
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1912 Excerpt:...OF 1000 K.W. CAPACITY EACH Bleeder Turbines to the left and in elevation The advantage derived from the bleeding at the entrance of the lowpressure section, is shown graphically in Fig. 8, the upper portion of which indicates the pressure variation at the entrance of the intermediate section. With the bleeder connection at this point, considerable throttling losses occur, as will be appreciated from lines A and B representing the pressure at the latter section and the heating system respectively. For every pound of steam bled, there will be a loss in expansive energy corresponding to the pressure drop from the intermediate section to tlie exhaust. If, however, the steam is expanded throughout this section before bleeding, the energy loss will be correspondingly reduced, the amount being equivalent to the additional work performed. The large drop in pressure occurring in the high-pressure stage does not indicate that this section is doing a proportionate share of the work, as the heat drop through high-pressure ranges is far less than through the same range at lower pressure. The lower set of curves, Fig. 8, compare the loss in capacity which would be caused by the two bleeding systems for varying percentages of steam bled, assuming an equal amount of steam passing through each turbine. The quantity of heat per pound theoretically lost by cutting short the expansion at the intermediate pressures determined by the pressure-load line A has been computed and expressed on a percentage basis for different amounts of steam bled. Values thus obtained are shown by dotted lines, the solid lines representing losses that occm with the improved method of bleeding from the low-pressure section. It is therefore evident that the vertical distance between curves correspondi...
Page Count:
338
Publication Date:
2012-03-06
ISBN-10:
1130264556
ISBN-13:
9781130264555
No comments yet. Be the first to share your thoughts!