阅读说明：本技术 一种利于发动机废气流量精确测量的文丘里管结构参数 (Venturi tube structural parameter beneficial to accurate measurement of engine exhaust gas flow ) 是由 董家枝 黄新周 刘显宏 于 2020-12-11 设计创作，主要内容包括：本发明公开了一种利于发动机废气流量精确测量的文丘里管结构参数,应用于文丘里管,文丘里管包括依次设置且相连接的进气段、喉部和出气段,进气段的直径为D1,长度为L1,喉部的直径为D2,长度为L2,出气段的末端直径为D3,长度为L3,发动机排量为L,其中,D1/D2＝2.0～2.5,D2/D3＝0.5～0.7,L/D1＝0.07～0.08,L/D2＝0.17～0.19,L/D3＝0.10～0.11,L1/L2＝6.0～6.5,L2/L3＝0.2～0.3。本发明根据发动机排量设定文丘里管的具体结构参数,可以更准确的通过压差传感器测出通过该文丘里管的EGR流量,可实现EGR率更精确的控制,更快速的响应。(The invention discloses a venturi tube structure parameter beneficial to accurate measurement of engine exhaust gas flow, which is applied to a venturi tube, wherein the venturi tube comprises an air inlet section, a throat part and an air outlet section which are sequentially arranged and connected, the diameter of the air inlet section is D1, the length of the air inlet section is L1, the diameter of the throat part is D2, the length of the throat part is L2, the diameter of the tail end of the air outlet section is D3, the length of the air outlet section is L3, and the engine displacement is L, wherein D1/D2 is 2.0-2.5, D2/D3 is 0.5-0.7, L/D1 is 0.07-0.08, L/D2 is 0.17-0.19, L/D3 is 0.10-0.11, L1/L2 is 6.0-6.5, and L2/L3 is 0.2-0.3. The invention sets the specific structural parameters of the Venturi tube according to the engine displacement, can more accurately measure the EGR flow passing through the Venturi tube through the differential pressure sensor, and can realize more accurate control and quicker response of the EGR rate.)

1. The venturi tube structure parameters beneficial to accurate measurement of the engine exhaust gas flow are applied to the venturi tube, and the venturi tube comprises an air inlet section, a throat part and an air outlet section which are sequentially arranged and connected, and is characterized in that the diameter of the air inlet section is D1, the length of the air inlet section is L1, the diameter of the throat part is D2, the length of the throat part is L2, the diameter of the end of the air outlet section is D3, the length of the air outlet section is L3, and the engine displacement is L, wherein D1/D2 is 2.0-2.5, D2/D3 is 0.5-0.7, L/D1 is 0.07-0.08, L/D2 is 0.17-0.19, L/D3 is 0.10-0.11, L1/L2 is 6.0-6.5, and L2/L3 is 0.2-0.3.

2. The venturi tube structure parameter facilitating accurate measurement of engine exhaust gas flow according to claim 1, wherein a differential pressure sensor seat is disposed on an outer wall of a middle portion of the venturi tube, and a differential pressure sensor is disposed on the differential pressure sensor seat and extends into the air intake section and the throat portion respectively.

Technical Field

The invention relates to the technical field of engines, in particular to a venturi tube structure parameter beneficial to accurate measurement of engine exhaust gas flow.

Background

The current situation of energy saving and emission reduction is severe, and the accurate control to the air intake flow of engine etc. has provided higher requirement, especially high temperature gas (like EGR waste gas), and ordinary flowmeter structure parameter range sets up unreasonablely, can't satisfy the instantaneous changeable operation requirement of engine operating mode, provides accurate regulation control signal for EGR valve opening control.

The existing scheme is generally based on the requirements of different load working conditions of an engine under a steady state condition, the throat size of a Venturi tube is set after the exhaust gas flow of the engine is calculated according to theory, the structural parameter range setting and size control are not specially verified, the working environment with the instantaneously changeable working conditions of the actual operation and the use working conditions of the engine is controlled unreasonably, the accurate control of the gas flow converted along with the instantaneously changeable working conditions of the engine cannot be realized, particularly, high-temperature gas such as EGR exhaust gas cannot reach the ideal gas mixture ratio, the engine cannot operate in the optimal state according to the use working conditions, and the power economy and the emission are not in the optimal state.

Disclosure of Invention

Aiming at the problems, through tests and robustness verification of a large number of special engine performance tests, the invention provides a venturi tube structure parameter beneficial to the accurate measurement of the engine exhaust gas flow, and the specific structure parameter of the venturi tube is set according to the engine displacement, so that the EGR flow passing through the venturi tube can be measured more accurately through a differential pressure sensor, the more accurate control of the EGR rate can be realized, and the quicker response can be realized.

The invention adopts the following technical scheme to realize the purpose:

the venturi tube comprises an air inlet section, a throat part and an air outlet section which are sequentially arranged and connected, wherein the diameter of the air inlet section is D1, the length of the air inlet section is L1, the diameter of the throat part is D2, the length of the throat part is L2, the diameter of the tail end of the air outlet section is D3, the length of the air outlet section is L3, and the engine displacement is L, wherein D1/D2 is 2.0-2.5, D2/D3 is 0.5-0.7, L/D1 is 0.07-0.08, L/D2 is 0.17-0.19, L/D3 is 0.10-0.11, L1/L2 is 6.0-6.5, and L2/L3 is 0.2-0.3.

Preferably, the outer wall of the middle part of the venturi tube is provided with a differential pressure sensor seat, the differential pressure sensor seat is provided with a differential pressure sensor, and the differential pressure sensor respectively extends into the air inlet section and the throat part.

The invention has the beneficial effects that:

through tests and robustness verification of a large number of special engine performance tests, the invention provides a venturi tube structure parameter beneficial to accurate measurement of engine exhaust gas flow, and the specific structure parameter of the venturi tube is set according to the engine displacement, so that the EGR flow passing through the venturi tube can be measured more accurately through a differential pressure sensor, and more accurate control and quicker response of the EGR rate can be realized.

The venturi tube structure parameter beneficial to the accurate measurement of the engine exhaust gas flow is the ratio of the diameters of all sections, the engine displacement and the ratio of the diameters are a constant, and the venturi tube suitable for the engine can be designed according to the constant and the engine displacement. When the air flow is led to the pressure difference sensor seat through the inlet and the throat passage, the air flow can be indirectly calculated according to the pressure change, and the accurate control and the quick response of the EGR are realized.

Drawings

FIG. 1 is a schematic structural diagram of structural parameters of a venturi tube for facilitating accurate measurement of engine exhaust gas flow according to an embodiment of the present invention.

In the figure, 1 is an air inlet section, 2 is a throat part, 3 is an air outlet section, and 4 is a differential pressure sensor seat.

Detailed Description

The present invention will be described in detail with reference to the accompanying fig. 1 and the embodiments.

Referring to fig. 1, the present embodiment provides a venturi tube structure parameter beneficial to the accurate measurement of the exhaust gas flow of an engine, which is applied to a venturi tube, and the venturi tube includes an air inlet section 1, a throat section 2 and an air outlet section 3, which are sequentially arranged and connected. The diameter of the air inlet section 1 is D1, and the length is L1. The throat 2 has a diameter D2 and a length L2. The tail end of the air outlet section 3 has a diameter D3 and a length L3. The engine displacement is L. Wherein D1/D2 is 2.0-2.5, D2/D3 is 0.5-0.7, L/D1 is 0.07-0.08, L/D2 is 0.17-0.19, L/D3 is 0.10-0.11, L1/L2 is 6.0-6.5, and L2/L3 is 0.2-0.3.

Through tests and robustness verification of a large number of special engine performance tests, the invention provides a venturi tube structure parameter beneficial to accurate measurement of engine exhaust gas flow, and the specific structure parameter of the venturi tube is set according to the engine displacement, so that the EGR flow passing through the venturi tube can be measured more accurately through a differential pressure sensor, and more accurate control and quicker response of the EGR rate can be realized.

In the embodiment, the outer wall of the middle part of the venturi tube is provided with a differential pressure sensor seat 4, the differential pressure sensor seat 4 is provided with a differential pressure sensor, and the differential pressure sensor respectively extends into the air inlet section 1 and the throat part 2.

The invention is beneficial to the accurate measurement of the exhaust gas flow of the engine, the structural parameters of the Venturi tube of each section, the ratio of the pipe diameter of each section and the ratio of the discharge capacity of the engine are constant, and the Venturi tube structure suitable for the engine can be designed according to the constant and the discharge capacity of the engine. When the air flow is led to the differential pressure sensor seat 4 through the air inlet section 1 and the throat part 2, the air flow can be indirectly calculated according to the pressure change, and the accurate control and the quick response of the EGR are realized.

Although the invention has been described in detail above with reference to specific embodiments, it will be apparent to one skilled in the art that modifications or improvements may be made based on the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.