2-Phase Flow Sensor for Pulverized Coal Mass Flow Rate and Distribution for Increased Reliability of a Coil Boiler During Steady and Transient Operations

In the energy industry, there currently is not a satisfactory solution for measurement of coal mass flow at the inlet of each burner of the boiler. Accurate monitoring of this fuel injection rate is important as it can provide the instantaneous feed information to the boiler and thereby the instantaneous combustion efficiency of the boiler can be ascertained. In a commercial coal-fired system, the coal injection to the pulverized combustor is made at multiple locations of the boiler through multiple injecting pipes connecting to the central coal hopper. The total feed rate to the boiler can be readily measured from the discharge rate from the central coal hopper. However, their precise distribution from the central hopper to each injecting pipe is usually not known. Knowing the instantaneous coal injection rate in the pipe to the boiler is essential to providing timely action to correct for maldistribution and ensure sufficient air- to-coal flow ratio is provided for complete combustion. The current detection of maldistribution of the coal feeding from the central hopper is based on the mal-performance of downstream combustion system performance such as low steam generation rate. Clearly, a delay in detection of the feeder maldistribution can affect the prolonged low boiler efficiency and hence economics of the boiler system. Tech4Imaging, LLC (T4I) will develop a capacitance-based feed forward real- time control system for measuring mass flow rates of feedstock for flex-fuel mode power plant operations. This Electrical Capacitance Volume Tomography (ECVT) multi-phase flow meter project will result in a commercially viable solution for adjusting inlet fuel feed based on online, real-time evaluation and measurement to control power generation efficiencies that will result in lower total operating costs. In addition, the system will be designed to operate in remote areas, and operation will not require highly-specialized training, thus allowing for employment of a locally available labor force. The proposed combination of capacitance sensors, with their proven ability to measure multiple flow components, in conjunction with software developed to assess these measurements as an operational control measure, will enable more control of power plant operations. In Phase I of this project, we will focus on the development of algorithms to determine volume fractions and velocities of multiple phases, and validation of measurements on a controlled multi-phase flow loop. These developments will move the innovation through Technology Readiness Level 5, where laboratory experiments will validate the proof-of-concept that an ECVT multi-phase flow meter can address this industrial issue.