Steel Piston Cooling Gallery Filled with Solid Coolant
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Solution Overview
Problem
Pistons in internal combustion engines face challenges with high temperature management, as conventional oil cooling degrades and can lead to oil coking at temperatures above 350°C, causing corrosion and erosion.
Innovation Solution
A steel piston with a cooling gallery filled with a solid coolant having higher thermal conductivity than steel, which reduces the need for conventional oil cooling and prevents oil coking by acting as a temperature buffer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional oil cooling is used in the cooling gallery, then cooling effect is achieved, but oil degrades and cokes at high temperatures above 350°C
Solution Approach 1:
The patent changes the physical state parameter of the coolant from liquid (oil) to solid, and changes the thermal conductivity parameter by selecting materials with higher thermal conductivity than steel. This resolves the contradiction by providing effective cooling through high thermal conductivity while eliminating oil degradation and coking issues associated with liquid oil at high temperatures.
Solution Approach 2:
The patent uses composite material filling the cooling gallery that has higher thermal conductivity than steel. This composite material provides superior heat dissipation compared to conventional oil, achieving better cooling effect without the harmful effects of oil degradation and coking that occur at temperatures above 350°C.
2Temperature
If high flow of oil is maintained constantly for cooling, then piston temperature is controlled, but oil must be changed periodically and engine life is reduced
Solution Approach 1:
The patent changes the coolant from liquid oil requiring continuous flow and periodic replacement to a solid material that remains stable indefinitely. The solid coolant with higher thermal conductivity maintains piston temperature control without degradation, eliminating the need for oil changes and extending engine life.
Solution Approach 2:
The patent replaces the disposable, degradable oil coolant with a permanent, non-degradable solid coolant. Unlike oil that must be periodically changed, the solid coolant remains effective throughout the engine's operational life, eliminating maintenance requirements and extending service intervals.
3Temperature
If cooling gallery temperature exceeds 350°C, then oil coking occurs and adheres to gallery surface, but effective cooling is needed
Solution Approach 1:
The patent changes the coolant from oil that cokes at temperatures above 350°C to a solid material that is thermally stable at these temperatures. The solid coolant with higher thermal conductivity provides effective cooling while resisting thermal decomposition, preventing coking and surface adhesion problems.
Solution Approach 2:
The patent converts the harmful effect of high temperature into a beneficial outcome by using a solid coolant that thrives at high temperatures. Instead of oil degrading and coking above 350°C, the solid coolant material maintains stability and provides enhanced cooling performance, turning the high-temperature challenge into an advantage.
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 solid coolant provides effective cooling and structural support, reducing corrosion and erosion while maintaining engine performance without the need for continuous oil flow, and preventing oil coking at high temperatures.
Implementation Method 1
A solid coolant having a thermal conductivity which is greater than the thermal conductivity of the steel material fills at least 15 volume percent (vol. %) of the cooling gallery
Data Source
AI summary
A steel piston for an internal combustion including a cooling gallery containing a solid coolant, such as an aluminum-based material, is provided. The solid coolant has a thermal conductivity which is greater than the thermal conductivity of the steel material and fills at least 15 volume percent (vol. %) of the cooling gallery. The solid coolant provides for exceptional cooling along a crown of the piston, reduces corrosion and erosion along the crown, and avoids the problem of oil coking.