限位装置是火电机组管道重要的控制位移结构。对于拉撑杆限位装置和球面盘限位装置两种不同结构型式，目前CAESAR II软件在进行计算分析时没有分别考虑。结合某660 MW电厂再热热段管道的设计情况，介绍了限位装置的种类、CAESAR II软件对其的处理方法以及再热热段管道布置情况，对拉撑杆限位进行仿真模拟，提出了一种在CAESAR II软件中建立拉撑杆限位实体单元的方法。将该法和常规的限位输入法的计算结果进行对比，研究了不同输入方法对管道热位移计算值的影响。结果表明：在限位装置吊点的热位移较大的情况下，拉撑杆限位装置对管道的热位移有较大影响，如采用常规的Restraints选项单向位移约束的限位输入方式，会导致热位移计算值偏差较大。可采用在CAESAR II软件中建立拉撑杆限位实体单元的方法，避免因管道实际热位移与设计值不符，给支吊架选型甚至管道的安全运行带来不利影响。

Limit device is an important control displacement structure of thermal power unit pipeline. At present, CAESAR II software does not take into account the two different configurations of tie rod limit device and spherical disk limit device. Combining with the design of reheat section pipeline of a 660 MW power plant, the types of limit device, the processing method of CAESAR II software and the arrangement of reheat section pipeline were introduced, the limit of tie rod was simulated, and a method of establishing the limit entity unit of tie rod in CAESAR II software was proposed. The results of this method were compared with those of the conventional limit input method, and the influence of different input methods on the calculated value of pipeline thermal displacement was studied. The results show that when the thermal displacement of the hanging point of limit device was large, the tie rod limit device had a great influence on the thermal displacement of the pipeline. If the limit input mode of one-way displacement constraint was adopted with the conventional Restraints option, the deviation of the calculated value of thermal displacement would be large. CAESAR II software could be used to establish the limit entity unit of the tie rod, so as to avoid the disadvantage of the actual thermal displacement of the pipeline to the selection of the support and suspension frame and even the safe operation of the pipeline due to the inconsistency between the actual thermal displacement of the pipeline and the design value.