Assessment of the use of solar energy sources and cooling seawater in a combination of a basic and two-stage regenerative organic Rankine cycle with a vapor compression refrigeration cycle

Abstract

This study evaluates the cooling and power generation of parabolic trough collectors (PTC) using a solar energy source through a system integrated into a combined organic Rankine cycle (ORC) and vapor compression refrigerant (VCR) cycle with R245fa as the fluid. The ORC cycle of the considered system is analyzed in two different variants: basic BORC_VCR and two-stage regenerative DORC_VCR. The energy, exergy efficiencies, and COPs for different operating parameters are compared for the two systems. The exergy efficiency of BORC_VCR and DORC_VCR systems is 3.44% and 3.92%, respectively, with a total exergy destruction of 423.4 kW and 422.6 kW. The designed system's contribution to other combined power and cooling systems in the literature is the ability to use seawater as a heat sink in the condenser of both cycles. Solar energy can serve as a heat source, while seawater can act as a heat sink in the condenser of both cycles. This is ideal for small-scale power and cooling requirements far from the electricity grid and eliminates the need for fossil fuels. The COP of the system increases from 0.3 to 1.8 when the seawater temperature drops from 30 to 5 degrees C (for DORC_VCR). The system's cooling capacity was also calculated for two specific provinces using annual meteorological data. The total cooling capacity obtained was 13,920 kW/year for Antakya and 16,915 kW/year for Adana.