Direct Injection Engine Fuel Cooling for PN Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Direct injection internal combustion engines face challenges in reducing Particulate Number (PN) due to increased fuel temperature causing liquid fuel attachment to the injection hole, leading to combustion and increased PN, which existing cooling techniques fail to address effectively.
Innovation Solution
A control method that independently controls the coolant temperature of the cylinder block and cylinder head to prevent fuel temperature from rising, thereby reducing the amount of liquid fuel attached to the injector's distal end and minimizing PN by cooling the fuel before it passes through the injection hole, using a separate coolant passage system to manage the coolant flow rate and maintain optimal temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fuel temperature is allowed to rise, then the fuel injection valve can operate stably, but the amount of liquid fuel attached to the injection hole increases and PN increases
Solution Approach 1:
The patent applies parameter changes by precisely controlling the fuel temperature within a specific range (5°C to 20°C below the flash boiling point) to prevent liquid fuel attachment while maintaining injection valve stability. This temperature parameter optimization resolves the contradiction between reliability and harmful emissions.
Solution Approach 2:
The patent implements preliminary anti-action by proactively cooling the fuel before it reaches the injection hole to prevent flash boiling and liquid fuel attachment. The cooling action is taken in advance to counteract the temperature rise that would otherwise cause increased PN.
2Temperature
If the coolant flow rate is increased to cool the fuel, then the fuel temperature can be controlled, but the engine cooling efficiency may be affected
Solution Approach 1:
The patent applies segmentation by dividing the coolant flow into separate pathways: one for fuel cooling (through the fuel injection valve coolant passage) and another for engine cooling (through the cylinder block and head passages). This allows independent control of coolant flow rates to simultaneously achieve fuel temperature control and maintain engine cooling efficiency.
Solution Approach 2:
The patent implements local quality by providing dedicated coolant passages for different thermal management needs: the fuel injection valve has its own coolant passage for localized fuel cooling, while the cylinder block and head have separate passages for engine cooling. This localized approach allows optimized temperature control in each region without compromising overall system performance.
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 effectively reduces the increase in PN by preventing flash boiling and minimizing fuel attachment, maintaining stable engine performance without affecting oil dilution or combustion stability.
Implementation Method 1
a rise of a fuel temperature when the fuel passes through an injection hole on a fuel injection valve increases an amount of liquid fuel attached to a peripheral area of the injection hole
Implementation Method 2
combustion of this liquid fuel increases the PN... cools the fuel before a fuel temperature when the fuel passes through an injection hole on a fuel injection valve reaches a temperature at which an amount of attached fuel to the fuel injection valve distal end increases
Data Source
AI summary
An object of a control method to control a direct injection internal combustion engine that directly injects fuel in a cylinder is to reduce an increase in PN caused by attachment of the fuel to a fuel injection valve distal end. The control method cools the fuel before a fuel temperature when the fuel passes through an injection hole on a fuel injection valve reaches a temperature at which an amount of attached fuel to the fuel injection valve distal end increases.