An improved whole model of beam pumping system was built. In the detail, for surface transmission system(STS), a new mathematical model was established considering the influence of some factors on the STS's torsio...An improved whole model of beam pumping system was built. In the detail, for surface transmission system(STS), a new mathematical model was established considering the influence of some factors on the STS's torsional vibration, such as the time variation characteristic of equivalent stiffness of belt and equivalent rotational inertia of crank. For the sucker rod string(SRS), an improved mathematical model was built considering the influence of some parameters on the SRS's longitudinal vibration, such as the nonlinear friction of plunger, hydraulic loss of pump and clearance leakage. The dynamic response and system efficiency of whole system were analyzed. The results show that there is a jumping phenomenon in the amplitude frequency curve, and the system efficiency is sensitive to motor power, pump diameter, stroke number, ratio of gas and oil, and submergence depth. The simulation results have important significance for improving the efficiency of beam pumping system.展开更多
The mathematical model of dynamic loads was developed based on an analysis of the polished rod load of beam pumps, and the variation of the dynamic loads and the computation of the minimum and maximum limits during a ...The mathematical model of dynamic loads was developed based on an analysis of the polished rod load of beam pumps, and the variation of the dynamic loads and the computation of the minimum and maximum limits during a complete pumping cycle were given out by solving the model.Field examples verify that it is necessary to take into account the inertial and vibration loads while calculating polished rod loads.During the prophase of the pumping production, the dynamic to polished rod load ratio is relatively large.Then the ratio decreases rapidly and becomes small after entering stable production.Moreover, the total deformation of rod and tubing in CBM wells is much smaller than that in oil fields, and the deformation caused by the dynamic loads is also relatively small.The result of this work is the calculation of the dynamic loads.The application of this calculation for the sucker rod pumping system in CBM wells can give the desired accuracy of polished rod load and the dynamometer cards, which provides a reasonable basis for the design and selection of beam pumps.展开更多
A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an import...A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an important factor that limits the long-term frequency stability. We minimize the drift of the light angle by using a fiber- coupled output, and lock the frequency of a distributed-feedback diode laser to the fluorescence spectrum of the atomic beam. The measured frequency stability is about 3.5 ×10^-11 at i s and reaches 1.5 × 10^-12 at 2000s. The Allan variance keeps going down for up to thousands of seconds, indicating that the medium- and long-term stability of the laser frequency is significantly improved and perfectly fulfills the requirement for the optical pumping cesium clock.展开更多
Because the load of the oil beam pumping unit driven by pure electric motor changes sharply during operation,the power of the driving motor does not match and the energy efficiency is low.In this paper,a new type of w...Because the load of the oil beam pumping unit driven by pure electric motor changes sharply during operation,the power of the driving motor does not match and the energy efficiency is low.In this paper,a new type of wind-driven hydro-motor hybrid power system is proposed.The motor and the hydraulic motor are jointly driven,and the energy is recovered by a hydraulic pump with controllable displacement,so that the speed of the driving motor is relatively stable.In order to control the fan speed and keep up with the drastic changes of the outside wind speed,a control strategy of hybrid power system based on wind speed feed-forward compensation is proposed.Through simulation and experimental results,the following conclusions can be drawn:to begin with,the mathematic model is proved to be effective;next,simulation studies show that the proposed feed-forward control method can improve the response rate as well as reduce the response lag.This research can be a reference for the application of the feed-forward control method on the hybrid power system of beam pumping unit.system.展开更多
由于煤层气井抽水机电动机负荷的动态交变特性,导致抽水机电动机周期性运行于电动和发电状态,造成电能严重浪费。为解决这一问题,结合抽水机负载及悬点运动规律,提出一种基于变频器变频-恒频分段协调工作的抽水机电动机节能控制新策略...由于煤层气井抽水机电动机负荷的动态交变特性,导致抽水机电动机周期性运行于电动和发电状态,造成电能严重浪费。为解决这一问题,结合抽水机负载及悬点运动规律,提出一种基于变频器变频-恒频分段协调工作的抽水机电动机节能控制新策略。该控制策略取消了抽水机按上下冲程划分运行区间的做法,将运行区间重新划分为变频段和恒频段;在变频段改变抽水机电动机工作频率,将抽水机负荷端势能转化为动能,抽水机依靠自身能量转化运行,电动机不做功;在恒频段电动机工作于电动状态,驱动抽水机工作,此时电能转化为机械能。在现场以一台YVP180L-8,11 k W感应电机及其驱动的CYJY4-1.5-9 HB型煤层气井抽水机作为试验平台,对变频、恒频以及提出的变频-恒频分段节能控制策略进行综合节能情况对比。现场实测结果表明:所提控制策略会使抽水机运动和负荷特性发生改变;同时该控制策略能够有效解决能量回馈问题,避免能量回馈电机,较其他两种控制策略系统节电率提高10%;该控制策略具有较强通用性,为煤层气抽采系统节能降耗提供了新的研究思路和角度。展开更多
基金Projects(50974108,51174175) supported by the National Natural Science Foundation of China
文摘An improved whole model of beam pumping system was built. In the detail, for surface transmission system(STS), a new mathematical model was established considering the influence of some factors on the STS's torsional vibration, such as the time variation characteristic of equivalent stiffness of belt and equivalent rotational inertia of crank. For the sucker rod string(SRS), an improved mathematical model was built considering the influence of some parameters on the SRS's longitudinal vibration, such as the nonlinear friction of plunger, hydraulic loss of pump and clearance leakage. The dynamic response and system efficiency of whole system were analyzed. The results show that there is a jumping phenomenon in the amplitude frequency curve, and the system efficiency is sensitive to motor power, pump diameter, stroke number, ratio of gas and oil, and submergence depth. The simulation results have important significance for improving the efficiency of beam pumping system.
基金Supported by the National Science and Technology Special Project of China(2008ZX05038-004)Shandong Province Science and Technology Development Project(2009GG10007008)
文摘The mathematical model of dynamic loads was developed based on an analysis of the polished rod load of beam pumps, and the variation of the dynamic loads and the computation of the minimum and maximum limits during a complete pumping cycle were given out by solving the model.Field examples verify that it is necessary to take into account the inertial and vibration loads while calculating polished rod loads.During the prophase of the pumping production, the dynamic to polished rod load ratio is relatively large.Then the ratio decreases rapidly and becomes small after entering stable production.Moreover, the total deformation of rod and tubing in CBM wells is much smaller than that in oil fields, and the deformation caused by the dynamic loads is also relatively small.The result of this work is the calculation of the dynamic loads.The application of this calculation for the sucker rod pumping system in CBM wells can give the desired accuracy of polished rod load and the dynamometer cards, which provides a reasonable basis for the design and selection of beam pumps.
基金Supported by the National Fundamental Research Program of China under Grant No 2011CB921501the National Natural Science Foundation of China under Grant Nos 91336103,10934010 and 61078026
文摘A method is presented to improve the laser frequency stabilization for the optical pumping cesium clock. By comparing the laser frequency stabilization of different schemes, we verify that the light angle is an important factor that limits the long-term frequency stability. We minimize the drift of the light angle by using a fiber- coupled output, and lock the frequency of a distributed-feedback diode laser to the fluorescence spectrum of the atomic beam. The measured frequency stability is about 3.5 ×10^-11 at i s and reaches 1.5 × 10^-12 at 2000s. The Allan variance keeps going down for up to thousands of seconds, indicating that the medium- and long-term stability of the laser frequency is significantly improved and perfectly fulfills the requirement for the optical pumping cesium clock.
基金This project was supported by the Science Research Foundation of Inner Mongolia University for the nationalities grant no.NMDGP1704 the Inner Mongolia nature Science Foundation(grant no.2016MS0622)National nature Science Foundation grant no.51865046Science and technology innovation leading project of Inner Mongolia grant no.KCBJ2018028。
文摘Because the load of the oil beam pumping unit driven by pure electric motor changes sharply during operation,the power of the driving motor does not match and the energy efficiency is low.In this paper,a new type of wind-driven hydro-motor hybrid power system is proposed.The motor and the hydraulic motor are jointly driven,and the energy is recovered by a hydraulic pump with controllable displacement,so that the speed of the driving motor is relatively stable.In order to control the fan speed and keep up with the drastic changes of the outside wind speed,a control strategy of hybrid power system based on wind speed feed-forward compensation is proposed.Through simulation and experimental results,the following conclusions can be drawn:to begin with,the mathematic model is proved to be effective;next,simulation studies show that the proposed feed-forward control method can improve the response rate as well as reduce the response lag.This research can be a reference for the application of the feed-forward control method on the hybrid power system of beam pumping unit.system.
文摘由于煤层气井抽水机电动机负荷的动态交变特性,导致抽水机电动机周期性运行于电动和发电状态,造成电能严重浪费。为解决这一问题,结合抽水机负载及悬点运动规律,提出一种基于变频器变频-恒频分段协调工作的抽水机电动机节能控制新策略。该控制策略取消了抽水机按上下冲程划分运行区间的做法,将运行区间重新划分为变频段和恒频段;在变频段改变抽水机电动机工作频率,将抽水机负荷端势能转化为动能,抽水机依靠自身能量转化运行,电动机不做功;在恒频段电动机工作于电动状态,驱动抽水机工作,此时电能转化为机械能。在现场以一台YVP180L-8,11 k W感应电机及其驱动的CYJY4-1.5-9 HB型煤层气井抽水机作为试验平台,对变频、恒频以及提出的变频-恒频分段节能控制策略进行综合节能情况对比。现场实测结果表明:所提控制策略会使抽水机运动和负荷特性发生改变;同时该控制策略能够有效解决能量回馈问题,避免能量回馈电机,较其他两种控制策略系统节电率提高10%;该控制策略具有较强通用性,为煤层气抽采系统节能降耗提供了新的研究思路和角度。
