264 POWER PLANT ENGINEERING
THEORETICAL QUESTIONS
1.Draw the layout of diesel power plant.
2.Write a short notes on super charging.
3.What are the basic types of I.C. Engine?
4.Discuss the advantage and disadvantage of a diesel engine.
5.State the applications of a diesel power plant?
6.Write a note on fuel system of diesel power plant.
7.Write a note on lubrication system of diesel power plant.
8.How air intake and admission system of diesel power plant works?
9.What are the advantages of supercharger?
10.Write a note on exhaust system of diesel power plant.
11.Write a note on cooling system of diesel power plant.
12.Write a note on heat balance sheet.
13.Name and explain various types of fuel injection systems.EXERCISES
1.A quality governed four-stroke, single cylinder gas engine has a bore of 146 mm and a stroke
of 280 mm. At 475 r.p.m. and full load the net load on the friction brake is 433 N, and the
torque arm is 0.45 m. The indicator diagram gives a net area of 578 mm^2 and a length of 70
mm with a spring rating of 0.815 bar/mm.
Calculate:
(i) The indicated power
(ii) Brake power
(iii) Mechanical efficiency. [Ans. (i) 12.5 kW (ii) 9.69 kW (iii) 77.596]
2.A single cylinder four-stroke gas engine has a bore of 178 mm and a stroke of 330 mm and is
governed by hit and miss principle. When running at 400 r.p.m. at full load, indicator cards
are taken which give a working loop mean effective pressure of 6.2 bar, and a pumping loop
mean effective pressure of 0.35 bar. Diagrams from the dead cycle give a mean effective
pressure of 0.62 bar. The engine was run light at the same speed (i.e., with no load), and a
mechanical counter recorded 47 firing strokes per minute.
Calculate:
(i) Full load brake power
(ii) Mechanical efficiency of the engine. [Ans. (i) 13.54 kW; (ii) 84.7°10]
3.The efficiency ratio for the Otto engine is 0.60. The engine has four cylinder 7.5 cm by 11.4
cm stroke, having a compression ratio of 5, and consuming 7 kg of petrol per hour when
running at 2000 rev/min. Taking calorific value of petrol as 44193.785 kJ/kg. Estimate the
effective pressure. [Ans. 7.11 bar]