Reversible solid oxide electrolysis system using heat recovery

摘要

The present invention relates to a bidirectional water electrolysis system. According to an embodiment, the bidirectional water electrolysis system includes: a bidirectional water electrolysis fuel cell comprising an anode, a cathode, and an electrolyte interposed therebetween, and able to be operated in one mode among a water electrolysis mode, in which oxygen and hydrogen are generated by electricity and steam supplied from the outside, and a fuel cell mode, in which electricity and water are generated by a chemical reaction between oxygen and hydrogen supplied from the outside; a first heat exchanger exchanging heat between hydrogen and steam, which are supplied to the anode, and first discharge gas discharged from the anode; first and second air passages transferring air to be supplied to the anode; a separating part separating the second discharge gas, discharged from the anode, into the first and second separation passages; a second heat exchanger exchanging heat between the transferred gas through the first air passage and the second discharge gas transferred through the first separation passage; and a third heat exchanger exchanging heat between the air discharged through the second air passage and the second discharge gas transferred through the second separation passage.