Solution heat accumulating type cold and hot water system and refrigerating and heating method thereof

Heat energy generated by a low-temperature heat source is used as a driving heat source, a neutral solution with strong hygroscopicity is used as an absorbent, water is used as an evaporant, and heat in a low-grade waste heat source is extracted by using the characteristic that the water is boiled at a low boiling point in a low-pressure vacuum state; technological hot water, heating hot water or refrigeration is prepared through recovery and conversion. The absorber is provided with a liquid storage area, it is guaranteed that the system has sufficient solution storage capacity, the system can store part of concentrated solution when waste heat sources are rich, due to the fact that the storage area and the absorber are integrally designed, the heat preservation effect is achieved, part of concentrated solution can be taken to enter the system to be circulated when the waste heat sources are few, and the circulation amount and the circulation concentration are increased; therefore, the system can stably oper