Page 162 - Steam Turbines Design, Applications, and Rerating
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142 Chapter Eight
(a)
(b)
(c)
Figure 8.3 Speed vs. time and load relationships of isochronous
governors. (a) speed vs. load; (b) speed vs. time of a stable system;
(c) allowable maximum speed rise vs. load. (Elliott Company, Jean-
nette, Pa.)
obtained when the turbine is developing rated power output at rated
speed, and the load is suddenly dropped to zero. An industrially allow-
able maximum speed rise vs. load relationship is shown in Fig. 8.3c.
(max. speed @ zero power output) − rated speed
% Speed rise =
(0.01) (rated speed)
