Experimental study of a solid oxide fuel cell afterburner for a 30 kW generator module: A comparative performance analysis

Abstract

A comprehensive performance test is conducted on a diffusion burner designed for a 30 kW-class methane solid oxide fuel cell (SOFC) power generation system. To facilitate this assessment, a test system is established, capable of simulating the gas composition and temperature of the anode and cathode at the outlet of the fuel cell stack under various typical operating conditions. The test results demonstrate the afterburner's exceptional robustness, minimal pressure loss, and low emission characteristics. Notably, the afterburner can be ignited and started at low load (6LPM, 20 % of the rated methane flow rate) and can achieve low-load heating (4LPM, at approximately 13 % of the rated methane flow rate) with a significant excess air coefficient of 46.2. Remarkably, the afterburner maintains its reignition capability under all operating conditions. Operational stability is observed with a water-to-carbon ratio below 3, displaying robust resistance to fluctuations in water vapor and airflow. Under generating condition, the afterburner exhibits self-ignition capabilities without the need for an external igniter following flameout. The pressure losses within both the anode and cathode flows remain well below 200Pa, while NOx and CO emissions are recorded at 1.7mg/kWh and 66.2mg/kWh, respectively, complying with the stringent EU EN676:2020 standards.