自然通风通风量的测量及预测

论文总字数：27828字

摘 要

人们每天约80%的时间都在室内，所以病态建筑综合征的主要原因是室内空气品质的恶劣。室内新风量的增加能够使室内污染物浓度有所降低，从而提高室内空气品质。作为一种完全不需要消耗机械动力的纯天然通风形式，自然通风一直以来都受到专家学者的青睐。

自然通风主要通过实验和模型计算来研究，实验通过示踪气体的浓度变化通过方程拟合来计算通风量。而模拟法通过一些理论分析方法来计算得到自然通风的通风量。现在已有的仿真工具中如果有明确初始条件，最后的状态变化的结果与实际的自然通风可能有很大出入。所以通过实验对于自然通风复杂的影响因素进行研究能够优化预测模型以更好的控制室内空气流动，对于判断仿真结果的准确性和有效性有很大的意义^[5]。为了得到更加精准的结果，考虑到结合CO₂和SF₆的优缺点同时也比较在实验过程和结果上的区别，采取两种示踪气体同时测量的方式，利用SF₆的高精准性和CO₂的便捷性，使实验结果更加可靠。本次研究的内容包括，设计研究各种因素的对比实验方案，包括方法选择、实验设备、实验室布置，同时通过一系列实验验证实验方案可行性分析。通过在不同的温差、风速、窗户开度、纱窗种类下用示踪气体衰减法进行实验后，通过分析实验数据，得出这些因素对自然通风的通风量影响程度。最后结合MIX软件对不同温差、风速和窗户开度下的实验工况下的通风量进行计算，与实验结果对比后，提出MIX模型预测的修正建议。

关键字: 自然通风，示踪气体，换气次数

Abstract

The indoor air quality is the main reason leading to SBS syndrome for people spend 80% of the time indoors. The increasing in indoor fresh air volume can reduce the concentration of indoor polluted air. As a non-consumption of natural natural ventilation, natural ventilation has always been the favor of experts and scholars. In order to research the influence factors of natural ventilation, it is necessary to measure the air change between the building and the outside in the case of natural ventilation. However, due to natural ventilation in the case of low wind speeds,variable flow, complex access, it is difficult to use the general measurement to measure the air change rate of natural wentilation^[1].

Natural ventilation is normally studied by artificial experiments and computer model calculation. The air change rate is calculated by fitting the equation to the concentration curve of tracer gas. However, the simulation method simulate the natural ventilation through a number of theoretical analysis method. If the simulation tools have a clear initial condition, the final state change results with actual natural ventilation will have great discrepancies. Therefore, the study of the complexity of the natural ventilation characteristics can help to accurately predict and control the natural flow of indoor air and to determine the accuracy and effectiveness of the simulation results ^[5]. In order to gain more exact results, we take the advantages and disadvantages combined with carbon-dioxide and Sulfur-hexafluoride into account, and also compared the experimental process and the results of the difference between two kinds of tracer gas to take the same time to measure. The strength of high precision of SF₆ and convenience of CO₂ could make the experimental results more reliable. The contents of this study include the design of experimental programs for this subject, including experimental methods, laboratory equipment, laboratory layout, and through a series of experiments to verify the feasibility of the experimental program analysis. By analyzing the experimental data with the tracer gas attenuation method under different temperature difference, wind speed, the windowing size and screen types, the influence degree of these factors on the air change rate of natural ventilation is obtained. Finally, the MIX software is used to calculate the ventilation volume under different temperature difference, wind speed and window opening. In addition to Compare the results of MIX with the experimental results, the revised scheme of MIX model is proposed.

KEY WORDS: natural ventilation, tracer gas, air change rate

目 录

摘 要 I

Abstract II

目 录 III

第一章 绪论 1

1.1概述 1

1.2自然通风通风量测量与预测的研究现状 2

1.2.1自然通风通风量测量方法的研究现状 2

1.2.2自然通风理论模型的研究现状 2

1.3本文的研究的目的及内容 3

第二章 示踪气体测量自然通风通风量的实验方案 4

2.1示踪气体的选择 4

2.1.1一氧化二氮 4

2.1.2六氟化硫 4

2.1.3二氧化碳 4

2.1.4小结 5

2.2示踪气体测量方法的选择 5

2.2.1浓度衰减法 6

2.2.2恒量释放法 7

2.2.3恒定浓度法 7

2.2.4小结 7

2.3实验设备的选择 8

2.4小结 8

第三章示踪气体测量方案设计 9

3.1实验方法的确定 9

3.2实验设备 9

3.3实验室布置 12

3.4实验方案的可行性分析 13

3.4.1非均匀性对测量的影响 14

3.4.2实验测点布置的可行性分析 15

3.4.3衰减时间与示踪气体释放浓度大小对实验结果的影响 16

3.5小结 16

第四章 MIX模型描述 17

4.1概述 17

4.2自然通风MIX模型描述 17

4.3小结 18

第五章 不同工况下自然通风通风量的比较 20

5.1不同示踪气体测量结果的比较 20

5.2热压和风压对自然通风通风量的影响 22

5.2.1不同热压状况下自然通风的对比 23

5.2.2不同风压状况下自然通风的对比 24

5.3不同的窗户开度下自然通风量的比较 25

5.4纱窗对自然通风的影响 27

5.5小结 28

第六章 结论与展望 29

参考文献 30

致 谢 31

第一章 绪论

剩余内容已隐藏，请支付后下载全文，论文总字数：27828字