To improve the collection and regeneration efficiency of strong solution under extreme conditions

this paper reveals a solar grading collector/regenerator method with inter-grade and same-grade heat exchangers. Based on heat and mass balance in the packed reservoir

a model of solar grading collector/regenerator system in which pre-dehumidification solution parameters could be adjusted is established. Numerical simulation shows that there are critical points in regeneration efficiency of grading regeneration under variety of outdoor situations compared with single-stage regeneration. Grading regeneration is preferable to single-stage regeneration while outdoor environmental temperature and relative humidity are above the critical points as well as sun radiation intensity is lower than the critical point. Finally

the applying ranges of grading collector/regenerator system on environmental parameters and solution concentration are comprehensively provided in this paper and it is found that the situations of lower radiation from sun and higher temperature and relatively humidity are beneficial to regenerate solution of high concentration by grading collector/regenerator system.