Canister Intermediate Chamber Adsorbent Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing canisters for vehicle fuel tanks often discharge unadsorbed evaporated fuel into the atmosphere due to insufficient adsorption capacity in their chambers, leading to inefficiencies and potential upsizing issues.
Innovation Solution
Incorporating an intermediate chamber with a third adsorbent of lower adsorption capacity than the main and sub chambers, strategically positioned between them, along with optimized dimensions and placement within the flow path, to delay fuel discharge and reduce ventilation resistance, thereby minimizing atmospheric emissions while maintaining a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a blow-by prevention part is arranged adjacent to the atmosphere port, then evaporated fuel discharge to the atmosphere is inhibited, but the canister size increases
Solution Approach 1:
The canister is divided into multiple chambers (first chamber, second chamber, intermediate chamber) with distinct functions. The intermediate chamber acts as a buffer zone between the main adsorption chambers and the atmosphere port, segmenting the fuel flow path to prevent direct discharge while maintaining compact overall structure.
Solution Approach 2:
The intermediate chamber serves as an intermediary element between the main chambers and the atmosphere port. It mediates the fuel flow by providing an additional adsorption stage that captures evaporated fuel before it reaches the atmosphere port, preventing direct discharge without requiring a large blow-by prevention part.
2Volume of stationary object
If the intermediate chamber is made compact with smaller adsorption capacity, then canister size is inhibited from increasing, but evaporated fuel discharge reduction effectiveness may be compromised
Solution Approach 1:
Different chambers are assigned different adsorption capacities based on their local functions. The intermediate chamber has smaller adsorption capacity compared to the main chambers, which is sufficient for its specific role as a buffer and secondary adsorption stage. This local differentiation optimizes the overall system performance while maintaining compact size.
Solution Approach 2:
The intermediate chamber provides partial adsorption action rather than complete adsorption. It handles the portion of evaporated fuel that escapes from the main chambers, providing sufficient protection against atmospheric discharge without requiring excessive adsorption capacity that would increase canister volume.
3Volume of stationary object
If the intermediate chamber length is reduced to maintain compact design, then canister size is controlled, but ventilation resistance may increase
Solution Approach 1:
The intermediate chamber is designed with optimized dimensional proportions, specifically controlling the length-to-equivalent-diameter ratio. By adjusting the chamber's cross-sectional dimensions rather than only its length, the design maintains adequate ventilation resistance performance while keeping the chamber compact and contributing to overall canister size 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 configuration effectively reduces the discharge of evaporated fuel into the atmosphere, enhances desorption properties, and prevents canister upsizing, while maintaining efficient fuel absorption and desorption processes.
Implementation Method 1
an intermediate chamber arranged between the main chamber and the sub chamber in a flow path of the evaporated fuel, the intermediate chamber being connected to each of the main chamber and the sub chamber, a first adsorbent stored in the main chamber, a second adsorbent stored in the sub chamber, and a third adsorbent stored in the intermediate chamber
Implementation Method 2
The canister adsorbs the evaporated fuel to an adsorbent, desorbs fuel from the adsorbent with taken-in air for purging, and supplies the purged fuel to an engine
Data Source
AI summary
Provided is a canister that can inhibit discharge of evaporated fuel to the atmosphere. One aspect of the present disclosure is a canister. The canister includes a charge port, a purge port, an atmosphere port, a main chamber to which a charge port and a purge port are connected, a sub chamber to which the atmosphere port is connected, an intermediate chamber arranged between the main chamber and the sub chamber in a flow path of an evaporated fuel, the intermediate chamber being connected to each of the main chamber and the sub chamber, a first adsorbent stored in the main chamber, second adsorbent stored in the sub chamber, and a third adsorbent stored it intermediate chamber. An adsorption capacity of the third adsorbent is smaller than each of an adsorption capacity of the first adsorbent and an adsorption capacity of the second adsorbent.