A method for calculating the total amount of actual driving emissions of light vehicles

Abstract

The present invention belongs to the field of motor vehicle emission detection, and specifically provides a method for calculating the total amount of actual driving emissions of light vehicles, including: step 1: determining the measurement method required for calculating the total amount of actual driving emissions of light vehicles and the number of light vehicles in each emission stage, and measuring the pollution area; step 2: dividing the VSP interval and calculating the actual driving emission factor of light vehicles in each emission stage according to the measurement method and the actual driving operation status of the light vehicles; step 3: determining the correction coefficient according to the influence of temperature, air conditioning, mileage degradation, and oil products on the emission factor. Step 4: calculating the total amount of actual driving emissions of light vehicles according to the actual driving emission factor, correction coefficient, ownership and annual average mileage of light vehicles. The method fully considers the influence of temperature differences in different months, changes in ethanol gasoline components, etc. on the total amount of emissions, and proposes a correction method, which provides key reference data for the monitoring and control of mobile source emission pollutants.

Description

Technical Field

[0001] The present invention relates to the field of vehicle emission detection, and in particular to a method for calculating the total amount of actual driving emissions of a light vehicle. Background Art

[0002] Mobile source pollution has become an important source of air pollution in large and medium-sized cities in my country, and the need to strengthen mobile source pollution control is becoming more urgent. Motor vehicle pollutant emissions are the main component of mobile source emissions and are also a problem of continuous concern in the field of environmental monitoring. With the update of emission standards, the limits on motor vehicle pollutant emissions have gradually become stricter, and the Euro VII emission draft also puts forward higher requirements for motor vehicle pollutant emissions. Therefore, the assessment of the total amount of actual driving emissions of light vehicles provides key reference data for the monitoring and control of mobile source emissions pollutants.

[0003] The existing light vehicle emission total amount assessment method stays at the standard working condition, which cannot fully reflect the emission situation during actual driving, and lacks correction of actual driving influencing factors such as different temperature scenes, after the addition of ethanol gasoline, and when the vehicle deteriorates with the increase of mileage. Therefore, a light vehicle actual driving emission total amount assessment method that can solve the existing problems is needed. Summary of the invention

[0004] The purpose of the present invention is to address the defects of the prior art and propose a method for calculating the total amount of actual driving emissions of light vehicles. In the field of motor vehicle emission monitoring, a measurement method that conforms to the actual driving characteristics of light vehicles is adopted, and an accurate calculation model is used with an annual test cycle to realize the evaluation of the total amount of actual driving emissions of light vehicles. The total amount of emissions is corrected according to the influencing factors during the actual driving process, providing key reference data for the introduction of relevant laws and policies, and the monitoring and control of pollutants emitted by mobile sources.

[0005] The technical solution of the present invention is to provide a method for calculating the total amount of actual driving emissions of light vehicles, which specifically includes:

[0006] Step 1: Determine the measurement method and number of light vehicles required for calculating the total amount of actual driving emissions of light vehicles at each emission stage. The road method is used to measure the CO, NOx, and PN emissions of light vehicles during hot operation, and the chassis dynamometer method is used to measure THC and PM emissions, as well as CO, NOx, and PN during cold start.

[0007] Step 2: Based on the measurement method determined in step 1 and the actual driving status of the light-duty vehicle, divide the VSP interval and calculate the actual driving emission factor of the light-duty vehicle in each emission stage;

[0008] Step 3: Determine the correction factor based on the effects of temperature, air conditioning, mileage degradation, and oil quality on the emission factor.

[0009] Step 4: Calculate the total actual driving emissions of light vehicles based on the actual driving emission factor, correction coefficient, ownership and annual average mileage of light vehicles.

[0010] Furthermore, in step 2, the actual operation of light vehicles is divided into different VSP intervals according to the VSP and speed information during the actual operation process, and the average pollutant emission rates of different pollutants of light vehicles in each VSP interval at different emission stages are calculated. The average pollutant emission rates are accumulated according to the time distribution of typical working conditions in the required area to obtain the actual driving emission factors of light vehicles at each emission stage.

[0011] Furthermore, step 2 is specifically implemented in the following manner:

[0012] Step 2.1: Calculate the actual CO and NO emissions of light-duty vehicles during the thermal operation of each emission stage based on the road method pollutant emission measurement results. x , PN emission factor;

[0013] Step 2.2: Calculate the CO and NO emissions of the light-duty vehicle during the actual cold start process at each emission stage based on the chassis dynamometer method pollutant emission measurement results. x , THC, PN emission factors.

[0014] Step 2.3: Calculate the PM emission factor of the light-duty vehicle in actual driving and the THC emission factor in the hot running process at each emission stage based on the pollutant emission measurement results of the chassis dynamometer method;

[0015] Step 2.4: Calculate the actual driving emission factors of light vehicles based on the cold start and hot running emission factors of each light vehicle emission pollutant in each emission stage and the actual driving conditions.

[0016] Furthermore, step 3 is specifically implemented in the following manner:

[0017] Step 3.1: Determine the temperature correction coefficient of the actual driving emission of light vehicles under different temperature conditions;

[0018] Step 3.2: Determine the air conditioning correction factor for actual driving emissions of light vehicles;

[0019] Step 3.3: Determine the light vehicle actual driving emission mileage degradation correction factor;

[0020] Step 3.4: Determine the fuel correction factor for actual driving emissions of light vehicles.

[0021] The chassis dynamometer method is used to measure emission pollutants. The ratio of the measurement results of the same emission pollutants of light vehicles at the same emission stage when filled with ethanol gasoline and regular gasoline is the oil correction factor for the emission pollutants at that emission stage.

[0022] Further, in step 3.1, the emission pollutants are measured by the chassis dynamometer method under the environmental conditions of -7°C, 14°C, 23°C, 35°C and 40°C to determine the temperature correction coefficient under the different temperature conditions;

[0023] Furthermore, in step 3.2, chassis dynamometer measurement is performed with the air conditioner turned on and off in a high temperature environment to determine the air conditioner correction coefficient for actual driving emissions of the light vehicle.

[0024] Furthermore, in step 3.3, the measured light vehicle is driven on actual roads and completes a cumulative mileage of 100,000 km. Within 100,000 km, a chassis dynamometer method emission measurement is performed once for every 10,000 km of accumulated mileage. The emission values ​​of each pollutant at 6,400 km and 160,000 km are calculated after curve fitting using the least squares method, and the mileage degradation correction coefficient of each pollutant is determined by the ratio of the emission result at 160,000 km to the emission result at 6,400 km.

[0025] Furthermore, in step 3.4: the chassis dynamometer method is used to measure the emission pollutants, and the ratio of the measurement results of the same emission pollutants of the light vehicle in the same emission stage when filled with ethanol gasoline and ordinary gasoline is the oil correction coefficient of the emission pollutants in the emission stage.

[0026] Furthermore, in step 4, the total amount of actual driving emissions of different pollutants of different types of light vehicles at different emission stages is calculated. Calculated according to the following formula:

[0027] ;

[0028] Where: m j,i is the actual driving emission factor of light vehicles in the emission stage i of the j-emission pollutant; j is each emission pollutant, including CO, THC, NO x , PM, PN; i is the emission stage, including National III, National IV, National V, and National VI; v is the type of light vehicle, including microbus, small bus, and taxi; k1 is the mileage degradation correction factor; L is the mileage of light vehicles, km; L1 is the initial degradation mileage of light vehicles, km; K2 is the temperature correction factor, including the temperature correction factors at -7℃, 14℃, 23℃, 35℃, and 40℃; K3 is the oil correction factor, which is 1 when filling with ordinary gasoline; K4 is the air conditioning correction factor; T V is the average annual mileage of Class V light vehicles, km / year; Q v The number of Class V light vehicles in use;

[0029] Actual driving emission of different pollutants at different emission stages M j,i Calculated according to the following formula:

[0030] .

[0031] The present invention has the following beneficial effects:

[0032] In the field of motor vehicle emission monitoring, a measurement method that conforms to the actual driving characteristics of light vehicles is adopted, with an annual test cycle, and an accurate calculation model is used to achieve the evaluation of the total amount of actual driving emissions of light vehicles. According to the influencing factors in the actual driving process, the influence of temperature differences in different months, deterioration caused by the increase in vehicle age, and changes in ethanol gasoline components on the total amount of emissions is fully considered, and a correction method is proposed, which provides key reference data for the introduction of relevant laws and policies, and the monitoring and control of mobile source emission pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The present invention is a flowchart of a method for calculating the total amount of actual driving emissions of a light vehicle. DETAILED DESCRIPTION

[0034] The following is combined with Figure 1 The present invention patent is further explained.

[0035] This embodiment provides a method for calculating the total amount of actual driving emissions of a light vehicle, specifically including:

[0036] Step 1: Determine the measurement method and number of light vehicles at each emission stage required for calculating the actual total emission of light vehicles. The road method is used to measure the CO, NOx, and PN emissions of light vehicles during hot operation, and the chassis dynamometer method is used to measure THC and PM emissions, as well as CO, NOx, and PN during cold start.

[0037] According to the emission standards, the emission stages of light vehicles can be divided into National III, National IV, National V and National VI. In this embodiment, 10 National III light vehicles, 10 National IV light vehicles, 10 National V light vehicles and 10 National VI light vehicles are selected for measurement according to the standards of different stages.

[0038] In order to accurately measure the total emission of light vehicles during actual driving, this embodiment divides the actual driving of light vehicles into two processes: cold start and hot run.

[0039] The process from the engine starting up to the coolant temperature reaching 70° C. is the cold start process. After the engine coolant temperature reaches 70° C., it is the hot run process. This embodiment measures pollutants in the cold start and hot run processes respectively.

[0040] The pollutants emitted by the light vehicle in this embodiment are CO, THC, NO x , PN, PM. According to the standard requirements, there are two methods for measuring light vehicle emission pollutants: one is the chassis dynamometer method, which is carried out in a laboratory; the other is the road method, which is carried out on an actual road.

[0041] According to the standard requirements, the road method in this embodiment measures CO and NO x , PN emissions, and the cold start process needs to be excluded when calculating the road method measurement results. Therefore, the road method measurement results are the hot running process CO, NO x , PN emissions.

[0042] For THC, PM emissions, and CO, NO during cold start x , PN emissions, and chassis dynamometer method measurements. This embodiment meets all the conditions of equipment, working conditions, etc. required by various emission standards, and all measurements are sample size measurements.

[0043] Step 2: Based on the measurement method determined in step 1 and the actual driving status of the light-duty vehicle, divide the VSP interval and calculate the actual driving emission factor of the light-duty vehicle in each emission stage.

[0044] According to the VSP and speed information during the actual operation process, the actual operation of light vehicles is divided into different VSP intervals (Bin), and the average pollutant emission rates of different pollutants in each VSP interval of light vehicles in different emission stages are calculated. The average pollutant emission rates are accumulated according to the time distribution of typical working conditions in the required area to obtain the actual driving emission factors of light vehicles in each emission stage.

[0045] It should be noted that the selection of the typical operating conditions in the desired area should take into account the characteristics of the local traffic network and be the most representative travel route. This embodiment selects the Fourth Ring Road of Beijing and part of the Beijing Economic and Technological Development Zone as the typical operating conditions in Beijing.

[0046] The road method and chassis dynamometer method measurements described in this embodiment must be carried out in accordance with the working conditions specified in the standard. The selection of typical working conditions in the desired area is intended to convert the standard working condition measurement data into measurement data that conforms to the local typical working conditions through its VSP interval (Bin) distribution. This will be introduced in detail later. The VSP interval division is shown in Table 1 below:

[0047] Table 1

[0048]

[0049] According to the measurement method determined in step 1, the emission values ​​of various pollutants during the cold start and hot operation of light vehicles in each emission stage are measured, the average pollutant emission rate of different pollutants in each Bin interval of vehicles in different emission stages is calculated, and the actual driving emission factor of each pollutant emitted by light vehicles is calculated according to the time distribution of each Bin interval in the typical working conditions of the required area, which specifically includes the following steps:

[0050] Step 2.1: Calculate the actual CO and NO emissions of light-duty vehicles during the thermal operation of each emission stage based on the road method pollutant emission measurement results. x , PN emission factor.

[0051] The measurement methods for light-duty vehicle pollutant emissions in the National III, National IV and National V emission stages are the same, so road measurements are all carried out in accordance with "GB18352.5-2013 Light-duty Vehicle Pollutant Emission Limits and Measurement Methods (China Phase V)".

[0052] National VI stage light vehicles are measured on the road according to "GB 18352.6-2016 Light-duty Vehicle Pollutant Emission Limits and Measurement Methods (China Stage VI)".

[0053] In this embodiment, the measurement of light vehicle emission pollutants at each emission stage is performed in accordance with the above standards.

[0054] Taking the National VI stage light vehicle road method measurement as an example, according to Appendix D of "GB 18352.6-2016 Light Vehicle Pollutant Emission Limits and Measurement Methods (China VI Stage)", during the measurement process:

[0055] First, the measurement device should be installed in a way that minimizes the impact on vehicle emissions and performance, and the measurement equipment should be powered by an external power supply.

[0056] Then, the light vehicle should be measured continuously on the actual road in the order of urban area - suburban area - highway section.

[0057] The urban-suburban-highway sections are divided according to the instantaneous vehicle speed. The vehicle speed on the urban section is below 60km / h, the vehicle speed on the suburban section is between 60km / h and 90km / h, and the vehicle speed on the high-speed section is greater than 90km / h.

[0058] The driving proportion is expressed as a percentage of the total driving distance. The driving route should include 34% urban sections, 33% suburban sections and 33% expressway sections. The driving proportion error should be controlled within ±10%, but at least the proportion of urban sections must be greater than 29%.

[0059] At the same time, the minimum driving distance for light vehicles in urban areas, suburbs and highways is 16km, and the entire road law test should last between 90 and 120 minutes.

[0060] Taking the National VI light-duty vehicle as an example, first, according to the VSP and speed information of the light-duty vehicle during the road method measurement, the measurement process is divided into different VSP intervals (Bin), and the average emission rate of CO, NOx, and PN emission pollutants in each VSP interval of 10 National VI light-duty vehicles is calculated. The CO emission rate of each VSP interval during the hot operation process is shown in Table 2. It should be noted that step 2.1 of this embodiment only shows the CO emission rate information, which is intended to demonstrate the measurement method of this step.

[0061] Table 2

[0062]

[0063] Then, according to the time distribution of different bins and pollutant emission rates in the typical working conditions of the required area, the actual driving thermal operation process of the National VI light-duty vehicle CO, NO x , PN emission factor.

[0064] After the National III, National IV, and National V light vehicles are measured on the road according to their standard requirements, the above steps are repeated to obtain the actual driving thermal operation process CO, NO x , PN emission factors. CO, NO x , PN emission factors are shown in Table 3.

[0065] Table 3

[0066]

[0067] Step 2.2: Calculate the CO and NO emissions of the light-duty vehicle during the actual cold start process at each emission stage based on the chassis dynamometer method pollutant emission measurement results. x , THC, PN emission factors.

[0068] According to the measurement standard described in step 2.1, the exhaust pollutant emission measurement after cold start at room temperature is carried out. In this embodiment, the difference between the emission factors of the first ECE segment and the fourth ECE segment under the NEDC condition is used as the CO and NO emission factors of the cold start process of light vehicles in the National V and previous emission stages. x , THC, PN emissions, and the actual thermal operation process of light vehicles CO, NO x The calculation method of PN emission factors is similar. After dividing the VSP interval, the CO, NO and PN emission factors of light vehicles in the cold start process of the National V emission stage and earlier are obtained according to the actual working conditions. x , THC, PN emission factors.

[0069] For China VI light-duty vehicles, the difference between the low-speed section of the cold WLTC condition and the low-speed section of the hot WLTC condition is used as the CO and NO emission factor during the cold start process. x, THC, and PN emissions are divided into VSP intervals and weighted to obtain their emission factors. It should be noted that the cold WLTC condition is the first WLTC condition after the vehicle engine is started, and the hot WLTC condition is the WLTC condition after the vehicle enters the hot running process. Through the above steps, the actual cold start process of the light vehicle in each emission stage is obtained. x , THC, PN emission factors, see Table 4 for details.

[0070] Table 4

[0071]

[0072] Step 2.3: Based on the pollutant emission measurement results of the chassis dynamometer method, calculate the PM emission factor of the light vehicle in actual driving at each emission stage and the THC emission factor in the hot running process.

[0073] The measurement of PM in the chassis dynamometer method cannot decompose the cold start and hot operation processes. Therefore, this embodiment performs the chassis dynamometer method sample measurement described in step 2.2 under standard working conditions, and the measured PM emission result is the weighted mean value after dividing the VSP interval as the PM emission factor for light vehicles in each emission stage.

[0074] THC emission factor calculation process and NO x Similarly, weighted calculations are performed through the cold start process and the hot run process. The difference is that THC emissions during the hot run process are measured by the chassis dynamometer method. Taking the National VI light-duty vehicle as an example, the THC sample volume measurement results are divided into the VSP interval and the weighted average value is the THC emission factor during the hot run process under the standard WLTC cycle after the vehicle enters the hot run process. PM emission factors and THC emission factors during the hot run process are shown in Table 5.

[0075] Table 5

[0076]

[0077] Step 2.4: Calculate the actual driving emission factors of light vehicles based on the cold start and hot running emission factors of each light vehicle emission pollutant in each emission stage and the actual driving conditions.

[0078] According to the road method measurement data in step 2.1, the cold start and hot operation processes are weighted by mileage. Taking the proportion of cold start process as an example, it is the ratio of the average mileage during the cold start time of light vehicles to the average mileage per trip. In this embodiment, the average mileage of the light vehicle during the cold start process is 2km. It should be noted that the average mileage of the cold start process is obtained by the average distance traveled before the vehicle engine water temperature reaches 70°C in the road method test. The average mileage of light vehicles is obtained through the annual development report of the desired region. In this embodiment, the average mileage of light vehicles in Beijing is 11.4km. The actual driving emission factors of each pollutant emitted by light vehicles in each emission stage are obtained by the following formula:

[0079] ;

[0080] Where: for Emission of pollutants Actual driving emission factors of light vehicles during the emission phase; For each emission pollutant, including CO, THC, NO x , PM, PN; For each emission stage; for Emission of pollutants Emission stage light vehicles Actual driving emission factors during operation; For vehicle operation process, including cold start and hot operation; It is the ratio of the current vehicle operating status to the average trip mileage.

[0081] Step 3: Determine the correction factor based on the effects of temperature, air conditioning, mileage degradation, and oil quality on the emission factor.

[0082] Step 3.1: Determine the temperature correction coefficient for actual driving emissions of light-duty vehicles under different temperature conditions.

[0083] The chassis dynamometer method was used to measure the emission pollutants at -7°C, 14°C, 23°C, 35°C and 40°C, and the temperature correction coefficients under different temperature conditions were determined.

[0084] Taking the National V light-duty vehicle as an example, the test condition is the WLTC condition. Before the test, the vehicle runs a chassis dynamometer method WLTC cycle for pretreatment. After the pretreatment is completed, the vehicle is immersed in the corresponding test temperature for more than 6 hours. After the vehicle oil temperature and coolant temperature reach the corresponding immersion temperature ±2°C, the test begins. The pretreatment method for National III and National IV light-duty vehicles is the same as that for National V light-duty vehicles, and National VI light-duty vehicles run the CLTC cycle for pretreatment.

[0085] The effect of temperature on emission factors is also divided into cold start process and hot operation process. The cold start process measurement results at different temperatures are the emission results of the low-speed stage of the WLTC cycle. The ratio of the cold start process measurement results to the low-speed stage of the WLTC cycle at 23°C cold start is the temperature influence coefficient of the cold start process at different temperatures. The same is true for the hot operation process. Similarly, by weighting the mileage, the temperature correction coefficient of the actual driving emission factor of light vehicles at different temperatures is obtained.

[0086] It should be noted that chassis dynamometer measurements that meet regulatory requirements are all carried out at 23°C, with some deviations allowed. The emission factor in step 2 is also obtained at 23°C, so the temperature correction factor should be determined.

[0087] Step 3.2: Determine the air conditioning correction factor for actual driving emissions of light-duty vehicles.

[0088] The chassis dynamometer method is used to measure the air conditioning on and off in a high temperature environment to determine the air conditioning correction coefficient for the actual driving emissions of light vehicles.

[0089] Air conditioning measurement: Before the test, the vehicle runs at a constant speed of 90km / h for more than 20 minutes; after the vehicle is preheated, it is immersed in a 30℃ environment, all windows are closed, and the light intensity is set to 850±50W / ㎡ for at least 30 minutes to simulate the actual use of air conditioning in vehicles exposed to high temperatures in summer. The vehicle air conditioning is set to automatic mode, the temperature is set to 23℃, and the air conditioning cycle switch is set to the internal circulation blowing mode, and the chassis dynamometer method is used for measurement.

[0090] Measurement with air conditioning off: Before the test, the vehicle is run at a constant speed of 90km / h for more than 20 minutes; after the vehicle is preheated, the test environment temperature is set to 30℃, the vehicle air conditioning and all windows are turned off, and chassis dynamometer measurement is immediately carried out.

[0091] The emission measurement results with the air conditioning turned on are compared with the measurement results with the air conditioning turned off to obtain the air conditioning correction coefficient for the actual driving emissions of the light vehicle.

[0092] Step 3.3: Determine the light-duty vehicle actual driving emission mileage degradation correction factor.

[0093] The measured light vehicle is driven on the actual road and completes the cumulative mileage of 100,000 km. The chassis dynamometer method emission measurement is carried out once every 10,000 km of accumulated mileage within 100,000 km. To improve the accuracy, the light vehicle should be maintained before each measurement to ensure that it is in good condition. The emission values ​​of each pollutant at 6,400 km and 160,000 km are calculated after curve fitting using the least squares method, and the mileage degradation correction coefficient of each pollutant is determined by the ratio of the emission result of 160,000 km to the emission result of 6,400 km.

[0094] Step 3.4: Determine the fuel correction factor for actual driving emissions of light vehicles.

[0095] The chassis dynamometer method is used to measure emission pollutants. The ratio of the measurement results of the same emission pollutants of light vehicles at the same emission stage when filled with ethanol gasoline and regular gasoline is the oil correction factor for the emission pollutants at that emission stage.

[0096] Step 4: Calculate the total actual driving emissions of light vehicles based on the actual driving emission factor, correction coefficient, ownership and annual average mileage of light vehicles.

[0097] According to the type of light vehicles, light vehicles are divided into minibuses, small buses, taxis, etc. The number of different types of light vehicles and the average annual mileage are different. The actual total emission of different pollutants of different types of light vehicles at different emission stages ( ) is calculated according to the following formula:

[0098] ;

[0099] Where: m j,i for Emission of pollutants The actual driving emission factor of light vehicles in the emission stage; j is the emission pollutants, including CO, THC, NO x , PM, PN; is each emission stage, including National III, National IV, National V, and National VI; v is the type of light vehicle, including minivans, small buses, and taxis; k1 is the mileage degradation correction factor; L is the mileage of light vehicles, km; L1 is the initial degradation mileage of light vehicles, km; K2 is the temperature correction factor, including the temperature correction factors at -7℃, 14℃, 23℃, 35℃, and 40℃; K3 is the oil correction factor, which is 1 when filling with ordinary gasoline; K4 is the air conditioning correction factor; T V for Average annual mileage of light vehicles, km / year; Q v for The number of light vehicles of this type;

[0100] Actual driving emission of different pollutants at different emission stages M j,i Calculated according to the following formula:

[0101]

[0102] Although the principles of the present invention are described in detail above in conjunction with the preferred embodiments of the present invention, those skilled in the art should understand that the above embodiments are only explanations of the exemplary implementations of the present invention, and are not intended to limit the scope of the present invention. The details in the embodiments do not constitute limitations on the scope of the present invention. Without departing from the spirit and scope of the present invention, any obvious changes such as equivalent transformations and simple replacements based on the technical solutions of the present invention fall within the scope of protection of the present invention.

Claims

1. A method for calculating the total amount of actual driving emissions of light vehicles, specifically comprising: Step 1: Determine the measurement method and number of light vehicles required for calculating the total amount of actual driving emissions of light vehicles at each emission stage. The road method is used to measure the CO, NOx, and PN emissions of light vehicles during hot operation, and the chassis dynamometer method is used to measure THC and PM emissions, as well as CO, NOx, and PN during cold start. Step 2: Based on the measurement method determined in step 1 and the actual driving status of the light-duty vehicle, divide the VSP interval and calculate the actual driving emission factor of the light-duty vehicle in each emission stage; Step 2.1: Calculate the actual CO and NO emissions of light-duty vehicles during the thermal operation of each emission stage based on the road method pollutant emission measurement results. x , PN emission factor; Step 2.2: Calculate the CO and NO emissions of the light-duty vehicle during the actual cold start process at each emission stage based on the chassis dynamometer method pollutant emission measurement results. x , THC, PN emission factors; Step 2.3: Calculate the PM emission factor of the light-duty vehicle in actual driving and the THC emission factor in the hot running process at each emission stage based on the pollutant emission measurement results of the chassis dynamometer method; Step 2.4: Calculate the actual driving emission factor of the light-duty vehicle based on the cold start and hot running emission factors of each light-duty vehicle emission pollutant in each emission stage and the actual driving conditions; ； Where: is the actual driving emission factor of light vehicles in the emission stage i of the j-emission pollutant; j is each emission pollutant, including CO, THC, NO x , PM, PN; i is each emission stage; is the actual driving emission factor of the light vehicle r during the operation of the j-emission pollutant i emission stage; r is the vehicle operation process, including cold start and hot operation; It is the ratio of the current vehicle operation status to the average trip mileage; Step 3: Determine the correction factor based on the impact of temperature, air conditioning, mileage degradation, and oil quality on the emission factor; Step 4: Calculate the actual driving emissions of light vehicles based on the actual driving emission factor, correction factor, number of vehicles in use and average annual mileage; Actual driving emissions Calculated according to the following formula: ； Where: m j,i is the actual driving emission factor of light vehicles in the emission stage i of the j-emission pollutant; j is each emission pollutant, including CO, THC, NO x , PM, PN; i is the emission stage, including National III, National IV, National V, and National VI; v is the type of light vehicle, including microbus, small bus, and taxi; k1 is the mileage degradation correction factor; L is the mileage of light vehicles, km; L1 is the initial degradation mileage of light vehicles, km; k2 is the temperature correction factor, including the temperature correction factors at -7℃, 14℃, 23℃, 35℃, and 40℃; k3 is the oil correction factor, which is 1 when filling with ordinary gasoline; k4 is the air conditioning correction factor; T V is the average annual mileage of Class V light vehicles, km / year; Q v The number of Class V light vehicles in use; Actual driving emission of different pollutants at different emission stages M j,i Calculated according to the following formula: 。 2. The method for calculating the total amount of actual driving emissions of light vehicles according to claim 1, specifically comprising: Step 3 is implemented in the following ways: Step 3.1: Determine the temperature correction coefficient of the actual driving emission of light vehicles under different temperature conditions; Step 3.2: Determine the air conditioning correction factor for actual driving emissions of light vehicles; Step 3.3: Determine the light vehicle actual driving emission mileage degradation correction factor; Step 3.4: Determine the fuel correction factor for actual driving emissions of light vehicles.

3. The method for calculating the total amount of actual driving emissions of light vehicles according to claim 2 specifically comprises: In step 3.1, the chassis dynamometer method is used to measure the emission pollutants under the environmental conditions of -7°C, 14°C, 23°C, 35°C and 40°C to determine the temperature correction coefficient under different temperature conditions.

4. The method for calculating the total amount of actual driving emissions of light vehicles according to claim 2 specifically comprises: In step 3.2, chassis dynamometer measurements are performed with the air conditioner turned on and off in a high temperature environment to determine the air conditioning correction coefficient for actual driving emissions of light vehicles.

5. The method for calculating the total amount of actual driving emissions of light vehicles according to claim 2 specifically comprises: In step 3.3, the measured light vehicle is driven on actual roads and completes a cumulative mileage of 100,000 km. A chassis dynamometer method emission measurement is performed every 10,000 km of accumulated mileage within 100,000 km. The emission values ​​of each pollutant at 6,400 km and 160,000 km are calculated after curve fitting using the least squares method. The mileage degradation correction coefficient of each pollutant is determined by the ratio of the emission result at 160,000 km to the emission result at 6,400 km.

6. The method for calculating the total amount of actual driving emissions of a light vehicle according to claim 2 specifically comprises: In step 3.4: perform chassis dynamometer method to measure emission pollutants. The ratio of the measurement results of the same emission pollutants of light vehicles in the same emission stage when filled with ethanol gasoline and regular gasoline is the oil correction factor of the emission pollutants in that emission stage.

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