Page 244 - Design of Solar Thermal Power Plants

4.1 GENERAL SYSTEM DESCRIPTION 227

A meteorological station near the power plant can offer climatic
information relevant to the solar heat-collecting island. Direct solar
radiation data are used to determine the performance of the solar heat-
collecting section. The collection of wind speed data is essential because
under strong winds conditions, the relevant equipment of the solar heat-
collecting section must be in standby or shutdown status to prevent
damage. Based on the experiences of the Yanqing Dahan solar tower
power plant, the sampling period for wind speed data should be 10 s.
When the wind speed exceeds the set value for two consecutive periods,
the CFSC will give the instruction to stop the concentrating field and
report the instruction to the DCS.
The CFSC transmits real-time data with the power plant’s DCS, which
coordinates and controls the overall operations of the power-generating
area, heat-transfer pump-valve system, and solar heat-collecting section.
The DCS operator station supervises certain operational parameters
related to the solar collector and gives control instructions such as
stoppage, standby, hedging, and shutdown through the CFSC. In the
event of power-off of the communication control equipment or a CFSC
malfunction, the solar-concentrating field’s local controller must be able
to automatically give turnoff instructions to all concentrators in order to
prevent burnup of the receiver and solar tower.

4.1.4 Location and Environmental Requirements of the
Concentrating Field Supervisory Controller Control Room
The CFSC control room shall not be located in a dusty area with
great vibration or much dust, but rather in a position within the
solar-concentrating field that is conductive to signal transmission;
meanwhile, fire hazards, leakage, and toxicity of the heat-transfer fluid
and heat-storage system also must be considered. A parabolic trough
power plant should be located on the windward side of the concen-
trating field. The heliostat field control room of a solar tower power
plant shall be located far away from the solar heat-absorbing tower
in order to avoid falling objects from the tower as well as high-
temperature leakage.

4.1.5 Calculation Methods for Concentration Field Output

Concentrating field energy output acts as receiver input; thus
concentrating field output power field shall be determined in accordance
with receiver input power requests while considering the capacity of the
heat-storage system.
The input power of the solar-concentrating field and receiver may can
be determined two ways: (1) according to the annual peak value of the