加装导流装置的凝汽器喉部流场的三维数值模拟

针对凝汽器喉部布置低压加热器而导致喉部出口流场的不均匀现象,采用模型并结合壁面函数法,利用SIMPLEC算法编程,对某300 MW汽轮机凝汽器喉部加装导流装置前、后的流场进行了三维数值模拟和对比分析.结果表明:加装导流装置前.内置式低压加热器使凝汽器喉部出口流场的分布具有不均匀性;加装导流装置后,喉部出口流场的分布趋于均匀.通过数值模拟,给出了加装导流装置的最佳方案.汽轮机的实际运行情况表明:加装导流装置后,提高了凝汽器的真空,从而改善了汽轮机运行的经济性,达到了节能降耗的目的.

Three-Dimensional Numerical Simulation of the Flow Field in Condenser Throat with Flow Guide Dev

In allusion to the phenomenon of non-uniform flow field at the throat outlet caused by the low-pressure heaters laid in condenser throat,the flow field inside the condenser throat of 300MW steam turbine was numerically simulated,compared and analyzed before and after the flow guide devices installed by using the model combined with the wall-function method and the SIMPLEC algorithm method.Results indicated that,without the flow guide devices,the flow field at throat outlet was non-uniformity due to the low-pressure heaters installed inside the throat.The distribution of the flow field at the throat outlet trends to uniformity after the flow guide devices installed.The best scheme of installing flow guide devices is given through several numerical simulations.Practical operation of the steam turbine unit indicated that the condenser vacuum is increased and the economy of the unit's operation is improved after the flow guide devices installed.It can meet an objective of energy conservation and dissipation reduction.