Solid flow measurement method and system of recirculating fluidized bed

Abstract

The invention provides a solid flow measurement method of a recirculating fluidized bed, which comprises the following steps that: 1) two cross sections are selected from the descending section of a recirculating fluidized bed reactor as measurement surfaces; 2) the fan-beam ray is utilized to continuously measure the average volume fraction of the solid cross section of each measurement surface within a period; and the fan-beam ray is the fan-beam ray which can penetrate through the solid material in the reactor; and 3) the cross-correlation function R(tau) of the time functions of the average volume fractions of the solid cross sections of the two measurement surfaces is calculated, the time tau which makes the value of the cross-correlation function be maximum is found out, and is taken as the time for the solid material to move from an upper measurement surface to a lower measurement surface, and furthermore, the solid flow of the recirculating fluidized bed is calculated. The solid flow measurement method and the solid flow measurement system cannot disturb the flow field in the reactor or cause manual interval operation. The measurement result is true and reliable. The solid flow measurement method and the solid flow measurement system can be applied to high temperature, high pressure and even toxic extreme measurement environments.

Description

technical field [0001] The invention relates to the technical field of gas-solid two-phase flow measurement, in particular to a method and a measurement system for measuring solid flux in a circulating fluidized bed. Background technique [0002] Circulating fluidized bed reactors are widely used in petroleum smelting, chemical industry, metallurgy, electric power and other process industries, and play a huge role in national production. Only by accurately judging the flow area where the flow field system in the reactor is located, can the mass transfer and heat transfer of the reactor be effectively adjusted, thereby improving the overall efficiency of the reactor. Among the many parameters reflecting the operating state of the circulating fluidized bed, the solid flux G s It is the most important parameter to determine the basin where the system is located. The solid flux, also known as the solid circulation flow rate, refers to the solid mass passing through the unit cr...

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Problems solved by technology

The intrusive measurement process will interfere with the flow field to varying degrees, and even cause the material flow to be interrupted. Seriously, it will interfere with the material balance and pressure balance of the flow system, resulting in artificial gap operation; moreover, the measuring parts of the intrusive measurement are in direct contact with the flowing material , the static electricity generated by material friction will interfere with the sampling of the instrument, affecting the authenticity and reliability of the measurement results; moreover, because the industrial reactor is often in an extreme environment of high temperature, high pressure or even poisonous, it has high requirements for sealing. The intrusive measurement method is difficult to apply to this type of reactor

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