Reciprocating Engine Air Injection for Emission Control
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Solution Overview
Problem
Conventional reciprocating internal combustion engines with exhaust gas turbochargers face challenges in maintaining high excess air flow during acceleration from idling or low partial load, leading to increased nitrogen oxide and particle emissions due to insufficient boost pressure.
Innovation Solution
Incorporating an electromagnetically actuable injector valve that introduces additional air directly into the combustion chamber via a compressed air line, allowing for precise control of air intake and expulsion, even when intake and exhaust valves are closed, thereby maintaining a high excess air flow and reducing emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If additional air injection is provided from the brake air system during acceleration, then nitrogen oxide and particle emissions are minimized, but the charge air generated by the exhaust gas turbocharger cannot reach the engine and all air must be taken from the brake air system
Solution Approach 1:
The air supply system is segmented into two independent paths: the original charge air path from the turbocharger and a new direct air injection path from the brake air reservoir. This segmentation allows both paths to operate simultaneously without interfering with each other, resolving the contradiction by enabling emission control through direct injection while preserving the turbocharger's charge air delivery capability.
Solution Approach 2:
An electromagnetic valve is introduced as an intermediary component to control the direct air injection from the brake air reservoir. This valve acts as a mediator that can precisely regulate when and how much air is injected directly into the combustion chamber, enabling emission control during acceleration without requiring complete reliance on the brake air system.
2Ease of operation
If flaps are used to prevent air from returning to the intake system, then air injection during acceleration is improved, but the charge air from the exhaust gas turbocharger is prevented from reaching the engine
Solution Approach 1:
The air delivery system is divided into two separate pathways: one pathway uses flaps to control direct air injection from the reservoir, while the other pathway maintains open access for turbocharger charge air to reach the engine. This segmentation eliminates the conflict between air injection control and charge air delivery, allowing both functions to perform optimally simultaneously.
3Object-generated harmful factors
If the electromagnetic valve is used to introduce additional air into the combustion chamber, then a permanently high excess air flow is maintained reducing emissions, but the valve must be precisely controlled during compression stroke
Solution Approach 1:
The control system incorporates feedback mechanisms that monitor engine operating conditions, compression stroke timing, and air pressure in the brake reservoir. This feedback enables the control unit to precisely determine when to open the electromagnetic valve during the compression stroke and how long to keep it open, automatically adjusting valve control based on real-time engine state to maintain high excess air flow and reduce emissions.
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 enables reduced nitrogen oxide and particle emissions by ensuring a permanently high excess air flow and efficient operation, while also allowing for the generation of compressed air during overrun phases for braking energy recovery, eliminating the need for a separate air compressor and enhancing exhaust aftertreatment system effectiveness.
Implementation Method 1
an electromagnetic valve for introducing air is arranged in the combustion chamber and/or air discharge from the combustion chamber
Implementation Method 2
The electromagnetic valve is preferably arranged at the end of a compressed air line which connects the cylinder on which the electromagnetic valve is arranged to a compressed air reservoir of a compressed air system
Implementation Method 3
diesel engines for motor vehicles, in particular for commercial vehicles, are usually equipped with an exhaust gas turbocharger (ATL). The higher excess air that can be achieved in this way results in lower nitrogen oxide and particle emissions
Implementation Method 4
in the region of the closing of the intake valves, compressed air from a compressed air reservoir is introduced into the combustion chamber via the electromagnetic valve
Implementation Method 5
allowing for precise control of air intake and expulsion, even when intake and exhaust valves are closed, thereby maintaining a high excess air flow and reducing emissions
Data Source
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AI summary
The invention relates to a reciprocating internal combustion engine and an operating method for a reciprocating internal combustion engine. The reciprocating internal combustion engine comprises at least one air inlet valve (5) and one air outlet valve (6) arranged on the cylinder head, wherein an electromagnetic valve for supplying air to the combustion chamber (13) and/or supplying air from the combustion chamber (13) is arranged on the cylinder head (3). The method for operating a reciprocating internal combustion engine is characterized by the steps of supplying compressed air from the compressed air reservoir (1) to the combustion chamber (13) via the electromagnetic valve (4), in addition to the charge air supplied to the combustion chamber (13) via the at least one inlet valve (5); and/or of withdrawing compressed air from the combustion chamber (13) via the electromagnetic valve and supplying it to the compressed air reservoir (1).