Experimental study of hydraulic stability for variable water volume air conditioning System

The hydraulic stability of the variable water volume air conditioning system has a significant impact on the thermodynamic stability, service life of the pipe network and energy consumption. The hydraulic stability of variable water volume air conditioning system was investigated by means of experiments. An air conditioning system with variable water volume is served as the platform, and then the changes of the passive branches’ hydraulic characteristics are studied in valve action cycle of the active branch under the following three conditions: without pump control, constant differential pressure (DP) control or variable differential pressure set-point control. The results show that the branch with the small flow and high-pressure drop has the good hydraulic stability. Under the pressure difference control, the hydraulic stability of the system is improved obviously, the energy-saving effect of the pump is better, and the energy saving of the chilled water pump at least 20.8% when closed any branch valve. This study provides a reference for the design of variable water volume air conditioning systems with good hydraulic stability