折皱式防砂筛管过流性能测试及评价方法

常规防砂方法在复杂生产条件下极易被储层砂堵塞,从而显著降低其过流性能,为此,研制了折皱式(ZZS)防砂筛管。通过设计开展物模评价试验,将现场典型应用井位生产数据与常规筛管进行对比,论证了ZZS筛管在不同复杂生产条件下的过流性能。试验结果表明:新型折皱式防砂筛管过滤面积大,其筛网材料用量为常规优质筛管的4倍以上,可在一定程度上降低筛网堵塞对过流性能的不利影响,从而有效提高井筒供液能力;在高产液量、稠油、致密砂岩、砂岩粒度不均等复杂工况下,ZZS筛管的过流性能优于金属毡筛管,更优于配合砾石充填的绕丝筛管。研究结果可以为油田区块新型防砂技术的推广应用提供重要指导。

紧急切断阀过流性能检测装置的研制

文章介绍了紧急切断阀过流性能检测装置的总体设计方案,解决了紧急切断阀的自动夹紧的关键问题和人工读取试验结果的误差问题。通过本装置,能够实现紧急切断阀密封性能、耐压性能和过流性能试验。电脑检测系统自动记录相关试验数据,自动判断其性能是否符合有关标准要求并打印出报告,有效地提高紧急切断阀检验结果的准确性。

紧急切断阀过流性能检测装置的研制

本文介绍了紧急切断阀过流性能检测装置的总体设计方案,解决了紧急切断阀的自动夹紧的关键问题和人工读取试验结果的误差问题。通过本装置,能够实现紧急切断阀密封性能、耐压性能和过流性能试验。电脑检测系统自动记录相关试验数据,自动判断其性能是否符合有关标准要求并打印出报告,有效地提高紧急切断阀检验结果的准确性。

形状记忆膨胀颗粒防砂材料性能评价

针对油气井开采过程中的出砂问题,提出采用温敏性形状记忆聚合物材料填充射孔孔道的新型防砂方法,以达到简化施工程序、降低防砂成本和延长防砂有效期的目的。优选形状记忆聚氨脂泡沫作为原料,加工成粒径3~6 mm的不规则颗粒,并在颗粒外表面涂覆环氧树脂和固化剂,制备成膨胀颗粒防砂材料,试验评价了该防砂材料的膨胀性能、耐温性能、抗压强度、过流性能、挡砂性能和耐介质性能。试验结果表明:该防砂材料在温度60~70℃下开始膨胀,最高适应温度90℃;膨胀系数200%,在约束空间中膨胀胶结后可形成整体硬质挡砂屏障,抗压强度4.5 MPa,渗透率90 D,可阻挡粒径大于0.15 mm的地层砂;其过流性能和抗堵塞能力明显高于树脂涂覆砂防砂材料。该防砂材料防砂形成的挡砂屏障具有高渗透、高强度和抗堵塞的特点,利用该材料防砂具有成本低、施工简单和不留管柱等优点,具有很好的推广应用价值。

卧式污水叶轮泵水力优化设计及机械密封改进

设计了一款卧式污水叶轮泵,具有可自吸、无须持续引流、抗堵塞性强以及密封性好等特点。通过叶轮高速旋转产生的离心力带动污水进入泵体,将动能转化为静压能,使污水以较高的压力流向排出管道。工作前只需要保持泵体内储存有一定量引液,即可实现一次引流、长期自吸的功能。分析叶片数、叶轮出口宽度对污水泵的过流性能影响,参考经验公式和经验参数,优化叶轮的水力设计,提升抗堵塞性。此外,设置一对动环和静环紧密贴合组成密封面,在流体压力、弹簧弹力作用以及辅助密封圈的配合下,保持贴合并相对滑动,构成端面密封,防止泄漏。通过叶轮水力的优化设计,使得固体悬浮物通过性约为15.70%,工作效率约为66.19%,可以满足一般的污水处理需求。

景洪水力式升船机流量控制阀门比选

水力式升船机通过控制水流实现对升船机运行特性的控制,流量控制阀是水力式升船机的重要控制设备。结合景洪水力式升船机的水力学特性,比较了蝶阀、球阀及活塞阀的抗气蚀性能及过流能力,通过比较选择活塞阀作为流量控制阀。根据水力式升船机上下游对接精度要求高、空中运行要求快的特点,对流量控制阀的多种组合方案进行比选,创新提出了主辅阀门控制方案,辅阀小流量主要负责上下游对接,主阀大流量主要负责升船机空中运行,最终确定1台E型活塞阀为主阀、2台SZ型活塞阀为辅阀的阀门组合设计方案。景洪水力式升船机已正式投入试运行,流量控制阀设计方案经受了工程实际检验,研究成果可供类似工程参考。

Experimental and CFD Studies on the Performance of Microfiltration Enhanced by a Turbulence Promoter

This paper reports experimental and computational fluid dynamics(CFD) studies on the performance of microfiltration enhanced by a helical screw insert.The experimental results show that the use of turbulence pro-moter can improve the permeate flux of membrane in the crossflow microfiltration of calcium carbonate suspension,and flux improvement efficiency is strongly influenced by operation conditions.The energy consumption analysis indicates that the enhanced membrane system is more energy saving at higher feed concentrations.To explore the intrinsic mechanism of flux enhancement by a helical screw insert,three-dimensional CFD simulation of fluid flow was implemented.It reveals that hydrodynamic characteristics of fluid flow inside the channel are entirely changed by the turbulence promoter.The rotational flow pattern increases the scouring effect on the tube wall,reducing the particle deposition on the membrane surface.The absence of stagnant regions and high wall shear stress are respon-sible for the enhanced filtration performance.No secondary flow is generated in the channel,owing to the streamline shape of helical screw insert,so that the enhanced performance is achieved at relatively low energy consumption.

Convective Heat Transfer Enhancement of a Rectangular Flat Plate by an Impinging Jet in Cross Flow

Experiments were carried out to study the heat transfer performance of an impinging jet in a cross flow.Several parameters including the jet-to-cross-flow mass ratio(X=2%-8%), the Reynolds number(Red=1434-5735)and the jet diameter(d=2-4 mm) were explored. The heat transfer enhancement factor was found to increase with the jet-to-cross-flow mass ratio and the Reynolds number, but decrease with the jet diameter when other parameters maintain fixed. The presence of a cross flow was observed to degrade the heat transfer performance in respect to the effect of impinging jet to the target surface only. In addition, an impinging jet was confirmed to be capable of enhancing the heat transfer process in considerable amplitude even though the jet was not designed to impinge on the target surface.

Mechanism of Downcutting Erosion of Debris Flow over a Movable Bed

The phenomenon of debris flow is intermediate between mass movement and solid transport. Flows can be sudden, severe and destructive. Understanding debris flow erosion processes is the key to providing geomorphic explanations, but progress has been limited because the physical-mechanical properties, movement laws and erosion characteristics are different from those of sediment-laden flow. Using infinite slope theory, this research examines the process and mechanism of downcutting erosion over a moveable bed in a viscous debris flow gully. It focuses specifically on the scour depth and the critical slope for viscous debris flow,and formulas for both calculations are presented.Both scour depth and the critical conditions of downcutting erosion are related to debris flow properties(sand volume concentration and flow depth) and gully properties(longitudinal slope,viscous and internal friction angle of gully materials,and coefficient of kinetic friction). In addition, a series of flume experiments was carried out to characterize the scouring process of debris flows with different properties. The calculated values agreed well with the experimental data. These theoretical formulas are reasonable, and using infinite slope theory to analyze down cutting erosion from viscous debris flow is feasible.

Calculation of terminal velocity in transitional flow for spherical particle

The terminal velocity has been widely used in extensive fields, but the complexity of drag coefficient expression leads to the calculation of terminal velocity in transitional flow （1 〈 Re ≤ 1000） with much more difficulty than those in laminar flow （Re ≤ 1） and turbulent flow （Re ≥ 1000）. This paper summarized and compared 24 drag coefficient correlations, and developed an expression for calculating the terminal velocity in transitional flow, and also analyzed the effects of particle density and size, fluid density and viscosity on terminal velocity. The results show that 19 of 24 previously published correlations for drag coefficient have good prediction performance and can be used for calculating the terminal velocity in the entire transitional flow with higher accuracy. Adapting two dimensionless parameters （w＊, d＊）, a proposed explicit correlation, w＊=-25.68654 × exp （-d＊/77.02069）＋ 24.89826, is attained in transitional flow with good performance, which is helpful in calculating the terminal velocity.

基于毛蚶表面形态的渣浆泵仿生蜗壳耐磨特性研究

为了提高渣浆泵的使用寿命,研究其过流件的耐磨性能十分重要。蜗壳是影响渣浆泵寿命的主要过流件,为了提高蜗壳的耐磨性能,采用仿生技术,借鉴毛蚶表面形态,对渣浆泵蜗壳的耐磨特性进行了研究,开展了渣浆泵蜗壳的仿生设计工作。首先,基于毛蚶表面形态,设计了具有凸起条纹和凹槽的仿生结构;然后,基于DPM模型,引入了McLaury磨损预测模型,建立了渣浆泵固液两相流仿真模型;最后,分析了普通蜗壳与仿生蜗壳的壁面磨损情况、泵内颗粒速度及颗粒分布、泵内流场速度与压力分布。研究结果表明:渣浆泵扬程模拟结果与实验结果误差小于8%,固液两相流仿真模型具有较高精度;仿生蜗壳壁面平均磨损量减小了43.9%,最大磨损量减小了64.6%,仿生蜗壳平均磨损量和最大磨损量均大幅减小;仿生蜗壳的严重磨损区域明显减小,蜗壳螺旋室的磨损更加均匀,仿生设计对蜗壳减磨具有积极意义。仿生结构改变了颗粒-壁面碰撞后的运动方向,使颗粒在蜗壳螺旋室内均匀分布,从而减小了严重磨损区域;同时,仿生蜗壳有利于蜗壳输送颗粒,颗粒更易被流体带走,减少了颗粒停留时间,从而降低了壁面磨损。蜗壳耐磨仿生设计可以为渣浆泵过流件耐磨和延寿提供设计参考和理论依据。

An Experimental Investigation on Heat Transfer Performance of Nanofluid Pulsating Heat Pipe

The effect of SiO2 particles on heat transfer performance of a pulsating heat pipe （PHP） was investigated experi- mentally. DI water was used as the base fluid and contrast medium for the PHP. In order to study and measure the character, there are SiO2/H20 nanofluids with different concentration and applying with various heating powers during the experiment investigation. According to the experimental result, the high fraction of SiO2/H20 will de- teriorate the performance of PHP compared with DI water, i.e. the thermal resistance and the temperature of evaporation section increases. It is in contrary in the case of low fraction of SiO2/H20. Finally, the comparison of the thermal performances between the normal operation system and the static settlement system is given. It is found that both the thermal resistance of nanofluid PHP and the temperature of the evaporation section increase after standing for a period, and it is the same trend for the temperature fluctuation at the identical heating power for PHP.

Performance Analyses for a Cyclone Type Filter

Flow characteristics inside a cyclone filter were investigated by the use of computational fluid dynamics(CFD). For computations, SST model was adopted. Parametric study was carried out considering the filtering performance. Revolution speeds were changed from 100 to 550 with 50 increments. A skirt is the driving source for cyclone operation. The influence of several design factors, such as the skirt length, the skirt gap and the return length to filtering performance was investigated under the particle diameter 100μm of debris material(Al, s.g.=2.7). The filtering performance was also investigated with the skirt length 28 mm changing the debris diameters from 1μm to 50μm. The flow rate of the working fluid was maintained at 0.55kg/s. It has been verified that the most influential factors to the filtering efficiencies was the skirt gap between the cyclone generator and the cyclone vessel.