Cost optimization of heat exchanger inventory for mechanical subcooling refrigeration cycles

In this paper, thermoeconomic considerations are given to heat exchanger inventory allocation in vapor compression cycles with mechanical subcooling. Investigation is made with respect to constant work rate, heat rejection and cooling rates as well as heat transfer in the subcooler. It was found that no minima exist for any of the cost functions with respect to the absolute temperature ratio (ξ) and the average subcooling absolute temperature ratio (θ3). The derivatives for the integrated subcooling cycle can be generated from the derivatives of the dedicated subcooling cycle. It was concluded that the cost optimization of the integrated mechanical subcooling system is qualitatively the same as the dedicated subcooling system.

► Thermoeconomic considerations of both dedicated and integrated subcooling systems are investigated. ► Studies are carried out by considering with respect to (i) constant work rate, (ii) heat rejection, and (iii) cooling rates. ► Cost functions with respect to various parameters are examined for minimum total cost. ► Optimum configurations of dedicated and integrated subcooling systems have similarity.