Exhaust gas recirculation cooler

Abstract

The invention relates to an exhaust gas recirculation cooler, which comprises a shell and a plurality of pitted heat dissipation pipes arranged in an array, and the outer wall of each pitted heat dissipation pipe is evenly equipped with "eight" Glyph-shaped grooves and protrusions. The grooves and protrusions are evenly distributed along the length of the pipe body in the form of two alternately arranged combination units. The first combination unit is the opposite distribution of the expanded ends of two "eight"-shaped grooves. The overall shape is diamond-shaped, and the conical protrusion is set in the middle of two "eight"-shaped grooves at the expansion end; the second combination unit is two "eight"-shaped grooves. There is no conical protrusion between the two grooves; the protrusions on two adjacent opposite pitted heat sinks are arranged alternately. The use of pitted heat pipes can increase the flow of exhaust gas, increase the heat exchange area, limit the deposition of soot, and improve the heat exchange efficiency; the matrix arrangement is adopted to ensure the distance between the pipes, and the coolant has better cross flow.

Description

Exhaust gas recirculation cooler technical field [0001] The present invention relates to the technical field of automobile exhaust gas cooling, in particular to a kind of exhaust gas recirculation cooler. Background technique With the gradual implementation of National VI emission standards, how to reduce NOx (nitrogen oxides), PM (particles) in diesel engine exhaust It has become an important issue at present to meet the emission regulations of China VI. EGR (exhaust gas recirculation system system) as a high-efficiency NOX reduction technology, in medium and heavy-duty diesel engines to rival the three-way catalytic (SCR) system The technology plays an important role in meeting China VI emission regulations. Its working principle is that the waste generated by the combustion of the engine is The gas is cooled and returned to the combustion chamber. Due to the inertness of the exhaust gas, it does not participate in the combustion in the combustion chamber, but it...

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Problems solved by technology

[0004] At present, the exhaust gas recirculation cooler mainly adopts the hydroforming and welding integrated type, that is, the parts of the cooler are connected together by welding, including the cooler inlet chamber, the inlet main piece, the core body, the outlet main piece and the outlet chamber, In addition, plate-fin heat sinks are used to exchange heat for circulating exhaust gas. The disadvantage of this hydroformed and welded integrated cooler is that local welding deformation is prone to occur during the assembly process of each component, which reduces assembly accuracy and affects the assembly size at the engine end, resulting in It is difficult to assemble; it needs to install fasteners to fix it on the engine end, and the labor cost is relatively high; the existing plate-fin heat sink is made of aluminum, which has high heat transfer efficiency and can basically meet the performance requirements of the cooler, but the airflow The flow channel is small and easy to block. It is required that the medium does not corrode aluminum, the aluminum fins are thin, the design of the exhaust gas channel is difficult, and the thermal durability is low.

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