Currently in the field of energy and refrigeration

the developing of highperformance absord energy transfer systems may find an breakthrough in the field of ciculate medium. As ionic liquid has the characteristics of “nondetectable” vapor pressure

wide liquid termperature range

stable

nonflammable

fluidness in room temperature

it may become absorbefacient better than metal salts (for example: LiBr). Combined with water

it may be the new generation of assimilated working pairs that have excellent competences. Watersoluble ionic liquid ［BMIM］BF

4

and ［BMIM］

2

SO

4

as the research objects were chosen to test and analyse their thermal stability

fluidness and vapor pressure of their aqueous solutions by experiments. Based on the thermal properties of these two kinds of ionic liquid

the foundation was built for further research of heat pump and ciculate refrigeration

which used ionic liquid as the absorption workers.