raw · papers · ingested 2026-06-19
Design and Development of Intermittent Solid Adsorption Refrigeration System Running on Solar Energy
Source: https://www.researchgate.net/publication/296608120
Read from local Zotero full-text PDF (group 5183627 / Joule Heist).
Key findings
- Working pair & cycle: activated carbon (from coconut shell) / methanol, intermittent single-bed cycle. By day the solar-heated bed desorbs methanol → condenser → evaporator; at night the bed cools, re-adsorbs methanol, and the evaporative cooling forms ice in the water tank. No compressor (bed is the thermal compressor), no valves, no throttle valve — refrigerant flows by gravity. Zero electricity, zero running cost; ODP/GWP-safe.
- Adsorbent bed (the “heart”): flat-plate stainless steel box (chosen over aluminium, which catalyzes methanol decomposition), surface area 1 m², dimensions 1000×1000×70 mm from a 1 mm sheet. Holds 19 kg activated carbon; total steel mass ~20 kg; adsorbent layer thickness ~0.04 m. Internal stainless-steel fins ~0.15 m apart for heat transfer; a 0.01 m “false bottom” (per Pons & Guillemiont) for uniform methanol vapor distribution.
- Bed operating temperature: solar radiation drives the bed to 90-100 °C for desorption; covered by fibre-plastic plate (solar permeability ~0.92, higher than glass) with selective coating; thermally insulated case.
- Condenser: air-cooled, copper tubes (inlet/outlet 15.87 mm, condenser tube 9.525 mm, 4 tubes, total tube length 5337 mm), 165 aluminium fins, 355.6×368.3×129 mm.
- Evaporator & ice-box: stainless-steel evaporator 300×300×100 mm with four trapezoidal cells (0.03×0.04 m) for added surface area, partly immersed in a water container; wooden insulated ice-box 406×355×508 mm. Methanol evaporates at ~66-70 °C; whole system evacuated and pressure checked by vacuum gauge.
- Design rationale / conclusions: valveless layout reduces cost; condenser and evaporator sit directly under the collector so refrigerant flows in by gravity at low pressure. Adsorption bed (generator) design has the greatest effect on performance; quiet, no moving parts. Suited to off-grid ice-making; authors note further work needed on heat transfer, cost and higher-capacity adsorbents.