介绍国电泰州发电有限公司1 000 MW超超临界二次再热燃煤机组自启停控制系统(Automatic Plant Start-up and Shut down System,APS)的设计框架、启动条件、功能组设计、断点设计以及控制功能等,并针对APS系统投运存在的困难提出应对措...介绍国电泰州发电有限公司1 000 MW超超临界二次再热燃煤机组自启停控制系统(Automatic Plant Start-up and Shut down System,APS)的设计框架、启动条件、功能组设计、断点设计以及控制功能等,并针对APS系统投运存在的困难提出应对措施。应用结果表明,APS系统的投运大大缩短了机组启停时间,提高了机组启停的正确性、规范性,具有较好的经济效益。展开更多
T23 steel(2.25Cr–1Mo–1.6W–0.24V–0.05Nb,in wt.%)has been widely used as water walls in ultra-supercritical(USC)power plants.However,high reheat cracking susceptibility of T23 steel hazarded the safety of USC power ...T23 steel(2.25Cr–1Mo–1.6W–0.24V–0.05Nb,in wt.%)has been widely used as water walls in ultra-supercritical(USC)power plants.However,high reheat cracking susceptibility of T23 steel hazarded the safety of USC power plants.It is aimed to improve the reheat cracking susceptibility of T23 steel from the perspective of modifying chemical composition.Gleeble-3800 thermal simulator was used to simulate the coarse-grained heat-affected zone(CGHAZ)in T23 and modified T23 steels via thermal simulation of welding,and then evaluate the reheat cracking susceptibility in CGHAZ of T23 and modified T23 steels by the isothermal slow strain rate tensile test.The microstructure was systematically investigated by optical microscopy,scanning electron microscopy and transmission electron microscopy.The results show that the reheat cracking susceptibility of modified T23 steel is extremely improved.Compared with T23 steel,there are fewer M23C6 particles at the grain boundaries in modified T23 steel,and the degree of intergranular weakening is smaller.At the same time,not only MX in the grain interiors but also the solid-solutioned C and W in the matrix decrease in modified T23 steel,leading to the decline of intragranular strengthening.In addition,small grain size is beneficial to the improvement of the reheat cracking susceptibility of modified T23 steel.The decreased number of M23C6 at grain boundaries helps to retard the formation and propagation of reheat cracks because of decreased denuded zones.展开更多
文摘介绍国电泰州发电有限公司1 000 MW超超临界二次再热燃煤机组自启停控制系统(Automatic Plant Start-up and Shut down System,APS)的设计框架、启动条件、功能组设计、断点设计以及控制功能等,并针对APS系统投运存在的困难提出应对措施。应用结果表明,APS系统的投运大大缩短了机组启停时间,提高了机组启停的正确性、规范性,具有较好的经济效益。
基金National Key Research and Development Program of China(2016YFC0801901).
文摘T23 steel(2.25Cr–1Mo–1.6W–0.24V–0.05Nb,in wt.%)has been widely used as water walls in ultra-supercritical(USC)power plants.However,high reheat cracking susceptibility of T23 steel hazarded the safety of USC power plants.It is aimed to improve the reheat cracking susceptibility of T23 steel from the perspective of modifying chemical composition.Gleeble-3800 thermal simulator was used to simulate the coarse-grained heat-affected zone(CGHAZ)in T23 and modified T23 steels via thermal simulation of welding,and then evaluate the reheat cracking susceptibility in CGHAZ of T23 and modified T23 steels by the isothermal slow strain rate tensile test.The microstructure was systematically investigated by optical microscopy,scanning electron microscopy and transmission electron microscopy.The results show that the reheat cracking susceptibility of modified T23 steel is extremely improved.Compared with T23 steel,there are fewer M23C6 particles at the grain boundaries in modified T23 steel,and the degree of intergranular weakening is smaller.At the same time,not only MX in the grain interiors but also the solid-solutioned C and W in the matrix decrease in modified T23 steel,leading to the decline of intragranular strengthening.In addition,small grain size is beneficial to the improvement of the reheat cracking susceptibility of modified T23 steel.The decreased number of M23C6 at grain boundaries helps to retard the formation and propagation of reheat cracks because of decreased denuded zones.
