Description

LYNSB Series Ultrasonic Gas Flow Meter
 

1.1Introduction
LYNSB- Ultrasonic Gas Flow Meter (hereafter call Ultrasonic Meter) is the key and newly designed product with cutting-edge technology. It can be used in process measuring and custody transfer metering in fields such as gas production of oilfields,energy, and environmental protection. Compared with traditional flowmeters,
Ultrasonic Meter with remarkable performance like low pressure, low velocity, no pressure loss, high accuracy, is becoming the most advanced and quickly developed new flowmeter.

1.2 WorkingTheory
Ultrasonic wave is sonic wave with frequency larger than 20000Hz featured with better directionality, penetration and energy concentration, which makes Ultrasonic Meter the new advance flowmeter.
Ultrasonic Meter uses theory of acoustic transit time, as in Fig 1-1:
                                                          


Transducer A (Upstream) sends ultrasonic wave that transits in the pipe and will make total reflection when it touch the smooth and high hardness pipe bottom, and then it goes to B(Downstream) transducer that will receive this wave, which make one sonic path. After B receives the wave, it will send another ultrasonic wave that to be received by A. As the medium is actually carrier of sonic wave, when it flows, the transit time will be different with different flow velocity, which will result in flow velocity and flowrate after calculation of mathematical model.
Flow velocity:


Sound velocity:


Flowrate:


Where:
  V: Gas flow velocity (m/s)
  C: Sound velocity (m/s)
  F: Volume of flowing medium (m3/h)
  D: Diameter of pipe (m)
  : Angle of path to the flow (o)
  : Transit time from transducer A to B (s)
  : Transit time from transducer B to A (s)
  : Sound delay time by circuit, cable and transducer from A to B/ Sound delay time by circuit, cable and transducer from B to A (s)
 

• Features 

Compared with traditional flowmeter, Ultrasonic Meter has outstanding features:
1)  Good performance for measuring low frequency pulsating flow and stable flow;
2)  Can be used for tough medium like gas with little vapor or coal tar;
3)  High accuracy up to 0.5%, and repeatability less than 0.1%;

1. Wide turndown ratio, up to 1:50;
2. Bi-direction measurement, suitable for small working pressure and low flow velocity;
3. Multi-path measurement can reduce the influence of turbulent flow, and the meter can also work normally when one path broken down;
4. No movable parts inside, near no pressure drop, little maintenance;
5. Self-diagnose function will help to judge, correct and alarm for failures, thus reduce measurement loss;
6. It can output flowrate in standard condition after temperature and pressure compensation.  
   < >Ultrasonic MeterIn long transportation line of natural gas;
7. In city gas;
8. For well head gas in oilfield;
9. Boiler gas;
10. In large gasification process;
11. Industrial waste gas and torch gas.

2. Product Performance

2.1 Performance 

As in Table 2-1.
Table2-1 Product Performance

Accuracy	±0.5%, ±1.0%, ±1.5%
Diameter	DN25mm~DN300mm
Turndown Ratio	>1:30
Medium	Gas, liquid
Output Signal	Pulse, 4~20mA
Communication Protocol	MODBUS Protocol
Ex-proof	Common type, Ex-proof type
Protection	IP65
Ex-proof Grade	Exdib II BT4(GYB101058)
Working Temp.	-40ºC ~+85ºC
Max. Overload Flowrate	120%
Power Supply	DC 24V (600mA), DC12V(1A)
Nominal Pressure	1.6MPa ,2.5MPa,4.0MPa,6.3MPa, 10.0MPa,16MPa,25MPa, 42MPa

 
 

2.2 Flow Range

Table2-2 Flow Range in Working Condition

Accuracy	0.5%	1.0%	1.5%
Repeatability	0.1	0.2	0.3
Velocity (m/s)	(1.25~25m/s)	(1.0~25m/s)	(0.8~25 m/s)
Size (mm)	Flowrange (m3/h)
25	2.2~45	1.8~45	1.4~45
40	5.5~115	4.5~115	3.6~115
50	9~180	7~180	5.5~180
80	23~450	18~450	14~450
100	35~700	28~700	23~700
150	80~1600	64~1600	50~1600
200	140~2830	115~2830	90~2830
250	220~4420	180~4420	140~4420
300	320~6360	250~6360	200~6360

Notes:
1) The above flowerage is in working condition, while flowrange standard condition (0.1MPa, 20ºC)shall be convert to flowrange in working condition for model selection.
2) Unit for pressure is MPa, and unit for temperature is ºC;
3) For Ultrasonic Meter ≥4.0MPa, the flowmeter must work with pressure ≥0.5MPa

2.3 Accuracy 

Table 2-3 Accuracy

Accuracy		0.5	1.0	1.5
Max. Error	Qt≤Q<Qmax	±0.5%	±1.0%	±1.5%
	Qmin≤Q<Qt	±1.0%	±2.0%	±3.0%
Repeatability		Less than 1/5*Max. error
Turndown ratio		1:20	1:25	1:30

Note: Q_t is the transition flowrate at 3m/s.

2.4 Temperature and Pressure Measurement 

Table 2-4 Accuracy of Pressure and Temperature measurement

Item	Range	Accuracy
Temperature	-40 ~+85ºC	±0.5ºC
Pressure	0 ~10.0MPa	0.25 %FS

2.5 Current Output 4~20mA

The current output is passive and the flowrate in standard condition relative to 20mA can be revised.
Table 2-5 Parameters for 4~20mA passive output

Range	(4~20)mA
Basic Error	0.2% FS
Temperature influence	±0.01% / ºC
The sample resistance shall be 250~600 Ω

2.6 Positive Frequency Output

Positive frequency output shows gas flowrate in standard condition and its pulse equivalent can be revised.
Table 2-6 Parameters for frequency output

Frequency Range	(0~2)kHz
Basic Error	±0.0005%
Temperature influence	±0.0001% / ºC

2.7 RS485 Output

RS485 of Ultrasonic Meter use Modbus protocol and RTU mode. Please refer to item 5.5 of user manual, or contact local agency.

2.8 Working Condition 

Table 2-7 Ambient condition

Ambient temperature	-25ºC~+55ºC
Relative Humidity	≤ 80% (25ºC)
magnetic field intensity	<400A/m
Mechanical vibration	f<30Hz, amplitude<0.1m
Magnetic interference	Avoid such interference
Sonic noise	Avoid such noise

2.9 Power Consumption

Normal power consumption is 5W, max. 7W.

2.10 Weight 

Table 2-8 Weight for Ultrasonic Meter

Size	mm	25	40	50	80	100	150	200	250	300
Weight	Kg	17	21	24	30	35	49	70	92	117

Note: the above weight is for Ultrasonic Meter with PN=1.6mpa






Why Yinuo
(1) For electronic products, we have automatic chip mounter (SMT) production line and high/low temp. testing equipment.
(2) For mechanical products, we have advantage on casting, machining, and welding.
(3) For calibration, we have calibration facilities approved by China government for oil, water and gas.
(4) For flowmeter, we are Top leaders in China for both of Coriolis Mass Flowmeter & PD flowmeter, which be approved the UL, CE, CCS (China) and BV certificate (France) for marine market.
(5) For pump, we have large capacity transportation of oil, chemical, water, and wastewater even if contain some participles and we also design and produce twin-screw pump for high pressure, high viscosity liquid with multiphase.
(6) For SCADA loading & metering/ Skid Mount System, we also have much experience in China and in Afghanistan, Angola, Equatorial Guinea, Myanmar and are trying to promote in all over the world.