WO2019000258A1

WO2019000258A1 - Gas turbine flowmeter detection device and detection method

Info

Publication number: WO2019000258A1
Application number: PCT/CN2017/090471
Authority: WO
Inventors: 张丛
Original assignee: 深圳市樊溪电子有限公司
Priority date: 2017-06-26
Filing date: 2017-06-28
Publication date: 2019-01-03
Also published as: CN107131932A

Abstract

A gas turbine flowmeter detection device using gas as a medium. The detection device comprises: a cover body (1), a liquid tank (2), a telecommunication generator (3), a verification tank (4), a pressure compensation mechanism (5), a tank connector (6), a gas source (7), a plurality of valves (8, 9, 10, 11, 12, 13), a water level gauge, and a plurality of test pipelines. The cover body (1) and the liquid tank (2) constitute a volume-variable sealed cavity; during descent of the cover body (1), the internal gas pressure of the sealed cavity is maintained at a constant value by means of the pressure compensation mechanism (5), and does not change with a depth of the cover body (1) immersing in a sealing liquid; the cover body (1) is provided with two baffles, and the volume between the baffles is fixed; an instantaneous flow rate can be calculated by measuring a time that the two baffles pass through in sequence the telecommunication generator (3). A gas turbine flowmeter detection method using the detection device standardizes detection process.

Description

Detection device and detection method of gas turbine flowmeter

Technical field

The invention relates to a detection technology of a flowmeter, in particular to a detection device and a detection method of a gas turbine flowmeter.

Background technique

Turbine flowmeter is the main type of velocity flowmeter. When the fluid to be measured flows through the turbine flow sensor, under the action of the fluid, the impeller rotates under force, and its rotational speed is proportional to the average flow velocity of the pipeline. At the same time, the blade is periodic. The cutting electromagnet generates magnetic lines of force and changes the magnetic flux of the coil. According to the principle of electromagnetic induction, a pulsating potential signal, that is, an electric pulse signal, is induced in the coil, and the frequency of the electric pulsating signal is proportional to the flow rate of the fluid to be measured. Turbine flowmeters have the advantages of high precision, good repeatability, zero drift, and high turndown ratio. Turbine flowmeters feature high-quality bearings and specially designed baffles, which greatly reduce wear and tear, are insensitive to peaks, and can provide reliable measurement variables even under harsh conditions. The turbine flow meter output is pulsed, easy to digitize, the turbine flowmeter has low pressure loss, the blades are corrosion resistant, and the viscous and corrosive media can be measured.

The gas turbine flow meter is a precision flow measuring instrument that can be used to measure the flow and total amount of liquid in conjunction with the corresponding flow meter. Gas turbine flowmeters are widely used in metrology and control systems in petroleum, chemical, metallurgical, scientific research and other fields. Gas turbine flow meters equipped with sanitary joints can be used in the pharmaceutical industry. The working principle of the gas turbine flowmeter is: when the fluid to be measured flows through the sensor, the impeller in the sensor is rotated by the kinetic energy of the fluid, and the impeller periodically changes the magnetic resistance in the magnetoelectric induction system. The value is such that the magnetic flux passing through the coil periodically changes to generate an electrical pulse signal, which is amplified by the amplifier and displayed or transmitted to a corresponding flow totalizer, PLC or host computer for flow or total measurement. The basic structure of the gas turbine flow sensor is shown in Figure 1. It consists mainly of the housing, front guide frame, impeller, rear guide frame, compression ring, fueling system (above DN40) and amplifier or display converter.

The integrated gas turbine flowmeter is an explosion-proof design that displays total flow, instantaneous flow and flow full percentage. The battery uses a long-lasting lithium battery. The battery life of the single-function integrated meter can reach more than 5 years, and the battery life of the multi-function display meter can reach more than 12 months. The integrated meter can display a large number of flow units, including cubic meters, gallons, liters, standard cubic meters, standard liters, etc., can set fixed pressure, temperature parameters to compensate for gas, and occasions where pressure and temperature parameters change little. The meter can be used for fixed compensation integration.

However, at present, gas turbine flowmeters have a single standard of measurement environmental conditions. The verification procedures follow different artificial regulations and are not standardized enough to accurately determine the quality of the gas turbine flowmeter and the technical defects of calibration.

Summary of the invention

The object of the present invention is to provide a gas turbine flowmeter detecting device, which uses gas as a medium to verify, calibrate and inspect a gas flowmeter, including a cover body, a liquid tank, a telecommunication generator, a verification tank, a pressure compensation mechanism, The splicer, the air source and the plurality of valves are further composed of a water level gauge and a plurality of test pipelines, wherein the hood and the liquid tank form a variable-volume sealed cavity, and the hood passes through the descending process The pressure compensating mechanism maintains a constant value of the internal gas pressure of the sealed cavity, which does not vary with the depth at which the cover body is immersed in the sealing liquid, and the cover body has two baffles between the baffles The volume is fixed by measuring the time that the two baffles have passed through the telecommunication generator in succession, The instantaneous flow rate of the gas turbine flow meter can be calculated.

Preferably, the cover is movable.

Preferably, the liquid tank is fixed.

Preferably, a pulley, a guide post and an outer guide wheel mechanism are also included for varying the volume of the sealed cavity.

The object of the present invention is also achieved by a detection method of a gas turbine flowmeter, comprising the following steps:

(1) Set the measurement conditions, including atmospheric temperature, atmospheric relative humidity, atmospheric pressure, medium temperature for verification, power supply voltage, and power frequency;

(2) installing the turbine flowmeter on the detecting device according to the JJG1037-2008 turbine flowmeter verification procedure under the specified measurement conditions;

(3) Using air as the verification medium, adjust the flow point to a certain percentage of the maximum flow rate, run for a certain period of time, and wait for the medium temperature, pressure and flow rate to stabilize after formal verification;

(4) According to the verification procedure, set a plurality of 1.5-stage turbine flowmeter verification flow points, and measure the detected flowmeter pulse signal and the standard gas flow device measured at the jth point of the i-th point at the point. The ratio of the standard volume flow rate is taken as the meter factor of the jth measurement at the i-th point;

(5) Establishing a mathematical model for evaluating the relative uncertainty of the input of the detection device of the gas turbine flow meter to determine the quality level of the gas turbine flow meter.

Preferably, the turbine flow meter and the front and rear straight pipe sections of the step (2) need to be installed coaxially.

Preferably, the step (3) adjusts the flow point to a 70% flow point of the maximum flow for 5 minutes.

Preferably, the step (4) sets four flow points, which are Qmin, 0.6Qmin, 0.4Qmax, and Qmax, respectively.

Preferably, the step (4) is for a flowmeter with a range ratio <20:1, and the boundary flow is 0.6Qmin=0.2Qmax.

Preferably, the mathematical model of the step (5) is to calculate the meter coefficient and the propagation rate of the i-th measuring flowmeter.

The device and method adopt a positive pressure method, and a certain volume of a standard gas flows through a turbine flowmeter, thereby realizing verification of the flowmeter, and the flow range of the flow itself is relatively small, and is suitable for verifying a flowmeter with a small diameter. It conforms to the state of the flowmeter in actual work and standardizes the verification work.

The above as well as other objects, advantages and features of the present invention will become apparent to those skilled in the <

DRAWINGS

Some specific embodiments of the present invention will be described in detail, by way of example, and not limitation, The same reference numbers in the drawings identify the same or similar parts. Those skilled in the art should understand that the drawings are not necessarily drawn to scale. The objects and features of the present invention will become more apparent in consideration of the following description in conjunction with the accompanying drawings.

1 is a schematic structural view of a gas turbine flow meter according to the prior art;

2 is a schematic structural view of a gas turbine flowmeter detecting device according to an embodiment of the present invention;

3 is a flow chart of a method for detecting a gas turbine flow meter in accordance with an embodiment of the present invention.

Detailed ways

Referring to Figure 2, a gas turbine flow meter detecting device uses a gas as a medium to calibrate, calibrate and inspect a gas flow meter, including a cover 1, a liquid tank 2, a telecommunication generator 3, an assay tank 4, and a pressure. The compensation mechanism 5, the splicer 6, the air source 7 and the plurality of

valves

8, 9, 10, 11, 12, 13 are also composed of a water level gauge and a plurality of test pipelines (not shown), and the cover body can be Moving, the liquid tank is fixed, and the cover body and the liquid tank form a variable-volume sealed cavity, and the volume of the sealing cavity is changed by the pulley, the guide post and the outer guide wheel mechanism, and the pressure is passed during the falling of the cover body. The compensation mechanism maintains the internal gas pressure of the sealed cavity to a certain value, which does not change according to the depth at which the cover body is immersed in the sealing liquid, and the cover body has two baffles, and the volume between the baffles is fixed, and the measurement is performed. The instantaneous flow rate of the gas turbine flow meter can be calculated by the time that the two baffles pass through the telecommunication generator.

Referring to Figure 3, a gas turbine flow meter detection method is implemented, including the following steps: (1) setting measurement conditions, including atmospheric temperature, atmospheric relative humidity, atmospheric pressure, medium temperature for verification, Power supply voltage, power supply frequency; (2) Under the specified measurement conditions, according to the JJG1037-2008 turbine flowmeter verification procedure, the turbine flowmeter is installed on the detection device, and the turbine flowmeter and the front and rear straight pipe sections need to be coaxially installed; (3) Using air as the verification medium, adjust the flow point to 70% of the maximum flow rate, run for 5 minutes, wait for the medium temperature, pressure and flow to stabilize and then perform formal verification; (4) Set multiple 1.5 according to the verification procedure. The turbine flowmeter verifies the flow point and sets four flow points, which are Qmin, 0.6Qmin, 0.4Qmax, Qmax. For flowmeters with a range ratio <20:1, the boundary flow is 0.6Qmin=0.2Qmax, which will be The ratio of the detected flowmeter pulse signal measured by jth point to the standard volume flow rate measured by the standard gas flow device at this point is taken as the meter coefficient measured at the jth point of the i-th point; (5) establishing a mathematical model And evaluating a relative uncertainty of the input amount of the detecting device of the gas turbine flow meter to determine a quality level of the gas turbine flow meter, and the mathematical model is for calculating the meter coefficient of the i-th measuring flowmeter to be detected and transmitting Rate.

Where K=N _i /V _i , (1)

K is the meter factor of the i-th measurement of the flowmeter to be inspected, (m ³ ) ^-1

N _i is the number of pulses measured by the meter for the i-th measurement of the measured flow meter;

V _i is the cumulative flow rate of the i-th measuring device, m ³

The rate of transmission is:

At atmospheric temperature (23.5±1) oc, atmospheric relative humidity is (38±1)% RH, atmospheric pressure (94.5±0.5) kPa, medium temperature for verification (18.5±0.1) oc, power supply voltage is 220V, power supply frequency is 50Hz Under the measurement environment conditions, a 0.5-120m ³ /h, DN25mm gas turbine flowmeter is used for verification. The flow rate is selected for 60 seconds at the maximum flow rate of 70%, the cumulative flow rate is 250L, and the industrial control measuring device continuously measures 6 times. For a set of measurement columns, the standard deviation of single test is 10.13, and the average uncertainty of 3 is 0.15%. Combined with the extended uncertainty and coefficient of the gas turbine flowmeter given by the manufacturer, the relative standard uncertainty of synthesis is obtained. It is 0.21%. However, after the above values are obtained by measuring at other given measurement flow points, the measurement repeatability is taken as the maximum value, and the expansion uncertainty is 0.42%. Under the extended uncertainty, the standard qualified gas turbine flowmeter is used. .

The device and method adopt a positive pressure method, and a certain volume of standard gas flows through the turbine flowmeter, thereby realizing verification of the flowmeter, and the flow range of the flow itself is relatively small, and is suitable for verifying a flowmeter with a small diameter, conforming to the flowmeter. The state of actual work, standardizes the verification work.

The present invention has been described with reference to the specific illustrative embodiments, and is not limited by the scope of the appended claims. It will be appreciated by those skilled in the art that the embodiments of the invention can be modified and modified without departing from the scope and spirit of the invention.

Claims

A gas turbine flowmeter detecting device uses a gas as a medium to perform verification, calibration and inspection on a gas flowmeter, and is characterized in that it comprises a cover body (1), a liquid tank (2), a telecommunication generator (3), The calibration tank (4), the pressure compensating mechanism (5), the splicer (6), the gas source (7) and a plurality of valves (8, 9, 10, 11, 12, 13) are also composed of a water level gauge and a plurality of a test tube, the cover body (1) and the liquid tank (2) constitute a variable-volume sealed cavity, and the cover body (1) is lowered by the pressure compensating mechanism (5) during the lowering process The internal gas pressure of the sealed cavity is maintained at a constant value that does not vary with the depth at which the cover (1) is immersed in the sealing liquid, the cover (1) having two baffles between the baffles The volume is fixed and the instantaneous flow rate of the gas turbine flow meter can be calculated by measuring the time that the two baffles pass through the telecommunication generator (3).
A detecting device for a gas turbine flow meter according to claim 1, characterized in that the cover (1) is movable.
A detecting device for a gas turbine flow meter according to claim 1, characterized in that the liquid tank (2) is fixed.
A detecting device for a gas turbine flow meter according to claim 1, further comprising a pulley, a guide post and an outer guide wheel mechanism for changing a volume of said sealed cavity.
A method for detecting a gas turbine flowmeter using the detecting device according to any one of claims 1 to 4, characterized in that it comprises the following steps:

(1) Set the measurement conditions, including atmospheric temperature, atmospheric relative humidity, atmospheric pressure, medium temperature for verification, power supply voltage, and power frequency;

(2) installing the turbine flowmeter on the detecting device according to the JJG1037-2008 turbine flowmeter verification procedure under the specified measurement conditions;

(3) Using air as the verification medium, adjust the flow point to a certain percentage of the maximum flow rate, run for a certain period of time, and wait for the medium temperature, pressure and flow rate to stabilize after formal verification;

(4) According to the verification procedure, set a plurality of 1.5-stage turbine flowmeter verification flow points, and measure the detected flowmeter pulse signal and the standard gas flow device measured at the jth point of the i-th point at the point. Worth The ratio of the quasi-volumetric flow rate is taken as the meter factor of the jth measurement at the i-th point;

(5) Establishing a mathematical model for evaluating the relative uncertainty of the input of the detection device of the gas turbine flow meter to determine the quality level of the gas turbine flow meter.
The method for detecting a gas turbine flowmeter according to claim 5, wherein the turbine flowmeter and the front and rear straight pipe sections of the step (2) need to be coaxially mounted.
The method of detecting a gas turbine flow meter according to claim 5, wherein the step (3) adjusts the flow point to a flow rate of 70% of the maximum flow rate for 5 minutes.
The method for detecting a gas turbine flowmeter according to claim 5, wherein the step (4) sets four flow points, which are Qmin, 0.6Qmin, 0.4Qmax, and Qmax, respectively.
The method for detecting a gas turbine flowmeter according to claim 5, wherein said step (4) is for a flowmeter having a range ratio of <20:1, and a boundary flow rate of 0.6 Qmin = 0.2 Qmax.
The method of detecting a gas turbine flowmeter according to claim 5, wherein the mathematical model of the step (5) is to calculate the meter coefficient and the propagation rate of the flowmeter to be inspected for the i-th measurement.