Table 3 The comparison between the universal and endoreversible thermodynamic limits.

Least work

0.78 kWh/m³ or 2.8 kJ/kg^12,13

1.06 kWh/m³ at r = 0.5 or 3.8 kJ/kg

For example, the endoreversible TL at 50% recovery ratio is extracted from^12,71

Q_SPE

 = W_{TL_universal}/(1 – T_o/T_adia)

 = 0.9437 kWh_SPE/m³

= W_{TL_endoreversible} / (1 – T_o/T_adia)

 = 1.282 kWh_SPE/m³

Actual Q_SPE to Q_TL

e.g., the average energy consumption (W_a) of SWRO = 3.5 kWh_elec/m³

= Q_SPE,a/Q_{SPE, TL_universal}

 = (3.5*CF_elec)/(0.9437) = 6.59

or 15.1% of universal TL

 = Q_SPE,a/Q_{SPE, TL_endoreversible}

= (3.5*CF_elec)/ (1.282) = 4.85 or 20.6% of endoreversible TL