HEAT MASS TRANSFER MODEL OF A HONEYCOMBED ROTARY DESICCANT WHEEL AND EXPERIMENT

Zhang Xuejun  Dai Yanjun  Wang Ruzhu

(Institute of Refrigeration and Cryogenics, Shanghai Jiaotong University, Shanghai 200030)

Abstract: Based on the practical structure of the honeycombed rotary desiccant wheel and the nature of heat and mass transfer in the sinusoidal corrugated air duct, a one-dimensional coupled heat and mass transfer model, which is expected for use in designing and manufacturing of a honeycombed rotary desiccant wheel, is presented. The mathematical model has been validated experimentally with a real desiccant wheel. It is found that the calculation results are in reasonable agreement with the experimental data. Based on this model, the temperature and humidity profiles in the wheel during both the dehumidification and the regeneration processes are analyzed and verified by experimental results. The numerical results indicate that in the regeneration process a hump curve of air humidity ratio along the channel exists all the time. To improve the regeneration efficiency, the migration time of the hump moving to the duct exit should be reduced. With the numerical analysis of the hump curve, the influences of some operating parameters on the hump value at the duct exit and its migration time are discussed.

Key words: Rotary desiccant wheel  Heat and mass transfer  Mathematic model

CLC No: TK511

国家重大基础研究规划973课题(G2000026309)和上海市重点基础研究(02DJ14044)资助项目. Received 20040307, received in revised form 20040912