RU2010168C1 - Method of measurement of flow rate of substance - Google Patents

Abstract

FIELD: measurement technology. SUBSTANCE: flow under test is passed via measuring section of pipe line located on Earth surface in horizontal plane accurately along meridian and pressure differential is measured in diametrically opposite points of pipe line section. Due to forces of Coriolis acceleration caused by rotation of Earth, pressure differential arises which is proportional to rate of flow. EFFECT: enhanced accuracy. 1 dwg

Description

 The invention relates to measuring equipment, in particular to measuring the mass flow rate of a substance flow transported through large diameter pipes, for example, in gas mains.

 Known methods of measuring the flow of a substance using for this purpose various measurements of the dynamic characteristics of the flow of a substance [1].

 The disadvantage of these methods is that for their implementation, sensitive elements have to be placed in the flow of matter, which, on the one hand, creates additional resistance to the movement of the substance and leads to the need to introduce additional power to ensure the transportation of the substance, and on the other hand, the flow of the substance by to sensitive elements, changes its characteristics.

 Along with these methods, there are methods that do not use sensitive elements placed in the stream, for example, use the Coriolis acceleration created in the stream. Closest to the proposed method is a method for determining the flow rate of a substance using a vibratory flow transducer [2].

 In this method, the flow of a substance, the flow rate of which is measured, is directed through a pipe oscillating.

 Due to this reason, Coriolis acceleration occurs, affecting the tube walls from the side of the substance. By measuring the force generated by the Coriolisol acceleration, the mass flow rate is calculated.

 The disadvantage of this method is the need to create additional movement of the pipe, which makes this method not applicable to use on the main pipeline.

 The use of vibratory flow meters to measure large flows, such as those found on gas pipelines, encounters the difficult task of manufacturing a vibrating pipe of large diameter, having a mass of tens of tons. But even if such a vibrator is made, due to the low frequency of natural vibrations due to its large mass, it is not possible to obtain sufficiently reliable measurements over time intervals that are acceptable for practical purposes.

 The purpose of the invention is to increase the reliability and accuracy of measurements.

 The goal is achieved in that in a method for measuring the flow rate of a substance, including passing the measured flow through the measuring section of the pipeline and measuring its dynamic parameter, which is used to judge the flow rate, the measuring section of the pipeline is placed horizontally along the meridian on the surface of the earth, and the pressure difference is measured as a dynamic parameter at two diametrically opposite points of the cross section of the pipeline.

 The penetration of the pipe into the soil is not taken into account, since it does not affect the change in the dynamic parameters of the movement of matter in the pipeline.

 The essence of the method is to measure the effect on the flow of a substance moving through a pipeline with a certain relative speed of Coriolis acceleration arising under the influence of the speed of rotation of the Earth.

- относительная скорость потока вещества;

- вектор скорости вращательного движения Земли; ω_пер - угловое ускорение Земли на широте нахождения измерительного участка трубопровода; Р₃ - давление вещества в западном направлении; Р_в - давление вещества в восточном направлении.The drawing shows an embodiment of the proposed method, which shows the pipe 1 of the main pipeline, connecting tubes 2 of the differential pressure gauge, differential pressure gauge 3.

- relative flow rate of the substance;

is the velocity vector of the Earth's rotational motion; ω _per - angular acceleration of the Earth at the latitude of the measuring section of the pipeline; P ₃ is the pressure of the substance in a westerly direction; P _in - the pressure of the substance in the east.

Coriolis force I _k acting on a substance is
I _k = m _in ˙ω _k = ΔP, where m _in is the mass of the substance;
ω _to - Coriolis acceleration;
ΔP = P _s -P _in - pressure drop.

=

Если магистральный трубопровод расположен вдоль меридиана, то
sin α = 1
m_в=

= ΔP·K где K =

Исследования заявляемого способа показали, что предлагаемый способ обеспечивает возможность его применения в многофазном потоке трубопроводов большого диаметра (до 1400 мм). При этом обеспечивается повышение точности непрерывного измерения расхода вещества до 0,5 % (по сравнению с прототипом в 2 раза). (56) 1. Кремлевский П. П. Измерение расхода многофазных потоков, Л. : Машиностроение, 1982, с. 101.Based on this:
m _in =

=

If the main pipeline is located along the meridian, then
sin α = 1
m _in =

= ΔP · K where K =

Studies of the proposed method showed that the proposed method provides the possibility of its use in a multiphase flow of large diameter pipelines (up to 1400 mm). This increases the accuracy of continuous measurement of the flow rate of the substance up to 0.5% (compared with the prototype 2 times). (56) 1. Kremlevsky P.P. Measurement of the flow of multiphase flows, L.: Mechanical Engineering, 1982, p. 101.

 2. Kremlevsky P. P. The measurement of the flow of multiphase flows, L.: Mechanical Engineering, 1982, p. 95.

Claims (1)

 METHOD FOR MEASURING CONSUMPTION OF SUBSTANCE, including the passage of the measured flow through the measuring section of the pipe and measuring its dynamic parameter, by which the flow is judged, characterized in that the measuring section of the pipe is located at a constant distance from the Earth diametrically opposite points of the pipe section.

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