某办公室夏季热舒适性数值模拟与实测分析

本文通过测试空调出风口的温湿度和风速,作为仿真计算的边界条件,然后利用CFD对某办公室进行数值模拟,得出了房间的温湿度分布、气流的运动状态和房间热舒适性评价指标(PMV-PPD)等,对办公室的热舒适性做出了总体分析评价.     

上出风壁挂式空调器舒适性的数值模拟及实验研究

本文结合壁挂式房间空调器的使用特点,运用CFD方法模拟室内空调热环境,对上出风壁挂式空调器的热舒适性进行了研究分析;同时通过搭建房间环境热舒适实验室,对模拟和实验结果进行对比和分析,验证数值计算模型的准确性.     

供暖房间动态热环境及热舒适分析

将热舒适评价标准模型与供暖房间热环境动态数值模拟相结合，以西安地区为算例，对供暖房间１１个工况进行了室内动态热环境及热舒适模拟与分析，证实了现行规范的可行性．     

通风降温建筑室内热环境模拟及热舒适研究

将热舒适评价标准ＰＭＶ／ＰＰＤ模型与建筑动态热模拟及计算流体动力学（ＣＦＤ）模拟相结合，分别对重庆地区自然通风房间和埋管送风通风房间进行了室内气候及热舒适性模拟与分析，结果表明，埋管系统通风降温可以改善炎热地区的室内热舒适性。     

地板送风房间的气流组织与热舒适性

综合考虑地板送风参数及其室内气流组织及舒适性的影响,采用CFD技术对地板送风房间的气流组织进行数值模拟,并用空气分布特性指标(ADPI)对模拟结果进行评价,为地板送风可以使房间达到良好稳定的气流组织及舒适性提供了有效根据。     

孔板送风对壁挂式空调房间热舒适性的影响

为研究孔板送风方式对壁挂式空调房间热舒适性的影响,采用Airpak软件分别对在相同送风量和送风温度下采用传统射流送风和孔板送风的气流组织进行数值模拟,通过对温度场、速度场、PMV-PPD值的对比分析,评价两种送风方式下的室内热舒适性,并采用实验测试的方法,对模拟结果的准确性进行实验验证。结果表明:送风方式对室内热舒适性影响明显,孔板送风对室内气流组织的改进和热舒适性的提高有较显著效果,夏季工况采用孔板送风可以起到节省能耗的作用。     

办公室空调房间热环境数值模拟研究

运用k-ε湍流模型对某办公室空调房间气流组织和热舒适性进行了数值模拟,利用有限容积法和SIMPLE算法对微分方程进行离散求解.研究了室内空气龄云图、温度云图、速度矢量图、PMV云图、PPD云图分布规律.模拟结果表明:室内热环境满足健康、舒适、节能等方面的要求.利用TEST0445型多功能测量仪对人员办公区的空气温度、气流速度进行了测量,测量数据与模拟结果基本一致.在空调系统设计阶段,采用CFD技术可预测室内气流组织、热舒适性及为空调系统优化设计方案提供理论依据和科学指导.     

基于CFD的室内热环境模拟研究

本文首先对室内热环境的评价指标和热舒适的定义作了简单概述,然后以现场测试过的房间为模型房间,建立相应的数学模型,并以测试到的一部分参数为边界条件,采用CFD程序里的k-ε方程模型对重庆大学学生寝室室内热环境参数分布进行了模拟,并结合现场测试结果进行比较分析,表明温度场的实验结果与模拟分析结果趋于一致,说明本文对室内热环境的模拟过程的数学模型是合理的.最后,对房间温度场和速度场的模拟结果进行了分析,同时对房间不同时刻模拟计算所得的模拟数据进行比较分析,指出室内热环境发生变化的原因,并得出寝室热舒适的评价.     

利用FDS软件预示风口布置对热舒适性的影响

本文以NIST开发的FDS程序为平台,采用LES方法对室内气流组织情况进行了数值模拟,对不同气流组织条件下的舒适性进行评价.主要完成了不同风口布置形式下室内的气流组织模拟,运用舒适性评价方法对采集到的数据进行了计箅,分析和比对了风口布置对热舒适性的影响.     

辐射供冷/置换通风空调系统的数值模拟与实验

本文利用CFD软件对运用辐射供冷/置换通风空调系统的房间进行了内部气流的数值模拟并进行了实验研究,得到温度场和速度场,尤其是室内温度梯度状况对热舒适性的影响。数值模拟的结果以及实验验证表明,在夏季运行工况下,该复合式空调系统可以提供优于普通空调系统的热舒适环境。     

碰撞射流通风供暖房间热环境特征的研究

采用数值模拟方法研究了碰撞射流通风系统的供热特性,对供热房间内热环境特征以及热舒适性的分析结果表明：在典型送风参数工况下,碰撞射流供热房间内靠近送风口附近位置处存在垂直温度分层,空气温度随房间高度增加而降低,工作区热舒适情况良好。     

某精装修住宅楼室内热舒适度实测分析

热舒适性是居住者对室内热环境满意程度的一项重要指标,除了与空气温度、湿度相关外,还与气流速度、室内空气品质密切相关.详细阐述了室内热舒适性的测试方法及评价方法,并结合工程案例的实测情况,分析客厅、主卧室、次卧室等主要功能房间的室内热舒适度.     

Optimization of air-conditioning system operating strategies for hot and humid climates

This paper describes research into the optimal operation of building heating, ventilation, and air-conditioning (HVAC) systems focusing on both temperature and humidity control. While most previous work on HVAC optimization has been limited to evaluation of conventional temperature-based control systems, this study emphasizes the humidity control issue in meeting both sensible and latent building loads. The analysis is based on a combination of a realistic simulation of a direct expansion (DX) air-conditioning system and a direct-search numerical optimization technique. The simulation models have been validated through comparisons with field data. Optimization was performed on five different system control variables to minimize system power consumption while meeting building loads and maintaining comfort. Indoor temperature and humidity are also optimized within standard comfort constraints. Building loads were modeled using an extended bin method that allows consideration of the interactions between loads and indoor conditions. Results indicate that minimum energy use typically occurs at low airflow rates, with indoor humidity levels below the upper comfort limit. Results also show that coil air bypass and evaporator circuiting control are typically not necessary unless operation would otherwise result in overcooling. The optimization results also translate to relatively simple strategies for system control. Significant savings are demonstrated over conventional control strategies used in packaged DX equipment.     

Thermal effect of temperature gradient in a field environment chamber served by displacement ventilation system in the tropics

The effect of vertical air temperature gradient on overall and local thermal comfort at different overall thermal sensations and room air temperatures (at 0.6 m height) was investigated in a room served by displacement ventilation system. Sixty tropically acclimatized subjects performed sedentary office work for a period of 3 h during each session of the experiment. Nominal vertical air temperature gradients between 0.1 and 1.1 m heights were 1, 3 and 5 K/m while nominal room air temperatures at 0.6 m height were 20, 23 and 26 °C. Air velocity in the space near the subjects was kept at below 0.2 m/s. Relative humidity at 0.6 m height was maintained at 50%. It was found that temperature gradient had different influences on thermal comfort at different overall thermal sensations. At overall thermal sensation close to neutral, only when room air temperature was substantially low, such as 20 °C, percentage dissatisfied of overall body increased with the increase of temperature gradient. At overall cold and slightly warm sensations, percentage dissatisfied of overall body was non-significantly affected by temperature gradient. Overall thermal sensation had significant impact on overall thermal comfort. Local thermal comfort of body segment was affected by both overall and local thermal sensations.     

不同送风速度下空调房间的气流组织数值模拟

以办公室空调房间为研究对象,运用计算流体力学(CFD)中Fluent软件数值模拟,对不同送风速度下空调房间的速度场、温度场进行三维数值模拟,对比分析不同送风速度对气流组织的影响。通过对几种不同工况下不同空间位置的速度云图、温度等值线图的分析,得到了不同送风速度对房间气流组织及热舒适性的影响。     

Airflow modelling in a computer room

This study concerns the numerical simulation of airflow and the prediction of comfort properties in a visualisation room of a research centre. Because simulation accuracy depends on the modelling level, special care has been given to fine details. Particular interest has been concentrated on the four-way ceiling air supply diffuser, on the furniture and on the thermal conditions given on computers and on mannequins.

The geometric model was created using the parametric features of the pre-processor Gambit, in combination with elements created with the Rhinoceros NURBS modelling tool.

Mass, momentum, energy, turbulence, species and radiation conservation equations were solved using Fluent commercial flow solver. Computed airflow and heat transfer parameters were used for numerical prediction of indoor air quality quantities based on ISO 7730. Basic parameters included air temperature, relative humidity and air velocity. These were combined with clothing insulation and metabolic activity measures to obtain standard IAQ indices such as the mean age of air, the predicted mean vote and the predicted percentage of dissatisfied room occupants.

Post-processing was carried out with standard Fluent elements and also using Vu, a multi-platform tool which also allows data to be displayed in the Cave immersive environment.     

基于CFD模拟的室内温湿度最佳测量位置研究

在实际工程中,温湿度传感器放置的位置不合适会造成测量的温湿度偏离室内温湿度的真实分布情况,从而影响室内温湿度的控制效果。本文采用FLUENT对空调房间进行模拟,采用基于均值的递推融合算法对选取的72个传感器检测到的温湿度值进行融合,使融合的值能够真实反映室内温湿度的分布情况,并以有效温度指数ET作为室内人员舒适度的评价标准,寻找室内最佳的温湿度测量位置。     

对热舒适、空气感觉质量及能耗的模拟研究

室内空调设计温度和新风量对热舒适，室内空气质量及能耗量有重要影响，然而对它们之间相互关系进行研究的文献却较少。通过计算机模拟空调系统在7种室内设计温度和7种新风量条件下的运行情况，得到不同的设计条件组合对热舒适、人体感觉空气质量及建筑能耗量的影响。基于这项分析，提出了此办公建筑合理的室内设计温度和新风量取值。     

基于投影寻踪的热舒适性评价模型

本文根据4个影响热舒适的主要因素(环境温度、风速、相对湿度和平均辐射温度),研究建立了热舒适评价的投影寻踪模型,利用该模型可将影响热舒适的多个指标转换为反映各指标综合信息的投影特征值,并根据投影特征值的差异性大小对热舒适进行客观评价。通过与实际环境的主观评价相比较,表明其评判结果与主观感受是一致的。这种方法计算简单、方便实用,为室内环境热舒适的评价问题提供了一条新的方法与思路。