Ocean live fish transport ship filtering oxygenation system and use method

Abstract

The invention discloses an ocean live fish transport ship filtering and oxygenation system and a use method. The ocean live fish transport ship filtering and oxygenation system comprises a circulating water filtering and oxygen mixing system and an oxygen preparation and storage standby system, and the circulating water filtering and oxygen mixing system is connected with the oxygen preparation and storage standby system; the circulating water filtering and oxygen mixing system comprises a filtering barrel, a water tank and an oxygen cone which are connected in sequence, the filtering barrel is connected with the circulating water inlet, a first branch and a second branch are connected between the water tank and the oxygen cone, the second branch is connected with a venturi jet device, and the venturi jet device is connected with the oxygen preparation and storage standby system; the oxygen preparation and storage standby system comprises an oxygen generator, an oxygen bottle and an oxygen compressor, and the oxygen generator, the oxygen bottle, the oxygen compressor and the Venturi jet device are all connected to the cross-shaped four-way joint. By means of intelligent oxygen supply control, the equipment is effectively protected while the oxygen supply stability is guaranteed, and the living environment and the health state of fishes in the whole transportation process are guaranteed.

Description

Technical Field

[0001] The invention relates to a filtering and oxygenating system and a use method thereof, and in particular to a filtering and oxygenating system and a use method thereof for an ocean-going live fish transport vessel. Background Art

[0002] Fish, with its excellent quality, has become a favorite on the tables of gourmets and consumers around the world. With the growing market demand for high-quality seafood, how to maintain the freshness of fish and transport them over long distances has become an urgent challenge facing the aquaculture industry.

[0003] In the process of large-scale and modernization of modern ocean-going fishing vessels, the scope of operation is constantly expanding to the deep sea, which puts higher requirements on the ship's management system, control system, navigation system, fishing system, etc. These systems are gradually being automated and intelligent. In this context, the live fish transportation life support system shows its great potential. It adopts improved water-based live transportation technology, which significantly improves the survival rate of fish transportation, effectively reduces transportation costs and improves economic benefits. The system can also improve the growth, appetite and immunity of fish during transportation, maintain fish quality, and meet the high standards of the market.

[0004] Despite this, traditional methods of transporting live fish still have many defects when facing high-density farming. In long-distance transportation, closed environments often lead to insufficient oxygen supply. Especially under high-density farming conditions, the consumption rate of dissolved oxygen is accelerated, which is more likely to cause a decrease in dissolved oxygen levels in the water, thereby triggering a stress response in fish, reducing their immunity, and even leading to large-scale deaths. This situation seriously affects transportation efficiency and economic benefits. In the prior art, oxygenation equipment mostly uses simple aeration or spraying methods. These methods have low oxygenation efficiency in high-density farming environments and cannot effectively meet the fish's demand for oxygen. Especially in long-distance transportation, this limitation is more obvious.

[0005] Therefore, a new and efficient solution is urgently needed to overcome these challenges, especially in high-density aquaculture environments, which requires a system that can continuously provide sufficient dissolved oxygen, improve water quality, and effectively reduce fish stress responses. Such a system should be able to adapt to different aquaculture densities and transportation distances, ensure the health and vitality of fish throughout the transportation process, and meet the market demand for high-quality live fish. Summary of the invention

[0006] Purpose of the invention: The purpose of the present invention is to propose a filtration and oxygenation system for ocean-going live fish transport ships and a method of use, which can achieve efficient injection, dissolution and continuous supply of oxygen in the environment of high-density breeding and long-distance transportation, so as to ensure the health and survival rate of fish during the entire transportation process.

[0007] Technical solution: The present invention includes a circulating water filtration and oxygen mixing system, an oxygen preparation and storage standby system, and the circulating water filtration and oxygen mixing system is connected to the oxygen preparation and storage standby system; the circulating water filtration and oxygen mixing system includes a filter barrel, a water tank and an oxygen cone connected in sequence, the filter barrel is connected to the circulating water inlet, a first branch and a second branch are connected between the water tank and the oxygen cone, a venturi ejector is connected to the second branch, and the venturi ejector is connected to the oxygen preparation and storage standby system; the oxygen preparation and storage standby system includes an oxygen generator, an oxygen cylinder and an oxygen compressor, and the oxygen generator, the oxygen cylinder, the oxygen compressor and the venturi ejector are all connected to a cross-way.

[0008] The first branch is provided with a flow-dividing tee, a first pressure sensor, a third solenoid valve and a flow-merging tee in sequence; the second branch is connected between the flow-dividing tee and the flow-merging tee.

[0009] The second branch starts from the diversion tee and is connected in sequence to the fourth solenoid valve, the second pressure sensor, the venturi ejector and the fifth solenoid valve, and then is connected to the converging tee to merge with the first branch. The venturi ejector is provided with a first check valve, and the first check valve is connected to the second check valve and the air inlet in sequence.

[0010] A liquid sensor is arranged in the water tank, a first drain port is arranged on one side of the water tank, and the other side of the water tank is connected with the oxygen cone through a water pump.

[0011] A circulating water outlet is arranged on one side of the oxygen cone, and a sixth solenoid valve is arranged at the circulating water outlet.

[0012] The oxygen cylinder and the oxygen compressor are connected to the cross-way through the fourth branch, the fourth branch is a spare loop branch, and the fourth branch starts from the cross-way and is connected in sequence to the third proportional solenoid valve, the compressor air inlet, the oxygen compressor, the air storage tank, the compressor air outlet, the three-way regulating valve, the fourth proportional solenoid valve, and then connected to the cross-way, and the oxygen cylinder is connected to the three-way regulating valve.

[0013] The venturi ejector is connected to the cross-way through a third branch, and a second proportional solenoid valve is arranged on the connecting pipeline.

[0014] A first proportional solenoid valve is arranged between the gas outlet and the cross-way of the oxygen concentrator.

[0015] The oxygen preparation and storage backup system is set to the following working mode:

[0016] Mode 1: The dissolved oxygen content is measured at the circulating water outlet. When the set dissolved oxygen content is reached, the second proportional solenoid valve and the third proportional solenoid valve are PID-regulated and controlled. Under the condition of maintaining the dissolved oxygen concentration of the circulating water outlet, the excess oxygen is compressed by the oxygen compressor and then connected to the oxygen cylinder; when the pressure of the oxygen cylinder reaches 80% of the set pressure storage rate, the oxygen generator, oxygen compressor, first proportional solenoid valve and third proportional solenoid valve are turned off, the outlet direction of the three-way regulating valve is adjusted to be connected with the fourth proportional solenoid valve, and the fourth proportional solenoid valve is opened or the oxygen cylinder is manually replaced;

[0017] Mode 2: When the oxygen generator and oxygen compressor are under maintenance or power outage, close the first proportional solenoid valve and the third proportional solenoid valve, and open the second proportional solenoid valve and the fourth proportional solenoid valve to maintain the oxygen required by the system; when the remaining pressure of the oxygen cylinder is lower than 20% of the design standard, replace the oxygen cylinder or switch to Mode 1.

[0018] A method for using a filtration and oxygenation system of an ocean-going live fish transport ship comprises the following steps:

[0019] Start the circulating water filtration system, the circulating water flows into the filter barrel, and the filtered water flows into the water tank;

[0020] Pressurize the circulating water in the water tank, adjust the opening of the third solenoid valve according to the real-time data of the first pressure sensor and the second pressure sensor, and control the water flow pressure;

[0021] The circulating water is fully mixed with oxygen in the Venturi ejector, and then is treated twice by the oxygen cone, and the sixth solenoid valve is opened to inject the circulating water rich in dissolved oxygen into the fish tank;

[0022] In the oxygen production part, the oxygen produced is introduced into the Venturi ejector through the oxygen generator in cooperation with the first proportional solenoid valve and the second proportional solenoid valve;

[0023] When the dissolved oxygen content in the fish tank reaches the set concentration, the opening of the second proportional solenoid valve is reduced, and the third proportional solenoid valve is opened at the same time to store the excess oxygen in the oxygen cylinder;

[0024] The third pressure sensor is used to monitor the oxygen concentration in the oxygen cylinder. When the preset value is reached, the oxygen generator, the first proportional solenoid valve and the third proportional solenoid valve are turned off, and the fourth proportional solenoid valve is opened at the same time, and the three-way regulating valve is connected to the fourth proportional solenoid valve to ensure the gas supply to the oxygen cylinder.

[0025] Beneficial effects: The present invention has the following advantages:

[0026] (1) The present invention adopts a Venturi ejector and utilizes the principle of fluid dynamics. Through its unique structure of convergent section, throat and diffuser section, the water flow velocity is significantly increased and local negative pressure is generated. Not only a large amount of air is inhaled, but also strong turbulence and shear force are formed in the throat, which further refines the oxygen bubbles and increases the gas-liquid contact area, thereby significantly improving the dissolution efficiency of oxygen in water.

[0027] (2) The circulating water with high dissolved oxygen content is treated twice by oxygen cones to ensure that there are no large bubbles in the water in the culture tank, maintain a stable water environment required for the survival of fish, and ensure that the water rich in dissolved oxygen can be continuously circulated throughout the culture tank to meet the oxygen needs of all fish during transportation, especially when pressure and respiratory demand increase;

[0028] (3) The present invention designs a double-layer check valve at the connection between the venturi ejector and the oxygen pipe, which plays a vital role in maintaining the efficiency and life of the oxygen generator, effectively preventing water from flowing back into the oxygen generator, ensuring optimal oxygen injection; the mechanism of the double-layer check valve consists of two independent check valves, each of which has a single opening direction. This configuration ensures that the water flow remains unidirectional, preventing any backflow that may damage the internal components of the oxygen generator. By preventing water backflow, the double-layer check valve design ensures that the oxygen generator operates efficiently without any interruption or performance degradation. This uninterrupted operation helps to maintain a consistent and sufficient oxygen supply for the fish throughout the transportation process;

[0029] (4) The oxygen preparation and storage part consists of an oxygen concentrator, an oxygen cylinder and an oxygen compressor, which are connected to a proportional solenoid valve and a cross-shaped four-way joint through the gas outlet, and are divided into a direct output branch and a backup loop branch; the direct output branch is responsible for injecting oxygen into the water through a venturi ejector, while the backup loop branch involves compressing and storing excess oxygen for emergency use;

[0030] (5) Two working modes are set to adapt to different operating conditions: Mode 1 is based on the measurement of dissolved oxygen at the circulating water outlet, and the proportional solenoid valve is controlled by PID regulation to maintain the required dissolved oxygen concentration, and the excess oxygen is compressed and stored; Mode 2 is enabled when the oxygen generator and air compressor are under maintenance or power outage. By switching the configuration of the proportional solenoid valve, the oxygen cylinder supply system is used to ensure stability and safety during transportation;

[0031] (6) An automated control mechanism was designed to monitor the pressure of the oxygen cylinder and intelligently adjust the three-way regulating valve and proportional solenoid valve group to achieve precise control of the oxygen supply. This not only improves the oxygen utilization efficiency and extends the service life of the equipment, but also ensures the survival of the fish in an emergency and reduces the pressure on the fish;

[0032] (7) Through intelligent oxygen supply control and effective protection of equipment while ensuring the stability of oxygen supply, the living environment and health status of fish are ensured during the entire transportation process; it not only improves the efficiency and success rate of live fish transportation, but also meets the market's high standards for high-quality live fish transportation, demonstrating its wide application potential and practical application value in the field of deep-sea live fish transportation;

[0033] (8) The present invention realizes the maximization of energy efficiency and the significant improvement of operation stability through the intelligent linkage between the circulating water filtration and oxygen mixing system and the oxygen preparation and storage backup system; the combination of the circulating water filtration and oxygen mixing system and the oxygen preparation and storage backup system improves the dissolution rate of oxygen, meets the needs of high-density aquaculture, ensures the continuity of oxygen supply and the excellent water quality, and reduces the use of energy through precise control, thereby realizing efficient and energy-saving operation of the system; in addition, the intelligent monitoring and automatic adjustment mechanism within the system can respond to changes in the external environment and the internal operating status in real time, and adjust the operating parameters of each component in time, thereby ensuring the stable operation of the system under various sea conditions and climatic conditions. The stable operation time exceeds 3650 hours, which greatly reduces the risk of ocean-going ships failing to replenish energy in time in the open sea; the stability of the living environment and health status of fish during the entire transportation process is significantly improved, thereby ensuring the survival rate and quality of fish during long-distance transportation. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0035] Figure 2 It is a schematic diagram of the structure of the Venturi ejector of the present invention;

[0036] Figure 3 It is a schematic diagram of the Venturi ejector check valve of the present invention. DETAILED DESCRIPTION

[0037] The present invention will be further described below in conjunction with the accompanying drawings.

[0038] like Figure 1As shown, the filtration and oxygenation system of the ocean-going live fish transport ship of the present invention includes a circulating water filtration and oxygen mixing system, an oxygen preparation and storage standby system, and the circulating water filtration and oxygen mixing system is connected to the oxygen preparation and storage standby system; the circulating water filtration and oxygen mixing system includes a filter barrel 3, a water tank 4 and an oxygen cone 19 connected in sequence, the filter barrel 3 is a drop-in biological filter, a layered partition is arranged inside, and the filter barrel 3 is fixed by a barrel wall bayonet, and a biological cabin layer is arranged 0.2m from the bottom, and the thickness of the biological cabin layer is 30cm. A drop-in portable bag is used, and a 0.1m porous filter cotton is placed in the biological cabin layer. The water flow path in the barrel is from bottom to top, and after filtering, it flows into the pressure-stabilizing water tank 4 from the side outlet. The filter barrel 3 is connected with a circulating water inlet 1, a second drain port 38 and an overflow port 40; a first solenoid valve 2 is arranged at the circulating water inlet 1, and a seventh solenoid valve 39 is arranged at the second drain port. The top of the water tank 4 is provided with an opening for flushing and ensuring the internal and external air pressure. A liquid sensor 41 is provided in the water tank 4. A first drain port 6 is provided on one side of the water tank 4, and the other side is connected to the oxygen cone 19 through a water pump 7. A second solenoid valve 5 is provided at the first drain port; the water pump 7 is connected to the oxygen cone 19 through a first branch 8, and the first branch 8 is connected to the oxygen cone 19 through a flange 18. A circulating water outlet 21 is provided on one side of the oxygen cone 19, and a sixth solenoid valve 20 is provided at the circulating water outlet 21. The circulating water outlet 21 can be connected to the live fish transport cabin. The circulating water with high dissolved oxygen content is secondary treated by the oxygen cone 19 to ensure that there are no large bubbles in the water in the breeding barrel, and to maintain a stable water environment required for the survival of fish. This design ensures that water rich in dissolved oxygen can be continuously circulated throughout the breeding cabin to meet the oxygen needs of all fish during transportation, especially when pressure and breathing needs increase.

[0039] The first branch 8 is provided with a diverting tee 9, a first pressure sensor 10, a third solenoid valve 11 and a converging tee 12 in sequence; a second branch 13 is connected between the diverting tee 9 and the converging tee 12, and the second branch 13 starts from the diverting tee 9 and is connected to the fourth solenoid valve 14, the second pressure sensor 15, the venturi ejector 16 and the fifth solenoid valve 17 in sequence, and then connected to the converging tee 12 and merged with the first branch 8. The first branch 8 and the second branch 13 are respectively controlled by the first pressure sensor 10 and the second pressure sensor 15 of the two branches to control the opening of the third solenoid valve 11, the fourth solenoid valve 4 and the fifth solenoid valve 17. According to the data feedback of the second pressure sensor 15, the fourth solenoid valve is adjusted to the optimal water pressure suitable for the venturi ejector, which is controlled at 0.6-0.8Mpa; the fifth solenoid valve 17 is a switch solenoid valve, which controls whether to use the second branch 13 pipe network through the fourth solenoid valve 4 and the fifth solenoid valve.

[0040] like Figure 2 and Figure 3As shown, the venturi ejector 16 is provided with a first check valve 161, which is connected to the second check valve 162 and the air inlet 167 in sequence; the first check valve 161 includes a first spring 163 and a first check plug 164; the second check valve 162 includes a second spring 165 and a second check plug 166. The double-layer check valve design plays a vital role in maintaining the efficiency and life of the oxygen generator, which can effectively prevent water from flowing back into the oxygen generator and ensure optimal oxygen injection. The mechanism of the double-layer check valve consists of two independent check valves, each of which has a single opening direction. This configuration ensures that the water flow remains unidirectional, preventing any backflow that may damage the internal components of the oxygen generator. By preventing water backflow, the double-layer check valve design ensures that the oxygen generator operates efficiently without any interruption or performance degradation. This uninterrupted operation helps to maintain a consistent and sufficient oxygen supply for the fish throughout the transportation process.

[0041] The circulating water filtration and oxygen mixing system is connected to the oxygen preparation and storage backup system through the venturi ejector 16. The oxygen preparation and storage backup system includes an oxygen generator 22, an oxygen cylinder 35 and an oxygen compressor 32. The oxygen generator 22, the oxygen cylinder 35, the oxygen compressor 32 and the venturi ejector 16 are all connected to the cross-shaped four-way 30. Among them, a first proportional solenoid valve 24 is provided between the gas outlet 23 of the oxygen generator 22 and the cross-shaped four-way 30. The oxygen cylinder 35 and the oxygen compressor 32 are connected to the cross-shaped four-way 30 through the fourth branch 28. The fourth branch 28 starts from the cross-way 30 and connects to the third proportional solenoid valve 27, the compressor air inlet 31, the oxygen compressor 32, the gas storage tank 33, the compressor air outlet 34, the three-way regulating valve 37, the fourth proportional solenoid valve 29, and then connects to the cross-way 30; the three-way regulating valve 37 is connected to the oxygen cylinder 35, and the outlet of the oxygen cylinder 35 is provided with a third pressure sensor 36; the venturi ejector 16 is connected to the cross-way 30 through the third branch 26, and the second proportional solenoid valve 25 is provided on the connecting pipeline. The branch between the oxygen generator 22 and the cross-way 30 is a direct output branch, and the fourth branch 28 is a backup loop branch. The direct output branch is responsible for injecting oxygen into the water through the venturi ejector, while the backup loop branch can compress and store excess oxygen for emergency use.

[0042] The oxygen preparation and storage backup system is set up in two modes: Mode 1 and Mode 2:

[0043] Mode 1 is: the dissolved oxygen content is measured by the circulating water outlet 21. When the set dissolved oxygen content is reached, the second proportional solenoid valve 25 and the third proportional solenoid valve 27 are PID-regulated and controlled. Under the condition of maintaining the dissolved oxygen concentration of the circulating water outlet, the excess oxygen is introduced into the oxygen compressor 32 through the pipe connected to the third proportional solenoid valve 27. The compressed oxygen is connected to the oxygen cylinder 35 through the compressor outlet 34, the air pipe and the three-way regulating valve 37; when the third pressure sensor 36 reaches 80% of the pressure storage rate set for the oxygen cylinder 35, the oxygen generator 22, the oxygen compressor 32, the first proportional solenoid valve 24 and the third proportional solenoid valve 27 are turned off, the outlet direction of the three-way regulating valve 37 is adjusted to be connected with the fourth proportional solenoid valve 29, the fourth proportional solenoid valve 29 is opened or the oxygen cylinder 35 is manually replaced in case of emergency.

[0044] Mode 2 is: when the oxygen generator 22 and the oxygen compressor 32 are under maintenance or power outage, the first proportional solenoid valve 24 and the third proportional solenoid valve 27 are closed, and the second proportional solenoid valve 25 and the fourth proportional solenoid valve 29 are opened to maintain the oxygen required by the system to ensure its stable and safe operation; when the remaining pressure of the oxygen cylinder 35 is 20% of the design standard, an alarm is issued to replace the oxygen cylinder 35 or switch to mode 1.

[0045] The method for using the filtration and oxygenation system of the ocean-going live fish transport ship of the present invention comprises the following steps:

[0046] Start the circulating water filtration system, open the first solenoid valve 2, and the circulating water flows into the filter barrel 3 for preliminary sediment filtration. The filtered water flows into the water tank 4 through the upper drain port to maintain the stability of the water pressure in the system;

[0047] The circulating water in the water tank 4 is pressurized by the water pump 7 to ensure that the flow rate and pressure of the water flow meet the operating conditions required by the oxygen cone 19. In this process, the water flow pressure is accurately controlled by adjusting the opening of the third solenoid valve 11 according to the real-time data of the first pressure sensor 10 and the second pressure sensor 15 to meet the oxygenation demand of the Venturi ejector 16; the fourth solenoid valve 14 and the fifth solenoid valve 17 are used to isolate the oxygenation part from the circulating water part when necessary to ensure that the system can be independently controlled according to actual needs;

[0048] The circulating water is fully mixed with oxygen in the venturi ejector 16, and then is subjected to secondary treatment through the oxygen cone 19 to ensure that the dissolved oxygen content in the water reaches the level required by the fish in the breeding tank; the sixth solenoid valve 20 is opened to inject the circulating water rich in dissolved oxygen into the fish tank to provide a suitable living environment for the fish;

[0049] In the oxygen production part, the oxygen generator 22 cooperates with the first proportional solenoid valve 24 and the second proportional solenoid valve 25 to introduce the generated oxygen into the venturi ejector 16 to meet the oxygen demand of the fish school;

[0050] When the dissolved oxygen content in the fish tank reaches the set concentration, the opening of the second proportional solenoid valve 25 is reduced, and the third proportional solenoid valve 27 is opened at the same time, and the excess oxygen is compressed by the oxygen compressor 32 and stored in the oxygen cylinder 35;

[0051] The third pressure sensor 36 is used to monitor the oxygen concentration in the oxygen cylinder 35. When the preset value is reached, the oxygen concentrator 22, the first proportional solenoid valve 24 and the third proportional solenoid valve 27 are turned off, and the fourth proportional solenoid valve 29 is opened at the same time, and the three-way regulating valve is adjusted to a state connected to the fourth proportional solenoid valve 29 to ensure that the oxygen cylinder 35 can supply gas stably, thereby extending the service life of the oxygen concentrator 22.

Claims

1. A filtration and oxygenation system for an ocean-going live fish transport ship, characterized in that: It includes a circulating water filtration and oxygen mixing system, an oxygen preparation and storage standby system, and the circulating water filtration and oxygen mixing system is connected to the oxygen preparation and storage standby system; the circulating water filtration and oxygen mixing system includes a filter barrel, a water tank and an oxygen cone connected in sequence, the filter barrel is connected to the circulating water inlet, a first branch and a second branch are connected between the water tank and the oxygen cone, a venturi ejector is connected to the second branch, and the venturi ejector is connected to the oxygen preparation and storage standby system; the oxygen preparation and storage standby system includes an oxygen concentrator, an oxygen cylinder and an oxygen compressor, and the oxygen concentrator, the oxygen cylinder, the oxygen compressor and the venturi ejector are all connected to a cross-way.

2. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 1, characterized in that: The first branch is provided with a flow-dividing tee, a first pressure sensor, a third solenoid valve and a flow-merging tee in sequence; the second branch is connected between the flow-dividing tee and the flow-merging tee.

3. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 2, characterized in that: The second branch starts from the diversion tee and is connected in sequence to the fourth solenoid valve, the second pressure sensor, the venturi ejector and the fifth solenoid valve, and then is connected to the converging tee to merge with the first branch. The venturi ejector is provided with a first check valve, and the first check valve is connected to the second check valve and the air inlet in sequence.

4. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 1, characterized in that: A liquid sensor is arranged in the water tank, a first drain port is arranged on one side of the water tank, and the other side of the water tank is connected with the oxygen cone through a water pump.

5. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 4, characterized in that: A circulating water outlet is arranged on one side of the oxygen cone, and a sixth solenoid valve is arranged at the circulating water outlet.

6. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 5, characterized in that: The oxygen cylinder and the oxygen compressor are connected to the cross-way through the fourth branch. The fourth branch starts from the cross-way and is connected in sequence to the third proportional solenoid valve, the compressor air inlet, the oxygen compressor, the gas storage tank, the compressor air outlet, the three-way regulating valve, the fourth proportional solenoid valve, and then connected to the cross-way. The oxygen cylinder is connected to the three-way regulating valve.

7. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 6, characterized in that: The venturi ejector is connected to the cross-way through a third branch, and a second proportional solenoid valve is arranged on the connecting pipeline.

8. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 7, characterized in that: A first proportional solenoid valve is arranged between the gas outlet and the cross-way of the oxygen concentrator.

9. The filtration and oxygenation system for ocean-going live fish transport vessels according to claim 8, characterized in that: The oxygen preparation and storage backup system is set to the following working mode: Mode 1: The dissolved oxygen content is measured at the circulating water outlet. When the set dissolved oxygen content is reached, the second proportional solenoid valve and the third proportional solenoid valve are PID-regulated and controlled. Under the condition of maintaining the dissolved oxygen concentration of the circulating water outlet, the excess oxygen is compressed by the oxygen compressor and then connected to the oxygen cylinder; when the pressure of the oxygen cylinder reaches 80% of the set pressure storage rate, the oxygen generator, oxygen compressor, first proportional solenoid valve and third proportional solenoid valve are turned off, the outlet direction of the three-way regulating valve is adjusted to be connected with the fourth proportional solenoid valve, and the fourth proportional solenoid valve is opened or the oxygen cylinder is manually replaced; Mode 2: When the oxygen generator and oxygen compressor are under maintenance or power outage, close the first proportional solenoid valve and the third proportional solenoid valve, and open the second proportional solenoid valve and the fourth proportional solenoid valve to maintain the oxygen required by the system; when the remaining pressure of the oxygen cylinder is lower than 20% of the design standard, replace the oxygen cylinder or switch to Mode 1.

10. A method for using the filtration and oxygenation system for a live fish transport vessel according to any one of claims 1 to 9, characterized in that: The following steps are involved: Start the circulating water filtration system, the circulating water flows into the filter barrel, and the filtered water flows into the water tank; Pressurize the circulating water in the water tank, adjust the opening of the third solenoid valve according to the real-time data of the first pressure sensor and the second pressure sensor, and control the water flow pressure; The circulating water is fully mixed with oxygen in the Venturi ejector, and then is treated twice by the oxygen cone, and the sixth solenoid valve is opened to inject the circulating water rich in dissolved oxygen into the fish tank; In the oxygen production part, the oxygen produced is introduced into the Venturi ejector through the oxygen generator in cooperation with the first proportional solenoid valve and the second proportional solenoid valve; When the dissolved oxygen content in the fish tank reaches the set concentration, the opening of the second proportional solenoid valve is reduced, and the third proportional solenoid valve is opened at the same time to store the excess oxygen in the oxygen cylinder; The third pressure sensor is used to monitor the oxygen concentration in the oxygen cylinder. When the preset value is reached, the oxygen generator, the first proportional solenoid valve and the third proportional solenoid valve are turned off, and the fourth proportional solenoid valve is opened at the same time, and the three-way regulating valve is connected to the fourth proportional solenoid valve to ensure the gas supply to the oxygen cylinder.

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