Plant-Wide Control of an Integrated Molten Carbonate Fuel Cell Plant

Abstract

This paper presents the design and part-load operation of a molten carbonate-micro gas turbine (MCFC/MGT) hybrid system (HS), and proposes a multiloop control strategy for the HS. A mathematical model of the system is introduced. Then, the structure of process is changed and the performance of HSs at part-load operation is studied. The novelty includes utilizing some part of the main fuel instead of auxiliary fuel in the combustion stage. The results show that the new configuration has more efficiency (about 63%). In order to keep the operating system within safe limits, variables of the control system are determined. Those controlled variables are as follows: stack temperature, fuel utilization (FU), turbine inlet temperature (TIT), and output power of HS. Based on relative gain array (RGA) analysis, control structures are suggested for two HS. Investigations on results of RGA analysis indicate that the new configuration has more interactions between inputs and outputs and so has different control structure. The dynamic simulation results show that the proposed control structure is achievable for MCFC/MGT HSs.