Evaluation of mercury speciation and removal through air pollution control devices of a 190 MW boiler

Air pollution control devices （APCDs） are installed at coal-fired power plants for air pollutant regulation. Selective catalytic reduction （SCR） and wet flue gas desulftLrization （FGD） systems have the co-benefits of air pollutant and mercury removal. Configuration and operational conditions of APCDs and mercury speciation affect mercury removal efficiently at coal-fired utilities. The Ontario Hydro Method （OHM） recommended by the U.S. Environmental Protection Agency （EPA） was used to determine mercury speciation simultaneously at five sampling locations through SCR-ESP-FGD at a 190 MW unit. Chlorine in coal had been suggested as a factor affecting the mercury speciation in flue gas; and low-chlorine coal was purported to produce less oxidized mercury （Hg^2＋） and more elemental mercury （Hg^0） at the SCR inlet compared to higher chlorine coal. SCR could oxidize elemental mercury into oxidized mercury when SCR was in service, and oxidation efficiency reached 71.0%. Therefore, oxidized mercury removal efficiency was enhanced through a wet FGD system. In the non-ozone season, about 89.5%-96.8% of oxidized mercury was controlled, but only 54.9%-68.8% of the total mercury was captured through wet FGD. Oxidized mercury removal efficiency was 95.9%-98.0%, and there was a big difference in the total mercury removal efficiencies from 78.0% to 90.2% in the ozone season. Mercury mass balance was evaluated to validate reliability of OHM testing data, and the ratio of mercury input in the coal to mercury output at the stack was from 0.84 to 1.08.

Flexible substructure online hybrid test system using conventional testing devices

This paper presents a substructure online hybrid test system that is extensible for geographically distributed tests. This system consists of a set of devices conventionally used for cyclic tests to load the tested substructures onto the target displacement or the target force. Due to their robustness and portability, individual sets of conventional loading devices can be transported and reconfigured to realize physical loading in geographically remote laboratories. Another appealing feature is the flexible displacement-force mixed control that is particularly suitable for specimens having large disparities in stiffness during various performance stages. To conduct a substructure online hybrid test, an extensible framework is developed, which is equipped with a generalized interface to encapsulate each substructure. Multiple tested substructures and analyzed substructures using various structural program codes can be accommodated within the single framework, simply interfaced with the boundary displacements and forces. A coordinator program is developed to keep the boundaries among all substructures compatible and equilibrated. An Interuet-based data exchange scheme is also devised to transfer data among computers equipped with different software environments. A series of online hybrid tests are introduced, and the portability, flexibility, and extensibility of the online hybrid test system are demonstrated.

Application of computational fluid dynamics in design of viscous dampers-CFD modeling and full-scale dynamic testing

Computational fluid dynamics(CFD)provides a powerful tool for investigating complicated fluid flows.This paper aims to study the applicability of CFD in the preliminary design of linear and nonlinear fluid viscous dampers.Two fluid viscous dampers were designed based on CFD models.The first device was a linear viscous damper with straight orifices.The second was a nonlinear viscous damper containing a one-way pressure-responsive valve inside its orifices.Both dampers were detailed based on CFD simulations,and their internal fluid flows were investigated.Full-scale specimens of both dampers were manufactured and tested under dynamic loads.According to the tests results,both dampers demonstrate stable cyclic behaviors,and as expected,the nonlinear damper generally tends to dissipate more energy compared to its linear counterpart.Good compatibility was achieved between the experimentally measured damper force-velocity curves and those estimated from CFD analyses.Using a thermography camera,a rise in temperature of the dampers was measured during the tests.It was found that output force of the manufactured devices was virtually independent of temperature even during long duration loadings.Accordingly,temperature dependence can be ignored in CFD models,because a reliable temperature compensator mechanism was used(or intended to be used)by the damper manufacturer.

Design and Experimental Investigation for Subsea Control Module Test System

As a core part of subsea production systems,subsea control modules(SCMs)are costly,difficult,and expensive to install and inconvenient to use in underwater maintenance.Therefore,performance and function tests must be carried out before launching SCMs.This study developed a testing device and an SCM test by investigating SCMs and their underwater.The testing device includes four parts:a hydraulic station,an SCM test stand,a signal generating device,and an electronic test unit.First,the basic indices of the testing device were determined from the performance and working parameters of the SCM.Second,the design scheme of the testing device for the SCM was tentatively proposed,and each testing device was designed.Finally,a practical measurement of the SCM,in combination with the hydraulic station,SCM test stand,signal generator,electronic unit,and highpressure water tank,was carried out according to the test requirements.The measurement mainly involved equipment inspection before testing and an experimental test for the SCM.The validity and feasibility of the testing device and method were simultaneously verified through an association test.

Flexible,efficient,and accurate tests for epidemics

Group testing involves discovering a small subset of distinguished subjects from a large population while efficiently reducing the total number of tests.It has been widely used for industrial testing,information technology,and biology,especially epidemic screening.Tests,in reality,are noisy for the presence of false outcomes.Some tests are accurate but time-consuming,while others are cheaper but less accurate.Exactly which test to use is constrained by various considerations,such as availability,cost,accuracy,and efficiency.In this paper,we propose flexible,efficient,and accurate tests(FEATs).FEATs are based on group testing with simple but careful designs by incorporating ideas such as close contact cliques and repeated tests.FEATs could dramatically improve the efficiency or accuracy of existing tests.For example,for accurate but slow tests,the FEAT can improve efficiency multiple times without compromising accuracy.On the other hand,for fast but inaccurate tests,the FEAT can sharply reduce the false-negative rate(FNR)and significantly increase efficiency.Theoretical justifications are provided.We point out some scenarios where the FEAT can be effectively employed.

Timetabling optimization of classrooms and self-study rooms in university teaching buildings based on the building controls virtual test bed platform considering energy efficiency

The energy consumption of a teaching building can be effectively reduced by timetable optimization.However,in most studies that explore methods to reduce building energy consumption by course timetable optimization,self-study activities are not considered.In this study,an MATLAB-EnergyPlus joint simulation model was constructed based on the Building Controls Virtual Test Bed platform to reduce building energy consumption by optimizing the course schedule and opening strategy of self-study rooms in a holistic way.The following results were obtained by taking a university in Xi’an as an example:(1)The energy saving percentages obtained by timetabling optimization during the heating season examination week,heating season non-examination week,cooling season examination week,and cooling season non-examination week are 35%,29.4%,13.4%,and 13.4%,respectively.(2)Regarding the temporal arrangement,most courses are scheduled in the morning during the cooling season and afternoon during the heating season.Regarding the spatial arrangement,most courses are arranged in the central section of the middle floors of the building.(3)During the heating season,the additional building energy consumption incurred by the opening of self-study rooms decreases when duty heating temperature increases.

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.

医疗器械检验报告审核和质量管理探讨

目的:医疗器械具有复杂性、特殊性、专业性、涉及门类广等特点,面对医疗器械开放自检及检验市场竞争日益加剧的形势,如何提升检验能力,适应产业的迅速发展,确保检验结果的科学性、公正性、权威性,是各医疗器械检验机构面临的共同挑战。方法:从医疗器械检验面临的挑战、法律法规要求、质量管理体系关注要点等方面进行阐述。结果:通过对报告审核中发现的问题,提出质量改进措施及建议。结论:医疗器械检验机构应持续提升检验能力,发展特色优势领域,积极应对医疗器械快速发展的需要及检验新形势,提质增效,应在医疗器械的质量检验工作中,引入风险管理理念并加强过程控制,从人、机、料、法、环等方面构建起全方位的保障体系,提高检验质量和效率,助力医疗器械高质量发展。

Theoretical and experimental research on a new system of semi-active structural control with variable stiffness and damping

In this paper,a new system of semi active structural control with active variable stiffness and damping (AVSD) is suggested.This new system amplifies the structural displacement to dissipate more energy,and in turn,effectively reduces the structural response in the case of relatively small story drifts,which occur during earthquakes.A predictive instantaneous optimal control algorithm is established for a SDOF structure equipped with an AVSD system Comparative shaking table tests of a 1/4 scale single story structural model with a full scale control device have been conducted.From the experimental and analytical results,it is shown that when compared to structures without control or with the active variable stiffness control alone, the suggested system exhibits higher efficiency in controlling the structural response,requires less energy input,operates with higher reliability,and can be manufactured at a lower cost and used in a wider range of engineering applications.

高压断路器操动机构驱动电机及其控制技术研究

高压断路器操动机构用电机驱动提高了断路器运行的可靠性与可控性,因此设计了一套适用于126 kV真空断路器的电机操动机构。基于操动机构动力学分析结果确定驱动电机转矩、转速要求,提出一种有限转角永磁无刷电机设计方案,研制样机进行联机试验完成动作要求检验。在此基础上,设计分段转矩控制策略,结合驱动电机输出转矩需求将操动机构的运动过程分为4个阶段,从降低触头碰撞、避免预击穿现象发生、提高断路器工作可靠性角度对各阶段电机输出转矩进行动态调节。结果表明:所研制的驱动电机配合分段转矩控制策略,在保证灭弧室对操动机构动作时间、动作速度要求的前提下,实现了操动机构的运动过程优化和工作可靠性提高,促进了断路器智能化操作进程。

基于乳化的智能型高效油烟废气净化装置研究

餐饮业产生的油烟废气蕴含大量有害气体,而传统抽油烟废气设备将没有经过任何去污染净化处理的油烟废气直接排放到空中,严重污染生活环境,危害人体健康,急需治理;针对治理餐饮业油烟废气污染环境难题,提出一种以提高油烟废气净化效率为目标进行优化控制的智能装置设计;装置实时监测油烟废气浓度和电解液pH值大小,通过控制超声波雾化强度喷射适量碱性水雾促进油烟废气乳化,又不会过量喷射碱性水雾造成二次环境污染;同时监测环境污染物颗粒浓度,开启负离子发生器,产生适量负离子与油烟废气颗粒结合使油烟废气颗粒变大更容易沉积,提高油烟废气净化效率;沉积的油烟废气沿着管道下流不但自动清洗黏附油垢,而且方便收集循环再利用;实验结果表明,装置不仅净化油烟废气控制有效,而且提升环境空气质量,既节能又环保,特别适合在食堂、街头地摊等规模使用排油烟废气地方,具有较好的实用性和广泛的应用前景。

200 N推力装置上肼类分解催化剂的应用性能

研究制备了一种单组元姿轨控发动机用肼类分解催化剂,采用200 N推力装置对其应用性能进行了研究和考察。在催化剂物化性能指标满足应用要求的基础上,利用200 N推力装置通过力学环境试验考察了催化剂力学环境适应性,通过双-10℃低温冷启动、低温稳态及脉冲、正负拉偏以及脉冲寿命热试考核程序考察了自制催化剂的低温冷启动性能、低温稳态性能、常温正负拉偏稳态性能以及脉冲寿命性能。结果表明:该催化剂肼催化分解效率在99%以上,机械强度高且力学环境适应性良好,具有较高的肼催化分解活性和稳定性,能够在200 N推力装置上于双-10℃正常启动,顺利完成了低温稳态、常温正负拉偏和脉冲寿命等考核程序,发动机室压平稳,响应特性良好,脉冲一致性好,可满足推力装置的使用要求。

基于大数据的超声波温控在线检测系统设计与实现

设计了一种基于大数据的在线超声波质量检测系统,包括滑座,滑座上设有调节机构、驱动机构、检测机构、转动件、限位机构,通过固定板转动检测仪的方式对结构板两侧进行自动检测,检测结果直接通过控制系统显示在计算机上,结合检测结果大数据分析与比对,改变了人工检测时需要手持检测仪不断变换位置,较为消耗体力,使检测效率不高的问题,可以实现时时调整检测位置和检测频率,检测方便,效率高,能够实现长距离海底管道的超声波无损检测。检测效率可以达到传统检测仪器的3倍以上,还可以准确定位缺欠位置,为故障诊断和排除提供了有力依据。系统可以利用计算机网络单元进行检测数据采集和分析,为长距离海底管道的检测提供技术支持和数据保障。

基于混合现实技术的船舶机舱集中操控试验装置设计与实现

文章提出一种基于混合现实(MR)的船舶机舱设备集中操控试验装置和管控方法,即时收集船舶机舱内数据,针对收集的数据建立数学模型,模拟舱内三维场景,从而对舱内设备实施控制。研究了基于MR的船舶机舱设备集中操控系统设计方案和方法,应用Faster R-CNN目标检测网络深度学习的船舶机舱设备状态指示识别框架与算法。从MR机舱设备集中操控流程、构建机舱三维模型及其优化、集中操控方法及其实操训练等环节的迭代研发,完成了MR机舱设备集中操控功能的测试验证。将混合现实技术应用于轮机设备操作、机舱资源管理等实践实训教学中,增强了船舱空间分析和可视化的交互效果。

高空低温低气压模拟试验装置研制

面向飞行器高空环境相关气动基础问题研究需求,由低温模拟库嵌套低压模拟舱构建了海拔40 km以上高空大气环境模拟试验装置,采用双回路控制算法实现了低气压参数的精确快速模拟,系统工作真空度10 min内可达200 Pa以下;通过开发的制冷系统无级调节技术和冷热双回路PID自适应技术,实现了温度的稳定节能输出,温度控制精度为±0.5℃,温度均匀性优于±1℃。设计配套了环形回流风洞、螺旋桨带动力及翼型试验子系统,为开展高空环境飞行器气动性能测试提供了可靠的试验平台和技术保障。

5种药剂对桑尼短体线虫的毒力测定和室内防效

【目的】筛选有效防治桑尼短体线虫(Pratylenchus thornei)的药剂,为燕麦短体线虫病的科学防治和安全生产提供参考。【方法】在室内条件下分别采用浸渍法和盆栽灌根法测定5种药剂对桑尼短体线虫的毒力和防效。【结果】5种药剂中41.7%氟吡菌酰胺SC对桑尼短体线虫毒力最强,LC_(50)为1.115 7 mg/L;2.5%高效氯氰菊酯EW毒力最低,LC_(50)为68.454 5 mg/L。41.7%氟吡菌酰胺SC和40%氟烯线砜EC灌根处理45 d后的线虫减退率分别为94.07%和97.07%,防效分别为84.67%和92.42%。【结论】41.7%氟吡菌酰胺SC和40%氟烯线砜EC对桑尼短体线虫的防效最好,建议在燕麦生产中推广应用。

模拟换流阀长期运行工况的高压大功率晶闸管电热联合老化系统研制

近年来国内多个直流换流站发生严重事故,经调查发现事故起因多为长时间运行的换流阀晶闸管发生不同程度的老化甚至绝缘能力丧失。掌握晶闸管参数退化规律是开展晶闸管运维监测、预防此类事故继续发生的基础。因此为了深入了解换流阀晶闸管老化过程中特性参数退化规律与老化机理,首先需要搭建试验所需的模拟换流阀运行过程的晶闸管老化试验装置。文中首先分析了换流阀晶闸管的实际运行工况,并基于此设计了晶闸管电热联合老化主电路,接着对电路中涉及到的控制单元,包括绝缘栅双极型晶体管(IGBT)的驱动电路与晶闸管的触发电路进行设计与搭建,并基于晶闸管的实际运行工况设计了晶闸管结温控制系统。为了获得晶闸管老化过程中特性参数的退化规律,设计了晶闸管漏电流在线监测系统与反向恢复离线测量系统。经过检验,各个模块以及主电路均能够保持长期稳定运行,为换流阀晶闸管的老化试验打下了良好基础。

液冷动力电池系统热管理控制策略优化探究

以某纯电动商用车65 kW·h磷酸铁锂液冷动力电池系统为研究对象,自主设计和搭建热管理试验台架,重点探究了不同环境温度和工况下热管理系统对电池温度的冷却效果。该热管理系统能够将电池温度控制在适宜范围内,但高温环境时能耗较高,遂开展热管理控制策略优化,优化后的控制策略在电池冷却效果和能耗方面均优于原控制策略,高温、高速工况和城市综合工况分别节能37.78%和78.63%,热管理能效明显提升。

用于严酷试验条件下核电人机控制设备自动测试装置的研制及应用

人机接口设备是核电厂安全级仪控系统(Digital Instrumentation and Control System,DCS)的重要部件,鉴定试验要求在试验应力下对其进行操作,并测试其功能和性能。核电DCS设备鉴定的部分试验条件十分严酷,很难在试验中对设备进行操作。之前采用的方法是测试人员穿防护设备进入温箱等严酷环境进行测试,既影响了试验效率,又可能对测试人员造成健康上的损害。本文首先分析了鉴定试验的环境特点;然后提出采用步进电机进行精确控制的方法,实现对人机接口设备的自动操作;最后结合鉴定试验特点,给出对机械臂的防护措施。基于该测试方法集成的自动测试装置已投入鉴定试验活动中,并实现了远程全自动操作。

适应度反向学习的平衡灰狼算法及其应用

针对传统灰狼优化算法位置更新时勘探与开发失衡,收敛速度慢且陷入局部最优的问题,提出一种改进的灰狼算法(balanced grey wolf algorithm based on fitness back learning,BGWO),引入非线性控制参数,增强算法前期勘探能力,加速收敛;在种群迭代阶段采用重心反向学习的最优适应度权重更新策略,平衡算法的勘探与开发。16组基准函数测试结果表明,改进后算法能自适应跳出局部最优,在加快算法收敛速度的同时提高全局收敛能力与精度。将BGWO应用于PV型旋风分离器粒级效率GBDT(gradient boosting decision tree)的建模,提高了GBDT的精度,模型相关系数0.980,均方误差0.00079,BGWO-GBDT与GBDT、PSO-GBDT和GWO-GBDT相对比,建模精度和稳定性明显提高,验证了BGWO的有效性。