Patent ID: 10107531

Abstract:
A method for controlling a chiller system, the chiller system comprising a primary side in the form of a vapor compression system, and a secondary side, is disclosed. The secondary side comprises a variable speed pump for providing a secondary fluid flow through the evaporator of the primary side in such a manner that heat exchange takes place between refrigerant of the primary side and fluid of the secondary side in the evaporator, the secondary side further comprising a temperature sensor arranged in the secondary fluid flow. The method comprises the steps of monitoring a temperature of the secondary fluid flow by means of the temperature sensor, and controlling the compressor capacity and the speed of the variable speed pump on the basis of the monitored temperature, and in order to obtain a predetermined setpoint temperature, in such a manner that the closed loop gain of the chiller system, K=Kp·Ke, where Kp is the gain of the compressor capacity controller and Ke is the gain of the evaporator, is kept substantially constant.