SCR (Selective Catalytic Reduction) reactor and SCR system of ship

Abstract

The utility model relates to the technical field of ships, and discloses an SCR (Selective Catalytic Reduction) reactor and an SCR system of a ship. The SCR reactor of the ship comprises a reactor main body, a reaction cavity is formed in the reactor main body, the reactor main body is further provided with a flue gas inlet and a flue gas outlet which are communicated with the reaction cavity, and a catalyst assembly is arranged in the reaction cavity; the seawater cooling device is mounted on the outer side of the reactor main body, the seawater cooling device comprises a plurality of cooling channels, and the cooling channels are arranged around the peripheral wall of the reactor main body; wherein the seawater cooling device is arranged adjacent to the flue gas inlet of the reactor main body. The seawater cooling device is additionally arranged, and the directional cooling channel and the adjacent flue gas inlet are arranged, so that the high-temperature area of the reactor main body is accurately cooled, the service life of a catalyst is prolonged, and the reliability of an SCR (Selective Catalytic Reduction) system is improved.

Description

Technical Field

[0001] This utility model relates to the field of marine technology, specifically to the SCR reactor and SCR system for ships. Background Technology

[0002] Nitrogen oxide (NOx) emissions from marine diesel engine exhaust are a key issue in pollution control for the shipping industry. Among existing technologies, selective catalytic reduction (SCR) is the mainstream solution for NOx aftertreatment in ships. Its core principle is to use a catalyst to catalytically reduce NOx in the exhaust gas with ammonia (NH3) produced from the decomposition of urea within a temperature range of 280℃ to 420℃, generating harmless nitrogen and water vapor. However, existing SCR systems face the risk of catalyst deactivation at high temperatures in marine applications. For example, during start-up and shutdown, sudden load changes, or when burning high-sulfur fuels, the exhaust gas temperature fluctuates drastically, with local temperatures potentially exceeding 420℃. Existing SCR systems lack temperature control mechanisms, leading to catalyst activity degradation and shortened lifespan due to high-temperature sintering or sulfur poisoning. Utility Model Content

[0003] In view of this, the present invention provides an SCR reactor and SCR system for ships to solve the problem of catalyst deactivation risk at high temperatures in SCR systems used in ships in related technologies.

[0004] In a first aspect, this utility model provides an SCR reactor for a ship, comprising:

[0005] The reactor body has a reaction chamber inside it. The reactor body is also provided with a flue gas inlet and a flue gas outlet that are respectively connected to the reaction chamber. A catalyst assembly is provided inside the reaction chamber.

[0006] A seawater cooling device is installed on the outside of the reactor body. The seawater cooling device includes several cooling channels arranged around the outer peripheral wall of the reactor body.

[0007] The seawater cooling device is located near the flue gas inlet of the reactor body.

[0008] Beneficial effects: By adding a seawater cooling device and through the layout of directional cooling channels and adjacent flue gas inlets, this invention achieves precise heat dissipation in the high-temperature area of ​​the reactor body, thereby extending catalyst life and improving the reliability of the SCR system.

[0009] In one optional embodiment, along the flue gas flow direction, the reaction chamber includes a cooling chamber and a catalytic chamber connected in sequence, the cooling chamber being connected to the flue gas inlet and the catalytic chamber being connected to the flue gas outlet;

[0010] The catalyst assembly is installed inside the catalyst chamber, and the seawater cooling device is installed outside the cooling chamber and arranged around the cooling chamber.

[0011] Beneficial effects: This invention achieves graded control of flue gas temperature and catalyst protection through the innovative design of a segmented reaction chamber and a surrounding seawater cooling device. The cooling chamber prioritizes the treatment of high-temperature flue gas, while the catalytic chamber focuses on the denitrification reaction. The two are synergistically optimized through directional heat dissipation from the seawater cooling device, thereby improving the stability, efficiency, and durability of the SCR system.

[0012] In one optional embodiment, the seawater cooling device includes multiple cooling channels, which are arranged at intervals along the flue gas flow direction. Each cooling channel surrounds the cooling chamber, and seawater required for cooling is introduced into the cooling channel.

[0013] Beneficial effects: The surrounding layout of multiple cooling channels expands the heat dissipation area. Combined with the high specific heat capacity of seawater and forced convection, it significantly improves cooling efficiency, increasing heat dissipation capacity by more than 30% compared to a single cooling channel design. Furthermore, the redundant design and independent loop layout of the cooling channels reduce the risk of single-point failures, ensuring continuous and efficient operation of the SCR system under harsh sea conditions. Simultaneously, this structure fully utilizes the external space of the reactor body, eliminating the need for additional system volume and adapting to the limited installation conditions on ships.

[0014] In one alternative embodiment, along the flow direction of the flue gas, the catalyst assembly includes a first catalyst layer, a phase change material buffer layer, and a second catalyst layer stacked sequentially.

[0015] Beneficial effects: On the one hand, the layered first and second catalyst layers can optimize the catalytic reaction process according to the specific composition and temperature conditions of the flue gas, thereby improving the overall denitrification efficiency of the SCR system. On the other hand, the presence of the phase change material buffer layer greatly enhances the adaptability and stability of the SCR system in the face of temperature fluctuations, reduces the risk of catalyst deactivation due to abnormal temperature, and extends the service life of the catalyst.

[0016] In one optional embodiment, both the first catalyst layer and the second catalyst layer are honeycomb structures with multiple vents, and the density of the vents ranges from 5 pores / square inch to 15 pores / square inch.

[0017] Beneficial effects: Ensures a low pressure drop, avoiding the impact of excessive pressure loss on engine efficiency.

[0018] Thus, by employing a honeycomb structure design with a specific pore density for the first and second catalyst layers, and combining this with the application of a phase change material buffer layer, the present invention solves the problems of low efficiency and susceptibility to temperature in traditional SCR systems, significantly improving the stability and reliability of the system.

[0019] In one alternative embodiment, the inlet diameter of the vent is larger than the outlet diameter within the first catalyst layer and the second catalyst layer.

[0020] Beneficial effects: The tapered vent design increases the effective contact area and time between flue gas and the catalyst, significantly improving NOx conversion rate and enabling the SCR system to achieve efficient denitrification at lower temperatures. It also reduces the frequency of clogging, lowers the workload and complexity of daily maintenance, and further enhances the system's reliability and operability.

[0021] In one optional embodiment, the first catalyst layer is a high-temperature resistant ceramic matrix, and the second catalyst layer is a high-efficiency denitrification module.

[0022] Beneficial effects: By selecting a high-temperature resistant ceramic matrix for the first catalyst layer and adopting a high-efficiency denitrification module for the second catalyst layer, this utility model not only improves the high-temperature resistance and denitrification efficiency of the SCR system, but also significantly enhances the reliability and durability of the system.

[0023] In one alternative embodiment, the ship's SCR reactor further includes:

[0024] At least one adjustable guide vane is rotatably mounted at the flue gas inlet of the reactor body and located within the reaction chamber. The adjustable guide vane extends from the flue gas inlet toward the reaction chamber, and the angle between the adjustable guide vane and the plane containing the flue gas inlet is adjustable.

[0025] Beneficial effects: The adjustable guide plate introduced in this embodiment not only optimizes the flow characteristics of flue gas after entering the SCR reactor, but also improves the stability and adaptability of the system, thereby improving denitrification efficiency, extending equipment life and reducing operating costs.

[0026] In one alternative embodiment, the ship's SCR reactor further includes:

[0027] Temperature sensors are installed at the flue gas inlet and / or flue gas outlet of the reactor body;

[0028] A nitrogen oxide sensor is installed on a pipe at a distance greater than one pipe diameter from the flue gas outlet to detect the concentration of nitrogen oxides in the flue gas.

[0029] A soot blowing device is connected to the reaction chamber and is used to soot blow the flue gas.

[0030] Beneficial effects: By integrating temperature sensors, nitrogen oxide sensors, and soot blowing devices, this utility model significantly enhances the intelligence level and environmental adaptability of the ship's SCR system, thereby achieving efficient, reliable, and environmentally friendly exhaust gas treatment.

[0031] Secondly, this utility model also provides a ship SCR system, comprising:

[0032] The SCR reactor for ships as described in the first aspect of this utility model. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is one of the structural schematic diagrams of an SCR reactor for a ship according to an embodiment of the present utility model;

[0035] Figure 2 This is a second schematic diagram of the structure of an SCR reactor for a ship, according to an embodiment of this utility model.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Reactor body; 11. Reaction chamber; 111. Cooling chamber; 112. Catalytic chamber; 12. Flue gas inlet; 13. Flue gas outlet; 2. Seawater cooling device; 21. Cooling channel; 31. First catalyst layer; 32. Phase change material buffer layer; 33. Second catalyst layer; 4. Adjustable guide plate; 5. Temperature sensor; 6. Nitrogen oxide sensor; 7. Soot blowing device. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0039] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0040] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model based on the specific circumstances.

[0041] In this embodiment of the utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0042] The following description, with reference to the accompanying drawings, introduces an SCR reactor for a ship and an SCR system having the SCR reactor provided by this utility model.

[0043] like Figure 1 and Figure 2 As shown, the SCR reactor of a ship according to the first aspect of the present invention includes a reactor body 1 and a seawater cooling device 2.

[0044] The reactor body 1 forms a reaction chamber 11 inside. The reactor body 1 is also provided with a flue gas inlet 12 and a flue gas outlet 13 that are respectively connected to the reaction chamber 11. A catalyst assembly is provided inside the reaction chamber 11.

[0045] The seawater cooling device 2 is installed on the outside of the reactor body 1. The seawater cooling device 2 includes several cooling channels 21, which are arranged around the outer peripheral wall of the reactor body 1. The seawater cooling device 2 is located near the flue gas inlet 12 of the reactor body 1.

[0046] The specific structure of the SCR reactor for a ship according to an embodiment of this utility model is described below:

[0047] The reactor body 1 provides the flow path for flue gas and the environment for the catalytic reaction, ensuring efficient NOx removal. Specifically, within the reactor body 1, the reaction chamber 11 is the core space for contact between the flue gas and the catalyst. Here, the flue gas reacts with urea solution to generate nitrogen and water, achieving denitrification. The flue gas inlet 12 and the flue gas outlet 13 are located at the bottom and top of the reactor body 1, respectively, to guide the high-temperature flue gas in and to discharge the purified flue gas. The catalyst assembly, fixed within the reaction chamber 11, employs a honeycomb structure and reduces NOx to harmless substances (such as nitrogen) through a catalytic reaction.

[0048] The seawater cooling device 2 reduces the temperature of the reactor body 1 through directional cooling, preventing catalyst activity degradation or structural damage due to high temperatures (>420°C). Specifically, the seawater cooling device 2 includes at least one cooling channel 21, which surrounds the outer peripheral wall of the reactor body 1, forming an annular water-cooled layer for absorbing heat from the reactor body 1. The cooling channel 21 is tightly fitted to the outer wall of the reactor body 1, transferring heat from the reactor body 1 to the seawater through thermal conduction. It should be noted that the cooling channel 21 is located near the flue gas inlet 12, thereby providing directional cooling for high-temperature areas at the flue gas inlet (such as instantaneous temperature rise during engine start-up or load changes). Furthermore, the seawater cooling device 2 can be connected to the ship's seawater pump system via external piping, and seawater is circulated through the cooling channel 21 and then discharged overboard.

[0049] Based on the above specific structural description, the working principle of this utility model is as follows: The cooling channel 21 surrounds the outer peripheral wall of the reactor body 1 and is preferentially arranged near the flue gas inlet 12. This area has the highest flue gas temperature (typically >350℃), requiring rapid heat dissipation to maintain the catalyst's active temperature range (285℃~450℃). The cooling channel 21 transfers heat from the reactor body 1 to the seawater through thermal conduction, utilizing the high specific heat capacity of seawater for efficient heat absorption. The seawater continuously flows within the cooling channel 21, continuously carrying away heat and preventing localized overheating. Simultaneously, the annular layout of the cooling channel 21 ensures the overall temperature uniformity of the reactor body 1, preventing thermal stress deformation caused by temperature differences.

[0050] In some specific scenarios, when the flue gas temperature exceeds the threshold (such as 420°C), the seawater cooling device 2 will automatically start, enhancing the heat dissipation capacity by increasing the seawater flow rate or extending the cooling time.

[0051] In one specific embodiment, the working process of the SCR system of this utility model is as follows:

[0052] During normal operation, high-temperature flue gas enters the reaction chamber 11 through the flue gas inlet 12 and comes into contact with the catalyst assembly to complete the denitrification reaction. The seawater cooling device 2 circulates at a basic flow rate to maintain the outer wall temperature of the reactor body 1 below 420°C, ensuring long-term stable operation of the catalyst. During the high-temperature abnormal response phase, when the flue gas temperature sensor 5 detects an inlet temperature >420°C (such as a sudden increase in engine load or start-stop conditions), the seawater cooling device 2 activates the standby pump, increasing the seawater flow rate to a high flow rate. The seawater velocity in the cooling channel 21 increases, thereby further improving the heat absorption efficiency. At this time, the area of ​​the cooling channel 21 adjacent to the flue gas inlet 12 prioritizes heat dissipation, rapidly reducing the inlet temperature of the reactor body 1 and preventing catalyst sulfur poisoning or sintering.

[0053] After the cooling cycle ends, i.e., when the flue gas temperature drops back to a safe range (<420℃), the seawater cooling device 2 resumes its basic flow rate to maintain system energy balance. The heat-absorbing seawater is discharged overboard through the drain pipe, completing a single cooling cycle.

[0054] In summary, by adding a seawater cooling device 2 and through the layout of the directional cooling channel 21 and the adjacent flue gas inlet 12, this utility model achieves precise heat dissipation of the high-temperature area of ​​the reactor body 1, thereby extending the catalyst life and improving the reliability of the SCR system.

[0055] Root Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, along the flue gas flow direction, the reaction chamber 11 includes a cooling chamber 111 and a catalytic chamber 112 connected in sequence. The cooling chamber 111 is connected to the flue gas inlet 12, and the catalytic chamber 112 is connected to the flue gas outlet 13.

[0056] The catalyst assembly is installed inside the catalyst chamber 112, and the seawater cooling device 2 is installed outside the cooling chamber 111 and arranged around the cooling chamber 111.

[0057] In this embodiment, the cooling chamber 111 is located at the front end of the reactor body 1 (near the flue gas inlet 12) and is used for pretreatment of high-temperature flue gas. The catalytic chamber 112 is located at the rear end of the reactor body 1 (near the flue gas outlet 13) and houses a catalyst assembly for completing the denitrification reaction. The cooling chamber 111 and the catalytic chamber 112 are connected sequentially along the flue gas flow direction. After entering the cooling chamber 111, the flue gas is pre-cooled before entering the catalytic chamber 112.

[0058] The flue gas inlet 12 is directly connected to the cooling chamber 111, where the flue gas first enters for temperature regulation. The flue gas outlet 13 is connected to the catalytic chamber 112, from which the purified flue gas is finally discharged. The seawater cooling device 2 is arranged around the outer wall of the cooling chamber 111, forming a ring-shaped cooling structure that directly dissipates heat from the cooling chamber 111. It can be understood that the cooling chamber 111 and the seawater cooling device 2 are tightly coupled through heat conduction, with the cooling channel 21 of the seawater cooling device 2 fitting against the outer wall of the cooling chamber 111 to achieve efficient heat exchange. The catalytic chamber 112 has no direct heat exchange path with the seawater cooling device 2, ensuring that the temperature inside the catalytic chamber 112 is only affected by the pre-cooled flue gas from the cooling chamber 111.

[0059] During flue gas flow, high-temperature flue gas (e.g., 350℃~450℃) enters the cooling chamber 111 from the flue gas inlet 12. The seawater cooling device 2 rapidly absorbs heat through the surrounding cooling channel 21, reducing the flue gas temperature to a suitable range for the catalyst (e.g., 285℃~420℃). The compartmentalized design of the cooling chamber 111 isolates the high-temperature flue gas from direct contact with the catalyst assembly, preventing catalyst deactivation due to instantaneous high temperature.

[0060] A seawater cooling device 2 is arranged around the outer wall of the cooling chamber 111, transferring heat from the cooling chamber 111 to the seawater through seawater circulation and heat conduction. The annular layout of the cooling channel 21 expands the heat dissipation area, improves cooling efficiency, and evenly distributes heat to prevent localized overheating of the cooling chamber 111. The cooled flue gas enters the catalytic chamber 112, making full contact with the catalyst assembly to complete the selective catalytic reduction (SCR) reaction. At this time, the separation design between the catalytic chamber 112 and the cooling chamber 111 ensures that the catalyst is always within a stable temperature range, avoiding activity decay or structural damage caused by high temperatures.

[0061] In summary, this invention achieves graded control of flue gas temperature and catalyst protection through the innovative design of a compartmentalized reaction chamber 11 and a surrounding seawater cooling device 2. The cooling chamber 111 prioritizes the treatment of high-temperature flue gas, while the catalytic chamber 112 focuses on the denitrification reaction. The two are synergistically optimized through the directional heat dissipation of the seawater cooling device 2, thereby improving the stability, efficiency, and durability of the SCR system.

[0062] like Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the seawater cooling device 2 includes multiple cooling channels 21, which are arranged at intervals along the flue gas flow direction. Each cooling channel 21 is arranged around the cooling chamber 111, and seawater required for cooling is introduced into the cooling channel 21.

[0063] In this embodiment, the seawater cooling device 2 includes multiple cooling channels 21, arranged at intervals along the flue gas flow direction (i.e., from the flue gas inlet 12 to the flue gas outlet 13). For example, the cooling channels 21 can be arranged spirally, annularly, or in parallel to ensure that they cover the entire outer peripheral wall of the cooling chamber 111. Each cooling channel 21 is arranged around the outer peripheral wall of the cooling chamber 111, forming an annular water-cooled layer that directly contacts the outer wall of the cooling chamber 111, achieving efficient heat conduction.

[0064] Each cooling channel 21 has a closed seawater circulation path inside, and the seawater is connected to the ship's seawater pump system through external pipelines to form an independent cooling circuit. The cooling channels 21 are arranged at intervals along the flue gas flow direction to avoid local overcooling or overheating, and the redundancy design of multiple channels improves the system reliability.

[0065] It is understandable that multiple cooling channels 21 are arranged at intervals along the flue gas flow direction to ensure that the heat on the outer wall of the cooling chamber 111 is absorbed evenly and to avoid the formation of local high-temperature areas. When a cooling channel 21 is blocked or fails, the other channels can still maintain their cooling function to ensure continuous operation of the system.

[0066] In this way, the surrounding layout of multiple cooling channels 21 expands the heat dissipation area. Combined with the high specific heat capacity of seawater and forced convection, it significantly improves cooling efficiency, increasing heat dissipation capacity by more than 30% compared to a single cooling channel 21 design. Furthermore, the redundant design and independent loop layout of the cooling channels 21 reduce the risk of single-point failures, ensuring the SCR system operates continuously and efficiently under harsh sea conditions. At the same time, this structure can fully utilize the external space of the reactor body 1 without increasing the system volume, adapting to the limited installation conditions of ships.

[0067] like Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the catalyst assembly includes a first catalyst layer 31, a phase change material buffer layer 32, and a second catalyst layer 33 stacked sequentially.

[0068] In this embodiment, the first catalyst layer 31 is located near the flue gas inlet 12, directly contacting the flue gas pre-cooled by the cooling chamber 111. It is primarily responsible for the initial catalytic reaction, rapidly reducing the NOx concentration in the flue gas. The phase change material buffer layer 32 is located between the first catalyst layer 31 and the second catalyst layer 33, serving to regulate and stabilize the temperature. When the flue gas temperature fluctuates, the phase change material buffers the temperature change by absorbing or releasing heat, protecting the catalyst from extreme temperatures. The second catalyst layer 33 is located near the flue gas outlet 13, further treating the remaining NOx components in the flue gas to ensure that the final emissions meet environmental standards.

[0069] The layers are tightly bonded together to form a unified catalyst assembly, ensuring that the flue gas can pass smoothly through each layer for a full catalytic reduction reaction. The phase change material buffer layer 32 not only serves as a temperature buffer medium but also provides some support, preventing physical damage (such as cracks) to the catalyst layer during long-term use.

[0070] Specifically, its working principle is as follows: The first catalyst layer 31 first performs preliminary treatment on the flue gas entering the catalytic chamber 112. Since this part of the flue gas has just been pre-cooled by the cooling chamber 111, its temperature is relatively low, but it still needs to start the catalytic reaction immediately to reduce the NOx content. When the flue gas temperature changes drastically (e.g., engine start-up or sudden load change), the phase change material absorbs excess heat or releases the stored heat to maintain the temperature around the catalyst layer within a stable range, avoiding a decrease in catalyst performance due to sudden temperature changes. The second catalyst layer 33 further treats the flue gas that has undergone preliminary catalysis but still contains a certain amount of NOx, ensuring that the final emissions meet stricter environmental protection requirements.

[0071] It is understandable that by placing a phase change material buffer layer 32 between the two catalyst layers, the impact of temperature fluctuations on catalyst activity can be effectively mitigated. The phase change material can automatically adjust its state within a specific temperature range to absorb or release heat, thereby maintaining the ideal temperature environment for catalyst operation.

[0072] In summary, on the one hand, the layered first and second catalyst layers 33 can optimize the catalytic reaction process according to the specific composition and temperature conditions of the flue gas, thereby improving the denitrification efficiency of the entire SCR system. On the other hand, the presence of the phase change material buffer layer 32 greatly enhances the adaptability and stability of the SCR system in the face of temperature fluctuations, reduces the risk of catalyst deactivation due to abnormal temperature, and extends the service life of the catalyst.

[0073] like Figure 1 and Figure 2 As shown, in some specific embodiments of this utility model, the first catalyst layer 31 and the second catalyst layer 33 are both honeycomb structures with multiple vents, and the density of their vents ranges from 5 pores / square inch to 15 pores / square inch.

[0074] In this embodiment, both the first catalyst layer 31 and the second catalyst layer 33 employ a honeycomb structure with multiple vent holes. This structure not only provides a larger surface area to increase contact opportunities with the flue gas but also helps reduce airflow resistance, allowing the flue gas to pass through the catalyst layer more smoothly. Simultaneously, the honeycomb structure design ensures more uniform gas flow between layers, reducing the risk of excessive wear or blockage in localized areas.

[0075] The pore density of each catalyst layer is limited to between 5 pores / square inch and 15 pores / square inch, for example, 10 pores / square inch. This design considers both ensuring sufficient catalytically active surface area and maintaining a low pressure drop to avoid impacting engine efficiency due to excessive pressure loss.

[0076] Thus, by employing a specific range of vent density design, this invention ensures sufficient catalytic active sites while avoiding excessive pressure drop, achieving a high NOx removal rate. Furthermore, by reducing the additional cleaning requirements caused by ash accumulation or blockage, the appropriate selection of the honeycomb structure and vent density helps lower system maintenance costs; simultaneously, it reduces the negative impact on the main unit caused by excessive pressure drop, optimizing the overall performance of the SCR system.

[0077] In summary, this embodiment of the invention, by employing a honeycomb structure design with a specific pore density for the first catalyst layer 31 and the second catalyst layer 33, and combining it with the application of a phase change material buffer layer 32, solves the problems of low efficiency and susceptibility to temperature in traditional SCR systems, and significantly improves the stability and reliability of the system.

[0078] like Figure 1 and Figure 2 As shown, further, within the first catalyst layer 31 and the second catalyst layer 33, the inlet diameter of the vent hole is larger than the outlet diameter.

[0079] Within the first catalyst layer 31 and the second catalyst layer 33, each vent is designed with an inlet diameter larger than an outlet diameter. This means the flue gas enters through a larger opening, and as it passes through the catalyst layer, the channel gradually narrows until it reaches a smaller outlet diameter. This design, a tapered or conical structure, helps guide the flue gas to distribute more evenly throughout the catalyst layer and increases the contact time between the flue gas and the catalyst surface as it passes through the catalyst layer.

[0080] It should be explained that the larger orifice at the inlet allows the flue gas to enter the catalyst layer at a lower velocity, reducing the wear on the catalyst surface caused by turbulence and direct impact. As the orifice size gradually decreases, the flue gas velocity increases, promoting thorough mixing between the gas and the catalyst and improving reaction efficiency.

[0081] Meanwhile, as the pore size gradually decreases, the flue gas velocity increases while passing through the catalyst layer, but it also encounters more resistance. This increases the actual residence time of the flue gas within the catalyst, providing more time for NOx to react chemically with the reducing agent, further improving denitrification efficiency. Furthermore, the larger inlet pore size reduces pressure loss upon flue gas entry, helping to maintain low-resistance operation of the entire SCR system.

[0082] Furthermore, compared to channels with a constant diameter, tapered channels are better able to resist particulate matter deposition, especially in marine applications where exhaust gases contain a significant amount of fly ash and other impurities. A larger inlet helps capture large particles, while the gradually narrowing aperture reduces the likelihood of fine particles accumulating at depth, thus mitigating clogging problems caused by ash buildup during long-term use.

[0083] In summary, the tapered vent design increases the effective contact area and time between flue gas and the catalyst, significantly improving NOx conversion and enabling the SCR system to achieve efficient denitrification at lower temperatures. Simultaneously, it reduces the frequency of clogging, lowers the workload and complexity of daily maintenance, and further enhances the system's reliability and operability.

[0084] like Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the first catalyst layer 31 is a high-temperature resistant ceramic matrix, and the second catalyst layer 33 is a high-efficiency denitrification module.

[0085] In this embodiment, the first catalyst layer 31 uses high-temperature resistant ceramic as the matrix material. This material has excellent thermal stability and mechanical strength, and can maintain structural integrity and catalytic activity under extreme temperature conditions. Since it is close to the flue gas inlet 12 and faces high-temperature flue gas that has not been sufficiently cooled (e.g., 350°C to 450°C), it is necessary to pay special attention to its high-temperature resistance to prevent physical damage or chemical deactivation under high-temperature conditions.

[0086] The second catalyst layer 33 is a high-efficiency denitrification module used to improve NOx conversion efficiency. The second catalyst layer 33 typically contains highly efficient noble metal or metal oxide catalyst components, such as platinum, palladium, vanadium, tungsten, and titanium. These components exhibit good low-temperature activity and high selectivity, effectively promoting the reduction reaction between NH and NOx. Furthermore, the second catalyst layer 33 is located at the rear end of the catalytic chamber 112 (near the flue gas outlet 13), where the flue gas has undergone preliminary cooling and the NOx concentration is relatively low, making it suitable for deep denitrification treatment to ensure that final emissions meet standards.

[0087] The specific purification process of the SCR reactor is as follows: The first catalyst layer 31 utilizes its high-temperature resistance to initiate catalysis when faced with high-temperature flue gas, rapidly reducing some of the NOx concentration and pre-treating the flue gas to lower its temperature to a range suitable for subsequent advanced treatment. The second catalyst layer 33 then targets the flue gas that has undergone preliminary treatment but still contains a certain amount of NOx, further removing residual NOx through its highly efficient denitrification capability, ensuring that the final emissions meet stringent environmental standards.

[0088] It should be explained that the first layer of the high-temperature resistant ceramic matrix not only bears the task of resisting high-temperature shock, but also can disperse heat to a certain extent, protecting the subsequent high-efficiency denitrification module from high-temperature damage. At the same time, the phase change material buffer layer 32 set between the two layers can further stabilize the temperature environment, ensuring that the entire catalytic process takes place within an ideal temperature range, maximizing the role of each catalyst layer.

[0089] In summary, by selecting a high-temperature resistant ceramic substrate for the first catalyst layer 31 and adopting a high-efficiency denitrification module for the second catalyst layer 33, this embodiment of the present invention not only improves the high-temperature resistance and denitrification efficiency of the SCR system, but also significantly enhances the reliability and durability of the system.

[0090] like Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the SCR reactor of a ship also includes at least one adjustable guide plate 4. The adjustable guide plate 4 is rotatably installed at the flue gas inlet 12 of the reactor body 1 and located inside the reaction chamber 11. The adjustable guide plate 4 extends from the flue gas inlet 12 toward the reaction chamber 11, and the angle between the adjustable guide plate 4 and the plane where the flue gas inlet 12 is located is adjustable.

[0091] In this embodiment, at least one adjustable guide plate 4 is designed to be rotatably installed at the flue gas inlet 12 of the reactor body 1 and located inside the reaction chamber 11. That is, the guide plate directly faces the high-temperature flue gas entering the SCR reactor, enabling preliminary control of the flue gas flow direction. The adjustable guide plate 4 extends from the flue gas inlet 12 into the reaction chamber 11, ensuring that it can begin to function at the beginning of the flue gas entering the reaction chamber 11, guiding the flue gas to be evenly distributed throughout the entire reaction chamber 11.

[0092] The angle between the adjustable guide vane 4 and the plane where the flue gas inlet 12 is located can be adjusted, thereby allowing the system to dynamically adjust the angle of the guide vane according to actual operating conditions (such as flue gas flow rate, temperature changes, etc.) to optimize the flue gas flow path and distribution.

[0093] During the flue gas flow process, by adjusting the angle of the adjustable guide plate 4, the direction and velocity distribution of the flue gas entering the reaction chamber 11 can be changed, so that the flue gas can be more evenly dispersed in the entire catalytic chamber 112, avoiding the problem of excessive catalyst wear or efficiency reduction caused by flue gas concentration in local areas.

[0094] Furthermore, during ship operation, engine loads fluctuate, leading to significant variations in flue gas flow and temperature. The adjustable deflector 4 can adjust its angle in real time according to these changes, maintaining optimal airflow guidance and ensuring efficient operation of the SCR system under different operating conditions.

[0095] Furthermore, a properly angled guide vane helps reduce the resistance encountered by the flue gas when entering the reaction chamber 11, thereby reducing the overall pressure loss of the system and improving energy efficiency. Simultaneously, by guiding the flue gas to flow uniformly, particulate matter deposition in certain areas can be reduced, lowering the risk of blockage due to ash accumulation and extending the catalyst's lifespan.

[0096] In summary, the adjustable guide plate 4 introduced in this embodiment not only optimizes the flow characteristics of flue gas after entering the SCR reactor, but also improves the stability and adaptability of the system, thereby improving denitrification efficiency, extending equipment life and reducing operating costs.

[0097] like Figure 1 and Figure 2 As shown, according to some embodiments of the present invention, the SCR reactor of a ship also includes a temperature sensor 5, a nitrogen oxide sensor 6, and a soot blowing device 7.

[0098] Temperature sensor 5 is installed at flue gas inlet 12 and / or flue gas outlet 13 of reactor body 1; nitrogen oxide sensor 6 is installed on a pipe at a distance greater than one pipe diameter from flue gas outlet 13, for detecting the concentration of nitrogen oxides in the flue gas. Soot blowing device 7 is connected to the reaction chamber 11 and is used to perform soot blowing treatment on the flue gas.

[0099] In this embodiment, temperature sensor 5 is installed at the flue gas inlet 12 and / or flue gas outlet 13 of the reactor body 1, thereby allowing the system to monitor the flue gas temperature before entering the SCR reactor and the flue gas temperature after catalytic treatment in real time. In this way, by measuring the temperature at these two key points, the thermal state of the entire SCR system can be accurately understood, ensuring that the catalyst is always within the optimal operating temperature range and avoiding catalyst deactivation or efficiency reduction due to excessively high or low temperatures.

[0100] The nitrogen oxide sensor 6 is installed at a distance of at least one pipe diameter from the flue gas outlet 13 to ensure that it detects a fully mixed flue gas sample, thereby obtaining a more accurate NOx concentration reading. This sensor is used to monitor the nitrogen oxide concentration in the purified flue gas in real time, ensuring that emissions meet environmental standards and providing feedback information for the system's automatic control.

[0101] The soot blowing device 7 is directly connected to the reaction chamber 11 and is mainly used to remove dust particles accumulated on the catalyst surface and in its pores, preventing increased pressure drop and reduced denitrification efficiency caused by dust accumulation. The soot blowing device 7 can be integrated into the reaction chamber 11 through compressed air nozzles or other forms of mechanical devices, and can be activated periodically or as needed to perform purging operations.

[0102] In practical applications, temperature sensor 5 continuously collects temperature data at the flue gas inlet 12 and outlet, and this information is fed back to the control system. If the temperature exceeds the set safety range, the control system will adjust the operating parameters of the seawater cooling device 2 (such as cooling water flow rate) or adjust the angle of the adjustable guide vane 4 to maintain suitable temperature conditions.

[0103] The concentration data provided by the nitrogen oxide sensor 6 can be used to evaluate the denitrification effect of the SCR system. When the NOx concentration exceeds the standard, the control system may increase the injection rate of urea solution or adjust other operating parameters to improve the denitrification efficiency until the standard is met.

[0104] The soot blowing device 7 automatically starts at preset time intervals or based on pressure difference changes, using high-pressure gas to impact the catalyst surface and remove accumulated dust and other impurities. This regular cleaning helps maintain the unobstructed flow of the catalyst layer, reduces unnecessary energy loss, and extends its service life.

[0105] In summary, by integrating a temperature sensor 5, a nitrogen oxide sensor 6, and a soot blowing device 7, this embodiment of the invention significantly enhances the intelligence level and environmental adaptability of the ship's SCR system, thereby achieving efficient, reliable, and environmentally friendly exhaust gas treatment.

[0106] like Figure 1 and Figure 2 As shown, the SCR system of a ship according to a second aspect of the present invention includes the SCR reactor of the ship as described in the first aspect of the present invention.

[0107] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. An SCR reactor for a ship, characterized in that, include: The reactor body (1) has a reaction chamber (11) inside it. The reactor body (1) is also provided with a flue gas inlet (12) and a flue gas outlet (13) respectively connected to the reaction chamber (11). A catalyst assembly is provided inside the reaction chamber (11). A seawater cooling device (2) is installed on the outside of the reactor body (1). The seawater cooling device (2) includes several cooling channels (21) which are arranged around the outer peripheral wall of the reactor body (1). The seawater cooling device (2) is located near the flue gas inlet (12) of the reactor body (1).

2. The SCR reactor for ships according to claim 1, characterized in that, Along the flow direction of the flue gas, the reaction chamber (11) includes a cooling chamber (111) and a catalytic chamber (112) connected in sequence. The cooling chamber (111) is connected to the flue gas inlet (12), and the catalytic chamber (112) is connected to the flue gas outlet (13). The catalyst assembly is installed inside the catalyst chamber (112), and the seawater cooling device (2) is installed outside the cooling chamber (111) and arranged around the cooling chamber (111).

3. The SCR reactor for ships according to claim 2, characterized in that, The seawater cooling device (2) includes multiple cooling channels (21), which are arranged at intervals along the flue gas flow direction. Each cooling channel (21) surrounds the cooling chamber (111), and seawater required for cooling is introduced into the cooling channel (21).

4. The SCR reactor for ships according to claim 2, characterized in that, Along the flow direction of the flue gas, the catalyst assembly includes a first catalyst layer (31), a phase change material buffer layer (32), and a second catalyst layer (33) stacked sequentially.

5. The SCR reactor for a ship according to claim 4, characterized in that, Both the first catalyst layer (31) and the second catalyst layer (33) are honeycomb structures with multiple vents, and the density of the vents ranges from 5 pores / square inch to 15 pores / square inch.

6. The SCR reactor for a ship according to claim 5, characterized in that, Within the first catalyst layer (31) and the second catalyst layer (33), the inlet diameter of the vent is larger than the outlet diameter.

7. The SCR reactor for a ship according to claim 4, characterized in that, The first catalyst layer (31) is a high-temperature resistant ceramic matrix, and the second catalyst layer (33) is a high-efficiency denitrification module.

8. The SCR reactor for a ship according to any one of claims 1 to 7, characterized in that, Also includes: At least one adjustable guide plate (4) is rotatably mounted at the flue gas inlet (12) of the reactor body (1) and located inside the reaction chamber (11). The adjustable guide plate (4) extends from the flue gas inlet (12) toward the reaction chamber (11), and the angle between the adjustable guide plate (4) and the plane of the flue gas inlet (12) is adjustable.

9. The SCR reactor for a ship according to any one of claims 1 to 7, characterized in that, Also includes: Temperature sensor (5) is installed at flue gas inlet (12) and / or flue gas outlet (13) of the reactor body (1); A nitrogen oxide sensor (6) is installed on a pipe at a distance greater than one pipe diameter from the flue gas outlet (13) for detecting the concentration of nitrogen oxides in the flue gas. A soot blowing device (7) is connected to the reaction chamber (11) and is used to blow soot onto the flue gas.

10. A ship's SCR system, characterized in that, include: The SCR reactor of a ship as described in any one of claims 1 to 9.

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