RU168398U1 - VARIABLE LIQUID FLOW METER - Google Patents

Abstract

The utility model relates to devices for monitoring and measuring the amount of working medium supplied to the consumer, for example, to measure the amount of a corrosion inhibitor, hydrate formation (methanol) supplied to the production lines of gas fields and wells. A variable differential pressure meter uses a micromanometer 1 measuring unit, which placed in a sealed housing 2 under the lens 4, through which the readings of the micromanometer are monitored. In the passage channel of the housing there is a replaceable diaphragm 3, which is pressed by the plug 5. The measuring unit of the micromanometer is located in the sealed cavity A and is isolated from the contact with the working medium with non-freezing fluid filling the sealed volume of the housing under the glass. An elastic compensator 6 is placed in the channel connecting the cavity with the outlet channel, forming a single sealed volume filled with a transparent non-freezing liquid with cavity A. To fill the cavity A and the elastic compensator 6 with liquid, a channel with a needle plug 7 is made in the housing 2. Using a nut 8, the lens 4 and the measuring unit 1 of the micromanometer are pressed against the housing 2. Radial holes 9 are made in the nut 8 to increase the illuminance of the micromanometer scale. the flow meter (positive chamber B) communicates with the measuring unit of the pressure gauge, and the outlet one - with the cavity A of the housing 2. A useful model of the flow meter allows the measurement of small flow rates at large absolute values Achen working fluid pressure in the absence of electric power, and also increases the reliability of operation with small geometrical sizes meter

Description

The utility model relates to devices for monitoring and measuring the amount of working medium supplied to the consumer, for example, to measure the amount of supplied corrosion inhibitor, hydrate formation (methanol) in the production lines of gas fields and wells.

When gas production is required to measure and control the volumetric flow rate of the corrosion inhibitor, hydrate formation supplied to the wells or production lines of gas fields. These measurements are necessary to calculate and control the amount of inhibitor supplied, which is necessary to prevent the formation of hydrates in the plumes of wells and technological lines of gas fields.

Known flow meters used in industry for measuring the flow of liquids, vapors and gases moving in pipelines:

- Tachometric flow meters (flow meters, counters). The main element of these flowmeters is an impeller or other body that makes continuous movement (most often rotational) under the action of a flow, the speed of which is proportional to the measured flow rate. The disadvantages of this group of flowmeters are: a complex mechanism for transmitting the rotational motion of the impeller located in the high-pressure cavity to a counter-showing mechanism of the flowmeter, inability to perceive small liquid flow rates, less than 50 l / h. (Automatic devices, regulators and control machines. Reference manual. Ed. 2nd, revised and additional. Kosharsky BD and other M .: Mashinostroenie, 1968. 87 pp. Ill. III. 1.);

- Flow meters of constant differential pressure (rotameters). The sensitive element of these flowmeters is any body (float, ball, disk) that receives the dynamic pressure of the flow, which flows around it and moves depending on the flow rate. The disadvantage of this group of flow meters is the inability to use at high absolute pressure values, since flowmeters for local measurement have tubes of glass or organic glass. (Automatic devices, regulators, and control machines. Reference manual. Ed. 2nd, revised and additional. Kosharsky BD and others. M: Mechanical Engineering, 1968. 99 pp. Ill. III. 7.);

- Electromagnetic (induction) flow meters. The principle of operation of these flow meters is based on measuring the electromotive force generated in the cross section of the stream when it flows in a magnetic field. The disadvantage of this group of flowmeters is the need to supply electricity to the flowmeter. (Automatic devices, regulators, and control machines. Reference manual. Ed. 2nd, revised and additional. Kosharsky BD and other M: Engineering, 1968. 111 pp. Ill. III. 9.);

- Ultrasonic flow meters. The principle of their action is based on the displacement of ultrasonic vibrations by a moving medium. The disadvantage of this group of flowmeters is the need to supply electricity to the flowmeter. (Automatic devices, regulators, and control machines. Reference manual. Ed. 2-nd, revised and additional. Kosharsky BD et al. M .: Engineering, 1968. 115 pp.);

- Flowmeters of variable differential pressure. These flowmeters are measuring sets and consist of a receiving transducer forming a pressure drop across the constricting device depending on the flow rate, connecting tubes with auxiliary devices and a differential pressure gauge. The disadvantage of this group of flowmeters is their large size and weight (up to 50 kg), in addition, many of them contain mercury. (Automatic devices, regulators, and control machines. Reference manual. Ed. 2nd, revised and additional. Kosharsky BD and other M .: Mashinostroenie, 1968. 117 pp. Ill. III. 12.).

Known liquid flow meters of variable differential pressure, containing a constricting device, a sensing element, a converting mechanism and an indicating device (Automatic devices, regulators and control machines. Reference manual. Ed. 2nd, revised and additional. Kosharsky BD and others M.: Mechanical Engineering, 1968. 117 pp. Ill. III. 12.).

A known liquid flow meter of variable differential pressure, comprising a sensing element in the form of an elastic membrane, a conversion mechanism that senses the movement of the membrane, and showing the device (SAMSON AG MESS UND REGELTECHNIK series T 9520 EN).

The disadvantages of the above meter are its low reliability, due to the possibility of wear and tear of the elastic membrane during long-term operation of the meter, as well as the large dimensions of the meter body, which makes it difficult to install in a well.

A known meter of fluid flow variable pressure difference (WO 02/12835 A2, G01F 1/00, 02/14/2002, S. 2-6, Fig. 1, 2).

The closest in the number of matching features, selected as a prototype, is a liquid flow meter of variable differential pressure RU 2365878 C2. The disadvantage of the prototype is the low reliability of the rubber separator, its rapid destruction leading to fluid leaks, as well as the difficulty in assembling the product. The proposed utility model is aimed at eliminating these shortcomings.

The problem achieved by the proposed utility model is to create such a technical solution that would allow measurements of small flow rates (less than 50 l / h) at high absolute pressure values in the absence of electricity, as well as to increase reliability and ease of maintenance .

To achieve the named technical result, the flow meter of the variable differential pressure fluid contains a constricting device and a micromanometer located in a single sealed housing under working pressure.

The inventive meter differs from the prototype in that the case is closed on the front side with a transparent protective glass in the form of a lens covered by a nut to control readings, while the measuring unit of the micromanometer is placed under the lens and is separated from the working medium by non-freezing silicone fluid filling the sealed volume of the case under the glass. To compensate for changes in the volume of the liquid (temperature and changes in the volume of the tubular spring of the pressure gauge), an elastic compensator is placed in the channel connecting the sealed cavity and the cavity behind the narrowing device (diaphragm), and a channel with a needle plug is made in the body to fill the cavity and the compensator with liquid.

The sensitive element is a measuring unit of the gauge of excessive pressure, placed in a durable case, having a durable glass for visual monitoring of the pressure gauge.

The proposed utility model is depicted in the drawings, where in FIG. 1 shows a longitudinal section of the meter, and in FIG. 2 is a graph of inhibitor flow versus pressure differential readings on a flow meter.

The liquid flow meter of a variable differential pressure contains a measuring unit of the micromanometer 1, which is placed in a sealed housing 2 under the lens 4, through which the readings of the micromanometer are monitored. In the passage channel of the housing there is a replaceable diaphragm 3, which is pressed by the stopper 5. The measuring unit of the micromanometer is located in the sealed cavity A and is isolated from the contact with the working medium with non-freezing fluid filling the sealed volume of the body under the glass. An elastic compensator 6 is placed in the channel connecting the cavity with the outlet channel, forming a single sealed volume filled with a transparent non-freezing liquid with cavity A. To fill the cavity A and the elastic compensator 6 with liquid in the housing 2, a channel with a needle plug 7 is made.

The inlet channel of the flow meter (positive chamber B) communicates with the measuring unit of the pressure gauge, and the outlet channel with the cavity A of the housing 2.

The device operates as follows. The working medium, passing through the diaphragm 3, creates a pressure drop, which is fixed by the measuring unit 1.

,The deviation of the pressure gauge needle corresponds to the pressure drop across the constriction device, which makes it possible to judge the flow rate. The relationship between the readings of the differential pressure on the manometer and the flow rate is determined by the formula:

,

where: μ - diaphragm flow coefficient, which is determined experimentally;

ω is the cross-sectional area of the aperture opening;

ΔP is the pressure drop across the constriction device;

ρ is the density of the medium passing through the indicator.

For example: a graph of the inhibitor flow rate versus the differential pressure readings on a flow meter for a throttle d = 1.5 mm is shown in FIG. 2.

Methanol was taken as a hydrate inhibitor.

The density of methanol ρ = 0.792 g / cm ³ .

Thanks to the use of this design of the flow meter, it becomes possible to measure small flow rates at large absolute pressure values of the working medium, as well as to increase the reliability of the meter itself, and its assembly during maintenance is simplified. Based on the above advantages, it becomes possible to use a flow meter in non-electrified wells.

Claims (2)

1. A liquid flow meter of variable differential pressure, consisting of a constricting device, a diaphragm and a micromanometer, placed in a single sealed housing under working pressure, closed from the front with a transparent protective glass to monitor the pressure gauge, the cavity of the housing under the glass where the manometer is located is filled elastic non-freezing liquid, characterized in that in the channel connecting the sealed cavity with the cavity behind the constricting device (diaphragm), an elastic compensator is placed well connected to the cavity. 2. A liquid flow meter of variable differential pressure according to claim 1, characterized in that a channel with a needle plug is made in the housing to fill the cavity and the compensator with liquid.