共查询到19条相似文献,搜索用时 156 毫秒
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主给水系统向蒸汽发生器提供合适温度、流量的水,以确保蒸汽发生器稳定运行。文章对海阳核电主给水系统流程、特点进行了简介,对主给水泵润滑油系统冲洗、主给水系统水压试验及系统冲洗进行了说明,重点对主给水系统调试过程出现的问题进行了经验反馈,对后续机组的系统调试工作具有一定的借鉴意义。 相似文献
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《核动力工程》2015,(6):92-96
为验证三代核电AP1000核电厂在非LOCA事故工况下,启动给水补给性能是否满足衰变热排出的纵深防御准则,保守认为事故发生后,反应堆停堆,厂用电及外电网丧失,主给水丧失,凝汽器热阱丧失,蒸汽发生器背压为安全阀最低整定压力,蒸汽发生器与启动给水泵均为单列可用。首先,验证凝结水储箱处于最低液位时,启动给水的最低补给能力能否满足不小于118.1 m3/h的准则要求;其次,论证事故后由于备用交流电源加载滞后而导致启动给水延后140 s投运,蒸汽发生器依靠自身缓冲水装量能否带走衰变热而不触发专设安全系统;再次,论证140 s后启动给水最低补给流量,能否稳定蒸汽发生器液位并使其回升;最后,验证凝结水储箱纵深防御水装量能否满足启动给水24 h连续补给的准则要求。本文通过对启动给水最低补给流量、蒸汽发生器缓冲水装量、启动给水液位控制,以及凝结水储箱水装量的保守计算分析,验证了AP1000启动给水在非失水事故(Non-LOCA)事故下衰变热排出功能设计的可靠性以及与纵深防御准则的一致性。 相似文献
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简要介绍了蒸汽发生器水位控制系统的运行方式和试验方法。试验项目包括旁通阀控制试验、主给水阀控制试验和旁通阀与主给水阀的切换试验。文中给出了试验结果,即在液位扰动和核动率扰动时,蒸汽发生器液位的变化过程。经过两个月的运行和瞬态试验,证明蒸汽发生器水位控制系统满足设计要求。 相似文献
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方家山核电机组在并网过程中曾出现过给水调节阀开度突跳导致蒸汽发生器水位大幅度波动的现象。文中从蒸汽发生器水位控制原理出发,分析并网过程中给水调节阀开度波动原因,并经理论计算与模拟机验证,给出并网过程中避免给水调节阀开度突跳导致蒸汽发生器水位波动的有效解决方案。 相似文献
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当前蒸汽发生器(SG)液位控制系统手自动切换信号复制回路的设计中,液位控制器运算基准为切换时的汽水失配信号,主给水流量调节阀由手动模式切到自动模式后导致SG液位控制系统失去快速调节给水流量的前馈作用。针对该问题,结合阳江核电厂4号机组SG液位高高跳堆事件,提出了针对手自动切换操作方式和系统设计的2种优化方案。针对操作方式的优化,在主给水流量调节阀投自动前,手动平衡汽水流量;针对系统设计的优化,增加汽水失配判断环节和前馈自动补偿环节。通过SG液位扰动试验证明,所提出的优化方案能有效提高手自动切换后控制系统的调节速度、减小超调量,对核电机组安全运行水平提升有重要贡献。 相似文献
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为研究低功率运行工况下压水堆核电厂蒸汽发生器给水环管热分层强度的影响因素和缓减措施,采用计算流体力学(CFD)方法,对给水环管内部流体的热分层现象进行了数值模拟。研究了功率提升过程中给水运行方式及给水环管结构对热分层强度的影响,从给水环管布置及结构两个方面提出了两种改进结构。结果表明:提高给水流量提升速率对热分层强度几乎没有影响,给水弯头弯曲半径增大能有效减弱给水弯头处的热分层强度,给水弯头向下布置能明显减弱给水环管内的热分层强度,给水管倾斜角度增大能有效减弱给水弯头、给水管的热分层强度,同时使得给水环的热分层强度增强。将给水弯头向下布置且给水管水平段改为多级阶梯渐缩-渐扩结构、多级球形渐缩-渐扩结构后,给水环管内的热分层现象能得到不同程度的缓解,因此提出的两种改进结构是较理想的改进结构。 相似文献
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B.S. Panigrahi A. Suriyanarayanan K.G. Subramianan G. Srinivasan D. Jambunathan P.V. Ramalingam R.P. Kapoor Reactor Operation Maintenance Group 《Progress in Nuclear Energy》2004,44(4):1269-320
The steam generator of fast breeder test reactor (FBTR) at Kalpakkam (India) is a once through Steam Generator (OTSG) which requires the feed water at high purity level. Therefore, for maintaining feed water chemistry, all volatile treatment (AVT) is adopted along with a full-flow deep bed Condensate Polishing Unit (CPU) in the steam water system. Operational difficulties such as premature termination of operation cycle of the CPU, enhanced impurity pickup resulting in increased load for CPU, early silica breakthrough, etc. were observed on occasions. This paper describes the modifications carried out in the steam water circuit to overcome these problems. A decade's experience in operating the CPU and maintaining the feed water quality is also discussed. 相似文献
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为给中国示范快堆给水控制系统的控制方案设计及直流蒸汽发生器结构参数设计提供必要参考依据,本文搭建了多模块直流式蒸汽发生器给水系统的仿真模型,对示范快堆给水系统的静态特性和动态特性进行了仿真研究。分析了蒸发器出口钠温和蒸汽发生器一次侧流量偏差等关键参数对各模块工作状态的影响,并得出了系统可靠工作条件下这些关键参数变化的限值。研究结果表明,为防止蒸发器出口蒸汽过热度不足,保证蒸发器可靠工作,需限制蒸发器出口钠温过低,以及蒸汽发生器一次侧流量相对于平均值过高。 相似文献
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以CPR1000型核电站3×50%电动给水泵为研究对象,采用基于RELAP5和Simulink程序开发的CPR1000数字化仪控系统仿真试验台,详细计算分析了给水泵单泵故障和双重故障对反应堆运行的影响及相应的缓解措施。结果表明,给水泵单泵故障对反应堆运行的影响较小,各相关参数能够很快重回事故前的稳态工况。在给水泵双重故障情况下:初始核功率在75%FP及以下时,不会出现蒸汽发生器(SG)低-低水位;初始核功率高于75%FP、汽机初始负荷在90%FP及以下时,需将汽机负荷阶跃降至50%FP,才不会出现SG低-低水位;汽机初始负荷在90%FP以上时,建议停堆。 相似文献
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A. Hoeld 《Nuclear Engineering and Design》1978,47(1):1-23
A newly developed nonlinear transient model for the calculation of the dynamic behaviour of a vertical natural-circulation U-tube steam generator together with its steam removal system is presented. The steam generator is considered to consist of a heat exchange section, a top plenum, a downcomer region and a steam removal system with a sequence of relief and/or safety valves, isolation, bypass, turbine-trip and turbine-control valves and a steam turbine. Possible perturbations from outside can be: inlet water temperature, inlet water mass flow and system pressure on the primary side, feed water temperature, feed water mass flow and outlet steam mass flow disturbed by actions of the different valves within the steam removal system on the secondary side. Based on this theoretical model the digital code UTSG has been established. Post-calculations of start-up tests at a PWR nuclear power plant simulating perturbations both on the primary and secondary side of the steam generator and similar calculations for the corresponding ATWS-cases will show the efficiency of the code UTSG and the underlying theoretical model. 相似文献
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It is necessary to develop PSA methodology and integrated accident management technology during low power/shutdown operations. To develop this technology, thermal-hydraulic analysis is necessarily required to access the trend of plant process parameters and operator's grace time after initiation of the accident. In this study, the thermal-hydraulic behavior in the loss of shutdown cooling system accident during low power/shutdown operations at the Korean standard nuclear power plant was analyzed using the best-estimate thermal-hydraulic analysis code, MARS2.1. The effects of operator's action and initiation of accident mitigation system, such as safety injection and gravity feed on mitigation of the accident during shutdown operations are also analyzed.When steam generators are unavailable or vent paths with large cross-sectional area are open in the accident, the core damage occurs earlier than the cases of steam generators available or vent paths with small cross-sectional area. If an operator takes an action to mitigate the accident, the accident can be mitigated considerably. To mitigate the accident, high-pressure safety injection is more effective in POS4B and gravity feed is more effective in POS5. The results of this study can contribute to the plant safety improvement because those can provide the time for an operator to take an action to mitigate the accident by providing quantitative time of core damage. The results of this study can also provide information in developing operating procedure and accident management technology. 相似文献