Low-source-temperature diffusion absorption refrigeration. Part II: Experiments and model assessment

•A passive low-source-temperature thermally driven refrigerator is demonstrated.•Refrigeration grade cooling is achieved at source temperatures of 110–130 °C.•System performance is measured over a range of operating and ambient conditions.•Proposed component and system models are assessed experimentally.•Close agreement with experiments is demonstrated for the system-level model.

The diffusion absorption refrigeration cycle can enable passive fully thermally activated refrigeration for off-grid applications. In the accompanying paper, a new system configuration was proposed that employs alternate working fluids (NH3–NaSCN–He), a coupling-fluid heated bubble-pump generator, and an enhanced absorber. Detailed component and system level models were formulated for this design. In Part II of this work, the subject of this paper, these results are applied to implement a complete low-source-temperature (110–130 °C) passively cooled diffusion absorption refrigeration (DAR) system. Cooling was achieved at temperature ranges suitable for refrigeration (Tevap = 6 → 3 °C, COP ~ 0.06) and air-conditioning (12 → 8 °C, COP ~ 0.14). Device performance was also assessed at elevated ambient temperatures, reduced ambient air velocities, and varying system pressures. Results from this investigation agreed well with the predictions of the models developed in Part I.