A pre-catalytic gas extraction LP-EGR system

Abstract

A pre-catalytic converter intake (LP-EGR) system belongs to the field of gasoline engine exhaust aftertreatment technology for energy saving and emission reduction. This invention includes an engine block, a turbocharger connected to the engine block, and a three-way catalytic converter connected to the turbine outlet of the turbocharger. It also includes an EGR intake manifold, an EGR cooler, an EGR control valve, and a turbocharger intake manifold. The EGR intake manifold is located upstream of the three-way catalytic converter. The inlet of the EGR cooler is connected to the EGR intake manifold. The inlet of the EGR control valve is connected to the outlet of the EGR cooler. The turbocharger intake manifold is connected to the compressor inlet of the turbocharger. The outlet of the EGR control valve is connected to the turbocharger intake manifold via a pipeline. This invention can significantly reduce engine fuel consumption and improve engine thermal efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of energy-saving and emission-reduction technology of gasoline engine exhaust aftertreatment, specifically relating to a pre-catalytic intake LP-EGR system. Background Technology

[0002] Exhaust gas recirculation (EGR) technology is an important means of reducing nitrogen oxide emissions from gasoline engines and improving fuel economy. Among them, the low-pressure EGR (LP-EGR) system draws exhaust gas from downstream of the three-way catalytic converter after the turbocharger, cools it in the EGR cooler, and then delivers it to the front of the turbocharger compressor inlet, where it mixes with fresh air before entering the cylinder.

[0003] However, in existing conventional LP-EGR systems, the exhaust gas intake point is typically located downstream of the three-way catalytic converter. This arrangement has a limitation resulting in a low usable EGR rate: the intake point is located after the three-way catalytic converter, where the exhaust back pressure is relatively low, and the pressure difference with the turbocharger compressor inlet is small. This insufficient pressure differential power to drive exhaust gas recirculation limits the maximum achievable EGR rate, thus restricting fuel-saving potential. Therefore, it is necessary to optimize the intake arrangement of existing LP-EGR systems to overcome these shortcomings. Utility Model Content

[0004] This invention addresses the aforementioned problems and overcomes the shortcomings of existing technologies by providing a pre-catalytic intake LP-EGR system. This invention can significantly reduce engine fuel consumption and improve engine effective thermal efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution.

[0006] This utility model provides a pre-catalytic converter intake (LP-EGR) system, including an engine body, a turbocharger connected to the engine body, and a three-way catalytic converter connected to the turbine outlet of the turbocharger. The system is characterized by further including an EGR intake manifold, an EGR cooler, an EGR control valve, and a turbocharger intake manifold. The EGR intake manifold is located upstream of the three-way catalytic converter. The inlet of the EGR cooler is connected to the EGR intake manifold. The inlet of the EGR control valve is connected to the outlet of the EGR cooler. The turbocharger intake manifold is connected to the compressor inlet of the turbocharger. The outlet of the EGR control valve is connected to the turbocharger intake manifold via a pipeline.

[0007] Furthermore, the EGR intake branch pipe is welded to the cylinder of the three-way catalytic converter.

[0008] Furthermore, the EGR intake branch is located before the carrier of the three-way catalytic converter.

[0009] Furthermore, the outlet of the EGR control valve is connected to the inlet pipe of the turbocharger via an EGR outlet hose.

[0010] Furthermore, the intake port of the EGR intake branch is located upstream of the carrier of the three-way catalytic converter.

[0011] The beneficial effects of this utility model.

[0012] Because the intake point of this invention is located before the three-way catalytic converter carrier, the exhaust pressure at this point is much higher than the inlet pressure of the turbocharger compressor, creating a strong pressure differential driving force. This allows the system to overcome the flow resistance of the EGR system and introduce sufficient exhaust gas even under high engine load and high boost conditions, thus achieving a higher EGR rate than traditional downstream intake methods, laying the foundation for deep fuel savings. A higher EGR rate means that less fuel can be used to achieve the same work requirement under more operating conditions, directly reducing the engine's fuel consumption rate and improving the engine's effective thermal efficiency. The intake point temperature is extremely high, and the moisture in the exhaust gas is in a gaseous state. The risk of condensation when flowing through the EGR cooler is relatively controllable, which helps reduce the corrosion of the pipeline by acidic condensate and minimizes the risk of condensation. Attached Figure Description

[0013] To make the technical problems solved, the technical solutions, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0014] Figure 1 This is a cross-sectional structural diagram of the present invention.

[0015] Figure 2 This is a schematic diagram of the external structure of this utility model.

[0016] The markings in the diagram are as follows: 1 is the engine block, 2 is the turbocharger, 3 is the three-way catalytic converter, 4 is the EGR intake manifold, 5 is the EGR cooler, 6 is the EGR control valve, 7 is the EGR outlet hose, 8 is the turbocharger intake manifold, and 9 is the carrier. Detailed Implementation

[0017] As shown in the accompanying drawings, this embodiment provides a pre-catalytic converter LP-EGR system, including an engine body, with a turbocharger 2 connected to the engine body 1. A three-way catalytic converter 3, acting as a tightly coupled catalytic converter, has its inlet end connected to the turbine outlet of the turbocharger 2.

[0018] The EGR intake branch pipe 4 is welded to the cylinder of the three-way catalytic converter 3, and its intake port is located upstream of the carrier 9 inside the three-way catalytic converter 3, that is, before the exhaust gas reaches the carrier 9.

[0019] The inlet of the EGR cooler 5 is connected to the EGR intake branch pipe 4 via a pipeline. The inlet of the EGR control valve 6 is connected to the outlet of the EGR cooler 5, and the EGR control valve 6 is used to regulate the flow rate of the recirculated exhaust gas.

[0020] The turbocharger intake pipe 8 is connected to the compressor inlet of the turbocharger 2. The outlet of the EGR control valve 6 is connected to the turbocharger intake pipe 8 through the EGR outlet hose 7.

[0021] The working principle is as follows: The high-temperature, high-pressure exhaust gas generated during engine operation drives the turbine of turbocharger 2 and is discharged. A portion of the exhaust gas, driven by high pressure, is drawn into the LP-EGR circuit from the EGR intake manifold 4 located upstream of the three-way catalytic converter carrier 9. This high-temperature exhaust gas first flows through the EGR cooler 5 to be cooled, and then flows through the EGR control valve 6. The engine control unit (ECU) precisely adjusts the opening of the EGR control valve 6 according to operating conditions. The adjusted exhaust gas is then delivered to the turbocharger intake manifold 8 via the EGR outlet hose 7, where it mixes with fresh air and is subsequently drawn into the compressor of turbocharger 2. After being pressurized, it is sent to the engine cylinders for combustion. The remaining exhaust gas continues to flow through the carrier 9 of the three-way catalytic converter 3 for purification before being discharged into the atmosphere.

[0022] The key is to ensure that the physical location of the LP-EGR intake is upstream of the three-way catalytic converter carrier 9, thereby obtaining a high-pressure, high-temperature exhaust gas source. This arrangement makes full use of exhaust pulse energy and pressure, providing a fundamental guarantee for achieving a high EGR rate, and ultimately achieving the goal of reducing fuel consumption and improving thermal efficiency.

[0023] It is understood that the above specific description of this utility model is only used to illustrate this utility model and is not limited to the technical solutions described in the embodiments of this utility model. Those skilled in the art should understand that modifications or equivalent substitutions can still be made to this utility model to achieve the same technical effect; as long as the use needs are met, they are all within the protection scope of this utility model.

Claims

1. A catalytic pre-gas type LP-EGR system comprising an engine body (1), a turbocharger (2) connected to the engine body (1), and a three-way catalyst (3) connected to a turbine outlet of the turbocharger (2), characterized by, It also includes an EGR intake manifold (4), an EGR cooler (5), an EGR control valve (6), and a turbocharger intake manifold (8). The EGR intake manifold (4) is located upstream of the three-way catalytic converter (3). The intake port of the EGR cooler (5) is connected to the EGR intake manifold (4). The intake port of the EGR control valve (6) is connected to the outlet port of the EGR cooler (5). The turbocharger intake manifold (8) is connected to the compressor inlet of the turbocharger (2). The outlet port of the EGR control valve (6) is connected to the turbocharger intake manifold (8) through a pipeline.

2. The pre-catalytic gas extraction LP-EGR system according to claim 1, characterized in that, The EGR intake branch pipe (4) is welded to the cylinder of the three-way catalytic converter (3).

3. The pre-catalytic gas extraction LP-EGR system according to claim 2, characterized in that, The EGR intake branch (4) is located before the carrier (9) of the three-way catalytic converter (3).

4. The pre-catalytic gas extraction LP-EGR system according to claim 1, characterized in that, The outlet of the EGR control valve (6) is connected to the inlet pipe (8) of the turbocharger via the EGR outlet hose (7).

5. The pre-catalytic gas extraction LP-EGR system according to claim 1, characterized in that, The gas intake port of the EGR intake branch (4) is located upstream of the carrier (9) of the three-way catalytic converter (3).

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