TRANSIENT ANALYSIS OF SIMULTANEOUS MULTIVARIABLE SIGNALS ON FUEL CELL/GAS TURBINE HYBRID TO DEFINE CONTROL STRATEGIES FOR CATHODE PARAMETERS AND COMPRESSOR STALL

摘要

Transients in a hybrid system composed of a solid oxide fuel cell (SOFC) and a gas turbine (GT) were evaluated during simultaneous manipulation of system airflow bypasses and turbine electric load. The three airflow bypass valves selected for study were chosen for their potential application in controlling dynamic excursions of the main fuel cell and gas turbine parameters in the system. The objective of this work was to understand the physical behavior by the simultaneous operation of the bypass valves along with the turbine electric load in order to formulate scenarios of control on the key parameters relevant to system failure, specifically from compressor stall and surge. Empirical data was collected using the National Energy Technology Laboratory Hybrid Performance project hardware simulation of a SOFC/GT hybrid. Step changes were implemented in all three valves for various open/close valve commands and increase/decrease of the turbine electric load simultaneously. The transient response of process variables was analyzed to determine the potential for mitigating or aggravating compressor stall and surge during load excursions.