Latent heat storage systems are vital for efficient energy management, offering a crucial means to store and release energy, thus enabling sustainable solutions for heating, cooling, and power generation. This study is the first research on how the eccentricity and rotation of the middle tube impact the entropy production characteristics of a triplex-tube latent heat storage system. The computational fluid dynamics is used to conduct the simulations. The system under investigation directs hot water through its inner and outer tubes, which results in the melting of the phase change material (PCM) located within the middle tube. The study delves into the influence of eccentricity magnitude (e=1–8 mm) and angle (α=0◦-315◦) on the entropy generation rate resulting from heat transfer and fluid friction. The findings revealed that eccentricity, in certain instances, leads to a reduction in both thermal (S˙g,h) and frictional (S˙g,f ) entropy generation rates. Among the scenarios examined, Case e=6 mm and α=270◦ exhibits the lowest S˙g,h of 19.434 W/K, while Case e=8 mm and α=270◦ demonstrates the highest S˙g,h of 21.751 W/K. Moreover, Case e=5 mm and α=315◦ demonstrated the lowest S˙g,f of 0.000359 W/K, while Case e=1 mm and α=45◦ showed the highest S˙g,f of 0.002970 W/K.
