Solid Oxide Fuel Cell APU for Electric Vehicle Range Extension
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Solution Overview
Problem
Current electric vehicles (EVs) face limitations due to bulky and costly battery systems, especially for long trips and cold weather conditions, and existing hybrid systems with internal combustion engines (ICE) suffer from emissions and low efficiency. Additionally, fuel cell electric vehicles (FCEVs) using proton exchange membrane (PEM) fuel cells are costly and inefficient for range extension due to the need for complex hydrogen reforming and storage.
Innovation Solution
A solid oxide fuel cell (SOFC) auxiliary power unit (APU) system that can recharge vehicle batteries and provide electricity to the grid during vehicle inactivity, utilizing waste heat for HVAC and offering a cost-effective, efficient means to supplement regional power grids and function as a backup generator, with the ability to operate on hydrocarbon fuels and provide heat to buildings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of moving object
If battery capacity is increased to extend vehicle range, then driving range is improved, but vehicle cost and battery size increase
Solution Approach 1:
The patent combines a fuel cell system with an electric vehicle battery system to create a hybrid power architecture. The fuel cell generator is integrated with the battery pack, allowing the fuel cell to recharge the battery during vehicle operation, thereby extending driving range without requiring a proportionally larger battery pack.
Solution Approach 2:
The fuel cell system serves multiple functions: it acts as a range extender by generating electricity to recharge the battery during driving, and simultaneously functions as a stationary power source when the vehicle is parked and connected to the electrical grid, providing backup power and reducing grid spinning losses.
2Duration of action of moving object
If internal combustion engine is added to extend range, then driving range is improved, but emissions and fuel efficiency worsen
Solution Approach 1:
The patent replaces the internal combustion engine with a fuel cell system that uses electrochemical reactions to generate electricity. This substitution eliminates the mechanical combustion process, thereby eliminating harmful emissions such as carbon monoxide, nitrogen oxides, and unburned hydrocarbons that are characteristic of ICE vehicles.
3Duration of action of moving object
If fuel cell system is used for range extension, then driving range is improved, but system cost and complexity increase
Solution Approach 1:
The fuel cell system is designed to serve dual purposes: extending driving range by recharging the battery during vehicle operation, and providing stationary power generation when the vehicle is parked and connected to the grid. This multi-functionality helps justify the added system complexity by providing multiple benefits from a single added component.
Solution Approach 2:
The fuel cell system is designed to automatically manage its own operation, including self-regulation of power output based on battery charge state and automatic connection/disconnection from the electrical grid when parked. This reduces the need for complex external control systems and simplifies overall system management.
4Use of energy by moving object
If vehicle battery is connected to grid for recharging, then battery charge is improved, but grid spinning losses increase
Solution Approach 1:
Instead of only drawing power from the electrical grid when parked, the patent enables the vehicle's fuel cell system to discharge electricity back to the grid during periods when the vehicle is stationary and connected. This inverts the traditional unidirectional charging relationship, allowing the vehicle to become a distributed power generation resource that reduces grid spinning losses and provides energy back to the utility.
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
The SOFC APU system extends vehicle range, reduces grid spinning losses, provides efficient power and heat, and increases the return on investment by utilizing waste heat and hydrocarbon fuels, while minimizing emissions and operational costs, making it suitable for various climates and power needs.
Implementation Method 1
A solid oxide fuel cell (SOFC) auxiliary power unit (APU) system that can recharge vehicle batteries
Implementation Method 2
utilizing waste heat for HVAC and offering a cost-effective, efficient means to supplement regional power grids and function as a backup generator
Data Source
AI summary
During periods of vehicle inactivity, a vehicle-based APU electric generating system may be coupled into a regional electric grid to send electricity into the grid. A currently-preferred APU is a solid oxide fuel cell system. When a large number of vehicles are thus equipped and connected, substantial electric buffering can be effected to the grid load. A vehicle-based APU can also function as a back-up generator to a docking facility in the event of power failure of the grid. Gaseous hydrocarbon is readily supplied by pipe in many locations as a commercial and residential heating fuel source, and a hydrocarbon reformer on the vehicle can be attached to the fuel source, enabling an APU to operate as a stationary power source indefinitely. An optional storage tank on the vehicle may be refueled with gaseous fuel, for example, while the battery is being electrically recharged by the grid.