Method for correcting pollutant emission of heavy duty vehicle in plateau environment, storage medium and PEMS

Abstract

The invention discloses a heavy duty vehicle pollutant emission correction method in a plateau environment, a storage medium and a PEMS, and the method comprises the steps: obtaining the plain PEMS emission data of a heavy duty vehicle, calculating the specific emission, calculating the window specific emission of NOx in the plateau environment according to the specific emission of the plain NOx, calculating the window specific emission of PN in the plateau environment according to the specific emission of the plain PN, and calculating the window specific emission of the PN in the plateau environment according to the window specific emission of the PN in the plateau environment. The plateau environment comprises correction factors such as altitude, environment temperature, fuel injection quantity, carbon loading quantity, exhaust temperature, exhaust flow, accumulated positive altitude increment and the like. Through verification, the correction method provided by the invention can more accurately estimate the pollutant emission condition in the plateau environment, so that the test efficiency and accuracy are improved.

Description

Technical Field

[0001] The present invention relates to the field of automotive emission data analysis, and particularly to a correction method, a storage medium, and a PEMS for heavy vehicle pollutant emissions in a plateau environment. Background Art

[0002] In recent years, the Portable Emission Measurement System (PEMS) has been widely used in the actual road emission tests of heavy vehicles. However, the pollutant emissions of heavy vehicles are greatly affected by the plateau environment, resulting in a large difference between the actual road emissions of heavy vehicles in the plateau environment and those in the plain. Usually, after a heavy vehicle completes the PEMS test on the plain, it is also necessary to go to the plateau for the PEMS test of this heavy vehicle to determine whether this heavy vehicle meets the regulatory requirements. Therefore, accurately estimating the pollutant emissions of heavy vehicles in a plateau environment can shorten the development cycle of heavy vehicles and save the PEMS test cost of heavy vehicles.

[0003] CN117074046A discloses a method and device for automotive laboratory emission tests in a plateau environment. This method obtains the actual road emission test data of a test vehicle at a preset altitude and calculates the pollutant emission factors based on these data. Although this method considers the influence of altitude on pollutants, it does not consider the influence of road slope (cumulative positive altitude increase).

[0004] CN118464475A discloses a method, device, equipment, and storage medium for detecting diesel vehicle emission factors in a plateau. This method determines the corresponding pollutant emission factors according to the slope coefficients of a diesel vehicle to be detected in each driving section, determines the load factors of the diesel vehicle to be detected in each driving section, and calculates the pollutant emission factors based on these data. Although this method considers the influence of road slope on pollutants, it does not consider the combined influence of environmental temperature and altitude.

[0005] In summary, the existing technology still needs to go to the plateau for actual road tests when using PEMS to test heavy vehicles, which will inevitably increase the R & D cost and test cycle of heavy vehicles. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the above deficiencies and provide a correction method, a storage medium, and a PEMS for heavy vehicle pollutant emissions in a plateau environment.

[0007] The technical solution of the present invention is as follows:

[0008] According to a first aspect, the present invention provides a method for correcting heavy vehicle pollutant emissions in a plateau environment. By obtaining the emission data of heavy vehicle PEMS pollutants on the plain and calculating the specific emissions, based on the altitude, ambient temperature, fuel injection quantity, carbon load, exhaust temperature, exhaust gas flow rate, and cumulative positive altitude increase amount in the plain and plateau environments, a heavy vehicle pollutant emission correction factor is calculated, and the heavy vehicle plateau PEMS window emissions are calculated based on the heavy vehicle pollutant emission correction factor in the plateau environment; the pollutants include nitrogen oxides (NOx) and particulate matter (PN).

[0009] Further, according to the specific emissions of heavy vehicle NOx on the plain, combined with the exhaust temperature factor, the cumulative positive altitude increase amount factor, and the influence function of altitude and ambient temperature on the fuel injection quantity, the specific emissions of NOx of heavy vehicles in the plateau environment are calculated:

[0010] E 高原,NOx =[∑(E 平原,NOx,i ×C i ×K i )]×f(H,T)

[0011] Where: ∑ is the summation operator, i is the operating conditions such as urban roads, suburban roads, or highways, etc. The specific emissions of NOx on urban roads can only be multiplied by the exhaust temperature factor and the cumulative positive altitude increase amount factor on urban roads. The same applies to suburban roads and highways; E 高原,NOx is the specific emissions of NOx of heavy vehicles in the plateau environment; E 平原,NOx is the specific emissions of NOx of heavy vehicles on the plain, C i is the exhaust temperature factor, K i is the cumulative positive altitude increase amount factor, and f(H,T) is the influence function of altitude and ambient temperature on the fuel injection quantity (if f(H,T) ≤ 0, it can be considered that altitude and ambient temperature have no influence on the fuel injection quantity, and at this time f(H,T) is not substituted into the calculation).

[0012] Further, according to the specific emissions of heavy vehicle PN on the plain, combined with the exhaust temperature factor, the cumulative positive altitude increase amount factor, the exhaust gas flow rate factor, the carbon load factor, and the influence function of altitude and ambient temperature on the fuel injection quantity, the specific emissions of PN of heavy vehicles in the plateau environment are calculated:

[0013] E 高原,PN =[∑(E 平原,PN,i ×C i ×K i ×F i ×L i )]×f(H,T)

[0014] Where: ∑ is the summation operator, i represents driving conditions such as urban roads, suburban roads, or highways. The PN ratio emissions of urban roads can only be multiplied by the exhaust temperature factor of urban roads, the cumulative positive altitude increase factor of urban roads, the exhaust gas flow factor of urban roads, and the carbon loading factor of urban roads. The same applies to suburban roads and highways; E 高原,PN is the window ratio emission of heavy-duty vehicle PN in a plateau environment; E 平原,PN is the specific emission of heavy-duty vehicle PN in a plain environment, C i is the exhaust temperature factor, K i is the cumulative positive altitude increase factor, F i is the exhaust gas flow factor, F i is the carbon loading factor, and f(H,T) is the influence function of altitude and ambient temperature on fuel injection quantity (if f(H,T) ≤ 0, it can be considered that altitude and ambient temperature have no influence on fuel injection quantity, and in this case, f(H,T) is not substituted into the calculation).

[0015] According to a second aspect, the present invention provides a computer-readable storage medium, on which a computer program is stored, and the computer program can be executed by a processor to implement the steps of a method for correcting pollutant emissions of heavy-duty vehicles in a plateau environment according to the present invention.

[0016] According to a third aspect, the present invention provides a PEMS applicable to heavy-duty vehicles in a plateau environment, including the computer-readable storage medium described above.

[0017] The beneficial effects of the present invention include:

[0018] (1) Through the method for correcting pollutant emissions of heavy-duty vehicles in a plateau environment provided by the present invention, enterprises can estimate the emission situation in a plateau environment by using this method after completing PEMS tests in a plain area, thus avoiding the need for repeated tests in a plateau area, significantly shortening the development cycle of heavy-duty vehicles, and greatly reducing the test cost;

[0019] (2) The present invention comprehensively considers multiple factors such as altitude, ambient temperature, fuel injection quantity, carbon loading, exhaust temperature, exhaust gas flow, and cumulative positive altitude increase, and calculates correction factors through an accurate mathematical model, so as to be able to more accurately estimate the pollutant emission situation in a plateau environment. This correction method improves the efficiency and accuracy of testing. Description of the Drawings

[0020] Figure 1 : Flow chart of an embodiment of the correction method of the present invention. Detailed Embodiments

[0021] The technical solutions of the present invention will be described in detail below through embodiments in combination with the drawings.

[0022] Embodiment 1

[0023] See Figure 1 As shown, in accordance with the "Limits and Measurement Methods for Pollutant Emissions from Heavy-Duty Diesel Vehicles (China Phase VI)" (GB17691—2018) standard, on the plain, PEMS is used to conduct on-road emission tests on heavy-duty vehicles, collecting data on environmental conditions (altitude, ambient temperature), engine operating parameters (fuel injection quantity, carbon loading, exhaust temperature, exhaust flow rate) during the plain test, cumulative positive altitude increase, and pollutant (NOx and PN) emission data, and calculating the specific emissions of pollutants according to the GB 17691—2018 standard.

[0024] Based on the specific emissions of NOx from heavy-duty vehicles on the plain, combined with the exhaust temperature factor, cumulative positive altitude increase factor, and the influence function of altitude and ambient temperature on fuel injection quantity, calculate the window specific emissions of NOx from heavy-duty vehicles in the plateau environment:

[0025] E 高原,NOx = [∑(E 平原,NOx,i × C i × K i )] × f(H,T) (1)

[0026] Where: i is the operating condition such as urban road, suburban road, or highway. The specific emissions of NOx on the urban road can only be multiplied by the exhaust temperature factor and cumulative positive altitude increase factor on the urban road. The same applies to suburban roads and highways; E 高原,NOx is the window specific emissions of NOx from heavy-duty vehicles in the plateau environment; E 平原,NOx is the specific emissions of NOx from heavy-duty vehicles in the plain environment, C i is the exhaust temperature factor, K i is the cumulative positive altitude increase factor, and f(H,T) is the influence function of altitude and ambient temperature on fuel injection quantity (if f(H,T) ≤ 0, it can be considered that altitude and ambient temperature have no influence on fuel injection quantity, and in this case, f(H,T) is not substituted into the calculation).

[0027] Exhaust temperature factor:

[0028]

[0029] Where, ET 平原 is the exhaust temperature in the plain environment; ET 高原 is the exhaust temperature in the plateau environment.

[0030] Cumulative positive altitude increase factor:

[0031]

[0032] Where, ΔH 平原 is the cumulative positive altitude increase in the plain environment; ΔH高原 is the cumulative positive altitude increase in the plateau environment.

[0033] Construct the influence function of altitude and ambient temperature on fuel injection quantity:

[0034] f(H,T) = c1 + c2H + c3T (4)

[0035] Where f(H,T) is the influence function of altitude and ambient temperature on fuel injection quantity; H is the altitude; T is the ambient temperature; c1, c2, and c3 are fitting coefficients.

[0036] Substitute each altitude, ambient temperature, and the corresponding fuel injection quantity into the influence function relationship of fuel injection quantity, and perform multiple linear regression fitting through Origin software to calculate the coefficients c1, c2, and c3 in the influence function relationship of fuel injection quantity; substitute the obtained coefficients into the influence function relationship of fuel injection quantity to obtain the influence function relationship of fuel injection quantity.

[0037] According to the specific emission of PN of heavy-duty vehicles on the plain, combined with the exhaust temperature factor, cumulative positive altitude increase factor, exhaust gas flow factor, carbon loading factor, and the influence function of altitude and ambient temperature on fuel injection quantity, calculate the window specific emission of PN of heavy-duty vehicles in the plateau environment:

[0038] E 高原,PN = [∑(E 平原,PN,i × C i × K i × F i × L i )] × f(H,T) (5)

[0039] Where: i is the working condition such as urban road, suburban road, or highway. The specific emission of PN on urban roads can only be multiplied by the exhaust temperature factor, cumulative positive altitude increase factor, exhaust gas flow factor, and carbon loading factor on urban roads. The same applies to suburban roads and highways; E 高原,PN is the window specific emission of PN of heavy-duty vehicles in the plateau environment; E 平原,PN is the specific emission of PN of heavy-duty vehicles on the plain, C i is the exhaust temperature factor, K i is the cumulative positive altitude increase factor, F i is the exhaust gas flow factor, L i is the carbon loading factor, and f(H,T) is the influence function of altitude and ambient temperature on fuel injection quantity (if f(H,T) ≤ 0, it can be considered that altitude and ambient temperature have no influence on fuel injection quantity, and in this case, f(H,T) is not substituted into the calculation).

[0040] Exhaust gas flow factor:

[0041]

[0042] Among them, EF 平原 is the exhaust gas flow rate in the plain environment; EF 高原 is the exhaust gas flow rate in the plateau environment.

[0043] Carbon loading factor:

[0044]

[0045] Among them, CL 平原 is the carbon loading in the plain environment; CL 高原 is the carbon loading in the plateau environment.

[0046] Example 2

[0047] Refer to Figure 1 As shown, select 1 N3-class National VI heavy-duty diesel vehicle to conduct PEMS tests in the plain (Xiangyang) environment, collect the actual altitude, ambient temperature, carbon loading, exhaust gas temperature, exhaust gas flow rate, cumulative positive altitude increase, and NOx and PN data during the plain test, and calculate the specific emissions of pollutants according to the National VI heavy-duty vehicle emission standards. The relevant information is shown in Table 1.

[0048] Use the cumulative average method to calculate the NOx and PN specific emissions on urban roads, suburban roads, and highways in the plain environment respectively:

[0049]

[0050] Among them, EF 累计 is the NOx and PN specific emissions calculated by the cumulative average method, mg / kWh or # / kWh; t1 is the start time of valid data, s; t j is the end time of valid data, s; E is the instantaneous emission rate, mg / s or # / s; W is the instantaneous work done, kWh.

[0051] Table 1

[0052]

[0053] Continue to select the above vehicle to conduct PEMS tests in the plateau (Kunming) environment, collect the actual altitude, ambient temperature, carbon loading, exhaust gas temperature, exhaust gas flow rate, cumulative positive altitude increase, and NOx and PN data during the plateau test. The relevant information is shown in Table 2.

[0054] According to the actual NOx and PN data, use the work-based window method required by the National VI heavy-duty vehicle emission standards to calculate the NOx and PN window specific emissions of this heavy-duty vehicle:

[0055]

[0056] Among them, EF窗口 The NOx and PN window specific emissions calculated by the work-based window method, mg / kWh or # / kWh; E 窗口 is the window emission, mg or #; W(t 2,i ) - W(t 1,i ) is the engine cycle work of the i-th average window, kWh.

[0057] Among all the NOx and PN window specific emissions, the 90th percentile values are respectively selected, which respectively represent the actual NOx window specific emission (38.98 mg / kWh) and PN window specific emission (1.64E+11 # / kWh) of heavy-duty diesel vehicles in the plateau environment.

[0058] Table 2

[0059]

[0060]

[0061] Substitute the data in Table 1 and Table 2 into formulas (2), (3), (6) and (7) in Example 1 respectively, and the exhaust temperature factor C 市区路 = 1.04, C 市郊路 = 1.03, C 高速路 = 1.10;

[0062] Cumulative positive altitude increase factor K 市区路 = 0.66, K 市郊路 = 0.58, K 高速路 = 0.53;

[0063] Exhaust gas flow factor F 市区路 = 1.24, F 市郊路 = 1.41, F 高速路 = 1.19;

[0064] Carbon loading factor L 市区路 = 0.77, L 市郊路 = 0.70, L 高速路 = 0.83.

[0065] Substitute the historical altitudes and ambient temperatures and the corresponding fuel injection amounts into formula (4) in Example 1, and perform multiple linear regression fitting through Origin software to calculate the fitting coefficients c1 = 8.3423, c2 = -0.00261, c3 = -0.08471 in the influence function relationship of the fuel injection amount.

[0066] Substitute the average altitude and ambient temperature in the plateau environment into formula (4) in Example 1 to obtain the influence coefficient f(H,T) of the fuel injection amount = 0.87.

[0067] Substitute the exhaust gas temperature factor C i , the cumulative positive altitude increase factor K i , and the influence coefficient f(H,T) of fuel injection quantity into formula (1) in Example 1 to calculate the window specific emission E of NOx for heavy-duty vehicles in a plateau environment 高原,NOx , and obtain the window specific emission E of NOx 高原,NOx = 37.41 mg / kWh.

[0068] Substitute the exhaust gas temperature factor C i , the cumulative positive altitude increase factor K i , the exhaust gas flow factor F i , the carbon loading factor L i , and the influence coefficient f(H,T) of fuel injection quantity into formula (5) in Example 1 to calculate the window specific emission E of PN for heavy-duty vehicles in a plateau environment 高原,PN , and obtain the window specific emission E of PN 高原,PN = 1.71E+11 # / kWh.

[0069] Finally, the window specific emissions E of NOx and PN 高原,NOx can be verified through the formula 高原,PN .

[0070] The deviation between the actual window specific emission of NOx and the calculated window specific emission of NOx is:

[0071]

[0072] The deviation between the actual window specific emission of PN and the calculated window specific emission of PN is:

[0073]

[0074] The deviations between the actual values of the window specific emissions of NOx and PN and the calculated values obtained by the method of the present invention are 4.03% and -4.27% respectively, both within the deviation range of ±5%, and it can be considered that the credibility of the corrected results is relatively high.

Claims

1. A correction method for heavy vehicle pollutant emissions in plateau environments, characterized in that Including: (1) Obtaining the PEMS emission data of heavy-duty vehicles on plain and calculating the specific emission; (2) Calculating the window specific emission of NOx in the plateau environment according to the specific emission of NOx on plain; E 高原,NOx = [∑(E 平原,NOx,i × C i × K i )] × f(H, T) Among them, E 高原,NOx is the window specific emission of NOx from heavy-duty vehicles in the plateau environment; E 平原,NOx is the specific emission of NOx from heavy-duty vehicles in the plain environment, C i is the exhaust gas temperature factor, K i is the cumulative positive altitude increase factor, i is the urban road, suburban road or highway, and f(H,T) is the influence function of altitude and ambient temperature on the fuel injection quantity. If f(H,T) ≤ 0, it is considered that altitude and ambient temperature have no influence on the fuel injection quantity, and in this case, f(H,T) is not substituted into the calculation; (3) Calculating the window specific emission of PN in the plateau environment according to the specific emission of PN on plain; E 高原,PN = [∑(E 平原,PN,i × C i × K i × F i × L i )] × f(H, T) Among them, E 高原,PN is the window ratio emission of PN for heavy-duty vehicles in the plateau environment; E 平原,PN is the specific emission of PN for heavy-duty vehicles in the plain environment, C i is the exhaust temperature factor, K i is the cumulative positive altitude increase factor, F i is the exhaust gas flow factor, L i is the carbon loading factor, i is the urban road, suburban road or highway, f(H,T) is the influence function of altitude and ambient temperature on the fuel injection quantity. If f(H,T) ≤ 0, it can be considered that altitude and ambient temperature have no influence on the fuel injection quantity, and in this case, f(H,T) is not substituted into the calculation.

2. The correction method according to claim 1, characterized in that, The exhaust gas temperature factor C i is as follows: Among them, ET 平原 is the exhaust gas temperature in the plain environment; ET 高原 is the exhaust gas temperature in the plateau environment.

3. The correction method according to claim 1, wherein The cumulative positive altitude increase factor K i is as follows: Among them, ΔH 平原 is the cumulative positive altitude increase in the plain environment; ΔH 高原 is the cumulative positive altitude increase in the plateau environment.

4. The correction method according to claim 1, wherein The influence function of altitude and ambient temperature on fuel injection quantity is: f(H,T) = c1 + c2H + c3T where f(H,T) is the influence function of altitude and ambient temperature on fuel injection quantity; H is the altitude; T is the ambient temperature; c1, c2, and c3 are fitting coefficients, c1>0, -1 < c2 < 1, -1 < c3 < 1; Substituting the obtained coefficients into the influence function relation of fuel injection quantity to obtain the influence function relation of fuel injection quantity.

5. The correction method according to claim 1, characterized in that, The exhaust gas flow factor F i is as follows: Among them, EF 平原 is the exhaust gas flow rate in a plain environment; EF 高原 is the exhaust gas flow rate in a plateau environment.

6. The correction method according to claim 1, wherein The carbon loading factor L i is as follows: Among them, CL 平原 is the carbon loading in the plain environment; CL 高原 is the carbon loading in the plateau environment.

7. The correction method according to claim 4, characterized in that, The fitting coefficients c1, c2, and c3 are respectively: c1 = 8.3423, c2 = -0.00261, c3 = -0.08471.

8. The correction method according to any one of claims 1 to 7, characterized in that, The obtaining of the PEMS emission data of heavy-duty vehicles on plain includes: Conducting actual road emission tests on heavy-duty vehicles using PEMS on plain in accordance with the standard of GB 17691-2018, collecting the environmental condition data, engine operation parameters, cumulative positive altitude increase amount, and pollutant emission data during the plain test, and calculating the specific emission of pollutants; the environmental conditions include altitude and ambient temperature; the engine operation parameters include fuel injection quantity, carbon loading, exhaust temperature, and exhaust flow rate; the pollutants include NOx and PN.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, This computer program can be executed by a processor to implement the steps of a method for correcting pollutant emissions of heavy-duty vehicles in a plateau environment as described in any one of claims 1-8.

10. A PEMS applicable to heavy-duty vehicles in plateau environments, characterized in that, Including a computer-readable storage medium as described in claim 9.

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