Supercharged Engine Crankcase Air Bleeding for Unburned Gas Dilution
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Solution Overview
Problem
Fuel gas in a combustion chamber can leak to the crank chamber in the crankcase, leading to a risk of ignition of unburned gas, which is undesirable due to the potential for explosion and a reduction in engine efficiency.
Innovation Solution
An engine system with an intake line guiding compressed air to the combustion chamber and an air extraction line guiding compressed air to the crank chamber, mixing with unburned gas to reduce its concentration and temperature, thereby reducing the risk of ignition while maintaining engine efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fuel gas concentration in crank chamber is high, then combustion efficiency improves, but ignition risk increases
Solution Approach 1:
The patent introduces compressed air through the air extraction line to the crank chamber, converting the harmful high-concentration unburned fuel gas into a beneficial diluted mixture. The compressed air serves dual purposes: it dilutes the fuel gas concentration below ignition thresholds while simultaneously providing oxygen that can be utilized for combustion, thus converting a safety hazard into a performance benefit
Solution Approach 2:
The air extraction line acts as an intermediary mechanism between the compressed air source and the crank chamber. It provides a controlled pathway for introducing air that dilutes the unburned fuel gas, mediating between the need for high fuel gas concentration (for efficiency) and the need to prevent ignition (for safety)
2Reliability
If air extraction line is added to reduce unburned gas concentration, then ignition risk decreases, but system complexity increases
Solution Approach 1:
The air extraction line is designed to perform multiple functions: it extracts compressed air from the intake system, delivers it to the crank chamber, and simultaneously achieves both dilution of unburned gas and temperature reduction. This multi-functionality reduces the need for separate dedicated systems, thereby limiting the increase in overall system complexity while achieving the safety objective
3Reliability
If compressed air flow rate is increased to dilute unburned gas, then ignition risk decreases, but engine efficiency decreases
Solution Approach 1:
The system dynamically adjusts the air extraction flow rate based on operating conditions. The control unit monitors parameters such as engine load, speed, and crank chamber conditions to optimize the amount of compressed air introduced, ensuring sufficient dilution to prevent ignition while minimizing the impact on combustion efficiency and overall engine 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
The system effectively reduces the risk of unburned gas ignition in the crank chamber while minimizing a decrease in engine efficiency by controlling the flow and temperature of compressed air, ensuring uniform distribution and dilution of unburned gas.
Implementation Method 1
an air extraction line for guiding the compressed air extracted from the intake line to a crank chamber in the crankcase
Implementation Method 2
mixing with unburned gas to reduce its concentration and temperature
Data Source
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AI summary
Provided is an engine system comprising: an engine including a cylinder and a piston accommodated in the cylinder; a fuel gas line for guiding fuel gas to a combustion chamber in the cylinder; and a supercharger including a compressor wheel for sending compressed air to the combustion chamber. The engine further includes a crankshaft positioned below the piston and for driving the piston, and a crankcase for accommodating the crankshaft. The engine system further comprises: an air supply line for guiding the compressed air delivered by the compressor wheel to the combustion chamber, and a bleeding line for guiding the compressed air bled from the air supply line to a crank chamber in the crankcase.