Single Pump EGR and Secondary Air Valve System
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Solution Overview
Problem
Existing secondary air and exhaust gas recirculation (EGR) systems in internal combustion engines face limitations in providing continuous EGR driving capability, especially when the throttle is fully open, leading to reduced emissions control and increased fuel consumption due to reliance on pressure differences.
Innovation Solution
A single pump and dual three-way valve system that selectively operates in secondary air, EGR, and boost modes, allowing the pump to supply secondary air to the exhaust system or EGR to the air intake system independently of throttle pressure, and enabling boost air to improve engine performance and reduce fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If EGR is driven by pressure difference between exhaust system and intake system, then EGR can be supplied to reduce emissions, but EGR driving capability is reduced when throttle is fully open
Solution Approach 1:
A pump is introduced as an intermediary device to actively drive EGR flow from the exhaust system to the intake system, replacing reliance on passive pressure difference. The pump ensures continuous EGR supply capability regardless of throttle position, resolving the contradiction between emissions reduction and adaptability to full-throttle conditions.
2Duration of action of stationary object
If secondary air system is used during cold start to add oxygen to exhaust gases, then warm up time is reduced, but system complexity increases with separate pump and control
Solution Approach 1:
The pump and control system are designed to perform multiple functions: driving secondary air during cold start, driving EGR during normal operation, and providing boost air during transient acceleration. This multi-functionality reduces overall system complexity by eliminating the need for separate dedicated systems for each function.
3Speed
If throttle is opened greater to improve acceleration, then air flow increases, but EGR driving capability is lowered due to reduced pressure difference
Solution Approach 1:
The pump acts as an intermediary that decouples EGR supply capability from throttle-induced pressure differences. By actively pumping EGR, the system maintains emissions control capability regardless of throttle position, allowing full throttle opening for acceleration without compromising EGR supply.
4Device complexity
If single pump is used to drive both secondary air and EGR, then device complexity is reduced, but control precision and reliability may be compromised
Solution Approach 1:
The system employs dynamic control through a multi-position valve that redirects the single pump's output to different destinations (secondary air system or EGR system) based on operating conditions. This dynamic switching mechanism maintains control precision and reliability while using a single pump, resolving the contradiction between simplicity and reliability.
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 decouples EGR driving from throttle pressure, extends EGR usage range, reduces fuel consumption by advancing spark timing, and enhances engine acceleration by increasing air flow and allowing more fuel injection.
Implementation Method 1
The pump is utilized to supply secondary air to the exhaust system or EGR to the air intake system
Data Source
AI summary
An internal combustion engine system includes an engine, an air intake system configured to provide intake air to the engine, and an exhaust system configured to receive exhaust gas from the engine. The engine system further includes a secondary air system including a pump, an exhaust gas recirculation (EGR) system, and a valve system operably associated with the secondary air system and the EGR system. The valve system is configured to operate in a secondary air mode where the pump is utilized to supply secondary air to the exhaust system, and an EGR mode where the pump is utilized to supply EGR to the air intake system.