Performance of gas turbine multi generation system regulated with compressor bypass extraction air energy storage

•Compressor bypass air extraction with energy storage for gas turbine CCHP system.•Performance of gas turbine multi-energy system at various load regulation strategies.•System capacity optimization for maximum energy efficiency in various load scenarios.•Improving operation flexibility of gas turbine-based multi energy system. In aim to improve system efficiency and flexibility at deep peak-load operation, a novel supply-side load regulation strategy was proposed for gas turbine-based CCHP (combined cooling, heating and power) systems, where the load was regulated through compressor bypass air extraction (CBAE) for energy storage in addition to inlet guide vane (IGV) regulation strategy. The part-load performance of gas turbine with CBAE was studied and compared with the performance under IGV regulation strategy; as well, the supply-demand coupling performance of the proposed CCHP system was investigated in three different scenarios of demand-side load distributions. Taking maximum overall energy efficiency as the optimization target, the design capacity of the proposed system was optimized and analyzed. The analysis indicates that, gas turbine part-load power efficiency under CBAE regulation is inferior to that under IGV regulation, whereas the former ensures gas turbine a higher capacity of power and heating than the latter. CBAE regulation strategy greatly improves heat-power ratio and enhances load adaptability. The case study shows that at a higher heat-power ratio, the overall energy efficiency of the proposed system is 1.75% greater, while the optimal capacity of gas turbine is 8.64% lower than that of the reference one.