Engine, control method thereof, and electric device

Abstract

The application discloses an engine, a control method thereof and an electric device. The control method of the engine comprises the following steps: detecting the concentration of nitrogen-containing compounds in a first stage of the engine, the first stage being an operation mode of the engine based on a first air-fuel ratio; obtaining the residual amount of nitrogen oxide compounds according to the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount of a previous stage of the first stage, the previous stage of the first stage being an operation mode of the engine based on a second air-fuel ratio, and determining whether the engine is switched to the operation mode based on the second air-fuel ratio according to the residual amount of nitrogen oxide compounds. According to the control method of the engine, the control method has high control accuracy, and is beneficial to accurate switching of the first stage and the second stage of the engine.

Description

Technical Field

[0001] This invention relates to the field of power equipment, and in particular to an engine and its control method, as well as electrical equipment. Background Technology

[0002] The vehicle may be equipped with at least one catalytic converter for reducing emissions (EM) in the exhaust. Exhaust gas flowing from the engine through the exhaust manifold is forced into and purified by the catalytic converter mounted on the exhaust pipe. Afterward, exhaust noise is reduced as it flows through a muffler, and then the exhaust is discharged into the air through the tailpipe.

[0003] Lean-burn technology is a technique that controls the air-fuel ratio during engine combustion to improve thermal efficiency and reduce emissions. In lean-burn mode, the air-fuel mixture has a higher proportion of air and a lower proportion of fuel, resulting in more complete combustion and improved fuel economy. Rich-burn technology mainly refers to increasing the fuel injection quantity to create a rich mixture in the combustion chamber, thereby achieving a highly efficient combustion process.

[0004] In related technologies, there are issues where the engine control strategy cannot switch between rich and lean combustion as desired, resulting in low control precision and thus causing vehicle exhaust pollutant emissions to exceed standards. Summary of the Invention

[0005] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, one objective of the present invention is to propose an engine control method with high control precision, which facilitates the accurate switching between the first and second stages of the engine.

[0006] Another object of the present invention is to provide an engine controlled by the above-described control method.

[0007] Another object of the present invention is to provide an electrical device employing the above-described engine.

[0008] According to a first aspect embodiment of the present invention, an engine control method includes the following steps: The concentration of nitrogen-containing compounds in the engine is detected in the first stage, which is the engine's operating mode based on a first air-fuel ratio; The remaining amount of nitrogen oxides is obtained based on the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount in the previous stage of the first stage. The previous stage of the first stage is the engine's operating mode based on the second air-fuel ratio. The engine is then switched to the operating mode based on the remaining amount of nitrogen oxides.

[0009] According to the engine control method of this invention, by detecting the concentration of nitrogen-containing compounds in the engine during the first and second stages, the detection results are accurate, the monitoring is timely, and real-time control is possible. The engine's operating mode can be adjusted promptly based on the obtained nitrogen oxide levels, exhibiting fast response and high accuracy. Furthermore, the NH3 generated in the first stage can react with the NOx stored in the second stage to produce N2, thereby reducing emissions and purifying the exhaust gas to meet emission standards. Simultaneously, fuel consumption can be reduced, thus improving engine performance.

[0010] According to some embodiments of the present invention, the concentration of nitrogen-containing compounds in the first stage is detected by a detection device.

[0011] According to some embodiments of the present invention, the detection element includes a first detection element disposed at the air intake of the trap of the engine. In the first stage, the first detection device detects the concentration of nitrogen-containing compounds at the air inlet as the concentration of nitrogen-containing compounds in the first stage.

[0012] According to some embodiments of the present invention, the detection element includes a first detection element and a second detection element, wherein the first detection element is disposed at the air inlet of the trap of the engine, and the second detection element is disposed at the air outlet of the trap. In the first stage, the concentration difference detected by the first detector and the second detector is the concentration of nitrogen-containing compounds in the first stage.

[0013] According to some embodiments of the present invention, the stage preceding the first stage is the second stage, and the nitrogen oxide storage amount is obtained based on the detected concentration of nitrogen-containing compounds in the second stage.

[0014] According to some embodiments of the present invention, the determination of the remaining amount of nitrogen oxides based on the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount in the previous stage of the first stage specifically includes: The remaining amount of nitrogen oxides is obtained by the difference between the amount of nitrogen oxides stored in the second stage and the amount of ammonia generated in the first stage, wherein the amount of ammonia generated in the first stage is obtained by continuously detecting the concentration of nitrogen-containing compounds in the first stage at a first time, and the amount of nitrogen oxides stored in the second stage is obtained by continuously detecting the concentration of nitrogen-containing compounds in the second stage at a second time.

[0015] According to some embodiments of the present invention, the remaining amount Q of the nitrogen oxide compound NOx Satisfy: Q NOx = -a×k Wherein, C1 is the concentration of nitrogen-containing compounds in the first stage, C2 is the concentration of nitrogen-containing compounds in the second stage, k is the balance coefficient, a is the compensation coefficient, t1 is the first time, and t2 is the second time.

[0016] According to some embodiments of the present invention, the detection element includes a first detection element disposed at the air intake of the trap of the engine. In the second stage, the first detection device detects the concentration at the air inlet as the concentration of nitrogen-containing compounds in the second stage.

[0017] According to some embodiments of the present invention, the detection element includes a first detection element and a second detection element, wherein the first detection element is disposed at the air inlet of the trap of the engine, and the second detection element is disposed at the air outlet of the trap. In the second stage, the concentration difference detected by the first detector and the second detector is the concentration of the nitrogen-containing compound in the second stage.

[0018] According to some embodiments of the present invention, the previous stage of the first stage is the second stage, and when the remaining amount of nitrogen oxides is less than a certain value, the engine switches from the first stage to the second stage; When the remaining amount of nitrogen oxides is greater than or equal to a certain value, the engine remains in the first stage.

[0019] According to some embodiments of the present invention, when the engine is in the previous stage of the first stage, it switches to the first stage after a second time.

[0020] According to some embodiments of the present invention, when the engine is used in electrical equipment, the electrical equipment has a parallel direct drive mode, and the control method is a control method in the parallel direct drive mode.

[0021] According to some embodiments of the present invention, the stage preceding the first stage is the second stage. When the engine is used for electrical equipment, the electrical equipment has a series range-extending mode. In the series range-extending mode, the control method includes the following steps: The engine is in the second stage, and after a second preset time, it switches to the first stage; The engine is in the first stage, and after a first preset time, it switches to the second stage; The first stage and the second stage alternate in sequence.

[0022] According to a second aspect embodiment of the present invention, the engine is controlled using the control method described in the first aspect embodiment.

[0023] According to some embodiments of the present invention, the engine includes: a body having a second stage and a first stage, the detection element being adapted to communicate with a controller of the electrical equipment; and a trap having a detection element thereon, the detection element detecting the concentration of nitrogen-containing compounds flowing down to the trap from the second stage and the first stage, the detection element being adapted to communicate with the controller.

[0024] According to some embodiments of the present invention, the engine further includes a catalytic converter, the inlet of which is connected to the exhaust manifold of the main body, and the outlet of which is connected to the intake port of the trap.

[0025] According to some embodiments of the present invention, the catalytic converter includes a three-way catalytic converter.

[0026] According to some embodiments of the present invention, the detection element is a nitrogen and oxygen sensor.

[0027] According to some embodiments of the present invention, the trap includes a dilute NOx trap.

[0028] An electrical appliance according to a third aspect of the present invention includes an engine controlled according to the control method described in the first aspect of the present invention, or an engine described in the second aspect of the present invention.

[0029] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0030] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart of an engine control method according to an embodiment of the present invention, wherein the electrical equipment is in parallel direct drive mode; Figure 2 This is a flowchart of an engine control method according to an embodiment of the present invention, wherein the electrical equipment is in series range extender mode; Figure 3 This is a schematic diagram of an engine according to an embodiment of the present invention.

[0031] Figure label: 100. Engine; 1. Main body; 2. Collector; 21. Air inlet; 22. Air outlet; 3. Catalytic converter; 31. Inlet; 32. Outlet; 4. Test items. Detailed Implementation

[0032] The embodiments of the present invention are described in detail below. The embodiments described with reference to the accompanying drawings are exemplary. Figures 1-3 A control method for an engine 100 according to an embodiment of the present invention is described.

[0033] like Figure 1 As shown, when the engine 100 is used for electrical equipment, the electrical equipment has a parallel direct drive mode and a series range extender mode. In the parallel direct drive mode, the control method of the engine 100 includes the following steps: The concentration of nitrogen compounds in engine 100 is detected in the first stage, which is the operating mode of engine 100 based on a first air-fuel ratio.

[0034] The remaining amount of nitrogen oxides is obtained based on the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount in the previous stage. The previous stage is the engine 100 operating mode based on the second air-fuel ratio. The remaining amount of nitrogen oxides determines whether the engine 100 switches to the operating mode based on the second air-fuel ratio (i.e., the second stage).

[0035] For example, the second stage is the lean-burn mode in conventional technology, and the first stage is the rich-burn mode in conventional technology. The first air-fuel ratio is when the air-fuel ratio λ is less than 1. The second air-fuel ratio is when the air-fuel ratio λ is greater than 1. That is, the concentration of nitrogen compounds (C1, i.e., the concentration of nitrogen compounds in the rich-burn mode of engine 100) is detected in the current first stage. The first stage is the operating mode when the air-fuel ratio λ of engine 100 is less than 1.

[0036] Based on the detected concentrations of the aforementioned nitrogen-containing compounds, and the concentrations of nitrogen-containing compounds in the previous stage (C2, i.e., the concentration of nitrogen compounds in the engine's 100 lean-burn mode) under the current first stage, the nitrogen oxide storage amount is obtained, and the remaining amount Q of nitrogen oxides is calculated. NOx (Also known as NOx storage), the operating mode of engine 100 is determined based on the remaining amount of nitrogen oxides. The second stage is the operating mode when the air-fuel ratio λ of engine 100 is greater than 1.

[0037] For example, electrical equipment such as plug-in hybrid vehicles have three driving modes: pure electric mode, series range-extended mode, and parallel direct drive mode. In series range-extended mode and parallel direct drive mode, engine 100 starts and operates, requiring exhaust aftertreatment to reduce pollutant emissions. Engine 100 has a second stage and a first stage. In the second stage, λ is greater than 1, the air-fuel mixture has a higher proportion of air and a lower proportion of fuel, resulting in more complete combustion and improved fuel economy. In the first stage, λ is less than 1, the air-fuel mixture has a lower proportion of air and a higher proportion of fuel; by increasing the fuel injection quantity, a rich mixture is formed in the combustion chamber, achieving a highly efficient combustion process.

[0038] In parallel direct drive mode, the engine 100 operates in alternating phases one and two. When the engine 100 is in phase one, the remaining amount of nitrogen oxides (i.e., the NOx storage amount Q) can be obtained by measuring the concentration C1 of nitrogen-containing compounds detected in the current state and the amount of nitrogen oxides stored in the previous phase two adjacent to the current state (which can be obtained by measuring the concentration C2 of nitrogen-containing compounds detected in the second phase). NOx In other words, in the first stage, it is necessary to perform calculations using the monitoring data of the current state and the monitoring data of the previous operating mode to determine whether the engine 100 should switch operating modes.

[0039] For example, the detection order of C2 and C1 mentioned above is not limited to the specific sequence, but refers to the detection of the corresponding nitrogen-containing compound concentration in the corresponding operating mode of engine 100. The nitrogen-containing compound concentration C2 in the second stage refers to the amount of NOx in the second stage. The nitrogen-containing compound concentration C1 in the first stage refers to the amount of ammonia (NH3) in the first stage. For the parallel direct drive mode, where the vehicle is directly driven by engine 100, the engine 100's operating conditions will change with vehicle speed. In this case, it is necessary to adjust the control strategy by detecting the stored NOx level.

[0040] This configuration addresses the issue of engine 100's operating conditions constantly changing with vehicle speed in parallel direct drive mode. By detecting the concentration of nitrogen compounds under different operating modes—that is, using the aforementioned rich-lean switching control strategy—fuel consumption can be reduced while ensuring emissions meet standards, thereby improving engine 100 performance. Furthermore, by detecting the concentration of nitrogen compounds in engine 100 under both the first and second stages, the detection results are accurate, monitoring is timely, and real-time control is possible, allowing for adjustments based on Q... NOx The engine 100's operating mode is controlled in a timely manner, with fast response and high accuracy. Furthermore, the NH3 generated by the engine 100 in the first stage can react with the NOx stored in the second stage to produce N2, thereby reducing emissions and purifying the exhaust gas to meet emission standards.

[0041] According to the control method of the engine 100 of the present invention, by detecting the concentration of nitrogen-containing compounds in the engine 100 in the first stage and the second stage, the detection result is accurate, the monitoring is timely, and the control is real-time, and can be based on Q. NOx The engine 100's operating mode is controlled in a timely manner, with fast response and high accuracy. Furthermore, the NH3 generated in the first stage of engine 100 can react with the NOx stored in the second stage to produce N2, thereby reducing emissions and purifying the exhaust gas to meet emission standards. Simultaneously, fuel consumption can be reduced, thus improving the performance of engine 100.

[0042] According to some embodiments of the present invention, in combination Figure 1 and Figure 3 The concentration of nitrogen-containing compounds in the first stage is detected by detector 4. In other words, the concentrations C2 and C1 of nitrogen-containing compounds in the second stage and the first stage are also detected by detector 4. For example, detector 4 can be a sensor. With this configuration, the detection results of C2 and C1 are accurate, the nitrogen oxide storage amount and the remaining amount of nitrogen oxides are accurately detected, the detection response is fast, and the detection results can be quickly fed back to the controller to control the switching of the engine 100's operating mode, thereby further improving the operability of the engine 100's control method, making the control method simple and accurate.

[0043] According to some embodiments of the present invention, the detection element 4 includes a first detection element disposed at the air intake 21 of the trap 2 of the engine 100. In a first stage, the first detection element detects the concentration of nitrogen-containing compounds at the air intake 21 as the concentration of nitrogen-containing compounds in the first stage. The first detection element can be used to detect the concentration of nitrogen-containing compounds (i.e., C1) at the air intake 21 in the first stage. Therefore, the detection result is accurate, which is beneficial to the control of the engine.

[0044] Combination Figure 1 and Figure 3 The detection element 4 includes a first detection element, which is disposed at the air intake 21 of the trap 2 of the engine 100. In the first stage, the first detection element detects the concentration C of nitrogen-containing compounds at the air intake 21. 11 Where, C1=C 11 .

[0045] For example, when only one first detector is set in detector 4, the first detector obtains the M under the first stage by timely detecting the concentration of nitrogen-containing compounds at the air inlet 21. NH3 With this configuration, the concentration of nitrogen compounds at the air intake 21 is close to the concentration of nitrogen compounds in the corresponding mode of the trap 2, so as to ensure the accuracy of the detection results and thus improve the control accuracy of the engine 100 control method.

[0046] According to other embodiments of the present invention, the detection element 4 includes a first detection element and a second detection element. The first detection element is disposed at the air inlet 21 of the trap 2 of the engine 100, and the second detection element is disposed at the air outlet 22 of the trap 2. In the first stage, the concentration difference detected by the first detection element and the second detection element is the concentration of nitrogen-containing compounds in the first stage.

[0047] In other words, in the first stage, the concentration difference of nitrogen-containing compounds detected by the first and second detectors is C1.

[0048] For example, in the second stage, the first detector measures the concentration C of nitrogen-containing compounds at the air inlet 21. 21 The second detection element detects the concentration C of nitrogen-containing compounds at the outlet 22. 22 Where, C2=C 21 -C 22 In the first stage, the first detection element detects the concentration C of nitrogen-containing compounds at the air inlet 21. 11 The second detection element detects the concentration C of nitrogen-containing compounds at the outlet 22. 12 Where, C1=C 11 -C 12 .

[0049] For example, to avoid Q caused by ammonia leakage at the outlet 22 of the trap 2. NOx The decrease in accuracy can be mitigated by installing a first detector and a second detector at the inlet 21 and outlet 22 of the trap 2, respectively. By subtracting the concentration values ​​at the inlet 21 and outlet 22, the accurate concentration of nitrogen-containing compounds in the trap 2 can be obtained. In other words, by installing the first and second detectors, C1 can be corrected to further improve its accuracy, thereby increasing Q. NOx This improves the accuracy of the control method, thereby further improving the rich-lean switching control strategy and further enhancing the control accuracy of the engine 100 control method.

[0050] According to some embodiments of the present invention, the stage preceding the first stage is the second stage, and the aforementioned nitrogen oxide storage amount is obtained based on the detected concentration of nitrogen-containing compounds in the second stage. Specifically, obtaining the remaining amount of nitrogen oxides based on the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount in the stage preceding the first stage includes: Based on the nitrogen oxide storage capacity in the second stage (e.g., M NOx ) and the amount of ammonia generated in the first stage (e.g., M NH3The difference between the ammonia generation in the first stage and the nitrogen oxides in the second stage is used to determine the remaining amount of nitrogen oxides. Specifically, the ammonia generation in the first stage is determined by continuously monitoring the concentration of nitrogen-containing compounds in the first stage at a given time interval, and the nitrogen oxides storage in the second stage is determined by continuously monitoring the concentration of nitrogen-containing compounds in the second stage at a given time interval.

[0051] In other words, in the lean-burn mode of engine 100, the nitrogen oxide storage amount in the second stage can be obtained by integrating the concentration of nitrogen-containing compounds detected in the second time period over time. In the rich-burn mode of engine 100, the nitrogen oxide storage amount in the second stage can be obtained by integrating the concentration of nitrogen-containing compounds detected in the first time period over time. When the second stage running time is fixed, the second time is the running time of the second stage. In the first stage, the detection element 4 can monitor the concentration of nitrogen-containing compounds in real time and perform time integration at the current monitoring time; the detection element 4 continuously monitors the concentration of nitrogen-containing compounds in the current stage.

[0052] For example, the remaining amount Q of nitrogen oxides NOx Satisfy: Q NOx = -a×k Where C1 is the concentration of nitrogen-containing compounds in the first stage, C2 is the concentration of nitrogen-containing compounds in the second stage, k is the balance coefficient, a is the compensation coefficient, t1 is the first time, and t2 is the second time. Specifically, in the second stage, the NOx concentration of the monitoring trap 2 is recorded and integrated over time to obtain M. NOx = In the first stage, the monitored ammonia concentration was recorded and integrated over time. NH3 = Then calculate the difference between the two to obtain Q. NOx Q NOx =M NOx -akM NH3 In the formula, k is the balance coefficient.

[0053] For example, when NOx is NO, the reaction between NO and NH3 is as follows: 6NO + 4NH3 = 5N2 + 2H2O, where k is 6 / 4. It should be noted that... and The time in the formula is based on the corresponding second or first stage time and is not necessarily a single numerical value. In the formula, 'a' is a compensation coefficient. Because some ammonia spontaneously oxidizes with oxygen in the actual reaction, leading to faster ammonia consumption, an additional compensation coefficient 'a' is needed to ensure the accuracy of the formula calculation. For example, 'a' varies depending on the catalyst used in the reaction process; no specific limitation is made here. The Q calculated using the above formula... NOxThe calculation is simple, the control method is more precise, and it is more conducive to the use of the engine 100.

[0054] According to some embodiments of the present invention, in combination Figure 1 and Figure 3 The detection element 4 includes a first detection element, which is located at the air intake 21 of the trap 2 of the engine 100. In the second stage, the first detection element detects the concentration of nitrogen-containing compounds at the air intake 21 as the concentration of nitrogen-containing compounds in the second stage.

[0055] In other words, the first detection device can detect C2 and C1 at the air intake 21 at different operating stages. C1 can be detected in the first stage, and C2 can be detected after switching to the second stage. Therefore, the detection results are accurate, which is beneficial for engine control.

[0056] Combination Figure 1 and Figure 3 The detection element 4 includes a first detection element, which is disposed at the air intake 21 of the trap 2 of the engine 100. In the second stage, the first detection element detects the concentration C of nitrogen-containing compounds at the air intake 21. 21 Where, C2=C 21 Through C 21 The above-mentioned nitrogen oxide storage amount was calculated.

[0057] For example, when only one first detector is set in detector 4, the first detector obtains the M value in the second stage by timely detecting the concentration of nitrogen-containing compounds at the air inlet 21. NOx and M in the first phase NH3 C2 and C1 are considered to be the concentrations of corresponding nitrogen-containing compounds in the trap 2 under the corresponding mode. With this setting, the concentration of nitrogen-containing compounds at the air intake 21 is close to the concentration of nitrogen-containing compounds in the trap 2 under the second stage, so as to ensure the accuracy of the detection results and thus improve the control accuracy of the engine 100 control method.

[0058] According to other embodiments of the present invention, the detection element 4 includes a first detection element and a second detection element. The first detection element is disposed at the air inlet 21 of the trap 2 of the engine 100, and the second detection element is disposed at the air outlet 22 of the trap 2. In the second stage, the concentration difference detected by the first detection element and the second detection element is the concentration of nitrogen-containing compounds in the second stage.

[0059] In other words, in the second stage, the concentration difference of nitrogen-containing compounds detected by the first and second detectors is C2. For example, in the second stage, the concentration of nitrogen-containing compounds detected by the first detector at the air inlet 21 is C2. 21 The second detection element detects the concentration C of nitrogen-containing compounds at the outlet 22. 22 Where, C2=C 21-C 22 By setting up a first and a second detection element, C2 and C1 can be calibrated to further improve their accuracy, thereby increasing Q. NOx This improves the accuracy of the control method, thereby further improving the rich-lean switching control strategy and further enhancing the control accuracy of the engine 100 control method.

[0060] According to some embodiments of the present invention, the stage preceding the first stage is the second stage. When the remaining amount of nitrogen oxides is less than a certain value (e.g., 0), the engine 100 switches from the first stage to the second stage. When the remaining amount of nitrogen oxides is greater than or equal to a certain value (e.g., 0), the engine (100) remains in the first stage.

[0061] For example, when Q NOx When Q < 0, engine 100 switches from stage one to stage two. NOx When ≥0, engine 100 remains in the first stage.

[0062] In other words, based on Q NOx The working principle of the second-stage and first-stage switching control strategy is as follows: In the first stage, Q NOx It gradually decreases due to the formation of NH3. When Q NOx When the NOx level approaches 0, it means that the NOx level in trap 2 is insufficient. Continuing to enrich the NOx will result in insufficient NOx reacting with NH3, causing NH3 to overflow. Therefore, it is necessary to switch to the second stage to replenish the NOx. When the NOx level drops to Q... NOx When Q < 0, meaning all NOx is converted to N2, the first stage switches to the second stage. If Q NOx When the value is ≥0, the first stage can continue to consume NOx.

[0063] This configuration addresses the issue of engine operating conditions constantly changing with vehicle speed in parallel direct drive mode. By employing the aforementioned limited rich-lean switching control strategy, fuel consumption can be reduced while ensuring emissions meet standards, thereby improving engine performance. Furthermore, by determining the NOx storage level Q... NOx The relationship with 0 is used to determine whether the engine 100 mode needs to be switched. The judgment method is simple, has a low error rate, and reduces the control difficulty. Moreover, the above judgment method is correct and reasonable, with fast response speed and high accuracy.

[0064] According to some embodiments of the present invention, in combination Figure 1 When engine 100 is in the previous stage (second stage) of the first stage, it switches back to the first stage after a second time.

[0065] In other words, when engine 100 operates in alternating stages of the second and first phases, NOx is stored and rises to a certain value through a fixed lean-burn time (i.e., the second time), at which point engine 100 switches to a rich-burn state. For example, the second time is calculated based on engine 100 operating conditions to set the operating time of the second phase. When the actual operating time of the second phase equals the second time, the system switches to the first phase. In the second phase, NOx is generated during the fixed lean-burn time (the second time), and the NOx concentration C2 is detected and integrated over time to obtain M. NOx At this point, t2 is the second time.

[0066] With this setup, it is only necessary to monitor and control the rich combustion time to switch from the first stage to the second stage in a timely manner. After the engine 100 runs in the second stage for a second time, it switches back to the first stage. Then, the time to switch to the second stage again is detected according to the above control method. There is no need to detect the parameters in the second stage in real time, which simplifies the control method of the engine 100 and also ensures the timely switching between the first stage and the second stage.

[0067] When the engine 100 is used for electrical equipment, the electrical equipment has a parallel direct drive mode and a series range-extending mode. The above control method is the control method in the parallel direct drive mode.

[0068] For the parallel direct drive mode of the vehicle, the control method of engine 100 is roughly as follows: Engine 100 is in the second stage, and switches to the first stage after a second time. In the second stage, the trap 2 absorbs and stores the NOx produced during lean combustion in engine 100, and the detector 4 detects the concentration of nitrogen-containing compounds C2 in engine 100.

[0069] When engine 100 is in the first stage, the concentration C1 of nitrogen-containing compounds in engine 100 in the first stage is detected, and Q is calculated. NOx Among them, when Q NOx When Q < 0, engine 100 switches from stage one to stage two. NOx When the value is ≥0, engine 100 remains in the first stage. In the first stage, catalytic converter 3 produces NH3 when engine 100 is running in a rich combustion state, and NH3 enters the trap 2 to react with the NOx stored during lean combustion to produce N2.

[0070] According to other embodiments of the present invention, the stage preceding the first stage is the second stage. When the engine 100 is used for electrical equipment, the electrical equipment also has a series range-extending mode. In the series range-extending mode, the control method includes the following steps: 1) Engine 100 is in the second stage, and after the second preset time, it switches to the first stage.

[0071] 2) When engine 100 is in the first stage, it will switch to the second stage after the first preset time.

[0072] 3) The first stage and the second stage alternate in sequence.

[0073] For example, combining Figure 2 For the series range extender mode, since the engine can operate within its high-efficiency range and the operating conditions are relatively stable, precise rich / lean combustion timing switching is used, such as... Figure 2 As shown. After engine 100 starts, it will calculate the required power generation based on factors such as the power required by the drive motor and the battery charge level, and automatically look up the table to select the optimal operating point to control engine 100 to enter the second stage of the corresponding operating point, running for the set lean combustion time T. 稀 After (second preset time), switch to the first stage of operation at the same operating point, setting the rich combustion duration T. 浓 (First preset time) to complete one rich / lean switching cycle. That is, the engine 100 operates in alternating phases one through two. This setting, for the series range extender mode where the operating conditions are relatively stable, allows the engine 100 to cycle between lean and rich combustion at fixed intervals. The control strategy is simple and efficient, reducing both fuel consumption and emissions.

[0074] According to the second aspect embodiment of the engine 100, combined with Figure 3 The engine 100 is controlled using the control method described in the first aspect embodiment above.

[0075] According to the second aspect embodiment of the present invention, the engine 100 controls the working mode of the engine 100 by adopting the above-described control method. The control strategy is simple and efficient, which reduces fuel consumption and emissions, and improves the performance of the engine 100.

[0076] According to some embodiments of the present invention, in combination Figure 3 The engine 100 includes a main body 1, a trap 2, and a controller. The main body 1 has a second stage and a first stage, and a detection element 4 is adapted to communicate with the controller of the electrical equipment. The trap 2 is provided with the detection element 4, which detects the concentration of nitrogen-containing compounds flowing down to the trap 2 from the second stage and the first stage, and the detection element 4 is adapted to communicate with the controller.

[0077] For example, when the electrical equipment is a vehicle, the vehicle is equipped with a controller that communicates with the detection element 4 and the main body 1, and the controller controls the main body 1 to switch between the second stage and the first stage. Furthermore, the main body 1 is equipped with an exhaust manifold (not shown), which discharges the exhaust gas from the main body 1 to the trap 2. The trap 2 can absorb and store the NOx produced by the engine 100 in the second stage. The detection element 4 can promptly feed back the detection results to the controller, enabling the controller to control the operating mode of the main body 1. With this configuration, the structure of the engine 100 is simple, and no modifications to the engine 100's structure are required; the control strategy has strong applicability. Moreover, the controller has a fast response and is highly sensitive, further improving the performance of the engine 100.

[0078] According to some embodiments of the present invention, with reference to Figure 3 The engine 100 also includes a catalytic converter 3, the inlet 31 of which is connected to the exhaust manifold of the main body 1, and the outlet 32 ​​of which is connected to the intake port 21 of the trap 2.

[0079] For example, in Figure 3 In the example, the catalytic converter 3 is located between the exhaust manifold of the main body 1 and the filter 2. In the second stage, harmful gases such as carbon monoxide (CO) and hydrocarbons (HC) emitted from the exhaust manifold flow to the catalytic converter 3, where they react to produce carbon dioxide and water. During this process, the filter 2 can absorb and store the NOx produced by the engine 100 in the second stage. In the first stage, the catalytic converter 3 produces NH3, which enters the filter 2 and reacts with the NOx stored during lean combustion to produce N2. This configuration simplifies the connection between the catalytic converter 3 and the filter 2, resulting in a reasonable layout that is beneficial for the exhaust gas treatment of the engine 100.

[0080] According to some optional embodiments of the present invention, the catalytic converter 3 includes a three-way catalytic converter 3 (TWC). This configuration allows carbon monoxide (CO) in the exhaust gas to be oxidized to carbon dioxide (CO2). Carbon monoxide is a toxic gas that binds to hemoglobin in the blood, reducing the blood's oxygen-carrying capacity and, in severe cases, endangering life. The three-way catalytic converter 3 can convert a large amount of carbon monoxide, reducing its emissions into the atmosphere and mitigating harm to humans and the environment. Furthermore, it can oxidize hydrocarbons (HC) to carbon dioxide and water. Hydrocarbons form photochemical smog, irritating the human respiratory tract and damaging plants; the three-way catalytic converter 3 can effectively reduce their emissions, mitigating photochemical pollution.

[0081] According to some optional embodiments of the present invention, the detection element 4 is a nitrogen oxide sensor. For example, the nitrogen oxide sensor can detect the concentration of nitrogen-containing compounds with a non-zero valence. The nitrogen oxide sensor can monitor the content of nitrogen oxides in vehicle exhaust in real time and accurately, providing accurate data support for the exhaust gas purification system, helping to determine whether exhaust gas treatment devices such as the three-way catalytic converter 3 are working properly, and whether maintenance or replacement is required, ensuring that the emission of nitrogen oxides in the exhaust gas meets environmental protection standards. Moreover, when working in conjunction with exhaust gas treatment equipment such as the three-way catalytic converter 3, the nitrogen oxide sensor can adjust the air-fuel ratio of the engine 100 and the operating parameters of the exhaust gas treatment system based on the detected nitrogen oxide concentration, so that the three-way catalytic converter 3 is in the optimal working state, improving the conversion efficiency of harmful gases such as nitrogen oxides, and further reducing exhaust pollutant emissions.

[0082] According to some alternative embodiments of the present invention, the trap 2 includes a lean NOx trap (LNT). The LNT is a trap for NOx emitted during lean-burn processes. x The NO is adsorbed onto the catalyst via a support and then transferred during the enrichment and combustion process. x The technology reduces NOx to non-toxic and harmless N2. In the second stage, LNT can effectively adsorb and store NOx in the exhaust gas. When engine 100 is in the second stage, the oxygen content in the exhaust gas is high. NOx will react with alkaline substances (such as barium and potassium) under the action of a catalyst to generate nitrates and other substances that are stored, thereby significantly reducing the NOx emission concentration in the exhaust gas and reducing air pollution. During the NOx capture process, LNT can also play a certain role in oxidizing and purifying carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas. Some catalyst components can promote the reaction of CO and HC with oxygen to generate carbon dioxide (CO2) and water (H2O), achieving synergistic treatment of multiple pollutants and further improving the exhaust gas purification effect. In addition, by timely capturing and treating NOx in the exhaust gas, LNT helps maintain the normal working condition of engine 100's exhaust system, reduces the corrosion and damage of NOx to internal components and the exhaust system of engine 100, makes engine 100 operation more stable and reliable, and extends the service life of engine 100.

[0083] According to a third aspect embodiment of the present invention, an electrical appliance includes an engine 100 controlled according to the control method of the first aspect embodiment described above, or an engine 100 according to the second aspect embodiment described above.

[0084] According to embodiments of the present invention, by employing the aforementioned engine 100, the exhaust emissions of the electrical equipment meet the standards, thereby improving the performance of the electrical equipment. For example, the electrical equipment can be a vehicle, ship, motorcycle, or train.

[0085] The engine 100, other components of the electrical equipment, and operation according to embodiments of the present invention are known to those skilled in the art and will not be described in detail here.

[0086] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0087] In the description of this invention, "a plurality of" means two or more.

[0088] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0089] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A control method for an engine (100), characterized in that, The control method includes the following steps: The concentration of nitrogen-containing compounds in the engine (100) in a first stage is detected, the first stage being the operating mode of the engine (100) based on a first air-fuel ratio; The remaining amount of nitrogen oxides is obtained based on the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount in the previous stage of the first stage. The previous stage of the first stage is the operating mode of the engine (100) based on the second air-fuel ratio. The remaining amount of nitrogen oxides determines whether the engine (100) switches to the operating mode based on the second air-fuel ratio.

2. The control method for the engine (100) according to claim 1, characterized in that, The concentration of nitrogen-containing compounds in the first stage is detected by the detection element (4).

3. The control method for the engine (100) according to claim 2, characterized in that, The detection element (4) includes a first detection element, which is disposed at the air inlet (21) of the trap (2) of the engine (100). In the first stage, the first detection device detects the concentration of nitrogen-containing compounds at the air inlet (21) as the concentration of nitrogen-containing compounds in the first stage.

4. The control method for the engine (100) according to claim 2, characterized in that, The detection element (4) includes a first detection element and a second detection element. The first detection element is located at the air inlet (21) of the trap (2) of the engine (100), and the second detection element is located at the air outlet (22) of the trap (2). In the first stage, the concentration difference detected by the first detector and the second detector is the concentration of nitrogen-containing compounds in the first stage.

5. The control method for the engine (100) according to claim 1, characterized in that, The preceding stage of the first stage is the second stage, and the nitrogen oxide storage amount is obtained based on the detected concentration of nitrogen-containing compounds in the second stage.

6. The control method for the engine (100) according to claim 5, characterized in that, The determination of the remaining amount of nitrogen oxides based on the detected concentration of nitrogen-containing compounds in the first stage and the nitrogen oxide storage amount in the previous stage specifically includes: The remaining amount of nitrogen oxides is obtained by the difference between the amount of nitrogen oxides stored in the second stage and the amount of ammonia generated in the first stage, wherein the amount of ammonia generated in the first stage is obtained by continuously detecting the concentration of nitrogen-containing compounds in the first stage at a first time, and the amount of nitrogen oxides stored in the second stage is obtained by continuously detecting the concentration of nitrogen-containing compounds in the second stage at a second time.

7. The control method for the engine (100) according to claim 6, characterized in that, The remaining amount Q of the nitrogen oxides NOx Satisfy: Q NOx = -a×k Wherein, C1 is the concentration of nitrogen-containing compounds in the first stage, C2 is the concentration of nitrogen-containing compounds in the second stage, k is the balance coefficient, a is the compensation coefficient, t1 is the first time, and t2 is the second time.

8. The control method for the engine (100) according to claim 5, characterized in that, The detection element (4) includes a first detection element, which is disposed at the air inlet (21) of the trap (2) of the engine (100). In the second stage, the first detection device detects the concentration at the air inlet (21) as the concentration of nitrogen-containing compounds in the second stage.

9. The control method for the engine (100) according to claim 5, characterized in that, The detection element (4) includes a first detection element and a second detection element. The first detection element is located at the air inlet (21) of the trap (2) of the engine (100), and the second detection element is located at the air outlet (22) of the trap (2). In the second stage, the concentration difference detected by the first detector and the second detector is the concentration of the nitrogen-containing compound in the second stage.

10. The control method for the engine (100) according to claim 1, characterized in that, The previous stage of the first stage is the second stage. When the remaining amount of nitrogen oxides is less than a certain value, the engine (100) switches from the first stage to the second stage. When the remaining amount of nitrogen oxides is greater than or equal to a certain value, the engine (100) remains in the first stage.

11. The control method for the engine (100) according to claim 1, characterized in that, When the engine (100) is in the previous stage of the first stage, it switches to the first stage after a second time.

12. The control method for the engine (100) according to any one of claims 1-11, characterized in that, When the engine (100) is used for electrical equipment, the electrical equipment has a parallel direct drive mode, and the control method is the control method under the parallel direct drive mode.

13. The control method for the engine (100) according to claim 1, characterized in that, The preceding stage of the first stage is the second stage. When the engine (100) is used for electrical equipment, the electrical equipment has a series range-extending mode. In the series range-extending mode, the control method includes the following steps: The engine (100) is in the second stage, and switches to the first stage after a second preset time; The engine (100) is in the first stage, and after a first preset time, it switches to the second stage; The first stage and the second stage alternate in sequence.

14. An engine (100), characterized in that, The engine (100) is controlled by the control method according to any one of claims 1-13.

15. The engine (100) according to claim 14, characterized in that, include: The main body (1) has a second stage and a first stage, and the detection element (4) is adapted to communicate with the controller of the electrical equipment; The trap (2) is provided with a detection element (4) which detects the concentration of nitrogen-containing compounds flowing down to the trap (2) in the second stage and the first stage. The detection element (4) is adapted to communicate with the controller.

16. The engine (100) according to claim 15, characterized in that, Also includes: The catalytic converter (3) has its inlet (31) connected to the exhaust manifold of the main body (1) and its outlet (32) connected to the inlet (21) of the trap (2).

17. The engine (100) according to claim 16, characterized in that, The catalytic converter (3) includes a three-way catalytic converter (3).

18. The engine (100) according to claim 15, characterized in that, The detection component (4) is a nitrogen and oxygen sensor.

19. The engine (100) according to any one of claims 15-18, characterized in that, The trap (2) includes a dilute NOx trap.

20. An electrical appliance comprising an engine (100) controlled by the control method according to any one of claims 1-13, or an engine (100) according to any one of claims 14-19.

Images