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Performance evaluation of an improved biomass-fired cogeneration system simultaneously using extractionsteam, cooling water, and feedwater for heating

《能源前沿（英文）》 2022年 第16卷 第2期   页码 321-335 doi: 10.1007/s11708-021-0741-4

摘要： An advanced cogeneration system based on biomass direct combustion was developed and its feasibility was demonstrated. In place of the traditional single heat source (extraction steam), the extraction steam from the turbine, the cooling water from the plant condenser, and the low-pressure feedwater from the feedwater preheating system were collectively used for producing district heat in the new scheme. Hence, a remarkable energy-saving effect could be achieved, improving the overall efficiency of the cogeneration system. The thermodynamic and economic performance of the novel system was examined when taking a 35 MW biomass-fired cogeneration unit for case study. Once the biomass feed rate and net thermal production remain constant, an increment of 1.36 MW can be expected in the net electric production, because of the recommended upgrading. Consequently, the total system efficiency and effective electrical efficiency augmented by 1.23 and 1.50 percentage points. The inherent mechanism of performance enhancement was investigated from the energy and exergy aspects. The economic study indicates that the dynamic payback period of the retrofitting project is merely 1.20 years, with a net present value of 5796.0 k$. In conclusion, the proposed concept is validated to be advantageous and profitable.

关键词： biomass-fired cogeneration     district heat production system     absorption heat pump     extraction steam     cooling water     low-pressure feedwater    

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Combination of steam-enhanced extraction and electrical resistance heating for efficient remediation

《环境科学与工程前沿（英文）》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1582-z

摘要：

● Coupling merits of SEE and ERH were explored by a laboratory-scale device.

关键词： Steam-enhanced extraction     Electrical resistance heating     Dense nonaqueous phase liquid     Soil remediation     Energy consumption    

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低渗高粘稀油油藏蒸汽采油技术研究

王立智,王云龙

《中国工程科学》 2012年 第14卷 第4期   页码 88-94

摘要：

为了探索高粘稀油油藏降低储层原油粘度、提高渗流能力、增加流度，进一步研究区块加密后提高采收率的新技术、新方法，2006—2008年开展了“蒸汽驱油现场先导试验”。针对油藏原油粘度高、渗透率低、粘土含量高、有效厚度小等特点，开展了室内物模实验，进行了蒸汽驱油可行性研究；应用数值模拟技术优选了注汽参数和驱替方式；开展了地层防膨预处理和井筒隔热技术研究。现场试验3个井组，累积增油1.81×104 t。通过试验研究，给出了低渗高粘稀油油藏适合蒸汽驱油技术的地质条件。

关键词： 低渗     高粘稀油     蒸汽采油    

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Entity and relation extraction with rule-guided dictionary as domain knowledge

《工程管理前沿（英文）》   页码 610-622 doi: 10.1007/s42524-022-0226-0

摘要： Entity and relation extraction is an indispensable part of domain knowledge graph construction, which can serve relevant knowledge needs in a specific domain, such as providing support for product research, sales, risk control, and domain hotspot analysis. The existing entity and relation extraction methods that depend on pretrained models have shown promising performance on open datasets. However, the performance of these methods degrades when they face domain-specific datasets. Entity extraction models treat characters as basic semantic units while ignoring known character dependency in specific domains. Relation extraction is based on the hypothesis that the relations hidden in sentences are unified, thereby neglecting that relations may be diverse in different entity tuples. To address the problems above, this paper first introduced prior knowledge composed of domain dictionaries to enhance characters’ dependence. Second, domain rules were built to eliminate noise in entity relations and promote potential entity relation extraction. Finally, experiments were designed to verify the effectiveness of our proposed methods. Experimental results on two domains, including laser industry and unmanned ship, showed the superiority of our methods. The F1 value on laser industry entity, unmanned ship entity, laser industry relation, and unmanned ship relation datasets is improved by +1%, +6%, +2%, and +1%, respectively. In addition, the extraction accuracy of entity relation triplet reaches 83% and 76% on laser industry entity pair and unmanned ship entity pair datasets, respectively.

关键词： entity extraction     relation extraction     prior knowledge     domain rule    

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Modeling analysis on solar steam generator employed in multi-effect distillation (MED) system

Zhaorui ZHAO, Bao YANG, Ziwen XING

《能源前沿（英文）》 2019年 第13卷 第1期   页码 193-203 doi: 10.1007/s11708-019-0608-0

摘要： Recently the porous bilayer wood solar collectors have drawn increasing attention because of their potential application in solar desalination. In this paper, a thermodynamic model has been developed to analyze the performance of the wood solar collector. A modeling analysis has also been conducted to assess the performance and operating conditions of the multiple effect desalination (MED) system integrated with the porous wood solar collector. Specifically, the effects of operating parameters, such as the motive steam temperature, seawater flow rate, input solar energy and number of effects on the energy consumption for each ton of distilled water produced have been investigated in the MED desalination system combined with the bilayer wood solar steam generator. It is found that, under a given operating condition, there exists an optimum steam generation temperature of around 145°C in the wood solar collector, so that the specific power consumption in the MED system reaches a minimum value of 24.88 kWh/t. The average temperature difference is significantly affected by the solar heating capacity. With the solar capacity increasing from 50 kW to 230 kW, the average temperature difference increases from 1.88°C to 6.27°C. This parametric simulation study will help the design of efficient bilayer wood solar steam generator as well as the MED desalination system.

关键词： solar energy     steam generating     multi-effect desalination    

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Intrinsic kinetics and external diffusion of catalytic steam gasification of fine coal char particles

Xuantao Wu, Jie Wang

《化学科学与工程前沿（英文）》 2019年 第13卷 第2期   页码 415-426 doi: 10.1007/s11705-018-1725-8

摘要： Catalytic steam gasification of fine coal char particles was carried out using a self-made laboratory reactor to determine the intrinsic kinetics and external diffusion under varying pressures (0.1–0.5 MPa) and superficial gas flow velocities (GFVs) of 13.8–68.8 cm?s . In order to estimate the gas release rate at a low GFV, the transported effect of effluent gas on the temporal gasification rate pattern was simulated by the Fluent computation and verified experimentally. The external mass transfer coefficients ( ) and the effectiveness factors were determined at lower GFVs, based on the intrinsic gasification rate obtained at a high GFV of 55.0 cm?s . The was found to be almost invariable in a wider carbon conversion of 0.2–0.7. The variations of at a median carbon conversion with GFV, temperature and pressure were found to follow a modified Chilton-Colburn correlation: (0.04< <0.19), where is total pressure and is atmospheric pressure. An intrinsic kinetics/external diffusion integrating model could well describe the gasification rate as a function of GFV, temperature and pressure over a whole gasification process.

关键词： coal char     catalytic steam gasification     pressure     kinetics     diffusion    

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High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in a steam

《机械工程前沿（英文）》 2023年 第18卷 第2期 doi: 10.1007/s11465-022-0741-z

摘要： Many heat transfer tubes are distributed on the tube plates of a steam generator that requires periodic inspection by robots. Existing inspection robots are usually involved in issues: Robots with manipulators need complicated installation due to their fixed base; tube mobile robots suffer from low running efficiency because of their structural restricts. Since there are thousands of tubes to be checked, task planning is essential to guarantee the precise, orderly, and efficient inspection process. Most in-service robots check the task tubes using row-by-row and column-by-column planning. This leads to unnecessary inspections, resulting in a long shutdown and affecting the regular operation of a nuclear power plant. Therefore, this paper introduces the structure and control system of a dexterous robot and proposes a task planning method. This method proceeds into three steps: task allocation, base position search, and sequence planning. To allocate the task regions, this method calculates the tool work matrix and proposes a criterion to evaluate a sub-region. And then all tasks contained in the sub-region are considered globally to search the base positions. Lastly, we apply an improved ant colony algorithm for base sequence planning and determine the inspection orders according to the planned path. We validated the optimized algorithm by conducting task planning experiments using our robot on a tube sheet. The results show that the proposed method can accomplish full task coverage with few repetitive or redundant inspections and it increases the efficiency by 33.31% compared to the traditional planning algorithms.

关键词： steam generator transfer tubes     mobile robot     dexterous structure     task planning     efficient inspection    

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A steam dried municipal solid waste gasification and melting process

Gang XIAO, Baosheng JIN, Mingjiang NI, Kefa CEN, Yong CHI, Zhongxin TAN

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 193-204 doi: 10.1007/s11783-010-0268-0

摘要： Considering high-moisture municipal solid waste (MSW) of China, a steam dried MSW gasification and melting process was proposed, the feasibility was tested, and the mass and energy balance was analyzed. Preliminary experiments were conducted using a fixed-bed drying apparatus, a 200 kg per day fluidized-bed gasifier, and a swirl melting furnace. Moisture percentage was reduced from 50% to 20% roughly when MSW was dried by slightly superheated steam of 150°C–350°C within 40 min. When the temperature was less than 250°C, no incondensable gas was produced during the drying process. The gasifier ran at 550°C–700°Cwith an air equivalence ratio (ER) of 0.2–0.4. The temperature of the swirl melting furnace reached about 1240°C when the gasification ER was 0.3 and the total ER was 1.1. At these conditions, the fly ash concentration in the flue gas was 1.7 g·(Nm ) , which meant over 95% fly ash was trapped in the furnace and discharged as slag. 85% of Ni and Cr were bound in the slag, as well as 60% of Cu. The mass and energy balance analysis indicates that the boiler heat efficiency of an industrial MSW incineration plant reaches 86.97% when MSW is dried by steam of 200°C. The boiler heat efficiency is sensitive to three important parameters, including the temperature of preheated MSW, the moisture percentage of dried MSW and the fly ash percentage in the total ash.

关键词： municipal solid waste (MSW)     steam drying     gasification and melting    

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Impacts of solar multiple on the performance of direct steam generation solar power tower plant with

Yan LUO, Xiaoze DU, Lijun YANG, Chao XU, Muhammad AMJAD

《能源前沿（英文）》 2017年 第11卷 第4期   页码 461-471 doi: 10.1007/s11708-017-0503-5

摘要： Solar multiple (SM) and thermal storage capacity are two key design parameters for revealing the performance of direct steam generation (DSG) solar power tower plant. In the case of settled land area, SM and thermal storage capacity can be optimized to obtain the minimum levelized cost of electricity (LCOE) by adjusting the power generation output. Taking the dual-receiver DSG solar power tower plant with a given size of solar field equivalent electricity of 100 MW in Sevilla as a reference case, the minimum LCOE is 21.77 ￠/kWh with an SM of 1.7 and a thermal storage capacity of 3 h. Besides Sevilla, two other sites are also introduced to discuss the influence of annual DNI. When compared with the case of Sevilla, the minimum LCOE and optimal SM of the San Jose site change just slightly, while the minimum LCOE of the Bishop site decreases by 32.8% and the optimal SM is reduced to 1.3. The influence of the size of solar field equivalent electricity is studied as well. The minimum LCOE decreases with the size of solar field, while the optimal SM and thermal storage capacity still remain unchanged. In addition, the sensitivity of different investment in sub-system is investigated. In terms of optimal SM and thermal storage capacity, they can decrease with the cost of thermal storage system but increase with the cost of power generation unit.

关键词： direct steam generation     solar power tower     solar multiple     thermal energy storage capacity     levelized cost of electricity (LCOE)    

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Thermal cracking of waste printed wiring boards for mechanical recycling by using residual steam preprocessing

Yao CHEN, Jinhui LI, Huabo DUAN, Zhishi WANG

《环境科学与工程前沿（英文）》 2011年 第5卷 第2期   页码 167-174 doi: 10.1007/s11783-011-0308-4

摘要： Mechanical waste-processing methods, which combine crushing and separation processes for the recovery of valuable materials, have been widely applied in waste printed wiring board (PWB) treatment. However, both the high impact toughness and the tensile and flexural strengths of whole PWB with a laminated structure result in great energy consumption and severe abrasion of the cutters during multi-level crushing. In addition, the high temperatures occurring in continual crushing probably cause the decomposition of the polymer matrix. A thermal-crack method using residual steam as the heating medium has been developed to pre-treat waste PWBs. This treatment reduces the mechanical strength in order to improve the recovery rate of valuable materials in subsequent mechanical recycling. The changes of the PWBs’ macro-mechanical properties were studied to evaluate thermal expansion impacts associated with changes in temperature, and the dynamic dislocation micro-structures were observed to identify the fracture mechanism. The results showed that thermal cracking with steam at the temperature of 500 K can effectively attenuate the mechanical properties of waste PWBs, by reducing the impact, tensile and flexural strengths respectively, by 59.2%, 49.3% and 51.4%, compared to untreated PWB. Thermal expansion can also facilitate the separation of copper from glass fiber by reducing peel resistance by 95.4% at 500 K. It was revealed that the flexural fracture was a transverse cracking caused by concentrated stress when the heating temperature was less than 500 K, and shifted to a vertical cracking after exceeding 500 K.

关键词： waste printed wiring board (PWB)     residue steam     thermal-crack     mechanical properties    

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Numerical simulation of a new hollow stationary dehumidity blade in last stage of steam turbine

Youmin HOU, Danmei XIE, Wangfan LI, Xinggang YU, Yang SHI, Hanshi QIN

《能源前沿（英文）》 2011年 第5卷 第3期   页码 288-296 doi: 10.1007/s11708-011-0160-z

摘要： As a result of adopting saturation steam and long blade, problems of water erosion of last stage blade for steam turbine become more prominent. In order to improve the operation reliability and efficiency of steam turbine, it is necessary to investigate the nonequilibrium condensing wet steam two phase flow and the dehumidity method. A wet steam model with user defined function based on FLUENT software was investigated to simulate the steam condensing flow in the cascades. The simulation consequences show that the pressure variations in simulation depict a good agreement with the experiment data. On the basis of the discrete phase model simulation results and experiment data, the efficiency of existing dehumidity blade with suction slot was calculated. A new stationary dehumidity blade was designed to elevate the dehumidity efficiency: the efficiency in the suction surface was increased by 21.5%, and that in the pressure surface was increased by 12.2%.

关键词： steam turbine     hollow stationary blade     dehumidity     numerical simulation    

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Thermodynamic analysis of steam reforming of glycerol for hydrogen production at atmospheric pressure

Ammaru Ismaila, Xueli Chen, Xin Gao, Xiaolei Fan

《化学科学与工程前沿（英文）》 2021年 第15卷 第1期   页码 60-71 doi: 10.1007/s11705-020-1975-0

摘要： Thermodynamic chemical equilibrium analysis of steam reforming of glycerol (SRG) for selective hydrogen production was performed based on the Gibbs free energy minimisation method. The ideal SRG reaction (C H O +3H O→3CO +7H ) and a comprehensive set of side reactions during SRG are considered for the formation of a wide range of products. Specifically, this work focused on the analysis of formation of H CO , CO and CH in the gas phase and determination of the carbon free region in SRG under the conditions at atmospheric pressure, 600€K–1100€K and 1.013 × 10 –1.013 × 10 Pa with the steam-to-glycerol feed ratios (SGFR) of 1:5–10. The reaction conditions which favoured SRG for H production with minimum coke formation were identifies as: atmospheric pressure, temperatures of 900€K–1050€K and SGFR of 10:1. The influence of using the inert carrier gas (i.e., N ) in SRG was studied as well at atmospheric pressure. Although the presence of N in the stream decreased the partial pressure of reactants, it was beneficial to improve the equilibrium yield of H . Under both conditions of SRG (with/without inert gas), the CH production is minimised, and carbon formation was thermodynamically unfavoured at steam rich conditions of SGFR>5:1.

关键词： steam reforming of glycerol     H2     N2     carbon deposition     thermodynamic analysis     Gibbs free energy minimisation    

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An extraction- assay system: Evaluation on flavonols in plant resistance to Pb and Cd by supercriticalextraction- gas chromatography

Xu Zhang, Huanhuan Yang, Xinlei Wang, Wen Song, Zhaojie Cui

《环境科学与工程前沿（英文）》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1059-2

摘要：

SFE-GC system is established for flavonols assessment.

Optimal parameters of SFE-GC are evaluated and determined.

Quercetin and kaempferol are detected in plant under heavy metal stress.

Gene expression analysis shows consistent regularity with content of flavonols.

ROS level is applied for elaborating the plant resistance status.

关键词： Flavonols     Heavy metal     Supercritical carbon dioxide extraction (SFE)     GC     Plant resistance    

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Feature extraction from slice data for reverse engineering

ZHANG Yingjie, LU Shangning

《机械工程前沿（英文）》 2007年 第2卷 第1期   页码 25-31 doi: 10.1007/s11465-007-0004-z

摘要： A new approach to feature extraction for slice data points is presented. The reconstruction of objects is performed as follows. First, all contours in each slice are extracted by contour tracing algorithms. Then the data points on the contours are analyzed, and the curve segments of the contours are divided into three categories: straight lines, conic curves and B-spline curves. The curve fitting methods are applied for each curve segment to remove the unwanted points with pre-determined tolerance. Finally, the features, which consist of the object and connection relations among them, are founded by matching the corresponding contours in adjacent slices, and 3D models are reconstructed based on the features. The proposed approach has been implemented in OpenGL, and the feasibility of the proposed method has been verified by several cases.

关键词： feasibility     corresponding     B-spline     pre-determined tolerance     extraction    

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A microextraction approach for rapid extraction and separation of Mn(II) and Co(II) using saponified

《化学科学与工程前沿（英文）》 2022年 第16卷 第6期   页码 963-972 doi: 10.1007/s11705-021-2081-7

摘要： In this paper, we proposed a microextraction approach for the extraction and separation of Mn(II) and Co(II) from sulfate solution simulating leachate of spent lithium-ion battery cathode materials using saponified di-(2-ethylhexyl)phosphoric acid system. The effects of the following operational variables were investigated: equilibrium pH, tri-n-butyl phosphate concentration, saponification rate, two-phase ratio and residence time. The results showcased that the microextractor can reach the extraction equilibrium within 20 s, thereby greatly reducing necessary extraction time comparing to that of conventional processes. The volumetric mass transfer coefficient showed 8–21 times larger than that of batch device. With the help of microextractor, 95% of Mn(II) was extracted with a single theoretical stage at a chosen two-phase ratio of 3:1, and the separation factor βMn/Co was as large as 65.5. In the subsequent stripping step, more than 99% of manganese from loaded phase was easily stripped under optimal conditions. The microextraction approach greatly enhances the mass transfer while enabling a continuous and controllable extraction process within a simple structure design. When extracting spent electrode material with microextractors, the comprehensive recovery of mangenese can reach 96%. The microextraction approach has a good applicability in the spent lithium-ion battery cathode materials recycling at both bench and industrial scales.

关键词： extraction equilibrium     mass transfer coefficient     microextraction     multicomponent extraction     di-(2-ethylhexyl)phosphoric acid    

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标题 作者 时间 类型 操作

Performance evaluation of an improved biomass-fired cogeneration system simultaneously using extractionsteam, cooling water, and feedwater for heating

期刊论文

Combination of steam-enhanced extraction and electrical resistance heating for efficient remediation

期刊论文

低渗高粘稀油油藏蒸汽采油技术研究

王立智,王云龙

期刊论文

Entity and relation extraction with rule-guided dictionary as domain knowledge

期刊论文

Modeling analysis on solar steam generator employed in multi-effect distillation (MED) system

Zhaorui ZHAO, Bao YANG, Ziwen XING

期刊论文

Intrinsic kinetics and external diffusion of catalytic steam gasification of fine coal char particles

Xuantao Wu, Jie Wang

期刊论文

High-efficiency inspecting method for mobile robots based on task planning for heat transfer tubes in a steam

期刊论文

A steam dried municipal solid waste gasification and melting process

Gang XIAO, Baosheng JIN, Mingjiang NI, Kefa CEN, Yong CHI, Zhongxin TAN

期刊论文

Impacts of solar multiple on the performance of direct steam generation solar power tower plant with

Yan LUO, Xiaoze DU, Lijun YANG, Chao XU, Muhammad AMJAD

期刊论文

Thermal cracking of waste printed wiring boards for mechanical recycling by using residual steam preprocessing

Yao CHEN, Jinhui LI, Huabo DUAN, Zhishi WANG

期刊论文

Numerical simulation of a new hollow stationary dehumidity blade in last stage of steam turbine

Youmin HOU, Danmei XIE, Wangfan LI, Xinggang YU, Yang SHI, Hanshi QIN

期刊论文

Thermodynamic analysis of steam reforming of glycerol for hydrogen production at atmospheric pressure

Ammaru Ismaila, Xueli Chen, Xin Gao, Xiaolei Fan

期刊论文

An extraction- assay system: Evaluation on flavonols in plant resistance to Pb and Cd by supercriticalextraction- gas chromatography

Xu Zhang, Huanhuan Yang, Xinlei Wang, Wen Song, Zhaojie Cui

期刊论文

Feature extraction from slice data for reverse engineering

ZHANG Yingjie, LU Shangning

期刊论文

A microextraction approach for rapid extraction and separation of Mn(II) and Co(II) using saponified

期刊论文