An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has u...An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has utilized the standard k-ε model and P1 model. The finite-rate/eddy-dissipation (finite-rate/ED) combustion model and non-premixed combustion model were both used to simulate accurately the combustion and the operation status of the steam cracking furnace. Three different surfaces of the steam cracking furnace were obtained from the simulation, namely:the flue gas temperature field of the entrance surface in long flame burners, the central surface location of tubes, and the crossover section surface. Detailed information on the flue gas temperature and the mass concentration fraction of these different surfaces in the steam cracking furnace can also be obtained by the simulation. This paper analyzed and compared the simulation results with the two combustion models, estimated the operation status of the steam cracking furnace, and reported that the finite-rate/ED model is appropriate to simulate the steam cracking furnace by comparing key simulation data with actual test data. This work has also provided a theoretical basis for simulating and operating the steam cracking furnace.展开更多
This paper put forward an evaluation model with which one can make a comprehensive calculation of enterprise operation status concerning profit ability, repaying capability, economic efficiency and developing potentia...This paper put forward an evaluation model with which one can make a comprehensive calculation of enterprise operation status concerning profit ability, repaying capability, economic efficiency and developing potential; and meanwhile the method of maximal distinction is employed to conduct the data synthesis of several targets and draw the conclusion of evaluation. Finally, a pratical illustration is given in this paper.展开更多
The value of social security funds, has always been an important part of our country social security enterprise as a whole, it is the one of the main ways to realize the social stability and national economic income. ...The value of social security funds, has always been an important part of our country social security enterprise as a whole, it is the one of the main ways to realize the social stability and national economic income. In the triple pressure with ageing population, inflation and social security transition, the value of the social security fund in our country is particularly acute. Analyses the receipts and expenditures of social security funds, investment and operation structure and put forward some rationalization proposal, which has significant meaning for a better play to the role of the social security fund and actively promote the innovation and development of China＇s social security fund management.展开更多
Diagnosing the operational status of High-voltage circuit breakers(HVCBs)is crucial for ensuring the safe and stable operation of the grid.Mechanical characteristic parameters are effective indicators for evaluating t...Diagnosing the operational status of High-voltage circuit breakers(HVCBs)is crucial for ensuring the safe and stable operation of the grid.Mechanical characteristic parameters are effective indicators for evaluating the performance of HVCBs.Recent studies have shown that the actions of the springs and cams in HVCBs can be used to detect the operational status of the mechanical mechanisms,which occur extremely quickly,usually in the speed of m/ms.In this paper,dynamic vision sensing technology was employed to rapidly and dynamically capture the movements of the springs and cam of the HPL245B1 HVCB.The data volume of a single experiment is less than 100 MB,whereas the data collected by a high-speed camera at the same frame rate exceeds 1 GB.Action data streams of the springs and cam were obtained and images were reconstructed from the event streams.The Lucas-Kanade optical flow algorithm and the normalised cross-correlation algorithm are applied to calculate the parameters of spring deformation characteristics and cam rotation characteristics for mechanical feature detection of HVCBs.This is the first attempt to utilize brain-inspired hardware technology for the status monitoring of electrical equipment.The advantages of dynamic vision sensing technology,such as high dynamic range,low data transmission,and low energy con-sumption,also offer significant benefits for air discharge monitoring and status moni-toring of electrical equipment.展开更多
Fault characteristic gas analysis is one of the important methods for monitoring the operating status of power equipment.This study presents the construction of a simulation model for a hollow-core photonic crystal fi...Fault characteristic gas analysis is one of the important methods for monitoring the operating status of power equipment.This study presents the construction of a simulation model for a hollow-core photonic crystal fibre(HC-PCF)-based photothermal spectroscopy gas detection system.The relationship between the phase change of the probe beam and the acetylene concen-tration,pump power,ambient temperature and the modulation frequency is examined.It is achieved by simulating the wavelength modulation of the pump beam and the phase change of the probe beam.The findings demonstrate that there is a linear positive correlation between the pump power and the amplitude of the phase change of the probe beam and the acetylene concentration.For example,acetylene concentration grew from 1 to 10,000 ppm,whereas phase change amplitude increased from 4.71×10^(−4) to 3.70 rad.The pump power grew from 7 to 2000 mW,whereas phase change amplitude increased from 3.73×10^(−4) to 1.01×10^(−1) rad.The phase change of the probe beam is non-linearly and negatively correlated with the ambient temperature.The ambient temperature decreases from 373.15 to 173.15 K,and phase change amplitude increases from 5.05×10^(−3) to 2.15×10^(−2) rad,an enhancement of 4.26 times.The modulation frequency is needed to balance the thermal conduction process in the HC-PCF.In the 1-100 Hz range,the amplitude of the phase change is stable and almost independent of the modulation frequency.In the 100-40,000 Hz range,the amplitude of the phase change decreases rapidly with the increase of the modulation frequency.The results of the paper provide a reference for constructing the HC-PCF-based photothermal spectroscopy gas detection system.展开更多
基金supported by the technology development fund of China Petroleum & Chemical Corporation (Sinopec 409045)
文摘An accurate and complete geometric model was constructed to simulate the combustion, flow and temperature environment in the radiant section of the steam cracking furnace. Simulation of flow and radiation status has utilized the standard k-ε model and P1 model. The finite-rate/eddy-dissipation (finite-rate/ED) combustion model and non-premixed combustion model were both used to simulate accurately the combustion and the operation status of the steam cracking furnace. Three different surfaces of the steam cracking furnace were obtained from the simulation, namely:the flue gas temperature field of the entrance surface in long flame burners, the central surface location of tubes, and the crossover section surface. Detailed information on the flue gas temperature and the mass concentration fraction of these different surfaces in the steam cracking furnace can also be obtained by the simulation. This paper analyzed and compared the simulation results with the two combustion models, estimated the operation status of the steam cracking furnace, and reported that the finite-rate/ED model is appropriate to simulate the steam cracking furnace by comparing key simulation data with actual test data. This work has also provided a theoretical basis for simulating and operating the steam cracking furnace.
文摘This paper put forward an evaluation model with which one can make a comprehensive calculation of enterprise operation status concerning profit ability, repaying capability, economic efficiency and developing potential; and meanwhile the method of maximal distinction is employed to conduct the data synthesis of several targets and draw the conclusion of evaluation. Finally, a pratical illustration is given in this paper.
文摘The value of social security funds, has always been an important part of our country social security enterprise as a whole, it is the one of the main ways to realize the social stability and national economic income. In the triple pressure with ageing population, inflation and social security transition, the value of the social security fund in our country is particularly acute. Analyses the receipts and expenditures of social security funds, investment and operation structure and put forward some rationalization proposal, which has significant meaning for a better play to the role of the social security fund and actively promote the innovation and development of China＇s social security fund management.
基金National Natural Science Foundation of China,Grant/Award Numbers:52077118,62411560155Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2024A1515012597。
文摘Diagnosing the operational status of High-voltage circuit breakers(HVCBs)is crucial for ensuring the safe and stable operation of the grid.Mechanical characteristic parameters are effective indicators for evaluating the performance of HVCBs.Recent studies have shown that the actions of the springs and cams in HVCBs can be used to detect the operational status of the mechanical mechanisms,which occur extremely quickly,usually in the speed of m/ms.In this paper,dynamic vision sensing technology was employed to rapidly and dynamically capture the movements of the springs and cam of the HPL245B1 HVCB.The data volume of a single experiment is less than 100 MB,whereas the data collected by a high-speed camera at the same frame rate exceeds 1 GB.Action data streams of the springs and cam were obtained and images were reconstructed from the event streams.The Lucas-Kanade optical flow algorithm and the normalised cross-correlation algorithm are applied to calculate the parameters of spring deformation characteristics and cam rotation characteristics for mechanical feature detection of HVCBs.This is the first attempt to utilize brain-inspired hardware technology for the status monitoring of electrical equipment.The advantages of dynamic vision sensing technology,such as high dynamic range,low data transmission,and low energy con-sumption,also offer significant benefits for air discharge monitoring and status moni-toring of electrical equipment.
基金supported by National Natural Science Foundation of China,Grant No.52277161.
文摘Fault characteristic gas analysis is one of the important methods for monitoring the operating status of power equipment.This study presents the construction of a simulation model for a hollow-core photonic crystal fibre(HC-PCF)-based photothermal spectroscopy gas detection system.The relationship between the phase change of the probe beam and the acetylene concen-tration,pump power,ambient temperature and the modulation frequency is examined.It is achieved by simulating the wavelength modulation of the pump beam and the phase change of the probe beam.The findings demonstrate that there is a linear positive correlation between the pump power and the amplitude of the phase change of the probe beam and the acetylene concentration.For example,acetylene concentration grew from 1 to 10,000 ppm,whereas phase change amplitude increased from 4.71×10^(−4) to 3.70 rad.The pump power grew from 7 to 2000 mW,whereas phase change amplitude increased from 3.73×10^(−4) to 1.01×10^(−1) rad.The phase change of the probe beam is non-linearly and negatively correlated with the ambient temperature.The ambient temperature decreases from 373.15 to 173.15 K,and phase change amplitude increases from 5.05×10^(−3) to 2.15×10^(−2) rad,an enhancement of 4.26 times.The modulation frequency is needed to balance the thermal conduction process in the HC-PCF.In the 1-100 Hz range,the amplitude of the phase change is stable and almost independent of the modulation frequency.In the 100-40,000 Hz range,the amplitude of the phase change decreases rapidly with the increase of the modulation frequency.The results of the paper provide a reference for constructing the HC-PCF-based photothermal spectroscopy gas detection system.
