Turbocharged Engine Charge Air Cooling and Prechamber Pressure Control
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Solution Overview
Problem
Existing gasoline engines face inefficiencies in combustion chamber and antechamber operations, particularly in managing charge air and exhaust gas mixtures for optimal combustion and fuel efficiency.
Innovation Solution
The engine design incorporates an exhaust gas turbocharger with a turbine and compressor to compress fresh air or a fresh air/exhaust gas mixture, with a charge air cooler and air turbine arrangement to generate a higher prechamber pressure than the combustion chamber, allowing for cooled and compressed charge air to be supplied to both chambers, enhancing fuel efficiency and combustion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If charge air is compressed to a higher degree in the exhaust gas turbocharger than necessary for filling the cylinders, then prechamber pressure is increased, but energy consumption increases
Solution Approach 1:
The charge air flow is segmented into two separate paths: one path supplies compressed charge air to the combustion chamber, while another path extracts compressed charge air at a higher pressure point to supply the pre-chamber. This segmentation allows the turbocharger to operate at higher compression for pre-chamber filling without unnecessarily increasing energy consumption for the main combustion chamber filling.
Solution Approach 2:
A charge air cooler is introduced as an intermediary component between the turbocharger compressor and the charge air distribution system. The cooler reduces the temperature of the compressed charge air, enabling efficient heat exchange and allowing the system to maintain higher pre-chamber pressure without proportionally increasing energy consumption.
2Temperature
If charge air is cooled in the charge air cooler, then temperature is reduced, but pressure is also reduced
Solution Approach 1:
The charge air flow is divided into two separate paths with different pressure requirements. The first path supplies cooled charge air to the combustion chamber at normal pressure, while the second path extracts charge air at a higher pressure point (downstream of the cooler) to supply the pre-chamber. This segmentation allows the cooler to reduce temperature without significantly impacting the pre-chamber pressure, as the extraction point is positioned where pressure has already been maintained.
Solution Approach 2:
The charge air is cooled in the charge air cooler before being distributed to the combustion chamber and pre-chamber. This preliminary cooling action reduces the temperature of the charge air, which improves combustion efficiency and allows the system to maintain higher pre-chamber pressure without proportionally increasing energy consumption.
3Temperature
If an air turbine is arranged downstream of the extraction point to expand the compressed charge air, then temperature and pressure are reduced, but device complexity increases
Solution Approach 1:
The air turbine is merged with the exhaust gas turbocharger, sharing a common shaft. The turbine expands the compressed charge air that has been extracted from the charge air line, while the compressor of the turbocharger compresses fresh air. This merging of the turbine and compressor functions into a single unit reduces overall system complexity compared to having separate turbine and compressor systems.
Solution Approach 2:
The exhaust gas turbocharger unit is designed to perform multiple functions: the compressor compresses fresh air for the combustion chamber, while the turbine expands the extracted compressed charge air to reduce its temperature and pressure before it reaches the pre-chamber. This multi-functionality reduces the need for separate components and simplifies the overall system architecture.
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 configuration improves fuel efficiency by generating a higher prechamber pressure through turbo cooling, reducing temperature and pressure in the antechamber, and optimizing the combustion process, making the engine suitable for lean operation and external exhaust gas recirculation.
Implementation Method 1
a exhaust gas turbocharger with a turbine and compressor to compress fresh air or a fresh air/exhaust gas mixture
Implementation Method 2
with a charge air cooler and air turbine arrangement to generate a higher prechamber pressure than the combustion chamber, allowing for cooled and compressed charge air to be supplied to both chambers
Implementation Method 3
an air turbine arrangement to generate a higher prechamber pressure than the combustion chamber
Implementation Method 4
an exhaust gas turbocharger with a turbine and compressor
Data Source
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AI summary
The invention relates to an internal combustion engine (1) comprising at least one cylinder (Z), wherein the at least one cylinder (Z) has a main combustion chamber (BK) for the combustion of a fuel/air mixture (K/FL) or a fuel/air/exhaust gas mixture (K/FF/FA) and a purged pre-chamber connected to the main combustion chamber (BK) via at least one transfer channel on the fluid side, and at least one exhaust gas turbocharger (200) comprising a turbine (201) for the expansion of the exhaust gas (FA) leaving the at least one cylinder (Z) and a compressor (202) for the compression of fresh air (FF) or a fresh air/exhaust gas mixture (FF/FA) supplied to the at least one cylinder (Z) as compressed charge air (FL).It is provided that in a charge air line (II) downstream of the compressor (202) a combustion chamber charge air line (II-1) is formed to supply the combustion chamber (BK; II-1) and a pre-chamber scavenging line (II-2) branching off at a withdrawal point (II-E', II-E", II-E''') is formed to supply the pre-chamber (VK; II-2), wherein downstream of the compressor (202) of the exhaust gas turbocharger (200) upstream of the withdrawal point (II-E', II-E", II-E''') at least one charge air cooler (LK1, LK2) is arranged to cool the charge air (FL) in the charge air line (II).