Optimizing Chilled Water Systems with Cooling Towers via Virtual Power Metrics and Extremum-Seeking Control

TL;DR

This paper introduces an extremum seeking control method combined with a virtual power meter to optimize cooling tower fan operation, achieving significant energy savings in chilled water systems without extra sensors.

Contribution

It develops a novel ESC approach using virtual power metrics, enabling energy-efficient control in systems lacking physical power meters.

Findings

Energy savings of approximately 15% during summer conditions.

Virtual power meter accuracy with 96.11% correlation.

Control strategy effective without additional instrumentation.

Abstract

This paper presents an extremum seeking control (ESC) method for cooling tower fans to minimize overall power consumption of a chilled water plant system. Simulation studies across different climate locations demonstrate energy savings of approximately 15% compared to conventional control during summer conditions. This paper also proposes a virtual power meter (VPM) to enable use of the strategy in systems that lack physical power meters. Validation tests for the VPMs against physical meters showed good accuracy with a correlation of 96.11% and a normalized error of 5.11%. Coupled with the VPM, the proposed ESC control solution can be implemented on systems using typically available sensor measurements without the need for additional instrumentation.