Diffusion absorption refrigeration (DAR) systems require no mechanical drive and operate solely on heat and gravity, making them attractive as electricity-free cooling technologies that can use low- to medium-temperature waste heat or solar energy. However, previous studies lack detailed numerical models that can predict performance without experimental data or fitting parameters, making it difficult to design DAR systems to meet specific requirements. In this study, a new numerical model was developed to enable more efficient design for DAR systems. The numerical model incorporates detailed heat and mass transfer and two-phase flow distribution in addition to the energy and mass balance equations. To validate the developed model, a DAR system using ammonia–water–helium was manufactured, and experiments were conducted. The DAR achieved a cooling temperature of 0.9 °C, a cooling capacity of 18 W and a coefficient of performance of 0.11. Model predictions of steady-state temperatures, mass flow rates, and cooling capacity were compared with experimental results. The comparison shows that, although discrepancies remain, particularly in temperature predictions (up to 40 °C), the model can predict the working fluid flow rate within 31% and estimate the cooling performance with a maximum error within 100%. These results demonstrate that the proposed model enables efficient design of DAR systems. • A novel numerical model was developed to accelerate DAR design and optimization • The model computes heat/mass transfer, two-phase pressure loss, and auxiliary gas flow • Without parameter fitting, the model matched experimental Cooling capacity within 100% • The developed DAR achieved a cooling capacity of 18 W with a COP of 0.11 • Comparison of model and experiments revealed pathways to improve DAR efficiency
MAEDA et al. (Sun,) studied this question.