Measures Wobbe Index,
Combustion Air Requirement
(CARI) and
Calorific Value of Natural Gas
and Fuel Gases
- Fast response (T90 < 5 sec)
- High accuracy and repeatability
- Automatic calibration
- Insensitive to ambient temperature
fluctuations
- Suitable for outdoor installation
- Effective measuring range 0-100% FS
- Output in MJ/Nm3, MJ/Sm3 and
BTU/SCF
- MODBUS RTU (RS485), Ethernet Link and analogue outputs
- Minimal maintenance
- Suitable for corrosive and dirty applications- Flameless analyser
- Residual oxygen content principle- Epoxy coated stainless steel enclosure
- Rugged design
- Optional specific gravity output
- Suitable for installation in EX environment
- Zero emission option
Introduction
The WIM COMPAStm series is the latest addition to the Hobré Instruments portfolio of process analysers for Wobbe Index, Heating Value/BTU and Combustion Air Requirement Index. Designed and manufactured in out factory in The Netherlands the WIM COMPAStm builds on more than 20 years of success of the WIROX, WIM 9600 and WIM 9900 series. Offering enmatched reliability, speed of response, accuracy and supported by profound application knowledge the WIM COMPAStm is the best choice for measuring gas combustion parameters.
Principle of operation
Sample gas is contiuously mixed with combustion air under controlled conditions followed by catalytic combustion in an elctrically heated furnace. The residual oxygen content in the flue gas is measured with an accurate and reliable zirconium oxide sensor. In the control unit following combustion parameters are calculated from the oxygen signal and the (optional) density signal: Wobbe Index, Combustion Air Requirement Index (CARI), Calorific Value (or BTU) and specific gravity.
Typical applications
Natural gas blending and storage. The speed of response and the high accuracy and repeatability of the WIM COMPAStm are providing many customers with a perfect signal for the feed forward control of gas blending operations as well as monitoring the quality of gas delivered to the grid including LNG regasification.
Fired heaters. Besides speed of response the availability of the CARI signal is a key benefit of the WIM series. Whereas the Wobbe Index is an excellent indication for the thermal load of a furnace, for air/fuel ratio control the CARI is a much better parameter. This is particularly the case when hydrogen, carbon monoxide and olefins are present in the fuel gas.
Gas turbine control. Gas turbines are sensitive to rapid changes in gas composition; besides poor fuel economy and a reduced lifetime improper control also results in higher CO and NOx emissions. The WIM provides the Wobbe Index, Heating Value and Specific Gravity in seconds. Optionally also CO2, n2 and Heat Ratio are available.
Steel industry and biogas. Dirty and wet gases are common in steel and biogas monitoring applications. The WIM COMPAStm sample handling system is kept at elevated temperature to prevent condensation and the hot section is resistant to significant sulfur levels.
Flare gas and sour gas monitoring. A special version of the WIM measures flare gas in accordance with USA Rule 1118 and is capable of dealing with bery high sulfer levels. The method closely follows ASTM-4891 and complies with expected new EPA Flare Emissions 40 CFR regulations.
WIM COMPAStm available in BASIC and F version. Please consult factory for other applications and options including outputs for hydrogen and total sulfer in fuel gas, CO2 emission from fuel gas and the integrated gas chromatograph option.
