检索结果-南通市图书馆

Analysis and Application of Variable Conductance heat pipe Air Preheater

维普期刊数据库评论

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 2011年第3期20卷 248-253页

作者： Chengming Shi Yang Wang Quan Liao Ying Yang College of Power Engineering Chongqing University Chongqing 400044 China

The heat transfer analysis of variable conductance heat pipe air preheater was carried out. The temperature trans-fer matrix was obtained for the air preheater that comprises several discrete heat transfer units with same or different heat transfer surface area in a parallel or counter flow mode. By using the temperature transfer matrix, the outlet fluid temperatures could be easily calculated for a given air preheater and inlet fluid temperatures. The active length of condenser in a variable conductance heat pipe is determined according to the flat interface model. With the same initial conditions, the comparisons between variable conductance heat-pipe air preheater and regular heat pipe air preheater has been analyzed and tested in terms of heat pipe wall temperature, heat transfer surface area and outlet fluid temperatures. Based on the real industrial applications, it has been confirmed that the variable conductance heat pipe air preheater has excellent performance of anti-corrosion and anti-ash-deposition especially at the variable working condition and the sulfur coal (5%-6% mass fraction of sulfur) condition.

关键词： variable conductance heat pipe air preheater anti-corrosion anti-ash deposition

A gravity heat pipe for high voltage vacuum interrupter

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第9期10卷 1305-1312页

作者： Xiao-ling YU Zhi-yuan LIU Quan-ke FENG Yi-jiang WEI Ji-mei WANG Xiang-jun ZENG School of Energy and Power Engineering Xi 'an Jiaotong University Xi 'an 710049 China School of Electrical Engineering Xi'an Jiaotong University Xi 'an 710049 China

To enhance nominal current of high voltage vacuum circuit breakers （VCBs）, a gravity heat pipe was proposed to replace stationary conducting rod of a high voltage vacuum interrupter. The heat pipe is composed of two coaxis tubes： the external tube is made of oxygen-free copper and the inner tube is made of stainless steel. The bottom end of the inner stainless steel tube is connected to the external copper tube by holes. Transient and static thermal performance of the heat pipe was measured, and the thermal resistance of it was compared with that of a solid copper rod with the same dimensions. Experimental results showed that thermal resistance of the heat pipe was about 1/3 of that of the copper rod, and it decreased slightly with the rising of the input heat flux. 3D thermal simulation on a 126 kV/2000 A single break VCB was done to compare the thermal performance between the proposed gravity heat pipe and the copper rod serving as the stationary conducting rod of the vacuum interrupter. Simulation results revealed that in the heat pipe case, the maximum temperature between contacts was 67 ℃ lower than that in the copper rod case.

关键词： heat pipe Vacuum circuit breakers (VCBs) Vacuum interrupters Nominal current Thermal simulation

Comparison Study of a Novel Tank PV/T Hot Water System and a heat pipe PV/T System

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2022年第6期31卷 2009-2021页

作者： XIE Yujie SIMBAMBA Mzee Mohamed CAO Xiaoling SUN Liangliang ZHOU Jinzhi YUAN Yanping School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China

A novel tank-Photovoltaic-thermal(PV/T) system is presented in this paper, and its energy performance has been compared with a traditional heat pipe PV/T system. The novel tank PV/T system combines photovoltaic cell, heat absorbing plate and hot-water storage tank which expands the heat exchange area, shortens the heat transfer path and saves the module installation space. A prototype system is constructed and tested in a cold weather condition and then compared with a heat pipe PVT system. The experimental results indicate that during the 10 days’ testing, the electrical, thermal and overall efficiency of the tank PV/T system ranges from 14.3% to 15.6%, 38.6% to 43.8% and 53.1% to 58.1%, respectively, while the heat pipe PVT system ranges from 10.9% to 12.2%, 39.3% to 41.2% and 50.5% to 53.4%, respectively. Based on these data, the electrical and thermal efficiency curve of the system with the novel tank-PVT system and heat pipe PVT system were generated. According to the comparison result, it shows that the novel tank-PVT system has a better thermal and electrical efficiency. This system provides a new design method for the development of the PV/T systems, which has a potential for PV/T systems building integration in the future.

关键词： tank PV/T heat pipe thermal and electrical efficiency instantaneous efficiency

Fabrication and thermal performance of grooved-sintered wick heat pipe

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2014年第2期21卷 668-676页

作者：蒋乐伦汤勇武汇岳周伟蒋琳珍 School of Engineering Sun Yat-sen University Key Laboratory of Surface Functional Structure Manufacturing of Guangdong Higher Education Institutes(South China University of Technology) School of Communication and Design Sun Yat-sen University School of Foreign Studies Yiwu Industrial and Commercial College

Some novel grooved-sintered composite wick heat pipes(GSHP) were developed for the electronic device *** grooved-sintered wicks of GSHP were fabricated by the processes of oil-filled high-speed spin forming and solid state *** wick could be divided into two parts for liquid capillary pumping flow:groove sintered zone and uniform sintered *** of the thermal resistance network model and the maximum heat transfer capability model of GSHP were *** with the theoretical values,the heat transfer limit and thermal resistance of GSHP were measured from three aspects:copper powder size,wick thickness and number of micro *** results show that the wick thickness has the greatest effect on the thermal resistance of GSHP while the copper powder size has the most important influence on the heat transfer *** certain copper powder size and wick thickness,the thermal resistance of GSHP can be the lowest when micro-groove number is about 55.

关键词： wick heat pipe electronics cooling thermal resistance heat transfer limit

The development of a high-performance Ni-superalloy additively manufactured heat pipe

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2022年第4期10卷 610-624页

作者： Sheng Li Khamis Essa James Carr States Chiwanga Andrew Norton Moataz M.Attallah School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Engineering University of BirminghamEdgbastonBirmingham B152TTUK Henry Moseley X-ray Imaging Facility Henry Royce Institute for Advanced MaterialsDepartment of MaterialsUniversity of ManchesterManchester M139PLUK European Thermodynamics Ltd 8 Priory Business ParkWistow RoadKibworthLeicestershire LE80RXUK Rolls-Royce plc P.O.Box 31Derby DE248BJUK School of Metallurgy and Materials University of BirminghamEdgbastonBirmingham B152TTUK

Additively manufacturing(AM)has been used to manufacture fine structures with structured/engineered porosity in heat management *** this study,laser powder bed fusion(LPBF)was used to manufacture a high-performance Ni-superalloy heat pipe,through tailoring LPBF process parameters to fabricate thin wall and *** using novel laser scanning strategies,wick structure heat pipes with maximised surface-area-to-volume ratio,fine features size around 100µm,and controlled porosity were successfully *** and X-ray microtomography(micro-CT)were used to investigate the 3D structure of the void space within the *** test results showed that most of the heat pipes made by LPBF had better performance than the conventionally manufactured *** study also investigated the influences of the process parameters on the porosity volume fraction and the feature *** results showed that LPBF process could fabricate thin structure due to the change of melt pool contact *** relationship between process parameters and bead size reported in this study could help design and manufacture heat pipe with complex fine structure.

关键词： Laser powder bed fusion(LPBF) heat pipe Melt pool Microtomography(micro-CT)

heat and Mass Transfer Characteristics of Alkali Metals in a Combined Wick of High-Temperature heat pipe

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2020年第2期16卷 267-280页

作者： Ping Yu Chuanhui Huang Lei Liu Huafeng Guo Chengqiang Liu College of Mechanical and Electrical Engineering Xuzhou University of TechnologyXuzhouChina

To study the heat and mass transfer characteristics of alkali metals in a combined porous wick in high-temperature heat pipes,a three-dimensional(3-D)numerical model is constructed by using the finite volume method,Darcy’s theory,and the theory of local thermal *** research finds that the pressure drop of fluids flowing through a combined porous wick exhibits an increasing trend with increasing flow velocity at the inlet and with decreasing permeability of the porous media;a combined porous wick of lower porosity and permeability and larger fluid velocity at the inlet is found to have a less uniformly distributed fluid velocity;the different temperatures of the fluid at the inlet mainly influence the inlet section of the computational model,while having negligible effect thereon in the axial direction(this embodies the thermal homogeneity of such heat pipes).The result reveals that the temperature change in fluids at the inlet does not significantly affect the overall temperature distribution in a combined wick.

关键词： Porous medium heat pipe numerical simulation combined wick

Fabrication of flatten grooved-sintered wick heat pipe

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2013年第9期23卷 2714-2725页

作者：蒋乐伦汤勇周伟蒋琳珍陆龙生中山大学工学院广州510006 华南理工大学机械与汽车工程学院广州510640 中山大学工学院广州510006 义乌工商学院义乌322000

With the rapid rising of heat flux and reduction of heat dissipating space of microelectronic devises, flattened sintered heat pipe has become an ideal conducting element of use in the electronic cooling field. A manufacturing technology named phase change flattening process is presented to fabricate the flattened grooved-sintered wick heat pipe （GSHP for short）. Deformation geometry of flattened GSHP and the elasto-plastic deformation of flattening process are analyzed theoretically and verified by experiments. The results show that the vapor pressure inside sintered heat pipe during flattening process is determined by the saturated vapor pressure equation; the width and vapor area of flattened heat pipe change greatly as the flattening proceeds; the maximum equivalent strain distributes at the interface between wick and vapor in the fiat section; the buckling phenomenon can be well eliminated when the flattening temperature reaches 480 K; phase change flattening punch load increases with flattening temperature and displacement.

关键词： heat pipe wick flattening elasto-plastic deformation buckling vapor pressure

Design of heat pipe Type Adsorption Ice Maker for Fishing Boats

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2005年第3期13卷 403-410页

作者：王丽伟王如竹夏再忠吴静怡 Institute of Refrigeration and CryogenicsShanghai Jiao Tong University Shanghai200030 China

A heat pipe type adsorption ice maker with two adsorbers for fishing boats is designed by using ammonia as refrigerant and compound of activated carbon-CaCl2 as adsorbent. This type of heat pipe adsorber can solve the problem of incompatibility between ammonia, copper, seawater and steel. The working process of the ice maker with 8.7kg adsorbent per bed is simulated. The results show that the optimal semi-cycle time is about 9 min at the evaporating temperature of -15℃, where the corresponding cooling power, specific cooling power per kilogram adsorbent SCP and coefficient of refrigerant performance COP are respectively 3.6kW, 217W·kg-1 and 0.404.

关键词： adsorption ice maker heat pipe ammonia seawater compound adsorbent

Analysis of behaviour of computational model to evaluate performance of heat pipe containing nanofluids

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2019年第5期26卷 1306-1326页

作者： Rodrigo Vidonscky PINTO Flávio Augusto Sanzovo FIORELLI University of Sao Paulo Escola PolitécnicaMechanical Engineering DepartmentAvenida Professor Mello Moraes223105508-030São Paulo(SP)Brazil

Application of nanofluids in heat pipes usually presents satisfactory experimental results regarding a thermal resistance reduction of the heat ***,the existing computational studies connecting heat pipes and nanofluids lack a deeper discussion regarding the validity of the models currently used for representing the behaviour of a nanofluid in a heat pipe,particularly for unusual base fluids and nanoparticles such as carbon nanotubes or ethylene ***,this comparative study presents the results of a set of computational simulations using pre-established equations for modelling a nanofluid in a heat pipe with experimental data from the *** results show agreement with the expected behaviour qualitatively and the presented maximum variations between 1.5% and 23.9% in comparison to the experimentally measured average ***,the experimentally obtained temperature distribution of a heat pipe could not be reached numerically only with the use of adequate thermal properties,indicating that the boiling phenomenon is more complex than the current model used for computational ***,the existence of an optimal particle volume fraction for using nanofluids in this application could be observed by combining different properties models.

关键词： heat pipe nanofluid computational analysis particle volume fraction