热管蓄冰过程的数值模拟研究．

通过建立热管的简化热阻模型,采用数值计算的方法模拟了热管的动态蓄冰。模拟结果与实验结果吻合。同时,对热管冷凝段和蒸发段的长度比为1：2和1：4两种形式进行了数值模拟比较。结果表明,1：4的布置形式更优。     

直线翼垂直轴风力机静态叶片结冰的观测与分析

设计制作了采用NACA0015翼型的直线翼垂直轴风力机叶片,安装于寒冷地区的室外.冬季,对雨雪等在静止叶片表面的附着情况进行了现场观测.将获得到的叶片表面结霜和结冰(霜状冰和瘤状冰)的观测结果与温度、湿度、风速和风向等气象条件进行了对比分析,研究了静止叶片表面结霜和结冰的产生机理与气象条件的影响关系.针对翼型表面瘤状结冰情况下翼型改变前后的静态升阻力系数进行了数值模拟计算,分析了翼型改变对升阻力特性和静态特性的影响.     

某地下商场冰蓄冷低温送风系统的模拟与分析

针对地下商场这样的特殊场所,采用冰蓄冷低温送风的具体情况需要进行特殊的研究与探讨。以成都天府广场地下步行街为研究对象,探讨了冰蓄冷低温送风系统送风温度的优化选择问题。根据地下商业建筑负荷特点,主要考虑人员、设备和照明散热引起的传热过程,建立了采用方形散流器变风量系统结合低温送风的空调房间计算模型,对气流组织进行了数值模拟。     

户式蓄冷空调系统的经济性分析

从理论的角度分析户式蓄冷空调的经济性,供户式蓄冷空调系统的开发和应用借鉴.     

蓄冷球凝固的FLUENT数值模拟研究

利用计算流体力学软件FLUENT凝固／熔化模型对一种相变材料蓄冷球的凝固过程进行数值模拟研究,得到了在第一类边界条件下蓄冷球凝固过程的温度场分布,相界面移动规律,并分析了凝固时间与壁面温度和球径的关系。本文所得到的结论对相变问题的数值模拟以及相变蓄能装置的设计具有重要的参考价值。     

冰球式蓄冷槽内冰球冻结和放热特性的数值模拟分析

在冰蓄冷系统中,冰球式蓄冰槽是一种常用的蓄冰设备;通过相变材料的潜热保存冷量。对冰球式蓄冰槽内冰球的冻结和解冻过程进行了数值模拟,通过对比冻结曲线和解冻曲线,探究了冰球不同的排布方式对冰球冻结速率和解冻速率的影响。结果显示:采用顺排方式的蓄冰槽冰球冻结时间为29 400 s,而采用错排方式的蓄冰槽冰球冻结时间为25 200 s,错排方式能够提高冰球在预冷阶段的冷却速率,从而降低冻结时间;在解冻过程中,错排方式融冰相变过程的时间明显小于顺排方式,而融冰后的显热阶段两种排列方式的差异不大。     

直接空冷系统主管道两相流的数值模拟

应用计算流体力学CFX软件对直接空冷系统主管道流场用N—S方程进行了模拟,对计算结果的分析以及与阻力经验公式计算结果的对比表明,CFX能较准确地模拟空冷器中气液分配时的流场。CFX可有效的用于指导直接空冷系统的研究、开发和设计。     

面板堆石坝防渗面板受水库结冰影响的数值模拟

为分析严寒地区混凝土面板堆石坝防渗面板受水库结冰影响,在考虑坝体填筑及水库降蓄水过程的基础上,通过施加静冰压力,研究了水库结冰对面板堆石坝坝体及面板的影响,并以西龙池抽水蓄能电站为例进行了分析。数值模拟采用有限元分析软件ANSYS,并利用其中的APDL二次开发功能,编制了邓肯—张E-B模型程序,用以建立坝体和坝面材料的应力应变关系,模拟加载卸载过程中弹性模量的变化,以得到冰荷载单独作用于面板及坝体的结果。研究结果表明,冰荷载前后对坝体的应力、应变和位移影响几乎可忽略不计;中间水位时,冰荷载对薄板的主应力值影响最大。研究为防渗面板采取相应的抗冰冻措施提供了依据。     

两种电子设备散热器的对比数值模拟研究

本文用Icepak软件分别对有热管和无热管散热器进行了数值模拟对比研究,对数值模拟的过程和结果进行分析比较,结果表明有热管散热器的效果明显强于无热管散热器,同时显示了Icepak在电子设备散热研发过程中的重要作用.     

150MW汽轮机低压缸末两级三维流动的数值模拟

以真实水蒸气为介质,采用Numeca软件中Fine/Turbo模块对某台150MW汽轮机低压缸末两级流场进行了数值模拟,通过对压力系数、极限流线等进行分析,得到了流场的内部细节特征,为进一步的叶型优化提供了依据。此外还对不同出口边界条件和不同背压值对级内流场的影响进行了分析,结果表明,出口边界条件的设定对末级动叶栅出口激波的强度有较大的影响,对次末级和末级静叶栅流动影响不大;级内流量一般不随背压的升高而改变。     

冰蓄冷空调系统经济性的影响因素

介绍了冰蓄冷空调系统的策略，通过建立冰蓄冷空调系统的经济性模型，进行了经济性优化计算，分析了蓄冷率、峰谷电价比、电力增容费和蓄冷方式等因素对冰蓄冷空调系统在初投资、运行电费和总费用方面的影响。     

Simulation of heat transfer in the cool storage unit of a liquid–air energy storage system

An energy storage system that stores energy in the form of liquid air was studied. In this system, the cool storage unit was the most important unit. From the viewpoint of safety and economy, it was most promising to store the cold energy as the sensitive heat of a solid such as pebbles or concrete. A simulator was developed to predict temperature variations of the solid cool storage unit. The simulator calculated unsteady heat transfer between a supercritical gas flow and the solid material. Comparison of calculated and experimental results showed that the temperature variation of the metal cool storage medium was accurate within 11%. The calculated results showed for the concrete cool storage unit that a smaller quantity of medium was required with a smaller pitch of the tube. The minimum quantity of concrete calculated at the smallest pitch was three times that of concrete, which was simply estimated from the heat capacity of concrete and air. The volume required for concrete cool storage was less than 1/100 that of reservoirs for a pumped‐hydro power station having a vertical drop of 500 m. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(4): 284–296, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10035     

Numerical simulation of rime ice accretion process on an airfoil

To simulate the ice accretion on an airfoil, a boundary moving technique is proposed to deal with the distortion of the airfoil surface due to ice accretion on the leading edge. Incorporating the two‐phase model of air‐supercooled droplets in the Eulerian coordinate system, this technique is applied to simulate the process of the rime ice accretion (the droplets freeze at the instant impinging on the airfoil) on the NACA 0012 airfoil, and the ice profile after ice accretion is achieved successfully. A brief comparison between the results of this paper and the experiment data indicates that the current method is applicable and effective. © 2005 Wiley Periodicals, Inc. Heat Trans Asian Res, 34(4): 226–234, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20064     

Numerical analysis of the discharging performance of a solar energy storage tank containing PCM modules

采用数值模拟软件FLUENT对含有相变储能模块的储热水箱(下文简称为相变储能水箱)和不含相变储能模块的普通水箱(直接进水)的释能工况进行数值模拟,并将模拟结果进行了对比.数值模拟结果表明水箱加入相变储能模块后,一方面相变储能模块的堆积起到了散流作用,减缓了进口水流造成的扰动;另一方面冷水进入水箱中通过相变储能模块缝隙时,相变储能模块对冷水有一定的加热作用.加入相变储能模块后,改善了释能过程的水箱内热分层效果,提高了储热水箱的释热总量.在流量为5 L/min时,相变储能水箱的释能效率比普通水箱的释能效率高7%,但是随着流量的增大,相变储能水箱的释能效率逐渐降低.     

Transient analysis of energy storage in a thermally stratified water tank

A one-dimensional transient heat conduction model to describe the decay of the thermocline in a stratified water tank is presented. The problem is formulated as an initial boundary value problem and the resulting governing equations in the fluid and in the storage wall are solved numerically to obtain the temperature profiles in the wall and the fluid. The formulation considers the axial conduction of heat, both in the fluid and in the solid wall. The mixing parameters introduced in the boundary conditions at the top and bottom of the tank in the fluid region account for mixing due to inlet and outlet streams with the stored fluid. The model is applicable to the storage of both hot and chilled water. The model is validated with experimental data from the literature. The parameters that influence the operation of a stratified thermal energy storage for both heat and cool storage are examined. © 1998 John Wiley & Sons, Ltd.     

低过冷度冰蓄冷溶液的实验研究及节能效益分析

加入成核添加剂能有效地降低冰蓄冷溶液的过冷度,使制冷主机的蒸发温度提高。分别对大过冷度和低过冷度、低过冷度和无过冷度结冰过程进行了实验比较,结果表明：使用低过冷度冰蓄冷溶液时,可采用较高的制冷主机蒸发温度,结冰时间较短,在工程实际应用中能起到较好的节能效果。     

Simulation modeling and analysis of a high temperature phase change heat storage and exchange device

相变储热因单位体积储热量大,储热和放热过程温度基本恒定等优点而成为目前研究的热点。相变过程中涉及固液两相间融化和凝固的传热问题,其储放热过程是一个复杂的非稳态相变过程。本文对高温相变储热换热装置进行换热特性研究,通过研究储热单元的换热特性,基于FLUENT软件,结合装置的设计参数和相变复合材料的物性参数,对相变储热系统储/放热过程中内部的温度分布、传热速率和储放热效率进行了数学建模及模拟分析,重点研究了不同传热流体速度对单元储/放热性能的影响规律。根据仿真结果,在相变储热装置的设计中,可选择合适的空气流速,以实现不同的散热功率及储放热时间,满足不同用户的用热需求。物理实验表明仿真结果偏差较小,可为高温相变储换热装置设计、优化等工作提供依据。     

Numerical simulation of high‐temperature phase change heat storage system

In this paper, numerical results pertaining to cyclic melting and freezing of an encapsulated phase‐change material (PCM) have been reported. The cyclic nature of the present problem is relevant to latent heat thermal energy storage system used to power solar Brayton engines in space. In particular, a physical and numerical model of the single‐tube phase change heat storage system was developed. A high‐temperature eutectic mixture of LiF‐CaF₂ was used as the PCM and dry air was used as the working fluid. Numerical results were compared with available experimental data. The trends were in close agreement. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(1): 32–41, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10132     

Numerical simulations on performance enhancement of a cross-flow latent thermal energy storage heat exchanger

基于列管式换热器具有传热面积大、结构紧凑、操作弹性大等优点,使其在相变储能领域具有广阔的应用前景。本文建立一种新型列管式相变蓄热器模型,在不考虑自然对流的情况下,利用Fluent软件对相变蓄热器进行二维储热过程的数值模拟。本文主要研究斯蒂芬数、雷诺数、列管排列方式、肋片数以及相变材料的导热系数对熔化过程的影响,并对熔化过程中固液分界面的移动规律进行了分析。模拟结果表明,内肋片强化换热效果明显,特别是对应用低导热系数相变材料[导热系数小于1 W/(m·K)]的列管式蓄热器,相对于无肋片结构,加入肋片（N_fn=2）可缩短熔化时间52.6%。