Recent content by Andy86

@Chestermiller I was only joking! Thanks for stepping in, I have now completed all my thermodynamics modules. VERY steep learning curve. Thanks for all the help! @jim hardy Thank you also for the guidance! Off to sit in a darkened room for 3 hours! Thanks Andy

@Chestermiller Thanks Chester- that completely blows my calculations out the water! Back to square 1 we go!

Apologies Jim, I am not sure what point your are trying to make? The question asks me for the Mass of the steam over an hour. Using the information I have I came up with M = 101.8 KG / H. Have I used an incorrect value somewhere?> I thought the heat capacity of water was constant @ 4.2 KJ /KG up...

Thanks for the constructive criticism >>> Correction... How much energy comes out when you cool a kg of flue gas from 1997 to 300 degrees? Mass = 28.9 g per mol of flue gas Flow rate = 1400 Kmol / hour Mass flow rate = 28.9g * (1400 * 1000) = 39, 886 KG / hour...

Thanks BvU & Jim, is this lot any closer? Thanks Andy Heat capacities of the flue gases at 1997°C / 2270K Co2 = 1.3865 KJ/KG H2O = 2.41267 KJ/KG O2 = 1.1999 KJ/KG N2 = 1.2985 KJ/KG Mass = Nmols * Molecular Mass Co2 = 3.9mols * 44 = 171.6g H2O = 4.75mols * 18 = 85.5g O2 = 0.6mols * 32 =...

Sorry heat capacity of flue gas

Homework Statement A fuel gas consists of 75% butane (C4H10), 10% propane (C3H8) and 15% butene (C4H8) by volume. It is to be fed to the combustion chamber in 10% excess air at 25ºC, where it is completely burnt to carbon dioxide and water. The flue gases produced are to be used to generate 5...

Ok Great, thanks for all your help Chester I really appreciate it. Andy

VERY! :-) So..... NET CV BY MASS n = PV / RT = 100000 * 1 / 8.314 * 298 = 40.3 MOL = 0.0403 KMOL CV = MK M^-3 / KMOL = 3.05 MJ M^-3 / 0.0403 KMOL = 75.6 MJ KMOL^-1 ?

NET CV BY VOL = 103.2MJ / M^-3 103.2 / 33.8 = 3.05MJ / M^-3

Meaning?

It doesn't look right that the CV is 3.12 MJ / m^3 as the gross CV is 108.1 MJ M^3, my calculated NET CV of 103.2 MJ M^3 looks more realistic?

That's the incorrect number of total mols in the mix, total ,mols is 33.8 > 34 Mols

Any thoughts?

EXCELLENT! how does this net CV by mass look... NET CV BY MASS n = PV / RT = 101300 * 1 / 8.314 * 298 = 40.0 mol = 0.0408 kmol CV = CV in MJ M^-3 / kmol M^3 = 103.2 MJ M^-3 / 0.0408 kmol = 2529.4 MJ kmol^-1 @ 25°C ??