COMPARATIVE ANALYSIS BETWEEN ORGANIC RANKINE CYCLE INTEGRATED CASCADED VAPOR COMPRESSION-ABSORPTION SYSTEMS
Hybrid systems reduce the carbon emissions and increase the energy utilization. Cascaded vapor compression-absorption refrigeration system combines the advantages of the vapor compression refrigeration system (VCRS), i.e., ability to achieve low temperature and vapor absorption refrigeration system (VARS), i.e., ability to use low-grade energy. The simultaneous energy (electricity and heat) need of the cascade system can be achieved through the integration of Organic Rankine cycle (ORC) as a cogeneration unit. In this study, waste heat ORC powered cascaded system with double-effect VARS and conventional VCRS is proposed and performance is compared with the waste heat ORC powered cascaded system with single-effect VARS and conventional VCRS. The proposed system with double-effect VARS requires higher condensation temperature of the ORC (about 160°C) compared to the system with single-effect VARS (about 110°C). The reduction in the VARS generator duty is 44.5% and ORC evaporator duty is 9.5%, with the use of double-effect VARS. As a result, the energetic efficiency of the proposed system is increased from 82% (using single-effect VARS) to 95.4% (using double-effect VARS).