Combustion and emissions (1) In a combustor propane is injected into high pressu
ID: 551674 • Letter: C
Question
Combustion and emissions
(1) In a combustor propane is injected into high pressure air at 600 K and 35 bar and establishes a stable diffusion flame upon ignition. Please determine the time (in milli-seconds) for 95% of fuel to be oxidized into water and carbon dioxide products in the reaction zone a. GIVEN: i. D[C3Hs]/Dt=-30,000*[C3H8]0.2*[O2]1.55*EXP(-20,000/T) Where [C3Hg] and (O2] are concentrations with units of kmole/m3 Where D[C,Hs]/Dt has units of kmole/(m3-millisecond) Tr is the mean flame temperature which is defined as the average of the initial temperature and the calculated adiabatic flame temperature Use Stanjan to calculate the adiabatic flame temperature assuming a constant pressure and enthalpy thermodynamic conditions; http://navier.engr.colostate.edu/dandv/code/code-4 1. 2. 3. 4. ii. The mole fraction of O2 in air is 21%. For the reaction rate assume the oxygen concentration is fixed (constant) and is based on the average value of the air oxygen concentration and an oxygen mole fraction of 7% at the flame front. i. Assume there is no dissociation of exhaust products b. EXPECTED OUTCOMES: i. figure showing [C3Hs] versus time from time equal zero until the reaction is at least 99% complete-use EXCEL or something comparable to generate this figure ii. Show all work and analysis to calculate the time at which 95% of the propane iii. Units of time should be reported in milli-seconds and concentration in units of v Any assumptions concerning the propane or oxygen concentrations during the has been consumed due to this global chemical reaction kmole/m3 flame propagation event must be discussed and rationalized to receive full creditExplanation / Answer
Combustion-a usually rapid chemical process (such as oxidation) that produces heat and usually light. It is also slower oxidation
Combustion reactions are almost always exothermic. Forexample when wood burns, it must do so in the presence of O2 and a lot of heat is produced
Emission is the production and discharge of something, especially gas or radiation.The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state.