raw · papers · ingested 2026-06-19
Experimental System of Solar Adsorption Refrigeration with Concentrated Collector
Source: https://doi.org/10.3791/55925
Read from local Zotero full-text PDF (group 5183627 / Joule Heist).
Key findings
- Working pairs: SAPO-34/water and ZSM-5/water; bed charged with 3.171 kg granular SAPO-34 zeolite (5.7 mm granules) and 3.152 kg ZSM-5, water as refrigerant. SAPO-34 outperformed ZSM-5 on both COP and SCP at all adsorption times.
- Best performance (SAPO-34, t_ads = 1800 s): COP = 0.169, Q_ref = 450.38 kJ, SCP = 78.91 W/kg; ZSM-5 at same time gave COP = 0.091, Q_ref = 260.96 kJ. COP uncertainty 6.2-9.4% across campaigns.
- At t_ads = 600 s SCP peaks (SAPO-34 = 169.74 W/kg, COP = 0.122; ZSM-5 = 91.20 W/kg, COP = 0.060); >2/3 of total refrigeration capacity is delivered in first 600 s. SCP and COP trade off oppositely with adsorption time.
- Adsorber bed: cylindrical tube (d = 64.5 mm stainless steel solar-absorbing tube inside d = 100 mm glass tube) reformed from a vacuum solar receiver; black-chrome selective coating (solar absorptance 0.95, IR emissivity 0.15, 0.08 mm thick); axial copper cooling channel (d = 20 mm) plus reticular mass-transfer channel (d = 10 mm).
- Solar input via automatic sun-tracking parabolic trough (aperture 2.407 m^2, reflective efficiency 0.70, glass transmittance 0.935); located at Beijing 39.89 N. Condensation pressure of water at 30 C taken as 4246 Pa; bed pre-heat starts below 800 Pa.
- Desorption degree E(t) for SAPO-34 rose from 54.9% at 1 h to 69.3% at 2 h; ZSM-5 showed worse desorption despite larger bed temperature rise (32.52 C vs 17.02 C over 600 s desorption), indicating ZSM-5 has better heat transfer but SAPO-34 superior overall.
- Four-step intermittent single-bed cycle: closed solar pre-heating, desorption to condenser, water-cooling of bed (aluminum-foil solar shielding), then adsorption from evaporator. Water cooling preferred over air cooling; silica gel would require desorption capped below 95 C to avoid dehydration.