Study On Unit Pipe Adsorbent Bed Of Adsorption Refrigeration System By Medium Temperature Waste Heat

Environmetal pollution and energy shortage are compelling reasons to look for adsorption refrigeration making use of low-grade thermal energy. However, the bottlenecks putting a brake on development of this technology are poor heat and mass transfer performance and system reliability. In order to solve these problems, heat pipe technology has been introduced in adsorption refrigeration, which can simplify cooling system. In this paper a unit pipe adsorbent bed was built, and influence of some specific parameters on refrigeration capability was analyzed to improve refrigeration performance of heat pipe adsorption refrigeration and provide the fundation for the promotion and application of this system. The main achievements are as follows:1.Designed and built a unit pipe adsorbent bed system. Meanwhile abundant annular adsorbent was made by solidification technology. A series of qualitative experiment of unit pipe adsorbent bed was done, and the outcomes indicate that evaporation/condensation length should be26cm.2.Completed a large amount of experiment in unit pipe adsorbent bed. According to experimental data, the conclusions were summarized as follows:①Performance tests of this system have to be run under different operating conditions.②Influence of different key parameters to the system performance has been analyzed, such as temperature of heat source, cycle time, and ratio of adsorption time and desorption time.③The best values of heat source temperature and cycle time in this system are310℃and60min, respectively.④If the temperature of heat source and the ratio of adsorption time and desorption time were310℃and0.72, unit pipe adsorbent bed system got the optimal cooling performance, which refrigeration capability and SCP were4.97W and57.72W/kg.3.According to the above research results, factors influencing on the cooling performance of unit pipe adsorbent bed were analyzed in theory. The results show that main factor are tube outside heat transfer, tube inside heat transfer, mass transfer resistance in adsorbent, and axial mass transfer resistance in tubes. In the future work, heat transfer and mass transfer should be enhanced simultaneously to optimize the design of unit pipe adsorbent bed.4.Experimental study on the cooling performance of unit pipe adsorbent bed had conducted by changing flow rate of working fluid, bonding way of adsorbent, thickness of the annular adsorbent layer and shape of adsorbent, thus improving adsorption ability of unit pipe adsorbent bed.