Fuel Cell Heat Management for Exhaust Water Vaporization
Solution Overview
Problem
Fuel cell vehicles produce substantial amounts of exhaust water that need to be managed efficiently to avoid soil contamination and require large drain tanks, posing safety and operational challenges.
Innovation Solution
A heat management system utilizing a compressor to transform exhaust water into heated steam, which is then expelled into the ambient environment, combined with an air heating arrangement to dissipate excess electric power during braking, and a control unit to manage the system's operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If exhaust water is expelled to the ground surface, then the water is removed from the vehicle, but soil contamination occurs which is hazardous
Solution Approach 1:
The system changes the temperature parameter of the exhaust water by heating it in the compressor to above 100°C, transforming it from liquid water to steam. This parameter change eliminates the harmful effect of soil contamination while maintaining effective water removal from the vehicle
Solution Approach 2:
The exhaust water undergoes a phase transition from liquid to gas (steam) through heating in the compressor. This phase transition allows the water to be expelled as steam rather than liquid, preventing soil contamination while achieving complete water removal
2Object-affected harmful factors
If a drain tank is used to store exhaust water, then soil contamination is avoided, but the tank needs to be substantial in size to avoid frequent emptying
Solution Approach 1:
By transforming exhaust water into steam through phase transition in the compressor, the system eliminates the need for liquid storage tanks entirely. The steam is directly expelled through the exhaust system, achieving both contamination prevention and eliminating the volume penalty of large drain tanks
Solution Approach 2:
The system extracts the water removal function from the traditional drain tank approach and integrates it into the exhaust system. The compressor serves dual purposes: power generation and water vaporization, eliminating the separate drain tank component
3Object-affected harmful factors
If the compressor is used to pressurize exhaust water and ambient air, then water is transformed into heated steam for safe expulsion, but the compressor requires power input
Solution Approach 1:
The system converts the harmful excess electric power generated during braking into a useful function by driving the compressor. This transforms what would be wasted energy into the driving force needed for water vaporization and expulsion, achieving environmental safety while utilizing otherwise lost energy
Solution Approach 2:
The compressor serves multiple functions simultaneously: it acts as a power generator during normal operation, provides mechanical power for vaporizing exhaust water, and dissipates excess braking energy. This merging of functions reduces overall system energy requirements
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
Effectively manages exhaust water, reduces environmental soiling, and dissipates excess electric power, ensuring safe and efficient operation of fuel cell vehicles.
Implementation Method 1
the inlet of the compressor is arranged in downstream fluid communication with the outlet of the fuel cell and configured to pressurize a mixture of exhaust water expelled from the fuel cell and ambient air
Implementation Method 2
The compressor can be advantageously used for transforming the exhaust water from the fuel cell into heated steam
Data Source
AI summary
A heat management system for a fuel cell vehicle propelled by an electric traction motor includes a fuel cell system comprising a fuel cell configured to generate electric power when receiving hydrogen through a hydrogen inlet and oxygen through an oxygen inlet, wherein the fuel cell includes an outlet configured to expel exhaust water formed in the fuel cell, and a compressor including an inlet configured to receive ambient air, and an outlet, wherein the inlet of the compressor is arranged in downstream fluid communication with the outlet of the fuel cell and configured to pressurize a mixture of exhaust water expelled from the fuel cell and ambient air.