TABLE OF CONTENTS Methods are available for achieving an alignment of the stationary components within the individual casings of the unit and the sections relative to each other. It is necessary to achieve this alignment so the efficiency of energy conversion and unit reliability is maximized within unit capability.
Within the casings there is a need to assemble the individual stationary elements (or their carriers) in the radial and axial position. (In this section only radial adjustment is being considered.) Figures 2.8.1 and 2.8.2 show the basic settings of the steam path components in the cold stationary position for impulse and reaction stages. (These requirements are considered in greater detail in later sections of this chapter.) These figures indicate the diameters and clearances that should be achieved for the complete circumference of the blade rows to assure a level of performance consistent with design predictions.
Figures 2.8.1 and 2.8.2 show the basic steam path diameters ("Dot" and "Dor") at discharge from the stationary blade rows. These figures also indicate there is some means in the impulse stage to make adjustment by modifying the dimension "Crx" to modify the actual position of the diameters. However, this adjustment does not modify the diameters themselves, but simply their location within the steam path. In the case of the reaction...
