Active Purge Pump Module for EVAP Systems
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Solution Overview
Problem
Existing evaporative emission control systems, particularly those with turbocharged engines, face inefficiencies as they divert pressurized air from the turbocharger to pull purge vapor into the engine, reducing engine power and turbocharger efficiency.
Innovation Solution
An active purge pump system module that operates independently of the engine to move purge vapor from a carbon canister to the engine, using a pump and bypass valve assembly to ensure sufficient vapor transfer without relying on manifold vacuum, allowing for efficient engine operation and reduced noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If manifold vacuum is used to draw air through the canister and pull purge vapor into the engine, then purge vapor transfer is achieved, but insufficient vacuum may be generated to draw sufficient amounts of air through the canister
Solution Approach 1:
The patent introduces an electric purge pump as an intermediary device to assist or replace the manifold vacuum function. The pump actively moves air through the canister and pulls purge vapor into the engine, ensuring sufficient vapor transfer regardless of vacuum availability. This mediator resolves the contradiction by providing a reliable alternative mechanism when natural vacuum is insufficient.
2Productivity
If pressurized air is directed away from the turbocharger to create vacuum for purging, then purge vapor transfer is achieved, but turbocharger efficiency is reduced and engine power increase is reduced
Solution Approach 1:
The electric purge pump serves as a mediator that eliminates the need to divert pressurized air from the turbocharger. By using electrical power to drive the pump instead of stealing compressed air, the system achieves purge vapor transfer without compromising turbocharger efficiency or engine power output.
Solution Approach 2:
The patent replaces the mechanical vacuum generation system (which relies on turbocharger operation) with an electrically-driven pump system. This substitution allows independent control of purge function without affecting the turbocharger's mechanical efficiency or the engine's power generation.
3Productivity
If a pump is used to move air independently of engine operation, then sufficient purge vapor transfer is achieved without sacrificing engine efficiency, but system complexity increases
Solution Approach 1:
The electric purge pump is designed to perform multiple functions: it can operate independently of engine operation to ensure purge vapor transfer, work in conjunction with existing EVAP system components, and potentially serve both purge and fuel tank venting functions. This multi-functionality justifies the added complexity by providing versatile control over vapor management.
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 transfers purge vapor to the engine, maintaining engine efficiency and turbocharger performance while enabling refueling and diagnostic testing, with reduced power consumption and noise.
Implementation Method 1
The active purge pump system module includes a pump in fluid communication with the canister. The pump is constructed and arranged to move air independently of operation of the engine.
Implementation Method 2
The bypass valve assembly is in fluid communication with an upstream side and a downstream side of the pump so as to bypass the pump. The bypass valve assembly is constructed and arranged to be moved between opened and closed position
Implementation Method 3
a purge valve connected between the canister and the air intake
Implementation Method 4
move purge vapor from the canister, through the purge valve, and to the engine to be consumed during combustion
Data Source
AI summary
An active purge pump system module is provided for an evaporative emission control (EVAP) system for a vehicle. The EVAP system includes a fuel tank, a vapor collection canister in communication with the fuel tank, an air intake, and a purge valve connected between the canister and the air intake. The active purge pump system module includes a pump in fluid communication with the canister to move air independently of operation of the engine. A bypass valve assembly communicates with an upstream side and a downstream side of the pump to bypass the pump. In a closed position of the bypass valve assembly, the pump, when activated, moves purge vapor from the canister, through the purge valve, and to the engine to be consumed during combustion, and when the bypass valve assembly is opened and the pump is deactivated, vehicle refueling is permitted.