Chapter 3 Steam

CHAPTER III: FUELS AND COMBUSTION

1. A bituminous coal has the following compositions: C= 71.5%

O=7.0 %

S=3.6 %

H=5.0%

N=1.3%

Ash=8.2%

W=3.4%

Calculate for complete combustion of the theoretical weight of air required in kgair/kgcoal.

a. 9.80 b. 8.80

c. 7.80 d. 6.80

Solution:
      :

 0    11.5  34.5     4.3!   8

 7.0%    11.5"71.5%%  34.5 5.0%    4.33"3.6%%   8 ' -./01    *. +, ( ) -.23/4

2. Calculate the higher heating value of liquid dodecane fuel. The chemical formula of Dodecane is C12H26.

a. 48, 255 kJ/kg b. 55,641 kJ/kg

c. 60,221kJ/kg d. 35,245 kJ/kg

Solution: 56  13,500   60890  9:: : %  %  %  %  :;

;< =

>    =: ∗ 100 >     0.00952"43.318%V>   ,. E€,+ 31 E€. ,+%

7. A circular fuel tank 45 ft long and 5.5 ft diameter is used for oil storage. Calculate the number of days the supply tank can hold for continuous operation at the following conditions. Steam flow= 2000lb/hr Steam dry and saturated at 200 psia Feedwater temperature= 230°F Boiler efficiency=75% Fuel Oil=34°API hg at 200 psia =2786.6 hf at 2300F=461.3

 200 uM "1.38 T %: ‚  2786.6  230w "110R%: ƒ  461.3

Ve V

Ve V

c. 17.57 days d. 19.26 days

a. 15.21 days b. 16.23 days Solution: g.  „ AM  :

>ƒ Jƒ

     ƒˆ‰d  30.27 JW 855

V  JW

>ƒˆ‰d  25,880.57 V .