【摘要】 设计了一种特殊的高效换热的板翅式吸附床,用于硅胶-水连续循环的吸附式制冷系统中。建立了吸附床的二维数学模型。因硅胶-水吸附式制冷系统具有很快的吸附和解吸过程,热量的及时传递成为极其关键的因素。因此在该模型中,只考虑了快速加热和冷却的传热过程,以寻求提高传热速度的途径。对于吸附床的各关键尺寸对换热性能的影响进行了对比和分析,并对实验结果也进行了对比分析。理论研究表明,吸附床的各参数的最优尺寸为:翅片间距为3～6mm,翅片高度为6～12mm,翅片厚度为0.03～0.15mm。实验结果表明,使用这种吸附床结构,系统的循环时间可短至420s。在硅胶的热导率仅为0.175W.(m2.℃)-1的情况下,吸附床的总传热系数可提高至370.8W.(m2.℃)-1。更多还原

【Abstract】 Adsorption system is a hot research subject recent years with the increasing problems of energy shortage and environmental pollution.In adsorption systems,heat transfer coefficient of the adsorber is the most important,since,with the same amount of uptake circulated in the system,the cycle time will decide the system cooling capacity.In this study,a specially designed,high efficient plate fin type adsorber is developed in a continuous silica gel adsorption refrigeration system to improve its performance.The two-dimension mathematical model for the adsorber is set up.As silica gel and water pair gives very quick adsorption and desorption process,the rate of heat transfer in desorption and adsorption process becomes very crucial for the system.Thus,only the heat transfer is considered in this model to seek the way to improve the process.The effect of the main dimensions of the adsorber is analyzed.The theoretical study demonstrates that the optimum design for this adsorber is: fin pitch 3—6 mm,fin height 6—12 mm and fin thickness 0.03—0.15 mm.Experimental results show that by using this design,the adsorption/desorption time can be as short as 420 s.The overall heat transfer coefficient of adsorber can be improved to 370.8 W·(m2·℃)-1though the heat conductivity of silica gel is only 0.175 W·(m2·℃)-1.更多还原