通風管道內(nèi)測定風速風量做哪些準備工作？

發(fā)布人：http://m.lessonsfromyesterday.com   發(fā)布時間：2021-05-04 16:42:41

通風管道現(xiàn)在受到廣泛地應(yīng)用，在工業(yè)送排風、空調(diào)通風等隨處可見它的身影。通風管道內(nèi)風速及風量的測定，是通過測量壓力換算得到的，是較為專門化的計算，下面由通風管道的工作人員測定管道內(nèi)的風度風量要做好哪些準備工作：

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、測定位置和測定點

1、 Measuring position and measuring point

1、測定位置的選擇

1. Selection of measuring position

通風管道內(nèi)風速及風量的測定，通過測量壓力換算得到。合理選擇測量斷面、減少氣流擾動對測量結(jié)果的影響很大，測量斷面應(yīng)盡量選擇在氣流平穩(wěn)的直管段上。測量斷面位置距異形部件的距離少是管道直徑的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.

測定時如發(fā)現(xiàn)任何一個測點出現(xiàn)零值或負值，表明氣流不穩(wěn)定，該斷面不宜作為測定斷面。氣流方向偏出風管中 心線15°以上，該斷面也不宜作測量斷面。

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、測試孔和測定點

2. Test hole and measuring point

須在同一斷面上多點測量，然后求出該斷面的平均值。

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

二、風道內(nèi)壓力的測定

2、 Measurement of pressure in air duct

測定儀器

Measuring instrument

氣體壓力的測量通常是用插入風道中的測壓管將壓力信號取出，在與之連接的壓力計上讀出，常用的儀器有畢托管和壓力計。

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、畢托管

1. Pitot

是一個彎成90°的雙層同心圓管，其開口端同內(nèi)管相通，用來測定全壓；在靠近管頭的外壁上開有一圈小孔，用來測定靜壓，按標準尺寸加工的畢托管校正系數(shù)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型畢托管

2. S-type pitot tube

是由兩根相同的金屬管并聯(lián)組成，測量時有方向相反的兩個開口，測定時，面向氣流的開口測得的相當于全壓，背向氣流的開口測得的相當于靜壓，這種畢托管在含塵污染源監(jiān)測中得到廣泛應(yīng)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形壓力計

3. U-shaped pressure gauge

由U形玻璃管制成，其中測壓液體視被測壓力范圍選用水、酒精或汞，U形壓力計不適于測量微小壓力，壓力值由液柱高差讀得換算。

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、傾斜式微壓計

4. Inclined micro manometer

測壓時，將微壓計容器開口與測定系統(tǒng)中壓力較高的一端相連，斜管與系統(tǒng)中壓力較低的一端相連，作用于兩個液面上的壓力差，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.

以上就是在通風管道中測量風速風量之前要做好的準備，只要做好了準備工作才有可能在測量中取得比較準確的數(shù)據(jù)結(jié)果，希望以上的分享對大家有段幫助，如您想要了解更多資訊內(nèi)容請點擊：山東通風管道http://m.lessonsfromyesterday.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://m.lessonsfromyesterday.com .