Measurement method:
The hot-wire (thermal) mass method of measurement is based on the dependence of the degree of cooling of a heated sensitive element, placed in the stream, due to flow rate. The heated sensitive element in gas flowmeters is a platinum resistance thermometer.
The instruments maintains in real time the constant difference of temperatures between the heated sensitive element of the hot-wire flowmeter and the thermal converter which measures gas temperature. The power needed for maintaining the constant temperature difference is proportional to the mass speed of the gas flow which passed through the metering section. The current value of gas flow rate is calculated according to the value of dissipated heat power of the hot-wire flowmeter, composition and thermophysical properties of gas, pressure parameters, as well as dimensions of the sensitive element of the primary transducer and pipeline cross-sectional area.
Flowmeter purpose:
The Turbo Flow TFG-S flowmeter is used for measurements of volumetric flow rate and mass flow rate of gas (natural, free (associated) petroleum, nitrogen, air, inert and other gases of known composition), reduced to the standard conditions.
Field of application:
Flowmeters are operated within automated systems for commercial metering of gas (natural, associated during oil product extraction, nitrogen, air, inert and other non-aggressive gases of known composition) at various industrial facilities and public utilities.
Specific features of flowmeter:
- Measuring pipeline diameter up to 1,400 mm;
- Up to 3 sensing devices can be mounted on the pipeline (increasing measurement accuracy);
- A multichannel configuration is possible;
- Explosion-proof housing of the primary transducer
Merits:
- High accuracy: relative measurement error not more than 1% throughout the range of operating flow rate;
- Very wide dynamic range 1:600. The instrument can be used for summer and winter gas consumption volumes, thus a single instrument is used instead of two;
- Option: measurement accuracy increase due to simultaneous collection of information from 3 primary transducers;
- The probe version creates no resistance to the flow;
- In case of failure it does not block gas supply to the consumer;
- Wide range of operating temperatures;
- Mounting without pressure release;
- Use both with natural and associated petroleum gas;
- High accuracy and repeatability of results for a wide range of household and process gases;
- Measurement of gases and gas mixtures in round and rectangular pipelines, other sections by special order;
- Quick setting by means of intuitive menu;
- Self-diagnostics and monitoring of malfunctions;
- The function of primary transducer self-cleaning is implemented;
- Universal protocol of exchange with automatic process control systems (MODBUS RTU).
Configuration options:
By primary transducer explosion protection:
- 1 Ex ib Gb [ia Ga] IIC T4 Gb;
- 1 Ex dib Gb [ia Ga] IIC T4 Gb.
By sensitive element design:
- No housing;
- In a housing.
Integrated/remote sensitive element for gas temperature measurement:
- Configuration 00 – for DN from 50 to 400 mm inclusive;
- Configuration 01 – for DN from 400 to 900 mm inclusive;
- Configuration 02 – for DN from 900 to 1,400 mm inclusive.
By number of primary transducers:
By configuration of primary transducers:
- With and without indicator;
- With keyboard (if indicator is available) and without keyboard.
By configuration of flow measurement cabinet:
- Full set;
- Only a power supply unit.
Technical specifications:
| Characteristic |
Value |
| Measurement range of volumetric gas flow rate under standard conditions, m3/h |
От 1,25 до 588000 |
| Pipeline diameter, mm |
от 50 до 1400 |
Limit of permissible relative error during measurement of volumetric gas flow rate, reduced to standard conditions, %
– using the manufacturer’s measuring section
– without using the manufacturer’s measuring section |
± 1.0 in the range 0.015 Qmax < Q < Qmax
± 2.0 in the range Qmin < Q < 0.015 Qmax
± 1.5 in the range 0.015 Qmax < Q < Qmax
± 2.5 in the range Qmin < Q < 0.015 Qmax |
| Gas temperature measurement range, °С |
От минус 60°С до плюс 300°С |
| Limits of permissible absolute error during temperature measurement, °С |
±(0,3+0,005|t|),
where t – measured temperature, °C |
| Limits of absolute error during time measurement, s |
± 1 for 24 h |
| Flow speed range, m/s |
from 0.03 to 350 |
| Upper limit of overpressure measurements, kPa |
up to 600
up to 32 |
| Working range of overpressure measurements, % of ULM |
from 33 to 100 |
| Upper limit of absolute pressure measurements, (ULM), MPa |
up to 32 |
| Working range of absolute pressure measurements, % of ULM |
От 33 до 100 |
| Dynamic range (Qmin/Qmax) |
1:600 |
| Sensitivity threshold |
0,3 Qmin |
| Limits of permissible relative error during pressure measurement, % |
±0,5 |
Performance specification:
| Characteristic |
Value |
PT* operating conditions:
– ambient air temperature, °C |
From minus 60 to plus 70 |
| Kind of PT* explosion protection |
Ex ib Gb [ia Ga] IIC T4 Gb
or 1 Ex dib Gb [ia Ga] IIC T4 Gb |
| Kind of FMC** explosion protection |
[Ex ib Gb] IIC |
| Protection degree of PT* as per GOST 14254-96 |
IP65 |
| Protection degree of FMC* as per GOST 14254-96 |
IP54 |
| Average mean time between failures, hours, at least |
60 000
|
* PT – primary transducer;
** FMC – flow measurement cabinet.
