Water Cooled EGR Cooler Brazed Supporter Corrosion
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Solution Overview
Problem
Existing water-cooled EGR coolers face issues with corrosion at bonded tube portions, leading to durability concerns and inefficient heat transfer due to the use of aluminum materials in high-temperature, corrosive environments, resulting in coolant leakage and reduced engine operation stability.
Innovation Solution
A water-cooled EGR cooler design featuring aluminum tubes and supporters with a zig-zag shape, where the supporters are brazed to the tubes to form a reinforcing bonded portion, enhancing corrosion resistance and maintaining a stable interval between tubes, and incorporating cooling pins for improved heat transfer efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If aluminum materials are used in EGR cooler tubes, then cost and weight are reduced, but corrosion resistance in high-temperature and corrosive environments deteriorates
Solution Approach 1:
The patent applies composite materials by combining aluminum tubes with stainless steel supporters. The aluminum tubes provide lightweight and cost-effective properties, while the stainless steel supporters provide corrosion resistance in the bonded portions. This composite structure resolves the contradiction by integrating materials with complementary properties - the aluminum material reduces weight and cost, while the stainless steel reinforcement maintains reliability in corrosive environments.
2Ease of manufacture
If aluminum tubes are used in high-temperature environment, then cost is reduced, but durability due to corrosion and coolant leakage deteriorates
Solution Approach 1:
The patent applies beforehand cushioning by pre-installing supporters at the bonded portions of the tubes before the corrosion and coolant leakage issues can develop. The supporters are positioned in advance to prevent corrosion propagation and provide structural reinforcement at the most vulnerable points (the bonded portions), thereby extending durability while maintaining cost-effectiveness of aluminum materials.
3Device complexity
If tube bonded portions are used to connect tubes, then assembly is simplified, but corrosion at bonded portions increases leading to coolant leakage
Solution Approach 1:
The patent applies intermediary by introducing supporters as a mediating element between the aluminum tubes at their bonded portions. The supporters act as an intermediate protective layer that prevents direct exposure of the bonded portions to corrosive environments. This intermediary structure maintains the simple assembly process while eliminating the harmful corrosion effect at the bonded portions.
4Reliability
If stainless material is used in EGR cooler, then corrosion resistance is improved, but weight increases and heat transfer efficiency decreases
Solution Approach 1:
The patent applies local quality by providing corrosion resistance only at the specific locations where it is most needed - the bonded portions of the tubes - rather than throughout the entire tube structure. The stainless steel supporters are strategically placed at the bonded portions to provide localized corrosion protection, while the majority of the tube structure remains as lightweight, high heat transfer efficiency aluminum material.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces corrosion at bonded portions, enhances durability, and improves engine operation stability by maintaining a stable coolant flow and efficient heat transfer, addressing the limitations of traditional EGR coolers.
Implementation Method 1
a water-cooled EGR cooler configured for cooling exhaust gas re-circulated from an exhaust line to an intake line with a coolant therein
Implementation Method 2
a coolant passage in which a coolant flows between the tubes
Implementation Method 3
an external surface of a first side of the supporter is bonded to an external surface of the tubes forming a reinforcing bonded portion wherein the supporter covers and seals the tube bonded portion
Data Source
AI summary
A water-cooled exhaust gas recirculation (EGR) cooler may include tubes positioned within a housing at a predetermined interval, which forms an exhaust gas passage that exhaust gas passes therethrough, and a tube bonded portion that seals internally and externally the tube is provided at a first side of the tube; and supporters interpose the tubes to define a predetermined interval between the tubes and positioned within the housing wherein a coolant passage which a coolant flows between the tubes is formed, wherein an external surface of a first side of the supporter is bonded to an external surface of the tubes to form a reinforcing bonded portion wherein the supporter covers and seals the tube bonded portion.