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During an engine trial on a six cylinder four stroke diesel engine, cylinder bore 180 mm, the stroke 200 mm, the following observations were recorded:

During an engine trial on a six cylinder four stroke diesel engine, cylinder bore 180 mm, the stroke 200 mm, the following observations were recorded : 1500 rpm, BP=245 kW , MEP=8 bar , fuel consumption : 70 Kg/hr , heating valve of fuel 44 MJ/Kg , Hydrogen content of the fuel 12%, air consumption 28 kg/min , mass of cooling water 85 kg/min, cooling water temperature rise 42 °C, cooling oil circulated through the engine = 50 Kg/min, temperature rise of cooling oil = 24°C ,specific heat of cooling oil 2.1 kJ/KgK, room temperature 30 °C, exhaust gas temperature 400°C, Cp of the dry exhaust gas 1.045 kJ/KgK,partial pressure of the steam in a exhaust gases 0.035 bar. Estimate the mechanical efficiency and draw heat balance sheet.

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i) Mechanical efficiency:

ii) Heat balance sheet:

a) Heat supplied in fuel(H.S.),

b) Heat energy utilised:

In B.P.,

Percentage heat carried away in cooling water:

Percentage of heat carried away by cooling oil:

iii) Heat Carried away by exhaust gases:

Mass of hydrogen in fuel

Mass of mixture inhaled/min,

a) % of heat carried away by flue gases in exhaust,

b) % of heat carried away by H 2 O vapour

iv) % of heat unaccounted for due to radiation etc.:

Heat Supplied Heat Expenditure %
Heat Input 51333.33 Heat in BP 28
Heat in Cooling Water 29
Heat in Cooling Oil 5
Heat Carried away by Exhaust
Heat carried away by flue exhaust gases 21
Heat carried away from H2O vapour 2
Heat unaccounted for 15
Total 100% 100
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