# emission parameters

 Register Blogs Members List Search Today's Posts Mark Forums Read September 18, 2014, 02:36 emission parameters #1 Member   ABDUL GAFOOR CP Join Date: Jul 2014 Posts: 30 Rep Power: 11 hiii..... In AVL we are getting the emission parameters as mass fractions only....can anybody suggest me the procedures to convert this mass fraction into g/kg of fuel or g/kWh units..... thanking you gafoor   November 23, 2014, 17:10 #2
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Rep Power: 11 Calculate the total number of moles in the exhaust gas from the volume flow rate(m3/hr) of exhaust gas using the ideal gas law PV=nRT.

Number of moles in the exhaust gas flow, n =RT/PV, where R (R = 8.3145 J/mol·K) isideal gas constant, V is exhaust flow rate in m3/hr, P is pressure in N/m2 and T istemperature in K.

2. Multiply by the ppm value (y*10-6, assume y is measured ppm of gas) for eachspecies of pollutant to get the moles per hour of that species

3. For each pollutant species, multiple by the molar mass (molecular weight) to getgrams per hour. Divide by power output in kW to get grams per kiloWatt-hour

I have also attached a calculation file for your understanding.
Attached Images emission.JPG (82.6 KB, 152 views)   November 24, 2014, 03:35 #3 Member   ABDUL GAFOOR CP Join Date: Jul 2014 Posts: 30 Rep Power: 11 thanks a lot for your valuable information..... regards gafoor   November 24, 2014, 03:59 emission parameters #4 New Member   Farhad Hossain Join Date: Aug 2014 Posts: 4 Rep Power: 11 Hi gafoor Do you help me about AVL Fire Spray and Combustion program? Best regards farhad   November 24, 2014, 04:25 #5 Member   ABDUL GAFOOR CP Join Date: Jul 2014 Posts: 30 Rep Power: 11 hii... i am also very new in AVL and also in CFD. though i will try my level best to help you.. feel free to ask me about your problems and we will discuss.... my mail ID is gafoorcp@yahoo.com regards gafoor Prateek manit likes this.   January 29, 2016, 18:33 Are AVL Fire emission results correct ? #6 New Member   muhammet Join Date: Jan 2016 Location: istanbul Posts: 2 Rep Power: 0 Hi all, i am using AVL fire but i am doubtful about the results of emissions. i did some simulation and tuned the cylinder pressure with exp. but the emissions did not tuned. i use extended zeldovich model for NO and one more; when i use the other model for NO, it gives different resuls at same temperature curve. could any one help me? thanks.   January 29, 2016, 18:46 #7 New Member   muhammet Join Date: Jan 2016 Location: istanbul Posts: 2 Rep Power: 0 i thing you can get total mass curve (or data) and then if you multiply the total mass with mass frac. you will get the mass of i species( for ex. NO ). then you must find the value of mass per hour ( with using the engine speed ). then devide it with power. TM = total mass* injector hole number (because it gives total mass results for only per hole) NO mass = NO mass frac.*TM NO [g/kWh] = {(NO mass)*(n/2)*60} / power ! engine speed must devided by 2 if it 4 strokes ! 60 is represent the minutes in hour.   April 6, 2016, 00:26 #8
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 Originally Posted by muhammet i thing you can get total mass curve (or data) and then if you multiply the total mass with mass frac. you will get the mass of i species( for ex. NO ). then you must find the value of mass per hour ( with using the engine speed ). then devide it with power. TM = total mass* injector hole number (because it gives total mass results for only per hole) NO mass = NO mass frac.*TM NO [g/kWh] = {(NO mass)*(n/2)*60} / power ! engine speed must devided by 2 if it 4 strokes ! 60 is represent the minutes in hour.

Paste the following code in a notepad and change the file extension from *.txt to *.frml
(frml is the extension which works as a formula file for AVL FIRE)

Upload this formula and you will get the NOx values in ppm directly

// --- NOx_ppm.frml ---
// Must be used with cell-selection only!
// Computes the average NOx concentration in [ppm] according
// to the specified assumed molar mass of NOx as fl2 result;
// molar mass of NOx in g/mol
#define REAL_assumed_molar_mass_of_NOx 38.0

\$\$init
double ppm_nox = 0.0;
if(!init){
if(divisor > 0.0) ppm_nox = sum / divisor * 1.0e6;
if(IAMPRO < 2){
print "NOx_ppm.frml: avg NOx concentration in", name, ":", ppm_nox, "[ppm]";
}
sum = ppm_nox;
divisor = 1.0;
}
\$\$formula
divisor += ap * vol / (8314.4 * temp);
return YNOXMF[index] * den * vol / REAL_assumed_molar_mass_of_NOx;

Once you get the NOx ppm values from above formula use the following:

NOx (gm/hr) = 0.001587 * NOx (ppm) * Exhaust Flow (kg/hr)
and NOx (gm/kWhr) = NOx (gm/hr) / Power (kW)

Since ESE diesel calculates BSFC (gm/kWhr) , Power (kW) and AFR, you can get following

a) Fuel Flow = BSFC (gm/kWhr) * Power (kW) = Fuel Flow (kg/hr)
b) Air Flow (kg/hr) = AFR * Fuel Flow
c) Exhaust Flow (kg/hr) = Air Flow + Fuel Flow

Please note all the above calcluations do not contain the NOx correction factor which is dependant on humidity, ambient temperature etc which of course cannot be determined by AVL FIRE.
Usually the NOx correction factor is 0.94 to 0.95 which will be further multiplied to the above NOx (gm/kWhr) value giving the final answer

This is taken from ISO 8178 emission calculation standard
In this standard the engine power has weightage factors which I have not considered here.. (for simplicity )   July 6, 2016, 12:23 #9 Senior Member   amin u3fi Join Date: Feb 2013 Posts: 137 Rep Power: 12 I used this formula but it does not work. could you please send me the .h file? amin_u50@yahoo.com  Tags avl fire, emission, mass fraction Thread Tools Search this Thread Show Printable Version Email this Page Search this Thread: Advanced Search Display Modes Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are Off Pingbacks are On Refbacks are On Forum Rules Similar Threads Thread Thread Starter Forum Replies Last Post Trues ANSYS 4 April 18, 2018 05:52 marcus85 OpenFOAM Pre-Processing 0 May 15, 2013 09:36 Maximus91 Main CFD Forum 1 October 24, 2012 13:20 HaZe OpenFOAM Running, Solving & CFD 3 January 28, 2012 02:05 SoobY ANSYS Meshing & Geometry 2 January 10, 2011 03:58

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