为了探索在不进行大规模改造前提下提高在役亚临界机组供电效率的途径,以华能岳阳电厂4号机组为示范,对提高在役亚临界机组运行汽温的可行性进行了研究和验证。研究了汽温提升方案的校核计算和确定方法,测试了汽温提升前后的热效率以及...为了探索在不进行大规模改造前提下提高在役亚临界机组供电效率的途径,以华能岳阳电厂4号机组为示范,对提高在役亚临界机组运行汽温的可行性进行了研究和验证。研究了汽温提升方案的校核计算和确定方法,测试了汽温提升前后的热效率以及机组关键参数的变化。结果表明,该机组在不对设备进行大的改造前提下实现了主蒸汽和再热蒸汽温度各提高5℃运行的目标,汽轮机热耗率降低21.2~23.5 k J/(kW·h),对应煤耗降低0.84~0.94 g/(kW·h)。利用机组的设计冗余,适当提高在役机组的运行汽温来改善效率是可行的,在校核计算中,锅炉高温受热面的安全是重点考虑因素。开发了一种在役机组提高效率的路线,相关技术和经验可供其他亚临界机组的提效借鉴。展开更多
The microstructure and mechanical properties of alloy 617 B in the process of 5000 h aging at 750 °C were systematically investigated by means of SEM, TEM and mechanical analysis. M23C6 particles were dispersed i...The microstructure and mechanical properties of alloy 617 B in the process of 5000 h aging at 750 °C were systematically investigated by means of SEM, TEM and mechanical analysis. M23C6 particles were dispersed inside grains and distributed discontinuously along grain boundaries and γ′ phases were situated at intragranular sites in the process of aging. The size of precipitates increased with increasing aging time. Inter- and intra-granular carbide and γ′ phase particles inside grains resulted in the precipitation strengthening of this aged alloy, enhancing the strength and hardness. The aged alloy possessed good stabilities of hardness and strength during aging. An obvious decrease of the toughness of this aged alloy was due to γ′ phase particles limiting plastic deformation to the area nearby grain boundaries, resulting in the occurrence of crack along grain boundaries. Additionally, the intergranular cracks apparently led to a decrease in the toughness for this aged alloy due to carbide particles at grain boundaries. The toughness of this aged alloy was fairly stable possibly due to the unchanged distribution of the precipitates during aging.展开更多
文摘为了探索在不进行大规模改造前提下提高在役亚临界机组供电效率的途径,以华能岳阳电厂4号机组为示范,对提高在役亚临界机组运行汽温的可行性进行了研究和验证。研究了汽温提升方案的校核计算和确定方法,测试了汽温提升前后的热效率以及机组关键参数的变化。结果表明,该机组在不对设备进行大的改造前提下实现了主蒸汽和再热蒸汽温度各提高5℃运行的目标,汽轮机热耗率降低21.2~23.5 k J/(kW·h),对应煤耗降低0.84~0.94 g/(kW·h)。利用机组的设计冗余,适当提高在役机组的运行汽温来改善效率是可行的,在校核计算中,锅炉高温受热面的安全是重点考虑因素。开发了一种在役机组提高效率的路线,相关技术和经验可供其他亚临界机组的提效借鉴。
基金Project(2012AA050501)supported by the National High-tech Research and Development Program of ChinaProject(NY20110102)supported by the National Energy Applied Technology and Engineering Demonstration Program,China+1 种基金Project(2012CB724401)supported by the National Basic Research Program of ChinaProject(003)supported by CSEE Youth Science & Technology Innovation,China
文摘The microstructure and mechanical properties of alloy 617 B in the process of 5000 h aging at 750 °C were systematically investigated by means of SEM, TEM and mechanical analysis. M23C6 particles were dispersed inside grains and distributed discontinuously along grain boundaries and γ′ phases were situated at intragranular sites in the process of aging. The size of precipitates increased with increasing aging time. Inter- and intra-granular carbide and γ′ phase particles inside grains resulted in the precipitation strengthening of this aged alloy, enhancing the strength and hardness. The aged alloy possessed good stabilities of hardness and strength during aging. An obvious decrease of the toughness of this aged alloy was due to γ′ phase particles limiting plastic deformation to the area nearby grain boundaries, resulting in the occurrence of crack along grain boundaries. Additionally, the intergranular cracks apparently led to a decrease in the toughness for this aged alloy due to carbide particles at grain boundaries. The toughness of this aged alloy was fairly stable possibly due to the unchanged distribution of the precipitates during aging.
