A system for improving the thermal efficiency of a fuel cell auxiliary system of an underwater carrier platform

Abstract

The present application relates to a kind of systems for improving the thermal efficiency of underwater transport platform fuel cell auxiliary system, including water circulation pipeline consisting of fuel cell stack, alloy hydrogen storage tank assembly, circulating water tank and circulating water pump in series;Hot water delivery pipeline;And, oxygen inlet pipeline and hydrogen inlet pipeline;The water outlet of the circulating water tank is divided into two routes, one is connected with fuel cell stack, another is connected with hot water delivery pipeline;The hot water delivery pipeline includes heating water tank that can provide hot water to fuel cell stack, and heating device in heating water tank and heat release by chemical reaction.The present application provides suitable circulating hot water in the temperature range of fuel cell stack and alloy hydrogen storage tank assembly by chemical reaction of heating agent and water heat release for fuel cell system when cold start, high-power variable load and continuous high-power operation, without increasing power consumption, so that the efficiency of the whole system is improved by more than 10%.

Description

Technical Field

[0001] This invention relates to the field of underwater vehicle platform power system technology, and in particular to a system for improving the thermal efficiency of an underwater vehicle platform fuel cell auxiliary system. Background Technology

[0002] In recent years, to achieve the leap from deep-sea exploration to deep-sea development, large-capacity, deep-diving underwater transport platforms have become a necessary prerequisite. For such platforms, their endurance and operational time are closely related to the energy carrying capacity and efficiency of their propulsion system. Fuel cells, with their advantages in energy density and power generation efficiency, have made them a viable option for underwater transport platform propulsion. For underwater transport platforms weighing several hundred tons, to achieve strong operational capabilities and endurance, besides carrying large amounts of energy, one effective approach is to optimize the design of the waste heat and cold generated by various devices within the platform. This reduces the auxiliary power consumption of cooling or heating equipment, thereby improving the overall efficiency of the propulsion system.

[0003] In an underwater vehicle platform powered by fuel cells, the main equipment in the entire power system includes: fuel cell stack, alloy hydrogen storage tank assembly, liquid oxygen tank, plate heat exchanger, circulating water pump, water tank, etc. As a new type of electrochemical power generation device, the fuel cell stack directly converts chemical energy into electrical energy through the electrochemical reaction of hydrogen and oxygen, thereby continuously supplying power to the load. However, in addition to requiring a suitable operating temperature range, it does not convert all energy into electrical energy. Some energy is ultimately manifested as heat. Therefore, during normal operation, circulating water is needed to remove the heat generated by the fuel cell stack during normal operation.

[0004] For underwater transport platforms, the main factors affecting system power generation efficiency include the following:

[0005] First, when the fuel cell is started for the first time, the stack needs hot water at a certain temperature to ensure the performance and reliability of the stack. In addition, when the system is subjected to high power load changes or continuous high power operation, the alloy hydrogen storage tank assembly needs hot water at a higher temperature to release hydrogen required to match the high power operation.

[0006] Second, the fuel cell stack in the system generates a certain amount of heat during normal operation, which needs to be removed by cooling water.

[0007] Third, the alloy hydrogen storage tank assembly needs to absorb heat to release hydrogen, and the liquid oxygen vaporizer needs to be supplied with hot water to provide enough oxygen for the fuel cell stack.

[0008] Therefore, it is evident that proper design of the heat and cold sources of this platform can effectively improve the efficiency of the power system, thereby enhancing the operational capability and endurance of the underwater transport platform.

[0009] In view of the above, and considering the requirements of the underwater vehicle platform for circulating water temperature during cold start-up, the requirements of the alloy hydrogen storage tank assembly for circulating water temperature during high-power load changes, continuous high-power operation, and normal operation, as well as the requirements of the liquid oxygen vaporizer for circulating water temperature when vaporizing oxygen, this invention proposes a system to improve the thermal efficiency of the fuel cell auxiliary system of the underwater vehicle platform. Summary of the Invention

[0010] To address the shortcomings of the existing systems, the applicant provides a system that improves the thermal efficiency of the fuel cell auxiliary system for underwater vehicles. This system generates heat through a chemical reaction between a heating agent and water, providing circulating hot water within a suitable temperature range for the fuel cell stack and alloy hydrogen storage tank components during cold starts, high-power load changes, and continuous high-power operation, without increasing electrical energy consumption.

[0011] The technical solution adopted in this invention is as follows:

[0012] A system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater vehicle platform, comprising:

[0013] A water circulation pipeline consisting of a fuel cell stack, an alloy hydrogen storage tank assembly, a circulating water tank, and a circulating water pump connected in series.

[0014] Hot water delivery pipelines that supply hot water to fuel cell stacks;

[0015] And, oxygen inlet lines and hydrogen inlet lines for supplying hydrogen and oxygen to the fuel cell stack for chemical reactions;

[0016] The outlet of the circulating water tank is divided into two paths: one path is directly connected to the fuel cell stack through the control of the circulating water solenoid valve, and the other path is connected to the hot water delivery pipeline through the control of the connecting solenoid valve.

[0017] The hot water delivery pipeline includes a heating tank capable of supplying hot water to the fuel cell stack, and a heating device installed in the heating tank that releases heat through a chemical reaction.

[0018] The alloy hydrogen storage tank assembly is connected to the circulating water tank via a second temperature-controlled three-way valve, which is also connected to a plate heat exchanger. The plate heat exchanger is connected to the circulating water tank and is also connected to both ends of the liquid oxygen vaporizer via a pipeline, so that the low-temperature fresh water cooled by the liquid oxygen vaporizer can exchange heat with the high-temperature water generated by the reaction of the fuel cell stack.

[0019] Its further features are:

[0020] The alloy hydrogen storage tank assembly includes multiple alloy hydrogen storage tanks connected in parallel.

[0021] A freshwater pump is installed on the connecting pipeline of the liquid oxygen vaporizer. The freshwater pump is used to draw freshwater. At the same time, a first temperature-controlled three-way valve is also installed on the connecting pipeline to control whether freshwater needs to be added according to the temperature.

[0022] The heating device heats the water tank by chemically reacting with a certain amount of water in the water tank. The heating device includes at least one heating chamber placed inside the water tank, and the heating chamber is filled with a heating agent. The heating chamber is connected to the water tank through a connecting pipe, and the opening and closing of the connecting pipe is controlled by a reaction control solenoid valve.

[0023] The heating agent is mainly composed of quicklime, sodium carbonate, iron powder, activated carbon and other substances.

[0024] The heating chamber is equipped with a lower plug and a quick connector on the connecting pipe. The upper end of the heating chamber has a feed port for adding heating agent, and an upper plug is provided at the feed port. A one-way valve is threaded onto the upper plug.

[0025] The heating water tank is equipped with a temperature sensor, a pressure sensor, a safety valve, and a first shut-off valve. A heating device solenoid valve is also connected to the outlet pipe of the heating water tank, and the outflow rate of hot water is controlled by the heating device solenoid valve.

[0026] The oxygen inlet pipeline includes a liquid oxygen storage tank and a liquid oxygen vaporizer connected in series on the fuel cell stack, and is equipped with an oxygen inlet explosion-proof solenoid valve and an oxygen inlet pressure reducing and stabilizing valve to control the pipeline pressure.

[0027] The hydrogen inlet pipeline includes multiple alloy hydrogen storage tanks connected in parallel, and each alloy hydrogen storage tank is equipped with a second shut-off valve for control. In addition, the hydrogen inlet pipeline is also equipped with a hydrogen inlet explosion-proof solenoid valve and a hydrogen inlet pressure reducing and stabilizing valve to control the pipeline pressure.

[0028] The beneficial effects of this invention are as follows:

[0029] This invention features a compact and rational structure, and is easy to operate. It utilizes the heat released from the chemical reaction between the heating agent and water to provide circulating hot water within a suitable temperature range for the fuel cell stack and alloy hydrogen storage tank assembly during cold starts, high-power load changes, and continuous high-power operation, without increasing electrical energy consumption. Based on the heat absorption and hydrogen release characteristics of the alloy hydrogen storage tank assembly, it effectively utilizes the waste heat generated during normal operation of the fuel cell stack. The cooling energy of liquid oxygen is used to cool the water in the low-temperature freshwater circulation pipeline, thereby better achieving heat exchange between the high-temperature and low-temperature freshwater circulation. The entire system fully utilizes cooling energy and waste heat without increasing electrical energy consumption, thus improving the overall system efficiency by more than 10%.

[0030] In addition, the present invention also has the following advantages:

[0031] 1. Heating is achieved through a controlled reaction between the heating agent and water. Because it is a one-time heating process, the heating agent occupies a small volume. The heating agent reacts with water to heat up rapidly, resulting in high heating efficiency and faster startup of the fuel cell stack. At the same time, it avoids the auxiliary power consumption generated by using electric heaters, greatly improving the working efficiency of the underwater transport platform. It is also more energy-efficient, reduces volume, and has strong practicality.

[0032] 2. This system fully considers the heat absorption and hydrogen release characteristics of the alloy hydrogen storage tank assembly, as well as the cooling capacity of liquid oxygen. By directly heating the alloy hydrogen storage tank assembly with the heat generated by the fuel cell stack, the system configuration is simplified, the temperature difference of heat exchange in multi-stage heat exchange is reduced, and the heat exchange efficiency is improved. It also effectively utilizes the waste heat generated during the normal operation of the fuel cell stack. There is no need for the system to provide heating water pipelines for the alloy hydrogen storage tank assembly, which not only improves the system efficiency but also simplifies the system configuration.

[0033] 3. Since the alloy hydrogen storage tank assembly needs to absorb a large amount of heat in a short time to ensure a stable supply of hydrogen at high power, a heating water tank is used to provide the alloy hydrogen storage tank assembly with the required circulating hot water by means of chemical reaction heating during high power loading and continuous high power operation, which effectively improves the system's response capability.

[0034] 4. When the underwater transport platform is running stably under a certain operating condition, the liquid oxygen vaporizer is placed in the fresh water circulation pipeline. The cooling capacity of the liquid oxygen in the liquid oxygen vaporizer is used to cool the low-temperature fresh water outlet temperature of the plate heat exchanger, which effectively reduces the cooling capacity of the system to external circulating water.

[0035] 5. By using a circulating water solenoid valve, the heating water tank pipeline can be bypassed according to the different heating water requirements of the underwater transport platform under different working conditions, so that the system efficiency can always be kept at a high level.

[0036] 6. This system is equipped with a heating water tank, which contains a heating chamber. The heating chamber contains a heating agent and can automatically control the opening and closing of the reaction control solenoid valve according to the temperature required by the pure water in the system. This allows water to enter the heating chamber, where a chemical reaction occurs and heat is released, thereby heating the water in the heating water tank and improving heating efficiency. At the same time, it avoids the need for additional power supply for heating, which meets the requirement that it is inconvenient to carry power supply equipment on underwater transport platforms.

[0037] 7. This system employs a second temperature-controlled three-way valve, which automatically distributes the high-temperature pure water from the alloy hydrogen storage tank assembly into and around the plate heat exchanger according to the set temperature range. This avoids excessive temperature fluctuations caused by all the high-temperature pure water entering the plate heat exchanger for cooling, and effectively improves the system's thermal efficiency. At the same time, a first temperature-controlled three-way valve is also employed, which allows the amount of low-temperature fresh water supplied from the outside to be controlled according to the cooling capacity provided by the liquid oxygen vaporizer, effectively improving the system's thermal efficiency. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the system of the present invention.

[0039] The components include: 1. Temperature sensor; 2. Pressure sensor; 3. Check valve; 4. Safety valve; 5. Heating water tank; 6. Upper plug; 7. Heating chamber; 8. Heating agent; 9. Lower plug; 10. Quick connector; 11. First shut-off valve; 12. Reaction control solenoid valve; 13. Heating device solenoid valve; 14. Circulating water solenoid valve; 15. Connecting solenoid valve; 16. Circulating water tank; 17. Fresh water pump; 18. First temperature-controlled three-way valve; 19. Liquid oxygen vaporizer; 20. Plate heat exchanger; 21. Second temperature-controlled three-way valve; 22. Oxygen inlet explosion-proof solenoid valve; 23. Alloy hydrogen storage tank assembly; 24. Oxygen inlet pressure reducing and stabilizing valve; 25. Second shut-off valve; 26. Hydrogen inlet explosion-proof solenoid valve; 27. Hydrogen inlet pressure reducing and stabilizing valve; 28. Fuel cell stack; 29. ​​Circulating water pump; 30. Liquid oxygen storage tank.

[0040] A. Water circulation pipeline; B. Hot water delivery pipeline; C. Oxygen inlet pipeline; D. Hydrogen inlet pipeline. Detailed Implementation

[0041] The specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0042] like Figure 1 As shown, this embodiment discloses a system for improving the thermal efficiency of an auxiliary fuel cell system for an underwater vehicle platform. The system includes a water circulation pipeline A, which is composed of a fuel cell stack 28, an alloy hydrogen storage tank assembly 23, and a circulating water tank 16 connected in series; a hot water delivery pipeline B for supplying hot water to the fuel cell stack 28; and an oxygen inlet pipeline C and a hydrogen inlet pipeline D for supplying hydrogen and oxygen to the fuel cell stack 28 for chemical reactions. The water circulation pipeline A also includes a circulating water pump 29 for pumping water into the fuel cell stack 28, thus achieving water circulation.

[0043] The alloy hydrogen storage tank assembly 23 includes multiple alloy hydrogen storage tanks connected in parallel; at the same time, the connection pipeline between the alloy hydrogen storage tank assembly 23 and the circulating water tank 16 is also connected to the high-temperature side of the plate heat exchanger 20 through a second temperature-controlled three-way valve 21. The plate heat exchanger 20 is also connected to the circulating water tank 16. The second temperature-controlled three-way valve 21 controls whether to connect to the plate heat exchanger 20 for heat exchange through temperature control.

[0044] In addition, the low-temperature side of the plate heat exchanger 20 is connected to both ends of the liquid oxygen vaporizer 19. The low-temperature fresh water cooled by liquid oxygen in the liquid oxygen vaporizer 19 exchanges heat with the high-temperature water generated by the reaction of the fuel cell stack 28 in the plate heat exchanger 20 to cool it down. The high-temperature water generated by the reaction of the fuel cell stack 28 is also heated by the water temperature connected to the liquid oxygen vaporizer 19 to improve the oxygen release efficiency.

[0045] A fresh water pump 17 is installed on the connecting pipe of the liquid oxygen vaporizer 19. The fresh water pump 17 is used to draw fresh water. At the same time, a first temperature-controlled three-way valve 18 is also installed on the connecting pipe to control whether fresh water needs to be added according to the temperature.

[0046] The outlet of the circulating water tank 16 is divided into two paths. One path is directly connected to the fuel cell stack 28 through the circulating water solenoid valve 14, and the other path is connected to the hot water delivery pipeline B through the connecting solenoid valve 15. After being heated, it is then connected to the fuel cell stack 28.

[0047] The hot water delivery pipeline B includes a heating tank 5 capable of supplying hot water to the fuel cell stack 28, and a heating device installed in the heating tank 5;

[0048] The heating device includes at least one heating chamber 7 placed inside a heating water tank 5. A heating agent 8 is placed inside the heating chamber 7. The heating agent 8 is mainly composed of quicklime, sodium carbonate, iron powder, activated carbon, and other substances. The heating chamber 7 is connected to the heating water tank 5 via a connecting pipe. The opening and closing of this connecting pipe is controlled by a reaction-controlled solenoid valve 12. A lower plug 9 is installed on the heating chamber 7, and a quick connector 10 is also provided on the connecting pipe to facilitate the replacement of the heating agent 8 in the heating chamber 7 after each task. In this embodiment, heating is achieved through a controlled reaction between the heating agent 8 and water. Because it is a one-time heating process, the heating agent 8 occupies a small volume. The heating agent 8 reacts rapidly with water to raise the temperature, resulting in high heating efficiency and faster startup of the fuel cell stack 28. It also avoids the auxiliary power consumption generated by using an electric heater, greatly improving the working efficiency of the underwater transport platform. Furthermore, it is more energy-efficient, reduces volume, and has strong practicality.

[0049] The heating water tank 5 is equipped with a temperature sensor 1, a pressure sensor 2, a safety valve 4, and a first shut-off valve 11 to improve the safety and visibility of the heating water tank 5, monitor the pressure and temperature of the heating water tank 5, control the pressure of the heating water tank 5 with the safety valve 4, and release water from the heating water tank 5 with the first shut-off valve 11. The upper end of the heating chamber 7 is provided with an inlet for adding heating agent 8, and an upper plug 6 is provided at the inlet. A one-way valve 3 is threaded on the upper plug 6 to facilitate pressure relief and prevent the pressure in the heating chamber 7 from being too high.

[0050] Meanwhile, a heating device solenoid valve 13 is also connected to the water outlet pipe of the heating water tank 5, which controls the flow rate of hot water.

[0051] The oxygen inlet pipeline C includes a liquid oxygen storage tank 30 and a liquid oxygen vaporizer 19 connected in series on the fuel cell stack 28. An oxygen inlet explosion-proof solenoid valve 22 and an oxygen inlet pressure reducing and stabilizing valve 24 are installed on the oxygen inlet pipeline C to control the pipeline pressure.

[0052] The hydrogen inlet pipeline D includes multiple alloy hydrogen storage tanks connected in parallel, and each alloy hydrogen storage tank is equipped with a second shut-off valve 25 for control. In addition, the hydrogen inlet pipeline D is also equipped with a hydrogen inlet explosion-proof solenoid valve 26 and a hydrogen inlet pressure reducing and stabilizing valve 27 to control the pipeline pressure.

[0053] For ease of understanding, the following structure is explained:

[0054] The heating water tank 5 is a device that heats water through a chemical reaction. It has a heating chamber 7 inside, in which a heating agent 8 is placed. The solenoid valve 12 can be automatically controlled to open and close according to the temperature required by the pure water in the system, so that water enters the heating chamber 7 and reacts with the heating agent 8 to release heat, thereby heating the water in the heating water tank 5.

[0055] The reaction control solenoid valve 12 is used to control the connection or disconnection of the heating agent 8 and the water pipeline.

[0056] The heating device solenoid valve 13 is used to control the connection or disconnection of the heating device's pipeline.

[0057] The circulating water solenoid valve 14 is used to control whether the pipeline between the circulating water tank 16 and the fuel cell stack 28 is directly connected.

[0058] The solenoid valve 15 is used to control whether the pipeline between the circulating water tank 16 and the heating device is directly connected;

[0059] The circulating water tank 16 is used to store the pure water required by the system and maintain stable pressure.

[0060] Freshwater pump 17 is used to provide water pressure for low-temperature freshwater pipelines.

[0061] The first temperature-controlled three-way valve 18 and the second temperature-controlled three-way valve 21 are valves with three pipeline interfaces, which can have one inlet and two outlets or two inlets and one outlet.

[0062] The liquid oxygen vaporizer 19 heats the low-temperature liquid oxygen flowing through it with fresh water, while simultaneously using the cooling energy of the liquid oxygen to lower the temperature of the low-temperature fresh water.

[0063] Alloy hydrogen storage tank assembly 23 is a device for storing hydrogen. Under normal circumstances, hydrogen exists in the alloy in atomic form. When hot circulating water is introduced into the alloy hydrogen storage tank assembly 23, hydrogen is released by heating.

[0064] The fuel cell stack 28 is an electrochemical power generation device that directly converts chemical energy into electrical energy through an electrochemical reaction between hydrogen and oxygen. To maintain its performance, it is necessary to continuously circulate cooling water to remove the waste heat generated.

[0065] Liquid oxygen storage tank 30 is a high-vacuum double-walled insulated container used to store cryogenic liquid oxygen.

[0066] Oxygen inlet explosion-proof solenoid valve 22 and hydrogen inlet explosion-proof solenoid valve 26 are used to connect or disconnect hydrogen and oxygen pipelines.

[0067] Workflow

[0068] By chemically reacting the heating agent 8 with water, the water in the heating water tank 5 is heated to a certain temperature. This allows the fuel cell system to provide hot water within a suitable temperature range for the fuel cell stack 28 and the alloy hydrogen storage tank assembly 23 during cold starts, high-power load changes, and continuous high-power operation, without increasing additional power consumption. The alloy hydrogen storage tank assembly 23 is connected in series with the cooling water pipeline of the fuel cell stack 28. Based on its heat absorption and hydrogen release characteristics, the waste heat generated during the normal operation of the fuel cell stack 28 is effectively utilized. The cooling capacity of the liquid oxygen in the liquid oxygen vaporizer 19 is used to cool the low-temperature fresh water outlet temperature of the plate heat exchanger 20, effectively reducing the cooling requirements of the external circulating water in this system, thereby improving the efficiency of the entire system by more than 10%.

[0069] This embodiment performs different control adjustments based on different states:

[0070] 1) Heating during cold start

[0071] When the underwater transport platform starts up cold, the circulating water required for the fuel cell stack 28 and the alloy hydrogen storage tank assembly 23 needs to be heated to a certain temperature to effectively reduce the start-up time and improve the dynamic response. Therefore, the reaction control solenoid valve 12 is opened according to the system control. The water in the heating water tank 5 enters the heating chamber 7 through the reaction control solenoid valve 12 and the quick connector 10, and reacts chemically with the heating agent 8 therein to release heat, thereby heating the water in the heating water tank 5. The heated water enters the fuel cell stack 28 and the alloy hydrogen storage tank assembly 23 through the heating device solenoid valve 13 and the circulating water pump 29, thereby heating the system during cold start. The configuration of the heating agent 8 meets the heating requirements of a single mission.

[0072] 2) Heating of alloy hydrogen storage tank assembly 23 during variable load and high power operation

[0073] When the underwater transport platform needs to be loaded or is running at high power continuously, the temperature of the circulating water flowing through the alloy hydrogen storage tank assembly 23 cannot rise in time, affecting the system's response capability. At this time, the reaction control solenoid valve 12 opens according to the system control, and the water in the heating water tank 5 enters the heating chamber 7 through the reaction control solenoid valve 12 and the quick connector 10. It reacts chemically with the heating agent 8 in the chamber to release heat, thereby heating the water in the heating water tank 5. The heated water passes through the heating device solenoid valve 13, the circulating water pump 29, and the fuel cell stack 28, and finally heats the alloy hydrogen storage tank assembly 23. The hydrogen produced by the heated alloy hydrogen storage tank assembly 23 passes through the second shut-off valve 25, and after being reduced and stabilized by the hydrogen inlet pressure reducing and stabilizing valve 27, it enters the fuel cell stack 28 through the hydrogen inlet explosion-proof solenoid valve 26, ensuring that the alloy hydrogen storage tank assembly 23 can release hydrogen that matches the corresponding power instantly, effectively improving the system's response capability.

[0074] 3) Under stable operating conditions, the alloy hydrogen storage tank assembly 23 recovers and utilizes the waste heat from the fuel cell stack 28.

[0075] When the underwater transport platform is running stably at a certain low power, the solenoid valve 15 is de-energized and closed, and the circulating water solenoid valve 14 is energized and opened, thereby bypassing the heating water tank 5. The pure water in the system is pressurized by the circulating water pump 29 to cool the fuel cell stack 28. The cooling water that has absorbed the waste heat of the fuel cell stack 28 flows into the alloy hydrogen storage tank assembly 23 to heat it. This effectively utilizes the waste heat generated during the normal operation of the fuel cell stack 28, eliminating the need for the system to provide heating water pipelines for the alloy hydrogen storage tank assembly 23. This not only improves efficiency but also simplifies the system configuration.

[0076] 4) Recover and utilize the cooling energy of the liquid oxygen vaporizer

[0077] When the underwater transport platform is running at a stable power, the entire low-temperature freshwater circulation pipeline exchanges heat with the high-temperature pure water circulation pipeline where the fuel cell stack 28 is located. Therefore, the temperature of the low-temperature freshwater in the freshwater pipeline rises to a certain extent after passing through the freshwater pump 17 and the plate heat exchanger 20. The cooling capacity of the liquid oxygen in the liquid oxygen vaporizer 19 is used to cool the freshwater outlet temperature of the plate heat exchanger 20, effectively reducing the cooling capacity of the system to external circulating water. At the same time, the low-temperature freshwater with the increased temperature will flow from the liquid oxygen storage tank 30 to the liquid oxygen vaporizer 19 to vaporize the liquid oxygen. After the vaporized oxygen is depressurized and stabilized by the oxygen inlet pressure reducing and stabilizing valve 24, it enters the fuel cell stack 28 through the oxygen inlet explosion-proof solenoid valve 22 and reacts with the hydrogen that enters at the same time.

[0078] 5) Automatic water distribution reduces heat loss.

[0079] In the pure water pipeline, when the temperature of the pure water coming out of the alloy hydrogen storage tank assembly 23 exceeds the set temperature range, the second temperature-controlled three-way valve 21 adjusts to reduce the amount of pure water directly entering the circulating water tank 16 and increase the amount of pure water entering the plate heat exchanger 20. When the temperature of the pure water coming out of the alloy hydrogen storage tank assembly 23 is lower than the set temperature range, the second temperature-controlled three-way valve 21 adjusts to increase the amount of pure water directly entering the circulating water tank 16 and reduce the amount of pure water entering the plate heat exchanger 20. This automatically distributes high-temperature pure water, preventing all high-temperature pure water from entering the plate heat exchanger 20 and reducing heat loss.

[0080] In the low-temperature freshwater pipeline, the first temperature-controlled three-way valve 18 enables the supply of low-temperature freshwater from the outside to be controlled according to the cooling capacity provided by the liquid oxygen vaporizer 19, thereby effectively improving the thermal efficiency of the system.

[0081] In summary, the present invention has the following advantages:

[0082] 1. This system fully considers the heat absorption and hydrogen release characteristics of the alloy hydrogen storage tank assembly 23, as well as the cooling capacity of liquid oxygen. The method of directly heating the alloy hydrogen storage tank assembly 23 with the heat generated by the fuel cell stack 28 not only simplifies the system configuration and reduces the heat exchange temperature difference of multi-stage heat exchange, thus improving the heat exchange efficiency, but also effectively utilizes the waste heat generated by the normal operation of the fuel cell stack 28. There is no need for the system to provide heating water pipelines for the alloy hydrogen storage tank assembly 23, which not only improves the system efficiency but also simplifies the system configuration.

[0083] 2. The heating water tank 5 uses a chemical reaction heating method to provide circulating water at a certain temperature required for the cold start of the system, which is necessary for the fuel cell stack 28 and the alloy hydrogen storage tank assembly 23. This avoids the use of traditional electric heating methods and effectively reduces the power consumption of the platform's auxiliary equipment.

[0084] 3. Since the alloy hydrogen storage tank assembly 23 needs to absorb a large amount of heat in a short time to ensure a stable supply of hydrogen when the power is high, the heating water tank 5 is used to provide the alloy hydrogen storage tank assembly 23 with the required circulating hot water by heating through chemical reaction when the system is under high power loading and continuous high power operation, which effectively improves the system's response capability.

[0085] 4. When the underwater transport platform is running stably under a certain working condition, the liquid oxygen vaporizer 19 is placed in the fresh water circulation pipeline. The cooling capacity of the liquid oxygen in the liquid oxygen vaporizer 19 is used to cool the low-temperature fresh water outlet temperature of the plate heat exchanger 20, which effectively reduces the cooling capacity of the system to external circulating water.

[0086] 5. By using the circulating water solenoid valve 14, the pipeline of the heating water tank 5 can be bypassed according to the different heating water requirements of the underwater transport platform under different working conditions, so that the efficiency of the system can always be kept at a high level.

[0087] 6. This system is equipped with a heating water tank 5, which contains a heating chamber 7. The heating chamber 7 contains a heating agent 8. The system can automatically control the opening and closing of the reaction control solenoid valve 12 according to the temperature required by the pure water in the system, so that the water enters the heating chamber 7 and undergoes a chemical reaction to release heat, thereby heating the water in the heating water tank 5, improving heating efficiency, and avoiding the need for additional power supply for heating, which meets the requirement that it is inconvenient to carry power supply equipment on the underwater transport platform.

[0088] 7. The system employs a second temperature-controlled three-way valve 21, which automatically distributes the amount of high-temperature pure water from the alloy hydrogen storage tank assembly 23 into and through the plate heat exchanger 20 according to the set temperature range. This avoids excessive temperature changes caused by all the high-temperature pure water entering the plate heat exchanger 20 for cooling, and effectively improves the thermal efficiency of the system.

[0089] 8. The system uses a first temperature-controlled three-way valve 18, which enables the amount of low-temperature fresh water supplied from the outside to be controlled according to the cooling capacity provided by the liquid oxygen vaporizer 19, effectively improving the thermal efficiency of the system.

[0090] This invention utilizes the exothermic effect of a chemical reaction to provide hot water within a suitable temperature range for the fuel cell stack 28 and the alloy hydrogen storage tank assembly 23 during cold starts, high-power load changes, and continuous high-power operation, thus avoiding the auxiliary power consumption associated with electric heaters. Based on the heat absorption and hydrogen release characteristics of the alloy hydrogen storage tank assembly 23, it is connected in series in the cooling water pipeline of the fuel cell stack 28. This method, where the heat generated by the fuel cell stack 28 directly heats the alloy hydrogen storage tank assembly 23, simplifies the system, effectively reduces the temperature difference in multi-stage heat exchange, and effectively utilizes the waste heat generated during the normal operation of the fuel cell stack 28 (as shown by the outlet of the fuel cell stack 28). Taking a circulating water temperature of 65℃ as an example, if the alloy hydrogen storage tank assembly 23 is directly connected in series with the cooling water pipeline of the fuel cell stack 28, it is equivalent to the 65℃ water directly heating the alloy hydrogen storage tank assembly 23. However, if the fuel cell stack 28 is connected in parallel with the alloy hydrogen storage tank assembly 23 through a plate heat exchanger 20, the high-temperature side of the plate heat exchanger 20 is the circulating water of the fuel cell stack 28, and the low-temperature side is the circulating water of the alloy hydrogen storage tank assembly 23. In this case, due to the additional plate heat exchanger 20, there is at least a heat exchange temperature difference of 15-20℃. That is to say, the outlet circulating water temperature of the fuel cell stack 28 is also 65℃, but the temperature of the water flowing into the alloy hydrogen storage tank assembly 23 in this way is only about 45℃.

[0091] By utilizing the cooling capacity of the liquid oxygen in the liquid oxygen vaporizer 19, the low-temperature freshwater outlet temperature of the plate heat exchanger 20 is cooled, effectively reducing the cooling capacity requirement of the external circulating water in this system.

[0092] The above description is an explanation of the present invention and not a limitation thereof. The scope of the present invention is defined by the claims. Within the scope of protection of the present invention, any form of modification may be made.

Claims

1. A system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater transport platform, characterized in that: include: A water circulation pipeline (A) is composed of a fuel cell stack (28), an alloy hydrogen storage tank assembly (23), a circulating water tank (16), and a circulating water pump (29) connected in series. Hot water delivery line (B) for supplying hot water to fuel cell stack (28) and alloy hydrogen storage tank assembly (23); In addition, oxygen inlet line (C) and hydrogen inlet line (D) are used to supply hydrogen and oxygen to the fuel cell stack (28) for chemical reactions. The outlet of the circulating water tank (16) is divided into two paths. One path is directly connected to the fuel cell stack (28) through the circulating water solenoid valve (14), and the other path is connected to the hot water delivery pipeline (B) through the connecting solenoid valve (15). The hot water delivery pipeline (B) includes a heating tank (5) that provides hot water, and a heating device installed in the heating tank (5) that releases heat through a chemical reaction; The alloy hydrogen storage tank assembly (23) is connected to the circulating water tank (16) via a second temperature-controlled three-way valve (21) and a plate heat exchanger (20). The plate heat exchanger (20) is connected to the circulating water tank (16). The plate heat exchanger (20) is also connected to both ends of the liquid oxygen vaporizer (19) via a pipeline, so that the low-temperature fresh water cooled by the liquid oxygen vaporizer (19) can exchange heat with the high-temperature water generated by the reaction of the fuel cell stack (28). The heating device heats the heating water tank (5) by chemically reacting with a certain amount of water in the heating water tank (5). The heating device includes at least one heating chamber (7) placed in the heating water tank (5). The heating chamber (7) is provided with a heating agent (8), and the heating chamber (7) is connected to the heating water tank (5) through a connecting pipe. The opening and closing of the connecting pipe is controlled by a reaction control solenoid valve (12).

2. The system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater transport platform as described in claim 1, characterized in that: The alloy hydrogen storage tank assembly (23) includes multiple alloy hydrogen storage tanks connected in parallel.

3. The system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater transport platform as described in claim 1, characterized in that: A fresh water pump (17) is installed on the connecting pipe of the liquid oxygen vaporizer (19). The fresh water pump (17) is used to extract fresh water. At the same time, a first temperature-controlled three-way valve (18) is also installed on the connecting pipe to control whether fresh water needs to be added according to the temperature.

4. The system for improving the thermal efficiency of an underwater vehicle platform fuel cell auxiliary system as described in claim 1, characterized in that: The heating agent (8) is mainly composed of quicklime, sodium carbonate, iron powder, activated carbon and other substances.

5. The system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater transport platform as described in claim 1, characterized in that: The heating chamber (7) is provided with a lower plug (9) and a quick connector (10) is provided on the connecting pipe. The upper end of the heating chamber (7) is provided with a feed port for adding heating agent (8). At the same time, an upper plug (6) is provided at the feed port. A one-way valve (3) is threaded on the upper plug (6).

6. The system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater transport platform as described in claim 1, characterized in that: The heating water tank (5) is equipped with a temperature sensor (1), a pressure sensor (2), a safety valve (4) and a first shut-off valve (11). The heating water tank (5) is also connected to a heating device solenoid valve (13) on the water outlet pipe. The outflow rate of hot water is controlled by the heating device solenoid valve (13).

7. The system for improving the thermal efficiency of a fuel cell auxiliary system for an underwater transport platform as described in claim 1, characterized in that: The oxygen inlet pipeline (C) includes a liquid oxygen storage tank (30) and a liquid oxygen vaporizer (19) connected in series on the fuel cell stack (28), and is equipped with an oxygen inlet explosion-proof solenoid valve (22) and an oxygen inlet pressure reducing and stabilizing valve (24) to control the pipeline pressure.

8. The system for improving the thermal efficiency of an auxiliary fuel cell system for an underwater transport platform as described in claim 1, characterized in that: The hydrogen inlet pipeline (D) includes multiple parallel alloy hydrogen storage tanks, and each alloy hydrogen storage tank is equipped with a second shut-off valve (25) for control. In addition, the hydrogen inlet pipeline (D) is also equipped with a hydrogen inlet explosion-proof solenoid valve (26) and a hydrogen inlet pressure reducing and stabilizing valve (27) to control the pipeline pressure.

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