Vortex Flow Meter in CEMS Flue Gas Monitoring-SURE Vortex Flow Meter LUGB-A Series

A large-scale thermal power plant, in response to the national Emission Standard of Air Pollutants for Thermal Power Plants (GB 13223-2011), has launched an ultra-low emission retrofit project for its 2×660MW units. The goal is to achieve real-time monitoring and data reporting of pollutants such as SO₂, NOx, and particulate matter. The focus of this project is to upgrade the flue gas flow monitoring unit. The traditional differential pressure instruments were replaced with the SURE Vortex Flow Meter LUGB-A Series to address the measurement challenges in high-dust and wide-temperature-variation conditions, meeting the regulatory requirements of the Ministry of Ecology and Environment for "installation, display, and connectivity".

Operating Conditions

1. High Temperature and Thermal Shock

• The flue gas temperature in the primary air duct reaches up to 400°C (with an instantaneous peak of 450°C), and there are severe temperature fluctuations during start-up and shutdown phases.

2. Dust Interference

• The flue gas contains dust with a concentration of ≤1000mg/m³ and a wide particle size distribution (0.1-100μm), which can easily cause instrument wear and signal distortion.

3. Wide Flow Rate Range

• During load adjustment, the flow rate varies rapidly from 15m/s to 50m/s, requiring a turndown ratio of ≥33:1.

4. Low Pressure Measurement

• The flue operates under negative pressure (-70mbar), necessitating high sensitivity for signal capture.

5. Data Compliance

• The flow measurement accuracy must reach ±0.5%, and support hourly average exceedance warnings in accordance with the HJ 75-2017 standard.

SURE Vortex Flow Meter LUGB-A Series Technical Solution

1. High Temperature and Structural Reinforcement

• Material and Heat Resistance

• The LUGB-A Series features a high-temperature design with a vortex generator made of SS316L stainless steel. The sensor is encapsulated in an insulated chamber for heat dissipation, supporting long-term operation at temperatures ranging from -40°C to +420°C.

• Vibration Resistance

• The fully welded structure has passed a 10g vibration test (IEC 60068-2-6), making it suitable for the shock during boiler start-up and shutdown.

2. Adaptation to Dusty Environments

• No Moving Parts Design

• The absence of mechanical moving parts eliminates the risk of dust jamming.

• Redundant Signal Processing

• The digital filter amplifier automatically filters out noise signals caused by particle collisions.

• Blow-off Interface

• A reserved compressed air blow-off interface (custom option) is available for DCS-triggered timed cleaning.

3. Wide Turndown Ratio and Low Pressure Measurement

• Wide Turndown Ratio

• The turndown ratio reaches 33:1, covering flow rates from 0.5m/s to 60m/s.

• Low Pressure Loss Design

• The optimized vortex generator shape results in a pressure loss of less than 0.5kPa (one-third of the traditional Venturi tube).

• Multi-parameter Compensation

• The built-in temperature and pressure sensors (T&P compensation model) convert actual flow to standard dry flue gas flow in real-time with an accuracy of ±0.5%.

4. System Integration and Compliance

• Data Output

• Supports 4-20mA + HART V7.0, which can be connected to the CEMS control computer.

• Certifications

• Certified with CE, SIL2, and Exd II CT6 Gb explosion-proof certification, meeting the data validity review requirements of HJ 75-2017.

Implementation Results

• Measurement Accuracy

• At a typical flow rate of 30m/s, the comparison error with the reference method (grid method) is ≤0.5% (accuracy of the A Series).

• Reliability Improvement

• Zero failures in a 2-year operation cycle, with maintenance costs reduced by 60% compared to the original system.

• Emission Control

• Flow data supports the calculation of SO₂/NOx emissions, helping the power plant reduce pollutant emission intensity to 15mg/m³ (better than the national standard of 35mg/m³).

• Regulatory Compliance

• CEMS data is directly connected to the provincial ecological cloud platform, with no exceedance warnings in the past 12 months.

Features

1. High Temperature Adaptability

• The +420°C temperature resistance covers the full load conditions of coal-fired units (according to the T4 code).

2. Economic Optimization

• The wide turndown ratio (33:1) reduces redundant instrument configurations, lowering overall costs by 40%.

3. Support for Carbon Neutrality Strategy

• Accurate emission data provides a reliable basis for carbon quota trading.