置换通风的研究与应用现状

简述了置换通风的原理,回顾了置换通风应用的发展过程,总结了置换通风系统的优缺点,介绍了置换通风的设计方法和设计关键参数的确定,分析了置换通风的工作机理,介绍了置换通风的CFD研究,并指出置换通风是一种值得推荐的暖通空调方式。     

置换通风与混合通风系统的比较研究

在分析空调系统置换通风和混合通风原理的基础上,从研究置换通风和混合通风气流组织特性出发,系统地分析比较了两种通风方式的通风效果及室内空气品质,并且对置换通风能耗等方面进行了分析。指出置换通风是一种高效、节能、高品质的通风方式。     

飞机座舱应用置换通风系统的节能分析

通过置换通风系统和混合通风系统的比较,阐述了置换通风系统的特点和优势.运用暖通空调领域设计置换通风系统的方法,并结合ISO7730 - 2005、ASHRAE62 - 1989和民航飞机相关标准对座舱通风的规定,以节能分析的方式得出了置换通风在飞机座舱通风系统应用上的节能优势.     

EnergyPlus软件在置换通风设计中的应用研究

介绍了EnergyPlus软件中的置换通风模型,采用EnergyPlus辅助某办公室置换通风系统设计,并采用CFD软件模拟了室内温度分布,结果表明,EnergyPlus可以精确地预测置换通风系统负荷,系统设计能满足热舒适要求。     

置换通风与混合通风室内舒适性对比研究

针对一个典型办公室,建立了置换通风系统和混合通风系统的物理模型及数学模型.利用AirPak软件对室内温度场、速度场进行了模拟计算,对比分析了置换通风和混合通风两种通风方式的舒适性.     

保证室内空气品质的置换通风的节能研究

介绍了置换通风的原理及其能够改善室内空气品质的原因,运用送风量及送风温度的公式,对置换通风及混合通风进行了计算比较。通过具体工程实例的计算表明:置换通风其送风量比混合通风的送风量减少16.7%,节约能耗41%,新风节能2.46W,是一种能改善室内空气品质的节能方法。     

封闭式焊接车间的节能型通风方式

通过对焊接工艺的相关特点--焊接烟尘和焊接烟羽的分析,在常用的工业厂房全面通风方式中选取置换通风作为封闭式焊接车间的通风方式,并用CFD分别模拟采用置换通风和采用混合通风的封闭式焊接车间,通过对比得到置换通风的优越性--节能.     

室内热源与太阳辐射耦合作用下的太阳能烟囱通风性能研究

针对太阳辐射和室内热源对太阳能烟囱的耦合作用,通过三维数值模拟,研究太阳辐射强度I、室内热源热流密度w、等效内热源面积s和太阳能烟囱进口距地面的高度h对太阳能烟囱通风性能的影响。研究结果表明:当太阳能烟囱结构参数相同时,室内热源和太阳辐射对太阳能烟囱通风量的影响相互促进;随着太阳能烟囱进口距地面高度h的逐渐增加,通风量持续增大,其增大幅度随着室内热源热流密度的增大而增大,随着太阳辐射强度的增大而减小;在相同条件下,太阳能烟囱通风量随着等效内热源面积的增大而增大。     

地板送风与置换通风特性比较

介绍了置换通风与地板送风的原理。从原理出发,对地板送风与置换通风在气流组织、通风效率、 空气品质和热舒适等方面的特性进行了比较。     

外热源干扰下电缆载流量计算及通风增容分析

为了更加准确地计算外热源干扰下电缆沟电缆载流量,实现通风增容目的,建立了外热源干扰下热-流耦合三维模型。采用ANSYS仿真获得电缆温度分布,进而利用双点弦截法精确计算电缆载流量,并在不考虑外热源情况下,通过IEC标准验证了该模型的准确性。通过实例仿真分析得出,外热源功率(表面温度)每升高1K,载流量下降0.9~1.8A;载流量随距离增大而变大,直至2.5m时影响不大;电缆载流量随通风速度变大而变大,但增长梯度变小;通风温度每升高1K,载流量下降3.5A,呈线性相关趋势。这为外热源干扰下电缆沟敷设提供了最佳施工方案,且为电缆沟电缆增容提供了指导。     

Energy efficient room air distribution

An environmental chamber has been used to compare the effectiveness of mixing and displacement ventilation in terms of heat and contaminant removal. Results are presented for CFD simulations of the air movement in the chamber and for measurements using a heated mannequin with displacement ventilation. The CFD simulations and the measurements suggest that displacement ventilation is more energy efficient than a mixing system.     

Simulation of Velocity and Temperature Distributions of Displacement Ventilation System with Single or Double Heat Sources

In order to obtain a better understanding of flow characteristics of displacement ventilation,thethree-dimensional numerical models are developed using the CFD technology.The numericalsimulation results are verified by experiments,based on this,the velocity and temperature distributionof three-dimensional displacement ventilation system with single and double heat sources are studied.Velocity and temperature fields under two different cases of heat source are analyzed and compared.The numerical results show that there are three layers in vertical temperature fields of displacementventilation system with single or double heat sources,and the vertical temperature distribution ofsingle heat source is different from that of double heat sources.When indoor load is large,the comfortrequirement of people indoor can't be satisfied with displacement ventilation system only,thus anadditional refrigeration system is necessary.Furthermore,under the condition of two heat sources,thedisplacement ventilation parameters can't be computed simply according to single heat source inletparameters,therefore the interaction between heat sources should be considered.     

Review of research into and application of chilled ceilings and displacement ventilation systems in Europe

This paper discusses the origination, development and current status of chilled ceilings, displacement ventilation and combined systems. Current knowledge of chilled ceilings (including ceiling panels and beams), displacement ventilation and combined systems is summarised and a comprehensive review of research into chilled ceilings and displacement ventilation systems is presented. Research work has been categorized, and some conclusions made. Opportunities for further work are discussed. Copyright © 2004 John Wiley & Sons, Ltd.     

会议室空调气流组织形式的数值模拟研究

办公区里的会议室为重要工作场所,其环境质量的优劣直接影响工作的效率。以计算流体力学和传热学为基础,利用CFD软件对室内混合通风与置换通风两种气流组织进行数值模拟。结果表明:在温度场、速度场、温度效率及人体热舒适性等方面,置换通风均优于混合通风方式。     

Numerical visualization of mass and heat transport for mixed convective heat transfer by streamline and heatline

Based on the method we suggested in a previous paper [Int. J. Heat Mass Transfer 45 (2002) pp. 2373-2385], the present work is to investigate the mixed convection problem. A two-dimensional, steady, laminar displacement ventilation model is adopted here for the interaction between the buoyancy driven natural convection and the external forced convection is important to achieve the goal of ventilation effectiveness. The solution is determined by the non-dimensional parameters Gr and Gr/Re², the influences of which on the resulting heat and fluid flow are discussed. To optimize the ventilation system, different outlet locations are investigated. Results and comparisons show that the displacement ventilation guarantees a high indoor air quality (IAQ) and is therefore a desired air-conditioning system.