WO2019000259A1

WO2019000259A1 - Detection device and method for circulating type gas turbine flowmeter

Info

Publication number: WO2019000259A1
Application number: PCT/CN2017/090472
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: CN107238424A; CN107238424B

Abstract

A detection device for a circulating type gas turbine flowmeter. Clean air is used as a medium, and the gas flowmeter is verified, calibrated and checked. The device comprises a vacuum pump (1), a gas storage tank (2), a collecting pipe container (3), a switching valve (4), a venturi nozzle (5), a stagnation container thermometer (6), a stagnation container pressure meter (7), a stagnation container (8), a flow regulating valve (9), a thermometer (10) behind a detected meter, a detected flowmeter (11) and a pressure meter (12) in front of the detected meter. The vacuum pump (1) sucks clean air from an inlet of an upstream straight pipe section of the detected flowmeter (11), the venturi nozzle (5) which needs to be opened and closed may be selected freely, the flow of the detected meter (11) is changed, the mass flow passing through the venturi nozzle (5) is calculated and obtained by means of temperature and pressure measurement, and verification is completed. Also provided is a gas turbine flowmeter detection method which employs the detection device, wherein the detection method has a short consumption time, improves the detection efficiency and has good repeatability.

Description

Detection device and detection method of circulating gas turbine flowmeter

Technical field

The invention relates to a detection technology of a flow meter, in particular to a detection device and a detection method of a circulating 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 non-standard measurement environment. 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. The flow range measured by the method is relatively small, and is only suitable for small-diameter flowmeters. There is no mature technology for the verification of large-diameter flowmeters.

Summary of the invention

The object of the present invention is to provide a detection device for a circulating gas turbine flowmeter, which uses a clean air as a medium to verify, calibrate and inspect a gas flow meter, including a vacuum pump, a gas storage tank, a manifold container, an on-off valve, and a venturi Inside nozzle, stagnation container thermometer, stagnation container pressure gauge, stagnation container, flow regulating valve, thermometer after checklist, flowmeter to be inspected, and pressure gauge before checklist, the vacuum pump will be air from the checklist Intake of the upstream straight pipe section inlet, passing through the straight pipe section before the inspection table, the inspection table and the downstream straight pipe section of the inspection table into the stagnation container, and the venturi is provided downstream of the stagnation vessel a nozzle for controlling the on-off valve downstream of the venturi nozzle, thereby selecting any of the venturi nozzles to be switched to achieve the purpose of changing the flow rate of the check meter, the stagnation container passing the stagnation container thermometer The temperature is measured, and the pressure is measured by the stagnation container pressure gauge, and the mass flow rate through the venturi nozzle is calculated to complete the verification of the check table.

Preferably, the clean air is supplied through a circulating gas path, and is pumped by the air pump.

Preferably, the vacuum pump provides a negative pressure.

The object of the present invention is also achieved by a detection method of a circulating 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 clean 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 instrument system of the i-th measurement of the flowmeter to be inspected. Number and transmission rate.

The negative pressure testing device and method are short in time, reduce labor intensity, improve detection efficiency, and do not require moving test equipment, and have good repeatability.

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 circulating gas turbine flowmeter detecting device according to an embodiment of the present invention;

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

Detailed ways

Referring to Figure 2, there is provided a detecting device for a circulating gas turbine flowmeter, which uses a clean air as a medium to verify, calibrate and inspect a gas flow meter, including a vacuum pump 1, a gas storage tank 2, a manifold tube 3, a switch Valve 4, venturi nozzle 5, stagnation container thermometer 6, stagnation container pressure gauge 7, stagnation container 8, flow regulating valve 9, thermometer after checklist 10, flow meter 11 to be inspected, and gauge before the meter 12, the vacuum pump 1 draws air from the upstream straight pipe section inlet of the flowmeter 11 to be inspected, passes through the straight pipe section before the flowmeter 11 to be inspected, the flowmeter 11 to be inspected, and the straight pipe section downstream of the flowmeter 11 to be inspected into the stagnation vessel 8 Downstream of the stagnation vessel 8, the venturi nozzle 5 is provided to control the on-off valve 4 downstream of the venturi nozzle 5 so that any of the venturi nozzles 5 to be switched is selected to achieve a change For the purpose of the meter flow, the stagnation container 8 is temperature-measured by the stagnation container thermometer 6, and passes through the stagnation The container pressure gauge 7 measures the pressure, and the mass flow rate through the venturi nozzle 5 is calculated to complete the verification of the flowmeter 11 to be inspected. The clean air is supplied through the circulating gas path, and the air pump is used for pumping, and the vacuum pump provides a negative pressure.

Referring to FIG. 3, a detection method of a gas turbine flowmeter includes the following steps: (1) setting measurement conditions, including atmospheric temperature, atmospheric relative humidity, atmospheric pressure, medium temperature for verification, power supply voltage, and power 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 straight pipe sections need to be coaxially installed; (3) air is used Verify the medium, adjust the flow point to the 70% flow point of the maximum flow, run for 5 minutes, wait for the medium temperature, pressure and flow to stabilize and then perform formal verification; (4) Set multiple 1.5-stage turbine flowmeter verification according to the verification procedure. Flow point, set four flow points, respectively Qmin, 0.6Qmin, 0.4Qmax, Qmax, for the flowmeter with a range ratio <20:1, the demarcation flow 0.6Qmin=0.2Qmax, will be the jth test at the i-th point The ratio of the measured flowmeter pulse signal and the standard gas flow device at the point of the standard volume flow measured at that point is taken as the meter coefficient of the jth measurement at the i-th point; (5) establishing a mathematical model to evaluate the gas Turbine flowmeter relative uncertainty of the input detecting means so as to determine the quality level of the gas turbine flowmeter, a mathematical model to calculate the i-th measurement subject flowmeter meter factor and transmission rates.

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 13.55, and the average uncertainty of 3 is 0.20%. 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 0.24%. 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 0.54%. Under the extended uncertainty, the standard qualified gas turbine flowmeter is used. .

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

The utility model relates to a detecting device for a circulating gas turbine flowmeter, which uses a clean air as a medium to verify, calibrate and inspect a gas flowmeter, and is characterized in that it comprises a vacuum pump (1), a gas storage tank (2) and a manifold container ( 3), on-off valve (4), venturi nozzle (5), stagnation container thermometer (6), stagnation container pressure gauge (7), stagnation container (8), flow regulating valve (9), checklist a rear thermometer (10), a flow meter (11) to be inspected, and a pressure gauge (12) before the meter, the vacuum pump (1) sucking the clean air from the upstream straight pipe inlet of the flowmeter (11) to be inspected, After the straight pipe section of the detected flow meter (11), the flowmeter to be inspected (11) and the downstream straight pipe section of the flowmeter to be inspected (11) enter the stagnation container (8), in the stagnation container (8) Downstream, the venturi nozzle (5) is provided to control the on-off valve (4) downstream of the venturi nozzle (5), so that any venturi nozzle (5) to be switched is selected to achieve For the purpose of changing the flow rate of the meter to be inspected, the stagnation vessel (8) is temperature-measured by the stagnation vessel thermometer (6), and the pressure is measured by the stagnation vessel pressure gauge (7), and the calculation is passed. The mass flow rate of the venturi nozzle (5) completes the verification of the flowmeter (11) to be inspected.
A detecting device for a circulating gas turbine flowmeter according to claim 1, wherein said clean air is supplied through a circulating gas path, and is evacuated by a gas pump.
A detecting device for a circulating gas turbine flowmeter according to claim 1, characterized in that the vacuum pump (1) provides a negative pressure.
A method for detecting a circulating gas turbine flowmeter using the detecting device according to any one of claims 1 to 3, comprising the steps of:

(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-level turbine flowmeter verification flow points, which will be in the i The ratio of the measured flow meter pulse signal measured at the jth time to the standard volume flow rate measured by the standard gas flow device at the point is taken as the meter coefficient measured at the jth point of 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 4, 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 4, 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 4, 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 4, wherein said step (4) is a flowmeter with a range ratio of <20:1, and a boundary flow rate of 0.6 Qmin = 0.2 Qmax.
The method for detecting a gas turbine flowmeter according to claim 4, 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.