Abstract
High Temperature ELectrolysers (HTEL) operate around 1,073 K, the temperature varying with the applied power. A restricted power range of 60-100 % should be respected to avoid thermal gradients higher than ±10 K cm-1. The present paper aims to propose control strategies to lower thermal gradients and extend the power range. Two strategies, based on the use of air flow at the anode, are proposed and analysed in detail. The first strategy, consisting of a constant ratio between the air flow and the produced oxygen flow, leads to an extended power range of up to 22 -100 % for a ratio of 14. However, since the air flow is heated up to 1,073 K, the impact on the system efficiency is consequent. A second control strategy, consisting of adapting the air flow to the thermal needs of the system, is proposed. The regulated air flow enables to extend the power range to 1-100 % and has an impact on the system efficiency only below 60 % load.
