Melting Temperature Of Phase Change Material Research Articles

Annual transient analysis of energetic, exergetic, and economic performances of solar cascade organic Rankine cycles integrated with PCM-based thermal energy storage systems

In this study, the annual transient analysis of the solar cascade organic Rankine cycle integrated with the phase change material (PCM) storage and parabolic trough collectors (PTC) has been conducted. The proposed system has been evaluated from energy, exergy, and economic points of view. Several PCMs, namely Isomalt, Adipic acid, Salicylic acid, Dimethylol propionic acid, A164, and KNO3–NaNO2–NaNO3 composition, have been compared to each other. Moreover, the effects of three different pairs of organic fluids, R245fa/R134a, R245fa/R500, and R245fa/R1234yf, have been examined on the system's performance. The annual investigation indicated that the closer the PCM melting temperature to the auxiliary heater setpoint temperature, the higher the solar fraction, exergy and energy efficiencies. Furthermore, the pair of R245fa/R500 had the best energy and exergy performances, which were 12.76% and 13.87%, respectively. The economic evaluation revealed that the case of R245fa/R500 combined with Dimethylol as the PCM thermal storage has the best economic performance with the NPV, LCOE, and PP of 186,622 $, 0.29 $/kWh, and 18 years, respectively. Also, the results of a sensitivity analysis showed that the NPV is extremely sensitive to the energy carriers prices and least sensitive to the PTC cost.

Numerical study of the feasibility of coupling vacuum isolation panels with phase change material for enhanced energy-efficient buildings

Effective thermal performance of a building envelope is crucial to reduce total energy consumption in buildings. In the past decades, different insulating materials and techniques have been proposed to improve building energy efficiency. Among various insulating materials vacuum insulation panels (VIPs), due to their extremely low thermal conductivity, become one of the emerging materials, striving for replacing conventional insulation materials. From different perspectives, phase change material (PCM) is another promising material with a large amount of latent heat capacity to improve building thermal inertia. Much research has been conducted for PCMs or VIPs individually. However, there are rare studies found in the literature to integrate both materials in the building envelopes. Therefore, this study aimed to evaluate the feasibility of an energy-saving building wall by coupling VIP with PCM as a compact unit that could significantly reduce heat flux through the wall, thereby leading to a tremendous reduction in energy consumption. The aging effect of VIP is also considered to examine its long-term thermal performance and compared with that of a traditional thermal insulation material-expanded polystyrene (EPS). The results reveal that the combined utilization of VIP and PCM in the same building envelope can reduce the heat flux oscillation through the wall more effectively, as compared to using the individual one. The maximum heat flux oscillation through the wall is found in direct proportion to the amplitude of the input loading, and inverse proportion to the VIP and PCM thickness. In addition to decreasing the heat flux oscillation through the wall, the integration of the PCM layer also causes a time delay on the peak heat fluxes, showing great potential to shift the electricity load from peak to off-peak hours. Results also show that the VIP with extremely low thermal conductivity allows the building envelope to achieve the same thermal performance with up to 77.3% of wall thickness saved compared with EPS. Moreover, the optimal integrating location of PCM is found to be on the interior side of the VIP layer under various loading conditions. The optimal PCM melting temperature of the PCM-VIP-based wall is highly dependent on the input loading conditions in direct proportion.

Design and Development of a PCM-Based Two-Phase Heat Exchanger Manufactured Additively for Spacecraft Thermal Management Systems

For spacecraft thermal management systems, it is crucial to diminish the overall mass of on-board thermal storage system and minimize the temperature fluctuations when the environmental temperature changes drastically. Since there is no atmosphere in outer space, heat can only be rejected to space using radiation (e.g., radiators). The heat sink conditions, and the heating power subjected to be rejected vary continuously at the orbiting stage of the spacecraft. Without thermal storage capability, the radiator is required to be large enough to release the highest power at the hottest of the heat sink. By engaging and integrating phase-change materials (PCMs) into a passive two-phase heat exchanger, the radiator can be designed and sized for the average rather than the maximum power. To meet the NASA needs, the prototype developed and fabricated in the present study is a novel two-phase heat exchanger that integrates PCMs within a vapor chamber through multiple thin drawers loaded with bulk PCM. The entire solid structure of the prototype is manufactured additively using Maraging Steel with the Direct Laser Metal Sintering (DLMS) technique. The chosen working fluid is Methanol to undertake two-phase heat transfer via saturated vapor from the heated surface of evaporator to the condenser surface, and the condensate then returns back to the heated region and keeps recirculated using the capillary pumping pressure performed by the wick structure without any reliance on the gravitational magnitudes. Depending on the heat sink temperature and PCM melting temperature, the developed heat exchanger can either function as a thermal capacitor or a two-phase heat exchanger with thermal storage capability, that is, two modes of operation to be engaged within the spacecraft's launching/landing stages or orbiting stage, respectively.In the present study, the geometry and number of the PCM-loaded drawers enclosed inside the heat exchanger's casing are optimized based on the mass ratio (the ratio of PCM mass to the total heat exchanger mass), additive manufacturing (AM) constraints, and total thermal resistances imposed on the system for either of the operation modes. The AM printed prototype with its all components are also represented along with technical drawings and specifications. Furthermore, the support structure model generated for metal printing of the proposed heat exchanger will be exposed and discussed. The wick structure design procedure is also presented and its main performance characteristics (e.g., effective pore size, effective thermal conductivity, porosity, and permeability) are reported to analytically examine the capillary pumping limit for the proposed heat exchanger.

Controlling the melting and solidification points temperature of PCMs on the performance and economic return of the water-cooled photovoltaic thermal system

The use of phase change materials (PCMs) in photovoltaic-thermal systems (PVT) is essential for developing PV systems and raising their productivity. PCM is distinguished by its many variations and properties, the most important of which is the melting point. In this study, the driven question and focus was on investigating which is better for use in a PVT, PCM systems with a high or low melting point? Two types of PCM were used in the study: paraffin wax (melting point 45 °C), Vaseline -petroleum jelly (melting point of 25 °C), and hybrid PCM (mixtures of the two PCMs in proportions of 25%, 50% and 75%). The study was conducted indoors by simulating the harshest condition in Iraq's weather in summer. The results showed that the wax and the Vaseline mixed entirely with an apparent decrease in the product's melting point.In contrast, the rest of the thermophysical properties of the product were relatively affected. The use of paraffin, petroleum jelly and 50% paraffin + 50% Vaseline in the PVT system caused a decrease in the surface temperatures of the photovoltaic cell, which resulted in a more significant improvement in the performance of the system. The maximum electrical efficiency reached was 13.7%, while the maximum thermal efficiency was 39.0%. Reducing paraffin melting point leads to better performance of PVT systems, as the hybrid paraffin (50% wax + 50% Vaseline) have better productivity than pure paraffin wax due to its lower melting point.

Annual performance analysis of a dual-air-channel solar wall system with phase change material in different climate regions of China

Applications of phase change material (PCM) in buildings have significant energy-saving potential. In this work, a dual-air-channel solar wall system with PCM is proposed, which has the following main functions: electricity generation, hot water supply, passive indoor space heating and ventilation cooling. Continuous experimental tests were conducted through two hot-box rooms in Hefei to confirm the energy saving effects of the system. Mathematical model of the system is established and validated against the experimental results. With the validated model, the annual performance of the system in three selected cities (Urumqi, Beijing and Hefei) is investigated. Annual electricity generation and average electrical efficiency of the three cities are 179.67 kWh, 179.21 kWh, 119.28 kWh and 11.22%, 10.67%, 11.06%. Annual energy saved are 863.24 kWh, 770.53 kWh and 576.43 kWh. Parametric analyses are also conducted. Proper increase of PV coverage is beneficial to the comprehensive performance of the system. Decrease of the thickness ratio of the outer and inner channel and increase of depth-to-width ratio of the channel can both enhance the thermal performance in heating season. The selection of melting temperature and thickness of PCM should be based on the weather condition of the region where the system is applied.

Judicious method of integrating phase change materials into a building envelope under Saharan climate

Phase change materials (PCMs) have been extensively used for thermal storage systems in buildings. To enhance the building's thermal and energy performance, PCMs can be embedded into envelope systems to reduce the cooling and heating demand. A PCM's melting temperature close to the thermal comfort range (20°C-26°C) can potentially be an attractive solution. In this work, the thermal and energy performance of a building in Saharan climate, specifically Ghardaïa in Algeria, was modeled using the TRNSYS-18 simulation package. A newly developed module (Type-285) was compiled for this version to evaluate different PCMs integration approaches in building envelope. Integration techniques have been evaluated based on three performance indicators, namely, monthly and annual energy savings, mean air temperature, and the daily average temperature fluctuation. When considering the conventional PCMs integration within the building envelope, a reduction of 36.4% in annual energy consumption was achieved. The study indicated that when PCMs are carefully integrated based on orientations and seasons, a reduction of 50.71% in annual energy consumption is possible, an additional 14.34% to the conventional PCMs integration. In addition, PCMs provided an enhanced thermal performance and a significant reduction in indoor temperatures that ranged between 2.36°C to 4°C. The study proposes an improved PCMs integration approach which can be possibly implemented if movable PCMs panels are used instead of the conventional static PCMs panels.

Experimental investigation on thermal properties of paraffin/expanded graphite composite material for low temperature thermal energy storage

The technology of latent heat storage with phase change materials (PCMs) is one of the promising means to improve the utilization of renewable energy. Nevertheless, its broad application will be limited due to the low thermal conductivity of PCMs. In this work, paraffin/expanded graphite (EG) composite PCMs by paraffin having a melting point of 62 °C and expanded graphite with three kinds of particle sizes were prepared and characterized. Environmental scanning electron microscope (ESEM) micrographs showed that EG was dispersed homogeneously in composite PCMs. Meanwhile, the distribution uniformity of expanded graphite in composite PCMs was evaluated quantitatively. The thermal conductivities of composite PCMs increase as the mass fraction of EG increases, and the thermal conductivity of paraffin/EG80 (5 wt.%) was 1.492 W/(m·K) in comparison with the value of pure paraffin was 0.355 W/(m·K). X-ray diffraction (XRD) analysis indicated that the fabrication process of composite PCMs was a purely physical process without a new substance produced. Differential scanning calorimeter (DSC) demonstrated that the latent heat of composite PCM was slightly less than the theoretical value. The addition of EG could lead to the improvement of the melting temperature of composite PCMs, while the decrease of the freezing temperature.

Phase change material based ventilation module - Numerical study and experimental validation of serial design

There is an increasing demand for innovative, efficient, and environmentally friendly cooling technologies as alternatives to the conventional vapor compression-based technologies. In this study, a theoretical and experimental investigation of a Phase Change Material (PCM)-based module for a ventilation system is presented. An in-situ application employing the considered PCM module is investigated. A one-dimensional numerical model is developed to predict the dynamic performance of the PCM-driven ventilation system. In addition, the model is validated with data collected from the experimental application and the PCM hysteresis behavior is calibrated. The developed model predicts the system well, with an average deviation of less than 6% and less than 4% for the PCM and air temperatures, respectively. Parametric analysis is conducted to assess the impact of design and operational parameters on the performance. This includes, volume flow rate, PCM mass and PCM phase change temperature interval. Larger PCM mass is found to decrease efficiency of the PCM module but increase the peak heat transfer. An optimal PCM melting temperature of 20 °C is found to increase the cooling provided per kg of PCM and peak cooling capacity as compared to the reference melting temperature of 22.32 °C by 38.4% and 71.1%, respectively.

Phase change materials effect on the thermal radius and energy storage capacity of energy piles: Experimental and numerical study

Geothermal energy is a renewable energy source whose use has been increased dramatically. It is primarily harvested by employing ground source heat pump (GSHP) technology due to its high coefficient of performance (COP) and low greenhouse gas emissions. This study aims to present a potential solution to the challenges preventing a higher adoption rate for ground source heat pump technology using building foundation piles as a ground heat exchanger (GHE) and implementing phase change materials (PCM) containers into the concrete shell. The study was conducted experimentally using two lab-scaled foundation piles (with and without PCM), with 3 layers of insulation. CFD numerical model was developed and validated against the experimental data. The modified model, by replacing the three insulations layers with a sand layer, was used to study the effect of different operating conditions on the heat storage capacity. Results revealed that implementing the PCM containers increased the energy storage from 16.4 to 48.2 kJ/kg (in the case of PCM 2), while the temperature distribution was always lower during the charging, due to the smaller thermal radius of the piles. By increasing the flow rate from the laminar regions to the turbulent regions, the storage capacity was increased by 10%. the study recommended using a turbulent flow inside the GHE and selecting the PCM melting temperature according to the time at which the peak load occurs.

Preparation and Characterization of Composite Phase Change Materials Based on Lauric‐Myristic Acid and Expanded Vermiculite with Carbon Layer

AbstractThe low thermal conductivity and poor shape stability of phase change materials (PCMs) limit their application in the field of energy‐saving buildings. Lauric‐myristic acid (LA‐MA)/modified expanded vermiculite (MEV) composites as form‐stable phase change materials (FS‐PCMs) were prepared in this study. To improve their heat transfer properties, expanded vermiculite (EV) was impregnated with sucrose, starch and glucose solutions and then carbonized at a high temperature to attain MEVs, which act as a matrix in the PCMs. LA‐MA was adsorbed into the MEVs to obtain the LA‐MA/MEV FS‐PCMs. Scanning electron microscopy (SEM) shows that both EV and MEV have highly porous structures and can be used as PCMs carriers. The composite PCMs impregnated with starch obtain the best heat transfer properties in comparison with the other two samples. The melting temperature of the composite PCMs is 34.2 °C and the melting latent heat value is 141.9 J/g. Thermogravimetric analysis (TGA) shows that the composite PCMs present good thermal stability. Overall, LA‐MA/MEV FS‐PCMs are promising energy efficient materials that can be used as building materials.

Investigation on heating performance of an integrated phase change material Trombe wall based on state space method

The integration of phase change material (PCM) into Trombe wall in a passive solar building is a potential way for the heating performance improvement of Trombe wall and effective utilization of solar energy. This work aims to explore the optimal combination of melting temperature and PCM layer thickness in the PCM Trombe wall in Beijing, Jiuquan, and Shenyang, which are located in three solar energy distribution zones of China, respectively. The state space model of a solar passive building with an integrated PCM Trombe wall is developed considering the two-dimensional heat transfer of PCM layer. The state space model is validated by the experimental results. The experimental and numerical results show that the heating capacity of Trombe wall has a remarkable influence on indoor air temperature. Based on the daily accumulative deviation of indoor air temperature and the heating capacity of Trombe wall, it is found from the simulated results that the optimum combination of PCM melting temperature and layer thickness are 23 °C and 5 cm for Beijing and Jiuquan, 21 °C and 5 cm for Shenyang. Besides, this study also obtains that the effective thicknesses of PCM layer corresponding to different melting temperatures of PCM are equal to or less than the PCM layer thickness.

The impact of wall and roof material on the summer thermal performance of building in a temperate climate

The main objective of this study was to compare the effect of phase change material (PCM) and reinforced concrete on the summer thermal performance of existing building in a temperate climate. Research has shown that the use of reinforce concrete walls and roof has greatly improved thermal performance of the rooms during periods of consistently rising internal temperatures due to increasing outdoor temperatures and high solar radiation. Lining the wall and roof surfaces with PCM with an optimum melting point of 21.7 °C did not reduce the indoor temperature below 23 °C even in the coldest month of June, with an average outdoor temperature of 15.7 °C, completely preventing its solidification. This suggests that during heat waves, problems with PCM solidification can be expected even with materials with much higher optimum melting temperatures. The results indicate that in a building without air conditioning, it may not be possible to plan an optimum range of PCM melting temperature that would allow it to be effective during all summer months. Replacing the lightweight structure with a very heavy one allowed to reduce the maximum daily indoor temperatures by 2.0–2.5 K during a 15-day intensive heat wave with an average outdoor maximum temperature of 32.4 °C. An analysis of air-conditioning market development trends in residential buildings allows us to conclude that a reduction of maximum daily indoor temperatures in such a range in the temperate climate of Zielona Góra in Poland should significantly reduce the need to install new air-conditioning systems in residential buildings at least until 2050, even under the IPPC RCP8.5 scenario.

Effect of PCM fraction and melting temperature on temperature stabilization of hybrid sensible/latent thermal energy storage system for sCO2 Brayton power cycle

In order to maximize the operational efficiency of a power cycle, it is desirable to maintain operation as close to the cycle’s design point as possible. For the supercritical carbon dioxide Brayton cycle, this means a turbine inlet temperature of approximately 650 °C to 750 °C, depending on design, with a pressure of about 20–25 MPa. This work numerically explores the use of a hybrid sensible/latent heat thermal energy storage system intended to provide a stable discharge temperature of approximately 650 °C while maximizing the system’s exergy efficiency. Low-cost sensible heat storage in rocks provides the majority of the energy storage capacity, while relatively small fraction of phase change material at the top of the tank provides the temperature stabilization capability. The phase change materials (PCM) used are salts and their mixtures with melting temperatures between 657 and 680 °C, while the PCM quantity is varied from 0 to 100% by volume of the tank, with greater resolution at lower PCM fractions. It is found that 1) increasing the PCM fraction leads to longer stabilization durations but lower initial discharge temperatures; 2) increasing the melting temperature increases the stabilization temperature but reduces the stabilization duration; and 3) both effects 1 and 2 show diminishing returns.

Thermal performance of concrete sandwich panels incorporating phase change materials: An experimental study

The employment of phase change materials (PCMs) in the construction of concrete building components has engaged many researchers’ interest. In this study, a novel reduced-scale experiment is employed to perform a parametric investigation of the thermal performance of PCM-integrated wall specimens considering two types of concrete, two types of PCM, and different thicknesses of the concrete and PCM layers. Moreover, three different ambient temperature profiles of a summer day in three different cities were considered as the outside ambient temperature to evaluate the performance of each PCM under different temperature conditions. The test procedure is capable of evaluating the thermal performance of different wall configurations under various temperature conditions. The inside temperature variations of the wall specimens were monitored as the thermal performance criteria. In consequence, integrating the PCM layer with normal concrete or with slimmer concrete layers resulted in better thermal performance of PCM in absorbing heat in comparison to lightweight concrete or thicker specimens due to the considerable effect of density and specific heat capacity of different types of concrete. Moreover, the compatibility of the melting temperature of PCMs with the ambient temperature of the considered cities in summer is assessed and discussed.

Effect of using PCMs and shading devices on the thermal performance of buildings in different Algerian climates. A simulation-based optimization

The use of phase change materials (PCMs) in the building envelope has emerged as an attractive passive design strategy that can be used to improve the energy performance of buildings. This paper discusses the effect of using PCMs on the thermal performance of shaded and unshaded lightweight structures in different Algerian climatic zones. A simulation-based optimization was carried out by coupling EnergyPlus and GenOpt tool, to determine the optimum melting temperature of PCM when integrated into the building envelope. Results show that the shaded building with PCM is a preferred design model in majority of Algerian climates when it is free floating. The annual percentage of thermal comfort ranges between 44.13% and 59.11% in cities where the PCMs showed positive potential. Furthermore, the optimization results show that the PCMs achieved a modest cooling energy saving for mechanically-ventilated buildings in summer, especially in hot-dry climate with optimal melting points equal to or close to 28 °C. The control of solar heat gain by using shading devices is critical to enhance the thermal performance in summer. In winter, the PCMs achieved a noticeable reduction in the heating energy requirements where it reached a maximum of 63.23% in the city of Tamanrasset. The shading device is not recommended during the winter because it hinders the use of solar radiation for passive heating. During this season, the optimal melting points of PCMs are generally bounded between 18.50 °C and 21.25 °C. When considering both periods, the most advantageous design varies from climatic zone to another.

Design of battery thermal management system based on phase change material and heat pipe

In this paper, the performance of battery thermal management system (BTMS) with phase change material (PCM) and heat pipe (HP) is studied. The performance of the BTMS is compared to that of the one with solely HP, find that PCM can effectively reduce the temperature difference in battery pack. Then, the influences of the environmental parameters, the parameters of the HP and PCM on system performance are investigated using numerical method. The results show that increasing environmental convective heat transfer coefficient (h), latent heat and thickness of PCM, or decreasing ambient temperature can reduce the maximum temperature in battery pack while increasing the temperature difference. Increasing the equivalent thermal conductivity of the started HP (kHP-S) and reducing the start temperature can improve the heat dissipation of battery pack. When the melting temperature of PCM is lower than the start temperature of HP, the temperature difference of battery pack is large. Furthermore, to improve the temperature uniformity in battery pack, an effective strategy for optimizing the thickness distribution of PCM is proposed without increasing the system volume and investment. The optimized results under different conditions show that adjusting the thickness distribution of PCM can effectively improve the system performance when kHP-S is small and h is moderate. The maximum temperature difference in battery pack is reduced by 30% after the optimization.

Numerical investigation on latent thermal energy storage in shell and corrugated internal tube with PCM and metal foam

A numerical investigation on Latent Heat Thermal Energy Storage System (LHTESS) based on an aluminum foam totally filled with phase change material (PCM) is accomplished. The PCM used is a pure paraffin wax with melting over a range of temperature and a high latent heat of fusion. The LHTESS geometry under investigation is a vertical shell and tube. The corrugated internal surface of the hollow cylinder is assumed at a constant temperature above the PCM melting temperature. The other external surfaces are assumed adiabatic. The paraffin wax phase change process is modelled with the enthalpy-porosity theory, while the metal foam is considered as a porous media obeying to the Darcy-Forchheimer law. Local thermal non-equilibrium (LTNE) model is assumed to analyze the heat transfer in the metal foam. The governing equations are solved employing the Ansys-Fluent code. The numerical simulations results, reported as a function of time, and concerning the LHTESS charging phase, are compared in terms of melting time, average temperature and energy storage rate. The corrugated internal surface effect is analyzed with respect to the wavelength and wave amplitude of the corrugation.

Numerical simulation of building wall incorporating phase change material for cooling load reduction

Phase change material (PCM) placed in the building wall changes the temperature profile within the wall and thus influences the heat transport to indoor environment. The effectiveness of these building walls depends on PCM location within the wall, PCM melting temperature, and PCM layer thickness. Considering these parameters, the numerical simulation has been conducted for a typical building wall and the obtained results are reported in terms of melt fraction of PCM and heat flux at the inner surface of the wall. From these results it is found that for the minimum heat transport to the indoor environment, the PCM layer should be embedded in between the fiberglass insulation layers, melting temperature of PCM should be in the range of indoor air temperature and PCM thickness should be higher. The numerical simulation has also been conducted considering actual weather conditions into account for three consecutive days with four different PCM (RT-26, RT-25, n-octadecane and RT-28). For three consecutive days, the percentage reduction of heat transport to the indoor environment is obtained 33.18%, 33.94%, 34.40% and 37.13% by using RT-26, RT-25, n-octadecane and RT-28 PCM, respectively.

Design Optimization of a Composite Solar Wall Integrating a PCM in a Individual House: Heating Demand and Thermal Comfort Considerations

Thermal energy storage (TES), which features an innovative technology, can enhance energy efficiency in the building sector and reduce CO2 emissions. Due to their high heat storage capacity, phase change materials (PCMs) have impressed many researchers. This paper investigates the energy performance of an individual house integrating a solar Trombe wall containing PCM with respect to heating demand and thermal comfort applications. The thermal energy performance of the design house was simulated using Dymola/Modelica, the thermal building simulation tool, whereby the optimization of objective functions as regards heating demand and thermal comfort was executed using GenOpt, the generic optimization software. Optimization of the solar Trombe wall focuses on the feasibility to find the optimal PCM parameters when running GenOpt, which consist of latent heat, melting temperature, PCM thickness and thermal conductivity, in order to minimize both the annual energy consumption for heating and the number of hours of thermal discomfort. The parametric study was first conducted for each PCM parameter so as to not only observe its effect on the identified energy performance, but also ensure the absence of errors in simulation runs before performing the optimization. The ‘Coordinate Search’ Generalized Pattern Search (GPS) algorithm was applied to minimize the objective function, whereas the ‘Weighted Sum Approach’ was used to solve the multi-objective function problem. Results showed that the higher the latent heat, the lower the heating demand and the greater the thermal comfort. The results of these parametric studies show that for the effect of the parameter on heating, demand is quite limited (1–2 kWh·m−2·year−1) whereas the effect on thermal comfort is more significant. The optimal PCM melting temperature is higher for warmer climates; it is also higher for the studied case applying the optimization method to minimize the objective function by assigning the number of hours of thermal discomfort (from 32.8 ∘C to 35.9 ∘C, depending on weather) than it is when applying the optimization method to reduce the objective function by assigning heating demand (from 31.5 ∘C to 32.9 ∘C, again depending on weather).

Thermal performance of nanoparticle enhanced phase change material in a concentric cylindrical enclosure

This paper presents the flow and heat transfer characteristics of melting behavior of phase change material (PCM) in the presence of nanoparticles. The melting process occurs in a concentric cylindrical enclosure filled with PCM (ice) and aluminum oxide (Al2O3) nanoparticles. The inner and outer walls of the concentric cylinder are considered as hot and cold walls and maintained at a constant wall temperature. The problem is modeled as unsteady, two-dimensional turbulent multiphase flow using the Eulerian multiphase model and SST k-ω turbulence model. The numerical simulation is performed using Ansys Fluent 19.2. The primary and secondary phases are specified with thermo-physical properties of ice and aluminum oxide. The transient melting behavior of PCM is investigated for different nanoparticle volume concentrations by varying the temperature difference between the hot and cold walls of concentric enclosure. The results are analyzed by plotting the streamline, velocity and temperature contours. The results indicate that the dispersion of aluminum oxide nanoparticles into phase change material increases the heat transfer rate and decreases the melting temperature of PCM. The results also indicate that the melting rate and thermal performance are significantly enhanced with increase in volume concentrations and temperature difference.