A Thermodynamics-Economics Coupled Multi-Regional Energy System Optimization Model: A Systematic Investigation of Carbon Trading Policies

The ongoing transition toward low-carbon energy and the rapid development of carbon trading markets are reshaping multi-regional energy systems.These systems are increasingly characterized by cross-regional interconnection and multi-energy collaboration.However, existing optimization models often oversimplify thermal networks and treat carbon pricing as an exogenous constraint, limiting their ability to reveal how carbon policies influence energy flows through physical infrastructures.This study proposes a two-stage thermodynamics-economics coupled optimization framework.The first stage focuses on minimizing total heat supply and distribution losses by optimizing supply temperatures under fixed flow conditions, based on a detailed thermal power flow model.The second stage integrates electricity, heat, and gas systems into a unified dispatch model that minimizes total operational and carbon trading costs.Carbon price signals are embedded into decision-making, enabling quantitative analysis of their impact on generation scheduling and interregional energy exchange.The proposed model establishes a clear path from physical efficiency to economic coordination, offering a systematic and scalable approach for evaluating carbon trading policies in complex energy networks.