Thermal-economic optimization of a distributed multi-generation energy system—A case study of Beijing

A simultaneous consideration of the thermodynamic, economic and emission criteria regarding both CO2 and NOx emissions of a distributed combined heating, cooling and power generation (tri-generation) system in an urban residential area in Beijing has been realized through thermo-economic optimization. Technologies such as gas turbine, internal combustion engine, absorption chiller and gas boiler are considered as options of the plant optimum configuration. System Net Present Value (NPV) is taken as the objective to be maximized. The presented mixed integer and non-linear programming (MINLP) problem is solved by a Genetic Algorithms (GAs) optimizer. The optimal plant configurations are found with the consideration of system configuration, design and operation under different economic and environmental legislation contexts.