Ejector Design Calculation Xls Upd -

Designing an ejector in Excel involves balancing thermodynamic mass and momentum equations to find the right dimensions for a specific entrainment ratio. While many engineers rely on manufacturer data sheets

Worksheet 5: Results Summary

• Optimal nozzle diameter (mm/in)
• Optimal throat diameter (mm/in)
• Predicted suction mass flow ($W_s$)
• Actual entrainment ratio vs. required
• Off-design performance curve (suction pressure vs. discharge pressure)

6. Parametric Study Using Excel Tables

Using Excel’s Data Table function, the designer can sweep: ejector design calculation xls

The efficiency of an ejector is captured through specific formulas integrated into the XLS cells: Isentropic Expansion: ejector design calculation xls

1. Critical pressure ratio: Motive 150 psig >> Suction 0.5 psia → Ratio = 300 → Underexpanded supersonic.
2. Optimal area ratio ($A_t/A_n$): 12.5
3. Nozzle throat diameter: 0.125 inches
4. Mixing throat diameter: 0.442 inches (since area ratio = 12.5 → diameter ratio = sqrt(12.5)=3.536)
5. Predicted motive steam flow: 450 lb/hr
6. Entrainment ratio (Er): 0.44 lb_air / lb_steam (matches HEI standard data within 5%)

| Parameter | Literature | Excel XLS | Error | |-----------|------------|-----------|-------| | Entrainment ratio | 0.85 | 0.83 | -2.4% | | Optimum area ratio | 12.4 | 12.8 | +3.2% | | Critical back pressure | 0.32 bar | 0.315 bar | -1.6% | ejector design calculation xls