Multiple fault diagnosis of down-hole conditions of sucker-rod pumping wells based on Freeman chain code and DCA

It is important to achieve continuous, stable and efficient pumping well operation in actual oilfield operation. Down-hole pumping well working conditions can be monitored in real-time and a reasonable production scheme can be designed when computer diagnosis is used. However, it is difficult to make a comprehensive analysis to supply efficient technical guidance for operation of the pumping well with multiple faults of down-hole conditions, which cannot be effectively dealt with by the common methods. To solve this problem, a method based on designated component analysis （DCA） is used in this paper. Freeman chain code is used to represent the down-hole dynamometer card whose important characteristics are extracted to construct a designated mode set. A control chart is used as a basis for fault detection. The upper and lower control lines on the control chart are determined from standard samples in normal working conditions. In an incompletely orthogonal mode, the designated mode set could be divided into some subsets in which the modes are completely orthogonal. The observed data is projected into each designated mode to realize fault detection according to the upper and lower control lines. The examples show that the proposed method can effectively diagnose multiple faults of down-hole conditions.

Effects of Driving Mode on the Performance of Multiple-Chamber Piezoelectric Pumps with Multiple Actuators

Due to the limited output capability of piezoelectric diaphragm pumps, the driving voltage is frequently increased to obtain the desired output. However, the excessive voltage application may lead to a large deformation in the piezoelectric ceramics, which could cause it to breakdown or become damaged. Therefore, increasing the number of chambers to obtain the desired output is proposed. Using a check-valve quintuple-chamber pump with quintuple piezoelectric actuators, the characteristics of the pump under different driving modes are investigated through experiments. By changing the number and connection mode of working actuators, pump performances in terms of flow rate and backpressure are tested at a voltage of 150 V with a frequency range of 60 Hz -400 Hz. Experiment results indicate that the properties of the multiple-chamber pump change significantly with distinct working chambers even though the number of pumping chambers is the same. Pump performance declines as the distance between the working actuators increases. Moreover, pump performance declines dramatically when the working piezoelectric actuator closest to the outlet is involved. The maximum backpressures of the pump with triple, quadruple, and quintuple actuators are increased by 39%, 83%, and 128%, respectively, compared with the pump with double working actuators; the corresponding maximum flow rates of the pumps are simply increased by 25.9%, 49.2%, and 67.8%, respectively. The proposed research offers practical guidance for the effective utilization of the multiple-chamber pumps under different driving modes.

Intra-acceptor hole relaxation in Be δ-doped GaAs/AlAs multiple quantum wells

This paper studies the dynamics of intra-acceptor hole relaxation in Be δ-doped GaAs/AlAs multiple quantum wells （MQW） with doping at the centre by time-resolved pump-probe spectroscopy using a picosecond free electron laser for infrared experiments. Low temperature far-infrared absorption measurements clearly show three principal absorption lines due to transitions of the Be acceptor from the ground state to the first three odd-parity excited states respectively. The pump-probe experiments are performed at different temperatures and different pump pulse wavelengths. The hole relaxation time from 2p excited state to ls ground state in MQW is found to be much shorter than that in bulk GaAs, and shown to be independent of temperature but strongly dependent on wavelength. The zone-folded acoustic phonon emission and slower decay of the wavefunctions of impurity states are suggested to account for the reduction of the 2p excited state lifetime in MQW. The wavelength dependence of the 2p lifetime is attributed to the diffusion of the Be atom δ-layer in quantum wells.

配置吸收式热泵的热电联产机组厂级智能运行优化

为提高配置吸收式热泵的热电联产机组的全厂运行经济性,基于案例电厂的运行历史数据,使用滑动窗口法进行数据预处理并提取稳态工况,建立配置吸收式热泵的热电联产机组煤耗预测数学模型。以全厂热电联产机组总煤耗最小为适应度函数,利用粒子群优化算法求解得出配置吸收式热泵的热电机组最佳背压和各台热电机组最佳抽汽量。基于以上研究设计了供热系统智能优化软件,实现供热系统在线监测与优化调节,对各供热单元分别提出优化指导,使机组运行经济性最佳,进而降低整体煤耗。计算结果表明:实行供热系统智能优化策略可为案例电厂供热系统平均每小时节省标准煤约1.81 t,节能效果显著。

深海钻探泥浆举升系统双泵协同机制研究

深海钻探泥浆举升系统在无隔水管泥浆循环钻井(RMR)工艺中具有关键作用。为了提升举升系统的安全余量和适应性,本文对多泵串并联机制进行了深入研究,详细描述了泥浆举升泵的串并联结构设计和工作原理,探讨了串联和并联运行时流量与扬程的关系以及泵组串并联工况点的数解法和图解法步骤。进一步地,利用模型泵实测特性曲线,使用图解法获取了双泵串并联工况下的Q-H特性曲线和工况点,并提出了双泵协同控制的建议。

胰岛素不同使用方式对小儿糖尿病患儿血糖水平的影响

目的分析胰岛素不同使用方式对小儿糖尿病患儿血糖水平的影响。方法回顾性选取2021年1月—2023年12月福建省晋江市医院收治的40例小儿糖尿病患儿的临床资料,根据不同治疗方式分为参照组(n=20,胰岛素多次皮下注射治疗)、观察组(n=20,胰岛素泵输注治疗),对比两组患儿血清炎性因子水平、血糖水平、临床指标。结果治疗前,两组血清炎性因子水平、血糖水平对比,差异无统计学意义(P均>0.05);治疗后,观察组的血清炎性因子水平、血糖水平低于参照组,差异有统计学意义(P均<0.05)。与参照组的临床指标对比,观察组胰岛素用量更少、餐后2 h血糖水平达标时间更早、住院时间更短,差异有统计学意义(P均<0.05)。两组临床治疗总有效率对比,差异无统计学意义(χ^(2)=2.057,P>0.05)。结论小儿糖尿病患儿治疗中选择胰岛素泵输注治疗,可降低患儿炎性因子水平,减少胰岛素用量,促使患儿血糖水平达标的同时,缩短住院时间,改善患儿血糖水平。

胰岛素泵与胰岛素多次注射对妊娠期糖尿病的治疗效果与安全性比较

目的探究胰岛素泵与胰岛素多次注射对妊娠期糖尿病患者的治疗效果与安全性。方法选取本院24例妊娠期糖尿病患者为研究对象,按照随机数字表法分为两组,各12例。多次注射组患者采取多次皮下注射胰岛素治疗,胰岛素泵组患者采取持续皮下胰岛素输注治疗。比较两组患者用药前后的血糖水平、用药期间低血糖发生率及妊娠结局。结果用药前,两组患者血糖水平比较差异无统计学意义(P>0.05)。用药后,胰岛素泵组患者的空腹血糖、餐后2h血糖、糖化血红蛋白水平明显低于多次注射组患者,差异有统计学意义(P<0.05)。两组患者胎膜早破发生率比较差异无统计学意义(P>0.05)。胰岛素泵组患者用药期间低血糖发生率低于多次注射组患者,自然分娩率高于多次注射组,差异有统计学意义(P<0.05)。结论相较于胰岛素多次注射给药,胰岛素泵给药能够有效控制妊娠期糖尿病患者的血糖水平,不良反应发生率更低,可以提高自然分娩率,具有较高的临床应用与推广价值。

抽水蓄能机组新型变工况自适应模糊控制策略

针对抽水蓄能机组工况之间频繁转换、常规比例-积分-微分控制(proportional-integral-derivative control,PID)控制对不同工况变化下适应性弱及现有的新型控制方法难以应用于实时性要求较高的可编程逻辑控制器(programmable logic controller,PLC)调速系统中等问题,同时考虑到导数分量易引入高频测量噪声。结合模糊控制理论,创新地提出了一种以水头和功率作为模糊推理输入变量的新型自适应模糊PI控制器(innovative adaptive fuzzy PI,IAFPI)。首先结合所设计的控制器建立了基于弹性水击和对数投影曲线法的抽水蓄能调节系统精细化模型;然后利用多目标粒子群算法(multiple objective particle swarm optimization,MOPSO)优化该模型的控制参数;最后结合我国某实际抽水蓄能电站数据,分别与传统PI、传统模糊PI控制在不同负荷不同水头下进行对比仿真试验;验证所设计的新型自适应模糊PI控制器可有效提高机组对工况变化的自适应性。

Generation and observation of multiple solitons from a mid-infrared ultrafast fiber laser

We demonstrate the generation of a unique regime of multiple solitons in a Tm-doped ultrafast fiber laser at~1938.72 nm.The temporal pulse-to-pulse separation among the multiple solitons,10 in a single-pulse bunch,increases from 0.89 ns to1.85 ns per round trip.In addition,with the increasing pump power,the number of bunched solitons increases from 3 up to 24linearly,while the average time separation in the soliton bunch varies irregularly between~0.80 and~1.52 ns.These results contribute to a more profound comprehension of nonlinear pulse dynamics in ultrafast fiber lasers.

LNG接收站高压泵方案探究与常见问题分析

高压泵是液化天然气(LNG)接收站重要的增压设施。为深入了解高压泵的设计要点,结合近年来LNG接收站工程的工艺路线,简要说明了高压泵的方案配置,并比较分析了不同工艺路线的区别和侧重点。介绍了高压泵的工作特点及市场供应情况。结合现有接收站的运行情况,总结归纳了几个与设计密切相关的典型性问题,并对其成因进行了分析。在设计和运行方面可以为后续的项目提供一些借鉴和参考。

复合多尺度注意熵在旋转机械多工况损伤识别中的应用

针对传统旋转机械损伤识别方法存在模型精度低和抗噪性差的问题,提出了一种基于复合多尺度注意熵(CMATE)和随机森林(RF)的旋转机械多工况损伤识别方法。首先,提出了一种新的测量时间序列复杂度的非线性动力学工具——复合多尺度注意熵;然后,利用CMATE提取旋转机械振动信号的损伤特征,其表征了旋转机械不同工况下的损伤特性;接着,将损伤特征输入至基于随机森林构造的多类别分类器中,进行了损伤识别;最后,采用滚动轴承-齿轮箱、齿轮箱和离心泵3种旋转机械数据集,并分别构造了9种工况和20种工况的多工况损伤数据集,对该损伤识别方法进行了实验研究。研究结果表明:该旋转机械损伤识别方法分别取得95%、97%和100%的识别准确率,在准确率和特征提取效率两方面优于其他的非线性动力学工具;并且在0 dB、1 dB、2 dB和3 dB这4种不同信噪比的噪声干扰下,依然取得了不错的损伤识别结果,证明了该模型具有可观的抗噪性;同时,该损伤识别方法能够稳定地识别旋转机械的不同负载和转速下的损伤,平均识别准确率分别达到了97.2%和93.5%,具有较好的实际应用潜力。

基于群井抽水试验的承压含水层水文参数反演分析

城市区域复杂环境条件下的深基坑工程往往涉及复杂的承压水处理问题,当承压含水层深度较大且采用悬挂帷幕结合坑内减压降水方案时,需合理评估承压水降水对周边环境的影响,而其关键是要确定合理的水文地质参数。本文结合位于长江漫滩地貌单元的某深基坑工程,在基坑实施前针对其深厚承压含水层开展了现场群井抽水试验,根据单井抽水试验的解析方法给出了初步的水文地质参数,在此基础上,建立了群井抽水试验的地下水渗流数值分析模型,基于反演分析确定了合理的水文地质参数,为分析基坑承压水降水对周边环境影响提供了直接依据。

皮下胰岛素泵与多次胰岛素皮下注射治疗2型糖尿病的效果对比

目的:探究皮下胰岛素泵与多次胰岛素皮下注射治疗2型糖尿病的效果。方法:选取新余市人民医院内分泌科2022年5月—2023年4月80例2型糖尿病患者,随机分为两组,各40例。对照组采用长效胰岛素+速效胰岛素一日多次胰岛素注射,研究组采用皮下胰岛素泵治疗。比较两组患者治疗前、治疗6 d后血糖控制情况、日均高血糖持续时间、日均血糖波动范围、治疗情况(低血糖发生率、胰岛素用量、控制血糖达标时间)。结果:治疗后两组各餐前与餐后2 h、睡前血糖水平与平均值均显著降低,差异均有统计学意义(P<0.05);但治疗前后两组各餐前与餐后2 h、睡前、血糖水平与平均值差异均无统计学意义(P>0.05);治疗前两组日均高血糖持续时间、日均血糖波动范围差异均无统计学意义(P>0.05),治疗后研究组日均高血糖持续时间、日均血糖波动范围均低于对照组,差异均有统计学意义(P<0.05);治疗后研究组低血糖发生率低于对照组,每天胰岛素用量少于对照组,控制血糖达标时间早于对照组,差异均有统计学意义(P<0.05)。结论:两种方法均能较好降低2型糖尿病患者血糖水平,但相较于多次胰岛素皮下注射,皮下胰岛素泵治疗可减少胰岛素用量,缩短血糖达标时间,降低低血糖发生率,并更好地控制血糖波动。

流动相在线混合模式和预混合模式对示差折光检测器的影响

目的:研究混合型流动相对不同品牌示差折光检测器造成的基线波动影响,提出改进和应对措施,为示差折光检测器及配套液相系统的使用提供参考和建议。方法:通过乙腈水70+30百分比作为流动相,利用不同品牌的示差折光检测器对葡萄糖进行测量,得出基线漂移、基线噪声、最小检测浓度、线性范围,考察示差折光检测器的性能。结果:通过预混合能降低流动相混合对示差折光检测器的干扰,但仍然会存在周期性的脉动干扰,使用泵后混合模式干扰最小。结论:示差折光检测器推荐使用多元泵后混合的配置,测量精度较高,如使用泵前混合,则应使用单并联式的输液泵,降低干扰,提高精度。

不同胰岛素法治疗1型糖尿病患儿酮症酸中毒的临床效果

目的探讨胰岛素多次和持续注射治疗1型糖尿病患儿酮症酸中毒的临床效果。方法选取2021年4月—2023年4月淄博市妇幼保健院收治的82例1型糖尿病酮症酸中毒患儿为研究对象,根据不同治疗方法分为两组,各41例,对照组采用胰岛素多次皮下注射,观察组采用胰岛素泵皮下持续注射,比较两组血糖水平(空腹血糖、餐后2 h血糖、糖化血红蛋白)、恢复时间(血糖达标、血酮恢复、尿酮体转阴及血pH值恢复时间)、胰岛素用量及不良事件。结果治疗3个月、6个月后,两组空腹血糖、餐后2 h血糖、糖化血红蛋白均降低,且观察组均低于对照组,差异有统计学意义(P均<0.05)。观察组血糖达标、血酮恢复、尿酮体转阴及血pH值恢复时间均短于对照组,胰岛素用量少于对照组,差异有统计学意义(P均<0.05)。观察组不良事件发生率为4.88%(2/41),低于对照组的21.95%(9/41),差异有统计学意义(P<0.05)。结论1型糖尿病酮症酸中毒患儿采取胰岛素泵皮下持续注射可促进血糖恢复正常,促进血酮、尿酮、pH值快速恢复,而且胰岛素用量少,不良事件少,提高安全性。

冷凝热回收地源热泵系统运行仿真研究

根据经验模型与样本数据在TRNSYS平台上建立开发了冷凝热回收地源热泵系统仿真模型,以夏热冬冷地区的上海市宾馆建筑为例,利用开发模型研究了冷凝热回收地源热泵系统长期运行的效益。仿真计算结果表明,与传统地源热泵+燃气锅炉系统相比,冷凝热回收地源热泵系统中长期运行能保持土壤温度稳定,土壤温升减少了76%,运行20年一次能源标准煤消耗量减少10%,冷凝热回收改造动态投资回收期为4年,具有更好的稳定运行与环保节能效益。

六边形变换器在全功率抽水蓄能系统中的应用研究

在抽水蓄能系统中,可调速机组可以适应更宽的水头范围,提高机组运行效率。六边形变换器(Hexverter)作为一种高压大容量变换器,可以解决目前变速抽水蓄能系统中变流装置容量小、能量转换效率低以及调速慢等问题。本文提出了基于六边形变换器的全功率抽水蓄能控制系统,对六边形变换器的一般数学模型进行了分析,提出的基于网侧和机侧两种频率的多重解耦控制策略可以实现网侧和机侧功率的控制以及机侧输出电压电流频率灵活可调,基于零序网络的桥臂直流电压平衡控制策略可以实现桥臂直流均压。最后通过仿真和实验验证了六边形变换器在全功率抽蓄系统的应用的有效性。

Study on Dynamic Characteristics of Hydraulic Pumping Unit on Offshore Platform

A new technology of offshore oil rod pumping production is developed for offshore heavy oil recovery. A new type of miniature hydraulic pumping unit with long-stroke, low pumping speed and compact structure is designed based on the spatial characteristics of offshore platforms. By combining the strengths of sinusoidal velocity curve and trapezoidal velocity curve, a kinematical model of the acceleration, the velocity and displacement of the pumping unit＇s hanging point is established. The results show that the pumping unit has good kinematic characteristics of smooth motion and small dynamic load. The multi-degree-of-freedom dynamic model of the single-well pumping unit is established. The first and second order natural frequencies of the sucker rod string subsystem and the pumping unit subsystem are studied. The results show that the first and the second order natural frequencies among the pumping rod string, pumping unit-platform subsystem and the dynamic excitation have differences over 5 times from each other, indicating that resonance phenomenon will not appear during the operation and the dynamic requirements for field use are met in the system.

Bubble Pump Models Verification Based on the Experimental Results

DAR （diffusion absorption refrigeration） cycle is driven by heat and has no moving parts. It is based on refrigerant and absorbent as the working fluid together with hydrogen as an auxiliary inert gas. To circulate the working fluid without a mechanical pump, the diffusion absorption cycle relies on a bubble pump. Experimental system was designed and operated. Its aim was to investigate the performance of a bubble pump operating with three lifting tubes. The experimental results of the system were compared to existing models. The comparison showed that there was a bad agreement between the experimental and the theoretical results.

Ultrafast optical beam deflection in a pump probe configuration

Propagation of a signal beam in an Al Ga As/Ga As waveguide multiple-prism light deflector is theoretically investigated by solving the scalar Helmholtz equation to obtain the dependences of the temporal and spatial resolvable characteristics of the ultrafast deflector on the material dispersion of Ga As including group velocity dispersion and angular dispersion,interface reflection,and interface scattering of multiple-prism deflector.Furthermore,we experimentally confirm that,in this ultrafast beam deflection device,the deflecting angle of the signal light beam is linear with the pump fluence and the temporal resolution of the ultrafast deflection is 10 ps.Our results show that the improvement of the temporal and spatial resolvable performances is possible by properly choosing the structural parameters and enhancing the quality of the device.