Energy and Exergy Analyses of a Solar-based Multi-generation Energy Plant Integrated with Heat Recovery System and Thermal Energy Storage

Abstract

An innovative multigeneration energy system driven by solar energy is proposed in this paper. The integrated model produces electricity, hydrogen, oxygen, and steam for heating purposes. The energy system comprises a pressurized cavity-based solar power tower, latent thermal energy storage (TES) unit, unfired gas turbine (GT) unit, regenerative steam Rankine cycle (SRC), copper-chlorine (Cu-Cl) thermochemical cycle, and heat recovery units. By utilization of a high-temperature ternary eutectic phase change material (PCM), a dynamic model is developed to deal with the intermittency of solar energy. Using energy and exergy approaches, the proposed system is investigated to assess exergy destruction rates and the overall system performance. A parametric study is performed to investigate the influence of design parameters such as the number of heliostats, the pressure ratio of GT, and temperatures of reactions on the system performance. The results showed that the energy system produces electricity, steam, hydrogen, and oxygen at a rate of 41.9 MW, 12.6 kg/s, 0.19 kg/s, and 0.76 kg/s, respectively. Energy and exergy efficiencies of the integrated system are found to be 49.9%, and 44.9%, respectively.