Two-Stage Supercharged Engine Cooling with Differential Coolant Temperatures
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Solution Overview
Problem
Supercharged combustion engines face inefficiencies in cooling compressed air to high pressures, leading to increased material costs for heat-tolerant components and higher loads on cooling systems.
Innovation Solution
A two-stage compression system with intermediate cooling using coolant from a second cooling system at a lower temperature, followed by cooling with coolant from a first system and then the surroundings, reduces the load on the second cooling system and maintains optimal air temperature before entering the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If air is compressed to high pressure in one step, then compression speed is improved, but air temperature becomes excessively high requiring expensive heat-tolerant materials
Solution Approach 1:
The compression process is divided into two distinct stages using two separate compressors. The first compressor performs initial compression, followed by intermediate cooling, then the second compressor performs final compression to achieve the desired high pressure. This segmentation prevents excessive temperature rise that would occur with single-stage compression to the same final pressure.
Solution Approach 2:
Cooling is performed as a preliminary action between the two compression stages. The air is cooled after the first compression step but before entering the second compressor. This intermediate cooling reduces the air temperature and specific volume, allowing the second compressor to handle more air efficiently while maintaining lower final temperatures.
2Temperature
If air is compressed in two stages with intermediate cooling, then air temperature after compression is reduced, but device complexity increases
Solution Approach 1:
The cooling system serves multiple functions: it cools the air between compression stages, cools the combustion engine, and provides overall thermal management for the system. By making the cooling system multi-functional, the patent reduces the need for separate dedicated cooling components, thereby offsetting some of the complexity introduced by the two-stage compression system.
Solution Approach 2:
The patent combines the cooling of compressed air with the cooling of the combustion engine into a single integrated cooling system. The coolant circulating through the engine also passes through heat exchangers that cool the compressed air, merging two cooling functions into one system to reduce overall complexity.
3Device complexity
If a single cooling system is used for both engine cooling and charge air cooling, then device complexity is reduced, but cooling effectiveness is insufficient
Solution Approach 1:
Different parts of the cooling system are designed with different properties to suit their specific functions. The first cooling system uses coolant at a temperature suitable for general engine cooling, while the second cooling system uses coolant at a lower temperature specifically for cooling the highly compressed air. This local differentiation of cooling temperatures ensures each component receives appropriately cooled fluid for its specific thermal requirements.
Solution Approach 2:
The patent changes the temperature parameter of the coolant by implementing two separate cooling systems with different operating temperatures. The second cooling system maintains coolant at a lower temperature than the first system, enabling it to effectively cool the hot compressed air that requires more aggressive cooling than the engine itself.
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 enhances compression efficiency, reduces the need for expensive heat-tolerant materials, and allows for effective cooling of both compressed air and exhaust gases, improving engine performance and reducing nitrogen oxide emissions.
Implementation Method 1
a compressor of a first turbo unit subjecting the air to a first compression step
Implementation Method 2
a first charge air cooler in which the compressed air is cooled by coolant from a first cooling system for cooling the combustion engine
Implementation Method 3
a compressor in a second turbo unit subjecting the air to a second compression step
Implementation Method 4
a second charge air cooler in which the compressed air is cooled by coolant from a second cooling system, the temperature of the coolant in the second cooling system being lower than the temperature of the coolant in the first cooling system
Implementation Method 5
a first cooling system for cooling the combustion engine
Implementation Method 6
the temperature of the coolant in the second cooling system being lower than the temperature of the coolant in the first cooling system
Data Source
Figure 1
Figure 2
AI summary
The present invention relates to an arrangement for a supercharged combustion engine (2). The arrangement comprises a first compressor (6a) adapted to subjecting the air to a first compression step, a second compressor (6b) adapted to subjecting the air to a second compression step, a first cooling system with a circulating coolant and a second cooling system with a circulating coolant which is at a lower temperature than the coolant in the first cooling system. The arrangement comprises a first charge air cooler (9a) applied between the first compressor (6a) and the second compressor (6b) and cooled by coolant from the second cooling system, a second charge air cooler (9b) arranged at a position downstream of the second compressor (6b) and cooled by coolant from the first cooling system, and a third charge air cooler (9c) applied at a position downstream of the second charge air cooler (9b) and cooled by coolant from the second cooling system.