Expansion Machine in Intake Bypass for Engine Energy Recovery
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Solution Overview
Problem
Internal combustion engines face challenges in minimizing fuel consumption and reducing pollutant emissions, particularly nitrogen oxide emissions, due to limitations in exhaust-gas recirculation and energy utilization, leading to inefficiencies and torque drops at lower rotational speeds.
Innovation Solution
The integration of an expansion machine, such as a turbine, in the intake system of the engine, which utilizes compressed charge air to generate additional energy and improve power output, combined with a bypass line and throttle element to route intake air through the turbine during over-run modes, and the use of variable turbine geometry and low-pressure exhaust-gas recirculation to optimize energy recovery and reduce emissions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If exhaust-gas recirculation rate is increased to reduce nitrogen oxide emissions, then pollutant emissions are reduced, but torque drops at lower rotational speeds occur
Solution Approach 1:
The exhaust gas recirculation system is segmented into high-pressure EGR path (from exhaust manifold before turbine) and low-pressure EGR path (from exhaust manifold after turbine), allowing independent control of recirculation rates for different operating conditions to balance emission reduction with torque maintenance
Solution Approach 2:
The system dynamically switches between high-pressure and low-pressure EGR paths based on operating conditions (rotational speed, load, temperature), enabling the engine to adaptively optimize the balance between nitrogen oxide reduction and torque output across different operating points
2Power
If supercharging is used to increase power output, then specific power is improved, but energy is wasted during over-run modes
Solution Approach 1:
The expansion machine converts the harmful effect of wasted energy during over-run modes into a beneficial power generation source by extracting energy from the compressed charge air and converting it to mechanical work, thereby turning energy loss into energy recovery
Solution Approach 2:
The system recovers energy from the compressed charge air that would otherwise be discarded during over-run modes by routing it through the expansion machine, transforming the waste energy into useful power output
3Use of energy by moving object
If expansion machine is added to harness energy, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The expansion machine serves multiple functions: it acts as a power generation device during over-run modes, a braking mechanism during acceleration phases, and an energy recovery device during normal operation, thereby justifying the added complexity through multi-functional utility
Solution Approach 2:
The expansion machine operates continuously throughout the engine cycle, extracting energy from the compressed charge air regardless of whether the engine is in over-run mode or normal operation, ensuring continuous energy recovery and improving overall system efficiency
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 enhances engine efficiency by harnessing otherwise wasted energy, improving power output while maintaining fuel consumption, reducing pollutant emissions, and mitigating torque drops at lower speeds, thereby addressing the limitations of existing systems.
Implementation Method 1
an expansion machine for gaining additional energy arranged in the bypass line
Implementation Method 2
The hot exhaust-gas flow is supplied to the turbine via an exhaust line and expands in said turbine with a release of energy
Implementation Method 3
The compressor delivers and compresses the charge air supplied to it via the intake line
Implementation Method 4
A charge-air cooler is often provided downstream of the compressor, by means of which charge-air cooler the compressed charge air is cooled before it enters the combustion chamber
Data Source
AI summary
Embodiments for an internal combustion engine having at least one cylinder, at least one exhaust line for discharging combustion gases via an exhaust-gas discharge system, and at least one intake line for supplying charge air via an intake system are provided. In one example, an internal combustion engine comprises an exhaust-gas recirculation arrangement which comprises a recirculation line which branches off from the exhaust-gas discharge system and which opens into the intake system, an exhaust-gas turbocharger comprising a compressor arranged in the intake system and a turbine arranged in the exhaust-gas discharge system, a throttle element which is arranged in the intake line downstream of the compressor, a bypass line which branches off from the intake line upstream of the throttle element and which opens into the intake line again downstream of the throttle element, and an expansion machine for gaining additional energy arranged in the bypass line.