Research On A Novel Silica-gel Adsorption Cooling System

Adsorption refrigeration as an environmental way of fetching cooling power, enjoying two advantages: energy saving and environmental protection, is the research hotspot all over the world. The main factors that effect the popularization of silica gel-water adsorption refrigeration system are poor thermal conductivity of silica gel and large refrigerant mass transfer resistance. For the mentioned reasons, compared with traditional way of refrigeration, silica gel-water adsorption refrigeration system occupies a larger space, and has a lower coefficience of cooling performance.In order to investigate the effects of fin length and fin pitch on the heat and mass transfer in a finned tube adsorber, a non-uniform temperature non-uniform pressure dynamic model is developed. The numerical results indicate that the mass transfer resistance is mainly decided by fin length and the mass transfer resistance is governed by fin pitch. Further, relative errors of average uptake are calculated by solving non-uniform pressure model and uniform pressure model, respectively and theoretical analysis are made to explain the trend of the mentioned errors. Meanwhile, the drawback that adsorption system takes a large space is also studied. Thought numerical simulation, fin pitch and fin length are optimized to get the maximum power density per unit volume of the system.This thesis proposes a novel pendulum type adsorption chiller integrated with heat pipes which can effectively improve the heat transfer efficiency of the adsorption bed. In the final part of this paper, a two-bed silica-gel cooling system of 5kW cooling capacity is designed and different circuit design parameters are calculated.