Akademik Veri Yönetim Sistemi
APPLIED THERMAL ENGINEERING, cilt.219, ss.1-12, 2023 (SCI-Expanded)
The present study concerns the development and
performance assessment of a novel hydrogen storage system which is operated at
a constant pressure where it is also integrated with a compressed air storage
system to supply the necessary pressure needs. The uniqueness of the system is
that there is a two-chamber storage system where the air is stored in one
chamber while hydrogen is stored in the other one. These two chambers work in a
synchronized manner where one is compressed while the other one is expanded.
For example, the air is compressed in the air chamber to expand hydrogen for
releasing to the fuel cell and vice versa. Integration of the compressed air
storage into the present system helps keep the hydrogen storage chamber at the
desired storage pressure. For this purpose, the air is compressed into the
chamber during the hydrogen discharging period, while air is released from the
chamber during the hydrogen charging period. In order to exploit the additional
benefit of the compressed air, an ammonia-fueled Brayton cycle is incorporated
into the current system. Furthermore, this newly developed system is first
analyzed thermodynamically by using both energy and exergy approaches to
confirm its conceptually correct functionality and write the balance equations
for system analysis and secondly assessed for its performance through energy
and exergy efficiencies. Moreover, the results indicate that the compressed air
as a part of the Brayton cycle covers the total energy demands of hydrogen
compression and cooling. In terms of storage efficiencies, the energy and
exergy efficiencies for the charging period are found to be 72.65% and 71.52%,
while they become 35.3% and 35.24% for discharging period, respectively. The
overall system energy and exergy efficiencies are calculated to be 35.00% and
34.38% for a period of 12 hour charging and a period of 6 hour discharging.