【摘要】 提出了汽轮机转子热应力的“复频法”建模。“复频法”根据转子热应力的形成机理，通过建立“蒸汽温度变化率－转子体全温差”与“转子体全温差－转子体内、外表面热应力”的复频域数学模型，然后由控制理论方便地得到“蒸汽温度变化率－转子体内、外表面热应力”的数学模型。这样的数学模型便于利用成熟的线性控制理论详尽地分析热应力的形成过程。在用于现场实时控制或监测时则可根据控制理论中的“主导极点”法得到问题的合理简化形式。数字仿真的结果表明“复频法”较好地统筹解决了转子热应力数学模型的精度与实时性之间的矛盾。图９参６更多还原

【Abstract】 AbstractA way of modelling thermal stress in steam turbine rotors by the frequency response method is proposed.Based on the thermal stress forming mechanism and aided by the theory of cybernetics,a mathematical model has been worked out with felicity, showing the relationship between steam temperature changerate and stress on the rotor’s inner as well as outer surface,by way of establishing in the frequency domain a mathematical relationship model between steam temperature change rate and the rotor’s body weighted temperature difference and the thermal stress on the rotor’s inner and outer surface.Such a mathematical model is very handy for analysing the forming process of thermal stress in detail by using the proven theory of linear cybernetics.Applied to real time on site control or monitoring,reasonably simplified models can be obtained with the concept of the dominant root method of cybernetics. Computer simulation results show that the frequency approach method presents a superior way ofsolving the contradiction between the precision of a thermal stress’s mathematical model and real time requirements.更多还原