1 / 6

Adiabatic Flame Temperature

Adiabatic Flame Temperature. Consider the case where the cylinder is perfectly insulated so the process is adiabatic ( Q = 0). W. P 2 =P a T 2 =T a. Q. Reaction. For a constant pressure process, the final products temperature, T a , is known as the adiabatic flame temperature (AFT).

cogdill
Download Presentation

Adiabatic Flame Temperature

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Adiabatic Flame Temperature Consider the case where the cylinder is perfectly insulated so the process is adiabatic (Q = 0) W P2=Pa T2=Ta Q Reaction For a constant pressure process, the final products temperature, Ta, is known as the adiabatic flame temperature (AFT). For a given reaction where the ni’s are known for both the reactants and the products, Ta can be calculated explicitly.

  2. Constant Pressure Adiabatic Flame Temperature w/products at equilibrium Ta,

  3. Constant Pressure Adiabatic Flame Temperature w/products at equilibrium

  4. Constant Volume Adiabatic Flame Temperature Consider the case where the piston is fixed and the cylinder is perfectly insulated so the process is adiabatic (Q = 0) W P2=PCV T2=Ta Q Reaction Note h = u + pv = u + RT, so

  5. Constant Volume Combustion Pressure Assuming ideal gas behavior: For large HCs the mole ratio term is small, e.g., for stoichiometric octane air For stoichiometric octane-air Ta is 2266K so PCV/Pi= 8.1

  6. Adiabatic Flame Temperaturew/Products at Equilibrium • One can calculate the AFT for the above stoichiometric reaction where the products are at equilibrium. • Note dissociation in the products will result in a lower AFT since dissociation reactions are endothermic. • Computer programs are used for these calculations

More Related