Gas analyzer for monitoring oxygen and CO (chemical burnout)
This gas analyzer is currently in the final stages of development.
Field of use: automated control systems for the optimal operation of coal-fired, heavy fuel oil, or natural gas-fired boilers, including those with a high sulfur content, process furnaces for various purposes.
As you know, the combustion process is controlled by the oxygen content in the exhaust gases. Automated control systems for the combustion process, which are based on stationary gas analyzers, also establish the optimal fuel-air ratio in terms of the oxygen content in the exhaust gases. Theoretically, the best situation can be considered when the content of residual oxygen approaches zero, that is, when all the oxygen is burned and at the same time it is enough to complete the combustion process.
However, in practice, even in the presence of a certain excess of oxygen in the exhaust gases (0.3 - 0.8% vol.), a sharp increase in the concentration of CO can occur. This is due to deterioration of the boiler equipment, unauthorized entry of air into the combustion zone, wear of the burners and deterioration of the homogenization of the fuel-air mixture, changes in the composition and quality of fuel, air humidity, etc. Therefore, in boilers, in order to exclude the possibility of increasing chemical burns and the formation of CO during the control and regulation of the oxygen combustion process, the excess oxygen content in flue gases is maintained at the level of 1.0 - 2.0% vol. At the same time, additional energy is spent on heating excess air, in addition, the burning of certain fuels with a high sulfur content, for example, high-sulfur fuel oil, in conditions of excess oxygen leads to an acceleration of sulfate corrosion processes and premature failure of the equipment.
Thus, to ensure the optimal operating mode of the fuel burning plant, it is necessary to maintain the oxygen content at the minimum acceptable level, close to zero, and at the same time continuously monitor the CO content in the exhaust gases, in order to prevent its level increase.
The gas analyzer allows you to determine not only the oxygen content, but also the content of the complex of hydrocarbons and CO (chemical burnout), and accordingly, to regulate the combustion process, based on this measurement with calibration by CO. This method of regulation is highly sensitive to changes in combustion characteristics.
Technical characteristics (planned)
|Measurement range O2, % vol.
|0,1 ... 25
|Range of measurements of CO, % vol.
|0 ... 0,5
|The temperature in the flue, °С
|25 ... 800
|Atmospheric pressure, kPa
|84,6 ... 104,7
|The main relative error for О2
|± 2,0 %
|The main relative error for СО
|± 4,0 %
|90% settling time Т0,9d, s
|no more 10
|Уunified current output, mA
|0 – 5, 4 – 20
|RS 485 MODBUS.RTU
|Length of immersion probe, mm
|up to 2300