资源类型

期刊论文 1099

会议视频 20

年份

2023 88

2022 116

2021 86

2020 53

2019 58

2018 48

2017 45

2016 45

2015 55

2014 56

2013 50

2012 58

2011 52

2010 71

2009 44

2008 47

2007 39

2006 17

2005 11

2004 17

展开 ︾

关键词

水资源 16

细水雾 14

可持续发展 6

泥水盾构 6

反渗透 5

数学模型 5

优化 4

数值模拟 4

水环境 4

环境 4

砂卵石地层 4

超滤 4

三峡工程 3

农业节水 3

半旱地农业 3

绿色化工 3

Preissmann格式 2

中国西北地区 2

京津冀 2

展开 ︾

检索范围:

排序: 展示方式:

Assessment of future climate change impacts on water-heat-salt migration in unsaturated frozen soil using

Hanli Wan, Jianmin Bian, Han Zhang, Yihan Li

《环境科学与工程前沿(英文)》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1302-5

摘要: Abstract • A model coupling water-heat-salt of unsaturated frozen soil was established. • Future temperature, precipitation, and evaporation increase in freeze–thaw period. • Soil water, heat, and salt transport are closely coupled during freeze–thaw period. • Freeze–thaw cycles and future climate change can exacerbate salinization. The transport mechanisms of water, heat, and salt in unsaturated frozen soil, as well as its response to future climate change are in urgent need of study. In this study, western Jilin Province in north-eastern China was studied to produce a model of coupled water-heat-salt in unsaturated frozen soil using CoupModel. The water, heat, and salt dynamics of unsaturated frozen soil under three representative concentration pathway (RCP) scenarios were simulated to analyze the effects of future climate change on unsaturated frozen soil. The results show that water, heat, and salt migration are tightly coupled, and the soil salt concentration in the surface layer (10 cm) exhibits explosive growth after freezing and thawing. The future (2020–2099) meteorological factors in the study area were predicted using the Statistical Downscaling Model (SDSM). For RCP2.6, RCP4.5, and RCP8.5 scenarios, future temperatures during the freeze–thaw period increased by 2.68°C, 3.18°C, and 4.28°C, respectively; precipitation increased by 30.28 mm, 28.41 mm, and 32.17 mm, respectively; and evaporation increased by 93.57 mm, 106.95 mm, and 130.57 mm, respectively. Climate change will shorten the freeze–thaw period, advance the soil melting time from April to March, and enhance water and salt transport. Compared to the baseline period (1961–2005), future soil salt concentrations at 10 cm increased by 1547.54 mg/L, 1762.86 mg/L, and 1713.66 mg/L under RCP2.6, RCP4.5, and RCP8.5, respectively. The explosive salt accumulation is more obvious. Effective measures should be taken to prevent the salinization of unsaturated frozen soils and address climate change.

关键词: Soil salinization     Climate change     Unsaturated frozen soil     Water-heat-salt balance     Soil environment change    

Mass and heat balance calculations and economic evaluation of an innovative biomass pyrolysis project

Quanyuan WEI, Yongshui QU, Tianwei TAN

《化学科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 355-361 doi: 10.1007/s11705-010-0567-9

摘要: Biomass can be converted into flammable gas, charcoal, wood vinegar, wood tar oil and noncombustible materials with thermo-chemical pyrolysis reactions. Many factors influence these processes, such as the properties of the raw materials, and temperature control and these will affect the products that are produced. Based on the data from a straw pyrolysis demonstration project, the mass and heat balance of the biomass pyrolysis process were analyzed. The statistical product and service solutions (SPSS) statistical method was used to analyze the data which were monitored on-site. A cost-benefit analysis was then used to study the viability of commercializing the project. The analysis included net present value, internal rate of return and investment payback period. These results showed that the straw pyrolysis project has little risk, and will produce remarkable economic benefits.

关键词: mass balance     heat balance     biomass pyrolysis     economic benefit    

Quantitative analysis of yield and soil water balance for summer maize on the piedmont of the North China

Jingjing WANG,Feng HUANG,Baoguo LI

《农业科学与工程前沿(英文)》 2015年 第2卷 第4期   页码 295-310 doi: 10.15302/J-FASE-2015074

摘要: The North China Plain (NCP) is a major grain production area in China, but the current winter wheat-summer maize system has resulted in a large water deficit. This water-shortage necessitates the improvement of crop water productivity in the NCP. A crop water model, AquaCrop, was adopted to investigate yield and water productivity (WP) for rain-fed summer maize on the piedmont of the NCP. The data sets to calibrate and validate the model were obtained from a 3-year (2011–2013) field experiment conducted on the Yanshan piedmont of the NCP. The range of root mean square error (RMSE) between the simulated and measured biomass was 0.67–1.25 t·hm , and that of relative error (RE) was 9.4%–15.4%, the coefficient of determination ( ) ranged from 0.992 to 0.994. The RMSE between the simulated and measured soil water storage at depth of 0–100 cm ranged from 4.09 to 4.39 mm; and RE and in the range of 1.07%–1.20% and 0.880–0.997, respectively. The WP as measured by crop yield per unit evapotranspiration was 2.50–2.66 kg·m . The simulated impact of long-term climate (i.e., 1980–2010) and groundwater depth on crop yield and WP revealed that the higher yield and WP could be obtained in dry years in areas with capillary recharge from groundwater, and much lower values elsewhere. The simulation also suggested that supplementary irrigation in areas without capillary groundwater would not result in groundwater over-tapping since the precipitation can meet the water required by both maize and ecosystem, thus a beneficial outcome for both food and ecosystem security can be assured.

关键词: AquaCrop     summer maize     soil water balance     water productivity    

土壤水盐定向迁移及排盐新模式研究

周和平,彭立新,徐小波

《中国工程科学》 2007年 第9卷 第11期   页码 120-126

摘要:

综述了我国盐碱地改良技术现状;研究了干旱地区节水灌溉条件下农田不同地面条件土壤水盐定 向迁移特征,提出了“盐分上移地表排”的排盐模式,对我国干旱农业灌区盐碱地改良治理新方法的研究探索 具有现实意义。

关键词: 土壤水盐定向迁移     排盐新模式     旱区    

Sea salt bittern-driven forward osmosis for nutrient recovery from black water: A dual waste-to-resource

Wenchao Xue, May Zaw, Xiaochan An, Yunxia Hu, Allan Sriratana Tabucanon

《环境科学与工程前沿(英文)》 2020年 第14卷 第2期 doi: 10.1007/s11783-019-1211-7

摘要: • A dual “waste-to-resource” application of FO was proposed. • Performance of sea salt bittern as an economic FO draw solution was evaluated. • High quality struvite recovery from black water using FO was demonstrated. • Feed pH is a key factor to control the form of recovered phosphorous. A dual “waste-to-resource” innovation in nutrient enrichment and recovery from domestic black water using a sea salt bittern (SSB)-driven forward osmosis (FO) process is proposed and demonstrated. The performance of SSB as a “waste-to-resource” draw solution for FO was first evaluated. A synthetic SSB-driven FO provided a water flux of 25.67±3.36 L/m2⋅h, which was 1.5‒1.7 times compared with synthetic seawater, 1 M NaCl, and 1 M MgCl2. Slightly compromised performance regarding reverse solute selectivity was observed. In compensation, the enhanced reverse diffusion of Mg2+ suggested superior potential in terms of recovering nutrients in the form of struvite precipitation. The nutrient enrichment was performed using both the pre-filtered influent and effluent of a domestic septic tank. Over 80% of phosphate-P recovery was achieved from both low- and high-strength black water at a feed volume reduction up to 80%‒90%. With an elevated feed pH (~9), approximately 60%‒85% enriched phosphate-P was able to be recovered in the form of precipitated stuvite. Whereas the enrichment performance of total Kjeldahl nitrogen (TKN) largely differed depending on the strength of black water. Improved concentration factor (i.e., 3-folds) and retention (>60%) of TKN was obtained in the high-nutrient-strength black water at a feed volume reduction of 80%, in comparison with a weak TKN enrichment observed in low-strength black water. The results suggested a good potential for nutrient recovery based on this dual “waste-to-resource” FO system with proper management of membrane cleaning.

关键词: Forward osmosis     Sea salt bittern     Black water     Nutrient recovery     pH    

Revolutionizing heat transport enhancement with liquid metals: Proposal of a new industry of water-freeheat exchangers

Haiyan LI, Jing LIU

《能源前沿(英文)》 2011年 第5卷 第1期   页码 20-42 doi: 10.1007/s11708-011-0139-9

摘要: Water is perhaps the most widely adopted working fluid in conventional industrial heat transport engineering. However, it may no longer be the best option today due to the increasing scarcity of water resources. Furthermore, the wide variations in water supply throughout the year and across different geographic regions also makes it harder to easily access. To address this issue, finding new alternatives to replace water-based technologies is imperative. In this paper, the concept of a water-free heat exchanger is proposed and comprehensively analyzed for the first time. The liquid metal with a low melting point is identified as an ideal fluid that can flexibly be used within a wide range of working temperatures. Some liquid metals and their alloys, which have previously received little attention in thermal management areas, are evaluated. With superior thermal conductivity, electromagnetic field drivability, and extremely low power consumption, liquid metal coolants promise many opportunities for revolutionizing modern heat transport processes: serving as heat transport fluid in industries, administrating thermal management in power and energy systems, and innovating enhanced cooling in electronic or optical devices. Furthermore, comparative analyses are conducted to understand the technical barriers encountered by advanced water-based heat transfer strategies and clarify this new frontier in heat-transport study. In addition, the unique merits of liquid metals that could lead to innovative heat exchanger technologies are evaluated comprehensively. A few promising industrial situations, such as heat recovery, chip cooling, thermoelectricity generation, and military applications, where liquid metals could play irreplaceable roles, were outlined. The technical challenges and scientific issues thus raised are summarized. With their evident ability to meet various critical requirements in modern advanced energy and power industries, liquid metal-enabled technologies are expected to usher a new and global era of water-free heat exchangers.

关键词: heat exchanger     liquid metal     water resource     heat transport enhancement     coolant     thermal management     process engineering     energy crisis     chip cooling    

Performance analysis of an air-source heat pump using an immersed water condenser

Jie JI, Huide FU, Hanfeng HE, Gang PEI,

《能源前沿(英文)》 2010年 第4卷 第2期   页码 234-245 doi: 10.1007/s11708-009-0056-3

摘要: A distributed model of an air-source heat pump (ASHP) system and its experimental setup using an immersed water condenser were presented. Dynamic performance of the ASHP was then evaluated by both simulation and experiment. The results indicated that the system coefficient of performance (COP) decreased as the condenser temperature increased, ranging from 4.41 to 2.32 with the average COP equaling 3.29 during the experiment. Comparisons between simulation results and experimental measurements demonstrated that the model was able to yield satisfactory predictions. Furthermore, temperature profiles of the refrigerant in the evaporator and condenser were also given. This paper provides the theoretical and experimental background for ASHP system optimization and a valuable reference for a solar air-source heat pump water heater when the solar irradiation energy is insufficient on cloudy or rainy days.

关键词: air-source     heat pump     distributed model     immersed water condenser    

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

《能源前沿(英文)》 2014年 第8卷 第3期   页码 394-402 doi: 10.1007/s11708-014-0310-1

摘要: The aim of this study is to evaluate the performance of a centralized open-loop ground-water heat pump (GWHP) system for climate conditioning in Beijing with a cold climate in China. Thus, a long-time test was conducted on a running GWHP system for the heating season from December 2011 to March 2012. The analysis of the testing data indicates that the average heat-pump coefficient of performance (COP) and the COP of the system (COPs) are 4.27 and 2.59. The low value and large fluctuation in the range of COP are found to be caused by the heat transfixion in the aquifer and the bypass in the circulation loop. Therefore, some suggestions are proposed to improve the performance for GWHPs in the cold climate region in China.

关键词: ground-water heat pump (GWHP)     actual coefficient of performance     heat transfixion    

Modeling water and heat transfer in soil-plant-atmosphere continuum applied to maize growth under plastic

Meng DUAN, Jin XIE, Xiaomin MAO

《农业科学与工程前沿(英文)》 2019年 第6卷 第2期   页码 144-161 doi: 10.15302/J-FASE-2019258

摘要:

Based on our previous work modeling crop growth (CropSPAC) and water and heat transfer in the soil-plant-atmosphere continuum (SPAC), the model was improved by considering the effect of plastic film mulching applied to field-grown maize in North-west China. In CropSPAC, a single layer canopy model and a multi-layer soil model were adopted to simulate the energy partition between the canopy and water and heat transfer in the soil, respectively. The maize growth module included photosynthesis, growth stage calculation, biomass accumulation, and participation. The CropSPAC model coupled the maize growth module and SPAC water and heat transfer module through leaf area index (LAI), plant height and soil moisture condition in the root zone. The LAI and plant height were calculated from the maize growth module and used as input for the SPAC water and heat transfer module, and the SPAC module output for soil water stress conditions used as an input for maize growth module. We used , the representation of evaporation resistance, instead of the commonly used evaporation resistance to reflect the change of latent heat flux of soil evaporation under film mulching as well as the induced change in energy partition. The model was tested in a maize field at Yingke irrigation area in North-west China. Results showed reasonable agreement between the simulations and measurements of LAI, above-ground biomass and soil water content. Compared with the original model, the modified model was more reliable for maize growth simulation under film mulching and showed better accuracy for the LAI (with the coefficient of determination = 0.92, the root mean square of error RMSE= 1.23, and the Nush-Suttclife efficiency E = 0.87), the above-ground biomass (with = 0.96, RMSE= 7.17 t·ha and E = 0.95) and the soil water content in 0–1 m soil layer (with = 0.78, RMSE= 49.44 mm and E = 0.26). Scenarios were considered to simulate the influence of future climate change and film mulching on crop growth, soil water and heat conditions, and crop yield. The simulations indicated that the change of LAI, leaf biomass and yield are negatively correlated with temperature change, but the growing degree-days, evaporation, soil water content and soil temperature are positively correlated with temperature change. With an increase in the ratio of film mulching area, the evaporation will decrease, while the impact of film mulching on crop transpiration is not significant. In general, film mulching is effective in saving water, preserving soil moisture, increasing soil surface temperature, shortening the potential growth period, and increasing the potential yield of maize.

关键词: film mulching     growth stage     leaf area index     maize growth     water and heat transfer    

Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

《能源前沿(英文)》 2011年 第5卷 第4期   页码 358-366 doi: 10.1007/s11708-011-0161-y

摘要: To investigate the performance of heat and mass transfer of ammonia-water during the process of falling film evaporation in vertical tube evaporator, a mathematical model of evaporation process was presented, the solution of which that needed a coordinate transformation was based on stream function. The computational results from the mathematical model were validated with experimental data. Subsequently, a series of parameters, such as velocity, film thickness and concentration, etc., were obtained from the mathematical model. Calculated results show that the average velocity and the film thickness change dramatically at the entrance region when <100 mm, while they vary slightly with the tube length in the fully developed region when >100 mm. The average concentration of the solution reduces along the tube length because of evaporation, but the reducing tendency becomes slow. It can be concluded that there is an optimalβrelationship between the tube length and the electricity generated. The reason for the bigger concentration gradient in the direction is that the smooth tube is chosen in the calculation. It is suggested that the roll-worked enhanced tube or other enhanced tube can reduce the concentration gradient in the film thickness direction and enhance the heat and mass transfer rate.

关键词: falling film evaporation     ammonia-water     heat and mass transfer    

Natural convection heat transfer of water in a horizontal circular gap

SU Guanghui, WU Yingwei, Kenichiro Sugiyama

《能源前沿(英文)》 2007年 第1卷 第2期   页码 167-173 doi: 10.1007/s11708-007-0021-y

摘要: An experimental study on the natural convection heat transfer on a horizontal downward facing heated surface in a water gap was carried out under atmospheric pressure conditions. A total of 700 experimental data points were correlated using Rayleigh versus Nusselt number in various forms, based on different independent variables. The effects of different characteristic lengths and film temperatures were discussed. The results show that the buoyancy force acts as a resistance force for natural convection heat transfer on a downward facing horizontal heated surface in a confined space. For the estimation of the natural convection heat transfer under the present conditions, empirical correlations in which Nusselt number is expressed as a function of the Rayleigh number, or both Rayleigh and Prandtl numbers, may be used. When it is accurately predicted, the Nusselt number is expressed as a function of the Rayleigh and Prandtl numbers, as well as the gap width-to-heated surface diameter ratio; and uses the temperature difference between the heated surface and the ambient fluid in the definition of Rayleigh number. The characteristic length is the gap size and the film temperature is the average fluid temperature.

关键词: function     diameter     different independent     different characteristic     horizontal downward    

Heat transfer with water flowing upward in a tube for pressures up to supercritical region

Yuzhou CHEN, Chunsheng YANG, Shuming ZHANG, Minfu ZHAO, Kaiwen DU,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 358-365 doi: 10.1007/s11708-009-0071-4

摘要: A heat transfer experiment was conducted in a tube of 6.07mm in diameter with water flowing upward, covering the ranges of pressure of 10―23MPa, mass flux of 288―1298kg/(m·s), local water temperature of 78°C―270°C, heat flux of 0.23―1.18MW/m and Reynolds number of 5.5×10―3.9×10. The experimental results were compared with the predictions of the Dittus-Boelter correlation, Jackson correlation, Bishop correlation, Swenson correlation and Yamagata correlation. Significant deterioration in heat transfer was observed in both subcritical and supercritical region due to the effect of buoyancy force, but it was not predicted reasonably by the existing correlations.

关键词: heat transfer     deterioration     buoyancy     supercritical water    

A conceptual methodology for simultaneous optimization of water and heat with non-isothermal mixing

Yanlong Hou, Wanni Xie, Zhenya Duan, Jingtao Wang

《化学科学与工程前沿(英文)》 2017年 第11卷 第2期   页码 154-165 doi: 10.1007/s11705-016-1593-z

摘要: A new conceptual methodology is proposed to simultaneously integrate water allocation and energy networks with non-isothermal mixing. This method employs a simultaneous model and includes two design steps. In the first step, the water allocation network (WAN), which could achieve the targets of saving water and energy, is obtained by taking account the temperature factor into the design procedure. The optimized targets of both freshwater and energy are reached at this step which ensures this approach is a simultaneous one. In the second step, based on the obtained WAN, the whole water allocation and heat exchange network (WAHEN) is combined with the non-isothermal mixing to reduce the number of heat exchangers. The thus obtained WAHEN can achieve three optimization targets (minimization of water, energy and the number of heat exchangers). Furthermore, the effectivity of our method has been demonstrated by solving two literature examples.

关键词: simultaneous integration     non-isothermal mixing     multi-target optimization     water and energy networks    

Water pumping analysis and experimental validation of beach well infiltration intake system in a seawatersource heat pump system

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

《能源前沿(英文)》 2015年 第9卷 第3期   页码 335-342 doi: 10.1007/s11708-015-0365-7

摘要: Based on energy conservation equation and Darcy’s law, a model of beach well infiltration intake system applied in a seawater source heat pump system was established. The model consists of the seawater seepage and the heat transfer process. A porous medium model in a software named FLUENT was applied to simulate the seepage and the heat transfer process. This model was also validated by field experiment conducted on the seashore in Tianjin, China. The maximum relative error between simulation results and experimental results was 2.1% (less than 5%), which was acceptable in engineering application. The porosity and coefficient of thermal conductivity of the aquifer soil were determined to be 0.49 W/(m·K) and 1.46 W/(m·K), respectively in the simulation. In addition, the influencing factors of pumping water of beach well were also analyzed. The pumping water was found to increase when the distance between the beach well and the impervious boundary becomes longer, when the distance between the beach well and the supplying water source shortens, when the diameter of the beach well enlarges, and the drawdown enlarges.

关键词: water pumping analysis     experimental validation     infiltration intake system     seawater source heat pump    

水平衡与国土空间协调发展战略研究

胡庆芳,陈秀敏,高娟,金君良,王银堂,张建云

《中国工程科学》 2022年 第24卷 第5期   页码 63-74 doi: 10.15302/J-SSCAE-2022.05.009

摘要:

构建健康水平衡是提升水土资源匹配性、促进国土空间高质量发展的基础,而科学系统保护与集约高效利用国土空间是实现健康水平衡、保障国家水安全的根本途径。鉴于我国水资源与生产力要素分布极不匹配、国土空间发展中未有效落实量水发展的情况,本文面向生态文明建设和国土空间规划需求,以“实现健康水平衡、促进国土空间高质量发展”为目标,根据“山水林田湖草”系统治理、水陆统筹的原则,构建了以“理清约束条件、制定控制目标,完善基础设施、优化时空配置,科学严格保护、系统综合整治,集聚协调开发、高效集约利用”为主要内容的水平衡与国土空间协调发展战略。最后,提出了系统监测评价水平衡状态、提升国家尺度水土资源匹配性、优化“三生”空间划分和科学务实绿化国土等重点建议。

关键词: 健康水平衡;国土空间;协调发展;综合应对战略;生态保护修复;高效集约利用    

标题 作者 时间 类型 操作

Assessment of future climate change impacts on water-heat-salt migration in unsaturated frozen soil using

Hanli Wan, Jianmin Bian, Han Zhang, Yihan Li

期刊论文

Mass and heat balance calculations and economic evaluation of an innovative biomass pyrolysis project

Quanyuan WEI, Yongshui QU, Tianwei TAN

期刊论文

Quantitative analysis of yield and soil water balance for summer maize on the piedmont of the North China

Jingjing WANG,Feng HUANG,Baoguo LI

期刊论文

土壤水盐定向迁移及排盐新模式研究

周和平,彭立新,徐小波

期刊论文

Sea salt bittern-driven forward osmosis for nutrient recovery from black water: A dual waste-to-resource

Wenchao Xue, May Zaw, Xiaochan An, Yunxia Hu, Allan Sriratana Tabucanon

期刊论文

Revolutionizing heat transport enhancement with liquid metals: Proposal of a new industry of water-freeheat exchangers

Haiyan LI, Jing LIU

期刊论文

Performance analysis of an air-source heat pump using an immersed water condenser

Jie JI, Huide FU, Hanfeng HE, Gang PEI,

期刊论文

Evaluation of the performance of a centralized ground-water heat pump system in cold climate region

Shilei LU,Zhe CAI,Li ZHANG,Yiran LI

期刊论文

Modeling water and heat transfer in soil-plant-atmosphere continuum applied to maize growth under plastic

Meng DUAN, Jin XIE, Xiaomin MAO

期刊论文

Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

期刊论文

Natural convection heat transfer of water in a horizontal circular gap

SU Guanghui, WU Yingwei, Kenichiro Sugiyama

期刊论文

Heat transfer with water flowing upward in a tube for pressures up to supercritical region

Yuzhou CHEN, Chunsheng YANG, Shuming ZHANG, Minfu ZHAO, Kaiwen DU,

期刊论文

A conceptual methodology for simultaneous optimization of water and heat with non-isothermal mixing

Yanlong Hou, Wanni Xie, Zhenya Duan, Jingtao Wang

期刊论文

Water pumping analysis and experimental validation of beach well infiltration intake system in a seawatersource heat pump system

Huan ZHANG,Shu LIU,Xuejing ZHENG,Gaofeng CHEN

期刊论文

水平衡与国土空间协调发展战略研究

胡庆芳,陈秀敏,高娟,金君良,王银堂,张建云

期刊论文