Liquid ammonia transport ship power generation system and liquid ammonia transport ship

Abstract

The present application provides a liquid ammonia transport ship power generation system and a liquid ammonia transport ship, the power generation system includes a fuel cell power generation assembly, which includes a first and a second heat exchanger, a fuel cell, a post-combustion chamber, a converter and an exhaust port. The flash gas of the liquid ammonia cargo tank enters the anode inlet of the fuel cell through the first side of the first heat exchanger. Air enters the cathode inlet of the fuel cell through the first side of the second heat exchanger. The anode and cathode outlets are connected to the post-combustion chamber. The fuel cell power output end is connected to the converter and output to the outside. The second side outlet of the first heat exchanger is connected to the second side inlet of the second heat exchanger, and the second side outlet of the second heat exchanger is connected to the exhaust port. The exhaust port of the post-combustion chamber is connected to the second side inlet of the first heat exchanger, the second side inlet of the second heat exchanger and the exhaust port through three branches, and each branch is provided with an on-off valve. The present application uses liquid ammonia flash gas as fuel, generates electricity through fuel cells to supply power to the ship, reduces carbon emissions, does not require reliquefaction, and realizes the rational use of waste heat.

Description

Technical Field

[0001] The present application relates to the technical field of fuel cell power generation, and more specifically, to a liquid ammonia transport ship power generation system and a liquid ammonia transport ship that uses fuel cells for power generation. Background Art

[0002] Boil-off gas (BOG) refers to the gas produced by the vaporization of liquid cargo in liquid cargo vessels due to heat exchange or pressure changes. For example, in liquid ammonia carriers, BOG is primarily formed by the evaporation of liquid ammonia. Ammonia is toxic and corrosive, and when mixed with air at certain concentrations, it poses a risk of combustion and explosion. Currently, the industry generally uses reliquefaction to treat BOG. This involves using a refrigeration cycle to condense the gaseous ammonia back into liquid form and return it to the cargo hold.

[0003] Existing reliquefaction systems typically include multi-stage compressors, expanders, heat exchangers, and condensers. Their complex process flow results in bulky equipment, making it difficult to efficiently deploy within the limited space of a vessel. Furthermore, reliquefaction systems require significant amounts of electricity to maintain low temperatures to prevent the evaporation of liquid ammonia. This electricity often comes from burning more fuel, creating a vicious cycle. Furthermore, residual BOG that is not fully liquefied during system operation, as well as BOG that exceeds the reliquefaction system's processing capacity, must be burned, resulting in energy waste.

[0004] In addition, as relevant international organizations have increasingly stringent requirements on ship carbon emissions and energy efficiency, liquid ammonia tankers face multiple challenges: on the one hand, it is necessary to optimize the space occupied by the BOG reliquefaction treatment system and the ship's energy efficiency; on the other hand, traditional ship propulsion systems still mainly rely on fossil fuel internal combustion engines for power, and their carbon emission levels are difficult to meet the industry's sustainable development goals of energy conservation and emission reduction. Summary of the Invention

[0005] The purpose of this application is to provide a liquid ammonia tanker power generation system and a liquid ammonia tanker, which can use liquid ammonia flash gas as fuel and generate electricity through solid oxide fuel cells to supply ship power, significantly reducing carbon emissions, and can streamline the reliquefaction system, avoiding energy consumption in the reliquefaction process, and can also achieve efficient and reasonable utilization of exhaust waste heat after power generation.

[0006] In a first aspect, a power generation system for a liquid ammonia carrier is provided, comprising a liquid ammonia cargo tank and a fuel cell power generation assembly. The fuel cell power generation assembly comprises a first heat exchanger, a second heat exchanger, a fuel cell, an afterburner, a converter, and an exhaust port. Both the first and second heat exchangers comprise a first side and a second side. Flash gas from the liquid ammonia cargo tank is delivered to the first side inlet of the first heat exchanger. The first side outlet of the first heat exchanger is connected to the anode inlet of the fuel cell, which in turn is connected to the afterburner. Air is delivered to the first side inlet of the second heat exchanger. The first side outlet of the second heat exchanger is connected to the cathode inlet of the fuel cell, which in turn is connected to the afterburner. The fuel cell power output is connected to the converter and output externally.

[0007] The second side outlet of the first heat exchanger is connected to the second side inlet of the second heat exchanger, which is in turn connected to the exhaust port. The exhaust port of the afterburner chamber is connected to the second side inlet of the first heat exchanger, the second side inlet of the second heat exchanger, and the exhaust port via three branches, each of which is equipped with an on-off valve.

[0008] In one feasible solution, the opening or closing of the on-off valve is controlled by comparing the temperature at the exhaust port of the post-combustion chamber, the temperature at the first side inlet of the first heat exchanger, and the temperature at the first side inlet of the second heat exchanger.

[0009] In an implementable solution, the three branches connecting the exhaust port of the after-combustion chamber and the second side inlet of the first heat exchanger, the second side inlet of the second heat exchanger and the exhaust end are respectively the first branch, the second branch and the third branch; a first on-off valve is provided on the first branch, a second on-off valve is provided on the second branch, and a third on-off valve is provided on the third branch; and a control module is also included, which is communicated with the first on-off valve, the second on-off valve and the third on-off valve and controls the opening or closing of each valve.

[0010] In an implementable solution, a first temperature sensor is provided at the exhaust port of the afterburner chamber, a second temperature sensor is provided at the first side inlet of the first heat exchanger, and a third temperature sensor is provided at the first side inlet of the second heat exchanger; the first temperature sensor, the second temperature sensor, and the third temperature sensor are communicatively connected to the control module.

[0011] In an implementable solution, the step of the control module controlling the first on-off valve, the second on-off valve, and the third on-off valve to open or close includes:

[0012] The control module obtains the temperature values of the first temperature sensor, the second temperature sensor, and the third temperature sensor, which are respectively 、 、 ;

[0013] Control module pair 、 、 Perform size comparison and issue corresponding control signals;

[0014] like , the control module controls the first on-off valve to remain open, and controls the second on-off valve and the third on-off valve to remain closed;

[0015] like and , the control module controls the second on-off valve to remain open, and controls the first on-off valve and the third on-off valve to remain closed;

[0016] like and , the control module controls the third on-off valve to remain open, and controls the first on-off valve and the second on-off valve to remain closed.

[0017] In one feasible solution, the liquid ammonia transport ship power generation system further includes a preheating device, which is arranged upstream of the first side inlet of the first heat exchanger and is used to heat the flash gas transported from the liquid ammonia cargo tank.

[0018] In one feasible solution, the preheating device is a trough solar collector.

[0019] In one feasible solution, the trough solar collector includes a parabolic reflector and a heat collecting tube. The heat collecting tube is connected to the pipeline from the liquid ammonia cargo tank to the first side inlet of the first heat exchanger. The parabolic reflector receives light and reflects and heats the heat collecting tube.

[0020] In one feasible solution, the liquid ammonia transport ship power generation system also includes a redundant pipeline, which forms a parallel pipeline with the heat collecting pipe. An inlet valve is set at the inlet end of the branch where the heat collecting pipe is located, an outlet valve is set at the outlet end of the branch where the heat collecting pipe is located, and a switch valve is set on the redundant pipeline.

[0021] In an implementable solution, the liquid ammonia transport ship power generation system also includes a buffer tank, a flow detector and a buffer controller; the buffer tank is located upstream of the preheating device and is connected to the pipeline in parallel, a buffer inlet valve is installed at the inlet of the buffer tank, a buffer outlet valve is installed at the outlet of the buffer tank, and a straight-through valve is installed in the pipeline parallel to the buffer tank; the flow detector is arranged on the outlet side of the liquid ammonia cargo tank, and the buffer controller is communicatively connected with the flow detector, the buffer inlet valve, the buffer outlet valve and the straight-through valve.

[0022] In one feasible solution, a flow expectation threshold is pre-stored in the buffer controller. The steps of the buffer controller controlling the buffer inlet valve, buffer outlet valve, and through valve to open or close include:

[0023] The buffer controller obtains the real-time flow value through the flow detector. ;

[0024] Buffer controller determines the real-time flow value and traffic expectation threshold size;

[0025] like , the buffer controller controls the buffer inlet valve and the buffer outlet valve to remain in a closed state, and controls the through valve to remain in an open state;

[0026] like , the buffer controller controls the buffer inlet valve and the buffer outlet valve to remain in the open state, and controls the through valve to remain in the open state.

[0027] In an implementable solution, the power output end of the converter includes a first interface and a second interface, the first interface is connected to the power load equipment, and the second interface is connected to the energy storage device.

[0028] In one feasible solution, the liquid ammonia transport ship power generation system includes a waste heat utilization module, which includes a first side and a second side. The discharge end enters the first side pipeline of the waste heat utilization module, and normal temperature water is introduced into the second side of the waste heat utilization module.

[0029] In one feasible solution, the liquid ammonia transport ship power generation system also includes a box structure and a temperature control component, at least the fuel cell is in the box structure; the temperature control component includes an electric heating rod placed in the box structure and a thermocouple placed in the fuel cell, and the temperature control component also includes a temperature controller, which determines the temperature in the fuel cell through the thermocouple and controls the power on or off of the electric heating rod.

[0030] On the second aspect, a liquid ammonia transport ship is also provided, including a hull and the aforementioned liquid ammonia transport ship power generation system; the hull includes an engine room and several liquid ammonia liquid cargo tanks, the liquid ammonia transport ship power generation system is arranged in the engine room, and the electric energy output by the converter of the liquid ammonia transport ship power generation system is used to drive the main engine of the ship.

[0031] Compared with the prior art, the beneficial effects of the present application include at least the following: the liquid ammonia carrier power generation system of the present application can consume liquid ammonia flash gas as fuel to generate electricity, and no longer needs to consume electricity to maintain low temperature to prevent the evaporation of reliquefied liquid ammonia. Therefore, the reliquefaction system can be abandoned, simplifying the fuel management system on board, greatly reducing energy consumption, and optimizing the ship structure, improving the utilization rate of ship space, and helping to increase the loading capacity of liquid ammonia carriers. At the same time, the liquid ammonia power generation system of the present application, whether it is the reaction products of the anode and cathode of the fuel cell or the combustion products of the afterburner, has almost no carbon emissions, significantly reducing greenhouse gas emissions, and also effectively reducing NO XFurthermore, since the amount of flash gas generated in the liquid ammonia cargo tank is sufficient, the liquid ammonia carrier power generation system of the present application can serve as the navigation and entire ship power source of the liquid ammonia carrier, thereby optimizing the internal combustion engine configuration, on the one hand, optimizing space occupancy, and on the other hand, providing support for achieving low-carbon or even zero-carbon emissions for ships.

[0032] In the liquid ammonia transport ship power generation system of the present application, the exhaust gas discharged from the after-combustion chamber is connected to the first heat exchanger, the second heat exchanger and the discharge end respectively through three branches provided with on-off valves, so that the high-temperature exhaust gas can be selectively used for preheating air, preheating ammonia fuel or directly discharged as needed, thereby more reasonably and effectively utilizing the exhaust heat of the after-combustion chamber, improving the system's waste heat cascade utilization rate, and avoiding the adverse effects of unreasonable waste heat utilization on the reaction of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 This is a schematic diagram of the composition of a liquid ammonia transport ship power generation system shown in an embodiment of the present application.

[0035] Figure 2 This is a schematic diagram of the composition of a liquid ammonia transport ship power generation system with automatic exhaust gas path selection function shown in an embodiment of the present application.

[0036] Figure 3 This is a schematic diagram of the composition of a liquid ammonia transport ship power generation system with a solar collector shown in an embodiment of the present application.

[0037] Figure 4 This is a schematic diagram of the composition of a liquid ammonia transport ship power generation system with redundant pipelines shown in an embodiment of the present application.

[0038] Figure 5 This is a schematic diagram of the composition of a liquid ammonia transport ship power generation system with a buffer tank shown in an embodiment of the present application.

[0039] Figure 6 This is a schematic diagram of the composition of a liquid ammonia transport ship power generation system with an energy storage device shown in an embodiment of the present application.

[0040] Figure 7 This is a schematic diagram of the composition of a liquid ammonia transport ship shown in an embodiment of the present application.

[0041] Figure 8 This is a schematic diagram of the composition of another liquid ammonia transport ship shown in an embodiment of the present application.

[0042] In the figure: 1. Fuel cell power generation assembly; 11. First heat exchanger; 12. Second heat exchanger; 13. Fuel cell; 14. Afterburner; 15. Converter; 16. Discharge end; 17. Control module; A1. First branch; A2. Second branch; A3. Third branch; P1. First on-off valve; P2. Second on-off valve; P3. Third on-off valve; H1. First temperature sensor; H2. Second temperature sensor; H3. Third temperature sensor; 2. Trough solar collector; 21. Collecting pipe; 3. Redundant pipeline; G1. Inlet valve; G2. Outlet valve; G3. Switch valve; 4. Buffer tank; 41. Flow detector; 42. Buffer controller; M1. Buffer inlet valve; M2. Buffer outlet valve; M3. Through valve; 5. Energy storage device; 6. Waste heat utilization module; 7. Temperature control assembly; 100. Liquid ammonia cargo tank; 200. Engine room. DETAILED DESCRIPTION

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0045] The inventors of this application proposed the technical solution of this application for the purpose of, on the one hand, improving the utilization rate of liquid ammonia flash gas and hoping to abandon the reliquefaction system to optimize the hull structure; on the other hand, to achieve further energy conservation and emission reduction.

[0046] At the same time, the inventors also discovered that in conventional solid oxide fuel cell power generation systems, gases that have not completely reacted at the anode and cathode of the fuel cell are transported to the afterburner for combustion. Because the exhaust gas discharged from the exhaust port of the afterburner is quite hot, the usual treatment method is to use this exhaust gas to preheat the air entering the fuel cell, and then discharge the exhaust gas after preheating. However, even after being used to preheat the air, the exhaust gas discharged from the afterburner still maintains a relatively high temperature. If it is discharged directly, a large amount of heat will be wasted, resulting in low energy utilization, which is actually an indirect waste of flash gas. In addition, in some power generation systems, the exhaust gas is further used to preheat the fuel gas after preheating the air. However, in certain specific circumstances, the temperature of the exhaust gas discharged from the afterburner may be lower than that of the fuel gas. At this time, if the exhaust gas is allowed to exchange heat with the fuel gas, not only will it fail to achieve effective preheating, but it will also lower the temperature of the fuel gas, resulting in side effects, thereby reducing the reaction efficiency and adding additional burden to the reaction process of the fuel cell.

[0047] In order to solve the above technical problems, Figure 1 As shown, an embodiment of the present application first provides a liquid ammonia transport ship power generation system, including a liquid ammonia cargo tank 100 and a fuel cell power generation assembly 1, the fuel cell power generation assembly 1 includes a first heat exchanger 11, a second heat exchanger 12, a fuel cell 13, an after-combustion chamber 14, a converter 15 and an exhaust port 16.

[0048] Both the first heat exchanger 11 and the second heat exchanger 12 include a first side and a second side. Flash gas from the liquid ammonia cargo tank 100 is delivered to the first side inlet of the first heat exchanger 11. The first side outlet of the first heat exchanger 11 is connected to the anode inlet of the fuel cell 13, which in turn is connected to the anode outlet of the fuel cell 13. Air is delivered to the first side inlet of the second heat exchanger 12. The first side outlet of the second heat exchanger 12 is connected to the cathode inlet of the fuel cell 13, which in turn is connected to the cathode outlet of the fuel cell 13. The electrical energy output of the fuel cell 13 is connected to a converter 15 and outputs externally.

[0049] The second side outlet of the first heat exchanger 11 is connected to the second side inlet of the second heat exchanger 12, which is in turn connected to the exhaust port 16. The exhaust port of the afterburner 14 is connected to the second side inlet of the first heat exchanger 11, the second side inlet of the second heat exchanger 12, and the exhaust port 16 via three branches, each of which is equipped with an on-off valve.

[0050] It should be noted that the fuel cell 13 in this embodiment is a solid oxide fuel cell (SOFC). As a high-efficiency energy conversion device, SOFC has great potential as a power option due to its high efficiency, strong fuel adaptability, and high-temperature waste heat recovery. Compared with traditional internal combustion engines, SOFC can not only significantly reduce greenhouse gas emissions, but also effectively reduce NO X Emissions of harmful substances.

[0051] In the liquid ammonia carrier power generation system of the present application, the flash gas (gasified ammonia) generated in the liquid ammonia cargo tank 100 is transported to the first heat exchanger 11 for heating and then enters the anode of the fuel cell 13 to undergo an electrochemical reaction. At the same time, the air is preheated by the second heat exchanger 12 and then enters the cathode of the fuel cell 13 to undergo an electrochemical reaction.

[0052] The reaction formula in the fuel cell 13 is:

[0053]

[0054]

[0055] Afterwards, the charge generated by the fuel cell 13 enters the converter 15, which is used to convert it into the rated voltage for the ship and then output the power supply to provide power for the ship's navigation. Since the amount of flash gas generated in the liquid ammonia cargo tank 100 is sufficient, the electricity generated by the fuel cell 13 is sufficient to fully supply the power demand for the ship's navigation, so it is sufficient even if the internal combustion engine power is not installed. In addition, in addition to the water generated by the electrochemical reaction, the high-temperature gas at the anode outlet of the fuel cell 13 also contains incompletely reacted ammonia and hydrogen generated by the decomposition of ammonia, while the high-temperature gas at the cathode outlet of the fuel cell 13 contains incompletely reacted air. The exhaust gases from the anode and cathode of the fuel cell 13 are both transported to the afterburner 14 for complete combustion.

[0056] Among them, the reaction formula in the afterburner 14 is:

[0057]

[0058] In summary, the liquid ammonia carrier power generation system of the present application can consume liquid ammonia flash gas as fuel to generate electricity, and no longer needs to consume electricity to maintain low temperature to prevent the evaporation of reliquefied liquid ammonia. Therefore, the reliquefaction system can be abandoned, simplifying the fuel management system on board, greatly reducing energy consumption, and at the same time optimizing the ship structure, improving the utilization rate of ship space, and helping to increase the loading capacity of liquid ammonia carriers. At the same time, the liquid ammonia power generation system of the present application, whether it is the reaction products of the anode and cathode of the fuel cell 13 or the combustion products of the afterburner 14, has almost no carbon emissions, significantly reducing greenhouse gas emissions, and also effectively reducing NO X Furthermore, since the amount of flash gas generated in the liquid ammonia cargo tank 100 is sufficient, the liquid ammonia carrier power generation system of the present application can serve as the navigation and entire ship power source of the liquid ammonia carrier, thereby optimizing the internal combustion engine configuration, on the one hand, optimizing space occupancy, and on the other hand, providing support for achieving low-carbon or even zero-carbon emissions for ships.

[0059] Ammonia is an ideal hydrogen carrier, with a volumetric hydrogen content of up to 121 kg H2 / m 3 , far exceeding liquid hydrogen and other organic hydrides. This means that ammonia can not only be used as a zero-carbon fuel directly for combustion or through reforming to produce hydrogen to fuel SOFCs, but its relative ease of storage and transportation also makes an ammonia-based energy supply chain more feasible. Using SOFCs as the sole power source, liquid ammonia carriers can achieve true zero-emission operation, as ammonia does not produce CO2 during combustion and can be synthesized from renewable energy, further reducing the carbon footprint of the entire life cycle.

[0060] In summary, this application utilizes fuel cells 13 as the primary power generation device for liquid ammonia carriers. With their high efficiency, flexibility, and environmental friendliness, they offer an alternative to traditional reliquefaction systems. Not only does this effectively address the boil-off gas issue, it also significantly improves energy efficiency, reduces operating costs, and minimizes environmental pollution, making a significant contribution to green shipping.

[0061] In the liquid ammonia transport ship power generation system of the present application, the high-temperature exhaust gas discharged from the exhaust port of the after-combustion chamber 14 has three exhaust branches reserved in the solution of the present application. Each branch is provided with an on-off valve, so that the high-temperature exhaust gas can be selectively used to preheat air, preheat ammonia fuel or directly discharged as needed.

[0062] For example, if the temperature of the fuel entering the first heat exchanger 11 is high enough to meet the temperature requirement of the fuel cell 13, then the high-temperature exhaust gas discharged from the afterburner 14 only needs to be passed into the second side of the second heat exchanger 12 to preheat the air more effectively.

[0063] For another example, if the temperature of the fuel entering the first heat exchanger 11 is no lower than the temperature of the high-temperature exhaust gas, it is only necessary to pass the high-temperature exhaust gas discharged from the after-combustion chamber 14 into the second side of the second heat exchanger 12, thereby avoiding the heat exchange process through the first heat exchanger 11 causing the fuel temperature to drop, thereby ensuring the reaction efficiency in the subsequent fuel cell 13.

[0064] For example, if the temperature of the fuel entering the first heat exchanger 11 is much lower than the temperature of the high-temperature exhaust gas, the high-temperature exhaust gas in the afterburner 14 can first enter the second side of the first heat exchanger 11 to preheat the fuel, and then enter the second side of the second heat exchanger 12 to preheat the air, thereby making more effective use of the heat of the high-temperature exhaust gas.

[0065] For example, if the exhaust gas emitted from the anode and cathode of the fuel cell 13 is small, the combustion temperature in the afterburner 14 is low, the exhaust gas emission volume is low, and the exhaust gas temperature is also low. Furthermore, the air entering the second heat exchanger 12 may have been preheated by other preheating devices and has a temperature higher than the exhaust gas temperature in the afterburner 14. In this case, the exhaust gas from the afterburner 14 can be directly delivered to the exhaust port 16.

[0066] In summary, in the liquid ammonia transport ship power generation system of the present application, the exhaust gas discharged from the after-combustion chamber 14 is connected to the first heat exchanger 11, the second heat exchanger 12 and the discharge end 16 respectively through three branches provided with on-off valves, so that the high-temperature exhaust gas can be selectively used for preheating air, preheating ammonia fuel or directly discharged as needed, thereby more reasonably and effectively utilizing the exhaust heat of the after-combustion chamber 14, realizing temperature complementarity and selective cascade utilization of energy, improving the cascade utilization rate of waste heat of the system, and avoiding the adverse effects of unreasonable waste heat utilization on the reaction of the fuel cell 13.

[0067] In some embodiments, by comparing the temperature at the exhaust port of the afterburner chamber 14, the temperature at the first side inlet of the first heat exchanger 11, and the temperature at the first side inlet of the second heat exchanger 12, the opening or closing of the on-off valve is controlled, thereby achieving reasonable and efficient utilization of the exhaust heat in the afterburner chamber 14.

[0068] In some embodiments, as Figure 2As shown, the three branches connecting the exhaust port of the afterburner 14 to the second side inlet of the first heat exchanger 11, the second side inlet of the second heat exchanger 12, and the exhaust port 16 are respectively the first branch A1, the second branch A2, and the third branch A3. A first on-off valve P1 is provided on the first branch A1, a second on-off valve P2 is provided on the second branch A2, and a third on-off valve P3 is provided on the third branch A3. The first on-off valve P1, the second on-off valve P2, and the third on-off valve P3 can be manual on-off valves, but preferably, the liquid ammonia carrier power generation system also includes a control module 17, which is in communication with the first on-off valve P1, the second on-off valve P2, and the third on-off valve P3 and controls the opening or closing of each valve.

[0069] In some embodiments, as Figure 2 As shown, a first temperature sensor H1 is provided at the exhaust port of the afterburner 14, a second temperature sensor H2 is provided at the first side inlet of the first heat exchanger 11, and a third temperature sensor H3 is provided at the first side inlet of the second heat exchanger 12. The first temperature sensor H1, the second temperature sensor H2, and the third temperature sensor H3 are in communication with the control module 17.

[0070] In this embodiment, the step of the control module 17 controlling the first on-off valve P1, the second on-off valve P2, and the third on-off valve P3 to open or close may include:

[0071] The control module 17 obtains the temperature values of the first temperature sensor H1, the second temperature sensor H2, and the third temperature sensor H3, which are respectively 、 、 ;

[0072] Control module 17 pairs 、 、 Perform size comparison and issue corresponding control signals;

[0073] like , the control module 17 controls the first on-off valve P1 to remain open, and controls the second on-off valve P2 and the third on-off valve P3 to remain closed; at this time, the high-temperature exhaust gas passes through the second side of the first heat exchanger 11 and the second side of the second heat exchanger 12 in sequence and then reaches the discharge end 16, thereby preheating the flash gas fuel and air;

[0074] like and , the control module 17 controls the second on-off valve P2 to remain open, and controls the first on-off valve P1 and the third on-off valve P3 to remain closed; at this time, the high-temperature exhaust gas passes through the second side of the second heat exchanger 12 and reaches the discharge end 16, achieving preheating of the air;

[0075] like and , the control module 17 controls the third on-off valve to remain open, and controls the first on-off valve and the second on-off valve to remain closed; at this time, the high-temperature exhaust gas directly reaches the exhaust end 16.

[0076] In addition, a temperature threshold value can be pre-stored in the control module 17 , this temperature threshold is used to indicate that the temperature of the fuel entering the fuel cell 13 has reached the required level and no further preheating is required. When, regardless of and The control module 17 can control the first on-off valve P1 to remain closed. When the control module 17 、 、 Perform size comparison and send corresponding control signals.

[0077] In summary, the control module 17 of this embodiment realizes a comprehensive comparison and judgment of the gas temperatures at the exhaust port of the afterburner 14, the first side inlet of the first heat exchanger 11, and the first side inlet of the second heat exchanger 12 based on the temperature data obtained by the first temperature sensor H1, the second temperature sensor H2, and the third temperature sensor H3, and then automatically adjusts the emission path of the high-temperature exhaust gas emitted by the afterburner 14, thereby realizing the reasonable and efficient reuse of the waste heat of the exhaust gas.

[0078] In some embodiments, the liquid ammonia carrier power generation system may further include a preheating device, disposed upstream of the first side inlet of the first heat exchanger 11, for heating flash gas delivered from the liquid ammonia cargo tank 100. The preheating device can effectively increase the temperature of the gas entering the anode of the fuel cell 13, thereby helping to improve power generation efficiency.

[0079] In a preferred embodiment, if Figure 3 As shown, the preheating device is a trough solar collector 2. In this way, when the ship is sailing during the day, the ammonia entering the first side of the first heat exchanger 11 can be preheated by solar energy.

[0080] Furthermore, the coordinated use of the trough solar collector 2 with the control module 17, the three branches, the on-off valves and the temperature sensors can achieve efficient distribution and utilization of energy, thereby improving power generation efficiency and waste heat utilization.

[0081] When the liquid ammonia transport ship is sailing under good sunlight, the trough solar collector 2 can significantly increase the temperature of the ammonia gas entering the first side of the first heat exchanger 11, so that the ammonia gas temperature reaches a higher level, so that the inlet temperature of the first side of the first heat exchanger 11 is higher than the temperature at the exhaust port of the afterburner 14 (i.e. ), or to achieve the required temperature requirement (i.e. At this time, the control module 17 can control the first on-off valve P1 to remain closed, that is, the exhaust gas discharged from the afterburner 14 does not need to pass through the first heat exchanger 11. On the one hand, the exhaust gas waste heat is saved and can be directly used to preheat air or directly transported to the discharge end 16 for other purposes, thereby improving the utilization efficiency of the exhaust gas waste heat. On the other hand, it can also prevent the exhaust gas with a temperature lower than the ammonia gas from absorbing the heat of the ammonia gas, thereby avoiding side effects.

[0082] When the liquid ammonia carrier is sailing in low-light conditions (e.g., at night), the trough solar collectors 2 are unable to perform their heating function. In this situation, the control module 17 can determine the gas temperatures at the exhaust port of the afterburner 14, the first side inlet of the first heat exchanger 11, and the first side inlet of the second heat exchanger 12, and selectively utilize the exhaust waste heat to preheat the fuel, air, or directly discharge the exhaust.

[0083] In some embodiments, as Figure 4 As shown, the trough solar collector 2 generally includes a parabolic reflector (not shown in the figure) and a heat collecting pipe 21. The heat collecting pipe 21 is connected to the pipeline from the liquid ammonia liquid cargo tank 100 to the first side inlet of the first heat exchanger 11. The parabolic reflector receives light and reflects and heats the heat collecting pipe 21 to achieve heating of the flash gas.

[0084] In some embodiments, as Figure 4 As shown, the liquid ammonia carrier power generation system may also include a redundant pipeline 3, which forms a parallel pipeline with the heat collecting pipe 21. The inlet end of the branch where the heat collecting pipe 21 is located is provided with an inlet valve G1, the outlet end of the branch where the heat collecting pipe 21 is located is provided with an outlet valve G2, and an on-off valve G3 is provided on the redundant pipeline 3. In this way, when the trough solar collector 2 requires maintenance, the inlet valve G1 and outlet valve G2 can be closed, and the on-off valve G3 can be opened to allow the flash gas to be transported through the redundant pipeline 3.

[0085] In some embodiments, as Figure 5As shown, the liquid ammonia carrier power generation system may also include a buffer tank 4, a flow detector 41, and a buffer controller 42. The buffer tank 4 is located upstream of the preheating device and connected to the pipeline in parallel. A buffer inlet valve M1 is installed at the inlet of the buffer tank 4, a buffer outlet valve M2 is installed at the outlet of the buffer tank 4, and a through valve M3 is installed in the pipeline parallel to the buffer tank 4. The flow detector 41 is located at the outlet of the liquid ammonia cargo tank 100, and the buffer controller 42 is in communication with the flow detector 41, the buffer inlet valve M1, the buffer outlet valve M2, and the through valve M3. The buffer controller 42 can obtain the flow rate of the flash gas output from the liquid ammonia cargo tank 100 through the flow detector 41 and then determine whether the flash gas is excessive. If so, the flow detector 41 can open the buffer inlet valve M1 to allow some flash gas to enter the buffer tank 4 for pre-storage, thereby preventing the fuel cell 13 from generating excessive unreacted gas and reducing the waste of flash gas.

[0086] When the gas in the buffer tank 4 is used, the buffer controller 42 may control the buffer inlet valve M1 and the buffer outlet valve M2 to remain open.

[0087] It should be noted that a compression device may be installed on the outlet side of the buffer tank 4 to increase the outlet pressure of the buffer tank 4 through the compression device to meet the subsequent pipeline pressure requirements.

[0088] In some embodiments, the buffer controller 42 may pre-store a flow rate expectation threshold value. Assume that the standard amount of ammonia required for the fuel cell 13 to achieve a high efficiency power generation level (which can be defined by the designer) is However, in order to ensure that the flow rate of the flash gas is sufficient to maintain the efficient power generation of the fuel cell 13, the flow rate threshold is set to At least not less than the standard ammonia volume size.

[0089] Therefore, in this embodiment, it is preferred to provide the buffer outlet valve M2 with a check characteristic, or to provide an independent check valve at the outlet of the buffer tank 4 .

[0090] Furthermore, the step of setting the buffer controller 42 to control the opening or closing of the buffer inlet valve M1, the buffer outlet valve M2, and the through valve M3 may include:

[0091] The buffer controller 42 obtains the real-time flow value through the flow detector 41 ;

[0092] Buffer controller 42 determines the real-time value of flow and traffic expectation threshold size;

[0093] like , the buffer controller 42 controls the buffer inlet valve M1 and the buffer outlet valve M2 to remain in a closed state, and controls the through valve M3 to remain in an open state, so that the flash gas is directly delivered to the first heat exchanger 11;

[0094] like , the buffer controller 42 controls the buffer inlet valve M1 and the buffer outlet valve M2 to remain in an open state, and controls the through valve M3 to remain in an open state, thereby temporarily taking over the excess flash gas through the buffer tank 4.

[0095] In some embodiments, the buffer inlet valve M1 and the through valve M3 can adopt proportional valves, and the buffer controller 42 can be used to control the opening ratio of the buffer inlet valve M1 and the through valve M3, thereby diverting the flash gas and controlling part of the flash gas to enter the buffer tank 4. The flash gas required for power generation is transported to the first heat exchanger 11 via the through valve M3.

[0096] In some embodiments, as Figure 6 As shown, the power output of converter 15 includes a first interface and a second interface. The first interface is connected to the power load device, and the second interface is connected to the energy storage device 5. During normal navigation of the ship, substantially all of the power generated by the fuel cell 13 is output through the first interface of converter 15 to supply the ship's navigation. When there is a surplus of power generated by the fuel cell 13, the excess power is transferred to the energy storage device 5 through the second interface of converter 15 for storage. It is then released and used by the energy storage device 5 when the ship's electricity consumption is peak-shaving and valley-filling.

[0097] In some embodiments, as Figure 6 As shown, the waste heat utilization module 6 includes a first side and a second side. A discharge end 16 is discharged through a pipeline on the first side of the waste heat utilization module 6. Normal temperature water (typically engine room fresh water) is introduced into the second side of the waste heat utilization module 6. This water exchanges heat with the high-temperature exhaust gas discharged from the discharge end 16, thereby discharging hot water that meets the ship's heat load requirements from the second side of the waste heat utilization module 6 and is then piped to a heat user. For example, the waste heat utilization module 6 may be a waste heat boiler.

[0098] In some embodiments, the liquid ammonia carrier power generation system further includes a box structure (not shown in the figure) and a temperature control component 7 (see Figure 6 ), at least the fuel cell 13 is located within the box structure to facilitate the hoisting of the entire fuel cell 13. Preferably, the entire fuel cell power generation assembly 1 is centralized within a box structure. The temperature control assembly 7 generally includes an electric heating rod placed within the box structure and a thermocouple placed within the fuel cell 13. The temperature control assembly 7 also includes a temperature controller, which uses the thermocouple to determine the temperature within the fuel cell 13 and control the powering on and off of the electric heating rod. The temperature control assembly 7 maintains a high temperature during operation of the fuel cell 13.

[0099] like Figure 7 and Figure 8 As shown, an embodiment of the present application also provides a liquid ammonia carrier, comprising a hull and the aforementioned liquid ammonia carrier power generation system. The hull includes an engine room 200 and several liquid ammonia cargo tanks 100. The liquid ammonia carrier power generation system is located in the engine room 200. The power output from the converter 15 of the liquid ammonia carrier power generation system is used to drive the ship's main engine.

[0100] The fuel cell power generation assembly 1 in the aforementioned liquid ammonia carrier power generation system can be placed inside or outside the engine room 200. The trough solar collector 2 is located outside the engine room 200, while the buffer tank 4, energy storage device 5, waste heat utilization module 6, temperature control assembly 7, etc. can be located inside the engine room 200.

[0101] The foregoing description is merely a partial list of preferred embodiments of the present application and is not intended to limit the present application. Persons skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A liquid ammonia transport ship power generation system, comprising a liquid ammonia cargo tank (100), characterized in that: Also included is a fuel cell power generation assembly (1), which includes a first heat exchanger (11), a second heat exchanger (12), a fuel cell (13), an afterburner (14), a converter (15), and an exhaust end (16); the first heat exchanger (11) and the second heat exchanger (12) both include a first side and a second side; Flash gas in the liquid ammonia cargo tank (100) is transported to the first side inlet of the first heat exchanger (11), the first side outlet of the first heat exchanger (11) is connected to the anode inlet of the fuel cell (13), and the anode outlet of the fuel cell (13) is connected to the afterburner (14); Air is delivered to the first side inlet of the second heat exchanger (12), the first side outlet of the second heat exchanger (12) is connected to the cathode inlet of the fuel cell (13), and the cathode outlet of the fuel cell (13) is connected to the post-combustion chamber (14); The power output end of the fuel cell (13) is connected to the converter (15) and outputs power to the outside; The second side outlet of the first heat exchanger (11) is connected to the second side inlet of the second heat exchanger (12), and the second side outlet of the second heat exchanger (12) is connected to the discharge end (16); The discharge port of the afterburner (14) is connected to the second side inlet of the first heat exchanger (11), the second side inlet of the second heat exchanger (12), and the discharge end (16) through a first branch, a second branch, and a third branch respectively; a first on-off valve is provided on the first branch, a second on-off valve is provided on the second branch, and a third on-off valve is provided on the third branch; A first temperature sensor is provided at the exhaust port of the afterburner (14), a second temperature sensor is provided at the first side inlet of the first heat exchanger (11), and a third temperature sensor is provided at the first side inlet of the second heat exchanger (12); It also includes a control module (17) that is in communication with each on-off valve and controls the opening or closing of each valve, and is in communication with each temperature sensor; The control module (17) pre-stores a temperature threshold , the temperature threshold It is used to indicate that the temperature of the fuel entering the fuel cell (13) has reached a desired level; the steps of the control module (17) controlling each on-off valve to open or close include: The control module (17) obtains the temperature values of the first temperature sensor, the second temperature sensor, and the third temperature sensor, which are respectively 、 、 ; The control module (17) determines and The size of , then control the first on-off valve to remain closed; if , then continue with the following steps; The control module (17) 、 、 Perform size comparison and issue corresponding control signals; like , the control module (17) controls the first on-off valve to remain open, and controls the second on-off valve and the third on-off valve to remain closed; like and , the control module (17) controls the second on-off valve to remain open, and controls the first on-off valve and the third on-off valve to remain closed; like and , the control module (17) controls the third on-off valve to remain open, and controls the first on-off valve and the second on-off valve to remain closed.

2. The liquid ammonia carrier power generation system according to claim 1, characterized in that: It also includes a preheating device, which is arranged upstream of the first side inlet of the first heat exchanger (11) and is used to heat the flash gas delivered from the liquid ammonia cargo tank (100).

3. The liquid ammonia carrier power generation system according to claim 2, characterized in that: The preheating device is a trough-type solar thermal collector (2).

4. The liquid ammonia carrier power generation system according to claim 3, characterized in that: The trough solar thermal collector (2) comprises a parabolic reflector and a heat collecting tube (21); the heat collecting tube (21) is connected to a pipeline from the liquid ammonia cargo tank (100) to the first side inlet of the first heat exchanger (11); the parabolic reflector receives light and reflects it to heat the heat collecting tube (21).

5. The liquid ammonia carrier power generation system according to claim 4, characterized in that: It also includes a redundant pipeline (3) which forms a parallel pipeline with the heat collecting pipe (21); an inlet valve is provided at the inlet end of the branch where the heat collecting pipe (21) is located; an outlet valve is provided at the outlet end of the branch where the heat collecting pipe (21) is located; and a switch valve is provided on the redundant pipeline (3).

6. The liquid ammonia carrier power generation system according to claim 2, characterized in that: It also includes a buffer tank (4), a flow detector (41) and a buffer controller (42); The buffer tank (4) is located upstream of the preheating device and is connected to the pipeline in parallel. A buffer inlet valve is installed at the inlet of the buffer tank (4), a buffer outlet valve is installed at the outlet of the buffer tank (4), and a straight-through valve is installed in the pipeline parallel to the buffer tank (4); The flow detector (41) is arranged at the outlet side of the liquid ammonia cargo tank (100), and the buffer controller (42) is communicatively connected with the flow detector (41), the buffer inlet valve, the buffer outlet valve, and the through valve.

7. The liquid ammonia carrier power generation system according to claim 6, characterized in that: The buffer controller (42) pre-stores a flow expectation threshold ; The steps of the buffer controller (42) controlling the buffer inlet valve, the buffer outlet valve, and the through valve to open or close include: The buffer controller (42) obtains the real-time flow value through the flow detector (41). ; The buffer controller (42) determines the real-time value of the flow and traffic expectation threshold size; like , the buffer controller (42) controls the buffer inlet valve and the buffer outlet valve to remain in a closed state, and controls the through valve to remain in an open state; like , the buffer controller (42) controls the buffer inlet valve and the buffer outlet valve to remain in an open state, and controls the through valve to remain in an open state.

8. The liquid ammonia carrier power generation system according to claim 1, characterized in that: The power output end of the converter (15) comprises a first interface and a second interface, wherein the first interface is connected to an electrical load device, and the second interface is connected to an energy storage device (5).

9. The liquid ammonia carrier power generation system according to claim 1, characterized in that: It comprises a waste heat utilization module (6), which comprises a first side and a second side, the discharge end (16) enters the first side pipeline of the waste heat utilization module (6), and the second side of the waste heat utilization module (6) is fed with normal temperature water.

10. The liquid ammonia carrier power generation system according to claim 1, characterized in that: It also includes a box structure and a temperature control component (7), at least the fuel cell (13) is located in the box structure; The temperature control assembly (7) includes an electric heating rod placed in the box structure and a thermocouple placed in the fuel cell (13). The temperature control assembly (7) also includes a temperature controller. The temperature controller determines the temperature in the fuel cell (13) through the thermocouple and controls the power on or off of the electric heating rod.

11. A liquid ammonia transport ship, characterized in that: A liquid ammonia transport ship power generation system comprising a hull and any one of claims 1 to 10; The hull comprises an engine room (200) and a plurality of liquid ammonia cargo tanks (100); the liquid ammonia transport ship power generation system is arranged in the engine room (200); and the electric energy outputted by the converter (15) of the liquid ammonia transport ship power generation system is used to drive the main engine of the ship.

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