NYLD-G Gas Eletromagnetic Flowmeter
The NYLD-G gas turbine flowmeter is a new generation of high precision, high
reliability gas precision measuring meter integrating temperature,
pressure, flow sensor and intelligent flow totalizer developed by
the advanced technology of flow meter at home and abroad, optimized
by theories of gas mechanics, fluid mechanics and electromagnetics,
which has excellent low pressure and high pressure metering
performance.
It has a variety of signal output modes and low sensitivity to
fluid disturbances, and is widely used in the measurement of
natural gas, coal gas, liquefied gas, light hydrocarbon gas.
This type of turbine flowmeter is an explosion-proof product with
an explosion-proof rating: ExdIICT6
NYLD-G Gas Eletromagnetic Flowmeter Technical Parameters
Basic Parameters
| Metercaliber(mm) andconnection mode | DN50, DN80,DN100,DN150,DN200,DN250, DN300mm caliber with flange
connection DN25,DN40, DN65,DN125mm can be customized |
| Accuracy grade | ±1.5%R,±1.%R |
| Range ratio | 1:10,1:20 |
| Meter materia | Body:cast aluminum or 304 stainless steel; impeller:high quality
aluminum alloy; display: cast aluminum |
| Measured medium temperature | -30 ° C ~ +80 ° C, |
| Ambient condition | Temperature: -20 ° C ~ +60 ° C, relative humidity 5%~90%.
atmospheric pressure |
| Power supply | External power supply:24VDC Internal power supply:3.6Vlithium battery |
Output signal | Pulse frequency signal output: low level is below 0.8V,high level is 8V Two-wire, three-wire 4-20mA current output |
Transmission distance | ≤1000m |
Signal wire interface | Internal thread M20×1.5 |
| Protection grade | IP65 |
Explosion-proof grade | Exd II CT6 |
Technical parameters
| Model specification Range | Nominal diameter DN | Flow range m3/h | Nominal pressure Mpa | Accuracy | Pressure loss kPa at Qmax |
| NYLD-G-25 A | 25 | 2.5 ~25 |
1.6 2.5 4.0 |
1. 5grade (Qmin ~qtx ±3% qtx~Qmax ±1.5%) 1.0grade (Qmin ~qtx ±2% qtx~Qmax ±1.0%) | 0.5 0.8 |
| NYLD-G-40 A | 40 | 5 ~ 50 |
NYLD-G-50 A B | 50 | 6~65 10~100 |
| NYLD-G-65 A | 65 | 15~200 | 0.8 1.2 2.2 |
NYLD-G -80 A B | 80 | 13~250 20~400 |
NYLD-G -100 A B NYLD-G -125 A | 100
125 | 20 ~400 32~650 25~700 | 0.3 0.7 1.9 |
NYLD-G -150 A B C | 150 | 32 ~650 50~1000 80~1600 |
1.6 2.5 | 0.6 1.0 1.7 |
NYLD-G -200 A B C | 200 | 50 ~ 1000 80~1600 130~2500 | 0.3 0.6 1.5 |
NYLD-G -250 A B C | 250 | 80 ~ 1600 130~2500 200~4000 | 0.4 0.6 2.0 |
NYLD-G -300 A B C | 300 | 130 ~2500 200~4000 320~6500 | 0.4 1.0 2.4 |
Note: the pressure loss at the maximum flow rate (Q) is the value
measured with dry air (density is about 1.2 kg/m) under normal
pressure, qt = 0.2Qmax.
NYLD-G Gas Eletromagnetic Flowmeter Operating Principle
When the fluid passes through the flowmeter, it is rectified and
accelerated by the action of the guide vane (or rectifier). Since
the impeller is at an angle to the fluid flow direction, at this
time,the turbine generates a rotational moment. After overcoming
the friction torque and the fluid resistance torque, the turbine
starts to rotate. In a certain flow range, the angular velocity of
the turbine rotation is proportional to the volume flow rate of the
fluid. According to the principle of electromagnetic induction, a
magnetic sensitive sensor is used to induce a pulse signal
proportional to the volume flow of the fluid from the synchronously
rotating communicating plate. This signal is sent to the volume
corrector and is processed together with signals such as
temperature and pressure, and displayed on the LCD screen. Its
structure principle is shown in Figure 1..
4.2Volume Corrector Working Principle
The volume corrector consists of temperature, pressure detection
analog channel, flow detection digital channel, micro processing
unit, liquid crystal drive circuit and other auxiliary circuits,
and it is equipped with an external signal interface.After
converting and processing the multi-channel signals sent from each
sensor, the signals is brought into the formula for operation
according to the gas equation to realize the local display and
remote transmission of various signals.
The gas equation can be written as
Where:
Vo — the volume unde3r the standard condition (m3);
V — the volume under the3 working condition (m3);
P=Pa+Pg — the absolute pressure (kPa) at the flowmeter pressure
detection point;
Pa — local atmospheric pressure (kPa);
Pg—the meter pressure (kPa) of the flowmeter pressure detection
point;
P0 — the standard atmospheric pressure (101.325kPa)
T0 — the absolute temperature under the standard condition
(293.15K, which can be 273.15K according to user requirements);
T — the absolute temperature of the measured medium (27315+t)K;
t — the temperature of the measured medium (°C);
Fz—Gas compression coefficient
Zn — the gas compression coefficient under standard sate
Zg — the gas compression coefficient under working condition;
NYLD-G Gas Eletromagnetic Flowmeter Design Features
■ High precision, good repeatability and wide range ratio,up to
1:20 (or wider);
■ Use integrated type new rectifier, the requirements for the front
and rear straight pipe sections are lower (front ≧5DN, rear ≧3DN);
■ Use a carefully designed dust-proof structure to ensure the
reliability of long-term bearing operation;
■ Designed with a unique fueling system to ensure reliable fueling,
easy maintenance and beautiful appearance;
■ Thetechnical indicators meet the requirements of I509951-1993,the
length of the body is 3DN, and the whole machine has reachedthe
international advanced level;
■ Thevolume corrector of the flowmeter can be rotated freely by
about 350 degrees, which can be easily read in various installation
modes.
■ Low speed, high life, low pressure loss, high precision;
■ It integrates high-precision temperature, pressure, flow sensor
and volume corrector, which can detect the temperature, pressure
and flow of the measured gas, and automatically track and
compensate the flow and correct the compression coefficient. The
meter has real-time database and communicatesvia RS485 interface
and meter reading network to facilitate centralized data collection
and real-time management;
■ Use high-performance microprocessor and modern digital filtering
technology, with powerful software functions and superior
performance;
■ Use floating point calculation and automatic correction of
five-segment meter coefficient, and has fault; self-diagnosis and
alarm function;
■ Use micro-power high-tech, with internal and external power
supply, and low power consumption;
■ Local display flow value with multiple signal output functions;
■ Use a high-contrast three-line LCD display, it can display
standard cumulative flow, standard volume flow, working volume
flow, medium temperature, pressure value and battery capacity
percentage with Chinese prompt;
■ With real-time data storage function, it can prevent data loss
when battery is replaced or suddenly power down . In the power-off
condition, internal parameters can be permanently saved.
■ With explosion-proof function, the explosion-proof mark is
ExdIIC6.
