Modeling and Verification of Natural Gas Residual Pressure Power Generation System

In natural gas purification plants, insufficient pressure difference often leads to unplanned shutdown of the residual pressure power generation system, causing significant economic losses. In order to solve the shutdown problem, it is necessary to accurately model the turboexpander. Existing studies mainly rely on steady-state assumptions, ignoring the time-varying nature of parameters such as pressure and flow, resulting in the inability to accurately simulate the actual engineering operation state. This study proposes a dynamic modeling framework for nozzle-valve collaborative control. First, the working principle of the turboexpander unit was studied. Then, according to the mathematical model of the turboexpander, it was built in Simulink. Finally, in order to verify the accuracy of the model, actual operation data was used for comparative analysis. The results show that the Simulink model can accurately reflect the dynamic characteristics and operation behavior of the system, and the root mean square error (RMSE) under different operating conditions is less than 2.5%.