| Diffusion-absorption refrigeration system has the advantage of utilizing low grade energy,which is in accordance with the current absorption refrigeration research at home and abroad.However, the high in generating temperature has limited the utilize of the traditionalammonia-water cooling system. This paper analyzes the present situation ofdiffusion-absorption refrigeration system, and aims at resolving the existing problems.This article chooses the widely used physical properties calculation equation includingPR equation and ammonia special property equation to calculate their physical properties.Using a computer program calculation diffusion-absorption refrigeration system of thermalproperties, analyzes the principle and refrigeration components mechanism. On the basis ofthis, a cooling device using the medium of ammonia-water-He, having a refrigerating capacityof50W was designed.The main factors of that affects the preheating time was analysis in the angle of theoperation characteristics of the refrigeration system in the paper. From the prospective of thechemistry, the internal factors that influenced the solubility temperature and boilingtemperature was revealed. The chemical compatibility, soft hard soda acid and hydrogenbonding theory was adopted to explain the inner relations between the inorganic solute andthe solvent. Similarly, the molecular hydrogen bonding strength and theory was adopted toexplain the inner relations between the polar organic solvent and solute, by which this paper islooking for theory basis in lowering the temperature of the medium. By analyzing thesolubility of ammonia and halogenated hydrocarbon and temperature, we concluded that inconstant pressure, the boiling temperature decreases with the increase of solutionconcentration. If there exists a hydrogen bonding between solvents and solute, then boilingtemperature grow with hydrogen bonding force.A diffusion-absorption refrigeration system performance experiment device was set up inorder to discuss the performance of NH3-H2O-H2, NH3-H2O-He and R22-DMF-Herespectively. It is revealed:1. The average evaporation temperature of taking hydrogen as auxiliary gas is5.03℃lower than that of helium. While the former preheating time is0.15h shorter than thelatter, COP of the former declines25%than the latter.2. When compared with NH3-H2O-He, the evaporation temperature of R22-DMF-Heincreases to6.25℃, and the preheating time decreases the0.24h, and the generatingtemperature reduces to128.45℃, and the pressure reduces to1.5MPa, while the COPhas no change.3. The minimum preheating time of R22-DMF-He is0.15h and the lowest drivetemperature is from125to132℃.4. The minimum evaporation temperature of NH3-H2O-H2system is-24.91℃.5. The maximum temperature fluctuations of NH3-H2O-He in stable operating situation is ±2.13℃.6. The maximum COP of NH3-H2O-He system is0.196. |
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