System-Oriented Dynamic Modelling and Power Consumption Simulationfor an Industrial Chiller Plant

Sammanfattning: Nowadays, the amount of energy consumed by Heating, Ventilation and Air Conditioning (HVAC) systemsposes threats to the improvement of global environment. Hence people have been dedicated to thedevelopment of energy-saving retrofit projects via optimized simulation in these chiller plants. However, recent research only focuses on the improvement of one or two devices instead of whole operating system,and researchers seldom pay attention to the comparison between different optimization strategies.As a result, by using Modelica/Dymola framework, a system-oriented dynamic model is constructed via theon-site investigation of an industrial chiller plant which located in Chengdu, China in this project. This system is composed of the individual control of multiple chillers, water pumps and cooling towers with a relative mean absolute error (RMAE) of 1.4% in the energy consumption simulation and hence can be regarded as a reliable model for further optimizations. After the implantation of two-months simulated data as system configuration, three optimization strategies including Baseline Strategy (BS), Sequence Optimization (SO) and Holistic Optimization (HO) within the full range cooling load ratio are investigated to explore the potentials of energy savings for this model. Among all three optimization approaches, HO strategy shows the outperforming reduction in energy consumption by 10.8% especially at low range of cooling load ratio. Moreover, based on HO method, two more advanced strategies which named as Holistic Optimization based on Cooling Load Time FrequencyAnalysis (HOTF) and Holistic Optimization based on Cooling Load Distribution Analysis (HOCL) are explored. The results turn out that both optimization strategies on this model can further decrease the energy consumption by 2.6% and 4.0% accordingly. In addition to this, HOTF also shows its own strength on low cost and operation simplicity.