Vehicle Heat Exchanger Flow Reducer for Tube Durability
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Solution Overview
Problem
Heat exchangers, such as charge air coolers, face durability issues due to high temperature gradients between hot and cold air regions, leading to potential tube cracking near the header.
Innovation Solution
Incorporating a flow reducer in the hot end tube to reduce fluid flow and velocity, thereby lowering the temperature gradient and thermal stresses on adjacent cold end tubes, increasing the heat exchanger's durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the hot air region and cold air region are located next to each other in the header, then the heat exchanger structure is compact and efficient, but the temperature gradient between adjacent hot end tube and cold end tube causes thermal stress and tube cracking
Solution Approach 1:
The patent applies local quality by introducing a flow reducer specifically in the hot end tube adjacent to the cold end tube, creating a localized modification to reduce fluid flow and velocity only where the temperature gradient problem occurs. This localized intervention reduces thermal stress at the critical location without affecting the overall heat exchanger performance.
2Productivity
If high fluid velocity is maintained in the hot end tube, then heat transfer efficiency is improved, but thermal stress on the tube increases due to high temperature gradient
Solution Approach 1:
The patent changes the flow velocity parameter locally in the hot end tube by introducing a flow reducer. This reduces the fluid velocity and consequently the temperature gradient, thereby decreasing thermal stress on the tube while maintaining acceptable heat transfer efficiency through the overall system design.
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 reduced temperature gradient and fluid velocity in the hot end tube minimize thermal stresses, enhancing the durability and longevity of the heat exchanger by reducing the risk of tube failure.
Implementation Method 1
the flow reducer reduces the air flow in the hot end tube
Implementation Method 2
the temperature difference between the hot end tube and the cold end tube leads to a high temperature gradient within a small area
Implementation Method 3
the gradient of temperature of the fluid in the cold end tube is reduced. Therefore, the thermal stresses that would normally be applied on these tubes are also lowered
Data Source
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AI summary
A heat exchanger comprises a first header, a second header, a plurality of tubes, and a flow reducer. The first header is connected to a hot fluid inlet and to a cold fluid outlet, so that the first header comprises a hot region and a cold region, separated by a wall. Each of the plurality of tubes provides fluid communication between the first and second headers, including one tube located next to the wall in the hot region of the first header, being called “hot end tube” , and one tube located next to the wall in the cold region of the first header, being called “cold end tube” . The flow reducer reduces the fluid flow in the hot end tube compared to the fluid flow in other tubes located in the hot region.