Page 337 - Steam Turbines Design, Applications, and Rerating

Elliott Shortcut Selection Method for Steam Turbines 311

Figure 15.2 Determination of approximate efficiency for multi-
valve, multistage turbines, metric units. (Elliott Company, Jean-
nette, Pa.)

Approximate steam flow = ASR × hp
= (7.40 lb/hph) (25,000 hp) = 185,000 lb/h

The Mollier diagram, Fig. 14.1 or 14.2, can be used to determine the
TSR for steam conditions not tabulated.
Figure 15.3 can be used to find approximate steam rates for turbines
operating at part load and speed. For example, find the approximate
steam rate when the 25,000 hp, 5000 r/min turbine we’ve discussed is
operated at 20,000 hp and 4500 r/min.

% hp = 20,000 hp/25,000 hp = 80%

% r/min = 4500 r/min/5000 r/min = 90%