Controller and method for reducing standby time when controlling the number of chillers to be operated

A control method using a controller of a chiller system that cools a load using a plurality of chillers, the control method comprising:

• an increasing or decreasing step, increasing or decreasing a number of chillers among the plurality of chillers to be operated after a predetermined standby time has elapsed from a previous increasing or decreasing step, and
• a reducing step, reducing the predetermined standby time when at least one of a chilled water temperature and a degree of change in the chilled water temperature satisfies a predetermined condition in the predetermined standby time after the number of the chillers to be operated is increased or decreased to prevent a light load stop.

A non-transitory readable recording medium storing a program that causes a computer, which forms a controller of a chiller system that cools a load using a plurality of chillers, to execute:

• an increasing or decreasing step, increasing or decreasing a number of the chillers among the plurality of chillers to be operated after a predetermined standby time has elapsed from a previous increasing or decreasing step, and
• a reducing step, reducing the predetermined standby time when at least one of the chilled water temperature and a degree of change in the chilled water temperature satisfies a predetermined condition in the predetermined standby time after the number of the chillers to be operated is increased or decreased to prevent a light load stop.