Start-Up and dynamic processes simulation of SOFC-MGT hybrid power system

Abstract

For the start-up process of a hybrid system consisting of a Micro Gas Turbine (MGT) and a Solid Oxide Fuel Cell (SOFC), the surge of the MGT is largely destructive. The MGT, which has a small thermal inertia, can start quickly. However, due to the large thermal inertia of SOFC, starting up SOFC quickly is easily malfunction. Therefore, fast and safe start-up process investigation of the coupling hybrid system is of great challenging and significance. This paper developed a dynamic model of the SOFC-MGT hybrid power systems and studied the rapid start-up process in the case of avoiding gas turbine surge and protecting SOFC by adding other afterburning, auxiliary systems, and bypass valves. The result shows that the bypass from compressor exit to atmosphere can effectively avoid system unstable and the strategy of starting the MGT and SOFC respectively is reasonable. The start-up process simulation provides a reference to the actual SOFC-MGT hybrid power systems.