Method for treating ammonia leakage, device and hybrid vehicle

Abstract

The application provides a method, device and hybrid vehicle for processing ammonia leakage. The method comprises: obtaining the mass flow of nitrogen oxides before and after the aftertreatment step, respectively, determining the catalyst utilization according to the mass flow, wherein the aftertreatment step represents the exhaust treatment step of the engine, and the catalyst utilization represents the utilization of the catalyst in the selective catalytic reduction device; obtaining the current temperature of the selective catalytic reduction device, determining the ammonia storage in the selective catalytic reduction device according to the catalyst utilization and the current temperature; and switching the torque of the engine to the first ammonia cleaning torque to reduce the leakage amount of ammonia at least in the case that the ammonia storage is greater than the preset ammonia threshold and the current temperature is greater than the preset temperature threshold. The application solves the problem of lacking a solution to ammonia leakage in the rapid heating process in the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas leakage processing, in particular to an ammonia leakage processing method and device, a computer readable storage medium and a hybrid vehicle. BACKGROUND

[0002] Nitrogen oxide (NOx) is a key emission pollutant of diesel engines. With the further tightening of emission regulations, SCR (Selective Catalytic Reduction, SCR for short) is commonly used to control NOx emissions. In the SCR carrier, NH3 decomposed from urea and NOx in the exhaust gas undergo catalytic reduction reaction. Most of the NH3 is reacted, and the NH3 that is not reacted is stored in the SCR carrier. When the urea injection amount is insufficient or the urea is stopped, the stored NH3 in the SCR carrier can continue to react with the NOx of the exhaust gas to reduce emissions. The ammonia storage capacity of the SCR carrier is related to the temperature of the SCR carrier. When the temperature is low, the ammonia storage capacity is strong. With the increase of temperature, the ammonia storage capacity gradually decreases. Especially when the temperature of the carrier rises sharply, the stored ammonia in the SCR carrier will escape rapidly. The ASC (Ammonia Slip Catalyst, ASC for short) cannot fully oxidize the released NH3, resulting in part of the NH3 being measured by the downstream NOx sensor, causing the emission to exceed the standard and reporting a 1.2 fault.

[0003] At present, many models have the problem of large ammonia leakage during temperature rise, especially light products. The aftertreatment volume is small, and the operating boundary is sensitive. The ammonia leakage during temperature rise is large, which leads to emission over-limit and high 1.2 fault rate. There is no solution to the ammonia leakage problem during the sharp temperature rise process in the prior art. SUMMARY

[0004] The main purpose of the present application is to provide an ammonia leakage processing method, device, computer readable storage medium and hybrid vehicle, so as to at least solve the problem that there is no solution to the ammonia leakage during the sharp temperature rise process in the prior art.

[0005] To achieve the above object, according to an aspect of the present application, a method for processing ammonia leakage is provided, which is applied to a hybrid system including at least an engine, an electric motor and a power battery, and includes: obtaining a first mass flow rate of nitrogen oxides before an after-treatment step and a second mass flow rate of nitrogen oxides after the after-treatment step, to obtain a first mass flow rate and a second mass flow rate, determining a catalyst utilization rate according to the first mass flow rate and the second mass flow rate, wherein the after-treatment step represents an exhaust treatment step of the engine, and the catalyst utilization rate represents a utilization rate of a catalyst in a selective catalytic reduction device; obtaining a current temperature of the selective catalytic reduction device, determining an ammonia storage amount in the selective catalytic reduction device according to the catalyst utilization rate and the current temperature; and switching a torque of the engine to a first ammonia cleaning torque to reduce an ammonia leakage amount, at least in a case that the ammonia storage amount is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, wherein an exhaust temperature of the engine at the first ammonia cleaning torque is lower than an exhaust temperature of the engine at a battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to a battery power state of the power battery.

[0006] Optionally, determining the ammonia storage amount in the selective catalytic reduction device according to the catalyst utilization rate and the current temperature includes: obtaining a one-to-one mapping relationship of the catalyst utilization rate, the current temperature and a predicted ammonia storage amount; and determining the predicted ammonia storage amount corresponding to the catalyst utilization rate and the current temperature according to the one-to-one mapping relationship, to obtain the ammonia storage amount.

[0007] Optionally, switching the torque of the engine to the first ammonia cleaning torque at least in a case that the ammonia storage amount is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold includes: obtaining a historical temperature of the selective catalytic reduction device, calculating a temperature difference between the current temperature and the historical temperature, wherein the historical temperature represents a temperature at a time point before a current time point corresponding to the current temperature; and determining that the engine is in an ammonia leakage high-risk state and switching the torque of the engine to the first ammonia cleaning torque in a case that the ammonia storage amount is greater than the preset ammonia threshold, the current temperature is greater than the preset temperature threshold, the temperature difference is positive and the temperature difference is greater than a preset temperature difference.

[0008] Optionally, switching the torque of the engine to the first ammonia cleaning torque includes: obtaining a current battery power state of the power battery; and switching the torque of the engine to the first ammonia cleaning torque in a case that the current battery power state represents that a battery power of the power battery is greater than a preset power threshold.

[0009] Optionally, after the torque of the engine is switched to the first ammonia removal torque, the method further comprises: obtaining a total demand torque; calculating a difference between the total demand torque and the first ammonia removal torque to obtain a second ammonia removal torque of the electric motor, and switching the torque of the electric motor to the second ammonia removal torque, wherein the total demand torque is greater than the first ammonia removal torque.

[0010] Optionally, the first mass flow rate and the second mass flow rate are used to determine the catalyst utilization rate, comprising: calculating a difference between the first mass flow rate and the second mass flow rate to obtain a conversion mass flow rate, and determining the catalyst utilization rate according to the conversion mass flow rate.

[0011] Optionally, the catalyst utilization rate is determined according to the conversion mass flow rate, comprising: obtaining a conversion coefficient, calculating a product of the conversion mass flow rate and the conversion coefficient to obtain a catalyst consumption amount, wherein the conversion coefficient represents a conversion rate between the nitrogen oxide and the catalyst; obtaining a catalyst injection amount, and calculating a ratio of the catalyst consumption amount to the catalyst injection amount to obtain the catalyst utilization rate.

[0012] According to another aspect of the present application, there is provided a device for processing ammonia leakage, applied to a hybrid power system, the hybrid power system comprising at least an engine, an electric motor and a power battery, the device for processing ammonia leakage comprising: a first determining unit configured to obtain a first mass flow rate of nitrogen oxide before a post-processing step and a second mass flow rate of nitrogen oxide after the post-processing step, and determine a catalyst utilization rate according to the first mass flow rate and the second mass flow rate, wherein the post-processing step represents an exhaust processing step of the engine, and the catalyst utilization rate represents a utilization rate of a catalyst in a selective catalytic reduction device; a second determining unit configured to obtain a current temperature of the selective catalytic reduction device, and determine an ammonia storage amount in the selective catalytic reduction device according to the catalyst utilization rate and the current temperature; and a switching unit configured to switch a torque of the engine to a first ammonia removal torque to reduce an ammonia leakage amount when at least the ammonia storage amount is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, wherein an exhaust temperature of the engine at the first ammonia removal torque is lower than an exhaust temperature of the engine at a battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to a battery power state of the power battery.

[0013] According to still another aspect of the present application, there is provided a computer readable storage medium comprising a stored program, wherein the computer readable storage medium controls a device where the computer readable storage medium is located to execute any one of the processing methods for ammonia leakage when the program runs.

[0014] According to a further aspect of the present application, a hybrid vehicle is provided, comprising: a hybrid system comprising at least an engine, an electric motor and a power battery; a controller comprising one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs comprising any one of the processing methods for ammonia leakage.

[0015] According to the technical solution of the present application, the mass flow of nitrogen oxides before and after the post-processing step is obtained respectively, and the catalyst utilization rate is determined according to the mass flow, wherein the post-processing represents the exhaust treatment of the engine, and the catalyst utilization rate represents the utilization rate of the catalyst in the selective catalytic reduction device; the current temperature of the selective catalytic reduction device is obtained, and the ammonia storage in the selective catalytic reduction device is determined according to the catalyst utilization rate and the current temperature; at least in the case that the ammonia storage is greater than the preset ammonia threshold and the current temperature is greater than the preset temperature threshold, the torque of the engine is switched to the first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine at the first ammonia cleaning torque is lower than the exhaust temperature of the engine at the battery power distribution torque, and the battery power distribution torque is the torque automatically distributed according to the battery power state of the power battery. In the prior art, the problem of ammonia leakage of the engine during the sharp temperature rise cannot be solved, and in the present application, the ammonia storage is predicted by the catalyst utilization rate, and the torque of the engine is controlled according to the ammonia storage to reduce the leakage amount of ammonia. Therefore, the problem of lack of solution to ammonia leakage during the sharp temperature rise in the prior art is solved, and the effect of reducing ammonia leakage is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0016] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application and the explanation thereof, to explain the present application, and do not constitute an improper limitation to the present application. In the drawings:

[0017] Figure 1 A hardware structure block diagram of a mobile terminal for executing the processing method for ammonia leakage provided by the embodiment of the present application is shown;

[0018] Figure 2 A flowchart of the processing method for ammonia leakage provided by the embodiment of the present application is shown;

[0019] Figure 3 A structural schematic diagram of a hybrid vehicle provided by the embodiment of the present application is shown;

[0020] Figure 4 A flowchart of a specific processing method for ammonia leakage provided by the embodiment of the present application is shown;

[0021] Figure 5 A relationship curve between SCR carrier temperature and conversion efficiency is shown according to an embodiment of the application.

[0022] Figure 6 A structural block diagram of a device for treating ammonia leakage is shown according to an embodiment of the application.

[0023] Among the above drawings, the following reference signs are included:

[0024] 102, processor; 104, memory; 106, transmission device; 108, input / output device. DETAILED DESCRIPTION

[0025] It should be noted that the embodiments and features in the application can be combined with each other without conflict. The application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0026] In order to enable those skilled in the art to better understand the application scheme, the technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the application.

[0027] It should be noted that the terms "first", "second" and the like in the specification and claims of the application and the above drawings are used to distinguish similar objects, and do not necessarily indicate a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application described herein can be implemented. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily limit to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0028] For the convenience of description, the following describes some nouns or terms related to the embodiments of the application:

[0029] Hybrid system: a set of electric drive system (i.e. electric motor and power battery) is installed on the basis of traditional car, engine and electric motor can drive wheels alone, also can work together to drive car, when the power battery is insufficient, the engine can also drive the motor to charge the battery.

[0030] The post-processing step is an exhaust treatment step of the engine, which generally includes the following steps:

[0031] DOC: Diesel Oxidation Catalyst, abbreviated as DOC, generally uses metal or ceramic as the carrier of the catalyst, and the main active component in the coating is precious metal and rare metal such as platinum and palladium. When the exhaust gas of the diesel engine passes through the catalyst, HC (hydrocarbon), CO (carbon monoxide) and other chemicals react with oxygen in the exhaust gas to generate non-polluting H2O and CO2, and the DOC achieves the purpose of purifying HC and CO in the exhaust gas;

[0032] DPF: Diesel Particulate Filter, abbreviated as DPF, through which PM (particulate matter) in the exhaust gas can be filtered and captured, which can reduce PM (particulate matter) in the exhaust gas. The filtering effect can usually reach 70%-90%. SCR mainly removes NOx (nitrogen oxides) in the exhaust gas. Using urea as a reducing agent, under the reduction of a selective catalyst, NOx (nitrogen oxides) in the exhaust gas is reduced to nitrogen and water;

[0033] SCR: Selective Catalytic Reduction, abbreviated as SCR, which mainly uses NH3 decomposed from urea to catalytically reduce NOx in the exhaust gas to reduce the emission level of exhaust gas NOx to meet regulatory requirements.

[0034] SCR: Selective Catalytic Reduction, abbreviated as SCR, which mainly uses NH3 decomposed from urea to catalytically reduce NOx in the exhaust gas, hybrid power system: based on traditional cars, a set of electric drive system (i.e. electric motor and power battery) is installed. The engine and the electric motor can both drive the wheels independently, or they can work together to drive the car. When the power battery is low, the engine can also drive the electric motor to charge the battery.

[0035] ASC: Ammonia Slip Catalyst, abbreviated as ASC, is a catalytic converter that oxidizes escaped ammonia (NH3) to nitrogen (N2), thereby reducing air pollution. It is one of the necessary post-processing catalytic technologies for ultra-low emission diesel vehicles.

[0036] As described in the background section, there is a lack of solutions for ammonia leakage during rapid heating in the prior art. To address the problem of the lack of solutions for ammonia leakage during rapid heating, embodiments of this application provide a method, apparatus, computer-readable storage medium, and hybrid vehicle for handling ammonia leakage.

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0038] The methods and embodiments provided in this application can be executed on a mobile terminal, computer terminal, or similar computing device. Taking running on a mobile terminal as an example, Figure 1 This is a hardware structure block diagram of a mobile terminal for a method of handling ammonia leakage according to an embodiment of the present invention. Figure 1 As shown, a mobile terminal may include one or more ( Figure 1 Only one is shown in the diagram. A processor 102 (which may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 104 for storing data are also shown. The mobile terminal may further include a transmission device 106 for communication functions and an input / output device 108. Those skilled in the art will understand that... Figure 1 The structure shown is for illustrative purposes only and does not limit the structure of the mobile terminal described above. For example, the mobile terminal may also include components that are more... Figure 1 The more or fewer components shown, or having the same Figure 1 The different configurations shown.

[0039] The memory 104 can be used to store computer programs, such as software programs of application software and modules, such as the computer program corresponding to the ammonia leakage processing method in the embodiments of the present application. The processor 102 can execute various functional applications and data processing, i.e., implement the above method, by running the computer program stored in the memory 104. The memory 104 can include a high-speed random access memory, and can further include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some examples, the memory 104 can further include a memory remotely arranged with respect to the processor 102, and the remote memory can be connected to the mobile terminal through a network. Examples of the above network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and a combination thereof. The transmission device 106 is used to receive or send data via a network. The specific examples of the above network can include a wireless network provided by a communication provider of the mobile terminal. In one example, the transmission device 106 includes a network adapter (NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 106 can be a radio frequency (RF) module, which is used to communicate with the Internet in a wireless manner.

[0040] In the embodiments, a processing method of ammonia leakage running on a mobile terminal, a computer terminal or a similar computing device is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that herein.

[0041] Figure 2 is a flowchart of the processing method of ammonia leakage according to the embodiments of the present application. As shown in Figure 2 applied to a hybrid system including at least an engine, a motor and a power battery, the method includes the following steps:

[0042] In step S201, the mass flow of nitrogen oxides before a post-processing step and the mass flow of nitrogen oxides after the post-processing step are obtained respectively to obtain a first mass flow and a second mass flow, and the catalyst utilization rate is determined according to the first mass flow and the second mass flow, wherein the post-processing step represents an exhaust treatment step of the engine, and the catalyst utilization rate represents the utilization rate of a catalyst in a selective catalytic reducer;

[0043] Specifically, the catalyst in the SCR (Selective Catalytic Reduction) is generally ammonia, and the ammonia storage in the SCR carrier can be predicted based on the catalyst utilization rate, i.e., the actual utilization rate of ammonia, by the following method: the mass flow rate of NOx before the aftertreatment step is subtracted from the mass flow rate of NOx after the aftertreatment step to obtain the mass flow rate of NOx converted by the aftertreatment; the actual urea consumption flow rate consumed to convert the NOx is calculated, and the actual urea consumption flow rate divided by the actual urea injection flow rate is the actual urea utilization rate, i.e., the catalyst utilization rate.

[0044] In step S202, the current temperature of the selective catalytic reducer is obtained, and the ammonia storage in the selective catalytic reducer is determined according to the catalyst utilization rate and the current temperature;

[0045] Specifically, the ammonia storage can be predicted based on the catalyst utilization rate and the current temperature of the SCR. In theory, when the SCR carrier, i.e., the selective catalytic reducer, has no ammonia storage, the utilization rate of urea is determined by the conversion efficiency, and the conversion efficiency of the SCR is directly related to the temperature of the SCR carrier, and the two are a relatively certain relationship curve. However, when there is ammonia storage in the SCR carrier, the stored ammonia also participates in the conversion of NOx, thereby increasing the utilization rate of urea. Therefore, the ammonia storage in the SCR carrier can be predicted based on the actual utilization rate of urea and the temperature of the SCR carrier. Under the condition of a certain temperature, the higher the actual utilization rate of urea is, the higher the level of ammonia stored in the carrier is.

[0046] In step S203, at least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the torque of the engine is switched to a first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine under the first ammonia cleaning torque is lower than the exhaust temperature of the engine under a battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to the state of charge of the power battery.

[0047] Specifically, the ammonia leakage risk state is identified based on the predicted ammonia storage and the temperature of the SCR: the ammonia storage is compared with the preset ammonia threshold, and when it is greater, it is considered that the carrier is in a high ammonia storage state; and when the temperature of the SCR is greater than the preset temperature threshold, it is considered that the engine is in a high temperature state; at least when the above two conditions are met, the temperature of the SCR carrier needs to be controlled in time to reduce ammonia leakage. Specifically, the torque of the engine can be switched to a first ammonia cleaning torque, and the exhaust temperature of the engine under the first ammonia cleaning torque is relatively low to reduce the exhaust temperature of the aftertreatment.

[0048] According to the embodiment, the mass flow of nitrogen oxides before and after the post-processing step is obtained respectively, and the catalyst utilization rate is determined according to the mass flow, wherein the post-processing refers to the exhaust treatment of the engine, and the catalyst utilization rate refers to the utilization rate of the catalyst in the selective catalytic reduction device; the current temperature of the selective catalytic reduction device is obtained, the ammonia storage in the selective catalytic reduction device is determined according to the catalyst utilization rate and the current temperature; and at least in the case that the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the torque of the engine is switched to a first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine at the first ammonia cleaning torque is lower than the exhaust temperature of the engine at the battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to the battery power state of the power battery. In the prior art, the problem of ammonia leakage of the engine during the sharp temperature rise process cannot be solved. In the present application, the ammonia storage is predicted according to the catalyst utilization rate, and the torque of the engine is controlled according to the ammonia storage to reduce the leakage amount of ammonia. Therefore, the problem of lack of solution to ammonia leakage during the sharp temperature rise process in the prior art is solved, and the effect of reducing ammonia leakage is achieved.

[0049] In the implementation process, the step S202 of determining the ammonia storage in the selective catalytic reduction device according to the catalyst utilization rate and the current temperature can be implemented by the following steps: step S2021 of obtaining a one-to-one mapping relationship between the catalyst utilization rate, the current temperature and the predicted ammonia storage; and step S2022 of determining the predicted ammonia storage corresponding to the catalyst utilization rate and the current temperature according to the one-to-one mapping relationship to obtain the ammonia storage. This method determines the ammonia storage by the above steps, which can accurately predict the current catalyst storage.

[0050] Specifically, since the SCR conversion efficiency is directly related to the temperature of the SCR carrier, i.e., the catalyst utilization rate, the current temperature and the predicted ammonia storage have a one-to-one mapping relationship, which can be in the form of a curve or a table, etc., therefore, the predicted ammonia storage corresponding to the catalyst utilization rate and the current temperature can be determined by the one-to-one mapping relationship, i.e., the current ammonia storage.

[0051] In some optional embodiments, the step S203 of switching the torque of the engine to the first ammonia cleaning torque can be implemented by the following steps: a step S2031 of obtaining a historical temperature of the selective catalytic reducer, and calculating a temperature difference between the current temperature and the historical temperature, wherein the historical temperature represents a temperature at a time point before the current time corresponding to the current temperature; and a step S2032 of determining that the engine is in the ammonia leakage high-risk state and switching the torque of the engine to the first ammonia cleaning torque when the ammonia storage is greater than the preset ammonia threshold, the current temperature is greater than the preset temperature threshold, the temperature difference is positive, and the temperature difference is greater than a preset temperature difference. The method further determines the switching of the torque of the engine to the first ammonia cleaning torque through the above steps, so as to more accurately determine the ammonia leakage risk and take further measures to prevent long-term ammonia leakage.

[0052] In the implementation process, in order to further determine the ammonia leakage risk, it is also necessary to judge the temperature variation range of the SCR carrier, i.e., the selective catalytic reducer, i.e., whether it is a rapid temperature rising process. It can be judged by whether the temperature difference between the historical temperature at a certain time point before the current time corresponding to the current temperature is greater than a preset temperature difference. The historical time point can be 10 minutes before the current time, and when the condition is met, it indicates that the engine is in the ammonia leakage high-risk state, and the torque of the engine is switched to the first ammonia cleaning torque.

[0053] In some optional embodiments, the step S203 of switching the torque of the engine to the first ammonia cleaning torque can be implemented by the following steps: a step S2033 of obtaining a current battery power state of the power battery; and a step S2034 of switching the torque of the engine to the first ammonia cleaning torque when the current battery power state indicates that the battery power of the power battery is greater than a preset power threshold. The method switches the torque when the current SOC (State of Charge, SOC for short) of the power battery indicates that the battery power is sufficient, so as to ensure that the engine has sufficient power.

[0054] Specifically, in order to ensure that the engine has sufficient power, the entering of the ammonia cleaning mode is triggered only when the engine is in the ammonia leakage high-risk state and the current SOC (battery power) is greater than a preset power threshold.

[0055] In some optional embodiments, after the torque of the engine is switched to the first ammonia-free torque, the method further comprises the following steps: step S204, obtaining a total demand torque; and step S205, calculating a difference between the total demand torque and the first ammonia-free torque to obtain a second ammonia-free torque of the electric motor, and switching the torque of the electric motor to the second ammonia-free torque, wherein the total demand torque is greater than the first ammonia-free torque. The method controls the torque of the electric motor to be converted through the above steps, so that the total torque load torque demand can be guaranteed.

[0056] In a specific implementation process, the total demand torque minus the engine set torque in the first ammonia-free mode obtains the set load of the electric motor in the ammonia-free mode, so as to control the electric motor to work. This control mode can effectively monitor the ammonia leakage risk state of the aftertreatment, and effectively reduce the exhaust temperature and the occurrence of ammonia leakage by controlling the engine torque when ammonia leakage is detected to have a high risk, thereby reducing the failure rate of more than 1.2.

[0057] In some optional embodiments, the step S201 of obtaining the mass flow rates of nitrogen oxides before and after the aftertreatment, and determining the catalyst utilization rate according to the first mass flow rate and the second mass flow rate can be achieved by the following steps: step S2011, calculating a difference between the first mass flow rate and the second mass flow rate to obtain a conversion mass flow rate, and determining the catalyst utilization rate according to the conversion mass flow rate.

[0058] In a specific implementation process, the first NOx mass flow rate minus the second NOx mass flow rate obtains the conversion mass flow rate; the actual urea flow rate consumed for converting the NOx is calculated, and the actual urea consumption flow rate is divided by the actual urea injection flow rate to obtain the actual urea utilization rate.

[0059] In some optional embodiments, the step S2012 can be achieved by the following steps: obtaining a conversion coefficient, calculating a product of the conversion mass flow rate and the conversion coefficient to obtain a catalyst consumption amount, wherein the conversion coefficient represents a conversion rate between the nitrogen oxides and the catalyst; obtaining a catalyst injection amount, and calculating a ratio of the catalyst consumption amount to the catalyst injection amount to obtain the catalyst utilization rate. The method calculates the catalyst utilization rate through the above steps, so that the catalyst utilization rate can be accurately calculated.

[0060] Specifically, the conversion relationship between NOx and urea can be determined by a conversion coefficient, so that the catalyst consumption amount is obtained by multiplying the conversion mass flow rate and the conversion coefficient; and the ratio of the catalyst consumption amount to the catalyst injection amount can obtain the catalyst utilization rate.

[0061] In order for those skilled in the art to more clearly understand the technical solutions of the present application, the implementation process of the ammonia leakage processing method of the present application will be described in detail below in conjunction with specific embodiments.

[0062] Figure 3 A structural schematic diagram of a hybrid vehicle provided by an embodiment of the present application is shown, which includes an engine, a clutch, a drive motor / generator, a power battery / BMS, a motor controller / MCU and an AMT system. Both the engine and the motor can drive the wheels alone, or can work together to drive the vehicle. When the power battery is insufficient, the engine can also charge the battery in combination with the motor.

[0063] The present embodiment relates to a specific ammonia leakage processing method, as shown, comprising the following steps: Figure 4

[0064] Step S1: subtract the original exhaust (before the aftertreatment step) NOx mass flow from the tail exhaust (after the aftertreatment step) NOx mass flow to obtain the conversion mass flow, calculate the product of the conversion mass flow and the NOx and urea conversion coefficient to obtain the actual urea consumption;

[0065] Step S2: calculate the ratio of the actual urea consumption to the actual urea injection flow to obtain the actual urea utilization rate;

[0066] Step S3: obtain the current temperature of the SCR, and determine the corresponding predicted ammonia storage (ammonia storage) according to the catalyst utilization rate (actual urea utilization rate) and the current temperature by looking up the ammonia storage prediction MAP;

[0067] Step S4: if the predicted ammonia storage (ammonia storage) is greater than the preset ammonia threshold, determine that the engine is in a high ammonia storage state;

[0068] Step S5: if the temperature difference between the current temperature and the historical temperature of the SCR is greater than the temperature rise amplitude threshold and the current temperature is greater than the preset temperature threshold, determine that the engine is in a high ammonia leakage risk state; Figure 5 A relationship curve diagram of the SCR carrier temperature and the conversion efficiency provided by an embodiment of the present application is shown, which is obtained by Figure 5 It can be seen that the SCR conversion efficiency is directly related to the temperature of the SCR carrier, and the two are a relatively certain relationship curve;

[0069] Step S6: if the current SOC is greater than the power limit value, the engine enters the ammonia cleaning mode;

[0070] Step S7: switch the engine demand torque based on the SOC torque distribution to the ammonia cleaning mode engine set torque (first ammonia cleaning torque); ​

[0071] Step S8: total demand torque minus engine set torque in ammonia purge mode to obtain motor set torque in ammonia purge mode, so as to control motor torque switch to output motor demand load and control motor to work.

[0072] The application further provides a device for processing ammonia leakage. It should be noted that the device for processing ammonia leakage can be used to execute the method for processing ammonia leakage. The device is used to realize the above-mentioned embodiments and preferred embodiments, and the description is omitted. As used below, the term "module" can be a combination of software and / or hardware that realizes a predetermined function. Although the device described in the following embodiments is preferably realized in software, hardware or a combination of software and hardware is also possible and is conceived.

[0073] The device for processing ammonia leakage is described below.

[0074] Figure 6 is a schematic diagram of the device for processing ammonia leakage according to the application. As shown in Figure 6 , the device comprises:

[0075] The first determination unit 10 is configured to obtain the mass flow of nitrogen oxides before the after-treatment step and the mass flow of nitrogen oxides after the after-treatment step, respectively, to obtain a first mass flow and a second mass flow, and to determine the catalyst utilization rate according to the first mass flow and the second mass flow, wherein the after-treatment step represents the exhaust treatment step of the engine, and the catalyst utilization rate represents the utilization rate of the catalyst in the selective catalytic reduction device.

[0076] Specifically, the catalyst in the SCR (Selective Catalytic Reduction) is generally ammonia, and the ammonia storage in the SCR carrier can be predicted based on the catalyst utilization rate, i.e., the actual utilization rate of ammonia. This is achieved by the following method: the mass flow of NOx before the after-treatment step is subtracted from the mass flow of NOx after the after-treatment step to obtain the mass flow of NOx converted by the after-treatment; the actual urea consumption flow consumed to convert the NOx is calculated, and the actual urea consumption flow divided by the actual urea injection flow is the actual urea utilization rate, i.e., the catalyst utilization rate.

[0077] The second determination unit 20 is configured to obtain the current temperature of the selective catalytic reduction device, and to determine the ammonia storage in the selective catalytic reduction device according to the catalyst utilization rate and the current temperature.

[0078] Specifically, based on the catalyst utilization rate and the current temperature of the SCR, the ammonia storage can be predicted. In theory, when the SCR carrier, i.e., the selective catalytic reducer, has no ammonia storage, the utilization rate of urea is determined by the conversion efficiency, and the SCR conversion efficiency is directly related to the temperature of the SCR carrier, and the two are a relatively certain relationship curve. However, when there is ammonia storage in the SCR carrier, the stored ammonia will also participate in the conversion of NOx, thereby increasing the utilization rate of urea. Therefore, based on the actual utilization rate of urea and the temperature of the SCR carrier, the ammonia storage of the SCR carrier can be predicted. Under the condition of a certain temperature, the higher the actual utilization rate of urea is, the higher the level of ammonia stored in the carrier is.

[0079] The switching unit 30 is configured to switch the torque of the engine to a first ammonia cleaning torque to reduce the leakage amount of ammonia, at least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold. The exhaust temperature of the engine under the first ammonia cleaning torque is lower than the exhaust temperature of the engine under a battery power distribution torque, which is an automatically distributed torque according to the state of charge of the power battery.

[0080] Specifically, based on the predicted ammonia storage and the SCR temperature, the ammonia leakage risk state is identified: the ammonia storage is compared with the preset ammonia threshold, and when it is greater, it is considered that the carrier is in a high ammonia storage state; and when the SCR temperature is greater than the preset temperature threshold, it is considered that the engine is in a high temperature state; at least when the above two conditions are met, the temperature of the SCR carrier needs to be controlled in time to reduce ammonia leakage. Specifically, the torque of the engine can be switched to a first ammonia cleaning torque, and the exhaust temperature of the engine under the torque is relatively low to reduce the exhaust temperature of the aftertreatment.

[0081] According to the embodiment, the mass flow of nitrogen oxides before and after the post-processing step is obtained respectively, and the catalyst utilization rate is determined according to the mass flow, wherein the post-processing refers to the exhaust treatment of the engine, and the catalyst utilization rate refers to the utilization rate of the catalyst in the selective catalytic reduction device; the current temperature of the selective catalytic reduction device is obtained, the ammonia storage in the selective catalytic reduction device is determined according to the catalyst utilization rate and the current temperature; at least in the case that the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the torque of the engine is switched to a first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine at the first ammonia cleaning torque is lower than the exhaust temperature of the engine at the battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to the battery power state of the power battery. In the prior art, the problem of ammonia leakage of the engine during the sharp temperature rise process cannot be solved. In the present application, the ammonia storage is predicted according to the catalyst utilization rate, and the torque of the engine is controlled according to the ammonia storage to reduce the leakage amount of ammonia. Therefore, the problem of lacking a solution device for ammonia leakage during the sharp temperature rise process in the prior art can be solved, and the effect of reducing ammonia leakage is achieved.

[0082] In the implementation process, the second determination unit includes a first acquisition module and a determination module. The first acquisition module is configured to acquire a one-to-one mapping relationship among the catalyst utilization rate, the current temperature, and the predicted ammonia storage. The determination module is configured to determine the predicted ammonia storage corresponding to the catalyst utilization rate and the current temperature according to the one-to-one mapping relationship, and obtain the ammonia storage. The device determines the ammonia storage through the above steps, which can accurately predict the current catalyst storage.

[0083] Specifically, since the SCR conversion efficiency is directly related to the temperature of the SCR carrier, i.e., the catalyst utilization rate, the current temperature, and the predicted ammonia storage have a one-to-one mapping relationship, which can be in the form of a curve or a table, etc., therefore, the predicted ammonia storage corresponding to the catalyst utilization rate and the current temperature can be determined through the one-to-one mapping relationship, i.e., the current ammonia storage.

[0084] In some optional embodiments, the switching unit comprises a calculation module and a first determination module. The calculation module is configured to obtain a historical temperature of the selective catalytic reduction device, and calculate a temperature difference between the current temperature and the historical temperature, wherein the historical temperature represents a temperature at a time point before the current time point corresponding to the current temperature. The first determination module is configured to determine that the engine is in the ammonia leakage high-risk state and switch the torque of the engine to the first ammonia cleaning torque, when the ammonia storage is greater than a preset ammonia threshold, the current temperature is greater than a preset temperature threshold, the temperature difference is positive, and the temperature difference is greater than a preset temperature difference.

[0085] In a specific implementation process, in order to further determine the ammonia leakage risk, it is also necessary to judge the temperature variation range of the SCR carrier, that is, the selective catalytic reduction device, that is, whether it is a rapid temperature rising process. It can be judged by whether the temperature difference between the historical temperature at a certain time point before the current time point corresponding to the current temperature is greater than a preset temperature difference. The historical time point can be 10 minutes before the current time point. When the condition is met, it indicates that the engine is in the ammonia leakage high-risk state, and the torque of the engine is switched to the first ammonia cleaning torque.

[0086] In some optional embodiments, the switching unit further comprises a second acquisition module and a first switching module. The second acquisition module is configured to obtain a current battery state of charge of the power battery. The first switching module is configured to switch the torque of the engine to the first ammonia cleaning torque when the current battery state of charge represents that the battery capacity of the power battery is greater than a preset capacity threshold. The device switches the torque through the above steps when the current SOC (State of Charge, SOC for short) of the power battery indicates that the battery capacity is sufficient, which can ensure that the engine has sufficient power.

[0087] Specifically, in order to ensure that the engine has sufficient power, the engine enters the ammonia cleaning mode only when the engine is in the ammonia leakage high-risk state and the current SOC (battery capacity) is greater than a preset capacity threshold.

[0088] In some optional embodiments, after the torque of the engine is switched to the first ammonia-free torque, the device further comprises an acquisition unit and a second switching unit, the acquisition unit is configured to acquire a total demand torque; the second switching unit is configured to calculate a difference between the total demand torque and the first ammonia-free torque, to obtain a second ammonia-free torque of the electric motor, and to switch the torque of the electric motor to the second ammonia-free torque, wherein the total demand torque is greater than the first ammonia-free torque. The device converts the torque of the electric motor through the above steps, which can ensure the total torque load torque demand.

[0089] In the specific implementation process, the total demand torque minus the engine set torque in the first ammonia-free mode obtains the set load of the electric motor in the ammonia-free mode, so as to control the electric motor to work. This control mode can effectively monitor the ammonia leakage risk state of the aftertreatment, and effectively reduce the exhaust temperature and the occurrence of ammonia leakage by controlling the engine torque when ammonia leakage is detected to have a high risk, thereby reducing the failure rate of more than 1.2.

[0090] In some optional embodiments, the first determination unit comprises a second determination module, configured to calculate a difference between the first mass flow and the second mass flow to obtain a conversion mass flow, and to determine the catalyst utilization rate according to the conversion mass flow.

[0091] In the specific implementation process, the first NOx mass flow minus the second NOx mass flow obtains the conversion mass flow; the actual urea flow consumed for converting the NOx is calculated, and the actual urea consumption flow is divided by the actual urea injection flow to obtain the actual urea utilization rate.

[0092] In some optional embodiments, the second determination module comprises a first calculation submodule and a second calculation submodule, the first calculation submodule is configured to acquire a conversion coefficient, to calculate a product of the conversion mass flow and the conversion coefficient to obtain a catalyst consumption amount, wherein the conversion coefficient represents a conversion rate between the nitrogen oxides and the catalyst; and the second calculation submodule is configured to acquire a catalyst injection amount, to calculate a ratio of the catalyst consumption amount to the catalyst injection amount to obtain the catalyst utilization rate. The device calculates the catalyst utilization rate through the above steps, which can accurately calculate the catalyst utilization rate.

[0093] Specifically, the conversion relationship between the NOx and the urea can be determined by a conversion coefficient, so that the catalyst consumption amount is obtained by multiplying the conversion mass flow and the conversion coefficient; and the ratio of the catalyst consumption amount to the catalyst injection amount can obtain the catalyst utilization rate.

[0094] The ammonia leakage processing device includes a processor and a memory, the first determination unit, the second determination unit, and the switching unit are all stored in the memory as program units, and the corresponding functions are realized by the processor executing the program units stored in the memory. The modules are all located in the same processor, or the modules are located in different processors in any combination.

[0095] The processor includes a core, and the core calls the corresponding program units in the memory. The core can be one or more, and the ammonia leakage problem can be solved by adjusting the core parameters.

[0096] The memory can include a non-permanent memory in a computer readable medium, a random access memory (RAM), and / or a non-volatile memory such as a read-only memory (ROM) or a flash memory (flash RAM), and the memory includes at least one memory chip.

[0097] The embodiment of the application provides a computer readable storage medium, which includes a stored program, wherein when the program runs, the device where the computer readable storage medium is located executes the ammonia leakage processing method.

[0098] Specifically, the ammonia leakage processing method includes:

[0099] In step S201, the mass flow of nitrogen oxides before a post-processing step and the mass flow of nitrogen oxides after the post-processing step are obtained respectively to obtain a first mass flow and a second mass flow, and the catalyst utilization rate is determined according to the first mass flow and the second mass flow, wherein the post-processing step represents an exhaust treatment step of the engine, and the catalyst utilization rate represents the utilization rate of a catalyst in a selective catalytic reduction device.

[0100] Specifically, the catalyst in the SCR (Selective Catalytic Reduction) is generally ammonia, and the ammonia storage in the SCR carrier can be predicted based on the catalyst utilization rate, that is, the actual utilization rate of ammonia. The method is as follows: the mass flow of NOx before the post-processing step is subtracted from the mass flow of NOx after the post-processing step to obtain the mass flow of NOx converted by the post-processing; the actual urea consumption flow consumed to convert the NOx is calculated, and the actual urea utilization rate, that is, the catalyst utilization rate, is obtained by dividing the actual urea consumption flow by the actual urea injection flow.

[0101] In step S202, the current temperature of the selective catalytic reduction device is obtained, and the ammonia storage in the selective catalytic reduction device is determined according to the catalyst utilization rate and the current temperature.

[0102] Specifically, based on the catalyst utilization rate and the current temperature of the SCR, the ammonia storage can be predicted. In theory, when the SCR carrier, i.e., the selective catalytic reducer, has no ammonia storage, the utilization rate of urea is determined by the conversion efficiency, and the SCR conversion efficiency is directly related to the temperature of the SCR carrier, and the two are a relatively certain relationship curve. However, when there is ammonia storage in the SCR carrier, the stored ammonia also participates in the conversion of NOx, thereby increasing the utilization rate of urea. Therefore, based on the actual utilization rate of urea and the temperature of the SCR carrier, the ammonia storage of the SCR carrier can be predicted. Under the condition of a certain temperature, the higher the actual utilization rate of urea is, the higher the level of ammonia stored in the carrier is.

[0103] In step S203, at least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the torque of the engine is switched to a first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine under the first ammonia cleaning torque is lower than the exhaust temperature of the engine under a battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to the state of charge of the power battery.

[0104] Specifically, based on the predicted ammonia storage and the SCR temperature, the ammonia leakage risk state is identified: the ammonia storage is compared with the preset ammonia threshold, and when it is greater than the preset ammonia threshold, it is considered that the carrier is in a high ammonia storage state; and when the SCR temperature is greater than the preset temperature threshold, it is considered that the engine is in a high temperature state; at least when the above two conditions are met, the temperature of the SCR carrier needs to be controlled in time to reduce ammonia leakage. Specifically, the torque of the engine can be switched to a first ammonia cleaning torque, and the exhaust temperature of the engine under the first ammonia cleaning torque is relatively low to reduce the exhaust temperature of the aftertreatment.

[0105] The embodiment of the present application provides a hybrid vehicle, comprising: a hybrid power system, the hybrid power system at least comprising an engine, an electric motor and a power battery; a controller comprising one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs comprise a method for processing ammonia leakage as described in any one of the following aspects:

[0106] In step S201, the mass flow of nitrogen oxides before an aftertreatment step and the mass flow of nitrogen oxides after the aftertreatment step are obtained respectively to obtain a first mass flow and a second mass flow, and the catalyst utilization rate is determined according to the first mass flow and the second mass flow, wherein the aftertreatment step represents an exhaust treatment step of the engine, and the catalyst utilization rate represents the utilization rate of a catalyst in a selective catalytic reducer;

[0107] Specifically, the catalyst in the SCR (Selective Catalytic Reduction) is generally ammonia, and the ammonia storage in the SCR carrier can be predicted based on the catalyst utilization rate, i.e., the actual utilization rate of ammonia, by the following method: the mass flow rate of NOx before the aftertreatment step is subtracted from the mass flow rate of NOx after the aftertreatment step to obtain the mass flow rate of NOx converted by the aftertreatment; the actual urea consumption flow rate consumed to convert the NOx is calculated, and the actual urea consumption flow rate divided by the actual urea injection flow rate is the actual urea utilization rate, i.e., the catalyst utilization rate.

[0108] In step S202, the current temperature of the selective catalytic reducer is obtained, and the ammonia storage in the selective catalytic reducer is determined according to the catalyst utilization rate and the current temperature;

[0109] Specifically, the ammonia storage can be predicted based on the catalyst utilization rate and the current temperature of the SCR. In theory, in the case that there is no ammonia storage in the SCR carrier, i.e., the selective catalytic reducer, the utilization rate of urea is determined by the conversion efficiency, and the conversion efficiency of the SCR is directly related to the temperature of the SCR carrier, and the two are a relatively certain relationship curve. However, when there is ammonia storage in the SCR carrier, the stored ammonia also participates in the conversion of NOx, thereby increasing the utilization rate of urea. Therefore, the ammonia storage in the SCR carrier can be predicted based on the actual utilization rate of urea and the temperature of the SCR carrier. Under the condition of a certain temperature, the higher the actual utilization rate of urea is, the higher the level of ammonia stored in the carrier is.

[0110] In step S203, at least in the case that the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the torque of the engine is switched to a first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine under the first ammonia cleaning torque is lower than the exhaust temperature of the engine under a battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to the state of charge of the power battery.

[0111] Specifically, the ammonia leakage risk state is identified based on the predicted ammonia storage and the temperature of the SCR: the ammonia storage is compared with the preset ammonia threshold, and in the case that it is greater, it is considered that the carrier is in a high ammonia storage state; and the temperature of the SCR is greater than the preset temperature threshold, and it is considered that the engine is in a high temperature state; at least in the case that the above two conditions are met, the temperature of the SCR carrier needs to be controlled in time to reduce the ammonia leakage. Specifically, the torque of the engine can be switched to a first ammonia cleaning torque, and the exhaust temperature of the engine under the first ammonia cleaning torque is relatively low to reduce the exhaust temperature of the aftertreatment.

[0112] The application further provides a computer program product comprising a computer program which, when executed by a processor, implements the steps of the method described in various embodiments of the application.

[0113] In step S201, the mass flow of nitrogen oxides before a post-processing step and the mass flow of nitrogen oxides after the post-processing step are obtained respectively to obtain a first mass flow and a second mass flow, and the catalyst utilization rate is determined according to the first mass flow and the second mass flow, wherein the post-processing step represents an exhaust treatment step of the engine, and the catalyst utilization rate represents the utilization rate of a catalyst in a selective catalytic reduction device.

[0114] Specifically, the catalyst in the SCR (Selective Catalytic Reduction) is generally ammonia, and the ammonia storage in the SCR carrier can be predicted based on the catalyst utilization rate, i.e., the actual utilization rate of ammonia, by the following method: the mass flow of NOx before the post-processing step is subtracted from the mass flow of NOx after the post-processing step to obtain the mass flow of NOx converted by the post-processing; the actual urea consumption flow consumed to convert the NOx is calculated, and the actual urea consumption flow divided by the actual urea injection flow is the actual urea utilization rate, i.e., the catalyst utilization rate.

[0115] In step S202, the current temperature of the selective catalytic reduction device is obtained, and the ammonia storage in the selective catalytic reduction device is determined according to the catalyst utilization rate and the current temperature.

[0116] Specifically, the ammonia storage can be predicted based on the catalyst utilization rate and the current temperature of the SCR. In theory, when the SCR carrier, i.e., the selective catalytic reduction device, has no ammonia storage, the utilization rate of urea is determined by the conversion efficiency, and the SCR conversion efficiency is directly related to the temperature of the SCR carrier, and the two are a relatively certain relationship curve. However, when there is ammonia storage in the SCR carrier, the stored ammonia also participates in the conversion of NOx, thereby increasing the utilization rate of urea. Therefore, the ammonia storage of the SCR carrier can be predicted based on the actual utilization rate of urea and the temperature of the SCR carrier. Under the condition of a certain temperature, the higher the actual urea utilization rate, the higher the level of ammonia stored in the carrier.

[0117] In step S203, at least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the torque of the engine is switched to a first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine under the first ammonia cleaning torque is lower than the exhaust temperature of the engine under a battery power distribution torque, and the battery power distribution torque is a torque automatically distributed according to the state of charge of the power battery.

[0118] Specifically, the ammonia leakage risk state is identified based on the predicted ammonia storage and the SCR temperature: the ammonia storage is compared with a preset ammonia threshold value, and in the case of being greater than the preset ammonia threshold value, it is considered that the carrier is in a high ammonia storage state; and the SCR temperature is greater than a preset temperature threshold value, then it is considered that the engine is in a high temperature state; at least in the case where the above two conditions are met, the SCR carrier temperature needs to be controlled in time to reduce ammonia leakage. Specifically, the torque of the engine can be switched to a first ammonia cleaning torque, and the exhaust temperature of the engine is relatively low at the torque, so as to reduce the exhaust temperature of the aftertreatment.

[0119] Obviously, those skilled in the art should understand that the above-mentioned modules or steps of the present application can be realized by a general computing device, which can be concentrated on a single computing device or distributed on a network composed of multiple computing devices, which can be realized by program codes executable by a computing device, so that they can be stored in a storage device and executed by a computing device, and in some cases, the steps shown or described can be executed in different order, or they can be made into individual integrated circuit modules, or multiple modules or steps can be made into a single integrated circuit module. Thus, the present application is not limited to any specific hardware and software combination.

[0120] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0121] The present application is described with reference to flowcharts and / or block diagrams according to the method, device (system), and computer program product of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be realized by computer program instructions. These computer program instructions can be provided to a general purpose computer, a special purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the computer or other programmable data processing device produce a device for implementing the functions specified in the flowcharts and / or block diagrams. Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks. Figure 1 The device for implementing the functions specified in one flow or multiple flows and / or blocks.

[0122] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0123] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0124] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0125] The memory can include non-persistent memory and / or volatile memory, such as a random access memory (RAM) including a cache area for the temporary storage of data. The memory can also include non-volatile memory, such as read only memory (ROM), electrically programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, or non-volatile random access memory (NVRAM), for the storage of information, such as data files or program

[0126] Computer readable media includes permanent and non-permanent, removable and non-removable media implemented in any method or technology for the storage of information. The information can be computer readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read only memory (ROM), electrically erasable programmable read only memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital versatile discs (DVDs) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer readable media does not include transitory media, such as modulated data signals and carrier waves.

[0127] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0128] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0129] 1) In the ammonia leakage handling method of this application, the mass flow rate of nitrogen oxides before and after the post-treatment step is obtained respectively, and the catalyst utilization rate is determined based on the mass flow rate. Here, post-treatment refers to the exhaust gas treatment of the engine, and catalyst utilization rate refers to the utilization rate of the catalyst in the selective catalytic reduction (SCR) unit. The current temperature of the SCR unit is obtained, and the ammonia storage in the SCR unit is determined based on the catalyst utilization rate and the current temperature. At least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the engine torque is switched to a first ammonia-clearing torque to reduce ammonia leakage. Under the first ammonia-clearing torque, the engine exhaust temperature is lower than the engine exhaust temperature under the battery power distribution torque, where the battery power distribution torque is the torque automatically distributed based on the battery's state of charge. Compared to existing technologies that cannot solve the problem of ammonia leakage during rapid engine heating, this application predicts ammonia storage through catalyst utilization and controls engine torque based on the ammonia storage to reduce ammonia leakage. Therefore, it can solve the problem of the lack of a solution for ammonia leakage during rapid heating in existing technologies, achieving the effect of reducing ammonia leakage.

[0130] 2) In the ammonia leakage processing device of the application, the mass flow of nitrogen oxides before and after the post-processing step is obtained respectively, and the catalyst utilization rate is determined according to the mass flow, wherein the post-processing refers to the exhaust treatment of the engine, and the catalyst utilization rate refers to the utilization rate of the catalyst in the selective catalytic reduction device; the current temperature of the selective catalytic reduction device is obtained, and the ammonia storage in the selective catalytic reduction device is determined according to the catalyst utilization rate and the current temperature; at least in the case that the ammonia storage is greater than the preset ammonia threshold and the current temperature is greater than the preset temperature threshold, the torque of the engine is switched to the first ammonia cleaning torque to reduce the leakage amount of ammonia, wherein the exhaust temperature of the engine at the first ammonia cleaning torque is lower than the exhaust temperature of the engine at the battery power distribution torque, and the battery power distribution torque is the torque automatically distributed according to the battery power state of the power battery. In the prior art, the problem of ammonia leakage during the rapid heating process of the engine cannot be solved. In the application, the ammonia storage is predicted by the catalyst utilization rate, and the torque of the engine is controlled according to the ammonia storage to reduce the leakage amount of ammonia. Therefore, the problem of lacking a solution device for ammonia leakage during the rapid heating process in the prior art can be solved, and the effect of reducing ammonia leakage is achieved.

[0131] The above only describes the preferred embodiments of the application and is not intended to limit the application. Those skilled in the art can make various changes and modifications to the application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application shall be included in the protection scope of the application.

Claims

1. A method for handling ammonia leakage, characterized in that, Applied to a hybrid power system, which includes at least an engine, an electric motor, and a power battery, the method for handling the ammonia leak includes: The mass flow rate of nitrogen oxides before the post-treatment step and the mass flow rate of nitrogen oxides after the post-treatment step are obtained to obtain a first mass flow rate and a second mass flow rate. The catalyst utilization rate is determined based on the first mass flow rate and the second mass flow rate. The post-treatment step refers to the exhaust gas treatment step of the engine, and the catalyst utilization rate refers to the actual urea utilization rate in the selective catalytic reduction unit. The current temperature of the selective catalytic reducer is obtained, and the ammonia storage in the selective catalytic reducer is determined based on the catalyst utilization rate and the current temperature. At least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the engine torque is switched to a first ammonia-clearing torque to reduce ammonia leakage. Under the first ammonia-clearing torque, the engine exhaust temperature is lower than the engine exhaust temperature under the battery power distribution torque. The battery power distribution torque is a torque automatically allocated based on the battery's state of charge. Obtaining the mass flow rates of nitrogen oxides before and after post-treatment, and determining the catalyst utilization rate based on the first and second mass flow rates, includes: calculating the difference between the first and second mass flow rates to obtain the conversion mass flow rate, and determining the catalyst utilization rate based on the conversion mass flow rate. Determining the catalyst utilization rate based on the conversion mass flow rate includes: obtaining a conversion coefficient, calculating the product of the conversion mass flow rate and the conversion coefficient to obtain the catalyst consumption, wherein the conversion coefficient characterizes the conversion rate between the nitrogen oxides and the catalyst; obtaining the catalyst injection rate, calculating the ratio of the catalyst consumption to the catalyst injection rate to obtain the catalyst utilization rate.

2. The method for handling ammonia leakage according to claim 1, characterized in that, Determining the ammonia storage in the selective catalytic reducer based on the catalyst utilization rate and the current temperature includes: Obtain a one-to-one mapping relationship between the catalyst utilization rate, the current temperature, and the predicted ammonia reserves; Based on the one-to-one mapping relationship, the catalyst utilization rate and the predicted ammonia reserves corresponding to the current temperature are determined, and the ammonia reserves are obtained.

3. The method for handling ammonia leakage according to claim 1, characterized in that, At least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, the engine torque is switched to the first ammonia-clearing torque, including: Obtain the historical temperature of the selective catalytic reducer, and calculate the temperature difference between the current temperature and the historical temperature, wherein the historical temperature represents the temperature at the time before the current time corresponding to the current temperature; If the ammonia storage is greater than a preset ammonia threshold, the current temperature is greater than a preset temperature threshold, the temperature difference is positive and greater than a preset temperature difference, the engine is determined to be in a high-risk state of ammonia leakage, and the engine torque is switched to the first ammonia-clearing torque.

4. The method for handling ammonia leakage according to claim 1, characterized in that, Switching the engine torque to the first ammonia-clearing torque includes: Obtain the current battery charge status of the power battery; When the current battery charge status indicates that the battery charge of the power battery is greater than a preset charge threshold, the torque of the engine is switched to the first ammonia-clearing torque.

5. The method for handling ammonia leakage according to claim 1, characterized in that, After switching the engine torque to the first ammonia-clearing torque, the method further includes: Obtain the total required torque; The difference between the total required torque and the first ammonia removal torque is calculated to obtain the second ammonia removal torque of the motor, and the torque of the motor is switched to the second ammonia removal torque, wherein the total required torque is greater than the first ammonia removal torque.

6. A device for handling ammonia leaks, characterized in that, Applied to a hybrid power system, the hybrid power system including at least an engine, an electric motor, and a power battery, the ammonia leakage handling device includes: The first determining unit is used to obtain the mass flow rate of nitrogen oxides before the post-treatment step and the mass flow rate of nitrogen oxides after the post-treatment step, respectively, to obtain a first mass flow rate and a second mass flow rate, and to determine the catalyst utilization rate based on the first mass flow rate and the second mass flow rate, wherein the post-treatment step refers to the exhaust gas treatment step of the engine, and the catalyst utilization rate refers to the actual urea utilization rate in the selective catalytic reduction unit. The second determining unit is used to obtain the current temperature of the selective catalytic reducer and determine the ammonia storage in the selective catalytic reducer based on the catalyst utilization rate and the current temperature. A switching unit is configured to switch the engine torque to a first ammonia-clearing torque, at least when the ammonia storage is greater than a preset ammonia threshold and the current temperature is greater than a preset temperature threshold, in order to reduce ammonia leakage. Under the first ammonia-clearing torque, the engine exhaust temperature is lower than the engine exhaust temperature under the battery power distribution torque. The battery power distribution torque is a torque automatically allocated based on the battery charge status of the power battery. The first determining unit includes a second determining module, used to calculate the difference between the first mass flow rate and the second mass flow rate to obtain the conversion mass flow rate, and to determine the catalyst utilization rate based on the conversion mass flow rate. The second determining module includes a first calculation submodule and a second calculation submodule. The first calculation submodule is used to obtain the conversion coefficient, calculate the product of the conversion mass flow rate and the conversion coefficient to obtain the catalyst consumption, wherein the conversion coefficient characterizes the conversion rate between the nitrogen oxides and the catalyst. The second calculation submodule is used to obtain the catalyst injection rate, calculate the ratio of the catalyst consumption to the catalyst injection rate to obtain the catalyst utilization rate.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the computer-readable storage medium to perform the ammonia leak handling method according to any one of claims 1 to 5.

8. A hybrid vehicle, characterized in that, include: A hybrid power system, the hybrid power system comprising at least an engine, an electric motor, and a power battery; A controller includes one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including methods for performing ammonia leak treatment as described in any one of claims 1 to 5.

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