A steel billet of 2000 kg mass is to be cooled from 1250 K to 450 K. The heat released during this process is to be used as a source of energy. The ambient temperature is 303 K and specific heat of steel is 0.5 kJ/kg K. The available energy of this billet is:
Availability of a system at any given state is:
Neglecting changes in kinetic energy and potential energy, for unit mass the
availability in a non-flow process becomes a = ɸ - ɸo, where ɸ is the
availability function of the
Gibb’s function is expressed as
Availability function is expressed as
Helmholtz function is expressed as
A heat reservoir at 900 K is brought into contact with the ambient at 300 K for
a short time. During this period 9000 kJ of heat is lost by the heat reservoir.
The total loss in availability due to this process is:
What will be the loss of available energy associated with the transfer of 1000
kJ of heat from constant temperature system at 600 K to another at 400 K
when the environment temperature is 300 K?