共查询到20条相似文献，搜索用时 46 毫秒
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通过对印度嘉佳电厂660MW机组因真空泵工作液温度引起凝汽器真空异常下降的分析,论述了水环式真空泵工作液温度不正常升高,易导致真空泵抽吸能力严重下降,引起凝汽器真空下降,影响机组负荷.针对以上情况,对电厂建机组在夏季高温季节时,降低真空泵工作液温度提出了一些建议. 相似文献
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贾寿松 《荆门职业技术学院学报》2009,24(9):32-35
以300 MW机组为研究对象,针对该类型机组采用汽动给水泵,小汽机排汽直接排入凝汽器,其热量没有被充分利用这一特点,对其进行无除氧器改造研究。提出了采用这种复合凝结水真空式除氧系统的方案,并对改造方案进行了热经济性分析,从而实现了热经济性最优,为300 MW机组的节能改造提供指导。 相似文献
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李晓勇 《胜利油田师范专科学校学报》2013,(4):30-31
胜利发电厂二期2暳300 MW机组在冬季供暖期间长期处于供热抽汽量较大、凝汽器热负荷较少的工况下运行。原凝汽器冷却水系统采用单元制运行方式,循环水流量较大,造成了胜利发电厂用电的浪费。在保证循环水系统安全可靠的前提下,胜利发电厂研究制定了二期机组在冬季供暖期双机一泵一塔方式的运行方案,通过系统改造,将循环水进行合理的分配,仅用一台循环水泵即能满足两台机组的冷却用水需求,有效地降低了用电率,达到机组节能目的。 相似文献
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通过对包头东华电厂机组凝结器真空低的原因分析,得出包头东华电厂机组真空低的主要原因为凝汽器本体疏水扩容器泄露及与真空系统直接相连的部分放空气门未关闭,并针对类似原因引起凝结器真空低提出应对措施,提高机组运行中真空,以提高机组的安全经济性。 相似文献
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邓道风 《商情·科学教育家》2011,(2)
影响凝汽器真空下降的因素很多,结合江西铜业集团贵溪冶炼厂动力车间技术改进经验,从真空系统严密性、凝汽抽气系统、循环水系统、凝汽器换热效率等几个方面进行分析,找出了原因,并提出了解决方法,对其它小功率机组的安全、经济运行有一定参考价值. 相似文献
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通过对现有循环水系统进行改进,在不同的循环水温度和负荷下,调节各机组的循环水流量或改变循环水泵的运行方式,达到凝汽器的最佳运行真空,降低机组发电综合煤耗,达到到节能降耗的目的。 相似文献
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张敬辉 《江西电力职业技术学院学报》2010,23(3)
循环水系统是火力发电厂的重要辅机系统,也是厂用电的消耗大户,其耗电量约占机组发电总量的1%~1.5%[1]。为保证凝汽器冷却需求,循环水泵容量一般都具有较大的裕度。为了合理利用循环水泵的出力,节能降耗,三河电厂通过对设备和控制逻辑的改进,实现了循环水系统的母管制运行。改造后的运行实践证明,循环水母管制运行降低了辅机能耗,兼顾了机组的安全,具有一定的优越性。 相似文献
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结合已建成和改造完成的无人值班泵站经验,以无锡某泵站为例,针对原自动化系统出现的种种问题,提出系统拓扑结构改造,机组LCU和闸门LCU软硬件功能整合。实现触摸屏软件、PLC软件以及站控级软件的升级优化。结合机组开停机时闸门联动的触发条件,详细讲解软件滤波去除真空断路器抖动的方法。在PLC和上位机流程中实现双向X型流道机组的双向引排功能。改造后的自动化系统最终实现泵站主机组、公用及辅助设备、变配电设备、节制闸设备的运行监视、事件报警、数据统计和记录、控制调节功能。 相似文献
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范玉东 《邢台职业技术学院学报》2005,22(1):70-72
在热电厂的供热机组已确定的条件下,供热方案的优劣就直接影响机组的供热能力、供热面积、热网投资、发电煤耗，影响热电厂的经济效益及热网供热系统的安全性、灵活性和可靠性。本文即是通过对铁煤集团热网工程的三环制供热方案及改造成低真空供热方案的比较分析,对热网工程中低真空供热的利弊进行了初步探讨。 相似文献
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《海外英语》2007,(5):10-11
Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help? 相似文献
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罗艳萍 《读与写:教育教学刊》2008,5(6)
The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity. 相似文献
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《海外英语》2007,(4):36
There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love. 相似文献
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Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject. 相似文献
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Richard Denner 《海外英语》2007,(4):14-15
Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose. 相似文献
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Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities. 相似文献
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RUZBEHANI Mohsen 《重庆大学学报(英文版)》2004,3(1):20-25
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec… 相似文献