大型汽轮发电机组可调节回热抽汽设计思想

Adjustable Regenerative System Design for Large-Scale Steam Turbine Generator Units

随着我国发电设备装机容量的不断增长,大型火电机组的平均负荷率持续降低。采用常规回热系统的汽轮发电机组工作在部分负荷时,机组的运行经济性将显著下降。针对常规回热系统存在的问题,提出可调节回热抽汽技术,可以有效提高机组部分负荷时的运行经济性。基于热力系统的全面计算分析方法,以350MW超临界机组为例,对其采用可调节回热抽汽技术的设计方法以及热经济性进行了详细的论述和分析。结果表明,采用该项技术,可使机组的加权热耗降低约25kJ/(kW·h),经济效益明显。

With the constant capacity growth of installed power generation equipment, the average load of large thermal power generating unit has been continuously decreased. The operation economy of the unit adopting normal heat regenerative system will remarkably decrease when it is under part load. The adjustable regenerative extraction technology which can improve the economy of the unit under part load is presented to solve the problem in conventional regenerative system. With a 350 MW supercritical unit being used as an example, the design and thermal economy of the regenerative system are analyzed in detail based on the overall calculation and analytic method, with the result that the weighted heat rate will be reduced by about 25 kJ/（kW·h） when the technology is adopted with significant cost-effectiveness.