ANNEX VIIEXAMPLE OF CALCULATION PROCEDURE

1.ESC TEST

1.1.Gaseous emissions

The measurement data for the calculation of the individual mode results are shown below. In this example, CO and NOx are measured on a dry basis, HC on a wet basis. The HC concentration is given in propane equivalent (C3) and has to be multiplied by 3 to result in the C1 equivalent. The calculation procedure is identical for the other modes.

P(kW)

Ta(K)

Ha(g/kg)

GEXH(kg)

GAIRW(kg)

GFUEL(kg)

HC(ppm)

CO(ppm)

NOx(ppm)

82,9

294,8

7,81

563,38

545,29

18,09

6,3

41,2

495

Calculation of the dry to wet correction factor KW,r (Annex III, Appendix 1, Section 4.2):

FFH = 1,9691 + 18,09545,29 = 1,9058math and KW2 = 1,608 × 7,811 000 + 1,608 × 7,81 = 0,0124math
KW,r = 1 - 1,9058 × 18,09541,06 - 0,0124 = 0,9239math

Calculation of the wet concentrations:

CO = 41,2 × 0,9239 = 38,1 ppmmathNOx = 495 × 0,9239 = 457 ppmmath

Calculation of the NOx humidity correction factor KH,D (Annex III, Appendix 1, Section 4.3):

A = 0,309 × 18,09/541,06 - 0,0266 = -0,0163mathB = - 0,209 × 18,09/541,06 + 0,00954 = 0,0026mathKH,D = 11-0,0163 × 7,81-10,71 + 0,0026 × 294,8-298 = 0,9625math

Calculation of the emission mass flow rates (Annex III, Appendix 1, Section 4.4):

NOx = 0,001587 × 457 × 0,9625 × 563,38 = 393,27 g/hmathCO = 0,000966 × 38,1 × 563,38 = 20,735 g/hmathHC = 0,000479 × 6,3 × 3 × 563,38 = 5,100 g/hmath

Calculation of the specific emissions (Annex III, Appendix 1, Section 4.5):

The following example calculation is given for CO; the calculation procedure is identical for the other components.

The emission mass flow rates of the individual modes are multiplied by the respective weighting factors, as indicated in Annex III, Appendix 1, Section 2.7.1, and summed up to result in the mean emission mass flow rate over the cycle:

CO

=

6,7 × 0,15 + 24,6 × 0,08 + 20,5 × 0,10 + 20,7 × 0,10 + 20,6 × 0,05 + 15,0 × 0,05 + 19,7 × 0,05 + 74,5 × 0,09 + 31,5 × 0,10 + 81,9 × 0,08 + 34,8 × 0,05 + 30,8 × 0,05 + 27,3 × 0,05math

=

30,91 g/h

The engine power of the individual modes is multiplied by the respective weighting factors, as indicated in Annex III, Appendix 1, Section 2.7.1, and summed up to result in the mean cycle power:

Pnmath

=

0,1 × 0,15 + 96,8 × 0,08 + 55,2 ×0,10 + 82,9 × 0,10 + 46,8 × 0,05 + 70,1 × 0,05 + 23,0 × 0,05 + 114,3 × 0,09 + 27,0 × 0,10 + 122,0 × 0,08 + 28,6 × 0,05 + 87,4 × 0,05 + 57,9 × 0,05math

=

60,006 kW

CO= 30,9160,006 = 0,0515 g/kWhmath

Calculation of the specific NOx emission of the random point (Annex III, Appendix 1, Section 4.6.1):

Assume the following values have been determined on the random point:

nZ

1 600 min-1

MZ

495 Nm

NOx mass,Z

487,9 g/h (calculated according to the previous formulae)

P(n)Z

83 kW

NOx,Z

487,9/83 = 5,878 g/kWh

Determination of the emission value from the test cycle (Annex III, Appendix 1, Section 4.6.2):

Assume the values of the four enveloping modes on the ESC to be as follows:

nRT

nSU

ER

ES

ET

EU

MR

MS

MT

MU

1 368

1 785

5,943

5,565

5,889

4,973

515

460

681

610

ETU = 5,889 + 4,973-5,889 × 1 600-1 368 / 1 785-1 368 = 5,377 g/kWhmathERS = 5,943 + 5,565-5,943 × 1 600-1 368 / 1 785-1 368 = 5,732 g/kWhmathMTU = 681 + 601-681 × 1 600-1 368 / 1 785-1 368 = 641,3 NmmathMRS = 515 + 460-515 × 1 600-1 368 / 1 785-1 368 = 484,3 NmmathEZ = 5,732 + 5,377-5,732 × 495-484,3 / 641,3-484,3 = 5,708 g/kWhmath

Comparison of the NOx emission values (Annex III, Appendix 1, Section 4.6.3):

NOx diff = 100 × 5,878-5,708 / 5,708 = 2,98 %math

1.2.Particulate emissions

Particulate measurement is based on the principle of sampling the particulates over the complete cycle, but determining the sample and flow rates (MSAM and GEDF) during the individual modes. The calculation of GEDF depends on the system used. In the following examples, a system with CO2 measurement and carbon balance method and a system with flow measurement are used. When using a full flow dilution system, GEDF is directly measured by the CVS equipment.

Calculation of GEDF (Annex III, Appendix 1, Sections 5.2.3 and 5.2.4):

Assume the following measurement data of mode 4. The calculation procedure is identical for the other modes.

GEXH(kg/h)

GFUEL(kg/h)

GDILW(kg/h)

GTOTW(kg/h)

CO2D(%)

CO2A(%)

334,02

10,76

5,4435

6,0

0,657

0,04

  1. (a)

    carbon balance method

    GEDFW = 206,5 × 10,760,657-0,040 = 3 601,2 kg/hmath
  2. (b)

    flow measurement method

    q = 6,06,0-5,4435 = 10,78mathGEDFW = 334,02 × 10,78 = 3 600,7 kg/hmath

Calculation of the mass flow rate (Annex III, Appendix 1, Section 5.4):

The GEDFW flow rates of the individual modes are multiplied by the respective weighting factors, as indicated in Annex III, Appendix 1, Section 2.7.1, and summed up to result in the mean GEDF over the cycle. The total sample rate MSAM is summed up from the sample rates of the individual modes.

GEDFWmath

=

3 567 × 0,15 + 3 592 × 0,08 + 3 611 × 0,10 + 3 600 × 0,10 + 3 618 × 0,05 + 3 600 × 0,05 + 3 640 × 0,05 + 3 614 × 0,09 + 3 620 × 0,10 + 3 601 × 0,08 + 3 639 × 0,05 + 3 582 × 0,05 + 3 635 × 0,05math

=

3 604,6 kg/h

MSAMmath

=

0,226 + 0,122 + 0,151 + 0,152 + 0,076 + 0,076 + 0,076 + 0,136 + 0,151 + 0,121 + 0,076 + 0,076 + 0,075

=

1,515 kg

Assume the particulate mass on the filters to be 2,5 mg, then

PTmass = 2,51,515 × 360,41 000 = 5,948 g/hmath

Background correction (optional)

Assume one background measurement with the following values. The calculation of the dilution factor DF is identical to Section 3.1 of this Annex and not shown here.

Md = 0,1 mg; MDIL = 1,5 kgmath

Sum of DF

=

1-1/119,15 × 0,15 + 1-1/8,89 × 0,08 + 1-1/14,75 × 0,10 + 1-1/10,10 × 0,10 + 1-1/18,02 × 0,05 + 1-1/12,33 × 0,05 + 1-1/32,18 × 0,05 + 1-1/6,94 × 0,09 + 1-1/25,19 × 0,10 + 1-1/6,12 × 0,08 + 1-1/20,87 × 0,05 + 1-1/8,77 × 0,05 + 1-1/12,59 × 0,05math

=

0,923

PTmass = 2,51,515-0,11,5 × 0,923 × 3 604,61 000 = 5,726 g/hmath

Calculation of the specific emission (Annex III, Appendix 1, Section 5.5):

Pnmath

=

0,1 × 0,15 + 96,8 × 0,08 + 55,2 × 0,10 + 82,9 × 0,10 + 46,8 × 0,05 + 70,1 × 0,05 + 23,0 × 0,05 + 114,3 × 0,09 + 27,0 × 0,10 + 122,0 × 0,08 + 28,6 × 0,05 + 87,4 × 0,05 + 57,9 × 0,05math

=

60,006 kW

PT = 5,94860,006 = 0,099 g/kWhmathPT = 5,726/60,006 = 0,095 g/kWh, if background correctedmath

Calculation of the specific weighting factor (Annex III, Appendix 1, Section 5.6):

Assume the values calculated for mode 4 above, then

WFE,i = 0,152 × 3 604,6/1,515 × 3 600,7 = 0,1004math

This value is within the required value of 0,10 ± 0,003.

2.ELR TEST

Since Bessel filtering is a completely new averaging procedure in European exhaust legislation, an explanation of the Bessel filter, an example of the design of a Bessel algorithm, and an example of the calculation of the final smoke value is given below. The constants of the Bessel algorithm only depend on the design of the opacimeter and the sampling rate of the data acquisition system. It is recommended that the opacimeter manufacturer provide the final Bessel filter constants for different sampling rates and that the customer use these constants for designing the Bessel algorithm and for calculating the smoke values.

2.1.General remarks on the Bessel filter

Due to high frequency distortions, the raw opacity signal usually shows a highly scattered trace. To remove these high frequency distortions a Bessel filter is required for the ELR-test. The Bessel filter itself is a recursive, second-order low-pass filter which guarantees the fastest signal rise without overshoot.

Assuming a real time raw exhaust plume in the exhaust tube, each opacimeter shows a delayed and differently measured opacity trace. The delay and the magnitude of the measured opacity trace is primarily dependent on the geometry of the measuring chamber of the opacimeter, including the exhaust sample lines, and on the time needed for processing the signal in the electronics of the opacimeter. The values that characterise these two effects are called the physical and the electrical response time which represent an individual filter for each type of opacimeter.

The goal of applying a Bessel filter is to guarantee a uniform overall filter characteristic of the whole opacimeter system, consisting of:

  • physical response time of the opacimeter (tp),

  • electrical response time of the opacimeter (te),

  • filter response time of the applied Bessel filter (tF).

The resulting overall response time of the system tAver is given by:

tAver = t2F + t2p + t2emath

and must be equal for all kinds of opacimeters in order to give the same smoke value. Therefore, a Bessel filter has to be created in such a way, that the filter response time (tF) together with the physical (tp) and electrical response time (te) of the individual opacimeter must result in the required overall response time (tAver). Since tp and te are given values for each individual opacimeter, and tAver is defined to be 1,0 s in this Directive, tF can be calculated as follows:

tF = t2Aver + t2p + t2emath

By definition, the filter response time tF is the rise time of a filtered output signal between 10 % and 90 % on a step input signal. Therefore the cut-off frequency of the Bessel filter has to be iterated in such a way, that the response time of the Bessel filter fits into the required rise time.

Image_r00039

In Figure a, the traces of a step input signal and Bessel filtered output signal as well as the response time of the Bessel filter (tF) are shown.

Designing the final Bessel filter algorithm is a multi step process which requires several iteration cycles. The scheme of the iteration procedure is presented below.

Image_r00040

2.2.Calculation of the Bessel algorithm

In this example a Bessel algorithm is designed in several steps according to the above iteration procedure which is based upon Annex III, Appendix 1, Section 6.1.

For the opacimeter and the data acquisition system, the following characteristics are assumed:

  • physical response time tp 0,15 s

  • electrical response time te 0,05 s

  • overall response time tAver 1,00 s (by definition in this Directive)

  • sampling rate 150 Hz

Step 1Required Bessel filter response time tF:

tF = 12-0,152 + 0,052 = 0,987421 smath

Step 2Estimation of cut-off frequency and calculation of Bessel constants E, K for first iteration:

fc
3,141510 × 0,987421 = 0,318152 Hzmath
Δt

1/150 = 0,006667 s

Ω
1tan 3,1415 × 0,006667 × 0,318152 = 150,07664math
E
11 + 150,076644 × 3 × 0,618034 + 0,618034 + 150,0766442 = 7,07948 × 10-5math
K
2 × 7,07948 × 10-5 × 0,618034 × 150,0766442-1-1 = 0,970783math

This gives the Bessel algorithm:

Yi = Yi-1 + 7,07948 E - 5 × Si + 2 × Si-1 + Si-2-4 × Yi-2 + 0,970783 × Yi-1-Yi-2math

where Si represents the values of the step input signal (either ‘0’ or ‘1’) and Yi represents the filtered values of the output signal.

Step 3Application of Bessel filter on step input:

The Bessel filter response time tF is defined as the rise time of the filtered output signal between 10 % and 90 % on a step input signal. For determining the times of 10 % (t10) and 90 % (t90) of the output signal, a Bessel filter has to be applied to a step input using the above values of fc, E and K.

The index numbers, the time and the values of a step input signal and the resulting values of the filtered output signal for the first and the second iteration are shown in Table B. The points adjacent to t10 and t90 are marked in bold numbers.

In Table B, first iteration, the 10 % value occurs between index number 30 and 31 and the 90 % value occurs between index number 191 and 192. For the calculation of tF,iter the exact t10 and t90 values are determined by linear interpolation between the adjacent measuring points, as follows:

t10 = tlower + Δt × 0,1-outlower/outupper-outlowermatht90 = tlower + Δt × 0,9-outlower/outupper-outlowermath

where outupper and outlower, respectively, are the adjacent points of the Bessel filtered output signal, and tlower is the time of the adjacent time point, as indicated in Table B.

t10 = 0,200000 + 0,006667 × 0,1-0,099208/0,104794-0,099208 = 0,200945 smatht90 = 0,273333 + 0,006667 × 0,9-0,899147/0,901168-0,899147 = 1,276147 smath

Step 4Filter response time of first iteration cycle:

tF,iter = 1,276147-0,200945 = 1,075202 smath

Step 5Deviation between required and obtained filter response time of first iteration cycle:

Δ = 1,075202-0,987421/0,987421 = 0,081641math

Step 6Checking the iteration criteria:

|Δ| ≤ 0,01 is required. Since 0,081641 > 0,01, the iteration criteria is not met and a further iteration cycle has to be started. For this iteration cycle, a new cut-off frequency is calculated from fc and Δ as follows:

fc,new = 0,318152 × 1 + 0,081641 = 0,344126 Hzmath

This new cut-off frequency is used in the second iteration cycle, starting at step 2 again. The iteration has to be repeated until the iteration criteria is met. The resulting values of the first and second iteration are summarised in Table A.

Table AValues of the first and second iteration

Parameter

1. Iteration

2. Iteration

fc

(Hz)

0,318152

0,344126

E

(-)

7,07948 E-5

8,272777 E-5

K

(-)

0,970783

0,96841

t10

(s)

0,200945

0,185523

t90

(s)

1,276147

1,179562

tF,iter

(s)

1,075202

0,994039

Δ

(-)

0,081641

0,006657

fc,new

(Hz)

0,344126

0,346417

Step 7Final Bessel algorithm:

As soon as the iteration criteria has been met, the final Bessel filter constants and the final Bessel algorithm are calculated according to step 2. In this example, the iteration criteria has been met after the second iteration (Δ = 0,006657 ≤ 0,01). The final algorithm is then used for determining the averaged smoke values (see next Section 2.3).

Yi = Yi-1 + 8,272777 × 10-5 × Si + 2 × Si-1 + Si-2-4 × Yi-2 + 0,968410 × Yi-1-Yi-2math
Table BValues of step input signal and Bessel filtered output signal for the first and second iteration cycle

Index i[-]

Time[s]

Step input signal Si[-]

Filtered output signal Yi[-]

1. Iteration

2. Iteration

- 2

- 0,013333

0

0,0

0,0

- 1

- 0,006667

0

0,0

0,0

0

0,0

1

0,000071

0,000083

1

0,006667

1

0,000352

0,000411

2

0,013333

1

0,000908

0,00106

3

0,02

1

0,001731

0,002019

4

0,026667

1

0,002813

0,003278

5

0,033333

1

0,004145

0,004828

~

~

~

~

~

24

0,16

1

0,067877

0,077876

25

0,166667

1

0,072816

0,083476

26

0,173333

1

0,077874

0,089205

27

0,18

1

0,083047

0,095056

28

0,186667

1

0,088331

0,101024

29

0,193333

1

0,093719

0,107102

30

0,2

1

0,099208

0,113286

31

0,206667

1

0,104794

0,11957

32

0,213333

1

0,110471

0,125949

33

0,22

1

0,116236

0,132418

34

0,226667

1

0,122085

0,138972

35

0,233333

1

0,128013

0,145605

36

0,24

1

0,134016

0,152314

37

0,246667

1

0,140091

0,159094

~

~

~

~

~

175

1,166667

1

0,862416

0,895701

176

1,173333

1

0,864968

0,897941

177

1,18

1

0,867484

0,900145

178

1,186667

1

0,869964

0,902312

179

1,193333

1

0,87241

0,904445

180

1,2

1

0,874821

0,906542

181

1,206667

1

0,877197

0,908605

182

1,213333

1

0,87954

0,910633

183

1,22

1

0,881849

0,912628

184

1,226667

1

0,884125

0,914589

185

1,233333

1

0,886367

0,916517

186

1,24

1

0,888577

0,918412

187

1,246667

1

0,890755

0,920276

188

1,253333

1

0,8929

0,922107

189

1,26

1

0,895014

0,923907

190

1,266667

1

0,897096

0,925676

191

1,273333

1

0,899147

0,927414

192

1,28

1

0,901168

0,929121

193

1,286667

1

0,903158

0,930799

194

1,293333

1

0,905117

0,932448

195

1,3

1

0,907047

0,934067

~

~

~

~

~

2.3.Calculation of the smoke values

In the scheme below the general procedure of determining the final smoke value is presented.

Image_r00041

In Figure b, the traces of the measured raw opacity signal, and of the unfiltered and filtered light absorption coefficients (k-value) of the first load step of an ELR-Test are shown, and the maximum value Ymax1,A (peak) of the filtered k trace is indicated. Correspondingly, Table C contains the numerical values of index i, time (sampling rate of 150 Hz), raw opacity, unfiltered k and filtered k. Filtering was conducted using the constants of the Bessel algorithm designed in Section 2.2 of this Annex. Due to the large amount of data, only those sections of the smoke trace around the beginning and the peak are tabled.

Image_r00042

The peak value (i = 272) is calculated assuming the following data of Table C. All other individual smoke values are calculated in the same way. For starting the algorithm, S-1, S-2, Y-1 and Y-2 are set to zero.

LA (m)

0,43

Index i

272

N ( %)

16,783

S271 (m-1)

0,427392

S270 (m-1)

0,427532

Y271 (m-1)

0,542383

Y270 (m-1)

0,542337

Calculation of the k-value (Annex III, Appendix 1, Section 6.3.1):

k =-1/0,430 × ln 1-16,783/100 = 0,427252 m-1math

This value corresponds to S272 in the following equation.

Calculation of Bessel averaged smoke (Annex III, Appendix 1, Section 6.3.2):

In the following equation, the Bessel constants of the previous Section 2.2 are used. The actual unfiltered k-value, as calculated above, corresponds to S272 (Si). S271 (Si-1) and S270 (Si-2) are the two preceding unfiltered k-values, Y271 (Yi-1) and Y270 (Yi-2) are the two preceding filtered k-values.

Y272math

=

0,542383 + 8,272777 × 10-5 × 0,427252 + 2 × 0,427392 + 0,427532-4 × 0,542337 + 0,968410 × 0,542383-0,542337math

=

0,542389 m-1math

This value corresponds to Ymax1,A in the following equation.

Calculation of the final smoke value (Annex III, Appendix 1, Section 6.3.3):

From each smoke trace, the maximum filtered k-value is taken for the further calculation.

Assume the following values

Speed

Ymax (m-1)

Cycle 1

Cycle 2

Cycle 3

A

0,5424

0,5435

0,5587

B

0,5596

0,54

0,5389

C

0,4912

0,5207

0,5177

SVA = 0,5424 + 0,5435 + 0,5587 / 3 = 0,5482 m- 1mathSVB = 0,5596 + 0,5400 + 0,5389 / 3 = 0,5462 m- 1mathSVC = 0,4912 + 0,5207 + 0,5177 / 3 = 0,5099 m- 1mathSV = 0,43 × 0,5482 + 0,56 × 0,5462 + 0,01 × 0,5099 = 0,5467 m- 1math

Cycle validation (Annex III, Appendix 1, Section 3.4)

Before calculating SV, the cycle must be validated by calculating the relative standard deviations of the smoke of the three cycles for each speed.

Speed

Mean SV(m-1)

Absolute standard deviation(m-1)

Relative standard deviation(%)

A

0,5482

0,0091

1,7

B

0,5462

0,0116

2,1

C

0,5099

0,0162

3,2

In this example, the validation criteria of 15 % are met for each speed.

Table CValues of opacity N, unfiltered and filtered k-value at beginning of load step

Index i[-]

Time[s]

Opacity N[%]

Unfiltered k-value[m-1]

Filtered k-value[m-1]

- 2

0,0

0,0

0,0

0,0

- 1

0,0

0,0

0,0

0,0

0

0,0

0,0

0,0

0,0

1

0,006667

0,02

0,000465

0,0

2

0,013333

0,02

0,000465

0,0

3

0,02

0,02

0,000465

0,0

4

0,026667

0,02

0,000465

0,000001

5

0,033333

0,02

0,000465

0,000002

6

0,04

0,02

0,000465

0,000002

7

0,046667

0,02

0,000465

0,000003

8

0,053333

0,02

0,000465

0,000004

9

0,06

0,02

0,000465

0,000005

10

0,066667

0,02

0,000465

0,000006

11

0,073333

0,02

0,000465

0,000008

12

0,08

0,02

0,000465

0,000009

13

0,086667

0,02

0,000465

0,000011

14

0,093333

0,02

0,000465

0,000012

15

0,1

0,192

0,004469

0,000014

16

0,106667

0,212

0,004935

0,000018

17

0,113333

0,212

0,004935

0,000022

18

0,12

0,212

0,004935

0,000028

19

0,126667

0,343

0,00799

0,000036

20

0,133333

0,566

0,0132

0,000047

21

0,14

0,889

0,020767

0,000061

22

0,146667

0,929

0,021706

0,000082

23

0,153333

0,929

0,021706

0,000109

24

0,16

1,263

0,029559

0,000143

25

0,166667

1,455

0,034086

0,000185

26

0,173333

1,697

0,039804

0,000237

27

0,18

2,03

0,047695

0,000301

28

0,186667

2,081

0,048906

0,000378

29

0,193333

2,081

0,048906

0,000469

30

0,2

2,424

0,057067

0,000573

31

0,206667

2,475

0,058282

0,000693

32

0,213333

2,475

0,058282

0,000827

33

0,22

2,808

0,066237

0,000977

34

0,226667

3,01

0,071075

0,001144

35

0,233333

3,253

0,076909

0,001328

36

0,24

3,606

0,08541

0,001533

37

0,246667

3,96

0,093966

0,001758

38

0,253333

4,455

0,105983

0,002007

39

0,26

4,818

0,114836

0,002283

40

0,266667

5,02

0,119776

0,002587

Values of opacity N, unfiltered and filtered k-value around Ymax1,A (≡ peak value, indicated in bold number)

Index i[-]

Time[s]

Opacity N[%]

Unfiltered k-value[m-1]

Filtered k-value[m-1]

259

1,726667

17,182

0,438429

0,538856

260

1,733333

16,949

0,431896

0,539423

261

1,74

16,788

0,427392

0,539936

262

1,746667

16,798

0,427671

0,540396

263

1,753333

16,788

0,427392

0,540805

264

1,76

16,798

0,427671

0,541163

265

1,766667

16,798

0,427671

0,541473

266

1,773333

16,788

0,427392

0,541735

267

1,78

16,788

0,427392

0,541951

268

1,786667

16,798

0,427671

0,542123

269

1,793333

16,798

0,427671

0,542251

270

1,8

16,793

0,427532

0,542337

271

1,806667

16,788

0,427392

0,542383

272

1,813333

16,783

0,427252

0,542389

273

1,82

16,78

0,427168

0,542357

274

1,826667

16,798

0,427671

0,542288

275

1,833333

16,778

0,427112

0,542183

276

1,84

16,808

0,427951

0,542043

277

1,846667

16,768

0,426833

0,54187

278

1,853333

16,01

0,40575

0,541662

279

1,86

16,01

0,40575

0,541418

280

1,866667

16,0

0,405473

0,541136

281

1,873333

16,01

0,40575

0,540819

282

1,88

16,0

0,405473

0,540466

283

1,886667

16,01

0,40575

0,54008

284

1,893333

16,394

0,416406

0,539663

285

1,9

16,394

0,416406

0,539216

286

1,906667

16,404

0,416685

0,538744

287

1,913333

16,394

0,416406

0,538245

288

1,92

16,394

0,416406

0,537722

289

1,926667

16,384

0,416128

0,537175

290

1,933333

16,01

0,40575

0,536604

291

1,94

16,01

0,40575

0,536009

292

1,946667

16,0

0,405473

0,535389

293

1,953333

16,01

0,40575

0,534745

294

1,96

16,212

0,411349

0,534079

295

1,966667

16,394

0,416406

0,533394

296

1,973333

16,394

0,416406

0,532691

297

1,98

16,192

0,410794

0,531971

298

1,986667

16,0

0,405473

0,531233

299

1,993333

16,0

0,405473

0,530477

300

2,0

16,0

0,405473

0,529704

3.ETC TEST

3.1.Gaseous emissions (diesel engine)

Assume the following test results for a PDP-CVS system

V0 (m3/rev)

0,1776

Np (rev)

23 073

pB (kPa)

98,0

p1 (kPa)

2,3

T (K)

322,5

Ha (g/kg)

12,8

NOx conce (ppm)

53,7

NOx concd (ppm)

0,4

COconce (ppm)

38,9

COconcd (ppm)

1,0

HCconce (ppm)

9,0

HCconcd (ppm)

3,02

CO2,conce (%)

0,723

Wact (kWh)

62,72

Calculation of the diluted exhaust gas flow (Annex III, Appendix 2, Section 4.1):

MTOTW = 1,293 × 0,1776 × 23 073 × 98,0-2,3 × 273 / 101,3 × 322,5 = 4 237,2 kgmath

Calculation of the NOx correction factor (Annex III, Appendix 2, Section 4.2):

KH, D = 11-0,0182 × 12,8-10,71 = 1,039math

Calculation of the background corrected concentrations (Annex III, Appendix 2, Section 4.3.1.1):

Assuming a diesel fuel of the composition C1H1,8

FS = 100 × 11 + 1,82 + 3,76 × 1 + 1,84 = 13,6mathDF = 13,60,723 + 9,00 + 38,9 × 10- 4 = 18,69mathNOx conc = 53,7-0,4 × 1-1/18,69 = 53,3 ppmmathCOconc = 38,9-1,0 × 1-1/18,69 = 37,9 ppmmathHCconc = 9,00-3,02 × 1-1/18,69 = 6,14 ppmmath

Calculation of the emissions mass flow (Annex III, Appendix 2, Section 4.3.1):

NOx mass = 0,001587 × 53,3 × 1,039 × 4 237,2 = 372,391 gmathCOmass = 0,000966 × 37,9 × 4 237,2 = 155,129 gmathHCmass = 0,000479 × 6,14 × 4 237,2 = 12,462 gmath

Calculation of the specific emissions (Annex III, Appendix 2, Section 4.4):

NOx = 372,391/62,72 = 5,94 g/kWhmathCO = 155,129/62,72 = 2,47 g/kWhmathHC = 12,462/62,72 = 0,199 g/kWhmath

3.2.Particulate emissions (diesel engine)

Assume the following test results for a PDP-CVS system with double dilution

MTOTW (kg)

4 237,2

Mf,p (mg)

3,03

Mf,b (mg)

0,044

MTOT (kg)

2,159

MSEC (kg)

0,909

Md (mg)

0,341

MDIL (kg)

1,245

DF

18,69

Wact (kWh)

62,72

Calculation of the mass emission (Annex III, Appendix 2, Section 5.1):

Mf = 3,030 + 0,044 = 3,074 mgmathMSAM = 2,159-0,909 = 1,250 kgmathPTmass = 3,0741,250 × 4 237,21 000 = 10,42 gmath

Calculation of the background corrected mass emission (Annex III, Appendix 2, Section 5.1):

PTmass = 3,0741,250-0,3411,245 × 1+118,69 × 4 237,21 000 = 9,32 gmath

Calculation of the specific emission (Annex III, Appendix 2, Section 5.2):

PT = 10,42/62,72 = 0,166 g/kWhmathPT = 9,32/62,72 = 0,149 g/kWh, if background correctedmath

3.3.Gaseous emissions (CNG engine)

Assume the following test results for a PDP-CVS system with double dilution

MTOTW (kg)

4 237,2

Ha (g/kg)

12,8

NOx conce (ppm)

17,2

NOx concd (ppm)

0,4

COconce (ppm)

44,3

COconcd (ppm)

1,0

HCconce (ppm)

27,0

HCconcd (ppm)

3,02

CH4 conce (ppm)

18,0

CH4 concd (ppm)

1,7

CO2,conce ( %)

0,723

Wact (kWh)

62,72

Calculation of the NOx, correction factor (Annex III, Appendix 2, Section 4.2):

KH,G = 11-0,0329 × 12,8-10,71 = 1,074math

Calculation of the NMHC concentration (Annex III, Appendix 2, Section 4.3.1):

  1. (a)

    GC method

    NMHCconce = 27,0-18,0 = 9,0 ppmmath
  2. (b)

    NMC method

    Assuming a methane efficiency of 0,04 and an ethane efficiency of 0,98 (see Annex III, Appendix 5, Section 1.8.4)

    NMHCconce = 27,0 × 1-0,04-18,00,98-0,04 = 8,4 ppmmath

Calculation of the background corrected concentrations (Annex III, Appendix 2, Section 4.3.1.1):

Assuming a G20 reference fuel (100 % methane) of the composition C1H4:

FS = 100 × 11 + 42 + 3,76 × 1 + 44= 9,5mathDF = 9,50,723 + 27,0 + 44,3 × 10- 4 = 13,01math

For NMHC, the background concentration is the difference between HCconcd and CH4concd

NOx conc = 17,2-0,4 × 1-1/13,01 = 16,8 ppmmathCOconc = 44,3-1,0 × 1-1/13,01 = 43,4 ppmmathNMHCconc = 8,4-1,32 × 1-1/13,01 = 7,2 ppmmathCH4 conc = 18,0-1,7 × 1-1/13,01 = 16,4 ppmmath

Calculation of the emissions mass flow (Annex III, Appendix 2, Section 4.3.1):

NOx mass = 0,001587 × 16,8 × 1,074 × 4 237,2 = 121,330 gmathCOmass = 0,000966 × 43,4 × 4 237,2 = 177,642 gmathNMHCmass = 0,000502 × 7,2 × 4 237,2 = 15,315 gmathCH4 mass = 0,000554 × 16,4 × 4 237,2 = 38,498 gmath

Calculation of the specific emissions (Annex III, Appendix 2, Section 4.4):

NOx = 121,330/62,72 = 1,93 g/kWhmathCO = 177,642/62,72 = 2,83 g/kWhmathNMHC = 15,315/62,72 = 0,244 g/kWhmathCH4 = 38,498/62,72 = 0,614 g/kWhmath

4.λ-SHIFT FACTOR (Sλ)

4.1.Calculation of the λ-shift factor (Sλ)88

Sλ = 21-inert %100n + m4-O*2100math

where:

Sλ

λ-shift factor;

inert %

% by volume of inert gases in the fuel (i.e. N2, CO2, He, etc.);

O2*

% by volume of original oxygen in the fuel;

n and m

refer to average CnHm representing the fuel hydrocarbons, i.e:

n = 1 × CH4 %100+ 2 × C2 %100+ 3 × C3 %100+ 4 × C4 %100+ 5 × C5 %100+ ..1-diluent %100mathm = 4 × CH4 %100 + 4 ×C2H4 %100 + 6 × C2H6 %100 + … 8 × C3H8 %100 + ..1-diluent %100math

where:

CH4

% by volume of methane in the fuel;

C2

% by volume of all C2 hydrocarbons (e.g. C2H6, C2H4, etc.) in the fuel;

C3

% by volume of all C3 hydrocarbons (e.g. C3H8, C3H6, etc.) in the fuel;

C4

% by volume of all C4 hydrocarbons (e.g. C4H10, C4H8, etc.) in the fuel

C5

% by volume of all C5 hydrocarbons (e.g. C5H12, C5H10, etc.) in the fuel;

diluent

% by volume of dilution gases in the fuel (i.e. O2*, N2, CO2, He etc.).

4.2.Examples for the calculation of the λ-shift factor Sλ

Example 1:G25: CH4 = 86 %, N2 = 14 % (by volume)

n = 1 × CH4 %100 + 2 × C2 %100 + ..1- diluent %100 = 1 × 0,861-14100= 0,860,86 = 1mathm = 4 × CH4 %100 + 4 × C2H4 %100 + ..1- diluent %100 = 4 × 0,860,86 = 4mathSλ = 21-inert %100n + m4-O*2100 = 21-14100 × 1 + 44 = 1,16math

Example 2:GR: CH4 = 87 %, C2H6 = 13 % (by vol)

n = 1 × CH4 %100 + 2 × C2 %100 + ..1- diluent %100 = 1 × 0,87 + 2 × 0,131-0100 = 1,131 = 1,13mathm = 4 × CH4 %100 + 4 × C2H4 %100 + ..1 - diluent %100 = 4 × 0,87 + 6 × 0,131 = 4,26mathSλ = 21-inert %100n + m4-O*2100 = 21-0100 × 1,13 + 4,264 = 0,911math

Example 3:USA: CH4 = 89 %, C2H6 = 4,5 %, C3H8 = 2,3 %, C6H14 = 0,2 %, O2 = 0,6 %, N2 = 4 %

n = 1 × CH4 %100 + 2 × C2 %100+ ..1 - diluent %100 = 1 × 0,89 + 2 × 0,045 + 3 × 0,023 + 4 × 0,0021-0,64 + 4100 = 1,11mathm = 4 × CH4 %100 + 4 ×C2H4 %100 + 6 × C2H6100 + .. + 8 × C3H81001 - diluent %100 = 4 × 0,89 + 4 × 0,045 + 8 × 0,023 + 14 × 0,0021-0,6 + 4100= 4,24mathSλ = 21-inert %100n + m4-O*2100 = 21-4100 × 1,11 + 4,244-0,6100 = 0,96math