85 results about "Nitrogen oxide sensor" patented technology

The invention provides a method for rapidly detecting the content of nitrogen oxides in air. The method comprises the following steps: acquiring original signal data of nitrogen oxides in air in a target detection area in real time through a plurality of nitrogen oxide sensors; performing noise reduction filtering processing on the original signal data to generate target signal data; performing signal drift compensation correction on the target signal data based on a preset sensor calibration model to generate standardized concentration data; performing space-time correlation analysis on the standardized concentration data through a nitrogen oxide concentration prediction algorithm model in combination with environment parameter data collected in real time to generate a target prediction concentration value; and comparing the target predicted concentration value with a preset concentration standard threshold value based on a fuzzy logic judgment algorithm, and constructing a detection report. The whole process from data acquisition to report generation is intelligent, and the detection flexibility is remarkably improved.

A system, method, and apparatus for detecting sensor tampering are provided. An aftertreatment system includes a first train having a first selective catalytic reduction (SCR) system, a first doser, and a first NOx sensor; a second train having a second SCR system, a second doser, and a second NOx sensor; and a controller. The controller determines satisfaction of activation conditions. The controller doses reductant to the first and second SCR systems. The controller determines the NOx levels of the first SCR system and the second SCR system. The controller adjusts the dosing of the first SCR system for a period of time. The controller measures the NOx levels of the first SCR system and the second SCR system. The controller determines a difference between the third and first NOx levels and a difference between the fourth and second NOx levels.The control generates an indication as to whether the first NOx sensor is displaced.

The invention discloses a nitrogen oxide sensor verification method and device and an engine. Whether a nitrogen oxide sensor has an untrusted fault or not can be judged in time. The nitrogen oxide sensor verification method comprises the following steps: when an oxygen concentration value measured by a target nitrogen oxide sensor is abnormal and oxygen concentration values measured by other nitrogen oxide sensors are normal, triggering a mutual verification mechanism; based on the mutual verification mechanism, calculating an oxygen concentration average value of the target nitrogen oxide sensor and all oxygen concentration average values of all nitrogen oxide sensors; when the absolute value of the difference value between the average oxygen concentration value and the average value of all the oxygen concentrations is larger than a preset threshold value, prompt information about the untrusted fault of the target nitrogen oxide sensor is sent out.

The application discloses a nitrogen oxide sensor signal detection method and device and a nitrogen oxide sensor. The method comprises the following steps: obtaining a plurality of first nitrogen oxide concentrations and a plurality of second nitrogen oxide concentrations after determining that an engine is started, wherein the first nitrogen oxide concentration is simulated by a nitrogen oxide signal simulator based on an adjusted nitrogen oxide signal, the second nitrogen oxide concentration is calculated by an electronic controller of the engine, and the nitrogen oxide sensor is used for detecting the concentration of nitrogen oxide in exhaust gas emitted by the engine; determining a correlation value and a characteristic value of the plurality of first nitrogen oxide concentrations and the plurality of second nitrogen oxide concentrations; and determining whether the nitrogen oxide signal sent by the nitrogen oxide sensor to the engine is abnormal based on the correlation value and the characteristic value. The application solves the technical problem that the related art cannot effectively determine whether the NOx sensor signal is tampered with, thereby reducing the reliability of the engine.

The application belongs to the field of automobile exhaust aftertreatment, and particularly relates to a two-dimensional calibration method for output results of a nitrogen oxide sensor, comprising the following steps: constructing a ratio table between accurate nitrogen oxide concentration values and corresponding nitrogen oxide concentration test values under different oxygen concentration and nitrogen oxide concentration environments, taking the oxygen concentration and the nitrogen oxide concentration test values as indexes of oxygen concentration and nitrogen oxide concentration in the ratio table respectively, determining the ratio, and correcting the nitrogen oxide concentration test values; constructing a ratio table between accurate oxygen concentration values and corresponding oxygen concentration test values under different second chamber pump currents Ip1 and different oxygen concentration environments, taking the current Ip1 corresponding to the oxygen concentration test value and the oxygen concentration test value as indexes of Ip1 and oxygen concentration in the ratio table respectively, determining the ratio, and correcting the oxygen concentration test values; and finally setting a control target parameter of Ip1 in dynamic control of the nitrogen oxide sensor, and applying the ratio table to the output of the nitrogen oxide sensor. The application can improve the measurement accuracy of the sensor and accelerate dynamic response tracking.

The present invention discloses an industrial furnace flue gas denitrification and heat recovery device, which relates to the field of flue gas treatment technology and includes a denitrification reactor, an air preheater, a multi-stage catalyst, a soot blowing mechanism, an ammonia generator, a reflux pipe, and a switching plate. The present invention provides a reflux pipe and a switching plate, and monitors the emission content of nitrogen oxides at the smoke outlet of the denitrification reactor through a nitrogen oxide sensor, so that the switching plate can control the connection between the reflux pipe and the smoke outlet of the denitrification reactor according to the emission content of nitrogen oxides, so as to control the emission content of nitrogen oxides in the flue gas and improve the emission standard. The present invention provides a multi-stage catalyst and provides a soot blowing mechanism above the multi-stage catalyst to perform steam soot blowing treatment on the multi-stage catalyst, so as to reduce the problem of ash accumulation in the flue gas blocking the catalyst passage, thereby affecting the catalytic efficiency, and improve the catalytic efficiency of the catalyst.

The present invention relates to a nitrogen oxide sensor fault diagnosis method, device, electronic device, and medium, belonging to the field of automotive technology. The method comprises: obtaining a target nitrogen oxide sensor's transition time from a lean oxygen mode to a rich oxygen mode, and obtaining the number of times the target nitrogen oxide sensor transitions from the lean oxygen mode to the rich oxygen mode, upon determining that the target nitrogen oxide sensor exceeds a dew point, determining that the target nitrogen oxide sensor's oxygen concentration is enabled, determining that the engine is in a normal combustion mode, and determining that the engine exhaust flow rate is greater than a first threshold; and determining whether the target nitrogen oxide sensor is faulty based on the transition time and the number of times the target nitrogen oxide sensor transitions from the lean oxygen mode to the rich oxygen mode. The present invention defines an operating condition suitable for sensor diagnosis, and when the engine enters this operating condition, performs nitrogen oxide sensor fault diagnosis based on the minimum transition time from the lean oxygen mode to the rich oxygen mode, thereby improving the accuracy of nitrogen oxide sensor fault diagnosis.

The invention discloses a nitrogen-oxygen sensor protocol adaptive detection device and method based on machine learning, and relates to the technical field of vehicle emission control. The equipment comprises an upper computer, a CAN (Controller Area Network) communication module, IO (Input / Output) equipment and a controllable power supply module, according to the method, precise matching of protocols is achieved through a three-layer cascade decision-making architecture based on a random forest classifier, stable communication is established in combination with automatic baud rate detection, and distinguishing detection and initialization of front and rear nitrogen oxygen sensors are achieved through dynamic pin state control and power-on and power-off management. And meanwhile, the system has comprehensive data extraction, real-time display and fault diagnosis optimization functions. The method solves the problems of low protocol matching accuracy, insufficient dynamic detection capability, incomplete data extraction, tedious operation, poor system adaptability and the like in the prior art, and has the advantages of high accuracy, strong adaptive capability, high automation degree, good compatibility and the like.

The application provides a method for detecting ammonia leakage of a three-way catalyst, related devices and electronic equipment. The method comprises: obtaining oxygen concentration data in a window, wherein the vehicle is in a steady state condition, and the oxygen concentration data detected by the nitrogen oxide sensor is greater than a preset value; determining whether the time proportion of the oxygen concentration data being less than a first threshold value in the window is greater than a second threshold value, and whether the oxygen concentration distribution is less than a third threshold value; determining that the three-way catalyst has ammonia leakage when the time proportion is greater than the second threshold value and the oxygen concentration distribution is less than the third threshold value; and determining that the three-way catalyst does not have ammonia leakage when the time proportion is less than or equal to the second threshold value or the oxygen concentration distribution is greater than or equal to the third threshold value. The application solves the problem that ammonia leakage in the three-way catalyst cannot be accurately identified in the prior art.

In a method for determining nitrogen oxides and ammonia in the exhaust gas of a vehicle equipped with a nitrogen oxide sensor, measured values ​​from the sensor are received. It is determined whether the measured values ​​show an increasing trend. If so, a lambda value is used to determine whether the sensor readings are representative of nitrogen oxides in the exhaust gas or of ammonia in the exhaust gas. Further measured values ​​from the nitrogen oxide sensor are then assigned to either nitrogen oxides or ammonia, based on the previous determination, until a predefined termination condition is met.Furthermore, an information signal is sent which includes information on whether the further measured values ​​of the nitrogen oxide sensor are still to be attributed to nitrogen oxides or ammonia.

The invention discloses a parameter correction system and method for low emission. The system comprises a gas machine aftertreatment device and an electric control unit. The gas machine post-treatment device comprises a first three-way catalyst converter, a second three-way catalyst converter and a particle trap; a temperature sensor is arranged between the first three-way catalyst converter and the second three-way catalyst converter, and a nitrogen oxide sensor is arranged between the second three-way catalyst converter and the particle trap; the temperature sensor and the nitrogen oxide sensor are electrically connected with the electric control unit respectively; the gas machine post-processing device is used for acquiring a first temperature and an actual oxygen concentration through a temperature sensor and a nitrogen oxide sensor and sending the first temperature and the actual oxygen concentration to the electric control unit; and the electronic control unit is used for correcting the original engine parameters of the engine and the sensor value of the nitrogen oxide sensor based on the first temperature and the actual oxygen concentration so as to optimize the performance and the fuel efficiency of the engine. According to the invention, the accuracy of emission control and the reliability of the system can be improved.

In a method for determining nitrogen oxides and ammonia in the exhaust gas of a vehicle equipped with a nitrogen oxide sensor, a lambda signal is received, and a lambda value is determined based on the lambda signal. This lambda value is representative of the vehicle's air-fuel ratio. Depending on the lambda value, it is determined whether the measured value from the nitrogen oxide sensor is representative of nitrogen oxides in the exhaust gas or whether it is representative of ammonia in the exhaust gas. If the measured value is determined to be representative of ammonia in the exhaust gas, the mass flow rate of the exhaust gas is calculated. Based on the mass flow rate and the lambda value, a nitrogen oxide fraction factor is determined for the measured value. Based on the nitrogen oxide fraction factor, the nitrogen oxide fraction and the ammonia fraction of the measured value are then determined.An information signal is sent that includes information about the nitrogen oxide content of the measured value and the ammonia content of the measured value.

The utility model discloses a tail gas treatment device for nitrogen oxide emission, and relates to the field of tail gas treatment devices for nitrogen oxide emission. The tail gas treatment device for nitrogen oxide emission comprises a tail gas pipeline, a nitrogen oxide storage catalyst, a particulate matter catcher and a selective catalytic reduction catalyst are arranged on the tail gas pipeline, an upstream oxygen sensor is arranged on the upstream of the nitrogen oxide storage catalyst, and a nitrogen-oxygen sensor is arranged on the downstream of the nitrogen oxide storage catalyst. According to the tail gas treatment device for nitrogen oxide emission, a downstream oxygen sensor is omitted at the downstream of the nitrogen oxide storage catalyst, an original nitrogen-oxygen sensor on a vehicle is used for detecting the oxygen concentration and confirming whether regeneration is finished or not, and the nitrogen-oxygen sensor is used for replacing the downstream oxygen sensor, so that the target of replacing the oxygen sensor with a single sensor is achieved; meanwhile, the function of the nitrogen-oxygen sensor is upgraded, and technical reserve is provided for subsequent emission upgrading.

The invention provides a urea injection control method for tail gas after-treatment of an extended-range lean-burn engine, which comprises the following steps: after a tail gas after-treatment system of the extended-range lean-burn engine is powered on and runs, starting a urea system to build pressure, and building the pressure of a urea pump to a first level; working condition parameters of the lean-burn engine are obtained, and an actual nitrogen-oxygen error e is calculated; constructing a feature vector X describing the current working condition of the engine according to the working condition parameters of the lean-burn engine and the actual nitrogen-oxygen error e, and inputting the feature vector X into the three-layer BP back-propagation neural network to obtain dynamically adjusted control parameters; determining a PID basic correction coefficient CPID based on the control parameter and the actual nitrogen-oxygen error e; performing long-term stability compensation on the basic correction coefficient CPID by fusing a temperature-time function to obtain a fusion correction coefficient C; and finally, according to the fusion correction coefficient C and the basic injection amount, the urea injection amount is dynamically adjusted in a zoning mode in combination with nitrogen and oxygen concentration data collected by a nitrogen and oxygen sensor, accurate control is achieved, and the balance between environmental protection standard reaching and fuel economy is achieved.

This application discloses an aftertreatment system, method, and vehicle that can achieve lower emissions while maintaining a substantially unchanged aftertreatment installation space. The aftertreatment system includes: a first nitrogen oxide (NOx) treatment device for reducing NOx and oxidizing and removing it with ammonia; a particulate matter treatment device for capturing particulate matter and catalytically generating nitrogen dioxide; a second NOx treatment device for reducing NOx and oxidizing and removing it with ammonia; a urea nozzle for injecting urea; a temperature sensor for detecting temperature; and a NOx sensor for detecting NOx concentration.

In a method for determining nitrogen oxides and ammonia in the exhaust gas of a vehicle, the vehicle having a nitrogen oxide sensor, measured values of the nitrogen oxide sensor are received. It is determined whether the measured values have an increasing curve. If the measured values have an increasing curve, a lambda value is taken as the basis for determining whether the measured values of the nitrogen oxide sensor are representative of nitrogen oxides in the exhaust gas or whether the measured values of the nitrogen oxide sensor are representative of ammonia in the exhaust gas. Furthermore, until a specified termination condition is met, additional measured values of the nitrogen oxide sensor are assigned to nitrogen oxides or ammonia according to the previous determination as to whether the measured values of the nitrogen oxide sensor are representative of nitrogen oxides in the exhaust gas or whether the measured values of the nitrogen oxide sensor are representative of ammonia in the exhaust gas, and an information signal is transmitted which comprises information as to whether the additional measured values of the nitrogen oxide sensor continue to be assigned to nitrogen oxides or ammonia.

An exhaust pipe discharges exhaust gas discharged from a hydrogen engine to the outside of a vehicle. An exhaust purification device reduces nitrogen oxides contained in the exhaust gas. A nitrogen oxide sensor acquires a measurement value that reflects the concentration of the nitrogen oxides contained in the exhaust gas, and outputs an output value that is a value that is larger the more the amount of moisture contained in the exhaust gas is subtracted from the measurement value. An injector injects urea water to the exhaust purification device. A control device causes the injector to inject an amount of urea water determined in accordance with the output value and the flow rate of the exhaust gas, in a case where the output value is a predetermined value or more. The control device causes the injector to inject an amount of urea water determined in accordance with the predetermined value and the flow rate of the exhaust gas, in a case where the output value is less than the predetermined value.

The application relates to a nitrogen oxide sensor based on Ag2Te / CeO2 sensitive material, a preparation method and a plant internet environment monitoring system, and belongs to the technical field of semiconductor gas sensors. The sensor is composed of an Al2O3 ceramic tube substrate with parallel and mutually independent annular gold electrodes at two ends of an outer surface, Ag2Te / CeO2 sensitive material coated on the outer surface of the Al2O3 ceramic tube substrate and the gold electrodes, and a nickel-chromium heating coil arranged in the Al2O3 ceramic tube substrate; the Ag2Te / CeO2 sensitive material can effectively promote the adsorption of nitrogen oxide molecules at low temperature and enhance the response; in addition, the hollow roll structure formed after the Ag2Te and CeO2 are compounded and the introduction of n-n heterojunction are also beneficial to the response of the sensor. The application combines the sensor with internet of things equipment and internet services, develops a plant internet environment monitoring system, and therefore has important application value for the construction of intelligent agriculture.

The utility model relates to the technical field of nitrogen-oxygen sensors, in particular to a nitrogen-oxygen sensor with gas inlet protection, which comprises a nitrogen-oxygen sensor body, a gas inlet protection device, a gas inlet protection device and a gas outlet protection device, the sleeve sleeves the gas inlet end of the nitrogen-oxygen sensor body, and a slot is formed in the outer wall of the sleeve in a penetrating manner; the driving ring is rotationally arranged on the sleeve in a sleeving manner; the elastic block is fixed on the driving ring and can be inserted into the sleeve through the slot; the lap joint block is fixed on the inner wall of the sleeve and is staggered from the slot in position; and the filter screen is arranged between the lap joint block and the slot and can be limited by the lap joint block and the elastic block. The device has the effect that the filter screen is convenient to disassemble and replace.

Concentration determination device of a cleaning system (301), wherein the cleaning system (301) comprises: an SCR catalyst (4) which is arranged in an exhaust pipe of an internal combustion engine to clean NOx in the exhaust gas of the internal combustion engine; a reducing agent supply unit (5; 302), which is provided and is arranged to supply urea or ammonia as a reducing agent to the SCR catalyst (4); an ammonia sensor (202) which is provided and arranged to detect an ammonia concentration of the exhaust gas flowing out of the SCR catalyst (4) as a downstream ammonia concentration; and a NOx sensor (201) which is provided and arranged to detect a NOx concentration of the exhaust gas flowing out of the SCR catalyst (4) as a downstream NOx concentration; wherein the concentration determination device is configured to determine a value of the downstream ammonia concentration based on a detection result of the ammonia sensor (202), characterized in that the concentration determination device comprises: a feed control section (S2, S30; S10, S35) which controls the reducing agent feed unit (5; 302) to supply the reducing agent to the SCR catalyst in a fuel-free state in which the supply of fuel to the combustion engine is stopped; a feed correction section (S50 to S120) which corrects the determined value of the downstream ammonia concentration based on a detection result of the NOx sensor (201) and an oxygen concentration of the exhaust gas after the feed of the reducing agent to the SCR catalyst (4) with the control of the reducing agent feed unit (5; 302) by the Feed correction section (S2, S30; S10, S35), wherein the concentration determination device converts the detection result of the ammonia sensor (202) into an ammonia concentration value according to an ammonia concentration correction formula which represents a relationship between first and second converted ammonia concentrations, wherein the first converted ammonia concentration is a value calculated according to a relationship formula between the detection result of the ammonia sensor (202) and the ammonia concentration of the exhaust gas, and the second converted ammonia concentration is a value calculated from the NOx sensor (201) detection result and the oxygen concentration of the exhaust gas, and wherein the concentration determination device determines the ammonia concentration value as the downstream ammonia concentration; and wherein the feed correction section (S2, S30; S10, S35) corrects the determined value of the downstream ammonia concentration by updating the ammonia concentration correction formula, wherein the ammonia concentration correction formula in a two-dimensional coordinate system, in which the ammonia concentration converted from the electromotive force is plotted along the x-axis and the ammonia concentration converted from the NOx output is plotted along the y-axis, represents a straight line in the two-dimensional coordinate system among several most recently stored, connects a maximum coordinate point and a minimum coordinate point with the output values ​​obtained from the gas sensor (201, 202).

This application discloses a parameter correction system and method for low emissions. The system includes: a gas engine aftertreatment device and an electronic control unit (ECU). The gas engine aftertreatment device includes a first three-way catalytic converter, a second three-way catalytic converter, and a particulate filter. A temperature sensor is disposed between the first and second three-way catalytic converters, and a nitrogen oxide (NOx) sensor is disposed between the second three-way catalytic converter and the particulate filter. The temperature sensor and the NOx sensor are electrically connected to the ECU. The gas engine aftertreatment device is used to acquire a first temperature and an actual oxygen concentration through the temperature sensor and the NOx sensor, and send them to the ECU. The ECU is used to correct the original engine parameters and the NOx sensor values ​​based on the first temperature and the actual oxygen concentration to optimize engine performance and fuel efficiency. Using this application can improve the accuracy of emission control and the reliability of the system.

The present invention provides a selective catalytic conversion correction method and system, belonging to the field of vehicle energy conservation and emission reduction calculation. The method includes: obtaining the correction amount of the nitrogen oxide sensor according to the HC injection flow rate and the oxygen concentration at the engine outlet, taking the sum of the measured value and the correction amount as the true measured value of this nitrogen oxide sensor, taking the product of the true measured value, the exhaust gas flow rate and the conversion coefficient as the theoretical NH3 injection amount, determining the open-loop set conversion efficiency according to the space velocity and temperature of the selective catalytic conversion device, and taking the product of the open-loop set conversion efficiency, the efficiency correction coefficient based on the temperature of the selective catalytic conversion device, the correction coefficient based on the HC injection amount and the theoretical NH3 injection amount as the final NH3 injection amount; the present invention corrects the NOx sensor by the input HC amount to obtain the correct input NOx concentration, and then corrects the current set efficiency by the HC amount, ensuring the accuracy of NOx control.

The application discloses a modeling method for a nitrogen oxygen sensor NOx pump unit, and belongs to the field of automobile sensors. The method comprises the following steps: considering the reduction reaction of NO and O2 on an electrode to establish an electrochemical sub-model of the NOx pump unit, wherein the electrochemical sub-model comprises Nernst voltage, cathode and anode concentration loss, cathode and anode activation loss and Ohm loss; considering gas diffusion and early decomposition of NO in a second chamber to establish a gas diffusion sub-model of the NOx pump unit, wherein the gas diffusion sub-model comprises diffusion of gas in a diffusion channel and diffusion of gas in the electrode; combining the electrochemical sub-model and the gas diffusion sub-model through a limiting current to obtain a combined model, and the combined model is used for parameter setting and working control of the nitrogen oxygen sensor. Through the combined model which considers all characteristics in the pump unit and eliminates the intermediate variable of gas concentration, the precision and calculation speed of the sensor model are improved.

A diesel engine system (101) for an agricultural machine (100) includes a diesel internal combustion engine (ICE) (201) configured to combust fossil diesel fuel and alternative diesel fuel, a knock sensor (213) integrated in the diesel internal combustion engine (201), a NOx sensor (209) and an electronic control unit (210). The electronic control unit (210) is configured to receive a knocking signal from the knock sensor (213), receive a NOx concentration signal from the NOx sensor (209), determine a fuel specific characteristic value based on the knocking signal and the NOx concentration signal, determine a fuel specific reference value, compare the fuel specific characteristic value with the fuel specific reference value, and determine whether the combusted diesel fuel is fossil diesel fuel or alternative diesel fuel.

An engine control system includes one or more oxygen (O2) sensors disposed proximate to a three-way catalytic converter (TWC) in an exhaust system of the vehicle, a nitrogen oxides (NOx) sensor configured to measure an NOx level of the exhaust gas downstream of the TWC, and a controller. The controller is programmed to determine a downstream O2 sensor control error, compare the O2 sensor control error to a predetermined threshold voltage, enable an NOx control logic if the O2 sensor control error is less than the predetermined threshold voltage, monitor the NOx sensor and integrate a measured NOx concentration for a predetermined time threshold or NOx flow threshold, determine a lambda compensation based on the integrated NOx concentration, and adjust an air / fuel ratio of the engine based on the lambda compensation to reduce NOx breakthrough.

This prevents the deterioration of exhaust emissions when the engine restarts after intermittent shutdown. [Solution] An engine system comprising an upstream catalyst and a downstream catalyst, which are three-way catalysts having oxygen storage capacity; an air-fuel ratio sensor provided between the two catalysts; a NOx sensor provided downstream of the downstream catalyst; and a control device that controls the engine so that the air-fuel ratio becomes a target air-fuel ratio, wherein the control device includes a first candidate calculation unit that calculates a first candidate for a return target air-fuel ratio used for return control from intermittent stop based on the air-fuel ratio detected by the air-fuel ratio sensor during intermittent stop of the engine; an oxygen concentration calculation unit that calculates an oxygen concentration based on the pump cell current of the NOx sensor during the intermittent stop; a second candidate calculation unit that calculates a second candidate for the return target air-fuel ratio based on the oxygen concentration; and a setting unit that sets a final return target air-fuel ratio used for the return control, taking into consideration the first candidate and the second candidate.

The utility model provides a nitrogen oxide sensor ceramic chip, a nitrogen oxide sensor and a vehicle, belongs to the field of vehicle tail gas measurement, and solves the problem that gas is not further buffered when entering a third cavity from a second cavity, so that the measurement precision is reduced. The nitrogen oxide sensor ceramic chip comprises a chip body, a main pump oxygen electrode, an auxiliary pump oxygen electrode and a measuring electrode, a first cavity, a second cavity and a third cavity are formed in the chip body, the first cavity and the second cavity are arranged in a spaced mode in the first direction, the second cavity and the third cavity are arranged in a spaced mode in the second direction, and the first direction is perpendicular to the second direction; one end of the first cavity is communicated with the inlet of the chip body, and the other end is communicated with the second cavity; in the second direction, the second cavity is communicated with the third cavity, the main pump oxygen electrode is arranged in the first cavity, the auxiliary pump oxygen electrode is arranged in the second cavity, and the measuring electrode is arranged in the third cavity. To-be-measured gas entering the third cavity can be buffered, and the measurement precision is improved.

This application discloses a fault detection method, device, and electronic equipment for an SCR system. The method includes: determining the volume of urea consumed within a preset time period based on a urea tank level sensor; determining a first mass of urea consumed within the preset time period based on the consumed volume and a preset density value of urea; determining a second mass of urea consumed based on the urea injection rate of the urea nozzle within the preset time period; determining a third mass of urea consumed based on the upstream and downstream nitrogen oxide consumption monitored by a nitrogen oxide sensor within the preset time period; determining whether there is a faulty mass among the first, second, and third masses of urea consumed; if the first mass of urea consumed is a faulty mass, determining that the urea tank level sensor has failed; if the second or third mass of urea consumed is a faulty mass, determining that the urea nozzle has failed. This application improves the accuracy of SCR system fault self-diagnosis, accurately locates faults, and facilitates fault troubleshooting and maintenance.

The invention relates to a method for performing a diagnosis of a nitrogen oxide sensor arranged in the exhaust system of a spark-ignition internal combustion engine of a motor vehicle, in particular a P2 hybrid vehicle. The method determines the current engine speed when the release conditions for the diagnosis are met and it is determined that the vehicle's accelerator pedal has been depressed. From a characteristic curve stored in an electronic computing unit, a minimum overrun time required for performing the diagnosis is calculated for the determined current engine speed. The current vehicle speed is also determined. Depending on the determined minimum overrun time and the determined current vehicle speed, an actual value is read from a characteristic map stored in the electronic computing unit.Then, when the actual value matches a target value, the internal combustion engine is operated in an unfired overrun mode, and the diagnosis is carried out during the unfired overrun mode.