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raw · papers · ingested 2026-06-19

Studies on the feasibility of adsorption cooling technologies

Source: https://doi.org/10.1088/1742-6596/1473/1/012050

Read from local Zotero full-text PDF (group 5183627 / Joule Heist).

Key findings

  • Built a single-bed silica gel/water adsorption cooling rig (three vacuum chambers: adsorber, condenser, evaporator) with solar water heating; experiments used 20 mL water in evaporator, P_evap ~665 mm Hg, P_adsorber/P_condenser ~680 mm Hg, 16 min adsorption/desorption phase.
  • Measured COP increased with heat-source (hot water) temperature: 0.51 at 60 C, 0.66 at 70 C, 0.67 at 80 C; lowest evaporator temperatures reached 16.5, 14.3, and 13.2 C respectively. Adsorbate regeneration achievable even at ~60 C.
  • Working-pair guidance: activated carbon-methanol and silica gel-water best for low-temperature drive (heat source below 100 C); zeolite-water needs ~200 C. Adsorption refrigeration can be driven from heat sources as low as 50 C.
  • Four-step cycle (pre-heating, desorption, pre-cooling, adsorption) on a single adsorber-desorber bed; vacuum maintenance essential and identified as a reliability limitation along with weather-dependent solar heat supply.
  • Literature survey of reported performance: silica gel/water flat-tube chiller COP 0.45 / SCP 176 W/kg; two-bed silica gel/water COP up to 0.5 (cycle 1100 s, collector 38.64 m^2); compact silica gel/water with heat+mass recovery COP 0.49, 9.60 kW (optimal cycle 720 s, mass recovery 80 s, heat recovery 20 s); waste-heat silica gel/water COP 0.62, SCP 208 W/kg.
  • Zeolite-water performance cited: COP 0.25, 5 kW, SCP up to 200 W/kg at evaporating 6.5 C (cycle 1320 s); mobile double-bed zeolite-water COP 0.4, SCP 600 W/kg. Activated carbon-methanol COP 0.12-0.125, SCP 16 W/kg; activated carbon fibre-ethanol COP 0.6 (cycle 600-700 s, heat source 60-95 C).
  • Common adsorbent-refrigerant pairs tabulated: silica gel/water, silica gel/ammonia, zeolite/water, activated carbon/methanol or ethanol, CaCl2/ammonia, metal hydrides/hydrogen, metal chlorides/ammonia. System performance remains below vapour-compression but is environmentally benign.