Thermal management PEMFC

FCS water management is the key factor for an efficient and reliable operation of a PEMFC stack. Membrane hydration control and water balance for a durable operation of FCS are the main objectives of this sub-system, whose design and control issues, strictly connected to thermal management but also to reactant subsystem components, are discussed in Sect. 4.5. The possibility of interactions between the wet and warm cathode outlet stream and the components of thermal and water management sub-systems is also discussed. 

Kandlikar SG, Lu Z (2009) Thermal management issues in a PEMFC stack-A brief review of current status. Appl Thermal Eng 29 1276-1280... 

The overall objective is to operate PEMFCs at lOO-MO C to improve CO tolerance, mitigate water and thermal management challenges and reduce membrane cost. The basic approach is to develop a composite membrane consisting of mechanical support and high-temperature proton conduction phases. In order to improve cathode performance, modification of cathode formulation and structure is on-going. Promising solid superacids are incorporated into the cathode. 

Due to the low operation temperature of PEMFC an extra reactor is needed to convert the carbon monoxide into hydrogen by the water gas shift reaction. The extra reactor needs water or steam supply for the water gas shift reaction and the operation temperature of the shift catalyst has to maintain. So the shift reactor has to be part of the thermal management of PEMFC system. So the thermal management of a PEMFC system becomes more complex in comparison to a SOFC system. 

One possibility for an internal thermal management concept is the cooling with increased and adapted cathode air flow rate. This influences the HT-PEMFC stack design only slightly. Only the... 

It can be concluded that both variants of cooling via forced convection in separate channels are well suited as an active thermal management concept for HT-PEMFC stacks. In the whole operating range the produced heat can be removed by means of this active cooling... 

Thermal management of PEMFC is key to ensure high cell performance and efficiency. The irreversibility of electrochemical reactions and joule heating are the most important factors causing heat generation inside PEM fuel cells. The temperature distribution in the cell has a strong impact on the cell performance. It influenees the water distribution by means of condensation and affects the multi-component gas diffusion transport characteristics through thermo capillary forces and thermal buoyancy. 

Significant improvement in PEMFC thermal management. By elevating the temperature of the fuel cell stack, thermal management can be simplified due to more efficient waste heat removal. 

As noted, PFSA-based polymer electrol34e membranes used in current PEMFCs require thermal and water management systems to cmitrol temperature and keep the membrane humidified. These extra components increase the weight and volume of... 

Abstract Most of the transport processes of a fuel cell take place in the gas diffusion media and flow fields. The task of the flow fleld is to uniformly distribute the reactant gases across the electrochemically active area and at the same time ensure an adequate removal of the reactant products, which is water on the cathode side in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFC). Gas diffusion media are required to supply the reactant under the land areas of the flow fleld at the same time, the gas diffusion media has to ensure a good thermal as well as water management to avoid any non-optimum conditions. Characterization tools for gas diffusion media are presented, flow fleld types and design criteria are discussed and the effect of both components on the performance of a fuel cell are highlighted. System aspects for different fuels (hydrogen, vapor-fed DMFCS, liquid fed DMFCs) are compiled and the different loss contributions and factors determining the performance of a fuel cell system are shown. 

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