Automatic liquid supplementing device of post-processing system of marine diesel engine

Abstract

The utility model relates to the technical field of ships, and discloses an automatic liquid supplementing device of a post-processing system of a marine diesel engine, which comprises a daily cabinet, a liquid storage cabinet and a connecting pipeline. The daily cabinet is connected with a marine diesel engine post-processing system, the liquid storage cabinet is used for storing urea solution, and the installation height of the liquid storage cabinet is larger than that of the daily cabinet. One end of the connecting pipeline is connected with the liquid storage cabinet, and the other end selectively communicates with the daily cabinet. When the liquid level in the daily cabinet is lower than a first liquid level threshold value, the liquid storage cabinet can be communicated with the daily cabinet through the connecting pipeline. According to the automatic liquid supplementing device, driving mechanisms such as a urea pump do not need to be additionally arranged, automatic liquid supplementing for the marine diesel engine post-processing system is achieved only by reasonably arranging the positions of the liquid storage cabinet and the daily cabinet, the structural design is simple, the installation construction steps of the automatic liquid supplementing device on a ship can be simplified, the construction cost and construction difficulty are reduced, and the working efficiency is improved. And faults caused by frequent start and stop of the machine are avoided by means of automatic liquid supplementing by gravity, and the working reliability is high.

Description

Technical Field

[0001] The utility model relates to the technical field of ships, in particular to an automatic liquid replenishing device for a post-processing system of a ship diesel engine. Background Art

[0002] The post-treatment system of marine diesel engines (Selective Catalytic Reduction (SCR)) is mainly used to treat the exhaust gas of marine diesel engines to prevent air pollution. SCR technology is based on the catalytic reaction of ammonia and nitrogen oxides (NOx). By introducing ammonia (urea solution) under the action of the catalyst, NOx is converted into harmless nitrogen and water, effectively removing NOx from diesel engine exhaust and meeting the NOx emission standards.

[0003] The marine diesel engine aftertreatment system will continuously consume urea solution during operation. To ensure the normal operation of the equipment, urea solution needs to be replenished regularly. The existing urea solution replenishment device usually uses a urea pump to pump urea solution to the marine diesel engine aftertreatment system. However, the cost of the urea pump is high and the economic efficiency is poor. In addition, the urea pump is frequently started and stopped, which is prone to failure and can easily cause the marine diesel engine aftertreatment system to fail to operate normally.

[0004] Therefore, there is an urgent need for an automatic liquid replenishing device for a marine diesel engine aftertreatment system to solve the above problems. Utility Model Content

[0005] Based on the above problems, the purpose of the utility model is to provide an automatic fluid replenishing device for a ship diesel engine after-treatment system, which can automatically replenish the ship diesel engine after-treatment system with simple structural design, easy implementation and high working reliability.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] Provided is an automatic liquid filling device for a marine diesel engine aftertreatment system, comprising:

[0008] Daily cabinet, connected to the ship diesel engine after-treatment system;

[0009] A liquid storage cabinet, used for storing urea solution, wherein the installation height of the liquid storage cabinet is higher than the installation height of the daily cabinet;

[0010] A connecting pipeline, one end of which is connected to the liquid storage cabinet and the other end of which is selectively connected to the daily cabinet; when the liquid level in the daily cabinet is lower than a first liquid level threshold, the liquid storage cabinet can be connected to the daily cabinet through the connecting pipeline.

[0011] As an optional solution for the automatic refilling device of the marine diesel engine aftertreatment system of the utility model, a control component is provided on the connecting pipeline, and the control component is used to control the on-off of the connecting pipeline so that the liquid storage tank is selectively connected to the daily cabinet through the connecting pipeline.

[0012] As an optional solution for the automatic fluid replenishing device of the ship diesel engine after-treatment system of the utility model, a plurality of daily cabinets are provided, and the connecting pipeline includes a main pipeline and a plurality of branch pipelines. The first end of the main pipeline is connected to the liquid storage cabinet, one end of each of the plurality of branch pipelines is connected to the second end of the main pipeline, and the other ends of the plurality of branch pipelines are connected to the plurality of daily cabinets in a one-to-one correspondence.

[0013] As an optional solution of the automatic liquid replenishing device of the marine diesel engine aftertreatment system of the utility model, the control component includes a first control valve arranged on the main pipeline, and the first control valve is used to control the on-off of the main pipeline.

[0014] As an optional solution of the automatic liquid replenishing device of the marine diesel engine aftertreatment system of the utility model, the control component includes a second control valve arranged on the branch pipeline, and the second control valve is used to control the on-off of the branch pipeline.

[0015] As an optional solution of the automatic rehydration device of the marine diesel engine aftertreatment system of the utility model, a filtering device is provided on the main pipeline and / or the branch pipeline, and the filtering device is used to filter the urea solution in the main pipeline and / or the branch pipeline.

[0016] As an optional solution for the automatic rehydration device of the ship diesel engine aftertreatment system of the utility model, the branch pipeline includes a first pipe segment, a second pipe segment and a third pipe segment connected in sequence, the end of the first pipe segment away from the second pipe segment is connected to the main pipeline, the end of the third pipe segment away from the second pipe segment is connected to the daily cabinet, and the height of the first pipe segment is higher than the height of the third pipe segment.

[0017] As an optional solution for the automatic rehydration device of the ship diesel engine aftertreatment system of the utility model, the connecting pipeline also includes an extension pipeline, which is connected to the second end of the main pipeline, and one end of each of the multiple branch pipelines is connected to the extension pipeline and is spaced apart along the length direction of the extension pipeline.

[0018] As an optional solution for the automatic liquid replenishing device of the marine diesel engine aftertreatment system of the utility model, a liquid level detection component for detecting the liquid level is arranged in the daily cabinet, and the liquid level detection component is communicatively connected with the control component. When the liquid level value detected by the liquid level detection component is lower than the first liquid level threshold, the control component controls the connecting pipeline to be connected. When the liquid level value detected by the liquid level detection component is higher than the second liquid level threshold, the control component controls the connecting pipeline to be disconnected. The second liquid level threshold is greater than the first liquid level threshold.

[0019] As an optional solution for the automatic rehydration device of the ship diesel engine aftertreatment system of the utility model, the daily cabinet is provided with a first interface and a second interface, the first interface is used to connect to the connecting pipeline, and the second interface is used to connect to the ship diesel engine aftertreatment system.

[0020] The beneficial effects of the utility model are:

[0021] The automatic refilling device for the after-treatment system of a marine diesel engine provided by the utility model has a higher installation height of the liquid storage cabinet than that of the daily cabinet, that is, the terrain of the location of the liquid storage cabinet is higher than that of the daily cabinet. Therefore, when the liquid level in the daily cabinet is lower than the first liquid level threshold, it is only necessary to control the connection of the connecting pipeline, so that the urea solution in the liquid storage cabinet can automatically flow to the daily cabinet with lower terrain through the connecting pipeline under the action of its own gravity, so as to realize automatic refilling, so that the daily cabinet can always provide sufficient urea solution for the after-treatment system of the marine diesel engine, and ensure the normal operation of the after-treatment system of the marine diesel engine. When the liquid level in the daily cabinet is higher than the second liquid level threshold, the connecting pipeline is controlled to be disconnected, and the liquid flow into the daily cabinet is stopped. The automatic refilling device does not need to set up additional driving mechanisms such as urea pumps, and can realize automatic refilling for the after-treatment system of the marine diesel engine only by reasonably arranging the positions of the liquid storage cabinet and the daily cabinet. The structural design is simple, easy to implement, and can simplify the installation and construction steps of the automatic refilling device on the ship, reducing the construction cost and construction difficulty. At the same time, the automatic liquid replenishment method relying on gravity does not cause failures due to frequent starting and stopping of the machine, thereby improving the working reliability of the automatic liquid replenishment device. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the contents of the embodiments of the present invention and these drawings without paying any creative work.

[0023] Figure 1 It is an axonometric diagram of an automatic liquid replenishing device for a marine diesel engine aftertreatment system provided by a specific embodiment of the utility model;

[0024] Figure 2 It is a top view of the automatic liquid filling device of the marine diesel engine after-treatment system provided by the specific embodiment of the utility model;

[0025] Figure 3 It is a front view of an automatic liquid filling device for a marine diesel engine aftertreatment system provided by a specific embodiment of the utility model;

[0026] Figure 4 It is a schematic diagram of the connection between the liquid level detection component and the control component and the control module provided in the specific implementation mode of the utility model.

[0027] In the figure:

[0028] 1-Daily cabinet; 2-Liquid storage cabinet; 3-Connecting pipeline; 4-Liquid level detection component; 5-Control module;

[0029] 11-first interface; 12-second interface;

[0030] 31-main pipeline; 32-branch pipeline; 33-extension pipeline;

[0031] 311-first control valve; 312-filter device;

[0032] 321-first pipe section; 322-second pipe section; 323-third pipe section;

[0033] 3211-Second control valve. DETAILED DESCRIPTION

[0034] In order to make the technical problems solved by the utility model, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the embodiments of the utility model will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0035] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] like Figures 1 to 3 As shown, this embodiment provides an automatic liquid replenishing device for a marine diesel engine aftertreatment system, and the automatic liquid replenishing device includes a daily cabinet 1, a liquid storage cabinet 2 and a connecting pipeline 3.

[0038] The daily cabinet 1 is connected to the ship diesel engine aftertreatment system, the liquid storage cabinet 2 is used to store urea solution, and the installation height of the liquid storage cabinet 2 is higher than the installation height of the daily cabinet 1. One end of the connecting pipe 3 is connected to the liquid storage cabinet 2, and the other end is selectively connected to the daily cabinet 1; when the liquid level in the daily cabinet 1 is lower than the first liquid level threshold, the liquid storage cabinet 2 can be connected to the daily cabinet 1 through the connecting pipe 3.

[0039] The automatic liquid replenishing device for the marine diesel engine aftertreatment system provided in this embodiment has a higher installation height of the liquid storage tank 2 than that of the daily cabinet 1, that is, the terrain at the location of the liquid storage tank 2 is higher than the terrain at the location of the daily cabinet 1 (e.g. Figure 3 As shown), therefore, when the liquid level in the daily cabinet 1 is lower than the first liquid level threshold, it is only necessary to control the connection line 3 to be turned on, so that the urea solution in the liquid storage cabinet 2 can automatically flow to the daily cabinet 1 with a lower terrain through the connection line 3 under the action of its own gravity, so as to realize automatic liquid replenishment, so that the daily cabinet 1 can always provide sufficient urea solution for the ship diesel engine after-treatment system, and ensure the normal operation of the ship diesel engine after-treatment system. When the liquid level in the daily cabinet 1 is higher than the second liquid level threshold, the connection line 3 is controlled to be disconnected, and the liquid is stopped from flowing into the daily cabinet 1. The automatic liquid replenishment device does not need to set up additional driving mechanisms such as urea pumps. It can realize automatic liquid replenishment for the ship diesel engine after-treatment system only by reasonably arranging the positions of the liquid storage cabinet 2 and the daily cabinet 1. The structural design is simple and easy to implement, and it can simplify the installation and construction steps of the automatic liquid replenishment device on the ship, reducing the construction cost and construction difficulty. At the same time, the method of automatic liquid replenishment by gravity does not have failures caused by frequent start and stop of the machine, which improves the working reliability of the automatic liquid replenishment device.

[0040] In addition, since the driving mechanism such as the urea pump is omitted, the weight of the entire device is reduced, which makes it easier to construct and install, and can reduce the load weight for the ship.

[0041] Further, in this embodiment, referring to Figure 3In the orientation, the horizontal plane where the bottom of the liquid storage tank 2 is located is higher than the horizontal plane where the top of the daily cabinet 1 is located, so that there is a sufficient terrain difference between the liquid storage tank 2 and the daily cabinet 1, ensuring that the urea solution in the liquid storage tank 2 can smoothly pass into the daily cabinet 1 through the connecting pipe 3.

[0042] Optionally, see Figure 1 and Figure 2 , the daily cabinet 1 is provided with multiple, the connecting pipeline 3 includes a main pipeline 31 and multiple branch pipelines 32, the first end of the main pipeline 31 is connected to the liquid storage cabinet 2, one end of the multiple branch pipelines 32 are all connected to the second end of the main pipeline 31, and the other end of the multiple branch pipelines 32 is connected to the multiple daily cabinets 1 in a one-to-one correspondence. The multiple daily cabinets 1 correspond to the multiple generator sets of the ship diesel engine aftertreatment system in a one-to-one manner, and can provide urea solution for the multiple generator sets of the ship diesel engine aftertreatment system, so that one liquid storage cabinet 2 can automatically replenish liquid for multiple daily cabinets 1 through the connecting pipeline 3, further reducing the construction cost of the automatic liquid replenishment device. Especially for the diesel engine aftertreatment system with multiple generator sets, since multiple urea pumps can be omitted, the cost of the automatic liquid replenishment device is greatly reduced, and it is easier to promote and use.

[0043] For example, Figure 1 and Figure 2 As shown, four daily cabinets 1 are provided, and the liquid storage cabinet 2 is connected to the four daily cabinets 1 through a main pipeline 31 and four branch pipelines 32 . The liquid storage cabinet 2 can replenish urea solution for the four daily cabinets 1 .

[0044] In other embodiments, the number of daily cabinets 1 can be adaptively increased or decreased according to the number of generator sets of the ship diesel engine after-treatment system, and is not limited to the number listed above.

[0045] Optionally, a control component is provided on the connecting pipeline 3, and the control component is used to control the opening and closing of the connecting pipeline 3, so that the liquid storage cabinet 2 is selectively connected with the daily cabinet 1 through the connecting pipeline 3. When the liquid level of the daily cabinet 1 is lower than the first liquid level threshold, the connecting pipeline 3 is controlled by the control component to be connected, so that the urea solution in the liquid storage cabinet 2 can automatically flow into the daily cabinet 1 along the connecting pipeline 3. When the liquid level of the daily cabinet 1 is higher than the second liquid level threshold, the connecting pipeline 3 is controlled by the control component to be disconnected, and the liquid replenishment to the daily cabinet 1 is stopped. Automatic liquid replenishment to the daily cabinet 1 can be achieved by adjusting the control component, and the control is convenient.

[0046] Optionally, see Figure 1 and Figure 2The control component includes a first control valve 311 disposed on the main line 31, and the first control valve 311 is used to control the on and off of the main line 31. By controlling the opening and closing of the first control valve 311, the main line 31 can be turned on or off, thereby controlling whether the liquid storage tank 2 replenishes liquid to the daily cabinet 1. When only the first control valve 311 is disposed on the main line 31, it is possible to synchronously control the simultaneous replenishment or stop of liquid replenishment to multiple daily cabinets 1.

[0047] Furthermore, the control component includes a second control valve 3211 disposed on the branch pipeline 32, and the second control valve 3211 is used to control the on-off of the branch pipeline 32. When the first control valve 311 is opened and the second control valve 3211 is also opened, the corresponding main pipeline 31 and the branch pipeline 32 can be connected, so as to automatically replenish the corresponding daily cabinet 1. In this embodiment, a second control valve 3211 is disposed on each branch pipeline 32. In this configuration, the second control valve 3211 on the corresponding branch pipeline 32 can be accurately controlled to be opened or closed according to the liquid level of each daily cabinet 1, so that only the daily cabinet 1 that needs to be replenished is replenished, and the automatic replenishment control is more accurate.

[0048] Optionally, a liquid level detection component 4 for detecting the liquid level is provided in the daily cabinet 1, and the liquid level detection component 4 is in communication connection with the control component. When the liquid level value detected by the liquid level detection component 4 is lower than the first liquid level threshold, the control component controls the connection pipeline 3 to be turned on. When the liquid level value detected by the liquid level detection component 4 is higher than the second liquid level threshold, the control component controls the connection pipeline 3 to be turned off. The second liquid level threshold is greater than the first liquid level threshold. Further, refer to Figure 4 The automatic liquid replenishing device of the marine diesel engine aftertreatment system also includes a control module 5, and the control component includes a first control valve 311 arranged on the main pipeline 31 and a second control valve 3211 arranged on the branch pipeline 32. The control module 5 is connected to the liquid level detection component 4, the first control valve 311, and the second control valve 3211. When the liquid level detected by the liquid level detection component 4 is lower than the first liquid level threshold, the control module 5 receives a corresponding electrical signal, and then controls the first control valve 311 and the second control valve 3211 to open, so that the connecting pipeline 3 is connected. When the liquid level detected by the liquid level detection component 4 is higher than the second liquid level threshold, the control module 5 receives a corresponding electrical signal, and controls the first control valve 311 and the second control valve 3211 to close, so that the connecting pipeline 3 is disconnected, thereby realizing automatic control to replenish or stop replenishing liquid to the daily cabinet 1. The above-mentioned first liquid level threshold is greater than 0, and the second liquid level threshold is not higher than the maximum liquid level value of the daily cabinet 1. The first liquid level threshold and the second liquid level threshold can be adaptively set according to factors such as the specifications of the daily cabinet 1.

[0049] Exemplarily, the first control valve 311 is an electric ball valve, the second control valve 3211 is an electromagnetic valve, and the liquid level detection element 4 is a liquid level switch or a liquid level meter, etc., which is easy to realize electric control.

[0050] Optionally, see Figure 1 , a filter device 312 is provided on the main pipeline 31, and the filter device 312 is used to filter the urea solution in the main pipeline 31. The setting of the filter device 312 can prevent impurities in the urea solution in the liquid storage tank 2 from entering the branch pipeline 32 and the post-processing system of the ship diesel engine, avoid the problem of pipeline blockage, and ensure the working reliability of the automatic liquid replenishing device. Exemplarily, the filter device 312 is a urea solution filter.

[0051] In other embodiments, a filter device 312 may also be provided on the branch pipeline 32 to further prevent impurities from entering the post-treatment system of the ship diesel engine.

[0052] Optionally, see Figure 1 and Figure 3 The branch pipeline 32 includes a first pipe section 321, a second pipe section 322 and a third pipe section 323 connected in sequence. The end of the first pipe section 321 away from the second pipe section 322 is connected to the main pipeline 31, and the end of the third pipe section 323 away from the second pipe section 322 is connected to the daily cabinet 1, and the height of the first pipe section 321 is higher than the height of the third pipe section 323. Figure 3 In the orientation, the first pipe section 321 and the main pipeline 31 are at the same height, and the third pipe section 323 is below the first pipe section 321, so that the liquid storage cabinet 2 on high ground and the daily cabinet 1 on low ground can be connected.

[0053] In other embodiments, the branch pipeline 32 may also include more pipeline sections, which can be adjusted according to the actual installation layout space between the liquid storage cabinet 2 and the daily cabinet 1, as long as the installation position of the liquid storage cabinet 2 can be ensured to be higher than the installation position of the daily cabinet 1.

[0054] Optionally, see Figure 1 and Figure 2 The connecting pipeline 3 also includes an extension pipeline 33, which is connected to the second end of the main pipeline 31, and one end of each of the multiple branch pipelines 32 is connected to the extension pipeline 33, and is spaced apart along the length direction of the extension pipeline 33. The arrangement of the extension pipeline 33 facilitates the transition connection between the multiple branch pipelines 32 and the main pipeline 31, realizes the reasonable layout of the connecting pipeline 3 between the liquid storage cabinet 2 and the multiple daily cabinets 1, and can improve the convenience of the installation and construction of the automatic liquid replenishing device.

[0055] Optionally, see Figure 2The daily cabinet 1 is provided with a first interface 11 and a second interface 12. The first interface 11 is used to connect with the connecting pipeline 3, and the second interface 12 is used to connect with the ship diesel engine after-treatment system. In this embodiment, the first interface 11 and the second interface 12 are both pipe joints provided on the daily cabinet 1. The diameter of the branch pipeline 32 is slightly larger than the diameter of the first interface 11. It is only necessary to seal the branch pipeline 32 with the first interface 11, and the installation operation is simple. Similarly, the second interface 12 can be plugged into the pipeline for conveying urea solution of the ship diesel engine after-treatment system.

[0056] This embodiment also provides an automatic liquid filling method for a marine diesel engine aftertreatment system, which is applied to the automatic liquid filling device for a marine diesel engine aftertreatment system as described above. The automatic liquid filling method for a marine diesel engine aftertreatment system comprises the following steps:

[0057] S1, real-time detection of the liquid level of the urea solution in the daily cabinet 1;

[0058] S2, when the liquid level value of the daily cabinet 1 is lower than the first liquid level threshold, the connecting pipe 3 is controlled to be turned on, so that the urea solution in the liquid storage cabinet 2 flows into the daily cabinet 1 through the connecting pipe 3;

[0059] S3. When the liquid level value of the daily cabinet 1 is higher than the second liquid level threshold, the connecting pipeline 3 is controlled to be disconnected.

[0060] Among them, the liquid level detection component 4 (such as a liquid level switch or a liquid level meter) is used to detect the liquid level of the urea solution in the daily cabinet 1 in real time, and the connecting pipeline 3 is turned on or off by controlling the opening and closing of the control component on the connecting pipeline 3. Specifically, the automatic liquid replenishing device of the marine diesel engine aftertreatment system also includes a control module 5, and the control component includes a first control valve 311 arranged on the main pipeline 31 and a second control valve 3211 arranged on the branch pipeline 32. The control module 5 is connected to the liquid level detection component 4, the first control valve 311, and the second control valve 3211. When the liquid level detected by the liquid level detection component 4 is lower than the first liquid level threshold, the control module 5 receives a corresponding electrical signal, and then controls the first control valve 311 and the second control valve 3211 to open, so that the connecting pipeline 3 is turned on. When the liquid level detected by the liquid level detection component 4 is higher than the second liquid level threshold, the control module 5 receives a corresponding electrical signal and controls the first control valve 311 and the second control valve 3211 to close, so that the connecting pipeline 3 is disconnected, thereby realizing automatic control to replenish or stop replenishing liquid to the daily cabinet 1.

[0061] The automatic liquid replenishing method only needs to control the opening and closing of the first control valve 311 and the second control valve 3211 according to the liquid level information detected by the liquid level detection component 4. The control logic is simple and easy to implement, which can reduce the failure rate and improve the working reliability of the automatic liquid replenishing device.

[0062] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention is described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An automatic liquid replenishing device for a marine diesel engine aftertreatment system, characterized in that: include: A daily cabinet (1) connected to a ship diesel engine after-treatment system; A liquid storage cabinet (2) for storing urea solution, wherein the installation height of the liquid storage cabinet (2) is higher than the installation height of the daily cabinet (1); A connecting pipeline (3) has one end connected to the liquid storage cabinet (2) and the other end selectively connected to the daily cabinet (1); when the liquid level in the daily cabinet (1) is lower than a first liquid level threshold, the liquid storage cabinet (2) can be connected to the daily cabinet (1) via the connecting pipeline (3).

2. The automatic liquid replenishing device for the after-treatment system of a marine diesel engine according to claim 1, characterized in that: The connecting pipeline (3) is provided with a control component, and the control component is used to control the opening and closing of the connecting pipeline (3), so that the liquid storage cabinet (2) is selectively connected to the daily cabinet (1) through the connecting pipeline (3).

3. The automatic liquid replenishing device of the marine diesel engine aftertreatment system according to claim 2, characterized in that: The daily cabinet (1) is provided with a plurality of connecting pipelines (3), including a main pipeline (31) and a plurality of branch pipelines (32); a first end of the main pipeline (31) is connected to the liquid storage cabinet (2); one end of each of the plurality of branch pipelines (32) is connected to a second end of the main pipeline (31); and the other ends of the plurality of branch pipelines (32) are connected to the plurality of daily cabinets (1) in a one-to-one correspondence.

4. The automatic liquid replenishing device for the after-treatment system of a marine diesel engine according to claim 3, characterized in that: The control component comprises a first control valve (311) arranged on the main pipeline (31), and the first control valve (311) is used to control the on-off of the main pipeline (31).

5. The automatic liquid replenishing device for the after-treatment system of a marine diesel engine according to claim 3, characterized in that: The control component comprises a second control valve (3211) arranged on the branch pipeline (32), and the second control valve (3211) is used to control the opening and closing of the branch pipeline (32).

6. The automatic liquid replenishing device of the marine diesel engine aftertreatment system according to claim 3, characterized in that: The main pipeline (31) and / or the branch pipeline (32) are provided with a filtering device (312), and the filtering device (312) is used to filter the urea solution in the main pipeline (31) and / or the branch pipeline (32).

7. The automatic liquid replenishing device for the after-treatment system of a marine diesel engine according to claim 3, characterized in that: The branch pipeline (32) comprises a first pipe section (321), a second pipe section (322) and a third pipe section (323) which are connected in sequence; an end of the first pipe section (321) away from the second pipe section (322) is connected to the main pipeline (31); an end of the third pipe section (323) away from the second pipe section (322) is connected to the daily cabinet (1); and the height of the first pipe section (321) is higher than the height of the third pipe section (323).

8. The automatic liquid replenishing device for the after-treatment system of a marine diesel engine according to claim 3, characterized in that: The connecting pipeline (3) further comprises an extension pipeline (33), wherein the extension pipeline (33) is connected to the second end of the main pipeline (31), and one end of each of the plurality of branch pipelines (32) is connected to the extension pipeline (33) and is spaced apart along the length direction of the extension pipeline (33).

9. The automatic liquid replenishing device of the marine diesel engine aftertreatment system according to any one of claims 2 to 8, characterized in that: The daily cabinet (1) is provided with a liquid level detection component (4) for detecting the liquid level. The liquid level detection component (4) is in communication connection with the control component. When the liquid level value detected by the liquid level detection component (4) is lower than the first liquid level threshold, the control component controls the connecting pipeline (3) to be turned on. When the liquid level value detected by the liquid level detection component (4) is higher than a second liquid level threshold, the control component controls the connecting pipeline (3) to be turned off. The second liquid level threshold is greater than the first liquid level threshold.

10. The automatic liquid replenishing device for a marine diesel engine aftertreatment system according to any one of claims 1 to 8, characterized in that: The daily cabinet (1) is provided with a first interface (11) and a second interface (12), wherein the first interface (11) is used to connect to the connecting pipeline (3), and the second interface (12) is used to connect to the ship diesel engine after-treatment system.

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