Page 280 - Design of Solar Thermal Power Plants

262 4. DESIGN OF THE CONCENTRATION SYSTEM

is less than the lower limit of the range, the deviation correction
process finishes, and the azimuth deviation angle and elevation
deviation angle are recorded as the corrected values of X and Y
separately in the database while recording the completion date and
time of deviation correction. In the event that the number of deviation
corrections is equivalent to the maximum number of deviation
corrections, and the absolute value of the deviation is greater than the
upper limit of the range, it means that the deviation rectification fails,
and the respective data will not be recorded in the database.
After completion of deviation correction, the serial number of the
deviation correction heliostat will be automatically reset, and the
system returns back to the status of “deviation correction to be
performed,” waiting for the operator to input the next serial number
of the deviation correction heliostat.
2. Automatic deviation correction. Under automatic deviation
correction status, when pressing the “Initiate Automatic Deviation
Correction” button, the system will automatically select the
deviation correction heliostat number based on historical data and
initiate the deviation-correction process (refer to Fig. 4.24).
Once the heliostat has reached the deviation-correction point, the
camera is initiated. If the absolute value of deviation is less than the

FIGURE 4.24 Picture of automatic deviation correction operational control system at the
Badaling solar thermal power plant.