第一次使用孔板流量計的正確方法?
信息來源: 華恒 | [ 2019-04-09 ] 點擊量: 373

   第一次使用孔板流量計的正確方法?西安華恒儀表制造有限公司為您講解:孔板流量計一般管道式充滿液體的,液體經過節流裝置時,流束將在節流裝置會局部收縮,增加流速,壓力低,所以節流件前后會減低壓力,就是壓差,介質流動的流量越大,壓差就越大,一般氣體孔板流量計通過測量差壓計算出流體的速度。

 
  The correct way to use orifice flowmeter for the first time?Xi'an Huaheng Instrument Manufacturing Co.,Ltd.will explain to you:orifice flowmeter is usually filled with liquid in pipeline.When liquid passes through the throttle device,the flow beam will shrink locally,increase the flow rate,and the pressure is low.Therefore,the pressure difference will be reduced before and after the throttle piece.The larger the flow rate of medium,the larger the pressure difference will be.The general orifice flowmeter will measure the differential pressure gauge by measuring the differential pressure gauge.Calculate the velocity of the fluid.
 
  安裝前節流件用的直管最好是光滑的,如果不光滑,流量系數就要用到粗糙度修正系數來計算。
 
  The straight pipe used for throttling before installation should be smooth.If it is not smooth,the flow coefficient should be calculated by roughness correction coefficient.
 
  節流件前后的直管段一定要直;直管段一定要圓的,而且對節流件前2D范圍,有一定的圓度指標;節流件前后直管段長度要保留足,這段足夠長的直管段和節流件前的局部阻力件形式有關和直徑比
 
  The straight pipe section must be straight before and after the throttle piece;the straight pipe section must be round,and have a certain roundness index for the range of 2D before the throttle piece;the length of the straight pipe section before and after the throttle piece should be kept enough,and the form and diameter ratio of the long straight pipe section and the local resistance parts before the throttle piece are relevant and diameter ratio.
 
  節流裝置設計計算時,孔板外徑與環室配合處的間隙留得足夠大是假定孔板和環室溫度相同,但實際上不可能相同,孔板被環室包圍著,而且有高溫流體為其提供熱量,所以溫度高,得到充分膨脹。
 
  When designing and calculating the throttling device,the clearance between the orifice plate outer diameter and the ring chamber is large enough to assume that the temperature of the orifice plate and the ring chamber is the same,but in fact it is impossible to be the same.The orifice plate is surrounded by the ring chamber,and there is high temperature fluid to provide heat for it,so the temperature is high and it is fully expanded.
 
  而環室內圓與流體接觸,但外圓與大氣接觸,加上外部環境溫度等因素,使其溫度下降得很低,從而導致預留的間隙不夠用,引起孔板變形。
 
  The inner circle of the ring contacts with the fluid,but the outer circle contacts with the atmosphere,and the external environment temperature and other factors make the temperature drop very low,resulting in insufficient reserved clearance,causing the orifice plate to deform.
 
  孔板流量計按國標規定進行設計、制造和檢定的標準孔板無需實流標定,精度高、結構簡單、制造成本低,但壓力損失在所有標準節流裝置中最大,不適用于要求壓力損失小的情況,標準孔板廣泛用于石油、化工、冶金、電力等行業。
 
  The orifice plate flowmeter designed,manufactured and calibrated according to the national standard does not need real-flow calibration.It has high accuracy,simple structure and low manufacturing cost.However,the pressure loss is the largest in all standard throttling devices,and it is not suitable for situations requiring low pressure loss.The standard orifice plate is widely used in petroleum,chemical,metallurgical,power and other industries.
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