Turbocharged Engine Cooling Circuit Segmentation
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Solution Overview
Problem
In turbocharged internal combustion engines, high charge air pressure and temperature, combined with humidity, lead to condensation of water vapor, causing corrosion and erosion of engine components, and pose challenges in cooling water system design and control, especially in two-stage turbocharged engines where the cooling needs are higher and lubrication oil temperature must be maintained within safe limits.
Innovation Solution
The method involves configuring at least two lubrication oil coolers within the cooling liquid circuit, one upstream and one downstream of the charge air cooler, to control the heat exchange power, ensuring the charge air temperature remains above the dew point and maintaining lubrication oil temperature within operational ranges by adjusting the heat exchange power of these coolers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If charge air is cooled by a charge air cooler to reduce condensation, then the temperature of charge air must be kept above dew point, but this limits the ability to sufficiently cool charge air in high humidity conditions
Solution Approach 1:
The cooling system is segmented into two separate circuits: a low-temperature cooling circuit for charge air cooling and a high-temperature cooling circuit for lubrication oil cooling. This segmentation allows independent control of each cooling function, enabling the charge air to be cooled more effectively without being constrained by lubrication oil temperature requirements.
Solution Approach 2:
The patent introduces an intermediate heat exchanger that transfers heat from the low-temperature cooling circuit to the high-temperature cooling circuit. This intermediary allows the systems to be thermally coupled while maintaining operational independence, enabling heat recovery from the charge air cooling process to pre-cool the lubrication oil.
2Device complexity
If a single cooling circuit is used for both charge air and lubrication oil, then device complexity is reduced, but controllability of temperatures is compromised
Solution Approach 1:
The cooling system is segmented into functionally independent circuits with separate control mechanisms. Each circuit has its own cooler and control system, enabling precise temperature control of charge air and lubrication oil independently, while the overall architecture remains relatively simple through modular 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
This approach reduces condensation in the charge air system, minimizing corrosion and erosion, while improving the controllability of engine lubrication oil and cooling liquid temperatures, ensuring they remain within optimal ranges.
Implementation Method 1
the pressurised charge air is cooled by a charge air cooler
Implementation Method 2
water vapour in charge air condenses into water
Implementation Method 3
lubrication oil for engine lubrication in a lubrication oil circuit is cooled by a lubrication oil cooler
Data Source
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AI summary
Method of operating a turbocharged internal combustion engine (1), which comprises a cooling liquid circuit (13) for engine (1) cooling liquid, in which method - charge air is pressurised at a turbo charger (6), - the pressurised charge air is cooled by a charge air cooler (10), - there are provided at least two lubrication oil coolers (14a, 14b) which are configured to the cooling liquid circuit (13) so that one lubrication oil cooler (14a) is connected to a upstream position in relation to the charge air cooler (10) and one lubrication oil cooler (14b) is connected to a downstream position in relation to the charge air cooler (10), the temperature of the charge air after said charge air cooler (10) is kept higher than corresponding dew point (Td) and the temperature of the lubrication oil is kept within an operational range (Tlo) by controlling the heat exchange power of said lubrication oil coolers (14a, 4b).