A hybrid system using a looped multi-stage thermoacoustically-driven cryocooler to harvest the waste heat from a direct carbon solid oxide fuel cell

摘要

A novel hybrid system model is established to assess the feasibilities of using a looped multi-stage thermoacoustically-driven cryocooler (LMSTDC) to harvest the waste heat from a direct carbon solid oxide fuel cell (DC-SOFC). Mathematical expressions for the equivalent power output and equivalent efficiency of the proposed hybrid system are given and the performance characteristics are investigated under different operating conditions. The results demonstrate that the LMSTDC can effectively harvest the possible waste heat released in the DC-SOFC, especially under a large working current density. The peak equivalent power density and efficiency of the hybrid system can be, respectively, up to 6500.0 W m~(-2) and 51.8% at 1173.0 K and 30,000.0 A m~(-2). Comprehensive numerical calculations are carried out to examine the impacts of the working temperature, the working current density, the distance between the anode and carbon layer, and the engine stage number in the LMSTDC on the hybrid system performance.