless steel baffles 51 in the middle, spaced 0.5 meters apart. One baffle is fixed to the bottom and sides against the wall, with a 0.5-meter vertical gap at the top. The other baffle is suspended 0.5 meters above the ground, fixed to the wall on both sides, and flush with the top of spawning tank 1. The downstream of biological filter 5 can be connected to two inlet tanks via pipes. A ground source heat pump heating pipe is installed in biological filter 5. An aeration disc is installed at the bottom of biological filter 5. Biological packing material is placed inside biological filter 5, filling 50% of its volume.

[0046] Intake pools: 1.5 meters deep. Each intake pool is connected to spawning pool 1 via four airlift intake devices 6.3, which are powered by blowers. Ultraviolet sterilization tubes are installed in the intake pools (including the first intake pool 6.1 and the second intake pool 6.2).

[0047] Egg collection pool 7: 1.5 meters deep, connected to the bottom pipe of vortex egg collection pool 2 upstream. The inlet is a pull-in pipe structure, which can control the height of the outlet from vortex egg collection pool 2 to egg collection pool 7, thereby controlling the flow rate of the water. Vortex egg collection pool 2 has two outlets. One outlet is a return outlet, which pumps water back to egg collection pool 1. The other outlet is a bottom drain outlet, which controls the drainage through a PVC pull-in pipe, directly draining water to the drainage ditch.

[0048] Airlift water inlet 6.3: Microporous aeration heads are installed inside the PVC pipe, and airlift and water propulsion are achieved through aeration by a blower.

[0049] The bottom of each of the following ponds—swirl-flow egg collection pond 2, side drainage pond 3, sedimentation pond 4, biological filter pond 5, inlet pond, and egg collection pond 7—has a bottom drain pipe leading to a drainage ditch. The diameter of the drain pipe is 50 mm.

[0050] Outdoor ecological purification area: Its purification process is the same as the "three ponds and two dams" technology for treating pond aquaculture wastewater, which will not be described in detail here.

[0051] like Figure 3As shown, the energy-saving dual-circulation freshwater fish spawning pond system of the present invention has three operating modes, and its working principle is as follows:

[0052] 1. Water circulation route for fattening mode: ① Spawning pond 1 → Side drainage pond 3 → Biological filter 5 → First inlet pond 6.1 → Air lift water inlet 6.3 → Liquid level valve → Spawning pond 1, ② Spawning pond 1 → Swirl egg collection pond 2 → Multi-stage sedimentation pond 4 → Second inlet pond 6.2 → Air lift water inlet 6.3 → Liquid level valve → Spawning pond 1. At this time, the main function of swirl egg collection pond 2 is the initial sedimentation of uneaten feed and feces, and the water circulation is controlled by the kinetic energy provided by the blower.

[0053] 2. Spawning pool water circulation route: Spawning pool 1 → vortex spawning pool 2 → egg collection pool 7 → return water pump 7.3 → spawning pool 1. At this time, the main function of vortex spawning pool 2 is to collect eggs, and the return water pump 7.3 provides kinetic energy to control the water circulation.

[0054] 3. Water supply route in the water replenishment mode: Water is supplied from the water source pool to the spawning pool 1 through the level valve in the spawning pool 1.

[0055] It should be noted that the water temperature and quality of the spawning pond system can be regulated in tandem by using blowers, water quality testing equipment, ultraviolet sterilizers, water source heat pumps, and drainage ditches.

[0056] The method of using the energy-saving dual-circulation freshwater fish spawning pond system of the present invention is as follows:

[0057] Preparation before introducing parent stock into the pond: Start the blower and use the blower to aerate the water and push the water through the air lift water inlet 6.3. If the water temperature is below 18℃, turn on the water source heat pump to heat the water and run it for about 15 days to cultivate nitrifying bacteria in the biological filter 5 and allow the biological packing material in the biological filter 5 to form a biofilm.

[0058] Management of parent stock after introduction into the pool: Regularly test water quality indicators such as ammonia nitrogen, nitrite, dissolved oxygen, temperature, and pH. Control the water exchange or air exchange rate through air pumps or level valves, and adjust the water level by installing a level control valve at the inlet.

[0059] Egg collection operation: During egg collection, the fish eggs are discharged from the center of the bottom of the spawning pond 1 through the egg collection tube 2.1 to the swirling egg collection pond 2. The height of the egg collection tube 2.1 is adjusted to 30cm below the upper opening of the swirling egg collection pond 2. The overflow outlet 2.2 of the swirling egg collection pond 2 leading to the multi-stage sedimentation pond 4 is closed by pulling the insertion tube. The height of the egg collection tube 7.1 is adjusted to 30cm-40cm below the upper opening of the spawning pond 1. The outlet position of the egg collection tube 7.1 is adjusted to guide the water to the egg collection net cage 7.2. The water level of the egg collection pond 7 is controlled by pumping water into the spawning pond 1 through the return water pump 7.3. The return water pump 7.3 is electrically connected to a water level controller, and the water level is automatically regulated by the water level controller.

[0060] Water purification method during spawning: Bottom drainage is achieved by opening the drain pipe switches at the bottom of the vortex egg collection tank 2, side drainage tank 3, sedimentation tank 4, biological filter tank 5, water inlet tank, and egg collection tank 7. During the production process, drainage is carried out every 5-7 days. The discharged wastewater is discharged to the outdoor purification tank for purification treatment through the drainage ditch. Side drainage accounts for 90% of the total water exchange, and bottom drainage accounts for 10% of the total water exchange.

[0061] Water purification methods during aquaculture: During the aquaculture process, close the valves between the vortex egg collection pond 2 and the egg collection pond 7. The upper clear water is discharged to the biological filter pond 5 for purification through the side drain outlet, and then returned to the aquaculture pond for recycling. The bottom sewage flows to the vortex egg collection pond 2 through the bottom drain pipe for preliminary sedimentation, and then overflows to the multi-stage sedimentation pond 4 for purification. During the aquaculture process, biological filter brushes are hung in the multi-stage sedimentation pond 4 to effectively settle uneaten feed and feces. If the water quality is found to be substandard, close the gate valve for overflow from the multi-stage sedimentation pond 4 to the inlet. The bottom drainage of the multi-stage sedimentation pond 4 is directly discharged to the outdoor ecological purification area for purification.

[0062] Specifically, in mid-September each year, the pre-operation system is activated, the fattening mode is turned on, the microorganisms in the biological filter are cultivated, and the water quality is stabilized. In October each year, 5 shad broodstock are released into the water at a rate of 5 fish per cubic meter of water. When the temperature is below 22℃, the water source heat pump is turned on to keep the water temperature in the spawning pond constant. The stable high temperature in winter can stimulate the gonad development of the broodstock. In April of the following year, the shad begin to mate and spawn. The egg collection mode is turned on regularly to achieve automatic egg collection. The net cages can be manually retrieved.

[0063] After the shad breeding season ends, the yield of commercial shad is 5 kg / cubic meter. During the breeding process, the system operates well, and after testing, the wastewater from the breeding process consistently meets the standards after being treated by the system described in this invention.

[0064] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An energy-saving dual-circulation freshwater fish spawning pond system, characterized in that, Includes a spawning pond (1) and an aquaculture recycling system connected to the spawning pond (1); The aquaculture recycling system includes a first recycling tailwater treatment system and a second recycling tailwater treatment system. The first recycling tailwater treatment system includes a side drainage pool (3) connected to the side wall of the spawning pool (1) and a first inlet pool (6.1). A biological filter (5) is connected between the side drainage pool (3) and the first inlet pool (6.1). The second recycling tailwater treatment system includes a vortex egg collection pool (2) connected to the bottom of the spawning pool (1). The vortex egg collection pool (2) is connected to the second inlet pool (6.2) through a multi-stage sedimentation pool (4). The outlet of the second inlet pool (6.2) is connected to the spawning pool (1). The bottom of the vortex egg collection pool (2) is connected to an egg collection pool (7). The vortex egg collection pool (2) and the egg collection pool (7) together form the spawning recycling system. Bottom drain pipes are provided at the bottom of the vortex egg collection tank (2), side drainage tank (3), multi-stage sedimentation tank (4), biological filter (5), first inlet tank (6.1), second inlet tank (6.2) and egg collection tank (7); When the spawning pond system is in the breeding period, the connection between the vortex egg collection pond (2) and the egg collection pond (7) is disconnected, and the water in the spawning pond (1) is circulated and filtered through the breeding cycle treatment system. When the spawning pond system is in the spawning period, the connection between the vortex egg collection pond (2) and the multi-stage sedimentation pond (4) is disconnected, and the fish eggs in the spawning pond (1) are collected through the spawning cycle treatment system.

2. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 1, characterized in that, The side wall of the spawning pool (1) is provided with a side drain outlet (3.1), which is connected to the side drain pool (3) through a connecting pipe.

3. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 1, characterized in that, The biofilter (5) is equipped with a ground source heat pump heating pipe, and an oxygenation plate is installed at the bottom of the biofilter (5). The biofilter (5) is filled with biological packing material, and the volume of the biological packing material is 50% of the volume of the biofilter (5).

4. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 1, characterized in that, The bottom of the vortex egg collection pool (2) is provided with an egg collection tube (2.1). The inlet end of the egg collection tube (2.1) is connected to the center of the bottom of the spawning pool (1) and the outlet end extends upward to the upper middle part of the vortex egg collection pool (2).

5. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 4, characterized in that, The side wall of the vortex egg collection pool (2) is provided with an overflow outlet (2.2) of the egg collection pool that is connected to the upstream of the multi-stage sedimentation pool (4).

6. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 5, characterized in that, The multi-stage sedimentation tank (4) is equipped with several overflow baffles (4.1). The overflow baffles (4.1) are used to divide the multi-stage sedimentation tank (4) into several sedimentation chambers. The upper part of the water in the multi-stage sedimentation tank (4) overflows into the second inlet tank (6.2) through the downstream upper opening, and the lower part of the water is discharged through the bottom drain pipe.

7. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 1, characterized in that, Several air-lift water inlets (6.3) are provided between the first water inlet pool (6.1) and the spawning pool (1), and between the second water inlet pool (6.2) and the spawning pool (1). Ultraviolet sterilization tubes are provided in both the first water inlet pool (6.1) and the second water inlet pool (6.2).

8. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 1, characterized in that, The egg collection pool (7) is equipped with a return water pump (7.3), which pumps water from the egg collection pool (7) to the spawning pool (1) to control the water level of the egg collection pool (7).

9. The energy-saving dual-circulation freshwater fish spawning pond system according to claim 8, characterized in that, The egg collection pool (7) is equipped with an egg collection net box (7.2) located below the outlet of the egg collection tube (7.1).

10. A method of using an energy-saving dual-circulation freshwater fish spawning pond system, applied to the energy-saving dual-circulation freshwater fish spawning pond system as described in any one of claims 1-9, characterized in that, include: Preparation before parent stock is introduced into the pool: Start the blower and use the blower to aerate the water and push the water through the air lift water inlet (6.3). If the water temperature is below 18℃, turn on the ground source heat pump to heat the water and run it for 15 days to cultivate nitrifying bacteria in the biological filter (5) and allow the biological packing material in the biological filter (5) to attach to the biofilm. Management of parent stock after introduction into the pool: Regularly test the ammonia nitrogen, nitrite, dissolved oxygen, temperature and pH in the water. Control the water exchange or air exchange rate through air pumps or level valves, and adjust the water level by installing a level control valve at the inlet. Egg collection operation: During egg collection, the fish eggs are discharged from the center of the bottom of the spawning pond (1) through the egg collection tube (2.1) to the swirling egg collection pond (2). The height of the egg collection tube (2.1) is adjusted to 30cm below the top of the swirling egg collection pond (2). The overflow outlet (2.2) of the swirling egg collection pond (2) leading to the multi-stage sedimentation pond (4) is closed. The height of the egg collection tube (7.1) is adjusted to 30cm-40cm below the top of the spawning pond (1). The outlet position of the egg collection tube (7.1) is adjusted to guide the water to the egg collection net box (7.2). The water level of the egg collection pond (7) is controlled by pumping water into the spawning pond (1) through the return water pump (7.3). The return water pump (7.3) is electrically connected to a water level controller. The water level is automatically controlled by the water level controller. Water purification during aquaculture: During the aquaculture process, the valve between the vortex egg collection pond (2) and the egg collection pond (7) is closed. The upper clear water is discharged to the biological filter pond (5) for purification through the side drain outlet, and then returned to the aquaculture pond for recycling. The bottom sewage flows to the vortex egg collection pond (2) through the bottom drain pipe for preliminary sedimentation, and then overflows to the multi-stage sedimentation pond (4) for purification. During the aquaculture process, biological filter brushes are hung in the multi-stage sedimentation pond (4) to effectively settle residual feed and feces. If the water quality is found to be substandard, the gate valve of the multi-stage sedimentation pond (4) overflowing to the inlet is closed, and the bottom drainage of the multi-stage sedimentation pond (4) is directly discharged to the outdoor ecological purification area for purification. Water purification during spawning: Bottom drainage is achieved by opening the drain pipe switches at the bottom of the vortex egg collection pond (2), side drainage pond (3), multi-stage sedimentation pond (4), biological filter pond (5), first inlet pond (6.1), second inlet pond (6.2), and egg collection pond (7). During the production process, drainage is carried out every 5-7 days. The discharged wastewater is discharged to the outdoor purification pond for purification treatment through the drainage ditch. Side drainage accounts for 90% of the total water exchange, and bottom drainage accounts for 10% of the total water exchange.

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