A review on signal processing techniques utilized in the fault diagnosis of rolling element bearings

Design With Operational Amplifiers And Analog Integrated Circuits

Industrial cyber-physical systems (ICPSs) are the backbones of Industry 4.0 and as such, have become a core transdisciplinary area of research, both in industry and academia. New challenges brought about by the growing scale and complexity of systems, insufficient information exchange, and the exploitation of knowledge available have started threatening the overall system safety and stability. This work is motivated by these challenges and the strategic and practical demands of developing ICPSs for safety-critical systems such as the intelligent factory and the smart grid. It investigates the current status of research in ICPS monitoring and control, and reviews the recent advances in monitoring, fault diagnosis, and control approaches based on data-driven realization, which can take full advantage of the abundant data available from past observations and those collected online in real time. The practical requirements in the typical ICPS applications are summarized as the major issues to be addressed for the monitoring and the safety control tasks. The key challenges and the research directions are proposed as references to the future work.

Data-Driven Monitoring and Safety Control of Industrial Cyber-Physical Systems: Basics and Beyond

Experimental and numerical study of fluidization and pressure drop of spherical and non-spherical particles in a model scale fluidized bed

Electrostatics in gas-solid fluidized beds: A review

Oscillation frequency measurement of gaseous diffusion flames using electrostatic sensing techniques

The combustion characteristics of individual coal particles are the basis for a deep understanding of the macroscopic pulverised coal combustion in power plant boilers. This work proposes a quantitative method to characterise the combustion behaviours of individual pulverised coal particles by measuring a set of physical parameters from digital images of the particles. The combustion process of pulverised particles of bituminous coal in a visual drop tube furnace was recorded by a high-speed camera with a frame rate of 6200 frames per second. An improved-Canny algorithm was developed to extract the combustion zones of a coal particle in both the volatile and char combustion phases. Using the improved-Canny and Otsu algorithms, the unburned part of the particle was identified in the volatile combustion phase. Characteristic parameters of coal particles, including the area, brightness, length, width and aspect ratio of volatile flame, and falling velocity, were derived from the processed images. The results obtained show that the volatile and char combustion took place successively and the volatile matter was combusted almost as soon as it was released. The particle travelled upward for around 14 ms during the early stage of combustion due to the influence of devolatilisation and volatile combustion. The particle also exhibited a slight difference in the rotation frequency at different combustion phases.

https://iopscience.iop.org/article/10.1088/1361-6501/abc2ea/pdf

Characterisation of the combustion behaviours of individual pulverised coal particles entrained by air using image processing techniques

On-line measurement of pulverized fuel (PF) distribution between primary air pipes on a coal-fired power plant is of great importance to achieve balanced fuel supply to the boiler for increased combustion efficiency and reduced pollutant emissions. An instrumentation system using multiple electrostatic sensing heads are developed and installed on 510 mm bore primary air pipes of a 600 MW coal-fired boiler for the measurement of mass flow distribution of PF. An array of electrostatic electrodes with different axial widths is housed in a sensing head. An electrode with a greater axial width and three narrower electrodes are used to derive the electrostatic signals for the determination of PF mass flow rate and velocity, respectively. The measured PF velocity is used for the calibration of coal mass flow rate. On-plant comparison trials of the developed system were conducted under typical operating conditions. Isokinetic sampling equipment is used to obtain reference data to evaluate the performance of the system. Experimental data demonstrate that the developed system is effective and reliable for the on-line continuous measurement of PF mass flow distribution between the primary air pipes of the same mill.

/pdf/measurement-of-the-mass-flow-distribution-of-pulverized-coal-11urj3vdwz.pdf

Measurement of the mass flow distribution of pulverized coal in primary air pipes using electrostatic sensing techniques

The utility model discloses a comb-type pulverized coal balancing valve, which solves the problem that primary air pulverized coal flow cannot be effectively adjusted since an adjustable shrinkage cavity commonly adopted by coal-fired power plants cannot effectively adjust the resistance of a primary air pipeline under the condition of operation with powder. The comb-type pulverized coal balancing valve comprises a valve core (1), a shell (2), a bearing (3) and an electric actuating mechanism (4), wherein the valve core (1) is formed by blades (5) and a rotary shaft (6). The comb-type pulverized coal balancing valve is characterized in that the blades (5) are sequentially distributed on the rotary shaft (6) in a comb shape; the rotary shaft (6) is connected with the shell (2) through the bearing (3); the valve core (1) can be rotated at an angle of 0-90 degrees in the pipeline. Under the condition of operation with powder, the comb-type pulverized coal balancing valve can flexibly, effectively and continuously adjust the resistance of the pipeline, so that the distribution of powder in each primary air pipe is more uniform, and the aim of optimizing combustion is achieved.

Comb-type pulverized coal balancing valve

Gas-solid two-phase flows are widely seen in many industrial processes. A good exampleis the pneumatically conveyed pulverised fuel flow in the power generation industry. As a significant renewable fuel source, biomass has been widely adopted in electrical power generation. The particle size distribution of pneumatically conveyed biomass correlates closely with combustion efficiency and pollutant emissions and should therefore be monitored on anin-line, continuous basis. In this paper an integrated instrumentation system using both a piezoelectric sensorand anelectrostatic sensor arrayis proposed to measure the size distribution and flow velocity of biomass particles. A prototype system was tested on a 250mm bore pipe at a biomass-fired power plantand its performance has been evaluated under industrial conditions.

Xiangchen Qian

Papers

Oscillation frequency measurement of gaseous diffusion flames using electrostatic sensing techniques

Characterisation of the combustion behaviours of individual pulverised coal particles entrained by air using image processing techniques

Measurement of the mass flow distribution of pulverized coal in primary air pipes using electrostatic sensing techniques

Comb-type pulverized coal balancing valve

In-line continuous sizing of biomass particles in gas-solid two-phase flow at a biomass-fired power plant