The boiler air supply duct experiences significant airflow disturbances and low pressure difference values. To achieve long-term stable pressure measurement, it is necessary not only to select the Longlv PTL802 micro-differential pressure transmitter which is suitable for micro-differential pressure conditions, but also to utilize standardized pressure tapping, pressure conduit laying, buffering, dust removal, and other supporting installation methods. The combination of these two can completely solve the problems of wind pressure fluctuations and data jumps, providing stable and reliable data support for boiler air supply system condition monitoring and fault warning.

1. The difficulty of pressure measurement in boiler air supply ducts, and why the data tends to fluctuate

The boiler's air supply duct primarily utilizes air as the medium. Factors such as fan start-stop operations, damper adjustments, and furnace negative pressure fluctuations can all induce airflow shocks. Uneven wind speeds, vortexes, and dust accumulation within the pipeline can easily lead to frequent fluctuations in pressure difference values.

The air supply system operates under typical micro-pressure differential conditions, with relatively small pressure differential values before and after normal operation. Ordinary pressure measurement equipment is prone to interference from airflow disturbances, resulting in data drift and false alarm triggers, making it impossible to accurately diagnose issues such as duct blockages, fan output anomalies, and damper opening malfunctions. For long-term stable monitoring of duct pressure differential, it is necessary to use a dedicated transmitter that is suitable for micro-differential pressure measurement and resistant to airflow interference, paired with standardized installation methods.

II. The stable advantage of Longlv PTL802 micro-differential pressure transmitter in adapting to boiler air supply pressure measurement

 Optimized for micro-differential pressure measurement, ensuring no distortion of weak pressure difference signals

 The boiler air duct operates within a narrow pressure difference range during normal operation, falling under the category of micro-pressure difference measurement scenarios. The PTL802 is specifically designed for the acquisition and calibration of minute pressure differences. Even with a slight pressure difference between the two ends, it can output a continuous and stable signal without any numerical jumps, accurately capturing subtle changes in air duct resistance.

 Resistance to airflow impact and vibration interference

 Continuous operation of boiler fans can cause pipeline vibration and instantaneous airflow pulse impact. This type of micro-differential pressure transmitter has excellent resistance to vibration and instantaneous wind pressure impact. When the fan load is increased or decreased, or the air damper is adjusted, there is no zero drift, and the online measurement values remain stable over a long period of time.

 Resistant to wind tunnel dust conditions, not prone to blockage of pressure tapping pathways

 The air supply duct carries boiler dust and fine soot particles. The equipment is equipped with a pressure measurement structure suitable for the air duct, which reduces the entry of dust into the measurement chamber and causes blockage, avoiding distortion of pressure difference measurement after long-term use. It is suitable for the harsh environment of boiler rooms with high dust levels.

 Stable signal transmission, compatible with boiler central control system

 Outputting standardized universal signals that can be directly integrated into boiler PLC and DCS central control platforms, the central control interface displays the air duct pressure difference curve in real-time and stability, without data distortion due to long-distance transmission or on-site electromagnetic interference, facilitating real-time monitoring of air supply conditions by operation and maintenance personnel.

III. Four practical methods to ensure more stable pressure difference measurement in boiler air supply ducts

1. The pressure tapping point should be reasonably selected to avoid the vortex region

Pressure taps should not be located at pipe bends, fan inlets and outlets, or the vortex sections before and after air valves. They should preferably be chosen at straight pipe sections, with sufficient straight pipe reserved before and after to reduce wind pressure fluctuations caused by turbulence and lower pressure difference variations from the source. Pressure taps on both high and low pressure sides should maintain the same cross-sectional height to avoid measurement errors caused by the self-weight of the medium.

2. Standardize the laying of pressure guiding pipelines to buffer the impact of airflow

The pressure guiding pipe should not be too short, and a reasonable buffer distance should be reserved to utilize the pipeline space to buffer the instantaneous wind pressure pulse in the air duct. The pipeline should maintain a slight downward inclination to prevent dust and water from flowing back into the measuring end of the transmitter. The pipeline turns should be gentle to avoid airflow blockage caused by sharp turns, ensuring uniform and smooth pressure transmission.

3. Install buffering auxiliary accessories to mitigate wind pressure fluctuations

A buffer device is installed in the middle section of the pressure guiding pipeline to filter the transient high-pressure shocks generated by the start and stop of the fan and the opening and closing of the air valve, smoothly transmitting the air pressure to the PTL802 micro-differential pressure transmitter. This significantly reduces data jumps caused by transient peaks, resulting in a smoother measurement curve.

4. Clean the pressure tapping pipeline regularly to prevent dust accumulation

Dust in the air supply duct is prone to accumulate at the pressure taps and inside the pressure conduits, causing pressure transmission to be obstructed. Regularly dredge the pressure taps and purge the pressure conduits to ensure normal pressure transmission on both high and low pressure sides, maintaining long-term stable pressure measurement by the transmitter.

IV. The value of boiler operation and maintenance brought by stable pressure measurement

After stable monitoring of air duct pressure difference, hidden dangers such as dust accumulation and blockage of the air supply filter screen, increased resistance due to dust accumulation in the air duct, and abnormal operation of the fan can be accurately identified. A graded pressure difference warning system can be set up to arrange dust removal and maintenance in advance, thus avoiding insufficient air volume leading to incomplete combustion of the boiler and a decrease in thermal efficiency.

Compared to traditional mechanical differential pressure monitoring devices, the PTL802 can achieve 24-hour uninterrupted digital stable monitoring without frequent false alarms, reducing the frequency of manual on-site inspections and enhancing the reliability of boiler automation operation.