CN117869049A - Detection method for blockage of injection pipeline in gas-assisted double-injection system in SCR system - Google Patents
Detection method for blockage of injection pipeline in gas-assisted double-injection system in SCR system Download PDFInfo
- Publication number
- CN117869049A CN117869049A CN202410126009.0A CN202410126009A CN117869049A CN 117869049 A CN117869049 A CN 117869049A CN 202410126009 A CN202410126009 A CN 202410126009A CN 117869049 A CN117869049 A CN 117869049A
- Authority
- CN
- China
- Prior art keywords
- injection
- pressure
- urea
- blockage
- pipeline
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002347 injection Methods 0.000 title claims abstract description 100
- 239000007924 injection Substances 0.000 title claims abstract description 100
- 238000001514 detection method Methods 0.000 title claims abstract description 40
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 claims abstract description 130
- 239000004202 carbamide Substances 0.000 claims abstract description 130
- 239000007921 spray Substances 0.000 claims abstract description 82
- 239000000243 solution Substances 0.000 claims abstract description 64
- 238000006243 chemical reaction Methods 0.000 claims abstract description 30
- 238000000034 method Methods 0.000 claims description 23
- 230000009977 dual effect Effects 0.000 claims description 12
- 230000000903 blocking effect Effects 0.000 abstract description 16
- 239000007789 gas Substances 0.000 description 68
- 238000002425 crystallisation Methods 0.000 description 21
- 230000008025 crystallization Effects 0.000 description 21
- 238000004140 cleaning Methods 0.000 description 7
- 238000005507 spraying Methods 0.000 description 7
- 238000010531 catalytic reduction reaction Methods 0.000 description 6
- 230000003137 locomotive effect Effects 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 230000003197 catalytic effect Effects 0.000 description 4
- 239000013078 crystal Substances 0.000 description 4
- 238000007664 blowing Methods 0.000 description 3
- 238000001914 filtration Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000005856 abnormality Effects 0.000 description 2
- 238000000889 atomisation Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000001125 extrusion Methods 0.000 description 2
- 239000000295 fuel oil Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000010408 sweeping Methods 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 231100000719 pollutant Toxicity 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Exhaust Gas After Treatment (AREA)
Abstract
The invention provides a detection method for blocking of an injection pipeline in a gas-assisted double-injection system in an SCR system, which relates to the technical field of tail gas treatment and comprises the following steps: starting a train engine, and starting a urea pump to build pressure; waiting for a urea solution injection state; opening a pipeline to detect blockage; opening two metering valves, enabling urea solution to flow through two pipelines, respectively obtaining the urea pressure in the two pipelines, and judging whether the urea pressure is normal or not; judging whether the urea solution injection condition is met; starting a spray gun to detect blockage; calculating conversion efficiency of NOX of two paths of tail gas channels, and judging whether the conversion efficiency of NOX is normal or not; and when the engine is judged to be closed, the spray gun blockage detection is judged to be completed, and the system operation is ended. The detection method for the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system can solve the problem that two paths of high-pressure spray guns and pipelines thereof cannot be detected in a targeted manner when the injection unit is blocked in the prior art, and can effectively position the blockage position.
Description
Technical Field
The invention relates to the technical field of tail gas treatment, in particular to a detection method for blockage of an injection pipeline in a gas-assisted double-injection system in an SCR system.
Background
The fuel oil train generally needs to adopt an exhaust gas treatment system to treat harmful substances in the exhaust gas of the train, and more NOx exists in the harmful substances in the exhaust gas of the train; in view of this, the patent of China patent application No. 202111455587.1 discloses an exhaust gas purification system for a fuel train, which comprises an air inlet unit, a catalytic oxidation and filtration unit, a urea mixing cavity, a catalytic reduction unit and an exhaust unit; the exhaust gas discharged from the exhaust port of the engine sequentially passes through the air inlet unit, the catalytic oxidation filtering unit, the urea mixing cavity and the catalytic reduction unit, and finally is discharged from the exhaust port, wherein the catalytic oxidation filtering unit comprises a DOC carrier (diesel catalytic oxidizer) and a DPF carrier (diesel particulate filter), and the catalytic reduction unit comprises an SCR carrier (selective catalytic reduction unit); the SCR carrier is arranged in the catalytic reduction unit, so that NOx nitrogen and oxygen pollutants discharged in the fuel oil train can be effectively cleaned.
However, in the patent, a single-way spray gun is used for spraying a large amount of urea solution to the tail gas, and after the tail gas mixed urea solution enters the catalytic reduction unit, the NOx in the tail gas cannot be converted well due to poor atomization effect of the urea solution; in order to solve the problem, the prior art adopts two tail gas channels and two ways of spray guns to treat the tail gas simultaneously on the basis, and adds a gas-assisted mode, and high-pressure gas is added before urea solution injection, so that the high-pressure gas can enable the urea solution to achieve a better atomization effect, and the conversion efficiency of NOx in the tail gas is improved.
However, when the dual jet assisted SCR injection system is used, if the injection unit is blocked, the design of the two-way high pressure spray gun prolongs the time required for blocking detection, and the two-way high pressure spray gun and the pipeline thereof cannot be detected in a targeted manner.
Disclosure of Invention
Aiming at the problems, the detection method for the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system can solve the problem that two high-pressure spray guns and the pipelines thereof cannot be detected pertinently when an injection unit is blocked in the prior art, and can effectively position the blockage position.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the invention provides a detection method for blockage of an injection pipeline in an air-assisted double-injection system in an SCR system, which comprises the following steps:
s101: starting a train engine, and starting a urea pump to build pressure;
s102: after the urea pump is pressurized, waiting for the urea solution injection state;
s103: when the urea solution injection state is met, a pipeline blockage detection module is started; setting time of normally open 1s for two metering valves in a urea metering module in an injection unit, at the moment, conveying urea solution to the injection unit by a urea pump, enabling the urea solution to flow through two pipelines, respectively acquiring urea pressure in the two pipelines by a pressure difference sensor in the pipelines, and judging whether the urea pressure is normal or not; when the urea pressure is higher than the target pressure, the pipeline is considered to be blocked, and a first fault mode is entered;
s104: judging whether the urea solution injection condition is met after the pipeline blockage detection is completed; if the urea solution injection condition is not met, the engine is closed, and the system operation is ended;
s105: when the urea solution injection condition is met, starting a spray gun blockage detection module; a front NOX sensor is arranged at the position in front of the SCR carrier in the two paths of exhaust channels, a rear NOX sensor is arranged at the position in the rear of the SCR carrier in the two paths of exhaust channels, a metering valve of the two paths of high-pressure spray guns in the injection unit is opened, the front NOX sensor in the two paths of exhaust channels counts the content of NOX before the exhaust is treated, the rear NOX sensor counts the content of NOX after the exhaust is treated, the conversion efficiency of the NOX of the two paths of exhaust channels is calculated according to the data of the front NOX sensor and the rear NOX sensor respectively, and whether the conversion efficiency of the NOX is normal or not is judged; when the conversion efficiency is smaller than the target value, the high-pressure spray gun on the way is considered to be blocked, and a second fault mode is entered; when the conversion rate is greater than the target value, S104 is re-executed;
s106: and when the engine is judged to be closed, the spray gun blockage detection is judged to be completed, and the system operation is ended.
According to the detection method for the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system, preferably, the injection state in the step S102 is that the pressure of the urea pump reaches the pressure building threshold value, and the state after the pressure building is maintained.
According to the detection method for the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system, preferably, the injection condition in the step S104 is that the exhaust temperature in the tail gas channel reaches 200 ℃.
In the method for detecting blockage of the injection pipeline in the gas-assisted dual-injection system in the SCR system provided by the present invention, preferably, the step S103 further includes feeding back the blockage information of the pipeline after the first failure mode is entered.
In the method for detecting blockage of the injection pipeline in the gas-assisted dual-injection system in the SCR system provided by the invention, preferably, the step S105 of feeding back the blockage information of the high-pressure spray gun after entering the second fault mode is further included.
According to the method for detecting blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system, preferably, the urea pressure in the step S103 is the pressure generated by extrusion of the urea solution in the pipeline.
The technical scheme has the following advantages or beneficial effects:
the invention provides a detection method of injection pipeline blockage in an air-assisted double-spray system in an SCR system, wherein in the steps S103 and S105, a pipeline blockage detection method and a spray gun blockage detection method are disclosed; because the gas-assisted double-spraying system is adopted, and two tail gas channels are adopted for treating tail gas simultaneously, two high-pressure spray guns are matched, the two high-pressure spray guns provide urea solution required by spraying through two pipelines, when the high-pressure spray guns cannot normally spray the urea solution, the reason for causing the abnormality of the high-pressure spray guns cannot be accurately and rapidly found, the specific blocking positions of the two high-pressure spray guns and the pipeline thereof can be detected by the method of detecting the blocking of the spray guns firstly, the blocking positions are effectively positioned, and the time for manual detection is reduced.
In the detection method of the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system, in the step S103, the pipeline blockage detection adopts a mode of placing a differential pressure sensor in the pipeline, the urea pressure is adopted to judge whether the pipeline is blocked by crystallization, when the pipeline is blocked by crystallization, the pressure of urea solution in the pipeline is increased, the urea pressure can be clearly monitored through the differential pressure sensor, so that whether the pipeline is blocked by crystallization is judged, and the situation of the blockage by crystallization in the pipeline is fed back through data acquired by the differential pressure sensor;
when the pipeline blockage detection fails to prove that the pipeline is blocked by crystallization, a method for calculating the conversion efficiency of NOX is adopted in the step S105 to judge whether the high-pressure spray gun is blocked or not, when the high-pressure spray gun is blocked by crystallization, the front NOX sensor can detect the NOX content of the tail gas which is not treated, the rear NOX sensor can detect the NOX content of the tail gas which is treated, the conversion efficiency of NOX in the tail gas channel can be calculated through the data of the front NOX sensor and the rear NOX sensor, if the conversion efficiency of NOX in the tail gas channel is low, the high-pressure spray gun fails to spray normal urea solution in unit time, and therefore the existence of crystallization blockage in the high-pressure spray gun is further indicated.
Drawings
The invention and its features, aspects and advantages will become more apparent from the detailed description of non-limiting embodiments with reference to the following drawings. Like numbers refer to like parts throughout. The drawings are not intended to be drawn to scale, emphasis instead being placed upon illustrating the principles of the invention.
Fig. 1 is a flow chart of a method for detecting blockage of an injection line in a gas-assisted dual-injection system in an SCR system according to embodiment 1 of the present invention.
Fig. 2 is a schematic structural diagram of a dual jet assisted SCR injection system according to embodiment 1 of the present invention.
Fig. 3 is a block diagram of electrical connection lines of a dual jet assisted SCR spray system according to embodiment 1 of the present invention.
Detailed Description
The invention will now be further described with reference to the accompanying drawings and specific examples, which are not intended to limit the invention.
Example 1:
for convenience of explanation, embodiment 1 of the present invention provides a dual jet assisted SCR injection system, as shown in fig. 2 to 3, comprising a first high pressure spray gun 1 for spraying atomized urea solution, a first exhaust gas channel 2 for treating an exhaust port of an engine, a high pressure air source supply module 3 for supplying external high pressure air, a second high pressure spray gun 4, a second exhaust gas channel 5, a urea tank 11, a urea supply module 12, a urea metering module 13 for controlling urea solution spraying, a urea purge cleaning module 31, a sensor module 6 for collecting data, a controller 7, a locomotive ECU8, and a power module 9; the first high-pressure spray gun 1 is arranged in the first tail gas channel 2; the high-pressure air source supply module 3 is communicated with the first high-pressure spray gun 1 through a pipeline; the second high-pressure spray gun 4 is arranged inside the second tail gas channel 5; the high-pressure air source supply module 3 is communicated with the second high-pressure spray gun 4 through a pipeline; the urea tank 11 is communicated with the urea supply module 12 through a pipeline; the urea supply module 12 is communicated with the urea metering module 13 through a pipeline; the urea metering module 13 is communicated with the first high-pressure spray gun 1 through a pipeline; the urea metering module 13 is communicated with the second high-pressure spray gun 4 through a pipeline; the urea blowing and cleaning module 31 is communicated with the high-pressure air source supply module 3 through a pipeline; the controller 7 is electrically connected with the urea supply module 12, the urea metering module 13, the high-pressure air source supply module 3, the urea blowing and cleaning module 31 and the sensor module 6; the locomotive ECU8 is electrically connected with the controller 7; the power supply module 9 is electrically connected with the controller 7, the urea supply module 12, the urea metering module 13, the high-pressure air source supply module 3, the urea blowing and cleaning module 31, the locomotive ECU8 and the sensor module 6;
the first exhaust passage 2 and the second exhaust passage 5 each include an exhaust pipe 21, a DPF carrier 22, and an SCR carrier 23; regarding the exhaust direction of the exhaust gas in the exhaust pipe 21 as the front-to-rear direction of the exhaust pipe 21; a DPF carrier 22 and an SCR carrier 23 are placed in the exhaust pipe 21; the DPF carrier 22 is located in front of the SCR carrier 23; the first high pressure spray gun 1 is located between the DPF carrier 22 and the SCR carrier 23 of the first exhaust gas channel 2; the second high pressure spray gun 4 is located between the DPF carrier 22 and the SCR carrier 23 of the second exhaust gas channel 5;
the sensor module 6 comprises several temperature sensors 61, a differential pressure sensor 62 and a NOx sensor 63; all temperature sensors 61 are distributed in exhaust pipe 21; all temperature sensors 61 are located in front of the DPF carrier 22; all differential pressure sensors 62 are distributed in the pipeline between urea supply module 12 and urea dosing module 13; the entire NOx sensor 63 is distributed in the exhaust pipe 21; all NOx sensors 63 are located on the front and rear sides of the SCR carrier 23, respectively.
When the dual jet assistant SCR jet system is used, the locomotive ECU8 judges whether the locomotive engine is in a starting state, the temperature sensor 61 monitors the temperature in the exhaust pipe 21, the controller 7 controls the urea supply module 12 to extract urea solution from the urea tank 11 if the engine is started, the urea metering module 13 opens the metering valve to send the urea solution to the first high-pressure spray gun 1 and the second high-pressure spray gun 4, the pressure difference of the urea solution in the pipeline is recorded by the pressure difference sensor 62 in the pipeline, the high-pressure gas is simultaneously supplied to the first high-pressure spray gun 1 and the second high-pressure spray gun 4 by the high-pressure gas supply module 3, the urea solution in the first high-pressure spray gun 1 and the second high-pressure spray gun 4 is assisted to be atomized, the urea solution after being sprayed by the first high-pressure spray gun 1 in the first exhaust gas channel 2 and the second high-pressure spray gun 4 in the second exhaust gas channel 5 is firstly filtered by the DPF carrier 22, the filtered exhaust gas and the atomized urea solution is mixed to pass through the carrier 23 in the exhaust pipe 21 to be catalyzed and the NOx content before and after the treatment is recorded by the front and rear sensor 63; after the tail gas treatment is finished, the high-pressure gas is supplied to the urea sweeping and cleaning module 31 by the high-pressure gas supply module 3, and the urea sweeping and cleaning module 31 is used for cleaning the urea solution remained in the pipeline and the spray gun.
However, when the dual jet assisted SCR jet system is used, if the jet unit is blocked, the design of the two high pressure spray guns will prolong the time required for blocking detection, and the two high pressure spray guns and the pipeline thereof cannot be detected in a targeted manner, in order to solve the problem, as shown in fig. 3, the method for detecting blocking of the jet pipeline in the air assisted dual jet system in the SCR system provided by embodiment 1 of the present invention comprises the following steps:
s101: starting a train engine, and starting a urea pump to build pressure;
s102: after the urea pump is pressurized, waiting for the urea solution injection state;
s103: when the urea solution injection state is met, a pipeline blockage detection module is started; setting time of normally open 1s for two metering valves in a urea metering module in an injection unit, at the moment, conveying urea solution to the injection unit by a urea pump, enabling the urea solution to flow through two pipelines, respectively acquiring urea pressure in the two pipelines by a pressure difference sensor in the pipelines, and judging whether the urea pressure is normal or not; when the urea pressure is higher than the target pressure, the pipeline is considered to be blocked, and a first fault mode is entered;
s104: judging whether the urea solution injection condition is met after the pipeline blockage detection is completed; if the urea solution injection condition is not met, the engine is closed, and the system operation is ended;
s105: when the urea solution injection condition is met, starting a spray gun blockage detection module; a front NOX sensor is arranged at the position in front of the SCR carrier in the two paths of exhaust channels, a rear NOX sensor is arranged at the position in the rear of the SCR carrier in the two paths of exhaust channels, a metering valve of the two paths of high-pressure spray guns in the injection unit is opened, the front NOX sensor in the two paths of exhaust channels counts the content of NOX before the exhaust is treated, the rear NOX sensor counts the content of NOX after the exhaust is treated, the conversion efficiency of the NOX of the two paths of exhaust channels is calculated according to the data of the front NOX sensor and the rear NOX sensor respectively, and whether the conversion efficiency of the NOX is normal or not is judged; when the conversion efficiency is smaller than the target value, the high-pressure spray gun on the way is considered to be blocked, and a second fault mode is entered; when the conversion rate is greater than the target value, S104 is re-executed;
s106: and when the engine is judged to be closed, the spray gun blockage detection is judged to be completed, and the system operation is ended.
The embodiment 1 of the invention provides a detection method for blocking injection pipelines in an air-assisted double-injection system in an SCR system, wherein in step S103 and step S105, a pipeline blocking detection method and a spray gun blocking detection method are disclosed; because the gas-assisted double-spraying system is adopted, and two tail gas channels are adopted for treating tail gas simultaneously, two high-pressure spray guns are matched, the two high-pressure spray guns provide urea solution required by spraying through two pipelines, when the high-pressure spray guns cannot normally spray the urea solution, the reason for causing the abnormality of the high-pressure spray guns cannot be accurately and rapidly found, the specific blocking positions of the two high-pressure spray guns and the pipeline thereof can be detected by the method of detecting the blocking of the spray guns firstly, the blocking positions are effectively positioned, and the time for manual detection is reduced.
In the detection method of the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system provided by the embodiment 1 of the invention, in the steps S101 to S102, the pipeline blockage detection and the high-pressure spray gun detection are prepared, so that the urea pump can normally supply urea solution for the pipeline;
in step S103, the pipeline blockage detection adopts a mode of placing a differential pressure sensor in the pipeline, adopts urea pressure to determine whether the pipeline is blocked by crystallization, when the pipeline is blocked by crystallization, the pressure of urea solution in the pipeline is increased, the urea pressure is increased, and the urea pressure can be clearly monitored by the differential pressure sensor, so as to determine whether the pipeline is blocked by crystallization;
in step S104, in order to fully meet the condition of the reaction of NOX and urea solution, judgment of the injection condition of urea solution is added, and the reaction condition of NOX and urea solution in two paths of tail gas pipelines is controlled, so that the conversion efficiency of the NOX obtained in practice is more referential, and the situation of crystallization blockage in the high-pressure spray gun is more favorably demonstrated;
when the pipeline blockage detection fails to prove that the pipeline is blocked by crystallization, in step S105, a method for calculating the conversion efficiency of NOX is adopted to judge whether the high-pressure spray gun is blocked or not, when the high-pressure spray gun is blocked by crystallization, the front NOX sensor can detect the NOX content of the tail gas when the tail gas is not treated, the rear NOX sensor can detect the NOX content of the tail gas after the tail gas treatment, the conversion efficiency of NOX in the tail gas channel can be calculated through the data of the front NOX sensor and the rear NOX sensor, and if the conversion efficiency of NOX in the tail gas channel is low, the high-pressure spray gun fails to spray normal urea solution in unit time, so that the crystallization blockage exists in the high-pressure spray gun is further indicated.
In the method for detecting blockage of the injection pipeline in the gas-assisted dual-injection system in the SCR system provided in embodiment 1 of the present invention, preferably, the injection state in step S102 is a state in which the urea pump pressure reaches the pressure build-up threshold and maintains the pressure build-up; after the urea pump is started to build up pressure in step S101, the urea pump pressure needs to be maintained, so that the urea pump can continuously and uniformly supply urea solution to the pipeline; when the pipeline blockage is detected, the urea solution is continuously and uniformly supplied to the pipeline, so that the pressure of the urea solution in the pipeline can be accurately obtained in unit time, and the pressure can be more effectively compared with the target pressure to obtain more accurate judgment; when the spray gun is blocked and detected, the urea solution is continuously and uniformly supplied, so that the amount of the urea solution sprayed to the tail gas channel in unit time can be controlled, more accurate NOX conversion efficiency can be obtained, and whether the high-pressure spray gun is blocked by crystals can be better judged compared with the target conversion efficiency.
In the method for detecting blockage of the injection pipeline in the gas-assisted dual-injection system in the SCR system provided in embodiment 1 of the present invention, preferably, the injection condition in step S104 is that the exhaust temperature in the exhaust gas channel reaches 200 ℃; when the blocking condition of the high-pressure spray gun is judged, the judgment on the injection condition of the urea solution is needed to be added in order to fully meet the reaction condition of NOX and the urea solution, and the reaction temperature of NOX and the urea solution in two paths of tail gas pipelines is controlled, so that the actually obtained NOX conversion efficiency is more referential, and the demonstration of the existence of the blocking condition of crystals in the high-pressure spray gun is facilitated.
In the method for detecting blockage of an injection pipeline in a gas-assisted dual-injection system in an SCR system provided in embodiment 1 of the present invention, preferably, after "entering a first failure mode" in step S103, the method further includes feeding back blockage information of the pipeline; when the crystallization blockage exists in the pipeline, the condition that the crystallization blockage exists in the pipeline is fed back to the system in a mode of entering the first fault mode, the condition is distinguished from the condition that the high-pressure spray gun is blocked, and whether the actual condition of the crystallization blockage is serious in the pipeline is fed back through data acquired by the pressure difference sensor.
In the method for detecting blockage of the injection pipeline in the gas-assisted dual-injection system in the SCR system provided in embodiment 1 of the present invention, preferably, after entering the second failure mode in step S105, the method further includes feeding back blockage information of the high-pressure spray gun in the path; when the high-pressure spray gun is blocked by crystallization, the system is fed back in a second fault mode, the situation that the high-pressure spray gun is blocked by crystallization is distinguished from the situation that a pipeline is blocked, and meanwhile, the related data of NOX conversion efficiency can be transmitted to the system to judge whether the actual blocking situation of the high-pressure spray gun is serious.
In the method for detecting blockage of the injection pipeline in the gas-assisted dual-injection system in the SCR system provided in embodiment 1 of the present invention, preferably, the urea pressure in step S103 is a pressure generated by extrusion of the urea solution in the pipeline; when the urea pressure is adopted to judge whether the crystallization blockage exists in the pipeline, and when the crystallization blockage exists in the pipeline, the pressure of urea solution in the pipeline can be increased, so that the urea pressure is increased; the pressure of urea can be clearly monitored through the pressure difference sensor, so that whether the pipeline is blocked by crystals or not is judged, and the situation of the blockage of the crystals in the pipeline is fed back through data collected by the pressure difference sensor.
In summary, the method for detecting the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system can solve the problem that two paths of high-pressure spray guns and pipelines thereof cannot be detected in a targeted manner when the injection unit is blocked in the prior art, and can effectively position the blockage position.
Those skilled in the art will appreciate that the above-described modifications may be implemented by those skilled in the art in combination with the prior art and the above-described embodiments, and are not described herein. Such modifications do not affect the essence of the present invention, and are not described herein.
The preferred embodiments of the present invention have been described above. It is to be understood that the invention is not limited to the specific embodiments described above, wherein devices and structures not described in detail are to be understood as being implemented in a manner common in the art; any person skilled in the art will make many possible variations and modifications, or adaptations to equivalent embodiments without departing from the technical solution of the present invention, which do not affect the essential content of the present invention. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.
Claims (6)
1. The method for detecting the blockage of the injection pipeline in the gas-assisted double-injection system in the SCR system is characterized by comprising the following steps of:
s101: starting a train engine, and starting a urea pump to build pressure;
s102: after the urea pump is pressurized, waiting for the urea solution injection state;
s103: when the urea solution injection state is met, a pipeline blockage detection module is started; setting time of normally open 1s for two metering valves in a urea metering module in an injection unit, at the moment, conveying urea solution to the injection unit by a urea pump, enabling the urea solution to flow through two pipelines, respectively acquiring urea pressure in the two pipelines by a pressure difference sensor in the pipelines, and judging whether the urea pressure is normal or not; when the urea pressure is higher than the target pressure, the pipeline is considered to be blocked, and a first fault mode is entered;
s104: judging whether the urea solution injection condition is met after the pipeline blockage detection is completed; if the urea solution injection condition is not met, the engine is closed, and the system operation is ended;
s105: when the urea solution injection condition is met, starting a spray gun blockage detection module; a front NOX sensor is arranged at the position in front of the SCR carrier in the two paths of exhaust channels, a rear NOX sensor is arranged at the position in the rear of the SCR carrier in the two paths of exhaust channels, a metering valve of the two paths of high-pressure spray guns in the injection unit is opened, the front NOX sensor in the two paths of exhaust channels counts the content of NOX before the exhaust is treated, the rear NOX sensor counts the content of NOX after the exhaust is treated, the conversion efficiency of the NOX of the two paths of exhaust channels is calculated according to the data of the front NOX sensor and the rear NOX sensor respectively, and whether the conversion efficiency of the NOX is normal or not is judged; when the conversion efficiency is smaller than the target value, the high-pressure spray gun on the way is considered to be blocked, and a second fault mode is entered; when the conversion rate is greater than the target value, S104 is re-executed;
s106: and when the engine is judged to be closed, the spray gun blockage detection is judged to be completed, and the system operation is ended.
2. The method for detecting blockage of an injection line in a gas-assisted dual injection system of an SCR system as defined in claim 1, wherein the injection state in step S102 is a state in which the urea pump pressure reaches a pressure build-up threshold and a state after the pressure build-up is maintained.
3. The method for detecting blockage of an injection line in a gas-assisted dual injection system of an SCR system as defined in claim 1, wherein the injection condition of step S104 is an exhaust gas temperature in the exhaust passage reaching 200 ℃.
4. The method for detecting blockage of an injection line in a gas-assisted dual injection system of an SCR system as set forth in claim 1, wherein said entering a first failure mode in step S103 further comprises feeding back the blockage information of the line.
5. The method for detecting blockage of an injection line in a gas-assisted dual injection system of an SCR system as set forth in claim 1, wherein said entering a second failure mode in step S105 further comprises feeding back a blockage message for the high pressure injection gun.
6. The method for detecting blockage of an injection line in a gas-assisted dual injection system of an SCR system as claimed in claim 1, wherein the urea pressure in step S103 is a pressure generated by squeezing the urea solution in the line.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410126009.0A CN117869049A (en) | 2024-01-30 | 2024-01-30 | Detection method for blockage of injection pipeline in gas-assisted double-injection system in SCR system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202410126009.0A CN117869049A (en) | 2024-01-30 | 2024-01-30 | Detection method for blockage of injection pipeline in gas-assisted double-injection system in SCR system |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN117869049A true CN117869049A (en) | 2024-04-12 |
Family
ID=90596797
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202410126009.0A Pending CN117869049A (en) | 2024-01-30 | 2024-01-30 | Detection method for blockage of injection pipeline in gas-assisted double-injection system in SCR system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN117869049A (en) |
-
2024
- 2024-01-30 CN CN202410126009.0A patent/CN117869049A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101668931B (en) | Apparatus for diagnosis of abnormality in exhaust gas purification system | |
| CN110206623A (en) | A kind of motor exhaust post-processing control system and control method | |
| EP2078141B1 (en) | Dual injector system for diesel emissions control | |
| US8359833B2 (en) | Method for introducing a reductant into an exhaust stream | |
| CN104822914B (en) | Reducing agent spraying controlling system | |
| WO2011145567A1 (en) | Scr thawing control system | |
| CN104775876A (en) | Exhaust smoke passage integrated purification system for plurality of diesel engine test table frames | |
| US20140325961A1 (en) | Injector control method | |
| WO2011148810A1 (en) | Return control system | |
| CN110206621B (en) | Wide-temperature-window efficient diesel engine post-processing device and control method thereof | |
| CN104081015A (en) | Post-processing system apparatus and control method | |
| KR101489794B1 (en) | A Reducing Agent Supply Device for SCR System and Method thereof | |
| CN106382145B (en) | A kind of exhaust treatment system and control method based on NTP technology | |
| CN109653853B (en) | Diesel engine tail gas combined treatment system and control method | |
| CN103511039A (en) | Pneumatic type urea injection system | |
| KR102447698B1 (en) | Reductant supply system and method for managing the same | |
| WO2021203632A1 (en) | Exhaust gas after treatment system and control method therefor | |
| CN109538334A (en) | A kind of system and control method of forward and reverse alternating spray NTP regeneration DPF | |
| CN212671898U (en) | Diesel engine tail gas treatment system with closed-loop control | |
| CN211913352U (en) | Tail gas aftertreatment system | |
| CN210003364U (en) | kinds of post-processing system | |
| CN117869049A (en) | Detection method for blockage of injection pipeline in gas-assisted double-injection system in SCR system | |
| CN216342391U (en) | Tail gas post-treatment device for non-road diesel engine by using liquid ammonia as SDPF reducing agent | |
| CN114658514B (en) | DOC carrying NTP combined regeneration DPF system and control method | |
| CN107461249B (en) | Particle catcher regeneration control system based on CAN communication |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |