管道漏风量计算方法-SMACNA,美标US讲解分析
时间:2024-02-22 阅读:136
一、法规概述
标准 | 国家 | 描述 |
SMACNA HVAC Air Duct Leakage Test manual, First edition, 2012 | US | Duct construction leakage classification, expected leakage rates for sealed and unsealed ductwork, duct leakage test procedures, recommendations on use of leakage testing, types of test apparatus and test setup and sample leakage analysis. |
二、法规详情
法规内要求的计算公式如下:
Duct Class | 1/2-, 1-, 2-inwg | 3-inwg | 4-, 6-, 10-inwg |
Seal Class | C | B | A |
Sealing Applicable | Transverse Joints Only | Transverse Joints and Seams | Joints, Seams and All Wall Penetrations |
Leakage Class | |||
Rectangular Metal | 16 | 8 | 4 |
Round Metal | 8 | 4 | 2 |
Maximum air leakage is then defined as
F=CLP0.65
F = Maximum air leakage (cfm/100 ft2)
CL = Leakage class
P = Pressure (inwg)
三、细则分析
1)法规要求下的最大限值Fmax
以美国标准为例,测试时由客户提出密封等级(Seal Class)和测试压力P,
根据SMACNA标准确定Leakage Class CL,根据公式 F=CLP0.65 计算出最大泄漏率Fmax
为方便计算,提供如下测算表:
Allowable Leakage Factor (CFM/100 sq ft) | |||||||||||
Static pressure | 0 | 1 | 2 | 3 | 4 | 6 | 7 | 8 | 9 | 10 | |
CL | 1 | 0.0000 | 1.0000 | 1.5692 | 2.0423 | 2.4623 | 3.2048 | 3.5425 | 3.8637 | 4.1712 | 4.4668 |
2 | 0.0000 | 2.0000 | 3.1383 | 4.0847 | 4.9246 | 6.4096 | 7.0851 | 7.7275 | 8.3423 | 8.9337 | |
3 | 0.0000 | 3.0000 | 4.7075 | 6.1270 | 7.3869 | 9.6143 | 10.6276 | 11.5912 | 12.5135 | 13.4005 | |
4 | 0.0000 | 4.0000 | 6.2767 | 8.1694 | 9.8492 | 12.8191 | 14.1701 | 15.4550 | 16.6847 | 17.8673 | |
6 | 0.0000 | 6.0000 | 9.4150 | 12.2541 | 14.7737 | 19.2287 | 21.2552 | 23.1825 | 25.0270 | 26.8010 | |
8 | 0.0000 | 8.0000 | 12.5533 | 16.3387 | 19.6983 | 25.6382 | 28.3403 | 30.9100 | 33.3693 | 35.7347 | |
12 | 0.0000 | 12.0000 | 18.8300 | 24.5081 | 29.5475 | 38.4574 | 42.5104 | 46.3649 | 50.0540 | 53.6020 | |
16 | 0.0000 | 16.0000 | 25.1067 | 32.6775 | 39.3966 | 51.2765 | 56.6805 | 61.8199 | 66.7387 | 71.4694 | |
24 | 0.0000 | 24.0000 | 37.6600 | 49.0162 | 59.0949 | 76.9147 | 85.0208 | 92.7299 | 100.1080 | 107.2041 |
举例如下:
Static pressure : 6
CL :6
则F = 19.2287 即最大限值Fmax
2)实测管道的测试值F
QL—泄漏风量值(cfm)
Area—被测管道的表面积(ft2)
3)判定
F<Fmax则被测管道合格
GTI 管道漏风量测试机型号DALT6900,DALT6910仪器内置以上标准,无需计算,可以直接输出判定结果,操作简单方便!