Optimization of biomass gasification combined cooling, heating and power system integrated with solar energy

Abstract

The integration of solar energy with biomass gasification combined cooling, heating and power (BGCCHP) system is performed. The solar-assisted hybrid BGCCHP (SAHB) system following electricity load (FEL) and following thermal load (FTL) is optimized to maximize its energetic, economic and environmental benefits in comparison with typical separated production (TSP) system. Based on a hotel building in Beijing, the optimal configuration and performance of the SAHB system fueled by corn straw (CS), rice straw (RS), wood pellet (WP) and wheat straw (WS) are obtained. Results show that the annual primary energy consumption saving ratio (APECSR), annual total cost saving ratio (ATCSR), annual carbon dioxide emission reduction ratio (ACDERR) and comprehensive saving ratio (CSR) are from 92.60% to 123.57%, from 29.39% to 52.75%, from 92.15% to 132.37% and from 72.49% to 102.90%, respectively, which indicates that the SAHB system performs better in energetic, economic, environmental and comprehensive aspects compared with TSP system. The area of photovoltaic panel (PVP) is recommended to be 880.40 m2, i.e., the available roof area, which means that PVP is more conducive to improving the system performance compared with solar thermal collector (STC). The SAHB system operating under FTL is superior to that operating under FEL because more electricity is sold back to the electricity grid when the SAHB system operates under FTL. Among the biomass materials, CS yields the best energetic, economic, environmental and comprehensive performance. Under FEL, the CSR of CS is 3.28%, 0.90% and 2.84% larger than that of RS, WS and WP, respectively. Under FTL, the CSR of CS is 4.25%, 1.17% and 3.18% larger than that of RS, WS and WP, respectively. Sensitivity analysis shows that biomass price and gasification efficiency have the most significant impact on the system performance under FEL and FTL, respectively. When the biomass price of CS increases by 10.00%, the CSR under FEL decreases by 1.28%. On the contrary, the CSR under FTL increases by 1.88% when the gasification efficiency of CS increases by 10.00%.