It is difficult for a conventional heat pump to achieve a 65-100 ℃ heat supply in fields of material drying

printing

textile dyeing

electroplating

etc. In this study

a novel high-temperature heat pump based on a subcritical zeotropic mixture recuperative cycle was proposed for a hot water supply with a large temperature span. The zeotropic mixture feature of a large temperature glide at the isobaric process in the subcritical region and the recuperative concept were utilized to achieve a good thermal match between the working fluid and water sides with a large water temperature span. The influences of the key parameters such as the operating pressures

mixture composition

ambient temperature

and water temperature on system performance were analyzed. Based on a genetic algorithm

the discharge and suction pressures and mixture compositions of the system were optimized. The results indicated that the mixture recuperative heat pump exhibited an excellent performance under conventional operation conditions in traditional refrigeration and heat pump fields. When the ambient temperature was 25 ℃

the inlet water temperature was 15 ℃ and the outlet water temperature is 90 ℃. The coefficient of performance (COP) of the system reached 5.5

which is comparable to the performance of a CO2transcritical heat pump under the same working conditions.