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

Abstract

The invention provides a liquid ammonia transport ship power generation system and a liquid ammonia transport ship, the power generation system comprises a fuel cell power generation assembly, and the fuel cell power generation assembly comprises a first heat exchanger, a second heat exchanger, a fuel cell, a rear combustion chamber, a converter and a discharge end. Flash steam of the liquid ammonia liquid cargo tank enters the fuel cell anode inlet through the first side of the first heat exchanger. Air enters the fuel cell cathode inlet through the first side of the second heat exchanger. The anode and cathode outlets are connected with the rear combustion chamber. The electric energy output end of the fuel cell is connected with the converter and outputs outwards. The first heat exchanger second-side outlet is connected with the second heat exchanger second-side inlet, and the second heat exchanger second-side outlet is connected with the discharge end. A discharge outlet of the rear combustion chamber is connected with a second side inlet of the first heat exchanger, a second side inlet of the second heat exchanger and a discharge end through three branches, and each branch is provided with an on-off valve. The liquid ammonia flash steam is used as fuel, power is generated through the fuel cell to supply power to the ship, carbon emission is reduced, reliquefaction is not needed, and reasonable utilization of waste heat is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of fuel cell power generation, and in particular, to an ammonia carrier power generation system and an ammonia carrier that use fuel cells for power generation. Background Art

[0002] Boil Off Gas (BOG) refers to the gas generated by the vaporization of liquid cargo in a liquid cargo carrier due to environmental heat exchange or pressure changes. Taking an ammonia carrier as an example, BOG is mainly formed by the evaporation of liquid ammonia, and its main component is ammonia. Ammonia is toxic, corrosive, and has a risk of combustion and explosion when mixed with air to reach a specific concentration. Currently, the industry generally uses a re-liquefaction process to treat BOG, that is, gaseous ammonia is re-condensed into a liquid state through a refrigeration cycle and then returned to the cargo hold.

[0003] Existing re-liquefaction systems usually include equipment such as multi-stage compressors, expanders, heat exchangers, and condensers. Their complex process flow results in a large volume of equipment, making it difficult to arrange efficiently in the limited space of a ship. At the same time, the re-liquefaction system requires a large amount of electricity to maintain low-temperature conditions to prevent the evaporation of liquid ammonia, and this electricity often comes from burning more fuel, forming a vicious cycle. In addition, some residual BOG that is not completely liquefied and BOG that exceeds the processing limit of the re-liquefaction system during system operation need to be discharged by burning, resulting in energy waste.

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

[0005] The purpose of the present application is to provide an ammonia carrier power generation system and an ammonia carrier that can use ammonia boil-off gas as fuel and generate electricity through a solid oxide fuel cell to supply ship power, significantly reduce carbon emissions, can streamline the re-liquefaction system, avoid the energy consumption during the re-liquefaction process, and can also realize the efficient and reasonable utilization of the waste heat of the tail gas after power generation.

[0006] In a first aspect, a power generation system for a liquid ammonia carrier is provided, which includes a liquid ammonia cargo tank and a fuel cell power generation module. The fuel cell power generation module includes a first heat exchanger, a second heat exchanger, a fuel cell, a post-combustion chamber, a converter, and an emission end. Both the first heat exchanger and the second heat exchanger include a first side and a second side. The flash gas in the liquid ammonia cargo tank is transported to the inlet of the first side of the first heat exchanger. The outlet of the first side of the first heat exchanger is connected to the anode inlet of the fuel cell, and the anode outlet of the fuel cell is connected to the post-combustion chamber. Air is transported to the inlet of the first side of the second heat exchanger. The outlet of the first side of the second heat exchanger is connected to the cathode inlet of the fuel cell, and the cathode outlet of the fuel cell is connected to the post-combustion chamber. The electric energy output end of the fuel cell is connected to the converter and outputs power outward.

[0007] The outlet of the second side of the first heat exchanger is connected to the inlet of the second side of the second heat exchanger, and the outlet of the second side of the second heat exchanger is connected to the emission end. The emission port of the post-combustion chamber is connected to the inlet of the second side of the first heat exchanger, the inlet of the second side of the second heat exchanger, and the emission end through three branch lines, and an on-off valve is provided on each branch line.

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

[0009] In an implementable solution, the three branch lines connecting the emission port of the post-combustion chamber to the inlet of the second side of the first heat exchanger, the inlet of the second side of the second heat exchanger, and the emission end are respectively the first branch line, the second branch line, and the third branch line. A first on-off valve is provided on the first branch line, a second on-off valve is provided on the second branch line, and a third on-off valve is provided on the third branch line. It further includes a control module, which is communicatively connected to 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 emission port of the post-combustion chamber, a second temperature sensor is provided at the inlet of the first side of the first heat exchanger, and a third temperature sensor is provided at the inlet of the first side 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 steps for the control module to control the opening or closing of the first on-off valve, the second on-off valve, and the third on-off valve include:

[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] The control module performs operations on , , Perform size comparison and issue corresponding control signals;

[0014] If , 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] If 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] If 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 an implementable solution, the power generation system of the ammonia carrier 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 ammonia liquid cargo tank.

[0018] In an implementable solution, the preheating device is a trough solar collector.

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

[0020] In an implementable solution, the power generation system of the ammonia carrier further includes a redundant pipeline, which forms a parallel pipeline with the collector tube. An inlet valve is arranged at the inlet end of the branch where the collector tube is located, an outlet valve is arranged at the outlet end of the branch where the collector tube is located, and a switch valve is arranged on the redundant pipeline.

[0021] In an implementable solution, the power generation system of the ammonia carrier further includes a buffer tank, a flow detector and a buffer controller; the buffer tank is 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 through valve is installed in the pipeline parallel to the buffer tank; the flow detector is arranged on the outlet side of the ammonia liquid cargo tank, and the buffer controller is communicatively connected to the flow detector, the buffer inlet valve, the buffer outlet valve and the through valve.

[0022] In an implementable solution, a flow desired threshold value is pre-stored in the buffer controller ; the steps for the buffer controller to control the opening or closing of the buffer inlet valve, the buffer outlet valve and the through valve include:

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

[0024] The buffer controller determines the real-time value of the flow rate and the expected flow rate threshold for size;

[0025] If , the buffer controller controls the buffer inlet valve and the buffer outlet valve to remain closed, and controls the direct-through valve to remain open;

[0026] If , the buffer controller controls the buffer inlet valve and the buffer outlet valve to remain open, and controls the direct-through valve to remain open.

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

[0028] In an implementable solution, the power generation system of the ammonia carrier includes a waste heat utilization module, which includes a first side and a second side. The discharge end enters the pipeline on the first side of the waste heat utilization module, and the second side of the waste heat utilization module is passed through with normal temperature water.

[0029] In an implementable solution, the power generation system of the ammonia carrier further includes a box structure and a temperature control component. At least the fuel cell is located 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. The temperature control component further includes a temperature main controller, and the temperature main controller determines the temperature in the fuel cell through the thermocouple and controls the energization or power-off of the electric heating rod.

[0030] In a second aspect, an ammonia carrier is further provided, which includes a hull and the aforementioned power generation system of the ammonia carrier; the hull includes an engine room and a plurality of ammonia liquid cargo holds. The power generation system of the ammonia carrier is arranged at the engine room, and the electric energy output outward by the converter of the power generation system of the ammonia carrier is used to drive the main engine of the ship to work.

[0031] Compared with the prior art, the beneficial effects of the present application at least include the following: The power generation system of the ammonia carrier of the present application can consume the ammonia flash gas as fuel for power generation, without the need to consume electricity to maintain low temperature to prevent the evaporation of the re-liquefied ammonia. Therefore, the re-liquefaction system can be discarded, the fuel management system on the ship can be simplified, the energy consumption can be greatly reduced, and at the same time, the ship structure can be optimized, the space utilization rate of the ship can be improved, and it is helpful to increase the loading capacity of the ammonia carrier. At the same time, for the 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 post-combustion chamber, there is almost no carbon emission, which significantly reduces the emission of greenhouse gases, and at the same time effectively reduces NO XEmissions of harmful substances such as. Further, since the amount of flash gas generated in the liquid ammonia cargo tank is sufficient, the power generation system of the liquid ammonia carrier of the present application can be used as the navigation and ship-wide power source of the liquid ammonia carrier, thereby optimizing the internal combustion engine configuration. On the one hand, the space occupancy rate is optimized, and on the other hand, it provides assistance for achieving low-carbon or even zero-carbon emissions of the ship.

[0032] In the power generation system of the liquid ammonia carrier of the present application, the exhaust gas discharged from the post-combustor is respectively connected to the first heat exchanger, the second heat exchanger and the discharge end through three branches provided with on-off valves, so as to selectively use the high-temperature exhaust gas for preheating air, preheating ammonia fuel or directly discharging according to needs. Furthermore, the exhaust gas heat of the post-combustor is more reasonably and effectively utilized, the cascade utilization rate of the system waste heat is improved, and the adverse effects brought by unreasonable waste heat utilization to the reaction of the fuel cell can be avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

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

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

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

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

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

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

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

[0041] Figure 8 This is a schematic diagram showing the composition of another ammonia carrier shown in the embodiments of the present application.

[0042] In the figure: 1. Fuel cell power generation component; 11. First heat exchanger; 12. Second heat exchanger; 13. Fuel cell; 14. Rear combustion chamber; 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. Parabolic trough solar collector; 21. Collector tube; 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. Straight-through valve; 5. Energy storage device; 6. Waste heat utilization module; 7. Temperature control component; 100. Liquid ammonia cargo tank; 200. Engine room. Detailed implementation manners

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. Generally, the components of the embodiments of the present application described and illustrated in the drawings here 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 drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts fall within the scope of protection of the present application.

[0045] One of the purposes for the inventors of the present application to propose the technical solution of the present application is to improve the utilization rate of ammonia flash gas and to expect to discard the reliquefaction system to optimize the hull structure. On the other hand, it is to achieve further energy conservation and emission reduction.

[0046] Meanwhile, the inventors also found that in the power generation system of a conventional solid oxide fuel cell, the gases that have not fully reacted at the anode and cathode of the fuel cell are transported to the afterburner for combustion treatment. Since the temperature of the exhaust gas discharged from the outlet of the afterburner is quite high, the usual treatment method is to use this part of the exhaust gas to preheat the air entering the fuel cell, and then discharge the exhaust gas after completion of the preheating. However, even after being used to preheat the air, the exhaust gas discharged from the afterburner still retains a relatively high temperature. If directly discharged, it will cause a large amount of heat waste, resulting in low energy utilization rate, which is actually an indirect waste of flash steam. In addition, in some power generation systems, the exhaust gas will be further used to preheat the fuel gas after preheating the air. However, in certain specific situations, the temperature of the exhaust gas discharged from the afterburner may be lower than the temperature of the fuel gas. At this time, if the exhaust gas is allowed to exchange heat with the fuel gas, not only can effective preheating not be achieved, but instead the temperature of the fuel gas will be reduced, resulting in side effects, thereby reducing the reaction efficiency and adding an additional burden to the reaction process of the fuel cell.

[0047] To solve the foregoing technical problems, as Figure 1 shown, an embodiment of the present application first provides a power generation system for a liquefied ammonia carrier, including a liquefied 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 afterburner 14, a converter 15, and an emission end 16.

[0048] Both the first heat exchanger 11 and the second heat exchanger 12 include a first side and a second side. The flash steam in the liquefied ammonia cargo tank 100 is transported to the inlet of the first side of the first heat exchanger 11. The outlet of the first side of the first heat exchanger 11 is connected to the anode inlet of the fuel cell 13. The anode outlet of the fuel cell 13 is connected to the afterburner 14. Air is transported to the inlet of the first side of the second heat exchanger 12. The outlet of the first side of the second heat exchanger 12 is connected to the cathode inlet of the fuel cell 13. The cathode outlet of the fuel cell 13 is connected to the afterburner 14. The power output end of the fuel cell 13 is connected to the converter 15 and outputs power outward.

[0049] The outlet of the second side of the first heat exchanger 11 is connected to the inlet of the second side of the second heat exchanger 12. The outlet of the second side of the second heat exchanger 12 is connected to the emission end 16. The emission port of the afterburner 14 is connected to the inlet of the second side of the first heat exchanger 11, the inlet of the second side of the second heat exchanger 12, and the emission end 16 through three branches, and a on-off valve is provided on each branch.

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

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

[0052] Among them, the reaction formula in the fuel cell 13 is:

[0053]

[0054]

[0055] After that, the charge generated by the fuel cell 13 enters the converter 15, which is used to convert it into the rated voltage of the ship and then output for power supply to provide power for the ship's navigation. Since the amount of flash gas generated in the ammonia liquid cargo tank 100 is sufficient, the electric energy generated by the fuel cell 13 is sufficient to fully supply the power demand for the ship's navigation. Therefore, even without setting an internal combustion engine power, it is sufficient for use. In addition, in the high-temperature gas at the anode outlet of the fuel cell 13, in addition to the water generated by the electrochemical reaction, there are unreacted ammonia and hydrogen decomposed from ammonia, while the high-temperature gas at the cathode outlet of the fuel cell 13 is unreacted 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 power generation system of the ammonia carrier in this application can consume the flash vapor of ammonia as fuel for power generation, without the need to consume electricity to maintain low temperature to prevent the evaporation of re-liquefied ammonia. Therefore, the re-liquefaction system can be discarded, simplifying the fuel management system on board, significantly reducing energy consumption, optimizing the ship structure at the same time, improving the space utilization rate of the ship, and helping to increase the loading capacity of the ammonia carrier. At the same time, for the ammonia power generation system of this application, whether it is the reaction products of the anode and cathode of the fuel cell 13 or the combustion products of the post-combustion chamber 14, there is almost no carbon emission, significantly reducing the emission of greenhouse gases, and effectively reducing the emission of harmful substances such as NO X etc. Further, since the amount of flash vapor generated in the ammonia cargo tank 100 is large enough, the power generation system of the ammonia carrier in this application can be used as the power source for the navigation and the whole ship of the ammonia carrier, thus optimizing the internal combustion engine configuration, optimizing the space occupancy rate on the one hand, and providing assistance for realizing low-carbon or even zero-carbon emissions of the ship on the other hand.

[0059] Ammonia is an ideal hydrogen carrier, with a hydrogen content of up to 121 kg H 2 / m 3 , far exceeding that of liquid hydrogen and other organic hydrogen compounds. This means that ammonia can not only be used directly as a zero-carbon fuel for combustion or provide fuel for SOFC by reforming to produce hydrogen, but also due to its relatively easy storage and transportation characteristics, making the ammonia-based energy supply chain more feasible. Using SOFC as the only power source, the ammonia carrier can achieve truly zero-emission navigation because ammonia does not produce carbon dioxide during the combustion process and can be synthesized from renewable energy, further reducing the carbon footprint of the entire life cycle.

[0060] All in all, this application uses the fuel cell 13 as the main power generation device of the ammonia carrier. With its efficient, flexible and environmentally friendly characteristics, it provides a better choice than the traditional re-liquefaction device. It can not only effectively solve the problem of evaporation gas, but also significantly improve the energy utilization efficiency, reduce the operation cost, reduce environmental pollution, and make an important contribution to realizing green shipping.

[0061] In the power generation system of the ammonia carrier of this application, for the high-temperature tail gas discharged from the discharge port of the post-combustion chamber 14, three discharge branch roads are reserved in the solution of this application, and a cut-off valve is set on each branch road, so that the high-temperature tail gas can be selectively used to preheat air, preheat ammonia fuel or directly discharged according to needs.

[0062] For example, if the temperature of the fuel entering the first heat exchanger 11 is relatively high and already meets the temperature requirement for entering the fuel cell 13, at this time, only the high-temperature tail gas discharged from the post-combustion chamber 14 needs to be introduced into the second side of the second heat exchanger 12, so as to more effectively preheat the air.

[0063] For another example, if the temperature of the fuel entering the first heat exchanger 11 is already not lower than the temperature of the high-temperature exhaust gas, at this time, it is only necessary to introduce the high-temperature exhaust gas discharged from the afterburner 14 into the second side of the second heat exchanger 12, thereby avoiding the reduction of the fuel temperature caused by the heat exchange process of the first heat exchanger 11, and thus 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, at this time, the high-temperature exhaust gas from 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 full use of the heat of the high-temperature exhaust gas.

[0065] For another example, if the exhaust gas discharge amounts at the anode and cathode of the fuel cell 13 are very small, the combustion temperature in the afterburner 14 is relatively low, the exhaust gas discharge amount is relatively low, and the exhaust gas temperature is also relatively low. And the air entering the second heat exchanger 12 may have been preheated by other preheating devices first, and the temperature is already higher than the exhaust gas temperature of the afterburner 14. At this time, the exhaust gas of the afterburner 14 can be directly transported to the discharge end 16.

[0066] In summary, in the power generation system of the liquid ammonia carrier of the present application, the exhaust gas discharged from the afterburner 14 is respectively connected to the first heat exchanger 11, the second heat exchanger 12 and the discharge end 16 through three branches provided with on-off valves, so as to selectively use the high-temperature exhaust gas for preheating air, preheating ammonia fuel or direct discharge according to needs, thereby making more reasonable and effective use of the exhaust gas heat of the afterburner 14, realizing temperature complementarity and selective cascade utilization of energy, improving the cascade utilization rate of the system waste heat, and avoiding the adverse effects brought by unreasonable waste heat utilization to the reaction of the fuel cell 13.

[0067] In some embodiments, by comparing the temperature at the discharge port of the afterburner 14, the temperature at the inlet of the first side of the first heat exchanger 11 and the temperature at the inlet of the first side of the second heat exchanger 12, the opening or closing of the on-off valve is controlled, so as to realize the reasonable and efficient utilization of the exhaust gas heat of the afterburner 14.

[0068] In some embodiments, such as Figure 2As shown, the three branches connecting the discharge 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 discharge end 16 are the first branch A1, the second branch A2, and the third branch A3 respectively. 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 switch valves. However, preferably, the liquefied ammonia carrier power generation system further includes a control module 17, which is communicatively connected to 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 shown, a first temperature sensor H1 is provided at the discharge 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 communicatively connected to the control module 17.

[0070] In this embodiment, the steps for the control module 17 to control the opening or closing of the first on-off valve P1, the second on-off valve P2, and the third on-off valve P3 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] The control module 17 compares the magnitudes of 、 、 and issues corresponding control signals;

[0073] If , 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, realizing the preheating of the flash gas fuel and air;

[0074] If 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 then reaches the discharge end 16, realizing the preheating of the air;

[0075] If and Then, the control module 17 controls the third on-off valve to remain open and controls the first and second on-off valves to remain closed. At this time, the high-temperature tail gas directly goes to the discharge end 16.

[0076] In addition, a temperature threshold can be pre-stored in the control module 17 This temperature threshold is used to indicate that the fuel temperature entering the fuel cell 13 has reached the required level and preheating is no longer needed. Therefore, if When, regardless of And How big the size difference is, at this time, the control module 17 can control the first on-off valve P1 to remain closed. If When, then the control module 17 pairs , , Compare the sizes and send corresponding control signals.

[0077] In summary, the control module 17 of this embodiment realizes the comprehensive comparison and judgment of the gas temperatures at the discharge 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. Furthermore, it automatically regulates the discharge path of the high-temperature tail gas discharged from the afterburner 14 to achieve reasonable and efficient reuse of the waste heat of the tail gas.

[0078] In some embodiments, the power generation system of the liquid ammonia carrier may further include 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 transported from the liquid ammonia cargo tank 100. The preheating device can effectively increase the gas temperature entering the anode of the fuel cell 13, thereby helping to improve the power generation efficiency.

[0079] In a preferred embodiment, as Figure 3 Shown, the preheating device is a trough solar collector 2. In this way, when the ship is sailing during the day, solar energy can be used to preheat the ammonia gas entering the first side of the first heat exchanger 11.

[0080] Furthermore, the combined 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 the power generation efficiency and the waste heat utilization level.

[0081] When the liquid ammonia carrier is sailing under good lighting conditions, the trough solar collector 2 can significantly increase the temperature of the ammonia gas entering the first side of the first heat exchanger 11, making the ammonia gas temperature reach a relatively high level, so that the temperature at the first-side inlet of the first heat exchanger 11 is higher than the temperature at the discharge port of the afterburner 14 (i.e., ), or reach the required temperature demand (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 no longer needs to pass through the first heat exchanger 11. On the one hand, the waste heat of the exhaust gas can be saved and can be directly used to preheat the air or directly transported to the emission end 16 for other uses, improving the utilization efficiency of the exhaust gas waste heat. On the other hand, it can also prevent the exhaust gas below the ammonia temperature from absorbing the heat of ammonia, thereby avoiding side effects.

[0082] When the liquid ammonia carrier sails under poor lighting conditions (such as at night), the trough solar collector 2 cannot play a heating role. At this time, the control module 17 can judge the gas temperatures at the discharge 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 then selectively use the waste heat of the exhaust gas to preheat the fuel, air, or directly discharge it.

[0083] In some embodiments, as Figure 4 shown, the trough solar collector 2 generally includes a parabolic reflector (not shown in the figure) and a collector pipe 21. The collector pipe 21 is connected to the 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 to heat the collector pipe 21 to achieve heating of the flash vapor.

[0084] In some embodiments, as Figure 4 shown, the liquid ammonia carrier power generation system can also include a redundant pipeline 3, which forms a parallel pipeline with the collector pipe 21. An inlet valve G1 is provided at the inlet end of the branch where the collector pipe 21 is located, an outlet valve G2 is provided at the outlet end of the branch where the collector pipe 21 is located, and a switch valve G3 is provided on the redundant pipeline 3. In this way, when the trough solar collector 2 needs to be maintained, the inlet valve G1 and the outlet valve G2 can be closed, and the switch valve G3 can be opened to allow the flash vapor to be transported through the redundant pipeline 3.

[0085] In some embodiments, as Figure 5As shown in the figure, the power generation system of the liquid ammonia carrier may further 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 is connected to the pipeline in parallel. A buffer inlet valve M1 is installed at the inlet of the buffer tank 4, and a buffer outlet valve M2 is installed at the outlet of the buffer tank 4. A direct-through valve M3 is installed in the pipeline parallel to the buffer tank 4. The flow detector 41 is arranged on the outlet side of the liquid ammonia cargo tank 100, and the buffer controller 42 is communicatively connected to the flow detector 41, the buffer inlet valve M1, the buffer outlet valve M2, and the direct-through valve M3. The buffer controller 42 can obtain the flow rate of the flashed gas output by the liquid ammonia cargo tank 100 through the flow detector 41, and then determine whether the flashed gas is excessive. If it is excessive, at this time, the flow detector 41 can open the buffer inlet valve M1 to allow part of the flashed gas to enter the buffer tank 4 for pre-storage, so as to prevent the fuel cell 13 from generating too much unreacted gas, and further reduce the waste of the flashed gas.

[0086] When using the gas in the buffer tank 4, the buffer controller 42 can control to keep the buffer inlet valve M1 and the buffer outlet valve M2 open.

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

[0088] In some embodiments, a flow rate expectation threshold can be pre-stored in the buffer controller 42 ; assuming that the standard ammonia gas volume required for the fuel cell 13 to reach the high-efficiency power generation level (which can be defined by the designer) is , however, in order to ensure that the flow rate of the flashed gas is sufficient to maintain the high-efficiency power generation of the fuel cell 13, the set flow rate expectation threshold is at least not less than the size of the standard ammonia gas volume .

[0089] Therefore, in this embodiment, it is preferably set that the buffer outlet valve M2 has a check valve characteristic, or an independent check valve is provided at the outlet of the buffer tank 4.

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

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

[0092] The buffer controller 42 determines the size of the real-time flow rate value and the flow rate expectation threshold ;

[0093] If , the buffer controller 42 controls the buffer inlet valve M1 and the buffer outlet valve M2 to remain closed, and controls the direct-through valve M3 to remain open, so that the flash steam is directly transported to the first heat exchanger 11;

[0094] If , the buffer controller 42 controls the buffer inlet valve M1 and the buffer outlet valve M2 to remain open, and controls the direct-through valve M3 to remain open, and then temporarily receives the excessive flash steam through the buffer tank 4.

[0095] In some embodiments, the buffer inlet valve M1 and the direct-through valve M3 can adopt proportional valves, and the buffer controller 42 is used to control the opening ratio of the buffer inlet valve M1 and the direct-through valve M3, so as to shunt the flash steam, control part of the flash steam to enter the buffer tank 4, and the flash steam required for power generation is transported to the first heat exchanger 11 through the direct-through valve M3.

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

[0097] In some embodiments, as Figure 6 shown, it includes a waste heat utilization module 6, which includes a first side and a second side. The discharge end 16 is discharged through the first side pipeline of the waste heat utilization module 6. The second side of the waste heat utilization module 6 is introduced with normal temperature water (generally engine room fresh water), and after heat exchange with the high-temperature tail gas discharged from the discharge end 16, the second side of the waste heat utilization module 6 discharges hot water that meets the ship's heat load requirements and leads to the heat user through the pipeline. For example, the waste heat utilization module 6 can be a waste heat boiler.

[0098] In some embodiments, the power generation system of the liquid ammonia carrier ship 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 in the box structure to facilitate the hoisting of the whole fuel cell 13. Preferably, the fuel cell power generation assembly 1 is concentrated in a box structure as a whole. Among them, the temperature control component 7 generally includes an electric heating rod placed in the box structure and a thermocouple placed in the fuel cell 13. The temperature control component 7 further includes a temperature main controller, and the temperature main controller determines the temperature in the fuel cell 13 through the thermocouple and controls the energization or de-energization of the electric heating rod. Through the action of the temperature control component 7, the high-temperature state during the operation of the fuel cell 13 is maintained.

[0099] As Figure 7 and Figure 8 shown, the embodiment of the present application further provides an ammonia carrier, which includes a hull and the aforementioned ammonia carrier power generation system. The hull includes an engine room 200 and a number of ammonia liquid cargo tanks 100. The ammonia carrier power generation system is arranged at the engine room 200. The electric energy output by the converter 15 of the ammonia carrier power generation system is used to drive the main engine of the ship to work.

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

[0101] The above are only some preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A liquid ammonia transport ship power generation system, comprising a liquid ammonia cargo tank (100), characterized in that: It also includes 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; The 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 post-combustion chamber (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 electric energy output end of the fuel cell (13) is connected to the converter (15) and outputs the electric energy 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 post-combustion chamber (14) is respectively 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 three branches, and each branch is provided with an on-off valve.

2. The liquid ammonia transport ship power generation system according to claim 1, characterized in that: The opening or closing of the on-off valve is controlled by comparing the temperature at the exhaust port of the post-combustion 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).

3. The liquid ammonia carrier power generation system according to claim 1, characterized in that: The three branches connecting the discharge port of the post-combustion chamber (14) with 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) are respectively a first branch, a second branch and a 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; It also includes a control module (17) which is in communication 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.

4. The liquid ammonia transport ship power generation system according to claim 3, characterized in that: A first temperature sensor is arranged at the discharge port of the post-combustion chamber (14), a second temperature sensor is arranged at the first side inlet of the first heat exchanger (11), and a third temperature sensor is arranged at the first side inlet of the second heat exchanger (12); The first temperature sensor, the second temperature sensor and the third temperature sensor are communicatively connected to the control module (17).

5. The liquid ammonia transport ship power generation system according to claim 4, characterized in that: The step of the control module (17) controlling the first on-off valve, the second on-off valve and the third on-off valve to open or close comprises: 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) , , Perform size comparison and send 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.

6. The liquid ammonia carrier power generation system according to any one of claims 1 to 5, characterized in that: It also comprises 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).

7. The liquid ammonia transport ship power generation system according to claim 6, characterized in that: The preheating device is a trough-type solar thermal collector (2).

8. The liquid ammonia transport ship power generation system according to claim 7, 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 a first side inlet of the first heat exchanger (11); the parabolic reflector receives light and reflects light to heat the heat collecting tube (21).

9. The liquid ammonia transport ship power generation system according to claim 8, characterized in that: It also comprises a redundant pipeline (3) which forms a parallel pipeline with the heat collecting pipe (21); an inlet valve is arranged at the inlet end of the branch where the heat collecting pipe (21) is located; an outlet valve is arranged at the outlet end of the branch where the heat collecting pipe (21) is located; and a switch valve is arranged on the redundant pipeline (3).

10. The liquid ammonia transport ship power generation system according to claim 6, 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 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.

11. The liquid ammonia transport ship power generation system according to claim 10, 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 rate Expected flow 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.

12. The liquid ammonia transport ship 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, the first interface being connected to a power load device, and the second interface being connected to an energy storage device (5).

13. 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 introduced with normal temperature water.

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

15. 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 14; The ship 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 externally by the converter (15) of the liquid ammonia transport ship power generation system is used to drive the ship's main engine to operate.

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