Temperature compensation integrated vortex flowmeter

Products overview:

ZW - LUGB seriesMainly used in industrial pipeline medium fluid flow measurement, such as gas, liquid and vapor, and other media.Is characterized by small pressure loss, wide range, high precision, working condition of the measurement volume flow is almost not affected by the fluid density, the influence of the parameters such as pressure, temperature, viscosity.No moving mechanical parts, so high reliability, small amount of maintenance.Instrument parameters can be long-term stability.This instrument USES piezoelectric stress sensor, high reliability, can be in - 20 ℃ ~ + 250 ℃ temperature range.There are standard signal simulation and digital pulse signal output, easy with a computer digital systems, such as a more advanced, the ideal flowmeter.

By visible on type, VSF output pulse frequency of the signal is not affected by fluid physical properties, and composition change, namely the instrument coefficient in only within a certain range of Reynolds number and swirl through the body and the shape size and so on.But as flow meter need to be detected in the material balance and energy metering mass flow rate, the flow meter should be monitored at the same time the output signal of the volume flow rate and fluid density, fluid property and has a direct influence on flow metering or components.

Vortex flowmeter is based on the principle of karman vortex closed pipe fluid flow measurement of new type flowmeter.Medium because of its good adaptability, no compensation can be directly measured temperature and pressure steam, air, gas, water, and the operation condition of the liquid volume flow, temperature, pressure sensor to measure standard conditions and volume flow to mass flow, is the ideal substitute of orifice flowmeter.

Second, the working principle:
ZW - LUGB series temperature pressure compensation integration measuring principle of vortex flowmeter is by the design, testing probe in the flow field in the vortex body and the corresponding electronic circuit, etc.When the fluid flows through the spiral body occurs, it is formed on both sides of the two rows of vortex variations, this vortex is known as the karman vortex street.On the basis of the theory of karman vortex street and proposed the karman vortex street frequency is proportional to the velocity of the fluid, the relation between the frequency and velocity are presented: f = St * V/d type:
F vortex frequency (Hz)
V vortex occurred body on both sides of the average flow velocity (m/s)
St, luo hall coefficient (constant)
These variations of vortex is formed a series of variations of negative pressure, the pressure on detecting probe, and produce a series of alternating electric signals, after dealing with the preamplifier conversion, plastic, amplification, the output is proportional to the vortex synchronous pulse frequency signal (or standard).

Applications:
ZW - LUGB series temperature pressure compensation integrated vortex flowmeter can be widely used in large, medium and small various water supply and drainage pipe, industrial circulation, sewage treatment, oil and chemical reagents and compressed air, saturation and superheated steam, gas and all kinds of medium flow rate measurement.
Four, the main features:
1, z advantage is ant-vibration performance is very good, no zero drift, high reliability.
2, sensors, versatility is very strong, so that the sensor has good compatibility with advanced CNC processing equipment sensor table body and spiral body, etc., to ensure the machining accuracy, so that the parts (especially spiral body) versatility, thus truly will not affect by parts to replace the repeatability and precision of the sensor;Can produce a strong and stable vortex signal.
3, in a certain range of Reynolds number, flow characteristic from the fluid pressure, the influence of the temperature, viscosity, density, composition, is only involved in the body shape and size of the vortex.
4, output is proportional to the flow of the pulse signal or analog signal, no zero drift, high precision, convenient and computer connected to the Internet.
5, simple structure, no moving parts, high reliability, convenient in operation and maintenance.
6, detecting element, not contact with the media, stable performance and long service life, sensor detection probe with spiral body separate installation, and high temperature piezoelectric crystal seal in detecting probe, not contact with the measured medium, so vortex flowmeter has the characteristics of simple structure, high universality and high stability.
7, wide measuring range, range than can reach 1:10.
8, measure the volume flow without compensation, when the vortex of the output signal is actually with a linear relationship with velocity, namely is proportional to the volume flow.The purpose of the pressure and temperature compensation is to get the fluid density, multiply by volume flow to mass flow, if the measurement of the volume of a gas flow would be no need for compensation.
Five, the technical parameters:
1, the measured medium: liquid, gas, steam;
2, measuring range: (see table below);
3: (see table), nominal size of non-standard products can be customized according to user requirements special;
4, temperature range: piezoelectric - 40 ℃ ~ 350 ℃ capacitive - 60 ℃ ~ 450 ℃;
5, pressure specifications: PN1.6 Mpa;PN2.5 Mpa;Specifications can be customized special PN4.0 Mpa, higher pressure;
6, fan surrounded degree: normal range "extended range 1:15;
7, the pressure loss coefficient: Cd 2.6 or less;
8, system measuring accuracy: liquid, gas, plus or minus 1% of the value;
Steam steamed value plus or minus 1.5%;
Insert the value plus or minus 2.5%;
9, the power supply voltage: sensor + 12 VDC and + 24 VDC (optional) transmitter + 24 VDC;
Site type display instrument with 3.6 V lithium batteries;
10, output signal, sensor pulse frequency signal 0.1 ~ 3000 hz low level 1 v high level 6 v or more or less;
. Transducer two wire system 4 ~ 20 ma DC current signal;
11, allows vibration acceleration: piezoelectric capacitive acuities were 1.0 g 0.2 g or less;
: 12, the environment temperature sensors: - 30 ℃ ~ 65 ℃ transmitter, scene shows: - 10 ℃ to 50 ℃.
13, environment humidity: 5 ~ 85% relative humidity;
14 and the atmospheric pressure: 86 ~ 106 kpa;
15, signal remote transmission distance: 500 m or less.
16, signal interface: internal thread M20 x 1.5;
17, explosion-proof grade: (ia) Ⅱ CT2 - T5;
18, protection grade: regular IP65 diving IP68;
19, instrument material: instrument shell adopts aluminium alloy, the table body part adopts 304 stainless steel material, also can according to user requirements the use of special materials.
Six, field requirements:
1, low maintenance - most of the vortex flowmeter are on the market with induction swirl hole or plug-in measurement, once the impurities embedded in the medium pressure hole or sensing element and the table body, the gap between the signal is weak or unstable.A good design should be not easy to plug part, thereby reducing amount of maintenance.
2, inductive components online replacement - some manufacturer of inductive components and vortex street close 2 for one, seemingly simple design to the actual use of inconvenience.Because once induction part failure, you need to medium to the pipe emptying replacement parts, after pressure relief effect production.Perfect design should be separated the two, so can replace the induction part alone, without emptying the media.
3, vortex flowmeter is vulnerable to vibration interference, well-designed vortex flowmeter can through hardware and digital signal processing to exclude interference, and the stability of the signal is obtained.
4, vortex flow meter before and after the installation of a hassle to very long straight section, some manufacturers can offer within the flowmeter reducing design, greatly reduces the user specifically MenWei vortex flowmeter with the demａnd of the straight pipe.
Need to pay attention to during the period of seven, debugging, using question:
1, flowmeter, on-site installation, maintenance, must abide by the "explosion-proof gas do not open" warnings, and in the open before turn off the power supply.
2, vortex flow meter used in outdoor, suggestion and side shields.
3, shall not be arbitrarily fixed part loosen the flowmeter.The protection of the pressure sensor.Users in the use of traffic time, should pay attention to the flow pressure overload value of pressure sensor is rated working pressure of 1.5 times (that is, the media zui high pressure of 1.5 times).Selection should be within the prescribed flow range, prevent overspeed operation, in order to obtain the ideal accuracy and ensure the normal service life.(due to pressure test, purging pipes or exhaust overdrive, and turbine operation in the reverse flow meter can cause damage)
4 when put into operation, the vortex street flowmeter, should slowly open valve, prevent damage of instantaneous flow and the turbine.Add lubricant should be according to the sign, the number of refueling depends on temperament clean degree, usually 2 ~ 3 times a year.
5, vortex street flowmeter runtime or alternate internal related parameters are not allowed to open the rear cover, otherwise will affect the normal operation of the meter.
Eight, install and use the items that should be paid attention to:
Vortex street no mechanical moving parts, small size, corrosion resistance, stable performance, can be directly display medium work pressure, temperature, flow rate and volume under standard state, wide range, the advantages of small measurement error, has been widely used in oil and gas well production measurement and gas sales.In field application over the years, we believe that the meter is suitable for relatively clean dry gas metering, gradually become small and medium-sized gas meters.To guarantee the accuracy of the flowmeter measurement, reduce the measuring error, please note:
1, the selection of reasonable
Don't make the actual zui small flow meter QVmin below the selected through runoff flow range limit.
2, installation is correct
Upstream of the vortex flowmeter should have at least 10 d measuring straight pipe length.Straight pipe inner surface should be smooth, cannot have the steps, more smooth connecting flange weld, flange gasket can't into the pipe.Don't put the wrong installation direction of the flow meter.Tests showed that: all the unreasonable installation, will lead to the flowmeter measurement value is low.
3, away from the source of shocks, or install piers in upstream or downstream flow meter, in order to avoid the influence of the pipeline vibration.Avoid strong magnetic field disturbance to the flow meter chip.
4, temperament is relatively clean
Especially not a gas liquid two phase flow;Temperament is dirty, should clean instant flow meter.
5, and reduce the influence of flow pulsation
It can be installed in front of the flow meter buffer tank, or extended length of straight pipe upstream of the flow meter, computation.
6, timely flowmeter for metrological verification, to ensure accurate and reliable value.
Nine, selection of key points:
Correct selection to ensure that the use of vortex flowmeter is better.Should choose what kind of vortex street flowmeter is based on the current body to determine the physical properties and chemical properties of the medium?Make the size of vortex flowmeter, flow range, lining materials, electrode materials and output current, etc?To be the nature of the flow volume and flow measurement requirements.
1, precision function
Precision grade and function in accordance with the requirements of measurement and choose the instrument using fine grade, cost-effective.Such as for trade settlement, product transfer and energy measurement occasions, should choose high precision grade, such as 1.0, 0.5, or higher level;Used in process control, according to the requirements of control choose not with precision grade;Some just check process flow, without having to do precise control and measurement, can choose lower precision grade, such as 1.5, 2.5, 4.0, and even then you can choose cheap plug-in vortex flowmeter.
2, medium can be measured
Medium velocity and diameter, full scale measurement generally medium, the full flow of vortex flowmeter can measure medium velocity in 0.5-12 m/s within the scope of selection, range is wide.Choose different instrument specifications (diameter) and process piping, the same shall consider whether measuring flow range within the scope of the flow velocity, namely when the pipeline flow rate is low, can not meet the requirement of the flow meter, or under the velocity measurement accuracy of the quasi cannot guarantee, the need to reduce the size instrument, which carry high tube flow velocity, measurement results are satisfied.
3, the selection of vortex flow transmitter
In saturated vapor measurement using VA type piezoelectric vortex flow transmitter, due to the vortex flow meter range wide, therefore, in practice, the measurement of saturated steam flow main consideration shall not be less than the lower limit of vortex flowmeters, that is to say, must satisfy the fluid flow rate shall be not less than 5 m/s.According to the size of the YongQiLiang chooses different caliber of vortex flow transmitter, rather than with the existing technology to choose transmitter diameter pipe size.
The choice of 4 pressure transmitter, pressure compensation
Because of the saturated steam pipe length, pressure fluctuation is bigger, pressure compensation must be used, considering the pressure, temperature and density, the relation between measurement using pressure compensation, because the pipeline saturated steam pressure in the range 0.3 0.7 MPa, pressure transmitter ranges 1 MPa.
5, display instrument selection
Display instrument intelligent flow display, a voltage compensation, the instantaneous flow and cumulative flow integrating function.

Ten, installation requirements:
1, the sensor can be installed indoors, can also be installed in the outdoor.Environmental conditions to conform to the requirements.
2, sensors should be installed in a horizontal, vertical or inclined (fluid flow from bottom to top) and its corresponding pipe nominal diameter.
3, sensors installed on a mechanical vibration of pipeline should be avoided.Should be considered when the vibration is inevitable, at about 2 dn from sensor before and after the straight pipe and fixing racks.
4, avoid install the sensor sensing has strong electromagnetic interference, thermal radiation, corrosive gas, the space is little, and maintenance is not convenient.
5, when measured medium contains many impurities, at the request of straight pipe upstream from sensors mounted outside the length of the filter.
6, either upstream or downstream of the sensor should be configured with a certain length of straight pipe, straight pipe inner surface should be clean, smooth, no obvious convex concave, fouling and peeling phenomenon.Its length should conform to the requirements of figure 2.Installation of the liquid sensor, near the pipe should be filled with liquid to be tested.
7, straight pipe diameter as far as possible consistent with the sensor size, if not consistent, slightly larger diameter than the sensor size should be adopted, the error to 3% or less is not more than 5 mm.
Eleven, matters needing attention:
1, special flange and straight pipe welding can't with the sensor.
2, when installation should make the flow of sensor mark the direction of flow and the pipe.
3, before the installation of sensor and the flange must be put away in sealing ring grooves.The location of the pressure and temperature measurement point, pressure downstream of the sensor in 3 ~ 5 dn, temperature measuring points in the downstream of 5 ~ 8 dn.
4, when measuring high temperature medium, do not use heat insulation material to wrap around the sensor link rod.
Five, connection of shielded cable, should as far as possible away from the interference of strong electromagnetic field.Absolutely not allowed with high voltage cable laying, shielded cable to shorten as far as possible, and shall not be volume, in order to reduce stray inductance, length should not exceed 200 m.
6, before installation of sensors, pipeline cleaning must be conducted.Flow after rinse tube impurities, avoid clogging sensor.Measuring liquid pipe must be full of measured liquid, prevent the interference of bubbles.
7, measuring gas pipelines to prevent the interference of reservoir fluid.Installation position as shown in figure 5.Replace the probe body under the high temperature and high pressure, it must be safe operation, high temperature protection.After cooling step-down replaceable probe at the bottom of the safety conditions.

Twelve, flowmeter selection guidelines:

Determine the structure of the sensor

1, connection mode: flange card mounted body without flange (table) or flange connection type (table body itself with flange).General advice to choose flange mounted, because of its compact structure, low price, and short delivery cycle.

2, the structure type: one-piece structure and split type structure.Generally USES the one-piece structure, only on special occasions, adopts the split type structure (such as: medium at high temperature, environmental temperature or humidity is high, with the scene display for easy reading).

3, display mode: no scene shows, with the scene display and carry only the scene.Scene shows refers to on the header is equipped with LCD display, can display the cumulative flow and transient flow parameters, such as.

4, the signal output way: the pulse signal output and 4 ~ 20 ma current standard signal output.The pulse signal output normally recommended, because directly and vortex shedding frequency corresponding to the pulse signal, without conversion, has a zui high accuracy;At the same time, in the usual transmission distance, pulse signal transmission effect is better.Standard and is commonly used in current signal output terminal or control system of the flow measurement system.

5, explosion-proof forms: the explosion proof type and safety explosion-proof type.If the medium to be measured is flammable and explosive substances or measuring environment is flammable and explosive substances, should choose explosion-proof type.

Determine the configuration of the vortex flowmeter:

1, the density compensation:

When measuring the mass flow rate of steam, due to its density changes with the change of temperature and pressure, so to compensate for steam, at any time with a platinum thermal resistance and pressure transmitter with vortex sensor with mass flow measurement system.There is a measurement of saturated steam and superheated steam, to be stable if the temperature and pressure to reduce the equipment cost, can also according to the working state, by setting a fixed value density compensation.Other media can according to the actual situation of mass flow measurement system.

2, of intelligent flow totalizer.especially options:

Requires only display parameters, can choose digital display or LCD display; intelligent flow totalizer.especiallyNeed to trace the historical data, with memory function, should choose intelligent flow settlement paperless recorder;Measure the full and steam, should choose with automatic temperature compensation density or pressure; automatic compensation of density flow totalizer.especiallyMeasurement of superheated steam, should choose along with temperature and pressure compensation density flow integrating instrument;Using the remote communication, should consider intelligent flow totalizer.especially with RS485 and RS232 communication interface.Requirements and control system of the flow measurement system, intelligent flow integrating instrument should take 4 ~ 20 ma standard current signal output interface;

When needed, should configure a backup power supply, so that all of a sudden power failure meter can be measured normal.When needed, should with meter box, place the intelligent flow integrating instrument, instrument box, with a lock made of intelligent flow totalizer.especially set parameters cannot be adjusted freely, with anti-theft function, at the same time, the instrument is equipped with protection circuit in the oven, play a role of protection of intelligent flow totalizer.especially.

3, remote monitoring: in need multi-point measurement, distribution area is larger, the need for real-time monitoring, can use the GSM/GPRS communication network or wireless private network remote traffic monitoring system, realize real-time monitoring and management of the pipeline flow.

4, the determination of the calibre of the sensor, the sensor diameter is different, its measuring range is different, and each kind of caliber its measuring range as the measured medium type and condition of the change of temperature, pressure change, first determine the medium under the working condition.

Thirteen, standard of flow range profile: unit (m3 / h)

14, selection of coding:

15,Order to choose selection guidelines:

Name and model number of 1, 1), (2) the diameter, flow range, (3) whether or not to bring the attached so that we can correct selection for you, (4) using pressure, (5) the use of medium temperature.

2, if has been selected by design units in the way of vortex street flowmeter types, please press type vortex flowmeter directly order from our sales department.

3, when using occasions is very important, or the environment is complex, please try to provide the design drawings and detailed parameters, by wei experts in our audit checks for you.

After-sales service commitment:

1, from the date of signing of the contract, I in the way provided for products of the company offers free maintenance and maintenance service, commitment to lifelong maintenance service;

2, jiangsu wei measurement and control instrument co., LTD. Sales manager will be in regular contact with customers, understａnd the usage of products, and solve the problems of the customers to use in the process of produce, free of charge to provide technical support;

3 the man-made damage is found, the warranty period, our company is responsible for the maintenance, and the resulting maintenance fee;

4, product quality problems or are not satisfied with product, the user can choose unconditional return, wei tt&c don't charge any fees, appear quality problem, bear the freight back and forth.