Thermoeconomic Evaluation of Integrated Solar Combined Cycle Systems (ISCCS)

Abstract

Three alternatives for integrating a solar field with the bottoming cycle of a combined cycle plant are modeled: parabolic troughs with oil at intermediate and low cycle pressures and Fresnel linear collectors at low cycle pressure. It is assumed that the plant will always operate at nominal conditions, using post-combustion during the hours of no solar resource. A thermoeconomic study of the operation of the plant throughout a year has been carried out. The energy and exergy efficiencies of the plant working in fuel only and hybrid modes are compared. The energy efficiencies obtained are very similar; slightly better for the fuel only mode. The exergy efficiencies are slightly better for hybrid operation than for fuel-only mode, due to the high exergy destruction associated with post-combustion. The values for solar electric efficiency are in line with those of similar studies. The economic study shows that the Fresnel hybridization alternative offers similar performance to the others at a significantly lower cost.

Assessment of an integrated solar combined cycle system based on conventional and advanced exergetic methods

“…where N is the number of collectors and A is the area of collectors. The energy absorbed by the absorber tube was given by ri QQ   (5) where  is the optical efficiency of the collectors which depends on the surface reflectivity of compound parabolic concentrator (CPC), receiver transmissivity, receiver absorption rate, acquisition factor, mirror utilization rate, radiation, convective heat loss efficiency, and a correction factor of the incident angle.…”

“…However, the challenge is to reduce the cost of this technology compared with traditional power generation systems [4]. The ISCCS can provide significant solar integration allotment into the system, achieve substantial economic and environmental friendliness compared to solar integration into other types of power cycles [5]. The net thermal efficiency of the ISCCS plant has been demonstrated over 60% which is 5%~ 10% higher than the conventional CCPP systems [6].…”