Dual-Pass Ejector Purge Layout for Variable Intake Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional dual purge systems for turbocharged engines are costly due to complex gas line configurations and increased production expenses, and they struggle to effectively purge fuel evaporation gas under varying engine intake pressures.
Innovation Solution
A simplified dual purge system with a dual-pass ejector that integrates a bypass passage and check valves, allowing purge gas to flow through either a recirculation fluid line or a direct path depending on engine intake pressure, reducing the number of gas lines and components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional dual purge system is used to handle both negative and positive engine intake pressures, then the system can effectively purge fuel evaporation gas under varying engine conditions, but the gas line configuration becomes complex and production costs increase
Solution Approach 1:
The patent combines the functions of multiple gas lines into a single integrated gas line that handles both negative and positive pressure conditions. The canister is configured with a single gas line that includes a first passage for negative pressure purge and a second passage for positive pressure purge, eliminating the need for separate gas lines and reducing system complexity.
Solution Approach 2:
The single gas line is designed to perform multiple functions: it serves as both the negative pressure purge line and the positive pressure purge line. The gas line includes check valves and passages that enable it to adaptively handle different pressure conditions, making it a universal component that replaces multiple specialized lines.
2Adaptability or versatility
If a conventional dual purge system is implemented to purge fuel evaporation gas under positive engine intake pressure, then the purge function is restored for turbocharged engines, but the number of parts and production cost increase
Solution Approach 1:
The patent merges the positive pressure purge line and negative pressure purge line into a single integrated gas line structure. This consolidation reduces the number of parts that need to be manufactured and assembled, thereby lowering production costs while maintaining the dual purge functionality.
Solution Approach 2:
The single gas line is designed as a universal component that can handle both positive and negative pressure conditions through its internal passage configuration and check valves. This multi-functional design eliminates the need for multiple specialized components, simplifying manufacturing and reducing costs.
3Device complexity
If a single purge line is used to reduce system complexity, then production costs decrease, but the system cannot effectively handle both negative and positive engine intake pressures
Solution Approach 1:
The single gas line is segmented into multiple functional passages within its structure. The first passage handles negative pressure purge operations while the second passage handles positive pressure purge operations. This internal segmentation allows the single external gas line to perform multiple functions without increasing overall system complexity.
Solution Approach 2:
Check valves are introduced as intermediary components within the single gas line to mediate between different pressure conditions. The check valves automatically direct flow based on pressure differential, enabling the single gas line to adaptively handle both negative and positive pressure conditions without complex external control systems.
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 purges fuel evaporation gas under both negative and positive engine intake pressures, reducing production costs and simplifying the gas line configuration while maintaining efficient purge operations.
Implementation Method 1
a dual-pass ejector that integrates a bypass passage and check valves, allowing purge gas to flow through either a recirculation fluid line or a direct path depending on engine intake pressure
Implementation Method 2
a dual-pass ejector that integrates a bypass passage and check valves, allowing purge gas to flow through either a recirculation fluid line or a direct path depending on engine intake pressure
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A purge system for fuel evaporation gas may include an ejector, having a nozzle configured to allow driving fluid to pass therethrough, a driving inlet through which the driving fluid is supplied into the ejector, a suction inlet through which purge gas including a fuel component is drawn as suction fluid from a canister into the ejector, a diffuser outlet through which a mixture of the driving fluid that has passed through the nozzle and the drawn purge gas is discharged out of the ejector, and a suction passage extending from the suction inlet toward a downstream side of the nozzle based on a flow direction of the driving fluid, and a bypass passage coupled from the suction inlet to the driving inlet.