Venturi flow meter

Abstract

The invention discloses a Venturi flow meter, which comprises a shell, a Venturi tube and a flow dividing assembly, wherein the flow dividing assembly is located on the upstream of the Venturi tube. When the Venturi flow meter works, a gas flow from an EGR pipeline passes through the flow dividing assembly and then enters the Venturi tube. According to the Venturi flow meter, the flow dividing assembly is additionally arranged. Disordered gas can push a poking piece to rotate, the poking piece rotates to divide a hole, which is used for allowing the gas to pass through, of an annular supporting frame into two parts, and the flow division of the gas is achieved. In addition, the disordered gas can be subjected to the reaction of the poking piece, part of the gas colliding with the poking piece can be distributed to the side, which is not provided the poking piece, of the annular supporting frame, and the effect of redistributing the gas flow is achieved. The Venturi flow meter can effectively offset the influence of a bent pipeline of the EGR pipeline on the gas flow deviation, and optimizes the speed distribution of the gas flow entering the Venturi flow tube, so that the measurement precision of the Venturi flow meter is improved.

Description

technical field [0001] The invention relates to the technical field of engines, in particular to a Venturi flowmeter. Background technique [0002] Engine emission regulations are becoming more and more stringent, and EGR (exhaust gas recirculation) technology has become one of the technologies commonly used in engines. [0003] The EGR rate is the ratio of the amount of recirculated exhaust gas to the total amount of intake air inhaled into the cylinder. Reasonable control of the EGR rate is extremely important for the purification effect of nitrogen oxides and the emission of the whole machine. The control of the EGR rate also becomes the control of engine pollutants. The key to emissions, the accuracy of EGR flow measurement determines the accuracy of EGR rate control. [0004] The Venturi flowmeter requires uniform air velocity distribution at the throat, but due to the compact overall size of the EGR pipeline, the EGR pipeline upstream of the Venturi flowmeter is a ben...

AI Technical Summary

Problems solved by technology

[0004] The Venturi flowmeter requires uniform air velocity distribution at the throat, but due to the compact overall size of the EGR pipeline, the EGR pipeline upstream of the Venturi flowmeter is a bent pipeline, resulting in a significant deviation of the gas flow entering the Venturi flowmeter nature, and the degree of turbulence is high, which has an adverse effect on the measurement accuracy of the Venturi flowmeter

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