Method for measuring particulate emissions of non-reference gasoline

Abstract

The application provides a method for determining the particulate emission of non-reference gasoline, comprising the following steps: obtaining the oil parameters of each non-reference gasoline, determining the particulate index of each non-reference gasoline according to the oil parameters; determining the reference gasoline in the non-reference gasoline; obtaining the particulate emission of the reference gasoline, and determining the particulate emission calculation formula of the non-reference gasoline according to the particulate index of the reference gasoline and the particulate emission of the reference gasoline; finally, the standard particulate emission of the non-reference gasoline to be tested can be determined according to the particulate emission calculation formula of the non-reference gasoline. Thus, when the standard particulate emission of a certain non-reference gasoline needs to be determined, the standard particulate emission of the non-reference gasoline to be tested can be estimated according to the particulate emission calculation formula of the non-reference gasoline without determining on a test vehicle. Therefore, the standard particulate emission of any non-reference gasoline can be estimated by calculation.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of particulate matter emission determination, and particularly relates to a method for determining particulate matter emission of non-reference gasoline. BACKGROUND

[0002] Particulate matter emission is an important part of light-duty gasoline vehicle pollutant emission. The emission standards of China and major countries overseas have made provisions for the limit value of particulate matter emission of light-duty gasoline vehicles. In order to meet the requirements of national emission regulation standards, the particulate matter emission of the test vehicle gasoline needs to be effectively determined in the development process of gasoline engines and vehicles.

[0003] The existing determination of gasoline particulate matter emission is determined under the New European Driving Cycle (NEDC), and one method is to determine the particulate matter emission index according to the double bond equivalent of each component of gasoline, the vapor pressure of the component at 443K, and the mass fraction of the component. However, this method needs to determine all components in gasoline as completely and accurately as possible, which leads to more difficulty in actual use.

[0004] Therefore, the second method simplifies the first method. The second method screens other factors affecting particulate matter emission of gasoline by statistical methods, locks four high-correlation factors: 70% evaporation temperature (T70), heavy aromatic content (HAC), final boiling point (FBP), and olefin content (OC), and calculates the particulate matter emission of different gasolines according to the formula SPNI = 0.012 × T70 + 0.048 × HAC + 0.015 × FBP - 0.034 × OC - 2.721.

[0005] However, neither the first method nor the second method has a comparative study of test conditions. Moreover, with the new standard World Light-duty Test Cycle (WLTC) replacing the New European Driving Cycle (NEDC) and the sixth stage particulate matter emission standard of China adopting the World Light-duty Test Cycle (WLTC) completely, the accuracy of the existing method for determining the particulate matter emission of gasoline at room temperature lacks theoretical basis and actual research results. Moreover, since the World Light-duty Test Cycle (WLTC) adopts a transient condition, the New European Driving Cycle (NEDC) adopts a steady-state condition, and the average speed and engine load under the World Light-duty Test Cycle (WLTC) are higher than those under the New European Driving Cycle (NEDC), the wet wall effect and pool fire effect of the particulate matter emission are quite different under the two conditions. In addition, since the vapor pressure of the gasoline component has a great influence on the pool fire effect, the influence weight of the vapor pressure and the double bond equivalent in the first method on the particulate matter emission is not applicable to the determination of the particulate matter emission under the World Light-duty Test Cycle (WLTC).

[0006] In addition, gasoline is a mixture of thousands of hydrocarbons, oxygenates and other additives. A large number of studies have shown that the composition of gasoline has an important influence on the particulate matter emission of vehicles. Therefore, the emission standards of various countries all stipulate the requirements for reference gasoline for different emission test procedures. However, under the existing conditions, the reference gasoline has the problems of high cost, limited supply capacity and poor test flexibility due to the particularity of the components, and it is difficult to use for a large number of emission tests in the development process of vehicles and gasoline engines. Moreover, for vehicles with known emission levels, the actual emission of non-reference gasoline also needs to be estimated to confirm the actual particulate matter emission level of the vehicle when the gasoline component used for the emission test fluctuates. SUMMARY

[0007] The purpose of the present application is to solve the problem that the particulate matter emission of non-reference gasoline cannot be estimated in the prior art.

[0008] To solve the above problems, the embodiment of the present application discloses a method for determining the particulate matter emission of non-reference gasoline, comprising:

[0009] S1: obtaining the oil parameters of each non-reference gasoline, and determining the particulate matter index of each non-reference gasoline according to the oil parameters;

[0010] S2: determining the reference gasoline in the non-reference gasoline according to the particulate matter index of each non-reference gasoline and a preset particulate matter index interval;

[0011] S3: Obtain the particulate emission of the reference gasoline, and determine the particulate emission calculation formula of the non-reference gasoline according to the particulate index of the reference gasoline and the particulate emission of the reference gasoline;

[0012] S4: Determine the standard particulate emission of the non-reference gasoline to be tested according to the particulate emission calculation formula of the non-reference gasoline.

[0013] According to the above scheme, when the standard particulate emission of a certain non-reference gasoline needs to be determined, only after obtaining the oil parameters of several non-reference gasolines, the particulate index of each non-reference gasoline is calculated, then the reference gasoline in the non-reference gasoline in the preset particulate index interval is selected, and the particulate emission calculation formula of the non-reference gasoline is determined according to the particulate index and the particulate emission of the reference gasoline. Thus, when the standard particulate emission of a certain non-reference gasoline needs to be determined, it is not necessary to determine on the test vehicle, but only the standard particulate emission of the non-reference gasoline to be tested can be estimated according to the particulate emission calculation formula of the non-reference gasoline. Therefore, the standard particulate emission of any non-reference gasoline can be estimated.

[0014] According to another specific embodiment of the present application, the non-reference gasoline particulate emission determination method disclosed by the embodiment of the present application, in step S1, the oil parameters include the number of double bonds, vapor pressure and mass fraction of each component of each non-reference gasoline; and in step S1, the particulate index of the non-reference gasoline is calculated according to the following formula:

[0015]

[0016] Wherein, SPI is the particulate index of each non-reference gasoline; DBE i is the number of double bonds of component i; V.P(443K) i is the vapor pressure of component i at 443K; Wt i is the mass fraction of component i.

[0017] According to another specific embodiment of the present application, the non-reference gasoline particulate emission determination method disclosed by the embodiment of the present application, step S2 includes: determining at least five non-reference gasolines whose particulate index is within the preset particulate index interval as reference gasolines; wherein the preset particulate index interval is 1.5 to 2.5.

[0018] According to the scheme, the particulate emission of the plurality of non-reference gasoline can be calculated, the reference gasoline in the predetermined condition is selected from the plurality of non-reference gasoline for testing, and thus the particulate emission calculation formula of the non-reference gasoline can be determined. In addition, since the vapor pressure of the gasoline component has a greater impact on the pool fire effect, the weight of the number of double bonds of each component is reduced, and the weight of the vapor pressure is correspondingly increased, so that the correlation between the particulate index and the particulate emission of the non-reference gasoline can be more accurately reflected, and the calculation formula of the particulate emission is more accurate.

[0019] According to another specific embodiment of the present application, the method for determining the particulate emission of the non-reference gasoline disclosed by the embodiment of the present application, step S3 comprises:

[0020] S31: obtaining the emission parameters of each reference gasoline, and determining the particulate emission of each reference gasoline according to the emission parameters;

[0021] S32: drawing the correlation curve of the particulate index of the non-reference gasoline and the particulate emission of the non-reference gasoline according to the particulate index and the particulate emission of each reference gasoline, and determining the particulate emission calculation formula of the non-reference gasoline through linear fitting; wherein the particulate emission calculation formula of the non-reference gasoline is:

[0022] PN=aSpI+b

[0023] Wherein, PN is the particulate emission of the non-reference gasoline; a and b are constants; SPI is the particulate index of the non-reference gasoline.

[0024] According to another specific embodiment of the present application, the method for determining the particulate emission of the non-reference gasoline disclosed by the embodiment of the present application, in step S31, the emission parameters of each reference gasoline include the volume of the diluted exhaust gas, the particulate concentration of the diluted exhaust gas, and the particulate concentration of the diluted channel background; and step S31 further comprises:

[0025] S311: obtaining the volume of the diluted exhaust gas, the particulate concentration of the diluted exhaust gas, and the particulate concentration of the diluted channel background of each reference gasoline;

[0026] S312: calculating the particulate emission of each reference gasoline according to the volume of the diluted exhaust gas, the particulate concentration of the diluted exhaust gas, and the particulate concentration of the diluted channel background of each reference gasoline.

[0027] According to another specific embodiment of the present application, the method for determining the particulate emission of the non-reference gasoline disclosed by the embodiment of the present application, the particulate emission of each reference gasoline is calculated according to the following formula:

[0028]

[0029] Wherein, PN is the particulate emission of each reference gasoline; V is the volume of the diluted exhaust gas; k is the correction coefficient; is the particulate concentration of the diluted exhaust gas after correction; C b is the particulate concentration of the diluted air or the background of the dilution channel under the standard state; is the average particle concentration reduction coefficient of the volatile particle remover set by the dilution during the test; is the average particle concentration reduction coefficient of the volatile particle remover set by the dilution; d is the mileage of the test cycle.

[0030] According to the above scheme, the particulate emission of each reference gasoline can be calculated by obtaining the emission parameters of each reference gasoline, so as to determine the particulate emission calculation formula of the non-reference gasoline according to the particulate index and the particulate emission of the reference gasoline. Therefore, the non-reference gasoline does not need to be tested on the test vehicle, does not need to analyze the exhaust composition, and does not need to obtain the exhaust parameters, so as to realize the estimation of the particulate emission of the non-reference gasoline. The particulate emission of the non-reference gasoline to be tested is more convenient to obtain.

[0031] According to another specific embodiment of the present application, the non-reference gasoline particulate emission determination method disclosed by the embodiment of the present application comprises:

[0032] S41: obtaining the oil product parameters of the non-reference gasoline to be tested, and determining the particulate index of the non-reference gasoline to be tested according to the oil product parameters;

[0033] S42: determining the standard particulate emission of the non-reference gasoline to be tested according to the particulate index of the non-reference gasoline to be tested and the particulate emission calculation formula of the non-reference gasoline.

[0034] According to the above scheme, the non-reference gasoline to be tested can be directly estimated according to the particulate emission calculation formula of the non-reference gasoline. Therefore, the state can know the particulate emission of the non-reference gasoline without testing on the test vehicle, so as to take the particulate emission of the non-reference gasoline as the standard particulate emission of the reference gasoline. In addition, the vehicle factory can also estimate the particulate emission of the non-reference gasoline to be tested according to the formula before determining the non-reference gasoline to be tested, so as to estimate the particulate emission of the non-reference gasoline to be tested by the test vehicle.

[0035] According to another specific embodiment of the present application, the non-reference gasoline particulate emission determination method disclosed by the embodiment of the present application comprises:

[0036] S5: obtaining the emission parameters of the non-reference gasoline to be tested, and determining the particulate emission of the non-reference gasoline to be tested according to the emission parameters;

[0037] S6: comparing the particulate emission amount of the non-reference gasoline to be tested with the standard particulate emission amount of the non-reference gasoline to be tested to determine the particulate emission level of the test vehicle using the non-reference gasoline to be tested.

[0038] According to the above scheme, the state can directly calculate the standard particulate emission amount of the non-reference gasoline to be tested according to the particulate emission amount calculation formula of the non-reference gasoline, the vehicle factory can determine the particulate emission amount of the non-reference gasoline to be tested by obtaining the emission parameters of the emission of the non-reference gasoline, and determine whether the particulate emission amount of the test vehicle using the non-reference gasoline meets the standard particulate emission amount announced by the state. Thus, the particulate emission level of the test vehicle using the non-reference gasoline to be tested can be determined by comparing the results.

[0039] According to another specific embodiment of the present application, the particulate emission amount determination method of the non-reference gasoline disclosed in the embodiment of the present application further comprises the following steps after step S5:

[0040] S51: obtaining the particulate index of the reference gasoline and the particulate index of the non-reference gasoline to be tested, and calculating the particulate emission amount of the test vehicle using the reference gasoline according to the particulate index of the reference gasoline, the particulate index of the non-reference gasoline to be tested, and the particulate emission amount of the non-reference gasoline to be tested;

[0041] S52: comparing the particulate emission amount of the reference gasoline with the preset standard particulate emission amount of the reference gasoline to determine the particulate emission level of the test vehicle using the reference gasoline.

[0042] According to another specific embodiment of the present application, in step S51 of the particulate emission amount determination method of the non-reference gasoline disclosed in the embodiment of the present application, the particulate emission amount of the test vehicle using the reference gasoline is calculated according to the following formula:

[0043]

[0044] wherein PN r is the particulate emission amount of the test vehicle using the reference gasoline; PN t is the particulate emission amount of the non-reference gasoline to be tested; SPI t is the particulate index of the non-reference gasoline to be tested; SPI r is the particulate index of the reference gasoline.

[0045] The method for measuring the particulate emission of non-reference gasoline can be used to measure the particulate emission of non-reference gasoline on the test vehicle when the particulate emission of reference gasoline cannot be measured on the test vehicle, and the particulate emission of the test vehicle using reference gasoline can be determined according to the measured particulate emission of non-reference gasoline, the known particulate index of reference gasoline and the particulate index of non-reference gasoline to be tested. Thus, when the national test unit or the vehicle factory cannot use reference gasoline for testing, the non-reference gasoline can be directly used for testing, and the test result can be corrected to determine the particulate emission of the test vehicle using reference gasoline. Thus, the problem that the vehicle model cannot be announced due to the failure of testing using reference gasoline or the particulate emission of reference gasoline cannot be determined due to the testing using non-reference gasoline by the vehicle factory is avoided.

[0046] The present application has the following advantages:

[0047] The method for measuring the particulate emission of non-reference gasoline can be used to measure the particulate emission of non-reference gasoline on the test vehicle when the particulate emission of reference gasoline cannot be measured on the test vehicle, and the particulate emission of the test vehicle using reference gasoline can be determined according to the measured particulate emission of non-reference gasoline, the known particulate index of reference gasoline and the particulate index of non-reference gasoline to be tested. Thus, when the national test unit or the vehicle factory cannot use reference gasoline for testing, the non-reference gasoline can be directly used for testing, and the test result can be corrected to determine the particulate emission of the test vehicle using reference gasoline. Thus, the problem that the vehicle model cannot be announced due to the failure of testing using reference gasoline or the particulate emission of reference gasoline cannot be determined due to the testing using non-reference gasoline by the vehicle factory is avoided.

[0048] Further, in the world light-duty vehicle test procedure, the automobile working condition adopts instantaneous working condition, and the vapor pressure of gasoline components has a greater impact on the pool fire effect. Therefore, in the present application, the weight of the number of double bonds of components in the particulate index calculation of non-reference gasoline is reduced, and the weight of the vapor pressure is correspondingly increased. Thus, the particulate index can better reflect the influence of the vapor pressure, and the calculated particulate emission of non-reference gasoline is more accurate.

[0049] Further, when the test vehicle has never been tested with the reference gasoline, the particulate emission of the test vehicle using the reference gasoline can be determined according to the particulate index of the non-reference gasoline, the particulate index of the reference gasoline and the particulate emission of the non-reference gasoline. Thus, when the state or the vehicle manufacturer cannot use the reference gasoline to test but needs to know the particulate emission of the test vehicle using the reference gasoline, the particulate emission of the test vehicle using the reference gasoline can be corrected according to the particulate emission of the non-reference gasoline, and thus the particulate emission level of the test vehicle using the reference gasoline can be determined by comparing the correction result with the standard particulate emission of the reference gasoline published by the state. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 is a flowchart of the method for determining the particulate emission of the non-reference gasoline according to an embodiment of the present application;

[0051] Figure 2 is a graph of the relationship between the particulate index and the particulate emission of the direct injection supercharged engine vehicle according to an embodiment of the present application;

[0052] Figure 3 is a graph of the relationship between the particulate index and the particulate emission of the port injection engine vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0053] Other advantages and effects of the present application will be easily understood by those skilled in the art from the content disclosed in the specification. Although the description of the present application will be introduced in combination with the preferred embodiments, it does not mean that the features of the present application are limited to the embodiments. On the contrary, the purpose of introducing the present application in combination with the embodiments is to cover other options or modifications which can be extended based on the claims of the present application. In order to provide a deep understanding of the present application, many specific details will be included in the following description. The present application can also be implemented without using these details. In addition, in order to avoid confusion or obscure the focus of the present application, some specific details will be omitted in the description. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0054] It should be noted that in the specification, similar reference numbers and letters represent similar items in the following drawings, and thus once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0055] In the description of the present embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the application is usually placed, and are only for the convenience of describing the application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the application.

[0056] The terms "first", "second", and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance.

[0057] In the description of the present embodiment, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set", "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present embodiment can be understood according to the specific circumstances.

[0058] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0059] In order to solve the problem that the particulate matter emission of non-reference gasoline cannot be estimated in the prior art, the embodiments of the present application disclose a method for measuring the particulate matter emission of non-reference gasoline. Specifically, with reference to Figure 1 , the method for measuring the particulate matter emission of non-reference gasoline provided by the embodiments of the present application specifically comprises the following steps:

[0060] S1: obtaining the oil product parameters of each non-reference gasoline, and determining the particulate matter index of each non-reference gasoline according to the oil product parameters;

[0061] S2: determining the reference gasoline in the non-reference gasoline according to the particulate matter index of each non-reference gasoline and the preset particulate matter index interval;

[0062] S3: obtaining the particulate matter emission of the reference gasoline, and determining the particulate matter emission calculation formula of the non-reference gasoline according to the particulate matter index of the reference gasoline and the particulate matter emission of the reference gasoline;

[0063] S4: determining the standard particulate matter emission of the non-reference gasoline to be tested according to the particulate matter emission calculation formula of the non-reference gasoline.

[0064] With the above scheme, when the standard particulate matter emission of a certain non-reference gasoline needs to be determined, only after obtaining the oil parameters of a plurality of non-reference gasolines, the particulate matter index of each non-reference gasoline is calculated, then a reference gasoline in the non-reference gasolines in the preset particulate matter index interval is selected, and the particulate matter emission calculation formula of the non-reference gasoline is determined according to the particulate matter index and the particulate matter emission of the reference gasoline. Thus, when the standard particulate matter emission of a certain non-reference gasoline needs to be determined, it is not necessary to determine on the test vehicle, but only the particulate matter emission calculation formula of the non-reference gasoline can be used to estimate the standard particulate matter emission of the non-reference gasoline to be tested. Therefore, the standard particulate matter emission of any non-reference gasoline can be estimated.

[0065] It should be noted that the particulate matter emission in this application refers to the number of particulate matters in automobile exhaust, and the unit is piece / km.

[0066] Specifically, referring to Figures 1-3 The determination method of the particulate matter emission of the non-reference gasoline provided in this embodiment is described.

[0067] Firstly, step S1 is performed to obtain the oil parameters of each non-reference gasoline, and the particulate matter index of each non-reference gasoline is determined according to the oil parameters.

[0068] It should be noted that in step S1, the oil parameters include the number of double bonds, vapor pressure and mass fraction of each component of each non-reference gasoline.

[0069] Specifically, gasoline is composed of hundreds of petroleum and chemical components, and each component accounts for a certain proportion in gasoline. The number of double bonds refers to the number of double bonds of carbon elements of different components, the vapor pressure refers to the vapor pressure of different components at 443K, and the mass fraction refers to the mass proportion of different components in gasoline.

[0070] Among them, the number of double bonds and the vapor pressure are inherent characteristics of each component, which can be obtained by looking up the table. The mass fraction is determined by the standard method formulated by the American Society for Testing and Materials (ASTM).

[0071] More specifically, the determination of the mass fraction is determined by the ASTM D6730 standard. The standard test method of ASTM is a prescribed procedure used to identify, measure, and evaluate the quality, characteristics, and parameters of materials, products, systems, or services. Among them, the ASTM D6730 method specifies the determination method for petroleum products, fuels, etc. It can be used to determine the volume of isoparaffin, olefin, naphthene and aromatic hydrocarbon in gasoline components, and then the mass fraction of each component in gasoline can be determined.

[0072] It should be noted that the specific way of measuring the mass percentage of each component by the ASTM D6730 method can be measured by the skilled person in the art according to the existing measurement method, and this embodiment will not be further described, as long as the mass fraction of different components can be measured.

[0073] Further, the main mechanisms affecting the particulate emission of gasoline components are the following two points. The first point is the wetted wall pool fire effect in the cylinder during engine operation. The wetted wall pool fire effect refers to that the gasoline is directly injected onto the piston top surface or the cylinder wall surface, and the unatomized oil film is ignited to form a pool fire. The second point is that the mechanisms of different structures of gasoline components, i.e. alkanes and aromatic hydrocarbons, for forming particulate emissions are different. Therefore, quantifying the vapor pressure and unsaturation of different gasoline components is a more accurate method for measuring the particulate emission of the gasoline. Under the world light-duty vehicle test procedure, higher engine operating load leads to a greater degree of influence of the vapor pressure of gasoline components on particulate emissions. Accordingly, compared with the new European driving cycle, the influence of the unsaturation of gasoline components decreases, i.e. the use of gasoline with higher content of high-carbon alkanes will form higher particulate emissions under the world light-duty vehicle test procedure. Therefore, by adjusting the weights of the number of double bonds and the vapor pressure of gasoline components, the influence of the unsaturation of gasoline components can be reduced, and the influence of the vapor pressure can be correspondingly improved.

[0074] Therefore, in step S1, the particulate index of the non-reference gasoline is calculated according to the following formula:

[0075]

[0076] wherein SPI is the particulate index of each non-reference gasoline; DBE i is the number of double bonds of component i; V.P(443K) i is the vapor pressure of component i at 443K; Wt i is the mass fraction of component i.

[0077] Specifically, after obtaining the oil parameters of each non-reference gasoline, the number of double bonds, the vapor pressure and the mass fraction of each component are all substituted into the above formula, and then all the components are summed to obtain the particulate index of each non-reference gasoline.

[0078] It should be noted that 443K refers to a temperature of 443.

[0079] Next, step S2 is performed to determine the reference gasoline in the non-reference gasoline according to the particulate index of each non-reference gasoline and the preset particulate index interval.

[0080] Specifically, the step S2 comprises: determining the non-reference gasoline whose particulate matter index is within the preset particulate matter index interval as the reference gasoline.

[0081] It should be noted that the preset particulate matter index interval is 1.5 to 2.5.

[0082] More specifically, in the present application, after obtaining the particulate matter indexes of the plurality of non-reference gasoline, at least five non-reference gasoline whose particulate matter indexes are within the preset particulate matter index interval are selected as the reference gasoline.

[0083] It should be noted that in the present embodiment, at least five reference gasoline are selected which are uniformly distributed within the preset particulate matter index interval.

[0084] For example, when the particulate matter index interval is 1.5 to 2.5, five non-reference gasoline whose particulate matter indexes are 1.7, 1.9, 2.1, 2.3 and 2.5 can be selected as the reference gasoline. Of course, other non-reference gasoline whose particulate matter indexes are within the preset particulate matter index interval can also be selected by those skilled in the art as the reference gasoline. In addition, those skilled in the art can also randomly select non-reference gasoline whose particulate matter indexes are within the preset particulate matter index interval as the reference gasoline. However, in the present embodiment, non-reference gasoline which are uniformly distributed within the preset particulate matter index interval are selected in order to make the subsequent test more accurate.

[0085] It should be further noted that in the present embodiment, the preset particulate matter index interval is set to 1.5 to 2.5 because when the particulate matter index is less than 1, it is generally considered that the particulate matter emission is very small, and the order of magnitude is less than other gasoline. Therefore, the gasoline with a particulate matter index of 1 can be regarded as zero particulate matter emission gasoline. However, in the present embodiment, the preset particulate matter index interval is set to 1.5 to 2.5 in order to obtain more representative reference gasoline, so that the test results obtained are more accurate. Those skilled in the art can also select other intervals according to actual needs, such as 1.2 to 2.5, 1.2 to 2.7, 1.4 to 2.5, 1.5 to 2.4, 1.6 to 2.8, etc. In addition, the selected reference gasoline can be any number, and the particulate matter indexes of the selected reference gasoline can also not be uniformly distributed within the preset particulate matter index interval. Therefore, those skilled in the art can set the particulate matter index interval and select the test oil according to actual needs, and the present embodiment does not limit this.

[0086] Next, step S3 is performed to obtain the particulate matter emission of the reference gasoline, and a particulate matter emission calculation formula of the non-reference gasoline is determined according to the particulate matter index of the reference gasoline and the particulate matter emission of the reference gasoline.

[0087] Specifically, for example, non-reference gasoline with particle index of 1.7, 1.9, 2.1, 2.3, 2.5 is selected as reference gasoline, and the particle emission of the five reference gasolines is obtained respectively through test on the test vehicle.

[0088] It should be noted that the particle emission of the test oil is measured respectively according to the type I test in GB 18352.6-2016 《Light-duty Vehicle Emission Limit and Measurement Method (China Phase VI) 》 on the test vehicle.

[0089] Specifically, step S3 comprises:

[0090] S31: obtaining the emission parameters of each reference gasoline, and determining the particle emission of each reference gasoline according to the emission parameters.

[0091] More specifically, in step S31, the emission parameters of each reference gasoline comprise the volume of diluted exhaust gas, the particle concentration of diluted exhaust gas, and the particle concentration of diluted channel background; and step S31 further comprises:

[0092] S311: obtaining the volume of diluted exhaust gas, the particle concentration of diluted exhaust gas, and the particle concentration of diluted channel background of each reference gasoline;

[0093] S312: calculating the particle emission of each reference gasoline according to the volume of diluted exhaust gas, the particle concentration of diluted exhaust gas, and the particle concentration of diluted channel background of each reference gasoline.

[0094] Further, in the specific embodiment, the particle emission of each reference gasoline can be calculated according to the following formula:

[0095]

[0096] Wherein, PN is the particle emission of each reference gasoline; V is the volume of diluted exhaust gas; k is the correction coefficient; is the corrected particle concentration of diluted exhaust gas; C b is the particle concentration of diluted air or diluted channel background under standard state; is the average particle concentration reduction factor of the volatile particle remover set by dilution at the time of test; is the average particle concentration reduction factor of the volatile particle remover set by dilution of background gas; d is the mileage of the test cycle.

[0097] It should be noted that the particles mentioned in the embodiment are particulate matters. All the parameters involved in the formula and the method for obtaining the same can be referred to the prior art, and will not be described herein. In addition, the embodiment only describes a method for calculating the particulate matter emission of each reference gasoline, and other calculation methods can also be selected by those skilled in the art in other embodiments of the present application.

[0098] It should also be noted that at least three determination tests are performed for each reference gasoline in the embodiment, and the average of the test results of the three tests is taken as the particulate matter emission of each reference gasoline.

[0099] Further, S32: according to the particulate matter index and the particulate matter emission of each reference gasoline, a correlation curve of the particulate matter index of the non-reference gasoline and the particulate matter emission of the non-reference gasoline is drawn, and a linear fitting is performed to determine a particulate matter emission calculation formula of the non-reference gasoline; wherein

[0100] The particulate matter emission calculation formula of the non-reference gasoline is:

[0101] PN=aSPI+b

[0102] Wherein, PN is the particulate matter emission of the non-reference gasoline; a and b are constants; SPI is the particulate matter index of the non-reference gasoline.

[0103] Specifically, referring to Figure 2 and Figure 3 , Figure 2 is a comparison chart of the correlation analysis of the particulate matter emission index and the particulate matter emission of the direct injection supercharged engine vehicle according to the existing particulate matter emission index calculation formula and the correlation analysis of the particulate matter index and the particulate matter emission of the direct injection supercharged engine vehicle obtained by the actual test according to the particulate matter index calculation formula provided in the embodiment of the present application. Figure 3 is a comparison chart of the correlation analysis of the particulate matter emission index and the particulate matter emission of the port injection engine vehicle according to the existing particulate matter emission index and the correlation analysis of the particulate matter index and the particulate matter emission of the port injection engine vehicle obtained by the actual test according to the particulate matter index formula provided in the embodiment of the present application.

[0104] Specifically, existing studies have shown that when the New European Driving Cycle (NEDC) cycle is used, the particulate matter emission calculated by the following formula has a high correlation with the actual particulate matter emission of the test vehicle using the gasoline. In addition, the prior art also proves that both the port injection gasoline engine and the direct injection gasoline engine are applicable to this formula.

[0105] The particulate matter emission of the reference gasoline is calculated by the following formula in the prior art:

[0106]

[0107] wherein DBE i is the number of double bonds of gasoline component i; V.P(443K) i is the vapor pressure of gasoline component i at 443K; Wt i is the mass fraction of gasoline component i.

[0108] The particulate emission index calculated by the above formula and the particulate emission amount measured by the test vehicle in the prior art are referred to as Figure 2 and Figure 3 , and the correlation coefficient of the particulate index and the particulate emission amount of the reference gasoline for the direct injection supercharged engine vehicle is 0.8914. The correlation coefficient of the particulate index and the particulate emission amount of the reference gasoline for the port injection engine vehicle is 0.948.

[0109] However, in the present application, the weights of the number of double bonds and the vapor pressure are modified to calculate the particulate index of the reference gasoline or the non-reference gasoline. The particulate index of the reference gasoline is referred to as Figure 2 and Figure 3 , and the particulate index of the non-reference gasoline is determined, and the particulate index and the particulate emission amount of the reference gasoline are determined to achieve a higher correlation of the particulate index and the particulate emission amount of the non-reference gasoline. The particulate index and the particulate emission amount of the reference gasoline are referred to as Figure 2 and Figure 3 , and the correlation of the particulate index and the particulate emission amount of the reference gasoline for the direct injection supercharged engine vehicle can reach 0.9387, and the correlation of the particulate index and the particulate emission amount of the reference gasoline for the port injection engine vehicle can reach 0.9537. It is obviously higher than the correlation of the particulate index and the particulate emission amount of the reference gasoline calculated according to the particulate emission index calculation formula provided in the prior art. Therefore, by modifying the weights of the number of double bonds and the vapor pressure and selecting the reference gasoline, the particulate index and the particulate emission amount of the non-reference gasoline obtained by the test can achieve a higher correlation, so that the particulate emission amount calculation formula of the non-reference gasoline obtained can better reflect the value of the particulate emission amount of the non-reference gasoline, and the prediction result is more accurate.

[0110] It should be noted that the particulate emission amount calculation formula of the non-reference gasoline can be obtained by linear fitting by using existing analysis software. The specific linear fitting formula can be obtained by the least square method or data analysis fitting software such as digital graphics analysis software (origin software), that is, the relationship between the particulate index and the particulate emission amount, that is, the particulate emission amount calculation formula of the non-reference gasoline, can be directly fitted by using the fitting software. The correlation coefficient R 2The specific numerical value can be calculated by the method recorded in statistics. This embodiment does not limit this.

[0111] Next, step S4 is performed to determine the standard particulate emission of the non-reference gasoline to be tested according to the particulate emission calculation formula of the non-reference gasoline.

[0112] Specifically, when the particulate emission calculation formula of the non-reference gasoline is determined, the standard particulate emission of the non-reference gasoline to be tested can be determined.

[0113] Specifically, step S4 includes:

[0114] S41: Obtain the oil product parameters of the non-reference gasoline to be tested, and determine the particulate index of the non-reference gasoline to be tested according to the oil product parameters;

[0115] S42: Determine the standard particulate emission of the non-reference gasoline to be tested according to the particulate index of the non-reference gasoline to be tested and the particulate emission calculation formula of the non-reference gasoline.

[0116] By obtaining the oil product parameters of the non-reference gasoline to be tested, the particulate index of the non-reference gasoline to be tested is calculated by substituting the oil product parameters into the particulate index calculation formula of the non-reference gasoline. Then, the standard particulate emission of the non-reference gasoline to be tested can be obtained by substituting the calculated particulate index of the non-reference gasoline to be tested into the particulate emission calculation formula of the non-reference gasoline. Therefore, when an enterprise needs to determine the particulate emission of a certain non-reference gasoline, the particulate emission result of the test vehicle using a specific non-reference gasoline can be estimated in advance according to the calculation formula, and the risk of failure of the announcement can be reduced.

[0117] Further, step S4 further includes:

[0118] S5: Obtain the emission parameters of the non-reference gasoline to be tested, and determine the particulate emission of the non-reference gasoline to be tested according to the emission parameters.

[0119] S6: Compare the particulate emission of the non-reference gasoline to be tested with the standard particulate emission of the non-reference gasoline to be tested to determine the particulate emission level of the test vehicle using the non-reference gasoline to be tested.

[0120] Specifically, the particulate emission of the non-reference gasoline to be tested is determined on the test vehicle according to the national I-type test, and then the particulate emission of the non-reference gasoline to be tested determined on the test vehicle is compared with the calculated standard particulate emission of the non-reference gasoline to be tested, so that whether the particulate emission level of the test vehicle using the non-reference gasoline to be tested meets the national particulate emission level of the non-reference gasoline can be determined.

[0121] Further, the step S5 further includes:

[0122] S51: obtaining the particulate index of the reference gasoline and the particulate index of the non-reference gasoline to be tested, and calculating the particulate emission of the test vehicle using the reference gasoline according to the particulate index of the reference gasoline, the particulate index of the non-reference gasoline to be tested, and the particulate emission of the non-reference gasoline to be tested;

[0123] S52: comparing the particulate emission of the reference gasoline with the preset standard particulate emission of the reference gasoline to determine the particulate emission level of the test vehicle using the reference gasoline.

[0124] Specifically, in the embodiment of the present application, the particulate emission of the test vehicle using the reference gasoline can also be determined according to the particulate emission of the non-reference gasoline. First, the particulate emission of the non-reference gasoline to be tested is determined on the test vehicle through the I-type test, second, the particulate index of the non-reference gasoline to be tested is calculated according to the particulate index calculation formula of the non-reference gasoline, then because the components of the reference gasoline are fixed, the particulate index of the reference gasoline can be known by looking up the table, and finally the particulate emission of the test vehicle using the reference gasoline can be calculated.

[0125] More specifically, in the step S51, the particulate emission of the test vehicle using the reference gasoline is calculated according to the following formula:

[0126]

[0127] wherein, PN r is the particulate emission of the test vehicle using the reference gasoline; PN t is the particulate emission of the non-reference gasoline to be tested; SPI t is the particulate index of the non-reference gasoline to be tested; SPI r is the particulate index of the reference gasoline.

[0128] By substituting the particulate emission and the particulate index of the non-reference gasoline to be tested, and the particulate index of the reference gasoline into the formula, the particulate emission of the test vehicle using the reference gasoline can be determined.

[0129] It should be noted that, because when the particulate matter index is less than 1, it is generally considered that the particulate matter emission is small, and the order of magnitude is less than other gasoline. Therefore, the gasoline with a particulate matter index of 1 can be regarded as zero particulate matter emission gasoline, which is used for correction when the test vehicle uses non-reference gasoline to determine the particulate matter emission. Therefore, in the embodiment of the present application, the particulate matter emission of the non-reference gasoline can be corrected to the particulate matter emission when the test vehicle uses the reference gasoline by determining the particulate matter emission of the non-reference gasoline.

[0130] After obtaining the corrected particulate matter emission of the reference gasoline, the vehicle factory can compare the standard particulate matter emission limit value of the reference gasoline published by the state with the calculated particulate matter emission of the reference gasoline to determine whether the particulate matter emission level of the test vehicle using the reference gasoline meets the state standard.

[0131] It should be noted that the reference gasoline is the gasoline specified in the emission standard of each country for emission test, which has stricter requirements on each index of gasoline than the commercially available gasoline, and the purpose is to test the emission under controllable gasoline components to avoid the change of emission caused by the difference of gasoline. GB 18352.6-2016 “Light-duty Vehicle Emission Limit Values and Measurement Methods (China Phase VI)” and Economic Commission of Europe (ECE) both stipulate their own reference gasoline indexes.

[0132] The method for determining the particulate matter emission of the non-reference gasoline provided by the present application can first determine the particulate matter index of the non-reference gasoline according to the oil product parameters of the non-reference gasoline, then determine the reference gasoline in the non-reference gasoline, determine the particulate matter emission of the reference gasoline, and determine the particulate matter emission calculation formula of the non-reference gasoline according to the particulate matter index and the particulate matter emission of the reference gasoline. Therefore, when the state or the vehicle factory needs to determine a certain non-reference gasoline, the particulate matter index of the non-reference gasoline to be tested can be directly substituted into the particulate matter emission formula of the non-reference gasoline for calculation, and there is no need to test on the test vehicle. Thus, the particulate matter emission of the non-reference gasoline is estimated.

[0133] Further, because the instantaneous working condition is adopted in the world light-duty vehicle test procedure, and because the vapor pressure of the gasoline components has a greater impact on the pool fire effect, in the present application, the weight of the number of double bonds of the components is reduced in the calculation of the particulate matter index of the non-reference gasoline, and the weight of the vapor pressure is correspondingly increased. Thus, the particulate matter index can better reflect the influence of the vapor pressure, and the calculated particulate matter emission of the non-reference gasoline is more accurate.

[0134] Further, when the test vehicle has never used the reference gasoline, the particulate emission of the test vehicle using the reference gasoline can be determined according to the particulate index of the non-reference gasoline, the particulate index of the reference gasoline and the particulate emission of the non-reference gasoline. Thus, when the state or the vehicle factory cannot use the reference gasoline for the experiment but needs to know the particulate emission of the test vehicle using the reference gasoline, the particulate emission of the test vehicle using the reference gasoline can be corrected according to the particulate emission of the non-reference gasoline, and thus the particulate emission level of the test vehicle using the reference gasoline can be determined according to the correction result and the standard particulate emission of the reference gasoline published by the state.

[0135] Further, the present application relates to a method for determining the particulate emission of a gasoline engine of a test vehicle using a non-reference gasoline in a type I test under the World Light-duty Vehicle Test Procedure. The method can be used in the fields of product development, verification and announcement of the vehicle and gasoline engine whose emission standard adopts the World Light-duty Vehicle Test Procedure.

[0136] In order to avoid the influence of fuel components on vehicle emissions, when formulating emission regulations, the state usually stipulates the requirements of the reference gasoline used in the emission test. However, since the requirements of the reference gasoline are very strict, only specific refiners can produce it, the supply capacity is limited and the price is high. Therefore, when performing the emission test, the state test unit or the vehicle factory often uses non-reference gasoline to determine the particulate emission. The purpose of the present application is to determine the particulate emission at normal temperature under the World Light-duty Vehicle Test Procedure in a convenient and accurate manner, so that when determining the particulate emission of the reference gasoline in the normal temperature emission test, the particulate emission of the non-reference gasoline can be corrected to obtain the particulate emission of the reference gasoline. At the same time, for the vehicle whose particulate emission of the reference gasoline is known, the particulate emission of the non-reference gasoline can be estimated.

[0137] Thus, the method for determining the particulate emission of the non-reference gasoline provided by the present application can be used in the fields of product development, verification and announcement of the vehicle and gasoline engine whose emission standard adopts the World Light-duty Vehicle Test Procedure, which can improve the flexibility of the test, reduce the procurement cost of the reference gasoline, avoid the deviation of the particulate emission of the reference gasoline caused by using the non-reference gasoline for the emission test instead of the reference gasoline, and reduce the risk of failure of the state announcement test.

[0138] While the application has been illustrated and described in connection with certain preferred embodiments thereof, it will be readily apparent to those of ordinary skill in the art that various changes in form and detail can be made therein without departing from the spirit and scope of the application. It is intended to encompass all such changes and alterations in the details thereof.

Claims

1. A method for determining the particulate emissions of a non-reference gasoline, characterized in that, The method comprises the following steps: S1: obtaining oil parameters of each non-reference gasoline, and determining a particulate index of each non-reference gasoline according to the oil parameters, wherein the oil parameters comprise the number of double bonds, vapor pressure and mass fraction of each component of each non-reference gasoline, and the particulate index of the non-reference gasoline is calculated by the following formula: wherein SPI is the particulate index of each of the non-reference gasoline; DBE i is the number of double bonds of the component i; V.P(443K) i is the vapor pressure of the component i at 443K; Wt i is the mass fraction of the component i; S2: determining a reference gasoline in the non-reference gasoline according to the particulate index of each non-reference gasoline and a preset particulate index interval; S3: obtaining the particulate emission of the reference gasoline, and determining a particulate emission calculation formula of the non-reference gasoline according to the particulate index of the reference gasoline and the particulate emission of the reference gasoline; S4: when it is determined that the particulate emission of the non-reference gasoline to be tested used by the test vehicle needs to be determined, determining the standard particulate emission of the non-reference gasoline to be tested used by the test vehicle according to the particulate emission calculation formula of the non-reference gasoline; S5: when it is determined that the particulate emission of the reference gasoline used by the test vehicle cannot be determined, obtaining an emission parameter of the non-reference gasoline to be tested used by the test vehicle, and determining the particulate emission of the non-reference gasoline to be tested used by the test vehicle according to the emission parameter; S51: obtaining the particulate index of the reference gasoline and the particulate index of the non-reference gasoline to be tested, and calculating the particulate emission of the reference gasoline used by the test vehicle according to the particulate index of the reference gasoline, the particulate index of the non-reference gasoline to be tested and the particulate emission of the non-reference gasoline to be tested used by the test vehicle.

2. The method of claim 1, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. The step S2 comprises: determining that the non-reference gasoline whose particulate index is in the preset particulate index interval is the reference gasoline; wherein The preset particulate index interval is 1.5 to 2.

5.

3. The method of claim 2, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. The step S3 comprises: S31: obtaining an emission parameter of each reference gasoline, and determining the particulate emission of each reference gasoline according to the emission parameter; S32: drawing a correlation curve of the particulate index of the non-reference gasoline and the particulate emission of the non-reference gasoline according to the particulate index and the particulate emission of each reference gasoline, and determining the particulate emission calculation formula of the non-reference gasoline by linear fitting; wherein The particulate emission calculation formula of the non-reference gasoline is: PN=aSPI+b wherein PN is the particulate emission of the non-reference gasoline, a and b are constants, and SPI is the particulate index of the non-reference gasoline.

4. The method of claim 3, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. In the step S31, the emission parameter of each reference gasoline comprises the volume of diluted exhaust gas, the particulate concentration of diluted exhaust gas and the particulate concentration of diluted channel background; and The step S31 further comprises: S311: obtaining the volume of diluted exhaust gas, the particulate concentration of diluted exhaust gas and the particulate concentration of diluted channel background of each reference gasoline. S312: Calculate the particulate emission of each reference gasoline according to the volume of the diluted exhaust gas of each reference gasoline, the particulate concentration of the diluted exhaust gas, and the particulate concentration of the dilution channel background.

5. The method of claim 4, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. The particulate emission of each reference gasoline is calculated according to the following formula: wherein PN is the particulate emission of each of the reference gasoline; V is the volume of the diluted exhaust gas; k is a correction factor; C is the particulate concentration of the diluted exhaust gas after correction; C b C is the particulate concentration of the diluted air or diluted passage background under standard conditions; C is the average particle concentration reduction factor of the volatile particle remover set for dilution at the time of the test; C is the average particle concentration reduction factor of the volatile particle remover set for dilution of the background gas; d is the mileage of the test cycle.

6. The method of claim 5, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. The step S4 comprises: S41: Obtain the oil product parameters of the non-reference gasoline to be tested, and determine the particulate index of the non-reference gasoline to be tested according to the oil product parameters; S42: Determine the standard particulate emission of the non-reference gasoline to be tested according to the particulate index of the non-reference gasoline to be tested and the particulate emission calculation formula of the non-reference gasoline.

7. The method of determining particulate emissions of a non-reference gasoline according to any one of claims 3 to 6, wherein The step S5 further comprises: S6: Compare the particulate emission of the non-reference gasoline to be tested with the standard particulate emission of the non-reference gasoline to be tested to determine the particulate emission level of the test vehicle when using the non-reference gasoline to be tested.

8. The method of claim 7, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. The step S51 further comprises: S52: Compare the particulate emission of the reference gasoline with the standard particulate emission of the reference gasoline to determine the particulate emission level of the test vehicle when using the reference gasoline.

9. The method of claim 8, wherein the non-reference gasoline is a gasoline having a sulfur content of 50 ppm or less. In the step S51, The particulate emission of the test vehicle when using the reference gasoline is calculated according to the following formula: wherein PN r is the particulate emissions amount for the test vehicle with reference gasoline; PN t is the particulate emissions amount for the non-reference gasoline to be tested; SPI t is the particulate index for the non-reference gasoline to be tested; SPI r is the particulate index for the reference gasoline.

Images