喷嘴+补汽新型调节技术的经济性分析

Economic analysis for nozzle governing with overload valve regulation technology

为了保持喷嘴调节汽轮机组部分负荷工况下主蒸汽压力高的优点,同时减弱调节级效率低对高压缸通流效率的影响,有效提高汽轮机组部分负荷工况下的经济性,本文在分析研究了现有汽轮机进汽调节技术的基础上,提出了喷嘴+补汽新型调节技术。以超临界660 MW机组为例,分别分析喷嘴+补汽调节和单一补汽调节对汽轮机热力特性和经济性的影响。结果表明:喷嘴+补汽调节机组和补汽调节机组在90%THA工况附近经济性相当,随着负荷的降低,喷嘴+补汽调节机组经济性优于补汽调节机组,且这种优势逐步加大;全年负荷范围为40%THA～85%THA的机组,采用喷嘴+补汽调节的经济性更高。

To keep the high main steam pressure of the nozzle governing steam turbine under partial load conditions,weaken the influence of low efficiency of governing stage on flow efficiency of high pressure cylinder,and effectively improve the economic efficiency of the steam turbine under partial load conditions,this paper proposes a new nozzle governing method with overload valve regulation,on the basis of analyzing the existing governing methods of steam turbine.Taking a supercritical 660 MW unit as an example,the paper analyzes the thermal characteristics and economic performance of the steam turbines using the new governing method of nozzle governing with overload valve regulation and bypass governing.The results show that,the economy of the turbine adopting the new regulation technology is similar to that employing the bypass governing near 90%THA condition,while as the unit load decreases,the economy of the turbine adopting the new regulation technology is better than that employing the bypass governing,and this advantage gradually increases.For the units of which the load ranges from 40%THA to 85%THA within the whole year,applying the new regulation technology can reach a higher economic efficiency.