Design Calculation Xls ((full)) — Ejector
Mastering Ejector Design: Why You Need a Robust Calculation Spreadsheet (XLS)
5. Validation Example
Case study from literature: Steam ejector (El-Dessouky et al., 2002)
- Motive: 8 bar, sat. vapor
- Suction: 0.1 bar
- Discharge: 0.3 bar
Results comparison:
| 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
Conclusion: Excel model is sufficiently accurate for preliminary design.
2.3 ESDU Data Sheets (Most Accurate for Industrial Use)
The Engineering Sciences Data Unit (ESDU) publication 85032 (Ejector performance) provides 30+ empirical charts. Your .xls can digitize these charts using lookup tables or polynomial regression curves. Mastering Ejector Design: Why You Need a Robust
Tab 2: Fluid Properties Calculator
Use either:
- Built-in steam tables (via VBA user-defined functions) for steam.
- External REFPROP links (via COM add-in) for complex gases.
- Approximate polynomials for ideal gases.
Example formula for water vapor pressure (Antoine equation): Motive: 8 bar, sat
=10^(A - B/(C+T)) ' Where A,B,C are constants for the fluid
3. Core Calculation Steps in Excel
A well-structured ejector design XLS typically follows these steps:
