通风管道内测定风速风量做哪些准备工作？

发布人：http://www.sftfgd.com   发布时间：2021-05-04 16:42:41

通风管道现在受到广泛地应用，在工业送排风、空调通风等随处可见它的身影。通风管道内风速及风量的测定，是通过测量压力换算得到的，是较为专门化的计算，下面由通风管道的工作人员测定管道内的风度风量要做好哪些准备工作：

Ventilation duct is now widely used in industrial air supply and exhaust, air conditioning and ventilation. The measurement of wind speed and air volume in the ventilation duct is obtained by measuring the pressure conversion, which is a more specialized calculation. The following preparations should be made by the staff of the ventilation duct to measure the wind speed and air volume in the duct:

一、测定位置和测定点

1、 Measuring position and measuring point

1、测定位置的选择

1. Selection of measuring position

通风管道内风速及风量的测定，通过测量压力换算得到。合理选择测量断面、减少气流扰动对测量结果的影响很大，测量断面应尽量选择在气流平稳的直管段上。测量断面位置距异形部件的距离少是管道直径的1.5倍。

The measurement of wind speed and air volume in ventilation duct is obtained by measuring pressure conversion. Reasonable selection of measurement section and reduction of air flow disturbance have great influence on the measurement results. The measurement section should be selected on the straight pipe section with stable air flow as far as possible. The distance between the measuring section and the abnormal parts is at least 1.5 times of the pipe diameter.

测定时如发现任何一个测点出现零值或负值，表明气流不稳定，该断面不宜作为测定断面。气流方向偏出风管中 心线15°以上，该断面也不宜作测量断面。

If zero value or negative value is found at any measuring point during the measurement, it indicates that the air flow is unstable, and this section should not be used as the measuring section. The air flow direction deviates from the center line of air duct by 15 ° Above, this section is not suitable for survey.

2、测试孔和测定点

2. Test hole and measuring point

须在同一断面上多点测量，然后求出该断面的平均值。

It is necessary to measure multiple points on the same section, and then calculate the average value of the section.

二、风道内压力的测定

2、 Measurement of pressure in air duct

测定仪器

Measuring instrument

气体压力的测量通常是用插入风道中的测压管将压力信号取出，在与之连接的压力计上读出，常用的仪器有毕托管和压力计。

Gas pressure is usually measured by taking out the pressure signal from the pressure tube inserted into the air duct and reading it on the pressure gauge connected with it. Pitot tube and pressure gauge are commonly used instruments.

1、毕托管

1. Pitot

是一个弯成90°的双层同心圆管，其开口端同内管相通，用来测定全压；在靠近管头的外壁上开有一圈小孔，用来测定静压，按标准尺寸加工的毕托管校正系数近似等于1。

It's a 90 ° The open end of the double concentric tube is communicated with the inner tube to measure the total pressure; There is a circle of small holes on the outer wall near the pipe head to measure the static pressure. The pitot tube correction coefficient processed according to the standard size is approximately equal to 1.

2、S型毕托管

2. S-type pitot tube

是由两根相同的金属管并联组成，测量时有方向相反的两个开口，测定时，面向气流的开口测得的相当于全压，背向气流的开口测得的相当于静压，这种毕托管在含尘污染源监测中得到广泛应用。

The pitot tube is composed of two identical metal tubes in parallel. When measuring, there are two openings in opposite directions. When measuring, the opening facing the air flow is equivalent to the total pressure, and the opening facing the air flow is equivalent to the static pressure. This pitot tube is widely used in the monitoring of dust pollution sources.

3、U形压力计

3. U-shaped pressure gauge

由U形玻璃管制成，其中测压液体视被测压力范围选用水、酒精或汞，U形压力计不适于测量微小压力，压力值由液柱高差读得换算。

It is made of U-shaped glass tube, in which the pressure measuring liquid is water, alcohol or mercury according to the pressure range to be measured. The U-shaped manometer is not suitable for measuring small pressure, and the pressure value is converted from the height difference of the liquid column.

4、倾斜式微压计

4. Inclined micro manometer

测压时，将微压计容器开口与测定系统中压力较高的一端相连，斜管与系统中压力较低的一端相连，作用于两个液面上的压力差，使液柱沿斜管上升。

When measuring pressure, the opening of the micro manometer container is connected with the higher pressure end in the measuring system, and the inclined pipe is connected with the lower pressure end in the system. The pressure difference acting on the two liquid levels causes the liquid column to rise along the inclined pipe.

以上就是在通风管道中测量风速风量之前要做好的准备，只要做好了准备工作才有可能在测量中取得比较准确的数据结果，希望以上的分享对大家有段帮助，如您想要了解更多资讯内容请点击：山东通风管道http://www.sftfgd.com。

The above is the preparation before measuring the wind speed and air volume in the ventilation duct. As long as the preparation is well done, it is possible to obtain more accurate data results in the measurement. I hope the above sharing will help you. If you want to know more, please click: Shandong ventilation duct http://www.sftfgd.com .