In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbul...In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.展开更多
Cold rolling circulating water station mainly supplies circulating cooling water for each unit in the cold rolling plant. The actual operation condition of circulating water pump deviates from the design, and the wate...Cold rolling circulating water station mainly supplies circulating cooling water for each unit in the cold rolling plant. The actual operation condition of circulating water pump deviates from the design, and the water pump runs away from the high efficiency zone. The existing problems in operation are analyzed, and corresponding measures are taken, which greatly reduces the energy consumption of the pumping station and achieves good results.展开更多
Throughout the lifecycle of Nuclear Power Equipment(NPE),maintaining high-safety maintenance services is essential for optimal operation.Traditional time-based maintenance strategies are limited in NPE contexts due to...Throughout the lifecycle of Nuclear Power Equipment(NPE),maintaining high-safety maintenance services is essential for optimal operation.Traditional time-based maintenance strategies are limited in NPE contexts due to stringent safety requirements and high costs of complex systems.Specifically,maintenance processes lack transparency,state monitoring relies heavily on manual inspections,and decisions depend passively on individual expertise.Digital Twin(DT)effectively breaks down"information silos,"leverages data value,and enables proactive maintenance decision-making for NPE.However,DT application in the nuclear industry is still exploratory,with limited systematic and practical research,especially for critical equipment maintenance.This paper introduces a DT-based intelligent maintenance decision system featuring three key technologies:DT modeling,state monitoring with dynamic early warning,and systematic intelligent decision-making and verification.A DT-based prototype using a cooling water pump case study preliminarily validates the state monitoring model's accuracy.Results indicate that the proposed framework and methods are feasible and hold significant application potential.展开更多
基金Project supported by the Priority Academic Development Program of Jiangsu Higher Education Institutions, ChinaProject(CXZZ12_0680) supported by Postgraduate Innovation Foundation of Jiangsu Province, ChinaProject(12JDG082) supported by the Advanced Talent Foundation of Jiangsu University, China
文摘In order to investigate the effect of sampling frequency and time on pressure fluctuations, the three-dimensional unsteady numerical simulations were conducted in a circulating water pump. Through comparison of turbulence models with hydraulic performance experiment, SST k-co model was confirmed to study the rational determination of sampling frequency and time better. The Fast Fourier Transform （FFT） technology was then adopted to process those fluctuating pressure signals obtained. On these bases, the characteristics of pressure fluctuations acting on the tongue were discussed. It is found that aliasing errors decrease at higher sampling frequency of 17 640 Hz, but not at a lower sampling frequency of 1 764 Hz. Correspondingly, an output frequency range ten-times wider is obtained at 17 640 Hz. Compared with 8R, when the sampling time is shorter, the amplitudes may be overvalued, and the frequencies and amplitudes of low-frequency fluctuations can not be well predicted. The frequencies at the tongue are in good agreement with the values calculated by formula and the frequency compositions less than the blade passing frequency are accurately predicted.
文摘Cold rolling circulating water station mainly supplies circulating cooling water for each unit in the cold rolling plant. The actual operation condition of circulating water pump deviates from the design, and the water pump runs away from the high efficiency zone. The existing problems in operation are analyzed, and corresponding measures are taken, which greatly reduces the energy consumption of the pumping station and achieves good results.
基金supported by the National Natural Science Foundation of China[52105530&51975463]the National Key Research and Development Program of China[2021YFB3301400]+2 种基金the Fundamental Research Funds for the Central Universities[xzy012022053]Natural Science Basic Research Program of Shaanxi[2022JQ-516]the Postdoctoral Science Foundation[22021M692556].
文摘Throughout the lifecycle of Nuclear Power Equipment(NPE),maintaining high-safety maintenance services is essential for optimal operation.Traditional time-based maintenance strategies are limited in NPE contexts due to stringent safety requirements and high costs of complex systems.Specifically,maintenance processes lack transparency,state monitoring relies heavily on manual inspections,and decisions depend passively on individual expertise.Digital Twin(DT)effectively breaks down"information silos,"leverages data value,and enables proactive maintenance decision-making for NPE.However,DT application in the nuclear industry is still exploratory,with limited systematic and practical research,especially for critical equipment maintenance.This paper introduces a DT-based intelligent maintenance decision system featuring three key technologies:DT modeling,state monitoring with dynamic early warning,and systematic intelligent decision-making and verification.A DT-based prototype using a cooling water pump case study preliminarily validates the state monitoring model's accuracy.Results indicate that the proposed framework and methods are feasible and hold significant application potential.
