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期刊论文 22

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2023 1

2022 1

2021 5

2019 2

2017 3

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关键词

DPP);分布式功率转换器;开关电容转换器 1

MPPT);差分功率处理(Differential power processing 1

两亲高分子 1

亲水 1

全局优化 1

共混微孔膜 1

共混膜 1

分段线性松弛 1

子模块级最大功率点跟踪(Sub-module-level maximum power point tracking 1

抗污染 1

油水分离 1

浸没沉淀 1

聚(乙烯-乙烯醇) 1

聚乙烯吡咯烷酮 1

表面富集 1

连续时间调合模型 1

遍历保密容量,最大比合并,加权误差,物理层保密,选择合并,单输入多输出 1

非线性汽油调合 1

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Influence of nozzle height to width ratio on ignition and NO

Liutao SUN, Yonghong YAN, Rui SUN, Zhengkang PENG, Chunli XING, Jiangquan WU

《能源前沿(英文)》 2021年 第15卷 第2期   页码 431-448 doi: 10.1007/s11708-021-0726-3

摘要: To improve the ignition behavior and to reduce the high NO emissions of blended pulverized fuels (PF) of semicoke (SC), large-scale experiments were conducted in a 300 kW fired furnace at various nozzle settings, i.e., ratios (denoted by / ) of the height of the rectangular burner nozzle to its width of 1.65, 2.32, and 3.22. The combustion tests indicate that the flame stability, ignition performance, and fuel burnout ratio were significantly improved at a nozzle setting of / = 2.32. The smaller / delayed ignition and caused the flame to concentrate excessively on the axis of the furnace, while the larger / easily caused the deflection of the pulverized coal flame, and a high-temperature flame zone emerged close to the furnace wall. NO emissions at the outlet of the primary zone decreased from 447 to 354 mg/m (O = 6%), and the ignition distance decreased from 420 to 246 mm when the / varied from 1.65 to 3.22. Furthermore, the ratio (denoted by / ) of the strong reduction zone area to the combustion reaction zone area was defined experimentally by the CO concentration to evaluate the reduction zone. The / rose monotonously, but its restraining effects on NO formation decreased as / increased. The results suggested that in a test furnace, regulating the nozzle / conditions sharply reduces NO emissions and improves the combustion efficiency of SC blends possessing an appropriate jet rigidity.

关键词: rectangular jet burner     nozzle height to width ratio     ignition characteristics     pyrolyzed semicoke (SC) and bituminous blend     NOx formation    

Effects of pyrolyzed semi-char blend ratio on coal combustion and pollution emission in a 0.35 MW pulverized

Yonghong YAN, Liutao SUN, Zhengkang PENG, Hongliang QI, Li LIU, Rui SUN

《能源前沿(英文)》 2021年 第15卷 第1期   页码 78-90 doi: 10.1007/s11708-020-0678-z

摘要: The effects of blend ratio on combustion and pollution emission characteristics for co-combustion of Shenmu pyrolyzed semi-char (SC), i.e., residuals of the coal pyrolysis chemical processing, and Shenhua bituminous coal (SB) were investigated in a 0.35 MW pilot-scale pulverized coal-fired furnace. The gas temperature and concentrations of gaseous species (O , CO, CO , NO and HCN) were measured in the primary combustion zone at different blend ratios. It is found that the standoff distance of ignition changes monotonically from 132 to 384 mm with the increase in pyrolyzed semi-char blend ratio. The effects on the combustion characteristics may be neglected when the blend ratio is less than 30%. Above the 30% blend ratio, the increase in blend ratio postpones ignition in the primary stage and lowers the burnout rate. With the blend ratio increasing, NO emission at the furnace exit is smallest for the 30% blend ratio and highest for the 100% SC. The NO concentration was 425 mg/m at 6% O and char burnout was 76.23% for the 45% blend ratio. The above results indicate that the change of standoff distance and NO emission were not obvious when the blend ratio of semi-char is less than 45%, and carbon burnout changed a little at all blend ratios. The goal of this study is to achieve blending combustion with a large proportion of semi-char without great changes in combustion characteristics. So, an SC blend ratio of no more than 45% can be suitable for the burning of semi-char.

关键词: pulverized-coal combustion     pyrolyzed semi-char     ignition characteristics     pollution emission     char burnout     blend ratio    

Modeling of unconfined compressive strength of soil-RAP blend stabilized with Portland cement using multivariate

Ali Reza GHANIZADEH, Morteza RAHROVAN

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 787-799 doi: 10.1007/s11709-019-0516-8

摘要: The recycled layer in full-depth reclamation (FDR) method is a mixture of coarse aggregates and reclaimed asphalt pavement (RAP) which is stabilized by a stabilizer agent. For design and quality control of the final product in FDR method, the unconfined compressive strength of stabilized material should be known. This paper aims to develop a mathematical model for predicting the unconfined compressive strength (UCS) of soil-RAP blend stabilized with Portland cement based on multivariate adaptive regression spline (MARS). To this end, two different aggregate materials were mixed with different percentages of RAP and then stabilized by different percentages of Portland cement. For training and testing of MARS model, total of 64 experimental UCS data were employed. Predictors or independent variables in the developed model are percentage of RAP, percentage of cement, optimum moisture content, percent passing of #200 sieve, and curing time. The results demonstrate that MARS has a great ability for prediction of the UCS in case of soil-RAP blend stabilized with Portland cement ( is more than 0.97). Sensitivity analysis of the proposed model showed that the cement, optimum moisture content, and percent passing of #200 sieve are the most influential parameters on the UCS of FDR layer.

关键词: full-depth reclamation     soil-reclaimed asphalt pavement blend     Portland cement     unconfined compressive strength     multivariate adaptive regression spline    

Influence of soft rock-fill material as dam embankment with central bituminous concrete membrane

Peter TSCHERNUTTER

《结构与土木工程前沿(英文)》 2011年 第5卷 第1期   页码 63-70 doi: 10.1007/s11709-010-0016-3

摘要: This paper demonstrates the difficulties in determining the relevant material parameters for a valuation of the deformation behavior of the up- and downstream dam shell by means of an embankment dam of medium height. Laboratory as well as field tests on solid rock-fill material were performed before the beginning of construction. During the construction the properties of the available rock-fill changed from solid to soft materials. This gave rise to the necessity of adjusting the dam design of the downstream dam shoulder. Several times higher dam settlements as well as significant differential settlements between the up- and downstream dam shell were observed during construction and operation. Apart from this situation, the dam has been operated for nearly 20 years and the behavior of the water barrier has been very good.

关键词: embankment dam     bituminous concrete membrane     rock-fill material properties     deformation behavior    

Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

Yandi ZHANG, Yinhe LIU, Xiaoli DUAN, Yao ZHOU, Xiaoqian LIU, Shijin XU

《能源前沿(英文)》 2021年 第15卷 第1期   页码 14-25 doi: 10.1007/s11708-020-0805-x

摘要: In the process of pyrolysis and combustion of coal particles, coal structure evolution will be affected by the ash behavior, which will further affect the char reactivity, especially in the ash melting temperature zone. Lu’an bituminous char and ash samples were prepared at the N and air atmospheres respectively across ash melting temperature. A scanning electron microscope (SEM) was used to observe the morphology of char and ash. The specific surface area (SSA) analyzer and thermogravimetric analyzer were respectively adopted to obtain the pore structure characteristics of the coal chars and combustion parameters. Besides, an X-ray diffractometer (XRD) was applied to investigate the graphitization degree of coal chars prepared at different pyrolysis temperatures. The SEM results indicated that the number density and physical dimension of ash spheres exuded from the char particles both gradually increased with the increasing temperature, thus the coalescence of ash spheres could be observed obviously above 1100°C. Some flocculent materials appeared on the surface of the char particles at 1300°C, and it could be speculated that -Si N was generated in the pyrolysis process under N . The SSA of the chars decreased with the increasing pyrolysis temperature. Inside the char particles, the micropore area and its proportion in the SSA also declined as the pyrolysis temperature increased. Furthermore, the constantly increasing pyrolysis temperature also caused the reactivity of char decrease, which is consistent with the results obtained by XRD. The higher combustion temperature resulted in the lower porosity and more fragments of the ash.

关键词: bituminous char     pyrolysis     ash     structure evolution     reactivity    

utilization of coal resources: The polygeneration system of a combination of the gasified coal gas and the pyrolyzed

Kechang XIE, Fan LI

《化学科学与工程前沿(英文)》 2010年 第4卷 第4期   页码 383-384 doi: 10.1007/s11705-010-0526-5

A study on quality evaluation for bituminous mixture using X-ray CT

Satoshi TANIGUCHI, Keiichiro OGAWA, Jun OTANI, Itaru NISHIZAKI

《结构与土木工程前沿(英文)》 2013年 第7卷 第2期   页码 89-101 doi: 10.1007/s11709-013-0197-7

摘要: The objective of this paper is to propose a new quality evaluation method for asphalt concrete mixture using X-ray CT scanner. To achieve this aim, asphalt mixtures should be subjected to the X-ray CT scanning and its characteristics should be clarified. The approach employed in this study was as follows: 1) Coarse aggregate, fine aggregate, filler and bitumen were prepared; 2) dense-graded, coarse-graded and porous asphalt mixtures were made; 3) materials and mixtures were subjected to the X-ray CT scanning; 4) frequency of CT-value, threshold value, average slice CT-value, average segment CT-value were computed. In the material examination, CT-value of aggregate becomes smaller in the order of coarse aggregate, fine aggregate and filler and CT image of bitumen was nearly homogeneous. In the mixture examination, histograms of CT-value and four segmentation images made from CT images expressed the material and mixture characterization such as particle size and the difference in bitumen content and mixture type visibly and the bitumen content varies with the threshold values. In addition, the average segment CT-value without threshold value by dividing the fine aggregate from the coarse aggregate and average CT-value of the coarse aggregate, especially is highly correlated with average CT-value of the bitumen.

关键词: asphalt concrete mixture     aggregate     bitumen     bitumen content     quality evaluation     X-ray CT    

Investigation of effects of Cocamide Diethanolamide chemical on physical and rheological properties of bituminous

《结构与土木工程前沿(英文)》 2022年 第16卷 第1期   页码 99-116 doi: 10.1007/s11709-021-0799-4

摘要: In this study, bituminous binder was modified with Cocamide Diethanolamide chemical, a non-ionic surfactant, and the physical and rheological properties of modified binders were investigated. In addition, Cocamide Diethanolamide has been used for the first time to modify bituminous binder, and this situation makes the study distinctive. Bituminous binder was modified more than once with the chemical by changing modification parameters and using certain additive ratios (1%, 3%, and 5%). The effects of different modification parameters and chemical additive on modified samples were investigated with conventional bitumen tests (softening point, penetration, ductility) and Superpave tests (rotational viscometer, rolling thin film oven test, pressure aging vessel, dynamic shear rheometer, bending beam rheometer). In addition, the structural characteristics of the reference binder and modified samples were examined by X-ray diffraction, Fourier Transform Infrared Spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The examinations showed that Cocamide Diethanolamide softens bituminous binder and lowers processing temperatures. In addition, compared to reference binder, rutting resistances of modified bituminous binders decreased with the increase of additive ratio. However, modification with Cocamide Diethanolamide increased the resistance to fatigue cracks and thermal cracks.

关键词: Cocamide Diethanolamide     bitumen modification     rheology     Superpave tests    

Numerical simulation of combustion characteristics at different coal concentrations in bituminous coal

Chunlong LIU, Qunyi ZHU, Zhengqi LI, Qiudong ZONG, Yiquan XIE, Lingyan ZENG

《能源前沿(英文)》 2013年 第7卷 第2期   页码 255-262 doi: 10.1007/s11708-013-0255-9

摘要: With the objective of producing a full-scale tiny-oil ignition burner, identical to the burner used in an 800 MWe utility boiler, numerical simulations were performed using Fluent 6.3.26 to study the progress of ignition for four coal concentration settings covering sub-operation conditions prevailing during the experiments performed with the burner. The numerical simulations conformed to the experimental results, demonstrating the suitability of the model used in the calculations. Simulations for a coal concentration of 0.40 kg/kg corresponding to a single burner operating at its rated output were also conducted, which indicated that gas temperatures along the burner centerline were high. As gas flowed to the burner nozzle, the high-temperature region expanded, ensuring a successful pulverized-coal ignition. With increasing coal concentration (0.08–0.40 kg/kg), the gas temperature along the burner centerline and at the first and second combustion chamber exits decreased at the equivalent radial points. At the center of the second combustion chamber exit, the O concentrations were almost depleted for the five coal concentrations, while the CO concentrations peaked.

关键词: numerical simulation     tiny-oil ignition burner     pulverized coal     temperature field    

Influence of different oil feed rate on bituminous coal ignition in a full-scale tiny-oil ignition burner

Chunlong LIU, Qunyi ZHU, Zhengqi LI, Qiudong ZONG, Xiang ZHANG, Zhichao CHEN

《能源前沿(英文)》 2013年 第7卷 第3期   页码 406-412 doi: 10.1007/s11708-013-0266-6

摘要: To reduce oil consumption during firing-up and partial-load operation, a tiny-oil ignition burner has been recommended. Through reacting-flow experiments performed on a full-scale experimental setup, the influence of different oil flow rates on bituminous coal combustion as well as flow rates without coal feed was analyzed. The ignition burner is identical to that normally used in an 800 MWe utility boiler. Under operating conditions with flow rates of 50, 100, and 150 kg/h, gas temperature distributions were measured in the burner. At the equivalent measuring points at the exits of the first and second combustion chambers, these distributions remained almost unchanged under a constant coal feed rate of 4 t/h. However on the burner centerline, distributions increased slightly with increasing flow rate. Different gas concentrations were measured at the center of the burner exit. For instance, the O concentration at the burner exit varied from 0.01% to 0.31% whereas CO concentrations were more than 10000 ppm. At the same coal feed rate of 4 t/h, burner resistances are 480, 600, and 740 Pa for oil flow rates of 50, 100, and 150 kg/h, respectively.

关键词: ignition     coal     burner     boiler     oil flow rate    

Numerical simulation of bituminous coal combustion in a full-scale tiny-oil ignition burner: influence

Zhengqi LI, Chunlong LIU, Xiang ZHANG, Lingyan ZENG, Zhichao CHEN

《能源前沿(英文)》 2012年 第6卷 第3期   页码 296-303 doi: 10.1007/s11708-012-0191-0

摘要: The progression of ignition was numerically simulated with the aim of realizing a full-scale tiny-oil ignition burner that is identical to the burner used in an 800 MWe utility boiler. The numerical simulations were conducted for four excess air ratios, 0.56, 0.75, 0.98 and 1.14 (corresponding to primary air velocities of 17, 23, 30 and 35 m/s, respectively), which were chosen because they had been used previously in practical experiments. The numerical simulations agreed well with the experimental results, which demonstrate the suitability of the model used in the calculations. The gas temperatures were high along the center line of the burner for the four excess air ratios. The flame spread to the burner wall and the high-temperature region was enlarged in the radial direction along the primary air flow direction. The O concentrations for the four excess air ratios were 0.5%, 1.1%, 0.9% and 3.0% at the exit of the second combustion chamber. The CO peak concentration was very high with values of 7.9%, 9.9%, 11.3% and 10.6% for the four excess air ratios at the exit of the second combustion chamber.

关键词: numerical simulation     tiny-oil ignition burner     pulverized coal     temperature field    

nominal maximum aggregate sizes in the bending beam rheometer on the prediction of thermal properties of bituminous

Chun-Hsing HO,María Francisca Martínez GONZÁLEZ,Cristina Pilar Martín LINARES

《结构与土木工程前沿(英文)》 2017年 第11卷 第1期   页码 1-7 doi: 10.1007/s11709-016-0367-5

摘要: The objective of this research is to evaluate an impact of asphalt mixture beams with varying sizes of aggregate in the Bending Beam Rheometer (BBR) for testing/predicting thermal cracking properties of asphalt pavements. The BBR test has following benefits: the equipment is cheaper, it uses smaller specimens, faster conditioning, easier availability for quality control, easier to manage, etc. However some concerns have been raised: some consider that the size of the aggregate may affect the test’s results; the other concern is that such small beams cannot represent the whole properties of the asphalt pavement. To address these criticisms, imaging techniques, statistical analysis, and viscoelastic modeling are used. Asphalt thin beams prepared with three different nominal maximum aggregate size (NMAS) (12.5mm, 9.5 mm, and 4.75 mm) were tested at three different temperatures (-18°C, -24°C, and -30°C). Based on results from statistical analyses and viscoelasticity, the ratio of asphalt binders and voids and stiffness differences among the three NMAS specimens are not significant, meaning that the impact of asphalt thin beams prepared with the three NMAS on the prediction of thermal cracking is minimal and can be neglected.

关键词: bending beam rheometer     thin beams     thermal cracking    

存在信道状态估计误差的最大比合并/选择合并分集技术在单输入多输出窃密系统中的遍历保密容量分析 Article

Hui ZHAO, You-yu TAN, Gao-feng PAN, Yun-fei CHEN

《信息与电子工程前沿(英文)》 2017年 第18卷 第4期   页码 578-590 doi: 10.1631/FITEE.1500430

摘要: 在物理层中,本文研究了存在信道估计误差的最大比合并/选择合并的保密容量性能。在一个单输入多输出窃密信道中,信源向一个装备M根接收天线并采用最大比合并/选择合并技术处理多径信号的信宿发送保密信息。与此同时,一个窃密者装备N根接收天线并采用最大比合并/选择合并技术来提高窃密的成功率。我们分别推导了两种情况下遍历保密容量的精确和近似闭式表达式:(1)最大比合并带有信道估计误差;(2)选择合并带有信道延迟。此外,本文得到了高信噪比斜率和高信噪比功率补偿两个重要的参数,它们在高信噪比条件下决定了遍历保密容量。最后,本文通过仿真分析验证了所得到的闭式表达式的准确性。

关键词: 遍历保密容量,最大比合并,加权误差,物理层保密,选择合并,单输入多输出    

聚乙烯吡咯烷酮/聚(乙烯-乙烯醇)共混膜的制备及其油水分离性能

白云翔,吴国梁,张春芳,顾瑾,孙余凭

《中国工程科学》 2014年 第16卷 第7期   页码 79-83

摘要:

将聚乙烯吡咯烷酮(PVP)与聚(乙烯-乙烯醇)(EVAL)共混,采用浸没沉淀法制备了PVP/EVAL共混膜,并用于油水乳液分离过程。通过全反射红外光谱、扫描电子显微镜、拉伸试验、接触角测试等对膜的组成、结构形态、机械性能、亲水性进行了表征,并研究了PVP添加量对共混膜油水分离性能的影响。结果表明:添加PVP能较显著地改变EVAL膜的结构,且共混膜的机械强度和亲水性得到明显改善,当PVP添加量为10 wt%(PVP在铸膜液中的质量分数)时,其拉伸强度和断裂伸长率分别为纯EVAL膜的1.88 倍和1.34 倍。当PVP 添加量为4 wt%时,油水分离稳定通量为纯EVAL 膜的1.81 倍,截留率为92.2 %,比纯EVAL 膜略高。PVP 添加量为10 wt%的PVP/EVAL 共混膜清洗后通量恢复率由纯EVAL 膜的51 %增至77.98 %。

关键词: 聚乙烯吡咯烷酮     聚(乙烯-乙烯醇)     共混膜     油水分离     浸没沉淀    

Expulsive force in the development of CO

Haizhu WANG,Gensheng LI,Zhonghou SHEN,Zhenguo HE,Qingling LIU,Bin ZHU,Youwen WANG,Meng WANG

《能源前沿(英文)》 2019年 第13卷 第1期   页码 1-8 doi: 10.1007/s11708-017-0458-6

摘要: With the rapid development of global economy, an increasing amount of attention has been paid to the emission of greenhouse gases, especially CO . In recent years, dominated by the governments around the world, several significant projects of CO sequestration have been conducted. However, due to the huge investment and poor economic effects, the sustainability of those projects is not satisfactory. Supercritical CO (SC-CO ) has prominent advantages in well drilling, fracturing, displacement, storage, plug and scale removal within tubing and casing, which could bring considerable economic benefits along with CO sequestration. In this paper, based on physicochemical properties of SC-CO fluid, a detailed analysis of technical advantages of SC-CO applied in oil and gas development is illustrated. Furthermore, the implementation processes of SC-CO are also proposed. For the first time, a recycling process is presented in which oil and gas are extracted and the CO generated could be restored underground, thus an integrated technology system is formed. Considering the recent interests in the development of enhancing hydrocarbon recoveries and CO sequestration, this approach provides a promising technique that can achieve these two goals simultaneously.

关键词: CO2 sequestration     SC-CO2 jet     well drilling     fracturing     oil and gas    

标题 作者 时间 类型 操作

Influence of nozzle height to width ratio on ignition and NO

Liutao SUN, Yonghong YAN, Rui SUN, Zhengkang PENG, Chunli XING, Jiangquan WU

期刊论文

Effects of pyrolyzed semi-char blend ratio on coal combustion and pollution emission in a 0.35 MW pulverized

Yonghong YAN, Liutao SUN, Zhengkang PENG, Hongliang QI, Li LIU, Rui SUN

期刊论文

Modeling of unconfined compressive strength of soil-RAP blend stabilized with Portland cement using multivariate

Ali Reza GHANIZADEH, Morteza RAHROVAN

期刊论文

Influence of soft rock-fill material as dam embankment with central bituminous concrete membrane

Peter TSCHERNUTTER

期刊论文

Effect of temperature on Lu’an bituminous char structure evolution in pyrolysis and combustion

Yandi ZHANG, Yinhe LIU, Xiaoli DUAN, Yao ZHOU, Xiaoqian LIU, Shijin XU

期刊论文

utilization of coal resources: The polygeneration system of a combination of the gasified coal gas and the pyrolyzed

Kechang XIE, Fan LI

期刊论文

A study on quality evaluation for bituminous mixture using X-ray CT

Satoshi TANIGUCHI, Keiichiro OGAWA, Jun OTANI, Itaru NISHIZAKI

期刊论文

Investigation of effects of Cocamide Diethanolamide chemical on physical and rheological properties of bituminous

期刊论文

Numerical simulation of combustion characteristics at different coal concentrations in bituminous coal

Chunlong LIU, Qunyi ZHU, Zhengqi LI, Qiudong ZONG, Yiquan XIE, Lingyan ZENG

期刊论文

Influence of different oil feed rate on bituminous coal ignition in a full-scale tiny-oil ignition burner

Chunlong LIU, Qunyi ZHU, Zhengqi LI, Qiudong ZONG, Xiang ZHANG, Zhichao CHEN

期刊论文

Numerical simulation of bituminous coal combustion in a full-scale tiny-oil ignition burner: influence

Zhengqi LI, Chunlong LIU, Xiang ZHANG, Lingyan ZENG, Zhichao CHEN

期刊论文

nominal maximum aggregate sizes in the bending beam rheometer on the prediction of thermal properties of bituminous

Chun-Hsing HO,María Francisca Martínez GONZÁLEZ,Cristina Pilar Martín LINARES

期刊论文

存在信道状态估计误差的最大比合并/选择合并分集技术在单输入多输出窃密系统中的遍历保密容量分析

Hui ZHAO, You-yu TAN, Gao-feng PAN, Yun-fei CHEN

期刊论文

聚乙烯吡咯烷酮/聚(乙烯-乙烯醇)共混膜的制备及其油水分离性能

白云翔,吴国梁,张春芳,顾瑾,孙余凭

期刊论文

Expulsive force in the development of CO

Haizhu WANG,Gensheng LI,Zhonghou SHEN,Zhenguo HE,Qingling LIU,Bin ZHU,Youwen WANG,Meng WANG

期刊论文