Economic Assessment and Optimal Sizing of Energy and Storage Systems of a Grid-Connected Turbo-Expander Based Microgrid with Simultaneous Recovery of Cooling and Electrical Energy at Natural Gas Pressure Reduction Stations

This paper proposes a novel microgrid configuration integrated with a turbo-expander (TE), in which the recovered cooling and electrical energy are utilized to supply part or all of the microgrid demand. The proposed grid-connected microgrid is designed to optimally select the type and capacity of energy generation and storage systems over a ۲۰-year planning horizon. A multi-objective optimization framework based on the Particle Swarm Optimization (PSO) algorithm is employed to minimize the annualized capital investment as well as operation and maintenance (O&M) costs. The microgrid comprises an internal combustion engine (ICE), photovoltaic (PV) system, battery bank (BB), auxiliary boiler (AB), heat storage tank (HST), absorption chiller (AC), and electric chiller (EC) to meet the electrical, heating, and cooling demands. A comparative economic analysis is performed for two optimal configurations, with and without the TE. The results demonstrate that the TE-based microgrid reduces O&M and emission costs by approximately ۳۴% and ۳۵.۲%, respectively, compared with the conventional microgrid. Moreover, cash flow analysis verifies the economic feasibility of the proposed TE-based microgrid.

کلیدواژه ها:

Turbo-Expander ، Exergy ، Microgrid ، Optimal sizing problem ، Cash flow analysis