A low-error calibration model for an electrostatic gas-solid flow sensor fusion obtained via machine learning techniques with experimental data

Sensor fusion is the use of software that intelligently combines data from multiple sensors inorder to improve overall system performance. This technique can be applied to measurementof mass flow rate of solids in a pipeline with non-intrusive electrostatic techniques. Data fusionfrom multiple heterogeneous/homogenous sensors can overcome limitations of an individualsensor and measured variable. It is shown that the output voltage of a ring-shaped electrode ispredominantly a function of solids mass flow rate, air-solids ratio and particle velocity. Byadditionally incorporating measured flow velocity in a proposed mathematical model (obtainedvia machine learning), meter output voltage could be predicted/calculated with superioraccuracy, for a range of different flow parameters from numerous experiments with a pneumaticconveying system. A transposed model utilised in software enables accurate mass flowmeasurement with velocity compensation. Accurate mass flow measurement facilitatesenhanced monitoring and controllability of blast furnaces, power stations, chemical reactorsetc. where there is a flow of solid fuel/reactant in pipelines. Optimisation of highly materiallyconsumptive and energy intensive processes can yield significant reductions in waste andemissions (CO2, NOx) and increased efficiencies in global production of energy and materials.Keywords: sensor fusion, machine learning, electrostatic flow measurement, gas-solid flow,pneumatic conveying, non-linear regressio

Determination and optimization of the mathematic model using the non-linear least square and iteration methods

The mathematic model of ring-shaped electrostatic sensor is often represented by its spatial sensitivity, which is defined as the ratio between the induced charge on the electrode to the charge carried by a particle at a different location in the sensing zone. The first step of this study was carried out to investigate the response of the electrode to a charged particle moving axially and radially [1] through simulation, and the second step was to optimize the mathematic model using the non-linear least square and iteration methods. Based on the response to single charge particles, the spatial response of the electrode to a flow stream at different radial position was derived. The purpose of modelling was to establish an accurate analytical expression of the sensor response to single charged particles and flow streams for further study of spatial sensitivity compensation

Reweighting Signal Spectra to Improve Spatial Sensitivity for an Electrostatic Sensor

The ring-shaped electrostatic sensor is a gas–solid flow measurement system, which has a problem of flow profile dependency. To deal with this problem, a method was introduced in this paper, which was to repeatedly use the successive “tails” of the sensor’s overall output power spectrum to identify elementary frequency components corresponding to the equivalent roping flow streams. From the radial locations of these equivalent flow streams, the decomposed power frequency spectral components were then reweighted accordingly. Through such signal processing, an improved electrostatic sensor spatial sensitivity was achieved without modifying the sensor’s structure. The method of interpolation was presented and discussed, and the effect of velocity profile on the proposed method was evaluated under different velocity profiles

Atmospheric-pressure pulsed discharges and plasmas: Mechanism, characteristics and applications

Pulsed discharge plasma and its application is one of the promising directions in civilian areas of pulsed power technology. In order to promote the research and development of the theory and application technology for pulsed discharge plasma, in this paper, recent progress on the mechanism of nanosecond-pulse gas discharge and the characteristics and applications of typical pulsed plasma at the Institute of Electrical Engineering, Chinese Academy of Sciences is reviewed. Firstly, progress on mechanism of nanosecond-pulse discharge based on runaway electrons and measurement technology of runaway electrons is introduced. Then, the characteristics of three typical discharges, including direct-driven pulsed discharge, pulsed dielectric barrier discharge and pulsed plasma jet, are reviewed. Furthermore, typical plasma applications of pulsed plasma on surface modification and methane conversion are presented

Improvement of spatial sensitivity of an electrostatic sensor for particle flow measurement

The ring-shaped electrostatic sensor is a typical particulate flow measurement system, which suffers from flow profile dependency due to its non-uniform spatial sensitivity. In this paper, a method based on sensor’s output power frequency spectrum is proposed, which can be realized by repeatedly decomposing the sensor’s overall output power spectrum to identify elementary frequency spectra corresponding to equivalent flow streams. The decomposed components can then be re-weighed to improve the uniformity of spatial sensitivity. This is a low cost approach, and there is no need to modify simple structure of the current sensor

A stability and spatial-resolution enhanced laser absorption spectroscopy tomographic sensor for complex combustion flame diagnosis

A novel stable laser absorption spectroscopy (LAS) tomographic sensor with enhanced stability and spatial resolution is developed and applied to complex combustion flame diagnosis. The sensor reduces the need for laser collimation and alignment even in extremely harsh environments and improves the stability of the received laser signal. Furthermore, a new miniaturized laser emission module was designed to achieve multi-degree of freedom adjustment. The full optical paths can be sampled by 8 receivers, with such arrangement, the equipment cost can be greatly reduced, at the same time, the spatial resolution is improved. In fact, 100 emitted laser paths are realized in a limited space of 200mm×200 mm with the highest spatial resolution of 1.67mm×1.67 mm. The stability and penetrating spatial resolution of the LAS tomographic sensor were validated by both simulation and field experiments on the afterburner flames. Tests under two representative experiment states, i.e., the main combustion and the afterburner operation states, were conducted. Results show that the error under the main combustion state was about 4.32% and, 5.38% at the afterburner operation state. It has been proven that this proposed sensor can provide better tomographic measurements for combustion diagnosis, as an effective tool for improving performances of afterburners