Compression Ignition Engine Fuel Injection Temperature Control
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Solution Overview
Problem
Current combustion control systems for compression ignition internal combustion engines face challenges in achieving high energy efficiency and reduced pollutant production across all operating conditions, particularly due to limitations in controlling combustion timing and pressure gradients, leading to increased CO2 and NOx emissions that may not comply with future emission regulations.
Innovation Solution
A method that controls combustion by varying the fuel injection temperature, using a combination of two fuel fractions injected at different temperatures, with one fraction injected during the intake and compression stroke and the other at the end of the compression stroke, allowing for precise control of reactivity and concentration stratification to optimize engine efficiency and emissions across various load conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high compression ratios are used to improve energy efficiency, then thermal efficiency increases, but combustion timing control becomes difficult and detonation occurs
Solution Approach 1:
The patent changes the physical parameter of fuel temperature to control reactivity. By heating fuel to 100-600°C before injection, the fuel's self-ignition characteristics are modified, enabling precise combustion timing control even at high compression ratios. This resolves the contradiction by providing a new control dimension (temperature) that decouples compression ratio from combustion timing control.
Solution Approach 2:
The patent applies preliminary heating to the fuel before injection to advance its reactivity state. This preliminary thermal action allows the fuel to be ready for controlled ignition at the desired moment, preventing detonation while maintaining high compression ratios for efficiency.
2Reliability
If high reactivity fuel is used to achieve stable combustion, then combustion reliability improves, but NOx emissions increase due to high combustion temperatures
Solution Approach 1:
The patent modifies the temperature parameter of the injected fuel to precisely control reactivity. By optimizing injection temperature, the fuel achieves sufficient reactivity for stable combustion while the resulting combustion process maintains lower peak temperatures, reducing NOx formation. This resolves the contradiction by providing fine-grained control over the combustion process.
3Measurement precision
If multiple injection systems with different temperatures are used to control reactivity, then combustion timing precision improves, but device complexity increases
Solution Approach 1:
The patent segments the fuel injection into two distinct systems: a first injection system for the majority of fuel at ambient temperature, and a second injection system for a fraction of fuel at elevated temperature (100-600°C). This segmentation enables precise combustion timing control through the temperature-modified fraction while keeping the overall system architecture relatively simple and modular.
4Stability of the object's composition
If high injection pressure is used to achieve homogeneous mixing, then mixture homogeneity improves, but energy consumption increases and injection system complexity increases
Solution Approach 1:
The patent changes the temperature parameter of the injected fuel to enhance mixing efficiency. The heated fuel (100-600°C) has improved volatility and mixing characteristics that allow for more effective atomization and distribution at lower injection pressures, reducing energy consumption while maintaining homogeneous mixture quality.
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 enables high energy efficiency and reduced pollutant production, particularly in NOx and particulate matter, while maintaining a simple engine structure, and allows the engine to operate efficiently and emit fewer pollutants across all possible operating points, potentially eliminating the need for exhaust gas after-treatment systems.
Implementation Method 1
heating a second fraction of the fuel quantity, equal to the remaining fraction of the fuel quantity, to an injection temperature of over 100°C
Implementation Method 2
injecting the second fraction of the fuel quantity heated at the injection temperature into the cylinder at the end of the compression stroke
Implementation Method 3
the combustion of a compression ignition internal combustion engine
Data Source
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AI summary
A method to control the combustion of a compression ignition engine (1) having the steps of: establishing, for each combustion cycle, a fuel quantity (Q) to be injected into the cylinder (2); injecting a first fraction (Fl) of the fuel quantity (Q); heating a second fraction (F2) of the fuel quantity (Q), which is equal to the remaining fraction of the fuel quantity (Q), to an injection temperature (T) higher than 100°C; injecting the second fraction (F2) of the fuel quantity (Q) heated to the injection temperature (T) into the cylinder (2) at the end of the compression stroke and at no more than 60° from the top dead centre (PMS); and decreasing the injection temperature (T) and the ratio between the second fraction (F2) and the first fraction (Fl) as the internal combustion engine (1) increases and as the rotation speed of the internal combustion engine (1) increases.