Solar energy conversion with thermal cycles - Solar Energy Sciences and Engineering Applications - page 465

Figure 14.5.4 Power block scheme for a direct cycle.

Table 14.5.3 Stream properties for the direct layout (DSG) (Giostri et al., 2012).

Stream Fluid type M [kg/s] p [bar] T [ ◦ C]

1 Water 73.7 100* 279.3*

2 Steam 73.7 91.3 304.7

3 Steam 56.8 89.3 302.8

4 Steam 56.8 81.0 540.0*

5 Steam 36.7 0.096 45.0*

6 Steam 2.4 9.2 256.1

7 Water 44.1 8.7* 143.9

8 Water 56.8 100* 260.4*

(*) Assumptions

in Figure 14.5.5 and Table 14.5.3. The DSG plant considered has steam SH, like the
more recent Novatec technology, but no RH.
The feedwater line is composed of seven regenerators, one being the deareator.
The steam turbine, with no RH, has a lower vapour fraction at the outlet compared to
the indirect cycle. Evaporation in the solar field is based on a reboiler concept: steam
quality at the evaporation section outlet is kept below 1 (i.e. 0.77 (Forristall, 2003))
to guarantee good wettability of the collector, thus preventing the formation of hot