检索结果-南通市图书馆

Synthesis and thermal properties of nanoencapsulation of paraffin as phase change material for latent heat thermal energy storage

在线全文

学校读者我要写书评

暂无评论

Energy and Built Environment 2020年第4期1卷 410-416页

作者： Nan Zhang yanping yuan School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

In this work,a series of nanoencapsulated phase change materials(NanoPCMs)with paraffin wax(PW)as core and melamine-formaldehyde(MF)as shell were synthesized by the in-situ polymerization *** morphol-ogy,chemical structure and thermal properties of prepared NanoPCMs were characterized by scanning electron microscope,Fourier transform infrared,differential scanning calorimetry and thermogravimertic *** results show that the PW is successfully encapsulated in the MF without chemical interaction,and the NanoPCMs present regular spherical shape with the average diameter of 260-450 *** encapsulation efficiency of the NanoPCMs increases with the augment of the supplied amount of core *** maximum encapsulation efficiency of the NanoPCMs can reach up to approximately 75%.The NanoPCMs can maintain excellent thermal reliability and stability after 2000 thermal *** prepared NanoPCMs can be well applied in the latent heat thermal energy storage and thermal management systems due to their remarkable encapsulation efficiency and thermal properties enable them to.

关键词： Nanoencapsulted PCMs Encapsulation efficiency Thermal properties Thermal energy storage

Flue Gas Water Recovery by Indirect Cooling Technology for Large-Scale Applications: A Review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2020年第5期29卷 1223-1241页

作者： ZHONG Wei JI Wenhui CAO Xiaoling yuan yanping School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

With social development and economic enhancement,energy is facing significant worldwide demand,and fossil fuels are the prime energy sources for various energy systems over past ***,among fuel-consumed applications,power plants are the primary source of energy *** is a lot of waste heat and steam accompanied by the latent heat produced in the exhaust flue ***,the latent heat recovery from the flue gas plays an important role in increasing the efficiency of the system and saving *** recover the heat and mass in power plants,three primary methods are proposed to condense the vapor based on previous studies:(1)flue gas condensation technology,(2)liquid desiccant-based dehydration(LDD)technology and(3)membrane *** paper mainly reviews and summaries the indirect cooling technology in flue gas condensation *** numerical simulation and theory of flue gas condensation are *** heat exchanger types and conducted experiments are also *** performance of the indirect cooling technology is affected not only by its own configuration and design but also by the flue gas inlet temperature,velocity,water vapor mass fraction,*** major concerns and outlook of practical applications for further study are attributed to the heat exchanger size and cost,acid corrosion,ash accumulation in flue gas,etc.

关键词： flue gas condensation water recovery heat exchanger power plants

Wall-Attached Night Ventilation Combined with Phase Change Material Wallboard in Hot Summer:An Experimental Study on the Thermal Performance

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第2期31卷 318-331页

作者： JI Wenhui yuan yanping LI Yajun YU Min School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

Night ventilation is regarded as a promising cooling strategy by storing night cooling in the thermal mass of the ***,night ventilation performance in hot summer is restricted by the climatic *** this paper,we propose a new solution as the integration of wall-attached night ventilation(WANV)and phase change material wallboard(PCMW).The principle of the proposed system is to utilize the wall-attached jet ventilation to achieve forced convection and to adopt latent energy storage of PCMW to enlarge the energy storage density capabilities,and the coupling method is expected to improve the night ventilation *** experiments were conducted to evaluate the thermal performance of the hybrid system by evaluating indoor temperature history,thermal comfort time and cooling *** to the high thermal energy storage density capability of PCMW,it was found that the presence of PCMW has a negative influence on night cooling efficiency but still has a positive influence on the overall cooling *** proposed WANV combined with the PCMW system significantly increased the temperature decrease of room air and west wall inside surface during one hour's night ventilation by 94.97%and 67.74%,respectively,and reached an extension of 38.42%of indoor thermal comfort *** results highlight the potential of WANV integration of PCMW to improve the thermal performance of night ventilation.

关键词： night ventilation wall-attached jet ventilation phase change material wallboard thermal performance

Numerical investigation on temperature–humidity field under mechanical ventilation in the construction period of hot-humid tunnel along the Sichuan–Tibet Railway

在线全文

学校读者我要写书评

暂无评论

Underground Space 2023年第1期8卷 123-143页

作者： Kaiming Zhao yanping yuan Fujian Jiang Xiaoling Cao School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

High temperature–humidity environment is one of the severe challenges in constructing Sichuan–Tibet railway *** enhancing construction efficiency and guaranteeing tunnel worker safety,addressing the high temperature–humidity environment has irreplaceable *** study innovatively investigated the distribution law and evolution process of the thermal–humidity coupling field dur-ing tunnel ***,the corresponding ventilation measures were proposed based on the evaluation heat index(HI).If the initial temperature of the surrounding rock is constant,the distance between the ventilation duct outlet and the tunnel working face should not be greater than 30 ***,the cooling performance of ventilation will be significantly weakened;If this temperature ranges in 65–85℃,the recommended ventilation velocity is 10–25 m/s,and the ventilation distance should not exceed 20 *** con-clusions in this study are beneficial to better understand the high temperature–humidity environment in tunnel construction and can be a guideline for practical engineering application.

关键词： CFD simulation Heat and mass transfer Tunnel environment Tunnel ventilation

Numerical simulation of smoke stratification in tunnel fires under longitudinal velocities

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Underground Space 2021年第2期6卷 163-172页

作者： Yuhao Guo Zhongyuan yuan yanping yuan Xiaoling Cao Peng Zhao School of Mechanical Engineering Southwest Jiaotong University111Second Ring RoadChengdu CitySichuan Province 610031PR China

Use of the longitudinal critical velocity in tunnel fires may destroy the stratification of smoke downstream,which is not conducive to the evacuation of downstream tunnel *** the longitudinal velocity can maintain stratification,but the appropriate longitudinal velocity range is *** of smoke under the longitudinal velocity is studied using Fire Dynamics Simulator(FDS).The aims of this paper are to explore the relationship between the longitudinal velocity and smoke stratification and to obtain a proper velocity range that can maintain clear downstream *** on Newman's theory,the"stratification velocity"is proposed,which is the maximum velocity that maintains downstream smoke stratification.A good correspondence between the average Froude number within 200 m downstream and the longitudinal velocity and heat release rate(HRR)is *** correlation between the temperature stratification and Froude number is ***=0.49 can be used to distinguish whether the stratification is *** relationship between the critical velocity and the stratification velocity is also discussed.

关键词： Tunnel fire Longitudinal ventilation Smoke stratification

Pyrolysis,combustion,and fire spread characteristics of the railway train carriages:A review of development

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy and Built Environment 2023年第6期4卷 743-759页

作者： Jidan Zhang Wenhui Ji Zhongyuan yuan yanping yuan School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

Fires in the railway trains are prone to cause large numbers of casualties,serious economic losses,and huge negative social *** railway train carriage is a special confined built environment,where the pyrolysis,combustion,and fire spread process are different from those fire accidents in open *** the fire characteristics of the railway train carriages is the key issue to determine the fire prevention and control ***,this paper attempts to assess and identify the characteristics of pyrolysis,combustion,and fire spread of railway trains based on the exising *** review documents the pyrolysis and combustion characteristics of single train material and the combustible module,summarizes the heat release rate(HRR)calculation methods and the HRR profile for different types of trains,as well as introduces the research progress in the flame spread and *** main gaps and issues to be solved in terms of the effects of train speed,altitudes,and application of new energy trains are further discussed.

关键词： Fire safety Railway trains Pyrolysis Heat release rate Fire spread Flashover

Recent progress in modelling and simulation technologies of energy efficiency and environmental quality in the built environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Building Simulation 2022年第7期15卷 1175-1176页

作者： Wenhui Ji yanping yuan Liangliang Sun Xudong Zhao School of Mechanical Engineering Southwest Jiaotong UniversityNo.111North Section 1Second Ring RoadChengdu 610031China University of Hull School Engineering and Computer ScienceKingston Upon Hull HU67RXN HumbersideUK

The International Conference for Global Chinese Academia on Energy and Built Environment(ICCEBE)is a premier international event covering a broad range of topics on clean energy utilization,energy efficiency and environmental quality in the built *** conference aims to provide a forum to share cutting-edge achievements in the built environment,and to promote academic collaboration and cooperation among worldwide Chinese scholars.

关键词： energy modelling collaboration

Flow Characteristics and Aerodynamic Heating of Tube Trains in Choked/Unchoked Flow:A Numerical Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2023年第4期32卷 1421-1434页

作者： SUI Yang YU Qiujun NIU Jiqiang CAO Xiaoling YANG Xiaofeng yuan yanping Graduate School of Tangshan Southwest Jiaotong UniversityTangshan063000China School of Mechanical Engineering Southwest Jiaotong UniversityChengdu610031China State Key Laboratory of Aerodynamics China Aerodynamics Research and Development CenterMianyang621000China

Hyperloop has become one of the key reserve technologies for future high-speed rail *** gas in the tube is compressed and rubbed,leading to a strong aerodynamic heating *** research on the flow field characteristics and aerodynamic heating effect of hyperloop is in its infancy,and that on the flow field structure is *** this study,the nozzle theory was used to make a preliminary judgment on the choked flow phenomenon in the *** on the flow results obtained under different working conditions,the identification basis of the choked flow phenomenon in the hyperloop was ***,the effect of the choked/unchoked flow on the flow structure,temperature,and pressure distribution of the annular space in the tube was *** on traditional high-speed railway aerodynamics,according to relevant theories and calculation in aerospace field,and combined with the model test data,the reliability verification analysis on the characteristics of the flow field are carried *** structure of the flow filed in the tube can be divided into choked and *** judgment is dependent on whether the throat reaches the speed of *** the choked flow,a normal shock wave is formed in front of the tube *** temperature rise of the local flow field exceeds 50 K;the temperature rise of the stagnation region exceeds 88 K,and the pressure is approximately 1.7 times that of the initial pressure in the *** the flow is unchoked,differences arise in the distribution of the flow field corresponding to different incoming Mach *** the incoming flow is supersonic,the flow field maintains a supersonic speed,and a bow-shaped shock wave is formed at the front of the tube *** to the shock wave or expansion wave,the local flow field exhibits significant fluctuations in temperature and ***,when the incoming flow is subsonic,the flow field in the tube maintains a subsonic speed,and no shock wave structure is

关键词： hyperloop choked/unchoked flow aerodynamic phenomenon numerical simulation

A Review on the Heat Pipe Photovoltaic/Thermal(PV/T)System

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2021年第5期30卷 1469-1490页

作者： ZHOU Jinzhi ZHONG Wei WU Dan yuan yanping JI Wenhui HE Wei School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China School of Architecture and Design Southwest Jiaotong UniversityChengdu 610031China Department of Building Environment and Equipment Hefei University of TechnologyHefei 230009China

The Photovoltaic/thermal(PV/T)system combines the conventional PV panel with solar collector into one integrated system,which could achieve the function of generating power and providing thermal energy at the same ***,it has become the most promising solar system for building *** of the PV/T systems use water as the coolant,which could cause freezing problem in *** overcome this problem,the heat pipe PV/T system is developed to provide electrical and thermal energy stably without the seasonal *** some published review works have involved this type of PV/T system,they just stated a simple introduction on it,acting as a small part of their *** paper focuses on the heat pipe PV/T system independently and provides a comprehensive and in-depth analysis of its ***,the structure and operational principles of the heat pipe PV/T module and system are introduced *** the features and performance of different types of heat pipe PV/T systems,i.e.,integral heat pipe,loop heat pipe,and pulsating heat pipe PV/T system,are presented and *** is followed by the review on the performance of the systems which combine heat pipe PV/T module and other ***,the research gaps in this field are identified,and some future research trends and directions are recommended.

关键词： heat pipe PV/T operating principle different types energy and exergy performance