含锅炉喷水减温系统的火电机组动态模型及响应特性

A Dynamic Model and Response Characteristics of Thermal Power Units Considering the Boiler Water Spray Desuperheating System

适用的锅炉及喷水减温系统模型,是火电机组动态仿真及优化控制的基础。根据合理的热动力学假设,基于能量和质量守恒定律,建立了喷水减温装置的机理模型,结合电力系统动态稳定仿真需求,利用线性化、拉普拉斯变换等处理得到适用的传递函数,进而建立考虑锅炉及喷水减温装置影响的汽轮机系统模型,可应用于火电机组热力系统动态特性仿真分析。算例仿真及实测分析比较了各变量对功率响应的影响,验证了仿真模型的有效性。结果表明,含喷水减温装置及锅炉的汽轮机系统模型具有更好的仿真效果;喷水减温系统对主蒸汽参数产生的影响较小,但对提高热力设备对电网影响仿真的准确性有重要作用;在大扰动及中长期仿真分析中,考虑锅炉喷水减温系统对机组动态响应的影响很有必要。

Applicable boiler and water spray desuperheating system models are the basis for the dynamic simulation and optimal control of thermal power units.Based on reasonable thermodynamic assumptions and the law of energy and mass conservation,the mechanism model of the water spray desuperheating device is established.Combined with the requirements of power system dynamic stability simulation,an applicable transfer function is obtained through methods such as linearization and Laplace transform,and then the steam turbine system model considering the influence of boiler and water spray desuperheating device is established and applied to the simulation analysis of the thermal system dynamic characteristics of thermal power units.The influence of various variables on the power response are compared through simulation examples and actual measurements and analysis,and the effectiveness of the simulation model is verified.The results show that the steam turbine system model with water spray desuperheating device and boiler yields better simulation results.The water spray desuperheating system has little influence on the main steam parameters,but it plays an important role in improving the simulation accuracy of the impact of thermal equipment on the power grid.It is necessary to take into consideration the influence of boiler water spray desuperheating system on the dynamic response of units in the large disturbance and mid-term and long-term simulation analysis。