Research on the optimal absorption refrigeration configurations of screened low-GWP organic working fluids via pinch technology

Organic absorption cooling, as an environmentally friendly technology, has significant potential for building energy conservation and emission reduction. To systematically screen efficient working fluids and optimize heat recovery configurations, this study proposes a novel methodology integrating pinch technology as a comprehensive framework for heat integration analysis in both single-stage absorption refrigeration systems (SSARS) and compression-assisted absorption refrigeration systems (LCARS). Through application of problem table and grid methods, ideal optimal heat integrations for maximum heat recovery under various operating conditions were initially established. The ideal optimal coefficient of performance (COP) served as the performance potential for working pair screening. Among 28 candidate mixtures, R152a + NMP emerged as the optimal candidate, demonstrating the highest average performance potential (0.538) in SSARS and the third-highest average potential (1.139) in LCARS. Detailed thermodynamic analyses elucidated the heat integration mechanisms of R152a + NMP across different conditions. Additionally, a novel configuration termed MHR-LCARS was developed, featuring flexible internal heat recovery through parameter-controlled adjustments to accommodate varying conditions. The MHR-LCARS demonstrated significant COP enhancements over original systems, achieving maximum values of about 0.876 (compression ratio = 1) and 0.989 (compression ratio = 1.5), effectively realizing 79.133 % and 99.198 % of the performance potential respectively.