Ericsson
Cycle:
The Ericsson cycle consists of two isothermal and two
constant pressure processes.
The processes are:
Process 1-2: Reversible isothermal compression.
Process 2-3: Constant pressure heat addition.
Process 3-4: Reversible isothermal expansion.
Process 4-1: Constant pressure heat rejection.
The heat addition and rejection take place at constant pressure
as well as isothermal processes. Since the process 2-3 and 3-4 are parallel to each
other on the T-s diagram, the net effect is that the heat need to be added only
at constant temperature T3=T4 and rejected at the constant temperature T1=T2.
The cycle is shown on p-v and T-s diagrams in Fig.4.3. The advantage of the
Ericsson cycle over the Carnot and Stirling cycles is its smaller pressure
ratio for a given ratio of maximum to minimum specific volume with higher mean
effective pressure.
Fig.4.3. Ericsson cycle on p-v and T-s diagrams
The thermal efficiency of Ericsson cycle is given by,
(derivation is same as that of Stirling cycle),
The Ericsson cycle does not find practical application in
piston engines but is
approached by a gas turbine employing a large number of
stages with heat exchangers,
insulators and reheaters.
No comments:
Post a Comment