A Review Paper on Thermal Performance Evaluation of Water-Cooled Glycol Chiller with Different Coolant Compositions and Optimization Strategies

Water-cooled chillers combined with additional glycol loops are heavily used across assorted and manifold industries, comprising food processing, data centers, and trade-related HVAC systems. The addition of antifreeze agents like Ethylene Glycol (EG) and Propylene Glycol (PG) introduces meaningful changes in thermophysical attributes, leading to adjusted heat transfer coefficients and increased pumping penalties. This review paper synthesizes present-day and recent inquiry on the performance of minor coolants, assessing the thermodynamic and hydraulic impacts of diverse and assorted glycol compositions. Furthermore, it examines advanced methods to augment chiller productivity, similar as the application of ternary mixtures, the integration of nanoparticles to formulate high-conductivity nanofluids, and the implementation of data-driven predictive control algorithms. By analyzing methodologies spanning from experimental test rigs to mixed-integer nonlinear derivable predictive control (MI-DPC), this paper creates an exhaustive and inclusive framework for optimizing water-cooled glycol chillers. The results provide crucial insights into achieving ideal and perfect trade-offs between freeze protection, thermal productivity, and overall system Coefficient of Performance (COP).