供热机组发电负荷-机前压力-抽汽压力简化非线性动态模型

Simplified Nonlinear Dynamic Model of Generating Load-Throttle Pressure-Extraction Pressure for Heating Units

针对抽汽式供热机组利用调节蝶阀控制抽汽压力来调节供热抽汽质量流量的特点,通过分析汽轮机供热抽汽环节的能量平衡特性,建立微分方程形式的供热机组给煤质量流量-汽轮机调门开度-调节蝶阀开度与发电负荷-汽轮机前压力-抽汽压力的简化非线性动态模型.在此基础上分别进行了发电负荷、机组抽汽压力和热网循环水质量流量扰动仿真试验.结果表明:模型输入输出关系符合机组实际情况,能够解释供热系统中通过调节供热抽汽压力维持供热抽汽质量流量跟随供热负荷需求变化的内在机理.

Based on the features of extraction heating units that use adjusting butterfly valve to control ex- traction pressure for the regulation of heating extraction flow, and by analyzing the energy balance in ex- traction heating link of turbine, differential equations were constructed for simplified nonlinear dynamic model of the generating load-throttle pressure-extraction pressure versus the fuel flow-opening of turbine governor valve-opening of adjusting butterfly valve. On above basis, the disturbance of generating load command, extraction pressure command and mass flow of circulating water in the heating network were simulated. Simulation results show that the relations between model inputs and ouputs are in accord with actual operation conditions of heating units, which can well explain the intrinsic mechanism by controlling extraction pressure to make the extraction flow follow the heating load demand.