control system in cooling tower of ECS performs stably and
reduces the power consumption dramatically.
The overall coefficient of performance (COP) of SACH-k2,
COPo, including the power consumption of all the peripheral
devices is defined as:
COPo ¼ QL=WIAC þWsolar pump þWCT þ Wfreon pump (3)
where WIAC is the power consumption of IAC, Wsolar pump is
the pumping power of solar collector pump,WCT is the power
consumption of cooling tower including fan and water pump,
Wfreon pump is the circulation pump of ECS.
It is seen from Table 8 that COPo increases from 2.94e3.3
(IAC alone) to 4.06e4.5 (SACH-k2), about 33e43% increase. The
IAC power input decreases about 45%. The solar-driven ECS
sub-cools the condenser of IAC about 15 C and improves the
performance of IAC. In addition, the power consumption of
peripheral devices in SACH-k2 is reduced by using advanced
control technology, including the MPPT control of solar heating
system (Huang et al., 2012). The highest COPo of SACH-k2