System capable of measuring flow velocity of gas by sound, and measuring method

Abstract

The invention discloses a system capable of measuring flow velocity of gas by sound, and a measuring method, which belong to the measuring field of flow velocity of fluids. According to the system, an acoustic wave emission device and an acoustic wave signal sensor are fixed to the pipe wall of a pipeline in which gas flows, and are connected with a power amplifier, a data acquisition device and a computer; the acoustic wave emission device sends out acoustic wave signals; the acoustic wave signals are encoded by adopting a SpectraLAb software, after the acoustic signals are converted into analog signals through an acoustic card, measuring acoustic wave signals are sent out through the power amplifier, the acquired data is input into the computer through a data acquisition card, the computer processes the acquired data so as to obtain acoustic wave travel time, and finally, the flow velocity v of the gas is obtained by calculation. The measuring method disclosed by the invention belongs to the non-contact type measuring method of the flow velocity of gas, and can be applicable for the measurement of the flow velocity of gas under various complicated environments, the system is simple and convenient to mount, the original equipment does not need to be destroyed, the measuring precision is high, and the measuring error can be within 5%.

Description

technical field [0001] The invention belongs to the field of fluid flow velocity measurement, in particular to a system and a measurement method for audibly measuring gas flow velocity. Background technique [0002] Accurate measurement of gas flow rate is of great significance in practical engineering applications. There are several methods for measuring gas flow rate: [0003] 1. Pitot tube and Venturi tube: This method is based on the Bernoulli equation and is a traditional contact measurement method. During long-term use, corrosion and wear are prone to occur, which reduces the measurement accuracy. [0004] 2. Hot wire anemometer: The principle is to place a thin metal wire (called hot wire) heated by electricity in the airflow, the heat dissipation of the hot wire in the airflow is related to the flow velocity, and the heat dissipation causes the temperature change of the hot wire to cause the resistance change. The flow rate signal is converted into an electrical sig...

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Problems solved by technology

However, these methods are point measurements, which are weak in reflecting changes in spatial structure. At the same time, high cost is another important factor limiting their development.

[0006] 4. Particle image velocimeter: The rapid development of image technology makes it possible to use high-speed shooting to intuitively reflect the instantaneous flow of the whole field, but it is only used for laboratory observation of experimental results, and has not been put into practical application in engineering

However, due to the serious energy attenuation of ultrasonic waves during the propagation process, it is difficult to propagate in a long distance, and at the same time, the ultrasonic waves have a short wavelength and are easily interfered by obstacles, so they are greatly limited in practical applications.

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