evaporator temperature control, and the optimal control of
fan power in cooling tower of ECS.
From the results of test runs, the generator liquid level
control in ECS performs quite well and keeps stable performance
of ejector under variable solar radiation. The ECS
evaporator temperature control also performs satisfactorily to
keep ejector performance normally under low and variable
solar radiation. The fan power control system in cooling tower
of ECS performs stably and reduces the power consumption
dramatically.
The COPo increases from 2.94e3.3 (IAC alone) to 4.06e4.5
(SACH-k2), about 33e43%. The IAC power input decreases
about 45%. The solar-driven ECS sub-cools the condenser of
IAC by 10e20 C and improves the performance of IAC. The
highest COPo of SACH-k2 is 4.5 which reach the target of solar
cooling technology suggested by Wiemken et al. (2010). The
present test results of SACH-k2 indicate that the solar
thermally-driven ejector air conditioning technology which
integrates different advanced technologies, including MPPT of
solar heating system, ECS generator liquid level control, ECS
condenser temperature control, fan power control of
ECS cooling tower, becomes more mature toward
commercialization.
Further performance improvement of SACH-k2 is still
possible. We found that there is excess cooling capacity
generated by ECS during high solar radiation periods, due to
fixed heat exchanger design of intercooler. By increasing the
size of intercooler, COPo may be increased further. This means
that it is possible to obtain a COPo higher than 6.0.