一、Product Summary
Dear users, thank you for using our company's precession vortex gas flowmeter. Please read this instruction manual carefully before using it, so that you can easily use our products.
Precession vortex flowmeter is a new type of gas flow meter which adopts advanced micro-processing technology, has the advantages of strong function, wide flow range, simple operation and maintenance, convenient installation and use, etc. Its main technical indexes reach the advanced level of similar products abroad.
二、Working Principle
The flow profile of the flow sensor in the precession vortex flowmeter is similar to the profile of a Venturi tube, and a group of spiral guide vanes are placed on the inlet side. When the fluid enters the flow sensor, the guide vane forces the fluid to generate severe vortex flow; When the fluid enters the diffusion section, the vortex flow is affected by backflow and starts to rotate twice, forming a gyro-type vortex precession phenomenon. The precession frequency is proportional to the flow rate, and is not affected by the physical properties and density of the fluid. The precession frequency of the second rotation of the fluid measured by the detection element can obtain good linearity in a wide flow range. The signal is amplified, filtered and shaped by a preamplifier and converted into a pulse signal proportional to the flow rate, and then sent to a microprocessor together with detection signals such as temperature and pressure for integration processing, and the measurement results (instantaneous flow rate, accumulated flow rate, temperature and pressure data) are displayed on a liquid crystal display screen. The flowmeter is composed of temperature and pressure detection analog channel, flow sensor channel and microprocessor unit, and is equipped with external output signal interface to output various signals.
三、Function List
|
Serial Number |
Functions |
Comments |
|
1 |
Metering function |
1. Ultrasonic measurement |
|
2 |
Gas metering data history memory local |
1. For the latest 90 days, the measurement data is stored every hour 2. The latest 180 days, the measurement data is stored every day 3. Monthly storage of measurement data in the latest year |
|
3 |
Power supply |
The main battery is the normal power supply, and the other battery is the backup battery |
|
4 |
Main battery capacity level indication |
1. report that current battery capacity level suffix to the server in each metering data message uplink report 2. Low battery threshold: 20% and will trigger the uplink report of low battery capacity alarm message, which will be reported every 24 hours until the standby battery switch threshold. 3. Battery switch threshold: 10% capacity will trigger the backup battery switch. |
|
5 |
Backup the battery switch only in the following cases, otherwise use the main battery |
1. Pull out the main battery or the main battery does not exist 2. The power of the main battery meets the switching threshold (10%) 3. The backup battery switch is automatic, so it will never be powered off. |
|
6 |
Backup Battery Function |
1. Maintain local metering of water flow 2. measurement data history storage and maintenance proces 3. Spare battery life should exceed at least 7 days 4. When the power supply is switched to the backup battery, the backup battery switch alarm information will go up to the server to tell the switch that it has occurred. |
|
7 |
Backup battery protection during transportation |
Prior to field activation, the gas meter is only equipped with a spare battery, which is protected against consumption during storage or transportation at this stage |
|
8 |
Wireless/wired technology |
Lorawan/NBIOT/GPRS/RS485 |
|
9 |
Fixed time measurement data report |
1. Latest cumulative measurement data 2. Gas meter status: valve status/power supply 3. Battery capacity level 4. Downlink Signal Strength Indication RSSI/SNR |
|
10 |
Alarm Message Uplink Report |
1. Battery Capacity Low Level Alarm 2. Backup battery switch alarm 3. Valve fault alarm 4. Vibration alarm (the meter has a buzzer, which can realize sound alarm when vibrating and is generally used for earthquake protection) 5. High temperature alarm (alarm is not realized at present, only temperature is monitored, which is generally used for fire protection) |
|
11 |
Downlink Configuration/Query |
1. Set/Query Periodicity of Periodic Measurement Data Report 2. On/Off/Setting/Query/Time of Fixed Time Measurement Data Report 3. Modify accumulated traffic data for calibration 4. Read the current accumulated traffic data 5. Read the battery capacity level 6. Valve Control Close/Open |
|
12 |
Screen digital display |
1. The screen displays four screens, and the screen can be cut 2. Display contents: current reading, electric quantity, balance, valve status, signal status, temperature, time and vibration reminder 3. Display mode: The button lights up and automatically closes after 5 seconds without operation, and the screen can be cut |
|
13 |
433 air leakage detection linkage valve closing |
1. Monitor methane in real time, and give an alarm if the concentration exceeds 5% LEL 2. Receive sensor data through 433 communication, and perform valve closing operation Communication distance 50m (recommended to be installed near gas meter) |
四、Performance characteristics
1, no mechanical movable parts, corrosion resistance, stability and reliability, long service life, long-term operation without special maintenance;
2; Mechatronics is realized, and manual duty is not required in the daily metering process;
3; The process installation conditions are not harsh, and the straight pipe sections upstream and downstream of the instrument can be greatly shortened compared with orifice plate and vortex flowmeter;
4. The measurement accuracy of the system can meet the current trade measurement requirements (≤ 1. 5%);
5; The flow measurement range is wide, and it can effectively work in some small flow areas that the orifice plate and vortex flowmeter cannot set foot in;
6; Small volume, light weight and convenient offline calibration;
7; The measurement signal can be displayed locally or transmitted remotely as required;
8; Instrument management personnel do not need professional training, and measurement parameters such as flow rate, pressure and temperature can be directly read from the meter head without conversion;
9. Only the parameters of the battery (micropower consumption) and the measured medium need to be replaced regularly.
10. Large pressure loss;
When the circulating medium is gas, the pressure loss is about 3 ~ 4 times that of vortex flowmeter.
五、Technical Parameters
|
Technical parameter name |
Parameters |
|
Ambient Temperature |
-20 ~ + 65 ℃ |
|
Humidity |
5% to 90% |
|
Communication |
RS485 |
|
Atmospheric pressure |
86KPa ~ 106KPa |
|
Wide range ratio |
25: 1 |
六、Product structure and size
| Product specifications | DN50/DN100/DN150/DN200 |
| ambient temperature | –20～+65℃ |
| humidity | 5%～90% |
| atmospheric pressure | 86 ～106 kPa |
| Communication mode | RS485 |
| Wide range ratio | 25:1 |
