浅析外高桥三期1000 MW机组低加技术特点

Technical Features of the LP Feedwater Heater in 1000 MW Power Unit of PhaseⅢ,Waigaoqiao Project

表面式给水加热器用一定热焓及压力的蒸汽或冷凝水,在某温度范围内加热定量的给水,它的特点是加热介质与被加热工质互不混合,通过管壁传递热量。传热管内是给水,传热管外是蒸汽。文中简述了外高桥三期低压加热器系统和结构的特点,为有利于提高低压加热器运行的可靠性和经济性,该低加采用先进的设计计算方法,选择最佳汽、水流速,以提高传热效果和降低流动阻力。低加机组改善了汽轮机的通流特性,减少了蒸汽的冷源损失,从而提高了电厂的热经济性。

Steam or condensate with certain enthalpy and pressure is used in surface feedwater heater. The quantitative feedwater should be heated in certain scope, the feature of which is no blending between heating medium and heated working medium and heat is transferred through tube walls. Feedwater is in the tube while steam is out of tubes. The features of LP heater system and structure of phase Ⅲ, Waigaoqian Project have briefly been described in the article. The optemum steam and water velocity have been selected based on advanced calculation way in design so as to increase heat transfer result and decrease flowing loss in order to upgrade the reliability and economy of LP heater＇s operation. LP heaters will improve the passage performance of turbine and reduce the cold loss of steam so as to upgrade the heat economy of power plant.