Constant-temperature control method and system of air-cooled module unit

The invention relates to the technical field of air conditioners, in particular to a constant-temperature control method and system of an air-cooled module unit. The air-cooled module unit comprises a shell-and-tube heat exchanger, a fan and a compressor. A first temperature sensor is arranged at the water inlet end of the shell-and-tube heat exchanger and used for detecting the real-time water temperature. The method comprises the steps that the set target water temperature, the set real-time water temperature and the current running state of the compressor are obtained; the deviation between the target water temperature and the real-time water temperature is calculated, and when the deviation is within the threshold range, the compressor is controlled to keep running in the current running state; and when the deviation exceeds the threshold range, the running mode and running duration of the compressor are determined according to the interval range where the deviation is located, and the compressor is contr