9 January 2018

Ericsson cycle

The Ericsson cycle is a thermodynamic cycle that can be invented by John Ericsson in 1840.

What is the Ericsson cycle?

In the Ericsson cycle, two isothermal processes and two constant pressure process are done in a heat engine. 

This cycle is mostly used in a closed cycle gas turbine. 

Process of Ericsson cycle :

The Ericsson cycle consist of four processes following below :
  • reversible isothermal gas expansion process is air as a working fluid which is heated from the heat addition process so work is done during this process.
  • constant pressure heat transfer or isobaric process is the air passed through the re-generator is released as exhaust gas. The heat absorbed by the re-generator is used during the next part of the cycle. 
  • reversible isothermal gas compression process is air is drawn into the engine is compressed and pressurized air drawn into the air storage sink.
  • constant pressure heat transfer is the compressed air at high pressure passe through the regenerator and absorbs the previously stored heat then flows to the piston and cylinder where it gets expands and produces the work.  

Efficiency of Ericsson cycle :

The efficiency of Ericsson cycle is given by :

                                         Ŋcycle = Wnet / Q =  T1 – T2 / T

Although the thermodynamic process of the Ericsson cycle differ from those of the Carnot cycle both cycles have the same value of the thermal efficiency when both are operating between its T1 and T2.

The Ericsson cycle doesn't have any practical application but is mainly used in a gas turbine employing a large number of stages with insulators, reheaters and heat exchangers.