Coupling of a Solid Oxide Fuel Cell Auxiliary Power Unit with a Vapour Absorption Refrigeration System for Refrigerated Truck Application

Modelling studies have been carried out to investigate coupling of an SOFC APU with a small scale NH3-H2O based Vapour Absorption Refrigeration System (VARS) for a refrigerated truck/trailer application, by using hot cathode exhaust from the SOFC stack to drive the VARS. A bottom up design and modelling approach has been adopted where the end requirements, cooling load in this case, are identified first followed by upstream modelling of the SOFC and VARS unit. This approach enables design of system/components to meet the desired end requirements rather than compromise or fall short of the desired goal. Initial modelling results show that it is indeed possible to couple an SOFC with a VARS on a small scale (< 10 kW cooling load) for the refrigerated truck application. As this novel strategy utilizes both heat and power from the SOFC it promises a higher total efficiency up to 80% and also removes a significant part of the load from the main diesel engine, thereby leaving the engine to carry out the task of only propelling the vehicle. The excess electrical power from the SOFC could also be used to charge the vehicle batteries.