TY - JOUR
T1 - Dynamic behavior and control strategy study of CO2/H2O co-electrolysis in solid oxide electrolysis cells
AU - Wang, Yuqing
AU - Banerjee, Aayan
AU - Deutschmann, Olaf
PY - 2019/2/1
Y1 - 2019/2/1
N2 - The co-electrolysis of CO2 and H2O in high temperature solid oxide electrolysis cells (SOECs) is a promising energy storage method for intermittent renewable energy sources. In this paper, a three-dimensional (3D) continuum model of a 3-kW 40-cell planar SOEC stack is employed to study the dynamic behavior and control strategy under variable working conditions. The dynamic responses of stack power, current density, output H2/CO ratio and stack temperature are evaluated for a scaled real-time wind power input over a whole day. The fluctuation of the wind power input leads to SOEC stack temperature fluctuation, which illustrates the need for temperature control. Two representative cases with voltage step changes in both endothermic and exothermic operation modes are studied to predict the temperature control by the variation of excess air ratio. The effects of excess air ratio on both the steady-state temperature gradient and the transient temperature variation rate are analyzed in both cases. The temperature fluctuation is successfully controlled by applying an excess air ratio profile that changes with the wind power input.
AB - The co-electrolysis of CO2 and H2O in high temperature solid oxide electrolysis cells (SOECs) is a promising energy storage method for intermittent renewable energy sources. In this paper, a three-dimensional (3D) continuum model of a 3-kW 40-cell planar SOEC stack is employed to study the dynamic behavior and control strategy under variable working conditions. The dynamic responses of stack power, current density, output H2/CO ratio and stack temperature are evaluated for a scaled real-time wind power input over a whole day. The fluctuation of the wind power input leads to SOEC stack temperature fluctuation, which illustrates the need for temperature control. Two representative cases with voltage step changes in both endothermic and exothermic operation modes are studied to predict the temperature control by the variation of excess air ratio. The effects of excess air ratio on both the steady-state temperature gradient and the transient temperature variation rate are analyzed in both cases. The temperature fluctuation is successfully controlled by applying an excess air ratio profile that changes with the wind power input.
KW - Co-electrolysis
KW - Dynamic characteristic
KW - Renewable energy storage
KW - SOEC stack
KW - Temperature control strategy
UR - http://www.scopus.com/inward/record.url?scp=85057101477&partnerID=8YFLogxK
U2 - 10.1016/j.jpowsour.2018.11.047
DO - 10.1016/j.jpowsour.2018.11.047
M3 - Article
AN - SCOPUS:85057101477
SN - 0378-7753
VL - 412
SP - 255
EP - 264
JO - Journal of power sources
JF - Journal of power sources
ER -