I. Status of high-temperature direct-input oxygen and carbon monoxide online analyzer technology
As national emission standards for atmospheric pollutants from boilers have increased, NOx emission requirements have become more stringent, and to further reduce NOx emissions, large-scale boilers have been extensively retrofitted with low nitrogen burners, and local areas of the chamber have been filled with reduced atmospheres as a result of the use of low nitrogen combustion techniques due to unreasonable air classification in the furnace, and CO, H2 and H2S concentrations are high and O2 are low. The resulting reaction of a large number of free S atoms with water cold walls produces high temperature corrosion, which leads to a decrease in wall thickness and intensity, leading to problems in the non-stop or large-scale re-barreling of aircraft;
(b) The impact on boiler efficiency due to the significant increase in the concentration of smoked CO and H2 in boilers;
Existing detection devices do not have any means of detection in high-temperature flue gas areas, particularly those prone to high-temperature corrosion, and operational regulation and combustion adjustments are lacking data support.
II. Importance of high-temperature direct-input oxygen and carbon monoxide online analyzer applications
(1) Practice has shown that CO2 concentrations after low nitrogen combustion modifications are sensitive to changes in chamber oxygen levels and that CO and O2 in all regions, especially in high-temperature areas, can be monitored in real time to ensure boiler efficiency while reducing NOX emissions;
1. The levels of O2, CO, H2 and H2S in the peri-wall areas on both sides of the main and burning areas were found to be affected by the crew load, operational oxygen levels, burn-out excretion and the combustion of wind distribution methods through combustion adjustment tests; The higher the crew load, the lower the O2 concentration in the peri-wall area of the side wall, the higher the CO, H2 and H2S, and the higher the crew load above 75% BRL, the greater the zero concentration of O2 in the peri-wall area of the peri-water wall on both sides, which, through the monitoring of CO and O2 in the oxygen-deficit area, can effectively guide operators to make combustion adjustments to avoid or mitigate high temperature corrosion and improve the reliability of the boiler;
2. The combustion optimization adjustment test for boilers shows a strong correlation between CO and O2 in the pneumatic composition of boilers, which, by monitoring CO emission concentration values and variations, will allow for a more accurate identification of the best operating oxygen and a more accurate determination of the current boiler combustion efficiency; Integrated control of CO and O2 through the monitoring of CO and O2 in key regions is beneficial for the economic operation of boilers;
3. Data support can be provided for high temperature corrosive cause analysis and governance programmes through the installation of CO and O2 measurement devices in high temperature areas;
4. The installation of CO and O2 measuring devices in high-temperature areas can provide more scientific and intuitive large-data support for the optimization of boiler combustion and lay the foundation for achieving the smart control of boiler combustion.
5. Technical parameters for high-temperature direct-input oxygen and carbon monoxide online analyzer
(2) Display of instruments
2x20-bit 5x7-point liquid crystal display module showing oxygen, carbon monoxide content, oxygen voltage, temperature, mA current and various alarm records when back light sets a measurement state
(3) Measurement and precision
Oxygen: 0–100%; carbon monoxide: 0–1000 ppm; relative accuracy: ±0.2%; repeatability: ±0.5%
(4) Measurement of gas temperature
0℃-1400℃
(5) Standard air calibration
Semi-automatic single-point calibration, a standard gas (which may be air) calibration constant of a battery, a logarithmic tilt, full automatic calibration (optional function), instrument time control of the electromagnetic valve breaking out of the standard air, automatic calibration system
(6) Water and pressure compensation function
Instrument compensates for oxygen measurement errors through measured gas water content and pressure
(7) Two-way standard current output
Optical isolation 4-20MA（ or 0-10MA） Two-way powered standard current output. ， Load 600-1200 Om.
First-way oxygen output; Second circuit output carbon monoxide content
(8) Output Range Settings
Output of linear calibration of mA currents within range to carbon monoxide content
(9) Temperature and humidity of the environment
Temperature 0℃-55℃； Humidity 5-99%RH（ No trace. ）
(10) Boxes
Standard Type H300×W500×160 Approximately 8KG
(11) Autodiagnosis Alert
Automatic diagnostic function, warning instructions for detector temperature exceeding limit, heat-firing, heat-firing, verification of the illegality of parameters, circuit failure, etc.
(12) Communications interface (optional features)
Serial input/export RS232; web portal RS485; selected on-site bus communication protocol
III. Advantages of detection
(1) Exemption from maintenance
(b) The background is not drifting and no periodic calibration is required;
(2) Preserve corrosion
(a) High sulphur high fluorine corrosion in the environment;
(3) Resilient wear and tear
Three-layer shell protection, high dust environment;
(4) High temperature tolerance
Superwider temperature range ： Detective. 0-1400℃， Pipes 1700℃；
(5) Anti-cold-thermal shocks
(b) High-water environment anti-snorting properties;
(6) Simple structure for maintenance
You don't have to take off a whole probe and open a wire box to replace the pipe.
(b) Parts such as thermoelectric dolls and inner electrodes;
(7) Correct
Directly insert into the furnace to avoid maintenance problems of the pumping system, avoid leakages in the air during the pumping and improve the accuracy of the measurements.
IV. Scope of the high-temperature straight-plug oxygen and carbon monoxide online analyzer application
The levels of oxygen and carbon monoxide in boilers, furnaces, kilns, incinerators, as well as in processes and processes or processes that emit gas after combustion are measured in real time.
V. Questions and answers on high-temperature straight-plug oxygen and carbon monoxide online analyzer technology
1. Why is this product detector not drifting without calibration?
The general aerobic probe background is drifting, requiring periodic calibration, which will ensure some precision over a period of time after each calibration, but will result in increasing measurement error over time and only frequent calibration.
The reason for this movement is that, during the course of use, materials forming the various components of the probe (including internal electrodes, zirconium oxides, outer electrodes) are ageing over time, and the materials change, leading to a change in the exposure of the inner electrodes to the oxenium oxide (thermal voltage or thermal dove effect), as well as a change in the exposure of the oxidation to the outer electrode. If internal and external electrodes are not at the same temperature as the oxidation point, a change in the thermal voltage is a movement of background voltage.
The product is a 1 mm round with a diameter of 6.5 mm thick, small size, heated with a screwdriver heater on the pipe, and an oxidation tablet in the middle of the heater, thus bringing temperatures on both sides of the oxidation tablets to the same extent and eliminating the problem of movement of local power. This could not be done for structural and size reasons for all other oxidizing probes.
2. Why does the product detect long-term stability and reliability?
The general oxidation probe is fitted with a very short tube from the front of the probe and assembled by mechanical sealing. Since oxidation is a ceramic material, heaters are present on a local level of the argon, and thermal stress at high temperatures can cause seal leaks and leaks in the catheters due to differences in the thermal inflationary factors of metals, sealed materials and ceramic materials. This is the main reason for the error of the probe until it lapses.
The structure of this product is different, with the pipe using ceramic welding to weld round oscillated tablets with a diameter of 6.5 mm and a diameter of 1 mm to the end of the steel and jade porcelain tube with a diameter of 8 mm and a diameter of 6 mm to form an oscillation tube, the length of which is close to the length of the probe. Probes are loaded from the back with gill tubes and are sealed with O-style flexible seals. Since seals are valid, not at the front end of the high temperature, but at the low temperature close to the wire box, they completely address the problem of low seals and heat stress causing leaks to the gill pipe, so that the probe strictly meets the power equation within the full range, with an oxygen detection rate of 10-30 per cent.
Why does this product probe apply to high temperature and high moisture environments?
The normal aerobic probe ' s cavity is made up of metal and oxidation through glue and welding, and the higher the temperature, the more the catheter is prone to seal leaks and leaks from the cavity tube, so that when the flue gas temperature exceeds 400°C detection lifetime, it is significantly reduced.
The tube of this product uses full ceramic materials and the temperature of the tube itself is as high as 1,700°C. The probe uses temperatures of up to 1,400°C, which are significantly higher than the normal detector's 600°C limit, and the life of the tube at the same temperature is significantly longer.
The tube of this product detector uses small size oxidizing tablets, with small heat capacity, and hot heat does not cause heat stress damage, so the probe can also be used in high-water environments, and short-lived water is not damaged and is suitable for hydrometric measurements. However, the general oxidation is damaged by a break in water due to the structure and size of the pipe.
4. Why does the product probes apply to high sulphur-rich environments?
The normal aerobic probe leads are usually welded in platinum, but the sulphur in the flue gas is corrosive to platinum, and platinum coatings of the platinum tube are also corroded with platinum coatings (known as oxidation tube poisoning) when the sulphur is high.
This product probe uses special coating material (e.g. electrode sulfur-resistant strong) and uses different electrodes of exposure, with an automatic scalable spring top contact in the tube of the probe. The electrodes do not have problems due to sulphur corrosion and thermal swelling and cooling, and their reliability is significantly enhanced and they can work in flue gas concentrations of up to 14 per cent. The interior is also supported by a small diameter metal tube, which in fact has three layers of grinding protection for the cascading tube, metal support tube, and the outer tube.
Why does this product detector apply in situations of severe wear and tear of high dust?
The normal oxygen probe is the installation of a very short tube in the front of the probe, which is connected to the reference gas on the inside side of the tube wall, so that the measurement function is destroyed once the tube wall is worn through and the measured gas enters the reference gas. The tube of this product detector uses small size oxidizing tablets, with small heat capacity, and hot heat does not cause heat stress damage, so the probe can also be used in high-water environments, and short-lived water is not damaged and is suitable for hydrometric measurements. However, the general oxidation is damaged by a break in water due to the structure and size of the pipe.