The invention belongs to the technical field of
energy conservation, and relates to a variable frequency energy-saving control method for a
refrigeration system. The control method comprises the steps of: determining the
mass flow of a
refrigerant according to the change or change trend of
cooling load, then determining consumed power of a compressor which satisfies the flow, predicting the minimum condensation pressure which ensures that the
thermal load of a condenser satisfies the
cooling load and the power change of the compressor through an established energy-saving control
mathematical model, and gradually adjusting the
power frequency of the compressor to ensure that the rotating speed of the compressor reaches a predicted value; and adjusting the opening degree of an expansion valve to ensure that the condensation pressure reaches to be lowest, realizing the minimum
pressure difference operation between the condenser and an
evaporator, and ensuring that the operation
energy consumption of the
refrigeration system is lowest. The method solves the optimizing control problem of the compressor, the expansion valve and a
fan in the
system, utilizes the energy-saving control
mathematical model to perform joint regulation on controllable factors (such as the rotating speed of the compressor, the opening degree of the expansion valve, and the
air volume of an outdoor unit) of the operation of the system, ensures that the
refrigeration system operates at a best
operating point, and realizes the further
energy conservation of the refrigeration system based on the variable
frequency regulation.