A method and apparatus for rack rapid aging of catalytic converters

Abstract

The application provides a method and device for quick aging of a catalytic converter on a test bench, which controls engine cylinder-specific air-fuel ratios by an ECU, and makes the catalytic converter aged under first exhaust temperature conditions by alternating rich and lean air-fuel ratios, so that the OSC data and the emission conversion efficiency data of the catalytic converter reach preset targets. The application realizes alternating rich and lean air-fuel ratios by activating cylinder-specific air-fuel ratio control, and further increases the thermal load of the catalytic converter, strengthens the aging process, shortens the aging time, and does not need to install an additional secondary air supply system on the device during the aging process as in the prior art, so that the test cost can be reduced and the test risk can be lowered.

Description

Technical Field

[0001] This invention relates to the technical field of testing devices and methods for vehicle-related components, specifically to a method and apparatus for rapid bench aging of a catalyst. Background Technology

[0002] Faced with worsening environmental problems and increasingly stringent emission regulations, the three-way catalytic converter, with its high conversion efficiency for major pollutants from gasoline engines, has become an important measure to reduce vehicle emissions. However, the performance of the three-way catalytic converter gradually deteriorates with increased use, leading to a decrease in conversion efficiency and an increase in vehicle exhaust emissions. According to the national emission regulations for light-duty gasoline vehicles, the durability requirements for pollutant control devices stipulate that a whole-vehicle testing method involves running the device on roads or a chassis dynamometer for 200,000 kilometers to certify its durability. The whole-vehicle testing method is time-consuming, costly, and carries significant testing risks.

[0003] Research has revealed that thermal aging is the primary cause of decreased catalyst conversion efficiency. By applying the Arrhenius equation relating thermal aging to catalyst lifespan, bench aging can achieve the same aging process as vehicle dynamometer or road durability tests. Bench aging of the catalyst involves a higher thermal load, significantly reducing the aging time.

[0004] Invention Patent Content

[0005] This invention provides a method for rapidly aging a catalyst on a test bench, aiming to clone an aging catalyst equivalent to that produced during chassis dynamometer or road testing of a complete vehicle. The aging catalyst is an important tool in the engine matching and calibration process. The aging catalyst produced by this invention can be used for emission durability calibration and verification in project development, as well as OBD diagnostic calibration of the aging catalyst. The objective of this invention is achieved through the following technical solutions:

[0006] This invention provides a method for rapid bench aging of a catalyst, which uses an ECU to control the air-fuel ratio of each cylinder of the engine on a bench, and uses alternating rich and light fuel injection to age the catalyst under the first exhaust temperature condition until the OSC data (i.e., the oxygen storage capacity of the catalyst, usually characterized by oxygen storage amount) and emission conversion efficiency data both reach the preset target.

[0007] Specifically, the method includes the following steps:

[0008] Step S100: Determine the baseline maximum exhaust temperature operating condition when the engine does not enter the enrichment protection zone based on universal characteristics;

[0009] Step S200: Start the engine and adjust the engine operating conditions to the baseline maximum exhaust temperature condition determined in step S100;

[0010] Step S300: Activate the engine's air-fuel ratio cylinder control through the ECU and set the air-fuel ratio richness distribution coefficient so that the catalyst center temperature is at the first exhaust temperature condition, and stably run the aging process of the catalyst under the first exhaust temperature condition.

[0011] Step 400: When aging reaches the preset time node, start acquiring OSC data and emission conversion efficiency data until the current OSC value and emission conversion rate both reach the preset target to complete aging.

[0012] Furthermore, in the first exhaust temperature condition, the catalyst center temperature T satisfies Tmax-10℃<T<Tmax, where Tmax is the catalyst's tolerance limit temperature.

[0013] Furthermore, the air-fuel ratio richness / leanness distribution coefficient ranges from 0.05 to 0.15. The setting of the air-fuel ratio richness / leanness distribution coefficient is based on the catalytic converter's tolerance limit temperature, while also ensuring stable engine operation without misfires or vibrations. Under the premise of not damaging engine components and ensuring stable operation, a higher air-fuel ratio richness / leanness distribution coefficient results in higher engine exhaust temperatures and a shorter aging time required to approach the tolerance limit temperature. Taking a four-cylinder engine as an example, after activating the cylinder-to-cylinder air-fuel ratio distribution, two cylinders will exhibit a rich air-fuel ratio and two lean air-fuel ratios: if the distribution coefficient is set to 0.1, the excess air coefficient of two cylinders will be 0.9, and the excess air coefficient of the other two cylinders will be 1.1, thus achieving alternating rich and lean air-fuel ratio changes. Different engines have different performance parameters and calibrations, and the air-fuel ratio richness / leanness distribution setting value will also vary, needing to be determined based on the actual operating conditions of the engine. This invention sets it to 0.05–0.15 based on empirical values, which typically allows for efficient and high-quality completion of the aging process within this range.

[0014] Furthermore, in step S400, the method for generating the current OSC value includes continuously collecting multiple OSC values, counting the number of OSC collections, and when the count reaches a preset counting threshold, calculating the average of the multiple counted OSC values ​​to obtain the current OSC value.

[0015] Furthermore, step S300 specifically includes the following steps:

[0016] Step S301 - Activate the engine's air-fuel ratio cylinder control via ECU;

[0017] Step S302 - Set the air-fuel ratio distribution coefficient and keep the engine running;

[0018] Step S303 - Read the catalyst center temperature T;

[0019] Step S304 - Determine whether the catalyst center temperature T is under the first exhaust temperature condition. If the determination result is yes, otherwise return to step S302 and reset the air-fuel ratio distribution coefficient. If the determination result is yes, then continue to run the engine under the current condition to enter the aging process of the catalyst.

[0020] Furthermore, step S400 specifically includes the following steps:

[0021] Step S401 - Determine whether the engine operating condition is within the OSC calculation window. If the determination result is yes, proceed to step S402. If the determination result is no, return to step S304 to continue aging. Here, the OSC calculation window is determined by the calibration data. When certain speed, load, gear, exhaust flow, etc. are met for a period of time, the engine can enter the OSC calculation window.

[0022] Step S402 - Collect OSC values ​​at a preset frequency and count the number of collected OSC values. When the count reaches a preset counting threshold, proceed to step S403.

[0023] Step S403 - Calculate the average value of multiple OSC values ​​within the current counting period as the current OSC value, and simultaneously obtain the current exhaust gas emission conversion efficiency;

[0024] Step S404 - Determine whether the aging endpoint has been reached based on the current OSC value and exhaust gas emission conversion efficiency calculated in step S403; if the determination result is yes, then end the aging process; otherwise, return to step S402 to collect the OSC and exhaust gas emission conversion efficiency calculation for the next cycle.

[0025] The present invention further provides an apparatus for rapid bench aging of a catalyst, comprising a controller, an engine, a sensor assembly, and an emissions analyzer. The engine is equipped with the catalyst, and the emissions analyzer is used to monitor exhaust emissions filtered by the catalyst and generate emissions conversion efficiency data. The controller is connected to the vehicle ECU, and the ECU is used to activate the engine's cylinder air-fuel ratio control and monitor OSC data. The controller is used to receive detection signals transmitted by the sensor assembly, OSC data transmitted by the ECU, and emissions conversion efficiency data transmitted by the emissions analyzer, and instructs the ECU to perform actions such as activating the engine's cylinder air-fuel ratio and adjusting engine operating conditions. The sensor assembly includes a catalyst temperature sensor, a fuel temperature sensor, an intake air pressure sensor, a cylinder pressure sensor, and a fuel pressure sensor.

[0026] Furthermore, the controller includes a data acquisition module, a calculation module, a judgment module, a counting module, and an output control module:

[0027] Data acquisition module - used to receive detection signals transmitted by sensor components, OSC data transmitted by ECU, and OSC data and emission conversion efficiency data transmitted by emission analyzer;

[0028] The counting module counts the number of OSC values ​​collected when entering the OSC calculation window. When the count reaches a preset counting threshold, the calculation module is triggered to calculate the current OSC value.

[0029] Calculation module - Calculates the current OSC value based on the OSC data received by the data acquisition module and the count count by the counting module;

[0030] Judgment Module - Based on the current OSC value calculated by the calculation module and the emission conversion efficiency data collected by the data acquisition module, determine whether the aging endpoint has been reached;

[0031] Output control module - used to output commands to the ECU to adjust the air-fuel ratio of each engine cylinder and the engine operating conditions.

[0032] The beneficial effects of this invention are as follows:

[0033] (1) This invention achieves the alternating rich and lean air-fuel ratio by activating the cylinder control of the air-fuel ratio, thereby increasing the heat load of the catalyst, strengthening the aging process, and shortening the aging time. During aging, there is no need to install an additional secondary air supply system on the equipment as in the prior art, thus reducing the test cost and lowering the test risk.

[0034] (2) This invention changes the OSC calculation logic from a single calculation within a driving cycle to a continuous calculation, which more accurately determines the aging endpoint and makes the aging process precise and controllable. Attached Figure Description

[0035] Figure 1 The diagram shown is a schematic flowchart of the aging process of the method in Embodiment 1 of the present invention;

[0036] Figure 2 The diagram shown is a schematic diagram of the aging device according to Embodiment 2 of the present invention. Detailed Implementation

[0037] The technical solution of the preferred embodiment of the method and apparatus for rapid aging of a benchtop catalyst according to the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0038] Example 1:

[0039] This embodiment provides a method for rapid bench aging of a catalytic converter. The method uses the engine as the heat source for thermal aging of the catalytic converter on a test bench, and utilizes the vehicle ECU to activate the engine's air-fuel ratio control to complete the aging of the three-way catalytic converter. Specifically, it includes the following steps:

[0040] Step S100: Determine the baseline maximum exhaust temperature operating condition when the engine does not enter the enrichment protection zone based on universal characteristics;

[0041] Step S200: Start the engine and adjust the engine operating conditions to the baseline maximum exhaust temperature condition determined in step S100;

[0042] Step S300: Activate the engine's air-fuel ratio cylinder control via the ECU and set the air-fuel ratio richness / slightness distribution coefficient to ensure the catalyst center temperature is at the first exhaust temperature condition, and stably operate the catalyst aging process under this first exhaust temperature condition; preferably, the execution process of step S300 is as follows:

[0043] Step S301 - Activate the engine's air-fuel ratio cylinder control via ECU;

[0044] Step S302 - Set the air-fuel ratio distribution coefficient and keep the engine running;

[0045] Step S303 - Read the catalyst center temperature T;

[0046] Step S304 - Determine whether the catalyst center temperature T satisfies Tmax-10℃<T<Tmax. If the determination result is yes, otherwise return to step S302 and reset the air-fuel ratio distribution coefficient. If the determination result is yes, the engine continues to run under the current operating conditions and enters the aging process of the catalyst, where Tmax is the catalyst's tolerance limit temperature.

[0047] Step 400: When aging reaches a preset time node, OSC data and emission conversion efficiency data are acquired until both the current OSC value and emission conversion rate reach the preset target, thus completing the aging process. The method for generating the current OSC value includes continuously collecting multiple OSC values ​​and counting the number of OSC collections. When the count reaches a preset counting threshold (e.g., 20 times), the average of the multiple counted OSC values ​​is calculated to obtain the current OSC value. Preferably, the execution process of step S400 is as follows:

[0048] Step S401 - Determine whether the engine operating condition is within the OSC value calculation window. If the determination result is yes, proceed to step S402. If the determination result is no, otherwise return to step S304 to continue aging.

[0049] Step S402 - Collect OSC values ​​at a preset frequency, and simultaneously count the number of collected OSC values.

[0050] When the count reaches the preset count threshold, proceed to step S403;

[0051] Step S403 - Calculate the average value of multiple OSC values ​​within the current counting period as the current OSC value, and simultaneously obtain the current exhaust gas emission conversion efficiency;

[0052] Step S404 - Determine whether the aging endpoint has been reached based on the current OSC value and exhaust gas emission conversion efficiency calculated in step S403; if the determination result is yes, then end the aging process; otherwise, return to step S402 to collect the OSC and exhaust gas emission conversion efficiency calculation for the next cycle.

[0053] In a preferred embodiment, the air-fuel ratio enrichment distribution coefficient ranges from 0.05 to 0.15.

[0054] This embodiment utilizes the ECU to control the air-fuel ratio of each cylinder in the engine. Through alternating rich and light fuel injection, the catalytic converter is aged under the first exhaust temperature condition until both the OSC (oxygen storage capacity) and emission conversion efficiency reach the preset targets. This can quickly complete the aging process of the three-way catalytic converter, and its control process is economical and precise.

[0055] Example 2:

[0056] This embodiment provides a device for rapid bench aging of a catalytic converter, comprising a controller, an engine system, a sensor assembly, and an emissions analyzer. The engine system is connected to a vehicle ECU on a test bench. The engine is equipped with a three-way catalytic converter, which is located at the exhaust manifold of the engine system. The emissions analyzer is used to monitor exhaust emissions filtered by the catalytic converter and generate emissions conversion efficiency data. The controller is connected to the vehicle ECU, which is used to activate the engine's cylinder air-fuel ratio control and monitor OSC data. The controller receives detection signals transmitted by the sensor assembly, OSC data transmitted by the ECU, and emissions conversion efficiency data transmitted by the emissions analyzer, and instructs the ECU to perform actions such as activating the engine's cylinder air-fuel ratio and adjusting engine operating conditions. The sensor assembly includes sensors such as a catalytic converter temperature sensor, a fuel temperature sensor, an intake air pressure sensor, a cylinder pressure sensor, and a fuel pressure sensor, which transmit signals related to pressure, temperature, humidity, etc., required for the engine system to operate as required.

[0057] In a preferred embodiment, the intake pressure sensor includes an atmospheric pressure sensor, a post-air filter pressure sensor, a pre-intercooler pressure sensor, a post-intercooler pressure sensor, an intake manifold pressure sensor, and a crankcase pressure sensor; the fuel temperature sensor includes an oil temperature sensor, a coolant temperature sensor, and an intake manifold temperature sensor; more preferably, the sensor assembly also includes an intake air temperature sensor, a pre-turbo temperature sensor, a pre-turbo pressure sensor, and a post-turbo temperature sensor.

[0058] In a preferred embodiment, the controller comprises a data acquisition module, a calculation module, a judgment module, a counting module, and an output control module: The data acquisition module receives detection signals transmitted from sensor components, OSC data transmitted from the ECU, and OSC data and emission conversion efficiency data transmitted from the emission analyzer; the counting module counts the number of OSC values ​​collected when entering the OSC calculation window, and triggers the calculation module to calculate the current OSC value when the count reaches a preset counting threshold; the calculation module calculates the current OSC value based on the OSC data received by the data acquisition module and the count count from the counting module; the judgment module determines whether the aging endpoint has been reached based on the current OSC value calculated by the calculation module and the emission conversion efficiency data collected by the data acquisition module; and the output control module outputs commands to the ECU to activate the engine's cylinder air-fuel ratio and adjust the engine's operating conditions.

[0059] In a preferred embodiment, the judgment module includes a first judgment unit, a second judgment unit, a third judgment unit, and a fourth judgment unit. The first judgment unit determines whether the engine is at its highest baseline exhaust temperature based on signals transmitted from various sensors detecting engine operating conditions. If the determination is yes, the ECU is triggered to activate air-fuel ratio cylinder control; otherwise, the controller is triggered to adjust the engine operating conditions. The second judgment unit determines whether the catalytic converter is at its first exhaust temperature condition based on the catalytic converter center temperature transmitted from the catalytic converter temperature sensor. If the determination is no, the ECU is triggered to adjust the air-fuel ratio distribution coefficient; if the determination is yes, the controller is triggered to start the engine. The engine system continues to operate under the current conditions. The third judgment unit is used to determine whether the engine system is in the OSC calculation window based on the engine system operation signals transmitted by each sensor. If the judgment result is yes, the ECU is triggered to acquire the OSC data under the current conditions. If the judgment result is no, the controller is triggered to instruct the engine system to continue operating under the current conditions. The fourth judgment unit is used to determine whether the aging target has been achieved based on the current OSC value calculated by the calculation module and the emission conversion efficiency transmitted by the emission analyzer. If the judgment result is yes, the controller is triggered to confirm that the aging endpoint has been reached and end the aging process. If the judgment result is no, the controller is triggered to control the engine to continue running the aging process.

[0060] In a preferred embodiment, the controller is further provided with a timing module to measure the transfer time between different process nodes during the aging process.

[0061] In a preferred embodiment, the controller is further provided with an alarm module, which triggers an alarm when the controller receives abnormal signals transmitted by the engine's sensors.

[0062] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention; the dimensions described in the drawings and embodiments are not related to the specific physical object and are not used to limit the protection scope of the present invention. The physical dimensions can be selected and changed according to actual needs.

Claims

1. A method for rapid aging of a benchtop catalyst, characterized in that, The engine uses an ECU to control the air-fuel ratio of each cylinder, and through alternating rich and lean combustion, the catalytic converter ages under first exhaust temperature conditions until both OSC and emission conversion efficiency reach preset targets; this includes the following steps: Step S100: Determine the baseline maximum exhaust temperature operating condition when the engine does not enter the enrichment protection zone based on universal characteristics; Step S200: Start the engine and adjust it to the baseline maximum exhaust temperature condition determined in step S100; Step S300: Activate the engine's air-fuel ratio cylinder control through the ECU and set the rich-lean air-fuel ratio distribution coefficient so that the catalyst center temperature is at the first exhaust temperature condition, and stably run the aging process of the catalyst under the first exhaust temperature condition. Step S400: Obtain OSC data and emission conversion efficiency data until the current OSC value and emission conversion efficiency data both reach the preset target to complete the aging process.

2. The method for rapid aging of a benchtop catalyst according to claim 1, characterized in that, In the first exhaust temperature condition, the catalyst center temperature T satisfies T max -10℃ < T < T max T max To ensure the catalyst can withstand extreme temperatures.

3. The method for rapid aging of a benchtop catalyst according to claim 1, characterized in that, The concentration-to-dilute ratio coefficient ranges from 0.05 to 0.

15.

4. The method for rapid aging of a benchtop catalyst according to claim 1, characterized in that, In step S400, the method for generating the current OSC value includes continuously collecting multiple OSC values ​​and counting the number of OSC collections. When the count reaches a preset counting threshold, the average of the multiple counted OSC values ​​for the current period is calculated to obtain the current OSC value.

5. The method for rapid aging of a benchtop catalyst according to claim 4, characterized in that, Step S300 specifically includes the following steps: Step S301: Activate the engine's air-fuel ratio cylinder control via ECU; Step S302: Set the air-fuel ratio richness / leanness distribution coefficient to keep the engine running; Step S303: Read the catalyst center temperature T; Step S304: Determine whether the catalyst center temperature T meets the conditions for the first exhaust temperature operation. If the determination result is yes, otherwise return to step S302 and reset the air-fuel ratio rich-lean distribution coefficient. If the judgment result is yes, then the engine will continue to operate under the current conditions and enter the aging process of the catalytic converter.

6. The method for rapid aging of a benchtop catalyst according to claim 5, characterized in that, Step S400 specifically includes the following steps: Step S401: Determine whether the engine operating condition is within the OSC value calculation window. If the determination result is yes, proceed to step S402. If the determination result is no, return to step S304 to continue aging. Step S402: Collect OSC values ​​at a preset frequency and count the number of collected OSC values. When the count reaches a preset counting threshold, proceed to step S403. Step S403: Calculate the average value of multiple OSC values ​​within the current counting period as the current OSC value, and simultaneously obtain the current exhaust gas emission conversion efficiency. Step S404: Determine whether the aging endpoint has been reached based on the current OSC value and exhaust gas emission conversion efficiency calculated in step S403. If the judgment result is yes, then the aging process ends; otherwise, return to step S402 to collect the OSC of the next cycle and step S403 to calculate the exhaust gas emission conversion efficiency.

7. An apparatus for a benchtop rapid aging catalyst, characterized in that, Includes controllers, engine systems, sensor assemblies, and emissions analyzers. The engine system is equipped with a catalytic converter, and the emission analyzer is used to monitor the exhaust emissions filtered by the catalytic converter and generate emission conversion efficiency data. The controller is connected to the vehicle ECU, and the ECU is used to activate the engine air-fuel ratio cylinder control and monitor OSC data according to the method of bench rapid aging catalyst according to any one of claims 1 to 6; The controller is used to receive detection signals transmitted by the sensor assembly, OSC data transmitted by the ECU, and emission conversion efficiency data transmitted by the emission analyzer, and instructs the ECU to perform actions such as activating the engine cylinder air-fuel ratio and adjusting the engine operating conditions. The sensor assembly includes a catalytic converter temperature sensor, a fuel temperature sensor, an intake air pressure sensor, a cylinder pressure sensor, and a fuel pressure sensor.

8. The apparatus for a benchtop rapid aging catalyst according to claim 7, characterized in that, The controller includes a data acquisition module, a calculation module, a judgment module, a counting module, and an output control module. The data acquisition module is used to receive detection signals transmitted by the sensor components, OSC data transmitted by the ECU, and emission conversion efficiency data transmitted by the emission analyzer; The counting module counts the number of OSC values ​​collected when entering the OSC calculation window. When the count reaches a preset counting threshold, the calculation module is triggered to calculate the current OSC value. The calculation module calculates the current OSC value based on the OSC data received by the data acquisition module and the count count from the counting module. The judgment module determines whether the aging endpoint has been reached based on the current OSC value calculated by the calculation module and the emission conversion efficiency data collected by the data acquisition module. The output control module is used to send commands to the ECU to activate the air-fuel ratio of each engine cylinder and adjust the engine operating conditions.

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