Self-adaptive resetting method of differentialpressure and its application for variable frequency chilled water pump systems

Based on the energy saving principle of variable frequency control and the differential pressure control for the chilled water pump systems, proposes a self-adaptive control method of differential pressure resetting and develops an online control toolkit. The toolkit can collect the real-time operating information of air conditioning system automatically, reset the differential pressure set-point automatically for the chilled water pumps according to the regulating valve position of all air handling units, the voltage frequency of all inverters and the monitored differential pressure of all closed loops to adapt to the change of cooling load of air conditioning system and reduce the energy consumption of chilled water pumps as much as possible. The toolkit has been applied in the central air conditioning system of a large-scale office building in Hong Kong and achieved the significant energy-saving effect.