|
|
| Creator |
|
| Language |
|
| Academic Year Conferred |
|
| Conferring University |
|
|
|
| Degree |
|
| Degree Type |
|
| Publication Type |
|
| Access Rights |
|
| Abstract |
This study has two main aims. One is to investigate the performance results of a compact adsorption cooling system using activated carbon as the adsorbent with ethanol as refrigerant. The other is to ...establish the detailed simulation model by modifying the present lumped parameter model which has been used to predict the performance of the adsorption systems. In order to achieve these targets, extensive experiments and simulation works have been carried out on the compact adsorption cooling system. The results of these studies are furnished in six chapters. A broad literature review on the development of adsorption cooling systems utilizing activated carbon as the adsorbent and alcohol as the refrigerant are introduced. Most of the studies that have been published mainly focused on the isotherms and kinetics of the activated carbon ethanol pair where the effects of the heat exchanger construction on the thermal energy and mass removal during in working are not considered. From above perspective, the performance of the compact adsorption cooling system which consists of one adsorbent bed which is packed with activated carbon and another heat exchanger working as evaporator or condenser depending on the operation mode are presented. The heat exchanger employed were specially designed to advance the amount of activated carbon packing density, however to decrease the mass of heat exchanger and volume at the same time as compared to fin tube heat exchanger. The performance of the adsorption cooling system were investigated experimentally by varying the regeneration temperature ranging from 60℃ to 80℃ and evaporation temperature ranging from 5℃ to 25℃. The results presented that the maximum peak value of the cooling effect reaches about 900W with the COP of 0.59 under the evaporation temperature of 25℃ with the desorption temperature of 80℃, the adsorption and condensation temperature of 30℃. Influence of kinetics parameters are presented by applying two types of kinetics parameters to the lumped parameter model. Validation of kinetics parameters is also conducted in comparison to the experimental data. It was revealed that the isothermal assumption kinetics parameter didn’t predict the experimental results in terms of outlet temperature obviously while the non--isothermal kinetics estimated significantly better than isothermal one. The detailed lumped parameter model was established to overcome the failure in prediction of changes in adsorption uptake during pre--cooling and pre--heating process. The energy balance of vapor refrigerant inside adsorber is considered in the modified model. It was found that the there is a pressure change which causes changes in adsorption uptake during thermal compression process. The influence of vacant volume inside adsorber against the adsorbent bed volume was also investigated to understand the importance of adsorber design. The modification model could be useful to design the adsorber properly and extended to other simulation studies such as for adsorption heat pump and adsorption thermal storage systems.show more
|
Export Mendeley
3052473_fulltext