基于稳态建模的多抽汽机组热电耦合特性研究

Study on thermoelectric coupling characteristics of multi-extraction steam units based on steady-state modeling

随着集中供热的发展,我国热能工程领域对热电联产机组热电解耦的需求日益迫切。本文针对这一需求开展了热电机组特性研究。基于模块化建模方法开发了电厂热力系统稳态建模仿真软件,实现了热力系统常用设备的泛化通用型部件模块的开发,同时开发了流模块以构建实际热力系统的拓扑结构。该软件具有较强的通用性,可满足电厂的泛化建模需求。在此基础上,对多抽汽方案的热电联产机组热电耦合关系进行了研究。通过对设计工况的建模校核,基于低误差的校核结果模型,进行了机组的衍生工况建模研究。结果表明,多抽汽方案的热电联产机组在定负荷下也可通过不同的供热抽汽方案组合实现热电解耦,可减小机组为调节热电关系进行变负荷时带来的损耗。

With the improvement of district heating in the field of thermal energy engineering, there is an urgent demand for thermoelectric decoupling of cogeneration units. This paper investigates the characteristics of thermoelectric units from the aspect of thermoelectric decoupling. Based on the modular modeling method, the steady-state modeling and simulation software for the thermal power plant system is developed. The developed software includes generalized general-purpose component modules for common equipment of the thermal system. In addition, it uses the design of flow module to construct the topological structure of the actual thermal system and can carry out the generalized modeling for various thermal power plants. Based on the software, the thermoelectric coupling relationship of cogeneration units with multiple extraction steam schemes is studied. The modeling and validation of the design conditions are carried out based on the design conditions of a demo plant. With the validated models, this study carries out thermoelectric decoupling based on extended working conditions. The simulation results show that, cogeneration units with multiple extraction steam schemes can achieve thermoelectric decoupling even under constant load via different combinations of heating and steam extraction schemes. It also reduces the loss caused by varying loads of units through the adjustment of the thermoelectric relationship of the plant.