Stochastic chiller sequencing control for multiple-chiller plants

This paper deals with the uncertainties associated with total cooling load (TCL)-based chiller sequencing control. The TCL-based control determines the switch-on/off thresholds according to building instantaneous cooling load and chiller maximum cooling capacity. One challenge for practical applications of this method is that the measure of the cooling load and the estimate of the chiller maximum cooling capacity suffer heavily from uncertainties. To deal with the uncertainties, a stochastic chiller sequencing control is proposed in this paper. The switch-on/off thresholds are determined in the framework of statistics. An algorithm to realize the stochastic control is developed. Case studies compare the stochastic control with the conventional deterministic method, and the results show that the proposed method can improve the robustness of chiller sequencing operation.