During test on a diesel engine the power developed by the engine is used for driving a DC generator with output of 210 ampere at 200 volt. The efficiency of generator is 82%. The fuel of 42600 kJ/kg calorific value is supplied to the engine at 11.2 kg/hr. The air fuel ratio was 18:1. The exhaust gases were passed through an exhaust gas calorimeter for which the observations were as follows:

Water circulated through at 580 liters/hr, temperature rise of water through calorimeter is equal to 36°C. Temperature of exhaust gases at exit from calorimeter is 98°C. Ambient temperature is 20°C. Heat lost to jacket cooling water is 32% of total heat supplied. If the specific heat of exhaust gases be 1.05 kJ/kgK, draw up the heat balance sheet on minute basis.

C.V. =42600 kJ/kg, I=210 A, V= 200V,

A/F= 18:1=

Temperature rise of cooling water through calorimeter=36°C,

Analyzing heat balance sheet on minute basis

1) Rate of heat supplied

2) Rate of heat distribution

a) B.P.

Substituting the values we get,

b) Rate at which heat is carried away by cooling water

c) Rate at which heat is carried away by exhaust gases

By energy balance of calorimeter,

Rate at which heat is given by exhaust gases in calorimeter = Rate at which heat is gained by cooling water in calorimeter

Therefore, following is the heat balance sheet :