Although the technology of absorption refrigeration and heat pump has been widely used in the field of low-grade energy (such as industrial waste heat and geothermal sources), it can’t meet the diversified needs of energy utilization due to the defects of thermal properties and limitations of temperature range of traditional working pairs (such as NH3/H2O, H2O /LiBr).

Through three years of efforts, researchers from IET selected a kind of novel working pair with excellent cycling performance and wide application prospect from numerous ionic liquids. Based on the novel working pair named [mmim]DMP/CH3OH, the first 12 kW [mmim]DMP/CH3OH absorption test machine was developed. Research on the machine showed that the technical indexes of [mmim]DMP/CH3OH could match that of solution, better than other kinds of ionic liquid refrigerants that had been found. The related work had attracted attention from domestic and foreign peers, two SCI papers were published, and the researchers were invited to write English monograph.

As a kind of novel green refrigerant, ionic liquids have attracted great attention in the R&D of absorption system for their unique physical and chemical properties. Efforts on research of novel working pairs have never been interrupted. The starting time of IET on the work was almost synchronous with that of other countries. Since the concept of ionic liquid working pairs firstly put forward in 2004 in China, researchers from IET have made leapfrog progress in this research. Recently, a kind of novel [bmim]Zn2Cl5-NH3 absorption refrigeration/heat pump refrigerant working pair was developed, which was considered as an original innovative work in the domestic and the international. Heat pump with this kind of working pair had the advantages of both CFCs and HCFCs heat pump, the successful development of which will help to get rid of the problems of expansion, agglomeration and the performance attenuation traditional pump adsorbent faced, and create highly commercial value. The related research was still carried out intensely.