A method and device for detecting urea over spraying, an electronic device and a storage medium

Abstract

This invention discloses a method, apparatus, electronic device, and storage medium for detecting urea over-injection. The method determines the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate injector. When this time difference is less than a time difference threshold, the current operating condition of the engine is acquired. If the current operating condition meets preset steady-state conditions, the variation in SCR efficiency is obtained by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle. When this variation exceeds a threshold, urea over-injection is confirmed. This invention determines whether urea over-injection has occurred by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle during normal engine operation to obtain the variation in SCR efficiency. This allows for timely adjustments to urea injection, avoiding resource waste, reducing pollution, and optimizing the environment.

Description

Technical Field

[0001] This invention relates to the field of circuit breaker technology, and more specifically, to a method, apparatus, electronic device, and storage medium for detecting urea over-spraying. Background Technology

[0002] Currently, the main method used in the aftertreatment system of China VI diesel engines to reduce NOx in engine exhaust is through SCR (Selective Catalytic Reduction). Its working principle is as follows: urea injected by the urea injector is converted into NH3 through evaporation, pyrolysis, and hydrolysis. NH3 then acts as a reducing agent, converting NOx in the engine exhaust into harmless N2, which is released into the air. Therefore, reducing NOx emissions can reduce pollution and optimize the environment. Precise urea injection is one of the key factors in reducing NOx emissions.

[0003] However, if the NOx emissions during normal engine operation are low, but the urea injector sprays too much urea due to aging or other reasons, it will lead to urea over-injection during engine operation. The over-injected urea will be discharged with the engine exhaust, not participating in the oxidation-reduction reaction of NOx in the exhaust, thus wasting resources and causing some environmental pollution.

[0004] Therefore, how to detect urea over-injection during normal engine operation and adjust urea injection accordingly has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention discloses a method, apparatus, electronic device and storage medium for detecting urea over-injection, so as to realize the detection of urea over-injection during normal engine operation.

[0006] A method for detecting urea overspray includes:

[0007] Determine the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector;

[0008] When it is determined that the time difference is less than the time difference threshold, the current operating condition of the engine is obtained;

[0009] When it is determined that the current operating condition meets the preset steady-state conditions, the original engine emission and the urea emission from the urea nozzle are adjusted to obtain the change range of the selective catalytic reduction (SCR) efficiency.

[0010] When the change exceeds the amplitude threshold, it is determined that urea over-spraying has occurred.

[0011] Optionally, obtaining the current operating condition of the engine when it is determined that the time difference is less than a time difference threshold includes:

[0012] When it is determined that the time difference is less than the time difference threshold, the current exhaust flow rate, current exhaust temperature, current exhaust flow rate change rate, and current exhaust temperature change rate of the engine are obtained.

[0013] The current operating conditions include: the current exhaust flow rate, the current exhaust temperature, the current exhaust flow rate change rate, and the current exhaust temperature change rate.

[0014] Optionally, determining that the current operating condition satisfies the preset steady-state condition includes:

[0015] The current exhaust flow rate is determined to be within the preset flow rate range;

[0016] The current exhaust temperature is determined to be within a preset temperature range;

[0017] It is determined that the current exhaust flow rate change rate is lower than the flow rate change rate threshold;

[0018] Furthermore, it is determined that the current temperature change rate is lower than the temperature change rate threshold.

[0019] Optionally, adjusting the original engine emissions and the amount of urea injected by the urea nozzle to obtain the variation range of the selective catalytic reduction (SCR) efficiency includes:

[0020] Increase the original emissions of the engine;

[0021] The control aftertreatment system increases the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0022] Before and after the increase in the original engine emissions and the increase in the urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the reduction range;

[0023] Accordingly, determining that urea over-spraying has occurred when the change amplitude exceeds the amplitude threshold includes:

[0024] When the reduction magnitude is greater than the reduction threshold, it is determined that urea over-spraying has occurred, wherein the magnitude threshold includes the reduction threshold.

[0025] Optionally, adjusting the original engine emissions and the amount of urea injected by the urea nozzle to obtain the variation range of the selective catalytic reduction (SCR) efficiency includes:

[0026] Reduce the original emissions of the engine;

[0027] The control aftertreatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0028] Before and after the reduction of the original engine emissions and the urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the increase.

[0029] Accordingly, determining that urea over-spraying has occurred when the change amplitude exceeds the amplitude threshold includes:

[0030] When the increase is greater than the increase threshold, it is determined that urea over-spraying has occurred, wherein the increase threshold includes the increase threshold.

[0031] Optionally, adjusting the original engine emissions and the amount of urea injected by the urea nozzle to obtain the variation range of the selective catalytic reduction (SCR) efficiency includes:

[0032] Increase the original emissions of the engine;

[0033] The control aftertreatment system increases the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0034] Before and after the increase in the original engine emissions and the increase in the urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the reduction range;

[0035] When the reduction is greater than the reduction threshold, the original engine emissions of the engine are reduced.

[0036] The control aftertreatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0037] Before and after the reduction of the original engine emissions and the urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the increase.

[0038] Accordingly, determining that urea over-spraying has occurred when the change amplitude exceeds the amplitude threshold includes:

[0039] When the increase is greater than the increase threshold, it is determined that urea over-spraying has occurred, wherein the increase threshold includes the decrease threshold and the increase threshold.

[0040] Optionally, adjusting the original engine emissions and the amount of urea injected by the urea nozzle to obtain the variation range of the selective catalytic reduction (SCR) efficiency includes:

[0041] Reduce the original emissions of the engine;

[0042] The control aftertreatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0043] Before and after the reduction of the original engine emissions and the urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the increase.

[0044] When the increase exceeds the increase threshold, the original engine emissions of the engine are increased;

[0045] The control aftertreatment system increases the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0046] Before and after the increase in the original engine emissions and the increase in the urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the reduction range;

[0047] Accordingly, determining that urea over-spraying has occurred when the change amplitude exceeds the amplitude threshold includes:

[0048] When the decrease is greater than the decrease threshold, it is determined that urea over-spraying has occurred, wherein the decrease threshold includes the increase threshold and the decrease threshold.

[0049] A device for detecting urea overspray, comprising:

[0050] The time difference determination unit is used to determine the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector;

[0051] The operating condition acquisition unit is used to acquire the current operating condition of the engine when it is determined that the time difference is less than the time difference threshold.

[0052] The emission adjustment unit is used to adjust the original engine emission and the urea emission from the urea nozzle when it is determined that the current operating condition meets the preset steady-state conditions, so as to obtain the change range of selective catalytic reduction (SCR) efficiency.

[0053] The over-spray determination unit is used to determine that urea over-spraying has occurred when the change amplitude is greater than the amplitude threshold.

[0054] An electronic device, comprising: a memory and a processor;

[0055] The memory is used to store at least one instruction;

[0056] The processor is used to execute at least one instruction to implement the urea overspray detection method described above.

[0057] A computer-readable storage medium storing at least one instruction that, when executed by a processor, implements the urea overspray detection method described above.

[0058] As can be seen from the above technical solution, this invention discloses a method, device, electronic equipment, and storage medium for detecting urea over-injection. It determines the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate injector. When this time difference is less than a time difference threshold, the current operating condition of the engine is obtained. If the current operating condition meets preset steady-state conditions, the variation range of SCR efficiency is obtained by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle. When this variation range is greater than a threshold, urea over-injection is determined. This invention, during normal engine operation, determines whether urea over-injection has occurred by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle to obtain the variation range of SCR efficiency. This allows for timely adjustments to urea injection, avoiding resource waste, reducing pollution, and optimizing the environment. Attached Figure Description

[0059] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the published drawings without creative effort.

[0060] Figure 1 This is a flowchart of a method for detecting urea overspray disclosed in an embodiment of the present invention;

[0061] Figure 2 This is a schematic diagram of the structure of a urea overspray detection device disclosed in an embodiment of the present invention;

[0062] Figure 3 This is a schematic diagram of the structure of an electronic device disclosed in an embodiment of the present invention. Detailed Implementation

[0063] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0064] This invention discloses a method, apparatus, electronic device, and storage medium for detecting urea over-injection. The method determines the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate injector. When this time difference is less than a time difference threshold, the current operating condition of the engine is acquired. If the current operating condition meets preset steady-state conditions, the variation in SCR efficiency is obtained by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle. When this variation exceeds a threshold, urea over-injection is confirmed. This invention determines whether urea over-injection has occurred by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle during normal engine operation to obtain the variation in SCR efficiency. This allows for timely adjustments to urea injection, avoiding resource waste, reducing pollution, and optimizing the environment.

[0065] See Figure 1 The present invention discloses a flowchart of a method for detecting urea overspray, the detection method comprising:

[0066] Step S101: Determine the time difference between the current running time of the engine and the last regeneration time of the diesel particulate collector.

[0067] Among them, the regeneration of the diesel particulate filter (DPF) refers to the fact that China VI products need to increase the exhaust temperature inside the aftertreatment box by means of injecting fuel in front of the aftertreatment box to burn off the carbon inside the aftertreatment box. The engine mode under this condition is the regeneration mode.

[0068] Step S102: When it is determined that the time difference is less than the time difference threshold, the current operating condition of the engine is obtained.

[0069] The value of the time difference threshold is determined according to actual needs, such as 8 hours, but this invention does not limit it.

[0070] In practical applications, the current operating conditions of an engine include, but are not limited to, current exhaust flow rate, current exhaust temperature, current exhaust flow rate change rate, and current exhaust temperature change rate.

[0071] Therefore, when the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector is less than the time threshold, the current exhaust flow rate, current exhaust temperature, current exhaust flow rate change rate, and current exhaust temperature change rate of the engine are obtained.

[0072] The engine's current exhaust flow rate and current exhaust temperature can be obtained directly.

[0073] The rate of change of the engine's current exhaust flow rate refers to the rate of change of the engine's current exhaust flow rate relative to the exhaust flow rate at the previous moment.

[0074] The current exhaust temperature change rate of an engine refers to the rate of change of the current temperature flow rate of the engine at the current moment relative to the temperature flow rate at the previous moment.

[0075] In this embodiment, when it is determined that the time difference between the current running time of the engine and the last regeneration time of the diesel particulate collector is not less than the time threshold, it is determined that there will be no urea over-injection phenomenon, and the urea over-injection detection process ends at this time.

[0076] Step S103: When it is determined that the current operating condition meets the preset steady-state conditions, adjust the original engine emission and the urea emission from the urea nozzle to obtain the change range of SCR efficiency.

[0077] Specifically, determining that the current operating condition meets the preset steady-state conditions may include:

[0078] Ensure the current exhaust flow rate is within the preset flow rate range;

[0079] Ensure the current exhaust temperature is within the preset temperature range;

[0080] Determine that the current exhaust flow rate change rate is lower than the flow rate change rate threshold;

[0081] Furthermore, the current temperature change rate is lower than the temperature change rate threshold.

[0082] In practical applications, the values ​​of the preset flow range, preset temperature range, flow rate change threshold, and temperature change threshold are determined according to actual needs, and this invention does not impose any limitations on them.

[0083] Step S104: When the change amplitude is greater than the amplitude threshold, it is determined that urea over-spraying has occurred.

[0084] The value of the amplitude threshold is determined according to actual needs, and this invention does not limit it.

[0085] When the change in SCR efficiency is not greater than the amplitude threshold, it is determined that there will be no urea over-spraying phenomenon, and the urea over-spraying detection process is directly terminated.

[0086] In summary, this invention discloses a method for detecting urea over-injection. It determines the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate injector. When this time difference is less than a time difference threshold, the current operating condition of the engine is obtained. If this current operating condition meets preset steady-state conditions, the variation in SCR efficiency is obtained by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle. When this variation exceeds a threshold, urea over-injection is confirmed. This invention determines whether urea over-injection has occurred by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle during normal engine operation to obtain the variation in SCR efficiency. This allows for timely adjustments to urea injection, avoiding resource waste, reducing pollution, and optimizing the environment.

[0087] Based on the above discussion, it can be seen that after the DPF regeneration is completed in this embodiment, under the steady-state operating conditions of the engine (no drastic changes in exhaust temperature, exhaust flow rate, exhaust flow rate change rate, and exhaust temperature change rate), the original exhaust gas undergoes a step change. Based on the trend of the SCR efficiency of the after-processor changing with the original exhaust gas step change, it is possible to identify whether there is an over-injection of urea.

[0088] In practical applications, adjusting the engine's original emissions and the amount of urea injected by the urea nozzle includes:

[0089] (1) Increase the original engine emissions and the amount of urea injected from the urea nozzle;

[0090] (2) Reduce the original engine emissions and the amount of urea injected from the urea nozzle.

[0091] The magnitude of change in CR efficiency differs in these two cases.

[0092] Therefore, to further optimize the above embodiments, step S103 may specifically include:

[0093] 1) Increase the original emissions of the engine.

[0094] 2) The aftertreatment system is controlled to increase the amount of urea injected from the urea nozzle based on the ammonia-nitrogen ratio.

[0095] The ammonia-to-nitrogen ratio refers to the ratio of the mass of urea injected by the urea nozzle in the aftertreatment system to the mass of NH3 emitted by the engine.

[0096] In this embodiment, the original engine emissions and the urea emissions injected by the urea nozzle meet the preset ammonia-nitrogen ratio.

[0097] 3) Before and after the increase in original engine emissions and urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet. The change range includes the reduction magnitude.

[0098] Wherein, SCR efficiency = (original engine emissions - urea emissions) / original engine emissions.

[0099] In practical applications, first calculate the SCR efficiency before increasing the original engine emissions and urea emissions, then calculate the SCR efficiency after increasing the original engine emissions and urea emissions, and subtract the two SCR efficiencies to obtain the reduction in SCR efficiency.

[0100] Accordingly, step S104 may include:

[0101] When the reduction rate is greater than the reduction threshold, it is determined that urea over-spraying has occurred. The reduction threshold includes the magnitude threshold.

[0102] Therefore, to further optimize the above embodiments, step S103 may further include:

[0103] 1) Reduce the original emissions of the engine.

[0104] 2) The control post-treatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-nitrogen ratio.

[0105] In this embodiment, the original engine emissions and the urea emissions injected by the urea nozzle meet the preset ammonia-nitrogen ratio.

[0106] 3) Before and after the reduction of the original engine emissions and urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet. The change range includes the increase.

[0107] Wherein, SCR efficiency = (original engine emissions - urea emissions) / original engine emissions.

[0108] In practical applications, first calculate the SCR efficiency before reducing the original engine emissions and urea emissions, then calculate the SCR efficiency after reducing the original engine emissions and urea emissions, and subtract the two SCR efficiencies to obtain the increase in SCR efficiency.

[0109] Accordingly, step S104 may include:

[0110] When the increase exceeds the increase threshold, it is determined that urea over-spraying has occurred, where the increase threshold includes the increase threshold.

[0111] In practical applications, to improve the accuracy of detecting urea over-injection, the process of increasing the original engine emissions and the amount of urea injected from the urea nozzle can be combined with the process of decreasing the original engine emissions and the amount of urea injected from the urea nozzle. When both conditions are met, it is determined that urea over-injection has occurred.

[0112] Therefore, to further optimize the above embodiments, step S103 may further include:

[0113] 1) Increase the original engine emissions;

[0114] 2) The aftertreatment system is controlled to increase the amount of urea injected from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0115] 3) Before and after the increase in the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the reduction in SCR efficiency is obtained, wherein the change range includes the reduction range;

[0116] 4) When the reduction is greater than the reduction threshold, reduce the original engine emissions;

[0117] 5) The aftertreatment system is controlled to reduce the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0118] 6) Before and after the reduction of the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the increase in SCR efficiency is obtained, wherein the change range includes the increase.

[0119] Accordingly, step S104 may include:

[0120] When the increase exceeds the increase threshold, it is determined that urea over-spraying has occurred. The increase threshold includes a decrease threshold and an increase threshold.

[0121] To further optimize the above embodiments, step S103 may further include:

[0122] 1) Reduce the original emissions of the engine;

[0123] 2) The aftertreatment system controls the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0124] 3) Before and after the reduction of the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the increase in SCR efficiency is obtained, wherein the change range includes the increase range;

[0125] 4) When the increase exceeds the increase threshold, increase the original engine emissions;

[0126] 5) The aftertreatment system is controlled to increase the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0127] 6) Before and after the increase in the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the reduction in SCR efficiency is obtained, wherein the change range includes the reduction range;

[0128] Accordingly, step S104 may include:

[0129] When the decrease is greater than the decrease threshold, it is determined that urea over-spraying has occurred, wherein the decrease threshold includes the increase threshold and the decrease threshold.

[0130] In summary, this invention, during normal engine operation, adjusts the original engine emissions and the amount of urea injected by the urea nozzle to obtain the variation range of SCR efficiency, thereby determining whether urea over-injection has occurred. This allows for timely adjustments to urea injection, preventing resource waste, reducing pollution, and optimizing the environment.

[0131] Corresponding to the above method embodiments, the present invention also discloses a detection device for urea overspray.

[0132] See Figure 2 The present invention discloses a schematic diagram of a urea overspray detection device, which may include:

[0133] The time difference determination unit 201 is used to determine the time difference between the current running time of the engine and the last regeneration time of the diesel particulate collector.

[0134] The operating condition acquisition unit 202 is used to acquire the current operating condition of the engine when it is determined that the time difference is less than the time difference threshold.

[0135] The value of the time difference threshold is determined according to actual needs, such as 8 hours, but this invention does not limit it.

[0136] In practical applications, the current operating conditions of an engine include, but are not limited to, current exhaust flow rate, current exhaust temperature, current exhaust flow rate change rate, and current exhaust temperature change rate.

[0137] Therefore, the operating condition acquisition unit 202 can be specifically used for:

[0138] When the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector is less than the time threshold, the current exhaust flow rate, current exhaust temperature, current exhaust flow rate change rate, and current exhaust temperature change rate of the engine are obtained.

[0139] The engine's current exhaust flow rate and current exhaust temperature can be obtained directly.

[0140] The rate of change of the engine's current exhaust flow rate refers to the rate of change of the engine's current exhaust flow rate relative to the exhaust flow rate at the previous moment.

[0141] The current exhaust temperature change rate of an engine refers to the rate of change of the current temperature flow rate of the engine at the current moment relative to the temperature flow rate at the previous moment.

[0142] In this embodiment, when it is determined that the time difference between the current running time of the engine and the last regeneration time of the diesel particulate collector is not less than the time threshold, it is determined that there will be no urea over-injection phenomenon, and the urea over-injection detection process ends at this time.

[0143] The emission adjustment unit 203 is used to adjust the original emission of the engine and the emission of urea injected by the urea nozzle when it is determined that the current operating condition meets the preset steady-state conditions, so as to obtain the change range of selective catalytic reduction (SCR) efficiency.

[0144] Specifically, determining that the current operating condition meets the preset steady-state conditions may include:

[0145] Ensure the current exhaust flow rate is within the preset flow rate range;

[0146] Ensure the current exhaust temperature is within the preset temperature range;

[0147] Determine that the current exhaust flow rate change rate is lower than the flow rate change rate threshold;

[0148] Furthermore, the current temperature change rate is lower than the temperature change rate threshold.

[0149] In practical applications, the values ​​of the preset flow range, preset temperature range, flow rate change threshold, and temperature change threshold are determined according to actual needs, and this invention does not impose any limitations on them.

[0150] The over-spray determination unit 204 is used to determine that urea over-spraying has occurred when the change amplitude is greater than the amplitude threshold.

[0151] The value of the amplitude threshold is determined according to actual needs, and this invention does not limit it.

[0152] When the change in SCR efficiency is not greater than the amplitude threshold, it is determined that there will be no urea over-spraying phenomenon, and the urea over-spraying detection process is directly terminated.

[0153] In summary, this invention discloses a urea over-injection detection device. It determines the time difference between the current engine operating time and the last regeneration time of the diesel particulate injector. When this time difference is less than a time difference threshold, the current engine operating condition is obtained. If this current operating condition meets preset steady-state conditions, the change in SCR efficiency is obtained by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle. When this change exceeds a threshold, urea over-injection is confirmed. This invention determines whether urea over-injection has occurred by adjusting the engine's original emissions and the amount of urea injected from the urea nozzle during normal engine operation to obtain the change in SCR efficiency. This allows for timely adjustments to urea injection, avoiding resource waste, reducing pollution, and optimizing the environment.

[0154] Based on the above discussion, it can be seen that after the DPF regeneration is completed in this embodiment, under the steady-state operating conditions of the engine (no drastic changes in exhaust temperature, exhaust flow rate, exhaust flow rate change rate, and exhaust temperature change rate), the original exhaust gas undergoes a step change. Based on the trend of the SCR efficiency of the after-processor changing with the original exhaust gas step change, it is possible to identify whether there is an over-injection of urea.

[0155] In practical applications, adjusting the engine's original emissions and the amount of urea injected by the urea nozzle includes:

[0156] (1) Increase the original engine emissions and the amount of urea injected from the urea nozzle;

[0157] (2) Reduce the original engine emissions and the amount of urea injected from the urea nozzle.

[0158] The magnitude of change in CR efficiency differs in these two cases.

[0159] Therefore, to further optimize the above embodiments, the emission adjustment unit 203 can specifically be used for:

[0160] 1) Increase the original emissions of the engine.

[0161] 2) The aftertreatment system is controlled to increase the amount of urea injected from the urea nozzle based on the ammonia-nitrogen ratio.

[0162] The ammonia-to-nitrogen ratio refers to the ratio of the mass of urea injected by the urea nozzle in the aftertreatment system to the mass of NH3 emitted by the engine.

[0163] In this embodiment, the original engine emissions and the urea emissions injected by the urea nozzle meet the preset ammonia-nitrogen ratio.

[0164] 3) Before and after the increase in original engine emissions and urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet. The change range includes the reduction magnitude.

[0165] Wherein, SCR efficiency = (original engine emissions - urea emissions) / original engine emissions.

[0166] In practical applications, first calculate the SCR efficiency before increasing the original engine emissions and urea emissions, then calculate the SCR efficiency after increasing the original engine emissions and urea emissions, and subtract the two SCR efficiencies to obtain the reduction in SCR efficiency.

[0167] Accordingly, the overspray determination unit 204 can be specifically used for:

[0168] When the reduction rate is greater than the reduction threshold, it is determined that urea over-spraying has occurred. The reduction threshold includes the magnitude threshold.

[0169] To further optimize the above embodiments, the emission adjustment unit 203 can specifically be used for:

[0170] 1) Reduce the original emissions of the engine.

[0171] 2) The control post-treatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-nitrogen ratio.

[0172] In this embodiment, the original engine emissions and the urea emissions injected by the urea nozzle meet the preset ammonia-nitrogen ratio.

[0173] 3) Before and after the reduction of the original engine emissions and urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet. The change range includes the increase.

[0174] Wherein, SCR efficiency = (original engine emissions - urea emissions) / original engine emissions.

[0175] In practical applications, first calculate the SCR efficiency before reducing the original engine emissions and urea emissions, then calculate the SCR efficiency after reducing the original engine emissions and urea emissions, and subtract the two SCR efficiencies to obtain the increase in SCR efficiency.

[0176] Accordingly, the overspray determination unit 204 can be specifically used for:

[0177] When the increase exceeds the increase threshold, it is determined that urea over-spraying has occurred, where the increase threshold includes the increase threshold.

[0178] In practical applications, to improve the accuracy of detecting urea over-injection, the process of increasing the original engine emissions and the amount of urea injected from the urea nozzle can be combined with the process of decreasing the original engine emissions and the amount of urea injected from the urea nozzle. When both conditions are met, it is determined that urea over-injection has occurred.

[0179] Therefore, to further optimize the above embodiments, the emission adjustment unit 203 can specifically be used for:

[0180] 1) Increase the original engine emissions;

[0181] 2) The aftertreatment system is controlled to increase the amount of urea injected from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0182] 3) Before and after the increase in the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the reduction in SCR efficiency is obtained, wherein the change range includes the reduction range;

[0183] 4) When the reduction is greater than the reduction threshold, reduce the original engine emissions;

[0184] 5) The aftertreatment system is controlled to reduce the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0185] 6) Before and after the reduction of the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the increase in SCR efficiency is obtained, wherein the change range includes the increase.

[0186] Correspondingly, the overspray determination unit 204 can be specifically used for:

[0187] When the increase exceeds the increase threshold, it is determined that urea over-spraying has occurred. The increase threshold includes a decrease threshold and an increase threshold.

[0188] To further optimize the above embodiments, the emission adjustment unit 203 can specifically be used for:

[0189] 1) Reduce the original emissions of the engine;

[0190] 2) The aftertreatment system controls the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0191] 3) Before and after the reduction of the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the increase in SCR efficiency is obtained, wherein the change range includes the increase range;

[0192] 4) When the increase exceeds the increase threshold, increase the original engine emissions;

[0193] 5) The aftertreatment system is controlled to increase the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio;

[0194] 6) Before and after the increase in the original engine emissions and the urea emissions, based on the NOx at the engine outlet and the NOx at the SCR system outlet, the reduction in SCR efficiency is obtained, wherein the change range includes the reduction range;

[0195] Accordingly, the overspray determination unit 204 can be specifically used for:

[0196] When the decrease is greater than the decrease threshold, it is determined that urea over-spraying has occurred, wherein the decrease threshold includes the increase threshold and the decrease threshold.

[0197] In summary, this invention, during normal engine operation, adjusts the original engine emissions and the amount of urea injected by the urea nozzle to obtain the variation range of SCR efficiency, thereby determining whether urea over-injection has occurred. This allows for timely adjustments to urea injection, preventing resource waste, reducing pollution, and optimizing the environment.

[0198] Corresponding to the above embodiments, such as Figure 3 As shown, the present invention also provides an electronic device, which may include: a processor 1 and a memory 2;

[0199] The processor 1 and memory 2 communicate with each other via the communication bus 3.

[0200] Processor 1, for executing at least one instruction;

[0201] Memory 2 is used to store at least one instruction;

[0202] Processor 1 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention.

[0203] Memory 2 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0204] The processor executes at least one instruction to implement the detection process shown in the urea overspray detection method.

[0205] Corresponding to the above embodiments, the present invention also discloses a computer-readable storage medium that stores at least one instruction, which, when executed by a processor, implements the detection process shown in the method for detecting urea overspray.

[0206] In summary, this invention discloses an electronic device and a computer-readable storage medium that determines the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate filter. When this time difference is less than a time difference threshold, the current operating condition of the engine is obtained. If the current operating condition meets preset steady-state conditions, the variation range of SCR efficiency is obtained by adjusting the engine's original emissions and the amount of urea injected by the urea nozzle. When this variation range exceeds a threshold, urea over-injection is determined. This invention, during normal engine operation, determines whether urea over-injection has occurred by adjusting the engine's original emissions and the amount of urea injected by the urea nozzle to obtain the variation range of SCR efficiency. This allows for timely adjustments to urea injection, avoiding resource waste, reducing pollution, and optimizing the environment.

[0207] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0208] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0209] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for detecting urea overspray, characterized in that, include: Determine the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector; When it is determined that the time difference is less than the time difference threshold, the current operating condition of the engine is obtained; When it is determined that the current operating condition meets the preset steady-state conditions, the original engine emission and the urea emission from the urea nozzle are adjusted to obtain the change range of the selective catalytic reduction (SCR) efficiency. When the change exceeds the amplitude threshold, it is determined that urea over-spraying has occurred. The adjustment of the engine's original emissions and the amount of urea injected by the urea nozzle to obtain the change in the efficiency of selective catalytic reduction (SCR) technology includes: Increase the original emissions of the engine; The control aftertreatment system increases the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio; Before and after the increase in the original engine emissions and the urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the reduction range; When the reduction is greater than the reduction threshold, the original engine emissions of the engine are reduced. The control aftertreatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio; Before and after the reduction of the original engine emissions and the urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the increase. The determination that urea over-spraying has occurred when the change amplitude exceeds the amplitude threshold includes: When the increase is greater than the increase threshold, it is determined that urea over-spraying has occurred, wherein the increase threshold includes the decrease threshold and the increase threshold.

2. A method for detecting urea overspray, characterized in that, include: Determine the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector; When it is determined that the time difference is less than the time difference threshold, the current operating condition of the engine is obtained; When it is determined that the current operating condition meets the preset steady-state conditions, the original engine emission and the urea emission from the urea nozzle are adjusted to obtain the change range of the selective catalytic reduction (SCR) efficiency. When the change exceeds the amplitude threshold, it is determined that urea over-spraying has occurred. The adjustment of the engine's original emissions and the amount of urea injected by the urea nozzle to obtain the change in the efficiency of selective catalytic reduction (SCR) technology includes: Reduce the original emissions of the engine; The control aftertreatment system reduces the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio; Before and after the reduction of the original engine emissions and the urea emissions, the increase in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the increase. When the increase exceeds the increase threshold, the original engine emissions of the engine are increased; The control aftertreatment system increases the amount of urea emitted from the urea nozzle based on the ammonia-to-nitrogen ratio; Before and after the increase in the original engine emissions and the urea emissions, the reduction in SCR efficiency is obtained based on the NOx at the engine outlet and the NOx at the SCR system outlet, wherein the change range includes the reduction range; The determination that urea over-spraying has occurred when the change amplitude exceeds the amplitude threshold includes: When the decrease is greater than the decrease threshold, it is determined that urea over-spraying has occurred, wherein the decrease threshold includes the increase threshold and the decrease threshold.

3. The method for detecting urea overspray according to claim 1 or 2, characterized in that, The step of obtaining the current operating condition of the engine when it is determined that the time difference is less than a time difference threshold includes: When it is determined that the time difference is less than the time difference threshold, the current exhaust flow rate, current exhaust temperature, current exhaust flow rate change rate, and current exhaust temperature change rate of the engine are obtained. The current operating conditions include: the current exhaust flow rate, the current exhaust temperature, the current exhaust flow rate change rate, and the current exhaust temperature change rate.

4. The method for detecting urea overspray according to claim 3, characterized in that, Determining that the current operating condition meets the preset steady-state conditions includes: The current exhaust flow rate is determined to be within the preset flow rate range; The current exhaust temperature is determined to be within a preset temperature range; It is determined that the current exhaust flow rate change rate is lower than the flow rate change rate threshold; Furthermore, it is determined that the current temperature change rate is lower than the temperature change rate threshold.

5. A device for detecting urea overspray, used to perform the method according to any one of claims 1-4, characterized in that, include: The time difference determination unit is used to determine the time difference between the current operating time of the engine and the last regeneration time of the diesel particulate collector; The operating condition acquisition unit is used to acquire the current operating condition of the engine when it is determined that the time difference is less than the time difference threshold. The emission adjustment unit is used to adjust the original engine emission and the urea emission from the urea nozzle when it is determined that the current operating condition meets the preset steady-state conditions, so as to obtain the change range of selective catalytic reduction (SCR) efficiency. The over-spray determination unit is used to determine that urea over-spraying has occurred when the change amplitude is greater than the amplitude threshold.

6. An electronic device, characterized in that, The electronic device includes: a memory and a processor; The memory is used to store at least one instruction; The processor is used to execute at least one instruction to implement the urea overspray detection method as described in any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which, when executed by a processor, implements the urea overspray detection method as described in any one of claims 1 to 4.

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