Thermodynamic analysis of multi-heating cycles working around the critical point

Supercritical carbon dioxide cycles with multi-heating in Concentrating Solar Power plants

“…A greater number of heat supplies at different ranges of temperature could achieve higher efficiencies. However, our previous research showed that the benefit of adding a third heat supply is small and it probably does not outweigh the extra complexity that adheres (González-Portillo et al, 2020). The software Engineering Equation Solver (Klein, 1992) is used to model the standard and the multi-heating CSP systems.…”

“…Another possibility to reduce the internal irreversibility in the regenerator is the use of heat sources at low temperature (Ahn et al, 2014;González-Portillo et al, 2020;Kim et al, 2012;Linares et al, 2015;Syblik et al, 2019). Although the layout may differ from a source to the other, the concept is the same: additional heat sources at low temperature supply part of the thermal power reducing the power supplied at high temperature, which involves an increase in the exergy efficiency (González-Portillo et al, 2020). The problem of providing additional energy sources at different temperatures must be solved according to the origins of the available heat in the power plant.…”

“…The main optimization objective in the new CSP multi-heating system is to reduce entropy generation in the heating process by fitting the temperature level of the thermal feeding of a given component to the role of such component in the cycle. The reduction of entropy generation in multi-heating cycles has been previously addressed in previous research (González-Portillo et al, 2020), so this study focuses on the application to CSP systems. Different design conditions of the cycle involve different thermal requirements for the heat source.…”

Supercritical CO2 Binary Mixtures for Recompression Brayton s-CO2 Power Cycles Coupled to Solar Thermal Energy Plants

“…Valencia et al (2020), in their study on the influence of mixtures, concludes that there are two groups: mixtures that decrease the critical temperature (s-CO2/He, s-CO2/Kr, s-CO2/CH4 y s-CO2/C2H6) and mixtures that increase the critical temperature (s-CO2/COS, s-CO2/H2S, s-CO2/NH3, s-CO2/SO2, s-CO2/C5H10, s-CO2/C5H12), among others. So far, several studies have been conducted to discuss the feasibility and performance of the CO2-based supercritical mixtures power cycle [13][14][15][16][17][18][19][20].…”