Low-pressure EGR water heating structure

Abstract

The invention relates to a low-pressure EGR water heating structure which comprises a turbocharger, an EGR cooler, an EGR control valve, a mixing valve, a three-way pipe and an EGR pipeline. According to the technical scheme, the air inflow of low-pressure EGR is accurately controlled through the mixer, and therefore the EGR rate is accurately controlled. Through a heating water jacket structure, ice formed by condensed water in a pipeline in front of a supercharger impeller is heated, and the situation that the section of the pipe wall is reduced due to freezing, and the EGR rate of engine restart is affected is avoided; meanwhile, the situation that the engine cannot work normally due to the fact that crushed ice damages supercharger blades is avoided. The ice crushing net at the tail end of the EGR pipeline can ensure that ice blocks are rapidly and completely melted, and large ice blocks are prevented from entering a pressing shell to damage pressing wheel blades.

Description

technical field [0001] The invention belongs to the technical field of engines, and in particular relates to a low-pressure EGR water heating structure. Background technique [0002] EGR technology (exhaust gas recirculation technology) is a technology that uses a part of engine exhaust gas to participate in combustion again. The main purpose is to reduce the maximum combustion temperature in the cylinder, improve the thermal efficiency of the engine, and the oxygen concentration of the in-cylinder mixer, and destroy the environment for the formation of NOx, thereby reducing NOx emissions. [0003] EGR technology includes internal EGR and external EGR in two ways: [0004] Internal EGR increases the amount of residual exhaust gas in the cylinder by enlarging the valve overlap angle, that is, increasing the opening time of the intake valve in advance and delaying the closing time of the exhaust valve to participate in the next cycle, thereby realizing EGR; [0005] External...

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Problems solved by technology

[0012] The purpose of the present invention is to provide a low-pressure EGR water heating structure to solve the problem that the air volume before the supercharger of the low-pressure EGR cannot be accurately controlled, so that the EGR rate cannot be accurately controlled, and the water in the exhaust gas after the EGR cooler is condensed in the pipeline After icing, the section of the pipe wall becomes smaller, which affects the EGR rate of the engine restart, and at the same time, it will cause the crushed ice to damage the blades of the supercharger, resulting in the problem that the engine cannot work normally.

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