Abstract:
Cotemporary Energy issues, like depletion of energy resources, rising energy costs
and the related environmental issues demand exploration of renewable energy
technologies. Solar powered absorption refrigeration systems using evacuated tube
collector (ETC) or flat plate collector (FPC) is an emerging renewable energy
technology. These systems are very attractive alternative to conventional
refrigeration systems for reduction in peak load demand of electricity. This research
reveals the feasibility and optimization analysis of a solar absorption cooling (SAC)
system by using TRNSYS simulation software for Typical Meteorological Year data
of different cities of Pakistan (Islamabad, Lahore, Karachi, Multan and Quetta).
TRNSYS is a tool used for modeling of renewable energy systems. A simulation
model that contains solar collectors (FPC, ETC), storage tank, absorption chiller and
the building is developed. The results depict that absorption system of rated capacity
40,000 kJ/hr is required to provide cooling in the selected building located in NUST
Islamabad. The study also reveals that to increase the reliability of operation, an
optimized system containing 8 m2 area of ETC sloped at 15o is required. Hot water
storage tank of 0.6 m3 and auxiliary heater having set point temperature of 87 0C is
essential to provide effective cooling to the building. The economic analysis shows
that the system has payback period of 12 yrs. It could reduce to 10.3 yrs by using
natural gas auxiliary heater instead of Electric heater with net present value (NPV) of
8,10,263 PKR for Islamabad. Next, SAC system with ETC is tested for climatic
conditions of other four cities of Pakistan. It is investigated that Quetta has minimum
payback period with the highest NPV of all the analyzed cities. Meanwhile for
Lahore, payback period is the highest with a comparatively low NPV. CO2 emissions
for Karachi are the highest at Optimized conditions as compared to other selected
cities.
