Air separation equipment in the expander expansion and throttling temperature drop comparison, air from 0.6MPa throttling to 0.1MPa temperature drop is only 1 ℃ or so, and through the expander expansion, the theoretical temperature drop of up to 80 ~ 90 ℃, the temperature drop effect is much better than throttling.
The reason is that the throttling process does not output power externally, and the temperature reduction is caused by the increase of molecular potential energy. Gas expansion in the expander, the gas to promote the impeller rotation, or to promote the piston external work, and the expansion process is carried out very quickly, there is no energy input from the outside world, ideally can be regarded as an adiabatic process. According to the law of conservation of energy, the output of the work only by reducing the energy of the gas (enthalpy) to maintain the balance, so that the kinetic energy of the gas molecules in motion is reduced dramatically, reflected in the temperature drops dramatically.
Therefore, the expansion machine expansion, the temperature of the gas is reduced not only because the pressure is reduced, resulting in an increase in the potential energy of the molecules, so that the kinetic energy of the molecular movement caused by the reduction of the more mainly due to the external work caused by the effect of the temperature drop than the throttling of the effect is much larger.
