共查询到19条相似文献,搜索用时 125 毫秒
1.
2.
3.
国产三排汽200MW机组凝汽器由于设计年代早,运行存在不少问题。东方汽轮机厂采用90年代国际水平的排管设计,根据循环水质选用合适的冷却管材,并合理调整冷却管支撑间距更换冷却管的方法对其进行改造,可在大修期内完成旧管系拆除与新管系安装工作,并全面提高凝汽器性能。在胜利发电厂1#机国产200MW机组凝汽器改造上采用此方法,效果明显。 相似文献
4.
5.
文章详细论述了某核电厂凝汽器冷却钛管冲蚀事故状态,发现凝汽器旁路扩散器排放蒸汽能级高是凝汽器钛冷却管冲蚀事故的原因,并通过对凝汽器旁路扩散器及凝汽器冷却管布置结构研究发现通过改进可以有效防止钛冷却管的冲蚀。 相似文献
6.
目前凝汽器冷却管支撑跨距的设计校核普遍采用美国热交换学会(HEI)凝汽器标准,但该标准针对汽流激振的跨距计算不考虑凝汽器半侧运行工况。结合不同的跨距计算方法和实际工程数据,对凝汽器半侧运行工况下的跨距进行分析及计算,得出了半侧运行工况下冷却管许用跨距修正因数的计算公式,和基于HEI凝汽器标准许用跨距计算公式的半侧运行工况下的修正因数。由于此修正因数小于1,对于经常需要半侧运行的凝汽器,建议在设计冷却管跨距时采用跨距修正因数进行适当修正。研究成果对今后凝汽器半侧运行工况冷却管的跨距设计校核具有一定的参考意义。 相似文献
7.
8.
通过对凝汽器在不同运行参数条件下汽轮机系统严密性试验的仿真,分析了凝汽器在不同运行条件下,真空系统严密性试验对凝汽器冷却管热应力的影响。本文的结论对于减少冷却管热应力,防止凝汽器密封破坏,具有参考价值。 相似文献
9.
10.
11.
12.
13.
ABSTRACTThis paper examines the benefits to steam turbine output of retrofitting an air-cooled steam condenser with a hybrid (dry/wet) dephlegmator (HDWD) in a coal-fired, reheat, regeneration cycle. A hybrid dephlegmator concept has been proposed and shown to provide enhanced air-cooled condenser cooling performance while consuming only a small amount of water. The hybrid dephlegmator retrofit is shown to be able to increase turbine power output by up to 10.8% in certain cases. A corresponding increase in annual energy output of 2.56% can be achieved for continuous wet operation of the hybrid dephlegmator. A likely operating scenario, where hybrid dephlegmator units are sequentially operated in wet mode in order to maintain rated turbine power output over a wide range of ambient temperatures, results in an annual energy output increase of 1.33%. Based on these results, the payback period for an HDWD retrofit is between 3 and 6 years. The hybrid dephlegmator concept offers a simple, cost-effective, and sustainable solution to the issue of reduced air-cooled condenser performance at high ambient temperatures and is capable of providing clean dispatchable power. 相似文献
14.
改造前后凝汽器性能的数值模拟与分析 总被引:1,自引:0,他引:1
对某厂330 MW机组凝汽器改造前向心形管束布置和改造后TEPEE两山峰形管束布置的壳侧汽相流动与传热进行了数值模拟与比较.结果表明:改造前凝汽嚣结构设计不合理,上部管束得不到充分利用,导致凝汽器性能差;改造后TEPEE两山峰形管束布置使压降分布均匀,传热系数增大,更有利于凝汽器壳侧蒸汽的流动与传热.改造前后的性能试验结果表明:采用TEPEE两山峰形管束布置方式的凝汽器,其性能指标达到设计值,优于向心形管束布置方式;改造后凝汽器真空比改造前提高了1.743 kPa,端差下降4.63 K. 相似文献
15.
建立了某一凝汽器实际管束的流动计算模型,运用计算流体力学的方法,对该凝汽器水侧流场进行了三维数值模拟。采用分区对称计算方法,大大降低网格数量,从而详细预测了凝汽器水侧进出口水室以及其连接管和冷却水管束内的流动特性。计算结果可以清楚地表明:该凝汽器进口水室存在大量漩涡,使流动阻力增加,流动恶化;水室速度分布不均匀,进口水室管板中心区域流体流速较高而边缘区域较低,结构上存在一定问题;而出口水室的结构较为合理。这与采用多孔介质模型模拟的结论一致,进一步验证了采用多孔介质模型对凝汽器进行计算是正确可行的。计算结果同时表明,冷却水管束内流量和流速的分布是不均匀的,位于中心位置的冷却水管流量较大,而周边区域较小,最大流量差别可达到38%,且相邻管路的流量减小幅度与冷却水管布置有关。冷却水管内冷却水流量和流速的差异将会影响换热器的换热性能。计算结果可为分析研究管排流动不均而引起的换热效率问题提供条件,也可为凝汽器设计和结构优化提供依据。 相似文献
16.
真空严密性对凝汽器改造试验结果的影响 总被引:1,自引:0,他引:1
通过对真空系统中空气的存在对凝汽器性能影响的阐述,提出了凝汽器改造试验中,真空下降率对试验结果的修正方法,以期引起电厂重视真空系统对经济性的影响. 相似文献
17.
18.
AbstractUnexpected fouling in condensers on Central Electricity Generating Board power stations operating on the river Trent in the UK in the 1970s prompted an extensive investigation of the phenomenon. Fouling was caused by deposition of calcium phosphate rich scale on the cooling water side. A fouling test rig was specially constructed to study the performance of different chemical treatments. The rig ran two tubes in parallel, one with undosed water, and the latter’s data sets from over 100 “control” tests were analyzed to determine the mechanism and rate of fouling. The trends could not be explained in terms of conventional scaling indices. Insight into the mechanism was provided by separating precipitation (loss from solution) and deposition (adhesion of some of the precipitated mass to the heated surface): scaling was found to be caused by the deposition of particulates in the recirculating cooling water, driven by the change in pH as the water went through the evaporative cooling stage. Quantitative expressions for fouling were generated from tests on 1.83?m long tubes and were found to give a reasonable prediction of the fouling behavior observed on a full sized (18.3?m long) single condenser tube on an operating condenser. The results indicated that recirculating water systems need to be approached very differently to once-through systems, and the use of scaling indices for such systems is not recommended. 相似文献