Low-Cost FC System Concept with Fewer Parts and Adoption of Low-Cost Components 2012-01-1222
The most important issues in putting fuel cell electric vehicles (FCEVs) on the market include reducing the FC system size and cost. At Nissan, we have continued to research and develop key technologies for resolving these issues since the release of our 2005 model FCEV. This paper describes the low cost technologies that we have developed for our next-generation FCEV system.
The current generation FC system uses an anode gas recirculation system for hydrogen supply to prevent fuel starvation and flooding caused by product water. However, an analysis of flow in the anode channel has led to a better understanding of the transient properties of a compressive fluid, indicating the possibility of eliminating the anode recirculation system. Instead of using an electronically controlled 3-way valve for the cooling system, we have adopted a general-purpose thermostatic valve with a new flow system that was designed by using the correlation between the viscosity and temperature of the coolant. Moreover, the heating function of the air conditioner has been integrated with the FC cooling system.
As a result of developing these low cost technologies, the system power density is expected to be increased by 2.3 times by adopting a new FC stack concept and the system cost (per kilowatt) is expected to be reduced by one-fourth, compared with that of the 2005 model FCEV system described at the 2008 SAE World Congress (2008-01-042).