Investigation on the peak shaving potential of a new flexible two-stage heat pump for cooling

Abstract

This work introduces a new configuration of a flexible two-stage heat pump system (Co. 1) for cooling applications and compared it with the second configuration common in literature (Co. 2). This new system is investigated in comparison with other four systems under identical operating conditions: a baseline two-stage heat pump a baseline single-stage heat pump, and a flexible single-stage heat pump and a second configuration of the flexible two-stage heat pump. A control strategy is developed to regulate four operational modes — normal operation, charging, discharging, and standby, —depending on the cooling load, hour of the day, and status of the storage tanks. The weather data of London, UK, and Rome, Italy have been used to acquire the variable hourly cooling loads of a typical 4-story residential block via IESVE software. The results show that the flexible two-stage system and flexible single-stage systems achieve seasonal coefficients of performance (SCOP) 2.33 % and 2.55 % higher than the two baseline systems of two-stage and single-stage heat pumps, respectively. Furthermore, the heat pump demonstrates enhanced results in milder weather in London than in Rome. The newly proposed system in this study shows an overall higher SCOP than the other four compared heat pump systems.