Saved Bookmarks
| 1. |
An ideal heat engine, operating on a reversible cycle, produces 9 kW. The engine operates between 27°C and 927°C. What is the fuel consumption given that the calorific value of the fuel is 40000 kJ/kg? (a) 0.8 kg/hr(b) 1.02 kg/hr (c) 1.08 kg/hr (d) 1.28 kg/hr |
|
Answer» (c) 1.08 kg/hr Efficiency of the ideal reversible cycle \(\eta\) = 1 - \(\cfrac{T_2}{T_1}\) - 1 - \(\cfrac{(27+273)}{(927+273)}\) = 1 - \(\cfrac{300}{1200}\) = 0.75 or 75% \(\eta\) = \(\cfrac WQ\) = Q = \(\cfrac{W}{\eta}\) = \(\cfrac{9}{0.75}\) = 12 KW Q = mf × CV \(\therefore\) mf = \(\cfrac{Q}{CV}\) = \(\cfrac{12\,KW}{40000\,KJ/Kg}\) = \(\cfrac{12\,\times3600}{40000}\) = 1.08 kJ/hr |
|