Aboiler is capable of generating 8 kg steam per kg of fuel at 400 °c. feed water is supplied at pressure of 30 bar, 40 °c and leaves economiser at 150°c for entering to evaporator. steam leaves evaporator with dryness fraction of 0.98 and enters the superheater. fuel used has calorific value of 29000 kj/kg. considering no pressure loss inside the boiler determine boiler efficiency and fraction of heat given to steam in each section of boiler.

Abrake has a normal braking torque of 2.8 kip in and heat-dissipating cast-iron surfaces whose mass is 40 lbm. suppose a load is brought to rest in 8.0 s from an initial angular speed of 1600 rev/min using the normal braking torque; estimate the temperature rise of the heat dissipating surfaces.

Give heat transfer applications for the following, (i) gas turbines (propulsion) ) gas turbines (power generation). (iii) steam turbines. (iv) combined heat and power (chp). (v) automotive engines

Athin walled concentric tube exchanger is used to cool engine oil from 160°c to 60°c with water that is available at 25°c acting as a coolant. the oil and water flow rates are each at 2 kg/s, and the diameter of the inner tube is 0.5 m and the corresponding value of the overall heat transfer coefficient is 250 w/m2. oc. how long must the heat exchanger be to accomplish the desired cooling? cpwater=4.187 kj/kg-candcpengine el=2.035 kj/kg·°c, oil . 120]