Heat and Mass Transfer in Packed Bed Type Adsorber of Adsorption Refrigeration Cycle

对填充床型硅胶- a /蒸汽吸附器吸附和解吸过程的传热传质动态特性进行了实验和理论分析。实验结果如下：测定了该吸附剂/吸附对的吸附等温线。2 .不同吸附剂粒径填料床的换热动态行为没有差异，达到平衡状态所需的时间随着填料床层厚度的增加而增大。对填料床的有效导热系数进行了测量，发现不同粒径填料床的有效导热系数没有差异。在物理模型的基础上，对吸附床内的传热传质进行了理论分析，该模型同时考虑了固相和固相的多种机理。实验结果如下：该分析模型可以很好地预测实验所得的硅胶/蒸汽吸附器的动力学行为。结果表明，阻力对流体对颗粒传热的影响和对颗粒中吸附质扩散的影响都很小。固体颗粒的热传导在吸附填料床的传热传质动力学中起主导作用。

Experiments and theoretical analyzes were carried out on the dynamic characteristics of heat and mass transfer during adsorption and desorption processes in a packed bed type silica gel-A/steam adsorber. Following results were obtained from the experiments.1. An adsorption isotherm was determined for this adsorbent/adsorbate pair.2. There was no difference in the dynamic behavior of heat transfer for packed beds of different adsorbent particle diameter, and the time required to reach the eguilibrium state in the process became larger with the thickness of the packed bed layr.3. The effective thermal conductivity of packed bed was measured and there was found no difference in measured values for the beds of different particle diameter.Theoretical analyzes were performed for heat and mass transfer in the adsorbent bed, based on the physical model in which several mechanisms in both the adsobate fluid and particle solid phases are taken into consideration. Following results were obtained.1. The present analytical model was found to predict well the dynamic behavior of the silica gel/steam adsorber obtained in the experiments.2. Both the effects of the resistance to the heat transfer from the fluid to the particle and that to the diffusion of adsorbate in the particle were found to be very small.3. Thermal conduction in the solid particle was confirmed to play a dominant role in the dynamics of heat and mass transfer in adsorbent packed bed.