Online flue gas acid dew point meter

Application scope:

NernstDirect insertion online flue gas acid dew point meter(1735 Acid Dew) is a real-time online measurement of the acid dew point temperature in the flue gas of boilers and heating furnaces. Based on the measured acid dew point temperature, the exhaust temperature of boilers and heating furnaces can be effectively controlled, reducing low-temperature sulfuric acid dew point corrosion of equipment, improving operational thermal efficiency, increasing boiler operation safety, and extending equipment service life.

Application features:

due toNernstDirect insertion online flue gas acid dew point meter(1735 Acid Dew) 采By using an acid dew point sensor directly inserted into the flue, the acid dew point value in the boiler and heating furnace flue gas can be detected in real-time online, as well as the water vapor (% water vapor value) or dew point value (-50 ℃~100 ℃), water content (G grams/KG per kilogram), and humidity value RH. Users can control the exhaust gas temperature within a range slightly higher than the acid dew point of the flue gas based on the instrument display or two 4-20mA output signals to avoid low-temperature acidic corrosion and increase the safety of boiler operation.

Application principle:

In industrial boilers or power plant boilers, petroleum refining enterprises, and heating furnaces, fossil fuels (natural gas, refinery dry gas, coal, heavy oil, etc.) are generally used as fuel. These fuels contain a certain amount of sulfur to varying degrees, which will produce SO during peroxide combustion₂Due to the presence of excess oxygen in the combustion chamber, there is a small amount of SO under normal excess air conditions₂Further combine with oxygen to generate SO₃And Fe₂O₃And V₂O₅(Smoke and heated metal surfaces contain this component). All SO₂About 1-3% of it is converted into SO₃SO in high-temperature flue gas₃Gas does not corrode metals, but when the flue gas temperature drops below 400 ℃, SO₃It will combine with water vapor to generate sulfuric acid vapor, and its reaction formula is as follows:

SO₃ + H₂O----------H₂SO₄

When sulfuric acid vapor condenses onto the heating surface at the rear of the furnace, low-temperature sulfuric acid dew point corrosion occurs. At the same time, the sulfuric acid liquid condensed on the low-temperature heating surface will also adhere to the dust in the flue gas, forming a sticky ash that is difficult to remove, causing the flue gas channel to be blocked or even obstructed, while increasing resistance, thereby increasing the power consumption of the induced draft fan. The occurrence of corrosion and ash blockage is a hazard to the working condition of the boiler heating surface.

Due to the simultaneous presence of SO in the flue gas₃When water vapor meets, it produces H₂SO₄Steam causes an increase in the acid dew point of the flue gas. When the exhaust temperature is lower than the acid dew point temperature of the flue gas, H₂SO₄Steam will stick to the flue and heat exchanger to form H₂SO₄The solution corrodes the equipment, leading to heat exchanger leakage and flue damage. In the installation of supporting heating furnaces or boilers, their energy consumption accounts for about 50% of the total energy consumption of the device, and the exhaust gas temperature affects the thermal efficiency of the heating furnace and boiler operation. The higher the exhaust temperature, the lower the thermal efficiency. For every 10 ℃ increase in exhaust temperature, the thermal efficiency decreases by approximately 1%. The exhaust temperature is too low. If it is lower than the acid dew point temperature of the flue gas, it will cause equipment corrosion and pose a safety hazard to the operation of the heating furnace and boiler. The reasonable exhaust temperature of heating furnaces and boilers should be slightly higher than the acid dew point temperature of the flue gas. So determining the acid dew point temperature of heating furnaces and boilers is the key to improving their operational thermal efficiency and reducing operational safety hazards. At present, in combustion boilers and petroleum refining enterprises, in order to obtain the acid dew point of flue gas from heating furnaces and boilers, flue gas is generally selectedAcid dew point meterTo implement monitoring.

Technical Features:

Probe measurement: One instrument can simultaneously measure water dew point value, moisture content, and acid dew point value.

◆ Multi output control: The instrument has two 4-20mA current outputs and computer communication interfaces RS232 and RS485.

Measurement range: 0 ℃~200 ℃ Acid dew point value, 0-100% water vapor, -50 ℃ -100 ℃ dew point value, and moisture content (g/kg per kilogram).

◆ Alarm settings: The instrument has 1 universal alarm output and 3 programmable alarm outputs.

◆ Automatic calibration: The instrument will automatically monitor various functional systems and calibrate them to ensure the accuracy of the instrument during measurement.

Intelligent system: The instrument can have human-machine dialogue and complete various settings according to predetermined settings.

◆ Display output function: The instrument has a strong ability to display various parameters and has strong output and control functions for various parameters.

◆ Variable parameter selection: It can generate SO with different sulfur contents according to different fuels (lignite, washed coal, coal powder, natural gas, blast furnace gas, heavy oil, various grades of fuel oil, etc.)₂And the conversion of various fuels into SO₃The conversion rate selection directly obtains high-precision combustion flue gas acid dew point values for each fuel.

Specifications and parameters: