Combustion management
In situ O2 measurement is crucial in combustion management for industrial furnaces.
A controlled stoichiometric oxygen excess is necessary to insure staff and equipement’s safety, respect of production demands and efficiency by applying a setpoint.
Optimum combustion unit management is achieved by installing the sensor within the flue, and by performing a continuous in situ measurement with low response time. The technology of choice is Zirconia analyser, it can stand severe fumes conditions- temperature, corrosion, moisture, particle, …-. These analysers can be easily calibrated on site, the measured value can be checked, the sensor can go over 5 years lifetime and hardly any maintenance is necessary.
What’s defining O2/COe Zirconium measure ?
Optimisation
SETPOINT : O2 MEASURE
Production & Safety Veracity
Confidence – Relevance
Combustion regulation is done by applying a setpoint. The setpoint is generally expressed in O2% excess in fumes. This measurement is key and must comply with several required features:
- Short response time
- Relevant in situ oxygen measurement
- Easy & straightforward maintenance
- Long lifetime
- Analyzer calibration
- Veracity & confidence of the measurement:
→ Gas checking – at the analyser’s level – checking of the analyser value
→ Displayed value at transmitter’s level –checking of remote communication value
Control of setpoint relevance: O2+COe measurement
Management & Regulation
Combustion optimisation is done by controlling and correcting – if necessary – the setpoint.
The optimized efficiency of the combustion can be checked with the ratio between oxygen excess and unburnt gases in fumes.
Setpoint regulation can be defined by looking for the right balance, e.g. 1% of O2 for 100 to 200ppm of reducing gases (CO & H2).
ZIRCONIUM TECHNOLOGY
O2 measurement with Zirconium in combustion gases
Oxygen is measured between two Pt/Pt platinum electrodes.
There is an instantaneous oxidation of all reducing gases. The RedOx potential between the two electrodes can then be considered equal to the O2 partial pressure ratio between the measurement gas and the reference gas.
The connection between the P(O2) ratio and the measured voltage on electrodes complies with Nersnt law.
Reduction gases and fuel measurement with dual zirconium probe
The measurement is made between two different electrodes. The RedOx potential is a mixt potential P(Ox) + P(Red).
In comparison with the PO2, we can obtain a reductive potential measurement of the fumes expressed in COe ppm : equivalent CO. CO and H2 are the preeminent reducing gases in fuels.
