A Calculation Method of Equivalent Pipe Length of Reducing Pipe

Abstract

The invention discloses a method for calculating the equivalent pipe length of a variable-diameter pipe, which establishes a sound wave amplitude attenuation model and a straight pipe section leakage sound wave amplitude attenuation model; obtains gas operating parameters in the straight pipe section, and calculates the straight pipe section according to the gas operating parameters in the straight pipe section Sound wave amplitude attenuation factor; obtain the installation distance of the two sensors, collect the leakage sound wave signal of the leakage sound wave propagating through the variable diameter pipe section, and extract the leakage sound wave signal amplitude; substitute the leakage sound wave signal amplitude and the sound wave amplitude attenuation factor of the straight pipe section into the sound wave The amplitude attenuation model is used to obtain the sound wave propagation distance; according to the sound wave propagation distance in step 4 and the installation distance of the two sensors in step 3, calculate the equivalent pipe length of the reducer. The beneficial effect of the present invention is that the calculation method of the equivalent length of the variable diameter tube provided by the present invention can obtain the equivalent safety distance of the sensor by establishing the calculation formula of the equivalent tube length of the variable diameter tube, and improve the positioning accuracy.

Description

technical field [0001] The invention relates to the technical field of oil and gas pipeline leakage monitoring by acoustic wave method, in particular to a method for calculating the equivalent pipe length of a variable diameter pipe. Background technique [0002] At present, there are many leakage monitoring methods that can be applied to oil and gas pipelines. Among them, the acoustic wave method has many advantages compared with the traditional mass balance method, negative pressure wave method, and transient model method: high sensitivity, high positioning accuracy, and false alarms. Low rate, short detection time, strong adaptability; the measurement is the weak dynamic pressure change in the pipeline fluid, which has nothing to do with the absolute value of the pipeline operating pressure; the response frequency is wider, the detection range is wider, etc. [0003] In the research on the leakage detection and location technology of the gas pipeline acoustic method, the ...

AI Technical Summary

Problems solved by technology

[0007] The existing patents are less involved in the calculation of the installation distance between the upstream and downstream sensors, and the improvement of the leak location accuracy relies more on the method of improving the sound wave propagation speed and time difference. There is no description of the change in the installation distance between them. The specific performance is: insufficient consideration of the reflection, secondary reflection and interference of the sound wave when the sound wave encounters the reducing tube during the propagation process, which makes the attenuation of the sound wave amplitude significantly increased. Large, so that the calculation of the installation distance between the upstream and downstream sensors is inaccurate, resulting in leakage positioning errors

Images