Energy and exergy analyses of a parabolic trough solar power plant using carbon dioxide power cycle

Abstract

This paper examines both energy and exergy performances of parabolic trough collectors (PTCs), as part of a solar power plant, under different design and operating conditions. The proposed solar power plant utilizes an innovative supercritical carbon dioxide (S-CO2) power cycle to convert the heat produced by the PTCs to power. In addition, the present system integrates a thermal energy storage (TES) to overcome the intermittent nature of solar energy and extend the hours of operation. Therefore, detailed thermodynamic and heat transfer analyses are conducted to assess heat losses, exergy destructions, and energy and exergy efficiencies. The state-of-the-art PTCs technologies are considered to set the design parameters used in the modeling of the solar field. Furthermore, the effects of varying some operating conditions on the energy and exergy performance of the PTCs and the S-CO2 power cycle are investigated. These parameters include beam radiation intensity, beam incidence angle, and receiver emittance. Subsequently, the resultant impacts of changing these parameters on the overall solar power plant energy and exergy efficiencies are examined. The energy and exergy efficiencies of the PTC are found to be 66.35% and 38.51%, respectively.