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UO_2陶瓷微球是制造高温气冷核反应堆(HTGR)球状燃料元件的最重要的部件。为此,清华大学核能技术设计研究院开发了一种全胶凝工艺(TGU)。它是在传统的溶胶-凝胶工艺,即外胶凝(EGU)和内胶凝(IGU)工艺的基础上发展起来的,现已被选用为10MW高温气冷试验堆燃料芯核的生产工艺。该项研究的目的是从芯核的质量控制(QC)和质量保证(QA)的要求出发,采用批量试验方式,检验工艺参数和产品质量的稳定性。试验结果证明:当工艺参数被控制并固定时,芯核的质量能够满足质量规范的要求,即当胶体流量和喷嘴的振动频率被固定时,芯核的几何尺寸便随之固定;烧结温度和时间固定时,芯核密度亦随之固定;采用纯氢烧结时,O/U比便接近化学计量。对UO_2陶瓷微球的性能和结构也进行了研究。 相似文献
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《中国核科技报告》1994,(1)
UO_2陶瓷微球是制造高温气冷核反应堆(HTGR)球状燃料元件的最重要的部件。为此,清华大学核能技术设计研究院开发了一种全胶凝工艺(TGU)。它是在传统的溶胶-凝胶工艺,即外胶凝(EGU)和内胶凝(IGU)工艺的基础上发展起来的,现已被选用为10MW高温气冷试验堆燃料芯核的生产工艺。该项研究的目的是从芯核的质量控制(QC)和质量保证(QA)的要求出发,采用批量试验方式,检验工艺参数和产品质量的稳定性。试验结果证明:当工艺参数被控制并固定时,芯核的质量能够满足质量规范的要求,即当胶体流量和喷嘴的振动频率被固定时,芯核的几何尺寸便随之固定;烧结温度和时间固定时,芯核密度亦随之固定;采用纯氢烧结时,O/U比便接近化学计量。对UO_2陶瓷微球的性能和结构也进行了研究。 相似文献
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本文描述了高温气冷堆用的u0。燃料芯核的溶胶一凝胶法制造过程。它采用脲素络合硝酸铀酰制备胶体,用聚乙烯醇及四氢糠醇调节溶胶性质,通过振动喷嘴分散成滴在氨水柱中造粒。对溶胶喷射流均一造滴的条件进行了研究。 相似文献
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内胶凝法制备HTGR燃料芯核 总被引:2,自引:1,他引:1
用内胶凝工艺研制了高温气冷堆(HTGR)燃料芯核,对该工艺的各个过程,如:缺酸硝酸铀酰(Acid Deficient Uranyl Nitrate)溶液和溶胶液的配制,分散溶胶成液滴并胶凝成固体微球、洗涤、干燥、煅烧,还原烧结等过程进行了系统的研究,并在1kg 级装置上进行了条件最佳化试验,确定了最佳工艺参数。本工艺制备的 UO_2燃料芯核密度达98%理论密度以上 O/U 比为2.000±0.005,圆球度(D_(max)/D_(min))达1.03,破碎强度为2kg,闭孔尺寸为1μm 左右。各项性能符合我国10MW HTGR 燃料元件的要求。 相似文献
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制备致密UO_2微球的全胶凝方法 总被引:6,自引:0,他引:6
为了制备高温气冷反应堆用燃料芯核,致密UO_2微球,研究了一种新的溶胶-凝胶工艺.该流程具有经典的溶胶-凝胶工艺的优点,但克服了它们的缺点.已经知道,合理的配方设计和良好的干燥条件是克服破裂困难的关键因素.影响胶滴尺寸及其分布的控制因素是:极限流量、几何因子、物理因子和振动因子.微球干燥和焙烧参数的优化是依据热分析曲线来确定的.用SEM方法观察了热处理过程中的微观结构的变化.观察了真空烧结的重结晶现象.观察了UO_2·nH_2O的化学气相沉积.结果表明:晶粒大小随烧结温度增加而增加.本工艺适合于制备500μm直径的微球.其产率为90%.球度优于1.08.球径范围为470-530μm.1400-1450℃真空条件下的烧结密度范围为10.71-10.76 g/cm~3. 相似文献
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现代的反应堆稳压器的水位控制大都采用的是传统的PI调节器,对于这样一个非线性和时变性的复杂控制系统,PI调节器表现出来的常常是超调量大、调节时间长等并不理想的效果.本文提出以智能模糊控制器取代原有常规PI控制器的改进方案,并以大亚湾一期工程反应堆控制系统的稳压器水位控制为研究对象,着重阐述智能模糊控制原理在具体实践中的使用方法,最后对改造前后的系统输出进行LabVIEW仿真比较.仿真结果表明,模糊PI调节器不但克服了常规PI调节器的缺点,而且还提高了控制系统的实时性和抗干扰能力,值得广泛采用. 相似文献
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It is extremely important for tokamak to control the plasma position during routine discharge. However, the model of plasma in tokamak usually contains much of the uncertainty, such as structured uncertainties and unmodeled dynamics. Compared with the traditional PID control approach, robust control theory is more suitable to handle this problem. In the paper, we propose a H∞ robust control scheme to control the horizontal position of plasma during the flat-top phase of discharge on Joint Texas Experimental Tokamak (J-TEXT) tokamak. First, the model of our plant for plasma horizontal position control is obtained from the position equilibrium equations. Then the H∞ robust control framework is used to synthesize the controller. Based on this, an H∞ controller is designed to minimize the regulation/tracking error. Finally, a comparison study is conducted between the optimized H∞ robust controller and the traditional PID controller in simulations. The simulation results of the H∞ robust controller show a significant improvement of the performance with respect to those obtained with traditional PID controller, which is currently used on our machine. 相似文献
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系统采用西门子S7-400 PLC进行系统的总体控制,采用PROFIBUS-DP网络进行系统的通讯,实现了棒控系统的数字化控制,并对棒控系统的硬件设计、软件设计以及系统的调试进行了研究。该系统设计新颖,技术先进,符合国际发展趋势,对国产核电站数字化仪控系统的出口具有现实意义。 相似文献
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《Journal of Nuclear Science and Technology》2013,50(3):263-273
There has been increasing necessity for load following and/or AFC (Automatic Frequency Control) operation along with the growth in the share of nuclear power generation in the electric power network. Fuzzy logic control was investigated for application to a BWR recirculation flow control system, in order to obtain a rapid generator power response within an allowable neutron flux overshoot. The proposed controller has two control loops, generator power and neutron flux loop. The fuzzy logic is utilized for weighing these control loops and for controlling the neutron flux. By evaluating the controller performance by numerical simulations on the step response for generator power demand with the model BWR recirculation flow system, more rapid response was obtained than that for conventional proportional plus integral controllers with no neutron flux overshoot beyond alarm activation level. 相似文献
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《Fusion Engineering and Design》2014,89(5):553-557
ITER is targeting Q = 10 with 500 MW of fusion power. To meet this target, the plasma needs to be controlled and shaped for a period of hundreds of seconds, avoiding contact with internal components, and acting against instabilities that could result in the loss of control of the plasma and in its disruptive termination.Axisymmetric magnetic control is a well-understood area being the basic control for any tokamak device. ITER adds more stringent constraints to the control primarily due to machine protection and engineering limits. The limits on the actuators by means of the maximum current and voltage at the coils and the few hundred ms time response of the vacuum vessel requires optimization of the control strategies and the validation of the capabilities of the machine in controlling the designed scenarios.Scenarios have been optimized with realistic control strategies able to guarantee robust control against plasma behavior and engineering limits due to recent changes in the ITER design. Technological issues such as performance changes associated with the optimization of the final design of the central solenoid, control of fast transitions like H to L mode to avoid plasma-wall contact, and optimization of the plasma ramp-down have been modeled to demonstrate the successful operability of ITER and compatibility with the latest refinements in the magnetic system design.Validation and optimization of the scenarios refining the operational space available for ITER and associated control strategies will be proposed. The present capabilities of magnetic control will be assessed and the remaining critical aspects that still need to be refined will be presented. The paper will also demonstrate the capabilities of the diagnostic system for magnetic control as a basic element for control. In fact, the noisy environment (affecting primarily vertical stability), the non-axisymmetric elements in the machine structure (affecting the accuracy of the identification of the plasma boundary), and the strong component of eddy current at the start-up (resulting in a poor S/N ratio for plasma reconstruction for Ip < 2 MA requiring a robust plasma control) make the ITER magnetic diagnostic system a demanding part of the magnetic control and investment protection systems. Finally the paper will illustrate the identified roles of magnetic control in the PCS (plasma control system) as formally defined in the recent first step of the design and development of the system. 相似文献
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在CPR1000核电工程项目中存在着诸多参与安全功能的同时受1E和NC级DCS信号控制的非安全级设备,当1E和NC级命令同时到达时,需对1E和NC级DCS命令进行优选处理。本文提出一种优选控制技术,充分考虑不同信号优先级逻辑比较和1E级信号的定期试验回路设计。结果表明,非安全级优选控制技术通过了SL1和SL2抗震试验,为这类非安全级设备的不同级别的控制命令优选处理以及1E级命令的定期试验提供了解决方案。 相似文献