HEAT AND MASS TRANSFER CHARACTERISTICS OF HOLLOW FIBER MEMBRANE BASED GENERATOR IN VAPOR ABSORPTION REFRIGERA-TION SYSTEM

摘要

Vapor absorption refrigeration system could be efficiently driven by the low grade renewable heat associated with the exhaust gas from the car engine. The absorption cycle, however, has not yet obtained much attraction in the automobile application due to its large volume and weight per unit of cooling capacity. A micro-porous hydrophobic hollow fiber membrane acts as a selective barrier which allows vapor to pass through but blocks the passage of liquid. Therefore, it is expected that the hollow fiber membrane could be introduced for the applications of the compact and lightweight generator in the absorption refrigeration system by desorption of the refrigerant vapor across the hydrophobic membrane layers. A hollow fiber membrane module is experimentally tested to identify how the various working conditions, such as feed temperature, flow rate, and concentration of aqueous lithium bromide solution, influence on the heat and mass transfer performance during the desorption process. The theoretical model of the heat and mass transfer is firstly presented to understand the desorption mechnism, and are is compared with the experimental heat and mass transfer data to evaluate its feasibility.