Abstract: In this paper, the energy and exergy analysis of a thermal power plant is done at two different loads i.e. 100% and 70% load. The energy and exergy at inlet and outlet point of each component is calculated and specified with the help of data taken from the plant. The first and second law efficiency for each component of thermal power plant is calculated separately for design and off design load. The analysis shows that at design load maximum amount of exergy destruction occurs in the boiler, which is around 42% of the total exergy produced by the burning of coal and maximum energy loss occurs in the condenser which is 68.79%. The comparison of the performance of Plant is done at design and off design load and it is found out that plant performance is better at design load than its performance at off design load. The exergy destruction in boiler increases to 59% at off design load. Exergy efficiency of the boiler is significantly reduced at off design load than any other component of thermal power plant like turbine; boiler feed pump, heaters etc.
Keywords: Energy, Exergy, Exergy Destruction, Efficiency.