Diesel Engine Compression Ratio Optimization for High Boost
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Solution Overview
Problem
High levels of supercharging in diesel engines lead to increased final compression pressure, resulting in higher fuel consumption and reduced power output due to the limited conversion of fuel at peak pressure, which is not efficiently addressed by existing technologies.
Innovation Solution
A self-igniting internal combustion engine design with a boost pressure greater than 2.5 bar absolute, peak pressure less than 200 bar, specific power greater than 60 kW/l, specific engine torque greater than 150 Nm/l, and a geometric compression ratio less than 17:1, optimized to achieve increased performance without additional fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If high levels of supercharging are applied in diesel engines, then power output is improved, but final compression pressure increases excessively leading to higher fuel consumption
Solution Approach 1:
The patent applies parameter changes by reducing the geometric compression ratio from conventional values (18:1 to 20:1) to below 17:1 (specifically 14.5:1 to 16.5:1). This parameter modification allows the engine to operate with high supercharging levels (>2.5 bar absolute boost pressure) while maintaining final compression pressure below 200 bar, thereby enabling high power output without excessive fuel consumption
2Power
If high levels of supercharging are applied in diesel engines, then power output is improved, but peak pressure increases leading to reduced fuel conversion efficiency
Solution Approach 1:
The patent changes the compression ratio parameter to below 17:1, which fundamentally alters the pressure development characteristics during compression. This enables the engine to achieve high power output through increased boost pressure while keeping peak cylinder pressure below 200 bar, maintaining efficient isochoric fuel conversion even at high supercharging levels
3Power
If high levels of supercharging are applied in diesel engines, then performance is improved, but specific consumption increases
Solution Approach 1:
By reducing the geometric compression ratio below 17:1, the patent enables high performance operation with reduced specific fuel consumption. The lower compression ratio combined with high supercharging (>2.5 bar absolute) and controlled peak pressure (<200 bar) creates an optimized operating regime that improves the power-to-fuel-consumption ratio
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 design enhances performance while maintaining or reducing fuel consumption and pollutant emissions by adjusting compression ratios and temperatures, specifically achieving higher efficiency and power output in highly charged diesel engines.
Implementation Method 1
a boost pressure in the working cylinder at the nominal torque and/or nominal power point is greater than approximately 2.5 bar absolute
Implementation Method 2
a peak pressure in the working cylinder is less than approximately 200 bar
Data Source
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AI summary
The engine has a working cylinder, where charging pressure in the working cylinder in nominal torque and/or nominal horsepower is absolutely greater than 2.5 bar. The working cylinder has point pressure smaller than 200 bars and specific power greater than 60 kilowatt. The working cylinder has a specific motor torque greater than 150 Newton meter and geometric compression ratio smaller than 17:1. The engine is designed in such a manner that compression outlet temperature is smaller than 727 degrees Celsius in nominal horsepower. An independent claim is also included for a motor vehicle comprising an internal combustion engine with nitrogen oxide pretreatment emissions.