The invention provides an optimization control method for improving the energy efficiency ratio of the load of a multi-
machine-head
water chiller-heater unit, which comprises a first compressor
system, a second compressor
system and a control cabinet, the first compressor
system and the second compressor system are both provided with corresponding power meters and
microcomputer control modules, and the power meters and the
microcomputer control modules are used for detecting the system power. The system further comprises an
evaporator, a condenser, a temperature sensor, a flow meter and a
pressure sensor, the temperature sensor, the flow meter and the
pressure sensor are arranged on corresponding pipelines, the temperature sensor, the flow meter and the
pressure sensor are all connected with the
microcomputer control module, and differential loading and unloading strategies are adopted according to the load difference of the compressor. The operation parameters corresponding to the optimal COP are screened through multi-cycle iteration, and energy efficiency maximization under partial loads is achieved. The problem that in the prior art, when a multi-
machine-head unit runs in a partial load mode, the energy efficiency is low due to lack of fine coordination control is solved, and the energy-saving potential of the unit is remarkably improved.