Page 51 - Design of Solar Thermal Power Plants
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44                        1. INTRODUCTION

            TABLE 1.7 Relationship Between Rated Thermal Power and Annual Mean
                       Efficiency at PS10 Power Plant
            Item                     Data     Item                     Data
            Rated optical efficiency of  77%   Annual mean shading     >95.5%
            the concentration field            and blocking efficiency
                                              of the concentration field
            Annual mean optical     64.0%     Rated output solar      55.0 MW
            efficiency of the                  radiation power of the
            concentration field                concentration field
            Mean cosine efficiency of  >81%    Annual mean output      45.7 MW
            the concentration field            solar radiation power of
                                              the concentration field


                the rated output and annual mean output, different capacities and
                operational modes can be obtained, which normally are calculated
                based on the rated thermal power of the receiver.
                Besides the properties and thermal parameters of the concentrator
                and receiver themselves, major external factors that influence this
                value include position, irradiance, ambient air temperature, and
                wind speed.
             5. Receiver net thermal power (unit: W). This is the energy of the
                receiver transmitted to the working fluid within unit time.
             6. Thermal storage capacity (unit: J). This is the parameter for
                describing the amount of thermal storage.
             7. Emission ratio. This is the ratio of the radiant existence of the
                radiator to that of the full radiator (black body) under the same
                temperature, which is applicable for a specific wavelength or a
                certain wavelength range.
             8. Reflection. This is the process of radiation being reflected by the
                incident surface into the incident medium under the condition of
                no wavelength or frequency variation.
             9. Reflectance. This is the ratio of the reflected and incident radiation
                flux by the mirror.
            10. Absorption. This is the process of radiation energy being converted
                into other forms of energy by interaction with matter.
             11. Absorptance. This is the ratio of the radiation flux absorbed by the
                panel to the incident radiation flux, which is applicable for a
                specific wavelength or a certain wavelength range, and is
                recommended as 300e2500 nm.

            1.2.3.3 System Terms
            1. Design point power. This is the rated output electrical power of the
               system at the design point.
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