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Internal Combustion Engines - Jun 17
Mechanical Engineering (Semester 5)
Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Draw neat diagrams wherever necessary.
a) Engine Pollution and the NORMS.
b)Alternative fuels
c)Losses considered in Fuel-Air cycle
Assuming the following:
Cd for injector = 0.7 , S.G. for fuel = 0.875, Atmospheric pressure = 1 bar, Effectiveness pressure difference = Average pressure difference over the injection period Determine the total orifice area required per injector if the injection takes place over 15°crank angle.
Speed = 350 rpm
Net brake load = 65 kg
mep= 3 bar
Fuel consumption = 4 kg/h
Jacket cooling water flow rate = 500 kg/h
Jacket cooling temperature at inlet = 20°C
Jacket water temperature at outlet = 40°C
Test room temperature = 20°C
Temperature of exhaust gases = 400°C
Air used per kg of fuel = 32 kg
Cylinder diameter = 22 cm
Stroke = 28 cm
Effectiveness brake diameter = 1 m
Calorific value of a fuel = 43 MJ/kg
Proportion of hydrogen in fuel = 15%
Mean specific heat of dry exhaust gas = 1kJ/kg
Mean specific heat of a steam = 2.1 kJ/kg K
Sensible heat of water at room temperature = 62 kJ/kg
Latent heat of a steam = 2250kJ/kg
Find ip,bp and draw up a heat balance sheet for the test in KJ/min and in percentage.
Explain any four