Marine urea solution supply system

Abstract

The invention provides a marine urea solution supply system. The marine urea solution supply system comprises a urea solution storage cabinet, a urea supply pump unit, a urea control unit, a urea injector and a flushing unit. The urea supply pump unit is connected with an outlet of the urea solution storage cabinet, the urea control unit is connected with an outlet of the urea supply pump unit, the urea injector is connected with an outlet of the urea control unit, and the flushing unit comprises an inlet pipeline and an outlet pipeline. And the other end of the inlet pipeline is connected to a pipeline between the urea solution storage cabinet and the urea supply pump unit. The pipeline in the marine urea solution supply system can be flushed, so that urea residues or urea crystals in the pipeline are removed, blockage of the pipeline and a nozzle, damage to a pump set and the like are avoided, normal operation of an SCR system on a ship is guaranteed, and emission of nitrogen oxide of the ship meets the requirement.

Description

Technical Field

[0001] The present application relates to the technical field of shipbuilding, and in particular to a marine urea solution supply system. Background Art

[0002] According to the requirements of the relevant meetings of the International Maritime Organization's Marine Environment Protection Committee, ships entering nitrogen oxide emission control areas must meet Tier III emission standards. In the prior art, selective catalytic reduction (SCR) technology is applied to ship exhaust gas treatment. The SCR reaction uses ammonia as a reducing medium, and 40% urea solution is a reliable raw material for making ammonia. Urea solution has strict requirements on ambient temperature during storage. When the ambient temperature is 0-30°C, the storage validity period of urea solution is 12 months, and when the ambient temperature is 30-35°C, the storage validity period is 6 months. The urea solution will fail when the ambient temperature exceeds 35°C.

[0003] In the prior art, the ship's SCR system is arranged in the engine room, and the cabin environment design temperature is 45°C, which is much higher than the failure temperature of urea. Therefore, the urea storage tank is usually designed with a corresponding temperature control system, and the urea transfer pipeline is usually ignored. During the operation of the ship, the SCR system is only used in the nitrogen oxide emission control area and will be stopped outside the control area. Therefore, if the urea solution remaining in the pipeline is not discharged or cleaned in time, crystals will soon precipitate. In severe cases, it will cause pipeline blockage, nozzle blockage, and pump group damage, etc., resulting in the SCR system being unable to operate normally, and thus unable to meet the nitrogen oxide emission requirements.

[0004] In summary, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0005] The purpose of the embodiment of the present application is to provide a marine urea solution supply system, which can solve the pipeline crystallization problem of the marine urea solution supply system. The present application can prevent crystallization from occurring in the pipeline and remove crystals when they exist in the pipeline.

[0006] The present application provides a marine urea solution supply system, comprising:

[0007] Urea solution storage cabinet, used for providing urea solution;

[0008] a urea supply pump unit connected to the outlet of the urea solution storage tank and used for transferring the urea solution provided in the urea solution storage tank;

[0009] A urea control unit connected to the outlet of the urea supply pump unit and used for controlling the transport amount of the urea solution;

[0010] A urea injector is connected to the outlet of the urea control unit and is used to atomize the urea solution and evenly inject it;

[0011] The flushing unit comprises an inlet pipeline and an outlet pipeline, one end of the inlet pipeline is used for introducing fresh water or compressed air, the other end of the inlet pipeline is connected to the pipeline between the urea solution storage tank and the urea supply pump unit, one end of the outlet pipeline is connected to the pipeline between the urea control unit and the urea injector, and a urea discharge cabinet is arranged at the other end of the outlet pipeline, and the urea discharge cabinet is used for collecting waste liquid containing urea.

[0012] In an operative manner, the urea injector is further connected to a compressed air unit, and the compressed air unit is used to deliver compressed air to the urea injector to assist in atomizing the urea solution before output.

[0013] In an practicable manner, one end of the inlet pipeline of the flushing unit may be connected to the compressed air unit, and one end of the inlet pipeline of the flushing unit may also be connected to a fresh water hose valve after being switched.

[0014] In an operative manner, the compressed air unit comprises a first outlet and a second outlet, the first outlet is communicated with the urea injector, and a compressed air hose valve is arranged at the second outlet.

[0015] In an practicable manner, a first check valve is provided on the pipeline between the urea solution storage tank and the urea supply pump unit.

[0016] In one practicable manner, a second check valve is provided on the inlet pipeline.

[0017] In an operative manner, the urea supply pump unit further includes a first bypass line, the first bypass line is arranged in parallel with the supply pump, and a first stop valve is arranged on the first bypass line.

[0018] In an operative manner, the urea control unit further includes a second bypass line, two ends of the second bypass line are respectively connected to an inlet of the urea control unit and an outlet of the urea control unit, and a second stop valve is arranged on the second bypass line.

[0019] In one practicable manner, a third stop valve is provided on the outlet pipeline.

[0020] In an practicable manner, a fourth stop valve is provided at the inlet end of the urea injector.

[0021] Compared with the prior art, the beneficial effects of this application are:

[0022] In the technical solution of the present application, it can solve the crystallization problem of the pipeline of the marine urea solution supply system. The present application can prevent crystallization from occurring in the pipeline and remove crystals when they exist in the pipeline. By flushing and purging the pipeline in the marine urea solution supply system, the urea residue or urea crystals in the pipeline can be removed to avoid clogging of the pipeline, nozzle and damage to the pump group, etc., to ensure the normal operation of the SCR system on the ship, so that the emission of nitrogen oxides of the ship meets the requirements. The present application combines fresh water flushing and gas blowing to ensure that the urea solution in the pipeline can be cleaned. When crystals already exist in the pipeline, the crystals can be dissolved by flushing first to avoid crystals clogging the urea injector, and then blown off and dried. Through the setting of the urea discharge cabinet, the wastewater containing urea solution is directly discharged to pollute the environment, and the wastewater can also be prevented from flowing back into the system to cause secondary pollution. The present application uses the fresh water system and compressed air unit of the ship for flushing and purging, without the need to add additional equipment to achieve anti-crystallization and crystallization removal functions, and is economical and conducive to popularization and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of a marine urea solution supply system according to an embodiment of the present invention.

[0024] The reference numerals are described as follows:

[0025] 1. Urea solution storage cabinet; 2. Urea supply pump unit; 3. Urea control unit; 4. Urea injector; 5. Urea connecting pipe; 6. Guide plate; 7. Reactor; 8. Urea discharge cabinet; 9. Quick closing valve; 10. First check valve; 11. First stop valve; 12. Second stop valve; 13. Third stop valve; 14. Fourth stop valve; 15. Second check valve; 16. Compressed air hose valve; 17. Compressed air unit. DETAILED DESCRIPTION

[0026] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. These embodiments are only used to illustrate the present invention, but not to limit the present invention.

[0027] In the description of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting 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.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected 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.

[0029] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0030] See also Figure 1 The present application provides a marine urea solution supply system, comprising:

[0031] A urea solution storage cabinet 1, used for providing urea solution;

[0032] a urea supply pump unit 2 connected to the outlet of the urea solution storage tank 1 and used for transferring the urea solution provided in the urea solution storage tank 1;

[0033] A urea control unit 3 is connected to the outlet of the urea supply pump unit 2 and is used to control the transport volume of the urea solution according to the requirements of the catalytic reduction reaction;

[0034] A urea injector 4 is connected to the outlet of the urea control unit 3 and is used to atomize the urea solution and evenly inject it;

[0035] The flushing unit includes an inlet pipeline and an outlet pipeline, one end of the inlet pipeline is used to pass fresh water or compressed air, the other end of the inlet pipeline is connected to the pipeline between the urea solution storage tank 1 and the urea supply pump unit 2, one end of the outlet pipeline is connected to the pipeline between the urea control unit 3 and the urea injector 4, and the other end of the outlet pipeline is provided with a urea discharge cabinet 8, the urea discharge cabinet 8 is used to collect waste liquid containing urea. The flushing unit is used to pass compressed air or fresh water to remove urea residue in the pipeline between the urea solution storage tank 1 and the urea supply pump unit 2, the urea supply pump unit 2, the urea control unit 3, and the pipeline between the urea control unit 3 and the urea injector 4.

[0036] It should be noted that the waste liquid in the urea discharge cabinet 8 can be purified and reused as needed.

[0037] In an practicable manner, the urea injector 4 is further connected to a compressed air unit 17 , and the compressed air unit 17 is used to deliver compressed air to the urea injector 4 to assist the urea solution in being atomized and then outputted.

[0038] In an practicable manner, one end of the inlet pipeline of the flushing unit can be connected to the compressed air unit 17, and the same air source can be used for flushing operations to simplify the structure of the ship system. One end of the inlet pipeline of the flushing unit can also be connected to a fresh water hose valve to achieve the conversion of the cleaning medium introduced into the flushing unit.

[0039] Specifically, the compressed air unit 17 includes a first outlet and a second outlet, the first outlet is connected to the urea injector 4, and a compressed air hose valve 16 is arranged at the second outlet. Through the arrangement of the compressed air hose valve 16, the inlet pipeline can be quickly connected to the compressed air unit 17.

[0040] In one practicable manner, a first check valve 10 is provided on the pipeline between the urea solution storage tank 1 and the urea supply pump unit 2. During the flushing process of the pipeline, the first check valve 10 is opened to prevent the flushing fresh water from flowing back due to a large fresh water flow rate during flushing, thereby causing damage to the equipment.

[0041] It should be noted that the first check valve 10 is arranged before the inlet pipeline.

[0042] It should also be noted that a quick-closing valve 9 is provided at the outlet of the urea solution storage cabinet 1 , and the quick-closing valve 9 is used to control the urea solution storage cabinet 1 to perform emergency closure.

[0043] In one feasible manner, a second check valve 15 is provided on the inlet pipeline. When the urea solution supply system is in normal working condition, the second check valve 15 is opened to prevent the urea solution from flowing back into the flushing unit, thereby preventing the fresh water source from being polluted, endangering the safety of the ship's fresh water, and easily causing environmental pollution, posing a serious threat to the life safety of personnel and the safe operation of equipment.

[0044] In an operative manner, the urea supply pump unit 2 further includes a first bypass line arranged in parallel with the supply pump, a first stop valve 11 is arranged on the first bypass line, and both ends of the first bypass line are respectively connected to the inlet and outlet of the urea supply pump. Through the arrangement of the first bypass line, the pipelines before and after the supply pump are connected to flush the connecting pipeline of the urea supply pump unit 2.

[0045] In an operative manner, the urea control unit 3 further includes a second bypass line, the two ends of which are respectively connected to the inlet and the outlet of the urea control unit 3, and a second stop valve 12 is arranged on the second bypass line. The connection line of the urea control unit 3 is flushed by the arrangement of the second bypass line.

[0046] In an practicable manner, a third stop valve 13 is provided on the outlet pipeline, and the third stop valve 13 is used to control the opening and closing of the outlet pipeline.

[0047] In an operative manner, the output end of the urea injector 4 is connected to the SCR reaction unit, and the SCR reaction unit at least comprises: a vertically arranged urea connecting pipe 5, the bottom of which is an air inlet for exhaust gas from a ship generator, the side of which is connected to the urea injector 4, and the top of which is a reaction tank 7, wherein the exhaust gas from the ship generator in the reaction tank 7 and the atomized urea solution complete an oxidation-reduction reaction under the action of a catalyst.

[0048] In an operative manner, a plurality of guide plates 6 are arranged in the urea connecting pipe 5, and the plurality of guide plates 6 are evenly arranged along the axial direction of the urea connecting pipe 5. A plurality of vent holes are evenly distributed on the guide plates 6, and the atomized urea solution is more evenly transported to the reaction tank 7 through the arrangement of the guide plates 6.

[0049] In an practicable manner, a fourth stop valve 14 is provided at the inlet end of the urea injector 4 , and the fourth stop valve 14 is used to prevent gas mixed with urea or fresh water from flowing into the SCR reaction unit during the flushing process.

[0050] After the SCR system is shut down, in order to avoid the crystallization of urea solution in the pipeline of the marine urea solution supply system, the pipeline needs to be flushed and dried. At least the following contents are included:

[0051] S1 . Close the fourth stop valve 14 and the first check valve 10 to close the urea solution supply system.

[0052] S2. Open the first stop valve 11, the second stop valve 12, and the third stop valve 13 to connect all pipelines in the urea solution supply system.

[0053] S3, connect the inlet pipeline to the compressed air hose valve 16, open the second check valve 15, let the compressed air into the inlet pipeline, and make the compressed air pass through the second check valve 15, the first stop valve 11, the second stop valve 12, and the third stop valve 13 in sequence, and finally blow the remaining urea liquid in the pipeline into the urea discharge cabinet 8.

[0054] S4, close the compressed air hose valve 16, and connect the inlet pipeline to the fresh water source, let the fresh water flow into the inlet pipeline, and let the fresh water pass through the second check valve 15, the first stop valve 11, the second stop valve 12, and the third stop valve 13 in sequence to flush the pipeline, and discharge the waste liquid into the urea discharge cabinet 8 for collection.

[0055] S5. Connect the inlet pipeline to the compressed air hose valve 16 again, pass the compressed air into the inlet pipeline, and make the compressed air pass through the second check valve 15, the first stop valve 11, the second stop valve 12, and the third stop valve 13 in sequence to purge the pipeline to keep the pipeline dry and prevent urea crystals from forming in the pipeline.

[0056] When urea crystals already exist in the pipeline of the marine urea solution supply system, the following steps are used to dissolve the crystals in the pipeline:

[0057] S1 . Close the fourth stop valve 14 and the first check valve 10 to close the urea solution supply system.

[0058] S2. Open the first stop valve 11, the second stop valve 12, and the third stop valve 13 to connect all pipelines in the urea solution supply system.

[0059] S3, connecting the inlet pipeline to the fresh water source, passing fresh water into the inlet pipeline, and allowing the fresh water to pass through the second check valve 15, the first stop valve 11, the second stop valve 12, and the third stop valve 13 in sequence to flush the pipeline until the crystals are completely dissolved.

[0060] S4. Connect the inlet pipeline to the compressed air hose valve 16, pass the compressed air into the inlet pipeline, and make the compressed air pass through the second check valve 15, the first stop valve 11, the second stop valve 12, and the third stop valve 13 in sequence to purge the pipeline until it is dry.

[0061] S5, close the compressed air hose valve 16, the third stop valve 13, and the second check valve 15, and complete the decrystallization operation of the pipeline of the marine urea solution supply system.

[0062] In summary, the present application can flush the pipelines in the marine urea solution supply system to remove the urea residue or urea crystals in the pipelines, avoid clogging of pipelines and nozzles, and damage to the pump group, etc., to ensure the normal operation of the SCR system on the ship, so that the emission of nitrogen oxides of the ship meets the requirements. The present application combines fresh water flushing and gas blowing to ensure that the urea solution in the pipeline can be cleaned. When crystals already exist in the pipeline, the crystals can be dissolved by flushing first to avoid crystals clogging the urea injector 4, and then blown dry. Through the setting of the urea discharge cabinet 8, the wastewater containing urea solution is directly discharged to pollute the environment, and the wastewater can also be prevented from flowing back into the system to cause secondary pollution. The present application uses the fresh water system and compressed air unit 17 of the ship for flushing and purging, without the need to add additional equipment to achieve anti-crystallization and crystallization removal functions, and is economical and conducive to popularization and use.

[0063] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A marine urea solution supply system, characterized in that: include: Urea solution storage cabinet, used for providing urea solution; a urea supply pump unit connected to the outlet of the urea solution storage tank and used for transferring the urea solution provided in the urea solution storage tank; A urea control unit connected to the outlet of the urea supply pump unit and used for controlling the transport amount of the urea solution; A urea injector is connected to the outlet of the urea control unit and is used to atomize the urea solution and evenly inject it; The flushing unit comprises an inlet pipeline and an outlet pipeline, one end of the inlet pipeline is used for introducing fresh water or compressed air, the other end of the inlet pipeline is connected to the pipeline between the urea solution storage tank and the urea supply pump unit, one end of the outlet pipeline is connected to the pipeline between the urea control unit and the urea injector, and a urea discharge cabinet is arranged at the other end of the outlet pipeline, and the urea discharge cabinet is used for collecting waste liquid containing urea.

2. The marine urea solution supply system according to claim 1, characterized in that: The urea injector is also connected to a compressed air unit, and the compressed air unit is used to deliver compressed air to the urea injector to assist the urea solution in being atomized and then outputted.

3. The marine urea solution supply system according to claim 2, characterized in that: One end of the inlet pipeline of the flushing unit can be connected to the compressed air unit, and one end of the inlet pipeline of the flushing unit can also be connected to the fresh water hose valve after switching.

4. The marine urea solution supply system according to claim 3, characterized in that: The compressed air unit comprises a first outlet and a second outlet, the first outlet is communicated with the urea injector, and a compressed air hose valve is arranged at the second outlet.

5. The marine urea solution supply system according to claim 1, characterized in that: A first check valve is arranged on the pipeline between the urea solution storage tank and the urea supply pump unit.

6. The marine urea solution supply system according to claim 1, characterized in that: A second check valve is provided on the inlet pipeline.

7. The marine urea solution supply system according to claim 1, characterized in that: The urea supply pump unit further includes a first bypass pipeline, which is arranged in parallel with the supply pump, and a first stop valve is arranged on the first bypass pipeline.

8. The marine urea solution supply system according to claim 1, characterized in that: The urea control unit also includes a second bypass pipeline, two ends of which are respectively connected to the inlet of the urea control unit and the outlet of the urea control unit, and a second stop valve is arranged on the second bypass pipeline.

9. The marine urea solution supply system according to claim 1, characterized in that: A third stop valve is arranged on the outlet pipeline.

10. The marine urea solution supply system according to claim 1, characterized in that: A fourth stop valve is arranged at the inlet end of the urea injector.

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