Research On Boosting Adiabatic Absorption Refrigeration Cycle With LiBr-H₂O

Lithium - bromide absorption refrigerator is an important aspect in the development of refrigerators, however, some shortages greatly restrict its expanded application. By analyzing the characteristics of LiBr/H2O solution and the absorption refrigeration cycle, it is known that the absorption deficiency of water vapor into LiBr/H2O solution is the leading reason that results in its large-size, crystallization, difficulty to be cooled by air and high temperature of heat resource needed etc.After thermodynamics analysis, numerical calculation method is used to simulate the absorption effect of water vapor into LiBr/H2O solution droplets in the adiabatic absorber. The hypothesis that physical properties should be assumed as constant was discussed, and then the effect of heat and mass transfer before and after heightening the pressure of the adiabatic absorber was analyzed under different solution concentration. The results showed that solution absorption ability of the boosting adiabatic system is strengthened significantly, which provides theoretical base for the following new cycles established.A pressurizer was added in the adiabatic system to establish single - effect and double - effect boosting adiabatic system respectively. Then the simulation program of the refrigeration system was developed. The results showed that when it is cooled by air, heat transfer temperature difference could be more than 10℃without the risk of crystallization; When cooled by water, heat transfer areas of the system and the temperature of heat resource needed could be reduced effectively.The method of absorption-ejector hybrid was used to establish boosting adiabatic absorption - ejector hybrid refrigeration cycle. Different from normal absorption - ejector hybrid cycle that is to increase the coefficient of performance, the hybrid cycle in this study was to use the single - effect system, whose construction is simpler, to realize the function of the two - stage system, which can utilize lower heat resource. The boosting adiabatic absorption - ejector hybrid cycle could also be cooled by air effectively. However, the coefficient of performance of the hybrid cycle here is a bit lower.