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CN-122014386-A - Urea injection control method and related equipment

CN122014386ACN 122014386 ACN122014386 ACN 122014386ACN-122014386-A

Abstract

The invention discloses a urea injection control method and related equipment, and relates to the technical field of double-injection SCR systems, wherein the method comprises the steps of obtaining the temperature of ufSCR of the double-injection SCR system, judging whether leakage of NH 3 exists according to the temperature of ufSCR and the temperature rising rate, and controlling the urea injection quantity of ccSCR and ufSCR of the double-injection SCR system to be reduced to a set value when leakage of NH 3 exists until the storage quantity of NH 3 is smaller than a set storage minimum value, and recovering the urea injection quantity of ccSCR and ufSCR. The emission of NH 3 is reduced under the condition of effectively ensuring low emission of NOx, and simultaneously the emission of N 2 O side reaction generated in an SCR/ASC system due to excessive NH 3 is reduced, so that the effective reduction of total pollutants is realized.

Inventors

  • ZHONG KUN
  • LV ZHIHUA
  • GENG ZONGQI
  • FANG LE
  • GENG LEI
  • DAI ZIYANG

Assignees

  • 潍柴动力股份有限公司

Dates

Publication Date
20260512
Application Date
20260120

Claims (10)

  1. 1. A urea injection control method, applied to a dual-injection SCR system ‌, comprising: acquiring the temperature ufSCR of the double-spray SCR system; judging whether leakage of NH 3 exists or not according to the temperature and the heating rate of ufSCR; When NH 3 is leaked, the urea injection quantity of ccSCR and ufSCR of the double-injection SCR system is controlled to be reduced to a set value, and after the NH 3 storage quantity is smaller than the set storage minimum value, the urea injection quantity of ccSCR and ufSCR is recovered.
  2. 2. The urea injection control method of claim 1, wherein the presence of NH 3 slip is determined when the temperature of ufSCR is greater than a set temperature threshold and the ramp rate of ufSCR is greater than a set temperature change threshold.
  3. 3. A urea injection control method according to claim 1, characterized in that the urea injection quantity of control ccSCR is maintained at a minimum injection quantity.
  4. 4. The urea injection control method according to claim 1, characterized in that the urea injection quantity of ufSCR is reduced to a minimum injection quantity.
  5. 5. The urea injection control method of claim 1, wherein a minimum NH 3 storage is stored at a minimum value ufSCR to ensure NOx conversion efficiency.
  6. 6. The urea injection control method according to claim 1, wherein the micro-overspray is performed after the urea injection amount of control ccSCR is recovered to be normal.
  7. 7. A urea injection control system, characterized by being applied to a dual-injection SCR system ‌, comprising: an acquisition module configured to acquire a temperature of ufSCR of the dual-spray SCR system; A determination module configured to determine whether there is NH 3 slip based on a temperature and a ramp rate of ufSCR; The control module is configured to control the urea injection amounts of ccSCR and ufSCR of the dual-injection SCR system to be reduced to a set value when NH 3 is leaked, and to resume the urea injection amounts of ccSCR and ufSCR after the NH 3 storage amount is smaller than a set storage minimum value.
  8. 8. An electronic device comprising a memory and a processor and computer instructions stored on the memory and running on the processor, which when executed by the processor, perform the method of any one of claims 1-6.
  9. 9. A computer readable storage medium storing computer instructions which, when executed by a processor, perform the method of any of claims 1-6.
  10. 10. A computer program product comprising a computer program which, when executed by a processor, implements the method of any of claims 1-6.

Description

Urea injection control method and related equipment Technical Field The invention relates to the technical field of double-injection SCR systems, in particular to a urea injection control method and related equipment. Background The means for reducing NOx in diesel engines is mainly through the reaction of NH 3 produced by urea hydrolysis with NOx in an SCR (selective catalytic Reduction) system to produce pollution-free N 2. However, if the SCR temperature is too high, the NOx conversion efficiency is reduced, which will cause NH 3 stored in the SCR system to be released, and some excess NH 3 is discharged through ASC (Ammonia oxidation catalyst, amonia SLIP CATALYST), N 2 O is generated in ASC, resulting in excessive NH 3 and N 2 O emissions, and the excess NH 3 is generated by urea hydrolysis, so that excessive consumption of urea injection amount will be caused by excessive NH 3 waste, and the use cost is increased. Disclosure of Invention In order to solve the problems, the invention provides a urea injection control method and related equipment, which can effectively reduce NH 3 emission under the condition of ensuring low NOx emission, simultaneously reduce the emission of N 2 O side reaction generated in an SCR/ASC system due to excessive NH 3, and realize effective reduction of total pollutants. In order to achieve the above purpose, the present invention adopts the following technical scheme: in a first aspect, the present invention provides a urea injection control method applied to a dual-injection SCR system ‌, including: acquiring the temperature ufSCR of the double-spray SCR system; judging whether leakage of NH 3 exists or not according to the temperature and the heating rate of ufSCR; When NH 3 is leaked, the urea injection quantity of ccSCR and ufSCR of the double-injection SCR system is controlled to be reduced to a set value, and after the NH 3 storage quantity is smaller than the set storage minimum value, the urea injection quantity of ccSCR and ufSCR is recovered. Alternatively, when the temperature ufSCR is greater than the set temperature threshold and the ramp rate of ufSCR is greater than the set temperature change threshold, it is determined that NH 3 slip is present. Alternatively, the urea injection quantity of control ccSCR maintains a minimum injection quantity. Alternatively, the urea injection amount of ufSCR is reduced to the minimum injection amount. Alternatively, a minimum NH 3 storage amount is stored at a minimum value ufSCR to ensure NOx conversion efficiency. Alternatively, the control ccSCR may perform the micro-overspray after the urea injection amount is recovered to be normal. In a second aspect, the present invention provides a urea injection control system for a dual injection SCR system ‌, comprising: an acquisition module configured to acquire a temperature of ufSCR of the dual-spray SCR system; A determination module configured to determine whether there is NH 3 slip based on a temperature and a ramp rate of ufSCR; The control module is configured to control the urea injection amounts of ccSCR and ufSCR of the dual-injection SCR system to be reduced to a set value when NH 3 is leaked, and to resume the urea injection amounts of ccSCR and ufSCR after the NH 3 storage amount is smaller than a set storage minimum value. In a third aspect, the invention provides an electronic device comprising a memory and a processor and computer instructions stored on the memory and running on the processor, which when executed by the processor, perform the method of the first aspect. In a fourth aspect, the present invention provides a computer readable storage medium storing computer instructions which, when executed by a processor, perform the method of the first aspect. In a fifth aspect, the invention provides a computer program product comprising a computer program which, when executed by a processor, implements the method of the first aspect. Compared with the prior art, the invention has the beneficial effects that: The invention provides a urea injection control method, which is characterized in that whether the ufSCR has NH 3 leakage problem is judged by judging the temperature and the heating rate of ufSCR, if so, the urea injection quantity of ccSCR and ufSCR is reduced, the NH 3 storage quantity in ufSCR is reduced by increasing NOx before ufSCR and reducing the urea injection quantity of ufSCR, the NH 3 leakage risk is reduced, after ufSCR has no NH 3 leakage risk, the urea injection quantity of ccSCR and ufSCR is recovered, and the urea injection quantity of ccSCR is properly increased to reduce the NOx emission before ufSCR, so that the total NOx emission is reduced. The emission of NH 3 is reduced under the condition of effectively ensuring low emission of NOx, and simultaneously the emission of N 2 O side reaction generated in an SCR/ASC system due to excessive NH 3 is reduced, so that the effective reduction of total pollutants is realized. Additional aspec