POWER ENGINEERING & REFRIGERATION - QUESTION BANK
(a) Define : (i) Swept Volume (ii) Compression Ratio (iii) Piston Speed (iv) Air Standard
Efficiency (v) IP (vi) BP (vii) BSFC (viii) Mechanical Efficiency (ix) Volumetric
Efficiency (x) Brake thermal efficiency.
(b) Draw schematic diagram of turbojet engine.
(c) Explain the working of 4 stroke petrol engine with neat sketch.
(d) Represent Brayton cycle on P-V & T-S chart.
(e) What is supercharging ? State its advantages.
(f) List applications of gas turbine.
(g) List the basic requirement of solid propellent
(h) Explain Morse Test.
(i) Draw ‘Valve Timing Diagram’ for 4 stroke diesel engine.
(j) Explain working of catalytic convertor with neat sketch.
(k) In a test of a four cylinder four stroke engine 75 mm bore and 100 mm stroke the following
results were obtained at full throttle at a particular constant speed and with fixed setting of fuel
supply of 6.0 kg/hr.
B.P. with all cylinder working = 15.6 kW
B.P. with cylinder No. 1 cutout = 11.1 kW
B.P. with cylinder No. 2 cutout = 11.03 kW
B.P. with cylinder No. 3 cutout = 11.88 kW
B.P. with cylinder No. 4 cutout = 10.66 kW
If C.V. of fuel is 83600 kJ/kg, calculate:
(1) Mechanical efficiency
(2) Indicated thermal efficiency
(l) In a test on single cylinder four stroke petrol engine, the following results are obtained -
Cylinder bore = 15 cm, length of stroke = 25 cm, Indicated mean effective pressure = 7.353
x 105 N/cm², Engine speed = 400 RPM, Brake Torque = 225 N.m, Fuel consumption = 3
kg/sec., Calorific value of fuel = 44200 kJ/kg. Determine:
(i) Mechanical efficiency
(ii) Brake thermal efficiency
(iii) Specific fuel consumption of engine
(m) Following observations are recorded during a trial on four stroke diesel engine : Fuel
supplied = 0.1 kg/min. Calorific value of fuel : 41,840 kJ/kg Engine speed : 400 rpm
Effective diameter of brake drum = 1 m Net load on the brake drum = 1000 N Mass flow
rate of cooling water = 10 kg/min Rise in cooling water temperature = 25 ºC Air supplied : 6
kg/min Exhaust gas temperature : 200 ºC Specific heat of water : 4.186 kJ/kg ºk Specific
heat of exhaust gas : 1 kJ/kg ºk Room temperature = 30 ºC Prepare heat balance sheet on
minute basis.
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