System and method for storing electrolyte electric energy in a cargo hold of a chemical tanker

Abstract

The present application belongs to the technical field of ships, and proposes a system and method for storing electrolyte in cargo holds of a chemical tanker to generate electric energy, which comprises an internal combustion engine power generation system, a flow battery power generation system, an electric propulsion system and an electrolyte filling system. The system of the present application stores electrolyte in the cargo holds of the chemical tanker, greatly improves the battery capacity of the flow battery, and can solve the problem of short endurance mileage of the flow battery in ship application. In addition, the present application applies the above-mentioned system and proposes an electric energy supply method, which reasonably allocates the electric energy supply of the internal combustion engine and the flow battery according to the electrolyte loading condition of the chemical tanker in different berthing ports, so as to maximize the reduction of environmental pollution caused by the burning of fossil fuels by the ship, and is more environmentally friendly.

Description

Technical Field

[0001] This invention belongs to the field of marine technology, specifically relating to a system and method for storing electrolyte electrical energy in cargo holds of a chemical tanker. Background Technology

[0002] Battery-powered ships have gradually gained widespread attention in the shipping industry due to their advantages such as zero emissions and low noise. Currently, battery-powered ships mainly use fuel cells or batteries.

[0003] However, battery-powered ships still have a significant shortcoming in terms of range compared to traditional fuel-powered ships: due to the large power of the ship's main engine and the limited capacity of traditional batteries, the range of battery-powered ships is greatly restricted, making them only suitable for short-distance voyages.

[0004] Flow batteries are high-performance rechargeable batteries that utilize separate positive and negative electrolytes, each circulating independently. The electrolyte is stored in an external container of the battery stack. During discharge, the positive and negative electrolytes are pumped back into the stack to undergo a redox reaction. The battery capacity of a flow battery is related to the volume of the electrolyte. The larger the volume of electrolyte stored on a ship, the greater the battery capacity and the significantly longer the ship's range. Therefore, ensuring a ship's range requires a significant amount of space, which most ships often lack the capacity to store large quantities of electrolyte. Furthermore, the electrolyte is corrosive, so ships must have separate corrosion-resistant tanks or compartments to store it.

[0005] Existing chemical tankers typically have numerous independent cargo holds. For example, a 49,000-ton chemical tanker built by Hudong-Zhonghua Shipbuilding Group has over 30 cargo holds. These tankers can usually carry multiple shipments simultaneously, which may need to be unloaded at different ports. Furthermore, the ship may need to load additional cargo at each port of call for transport to other ports. Therefore, chemical tankers often have multiple segments within a single voyage, requiring frequent port calls for loading and unloading. During these frequent loading and unloading processes, many empty cargo holds frequently appear on the ship. Since the inner walls of chemical tankers' cargo holds are usually coated with anti-corrosion coatings or stainless steel, and tank cleaning is required after unloading, these empty holds are ideal for storing electrolytes. Moreover, the cargo holds themselves are quite large, and using them to store electrolytes can significantly increase the ship's cruising range.

[0006] Based on this, for chemical tankers with a large number of cargo holds and the conditions for storing electrolyte, this paper proposes a system and method for storing electrolyte in cargo holds of chemical tankers, which makes reasonable use of the empty cargo holds after frequent port calls. When the ship is fully loaded, the internal combustion engine is used as the power source. When the ship is carrying electrolyte, the flow battery is used as the power source, and the internal combustion engine is used as a supplementary power source. This solves the problem of the large storage space required for flow batteries on ships and has very good practical application value. Summary of the Invention

[0007] The purpose of this invention is to address the above-mentioned problems by providing a system and method for storing electrolyte electrical energy in the cargo hold of a chemical tanker.

[0008] The first objective of this invention is to provide a system for chemical tankers to utilize the electrical energy stored in the cargo hold of an electrolyte, the system comprising an internal combustion engine power generation system, a flow battery power generation system, an electric propulsion system, and an electrolyte refueling system.

[0009] The internal combustion engine power generation system includes an internal combustion engine and an internal combustion engine generator.

[0010] The flow battery power generation system includes: a positive electrolyte chamber, a negative electrolyte chamber, a positive electrolyte supply valve, a positive electrolyte circulation pump, a stack unit, a positive reflux valve, a negative electrolyte supply valve, a negative electrolyte circulation pump, a negative reflux valve, and an inverter unit.

[0011] The electric propulsion system includes a propulsion motor and a propeller.

[0012] The electrolyte filling system includes: a supply pump, a positive electrode storage tank, a negative electrode storage tank, an unloading pump, and an electrolyte recovery tank.

[0013] In the internal combustion engine power generation system, the internal combustion engine is connected to the internal combustion engine generator via a drive shaft, and the internal combustion engine generator is connected to the ship's power grid via a line.

[0014] In the flow battery power generation system, the positive electrolyte tank is a cargo hold used to load the positive electrolyte after the chemical tanker has unloaded and cleaned its cargo at the unloading port. The positive electrolyte tank is connected in sequence to the positive supply valve, the positive electrolyte circulation pump, the positive electrode of the stack unit, and the positive return valve through pipelines to form a closed loop. There are multiple positive electrolyte tanks on the ship, and the multiple positive electrolyte tanks are connected in parallel with the positive electrode of the stack unit. Each positive electrolyte tank has a positive supply valve and a positive return valve at both ends. The negative electrolyte tank is a cargo hold used to load negative electrolyte after the chemical tanker has unloaded and cleaned its cargo at the unloading port. The negative electrolyte tank is connected in sequence to the negative electrolyte supply valve, the negative electrolyte circulation pump, the negative electrode of the fuel cell stack unit, and the negative electrolyte return valve through pipelines to form a closed loop. There are multiple negative electrolyte tanks on the ship, and the multiple negative electrolyte tanks are connected in parallel with the negative electrode of the fuel cell stack unit. Each negative electrolyte tank has a negative electrolyte supply valve and a negative electrolyte return valve at both ends.

[0015] The fuel cell stack unit is connected to the inverter unit via a line, and the inverter unit is connected to the ship's power grid via a line.

[0016] The number of positive and negative electrolyte tanks mentioned above is the same. The actual number is set according to the number of empty tanks after the chemical tanker unloads at the port of call and the required voyage distance, and a certain redundancy should be reserved.

[0017] In the electric propulsion system, one side of the propulsion motor is connected to the ship's power grid via a line, and the other side is connected to the propeller via a drive shaft.

[0018] In the electrolyte filling system, the positive electrode storage tank is connected in sequence to the supply pump and the positive electrode electrolyte chamber via pipelines, wherein the positive electrode storage tank is used to load the positive electrode electrolyte that has been fully charged on land; the negative electrode storage tank is connected in sequence to the supply pump and the negative electrode electrolyte chamber via pipelines, wherein the negative electrode storage tank is used to load the negative electrode electrolyte that has been fully charged on land.

[0019] The positive electrode electrolyte tank is connected in sequence to the unloading pump and the electrolyte recovery tank via pipelines; the negative electrode electrolyte tank is connected in sequence to the unloading pump and the electrolyte recovery tank via pipelines.

[0020] The aforementioned supply pump, positive electrode storage tank, negative electrode storage tank, unloading pump, and electrolyte recovery tank are all located at the unloading port.

[0021] The workflow of each subsystem in this invention is as follows:

[0022] In an internal combustion engine power generation system, the energy generated by the internal combustion engine burning fossil fuels drives an internal combustion engine generator to produce electricity, which is then fed into the ship's electrical grid. In a flow battery power generation system, the positive electrolyte in the positive electrolyte tank is fed into the stack unit by a positive electrolyte circulation pump for reaction. Simultaneously, the negative electrolyte in the negative electrolyte tank is fed into the stack unit by a negative electrolyte circulation pump for reaction. Inside the stack unit, the active materials in the positive and negative electrolytes undergo a redox reaction, generating electricity. The electricity generated by the stack unit is then inverted by an inverter unit before being fed into the ship's electrical grid. In an electric propulsion system, the propulsion motor generates mechanical energy from electricity provided by the ship's electrical grid, driving the propeller to rotate and thus providing power to the ship.

[0023] In the electrolyte filling system, when a ship calls at a port of call, the cargo or electrolyte in the cargo hold is unloaded onto land using the unloading pump. Then, the supply pump is used to send the fully charged electrolyte in the positive and negative electrode storage tanks into different empty cargo holds on the ship.

[0024] The second objective of this invention is to propose a method for chemical tankers to utilize the electrical energy stored in the cargo hold of electrolytes, based on the aforementioned system. The main objective of this method is to propose an electrical energy supply principle.

[0025] When a chemical tanker is transporting the same cargo, the vessel loads the cargo directly from the port of departure to the port of destination, without calling at other ports during the voyage. During the voyage from departure to destination, when the vessel is fully loaded, the internal combustion engine generator system provides power. When the vessel loads another cargo at the port of destination and continues to another port, and there are still empty cargo holds, an electrolyte filling system is used to fill the empty cargo holds with electrolyte. Upon re-departure, the flow battery generator system provides power. If the electricity generated by the flow battery is insufficient for the vessel's navigation needs, the internal combustion engine generator system supplements the required electrical energy.

[0026] When a chemical tanker transports cargo in multiple shipments, the vessel must call at intermediate ports during its voyage from the port of departure to the port of destination. When fully loaded, the vessel is powered by an internal combustion engine generator system. After unloading at a port of call, if empty cargo holds remain unloaded or after reloading, an electrolyte filling system is used to fill these empty holds with electrolyte. Upon re-departure, a flow battery generator system powers the vessel. If the electricity generated by the flow battery is insufficient for navigation, the internal combustion engine generator system supplements the required electrical energy.

[0027] Furthermore, during the voyage of a chemical tanker transporting different cargoes, if the flow battery's power is depleted or the power stored in the positive and negative electrolyte tanks is insufficient to sustain the ship's next leg of the voyage, and the ship does not need to use the electrolyte tanks for refueling at the upcoming port, then after docking, the ship uses the electrolyte refueling system to unload the discharged electrolyte from the tanks onto land, and then refuels with fully charged electrolyte. If the ship needs to use the electrolyte tanks for refueling at the upcoming port, then after docking, the ship uses the electrolyte refueling system to unload the electrolyte from the tanks onto land, and then refuels with cargo. When the ship sets sail again, the internal combustion engine generator system provides power to the ship.

[0028] The beneficial effects of this invention are:

[0029] 1. The present invention makes full use of the empty cargo holds on chemical tankers to store the positive and negative electrolytes of flow batteries. Since the cargo holds of chemical tankers have a large capacity, storing electrolytes in cargo holds can greatly increase the battery capacity of flow batteries, thereby greatly increasing the ship's cruising range.

[0030] 2. This invention utilizes the cargo holds of chemical tankers to store electrolytes, eliminating the need to construct separate electrolyte tanks on the ship with anti-corrosion coatings or stainless steel interior walls. This not only saves a significant amount of ship space but also eliminates the manufacturing costs of electrolyte tanks, resulting in excellent economic efficiency.

[0031] 3. The method of the present invention can rationally allocate the power supply of the internal combustion engine and the flow battery according to the electrolyte loading situation of the chemical tanker at different ports of call, so that the ship can use a more reasonable propulsion method to provide power in different voyages. This method not only has a very high degree of flexibility, but also minimizes the environmental pollution caused by the ship burning fossil fuels, making it more environmentally friendly. Attached Figure Description

[0032] Figure 1 This is a system diagram of the present invention;

[0033] Figure 2 This is a route map of a chemical tanker under different conditions in the method of this invention;

[0034] Figure 3 This is a schematic diagram of the cargo holds of a chemical tanker after loading and unloading at different ports in scenario 1.

[0035] Figure 4 This is a system diagram of a chemical tanker refueling with electrolyte at port A;

[0036] Figure 5 This is a schematic diagram showing how a chemical tanker uses flow batteries to generate electricity after it departs from port A.

[0037] Figure 6This is a system diagram of a chemical tanker refueling and electrolyte replacement at port D;

[0038] Figure 7 This is a schematic diagram of the cargo holds and electrolyte tanks of a chemical tanker after loading and unloading at different ports in scenario 2.

[0039] In the attached diagram: 1. Internal combustion engine; 2. Internal combustion engine generator; 3. Positive electrolyte tank; 4. Negative electrolyte tank; 5. Positive electrolyte supply valve; 6. Positive electrolyte circulation pump; 7. Fuel cell stack unit; 8. Positive return valve; 9. Negative electrolyte supply valve; 10. Negative electrolyte circulation pump; 11. Negative return valve; 12. Inverter unit; 13. Propulsion motor; 14. Propeller; 15. Supply pump; 16. Positive electrolyte storage tank; 17. Negative electrolyte storage tank; 18. Unloading pump; 19. Electrolyte recovery tank. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] like Figure 1 , Figure 4 and Figure 6 As shown, the system includes an internal combustion engine power generation system, a flow battery power generation system, an electric propulsion system, and an electrolyte filling system.

[0042] The internal combustion engine power generation system includes an internal combustion engine 1 and an internal combustion engine generator 2.

[0043] The flow battery power generation system includes: a positive electrolyte tank 3, a negative electrolyte tank 4, a positive electrolyte supply valve 5, a positive electrolyte circulation pump 6, a stack unit 7, a positive reflux valve 8, a negative electrolyte supply valve 9, a negative electrolyte circulation pump 10, a negative reflux valve 11, and an inverter unit 12.

[0044] The electric propulsion system includes a propulsion motor 13 and a propeller 14.

[0045] The electrolyte filling system includes: a supply pump 15, a positive electrode storage tank 16, a negative electrode storage tank 17, a discharge pump 18, and an electrolyte recovery tank 19.

[0046] In the internal combustion engine power generation system, the internal combustion engine 1 is connected to the internal combustion engine generator 2 via a drive shaft, and the internal combustion engine generator 2 is connected to the ship's power grid via a line.

[0047] In the flow battery power generation system, the positive electrolyte tank 3 is a cargo hold used to load the positive electrolyte after the chemical tanker has unloaded and cleaned its cargo at the unloading port. The positive electrolyte tank 3 is connected in sequence to the positive supply valve 5, the positive electrolyte circulation pump 6, the positive electrode of the stack unit 7, and the positive return valve 8 through pipelines to form a closed loop. Multiple positive electrolyte tanks 3 are provided on the ship, and multiple positive electrolyte tanks 3 are connected in parallel with the positive electrode of the stack unit 7. Each positive electrolyte tank 3 has a positive supply valve 5 and a positive return valve 8 at both ends. The negative electrolyte tank 4 is a cargo hold used to load negative electrolyte after the chemical tanker has unloaded and cleaned its cargo at the unloading port. The negative electrolyte tank 4 is connected in sequence to the negative electrolyte supply valve 9, the negative electrolyte circulation pump 10, the negative electrode of the fuel cell stack unit 7, and the negative electrolyte return valve 11 through pipelines to form a closed loop. Multiple negative electrolyte tanks 4 are provided on the ship. Multiple negative electrolyte tanks 4 are connected in parallel with the negative electrode of the fuel cell stack unit 7, and each negative electrolyte tank 4 has a negative electrolyte supply valve 9 and a negative electrolyte return valve 11 at both ends.

[0048] The fuel cell stack unit 7 is connected to the inverter unit 12 via a line, and the inverter unit 12 is connected to the ship's power grid via a line.

[0049] The number of positive electrolyte tank 3 and negative electrolyte tank 4 mentioned above is the same. Their actual number is set according to the number of empty tanks after the chemical tanker calls at the port of call and unloads the cargo, as well as the required voyage distance, and a certain redundancy should be reserved.

[0050] In the electric propulsion system, one side of the propulsion motor 13 is connected to the ship's power grid via a line, and the other side is connected to the propeller 14 via a drive shaft.

[0051] like Figure 4 and Figure 6 In the electrolyte filling system shown, the positive electrode storage tank 16 is connected in sequence to the supply pump 15 and the positive electrode electrolyte chamber 3 via pipelines. The positive electrode storage tank 16 is used to load the positive electrode electrolyte that has been fully charged on land. The negative electrode storage tank 17 is connected in sequence to the supply pump 15 and the negative electrode electrolyte chamber 4 via pipelines. The negative electrode storage tank 17 is used to load the negative electrode electrolyte that has been fully charged on land.

[0052] The positive electrode electrolyte tank 3 is connected in sequence to the unloading pump 18 and the electrolyte recovery tank 19 via pipelines; the negative electrode electrolyte tank 4 is connected in sequence to the unloading pump 18 and the electrolyte recovery tank 19 via pipelines.

[0053] The aforementioned supply pump 15, positive electrode storage tank 16, negative electrode storage tank 17, unloading pump 18, and electrolyte recovery tank 19 are all located at the unloading port.

[0054] The workflow of each subsystem in this invention is as follows:

[0055] like Figure 1 and Figure 6 As shown, in the internal combustion engine power generation system, the energy generated by the internal combustion engine 1 burning fossil fuel drives the internal combustion engine generator 2 to generate electricity, which is then fed into the ship's electrical grid. In the flow battery power generation system, the positive electrolyte in the positive electrolyte tank 3 is fed into the stack unit 7 for reaction by the positive electrolyte circulation pump 6. Simultaneously, the negative electrolyte in the negative electrolyte tank 4 is fed into the stack unit 7 for reaction by the negative electrolyte circulation pump 10. Inside the stack unit 7, the active substances in the positive and negative electrolytes can undergo oxidation-reduction reactions, thereby generating electricity. The electricity generated by the stack unit 7 is then inverted by the inverter unit 12 and fed into the ship's electrical grid. In the electric propulsion system, the propulsion motor 13 generates mechanical energy from the electricity provided by the ship's electrical grid, driving the propeller 14 to rotate, thus providing power to the ship.

[0056] In the electrolyte filling system, taking the example of a ship filling electrolyte at ports A and D as described in the following technical solution, such as... Figure 4 and Figure 6 As shown in the diagram, A and D represent ports A and D, respectively. When a ship calls at a port of discharge, the cargo or electrolyte in the cargo hold is unloaded onto land using the unloading pump 18. Figure 4 The unloading process is not shown in the figure, only the electrolyte filling process is shown. Then, the supply pump 15 is used to send the fully charged electrolyte in the positive electrode storage tank 16 and the negative electrode storage tank 17 into the empty compartments on the ship.

[0057] Traditional battery-propelled ships are limited by the finite capacity of batteries and the heavy load on the main engine, resulting in insufficient range and typically only suitable for short-distance voyages. This invention addresses the characteristics of chemical tankers, which have numerous cargo holds and frequently call at ports for loading and unloading. It rationally utilizes the empty cargo holds that appear after frequent port calls to store electrolyte. Since the cargo hold capacity itself is very large—for example, a 38,000-ton chemical tanker has 30 cargo holds with a total capacity of approximately 43,000 m³—this invention addresses the issue of large cargo hold capacity. 3 Its individual cargo hold can have a capacity of up to 1400m³. 3 Therefore, applying this invention to cargo ships such as chemical tankers can greatly increase the electrolyte storage volume of the ship, thereby significantly improving the ship's endurance and solving the problem of the large storage space required for flow batteries on ships.

[0058] In actual transportation, the transportation plan for chemical tankers is usually not fixed. A single chemical tanker may transport the same shipment in one voyage, such as... Figure 2As shown in scenario 1, the ship sails directly from the loading port to the unloading port, unloads the cargo directly at the unloading port, and then returns to the loading port along the original route, or loads another shipment at the unloading port and heads to the next port to complete the next cargo order.

[0059] Chemical tankers may also involve the transport of different cargoes in a single voyage. In such cases, a chemical tanker voyage will be divided into multiple segments, such as... Figure 2 As shown in scenario 2, ships need to frequently call at different ports of call to unload cargo. When a ship calls at an intermediate port, due to the different conditions at each port, after a shipment of cargo is unloaded at the port, the cargo hold that held that shipment may be idle and become an empty cargo hold, or it may be used to load another shipment of cargo and then transport it to another port.

[0060] To better understand this method, the following description addresses possible scenarios involving chemical tankers transporting the same or different cargoes, and provides specific examples:

[0061] like Figure 3 As shown, when the cargo transported by the chemical tanker is all cargo designated as "A-type," the vessel loads the cargo directly from the port of departure to the port of destination, without calling at any other ports during the voyage. During the voyage from departure to destination, i.e., when the vessel is fully loaded, the internal combustion engine power generation system provides power. Upon arrival at the port of destination and after unloading the cargo, the cargo holds are cleaned. After cleaning, an electrolyte filling system is used to fill the empty cargo holds with electrolyte. When the vessel sets sail again, a flow battery power generation system provides power. If the electricity generated by the flow battery is insufficient for the vessel's navigation needs, the internal combustion engine power generation system supplements the required electrical energy.

[0062] like Figure 7 As shown, when a chemical tanker transports cargo in different shipments, the ship loads cargo shipments a, b, c, d, and e at the port of departure. Assuming the ship calls at ports A, B, C, D, and E during its voyage from the port of departure to the port of destination, the loading and unloading details at each port are as follows:

[0063] The ship unloads cargo c at port A; at port B, it unloads cargo b and loads cargo f and g, with cargo f requiring 2 cargo holds and cargo g requiring 1 cargo hold; at port C, it unloads cargo a and cargo f and loads cargo h, with cargo h requiring 2 cargo holds; at port D, it does not unload any cargo and loads cargo i, with cargo i requiring 1 cargo hold; at port E, it unloads cargo h and loads cargo j and cargo k, with cargo j requiring 2 cargo holds and cargo k requiring 4 cargo holds; at the destination port, all cargo is unloaded, and the ship returns to the departure port empty.

[0064] When the ship is sailing from its port of departure to port A, i.e., when it is fully loaded, the internal combustion engine power generation system provides power to the ship. After the ship arrives at port A, the cargo of shipment C is unloaded onto land, and then the cargo holds that contained shipment C are washed. Subsequently, the electrolyte filling system is used to fill the empty cargo holds on the ship with electrolyte.

[0065] During the ship's voyage from port A to port B, the flow battery power generation system is used first to provide power. When the electricity generated by the flow battery is insufficient to meet the ship's navigation needs, the internal combustion engine power generation system is switched to supplement the ship's required electrical energy. After the ship arrives at port B, cargo shipment b is unloaded onto land first, and then cargo shipments f and g are loaded. Since these two shipments require a total of 3 cargo holds, but the ship only has 2 empty cargo holds at this time, the electrolyte in one of the electrolyte tanks on the ship is first transferred to the electrolyte recovery tank 19 on land using the unloading pump 18, and the electrolyte with less charge is unloaded first. Then, cargo shipments f and g are loaded into the cargo holds in sequence. In addition, due to the high power of the ship's main engine, a large amount of electrical energy is consumed during navigation. Therefore, when the ship arrives at port B, the power of the flow battery may have been exhausted or the power stored in the positive and negative electrolyte tanks may not be sufficient to sustain the ship for the next leg of the voyage. The ship needs to recharge the electrolyte at port B. This invention adopts a direct electrolyte replacement method, using an electrolyte filling system to unload the electrolyte in the electrolyte tank to land, and then transport the fully charged electrolyte on land to the electrolyte tank to ensure the ship's continued navigation.

[0066] During the ship's voyage from port B to port C, the flow battery power generation system is used first to provide power. When the electricity generated by the flow battery is insufficient for the ship's navigation needs, the internal combustion engine power generation system is switched to supplement the ship's required electrical energy. Upon arrival at port C, cargo shipments a and f are first unloaded onto land, and then cargo shipment h is loaded. Since there are 5 empty cargo holds remaining after unloading cargo shipment a, while cargo shipment h only occupies 2 cargo holds, after loading and unloading at port C, the electrolyte filling system is used to fill the remaining 3 empty cargo holds with electrolyte. Simultaneously, if the electrolyte in the ship's existing electrolyte tanks needs recharging, the electrolyte in the electrolyte tanks is unloaded onto land using the electrolyte filling system, and then the already fully charged electrolyte on land is transferred to the electrolyte tanks to ensure the ship's continued voyage.

[0067] During the ship's voyage from port C to port D, the flow battery power generation system is used first to provide power. When the electricity generated by the flow battery is insufficient for the ship's navigation needs, the internal combustion engine power generation system is switched to supplement the ship's required electrical energy. Upon arrival at port D, i shipments of cargo need to be loaded. Since there are no empty cargo holds at this time, the electrolyte in one of the ship's electrolyte tanks is first transferred to the electrolyte recovery tank 19 on land using the unloading pump 18, prioritizing the unloading of electrolyte with lower charge levels. Then, i shipments of cargo are loaded into the cargo holds. Simultaneously, if the electrolyte in the ship's existing electrolyte tanks needs recharging, the electrolyte in the electrolyte tanks is unloaded to land using the electrolyte refueling system. Then, the already fully charged electrolyte on land is transferred to the electrolyte tanks to ensure the ship's continued voyage.

[0068] During the ship's voyage from port D to port E, the flow battery power generation system is used first to provide power. When the electricity generated by the flow battery is insufficient for the ship's navigation needs, the internal combustion engine power generation system is switched to supplement the ship's required electrical energy. Upon arrival at port E, cargo shipment h is first unloaded onto land. Then, the unloading pump 18 is used to transfer all the electrolyte on board to the electrolyte recovery tank 19 on land. Next, cargo shipments j and k are loaded onto the ship in sequence. Finally, during the voyage from port E to the destination port, the ship sails fully loaded again, using the internal combustion engine power generation system to provide power. Upon arrival at the destination port, all cargo is unloaded onto land. Then, the electrolyte filling system is used to fill the empty cargo holds with electrolyte. When the ship returns from the destination port to the departure port, the flow battery power generation system is used to provide power. When the electricity generated by the flow battery is insufficient for the ship's navigation needs, the internal combustion engine power generation system is switched to supplement the ship's required electrical energy.

[0069] The present invention rationally allocates the power supply of the internal combustion engine 1 and the flow battery. When there are many empty compartments on the ship, electrolyte is directly added to the cargo hold, and then the flow battery is used to provide power to the ship. When there are few empty compartments on the ship or the flow battery is low on power, the internal combustion engine 1 is switched to provide power to the ship. This method not only has a very high degree of flexibility, but also minimizes the environmental pollution caused by the burning of fossil fuels on ships, making it more environmentally friendly.

[0070] Furthermore, when a ship calls at a port of call for unloading, the present invention allows for the replacement of the fully charged electrolyte on land with the discharged electrolyte on the ship. This not only quickly restores the ship's power, greatly shortens the charging time, and improves the ship's transportation efficiency, but also provides a more complete electrolyte waste gas treatment process on land compared to that on the ship, avoiding the pollution of the port environment caused by the waste gas emitted into the atmosphere during the electrolysis process of the electrolyte on the ship.

[0071] The above description is only a preferred embodiment of the present invention, but the implementation is not limited to the above embodiments. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A system for storing electrolyte electrical energy in a cargo hold of a chemical tanker, characterized in that: The system includes an internal combustion engine power generation system, a flow battery power generation system, an electric propulsion system, and an electrolyte refueling system. The internal combustion engine power generation system includes an internal combustion engine (1) and an internal combustion engine generator (2). The flow battery power generation system includes a positive electrolyte tank (3), a negative electrolyte tank (4), a positive electrolyte supply valve (5), a positive electrolyte circulation pump (6), a stack unit (7), a positive return valve (8), a negative electrolyte supply valve (9), a negative electrolyte circulation pump (10), a negative return valve (11), and an inverter unit (12). The electric propulsion system includes a propulsion motor (13) and a propeller (14). The electrolyte filling system includes a supply pump (15), a positive electrolyte storage tank (16), a negative electrolyte storage tank (17), an unloading pump (18), and an electrolyte recovery tank (19). The positive electrode electrolyte tank (3) is connected in sequence to the positive electrode supply valve (5), the positive electrode electrolyte circulation pump (6), the fuel cell stack unit (7), and the positive electrode reflux valve (8) via pipelines, forming a closed loop. The negative electrode electrolyte tank (4) is connected in sequence to the negative electrode supply valve (9), the negative electrode electrolyte circulation pump (10), the fuel cell stack unit (7), and the negative electrode reflux valve (11) via pipelines, forming a closed loop. The fuel cell stack unit (7) is connected to the inverter unit (12) via a line, and the inverter unit (12) is connected to the ship's electrical grid via a line. The internal combustion engine (1) is connected to the internal combustion engine generator (2) via a drive shaft, and the internal combustion engine generator (2) is connected to the ship's electrical grid via a line. The propulsion motor (13) is connected to the ship's electrical grid on one side via a line, and to the propeller (14) on the other side via a drive shaft. The positive electrode storage tank (16) is connected in sequence to the supply pump (15) and the positive electrode electrolyte tank (3) via pipelines, and the negative electrode storage tank (17) is connected in sequence to the supply pump (15) and the negative electrode electrolyte tank (4) via pipelines. The positive electrode electrolyte tank (3) is connected in sequence to the unloading pump (18) and the electrolyte recovery tank (19) via pipelines, and the negative electrode electrolyte tank (4) is connected in sequence to the unloading pump (18) and the electrolyte recovery tank (19) via pipelines.

2. A system for storing electrolyte electrical energy in a cargo hold of a chemical tanker according to claim 1, characterized in that: The positive electrode storage tank (16) is used to store the positive electrode electrolyte that has been fully charged on land, and the negative electrode storage tank (17) is used to store the negative electrode electrolyte that has been fully charged on land.

3. A system for storing electrolyte electrical energy in a cargo hold of a chemical tanker according to claim 1, characterized in that: The positive electrolyte tank (3) is a cargo hold used to load the positive electrolyte after the chemical tanker has unloaded and cleaned its cargo at the unloading port. The negative electrolyte tank (4) is a cargo hold used to load the negative electrolyte after the chemical tanker has unloaded and cleaned its cargo at the unloading port.

4. A system for storing electrolyte electrical energy in a cargo hold of a chemical tanker according to claim 1, characterized in that: The positive electrode electrolyte chamber (3) is connected to the positive electrode of the fuel cell unit (7), and the negative electrode electrolyte chamber (4) is connected to the negative electrode of the fuel cell unit (7).

5. A method for storing electrolyte electrical energy in a cargo hold of a chemical tanker based on the system of claim 1, characterized in that: When a chemical tanker is transporting the same cargo, during the voyage from the port of departure to the port of destination (when the ship is fully loaded), the internal combustion engine power generation system provides power. When the ship loads another cargo at the port of destination and continues to another port, and there are still empty cargo holds on board, an electrolyte filling system is used to fill the empty cargo holds with electrolyte. When the ship sets sail again, a flow battery power generation system provides power. If the electricity generated by the flow battery is insufficient for the ship's navigation needs, the internal combustion engine power generation system supplements the ship's required electrical energy. When a chemical tanker is transporting cargo from different shipments, the internal combustion engine power generation system provides power to the ship when it is fully loaded. When the ship completes unloading at the port of call, and there are still empty cargo holds after the empty cargo holds are reloaded, an electrolyte filling system is used to fill the empty cargo holds with electrolyte. When the ship sets sail again, a flow battery power generation system provides power to the ship. When the electricity generated by the flow battery is insufficient to meet the needs of the ship's navigation, the internal combustion engine power generation system supplements the ship's required electrical energy.

6. A method for storing electrolyte electrical energy in a cargo hold of a chemical tanker according to claim 5, characterized in that: During the voyage of a chemical tanker transporting different cargoes, if the flow battery's power is depleted or the power stored in the positive and negative electrolyte tanks is insufficient to sustain the ship for the next leg of the voyage, and the ship does not need to use the electrolyte tanks for refueling at the upcoming port, then after docking, the ship uses an electrolyte refueling system to unload the electrolyte from the electrolyte tanks onto land, and then transfers fully charged electrolyte to the electrolyte tanks. When a ship needs to use the electrolyte tank to refuel cargo at a port it is about to dock at, the ship will use the electrolyte refueling system to unload the electrolyte from the electrolyte tank onto land after docking, and then refuel the cargo. When the ship sets sail again, the internal combustion engine power generation system will be used to provide power to the ship.

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