关于火电厂空冷平台数值模拟的探讨

在我国北方近期建设的火电厂项目空冷平台的数值模拟中,不少学者对外流场分析已经做了一定的研究。通过现代的流体计算软件,可以分析出各种外界因素(气温,风速,风向等)对整个冷凝器换热能力及汽轮机背压的影响。我们尤其关心的是在夏季高温大风条件下是否会引起汽轮机背压升高超过临界值,从而引起系统停机。同时,目前对冷凝单元内部的流动换热分析,还处在一个起步的阶段。尤其是在冬季极端低温情况下,如何正确地模拟出管内流动的冻结现象,对指导空冷平台冬季运行具有非常强的指导意义。本文作者利用国际知名的商业流体软件,结合正在进行的某火电厂新建工程,对空冷冷凝器的管内流动进行初步两相流分析。在目前阶段分析的结果与理论构想非常吻合。后续的具体模拟工作将随着工程的进行得到进一步的深化。

Numerical Simulation of Air Cooling Condenser System in Power Plant

Many researches have been focused on the simulation of the direct air-cooled condenser of power plant in north China.Those researches are mainly focus on the effects of ambient air temperature,wind speed and wind direction.For some extreme status,such as high temperature,high wind speed,the critic pressure will be overrated and the turbine will be shut down.Those extreme statuses are driving more attention.Others extreme statuses happen in winter when the system is started up.Because of low temperature of the environment,the system will face the risk of frozen.This paper focuses on simulation of direct air-cooled condenser system.By using CFD software,both the normal and the extreme status can be analyzed.The result of the analysis can give guidance for the design and the operation of the power plant.