Analysis of the Thermal Management of a High-Temperature Methanol Fuel Cell Using a Latent Heat Storage

Waste heat from industrial applications offers a high but mostly unused potential due to the time differences between its generation and possible consumption. By using waste heat, the energy efficiency can be increased and therefore, the overall costs and emissions can be reduced. This work shows the feasibility of increasing the energy efficiency of a high-temperature methanol fuel cell using a latent heat storage with the help of full-scale experiments. The fuel cell needs to be preheated for start up to reach its operation temperature. During operation, heat is generated at a temperature of 433 K and the system needs to be air-cooled to maintain its temperature. Instead of cooling the fuel cell with air and losing the heat to the environment, the waste heat is now stored in a latent heat storage to later be used for preheating the fuel cell. Different experiments are conducted to find the optimum operation point of the latent heat storage in combination with the fuel cell. The aging and the cycling stability of high density polyethylene, which is used as phase change material in the latent heat storage, is monitored as well as the mechanical stability of the system.