Hybrid Vehicle Catalyst Warming via Battery SOC Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hybrid vehicles, the existing methods for warming up electrically heated catalytic converters lead to increased fuel consumption due to the need to drive the internal combustion engine to replenish electrical energy, which can prolong engine driving time and worsen fuel efficiency.
Innovation Solution
The control unit manages the energizing of the electric heater and the driving of the internal combustion engine based on the battery's state of charge (SOC) to warm the catalytic converter using motoring power, thereby minimizing fuel consumption by optimizing the use of electrical energy and engine operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the electric heater-equipped catalytic converter is energized to warm up the catalyst, then the catalyst temperature is raised, but the battery voltage decreases and fuel consumption increases due to the need to replenish electrical energy
Solution Approach 1:
The system performs preliminary warming of the catalytic converter using the electric heater before the catalyst temperature drops below the activation threshold. By anticipating the temperature drop and warming the catalyst in advance when battery voltage is sufficient, the system avoids the need for frequent engine running solely for catalyst warming, thereby reducing overall fuel consumption while maintaining catalytic effectiveness
Solution Approach 2:
The system utilizes the vehicle's own electrical power system (battery and motor generator) to warm the catalytic converter, making the warming process self-contained without requiring external fuel consumption. The motor generator charges the battery using regenerative braking or engine power, and the stored electrical energy is then used to heat the catalyst, creating a self-sufficient energy cycle that minimizes additional fuel consumption
2Use of energy by moving object
If the internal combustion engine is driven to generate electric power for the electric heater, then the battery is recharged, but the driving time of the internal combustion engine increases and fuel consumption worsens
Solution Approach 1:
The system charges the battery in advance during periods when the engine is already running for propulsion or when regenerative braking is available, rather than running the engine solely to charge the battery. This preliminary charging ensures that electrical energy is available when needed for catalyst warming without extending engine operating time
Solution Approach 2:
The system recovers electrical energy through regenerative braking during deceleration and discards the need for separate engine-running charging cycles. By capturing and storing brake energy that would otherwise be wasted, the system accumulates electrical energy for catalyst heating without requiring additional engine operation, thereby reducing overall engine driving time and fuel 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 allows for efficient warming of the catalytic converter using motoring power, reducing the time the internal combustion engine needs to be driven for catalyst warming and minimizing the decline in fuel efficiency.
Implementation Method 1
an electric heater-equipped catalytic converter (EHC) that can be heated by being energized
Data Source
AI summary
When a manifold catalytic converter, which is a catalyst above an exhaust passage, is warmed, a control unit is configured to control the energization of an electric heater of the manifold catalytic converter, and/or the driving of an internal combustion engine in accordance with a battery SOC of a battery. This makes it possible in a hybrid vehicle to warm the manifold catalytic converter using an amount of electric power consumed by motoring of an electric motor, and generally to shorten a time taken to drive the internal combustion engine for catalyst warming.