RU101833U1 - GAS DENSITY ANALYZER - Google Patents

Abstract

 A gas density analyzer containing a series-connected flow stabilizer of the analyzed gas and a turbulent throttle with a pressure differential pressure transducer, characterized in that the analyzer further comprises a two-input computing device, a gas pressure stabilizer, the input of which is connected to the source of the analyzed gas, and the output to the volumetric flow stabilizer inlet, the chamber in which the volumetric flow stabilizer, turbulent throttle and measuring a pressure difference transducer and a temperature measuring transducer in the chamber, while the outputs of the pressure and temperature difference transducers are connected to a two-input computing device, and the volume flow stabilizer is made in the form of a laminar throttle and a pressure difference regulator on this choke.

Description

The utility model relates to the field of automatic control of technological parameters, namely, to means for measuring the density of gases in technological streams.

A known analyzer of gas density (Kivilis SS Density meters. M: Energy. 1980 - p.217), containing a chamber in which two turbines are located. One of the turbines is rotationally driven by a synchronous motor and directs to the second stream of the analyzed gas flowing through the chamber. The kinetic energy of the gas is perceived by the second impeller. At the same time, a torque appears on it, which is balanced by a spiral spring attached to the axis on which this turbine is mounted, and the angle of rotation of this axis is proportional to the gas density.

The disadvantage of this density analyzer is the presence of moving elements and, especially, a synchronous motor, the use of which in many technological processes requires its costly explosion-proof design.

The closest in technical essence is a gas density analyzer (Farzane N.G. et al. Technological measurements and instruments. M: Higher school. 1989. - p.280. Fig. 10.3b), containing a flow stabilizer of the analyzed volume connected in series gas and turbulent throttle with differential pressure transmitter. The sample gas flow stabilizer is a fan located in a chamber that is connected to a source of sample gas. It is rotationally driven by a synchronous motor and generates a stream of sample gas through the pipeline. A turbulent throttle is located in this pipeline to which a differential pressure transmitter is connected. With a constant volume flow of the analyzed gas through the turbulent throttle created by the fan, the pressure difference across the throttle carries information about the density of the analyzed gas.

The disadvantage of this density analyzer is the design complexity, namely, the presence of rotating elements and a synchronous motor, which in many cases require expensive explosion-proof performance.

The objective of the utility model is to simplify the design of a gas density analyzer.

EFFECT: creation of a simple gas density analyzer for technological flows, in which there are no moving and explosive and fire hazardous elements.

The technical result is achieved by the fact that a gas density analyzer containing in series with the flow connected a stabilizer of the volumetric flow rate of the analyzed gas and a turbulent throttle with a pressure differential pressure transducer, according to a utility model, further comprises a two-input computing device, a gas pressure stabilizer, the input of which is connected to the source of the analyzed gas, and the output is to the entrance of the volumetric flow stabilizer, the chamber in which the volumetric flow stabilizer is placed, tour ulentny throttle and the differential pressure transducer and a temperature transducer in the chamber, wherein outputs of measuring differential pressure and temperature transducers connected to a two-input computing device, a volume flow regulator is formed as a laminar throttle and the differential pressure regulator at this throttle.

This analyzer design allows simple means to measure the density of gases, because by maintaining a constant pressure drop across the laminar throttle at a constant temperature, it maintains a constant volumetric flow rate necessary to measure the density by the pressure difference across the turbulent throttle without the use of moving and explosive and fire hazardous elements. This possibility is determined by the fact that the viscosity of gases, especially natural gases transported through gas pipelines, usually varies slightly.

Compared with the prototype of the claimed design has a distinctive feature in the combination of elements and their relative position.

A diagram of a gas density analyzer is shown in FIG.

The gas density analyzer contains a series-connected flow rate stabilizer 1 of the analyzed gas and a turbulent throttle 2 with a differential pressure transducer 3 on this throttle.

The analyzer further comprises a two-input computing device 4, a pressure stabilizer 5, the input 6 of which is connected to the source of the analyzed gas 7, and the output 8 to the input 9 of the stabilizer of the volume flow 1 of the analyzed gas. In addition, the gas analyzer includes a chamber 10 in which a volume flow stabilizer 1, a turbulent throttle 2 and a pressure differential pressure transducer 3 are placed. For temperature measurements, a temperature transducer 11 is provided in the chamber. The outputs of the pressure differential sensors on the turbulent throttle 3 and temperature 11 are connected to a two-input computing device 4. the volume flow stabilizer 1 is made in the form of a laminar throttle 12 and a pressure difference regulator 13 on this Rossel. The output of the two-input computing device 4 is connected to the secondary device 14.

The analyzer works as follows. The analyzed gas under pressure comes from a pressure source 7 to a pressure stabilizer 5, at the outlet of which a constant pressure is maintained. From the output of this stabilizer, the analyzed gas enters the volume flow stabilizer 1. Here the gas flows sequentially through the differential pressure regulator 13 and the laminar throttle 12. Maintaining a constant differential pressure on the laminar throttle ensures a constant volume flow of the analyzed gas through the turbulent throttle 2, which is connected in series with the laminar throttle, and measuring the pressure difference across the turbulent throttle at a constant volume flow through it allows you to measure the density of gas to be analyzed.

Indeed, since laminar and turbulent throttles are connected in series, then at small pressure differences it is true:

,

where Q _L is the volumetric gas flow through the laminar throttle;

Q _T - volumetric gas flow through a turbulent throttle.

The volumetric gas flow through the laminar throttle can be described by the expression:

,

where K _L is a constant coefficient depending on the geometric parameters of the laminar throttle (capillary);

η is the dynamic viscosity of the analyzed gas;

Δp is the pressure difference on the laminar throttle.

If η changes slightly, i.e. η = const, and Δp _{L is} supported by a constant pressure differential stabilizer, then Q _L = const.

For a turbulent throttle dependence is known:

,

where ρ is the density of the analyzed gas;

K _T is a constant coefficient, depending on the parameters of the turbulent throttle (diaphragm);

Δp _T is the pressure difference across the turbulent throttle.

Because Q _L = Q _T , expression (3) can be represented as:

,

Where - conversion coefficient of the density analyzer.

Thus, the density of the analyzed gas can be determined from the value of the pressure difference across the turbulent throttle.

Experimental studies of the model of a gas density analyzer have shown that it is capable of providing uninterrupted measurement of the density of a natural gas stream with an error not exceeding ± 1%.

The advantage of the proposed technical solution:

- simplicity of design;

- low cost.

The proposed density analyzer can be implemented on the basis of standard gas flow stabilizers after minor modifications and standard pressure difference transducers.

The gas density analyzer can be used to control the gas flows of oil, gas, oil refining and petrochemical industries.

Claims (1)

A gas density analyzer containing a series-connected flow stabilizer of the analyzed gas and a turbulent throttle with a pressure differential pressure transducer, characterized in that the analyzer further comprises a two-input computing device, a gas pressure stabilizer, the input of which is connected to the source of the analyzed gas, and the output to the volumetric flow stabilizer inlet, the chamber in which the volumetric flow stabilizer, turbulent throttle and measuring a pressure difference transducer and a temperature measuring transducer in the chamber, while the outputs of the pressure and temperature difference transducers are connected to a two-input computing device, and the volume flow stabilizer is made in the form of a laminar throttle and a pressure difference regulator on this choke.