潍柴动力股份有限公司，山东 潍坊 261061
Abstract：In order to improve the measurement accuracy and boundary adaptability of the exhaust gas Venturi flowmeter, different exhaust gas measurement methods are compared, and the structure and measurement principle of the Venturi flowmeter are analyzed, a Venturi flowmeter with backflow measurement structure is designed. The measurement accuracy and boundary adaptability of Venturi flowmeter with and without backflow structure are then compared and analyzed through engine bench test. The results show that the measurement accuracy of the Venturi flowmeter with backflow measurement structure is higher. The minimum calibration factor of the modified pulse spectrum of the Venturi without backflow measurement structure is 0.5, and the calibration number coefficient of the modified pulse spectrum of the Venturi with backflow measurement structure is 0.9~1.1. The Venturi flowmeter without backflow measurement structure cannot accurately measure the exhaust pulse state, the Venturi flowmeter with backflow measurement structure is applicable to different operating modes of the engine and has high boundary adaptability.
Keywords:Venturi tube;backflow structure; measurement accuracy; boundary adaptability