In order to improve work performance of M aglev vibration test systems,the relationships of operating parameters between different components and system were researched. The working principle of photoelectric displace...In order to improve work performance of M aglev vibration test systems,the relationships of operating parameters between different components and system were researched. The working principle of photoelectric displacement sensor was analyzed. The relationship between displacement of transducer and the infrared light area received by sensor was given. The method of expanding the dynamic range of vibrator was proposed,which makes dynamic range of Maglev vibrator doubled. By increasing the amplification of the amplifier,the sensitive photoelectric displacement sensor can be maintained. Two modes of operation of the controller were analyzed. Bilateral work of vibration test system designed can further improve the stability of the system.An object vibration was measured by Maglev vibration test system designed when different vibration exciter frequencies were loaded. Experiments showthat the output frequency measured by Maglev vibration test system and loaded are the same. Finally,the errors of test system were analyzed. These errors of vibration test system designed can meet the requirements of application. The results laid the foundation for the practical application of magnetic levitation vibration test system.展开更多
理论分析了离子聚合物金属复合材料(ionic polymer metal composites,简称IPMC)的传感机理和数学模型;主要针对其传感性能进行了实验研究,给出了在不同工作频率下的传感器标定曲线与灵敏度测试结果,并分析了其灵敏变化原因;最后对传感...理论分析了离子聚合物金属复合材料(ionic polymer metal composites,简称IPMC)的传感机理和数学模型;主要针对其传感性能进行了实验研究,给出了在不同工作频率下的传感器标定曲线与灵敏度测试结果,并分析了其灵敏变化原因;最后对传感器进行的重复性能的测试。实验结果表明,IPMC传感器线性度好、重复性能好、在低频范围内灵敏度较高、检测结果稳定可靠。展开更多
Carbon dioxide flooding is an effective means of enhanced oil recovery for low permeability reservoirs. If fractures are present in the reservoir, CO2 may flow along the fractures, resulting in low gas displacement ef...Carbon dioxide flooding is an effective means of enhanced oil recovery for low permeability reservoirs. If fractures are present in the reservoir, CO2 may flow along the fractures, resulting in low gas displacement efficiency. Reservoir pore pressure will fluctuate to some extent during a CO2 flood, causing a change in effective confining pressure. The result is rock deformation and a reduction in permeability with the reduction in fracture permeability, causing increased flow resistance in the fracture space. Simultaneously, gas cross flowing along the fractures is partially restrained. In this work, the effect of stress changes on permeability was studied through a series of flow experiments. The change in the flowrate distribution in a matrix block and contained fracture with an increase in effective pressure were analyzed. The results lead to an implicit comparison which shows that permeability of fractured core decreases sharply with an increase in effective confining pressure. The fracture flowrate ratio declines and the matrix flowrate ratio increases. Fracture flow will partially divert to the matrix block with the increase in effective confining pressure, improving gas displacement efficiency.展开更多
基金supported by the Chinese National Natural Science Foundation under Grant (No. 51377037)
文摘In order to improve work performance of M aglev vibration test systems,the relationships of operating parameters between different components and system were researched. The working principle of photoelectric displacement sensor was analyzed. The relationship between displacement of transducer and the infrared light area received by sensor was given. The method of expanding the dynamic range of vibrator was proposed,which makes dynamic range of Maglev vibrator doubled. By increasing the amplification of the amplifier,the sensitive photoelectric displacement sensor can be maintained. Two modes of operation of the controller were analyzed. Bilateral work of vibration test system designed can further improve the stability of the system.An object vibration was measured by Maglev vibration test system designed when different vibration exciter frequencies were loaded. Experiments showthat the output frequency measured by Maglev vibration test system and loaded are the same. Finally,the errors of test system were analyzed. These errors of vibration test system designed can meet the requirements of application. The results laid the foundation for the practical application of magnetic levitation vibration test system.
文摘理论分析了离子聚合物金属复合材料(ionic polymer metal composites,简称IPMC)的传感机理和数学模型;主要针对其传感性能进行了实验研究,给出了在不同工作频率下的传感器标定曲线与灵敏度测试结果,并分析了其灵敏变化原因;最后对传感器进行的重复性能的测试。实验结果表明,IPMC传感器线性度好、重复性能好、在低频范围内灵敏度较高、检测结果稳定可靠。
基金supported by China National Key BasicResearch Development Program under grant 2006CB705805 entitled"Commercial Utilization of Greenhouse GasEnhanced Oil Recovery and Geological Storage:Study of Nonlinear Percolation Mechanisms of Multi-phase and Multi-component Mixtures of CO2 Flooding"National Key Sci-Tech Major Special Item under grant 2008ZX05009-004 entitled"The Development of Large-scale Oil and GasFields and Coal-bed Methane:New Technology on EnhancedOil Recovery in the Later Period of Oil Field Development".
文摘Carbon dioxide flooding is an effective means of enhanced oil recovery for low permeability reservoirs. If fractures are present in the reservoir, CO2 may flow along the fractures, resulting in low gas displacement efficiency. Reservoir pore pressure will fluctuate to some extent during a CO2 flood, causing a change in effective confining pressure. The result is rock deformation and a reduction in permeability with the reduction in fracture permeability, causing increased flow resistance in the fracture space. Simultaneously, gas cross flowing along the fractures is partially restrained. In this work, the effect of stress changes on permeability was studied through a series of flow experiments. The change in the flowrate distribution in a matrix block and contained fracture with an increase in effective pressure were analyzed. The results lead to an implicit comparison which shows that permeability of fractured core decreases sharply with an increase in effective confining pressure. The fracture flowrate ratio declines and the matrix flowrate ratio increases. Fracture flow will partially divert to the matrix block with the increase in effective confining pressure, improving gas displacement efficiency.
