Optimal Indirect Integration of Steam Rankine Cycles in Concentrated Solar Power Coupled with Thermochemical Storage

Abstract

Storing energy in thermo-chemical form is a promising alternative for renewable energy sources and one of the fields that could exploit its advantages is constituted by Concentrated Solar Power (CSP). High efficiencies, high energy densities, long-term storage and dispatchability in power generation could be tackled with the employment of a Calcium-Looping in a central tower CSP plant. Although Brayton cycles based on sCO2 and He probably represent the most efficient option, it can be interesting to investigate the integration of Steam Rankine cycles because of the lower costs and the higher stage of development that characterize this technology. The present work has the purposes of studying this kind of integration and analyze the system in both energy and economic terms. To perform a comprehensive investigation, the power block layout and its thermal feeding strategy are included in the analysis and optimized. In addition, a multi-objective optimization is performed to evaluate possible compromises between the two most important aspects related to the entire power plant.

Development of Thermochemical Heat Storage Based on CaO/CaCO3 Cycles: A Review

“…Karasavvas et al [65] integrated the Rankine cycle with the CO 2 Brayton cycle heat storage system and designed a scheme of continuous power generation with an efficiency of 31.5%. Tesio et al [66] optimized the indirect integration of the steam Rankine cycle in CaL-CSP from both energy and economic aspects, which determined the size and operating conditions of the main components. Ortiz et al [67] conducted an energy and sensitivity analysis on the closed system, and the results showed that various methods could be used to improve the system efficiency by adding gas-solid heat exchangers at both ends of the calciner and carbonator, increasing the turbine inlet temperature, and raising CaO conversion.…”