enthalpie.py

Created on April 15, 2024
953 Bytes
  chaleur degagee combustion
Qcomb=Mcarb*PCI
  rendement
Qcycle/Qcomb

        exemple
C7.25H13
 1. equation comb
C7.25H13+10.5(O2+3.76N2)
->7.25CO2+6.5H2O+39.48N2
 2. calculer PCO
M(C7.25H13)=100g/mol
M(O2+3.76N2)=137.28g
sachnt C7.25H13+10.5(O2+3.76N2)
10.5*137.28=1441.44g=M(air)
PCO=M(air)/M(carb) Mcarb=100g
PCO=1441.44/100=14.4

 3.a. a 298K calculerl'enthalpie eau gazeuse
deltarH = somme (produits(dfh)/reactifs(dfh)
=7.25dfh(CO2)+6.5dfh(H2O)g-(dfh(C7.25H13l)+10.5dfh)
=7.25*(-393)+6.5+(-242)-(-245)
=-4177.25KJ/mol=PCI

 3.b. eau liquide
-286K

 4.a. calcul PCI
M(C7.25H13)=100g/mol
100g->4177.25KJ
1000g->41.8MJ/Kg
PCI=41.8MJ/Kg
 4.b. calcul PCS  845g/L
100g->4463.25KJ
845g->37.7MJ/L

 enthalpie en kj/mol <0 car combustion
somme(DfH a droite de lequation)
-somme(DfH a geuche de lequation)
avec les coeff devant 

PCI massique eau gazeuse
enthalpie H2O gaz*1000/Mcarb

PCI massique eau liquide
enthalpie H2O liq*1000/Mcarb