abstract
The energy and exergy analysis has been carried out for the different components of a proposed
conceptual direct steam generation (DSG) solar–thermal power plant (STPP). It has been found that the
maximum energy loss is in the condenser followed by solar collector field. The maximum exergy loss is
in the solar collector field while in other plant components it is small. The possibilities to further improve
the plant efficiency are identified and exploited. For minimum exergy loss in receiver the inlet
temperature of water to the receiver, which is governed by the number of feed water heaters (FWHs),
bleed pressure and mass fraction of bleed steam, must be optimum. The only one FWH has been
proposed in conceptual DSG STPP. In order to evaluate the optimum bleed pressure and mass fraction of
bleed steam to maximize the STPP efficiency, the investigations are carried out for various bleed pressure
and mass fractions of bleed steam of proposed conceptual DSG STPP having one FWH. The investigations
for bleed pressure and mass fraction of bleed steam are also carried out by incorporating two and three
FWHs. It has been found that there will be significant improvement in efficiency by using three FWHs
and further gain in efficiency is possible by making provision for more FWHs.
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