示踪气体衰减法测定居室通风量的改进研究-资料分享下载-无忧分享网

摘要

有效的自然通风不但可以降低能耗，而且可以提供清新的自然空气来改善室

内热环境、有效排出室内污染物，提高室内空气品质。随着社会的进步和发展，

人们对室内空气品质的要求越来越高，室内空气品质与人们健康的关系也越来越

受到重视，其定量确定更为学者们研究关注的热点。示踪气体方法测定房间通风

量是众多方法中比较常用且较为准确的方法，但以往研究中，受示踪气体种类、

释放量的大小、示踪气体与室内空气的混合程度、测量方法选择、测点布置、数

据处理方法、房间几何结构及室外气象参数等影响，使该方法在准确测定房间通

风量方面产生较大误差，如何提高示踪气体准确测量自然通风量的问题，对房间

通风量的研究具有很重要的意义。

为研究一般气流组织下标准房间的示踪气体更准确的测定方法，选择一办公

室为实验研究对象，特搭建一实验系统，采用鼓风门提供房间定量机械通风量作

为实验标准风量，对采用二氧化碳示踪气体衰减法的测量方法及其改进进行了实

验研究。

实验中，通过定义不稳定度|S|≤2%，可确定释放阶段搅拌时间、初始浓度 C0、

显著衰减所需时间；利用房间浓度不均匀系数 KC，定量分析房间示踪气体与空气

混合均匀程度，并得出示踪气体释放阶段，在满足|S|≤2%且浓度不均匀系数 KC≤

10%的情况下，采用一台风扇摇头搅拌为好。实验及数值模拟结果表明，在实验条

件下，以保证室内外浓度差 200～350ppm 为原则确定示踪气体释放量，此时测得

的房间通风量较为准确。衰减初始阶段，浓度均匀性受门窗开启形式、气流组织、

换气次数的影响，室内浓度波动较大，但之后的衰减过程较为均匀，受以上因素

影响较小；整个衰减阶段 KC均小于 10%，满足均匀性要求。利用实验采用平均浓

度求换气次数和各点换气次数的平均值与实验标准通风量的误差均超过了 10%，

而位于通风路径上靠近排风 1/3～1/2L 处，且垂直高度在 1.1~2.0m 的测点，所得

测量精度较高，其误差在 10%以内。自然通风实测中，考虑气流不确定性、不稳

定性、室内人员开启门窗的生活习惯不同，在现场测点有限的情况下，将测点放

置在房间中心位置是比较合理的。

在数据处理方面，利用衰减法中显著衰减段的浓度实验数据，采用本文提出

的积分参数迭代方法进行数据处理，与通常计算相比，测点测量平均误差可由原

来的 30%减小至 5%～10%左右，测量精度明显提高。本实验研究表明，采用显著

衰减段积分参数迭代法进行数据处理时，测点分别位于通风路径中点、房间中心

位置，或采用多点测量浓度平均值时，获得实际通风量即标准风量 Q0与实测值 Q

之间关系分别为 Q0=(0.95～1.05)Q，Q0=(0.94～1.10)Q，Q0=(0.94～1.12)Q。自然通

风量测定时，利用上述修正系数和实测值，便可获得房间实际通风量。采用风压

系数法获得理论风量 Q’ 与利用上述方法获得的实际通风量 Q0关系为

Q0=(1.02~1.18)Q’，即可利用实验所获修正系数与理论计算值获得实际通风量。

综上所述，对于独立房间，采用二氧化碳示踪气体方法测定通风量时，通过

对释放量大小的确定，测点布置及数据处理方法的改进，其获得的测量结果精度

明显提高。研究成果为现场实测自然通风量提供了改进的测量方法。

关键词：示踪气体衰减法不稳定度浓度不均匀系数测点布置

数据处理积分参数迭代法数值模拟

ABSTRACT

Effective natural ventilation can not only reduce energy consumption, but also can

provide fresh air to improve indoor thermal environment, discharge indoor pollutants

effectively and improve indoor air quality. Along with social progress and the

increasingly demand for indoor air quality, the relationship between indoor air quality

and human health caughtmore attention, especially theventilationquantitative. The tracer

gas method for air ventilation of room is more commonly used and accurate. However

the type of tracer gas, the emission amount, the uniform distribution of tracer gas

concentration, measurement method,the sampling position,the data processing

method,the room geometry and outdoor meteorological parameters can cause biase in

the result of air ventilation quantity determination.So it is important to measure accurate

ventilation rate quantity by tracer gas technique.

An office room is selectedfor studying tracer gas method in the general airflow

standard room. An experimental system is built to study tracer gas method.This study

took blast doors for mechanical ventilation and took carbon dioxideas decay tracer gas

to analyze.

Mixing time, initial concentration C0 of the release phase and settling time  of

rapid decay period aredetermined by defining the instability coefficient | S | less than

2%.To analyzemixing uniformity oftrace gasconcentrationquantitatively, concentration

coefficient of uniformity KC is used. Using an oscillating fan can meet the

requirementsin a single room as |S| less than 2% and KC less than 10%.The research

with numerical simulation and experiments show that under the experimental conditions,

it is more accurate and reasonable when the tracer gas emissions to ensure the

concentration difference between inside and outside of 200ppm to 350ppm . It will

come up with great concentration fluctuation at the beginning of decey stage. The

concentration uniformity is effected by doors and windows open status, airflow and air

change rate.But during the decay process, KC is less than 10%, the indoor measurement

points have more uniform concentration even under the influence of the factors

mentioned above.The results show that the average concentration and sampling points

are not representative for the room ventilation rate, while the optimal sample position to

determine theventilation rate is 1/3 ~ 1/2L away from air outletandthe vertical height in

the 1.1m to 2.0m, the higher accuracy of the measurement error is within 10%.For

natural ventilation, considering air flow uncertainty, instability, the person’s different

living habits of opening doors and windows, it is more reasonable to set point at the

center of the room.

With data processing, collecting experimental data of the rapid decay period and

combining integral parameter iterative method,the average bias of the representative

pointsis reduced from 30% with the traditional calculation method to 5% ~ 10%,the

measurement accuracy is significantly improved.The results with integral parameter

iterative method to the mid-point of the ventilation path, the center point of the room

and the average value of the multi-points, the relationship between the actual value of

Q0 and the measured value of Q: Q0= (0.95 ~ 1.05) Q, Q0 = (0.90 ~ 1.10) Q, Q0 = (0.94 ~

1.12) Q.Using the correction coefficient in natural ventilation, the actual value of

ventilation can be obtained.Wind pressure coefficient method to calculate the value of

ventilation, the relationship between theoretical value Q ' and actual value Q0 is Q0 =

(1.02~1.18) Q’,the actual ventilation can be obtained by correction coefficient and the

calculated value.

In summary, the tracer gas method for a single room’s air ventilation, which

determined by size of emission, the arrangement of measuring points and improved data

processing method can be greatly improved the accuracy of the measurement results.

The research provides an improved measuring method for the measureing natural

ventilation rate.

Key word: tracer gas, instability, concentration coefficient of

uniformity, point positioning, data processing, integration

parameter iterative method, numerical simulation

中文摘要

ABSTRACT

第一章绪论 ......................................................... 1

1.1 课题来源及研究意义 ............................................. 1

1.2 国内外居室通风量测定方法研究现状 ............................... 2

1.3 示踪气体测定方法研究现状 ....................................... 3

1.3.1 示踪气体种类 ............................................... 3

1.3.2 示踪气体浓度测试仪器 ....................................... 5

1.3.3 浓度测点布置与测定时间 ..................................... 5

1.3.4 数据处理方法介绍 ........................................... 6

1.3.5 示踪气体测量方法存在的不足及限制条件 ....................... 7

1.3.6 已有改进方法 ............................................... 7

1.4 本课题的思考以及主要研究内容 ................................... 8

1.4.1 进一步改进示踪气体测试方法的思考 ........................... 8

1.4.2 本课题主要研究内容 ......................................... 9

1.4.3 研究关键技术及研究路线 .................................... 10

第二章示踪气体法风量测量原理及数据处理理论分析 ................... 11

2.1 示踪气体测量基本原理 .......................................... 11

2.1.1 风量测量的质量守恒原理 .................................... 11

2.1.2 各示踪气体测量方法原理 .................................... 11

2.2 示踪气体浓度均匀性及稳定性判据 ................................ 13

2.2.1 浓度混合均匀判定法则 ...................................... 14

2.2.2 浓度稳定时间判定法则 ...................................... 16

2.3 数据处理理论分析 .............................................. 17

2.3.1 数据处理方法理论基础 ...................................... 17

2.3.2 国标法 .................................................... 18

2.3.3 差分法 .................................................... 18

2.3.4 稳态法 .................................................... 19

2.3.5 非线性回归法 .............................................. 19

2.3.6 差分参数迭代法 ............................................ 19

2.4 本章小结 ...................................................... 21

第三章测点布置及其均匀性实验研究 .................................. 23

3.1 实验原理及研究对象介绍 ........................................ 23

3.2 示踪气体测量方法实验系统搭建 .................................. 24

3.2.1 测试仪器及其仪器主要性能 .................................. 24

3.2.2 实验系统搭建 .............................................. 25

3.2.3 实验风量范围确定 .......................................... 28

3.2.4 示踪气体浓度检测仪 ........................................ 29

3.3 实验方案设计 .................................................. 31

3.3.1 实验目的 .................................................. 31

3.3.2 实验方案 .................................................. 32

3.3.3 实验步骤 .................................................. 34

3.4 释放阶段室内示踪气体稳定时间及浓度均匀性分析 .................. 35

3.4.1 不同搅拌形式对搅拌稳定时间与浓度均匀性的影响分析 .......... 35

3.4.2 释放量大小对搅拌稳定时间及浓度均匀性的影响分析 ............ 40

3.5 衰减阶段室内示踪气体衰减时间及浓度均匀性分析 .................. 41

3.5.1 释放量大小对室内显著衰减时间及浓度均匀性影响分析 .......... 41

3.5.2 渗透风量测量时浓度均匀性分析 .............................. 44

3.5.3 不同窗户开启形式浓度均匀性与衰减时间分析 .................. 46

3.6 实验数据的处理方法及测点布置改进研究 .......................... 49

3.6.1 现有数据处理方法结果对比分析 .............................. 49

3.6.2 采用显著衰减段数据处理方法 ................................ 51

3.6.3 积分参数迭代方法的提出 .................................... 54

3.6.4 室内测点布置改进研究 ...................................... 61

3.7 本章小结 ...................................................... 64

第四章 CFD 在示踪气体衰减法中的应用研究 ............................. 67

4.1 数值模拟方法的介绍 ............................................ 67

4.1.1 数学模型理论基础 .......................................... 67

4.1.2 湍流模型及计算方法 ........................................ 68

4.2 建模及边界条件确定 ............................................ 68

4.2.1 物理模型的建立 ............................................ 68

4.2.2 网格生成及边界条件的确定 .................................. 70

4.3 数值模拟验证及其实验研究应用 .................................. 70

4.3.1 数值模拟结果验证 .......................................... 71

示踪气体衰减法测定居室通风量的改进研究

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