A Study On Indicator-Based Chiller Plant Commissioning Method

Chiller plant is one of the most important energy consumers in large-scalebuildings. Significant energy-saving benefit can be gained by expert diagnosis.However, current diagnosis relies on expert experience, making it hard to be duplicatedand continuously carried out. To realize streamlined chiller plant diagnosis, this paperpresents an indicator-based diagnosis method.First, a detailed analysis on the energy losses in chiller plants is given. The chillerplant is divided into four subsystems. The ideal energy efficiencies of these foursubsystems are provided, while the five level losses, including twenty problems, whichmake the real efficiencies worse than ideal values, are summarized.Based on the energy loss analysis, a hierarchical indicator system is presented toquantitatively describe the energy performance of chiller plants. The indicators in thefirst two stages reflect the energy efficiencies of chiller plant and its four subsystems,giving a general evaluation of the energy performance. The third stage indicators showthe energy losses caused by the twenty problems respectively, pointing out theenergy-saving potentials of the chiller plant.This paper then put forward an indicator-based diagnosis method for chiller plants,including five steps: data collection, preliminary evaluation, modeling, indicatorcalculation and conclusion. This diagnosis method is streamlined and easy to learn. Ithas been successfully applied in a large-scale commercial building in Hong Kong,which is introduced in detail to present this method.Besides energy diagnosis, the hierarchical indicator system has various usages inlife cycle management of chiller plants. In existing buildings, operators can have a clearview of their systems and find the problems in time. For designers, the indicator systemhelps them understand which problems are commonly existed in current buildings. Inconstruction period, the quality control can be improved based on the indicator system.