Optimization and comparative analysis of various organic Rankine cycle-based integrated systems for cooling and power cogeneration utilizing waste heat

Abstract

Waste heat recovery is crucial for reducing energy consumption and carbon emissions. The integration of organic Rankine cycle with absorption refrigeration, vapor compression refrigeration, and compression-absorption cascade refrigeration enables efficient cooling and power cogeneration from waste heat. However, existing studies lack a unified optimization method, a systematic comparison framework, and thorough application scenarios analysis. Herein, a comprehensive integrated system incorporating operational modes of organic Rankine cycle with these refrigeration technologies is developed. An economic optimization model is formulated to determine the optimal configuration and operating parameters for the integrated system under specified modes. A comparison framework is established to identify the system with the best economic performance. Using the proposed method, optimization and comparative analyses are conducted for six scenarios with distinct cooling energy demands. Results indicate that organic Rankine cycle integrated with absorption refrigeration and compression-absorption cascade refrigeration achieves superior economic performance under 500 kW at 25 °C and −25 °C, respectively. In contrast, integration with vapor compression refrigeration remains more economically advantageous under 5,000 kW or at 5 °C. Additionally, the effects of cooling energy and waste heat source conditions on economic performance are analyzed, and suitable application scenarios for each system are summarized. This research facilitates automatic design of organic Rankine cycle-based integrated systems with enhanced economic performance, providing valuable guidance for industrial waste heat utilization.