Secondary Air Conduit Valve for Exhaust Gas Backflow Limiting
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Solution Overview
Problem
Existing internal combustion engines face challenges in effectively injecting secondary air into the exhaust tract to heat up exhaust gas aftertreatment elements, particularly due to excessive backflow of exhaust gas into the secondary air conduit, which complicates the system with high power consumption, space requirements, and potential soiling issues.
Innovation Solution
A compact valve element with rotationally symmetrical impact bodies is integrated into the secondary air conduit, providing a high first flow resistance in the injection direction and a significantly higher second flow resistance in the backflow direction, preventing excessive exhaust gas backflow while allowing efficient secondary air injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional secondary air injection system is used, then secondary air can be injected into the exhaust tract, but exhaust gas backflows excessively into the secondary air conduit causing system complexity and power consumption
Solution Approach 1:
The valve element utilizes the natural pressure differential between the exhaust tract and secondary air conduit to automatically prevent backflow, eliminating the need for externally powered control systems. The system serves itself by using the existing pressure conditions to drive the check valve function.
Solution Approach 2:
The backflow prevention function is extracted from complex electronic control systems and implemented through a simple passive check valve mechanism, reducing overall system complexity while maintaining the essential secondary air injection capability.
2Reliability
If a conventional secondary air injection system is used, then secondary air can be injected into the exhaust tract, but power consumption increases due to backflow prevention requirements
Solution Approach 1:
The check valve operates passively using the natural pressure differential without requiring external power sources, motors, or electronic controls. The system leverages the existing pressure conditions to automatically prevent backflow, resulting in zero additional power consumption.
3Reliability
If a conventional secondary air injection system is used, then secondary air can be injected into the exhaust tract, but space and weight requirements increase
Solution Approach 1:
The backflow prevention function is extracted from heavy electronic control systems and implemented through a lightweight passive check valve mechanism, significantly reducing the weight of the secondary air injection system.
Solution Approach 2:
The check valve is integrated directly into the secondary air conduit, merging the backflow prevention function with the existing air delivery pathway, thereby eliminating additional components and reducing overall system weight.
4Reliability
If a conventional secondary air injection system is used, then secondary air can be injected into the exhaust tract, but soiling of the system occurs
Solution Approach 1:
The backflow prevention function is extracted from complex electronic systems and implemented through a simple check valve that physically blocks exhaust gas from entering the secondary air conduit, preventing soiling of the air delivery system.
Solution Approach 2:
The check valve acts as an intermediary barrier between the exhaust tract and secondary air conduit, allowing secondary air to pass through to the exhaust tract while blocking exhaust gas from backflowing into the secondary air system, thereby preventing soiling.
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 design enables rapid heating of exhaust gas aftertreatment elements, reduces power consumption, minimizes space and weight, and prevents soiling, thereby enhancing the efficiency and emissions performance of the internal combustion engine.
Implementation Method 1
the valve element has a first flow resistance along the injection direction, in particular for a gas such as the secondary air, a first flow resistance. Along a backflow direction in the opposite direction to the injection direction, the valve element has a second flow resistance, in particular for the gas, which is, in particular significantly, greater than the first flow resistance.
Implementation Method 2
the valve element has a plurality of impact bodies which are arranged consecutively and thus one after another along or in the injection direction
Implementation Method 3
the respective impact body has a respective region that widens continuously along the injection direction, in particular a conical or frustoconical first region B1
Data Source
AI summary
An internal combustion engine with an exhaust tract and with a secondary air system which has a secondary air conduit through which secondary air can flow in an injection direction. The secondary air can be introduced into the exhaust tract. A valve element is arranged in the secondary air conduit and has a first flow resistance along the injection direction and a greater second flow resistance along an opposite backflow direction, as a result of which a backflow taking place in the backflow direction can be limited. The valve element has a plurality of rotationally symmetrical impact bodies which are arranged consecutively along the injection direction and are connected to one another. The valve element is arranged in a length region of the secondary air conduit which is limited by a structural element of the internal combustion engine which is formed separately from the valve element.