Abstract
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This paper deals with a thermoeconomic analysis of a new combination of ammonia/water power generation
cycle and Turbine-Modular Helium Reactor (GT-MHR) cycle and liquefied natural gas (LNG) cryogenic
exergy. In the proposed power generation system, the GT-MHR waste heat is considered as heat
source as well as cryogenic exergy of LNG as thermal sink. Parametric study is performed to investigate
the effects of key parameters. Also, a comparative study is conducted for proposed system with the same
combined cycle without LNG cryogenic exergy. The results show that minimum temperature difference
in the evaporator, DTEV, has the greatest effect on the energy and exergy efficiencies as well as total cost
rate in comparison to other key parameters. For the proposed system, an increase in DTEV from 20 K to
30 K, leads to a reduction of 2.8% and 3.4%in both energy and exergy efficiencies and total cost rate,
respectively. The results also show that the temperature and pressure of ammonia/water solution exiting
the evaporator have the negligible effects on energy and exergy efficiencies. Also, ammonia concentration
of solution entering the separator, has the greatest effect on the product cost. Moreover, a multi-objective
optimization is performed to obtain optimal values of design parameters
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