Design and implementation of a pulverised coal flow monitoring system for coal-fired power plant applications

On-line continuous monitoring of pulverised coal in fuel injection pipelines will allow power plant operators to understand fuel conveying conditions and ultimately to achieve higher combustion efficiency and lower pollutant emissions. This paper presents the design, implementation and trials of an instrumentation system for on-line non-intrusive measurement of pulverised coal in a power plant environment. An array of three identical electrostatic electrodes is housed in a sensing head to determine multiple measurement results from different electrode pairs. Flow parameters such as flow velocity, relative mass flow rate and fuel distribution between injection pipes can be obtained by fusing the multiple results. On-plant trials on 488 mm bore pneumatic conveying pipelines at a 600 MW coal-fired power plant were undertaken following preliminary system evaluation tests on a 50 mm bore laboratory test rig. Experimental results demonstrate that monitoring of pulverised coal flow is achieved using the developed instrumentation system under real industrial conditions. The developed technology is likely to find immediate applications, leading to improved performance of coal-fired power plants, efficient use of fuel, and subsequent reductions in emissions.