Open System. Entropy
An ideal gas (R=0.29 kJ/(kg K) with constant specific heat,
cp=1.0 kJ/(kg K)),
is streaming through a pipe. The pressure in the entrance and exit plane are
equal ( = 2 MPa ) while the temperature changes from
40oC to 600oC due to heat transfer into the pipe.
The mass flowrate is 1.5 kg/sec.
Neglecting changes in kinetic and potential energies, determine :
- The amount of heat per second transferred into the pipe.
- If the process of heat transfer is performed in a reversible manner what
would the entropy change of the gas be if we assume that the heat
is transferred to the gas at a mean temperature of 320oC ?
( Hint : integral dQ/T )
- Determine the actual change in entropy of the gas.
- What should the relationship between the results from 2. and 3.
be ? Circle one of the following :
Equal || 2 greater 3 || 3 greater 2