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Impact of crude distillation unit model accuracy on refinery production planning

Gang FU, Pedro A. Castillo CASTILLO, Vladimir MAHALEC

《工程管理前沿（英文）》 2018年第5卷第2期页码 195-201 doi: 10.15302/J-FEM-2017052

摘要： In this work, we examine the impact of crude distillation unit (CDU) model errors on the results of refinery-wide optimization for production planning or feedstock selection. We compare the swing cut+ bias CDU model with a recently developed hybrid CDU model (Fu et al., 2016). The hybrid CDU model computes material and energy balances, as well as product true boiling point (TBP) curves and bulk properties (e.g., sulfur % and cetane index, and other properties). Product TBP curves are predicted with an average error of 0.5% against rigorous simulation curves. Case studies of optimal operation computed using a planning model that is based on the swing cut+ bias CDU model and using a planning model that incorporates the hybrid CDU model are presented. Our results show that significant economic benefits can be obtained using accurate CDU models in refinery production planning.

关键词： impact of model accuracy on production planning swing cut+ bias CDU model hybrid CDU model refinery feedstock selection optimization optimization of refinery operation

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Structural optimal design of a swing vane compressor

Junjie MA,Xiang CHEN,Zongchang QU

《能源前沿（英文）》 2019年第13卷第4期页码 764-769 doi: 10.1007/s11708-016-0449-z

摘要： In this paper, a novel swing vane rotary compressor (SVC) was introduced, which had significant advantages—simple mechanism, reduced frictional loss, reliable operation, and a comparatively higher compression ratio. Based on the swing vane compressor geometry model, thermodynamic model and kinetic model, the mathematical model of optimum design was established, and further theoretical and experimental studies were conducted. The length of the cylinder, radius of the rotor and cylinder were defined as design variables and the reciprocal of EER as objective function. The complex optimization method was adopted to study the structure of the swing vane compressor. The theoretical model could provide an effective method for predicting compressor performance, which would also contribute to structural optimization of the SVC. The study shows that the friction loss of the compressor are greatly reduced by optimized design in a given initial value, and the EER increased by 8.55%.

关键词： swing vane compressor simulation optimization design

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Depth of cut models for multipass abrasive waterjet cutting of alumina ceramics with nozzle oscillation

Jun WANG

《机械工程前沿（英文）》 2010年第5卷第1期页码 19-32 doi: 10.1007/s11465-009-0082-1

摘要： An experimental study of the depth of cut in multipass abrasive waterjet (AWJ) cutting of alumina ceramics with controlled nozzle oscillation is presented. It is found that this cutting technique can significantly increase the depth of cut by an average of 50.8% as compared to single pass cutting without nozzle oscillation under the corresponding cutting conditions and within the same cutting time. Predictive models for the depth of cut are then developed. The modelling process starts with single pass cutting using a dimensional analysis technique and the particle erosion theories applied to alumina ceramics, before progressing to the development of the models for multipass cutting. The models are finally assessed both qualitatively and quantitatively with experimental data. It is shown that the model predictions are in good agreement with the experimental data with the average deviations of about 1%.

关键词： abrasive waterjet engineering ceramics depth of cut cutting performance nozzle oscillation machining

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活塞驱动变压吸附反应器的模型化

胡鸣,周兴贵,顾峥,袁渭康

《中国工程科学》 2001年第3卷第12期页码 52-57

摘要：

建立了活塞驱动的快速变压吸附反应器模型，根据气缸与床层相通时压力、浓度和流率的连续性要求，提出了模型的边界条件。以2A↔B+C为反应体系，其中C为易吸附组分，A、B为不吸附组分，利用动态模拟软件gPROMS模拟考察了反应器长度、周期长度、活塞运动速率、产品收集速率和基础压力对反应性能和分离性能的影响。

关键词：变压吸附反应器变压吸附多功能反应器动态模拟

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A combined modulated feedback and temperature compensation approach to improve bias drift of a closed-loop

Ming-jun MA,Zhong-he JIN,Hui-jie ZHU

《信息与电子工程前沿（英文）》 2015年第16卷第6期页码 497-510 doi: 10.1631/FITEE.1400349

摘要： The bias drift of a micro-electro-mechanical systems (MEMS) accelerometer suffers from the 1/ noise and the temperature effect. For massive applications, the bias drift urgently needs to be improved. Conventional methods often cannot address the 1/ noise and temperature effect in one architecture. In this paper, a combined approach on closed-loop architecture modification is proposed to minimize the bias drift. The modulated feedback approach is used to isolate the 1/ noise that exists in the conventional direct feedback approach. Then a common mode signal is created and added into the closed loop on the basis of modulated feedback architecture, to compensate for the temperature drift. With the combined approach, the bias instability is improved to less than 13 μ , and the drift of the Allan variance result is reduced to 17 μ at 100 s of the integration time. The temperature coefficient is reduced from 4.68 to 0.1 m /°C. The combined approach could be useful for many other closed-loop accelerometers.

关键词： Bias drift Closed-loop MEMS accelerometer Modulated feedback approach Temperature compensation

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Dependence of error sensitivity of frequency on bias voltage in force-balanced micro accelerometer

Lili CHEN, Wu ZHOU

《机械工程前沿（英文）》 2013年第8卷第2期页码 146-149 doi: 10.1007/s11465-013-0260-z

摘要：

To predict more precisely the frequency of force-balanced micro accelerometer with different bias voltages, the effects of bias voltages on error sensitivity of frequency is studied. The resonance frequency of accelerometer under closed loop control is derived according to its operation principle, and its error sensitivity is derived and analyzed under over etching structure according to the characteristics of Deep Reaction Ion Etching (DRIE). Based on the theoretical results, micro accelerometer is fabricated and tested to study the influences of AC bias voltage and DC bias voltage on sensitivity, respectively. Experimental results indicate that the relative errors between test data and theory data are less than 7%, and the fluctuating value of error sensitivity under the range of voltage adjustment is less than 0.01 μm . It is concluded that the error sensitivity with designed parameters of structure, circuit and process error can be used to predict the frequency of accelerometer with no need to consider the influence of bias voltage.

关键词： Micro-Electro-Mechanical Systems (MEMS) micro accelerometer force-balanced micro accelerometer frequency error sensitivity

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liquid addition attained advanced nitrogen removal in low C/N ratio municipal wastewater through short-cut

Shengjie Qiu, Jinjin Liu, Liang Zhang, Qiong Zhang, Yongzhen Peng

《环境科学与工程前沿（英文）》 2021年第15卷第2期 doi: 10.1007/s11783-020-1318-x

摘要： Abstract • Sludge fermentation liquid addition resulted in a high NAR of 97.4%. • Extra NH4+-N from SFL was removed by anammox in anoxic phase. • Nitrogen removal efficiency of 92.51% was achieved in municipal wastewater. • The novel system could efficiently treat low COD/N municipal wastewater. Biological nitrogen removal of wastewater with low COD/N ratio could be enhanced by the addition of wasted sludge fermentation liquid (SFL), but the performance is usually limited by the introducing ammonium. In this study, the process of using SFL was successfully improved by involving anammox process. Real municipal wastewater with a low C/N ratio of 2.8–3.4 was treated in a sequencing batch reactor (SBR). The SBR was operated under anaerobic-aerobic-anoxic (AOA) mode and excess SFL was added into the anoxic phase. Stable short-cut nitrification was achieved after 46d and then anammox sludge was inoculated. In the stable period, effluent total inorganic nitrogen (TIN) was less than 4.3 mg/L with removal efficiency of 92.3%. Further analysis suggests that anammox bacteria, mainly affiliated with Candidatus_Kuenenia, successfully reduced the external ammonia from the SFL and contributed approximately 28%–43% to TIN removal. Overall, this study suggests anammox could be combined with SFL addition, resulting in a stable enhanced nitrogen biological removal.

关键词： Sludge fermentation liquid Municipal wastewater Advanced nitrogen removal Short-cut nitrification Partial anammox

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Pressure swing adsorption/membrane hybrid processes for hydrogen purification with a high recovery

Baojun Li,Gaohong He,Xiaobin Jiang,Yan Dai,Xuehua Ruan

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 255-264 doi: 10.1007/s11705-016-1567-1

摘要： Hydrogen was recovered and purified from coal gasification-produced syngas using two kinds of hybrid processes: a pressure swing adsorption (PSA)-membrane system (a PSA unit followed by a membrane separation unit) and a membrane-PSA system (a membrane separation unit followed by a PSA unit). The PSA operational parameters were adjusted to control the product purity and the membrane operational parameters were adjusted to control the hydrogen recovery so that both a pure hydrogen product (>99.9%) and a high recovery (>90%) were obtained simultaneously. The hybrid hydrogen purification processes were simulated using HYSYS and the processes were evaluated in terms of hydrogen product purity and hydrogen recovery. For comparison, a PSA process and a membrane separation process were also used individually for hydrogen purification. Neither process alone produced high purity hydrogen with a high recovery. The PSA-membrane hybrid process produced hydrogen that was 99.98% pure with a recovery of 91.71%, whereas the membrane-PSA hybrid process produced hydrogen that was 99.99% pure with a recovery of 91.71%. The PSA-membrane hybrid process achieved higher total H recoveries than the membrane-PSA hybrid process under the same H recovery of membrane separation unit. Meanwhile, the membrane-PSA hybrid process achieved a higher total H recovery (97.06%) than PSA-membrane hybrid process (94.35%) at the same H concentration of PSA feed gas (62.57%).

关键词： hydrogen purification PSA membrane separation hybrid process

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针对目标跟踪的两种基于最大期望算法测量值偏差估计过程的性能分析 None

Zhi-hua LU, Meng-yao ZHU, Qing-wei YE, Yu ZHOU

《信息与电子工程前沿（英文）》 2018年第19卷第9期页码 1151-1165 doi: 10.1631/FITEE.1800214

摘要：在现实目标跟踪问题中，传感器采集的测量值，比如系统缺陷，可能存在一定程度偏差。为正确估计目标的运动轨迹，测量值偏差的识别与估计将成为首要任务。首先，提出两种状态空间模型，分别把测量值偏差视为随机变量和常数。其次，假设测量值样本数足够大，基于最大期望算法，利用扩展卡尔曼滤波和平滑，针对两种模型提出不同的循环迭代偏差估计过程。最后，分析这两种估计过程的全局收敛结果，揭示其内在联系。结果表明，第二种估计过程比第一种估计过程更简单准确，并且收敛速度更快。批量处理测量值样本后，可同时获得目标运动轨迹和测量值偏差的估计结果。

关键词：非线性状态空间模型；测量值偏差；扩展卡尔曼滤波；扩展卡尔曼平滑；最大期望算法

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A method for quantifying bias in modeled concentrations and source impacts for secondary particulate

Cesunica E. Ivey, Heather A. Holmes, Yongtao Hu, James A. Mulholland, Armistead G. Russell

《环境科学与工程前沿（英文）》 2016年第10卷第5期 doi: 10.1007/s11783-016-0866-6

摘要： A method for quantifying source impacts for secondary PM species is derived. The method provides estimates of bias in modeled concentrations. Adjusted concentrations match corresponding observations at monitored locations. Sources impacts on secondary species are estimated over the US for 20 sources. Community Multi-Scale Air Quality (CMAQ) estimates of sulfates, nitrates, ammonium, and organic carbon are highly influenced by uncertainties in modeled secondary formation processes, such as chemical mechanisms, volatilization, and condensation rates. These compounds constitute the majority of PM mass, and reducing bias in estimated concentrations has benefits for policy measures and epidemiological studies. In this work, a method for adjusting source impacts on secondary species is developed that provides estimates of source contributions and reduces bias in modeled concentrations compared to observations. The bias correction adjusts concentrations and source impacts based on the difference between modeled concentrations and observations while taking into account uncertainties at the location of interest; and it is applied both spatially and temporally. We apply the method over the US for 2006. The mean bias for initial CMAQ concentrations compared to observations is −0.28 (OC), 0.11 (NO ), 0.05 (NH ), and −0.08 (SO ). The normalized mean bias in modeled concentrations compared to observations was effectively zero for OC, NO , NH , and SO after applying the secondary bias correction. 10-fold cross-validation was conducted to determine the performance of the spatial application of the bias correction. Cross-validation performance was favorable; correlation coefficients were greater than 0.69 for all species when comparing observations and concentrations based on kriged correction factors. The methods presented here address model uncertainties by improving simulated concentrations and source impacts of secondary particulate matter through data assimilation. Secondary-adjusted concentrations and source impacts from 20 emissions sources are generated for 2006 over continental US.

关键词： Particulate matter Source apportionment Secondary particulate matter Chemical transport modeling Receptor modeling

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Common biases in client involved decision-making in the AEC industry

Sujesh F. SUJAN, Arto KIVINIEMI, Steve W. JONES, Jacqueline M. WHEATHCROFT, Eilif HJELSETH

《工程管理前沿（英文）》 2019年第6卷第2期页码 221-238 doi: 10.1007/s42524-019-0026-3

摘要： Understanding of the constitution of client involved decisions is important for future improvements of the processes. Significant decisions in construction projects are reliant on heuristic processes where assumptions are developed from past experience. The paper presents a methodology to collect empirical data in an unstructured manner utilizing participant intuition and experience regarding project level collaboration, a term easily understood by practitioners. Empirical data collected from 6 focus group discussions in Norway and 18 individual interviews in Finland is associated with biases in decision making aimed at bridging the gap of understanding and literature’s insufficient coverage. An analytic framework was developed to suit the diverse emergence of concepts to allow application of psychological principles in a structured manner to empirical data. The paper contributes by identifying types of cognitive and motivational biases in client involved decisions. The biases are found to be alleviated by one another depending on the particular application of the decision. Findings suggest that normative beliefs exist developed from past experience and habitual thinking. A number of emerged biases in this domain are alleviated from normative beliefs which are discussed in this paper.

关键词： collaboration construction industry social science decision-making client cognitive bias motivational bias holistic analysis human factor

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Bioenergy recovery from landfill gas: A case study in China

Wei WANG, Yuxiang LUO, Zhou DENG

《环境科学与工程前沿（英文）》 2009年第3卷第1期页码 20-31 doi: 10.1007/s11783-009-0012-9

摘要： Landfill gas (LFG) utilization which means a synergy between environmental protection and bioenergy recovery was investigated in this study. Pressure swing adsorption technology was used in LFG purification, and laboratory experiment, pilot-scale test, and on-site demonstration were carried out in Shenzhen, China. In the laboratory experiment, A-type carbon molecular sieve was selected as the adsorbent by comparison of several other adsorbents. The optimal adsorption pressure and adsorption time were 0.25 MPa and 2 min, respectively, under which the product generation rate was 4.5 m /h and the methane concentration was above 90%. The process and optimization of the pilot-scale test were also reported in the paper. The product gas was of high quality compared with the National Standard of Compressed Natural Gas as Vehicle Fuel (GB18047-2000), when the air concentration in feed gas was under 10.96%. The demonstration project was composed of a collection system, production system, and utilization system. The drive performance, environmental protection performance, and economic feasibility of the product gas – as alternative fuel in passenger car, truck, and bulldozer – were tested, showing the feasibility technology for LFG utilization.

关键词： landfill gas (LFG) compressed purified landfill gas (CPLG) pressure swing adsorption (PSA) alternative vehicle fuel demonstration project

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风包粉系列浓淡煤粉燃烧技术的研究

秦裕琨,李争起,孙锐,陈力哲,孙绍增,朱群益,李瑞扬,高继慧,吴少华

《中国工程科学》 2002年第4卷第11期页码 42-49

摘要：

总结了哈尔滨工业大学15年来对浓淡煤粉燃烧技术的研究成果，阐述了浓淡煤粉燃烧技术的原理及所具有的风包粉流动特点，并通过工业试验验证了风包粉原理。针对我国电站锅炉燃煤的特点，提出了需要解决的5个问题，指出了浓淡燃烧技术的发展方向。

关键词：锅炉燃烧器浓淡燃烧 NO_x

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PSS sorbents for removing trace hydrogen sulfide in methane

Limei ZHONG, Li ZHOU

《化学科学与工程前沿（英文）》 2011年第5卷第3期页码 339-342 doi: 10.1007/s11705-010-0569-7

摘要： Sorbents of the pressure swing sorption process (PSS) to remove trace amount of H S (190 ppm) contained in methane were experimentally studied. The sorbents consist of adsorbent carrier (silica gel or activated carbon) and absorbent which spreads outside the carrier granules’ pores (triethanolamine, TEA or -methyl-2-pyrrolidone, NMP). The results of breakthrough and regeneration tests show that silica gel is more suitable to be the carrier than activated carbon and TEA is more suitable to be the absorbent than NMP. The loaded absorbent could enlarge the sorption capacity of H S considerably. And the BET tests indicate that the absorbent deposits on the surface of the carrier’s pores and can reduce the mesopores’ size and block the micropores.

关键词： pressure swing sorption H₂S methane carrier absorbent

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难加工材料高速切削力非线性特征规律的最大熵谱分析与小波分析

龙震海,王西彬,王好臣

《中国工程科学》 2004年第6卷第10期页码 28-31

摘要：

在切削速度范围157～1000 m/min内，综合应用析因试验与速度单因素试验，对航空用难加工材料2Cr13马氏体不锈钢进行了高速干式铣削试验。在分析其切削力显著性影响因素的基础上，对切削力随机信号进行了现代谱分析与小波分析。研究结果表明，高速切削马氏体不锈钢材料时，切削速度和每齿进给量之间的交互作用对切削力有显著影响；铣削深度和每齿进给量之间的交互作用在切削力响应信号中表现为低频周期信号；低频周期信号与高频信号叠加后，其波形的振幅将会增大。

关键词：难加工材料高速切削析因设计 Meyer小波变换 Mallat算法