Based on the momentum theorem, the fluid governing equation in a lifting pipe is proposed by use of the method combining theoretical analysis with empirical correlations related to the previous research, and the perfo...Based on the momentum theorem, the fluid governing equation in a lifting pipe is proposed by use of the method combining theoretical analysis with empirical correlations related to the previous research, and the performance of an airlift pump can be clearly characterized by the triangular relationship among the volumetric flux of air, water and solid particles, which are obtained respectively by using numerical calculation. The meso-scale river sand is used as tested particles to examine the theoretical model. Results of the model are compared with the data in three-phase flow obtained prior to the development of the present model, by an independent experimental team that used the physical conditions of the present approach. The analytical error can be controlled within 12% for predicting the volumetric flux of water and is smaller than that （±16%） of transporting solid particles in three-phase flow. The experimental results and computations are in good agreement for air-water two-phase flow within a margin of ±8%. Reasonable agreement justifies the use of the present model for engineering design purposes.展开更多
为研究涡街流量计在管道周期振动情况下的抗振性能,对国内广泛应用的应力式模拟涡街流量计,在气体流量管道周期振动试验装置上进行了不同振动加速度和方向的试验.通过对振动产生仪表系数相对误差的研究,得出模拟涡街流量计的抗振加速度...为研究涡街流量计在管道周期振动情况下的抗振性能,对国内广泛应用的应力式模拟涡街流量计,在气体流量管道周期振动试验装置上进行了不同振动加速度和方向的试验.通过对振动产生仪表系数相对误差的研究,得出模拟涡街流量计的抗振加速度,并分析了此时涡街流量传感器输出信号的品质特征.最后,为与模拟涡街作比较,对横河和ABB公司生产的数字涡街流量计进行了相同的管道周期振动试验,研究了数字涡街的抗振性能,并发现振动倍频信号是导致仪表系数相对误差出现的主要原因.
Abstract：
To study the pipeline periodic vibration influence on the anti-vibration performance of vortex flowmeters,some experiments under different vibrating accelerations and directions have been carried out on the application-specific pipe periodic vibrating facility. The analog vortex flowmeter based on piezoelectric effect is tested firstly and its meter coefficient relative error caused by vibrations is investigated. Then the anti-vibrating acceleration is obtained and the signal quality of the vortex flow sensor is analyzed as well. Finally, in comparison with the analog vortex flowmeter, the same pipeline periodic vibration experiments are performed on the digital vortex flowmeter products of Yokogawa and ABB. The anti-vibration performances of digital vortex flowmeters are studied and it is found that multiple frequency of pipe vibration is the main reason of their meter coefficient relative errors.展开更多
基于计算流体力学(computational fluid dynamics,CFD)理论,采用块划分网格、滑移网格与用户自定义程序(user defined function,UDF)等技术,结合流体体积函数(volume of fluid,VOF)两相流模型与RNG湍流模型对喷嘴摆动、分流器固定式换...基于计算流体力学(computational fluid dynamics,CFD)理论,采用块划分网格、滑移网格与用户自定义程序(user defined function,UDF)等技术,结合流体体积函数(volume of fluid,VOF)两相流模型与RNG湍流模型对喷嘴摆动、分流器固定式换入换出不同向型换向装置换向过程实现仿真,所用网格划分方案具有网格数量少、网格质量高等特点,仿真分析换向装置换向过程喷嘴内部水流流场变化对换向流量误差的影响。结果表明:在换向装置运动重复性一致、流量表计时器计时启动延迟一致、换入时间与换出时间相同条件下,换向过程中喷嘴内部水流流场变化造成换向流量相对误差达0.002 5%。展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.51374101 and 51474158)the National Basic Research Program of China(973 Program,Grant No.2014CB239203)the Scientific Research Project of Education Department of Hunan Province(Grant No.14B047)
文摘Based on the momentum theorem, the fluid governing equation in a lifting pipe is proposed by use of the method combining theoretical analysis with empirical correlations related to the previous research, and the performance of an airlift pump can be clearly characterized by the triangular relationship among the volumetric flux of air, water and solid particles, which are obtained respectively by using numerical calculation. The meso-scale river sand is used as tested particles to examine the theoretical model. Results of the model are compared with the data in three-phase flow obtained prior to the development of the present model, by an independent experimental team that used the physical conditions of the present approach. The analytical error can be controlled within 12% for predicting the volumetric flux of water and is smaller than that （±16%） of transporting solid particles in three-phase flow. The experimental results and computations are in good agreement for air-water two-phase flow within a margin of ±8%. Reasonable agreement justifies the use of the present model for engineering design purposes.
文摘为研究涡街流量计在管道周期振动情况下的抗振性能,对国内广泛应用的应力式模拟涡街流量计,在气体流量管道周期振动试验装置上进行了不同振动加速度和方向的试验.通过对振动产生仪表系数相对误差的研究,得出模拟涡街流量计的抗振加速度,并分析了此时涡街流量传感器输出信号的品质特征.最后,为与模拟涡街作比较,对横河和ABB公司生产的数字涡街流量计进行了相同的管道周期振动试验,研究了数字涡街的抗振性能,并发现振动倍频信号是导致仪表系数相对误差出现的主要原因.
Abstract：
To study the pipeline periodic vibration influence on the anti-vibration performance of vortex flowmeters,some experiments under different vibrating accelerations and directions have been carried out on the application-specific pipe periodic vibrating facility. The analog vortex flowmeter based on piezoelectric effect is tested firstly and its meter coefficient relative error caused by vibrations is investigated. Then the anti-vibrating acceleration is obtained and the signal quality of the vortex flow sensor is analyzed as well. Finally, in comparison with the analog vortex flowmeter, the same pipeline periodic vibration experiments are performed on the digital vortex flowmeter products of Yokogawa and ABB. The anti-vibration performances of digital vortex flowmeters are studied and it is found that multiple frequency of pipe vibration is the main reason of their meter coefficient relative errors.
文摘基于计算流体力学(computational fluid dynamics,CFD)理论,采用块划分网格、滑移网格与用户自定义程序(user defined function,UDF)等技术,结合流体体积函数(volume of fluid,VOF)两相流模型与RNG湍流模型对喷嘴摆动、分流器固定式换入换出不同向型换向装置换向过程实现仿真,所用网格划分方案具有网格数量少、网格质量高等特点,仿真分析换向装置换向过程喷嘴内部水流流场变化对换向流量误差的影响。结果表明:在换向装置运动重复性一致、流量表计时器计时启动延迟一致、换入时间与换出时间相同条件下,换向过程中喷嘴内部水流流场变化造成换向流量相对误差达0.002 5%。
