重庆地区居住建筑采暖空调期自然通风器效果研究

发布时间：2018-06-09 23:23

本文选题：自然通风器 + 通风换气效果　；参考：《重庆大学》2014年硕士论文

【摘要】：近年来居住环境中室内空气品质恶化事件不断发生，损害人体健康。建筑自然通风逐渐受到人们的重视。国内外学者对各种形式的自然通风已经作了大量研究。自然通风主要具有降温排热和通风换气两个作用，分别借以改善室内热舒适和室内空气品质状况，是一种节能环保的通风方式。利用自然通风原理制成的自然通风器可实现室内通风换气，改善空气品质。这类自然通风产品在住宅建筑中开始应用起来。但由于自然通风器的主要驱动力为热压和风压，作用力大小受到室外气象条件的限制，同时学术界又缺少自然通风器的实际使用效果的研究资料。故人们逐渐开始质疑这类产品在实际使用中对室内空气品质的改善效果。这也使得自然通风器得不到有效地推广。本文利用计算流体力学软件Fluent建立自然通风模型，进行数值模拟计算。在计算过程中选取不同室内外温差、室外风速等边界条件，模拟得到了室内浓度场分布和浓度随时间的变化过程，以此来评判自然通风器的通风换气效果。此后在重庆地区某住宅标准户型内建立了自然通风实验系统。实验设置了室内外6℃，8℃和10℃三种温差下通风器关闭，通风器开启、窗帘开启以及通风器开启、窗帘关闭的9种工况，测试了室内二氧化碳浓度变化情况。一方面测试结果与模拟结果进行对比分析，用以验证模型；另一方面以二氧化碳浓度为指标进一步分析了通风器对室内空气品质的改善效果。根据室内浓度变化，利用微环境质量平衡公式计算并分析了不同工况下室内的通风换气量，检验其是否能满足现行规范要求。文章最后部分还对极大影响自然通风器性能的室外风压因素进行了重点研究。本论文主要研究成果如下： 1）建立风压、热压自然通风模型，利用Fluent软件对不同工况下自然通风器的换气情况进行模拟分析，并得到室内二氧化碳浓度场，室内浓度变化随时间变化等等模拟结果。模拟研究证明在热压作用和风压作用下，自然通风器均能有效地排除室内二氧化碳，改善空气品质。随着热压力（温差）和风压力（风速）提高，通风效果越来越好，并且风压的影响要大于热压。 2）根据实测房间内二氧化碳浓度变化，绘制出不同热压、风压影响下，二氧化碳与时间的关系曲线，计算室内的通风量。从规范规定的室内二氧化碳浓度标准值与通风换气量两个指标来共同判断通风器的工作性能。研究结果表明在冬季采暖季节，8℃和10℃两种温差纯热压作用下，，通风器开启、窗帘开启或关闭状态时，室内二氧化碳浓度能得到有效的控制，房间通风量满足换气要求。自然通风器在改善室内空气品质方面具有一定的实际效果。同时这种效果会随着室外风压的加强能得到更好的改善。在夏季空调季节室外无风工况下，10℃温差条件时室内二氧化碳浓度和房间通风量基本满足要求。 3）实验过程中，通过开关窗帘的对比分析测试发现窗帘的阻碍对通风器的换气效果影响并不显著。室内外6℃温差时，主卧室关闭窗帘后室内CO2浓度仅上升了80ppm，通风器通风量下降了3.8m3/h。从另一个方面来说窗帘在夜间休息时才会关上，这时人们都处于睡眠休息状态，新陈代谢作用下降，二氧化碳释放量更低。因此拓展了自然通风器在夜间的应用范围。 4）从实验结果出发，研究了室外风压作用（类型、风速和风向）对室内二氧化碳的的影响规律。各工况的室内浓度稳定值遵循持续风阵风无风的规律，通风量遵循持续风阵风无风的规律。实验结果表明只要室外存在持续风作用（1m/s），即使风向背对通风器，室内浓度和换气次数分别满足1000ppm的标准值和主卧室需求换气1次/h的要求。由于室外风压的多变性与不可控，且往往热压和风压存在相互影响、相互促进的关系，风压对室内二氧化碳浓度的影响研究必然需要大量的重复实验以及多工况设置才能完善。
[Abstract]:In recent years, the deterioration of indoor air quality in the living environment has been constantly occurring, damaging human health. The natural ventilation of buildings has been gradually paid attention to. Scholars at home and abroad have done a great deal of research on various forms of natural ventilation. Natural ventilation mainly has two functions as cooling and ventilation and ventilation and ventilation to improve indoor thermal comfort respectively. And the indoor air quality is a kind of energy saving and environment-friendly ventilation mode. Natural ventilator made of natural ventilation can realize indoor ventilation and air quality and improve air quality. This kind of natural ventilation products begin to apply in residential buildings. But because the main driving force of natural ventilator is the hot pressure and wind pressure, the force size is large. Limited by outdoor weather conditions and lack of research materials on the actual use of natural ventilator in academia, people gradually began to question the improvement effect of these products on the indoor air quality in actual use.
In this paper, a natural ventilation model is established by using the software of computational fluid dynamics (Fluent). In the calculation process, the temperature difference between indoor and outdoor, outdoor wind speed and other boundary conditions are selected. The distribution of indoor concentration field and the change of concentration with time are simulated to judge the ventilation effect of the natural ventilator. The experimental system of natural ventilation was set up in a residential standard residence in Chongqing. The experiment set up 9 working conditions of the ventilator under 6, 8 and 10 degrees Celsius, 8 and 10 degrees temperature difference, the opening of the curtain, the opening of the blinds, the closing of the curtain, and the change of the carbon dioxide concentration in the room. The results are compared and analyzed to verify the model. On the other hand, the effect of air conditioner on indoor air quality is further analyzed with the concentration of carbon dioxide as the index. According to the change of indoor concentration, the ventilation rate of indoor air in different conditions is calculated and analyzed by using the formula of microenvironment quality balance, and it is tested whether it can meet the current rules. The last part of the article also focuses on outdoor wind pressure factors which greatly affect the performance of natural ventilator. The main research results in this paper are as follows:
1) establish the wind pressure, hot press natural ventilation model, use Fluent software to simulate and analyze the air change situation of natural ventilator under different working conditions, and get indoor carbon dioxide concentration field, indoor concentration change with time and so on simulation results. The simulation study proves that under the hot pressing and wind pressure, the natural ventilator can effectively row. In addition to indoor carbon dioxide, the air quality is improved. With the increase of the heat pressure (temperature difference) and the wind pressure (wind speed), the ventilation effect is getting better and better, and the effect of wind pressure is greater than that of the hot press.
2) according to the measured changes in the concentration of carbon dioxide in the room, the relationship curve of carbon dioxide and time under the influence of different hot pressure and wind pressure is drawn, and the ventilation volume in the room is calculated. The performance of the ventilator is judged by the standard value of indoor carbon dioxide concentration and the two indexes of ventilation and ventilation. The results show that the performance of the ventilator is used in winter. In warm season, under the effect of pure hot pressure of two kinds of temperature difference at 8 and 10 degrees, the indoor carbon dioxide concentration can be effectively controlled when the ventilator is opened, the curtain is opened or closed. The ventilation volume of the room meets the requirement of air exchange. In the summer air conditioning season, the indoor carbon dioxide concentration and room ventilation are basically satisfied when the temperature difference conditions are 10 degrees C in the summer air conditioning season.
3) during the experiment, through the contrast analysis and analysis of the switch curtains, it was found that the influence of the curtains to the ventilator was not significant. When the temperature difference between the main bedroom and the curtain was 6, the CO2 concentration of the main bedroom closed the curtain only increased by 80ppm, and the ventilation of the ventilator decreased by 3.8m3/h. in the other way the curtain would be closed at night rest. At this time, people are in a state of sleep and rest, and their metabolism is reduced, and the emission of carbon dioxide is lower. Therefore, the application of natural ventilator at night is expanded.
4) from the experimental results, the influence of outdoor air pressure (type, wind speed and wind direction) on indoor carbon dioxide is studied. The indoor concentration stability value of each working condition follows the law of continuous wind gust without wind, and the ventilation volume follows the law of continuous wind gust without wind. The experimental results show that there is a continuous wind (1m/s), even wind in outdoor air. At the back to the ventilator, the indoor concentration and air change times meet the standard value of 1000ppm and the requirement of 1 times /h in the main bedroom demand. Because of the variability and uncontrollability of the outdoor air pressure, and the mutual influence and the mutual promotion of the hot pressure and wind pressure, the study of the influence of the wind pressure on the concentration of the indoor two oxygen carbon is bound to need a great deal of weight. The complex experiment and the setting of multiple working conditions can be perfected.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU834

【参考文献】