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raw · papers · ingested 2026-06-19

Study of an innovative combined absorption-adsorption cooling system employing the same evaporator and condenser

Source: https://doi.org/10.1016/j.csite.2022.102690

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

Key findings

  • Combines a single-effect LiBr-H2O absorption chiller (ABC) with a two-bed silica gel/water adsorption chiller (ADC) sharing the same condenser and evaporator; the ABC generator is driven directly by the heat source and its outlet hot water then drives the ADC desorber bed in the series configuration.
  • At 85 C heat-source temperature, the combined series ABD-ADC configuration delivers cooling capacity 0.344 kW and COP 0.623; this is 4.06% higher capacity and 2.73% higher COP than the separated ABC+ADC system, and 58.34% higher capacity and 27.07% higher COP than the conventional single-stage ADC cycle.
  • Outlet chilled-water temperature fluctuation is much smoother for the combined system (+/-0.88 C) than the separated ABC-ADC system (+/-1.84 C), giving more continuous cooling.
  • Total hot-water mass flow 1.6 kg/s from solar storage tank; in series mode the full flow drives ABC then ADC, in parallel mode the 1.6 kg/s is split equally between the two cycles at the same inlet temperature.
  • Working pairs: LiBr-H2O for the absorption subsystem, RD silica gel/water for the adsorption subsystem; ADC modeled with adsorption-equilibrium correlation W = A(Tsg)[Psat(Tref)/Psat(Tsg)]^B and LDF kinetics with F0 = 15, surface diffusivity Ds = Dso exp(-Ea/RT).
  • Dynamic lumped-parameter MATLAB model with energy balances on adsorber/desorber, absorber, generator, condenser, evaporator; assumes uniform bed pressure/temperature, isenthalpic expansion, saturated condenser/evaporator outlets, superheated generator outlet. Validated against published data within ~0.2% (ABC) and ~10% (ADS).
  • Motivation: absorption cycles have higher thermal performance but crystallization issues; adsorption cycles run at lower hot-water temperatures; combining them captures both advantages and mitigates intermittency. Cited integrated cycles reached up to SCP 193.7 W/kg (parallel) and 157.9 W/kg (series).