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秦山核电二期工程主泵瞬态计算 总被引:4,自引:1,他引:3
采用国际惯用的主泵瞬态计算方法,对秦山核电二期工程主泵可能出现的3种瞬态进行了计算,计算结果表明;两台主泵同时丧失交流电源时,主泵惰转的半流量时间大于10s,单泵惰转时,未受影响环路反应堆冷却剂流量增大,主泵卡转子时,反应堆冷却剂流量急剧减小。 相似文献
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电网频率下降时CPR1000反应堆主泵和电机瞬态分析 总被引:1,自引:0,他引:1
本文根据电机学原理,用RETRAN-02程序模拟电网频率下降时电动机的运行特性。同时模拟了CPR1000主冷却剂泵的水力特性和反应堆冷却剂系统的阻力特性。完整地研究主冷却剂泵和电机在电网频率下降时的运行瞬态。最后分析电网频率以4 Hz/s下降时CPR1000主冷却剂泵和电机的瞬态行为。 相似文献
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主泵是核电站的心脏,是反应堆冷却剂系统的主要设备和压力边界之一,承担着确保堆芯传热所需的冷却剂流量的重要功能,运行期间必须保证主泵运行的安全可靠。在第11个燃料循环周期中,主泵A电机出现了润滑油损失异常的状况。为了保证电机正常运行,在功率运行期间进行了5次补油的应急处理。针对这个问题,对主泵电机润滑油损失异常的原因和油气散失通道作出了具体分析,在换料检修过程中对主泵电机进行了解体工作。对解决润滑油损失异常的具体解决方案做出了论述。通过具体检修方案的实施,最终使润滑油异常损失得到了很好的控制。 相似文献
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以缩比系数为1∶4的立式屏蔽电机反应堆主冷却剂循环泵(简称主泵)为研究对象,建立2台并联主泵反向旋转(模型1)和同向旋转(模型2)2种几何模型;运用计算流体力学(CFD)方法对2种模型的并联主泵内部流场进行稳态运行计算,从主泵的外特性、进口流动特性、入流品质、管内压力分布方面对模型1和模型2进行对比分析。结果表明,模型1中A、B主泵性能基本一致;模型2中A、B主泵的流量相对偏差基本在0.8%以内,最大值达到1.69%,扬程相对偏差稳定在1%以内,效率和轴功率相对偏差最大值分别达到6%和8%;模型2相对模型1流动稳定性更好、入流品质更高、管内压力分布较低,有利于设备的长期运行。 相似文献
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针对1 000 MW压水堆核电站主泵水力性能要求,在对核主泵进行水力设计和三维造型的基础上,采用CFD技术对失水事故工况核主泵气液两相流进行数值计算,并分析了失水事故工况下的核主泵气体分布,不同空泡份额工况下气体在流道内变化,以及空泡份额、冷却剂温度对核主泵扬程、效率的影响。计算结果表明:事故工况核主泵叶轮内气体主要分布在叶轮轮毂附近区域;沿叶轮轴向方向含气量逐渐增高,而沿径向方向含气量逐渐降低;当空泡份额在15%范围内,随着空泡份额的增加,扬程由113 m降低到85 m,效率由75%下降到65%,但仍能正常工作;当空泡份额大于15%,泵性能急剧下降,扬程下降到48 m,效率也降低到31%,泵丧失正常工作能力;冷却剂温度在270~350 ℃范围内,随着冷却剂温度增加,效率、扬程变化很小,但当温度超过350 ℃,主泵的性能急剧下降,致使主泵无法安全运行。 相似文献
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Wu Yu Wang Shouguo 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(18):3137-3139
A facility which is called atmospheric pressure and normal temperature plasma jet was introduced in this paper. After the wool surface was treated by this kind of facility with Ar in different irradiating times, the time-effect of the fabric wettability has been weakened, and if the parameters of the irradiating time and the voltage of the facility are appropriate, the time-effect of wettability can be effectively inhibited. With the stable wettability, the fabric can be dressed without PVA (polyvinyl alcohol) which can cause lager pollution in the textile field, so the method without the time-effect of the textile wettability will be useful in the field of clean textile production. Undoubtedly, the stable wettability of textile surface was caused by the stable hydrophilic molecules on the textile surface. Thus, the reaction process and results on the textile surface treated by plasma needs to be studied to optimize the parameters of the irradiating time and the voltage of the plasma jet. So the initial experimental studies on the optimization of the parameters of the plasma jet were discussed in this paper, and the authors believe that the method without the time-effect also can be used in other fields of plasma application. 相似文献
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《等离子体科学和技术》2016,18(4):382-387
In this paper,a two-dimensional physical model is established according to the discharging process in the Hall thruster discharge channel using the particle-in-cell method.The influences of discharge voltage on the distributions of potential,ion radial flow,and discharge current are investigated in a fixed magnetic field configuration.It is found that,with the increase of discharge voltage,especially during 250-650 V,the ion radial flow and the collision frequency between ions and the wall are decreased,but the discharge current is increased.The electron temperature saturation is observed between 400-450 V and the maximal value decreases during this region.When the discharge voltage reaches 700 V,the potential distribution in the axis direction expands to the anode significantly,the ionization region becomes close to the anode,and the acceleration region grows longer.Besides,ion radial flow and the collision frequency between ions and the wall are also increased when the discharge voltage exceeds 650 V. 相似文献
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Bo LIU 《等离子体科学和技术》2022,24(11):115301
The electromagnetic pulse excited by the collision between a hypervelocity meteoroid and a spacecraft is studied both numerically and theoretically. It is found that there are two kinds of electromagnetic pulse. The high-frequency electromagnetic pulse may be excited by the sum of all the electric dipoles. Each electron can be considered as an electric dipole. The low-frequency electromagnetic pulse is produced by the Langmuir oscillation of electrons. The energy flux density and the duration time of the excited low-frequency electromagnetic pulse by the meteoroid are also studied in the present paper. It is shown that the energy flux density increases as either the impact speed or the mass of the meteoroid increases. It is also shown that the duration time decreases as both the impact speed and the mass of the meteoroid increase. By measuring the strength and the duration time of the electromagnetic pulse excited by the collision between the hypervelocity meteoroid and spacecraft, we can estimate the speed and the mass of the hypervelocity meteoroid, which will be helpful in space flight and space exploration. 相似文献
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为探讨右侧卧位对左室下壁心肌衰减校正和心梗诊断的价值,对31名正常者和22名冠心病病人同时进行了仰卧位和右侧卧位的^99mTc-MIBI静息心肌显像,病人均作了冠状动脉血管造影。观察正常者在不同体位时下壁形态并通过靶心图计算各区象素计数。判定不同体位各供血区病变诊断的敏感性和特异性。结果表明,右侧卧位时下壁形态显示较好而且计数明显增高,P<0.05,同时对右冠状动脉病变的敏感性和特异性分别为100%和81.8%,较仰卧位明显提高,结果提示,右侧卧位不仅可使下壁衰减得以校正而且可提高对心梗诊断的准确性。 相似文献
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M. Yamamoto F. Arbeiter T. Yokomine E. Wakai J. Theile A. Garcia D. Rapisarda N. Casal A. Mas P. Gouat W. Leysen 《Fusion Engineering and Design》2013,88(6-8):746-750
Under Broader Approach (BA) Agreement between EURATOM and Japan, IFMIF/EVEDA (International Fusion Materials Irradiation Facility/Engineering Validation and Engineering Design Activities) has been performed since the middle of 2007. IFMIF presents three main facilities (the Accelerator Facility, Li Target Facility and Test Facilities). A previous design of IFMIF was summarized in the comprehensive design report [1]. The present EVEDA phase aims at producing a detailed, complete and fully integrated engineering design of IFMIF. The delivery of the “Intermediate IFMIF Engineering Design Report” is foreseen mid-2013. The goal of IFMIF is to obtain the indispensable design database to allow the design and licensing of DEMO and ensuring commercial reactors thanks to the materials data set obtained from planned evaluation tests such irradiations in high flux test modules (HFTM-vertical rig, HFTM-horizontal rig), medium flux test modules (creep fatigue test module, tritium release test module, liquid breeder validation module) and low flux test modules of IFMIF. In addition, the Startup Monitoring Module will be used for IFMIF commissioning. This paper is summarizing the overall current progress status of the engineering and conceptual design of the test modules in IFMIF/EVEDA. 相似文献
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本文通过对反应堆周期计响应时间、过冲量及噪声问题的分析,探论周期测量和周期保护信号分别处理的必要性和可能性,目的在于改善周期信号的品质,提高周期计的使用效果。本文首次报道了差分型周期计的响应函数。 相似文献
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