The Performance Of Solar Energy Adsorption Refrigeration Cooling System Using Evacuated Tubes Cooled By Water

Considering the weakness of the solar-power adsorbers in refrigeration/air conditioning,such as the effects of heat collecting in desorption period and heat loss in adsorption period,here,a new adsorber is proposed——evacuated tube which is cooled by water. Simulation calculations and experiments have been performed. With a view to the intermittent characteristics of solar-powered adsorption, a continuous cycle operation for the adsorption refrigeration cooling system with active carbon fibre (ACF)-methanol adsorption refrigeration working pair is carried out.With the operation conditions, the adsorber, the evaporator, the condenser, the receiver and the throttle are disigned. The adsorber is of the most importance in the adsorption system, so we provide the non-dynamic equilibrium model of active carbon fibre (ACF)-methanol adsorption refrigeration pair. The numerical simulation is carried out based on the recorded solar radiation data measured in Nanjing and daily ambient temperature for the typical clear days. The temperature field, the pressure field, the methanol concentration and the temperature of evacuted tube, and water tube are caculated. The effects of the conductivity coefficient of adsorbent, heat transfer coefficient of water fluid and diameter of tube on the performances of the system have been analyzed. The calculated results show that with the conductivity coefficient of adsorbent increasing, COP is increasing. When the heat transfer coefficient of water fluid is less than 500 W / m2?K, COP increases with the increasing of the heat transfer coefficient of water; COP almost keeps a constant with the increasing of the heat transfer coefficient of water fluid if that is over 500 W / m2?K. COP increases first then decreases with diameter of tube increasing, COP reaches maximum value at D=80mm.For the experiment equipment, three experiments are carried out: intermittent cycle that adsorption bed is cooled by nature convection, intermittent cycle that adsorption bed is cooled by water and continuous cycle that adsorption bed is cooled by water. The temperature, the pressure, and performance coefficience (COP) are measured and analysed under different conditions. The results show that COP of continuous cycle is more 6%～24% than that of intermittent cycle. Comparing the temperature of adsorber between the numerical and experimental results, the modeling of the system is reasonable.