二氧化碳管道输送被认为是大输量、长距离二氧化碳运输的最经济、高效和安全的方式。在对二氧化碳管道的规划设计或运行管理过程中，都需要对二氧化碳管道系统的水力热力稳态或非稳态运行过程进行仿真。提出了非等温二氧化碳管道系统稳态和非稳态运行仿真方法，首先基于PR（Peng Robinson）状态方程和热力学微分关系式得到二氧化碳管道运行仿真所需的物性参数计算表达式，然后提出了基于解常微分控制方程组的稳态运行仿真方法和基于时间递推和隐式中心差分法的非稳态运行仿真方法，构建了稳态和非稳态仿真数学模型，基于Newton-Raphson算法求解数学模型，得到二氧化碳管道运行参数的时空演化规律。基于本文中提出的仿真方法和OLGA仿真软件，比较和分析了气态和超临界态输送的二氧化碳管道稳态和非稳态运行仿真结果，稳态仿真结果中气态和超临界态管道系统沿程压力、温度的最大绝对误差分别为0.03 MPa、1.04 K和0.18 MPa、0.71 K，非稳态仿真结果中管道系统各节点流量和压力的最大相对误差分别为2.7%和2.9%。本文中所提出的非等温二氧化碳管道系统水力热力稳态和非稳态运行仿真方法可以为实际二氧化碳管道的运行调控和安全流动保障提供参考。

Carbon dioxide pipeline transportation is regarded as the most economical, efficient, and safe way for large-quantity, long-distance carbon dioxide transportation. In the process of planning, design, or operation of CO₂ pipelines, it is necessary to simulate the steady-state or unsteady operation considering the hydraulic and thermal process of CO₂ pipeline systems. A steady state operation simulation method and a transient operation simulation method for non-isothermal carbon dioxide pipeline system were proposed. Firstly, based on the PR(Peng Robinson) equation of state and the thermodynamic differential equations, the equations of the physical parameters of CO₂ required for the operation simulation were obtained, then the steady simulation method based on the ordinary differential governing equations and the transient simulation method based on time recursion and implicit central difference were proposed. The mathematical models of steady-state and transient-state operation simulation were established, and the mathematical models were solved based on the Newton-Raphson algorithm. The spatiotemporal evolution law of the operating parameters of the carbon dioxide pipeline can be obtained. Based on the proposed simulation method and OLGA simulation software, the simulation results of steady-state and transient-state operation of CO₂ pipelines transported in gaseous and supercritical states were compared and analyzed. The maximum absolute errors of pressure and temperature along the gaseous and supercritical pipeline systems were 0.03 MPa, 1.04 K, and 0.18 MPa, 0.71 K, respectively. The maximum relative errors of mass flow rate and pressure at different nodes of the CO₂ pipeline system are 2.7% and 2.9%, respectively. The hydraulic and thermal simulation methods of steady-state and transient-state operation of non-isothermal CO₂ pipeline systems proposed can provide a reference for the operation control and flow safety assurance of actual CO₂ pipelines.