Optimization of variable flow and variable air volume control strategy for an air source heat pump system applied in a pigeon house

Aiming at the increase of energy consumption in building environment control, this study proposes a variable water volume and variable air volume (VW–VAV) air source heat pump (ASHP) system based on indoor temperature control of the chilled water variable flow rate and PID control of variable air volume (VAV), and compared with traditional constant flow and constant air volume (VAV) and variable flow systems. The simulation results show that when using VW–VAV control, the temperature of the pigeon house environment can be maintained within the standard range (24–32 °C) throughout the year, resulting in energy-saving effects. The heating season energy rate is 29.3%, and the total energy savings rate throughout the year is 12.44%. The performance system is also better, with a seasonal energy efficiency ratio, heating seasonal performance factor, and annual performance factor of 2.39, 2.57, and 2.43, respectively. The experimental studies conducted on selected days during the summer show that the VW–VAV control strategy of the ASHPs has the lowest water supply temperature, minor fluctuations in the control signals of the water pump and fan, more stable changes in fan frequency, larger and more stable air volume at the fan outlet, and a maximum energy saving rate of 41.4%.