Self-correction heat type-precession vortex combined type gas flow measurement method

Abstract

The invention discloses a self-correction heat type-precession vortex combined type gas flow measurement method which comprises the following steps of: measuring by a heat type speed sensor to obtain a fluid temperature signal and a speed signal; measuring by a pressure sensor to obtain a pressure signal; sending the speed signal into a heat type flowmeter module and a precession vortex flowmeter module to obtain the heat type flow data Q heat; sending the fluid temperature signal and pressure signal into the precession vortex flowmeter module to obtain the precession vortex flow data Q vortex; dividing the flow range into a small flow section, a medium flow section and a large flow section; in the whole flow range, outputting the flow by use of the heat type flow data Q heat; and in the medium flow range, comparing the precession vortex flow data Q vortex with the heat type flow data Q heat, and correcting the heat type flowmeter instrument coefficient. The method adopts a combined type flowmeter and integrates the advantages of a heat type flowmeter and a precession vortex flowmeter, and has a large measurement range and a self-correction function.

Description

Technical field [0001] The invention relates to a flow measurement method, in particular to a self-correcting thermal and precession vortex combined gas flow measurement method. Background technique [0002] Thermal flowmeter is a flow detection instrument designed by the principle of thermal diffusion, and is generally used to measure gas mass flow. Thermal gas flow meters are divided into immersion type, heat distribution type and boundary layer type. Take the immersion type as an example to illustrate the working principle of thermal flow meters. A flow velocity probe with a heating element and a temperature probe are set in the pipeline, and the fluid takes away heat when flowing through the heating element. Ignoring the effects of radiation and heat conduction, the electric heating power of the electronic heating element is equal to the heat taken away by the convective heat transfer of the fluid per unit time, namely [0003] (1) [0004] W...

AI Technical Summary

Problems solved by technology

Judging from the information fed back by a large number of users, the main problems in the use of swirl vortex flowmeters are: the setting of the cut-off frequency is arbitrary; it is sensitive to interference signals such as noise or vibration; 4~5 times of the pressure loss of the flowmeter; the signal of the small flow is weak, and it is limited in use

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