Study On Time Series Method Of Pressure Fluctuation In A Combined Restraint Riser

There are many research and application of “riser-gas-solid distributor-fluidized bed”the combination of the constraint riser in the field of oil refining.While liquidity in a combination of constrained riser reactor to obtain a more in-depth understanding and guidance and improve its operation.However,studies have focused on the flow parameters of macroscopic or time.In industrial applications there are bed mode of operation to relatively zero bed mode of operation equipment vibration and operating parameters of the serious issue.So it have to be more in-depth study.Particularly microscopic or transients characteristic flow parameters.Therefore,the paper riser absolute pressure and differential pressure fluctuation signal as the main research content.Respectively compare conventional riser and riser combination binding compare.Relying on wavelet energy in this time and frequency domain as the main research method.In order to understand the riser of combination constrained export to this typical traits of mechanisms to provide theoretical support.The results show that,in the time domain binding composition riser pressure fluctuation signal standard deviation analysis.Obtained under different operating conditions showed a standard deviation of pressure fluctuation in the bed under the existing conditions,significantly higher than the standard deviation at zero pressure fluctuation bed conditions.Two modes of operation,the standard deviation of pressure fluctuation varies with the operating conditions and the variation trend along the axial direction.At zero bed operation mode,the standard deviation of pressure fluctuation increases with the increase of the particle concentration in the riser,decreasing trend along the axial direction.Under the bed operation mode,the standard deviation of pressure fluctuation increases with the increase of superficial gas velocity.The standard deviation of the particles increases with the increase of the cyclic strength of particles.Along the axial direction along with the increase of particle circulation intensity.From the monotone decreasing trend,the trend is gradually changed into a trend of decreasing and then increasing.The results of wavelet analysis of pressure fluctuation signals in a combined constrained lifting tube in the time frequency domain.Zero bed operation mode,The A7 and D5 are the main frequency of pressure fluctuation signal.The A7 and D2 are the main frequency of pressure fluctuation in the operation mode.The A7 frequency band is a global pressure pulsation,which is mainly influenced by the discontinuity of the inlet of the riser and the interaction between the gas and the lower part of the feed inlet.D2 band is one of the global pressure fluctuation,mainly by the riser outlet gas solid fluidized bed gas-solid distributor-fluidized on the riser(or gas-solid)flow behavior of gas pulsation constraints,and under the constraint effect influence.The influence of D5 is a kind of local pressure fluctuation,mainly by enhancing gas inside the tube suspension and influence of transport energy of particles,reflect is riser interactions between the local gas and particles,particles and between the particles,and particles agglomerate aggregation and disintegration behavior.The pressure fluctuating energy in the combined constrained riser is mainly affected by the main frequency and energy of each operation mode.The upper bed height increases,the outlet resistance of riser increases and the energy of D2 band increases.Gas solids distributor opening rate increase,will cause the pressure pulsation in the bed increases,resulting in the increase of energy band D2.