Thermodynamic performance analysis of air-to-air hybrid heat recovery unit driven by pump combined with booster

Abstract

The air conditioning energy consumption for fresh air handling in buildings increases yearly, especially in low energy buildings. This energy consumption can be greatly reduced when exhaust air is recovered for preheating or precooling fresh air. Then, significant savings in the total energy consumption in buildings will be achieved, which in turn helps achieve the carbon peak in the building field. In this paper, a booster/pump coupled energy recovery ventilator is proposed for energy recovery in buildings. The system performance, which depends on the loop number and combination strategies were analyzed and compared through model simulations. Results indicate that the heat transfer rate of different coupling systems increases with the temperature difference. In summer, the pump/booster driven dual-loop system has the highest average temperature effectiveness of 47.3% and average heat transfer rate of 4.97 kW. The booster/booster-driven dual-loop system has the highest average heat transfer rate of 5.07 kW and average temperature effectiveness of 47.1%. The average temperature effectiveness of the pump/booster/booster driven triple-loop system reaches up to 45% and average heat transfer rate of 4.73 kW. The booster/booster/booster-driven triple-loop system has the highest average heat transfer rate of 4.82 kW and average temperature effectiveness of 44.7%. In winter, the maximum average heat transfer rate and temperature effectiveness of the pump/booster driven dual-loop system are 8.54 kW and 44.44%, respectively. The maximum average heat transfer rate and temperature effectiveness of the pump/booster/booster driven triple-loop system are 7.90 kW and 41.5%, respectively. Throughout the year, the best coupling scheme of the dual-loop system is the pump/booster driven dual-loop system, and its average heat transfer rate and temperature effectiveness are 6.755 kW and 45.85%, respectively. The best coupling scheme of the triple-loop system is the pump/booster/booster-driven triple-loop system, and its average heat transfer rate and temperature effectiveness are 6.315 kW and 43.25%, respectively.