Research on Capture Performance of an Induction Type Microplastics Recovery Device

Microplastic wastes in ocean can include the harmful chemical material, and the harmful material is concentrated by marine species. The separation and collecting methods of microplastics in ocean are researched in the world. The authors proposed the microplastics recovery device composed of the plates. Besides, the device consists of the tilted inlet/outlet and the horizontal part. In the water flow such as the tidal and ocean currents, the microplastics can be extracted from the main flow due to the vortex flow generated at the inner part of this device. In this research, the effects of the flow velocity and the inlet/outlet tilt angle on the capture performance were investigated experimentally and numerically. In the numerical simulations using the discrete phase model, the tilt angle was changed in a range between 30 degrees and 150 degrees in increments of 15 degrees, and the particle tracks of plastics were derived in steady condition. On the other hand, the capture performances in three cases of tilt angle 45 degrees, 120 degrees and 150 degrees were compared by circulation type water channel tests in which the plastics denser than the water were swept away 30 times every flow velocity. As the result, it seems that the tilt angle of 120 degrees is suitable for the wide range of the flow velocity in river and ocean.

Struvite Recovery from Swine Waste Biogas Digester Effluent through a Stainless Steel Device under Constant pH Conditions

Objective To investigate the struvite precipitation under constant and non-constant pH conditions and to test a stainless steel device under different operating regimes to maximize the recovery of struvite. Methods The molar ratio of NH4^＋： Mg^2＋ PO43 was adjusted to 1： 1.2：1.2 and pH was elevated to 9.0. The absorbance measurement was used to trace the process of struvite crystallization. Wastewater and precipitate analysis was done by standard analytical methods. Results The pH constant experiment reported a significantly higher struvite precipitation （24.6±0.86 g） than the non-constant pH experiment （19.8±1.86 g）. The SAR ranged from 5.6 to 8.2 g m^-2h^-1 to 3.6-4.8 g m^-2h^-1 in pH constant and non-constant experiments, respectively. The highest struvite deposit on the device was found in regime 3 followed by in regimes 2 and 4. The highest PO4^3- （97.2%） and NH4^＋ （71%） removal was reported in the R1 regime. None of the influent Cu^2＋ or Zn^2＋ was precipitated on the device. Conclusion A higher struvite yield is evident in pH constant experiments. Moreover, the stainless steel device facilitates the isolation of heavy metal free pure （around 96%） struvite from swine waste biogas digester effluent contaminated with Cu^2＋ and Zn^2＋ and the highest yield is attainable with the device operating at 50 rpm with agitation by a magnetic stirrer.

Variants of Secondary Control with Power Recovery for Loading Hydraulic Driving Device

Current high power load simulators are generally incapable of obtaining both high loading performance and high energy efficiency. Simulators with high energy efficiency are used to simulate static-state load, and those with high dynamic performance typically have low energy efficiency. In this paper, the variants of secondary control（VSC） with power recovery are developed to solve this problem for loading hydraulic driving devices that operate under variable pressure, unlike classical secondary control（CSC） that operates in constant pressure network. Hydrostatic secondary control units are used as the loading components, by which the absorbed mechanical power from the tested device is converted into hydraulic power and then fed back into the tested system through 4 types of feedback passages（FPs）. The loading subsystem can operate in constant pressure network, controlled variable pressure network, or the same variable pressure network as that of the tested device by using different FPs. The 4 types of systems are defined, and their key techniques are analyzed, including work principle, simulating the work state of original tested device, static operation points, loading performance, energy efficiency, and control strategy, etc. The important technical merits of the 4 schemes are compared, and 3 of the schemes are selected, designed, simulated using AMESim and evaluated. The researching results show that the investigated systems can simulate the given loads effectively, realize the work conditions of the tested device, and furthermore attain a high power recovery efficiency that ranges from 0.54 to 0.85, even though the 3 schemes have different loading performances and energy efficiencies. This paper proposes several loading schemes that can achieve both high dynamic performance and high power recovery efficiency.

Optimized cardiac magnetic resonance imaging inversion recovery sequence for metal artifact reduction and accurate myocardial scar assessment in patients with cardiac implantable electronic devices

Late gadolinium enhancement(LGE) cardiovascular magnetic resonance(CMR) is the gold standard for imaging myocardial viability.An important application of LGE CMR is the assessment of the location and extent of the myocardial scar in patients with ventricular tachycardia(VT), which allows for more accurate identification of the ablation targets.However, a large percentage of patients with VT have cardiac implantable electronic devices(CIEDs), which is a relative contraindication for cardiac magnetic resonance imaging due to safety and image artifact concerns.Previous studies showed that these patients can be safely scanned on 1.5 T scanners provided that an adequate imaging protocol is adopted.Nevertheless, imaging patients with a CIED result in metal artifacts due to the strong frequency off-resonance effects near the device; therefore, the spins in the surrounding myocardium are not completely inverted, and thus give rise to hyperintensity artifacts.These artifacts obscure the myocardial scar tissue and limit the ability to study the correlation between the myocardial scar structure and the electro-anatomical map during catheter ablation.In this study, we developed a modified inversion recovery technique to alleviate the CIED-induced metal artifacts and improve the diagnostic image quality of LGE images in patients with CIEDs without increasing scan time or requiring additional hardware.The developed technique was tested in phantom experiments and in vivo scans, which showed its capability for suppressing the hyperintensity artifacts without compromising myocardium nulling in the resulting LGE images.

Theoretical Investigation on Internal Leakage and Its Effect on the Efficiency of Fluid Switcher-Energy Recovery Device for Reverse Osmosis Desalting Plant

This work is focused on the theoretical investigation of internal leakage of a newly developed pi lotscale fluid switcherenergy recovery device （FSERD） for reverse osmosis （RO） system. For the purpose of in creasing FSERD efficiency and reducing the operating cost of RO, it is required to control the internal leakage in a low level. In this work, the internal leakage rates at different leakage gaps and retentate brine pressures are investigated by computational fluid dynamics （CFD） method and validating experiments. It is found that the internal leak age has a linear relationship with the retentate brine pressure and a polynomial relationship with the scale of leakage gap. The results of the present work imply that low internal leakage and high retentate brine pressure bring benefits to achieve high FSRD efficiency.

Heat Transfer and Energy Utilization of Waste Heat Recovery Device with Different Internal Component

Steel industry is high energy-consuming industry, and its waste?heat recovery is critically?important for energy utilization. In this study, pipeline bundle is used to enhance heat transfer in?waste?heat recovery device,?and?associated gas-solid heat transfer and energy utilization performance with different pipeline arrangement, pipe diameter and shape of internal component are further analyzed. The temperatures of gas and particle in device with pipeline bundle periodically fluctuate in horizontal direction, and those in staggered system distribute more uniformly than those in paralleled system. Compared with paralleled device, exergy and waste heat utilization efficiency of staggered device have been improved, and they are both higher than?those without pipeline. As pipe diameter increases, exergy and waste heat utilization efficiency first increases and then decreases, and they reach the maxima with optimal pipe diameter.?As the width of internal component keeps constant, influence of its shape on heat transfer is very little.

Recovery after acute kidney injury requiring kidney replacement therapy in patients with left ventricular assist device: A metaanalysis

BACKGROUND Acute kidney injury(AKI)is a common and severe complication after left ventricular assist device(LVAD)implantation with an incidence of 37%;13%of which require kidney replacement therapy(KRT).Severe AKI requiring KRT(AKI-KRT)in LVAD patients is associated with high short and long-term mortality compared with AKI without KRT.While kidney function recovery is associated with better outcomes,its incidence is unclear among LVAD patients with severe AKI requiring KRT.AIM To identify studies evaluating the recovery rates from severe AKI-KRT after LVAD placement,which is defined by regained kidney function resulting in the discontinuation of KRT.Random-effects and generic inverse variance method of DerSimonian-Laird were used to combine the effect estimates obtained from individual studies.METHODS A total of 268 patients from 14 cohort studies that reported severe AKI-KRT after LVAD were included.Follow-up time ranged anywhere from two weeks of LVAD implantation to 12 mo.Kidney recovery occurred in 78%of enrollees at the time of hospital discharge or within 30 d.Overall,the pooled estimated AKI recovery rate among patients with severe AKI-KRT was 50.5%(95%CI:34.0%-67.0%)at 12 mo follow up.Majority(85%)of patients used continuous-flow LVAD.While the data on pulsatile-flow LVAD was limited,subgroup analysis of continuous-flow LVAD demonstrated that pooled estimated AKI recovery rate among patients with severe AKI-KRT was 52.1%(95%CI:36.8%-67.0%).Metaregression analysis did not show a significant association between study year and AKI recovery rate(P=0.08).There was no publication bias as assessed by the funnel plot and Egger's regression asymmetry test in all analyses.RESULTS A total of 268 patients from 14 cohort studies that reported severe AKI-KRT after LVAD were included.Follow-up time ranged anywhere from two weeks of LVAD implantation to 12 mo.Kidney recovery occurred in 78%of enrollees at the time of hospital discharge or within 30 d.Overall,the pooled estimated AKI recovery rate among patients with severe AKI-KRT was 50.5%(95%CI:34.0%-67.0%)at 12 mo follow up.Majority(85%)of patients used continuous-flow LVAD.While the data on pulsatile-flow LVAD was limited,subgroup analysis of continuous-flow LVAD demonstrated that pooled estimated AKI recovery rate among patients with severe AKI-KRT was 52.1%(95%CI:36.8%-67.0%).Metaregression analysis did not show a significant association between study year and AKI recovery rate(P=0.08).There was no publication bias as assessed by the funnel plot and Egger's regression asymmetry test in all analyses.CONCLUSION Recovery from severe AKI-KRT after LVAD occurs approximately 50.5%,and it has not significantly changed over the years despite advances in medicine.

基于空中回收的运载火箭尾舱挂取方案设计及仿真分析

运载火箭空中回收的挂取过程是整个回收过程中最关键的环节之一。针对运载火箭尾舱空中挂取的全流程,开展了将直升机作为回收平台的钩取装置设计,主要包括拉力传感器、过载保护装置、减载装置以及末端的执行机构。翼伞和减速伞从火箭尾舱的底部弹出,挂取装置可通过挂取翼伞顶部的牵顶伞实现对回收体的挂取操作。通过对挂取过程的仿真分析可以看出,回收体的质量增大时,过载显著增加,而当翼伞的收伞时间增加时,减载效果明显。

用于数据采集器测试的时间脉冲插值分析方法

地震数据采集器时间服务精度是评价设备性能的重要指标,一般使用标准时间源输出的时间脉冲信号采样数据进行分析计算,但受仪器采样率限制,时间偏差测试分辨率不高。设计了基于一阶差分和直方图分析的脉冲信号上升沿识别、高低电位分析和时间偏差分析算法,研究使用非线性插值分析方法对地震数据采集器采集的标准时间脉冲信号进行波形升采样恢复,并基于所提算法进行实验分析和讨论,在提高地震数据采集器时间偏差测试分辨率的同时,规范了测试数据处理方法和流程。

模块化撬装化CO_(2)回收技术研究与应用

在“碳达峰、碳中和”背景下,传统化工企业都将面临CO_(2)排放指标限制难题。CCUS(碳捕集、利用与封存)技术是解决CO_(2)排放难题的关键一招,化工企业首先需要依靠CO_(2)尾气捕集回收装置,实现上游源头减碳,再通过下游资源利用,进而形成经济可行的CCUS产业链。针对传统CO_(2)尾气回收装置建设过程中存在的占地面积大,土建费用高,灵活性差,施工周期长等突出问题,研发出模块化撬装化CO_(2)回收技术,可以有效降低前期投资成本和缩短施工周期。该技术根据装置工艺功能单元特点,基于模块化设计实现回收工艺模块划分,达到100%工厂化预制,现场模块化施工标准。同时,利用撬装化设计,合理布局管道阀门,实现模块内设备优化整合成撬,最终形成全流程模块化撬装化的CO_(2)回收装置。现场应用结果表明,相比传统CO_(2)尾气回收装置,模块化撬装化5×10^(4) t/a煤制氢CO_(2)尾气回收装置完全达到降低投资成本和缩短施工周期目标,其中土建费用降低74.0%,建设面积降低75.2%,工程施工周期缩短50.0%。

基于有源噪声控制系统的电声器件故障诊断技术研究

有源噪声控制系统是一种先进的噪声管理技术,其通过产生与入侵噪声相位相反的声波中和噪声,从而达到降噪效果。深入探讨基于有源噪声控制系统的电声器件故障诊断技术,详细介绍电声器件故障诊断技术的应用,包括整体设计方案、基于阻抗特性和信号均方根误差法的故障诊断系统设计,以及基于STM32的次级声源和误差传声器故障诊断系统的实现,确保系统的高效运行和长期稳定性。

基于激光增材制造粉末回收装置的改进

激光增材粉末制造是一项前沿性的先进制造技术,但现有激光增材制造设备在生产过程中有大量的金属粉末不能进入熔池参与成型而浪费。拟通过增设离心抽风机、粉末回吸嘴、粉末收集器、二级振动筛、振动源、一级振动筛、沉积基板、成型盒和激光送粉头等组成的一种粉末回收装置,对激光增材制造中未熔融成制件的粉末进行分级筛选,将符合颗粒度要求的金属粉末直接送入激光送粉装置进行回收利用,从而降低送粉能耗,有效提高材料的利用率,进而降低激光增材制造成本。

Progress of Microbial Enhanced Oil Recovery in Laboratory Investigation

This paper describes a simple, easy process for screening microorganisms, and introduces a laboratory simulation device and process of microbial enhanced oil recovery (MEOR) , which is a necessary research step for trial in oilfields. The MEOR mechanism and the influence of adsorption, diffusion, metabolism, nutrition, porosity, and permeability are analyzed. The research indicates that different microbes have different efficiencies in EOR and that different culture types play different roles in EOR. The effect of syrup is better than that of glucose, and larger porosity is favorable to the reproduction and growth of microbes, thereby improving the oil recovery. Using crude oil as a single carbon source is more appreciable because of the decrease in cost of oil recovery. At the end of this paper, the development of polymerase chain reaction (PCR) for the future is discussed.

短路电流对二次设备电磁干扰分析及抗干扰措施

目前智能配电网的建设不断推进,加快了配电开关一二次设备相关技术的发展,也对长期处于复杂电磁环境下的二次设备提出了更高的要求。文中基于合成试验回路搭建了短路电流对配电开关二次设备电磁干扰试验平台,开展开断故障电流对相关干扰对成套设备的影响研究,分析干扰信号产生原因、频谱特性。针对干扰的特性设计一套抗干扰测量系统,利用ATP-EMTP模拟合成回路进行仿真分析并进行实际测试验证。结果表明:成套设备进行开断试验时,二次设备端口会受到较大的干扰。电流波形也会发生畸变,干扰电流的最高可到26 A,且干扰电流受电流互感器磁饱和和退饱和的影响,通过增加抗干扰措施,二次设备输出准确度与之相比提升约40%。本次的试验结果可为一二次融合成套设备中二次设备电磁兼容研究提供相关依据。

基于无线通讯技术的松土装置应力应变监测系统设计与试验

【目的】测量滚筒式残膜回收机中的主要部件松土齿耙在作业过程中监测系统装置的应力应变状况,为提高残膜回收机工作效率、降低松土齿耙的故障率提供参考。【方法】设计松土齿耙应力应变监测系统,通过ANSYS分析确定监测点,采用DH5922N数据分析仪标定传感器,采集模块对松土齿的微小变形进行应力应变测量,连续监测松土齿应力应变数据,并针对松土齿耙壅土过载工况下提前预警。【结果】应力应变监测系统可以有效的对松土齿耙应力应变实时监测,模拟机具田间作业工况,轻度过载阈值为140 Mpa,严重过载阈值为180 Mpa,监测结果整体平均相对误差为10.12%,过载阈值设置可提前预警。【结论】松土齿耙应力应变监测系统主要由微处理器、应力应变采集模块、AD模数转换模块、电源模块、通讯模块、云平台可视化界面6部分组成,可实时监测松土齿耙的应力应变作业状况。

一种绳驱动AUV布放回收装置的结构设计与动力学分析

为了提高自主式水下航行器(AUV)布放回收的安全性和效率,以船舶起重机为基础,设计一种不仅能通过绳索自主调整吊笼的姿态,而且具有良好减摇效果的AUV水面布放回收装置。分析该装置的结构特性和机械理论模型,采用坐标转换法对吊笼的运动学位置、速度和加速度进行分析,并通过MATLAB软件对其进行仿真验证。在运动学模型的基础上对装置进行动力学分析,并利用ADAMS搭建绳索系统的虚拟样机并进行无激励和存在激励仿真验证。研究结果表明:在受船舶激励的情况下,横摇的减摇效果为78%,纵摇的减摇效果为75%;在给定轨迹下,4根绳索的变化比较稳定,能通过绳索调整吊笼的姿态,进而安全高效地完成AUV布放回收工作。

自驱旋转式能量回收装置的转速特性曲线

为研究自驱旋转式能量回收装置的转速特性曲线,采用理论分析的方法,构建一种新的转速预测模型,并应用Fluent 6DOF模型,通过UDF文件定义固体转子的质量与转动惯量等物理参数,构建了自驱旋转式能量回收装置转子的刚体被动旋转的数值模型,得到了转子在装置进口流量Q为70.2 m^(3)/h,装置出口压力p为6.0 MPa工况下的速度分布,以及各工况下转子所受驱动扭矩随时间的变化关系,并总结出转子启动过程中的转速变化规律.结果表明,各工况下转子的启动时间均低于2 s,且转子转速与流量成正比;理论模型与数值模型吻合度较高,Q为26.3 m^(3)/h工况下相对误差最高,达14.9%,Q为61.4 m^(3)/h工况下相对误差最小,为0.77%.

椭圆扭曲管能量回收器性能数值模拟及其节能应用

为解决目前传统新风系统常用的纸芯能量回收器存在新风、回风交叉污染及能量综合回收率低的问题,将椭圆扭曲管应用于空调新风系统,基于铝合金传热元件研发了一种新型高效的能量回收器。设计椭圆扭曲管和圆管两种不同结构的能量回收器,应用Fluent软件进行数值模拟,对比分析其换热和流动性能,并对其应用于空调新风系统的节能效果进行分析。结果表明,相对于圆管能量回收器,空气在通过椭圆扭曲管能量回收器时壳程温度下降得更快,管程温度提升也更快,换热系数更高,换热效果更好,尤其是处于夏季工况时换热效果较为明显。增设了能量回收器的新风机可以有效提升室内环境的舒适性,在夏热冬冷和寒冷地区节能效果显著。

不同能量回收组合工艺下海水淡化系统比能耗分析

能量回收装置能够降低反渗透海水淡化系统的比能耗与运营成本,是重要的核心节能装备。预设进水流量与回收率均相同的反渗透海水淡化系统,提出无透平单级、单透平单级、双透平双段、单透平段间增压这4种组合工艺,对反渗透系统进行工艺路线设计和设备选型研究。为验证组合工艺的性能,选取两种计算方式对系统比能耗进行分析。结果表明,能量回收技术能够降低系统比能耗,通过对透平式能量回收装置进行优化组合,特别是双透平双段式和单透平段间增压式的组合工艺能够大幅降低系统比能耗和综合成本。

液压挖掘机液能回收再利用节能装置测控系统

液压挖掘机动臂下降重力势能和回转制动动能均以节流和溢流的形式转化为了油液的热能,严重影响整机能效,亟需提高液压挖掘机液压系统的效率。针对这一问题,提出了基于三腔蓄能器的挖掘机液能回收再利用的节能装置方案,可以回收挖掘机动臂势能和回转制动动能,用于驱动动臂举升。首先,介绍了节能装置的工作原理。其次,设计并开发了节能装置的测控系统,采用CoDeSys编写了下位机控制器程序,直接控制节能装置的动作实现能量回收和再利用;运用C#语言开发了上位机程序进行节能装置电控系统和液压系统的模拟调试和数据监控,并实现了节能装置的远程无线通讯功能。试验结果表明:该测控系统实现了对插装阀开闭和比例节流阀开度的快速、精准控制;达到了对节能装置远程控制和数据实时采集的目标;节能装置的动臂势能回收效率为84.9%,动臂节能效率为52.8%,回转制动工况下的动能回收效率为41.1%。