Design and management of stand-alone turbo-expander-based microgrid with considering the uncertainty of input natural gas

摘要

The turbo-expanders (TE) can be used instead of pressure regulators at pressure reduction stations (PRS). In this case, besides reducing the pressure on natural gas (NG), mechanical work can be produced with the recovery of NG exergy. It can also meet the needs of a cooling system by cooling energy recovery of exhaust NG from TE. The recoverable power by TE depends on the flow, temperature, and pressure of NG passing through TE. NG network demand and weather conditions affect these three parameters throughout the year, so they are not constant. This paper presents an innovative approach to designing and managing energy and storage systems using scenario-based stochastic programming in a stand-alone TE-based microgrid. The type and size of energy and storage systems are selected based on the objective function of the optimization problem and constraints related to the design and operation of the microgrid. In order to model the uncertainty of flow, temperature, and pressure of input NG to PRS accurately, the dynamic and seasonal conduct of these variables are considered using recurrence plot (RP) analysis. Then, using the proposed uncertainties modeling, design and management of energy resources in stand-alone TE-based microgrid are done. As a result of considering uncertainty in NG parameters, TE capacity increased by 5. Furthermore, despite initial forecasts, the capital cost of TE-based microgrids has decreased by approximately 1.7.