Modeling an‎d Optimization of Air Conditioning System with Cooling Energy Storage Tank Containing Phase Change Materials: Investigating the Effect of Material Properties on System Performance

10/19/2026 12:00:00 AM

In this study, an integrated framework for modeling an‎d optimizing an air conditioning system equipped with a modular latent cooling energy storage tank based on phase change materials is presented. The first part of the work is dedicated to the development of a 3D unsteady model of a seven-tube tank (one central tube an‎d six peripheral tubes) in which the heat transfer in the PCM is modeled with an enthalpy-porosity approach an‎d the internal flow of the tubes is modeled by solving for mass, momentum, an‎d energy conservation. A structured experimental design was performed on three types of PCM with different properties, two tube center-to-center distances, an‎d three mass flow rates to measure the effect of material, geometry, an‎d operation on the charge/discharge time, recoverable energy, an‎d temperature uniformity. The purpose of this simulation is to investigate the behavior of a single module of the cooling energy storage system. The simulation results show that increasing the center-to-center distance to 150 mm systematically improves the thermal uniformity an‎d reduces the process duration; Also, choosing a PCM with a melting temperature slightly higher than the inlet charge fluid temperature accelerates the onset of freezing, although a higher latent capacity can increase the process time delay. In the second part, a 24-hour system-level model for a single-zone residential unit was constructed an‎d coupled to the CTES tank to enable simultaneous eva‎luation of thermodynamic an‎d economic performance. The problem was formulated as a multi-objective problem: minimizing the daily cost/energy with time-of-use tariff (J1), minimizing the daily exergy loss (J2), an‎d minimizing the equivalent daily economic cost including energy bill, peak cost, an‎d capital an‎d maintenance amortization (J3). The decision variables include the number of tanks, charge/discharge flow rates, an‎d phase timing, an‎d the constraints of load supply, thermal comfort, flow/pressure limits, an‎d SOC cycle closure were applied. The Pareto frontier revealed three leading strategies: the knee point with four tanks an‎d ψ_day≈0.28, the economic strategy with three tanks an‎d J3≈10.74 $/day, an‎d the exergy-driven strategy with six tanks an‎d ψ_day≈0.33, which minimizes J2 an‎d also reduces the power peak. These findings indicate that the combination of improved geometry, proper PCM selec‎tion, an‎d charge/discharge timing can simultaneously improve thermodynamic an‎d economic efficiency an‎d provide practical design guidelines for integrating CTES into the HVAC water circuit.

: مواد تغيير فازدهنده، ذخيره انرژي سرمايشي ، تهويه‌مطبوع ، شبيه‌سازي سه‌بعدي ، تحليل اقتصادي

Phase Change Materials (PCM), Cooling Energy Storage (CTES), HVAC, 3D Simulation, Multi-Objective Optimization, Exergy, Economic Analysis.

arshan galayeri

Dr. sepehr sanaye