Performance-Based PCS Model

Table 8.1 shows efficiency data of the elements: solar collector field, storage tanks and power conversion part. The yearly efficiency coefficients have been obtained from the monthly efficiency data.

This type of information is useful to evaluate the best and worst cases for making decisions taking risks into account. The steam turbine can be operated at 290°C or at 280°C. The return temperature of the generator is about 70°C lower than the inlet temperature PCS operating temperatures between 287°C and 292°C, which are considered to be in the high range while operating temperatures between 277°C and 282°C are considered low range. The gross process efficiency (in Eq. (8.19)), denoted by ngross, was computed (Eq. (8.14)) by a least squares fitting. The same happens with the net efficiency nnet = Рг/Phtf, where Pr is the generated power:

ngross = -2.44 ■ 10-5Pg2ross + 3.07 ■ 10-2Pgross + 9.54 (8.19)

nnet = -3.52 ■ 10-5Pn2et + 4.07 ■ 10-2Pr + 5.43 (8.20)

Table 8.2 shows power distribution at the PCS.