Aftertreatment Heating via Engine Compressor Mode in Hybrid Vehicles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Modern hybrid vehicles face significant challenges in reducing nitric oxide (NOx) emissions during cold starts, as the aftertreatment system, particularly selective catalytic reduction (SCR) systems, are ineffective during this period, necessitating a method to condition the aftertreatment system to meet stringent emission regulations.
Innovation Solution
A computer-implemented method and system that determines the temperature and power demand zones of a hybrid vehicle's aftertreatment system, setting it to compressor mode to heat the system when below a temperature threshold and in a low power demand zone, using a system control unit to control the combustion engine, electric motor, and electric heater to provide heated air to the aftertreatment system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the hybrid system operates in a modern configuration with SCR aftertreatment system, then NOx emissions can be reduced under normal operating conditions, but the aftertreatment system becomes ineffective during cold start, resulting in significant NOx emissions
Solution Approach 1:
The system performs preliminary heating action by operating the combustion engine as a compressor to heat air that is then directed to the aftertreatment system before normal operation begins. This preliminary heating ensures the SCR catalyst reaches its light-off temperature threshold before the vehicle enters service, making the aftertreatment system effective from the start.
Solution Approach 2:
The patent introduces an intermediary heating system that uses the combustion engine compressed air as a heat source to warm the aftertreatment system. This intermediary mechanism bridges the gap between cold start conditions and the temperature requirements for SCR effectiveness, allowing the harmful NOx emissions to be controlled once the intermediary heating achieves the necessary temperature.
2Reliability
If the combustion engine is used to heat the aftertreatment system during cold start, then the aftertreatment system effectiveness is improved, but the complexity of the hybrid system control increases
Solution Approach 1:
The combustion engine is given multiple functions: it serves as both a power source for vehicle operation and as a compressor for heating the aftertreatment system during cold start. By making the engine multi-functional, the system avoids adding separate dedicated heating equipment, thereby managing complexity while achieving reliable aftertreatment conditioning.
Solution Approach 2:
The system dynamically adjusts the combustion engine's operating mode based on real-time conditions. The engine can switch between normal power generation mode and compressor mode for heating, with the control system monitoring temperature thresholds and power demand zones to determine when to activate heating, creating a dynamic adaptive control strategy.
3Object-generated harmful factors
If the aftertreatment system is heated using the combustion engine as a compressor, then NOx emissions are reduced during cold start, but additional energy management complexity is introduced
Solution Approach 1:
The control system continuously monitors the aftertreatment system temperature and compares it against a light-off temperature threshold. When the temperature falls below the threshold during cold start, the system activates the combustion engine as a compressor. This feedback-based control ensures energy is used efficiently only when necessary to reach the emission control threshold, avoiding wasteful continuous operation.
Solution Approach 2:
The system changes operational parameters by transitioning the combustion engine from standard operation to compressor mode, and by monitoring temperature zones and power demand zones. These parameter changes allow the system to optimize energy usage by activating heating only when temperature and power demand conditions are appropriate, thereby reducing NOx emissions without excessive energy consumption.
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 approach effectively reduces NOx emissions by warming the aftertreatment system, enhancing the conversion efficiency of the SCR system and ensuring compliance with low NOx emission standards, especially during cold starts.
Implementation Method 1
setting the hybrid system to compressor mode to heat the aftertreatment system
Data Source
AI summary
Systems and methods for conditioning an aftertreatment system. For example, a computer-implemented method for conditioning an aftertreatment system of a hybrid system including an electric motor and a combustion engine includes: determining whether the aftertreatment system is in a first temperature zone below a first temperature threshold; determining whether a power demand corresponding to the operation of the hybrid system is in a first power demand zone below a power threshold; and if the aftertreatment system is determined to be in the first temperature zone and the power demand of the hybrid system is determined to be in the first power demand zone, setting the hybrid system to compressor mode to heat the aftertreatment system.