Cast shell type EGR cooler

Abstract

The invention relates to a cast shell type EGR cooler. An air inlet connector is connected with a telescopic structure with a corrugated pipe and a sleeve, the outer circumference of the telescopic structure is fixedly connected with an input end flange cover, and the input end flange cover is in bolted connection with one end of a cast pipe shell through an input end sealing gasket. The other endof the pipe shell is in bolted connection with a fixing structure and an output end flange cover with an output pipe connector through an output end sealing ring. The telescopic structure is welded to and connected with a pipe plate at one end of a pipe bundle, and a pipe plate at the other end of the pipe bundle is welded to and connected with the fixing structure. According to the cast shell type ERG cooler, the fixing structure is arranged at one end of the pipe bundle, the telescopic structure is arranged at the other end of the pipe bundle, the problem of dislocation between the pipe shell and the pipe bundle due to thermal expansion and cold contraction is solved, axial displacement compensation is conducted on a heat exchange core through a flexible structure of a double-layer corrugated pipe in the telescopic structure, the influence of thermal expansion and cold contraction on the heat exchange core is reduced, the double-layer corrugated pipe is placed at an air inlet end and combined with a shell water inlet structure, the water flow space is increased, and water flow uniformity is guaranteed.

Description

technical field [0001] The invention relates to a casting shell type EGR cooler, which is an auxiliary device of mechanical equipment and a cooler of a recirculation system of an automobile engine. Background technique [0002] With the continuous upgrading of automobile emission standards, exhaust gas recirculation systems have been widely applied to heavy-duty diesel and natural gas engines. Compared with light-duty engines, medium- and heavy-duty engines have large exhaust gas flow and high temperature. Considering the high vibration and high heat of heavy-duty engines Due to the thermal resistance and cold contraction effect caused by the impact and the risk of internal boiling, the EGR cooler needs to have high performance and high reliability. [0003] (1) Most of the cooling liquid of the prior art cooler directly exchanges heat with the tube bundle in the high-temperature exhaust gas circulation area, and the temperature on the gas side is as high as 800°C. If there ...

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Problems solved by technology

[0003] (1) Most of the cooling liquid of the prior art cooler directly exchanges heat with the tube bundle in the high-temperature exhaust gas circulation area, and the temperature on the gas side is as high as 800°C. If there is uneven distribution of local cooling liquid, it is easy to produce a dead zone of water flow, which affects Gas-liquid heat exchange, modal boiling occurs on the liquid side, the surface of the heat exchange tube bundle continues to dry, and thermal cracks occur on the wall of the tube bundle to fail

[0004] (2) Most of the tube bundle support methods of coolers in the prior art adopt the way of inter-tube support, that is, the channel fin structure is added between the tube bundles as the support between the tube bundles. There is no auxiliary support structure with the shell in the middle of the long tube bundle, and the natural frequency of the internal tube bundle will be relatively low. For the influence of thermal expansion and contraction stress caused by long-term vibration and thermal shock of the engine, reliability problems are prone to occur (especially in Structural failure at the end), prone to resonance

[0005] (3) In order to cope with the axial displacement of the tube bundle and the main radial support for the tube bundle, most of the current existing schemes adopt the structure of O-ring + end joint. For support, this method has high requirements for the reliability of the O-ring, and the O-ring is prone to failure if it is squeezed and worn for a long time

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