It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production sche...It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production scheme can be designed when computer diagnosis is used. However, it is difficult to make a comprehensive analysis to supply efficient technical guidance for operation of the pumping well with multiple faults of down-hole conditions, which cannot be effectively dealt with by the common methods. To solve this problem, a method based on designated component analysis （DCA） is used in this paper. Freeman chain code is used to represent the down-hole dynamometer card whose important characteristics are extracted to construct a designated mode set. A control chart is used as a basis for fault detection. The upper and lower control lines on the control chart are determined from standard samples in normal working conditions. In an incompletely orthogonal mode, the designated mode set could be divided into some subsets in which the modes are completely orthogonal. The observed data is projected into each designated mode to realize fault detection according to the upper and lower control lines. The examples show that the proposed method can effectively diagnose multiple faults of down-hole conditions.展开更多
Production characteristics of high speed rod are fast speed,complex section and internal microstructure evolution,which bring great problems to analyze and solve the quality disputes.Therefore,a serial process models ...Production characteristics of high speed rod are fast speed,complex section and internal microstructure evolution,which bring great problems to analyze and solve the quality disputes.Therefore,a serial process models have been developed based on the characteristics of high speed rod:due to rod stock to be square section,a two dimension model has been developed to predict the evolution of internal temperature and grain coarsening.As for the rod rolling process,an automatic section design system has been written, which can show section filling condition and process parameters such as temperature,pressure and recrystallization etc per pass.As for rod cooling stage,an integrated model which coupled phase transformation,temperature and final properties was developed and applied in real production with good results.展开更多
小型棒控压水堆舍弃了可溶硼,并高度依赖控制棒与可燃毒物棒控制堆芯的反应性。为研究控制棒对堆芯关键性能的影响,本文以核动力破冰船用KLT-40模型为对象,以轴向功率偏移、堆芯寿期、燃料利用率与径向功率峰因子为指标,开展长寿期小型...小型棒控压水堆舍弃了可溶硼,并高度依赖控制棒与可燃毒物棒控制堆芯的反应性。为研究控制棒对堆芯关键性能的影响,本文以核动力破冰船用KLT-40模型为对象,以轴向功率偏移、堆芯寿期、燃料利用率与径向功率峰因子为指标,开展长寿期小型棒控压水堆控制棒布置与动作策略设计分析。首先,基于OpenMC程序开发带棒燃耗程序;其次,比较堆芯带控制棒与无控制棒运行时的堆芯寿期等指标;最后,分析不同动作策略对轴向功率偏移等指标的影响。结果表明:控制棒将堆芯寿期从590 EFPDs(等效满功率天,Effective full power days)延长至650~698 EFPDs;低价值棒组优先动作策略使轴向功率偏移程度由−0.69与+0.80分别下降至−0.29与+0.52。因此,要准确计算长寿期压水堆寿期必须采用带控制棒燃耗计算策略,并且通过合理的动作策略能够有效减小控制棒带来的轴向功率偏移。展开更多
基金supported by the Key Program of National Natural Science Foundation of China (61034005)Postgraduate Scientific Research and Innovation Projects of Basic Scientific Research Operating Expensesof Ministry of Education (N100604001)Excellent Doctoral Dissertations Cultivation Project of Northeastern University
文摘It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production scheme can be designed when computer diagnosis is used. However, it is difficult to make a comprehensive analysis to supply efficient technical guidance for operation of the pumping well with multiple faults of down-hole conditions, which cannot be effectively dealt with by the common methods. To solve this problem, a method based on designated component analysis （DCA） is used in this paper. Freeman chain code is used to represent the down-hole dynamometer card whose important characteristics are extracted to construct a designated mode set. A control chart is used as a basis for fault detection. The upper and lower control lines on the control chart are determined from standard samples in normal working conditions. In an incompletely orthogonal mode, the designated mode set could be divided into some subsets in which the modes are completely orthogonal. The observed data is projected into each designated mode to realize fault detection according to the upper and lower control lines. The examples show that the proposed method can effectively diagnose multiple faults of down-hole conditions.
文摘Production characteristics of high speed rod are fast speed,complex section and internal microstructure evolution,which bring great problems to analyze and solve the quality disputes.Therefore,a serial process models have been developed based on the characteristics of high speed rod:due to rod stock to be square section,a two dimension model has been developed to predict the evolution of internal temperature and grain coarsening.As for the rod rolling process,an automatic section design system has been written, which can show section filling condition and process parameters such as temperature,pressure and recrystallization etc per pass.As for rod cooling stage,an integrated model which coupled phase transformation,temperature and final properties was developed and applied in real production with good results.
文摘小型棒控压水堆舍弃了可溶硼,并高度依赖控制棒与可燃毒物棒控制堆芯的反应性。为研究控制棒对堆芯关键性能的影响,本文以核动力破冰船用KLT-40模型为对象,以轴向功率偏移、堆芯寿期、燃料利用率与径向功率峰因子为指标,开展长寿期小型棒控压水堆控制棒布置与动作策略设计分析。首先,基于OpenMC程序开发带棒燃耗程序;其次,比较堆芯带控制棒与无控制棒运行时的堆芯寿期等指标;最后,分析不同动作策略对轴向功率偏移等指标的影响。结果表明:控制棒将堆芯寿期从590 EFPDs(等效满功率天,Effective full power days)延长至650~698 EFPDs;低价值棒组优先动作策略使轴向功率偏移程度由−0.69与+0.80分别下降至−0.29与+0.52。因此,要准确计算长寿期压水堆寿期必须采用带控制棒燃耗计算策略,并且通过合理的动作策略能够有效减小控制棒带来的轴向功率偏移。
