阅读说明：本技术 消除选择性催化还原系统结晶的系统及其方法 (System and method for eliminating crystallization of selective catalytic reduction system ) 是由 薛俊强 杜鑫 郝庆栋 于 2019-04-17 设计创作，主要内容包括：本发明提供一种消除选择性催化还原系统结晶的方法,属于发动机及尾气处理技术领域。所述方法包括：处于正常工作状态时,监测选择性催化还原系统内的结晶；当在所述选择性催化还原系统内监测到所述结晶时,切换所述正常工作状态至临时工作状态；处于所述临时工作状态时,执行与所述结晶对应的消除操作。本发明能对SCR后处理系统内结晶进行监测,本发明处理了SCR后处理系统内的结晶、降低了因NOX排放高导致的OBD报警次数、降低了为激活SCR性能进行再生的次数以防止多次再生导致的机油稀释,具有结构简单、成本低、使用效果好的优点。(The invention provides a method for eliminating crystallization of a selective catalytic reduction system, and belongs to the technical field of engines and tail gas treatment. The method comprises the following steps: monitoring crystallization in the selective catalytic reduction system when the system is in a normal working state; switching the normal operating state to a temporary operating state when the crystallization is monitored in the selective catalytic reduction system; and when the temporary working state is reached, executing elimination operation corresponding to the crystallization. The invention can monitor the crystallization in the SCR post-treatment system, treats the crystallization in the SCR post-treatment system, reduces the OBD alarm frequency caused by high NOX emission, reduces the regeneration frequency for activating the SCR performance so as to prevent engine oil dilution caused by multiple regeneration, and has the advantages of simple structure, low cost and good use effect.)

1. A method of eliminating crystallization in a selective catalytic reduction system, the method comprising:

s1), monitoring crystallization in the selective catalytic reduction system when the system is in a normal working state;

s2) switching the normal operation state to a temporary operation state when the crystallization is monitored in the selective catalytic reduction system;

s3) is in the temporary operating state, an erasing operation corresponding to the crystal is performed.

2. The method for eliminating crystallization in a selective catalytic reduction system according to claim 1, wherein step S1) comprises:

s101) setting a first system function to call a solution to react with the nitrogen oxide;

s102) constructing a crystallization monitoring strategy by utilizing a regeneration judgment strategy of a regeneration filtering medium;

s103) when the system is in a normal working state with the first system function, the crystallization monitoring strategy is utilized to monitor the crystallization in the selective catalytic reduction system.

3. The method for eliminating crystallization in a selective catalytic reduction system according to claim 2, wherein step S102) comprises:

and constructing a crystallization monitoring strategy by utilizing a diesel engine particulate matter filtering quality regeneration judgment strategy or a denitration quality regeneration judgment strategy.

4. The method for eliminating crystallization in a selective catalytic reduction system according to claim 3, wherein the step S102) of constructing the crystallization monitoring strategy by using the diesel particulate matter filter regeneration judgment strategy comprises:

s121) acquiring the current inlet and outlet pressure and inlet and outlet pressure difference of the diesel particulate filter, and triggering the regeneration operation of the diesel particulate filter when the inlet and outlet pressure exceeds a preset pressure threshold value or the inlet and outlet pressure difference exceeds a preset pressure threshold value, the first state duration time when the inlet and outlet pressure exceeds the preset pressure threshold value or the second state duration time when the inlet and outlet pressure exceeds the preset pressure threshold value exceeds the first preset duration time and the current working condition state is allowable;

s122) defining the step S121) as a diesel particulate matter filtering matter regeneration judgment strategy, replacing the diesel particulate matter filtering matter regeneration triggering operation in the diesel particulate matter regeneration judgment strategy with the crystallization monitoring determination, and taking the strategy after the replacement as the crystallization monitoring strategy.

5. The method for eliminating the crystallization of the selective catalytic reduction system according to claim 3, wherein the step S102) of constructing the crystallization monitoring strategy by using the denitrogenation regeneration judgment strategy comprises:

s121) obtaining the current conversion efficiency of the denitrator, and triggering denitrogenation regeneration operation when the conversion efficiency is lower than a preset efficiency threshold, the state duration time of the conversion efficiency lower than the preset efficiency threshold exceeds a second preset duration time, and the current working condition state is allowable;

s122) defining the step S121) as a denitrogenated substance regeneration judgment strategy, replacing the denitrogenated substance regeneration operation triggered in the denitrogenated substance regeneration judgment strategy with the determined monitored crystallization, and then taking the strategy after the replacement as a crystallization monitoring strategy.

6. The method for eliminating crystallization in a selective catalytic reduction system according to claim 1, wherein step S2) comprises:

s201) setting a second system function to call liquid to eliminate crystals;

s202) when the crystallization is monitored in the selective catalytic reduction system and the elimination operation is not carried out within the preset period time, switching the normal working state to a temporary working state with a second system function.

7. The method for eliminating crystals of a selective catalytic reduction system according to claim 1, wherein the elimination operation corresponding to the crystals in step S3) is performed and comprises:

s301) sucking back a residual solution to a storage medium of the residual solution by using a solution passage of the solution causing the crystallization and a driving source;

s302) closing the solution passage and suspending the monitoring of the nitrogen oxide;

s303) injecting a liquid into the selective catalytic reduction system through a liquid passage of the liquid for removing the crystals and the driving source to allow the liquid to remove the crystals.

8. The method for eliminating crystallization in a selective catalytic reduction system according to claim 7, wherein step S3) further comprises:

s304) after the ejection is stopped, suck back the liquid to a storage medium of the liquid by using the liquid passage and the driving source;

s305) closing the liquid passage and then opening the solution passage;

s306) switching the temporary working state to the normal working state and continuing monitoring the nitrogen oxide.

9. A control system for eliminating crystallization in a selective catalytic reduction system, comprising:

an engine control module for carrying out the method of any one of claims 1 to 8.

10. A monitoring system for eliminating crystallization in a selective catalytic reduction system, comprising:

the monitoring node has a filter parameter detection function and is used for receiving a collection signal of a control system and generating a sensing signal with information of the filter parameter from the collection signal;

a solution path having a function of passing a solution that causes crystallization in the selective catalytic reduction system;

a liquid passage having a function of passing the crystallized liquid eliminated in the selective catalytic reduction system;

a driving source for receiving a control signal of the control system, for receiving a normal driving signal or a temporary driving signal generated by the control system from the sensing signal, for performing opening or closing of the solution path and the liquid path by the temporary driving signal and the control signal, or for performing opening or closing of the solution path and the liquid path by the normal driving signal and the control signal, for driving the solution in the solution path to a filter by the normal driving signal and also for driving the liquid in the liquid path to the selective catalytic reduction system in the filter by the temporary driving signal.

11. The system of claim 10, wherein the monitoring node comprises:

and the pressure sensor is used for generating a sensing signal with information of inlet and outlet pressure and inlet and outlet pressure difference by the acquired signal.

12. The system of claim 10, wherein the monitoring node comprises:

and the nitrogen oxide sensor is used for generating a sensing signal with information of the numerical value of the content of the nitrogen oxide at the inlet and the outlet by the acquired signal.

13. The system of claim 10, wherein the monitoring node comprises:

a temperature-liquid level sensor having a function of detecting a storage medium parameter of the liquid or the solution, for generating a sensing signal having information of the storage medium parameter from the collected signal;

the sensing signal with the information of the storage medium parameter is used for the control system to judge whether the storage medium parameter exceeds a preset range or not and judge whether the storage medium parameter exceeding the preset range is recovered to the preset range or not.

14. The system for monitoring elimination of crystallization in a selective catalytic reduction system of claim 10,

the solution passage comprises a first liquid suction pipe and a transmission pipe;

the liquid passage comprises a second pipette and the transfer tube;

the driving source comprises a two-position three-way electromagnetic valve, a pump and an injection device;

the first end of the first liquid suction pipe is connected with the first end of the transmission pipe through the two-position three-way electromagnetic valve, and the second end of the first liquid suction pipe is also connected with a solution storage medium;

wherein the second end of the transfer pipe is connected with the spraying device through the pump;

wherein the first end of the second pipette is connected with the first end of the transfer pipe through the two-position three-way electromagnetic valve, and the second end of the second pipette is also connected with a liquid storage medium;

wherein the injection device is used for injecting the liquid or the solution into the selective catalytic reduction system.

15. The system for monitoring elimination of crystallization in a selective catalytic reduction system of claim 14,

the driving source is also used for turning on the spraying device by the control signal and the temporary driving signal, opening the first pipette tube and closing the second pipette tube by the two-position three-way solenoid valve, and setting the power direction of the pump to be the same as the flow direction of the solution flowing from the spraying device to the solution storage medium;

the drive source is also configured to turn on the ejection device by the control signal and the temporary drive signal with a delay, open the second pipette and close the first pipette by the two-position three-way solenoid valve, and set the power direction of the pump to the same direction as the flow direction of the liquid from the liquid storage medium to the ejection device;

the drive source is also configured to turn on the ejection device by the control signal and the temporary drive signal with a second delay, open the second pipette and close the first pipette by the two-position three-way solenoid valve, and set the power direction of the pump to the same direction as the flow direction of the liquid from the ejection device to the liquid storage medium.

16. A control apparatus for eliminating crystallization in a selective catalytic reduction system, comprising:

at least one processor;

a memory coupled to the at least one processor;

wherein the memory stores instructions executable by the at least one processor, the at least one processor implementing the method of any one of claims 1 to 8 by executing the instructions stored by the memory.

17. A computer readable storage medium storing computer instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 8.

Technical Field

The invention relates to the technical field of engine and tail gas treatment, in particular to a method for eliminating crystallization of a selective catalytic reduction system, a control system for eliminating crystallization of the selective catalytic reduction system, a monitoring system for eliminating crystallization of the selective catalytic reduction system, control equipment for eliminating crystallization of the selective catalytic reduction system and a computer readable storage medium.

Background

With the upgrading of emission regulations, the current scr (selective Catalyst reduction) aftertreatment system is widely applied to diesel engines, can effectively reduce Nitrogen Oxides (NOX) in exhaust gas, but the problem of urea crystallization is prominent in actual use, thereby causing the problems of On Board Diagnostics (OBD) alarm, frequent regeneration and engine oil dilution.

Disclosure of Invention

The invention aims to provide a system and a method for eliminating crystallization of a selective catalytic reduction system, and aims to solve the technical problems that in the prior art, the crystallization fault problem of an SCR aftertreatment system cannot be detected when urea injection is not stopped, crystallization monitoring cannot be realized, and further multiple OBD alarms and engine oil dilution caused by multiple triggered regeneration are caused due to the fact that crystallization faults are not found timely.

In order to achieve the above object, an embodiment of the present invention provides a method for eliminating crystallization of a selective catalytic reduction system, the method including:

s1), monitoring crystallization in the selective catalytic reduction system when the system is in a normal working state;

s2) switching the normal operation state to a temporary operation state when the crystallization is monitored in the selective catalytic reduction system;

s3) is in the temporary operating state, an erasing operation corresponding to the crystal is performed.

Specifically, step S1) includes:

s101) setting a first system function to call a solution to react with the nitrogen oxide;

s102) constructing a crystallization monitoring strategy by utilizing a regeneration judgment strategy of a regeneration filtering medium;

s103) when the system is in a normal working state with the first system function, the crystallization monitoring strategy is utilized to monitor the crystallization in the selective catalytic reduction system.

Specifically, step S102) includes:

and constructing a crystallization monitoring strategy by utilizing a diesel engine particulate matter filtering quality regeneration judgment strategy or a denitration quality regeneration judgment strategy.

Specifically, the step S102) of constructing the crystallization monitoring strategy by using the diesel particulate matter filter regeneration judgment strategy includes:

s121) acquiring the current inlet and outlet pressure and inlet and outlet pressure difference of the diesel particulate filter, and triggering the regeneration operation of the diesel particulate filter when the inlet and outlet pressure exceeds a preset pressure threshold value or the inlet and outlet pressure difference exceeds a preset pressure threshold value, the first state duration time when the inlet and outlet pressure exceeds the preset pressure threshold value or the second state duration time when the inlet and outlet pressure exceeds the preset pressure threshold value exceeds the first preset duration time and the current working condition state is allowable;

s122) defining the step S121) as a diesel particulate matter filtering matter regeneration judgment strategy, replacing the diesel particulate matter filtering matter regeneration triggering operation in the diesel particulate matter regeneration judgment strategy with the crystallization monitoring determination, and taking the strategy after the replacement as the crystallization monitoring strategy.

Specifically, the step S102) of constructing the crystallization monitoring strategy by using the denitrogenation regeneration judgment strategy includes:

s121) obtaining the current conversion efficiency of the denitrator, and triggering denitrogenation regeneration operation when the conversion efficiency is lower than a preset efficiency threshold, the state duration time of the conversion efficiency lower than the preset efficiency threshold exceeds a second preset duration time, and the current working condition state is allowable;

s122) defining the step S121) as a denitrogenated substance regeneration judgment strategy, replacing the denitrogenated substance regeneration operation triggered in the denitrogenated substance regeneration judgment strategy with the determined monitored crystallization, and then taking the strategy after the replacement as a crystallization monitoring strategy.

Specifically, step S2) includes:

s201) setting a second system function to call liquid to eliminate crystals;

s202) when the crystallization is monitored in the selective catalytic reduction system and the elimination operation is not carried out within the preset period time, switching the normal working state to a temporary working state with a second system function.

Specifically, the elimination operation corresponding to the crystallization in step S3) includes:

s301) sucking back a residual solution to a storage medium of the residual solution by using a solution passage of the solution causing the crystallization and a driving source;

s302) closing the solution passage and suspending the monitoring of the nitrogen oxide;

s303) injecting a liquid into the selective catalytic reduction system through a liquid passage of the liquid for removing the crystals and the driving source to allow the liquid to remove the crystals.

Specifically, step S3) further includes:

s304) after the ejection is stopped, suck back the liquid to a storage medium of the liquid by using the liquid passage and the driving source;

s305) closing the liquid passage and then opening the solution passage;

s306) switching the temporary working state to the normal working state and continuing monitoring the nitrogen oxide.

The embodiment of the invention provides a control system for eliminating crystallization of a selective catalytic reduction system, which comprises:

an engine control module for performing the aforementioned method.

The embodiment of the invention provides a monitoring system for eliminating crystallization of a selective catalytic reduction system, which comprises:

the monitoring node has a filter parameter detection function and is used for receiving a collection signal of a control system and generating a sensing signal with information of the filter parameter from the collection signal;

a solution path having a function of passing a solution that causes crystallization in the selective catalytic reduction system;

a liquid passage having a function of passing the crystallized liquid eliminated in the selective catalytic reduction system;

a driving source for receiving a control signal of the control system, for receiving a normal driving signal or a temporary driving signal generated by the control system from the sensing signal, for performing opening or closing of the solution path and the liquid path by the temporary driving signal and the control signal, or for performing opening or closing of the solution path and the liquid path by the normal driving signal and the control signal, for driving the solution in the solution path to a filter by the normal driving signal and also for driving the liquid in the liquid path to the selective catalytic reduction system in the filter by the temporary driving signal.

Optionally, the monitoring node includes:

and the pressure sensor is used for generating a sensing signal with information of inlet and outlet pressure and inlet and outlet pressure difference by the acquired signal.

Optionally, the monitoring node includes:

and the nitrogen oxide sensor is used for generating a sensing signal with information of the numerical value of the content of the nitrogen oxide at the inlet and the outlet by the acquired signal.

Optionally, the monitoring node includes:

a temperature-liquid level sensor having a function of detecting a storage medium parameter of the liquid or the solution, for generating a sensing signal having information of the storage medium parameter from the collected signal;

the sensing signal with the information of the storage medium parameter is used for the control system to judge whether the storage medium parameter exceeds a preset range or not and judge whether the storage medium parameter exceeding the preset range is recovered to the preset range or not.

Optionally, the solution pathway comprises a first pipette and a transfer tube;

the liquid passage comprises a second pipette and the transfer tube;

the driving source comprises a two-position three-way electromagnetic valve, a pump and an injection device;

the first end of the first liquid suction pipe is connected with the first end of the transmission pipe through the two-position three-way electromagnetic valve, and the second end of the first liquid suction pipe is also connected with a solution storage medium;

wherein the second end of the transfer pipe is connected with the spraying device through the pump;

wherein the first end of the second pipette is connected with the first end of the transfer pipe through the two-position three-way electromagnetic valve, and the second end of the second pipette is also connected with a liquid storage medium;

wherein the injection device is used for injecting the liquid or the solution into the selective catalytic reduction system.

Optionally, the driving source is further configured to turn on the spraying device by the control signal and the temporary driving signal, turn on the first pipette and turn off the second pipette by the two-position three-way solenoid valve, and set a power direction of the pump to be the same as a flow direction of the solution flowing from the spraying device to the solution storage medium;

the drive source is also configured to turn on the ejection device by the control signal and the temporary drive signal with a delay, open the second pipette and close the first pipette by the two-position three-way solenoid valve, and set the power direction of the pump to the same direction as the flow direction of the liquid from the liquid storage medium to the ejection device;

the drive source is also configured to turn on the ejection device by the control signal and the temporary drive signal with a second delay, open the second pipette and close the first pipette by the two-position three-way solenoid valve, and set the power direction of the pump to the same direction as the flow direction of the liquid from the ejection device to the liquid storage medium.

In another aspect, an embodiment of the present invention provides a control apparatus for eliminating crystallization of a selective catalytic reduction system, including:

at least one processor;

a memory coupled to the at least one processor;

wherein the memory stores instructions executable by the at least one processor, the at least one processor implements the aforementioned method by executing the instructions stored by the memory.

In yet another aspect, an embodiment of the present invention provides a computer-readable storage medium storing computer instructions, which, when executed on a computer, cause the computer to perform the foregoing method.

The invention realizes the crystal monitoring in the SCR post-treatment system and provides a means for treating the crystal;

the invention unexpectedly combines the monitoring means of the regenerated filtering medium and the regeneration judgment decision to realize the crystallization monitoring in the SCR after-treatment system;

the present invention surprisingly creates a crystallization monitoring strategy without adding any crystallization detection sensing device;

the method limits the times of misjudgment of the crystallization problem by setting the preset cycle time to judge whether the crystallization is eliminated in a short time;

the invention treats the crystallization in the SCR post-treatment system, reduces the OBD alarming times caused by high NOX emission, reduces the regeneration times for activating the SCR performance so as to prevent the engine oil dilution caused by multiple regeneration, and has the advantages of simple structure, low cost and good use effect.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the embodiments of the invention without limiting the embodiments of the invention. In the drawings:

FIG. 1 is a schematic diagram of a system for eliminating engine SCR aftertreatment crystallization according to an embodiment of the present invention;

FIG. 2 is a schematic logic diagram of a monitoring signal for eliminating engine SCR aftertreatment crystallization according to an embodiment of the invention.

Description of the reference numerals

1 Engine 2 Engine Control Module (ECM)

3 cooling liquid pipeline 4 electromagnetic switch

5 temp. -liquid level sensor 6 water pot

7 urea tank 8 water suction pipe

9 pipette 10 two-position three-way electromagnetic valve

11 liquid delivery pipe 12 urea pump

13 spray line 14 nozzle

Differential pressure and pressure sensor of Diesel Particulate Filter (DPF) of 15 Diesel engine

16SCR aftertreatment 17 outlet NOX sensor

18 inlet NOX sensor 19 tail pipe

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating embodiments of the invention, are given by way of illustration and explanation only, not limitation.