Application scope:

The DP900-G acid dew point analyzer 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:

After using the DP900-G acid dew point analyzer, the acid dew point value, oxygen content, water vapor (% water vapor value) or dew point value (-50 ℃~100 ℃), water content (G grams/KG per kilogram), and humidity value RH in the boiler and heating furnace flue gas can be accurately determined. 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's 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 produces SO2 during peroxide combustion. Due to the presence of excess oxygen in the combustion chamber, under normal excess air conditions, a small amount of SO2 further combines with oxygen to form SO3, Fe2O3, and V2O5 (which are present in the flue gas and heated metal surfaces). About 1-3% of all SO2 is converted into SO3. SO3 gas in high-temperature flue gas does not corrode metals, but when the flue gas temperature drops below 400 ℃, SO3 will combine with water vapor to generate sulfuric acid vapor. The reaction equation 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 SO3 and water vapor in the flue gas, the meeting of the two will produce H2SO4 vapor, resulting in 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, H2SO4 vapor will stick to the flue and heat exchanger to form H2SO4 solution, which will corrode the equipment, causing 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, a flue gas acid dew point meter is generally used for monitoring.

Technical features:

Dual probe measurement: One instrument can simultaneously measure oxygen content, 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: acid dew point value from 0 ℃ to 200 ℃, oxygen content from 1ppm to 100%, water vapor from 0 to 100%, dew point value from -50 ℃ to 100 ℃, and water 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 directly obtain high-precision combustion flue gas acid dew point values for different fuels (lignite, washed coal, coal powder, natural gas, blast furnace gas, heavy oil, various grades of fuel, etc.) based on the different sulfur content of SO2 generated and the conversion rate of each fuel to SO3.

Specifications and parameters: