Research Of Gas/solid Two-phase Flow Capacitance Cross-correlation Velocity Measurement Method

The flow system of gas/solid two-phase flow system is universal in nature andindustrial process, it is an important research topic for the parameters monitoring such asmovement speed, size and position of discrete phase, flow type and so on. This topic takesgas/solid two-phase fluid which cocurrent flows from bottom to top in vertical pipe asresearch object, and based on the cross-correlation theory of random process, combinedwith the modern sensor technology and information processing technology, takes themethod of computer simulation combined with experiment research, and takes simulationresearch to gas/solid two-phase flow capacitance cross-correlation velocity measurementsystem consisted of capacitance sensor through research the consist, working principle, andmathematical model of capacitance cross-correlation velocity measurement system. Thispaper takes Monte-Carlo method to establish the gas/solid two phase flow model, then studiesthe effect that solidified flow chart-type and non-solidified flow chart-type, the measurementmethod of flow velocity, the selection of parameters for sensors, the velocity distribution ofdiscrete phase, flow type and concentration on cross-correlation velocity measurement system,clears the physical meaning of cross-correlation speed.This topic makes a lot of experiment to cross-correlation velocity measurement system,the experiment results show that it is a rational feasible and effective approach for the testingstudy of two phase flow parameters through two phase flow mode simulated by monte carlomethod and correlator based on cross-correlation technology. At the same time, this paper hasdeep research on cross-correlation velocity measurement method including pixel-levelalgorithm, differential auto-correlation algorithm, polarity cross-correlation algorithm, andparameter estimation method which is improved method, and analyzes their advantages anddisadvantages on the basis of experimental simulation, study the relationship of parameterestimation method and cross-correlation algorithm. The experiment results show that when thespatial filtering effect of sensor makes the signal band narrow, the use of parameter estimationmethod can overcome or improve the insufficiency of commonly used cross-correlation methodsuch as larger random error, low resolution, slow dynamic response and so on. Finally, thistopic analyses the velocity distribution of churn flow and the influence of different velocitydistribution to gas/solid two phase flow cross-correlation measurement system. The researchand results above provide the theoretical basis to the on-line detection of gas/solid two phaseflow discrete phase concentration and speed, and the design and application of cross-correlationflow measurement system, it also provides effective means to the precise measurement ofgas/solid two phase flow cross-correlation flow velocity.