GPSA Ch. 14
| Parameter | Range |
|---|---|
| Economizer Pressure | Geometric mean of Pcond & Pevap |
| Flash Fraction | 10–25 wt% |
| Power Savings | 5–15% |
| COP Improvement | 5–20% |
| Liquid Retention | 3–10 min |
Flash Fraction:
Where hin = enthalpy of subcooled liquid entering economizer, hf,econ = saturated liquid enthalpy at economizer pressure, hg,econ = saturated vapor enthalpy at economizer pressure.
COP Improvement:
The economizer reduces compressor work by routing flash gas to an intermediate compression stage, avoiding re-compression from the lowest suction pressure.
Vessel Sizing: The economizer vessel is sized as a flash drum to separate vapor from liquid at the intermediate pressure. Diameter is set by vapor disengagement velocity (Souders-Brown), and length by liquid retention time with the specified L/D ratio and design margin.
Understand economizer design, flash gas separation, and refrigeration cycle optimization