Kröger Example 9.2.2
The horizontal array under a 6 m/s crosswind
Tier T: a textbook worked example - a published answer, not a measurement.
System: Indirect dry cooling, natural draft, horizontal array
- What was compared
- The water inlet and outlet temperatures, the air mass flow rate and the mixed air outlet temperature of the indirect natural-draft tower of Example 9.2.1, a horizontal array filling a 78.3 m inlet, under a 6 m/s wind at 10 m with the heat transfer rate held at 354.39 MW.
- Against
- Kröger's worked Example 9.2.2 (Kröger, Vol. 2, Section 9.2), a published calculation with Du Preez's pressure coefficients and the heat transfer correction for wind, and not a measurement.
- The agreement
- The water inlet temperature is reproduced to within 0.11 K (+0.033%), the water and mixed air outlet temperatures to within 0.035%, and the air mass flow rate to within 0.26%. The intermediate values Cpi, Cpo, αQ and the wind speed at the tower outlet agree with the example to the digits printed.
- What it shows
- The agreement verifies that Kröger's crosswind method is implemented as published, on the arrangement it was fitted for: horizontal bundles filling the inlet. It does not establish the method's accuracy, and it says nothing about a vertical ring of deltas.
- Source
- Kröger, D.G., Air-Cooled Heat Exchangers and Cooling Towers: Thermal-Flow Performance Evaluation and Design (PennWell, 2004)Vol. 2, Example 9.2.2 (Eqs. 9.2.4-9.2.11 on the tower of Example 9.2.1)