硅橡胶电缆材料真空烘烤除气参数实验分析方法

目的在于通过硅橡胶电缆护套材料真空出气性能研究,分析材料真空烘烤除气的参数。方法是依据真空中材料出气性能测试标准,测试电缆材料使用温度范围内,不同温度条件下材料的质量损失(TML)、收集的可凝挥发物量(CVCM),分析材料出气参数的变化。结果硅橡胶电缆材料出气温度85℃时,CVCM量值与75℃时基本相同,出气温度95℃时,CVCM量值是85℃时的4倍,且收集到的物质组分也明显增加;出气温度85℃条件下,24小时后材料的质量损失约占总质量损失的94%。结论通过材料出气性能实验方法,有效获得了硅橡胶电缆材料真空烘烤除气参数,体电阻率测试结果检验了真空烘烤除气参数的合理性。     

高压断路器状态智能监测系统设计

当前断路器监测相关研究成果监测覆盖性、故障诊断实时性和抗干扰性均较差,提出并设计基于DSP的高压断路器状态智能监测系统。将高压断路器状态智能监测系统整体分为信息数据采集层和管理层两部分,利用通信单元、时钟电源、电源单元、显示单元、接口单元和数据采集单元等模块构成监测系统硬件部分。主要分析并设计了信号数据采集单元和系统抗干扰关键技术,信号数据采集中包含分合闸线圈的电流采集、动触头行程数据采集、三相主回路数据采集和开关量输入信号数据采集几部分。监测系统软件部分,在系统上电后,断路器开始进行自检,如果自检未通过,将发出警报。系统对高压断路器各种信号数据进行实时采集,估计当前断路器运行状态,将正常信号实时传输至监测中心并显示;将开断信号及相关信息数据以优先级形式传输至监测中心并显示,管理人员利用监控显示单元对断路器状态进行智能监测。实验结果表明,该系统监测覆盖系数大、故障诊断延时短、抗干扰性能强。     

铝合金表面用导电屏蔽涂层耐介质腐蚀行为研究

通过研究不同尺寸及分布的银粉对涂层表面电阻的影响，确定了导电屏蔽涂料最佳配方，制备了一种高导电、耐腐蚀涂层。采用SEM、EDS、四探针电阻测试仪等分析涂层在空气、水、盐水、中性盐雾、酸性盐雾中表面形貌及性能变化，从而揭示涂层腐蚀行为。结果表明：经历500 h试验后，涂层在空气中几乎没有发生变化，但是在含水等电解质的环境中腐蚀迅速，并且腐蚀速率具有纯水<水汽<盐水<中性盐雾<酸性盐雾的特征。腐蚀的主要原因是由于基材Al与涂层形成了电偶腐蚀，腐蚀初期表现为起泡，随着腐蚀的加剧，涂层表面布满白色、黄色、褐色的疏松腐蚀产物且漆膜出现脱落，当腐蚀进一步加剧扩大，疏松产物转变为较为致密的产物附着于涂层表面，此外，涂层导电性能会随着腐蚀程度的变化出现不同等级的下降。     

一种导电混凝土的制备及其电阻率测量

本文综述了导电混凝土的发展以及应用情况，提出了用导电混凝土作为接地材料的设想，并选择氧化铁粉作为骨料，添加适量碳粉配制了一种导电混凝土来验证。通过改变不同的配比制作导电混凝土模型，用四电极法测量其电阻率，得出碳粉比例对其电阻率的影响。     

导电滑环热真空试验污染物抑制方法试验研究

针对目前航天器导电滑环热真空试验时可凝挥发物VCM抑制的控制需求,根据低温吸附原理,在传统热真空设备温度控制系统基础上,加装独立控温功能的低温冷屏,并开展VCM吸附能力验证试验,对比分析改造前后微量可凝挥发物总量,改造后真空容器内的VCM量减少约1_～2个数量级,说明冷屏对污染物有良好的抑制效果。     

几种过滤材料的静电性能测试及分析

滤料产生静电火花是袋式除尘器因静电火花产生火灾和爆炸事故的主要原因。文章从面电荷密度、摩擦电压、半衰期、表面电阻率、体积电阻率五个方面对国内主要类型的过滤材料进行了静电性能的测试。分析得出,滤料采用经向导电涤纶纤维、面层均匀导电涤纶纤维等防静电滤料可有效防止静电火花的产生。     

从PCB布局分析UPS小机的环境适应性设计

UPS小机的销售渠道和市场需求决定了其有更多泛工业领域的应用,这类应用环境中的污染物(灰尘和潮湿等)容易形成吸湿性导电尘,对UPS的环境适应性带来很大挑战。通过对比分析了三款10 KVA UPS在PCB布局上的优势,总结出UPS环境适应性是能够通过PCB布局来改善和提高,为UPS小机的环境适应性设计提供参考。     

断路器欠压脱扣器抗冲击设计

主要应用于舰船等有冲击场合的断路器，其抗冲击性能要求很高。介绍了断路器欠压脱扣器在抗冲击方面的设计方法，此方法可以有效地削弱冲击力对欠压脱扣器的影响。     

阻尼隔声板在噪声控制工程上的应用

对隔声材料的隔声功能进行了分析,根据两种以上不同质的复合材料可避开各自的阻隔波谷,能更有效地提高阻隔宽频噪声的总体性能的声学原理,提出了安装有阻尼层的隔声板,可有效提高隔声板的隔声量。     

环境室空气制冷系统流程方案比较

对环境室空气制冷系统的三种流程方案进行定性和定量的对比分析，论证了正升压式流程方案是最佳可行的方案，采用该方案可使低温制冷性能提高，投资和能耗大幅度减少。     

Configuration influence in relation to fluid flow of venturi system

Due to its simplicity and accurately measuring the flow rate, the venturi system is a special kind of pipe that is widely used in various applied fluid mixtures. One of the venturi system's important applications is ejectors devices that accurately facilitate adding air to water to sustain oxygen demand target levels in many waterworks engineering systems. This study aims to improve venturi system measurement accuracy through experimental investigation and analytical analysis for the venturi system conditional configuration parameters effect on target aeration operational efficiency. In the experiment work, different runs are implemented to characterize the performance of such aerators by describing the impact of venturi characteristics and configurations, including water flow rate, air inlets orifices diameters, inlet velocities, throat lengths, inlet angles, outlets angles, and outlet diameters on aeration efficiency. Results show that the venturi air vent diameter is an important governing parameter for determining aeration performance value. Additionally, an indicated increase in aeration performance with an increasing throat length to its diameter ratio. Meanwhile, the results revealed a varying noted effect of the venturi system characteristics and configurations on aeration performance. Moreover, the equations that relate venturi system configuration and Reynolds numbers with the aeration operational performance are developed to facilitate the target accurate aeration efficiency estimation.     

Analysis of PV module connected in different configurations under uniform and non-uniform solar radiations

This paper focuses on investigating the current--voltage (I--V) and power--voltage (P--V) characteristics of a photovoltaic (PV) module connected in various configurations like series, parallel, and series-parallel. The performance analysis of PV module has been carried out under uniform and non-uniform conditions such as change in irradiation (passing clouds), change in temperature, accumulation of dust, and change in wind speed using MATLAB-Simulink environment. From the observed results, it has been indicated that for a given number of PV modules, the array configurations affect the maximum available output power and more local maxima are found under partially shaded conditions. Moreover, the comparative analysis of PV module has been performed for various configurations under the above disturbances. From the results, it is evident that even under non-uniform conditions, the parallel configuration of PV modules is more prominent and maximum output power is obtained. Further, parallel layout is particularly convenient for minimizing shadowing effects. The parameters of the PV module have been obtained from the manufacturer datasheet (KC200GT) for these investigations.     

Impact of Watershed Subdivision and Soil Data Resolution on SWAT Model Calibration and Parameter Uncertainty1

Abstract: Impact of watershed subdivision and soil data resolution on Soil Water Assessment Tool (SWAT) model calibration and parameter uncertainty is investigated by creating 24 different watershed model configurations for two study areas in northern Indiana. SWAT autocalibration tool is used to calibrate 14 parameters for simulating seven years of daily streamflow records. Calibrated parameter sets are found to be different for all 24 watershed configurations, however in terms of calibrated model output, their effect is minimal. In some cases, autocalibration is followed by manual calibration to correct for low flows, which were underestimated during autocalibration. In addition to normal validation using four years of streamflow data for each calibrated parameter set, cross‐validation (using a calibrated parameter set from one model configuration to validate observations using another configuration) is performed to investigate the effect of different model configurations on streamflow prediction. Results show that streamflow output during cross‐validation is not affected, thus highlighting the non‐unique nature of calibrated parameters in hydrologic modeling. Finally, parameter uncertainty is investigated by extracting good parameter sets during the autocalibration process. Parameter uncertainty analysis suggests that significant parameters show very narrow range of uncertainty across different watershed configurations compared with nonsignificant parameters. Results from recalibration of some configurations using only six significant parameters were comparable to that from calibration using 14 parameters, suggesting that including fewer significant parameters could reduce the uncertainty arising from model parameters, and also expedite the calibration process.     

Pre-combustion CO2 capture from natural gas power plants,with ATR and MDEA processes

Among the various configurations of fossil fuel power plants with carbon capture, this paper focuses on pre-combustion techniques applied to natural gas combined cycles. With more detail, the plant configuration here addressed includes: (i) the steam reforming of natural gas, based on an air-blown autothermal process, following a recuperative pre-reforming treatment, (ii) the water gas shift producing CO₂ and H₂, (iii) the separation of CO₂ by means of a mixed physical–chemical absorption system using a MDEA solution, and (iv) a hydrogen fuelled combined cycle.Similar configurations have been studied quite extensively, being among the most attractive for full-scale realizations in a near-mid term future. This paper proposes a detailed thermodynamic study and optimization of the plant configuration, bringing to a reliable performance estimation based on today's best available technology as far as the various plant sections are concerned (gas and steam turbine, natural gas reforming process, CO₂ separation). The predicted LHV efficiency for the base configuration is about 50%. Being this value at the top of the range quoted in the open literature studies (35–50%), the paper includes a quite extensive sensitivity analysis, showing that more conservative assumptions may bring to significantly poorer performance, especially considering the pretty large number of operating parameters involved in the process.     

WATERSHED CONFIGURATION AND GEOGRAPHIC INFORMATION SYSTEM PARAMETERIZATION FOR SPUR MODEL HYDROLOGIC SIMULATIONS1

ABSTRACT: A grid cell geographic information system (GIS) is used to parameterize SPUR, a quasi-physically based surface runoff model in which a watershed is configured as a set of stream segments and contributing areas. GIS analysis techniques produce various watershed configurations by progressive simplification of a stream network delineated from digital elevation models (DEM). We used three watershed configurations: ≥ 2nd, ≥ 4th, and ≥ 13th Shreve order networks, where the watershed contains 28, 15, and 1 channel segments with 66, 37, and 3 contributing areas, respectively. Watershed configuration controls simulated daily and monthly sums of runoff volumes. For the climatic and topographic setting in southeastern Arizona the ≥ 4th order configuration of the stream network and contributing areas produces results that are typically as good as the ≥ 2nd order network. However both are consistently better than the ≥ 13th order configuration. Due to the degree of parameterization in SPUR, model simulations cannot be significantly improved by increasing watershed configuration beyond the ≥ 4th order network. However, a range of Soil Conservation Service curve numbers derived from rainfall/runoff data can affect model simulations. Higher curve numbers yield better results for the ≥ 2nd order network while lower curve numbers yield better results for the ≥ 4th order network.     

Experimental investigations on a forced convection solar air heater using packed bed absorber plates with phase change materials

In this work, the performance of a forced convection solar air heater was evaluated using using three packed bed absorber plate configurations and compared with flat absorber plate. The phase change material (paraffin wax) was packed in the pin-fin, trianglular and circular absorber plate configurations. The performance parameters such as, outlet air temperature, thermo-hydraulic efficiency, exergy efficiency and pressure drop were predicted and compared. The results showed that the packed bed absorber plate configurations using paraffin wax have higher outler air temperature in the range of 2–5°C with 3–40% higher thermo-hydraulic efficiency and 2–20% higher exergy efficiency when compared to flat absorber plate. However, the packed bed absorver plates have higher pressure drop when compared to flat absorber plate.     

Hydraulic characterisation of the Stuttgart formation at the pilot test site for CO2 storage, Ketzin, Germany

The paper presents an approach for the interpretation of hydraulic tests of a CO₂ storage reservoir. The sandstone reservoir is characterised by a fluviatile channel structure embedded in a low-permeability matrix. Pumping tests were carried out in three wells, with simultaneous pressure monitoring in each well.The hydraulic parameters (permeability and storativity) and the boundary configurations were calibrated using three different approaches: (i) parameter calibration and type curve interpretation for single-hole tests, (ii) calibration of the entire build-up phase for cross-hole tests, and (iii) calibration of the initial pressure response for cross-hole pumping tests. In addition, the arrival time of the pressure response was determined and provides additional information about the pathways of hydraulic connection.The measured pumping test permeabilities of the formation were much lower than those measured on the cores, which is very unusual. The pumping test permeabilities are mainly between 50 mD and 100 mD (millidarcy), while core samples show a mean aquifer permeability of 500–1100 mD. Based on this it was concluded that some kind of continuous low-permeability structure exists, which was supported by core material. Three possible aquifer configurations were considered. The first and second were derived from traditional pumping test analysis and were conceptualised using flow boundaries. Each of the analyses provides a different result. A method was developed in which these differences were resolved by interpreting the pressure response with respect to its spatial and temporal sensitivity. This solution lead to a third configuration which was mainly based on spatially-variable permeabilities. Taking into account the pumping test results, the geological background and the behaviour of injected CO₂, we consider only the third configuration to be realistic. The results are in good agreement with modelled CO₂ arrival times and pressure history.     

长庆低渗透油田废弃钻井液处理探讨

通过对长庆低渗透油田废弃钻井液性能分析,确定了固液分离-固化一体化处理思路;研究了不同破胶剂体系、破胶剂加量、絮凝剂分子量等对固液分离及出水率的影响;处理结果表明:添加20%粘土同时加入6%固化剂时固化体针入度可降至0.5mm以下,达到强度要求,又可降低成本。现场试验证实固液分离析出水和固化体浸出液均达到GB8978-1996《污水综合排放标准》二级标准。     

Comparative performance study of different configurations of organic Rankine cycle using low-grade waste heat for power generation

This paper aims at analyzing the feasibility of a waste heat recovery power generation plant based on parametric optimization and performance analysis using different organic Rankine cycle configurations and heat source temperature conditions with working fluid R-12, R-123, R-134a, and R-717. A parametric optimization of turbine inlet temperature(TIT) was performed to obtain the irreversibility rate, system efficiency, availability ratio, turbine work output, system mass flow rate, second-law efficiency, and turbine outlet quality, along the saturated vapor line and also on superheating at an inlet pressure of 2.50 MP in basic as well as regenerative organic Rankine cycle. The calculated results reveal that selection of a basic organic Rankine cycle using R-123 as working fluid gives the maximum system efficiency, turbine work output, second-law efficiency, availability ratio with minimum system irreversibility rate and system mass flow rate up to a TIT of 150°C and appears to be a choice system for generation of power by utilizing the flue gas waste heat of thermal power plants and above 150°C the regenerative superheat organic Rankine cycle configuration using R 123 as working fluid gives the same results.