汽轮机转子蒸汽冷却计算模型构建研究

提高初参数是火力发电实现节能与环保两项国策的重要措施。在蒸汽初温提高的条件下,为确保汽轮机部件的强度与寿命,需要在提高材料耐热性的同时采取蒸汽冷却技术,降低转子的温度与热应力。针对工程要求计算方法快捷、精确的特点,本文构造了转子根部冷却的一维参数计算模型,该模型综合考虑了冷却蒸汽对叶片表面的射流冲击冷却以及冷却蒸汽流过转子根部时的热传导冷却。应用该模型计算了超临界机组中压缸第一级转子经冷却后的温度场,并与三维计算结果比较,证明该模型能满足工程要求。

A Study of the Establishment of Turbine Rotor Steam-cooling Calculation Models

To raise initial parameters is an important measure for achieving energy savings and environmental protection,two national policies for coal-fired power plants.Under the condition of an enhanced initial steam temperature,the heat endurance properties of materials need to be upgraded simultaneously with the adoption of a steam cooling technology to lower the temperature and thermal stress of the turbine rotor,thereby guaranteeing the strength and service life of turbine parts and other components.In meeting the features of a quick and accurate calculation method required by engineering designs,a one-dimensional parameter calculation model was established for blade root cooling of rotors.The model can comprehensively accommodate all the influencing factors,including the jet-flow impact cooling of steam on the blade surface and heat conduction cooling by steam passing through the rotor root portion.The model has been used to calculate the temperature profile in the first stage of the medium pressure cylinder of a supercritical steam turbine unit.The comparison of the calculation results with three-dimensional ones indicates that the model can meet relevant engineering design requirements.