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Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

《化学科学与工程前沿(英文)》 2009年 第3卷 第1期   页码 12-19 doi: 10.1007/s11705-009-0151-3

摘要: Ionicliquids combined with supercritical fluid technology hold great promise as working solvents for developing compact processes. Ionic liquids, which are organic molten salts, typically have extremely low volatility and high functionality, but possess high viscosities, surface tensions and low diffusion coefficients, which can limit their applicability. CO , on the other hand, especially in its supercritical state, is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer. The solubility of CO in the ionic liquid is key to estimating the important physical properties that include partition coefficients, viscosities, densities, interfacial tensions, thermal conductivities and heat capacities needed in contactor design. In this work, we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO - ionic liquid solubility data and report new correlations for CO -ionic liquid systems with equations of state that have some industrial applications including: (1) general, (2) fuel desulfurization, (3) CO capture, and (4) chiral separation. New measurements of solubility data for the CO and 1-butyl-3-methylimidazolium octyl sulfate, [bmim][OcSO ] system are reported and correlated. In the correlation of the CO ionic liquid phase behavior, the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared. It is shown that excellent correlation of CO solubility can be obtained with either equation and they share some common characteristics regarding interaction parameters. In the Sanchez-Lacombe equation, parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO -ionic liquid solubility data.

关键词: compact processes     chiral ionic liquids     separations     thermodynamic properties     equations of state    

Creep of brazed plate-fin structures in high temperature compact heat exchangers

Shantung TU, Guoyan ZHOU

《机械工程前沿(英文)》 2009年 第4卷 第4期   页码 355-362 doi: 10.1007/s11465-009-0065-2

摘要: In recent years, the need for high temperature heat exchangers to improve the efficiency of power and chemical conversion systems has been growing. However, the creep design of the high temperature compact heat exchangers has been a primary concern because the working temperature can be well above the creep limit of the materials. To establish the high temperature design criterion for compact heat exchangers, creep behavior of the plate-fin structures and brazed joints are investigated in this paper. The time-dependent deformation and bending stress of the plate-fin structures are obtained analytically by simplifying the fins to elastic springs. The creep damage evolution inside the brazed joint is studied by coupling the finite element method with a damage constitutive equation. The significant effect of creep property mismatch in the brazed joint on the creep strength is demonstrated.

关键词: compact heat exchanger     creep     damage     brazing joint    

Sensitivity analysis and numerical experiments on transient test of compact heat exchanger surfaces

REN Hesheng, LAI Lingjun, CUI Yongzheng

《能源前沿(英文)》 2008年 第2卷 第4期   页码 374-380 doi: 10.1007/s11708-008-0079-1

摘要: A single-blow transient testing technique considering the effect of longitudinal heat conduction is suggested for determining the average convection heat transfer coefficient of compact heat exchanger surface. By matching the measured outlet fluid temperature variation with similar theoretical curves, the dimensionless longitudinal conduction parameter , the time constant of the inlet fluid temperature , and the number of heat transfer units can be determined simultaneously using the Levenberg-Marquardt nonlinear parameter estimation method. Both sensitivity analysis and numerical experiments with simulated measurements containing random errors show that the method in the present investigation provides satisfactory accuracy of the estimated parameter , which characterizes the heat transfer performance of compact heat exchanger surfaces.

关键词: coefficient     dimensionless longitudinal     longitudinal     temperature     conduction    

Discussion on back-to-back two-stage centrifugal compressor compact design techniques

Lei HUO, Huoxing LIU

《机械工程前沿(英文)》 2013年 第8卷 第4期   页码 390-400 doi: 10.1007/s11465-013-0278-2

摘要:

Design a small flow back-to-back two-stage centrifugal compressor in the aviation turbocharger, the compressor is compact structure, small axial length, light weighted. Stationary parts have a great influence on their overall performance decline. Therefore, the stationary part of the back-to-back two-stage centrifugal compressor should pay full attention to the diffuser, bend, return vane and volute design. Volute also impact downstream return vane, making the flow in circumferential direction is not uniformed, and several blade angle of attack is drastically changed in downstream of the volute with the airflow can not be rotated to required angle. Loading of high-pressure rotor blades change due to non-uniformed of flow in circumferential direction, which makes individual blade load distribution changed, and affected blade passage load decreased to reduce the capability of work, the tip low speed range increases.

关键词: back-to-back     two-stage     centrifugal compressor     design     Internal flow    

Flow and heat transfer in compact offset strip fin surfaces

DONG Junqi, CHEN Jiangping, CHEN Zhijiu

《能源前沿(英文)》 2008年 第2卷 第3期   页码 291-297 doi: 10.1007/s11708-008-0061-y

摘要: Experimental studies of air-side heat transfer and pressure drop characteristics of offset strip fins and flat tube heat exchangers were performed. A series of tests were conducted for 9 heat exchangers with different fin space, fi

关键词: different     air-side     transfer     pressure     offset    

Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

Lingchen Kong, Xitong Liu

《环境科学与工程前沿(英文)》 2020年 第14卷 第5期 doi: 10.1007/s11783-020-1269-2

摘要: Abstract • Mechanisms for selective recovery of materials in electrochemical processes are discussed. • Wastewaters that contain recoverable materials are reviewed. • Application prospects are discussed from both technical and non-technical aspects. Recovering valuable materials from waste streams is critical to the transition to a circular economy with reduced environmental damages caused by resource extraction activities. Municipal and industrial wastewaters contain a variety of materials, such as nutrients (nitrogen and phosphorus), lithium, and rare earth elements, which can be recovered as value-added products. Owing to their modularity, convenient operation and control, and the non-requirement of chemical dosage, electrochemical technologies offer a great promise for resource recovery in small-scale, decentralized systems. Here, we review three emerging electrochemical technologies for materials recovery applications: electrosorption based on carbonaceous and intercalation electrodes, electrochemical redox processes, and electrochemically induced precipitation. We highlight the mechanisms for achieving selective materials recovery in these processes. We also present an overview of the advantages and limitations of these technologies, as well as the key challenges that need to be overcome for their deployment in real-world systems to achieve cost-effective and sustainable materials recovery.

关键词: Materials recovery     Electrosorption     Capacitive deionization     Redox processes     Electrochemical precipitation    

A road-map for energy-neutral wastewater treatment plants of the future based on compact technologies

Hallvard Ødegaard

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0835-0

摘要: In the paper concepts for wastewater treatment of the future are discussed by the use of a) one flow diagram based on established, compact, proven technologies (i.e. nitrification/denitrification for N-removal in the mainstream) and b) one flow diagram based on emerging, compact technologies (i.e. de-ammonification in the main stream).The latter (b) will give an energy-neutral wastewater treatment plant, while this cannot be guaranteed for the first one (a). The example flow diagrams show plant concepts that a) minimize energy consumption by using compact biological and physical/chemical processes combined in an optimal way, for instance by using moving bed biofilm reactor (MBBR) processes for biodegradation and high-rate particle separation processes, and de-ammonification processes for N-removal and b)maximize energy (biogas) production through digestion by using wastewater treatment processes that minimize biodegradation of the sludge (prior to digestion) and pretreatment of the sludge prior to digestion by thermal hydrolysis. The treatment plant of the future should produce a water quality (for instance bathing water quality) that is sufficient for reuse of some kind (toilet flushing, urban use, irrigation etc.). The paper outlines compact water reclamation processes based on ozonation in combination with coagulation as pretreatment before ceramic membrane filtration. In the paper concepts for domestic wastewater treatment plants of the future are discussed by the use of a) one flow diagram based on established, compact, proven technologies (i.e. nitrification/denitrification for N-removal in the mainstream) and b) one flow diagram based on emerging, compact technologies (i.e. de-ammonification in the main stream).The latter (b) will give an energy-neutral wastewater treatment plant, while this cannot be guaranteed for the first one (a). The example flow diagrams show plant concepts that a) minimize energy consumption by using compact biological and physical/chemical processes combined in an optimal way, for instance by using moving bed biofilm reactor (MBBR) processes for biodegradation and high-rate particle separation processes, and de-ammonification processes for N-removal and b)maximize energy (biogas) production through digestion by using wastewater treatment processes that minimize biodegradation of the sludge (prior to digestion) and pretreatment of the sludge prior to digestion by thermal hydrolysis. The treatment plant of the future should produce a water quality (for instance bathing water quality) that is sufficient for reuse of some kind (toilet flushing, urban use, irrigation etc.). The paper outlines compact water reclamation processes based on ozonation in combination with coagulation as pretreatment before ceramic membrane filtration.

关键词: China concept WWTP     Energy-neutrality     De-ammonification     moving bed biofilm reactor (MBBR)    

A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Nikolaos Rakovitis, Nan Zhang, Jie Li, Liping Zhang

《化学科学与工程前沿(英文)》 2019年 第13卷 第4期   页码 784-802 doi: 10.1007/s11705-019-1858-4

摘要: The increasing demand of goods, the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their productivity with a simultaneous reduction of raw materials and utility consumption and efficient use of processing units. Optimal scheduling of their processes can lead facilities towards this direction. Although a great number of mathematical models have been developed for such scheduling, they may still lead to large model sizes and computational time. In this work, we develop two novel mathematical models using the unit-specific event-based modelling approach in which consumption and production tasks related to the same states are allowed to take place at the same event points. The computational results demonstrate that both proposed mathematical models reduce the number of event points required. The proposed unit-specific event-based model is the most efficient since it both requires a smaller number of event points and significantly less computational time in most cases especially for those examples which are computationally expensive from existing models.

关键词: scheduling     multipurpose batch processes     simultaneous transfer     mixed-integer linear programming    

小型回旋加速器虚拟样机技术

樊明武,余调琴,熊永前,陈德智,熊健,秦斌,洪月明,邓昌东

《中国工程科学》 2003年 第5卷 第10期   页码 8-13

摘要:

小型回旋加速器虚拟样机技术是把小型回旋加速器的理论计算、分析、信息技术与机械设计、加工、装配、调试、运行、维修等专家知识进行有机结合,在系统仿真和虚拟现实基础上发展起来的一种新概念技术。基于虚拟样机,可以实现创新设计,有效降低探索风险。文章探讨了回旋加速器虚拟样机系统框架,讨论了虚拟样机系统的体系结构和回旋加速器产品的全生命周期仿真,提出了基于全生命周期集成和多学科协同设计的回旋加速器虚拟样机的开发思路。

关键词: 小型回旋加速器     虚拟样机技术     增强现实    

Modeling of hydrological processes in arid agricultural regions

Jiang LI,Xiaomin MAO,Shaozhong KANG,David A. BARRY

《农业科学与工程前沿(英文)》 2015年 第2卷 第4期   页码 283-294 doi: 10.15302/J-FASE-2015076

摘要: Understanding of hydrological processes, including consideration of interactions between vegetation growth and water transfer in the root zone, underpins efficient use of water resources in arid-zone agriculture. Water transfers take place in the soil-plant-atmosphere continuum, and include groundwater dynamics, unsaturated zone flow, evaporation/transpiration from vegetated/bare soil and surface water, agricultural canal/surface water flow and seepage, and well pumping. Models can be categorized into three classes: (1) regional distributed hydrological models with various land uses, (2) groundwater-soil-plant-atmosphere continuum models that neglect lateral water fluxes, and (3) coupled models with groundwater flow and unsaturated zone water dynamics. This review highlights, in addition, future research challenges in modeling arid-zone agricultural systems, e.g., to effectively assimilate data from remote sensing, and to fully reflect climate change effects at various model scales.

关键词: hydrological processes     irrigation area     SPAC     crop growth     groundwater     canal seepage    

Automated synthesis of steady-state continuous processes using reinforcement learning

《化学科学与工程前沿(英文)》 2022年 第16卷 第2期   页码 288-302 doi: 10.1007/s11705-021-2055-9

摘要: Automated flowsheet synthesis is an important field in computer-aided process engineering. The present work demonstrates how reinforcement learning can be used for automated flowsheet synthesis without any heuristics or prior knowledge of conceptual design. The environment consists of a steady-state flowsheet simulator that contains all physical knowledge. An agent is trained to take discrete actions and sequentially build up flowsheets that solve a given process problem. A novel method named SynGameZero is developed to ensure good exploration schemes in the complex problem. Therein, flowsheet synthesis is modelled as a game of two competing players. The agent plays this game against itself during training and consists of an artificial neural network and a tree search for forward planning. The method is applied successfully to a reaction-distillation process in a quaternary system.

关键词: automated process synthesis     flowsheet synthesis     artificial intelligence     machine learning     reinforcement learning    

Effectiveness of tertiary treatment processes in removing different classes of emerging contaminants

《环境科学与工程前沿(英文)》 2022年 第16卷 第11期 doi: 10.1007/s11783-022-1583-y

摘要:

● Different advanced treatment processes were tested for ECs removal from wastewater.

关键词: Micropollutants     Wastewater     PAC     Membranes     UV     Tertiary treatment    

Fundamental influences of particles on stirred and unstirred venting processes of foaming systems

Henrik LEIMEISTER,Jörg STEINBACH

《化学科学与工程前沿(英文)》 2014年 第8卷 第2期   页码 141-148 doi: 10.1007/s11705-014-1423-0

摘要: Venting is the common safety measure to protect plant equipment against excessive overpressure. So far, scenarios in which particles were part of the system and should have been accounted for did ignore their presence; the scenarios were treated like a two-phase system. Current research shows that particles can have a major influence on the venting behaviour. Experimental results indicate that particles affect level swell and relief flow especially of foamy systems. Based on those results four different layers of influence of the particle have been identified and are presented in a first model. Based on this model recommendations for the development of new and more complex models are given.

关键词: venting     multi-phase    

Physical and chemical processes of wintertime secondary nitrate aerosol formation

Qi YING

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 348-361 doi: 10.1007/s11783-011-0343-1

摘要: The UCD/CIT model was modified to include a process analysis (PA) scheme for gas and particulate matter (PM) to study the formation of secondary nitrate aerosol during a stagnant wintertime air pollution episode during the California Regional PM /PM Air Quality Study (CRPAQS) where detailed measurements of PM components are available at a few sites. Secondary nitrate is formed in the urban areas from near the ground to a few hundred meters above the surface during the day with a maximum modeled net increase rate of 4 μg·m ·d during the study episode. The secondary nitrate formation rate in rural areas is lower due to lower NO . In the afternoon hours, near-surface temperature can be high enough to evaporate the particulate nitrate. In the nighttime hours, both the gas phase N O reactions with water vapor and the N O heterogeneous reactions with particle-bound water are important for secondary nitrate formation. The N O reactions are most import near the surface to a few hundred meters above surface with a maximum modeled net secondary nitrate increase rate of 1 μg·m ·d and are more significant in the rural areas where the O concentrations are high at night. In general, vertical transport during the day moves the nitrate formed near the surface to higher elevations. During the stagnant days, process analysis indicates that the nitrate concentration in the upper air builds up and leads to a net downward flux of nitrate through vertical diffusion and a rapid increase of surface nitrate concentration.

关键词: secondary nitrate aerosol     N2O5 heterogeneous reaction     process analysis    

Increasing significance of advanced physical/chemical processes in the development and application of

RULKENS Wim

《环境科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 385-396 doi: 10.1007/s11783-008-0073-1

摘要: The awareness of the problem of the scarcity of water of high quality has strongly changed the approach of wastewater treatment. Currently, there is an increasing need for the beneficial reuse of treated wastewater and to recover valuable products and energy from the wastewater. Because microbiological treatment methods are, only to a limited part, able to satisfy these needs, the role and significance of physical/chemical processes in wastewater treatment are gaining more and more interest. The specific future role and aim of the various physical/chemical treatment processes can be categorized in five groups: improvement of the performance of microbiological treatment processes, achievement of the high quality required for reuse of the effluent, recovery of valuable components and energy from the wastewater for beneficial reuse, desalination of brackish water and seawater, and treatment of concentrated liquid or solid waste residues produced in a wastewater treatment process. Development of more environmentally sustainable wastewater treatment chains in which physical/chemical processes play a crucial role, also requires application of process control and modeling strategies. This is briefly introduced by the elaboration of treatment scenarios for three specific wastewaters.

关键词: control     beneficial     valuable     scarcity     Development    

标题 作者 时间 类型 操作

Measurement and correlation of supercritical CO

Hiroshi MACHIDA, Ryosuke TAGUCHI, Yoshiyuki SATO, Louw J. FLOURUSSE, Cor J. PETERS, Richard L. SMITH

期刊论文

Creep of brazed plate-fin structures in high temperature compact heat exchangers

Shantung TU, Guoyan ZHOU

期刊论文

Sensitivity analysis and numerical experiments on transient test of compact heat exchanger surfaces

REN Hesheng, LAI Lingjun, CUI Yongzheng

期刊论文

Discussion on back-to-back two-stage centrifugal compressor compact design techniques

Lei HUO, Huoxing LIU

期刊论文

Flow and heat transfer in compact offset strip fin surfaces

DONG Junqi, CHEN Jiangping, CHEN Zhijiu

期刊论文

Emerging electrochemical processes for materials recovery from wastewater: Mechanisms and prospects

Lingchen Kong, Xitong Liu

期刊论文

A road-map for energy-neutral wastewater treatment plants of the future based on compact technologies

Hallvard Ødegaard

期刊论文

A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

Nikolaos Rakovitis, Nan Zhang, Jie Li, Liping Zhang

期刊论文

小型回旋加速器虚拟样机技术

樊明武,余调琴,熊永前,陈德智,熊健,秦斌,洪月明,邓昌东

期刊论文

Modeling of hydrological processes in arid agricultural regions

Jiang LI,Xiaomin MAO,Shaozhong KANG,David A. BARRY

期刊论文

Automated synthesis of steady-state continuous processes using reinforcement learning

期刊论文

Effectiveness of tertiary treatment processes in removing different classes of emerging contaminants

期刊论文

Fundamental influences of particles on stirred and unstirred venting processes of foaming systems

Henrik LEIMEISTER,Jörg STEINBACH

期刊论文

Physical and chemical processes of wintertime secondary nitrate aerosol formation

Qi YING

期刊论文

Increasing significance of advanced physical/chemical processes in the development and application of

RULKENS Wim

期刊论文