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基于蝶翅三级微纳米结构的定制光子工程辐射制冷纺织品 Article

郭竑宇, 牛田野, 俞建勇, 王学利, 斯阳

《工程(英文)》 2023年 第31卷 第12期   页码 120-126 doi: 10.1016/j.eng.2023.07.019

摘要:

通过将被动辐射制冷策略与个人热管理技术相结合,为缓解人体在户外活动中的热不适感提供了新的思路。然而,目前大多数被动辐射制冷材料在穿着舒适性和耐用性方面存在不足。本文采用微阵列技术,成功制备出了具有辐射制冷能力的定制光子工程可穿戴纺织品。所开发的辐射制冷纺织品(RCTs)具有一定的透气透湿性、结构稳定性和扩展光谱响应性(太阳光反射率91.7%、大气窗口发射率95.8%)。在正午炎热环境的室外降温测试中,RCTs所覆盖的皮肤模拟器温度比棉织物低4.4 ℃。这种仿生结构的开发为可穿戴、热湿舒适和结构稳定的辐射制冷纺织品在个人热管理领域的应用提供了新的见解。

关键词: 仿生材料     个人热管理     纺织品     辐射制冷    

Photothermal-Management Agricultural Films toward Industrial Planting: Opportunities and Challenges

Song Zhang,Zhang Chen,Chuanxiang Cao,Yuanyuan Cui,Yanfeng Gao,

《工程(英文)》 doi: 10.1016/j.eng.2023.06.016

摘要: As indispensable parts of greenhouses and plant factories, agricultural covering films play a prominent role in regulating microclimate environments. Polyethylene covering films directly transmit the full solar spectrum. However, this high level of sunlight transmission may be inappropriate or even harmful for crops with specific photothermal requirements. Modern greenhouses are integrated with agricultural covering materials, heating, ventilation, and air conditioning (HVAC) systems, and smart irrigation and communication technologies to maximize planting efficiency. This review provides insight into the photothermal requirements of crops and ways to meet these requirements, including new materials based on passive radiative cooling and light scattering, simulations to evaluate the energy consumption and environmental conditions in a greenhouse, and data mining to identify key biological growth factors and thereby improve new covering films. Finally, future challenges and directions for photothermal-management agricultural films are elaborated on to bridge the gap between lab-scale research and large-scale practical applications.

关键词: Greenhouse     Photothermal management     Passive radiative cooling     Light scattering    

A state-of-the-art review of solar passive building system for heating or cooling purpose

Arun Kumar NANDA,C K PANIGRAHI

《能源前沿(英文)》 2016年 第10卷 第3期   页码 347-354 doi: 10.1007/s11708-016-0403-0

摘要: The major portion of energy in a building is consumed by heating, ventilating, and air-conditioning (HVAC). The traditional heating and cooling systems contribute greatly to the emission of greenhouse gases, especially carbon dioxide. Four different ways, i.e., Trombe wall, solar chimney, unglazed transpired solar façade, and solar roof, are adopted for solar heating. Similarly, two major ways, i.e., evaporative cooling and building integrated evaporative cooling are adopted for cooling of the building. Therefore, an attempt has been made in this paper to compile the developments of solar heating and cooling technologies in a building.

关键词: HVAC     heating     cooling     solar heating     carbon dioxide (CO2) emissions    

A spectrally selective surface structure for combined photothermic conversion and radiative sky cooling

Bin ZHAO, Xianze AO, Nuo CHEN, Qingdong XUAN, Mingke HU, Gang PEI

《能源前沿(英文)》 2020年 第14卷 第4期   页码 882-888 doi: 10.1007/s11708-020-0694-z

摘要: The sun and outer space are the ultimate heat and cold sources for the earth, respectively. They have significant potential for renewable energy harvesting. In this paper, a spectrally selective surface structure that has a planar polydimethylsiloxane layer covering a solar absorber is conceptually proposed and optically designed for the combination of photothermic conversion (PT) and nighttime radiative sky cooling (RC). An optical simulation is conducted whose result shows that the designed surface structure (i.e., PT-RC surface structure) has a strong solar absorption coefficient of 0.92 and simultaneously emits as a mid-infrared spectral-selective emitter with an average emissivity of 0.84 within the atmospheric window. A thermal analysis prediction reveals that the designed PT-RC surface structure can be heated to 79.1°C higher than the ambient temperature in the daytime and passively cooled below the ambient temperature of approximately 10°C in the nighttime, indicating that the designed PT-RC surface structure has the potential for integrated PT conversion and nighttime RC utilization.

关键词: solar energy     photothermic conversion     radiative sky cooling     spectral selectivity     multilayer film    

Thermal radiative properties of metamaterials and other nanostructured materials: A review

Ceji FU, Zhuomin M. ZHANG

《能源前沿(英文)》 2009年 第3卷 第1期   页码 11-26 doi: 10.1007/s11708-009-0009-x

摘要: The ability to manufacture, control, and manipulate structures at extremely small scales is the hallmark of modern technologies, including microelectronics, MEMS/NEMS, and nano-biotechnology. Along with the advancement of microfabrication technology, more and more investigations have been performed in recent years to understand the influence of microstructures on radiative properties. The key to the enhancement of performance is through the modification of the reflection and transmission properties of electromagnetic waves and thermal emission spectra using one-, two-, or three-dimensional micro/nanostructures. This review focuses on recent developments in metamaterials–manmade materials with exotic optical properties, and other nanostructured materials, such as gratings and photonic crystals, for application in radiative energy transfer and energy conversion systems.

关键词: metamaterial     nanostructured material     thermal radiative property     radiative energy transfer    

Entropy flow, entropy generation, exergy flux, and optimal absorbing temperature in radiative transfer

Zeshao CHEN, Songping MO, Peng HU, Shouli JIANG, Gang WANG, Xiaofang CHENG,

《能源前沿(英文)》 2010年 第4卷 第3期   页码 301-305 doi: 10.1007/s11708-010-0006-0

摘要: Taking nonequilibrium radiative heat transfer between two surfaces as an example, the nonequilibrium thermodynamics of radiation is studied and discussed. The formulas of entropy flow, entropy generation, exergy flux, and optimal temperature of absorbing surface for maximum exergy output are derived. The result is a contribution to the thermodynamic analysis and optimization of solar energy utilization and can be applied in more complex radiative heat transfer cases.

关键词: radiative heat transfer     entropy generation     exergy     thermodynamics    

Modeling radiative effects of haze on summer-time convective precipitation over North China: a case study

Xuying WANG, Bin ZHANG

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0840-3

摘要: We modeled the impact of haze radiative effects on precipitation in North China. Shortwave heating induced by haze radiative effects would reduce heavy rainfalls. Convection was the key factor that whether precipitation was enhanced or suppressed. Precipitation was often suppressed where CAPE, RH and updraft velocities were high. The impact of haze radiative effect on summertime 24-h convective precipitation over North China was investigated using WRF model (version 3.3) through model sensitivity studies between scenarios with and without aerosol radiative effects. The haze radiative effect was represented by incorporating an idealized aerosol optical profile, with AOD values around 1, derived from the aircraft measurement into the WRF shortwave scheme. We found that the shortwave heating induced by aerosol radiative effects would significantly reduce heavy rainfalls, although its effect on the post-frontal localized thunderstorm precipitation was more diverse. To capture the key factors that determine whether precipitation is enhanced or suppressed, model grids with 24-h precipitation difference between the two scenarios exceeding certain threshold (>30 mm or<-30 mm) were separated into two sets. Analyses of key meteorological variables between the enhanced and suppressed regimes suggested that atmospheric convection was the most important factor that determined whether precipitation was enhanced or suppressed during summertime over North China. The convection was stronger over places with precipitation enhancement over 30 mm. Haze weakened the convection over places with precipitation suppression exceeding 30 mm and caused less water vapor to rise to a higher level and thus further suppressed precipitation. The suppression of precipitation was often accompanied with relatively high convective available potential energy (CAPE), relative humidity (RH) and updraft velocities.

关键词: Haze     Aerosol radiative effects     Convective precipitation    

用于个人降温和保暖的具有定制热传导和热辐射特性的双功能非对称织物 Article

Yucan Peng, Hiang Kwee Lee, David S. Wu, Yi Cui

《工程(英文)》 2022年 第10卷 第3期   页码 167-173 doi: 10.1016/j.eng.2021.04.016

摘要:

为了让人体感到热舒适,同时节约能源,个人热管理正逐渐成为一种颇有前景的策略。通过更好地控制人体散热,个人热管理可以实现有效的个人降温和保暖。本文提出了一种简单的表面改性方法,在商用织物的基础上定制热传导和热辐射特性,以便更好地管理从人体到环境的整个传热路径。本文对一种同时具有降温和保暖效果的双功能非对称织物(BAF)进行论证。凭借粗糙度不对称和表面改性等优点,BAF在降温模式下通过增强热传导和热辐射表现出显著的降温效果;在保暖模式下,两条路径的散热都减少,从而实现个人保暖。结果表明,在BAF的降温和保暖模式下测得的皮肤温差可达4.6 ℃,表明一件BAF衣服可以扩大人体的热舒适区。希望本研究可为用于个人热管理的织物的设计提供新的视角,并为现有的用于个人降温和保暖的织物的简单改性提供新的解决方案。

关键词: 织物     个人热管理     双功能非对称织物     热传导     热辐射    

Radiative properties of materials with surface scattering or volume scattering: A review

Qunzhi ZHU, Hyunjin LEE, Zhuomin M. HANG

《能源前沿(英文)》 2009年 第3卷 第1期   页码 60-79 doi: 10.1007/s11708-009-0011-3

摘要: Radiative properties of rough surfaces, particulate media and porous materials are important in thermal engineerit transfer between surfaces and volume elements in participating media, as well as for accurate radiometric temperature measurements. In this paper, recent research on scattering of thermal radiation by rough surfaces, fibrous insulation, soot, aerogel, biological materials, and polytetrafluoroethylene (PTFE) was reviewed. Both theoretical modeling and experimental investigation are discussed. Rigorous solutions and approximation methods for surface scattering and volume scattering are described. The approach of using measured surface roughness statistics in Monte Carlo simulations to predict radiative properties of rough surfaces is emphasized. The effects of various parameters on the radiative properties of particulate media and porous materials are summarized.

关键词: aerogel     fiber     particle scattering     radiative properties     soot     surface roughness    

Mechanistic insight into the biofilm formation and process performance of a passive aeration ditch (PAD

《环境科学与工程前沿(英文)》 2022年 第16卷 第7期 doi: 10.1007/s11783-021-1494-3

摘要:

• A Passive Aeration Ditch was developed to treat decentralized wastewater.

关键词: Decentralized wastewater     Passive aeration ditch     Biofilm formation     C/N ratio     Salinity     Model simulation    

Numerical modeling and performance evaluation of passive convergence-permeable reactive barrier (PC-PRB

《环境科学与工程前沿(英文)》 2023年 第17卷 第11期 doi: 10.1007/s11783-023-1731-z

摘要:

● A 2D finite-element solute transport model, PRB-Trans, is developed.

关键词: Passive convergence-permeable reactive barrier     Numerical modeling     Hydraulic behavior assessment     Pollutant treatment performance evaluation     Influential factors analysis    

Near-field radiative thermoelectric energy converters: a review

Eric TERVO, Elham BAGHERISERESHKI, Zhuomin ZHANG

《能源前沿(英文)》 2018年 第12卷 第1期   页码 5-21 doi: 10.1007/s11708-017-0517-z

摘要: Radiative thermoelectric energy converters, which include thermophotovoltaic cells, thermoradiative cells, electroluminescent refrigerators, and negative electroluminescent refrigerators, are semiconductor p-n devices that either generate electricity or extract heat from a cold body while exchanging thermal radiation with their surroundings. If this exchange occurs at micro or nanoscale distances, power densities can be greatly enhanced and near-field radiation effects may improve performance. This review covers the fundamentals of near-field thermal radiation, photon entropy, and nonequilibrium effects in semiconductor diodes that underpin device operation. The development and state of the art of these near-field converters are discussed in detail, and remaining challenges and opportunities for progress are identified.

关键词: energy conversion systems     luminescent refrigeration     near-field radiation     thermophotovoltaic     thermoradiative cell    

Parametric control of structural responses using an optimal passive tuned mass damper under stationary

Min-Ho CHEY, Jae-Ung KIM

《结构与土木工程前沿(英文)》 2012年 第6卷 第3期   页码 267-280 doi: 10.1007/s11709-012-0170-x

摘要: In this study, the structural control strategy utilizing a passive tuned mass damper (TMD) system as a seismic damping device is outlined, highlighting the parametric optimization approach for displacement and acceleration control. The theory of stationary random processes and complex frequency response functions are explained and adopted. For the vibration control of an undamped structure, the optimal parameters of a TMD, such as the optimal tuning frequency and optimal damping ratio, to stationary Gaussian white noise acceleration are investigated by using a parametric optimization procedure. For damped structures, a numerical searching technique is used to obtain the optimal parameters of the TMD, and then the explicit formulae for these optimal parameters are derived through a sequence of curve-fitting schemes. Using these specified optimal parameters, several different controlled responses are examined, and then the displacement and acceleration based control effectiveness indices of the TMD are examined from the view point of RMS values. From the viewpoint of the RMS values of displacement and acceleration, the optimal TMDs adopted in this study shows clear performance improvements for the simplified model examined, and this means that the effective optimization of the TMD has a good potential as a customized target response-based structural strategy.

关键词: tuned mass damper     parametric optimization     passive control     white noise     earthquake excitation    

Power maximization of variable-speed variable-pitch wind turbines using passive adaptive neural fault

Hamed HABIBI, Hamed RAHIMI NOHOOJI, Ian HOWARD

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 377-388 doi: 10.1007/s11465-017-0431-4

摘要:

Power maximization has always been a practical consideration in wind turbines. The question of how to address optimal power capture, especially when the system dynamics are nonlinear and the actuators are subject to unknown faults, is significant. This paper studies the control methodology for variable-speed variable-pitch wind turbines including the effects of uncertain nonlinear dynamics, system fault uncertainties, and unknown external disturbances. The nonlinear model of the wind turbine is presented, and the problem of maximizing extracted energy is formulated by designing the optimal desired states. With the known system, a model-based nonlinear controller is designed; then, to handle uncertainties, the unknown nonlinearities of the wind turbine are estimated by utilizing radial basis function neural networks. The adaptive neural fault tolerant control is designed passively to be robust on model uncertainties, disturbances including wind speed and model noises, and completely unknown actuator faults including generator torque and pitch actuator torque. The Lyapunov direct method is employed to prove that the closed-loop system is uniformly bounded. Simulation studies are performed to verify the effectiveness of the proposed method.

关键词: wind turbine nonlinear model     maximum power tracking     passive fault tolerant control     adaptive neural control    

Study on forced air convection cooling for electronic assemblies

LI Bin, TAO Wenquan, HE Yaling

《能源前沿(英文)》 2008年 第2卷 第2期   页码 158-163 doi: 10.1007/s11708-008-0009-2

摘要: The slotted fin concept was employed to improve the air cooling performance of plate-fin in heat sinks. Numerical simulations of laminar heat transfer and flow pressure drop were conducted for the integral plate fin, discrete plate fin and discrete slotted fin heat sinks. It is found that the performance of the discrete plate fin is better than that of the integral continuum plate fin and the performance of slotted fin is better than that of the discrete plate fin at the same pumping power of the fan. A new type of heat sink characterized by discrete and slotted fin surfaces with thinner fins and smaller spaces between fins is then proposed. Preliminary computation shows that this type of heat sink may be useful for the next generation of higher thermal load CPUs. The limit of cooling capacity for air-cooling techniques was also addressed.

关键词: concept     slotted     air-cooling     Preliminary computation     generation    

标题 作者 时间 类型 操作

基于蝶翅三级微纳米结构的定制光子工程辐射制冷纺织品

郭竑宇, 牛田野, 俞建勇, 王学利, 斯阳

期刊论文

Photothermal-Management Agricultural Films toward Industrial Planting: Opportunities and Challenges

Song Zhang,Zhang Chen,Chuanxiang Cao,Yuanyuan Cui,Yanfeng Gao,

期刊论文

A state-of-the-art review of solar passive building system for heating or cooling purpose

Arun Kumar NANDA,C K PANIGRAHI

期刊论文

A spectrally selective surface structure for combined photothermic conversion and radiative sky cooling

Bin ZHAO, Xianze AO, Nuo CHEN, Qingdong XUAN, Mingke HU, Gang PEI

期刊论文

Thermal radiative properties of metamaterials and other nanostructured materials: A review

Ceji FU, Zhuomin M. ZHANG

期刊论文

Entropy flow, entropy generation, exergy flux, and optimal absorbing temperature in radiative transfer

Zeshao CHEN, Songping MO, Peng HU, Shouli JIANG, Gang WANG, Xiaofang CHENG,

期刊论文

Modeling radiative effects of haze on summer-time convective precipitation over North China: a case study

Xuying WANG, Bin ZHANG

期刊论文

用于个人降温和保暖的具有定制热传导和热辐射特性的双功能非对称织物

Yucan Peng, Hiang Kwee Lee, David S. Wu, Yi Cui

期刊论文

Radiative properties of materials with surface scattering or volume scattering: A review

Qunzhi ZHU, Hyunjin LEE, Zhuomin M. HANG

期刊论文

Mechanistic insight into the biofilm formation and process performance of a passive aeration ditch (PAD

期刊论文

Numerical modeling and performance evaluation of passive convergence-permeable reactive barrier (PC-PRB

期刊论文

Near-field radiative thermoelectric energy converters: a review

Eric TERVO, Elham BAGHERISERESHKI, Zhuomin ZHANG

期刊论文

Parametric control of structural responses using an optimal passive tuned mass damper under stationary

Min-Ho CHEY, Jae-Ung KIM

期刊论文

Power maximization of variable-speed variable-pitch wind turbines using passive adaptive neural fault

Hamed HABIBI, Hamed RAHIMI NOHOOJI, Ian HOWARD

期刊论文

Study on forced air convection cooling for electronic assemblies

LI Bin, TAO Wenquan, HE Yaling

期刊论文