Question

A fuel (C12H26with hf= - 291010 kJ/kmole) at 25 C is burned in a steady flow with 120% theoretical air that also

enters at 25 C. The complete combustion products of the reaction leave the burner at 500 K. Determine the required

mass rate of flow of fuel if the reaction is to supply heat at the rate of 3000 kJ/s.

Answer 1

pageroi Answer: According to the given information, to determine the required mass rate of flow of -fuel, Given, G2 Hac lorth Hf - -191010 kulk mole. Steady -flows a 12046 CialHab Cod Combustion chamber H130 Qnet Reaktants, 998 K Products Sook latm. The reaction is, - Ciotat 37 Op 12 00g + 13 Hao.

Page:03 -- from Combustion oraction :- ikmole of feel bre quines 31/2 kmoles of Oz theoretical. • fo of og in ait : 214]. by mole : -theoretical and supplied 37 10.23 -Theoretical air supplied = 88.095 kmoles. Actual air supplied : 1904% of theoretical a 9. + 120 X 88,095 kmoles 100 a 1.2 x 88.095 Kinoles hi-rolal air supplied = 105.741 kmoles :: actual oxygen supplied = 214 of actical ain supplied. soal x 105.41 Kmoles. Tooxggen suppled = 22.2. kmoles, ... Actual Ną supplied a total ai91 -- oxygen supplied į 105 kmes - 12.2 kmoles HiNg supplied = 83.51 Kmales

page:ou then, Og in products .. 09 Sepplied - Oy theoretical requisud. 3. 12. 2 kmoles. - 34 kmales. - (aa.2-1865) Kmoles - 3.7 k moles. Now, Reactands I Amol kmol of fuell hi Ihs hi No Chethi-his)} | (NI) C12426 - lolo -291010 92,2 8767.9918967,99 Na 83.51 8682-12886€2.128 then, Hpa & Niſhi + (to - hos)]; s. -991016 ks/kmol feels geochants produck : Tp - Sook. Products Knoll kmol of fuell hi hr ht Nilhethi-hs) | ..Ni Ce -39352011066 53 18568 -4632222:36 12 1-gu1820 10352652 14870 13 +20 - 3052432 46 0 8767.99 Tulou 21963.83 12 8351 10 8682–18 14560 490861.09

page:05 Hp: £ Nj C hf + (-hs)); products -4632222.36 - 3052432.046 +21963.23 4490861-09 tp = --1151830.8 kg/kmol fuel. then, anet : Hip-HR 3-7141830.8 - (-991010) 3-7151830.8 + 991010 -. Qnet = -6880820.8 kJ/kmol og fuel. L is amount of heal obtained per Kmol og -fuel, Anet: 6880820.8 kJ -to obtain 3000 kg/s og hoat, amount of feed requeried - 3000 besis 6.88082018 kg/kmol 3 41359x104 Kmolls. 1.. amount of fuel requisuda 4,859x1054 kmolls.

het, Page:06 Holecular weight of feel : 110 glmol .110 kg/kmol. Therefore, amount of fuel requieud to supply, 3000 Kols = 4.359 x 104 kmolls. then, = 4.359 x164 Karotis x 1310 kg / kmet 30.0741 kg Is i amount of feel required to supply, 3000 kals 5010441 KgIs.