ERICSSON CYCLE (1850) AND ITS PROCESS

The Ericsson cycle is made up of two reversible isotherms and two reversible isobars.

For 1 kg Of Ideal gas

Q1-2 = W1-2 = RT1 ln (P1 / P2)

Q2-3 = Cp (T2 - T1) ; W2-3 = P2 (V3-V2) = R ( T2 - T1 )

Q3-4 = W3-4 = - RT2 ln ( P1 / P2 )

Q4-1 = Cp (T1-T4) ; W4-1 = P1(V1 - V4) = R (T1 - T2)

Since part of the heat is transferred at constant pressure and part at constant Temperature, the efficiency of the Ericsson Cycle is less than that of the Carnot cycle. But with ideal regeneration Q2-3 = Q4-1 so that all the heat is added from external source at T1 and all the heat is rejected to an external sink at T2, the efficiency of the cycle becomes equal to the Carnot cycle efficiency, since

N = 1 - (Q2 / Q1) = 1 - (T2 / T1)

The regenerative, Stirling and Ericsson cycles have the same efficiency as the Carnot cycle, but much less back work. Both cycles utilize regeneration, a process during which heat is transferred to a thermal energy storage device called a regenerator during one part of the cycle and is transferred back to the working fluid during another part of the cycle. Hot air engines working on these cycles have been successfully operated. But it is difficult to transfer heat to a gas at high rates, since the gas film has a very low thermal conductivity. So there has not been much progress in the development of hot air engines. However, since the cost of internal combustion engine fuels is getting excessive, these may find a field of use in the near future.

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