Toxic ammonia gas absorption system for liquid ammonia fuel ship

Abstract

A toxic ammonia gas absorption system for a liquid ammonia fuel ship comprises a toxic ammonia gas release source (100), an ammonia gas absorption tank (200), an ammonia gas guide pipeline and a diluted ammonia gas discharge pipeline. The ammonia gas absorption tank (200) is provided with an absorbent (201), a gas diffusion layer (202), a liquid level switch (203), a gas phase space (206) and a temperature control device (207). The system can improve the safety, the environmental protection property and the economical efficiency of the ammonia fuel used by the ship.

Description

Technical Field

[0001] The present application relates to the technical field of marine equipment, and in particular to a toxic ammonia absorption technology for a ship using ammonia as fuel. Background Art

[0002] As the global shipping industry faces increasingly stringent environmental protection requirements, especially the International Maritime Organization has set a goal of achieving net zero greenhouse gas emissions in the shipping industry by 2050, traditional fossil fuels can no longer meet the sustainable development needs of the future shipping industry. Ammonia fuel, as a zero-carbon fuel, is regarded as one of the ideal alternative fuels for the shipping industry due to its high energy density and easy storage and transportation.

[0003] However, in the process of promoting the use of ammonia fuel, people found that ammonia is highly toxic. Once leaked, it is very likely to threaten the health of crew members and equipment safety. According to statistics, when the concentration of ammonia at normal temperature and pressure reaches 2700ppm, it can be fatal for people to stay in this environment for 10 minutes; when the concentration reaches 20-50ppm, it will cause human discomfort. Therefore, on ammonia-fueled ships, how to effectively control and deal with accidental leaks of toxic ammonia has become a key technical issue that needs to be solved urgently.

[0004] At present, the existing ship ammonia treatment technology has some shortcomings. On the one hand, the traditional ammonia treatment equipment is inefficient and cannot fully absorb and neutralize the leaked ammonia, resulting in excessive emissions of residual ammonia and harming the environment. On the other hand, these devices are usually complex in structure and inflexible in connection, making it difficult to adapt to the personalized needs of ships of different types and sizes, limiting their promotion and application. In addition, the operation and maintenance of existing equipment is relatively cumbersome, and the degree of automation is not high, which increases the cost of use.

[0005] In view of the above technical problems, it is urgent to develop a safe, efficient, environmentally friendly, reliable, flexible and practical ship ammonia leakage treatment system. The system should not only be able to quickly and effectively absorb and treat the leaked toxic ammonia, control the ammonia concentration within a safe range, and ensure the safety of crew members and equipment; it should also have efficient ammonia absorption and conversion capabilities to minimize the emission of residual ammonia and achieve environmental protection standards; at the same time, the system should also have good adaptability and flexibility, be compatible with existing ship facilities, and meet the customized needs of different ship types; in addition, convenient operation and low-cost maintenance are also key considerations.

[0006] In summary, the development of a ship ammonia leakage treatment system that meets the above requirements is of great significance for promoting the safe application of ammonia fuel in the shipping industry and supporting the green and sustainable development of the industry. It will also bring new development opportunities to the field of ship design and manufacturing. Summary of the invention

[0007] The purpose of the present application is to provide a toxic ammonia absorption system for a liquid ammonia fuel ship to solve the problems raised in the above background technology.

[0008] Specifically, in the embodiment of the present application, the toxic ammonia release source collects ammonia leaked from the ship's liquid ammonia fuel system and then passes the ammonia into an ammonia absorption tank, which is provided with an absorbent for absorbing ammonia, and a liquid level switch for controlling the liquid level of the absorbent, thereby ensuring that the interior of the ammonia absorption tank has sufficient gas phase space. The ammonia absorption tank is also provided with a gas diffusion layer, and the position of the gas diffusion layer is set lower than the liquid level of the absorbent. The addition of the gas diffusion layer improves the absorption effect of the absorbent on ammonia, and can well control the displacement of ammonia. The ammonia absorption tank is also provided with a temperature control device for controlling the temperature in the tank. Since a lower temperature is more conducive to the absorption of ammonia by the absorbent, it is necessary to control the temperature in the tank;

[0009] An ammonia guide pipeline, one end of which is connected to the toxic ammonia release source and the other end of which is connected to the ammonia absorption tank, and is arranged below the gas diffusion layer, so that the ammonia collected by the toxic ammonia release source must pass through the gas diffusion layer during the floating process after being introduced into the absorbent of the ammonia absorption tank;

[0010] The diluted ammonia discharge pipeline is used to guide the slowly released ammonia after absorption from the ammonia absorption tank and discharge it to the external environment.

[0011] There is no moving equipment in this application, and there is almost no maintenance after one installation. Only the liquid level and pressure need to be controlled, and automatic control can be achieved. The mechanical structure inside the ammonia absorption tank is simple, and the packing layer does not need to be replaced during installation. The equipment cost and operating cost are relatively low.

[0012] Preferably, the liquid level switch can be implemented by adding a control valve at the water inlet or outlet to control the liquid level.

[0013] Preferably, the gas diffusion layer may be a random packing or a structured packing, or even a metal wire mesh.

[0014] Optionally, the absorbent may be water, sodium hydroxide solution or the like. When absorbents other than water are selected, these absorbents cannot be connected to the fresh water tank and the ballast tank.

[0015] Optionally, the ammonia absorption tank can be selected as a vertical container, so that the layout of the absorption tank can be reasonably optimized according to the area in the cabin.

[0016] The present application discloses a toxic ammonia absorption system for a liquid ammonia fuel ship, comprising:

[0017] Toxic ammonia release source, used to collect ammonia leaked from the ship's liquid ammonia fuel system;

[0018] An ammonia absorption tank, in which an absorbent for absorbing the ammonia is provided, and a liquid level switch is provided for controlling the liquid level of the absorbent, thereby ensuring that there is sufficient gas phase space inside the ammonia absorption tank, and a gas diffusion layer is also provided in the ammonia absorption tank, and the position of the gas diffusion layer is set lower than the liquid level of the absorbent, and a temperature control device is also provided in the ammonia absorption tank for controlling the temperature inside the tank;

[0019] an ammonia guide pipeline, one end of which is connected to the toxic ammonia release source, and the other end of which is connected to the ammonia absorption tank and is arranged below the gas diffusion layer, so that the ammonia collected by the toxic ammonia release source must pass through the gas diffusion layer during the floating process after being introduced into the absorbent of the ammonia absorption tank;

[0020] The diluted ammonia gas discharge pipeline is used to guide the ammonia gas slowly released after being absorbed by the absorbent from the ammonia gas absorption tank and discharge it to the external environment.

[0021] In a preferred example, the ammonia guiding pipeline includes a gas phase ammonia exhaust pipeline and a liquid phase ammonia exhaust pipeline; a multi-hole nozzle is provided at the end of the gas phase ammonia exhaust pipeline to increase the diffusion efficiency of the ammonia in the absorbent.

[0022] In a preferred example, the multi-hole nozzle includes a plurality of small holes evenly distributed along its circumference, which are used to disperse the ammonia in the ammonia guide pipeline into small bubbles, so as to increase the contact area between the ammonia and the absorbent and improve the ammonia absorption efficiency.

[0023] In a preferred example, the gas diffusion layer contains filler and is connected to the inner wall of the ammonia absorption tank via a positioning clip.

[0024] In a preferred example, the diluted ammonia discharge pipeline includes a ventilation pipe and a ventilation mast connected in sequence, one end of the ventilation pipe is connected to the gas phase space inside the ammonia absorption tank, and the other end is connected to the ventilation mast, which is used to guide the ammonia that is slowly released after being absorbed by the absorbent in the gas phase space inside the ammonia absorption tank to the ventilation mast for discharge into the atmosphere.

[0025] In a preferred embodiment, a temperature control device is provided in the ammonia absorption tank for adjusting the liquid temperature after absorbing ammonia to maintain a stable absorption rate.

[0026] In a preferred example, an absorbent spray system is provided at the end of the ventilation mast to further neutralize the concentration of ammonia discharged from the ammonia absorption tank into the ventilation pipe, and the waste liquid generated by the absorption liquid spray system flows back to the ammonia absorption tank through the diluted ammonia discharge pipeline.

[0027] In a preferred example, the ammonia absorption tank is also provided with a water inlet and a water outlet for cyclically updating the absorbent absorption to maintain the absorption efficiency of ammonia.

[0028] In a preferred example, the water source of the water inlet is a fresh water tank, and the water source downstream of the water outlet is a ballast tank.

[0029] In a preferred example, the toxic ammonia release source is selected from the following group: a receiving tray, a liquid ammonia fuel tank pressure release valve, a double-walled pipe ammonia discharge port, waste water from a breathable mast water spray system, and a closed place containing ammonia fuel.

[0030] In a preferred example, the liquid level switch controls the liquid level height of the absorbent to ensure that the volume of the gas phase space in the ammonia absorption tank accounts for at least 20% of the total volume of the ammonia absorption tank.

[0031] Compared with the prior art, the embodiments of the present application have at least the following differences and effects:

[0032] First, it significantly improves the safety of ships using ammonia fuel. This system effectively collects and absorbs accidentally leaked toxic ammonia by setting up an ammonia absorption tank and related guide and discharge pipelines. By using water to absorb and neutralize ammonia, the ammonia concentration in the environment can be quickly reduced and controlled within a safe range, avoiding poisoning of personnel and damage to equipment, thereby enhancing the overall safety of the ship.

[0033] Furthermore, the ammonia treatment efficiency is improved and emissions are reduced. A gas diffusion layer is provided in the ammonia absorption tank, and the porous nozzle at the end of the gas phase ammonia discharge pipeline is used to strengthen the full contact and mass transfer between ammonia and water, thereby improving the absorption efficiency. At the same time, the volume of the water tank is reduced by maintaining the gas-liquid contact area in the water tank. After treatment, most of the ammonia is converted into ammonium hydroxide solution, and the ammonia that meets the emission standards is slowly released after being absorbed by the absorbent and is discharged to a safe area through the discharge pipe, minimizing the release of toxic ammonia.

[0034] Furthermore, the system is flexible and adaptable. The system can be flexibly connected to potential ammonia leak sources such as pipelines, valves, tanks, etc. according to the ship layout, ensuring comprehensive coverage and rapid response. The system design is compatible with the existing structure and operating procedures of the ship and can be applied to ships of various types and sizes. In addition, the modular design of the system allows it to be adjusted according to different ship sizes and needs, providing a highly customized solution.

[0035] Furthermore, the operation and maintenance are simple and the cost is low. Compared with other ammonia treatment technologies, this system has a simple equipment structure, can realize automatic control, and can be quickly started when a leak occurs. It only needs regular water replenishment and maintenance. It is simple to operate and has high reliability. The design of the water tank takes into account the recycling of water and wastewater treatment. The water source can use the existing fresh water system, seawater system or other water sources on the ship, which is economical and practical.

[0036] Furthermore, the environmental benefits are significant. Converting ammonia into ammonium hydroxide through chemical neutralization reaction not only reduces the harm of toxic ammonia emissions to the environment, but also supports the goal set by the International Maritime Organization to achieve net zero greenhouse gas emissions in the shipping industry by 2050, which is of great significance to environmental protection.

[0037] To sum up, the toxic ammonia absorption system for liquid ammonia fuel ships provided in this application is safe and reliable, efficient and environmentally friendly, easy to operate and maintain, and has strong applicability. It can effectively control the risk of ammonia fuel leakage, promote the safe application of ammonia fuel in the shipping industry, and provide important support for the sustainable development of the shipping industry. It has broad application prospects.

[0038] A large number of technical features are recorded in the specification of this application, which are distributed in various technical solutions. If all possible combinations of technical features of this application (i.e., technical solutions) are to be listed, the specification will be too long. In order to avoid this problem, the various technical features disclosed in the above content, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (these technical solutions are all deemed to have been recorded in this specification), unless the combination of such technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed, and features C and D are equivalent technical means that play the same role. Technically, only one can be used, and it is impossible to use them at the same time. Feature E can be combined with feature C technically. Then, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, and the solution of A+B+C+E should be deemed to have been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is a schematic structural diagram of a toxic ammonia absorption system for a liquid ammonia fuel ship according to the first embodiment of the present application.

[0040] Figure 2 It is an exemplary structural schematic diagram of a nozzle in a toxic ammonia absorption system for a liquid ammonia fuel ship according to the first embodiment of the present application.

[0041] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0042] 100: Source of toxic ammonia release

[0043] 101: Takeover

[0044] 102: Liquid ammonia fuel tank pressure relief valve

[0045] 103: Double wall pipe ammonia discharge port

[0046] 104: Ventilation mast water sprinkler system wastewater

[0047] 105: Confined spaces containing ammonia fuel

[0048] 200: Ammonia absorption tank

[0049] 201: Absorbent

[0050] 202: Diffusion layer

[0051] 203: Liquid level switch

[0052] 204: Water entry hole

[0053] 205: Water outlet

[0054] 206: Gas Phase Space

[0055] 301: Gas phase ammonia exhaust pipeline

[0056] 302: Liquid phase ammonia discharge pipeline

[0057] 303: Check valve

[0058] 304: Nozzle

[0059] 401: Ventilation tube

[0060] 402: Breathable mast

[0061] 403: Water sprinkler system DETAILED DESCRIPTION

[0062] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that the technical solution claimed in the present application can be implemented even without these technical details and various changes and modifications based on the following embodiments.

[0063] The following is a brief description of some of the innovative features of this application:

[0064] After extensive and in-depth research, the inventor of this application proposed an innovative toxic ammonia absorption system to address the safety and environmental challenges faced by the current shipping industry using liquid ammonia fuel. The design concept of this system is based on the following core innovations:

[0065] 1. Special design of ammonia absorption tank:

[0066] 1) Gas diffusion layer: An innovative gas diffusion layer is installed inside the ammonia absorption tank. This layer is mainly composed of, for example, multiple layers of fillers to increase the contact area between ammonia and the absorbent. The diffusion layer is located in the middle or lower part of the tank to ensure that all ammonia entering the tank through the pipeline must pass through this layer, thereby increasing the contact time and area between ammonia and water and improving the efficiency of chemical absorption.

[0067] 2) Liquid level control system: Equipped with a high-precision liquid level switch to monitor the height of the absorbent in the tank in real time, ensuring that there is enough absorbent to absorb ammonia while maintaining the necessary gas phase space to avoid excessive pressure.

[0068] 2. Ammonia guide pipeline and porous nozzle:

[0069] 1) Ammonia guide pipeline: The specially designed ammonia guide pipeline connects the ammonia release source and the ammonia absorption tank. The pipeline is designed as a dual-channel system, including separate processing channels for gaseous and liquid ammonia, to ensure that all types of ammonia leaks are effectively introduced into the absorption system.

[0070] 2) Multi-hole nozzle: A multi-hole nozzle is installed at the end of the gas phase ammonia exhaust pipeline. The nozzle is designed with multiple small holes to evenly disperse the ammonia into tiny bubbles in the water tank, increase the contact area between ammonia and water, and accelerate the chemical reaction rate.

[0071] 3. Breathable mast and water sprinkler system:

[0072] 1) Venting Mast: Installed above the ammonia absorber, it is used to safely discharge the treated ammonia gas overboard. The design of the venting mast allows for efficient gas release while preventing ammonia gas from accumulating on board.

[0073] 2) Water spray system: A water spray system is installed at the end of the ventilation mast to further neutralize the emitted ammonia. This system can spray fine water droplets when necessary to react with ammonia and reduce the concentration of ammonia to a safe level.

[0074] These structural technical means together constitute a complete solution, aiming to improve the safety and environmental friendliness of liquid ammonia fuel ships during use. Each technical means is optimized according to the characteristics of ammonia and the requirements of the ship's use environment, ensuring that the system is both efficient and reliable.

[0075] In summary, the toxic ammonia absorption system of the present application has remarkable effects in improving shipping safety, operational convenience and environmental protection with its innovative technical concept and obvious practical application advantages, and is expected to be widely used in the shipping industry.

[0076] In the following description, many technical details are provided to help readers better understand the present application. However, those skilled in the art can understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in the claims of the present application can be implemented. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0077] Description of some concepts:

[0078] Toxic ammonia release sources, in this application, refer to locations or equipment on liquid ammonia fuel ships where ammonia leakage may occur, including liquid ammonia storage tanks, pipelines, valves, pumps, etc. In this application, release sources mainly include receiving pans, liquid ammonia fuel tank pressure relief valves, double-walled pipe ammonia discharge ports, ventilated mast water spray system wastewater, and enclosed spaces containing ammonia fuel.

[0079] The ammonia absorption tank is used in this application to absorb and neutralize leaked ammonia. The tank is filled with absorbent, has a water inlet and a water outlet, and is connected to the ship's fresh water tank and ballast tank to achieve automatic replenishment and recycling of the absorption liquid. Optionally, the absorbent can be fresh water, sodium hydroxide solution, ammonia water, calcium hydroxide solution, etc.

[0080] The gas diffusion layer, in this application, refers to a porous partition structure installed in the ammonia absorption tank, which is optionally made of multiple layers of stainless steel wire mesh. Its function is to strengthen the contact between ammonia and the absorption liquid, prolong the residence time of ammonia in water, and thus improve the absorption efficiency.

[0081] The ammonia guide pipeline, in this application, refers to the pipeline connecting the toxic ammonia release source and the ammonia absorption tank, which introduces the leaked ammonia into the absorption tank for treatment. Optionally, the guide pipeline is divided into a gas phase ammonia discharge pipeline and a liquid phase ammonia discharge pipeline, which transport gaseous and liquid ammonia respectively. Among them, a porous nozzle is installed at the end of the gas phase ammonia discharge pipeline to disperse the ammonia into fine bubbles to improve the mass transfer effect.

[0082] The porous nozzle in this application refers to a special nozzle installed at the end of the gas phase ammonia exhaust pipeline, with multiple small holes on the surface. When the ammonia-containing gas passes through the porous nozzle, it will be dispersed into a large number of tiny bubbles, significantly increasing the gas-liquid contact area and accelerating the absorption reaction rate.

[0083] The diluted ammonia discharge pipeline, in this application, refers to a pipeline connecting the gas phase space at the top of the ammonia absorption tank with the atmospheric environment, which is used to discharge the ammonia slowly released after being absorbed by the absorbent into the atmosphere.

[0084] The liquid level switch, in this application, refers to a liquid level control device installed in the ammonia absorption tank, which is used to adjust the liquid level of the absorption liquid in the tank in real time. When the liquid level drops to the set lower limit, the switch automatically opens the water inlet, replenishes fresh water to the upper limit, and then closes the water inlet to maintain the gas-liquid ratio in the tank and ensure the absorption effect.

[0085] The temperature control device, in this application, refers to a heat exchanger that removes heat through a heat carrier to maintain a stable temperature in the tank.

[0086] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0087] First embodiment

[0088] See also Figure 1 and Figure 2 The toxic ammonia absorption system for a liquid ammonia fuel ship of this embodiment includes:

[0089] The toxic ammonia release source 100 is used to collect ammonia leaked from a liquid ammonia fuel system of a ship.

[0090] The ammonia absorption tank 200 is provided with an absorbent 201 for absorbing the ammonia, and is provided with a liquid level switch 203 for controlling the liquid level of the absorbent 201, thereby ensuring that there is sufficient gas phase space 206 inside the ammonia absorption tank 200. The ammonia absorption tank 200 is also provided with a gas diffusion layer 202, and the position of the gas diffusion layer 202 is set lower than the liquid level of the absorbent 201. A temperature control device 207 is provided in the ammonia absorption pipe, which is a heat exchanger that uses low-temperature water to carry away the absorption heat in the tank.

[0091] An ammonia guide pipeline, one end of which is connected to the toxic ammonia release source 100, and the other end of which is connected to the ammonia absorption tank 200 and is arranged below the gas diffusion layer 202, so that the ammonia collected by the toxic ammonia release source 100 must pass through the gas diffusion layer 202 during the floating process after being introduced into the absorbent 201 of the ammonia absorption tank 200.

[0092] The diluted ammonia gas discharge pipeline is used to guide the ammonia gas slowly released after being absorbed by the absorbent 201 from the ammonia absorption tank 200 and discharge it to the external environment.

[0093] Further, in the toxic ammonia absorption system for liquid ammonia fuel ships of this embodiment, the toxic ammonia release source 100 refers to a location or equipment on the ship where ammonia may leak, such as a pressure release valve of a liquid ammonia fuel tank, a discharge port of a double-walled pipe, etc. The toxic ammonia generated by these leakage sources needs to be collected and processed. The ammonia absorption tank 200 is the core component of the system, and an absorbent 201 for absorbing ammonia is contained therein. A liquid level switch 203 is provided in the ammonia absorption tank 200 to control the absorbent liquid level and ensure that there is enough gas phase space 206 in the ammonia absorption tank for collecting ammonia. In addition, a gas diffusion layer 202 is also provided in the ammonia absorption tank 200, and its position is lower than the absorbent liquid level. The function of the gas diffusion layer is to increase the residence time and diffusion degree of ammonia in the absorbent and improve the absorption efficiency. The ammonia guide pipeline is composed of a gas phase ammonia discharge pipeline 301 and a liquid phase ammonia discharge pipeline 302, which guides the ammonia generated by the toxic ammonia release source 100 to the ammonia absorption tank 200. The outlet of the guide pipeline is located below the gas diffusion layer 202, so that the ammonia must pass through the diffusion layer during the floating process, fully diffused and dissolved in the absorbent. The diluted ammonia discharge pipeline is composed of a breathable pipe 401 and a breathable mast 402, which discharges the ammonia slowly released after being absorbed by the absorbent 201 in the ammonia absorption tank 200 to the external environment, generally discharged to high altitude through the breathable mast to dilute the concentration.

[0094] The toxic ammonia absorption system for a liquid ammonia fuel ship of this embodiment is further explained below.

[0095] Optionally, the ammonia guiding pipeline includes a gas phase ammonia exhaust pipeline 301 and a liquid phase ammonia exhaust pipeline 302 ; a multi-hole nozzle 304 is provided at the end of the gas phase ammonia exhaust pipeline 301 to increase the diffusion efficiency of the ammonia in the absorbent 201 .

[0096] Optionally, the porous nozzle 304 includes a plurality of small holes evenly distributed along its circumference, which are used to disperse the ammonia in the ammonia guide pipeline into small bubbles, so as to increase the contact area between the ammonia and the absorbent 201 and improve the ammonia absorption efficiency.

[0097] Furthermore, the ammonia gas guide pipeline may include two parts: a gas phase ammonia discharge pipeline 301 and a liquid phase ammonia discharge pipeline 302. The gas phase ammonia discharge pipeline 301 is mainly used to transport gaseous ammonia released from the leakage source, while the liquid phase ammonia discharge pipeline 302 is used to transport liquid ammonia released from the leakage source. In this way, the corresponding guide pipeline can be selectively used according to the specific form of ammonia leakage, thereby improving the applicability of the system.

[0098] As described above, in an optional example, a special porous nozzle 304 is designed at the end of the gas phase ammonia exhaust pipeline 301. The function of the porous nozzle 304 is to further disperse the ammonia gas transported from the pipeline into fine bubbles, thereby greatly increasing the contact area between the ammonia gas and the absorbent 201, strengthening the dissolution and absorption process of the ammonia gas, and ultimately improving the absorption efficiency of the ammonia gas by the entire system.

[0099] According to the structure of the above-mentioned porous nozzle 304, a number of small holes are evenly distributed on the outer wall of the porous nozzle 304. When ammonia enters the porous nozzle 304 from the pipeline, it will be dispersed into countless tiny bubbles through these small holes to form a "bubble plume". Compared with directly releasing a large amount of ammonia into the absorbent, this bubbling dispersion can significantly increase the residence time and diffusion range of ammonia in the absorbent, so that it can fully contact and react with the absorbent and be absorbed to the maximum extent. At the same time, the uniform distribution of small holes helps to evenly diffuse ammonia on the tank section, avoiding excessive local ammonia concentration affecting the absorption effect.

[0100] In general, by arranging the porous nozzle 304 at the end of the gas phase ammonia exhaust pipeline 301 and cleverly designing the microporous structure of the porous nozzle 304, the dissolution and absorption process of ammonia can be significantly enhanced, and the absorption conversion efficiency and processing capacity of the absorbent for ammonia can be improved. In practical applications, the aperture size, hole number density and other parameters of the porous nozzle 304 can be flexibly adjusted according to factors such as the amount of ammonia leakage and the size of the tank to obtain the best dispersed absorption effect.

[0101] It should be noted that the multi-hole nozzle 304 is not limited thereto. In other embodiments of the present application, the multi-hole nozzle 304 may be composed of a plurality of nozzle tubes, and each nozzle tube may be provided with injection holes of different shapes and sizes at different intervals as required.

[0102] For example, in addition to simple circular holes, the spray holes can also be designed into other shapes, such as elliptical, triangular, polygonal, etc. Spray holes of different shapes will have differences in atomization performance, pressure drop characteristics, etc. In addition, variable diameter holes can be used, that is, the inlet and outlet diameters of the spray holes are different, forming a structure similar to a Venturi tube, which helps to improve the atomization effect and anti-clogging ability.

[0103] For another example, on the basis of basic uniform distribution, gradient distribution can be adopted, that is, the aperture or hole spacing of the injection hole gradually changes from the center of the nozzle to the edge (that is, from the starting end of the nozzle tube close to the nozzle center to the end far from the nozzle center) to form different atomization areas. It can also be designed into special forms such as spiral distribution and serpentine distribution to produce swirl effect and enhance gas-liquid mixing.

[0104] Optionally, the gas diffusion layer 202 includes multiple layers of stainless steel wire mesh, and is connected to the inner wall of the ammonia absorption tank 200 via positioning buckles.

[0105] Furthermore, the gas diffusion layer 202 is one of the key components for improving the ammonia absorption efficiency. In this embodiment, the gas diffusion layer 202 adopts a multi-layer stainless steel wire mesh structure. Compared with a single-layer mesh plate, a multi-layer stainless steel wire mesh has a larger specific surface area and a more complex pore structure, which can further extend the residence time of ammonia in water and strengthen the full contact and mass transfer process between ammonia and water.

[0106] Specifically, the gas diffusion layer 202 can be composed of several layers of parallel stainless steel mesh, and the size and distribution of each mesh can be optimized according to actual needs. After the ammonia bubbles enter the diffusion layer from below, they will continue to rise in the gaps between the layers and contact more water molecules, thereby accelerating the rate of dissolution and absorption. At the same time, the material of the stainless steel mesh has good corrosion resistance and mechanical strength, and can work stably in the humid environment of the water tank for a long time.

[0107] It can be seen that using stainless steel wire mesh as the diffusion layer material has the following advantages:

[0108] 1) Stainless steel wire mesh has good mechanical strength and corrosion resistance, and can work stably in ammonia environment for a long time.

[0109] 2) The mesh size of the stainless steel wire mesh can be adjusted according to actual needs. By selecting the appropriate mesh size, the water flow resistance can be minimized and energy consumption can be reduced while ensuring the ammonia diffusion effect.

[0110] 3) The setting of multiple layers of stainless steel wire mesh can significantly increase the residence time and mass transfer area of ​​ammonia in water. As ammonia passes through the stainless steel wire mesh layer by layer, it will be continuously dispersed and broken, forming more and smaller bubbles, thereby accelerating the absorption and reaction rate.

[0111] Furthermore, in order to reliably fix the gas diffusion layer 202 at a specific position inside the water tank, a positioning buckle mechanism is also designed in this embodiment. Through the positioning buckle, the gas diffusion layer 202 can be firmly connected to the inner wall of the water tank 200 to avoid displacement or deformation due to water flow impact or vibration. The number and distribution of the positioning buckles can be reasonably designed according to the size and stress of the diffusion layer to ensure the stability of the entire diffusion layer structure.

[0112] In summary, using a multi-layer stainless steel wire mesh as the material of the gas diffusion layer 202 and fixing it inside the water tank by positioning buckles can significantly enhance the diffusion and absorption effect of ammonia, while having high structural reliability and service life. In practical applications, the performance of the diffusion layer can be optimized by adjusting the number of layers and mesh parameters of the stainless steel wire mesh, thereby further improving the processing efficiency and stability of the entire ammonia absorption system. For example, when the number of layers of the stainless steel wire mesh is 3 to 5, the mesh size of 0.8 mm to 1.2 mm will further enhance the diffusion and absorption effect of ammonia.

[0113] It should be noted that in the embodiments of the present application, the gas diffusion layer is not limited to multiple layers of stainless steel wire mesh or multiple layers of other metal wire mesh, but can also be a random packing or a structured packing. For example, common random packings such as Raschig rings, ball rings or Interlocks saddle rings can be used; structured packings such as structured corrugated plate packings, structured orifice plate packings or structured wire mesh packings can also be used. These fillers can effectively increase the gas-liquid contact area and prolong the residence time of ammonia in the absorbent, thereby improving the absorption efficiency. When selecting a specific filler type, factors such as its specific surface area, porosity, pressure drop, cost, and compatibility with ammonia need to be considered.

[0114] Optionally, the diluted ammonia discharge pipeline includes a ventilation pipe 401 and a ventilation mast 402 connected in sequence, one end of the ventilation pipe 401 is connected to the gas phase space 206 inside the ammonia absorption tank 200, and the other end is connected to the ventilation mast 402, which is used to guide the ammonia that is slowly released after being absorbed by the absorbent 201 in the gas phase space 206 inside the ammonia absorption tank 200 to the ventilation mast 402 for discharge into the atmosphere.

[0115] Optionally, a temperature control device 207 is provided in the ammonia absorption tank 200 to adjust the temperature of the absorbent 201. When the absorbent 201 absorbs ammonia, an exothermic reaction occurs, resulting in a temperature increase. In order to maintain the best absorption efficiency, the temperature control device 207 can keep the temperature of the absorbent 201 within a predetermined ideal range.

[0116] Optionally, a water spray system 403 is provided at the end of the ventilation mast 402 for further neutralizing the concentration of ammonia discharged from the ammonia absorption tank 200 into the ventilation pipe 401, and the wastewater generated by the water spray system 403 is refluxed to the ammonia absorption tank 200 through the diluted ammonia discharge pipeline, but not limited to this. In other embodiments of the present application, it can also be refluxed to the ammonia absorption tank 200 through the liquid phase ammonia discharge pipeline 302.

[0117] Further, if Figure 1As shown, one end of the air pipe 401 is connected to the gas phase space 206 inside the water tank 200, and the other end is connected to the air mast 402. During the floating process, the ammonia inside the water tank is fully contacted and reacted with water through the gas diffusion layer 202, and most of the ammonia is absorbed and removed. However, the ammonia that is absorbed by the absorbent 201 and slowly released enters the gas phase space 206 at the top of the tank. In order to prevent this part of ammonia from accumulating in the tank, it is guided to the air mast 402 through the air pipe 401 and finally discharged into the atmosphere.

[0118] The air pipe 401 is made of corrosion-resistant and high-temperature-resistant materials, such as stainless steel, polytetrafluoroethylene, etc.

[0119] The ventilation mast 402 is vertically arranged at a certain height above the ship deck. The height and outlet position of the mast should be reasonably designed according to the model of the ship and the environmental conditions of the navigation area to ensure that the discharged ammonia will not cause harm to the crew and equipment.

[0120] At the end of the ventilation mast 402, a water spray system 403 is also provided. Figure 1 As shown. For example, the water spray system 403 may be composed of a plurality of spray heads, which are connected to a fresh water pipeline. When ammonia is discharged from the air-permeable mast 402, the spray system 403 sprays atomized fresh water into the air flow, which further absorbs and dilutes the ammonia, thereby further reducing the concentration of the discharged ammonia and reducing the impact on the environment.

[0121] The ammonia-containing wastewater generated by the spray system 403 flows back to the ammonia absorption tank 200 through the diluted ammonia discharge pipeline to achieve water recycling. After the refluxed ammonia-containing wastewater enters the water tank, it mixes with the absorbent 201 in the tank and does not affect the normal operation of the water tank.

[0122] Therefore, by setting the ventilation pipe 401 and the ventilation mast 402, the ammonia gas slowly released after absorption is discharged into the atmosphere, and the ammonia concentration is further diluted by the water spray system 403 to ensure that the emission meets the standard. At the same time, the spray wastewater is returned to the absorption tank, realizing the recycling of water resources and reducing wastewater discharge.

[0123] Optionally, the ammonia absorption tank 200 is further provided with a water inlet 204 and a water outlet 205 for circulating and renewing the absorbent 201 to maintain the absorption efficiency of ammonia.

[0124] Optionally, the water source of the water inlet 204 is a fresh water tank, and the water source downstream of the water outlet 205 is a ballast tank.

[0125] Furthermore, in order to maintain the absorption efficiency of ammonia by the absorbent 201 in the ammonia absorption tank 200, the absorbent needs to be regularly circulated and updated. In this embodiment, the water tank 200 is provided with a special water inlet 204 and a water outlet 205 for realizing the circulation of the absorbent.

[0126] The water inlet 204 is located at the upper part of the water tank and is used to add fresh absorbent to the water tank. The water source for the supplement can be the fresh water tank on the ship. The fresh water tank generally stores treated clean water suitable for ammonia absorption. Through the water inlet 204, the water in the fresh water tank can be continuously added to the water tank to maintain the liquid level and absorption capacity of the absorbent 201.

[0127] The water outlet 205 is located at the lower part of the water tank, and is used to discharge the absorbent that has absorbed ammonia from the water tank. In order to save water and prevent pollution, the discharged ammonia-containing water will not be discharged directly, but will be introduced into the ballast tank of the ship. The ballast tank is a special compartment on the ship for loading ballast water. By adjusting the volume of ballast water, the draft and stability of the ship can be changed. Storing ammonia-containing water as ballast water in the ballast tank can reduce the risk of discharging ammonia-containing water on the one hand, and on the other hand, the alkalinity of ammonia-containing water can be used to inhibit the growth of microorganisms in the ballast tank, which plays a certain anti-fouling role.

[0128] By setting the water inlet 204 and the water outlet 205, the absorbent 201 in the ammonia absorption tank 200 can realize continuous or regular renewal cycle. During operation, the renewal frequency and renewal amount of the absorbent can be reasonably controlled according to parameters such as the ammonia absorption amount and the absorbent saturation, so as to ensure that there is always enough fresh absorbent in the water tank to maintain the absorption efficiency, and to avoid excessive renewal and waste of water resources. At the same time, the rational use of ship resources such as fresh water tanks and ballast tanks can maximize the cascade utilization and recycling of water resources, and improve the economy and environmental protection of the system.

[0129] Optionally, the toxic ammonia release source 100 is selected from the following group: a receiving tray 101, a liquid ammonia fuel tank pressure release valve 102, a double-walled pipe ammonia discharge port 103, a breathable mast water spray system wastewater 104, and a closed place containing ammonia fuel 105.

[0130] Furthermore, in liquid ammonia fueled ships, there are multiple potential sources of toxic ammonia release100, such as Figure 1 As shown, including but not limited to:

[0131] Receiver tray 101: Liquid ammonia fuel may leak or overflow during storage, transportation and use. Receiver tray 101 is usually set under storage tanks, pipelines, valves and other equipment to collect leaked liquid ammonia. The liquid ammonia collected in the receiver tray 101 will continue to evaporate and produce high-concentration ammonia gas, which needs to be handled in time.

[0132] Liquid ammonia fuel tank pressure release valve 102: There is a certain pressure inside the liquid ammonia storage tank. When the pressure exceeds the safety threshold, the pressure release valve 102 will automatically open and discharge the ammonia in the tank into the atmosphere to ensure the safety of the tank. The ammonia discharged by the pressure release valve 102 is very high in concentration and needs to be collected and treated.

[0133] Double-walled pipe ammonia discharge port 103: The liquid ammonia fuel pipeline adopts a double-walled structure, the inner pipe is used to transport liquid ammonia, and the outer pipe is used to collect ammonia generated when the inner pipe leaks. The annular space of the double-walled pipe needs to be provided with a discharge port 103 to discharge the collected ammonia. The ammonia discharged from the discharge port 103 also needs to be processed.

[0134] Wastewater 104 from the water spray system of the breathable mast: During the filling process of liquid ammonia fuel, a large amount of volatile ammonia will be generated in the storage tanks and pipelines. In order to prevent ammonia from diffusing on the deck of the ship, a water spray system is usually installed on the breathable mast to absorb and dilute the ammonia. The ammonia-containing wastewater 104 generated by the spray system will cause pollution if discharged directly, so it needs to be collected and treated. As mentioned above, one optional method is to return the diluted ammonia to the ammonia absorption tank 200 through the discharge pipeline to achieve water recycling. After the refluxed ammonia-containing wastewater enters the water tank, it mixes with the absorbent 201 in the tank and will not affect the normal operation of the water tank.

[0135] Closed spaces containing ammonia fuel 105: On ships, some equipment or pipelines in the liquid ammonia fuel system are located in closed spaces, such as the fuel preparation room, valve control room, etc. There may be ammonia leakage in these closed spaces 105, resulting in increased ammonia concentration, and the air in these areas needs to be collected and treated.

[0136] It should be pointed out that in actual applications, depending on the specific design and layout of the ship, there may be other release sources, such as sampling points, exhaust ports of analytical instruments, etc. As long as there is a possibility of ammonia leakage, it should be included in the treatment scope of the ammonia absorption system.

[0137] Optionally, the liquid level switch 203 controls the liquid level height of the absorbent 201 to ensure that the volume of the gas phase space 206 in the ammonia absorption tank 200 accounts for at least 20% of the total volume of the ammonia absorption tank 200 .

[0138] Furthermore, in the ammonia absorption tank 200 of the present application, the liquid level of the absorbent 201 in the tank can be reasonably controlled. On the one hand, the absorbent 201 is a key medium for absorbing and neutralizing ammonia, and a too low liquid level will lead to a decrease in absorption efficiency; on the other hand, sufficient gas phase space 206 needs to be left in the tank to accommodate the diffusion and retention of ammonia. Therefore, it is necessary to find the best balance between the liquid level and the volume of the gas phase space.

[0139] In this embodiment, optionally, a liquid level switch 203 is used to automatically control the liquid level in the water tank. Figure 1 Optionally, the liquid level switch 203 can be a common liquid level detection element such as a float type, a conductivity type, an ultrasonic type, etc., which will not be described in detail here. By real-time monitoring of the change of the water level in the tank, the opening of the water inlet 204 and the water outlet 205 is controlled to achieve automatic adjustment of the liquid level of the absorbent 201.

[0140] In this embodiment, the liquid level switch 203 is used to automatically control the liquid level in the water tank. Figure 1 As shown. The liquid level switch 203 can adopt common detection technologies on the market, such as float type, conductivity type, ultrasonic type, etc., to monitor and adjust the changes in the water level in the tank in real time. Since the liquid level switch itself belongs to the existing technology, and its specific working principle and type are widely known in the technical field, it will not be repeated here. This configuration allows the automatic adjustment of the absorbent 201 liquid level by controlling the opening of the water inlet 204 and the water outlet 205, ensuring the efficient operation of the system.

[0141] More specifically, when the water level in the tank drops to the set lower limit, the liquid level switch 203 opens the water inlet 204 to add water to the tank; when the water level rises to the set upper limit, the liquid level switch 203 closes the water inlet 204 to stop adding water. At the same time, the liquid level switch 203 can also control the opening of the water outlet 205. When the water level is too high, the water outlet 205 is opened to discharge part of the absorbent until the water level drops to a suitable range.

[0142] In this embodiment, optionally, the liquid level of the absorbent in the water tank is controlled within a specific range: ensuring that the volume of the gas phase space 206 in the ammonia absorption tank 200 accounts for at least 20% of the total volume of the water tank.

[0143] The setting of this control indicator is based on the following considerations:

[0144] If the volume of the gas phase space 206 is too small, the diffusion and residence time of the ammonia in the tank will be limited, the sufficient contact between the ammonia and the absorbent 201 will be reduced, and the absorption effect will be affected.

[0145] If the volume of the gas phase space 206 is too large, it will occupy the effective volume of the water tank, reduce the absorption load of the absorbent 201, and reduce the space utilization rate of the water tank.

[0146] The 20% gas phase space volume ratio can not only meet the needs of ammonia diffusion and absorption, but also ensure the treatment capacity and economy of the water tank.

[0147] It should be pointed out that in actual design, the specific volume ratio of the gas phase space 206 can be optimized and adjusted according to factors such as the shape, size, and material of the ammonia absorption tank 200 to achieve the best absorption effect and cost-effectiveness.

[0148] It should be pointed out that in the above embodiment, there is no moving equipment, and there is almost no maintenance after one installation. It is only necessary to control the liquid level and pressure, and automatic control can be achieved. The mechanical structure inside the ammonia absorption tank 200 is simple, and the packing layer does not need to be replaced during installation, so the equipment cost and operating cost are relatively low.

[0149] It should be pointed out that in the embodiments of the present application, the liquid level switch 203 may optionally be a liquid level control device that adds a control valve to the water inlet or outlet.

[0150] Optional absorbents may be water, sodium hydroxide solution or the like, in which case these absorbents cannot be connected to the fresh water tank and the ballast tank.

[0151] Optionally, the ammonia absorption tank 200 can be selected as a vertical container, so that the layout of the absorption tank can be reasonably optimized according to the area in the cabin.

[0152] Working principle:

[0153] The working principle of the toxic ammonia absorption system for liquid ammonia fuel ships of this embodiment is as follows:

[0154] Collecting ammonia: Toxic ammonia release source 100 collects liquid and gaseous ammonia that may leak from various parts of the ship's liquid ammonia fuel system, mainly including the receiving tray 101, the liquid ammonia fuel tank pressure release valve 102, the double-walled pipe ammonia discharge port 103, the breathable mast water spray system wastewater 104 and the closed place containing ammonia fuel 105, etc.

[0155] Guiding ammonia: The ammonia guiding pipeline introduces the collected ammonia into the ammonia absorption tank 200. The gas phase ammonia exhaust pipeline 301 guides the gaseous ammonia, and a porous nozzle 304 is provided at the end of the pipeline to disperse the ammonia into small bubbles. The liquid phase ammonia exhaust pipeline 302 guides the liquid ammonia. Both pipelines are connected to the position below the gas diffusion layer 202 in the water tank.

[0156] Ammonia absorption: After entering the absorption tank, ammonia rises in the absorbent 201 and passes through the gas diffusion layer 202 with a multi-layer stainless steel wire mesh structure. The ammonia is fully dispersed and fully contacts the water, and a chemical absorption reaction occurs to generate ammonia water. The diffusion layer prolongs the residence time of ammonia in the water and improves the absorption efficiency.

[0157] Liquid level control: The liquid level switch 203 monitors the water level in the tank, and controls the opening and closing of the water inlet 204 and the water outlet 205 to ensure that there is always enough absorbent 201 in the tank to absorb ammonia, and a certain gas phase space 206 is left. The fresh water tank supplies fresh water, and the ammonia water is discharged into the ballast tank through the water outlet, realizing the cascade utilization of water.

[0158] Discharge of residual ammonia: The ammonia gas slowly released after absorption enters the gas phase space at the top of the tank and is discharged through the diluted ammonia gas discharge pipelines 401 and 402. The water spray system 403 at the end of the pipeline further dilutes the ammonia concentration to a safe level. The spray water flows back to the absorption tank through the pipeline and is discharged into the ballast tank together with the ammonia water.

[0159] In short, this system efficiently absorbs the toxic ammonia leaked from the ship's liquid ammonia fuel system through key designs such as ammonia absorption tanks, gas diffusion layers, liquid level control, and ammonia discharge pipelines, significantly improving the safety, environmental protection, and economy of ammonia fuel used by ships. After ammonia enters the absorption tank, it is fully contacted with water and most of it is converted into ammonia water, and a small amount of residual ammonia is discharged in compliance with standards. The entire process realizes the cascade utilization and recycling of water resources.

[0160] The advantages of the above implementation are as follows:

[0161] 1) Significantly improve the safety of ships using ammonia fuel. This system effectively collects and absorbs accidentally leaked toxic ammonia by setting up an ammonia absorption tank and related guide and discharge pipelines. By using water to absorb and neutralize ammonia, the ammonia concentration in the environment can be quickly reduced and controlled within a safe range, avoiding poisoning of personnel and damage to equipment, thereby enhancing the overall safety of the ship.

[0162] 2) Improve ammonia treatment efficiency and reduce emissions. A gas diffusion layer is installed in the ammonia absorption tank, and the porous nozzle at the end of the gas phase ammonia discharge pipeline strengthens the full contact and mass transfer between ammonia and water, thereby improving the absorption efficiency. At the same time, the volume of the water tank is reduced by maintaining the gas-liquid contact area in the water tank. After treatment, most of the ammonia is converted into ammonium hydroxide solution, and the ammonia that is slowly released after absorption is discharged to a safe area through the discharge pipeline, which minimizes the release of toxic ammonia.

[0163] 3) Flexible system connection and strong adaptability. The system can flexibly connect potential ammonia leakage sources such as pipelines, valves, storage tanks, etc. according to the ship layout, ensuring comprehensive coverage and rapid response. The system design is compatible with the existing structure and operating procedures of the ship and can be applied to ships of various types and sizes. In addition, the modular design of the system allows it to be adjusted according to different ship sizes and needs, providing a highly customized solution.

[0164] 4) Easy operation and maintenance, low cost. Compared with other ammonia treatment technologies, this system has a simple equipment structure, can realize automatic control, and can be quickly started when a leak occurs. It only needs regular water replenishment and maintenance. It is easy to operate and has high reliability. The design of the water tank takes into account water recycling and wastewater treatment. The water source can use the existing fresh water system, seawater system or other water sources on the ship, which is economical and practical.

[0165] 5) Significant environmental benefits. Converting ammonia into ammonium hydroxide through chemical neutralization reactions not only reduces the harm of toxic ammonia emissions to the environment, but also supports the goal set by the International Maritime Organization to achieve net zero greenhouse gas emissions in the shipping industry by 2050, which is of great significance to environmental protection.

[0166] In summary, the toxic ammonia absorption system for liquid ammonia fuel ships provided in the above embodiments is safe and reliable, efficient and environmentally friendly, easy to operate and maintain, and has strong applicability. It can effectively control the risk of ammonia fuel leakage, promote the safe application of ammonia fuel in the shipping industry, and provide important support for the sustainable development of the shipping industry. It has broad application prospects.

[0167] In order to better understand the technical solution of the present application, a specific example is provided below for illustration. The details listed in the example are mainly for ease of understanding and are not intended to limit the scope of protection of the present application.

[0168] In general, this example proposes a toxic ammonia absorption system for a liquid ammonia fuel ship, which includes an ammonia absorption tank 200, an ammonia guide pipeline connecting a toxic ammonia release source 100 and the ammonia absorption tank 200, and a diluted ammonia release pipeline.

[0169] This example covers the main sources of ammonia leakage in the shipboard fuel filling and supply system, including but not limited to: receiving pan 101, liquid ammonia fuel tank pressure relief valve 102, double-walled pipe ammonia discharge port 103, breathable mast water spray system 403 wastewater 105 and enclosed places containing ammonia fuel (including fuel filling station, fuel tank connection place and fuel preparation room).

[0170] In this example, the ammonia absorption tank 200 is a liquid container, and its capacity is designed according to the actual needs of the ship. The liquid level in the tank is controlled by the liquid level switch 203 to ensure that there is enough gas phase space 206 in the tank. The absorbent in the fresh water tank will be introduced into the ammonia absorption tank 200 from the water inlet 204, and the absorbent 201 in the ammonia absorption tank 200 that has absorbed ammonia will be discharged to the preset position of the downstream ballast tank through the water outlet 205.

[0171] A gas diffusion layer 202 is provided in the ammonia absorption tank 200, and the diffusion layer 202 is firmly connected to the tank body on all sides. After all liquid and gaseous ammonia are connected to the ammonia absorption tank 200, they are led below the gas diffusion layer 202, forcing the ammonia to pass through the diffusion layer 202 during the floating process in the absorbent 201, so that the ammonia can fully contact the absorbent 201 in the tank and react chemically.

[0172] The ammonia guide pipeline connecting the toxic ammonia release source 100 and the ammonia absorption tank 200 includes a gas phase ammonia discharge pipeline 301 and a liquid phase ammonia discharge pipeline 302. One end of the gas phase ammonia discharge pipeline 301 and the liquid phase ammonia discharge pipeline 302 is connected to one of the toxic ammonia release sources 100, and the other end is connected to the gas diffusion layer 202 located in the ammonia absorption tank 200. A nozzle 304 is provided at the end of the gas phase ammonia discharge pipeline 301.

[0173] In this example, a nozzle 304 is arranged at the end of the gas-phase ammonia exhaust pipeline 301. The nozzle 304 provides multiple outlets for ammonia gas, which is beneficial for ammonia gas to diffuse in water and fully react chemically with water.

[0174] In this example, a diluted ammonia discharge pipeline is provided, and the diluted ammonia discharge pipeline includes a vent pipe 401 and a vent mast 402, wherein one end of the vent pipe 401 is connected to the gas phase space 206 of the ammonia absorption tank, and the other end is connected to the vent mast 402. Ammonia that is slowly released after being absorbed by the absorbent 201 in the gas phase space 206 can enter the vent mast 402 through the vent pipe 401. A water spray system 403 is provided at the end of the vent mast 402. If the ammonia concentration in the vent mast 402 does not meet the specification requirements, the water spray system 403 will further neutralize the ammonia concentration to meet the specification requirements. The wastewater generated by the water spray system 403 is connected to the ammonia absorption tank 200 through the liquid phase ammonia discharge pipeline 302.

[0175] The beneficial effect of this example is that by setting up the ammonia absorption tank 200 and the related guide and discharge pipelines, harmful ammonia is effectively collected and absorbed. After passing through the ammonia absorption tank 200, the concentration of liquid and gaseous ammonia can be greatly reduced, and can be discharged safely and efficiently. The system improves the safety of the ammonia fuel system on board, and reduces the manufacturing cost and maintenance difficulty of the ship.

[0176] More specifically, in this example, the toxic ammonia release source 100 includes a receiving tray 101, a liquid ammonia fuel tank pressure release valve 102, a double-walled pipe ammonia discharge port 103, a breathable mast water spray system 403 wastewater 105, and a closed place containing ammonia fuel (including a fuel filling station, a fuel tank joint and a fuel preparation room).

[0177] The ammonia absorption tank 200 includes an absorbent 201 in the tank, a gas diffusion layer 202 , a liquid level switch 203 , a water inlet 204 and a water outlet 205 .

[0178] The ammonia guide pipeline includes a gas phase ammonia discharge pipeline 301, a liquid phase ammonia discharge pipeline 302, a check valve 303 and a nozzle 304. The guide pipeline is arranged between the toxic ammonia release source 100 and the ammonia absorption tank. One end of the gas phase ammonia discharge pipeline 301 and the liquid phase ammonia discharge pipeline 302 is connected to one of the toxic ammonia release sources 100, and the other end is connected to the gas diffusion layer 202 located in the ammonia absorption tank 200. Among them, the end of the gas phase ammonia discharge pipeline 301 is provided with a nozzle 304.

[0179] The diluted ammonia gas discharge pipeline includes a ventilation pipe 401, a ventilation mast 402 and a water spray system 403. One end of the ventilation pipe 401 is connected to the gas phase space 206 of the ammonia absorption tank 200, and the other end is connected to the ventilation mast 402.

[0180] Optionally, the toxic ammonia release source 100 covers the main sources of ammonia leakage in the ship's fuel filling and supply system, including the receiving tray 101, the liquid ammonia fuel tank pressure relief valve 102, the double-walled pipe ammonia discharge port 103, the breathable mast water spray system 403 and the enclosed space containing ammonia fuel.

[0181] Optionally, an ammonia absorption tank 200 is provided to absorb the released toxic ammonia. An absorbent 201 is injected into the tank, and the liquid level in the tank is controlled by a liquid level switch 203 to ensure sufficient gas phase space 206. The water inlet 204 and the water outlet 205 are used to update the absorbent 201 in the tank. The water source of the water inlet 204 is a fresh water tank, and the downstream of the water outlet 205 is a ballast tank. A gas diffusion layer 202 is provided in the ammonia absorption tank 200 to ensure sufficient contact between ammonia and water and promote chemical reactions.

[0182] Optionally, the gas diffusion layer 202 is a multi-layer stainless steel wire mesh, the purpose of which is to promote full contact between gas and water to facilitate the chemical reaction between ammonia and water.

[0183] Optionally, a nozzle 304 is provided at the end of the gas phase ammonia exhaust pipeline 301. The nozzle 304 provides multiple (greater than 2) outlets for ammonia gas, which is conducive to the diffusion of ammonia gas in water.

[0184] Optionally, a water spray system 403 is provided in the ventilation mast 402 , and waste water generated by the system is connected to the ammonia absorption tank 200 through the liquid phase ammonia discharge pipeline 302 .

[0185] The specific details involved in this example are further explained below.

[0186] In this example, a rectangular ammonia absorption tank 200 with a capacity of 100 cubic meters is set in the side tank of the ship. It should be noted that the position of the ammonia absorption tank 200 can be flexibly set according to the specific conditions of the ship, such as above the deck or in other cabins or empty cabins.

[0187] In the toxic ammonia absorption system for liquid ammonia fuel ships of this example, a gas phase ammonia exhaust pipeline 301 is provided, which connects the ammonia absorption tank 200 and the gas phase toxic ammonia source, and the gas phase toxic ammonia source includes a liquid ammonia fuel tank pressure release valve 102, a double-walled pipe ammonia discharge port 103 and a closed place containing ammonia fuel (such as a fuel filling station, a fuel tank joint place, and a fuel preparation room). When the gas phase ammonia exhaust pipeline 301 passes through a cabin where a double-walled pipe is required, a double-walled pipe should be used. A multi-outlet nozzle 304 is set below the gas diffusion layer 202 at the end of the gas phase ammonia exhaust pipeline 301. More specifically, 6 outlet channels are set in this example. It should be pointed out that the specific number can be adjusted according to the needs of the ship to ensure that ammonia is effectively diffused into the absorbent 201.

[0188] This example is also provided with a liquid phase ammonia discharge pipeline 302, which connects the ammonia absorption tank 200 and the liquid phase ammonia discharge pipeline 302, such as the receiving plate 101 and the waste water 105 of the air permeable mast water spray system 403. The liquid phase ammonia discharge pipeline 302 is connected to the absorbent 201 in the ammonia absorption tank 200, and the end of the liquid phase ammonia discharge pipeline 302 is located below the gas diffusion layer 202.

[0189] A gas diffusion layer 202 composed of multiple layers of stainless steel mesh is arranged inside the ammonia absorption tank 200, and the mesh size should ensure that ammonia can be efficiently diffused to the absorbent 201. The gas diffusion layer 202 is firmly connected to the absorption tank by positioning buckles on all sides. It should be pointed out that in other embodiments of the present application, the specific fixing method can be flexibly designed, such as setting a bracket at the bottom of the tank to connect the diffusion layer 202.

[0190] The absorbent 201 in the fresh water tank is introduced into the ammonia absorption tank 200 through the water inlet 204, and the absorbent 201 that has absorbed ammonia is discharged to a preset position of the downstream ballast tank through the water outlet 205. A liquid level switch 203 is provided in the ammonia absorption tank 200 to control the liquid level height inside the ammonia absorption tank 200 to ensure sufficient gas phase space 206.

[0191] In this example, a ventilation pipe 401 is provided, one end of which is connected to the gas phase space 206 of the absorption tank, and the other end is connected to the ventilation mast 402. Ammonia gas slowly released after being absorbed by the absorbent 201 enters the ventilation mast 402 through the ventilation pipe 401, and a water spray system 403 is provided at the end of the ventilation mast 402. When the ammonia concentration in the ventilation mast 402 exceeds the standard, the water spray system 403 is turned on to further dilute the ammonia concentration to the specification requirements. Optionally, the wastewater generated by the water spray system 403 passes through the liquid phase ammonia discharge pipeline 302 or flows back to the ammonia absorption tank 200.

[0192] It should be noted that all documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. In addition, it should be understood that after reading the above teaching content of this application, those skilled in the art can make various changes or modifications to this application, and these equivalent forms also fall within the scope defined by the claims attached to this application.

[0193] Furthermore, in the claims and specification of this patent, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "including one" do not exclude the existence of other identical elements in the process, method, article or device including the elements. In the claims and specification of this patent, if it is mentioned that an action is performed according to an element, it means that the action is performed at least according to the element, which includes two situations: performing the action only according to the element, and performing the action according to the element and other elements.

[0194] Although the present application has been illustrated and described with reference to certain preferred embodiments thereof, it will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims

1. A toxic ammonia absorption system for liquid ammonia fuel ships, characterized in that ,include: A toxic ammonia release source (100) is used to collect ammonia leaked from a liquid ammonia fuel system of a ship; An ammonia absorption tank (200) is provided with an absorbent (201) for absorbing the ammonia gas, and is provided with a liquid level switch (203) for controlling the liquid level of the absorbent (201), thereby ensuring that the interior of the ammonia absorption tank (200) has sufficient gas phase space (206); a gas diffusion layer (202) is also provided in the ammonia absorption tank (200), and the position of the gas diffusion layer (202) is set lower than the liquid level of the absorbent (201); and a temperature control device (207) is also provided in the ammonia absorption tank for controlling the temperature inside the tank; An ammonia guide pipeline, one end of which is connected to the toxic ammonia release source (100) and the other end of which is connected to the ammonia absorption tank (200) and is arranged below the gas diffusion layer (202), so that the ammonia collected by the toxic ammonia release source (100) must pass through the gas diffusion layer (202) during the floating process after being introduced into the absorbent (201) of the ammonia absorption tank (200); The diluted ammonia gas discharge pipeline is used to guide the ammonia gas slowly released after being absorbed by the absorbent (201) from the ammonia gas absorption tank (200) and discharge it to the external environment.

2. The system according to claim 1, characterized in that The ammonia gas guiding pipeline comprises a gas phase ammonia discharge pipeline (301) and a liquid phase ammonia discharge pipeline (302); a multi-hole nozzle (304) is provided at the end of the gas phase ammonia discharge pipeline (301) to increase the diffusion efficiency of the ammonia gas in the absorbent (201).

3. The system according to claim 2, characterized in that The multi-hole nozzle (304) comprises a plurality of small holes evenly distributed along its circumference, and is used to disperse the ammonia in the ammonia guide pipeline into small bubbles, so as to increase the contact area between the ammonia and the absorbent (201), thereby improving the ammonia absorption efficiency.

4. The system according to claim 1, characterized in that The gas diffusion layer (202) contains filler and is connected to the inner wall of the ammonia absorption tank (200) via a positioning buckle.

5. The system according to claim 1, wherein: The diluted ammonia discharge pipeline comprises a ventilation pipe (401) and a ventilation mast (402) connected in sequence, wherein one end of the ventilation pipe (401) is connected to the gas phase space (206) inside the ammonia absorption tank (200), and the other end is connected to the ventilation mast (402), and is used to guide the ammonia slowly released after being absorbed by the absorbent (201) in the gas phase space (206) inside the ammonia absorption tank (200) to the ventilation mast (402) for discharge into the atmosphere.

6. The system according to claim 1, wherein: The ammonia absorption tank is provided with a temperature control device (207) for adjusting the liquid temperature after absorbing ammonia to maintain a stable absorption rate.

7. The system according to claim 5, characterized in that An absorbent spraying system (403) is provided at the end of the ventilation mast (402) for further neutralizing the concentration of ammonia discharged from the ammonia absorption tank (200) into the ventilation pipe (401), and the waste liquid generated by the absorption liquid spraying system (403) flows back to the ammonia absorption tank (200) through the diluted ammonia discharge pipeline.

8. The system of claim 1, wherein: The ammonia absorption tank (200) is also provided with a water inlet (204) and a water outlet (205) for performing cyclic renewal of the absorbent absorption (201) to maintain the absorption efficiency of ammonia.

9. The system according to claim 8, characterized in that The water source of the water inlet (204) is a fresh water tank, and the downstream of the water outlet (205) is a ballast tank.

10. The system according to claim 1, wherein: The toxic ammonia release source (100) is selected from the following group: a receiving tray (101), a liquid ammonia fuel tank pressure release valve (102), a double-walled pipe ammonia discharge port (103), a ventilated mast water spray system wastewater (104), and a closed place containing ammonia fuel (105).

11. The system according to claim 1, characterized in that The liquid level switch (203) controls the liquid level height of the absorbent (201) to ensure that the volume of the gas phase space (206) in the ammonia absorption tank (200) accounts for at least 20% of the total volume of the ammonia absorption tank (200).

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