Crankcase Ventilation via Intake Pressure Differential
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stationary gas engines face challenges in effectively ventilating the crankcase to prevent condensation and oil sludge formation due to blow-by gases, which often require energy-intensive pressure reduction of purge air, leading to undesirable energy losses and maintenance complexities.
Innovation Solution
A ventilation arrangement with a fluidically conductive connection between the intake arrangement and the crankcase, utilizing unregulated ventilation and return lines that automatically adjust gas flows based on pressure losses, eliminating the need for control valves and additional filters, and incorporating an oil separator to manage blow-by gases and oil separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If scavenging air is taken from the intake arrangement behind a charger and directed into the crankcase, then the crankcase ventilation effectiveness is improved, but energy losses increase due to the need to reduce the high pressure of the scavenging air
Solution Approach 1:
The invention extracts scavenging air from the intake arrangement at a point before the charger (intake air side) rather than from behind the charger. This extraction occurs at atmospheric pressure or slightly negative pressure, eliminating the need for pressure reduction and the associated energy losses while still providing effective crankcase ventilation.
2Object-affected harmful factors
If a separate purge air filter is installed, then the filtration of purge air is improved, but the device complexity and maintenance requirements increase
Solution Approach 1:
The invention makes the existing air filter in the intake arrangement serve a dual function: filtering both the main intake air and the purge air that is extracted for crankcase ventilation. This eliminates the need for a separate purge air filter, reducing device complexity and maintenance requirements while maintaining adequate filtration quality.
3Ease of operation
If control valves and regulating devices are installed to manage gas flows, then the flow control precision is improved, but the device complexity and manufacturing costs increase
Solution Approach 1:
The invention designs the ventilation arrangement with unregulated ventilation and return lines that automatically adjust gas flows based on pressure losses. The system self-regulates the balance between purge air flow and returned gases without requiring external control valves or regulating devices, thereby reducing device complexity and manufacturing costs while maintaining adequate flow control.
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 solution reduces the risk of condensation and oil sludge formation, minimizes energy losses, and simplifies the engine design, making it more reliable, low-maintenance, and cost-effective by automatically balancing gas flows and eliminating the need for complex control systems.
Implementation Method 1
The gas mixer is a device used to mix the fuel gas and intake air before the fuel gas-air mixture passes through the intake system into the cylinder of a stationary gas engine for combustion. Typically, such a gas mixer is designed as a Venturi nozzle. This locally constricts the cross-section of the intake system and increases the flow velocity of the intake air. This locally reduces the pressure.
Implementation Method 2
The gas mixer causes a pressure drop in the intake air flowing through it. Upstream of the gas mixer, at the extraction point, the pressure is higher than downstream of the gas mixer, at the return point. This pressure difference causes a portion of the intake air at the extraction point to flow through the ventilation line into the crankcase as purge air.
Implementation Method 3
The ventilation line and the return line are unregulated. This means that no control valves are provided in either the ventilation line or the return line. The respective gas flows through the ventilation line and the return line are automatically adjusted based on the resistances of the individual passive components with their respective pressure loss curves, so that the pressure loss across the gas mixer and in the ventilation arrangement is equal in each case.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to a stationary gas engine (2) with a ventilation arrangement (4) for ventilating a crankcase (6). It comprises an intake arrangement (10) through which intake air enters a cylinder (8) of the stationary gas engine (2). In the intake arrangement (10), an air filter (12) and a gas mixer (14), which mixes the intake air with a fuel gas, are arranged one after the other in the direction of airflow. The ventilation arrangement (4) directs purge air into the crankcase (6) via a ventilation line (16). Gas extracted from the crankcase (6) is returned via a return line (22) to a return point (24) on the intake arrangement (10). The purge air is drawn from the intake arrangement (10) at a draw-off point (18) between the air filter (12) and the gas mixer (14).The extracted gas is returned to a return point (24) which is located behind the gas mixer (14) on the intake arrangement (10) in the direction of flow of the intake air.