Analysis Of Phase Change Materials Research Articles

Performance assessment of single-sided operation in a high-temperature latent heat storage system under fault conditions during charging and discharging

As the high-temperature latent heat storage (LHS) market continues to expand, ensuring its safe and stable operation is paramount for facilitating its rapid development. In specific operational scenarios and instances of failures, large-scale integrated LHS systems may operate with either single or partial sets of heat exchange tubes. However, a notable research gap exists in the comprehensive exploration of the impact of partial operational conditions on the thermal performance of LHS systems. Consequently, this study conducted experiments involving both- and single-sided charging and discharging using a cylindrical high-temperature LHS system equipped with two sets of heat exchange tubes. To comprehend the ramifications of single-sided operation on temperature distribution across both active and inactive sides, as well as its influence on charging/discharging power and accumulated stored/released energy on the active side. The analysis of phase change material (PCM) temperature distribution revealed that single-sided charging significantly influenced the inactive side, while single-sided discharging exhibited a comparatively minor impact on the inactive side. As PCM melted during charging, temperature disparities diminished due to natural convection, while non-uniform temperature persisted in unmelted PCM. Examination of the PCM liquidus indicated that the metal heat exchange tube enhanced heat transfer on the inactive side, resulting in substantial PCM melting during charging. However, the heat transfer effect of metal heat exchange tubes during discharging was insignificant, leading to a considerable amount of liquid PCM on the inactive side after discharging. The total heat storage for both-sided charging was 1002.71 MJ, whereas, for single-sided charging using two tubes, it was 1074.42 MJ and 1000.60 MJ, respectively. Correspondingly, during discharging, the average powers were 682.74 MJ, 543.62 MJ, and 538.11 MJ, respectively. The cycle efficiency for the both-sided operation was 68.09 %, while those for single-sided operations of two tubes were 50.6 % and 53.78 %, respectively. The reduced cycle efficiencies of single-sided operations were attributed to prolonged charging and discharging durations and the presence of more liquid PCM on the inactive side after discharging.

Numerical simulation, ANN training and predictive analysis of phase change material with 3D printing lattice structures

This study simulated and analysed the performance of phase change material with three lattice structures, i.e., simple cubic, body-centered cubic, and face-centered cubic, at various porosities and heat fluxes. Three parameters are analysed, including the maximum temperature of the heated wall, melting and solidifying times of PCM. The findings suggest that as the porosity rises, the maximum temperature decreases, while the increase in heat flux leads to a higher maximum temperature. Both the melting and solidifying times extend as porosity increases. An artificial neural network trained by the Levenberg-Marquardt algorithm is used to predict these three parameters. The lattice structure type, porosity, and heat flux are established as the input parameters for the network. The ANN predictions demonstrated outstanding performance in estimating these parameters with a minimum MSE of 0.00015 and a maximum R of 0.99899. The trained ANN is used to predict the crucial parameters of PCM with 82% SC, BCC, and FCC lattice structures. An excellent agreement is observed between the ANN predicted results and the simulation outcomes with a maximum relative error of 9.43%.

Optimal Design and Simulation Analysis of Phase Change Material Composite Self-Insulating Block in a Typical Cold Region City of China in Summer

Background:: Incorporating PCMs (Phase Change Materials) into the building envelope can achieve the purpose of regulating heat transfer and enhancing indoor comfort. In recent years, lots of patents for new phase change concretes have been proposed and applied to the envelope. Objective:: This study aimed to explore the optimum phase change temperature and installation position of PCM by optimizing different concrete blocks to improve the thermal behavior of concrete compound self-insulating blocks. Methods:: Firstly, based on the existing patents, five new types of phase change self-insulating blocks were proposed. The thermal insulation performance of different blocks was tested using ANSYS simulation. Then, the feasibility of using EnergyPlus to simulate the thermal environment of the room was verified by taking a summer south-facing room in Hohhot City as a research object. Finally, 13 phase-change block types containing 4 phase-change temperatures and 3 PCM installation locations were designed for further testing. Results:: A three-row staggered perforated block was selected, and the heat transmission coefficient of the masonry wall was 0.437 W/(m2·K). The optimal phase change temperatures of outdoor, medium- temperature, high-temperature, and low-temperature periods in summer, were 24.0 oC, 30.0 oC, and 28.0 oC, respectively. The optimal phase change temperature in the whole summer was 26.0~ 28.0 oC, and the best phase transition layer location was the inner hole of the block. Conclusion:: The PCM mounting position has a greater effect on room temperature than the PCM phase change temperature. The study results are of great significance for stabilizing room temperature and building energy conservation.

Analysis of phase change material (PCM) melting utilizing environmentally friendly nanofluids in a double tube with spiral fins: A numerical study

Phase Change Materials (PCMs) show great potential for thermal energy storage applications due to their substantial latent heat release during the transition from solid to liquid phases. The objective of this numerical study is to assess the melting process of a phase change material (PCM) within a vertical helical coil designed as a latent heat storage system. Innovative enhancements to the system's performance are introduced through the utilization of environmentally friendly nanofluids, BH (Biogenic Hierarchical)–SiO2/water and OLE (Olive Leaf Extract)–TiO2/water, and three distinct configurations of spiral fins. A three-dimensional model is implemented to investigate the impact of the number of fins, nanoparticle concentration, initial temperature and velocity of the Heat Transfer Fluid (HTF), as well as various fin thicknesses. The porous enthalpy method within ANSYS-Fluent is employed to model the phase-changing process. The results indicate a significant reduction of 66.88 % in the melting time of solid PCM with the inclusion of three spiral fins compared to the configuration without fins. Furthermore, the thermal performance of BH–SiO2 is found to surpass that of OLE–TiO2, attributed to its higher thermal conductivity. Additionally, the analysis reveals that the melting time is more sensitive to the initial temperature of the HTF than its velocity.

Parametric analysis of phase change materials within cold climate buildings: Effects of implementation location and properties

Integrating phase change materials (PCMs) into buildings is a proven method to reduce heating and cooling loads in alignment with international targets to reduce energy and greenhouse gas emissions. However, although promising, PCM uptake has been limited, particularly in cold climates due to a lack of knowledge about their performance and lack of optimized PCM solutions. The objective of this study was to provide a comprehensive analysis of PCMs, integration strategies, and properties that lead to the largest space conditioning reductions in four cold climate cities within Canada. An experimentally validated EnergyPlus model was developed and used to simulate a thin layer of PCMs on surfaces adjacent to a conditioned space to predict their effects and trends that occur due to their placement in various locations within a room, geographic locations, and melting temperatures. It was found that the most effective location for PCM installation was the room walls for heating load reductions and floor for cooling load reductions, due to the incident solar energy profiles in each conditioning season. In the warmer two cities studied, the greatest benefits per unit PCM occurred with PCM in the floor, while the cooler two cities had the greatest benefits per unit PCM with it installed in the walls. The optimal choice of PCM to decrease heating load was 1–2 °C above the heating setpoint, while for decreasing cooling loads it was 1–2 °C below the cooling setpoint, regardless of the choice of conditioning setpoints or geographic location.

Economic analysis of phase change material integrated photovoltaic thermal systems: A short communication

Solar energy is the most prospective renewable resource that humankind has access to, for acquiring the most usable energy. Photovoltaic thermal systems (PVT) are deemed to be one among the most efficient methods for capturing solar energy because of their distinct ability to produce electrical power by photovoltaic conversion while simultaneously dissipating the heat generated in the process. The necessity of financial investment is a major stumbling block in putting this strategy into action in actual application. This paper delivers updated literature on the economic aspects of PVT-Phase change materials (PCM) systems (installation, operation, and maintenance) that several researchers had carried out. Payback time is taken into account while calculating the profitability of PVT systems. Finally, the performances of several PVT-PCM systems were compared, and the economic analysis confirmed that the PVT system is financially viable. PVT system holds tremendous potential to be incorporated in residential/commercial buildings. The PVT system is a promising technology that still needs refinement in terms of overall efficiency and environmental factors, according to the available literature assessments.

A Systematic Analysis of Phase Change Material and Optically Advanced Roof Coatings Integration for Athenian Climatic Conditions

Energy retrofit solutions that concern a building’s roof structure play a significant role in the enhancement of a building’s thermal behaviour. This study investigates the integration of phase change materials (PCMs) with cool coatings (CCs) or thermochromic coatings (TCCs), namely, a PCM roof, a PCM-CC roof, and a PCM-TCC roof, as alternative and novel tactics for the simultaneous control of solar heat transfer and solar heat reflection. An energy simulation analysis with the DesignBuilder tool is conducted for a one-story residence and the climatic conditions of Athens. The simulation results indicate that, compared to the existing concrete roof construction, the PCM roof, PCM-CC, and PCM-TCC roof systems demonstrate energy savings that reach up to 13.55%, 16.04%, and 21.70%, respectively. The systematic analysis reveals that the increase in PCM’s thickness leads to an increase in the total electricity savings of the buildings, but in the case of PCM-CC and PCM-TCC roof systems, they merely effect the cooling thermal loads. The mean phase transition temperature that favours the cumulative electricity savings is 28 °C in the case of PCM and PCM-TCC roof systems and 35 °C in the case of PCM-CC roof systems. The methodology of this study allows the design of efficient, integrated roof systems with advanced thermal and optical properties as energy retrofit solutions for Mediterranean climatic conditions.

Thermal analysis of phase change materials storage in solar concenter

Thermal analysis of high-temperature phase change materials (PCM) is conducted with the consideration of a 20% void and buoyancy-driven convection in a stainless-steel capsule. The effects of the thermal expansion and the volume expansion due to phase change on the energy storage and retrieval process are explored. The used water to fill the void between two different wax paraffin and stearic acid spheres is considered as a potential PCM for concentrated solar power. The charging/discharging process into and from the capsule wall is simulated under different boundary conditions for laminar and turbulent flows. Computational models are conducted by applying an enthalpy-porosity method and volume of fluid method to calculate the transport phenomena within the PCM capsule, including an internal air void. A simplified two-dimensional model of the PCM contained within the spheres is constructed and thermal analyses are performed for the transition from solid to liquid states. Simulated charging process modes are compared with the theory. According to experiments, the temperature distributions from 40-60 mm without and with 60 mm with copper fin have different behavior. The paraffin takes less time than stearic acid for total transformation at a rate of 0.5. The size of the sphere increases over the amount of time and the phase of the sphere to complete changes as stearic acid expands more than paraffin during the transition. Inserting a rectangular fin, that is made from copper into the ball reduces the cycle time and increases output.

Energy storage potential analysis of phase change material (PCM) energy storage units based on tunnel lining ground heat exchangers

Low geo-temperature geothermal energy in the surrounding rock can be extracted by tunnel lining ground heat exchangers (GHEs) and stored in phase change material (PCM) plates to realize the cold energy utilization. However, the research of the coupling heat transfer of tunnel lining GHEs and PCM plates has been rarely reported. In this study, a 3D coupling heat transfer model of tunnel lining GHEs and PCM plates was developed to investigate the cold energy storage performances of PCM plates under different PCM and tunnel parameters. The circulative iteration calculation is used to solve the coupling model. The results show that the cold energy storage of PCM plates utilizing tunnel lining GHEs for energy storage is feasible. The PCM melt fraction and solid phase PCM proportion within the PCM plates decrease and increase respectively with an increase in the PCM thermal conductivity and melting temperature and a reduction in the surrounding rock temperature. The cold energy storage efficiencies of PCM plates improve by 77.8% and 34.1% as the PCM thermal conductivity and melting temperature increase by 1 W/(m K) and 4 ℃. Moreover, the cold energy storage efficiency of PCM plate enhances by 68.5% as the surrounding rock temperature reduces from 10 to 1 ℃. A larger difference between the surrounding rock temperature and PCM melting temperature is efficient for the cold energy storage of PCM plates, and the cold energy storage time and temperature difference show a power function relationship. Finally, increasing the tunnel lining GHEs length is conducive to enhancing the cold energy storage efficiency of PCM plates, whereas this enhancement is limited. In actual applications, selecting a reasonable tunnel lining GHEs length is necessary.

A Brief Review and Its Incorporation with Bibliometric Analysis of Phase Change Materials for Thermal Energy Storage

Reduction of Food Losses and Wastes (FLW) through the use of cold chain is one strategy applied in accelerating the SDGs goals of zero hunger. The application of Thermal Energy Storage (TES) based on PCM (Phase Change Material) is considered as one of best efforts for the simultaneous reduction of food losses and wastes, reduction of energy consumption as well as preserve the right temperature for food product. This paper presents the review of phase change material for thermal energy purposes and its bibliometric analysis. Bibliometric analysis on term of cold chain logistics show that there is correlation between cold chain and terms of optimization, vehicle routing, carbon emission, refrigeration, and phase change materials. The definition of TES and PCM, as well as the advantages of TES based on latent material are described in this paper. PCMs is classified into solid-solid, solid-liquid, solid-gas and liquid-gas based on its phase. The potential generation of gas and larger volume on solid-gas and liquid-gas PCMs limits the application of those two types of PCMs. PCMs is also classified according to the phase change temperature in which low, medium and high temperature PCMs. Organic, inorganic and composite based PCMs are the classification of PCMs based on the chemical composition. Among the types of PCMs, this paper present a deep review of paraffin based organic PCMs. The appearance of term of thermal conductivity in bibliometric analysis on term of organic phase change materials is due to organic PCMs commonly have low thermal conductivity

Energy and exergy analysis of phase change material based thermoelectric generator with pulsed heat sources

Previous studies focus on the generation capacity of phase change material based thermoelectric generator (PCM-TEG) under a steady-state heat source or single pulsed heat source, which cannot fully reflect the dynamic characteristics of TEG under a diversified actual heat source. Meanwhile, the actual heat sources have unstable characteristics of intermittence and fluctuation, resulting in troubles for TEG to maintain effective thermal management and stable generation. In this work, a three-dimensional transient numerical model of PCM-TEG is proposed to characterize its energy harvesting process under multiple pulsed heat sources, including square, triangular, linear and sinusoidal patterns. The effect principle of heat fluxes and heat source periods on PCM-TEG is sensitively performed, aiming to detect the evolution laws of the temperature field and electric field. The energy and exergy analysis of PCM-TEG is determined to indicate its transmission and conversion process. A comparison analysis of PCM-TEG and TEG is carried out to appreciate the thermal management of PCM from temperature difference and failure-free cycle times. The power generation coupling mechanism of PCM-TEG is further developed concerning the phase transition process and power generation process. The results demonstrate that the temperature difference and output power of PCM-TEG change periodically with the pulsed heat sources. The electrical energy and exergy efficiencies of PCM-TEG under square pulsed heat source are 0.10% and 0.45%, higher than other heat sources. Simultaneously, the maximum output power and the electrical energy efficiency of PCM-TEG can be improved by 173.29% and 80% respectively with the enhanced heat flux. Furthermore, although the transient power generation capacity of TEG is weakened by integrating PCM on the hot side, it can alleviate the thermal fatigue of thermoelectric device and meet its thermal management requirements. This paper is informative to understand the dynamics characteristics and power generation coupling mechanism of PCM-TEG for energy harvesting.

Numerical analysis of Phase change material and graphene-based tunable refractive index sensor for infrared frequency spectrum

Here, we present the findings of parametric analysis into a phase transition material Ge2Sb2Te5(GST)-based, graphene-based, with a wide dynamic range in the infrared and visible electromagnetic spectrum. The suggested structure is studied in multi-layered configurations, built up with layers of GST, graphene, silicon, and silver materials. These multilayer structures' reflectance behavior has been described for refractive indices between 1.3 and 2.5. The complete design is simulated using a computational process called the finite element method. Additionally, we have investigated the impact of material heights on the structure's performance in general. We have presented several resonating tracing curves in polynomial equations to determine the sensing behavior across a specific wavelength range and refractive index values. The proposed design is also investigated at various inclined angles of incidence to ascertain its wide-angle stability. A computational study of the proposed structure can assist in the evolution of biosensors to identify a wide range of biomolecules, including malignant, hemoglobin urine, saliva-cortisol, and glucose.

Numerical analysis of phase change material filled with metal foam inside a cylindrical capsule

AbstractThis research study performs a numerical assessment of the inward solidification of phase change material (PCM) integrated with metal foam (MF) encapsulated in a horizontal cylindrical geometry. The cylinder is not at melting temperature at the beginning, and its outer surface is subjected to convection boundary conditions. The 1D phase change model is resolved by applying the temperature transforming technique using an in‐house computer program written in C++. Four different MF materials, aluminum, copper, nickel, and stainless steel, with various porosities, are used to examine the thermal behavior of the storage system. It is found that the use of copper as a MF with higher effective thermal conductivity remarkably enhances the elapsed time for complete solidification. Additionally, for a porosity value of 0.92, the time for total solidification of copper is diminished by 94%, while the complete solidification time for Stainless Steel is decreased by 65% in comparison to the situation where no MF is used.

Thermal analysis of phase change material encapsulated li-ion battery pack using multi-scale multi-dimensional framework

Li-ion batteries are employed to propel Electric vehicles (EVs) and Hybrid Electric Vehicles (HEVs) into a clean and sustainable future. A battery pack experiences high heat generation under extreme and abusive conditions, which may lead to catastrophic thermal runaway. The present study proposes an efficient and economical Phase Change Material (PCM) based Battery Thermal Management System (BTMS) to avoid thermal runaway. A 3D simulation is performed on a single battery (1P1S) and a battery pack consisting of six batteries stacked in series (1P6S), with and without PCM, using the multi-scale multi-dimensional Newman, Tiedemann, Gu, and Kim (NTGK) model in ANSYS. The NTGK model analyzes the battery pack's discharge behavior and thermal performance. For PCM-based BTMS, the NTGK is coupled with the solidification and melting model. The effect of ambient temperature, discharge rate, and convective heat transfer coefficient on 1P1S and 1P6S battery packs with and without PCM is investigated under extreme and abusive conditions. The ambient temperature (Tamb) significantly impacts PCM selection and battery performance. The effective T­amb – PCM combinations are proposed for the optimal working of the battery pack. Under the extreme conditions of the fast-discharging rate, the PCM-based BTMS reduces the maximum battery temperature by 25.3 K and 19.5 K and improves the temperature uniformity by 5.3 K and 3.6 K at 5C and 4C discharge rates, respectively. Also, at Tamb of 300 K, the proposed PCM-based BTMS significantly reduces the maximum temperature by 60.4 K, 46 K, and 29.3 K when the external shorting resistance is 0.10, 0.15, and 0.25 Ω, respectively. The proposed cooling system averts the thermal runaway when external shorting is 0.10 Ω, and internal shorting is >0.1 μΩ. This research will be helpful in the further development of PCM-based thermal management systems for large-scale and commercial applications.

Structural Analysis of Phase Change Materials (PCMs)/Expanded Graphite (EG) Composites and Their Thermal Behavior under Hot and Humid Conditions.

Expanded graphite (EG) has been used to store phase change materials (PCM) to enhance thermal conductivity and avoid leakage. However, systematic investigation on physical structure of various embedded PCMs in EG is not reported. Besides, the effect of environment on thermal behavior of PCM/EG composites has not been investigated yet. In this work, three common PCMs (including myristic acid (MA), polyethylene glycol (PEG) and paraffin wax (PW)) were embedded in EG and three PCM/EG composites were obtained. As a result, capillary force between EG and PCMs supported encapsulation of PCMs in EG. PCM/EG composites had narrower phase change range while supercooling degree values were different when various PCMs were used. Besides, the hot and humid environment had a side effect on thermal energy storage of PCMs and PCM/EG composites. The inherent hydrophilicity of PCMs was essential for resistance against side effect of moisture on thermal energy storage.

Energy storage analysis of phase change materials (PCMs) integrated with thermal conductivity enhancers (TCEs)

A numerical analysis aiming to investigate the influence of numerous parameters on the energy storage systems has been conducted. The system performance working with phase change materials (PCMs) is evaluated in terms of complete melting time and metal foam radial distance in annulus. A comprehensive transient analysis is presented to monitor the melting behavior of the integrated PCM in the presence of porous metal foam sleeves under constant volume at various locations as thermal conductivity enhancers (TCEs). Aluminum alloy T-6201 is used for the porous metallic foam, while paraffin is introduced as PCM. The porosity, pore size (PPI), various PCM materials, and porous distance from the heat sources were investigated. Results show that porous TCEs radial distance from the applied heat sources has a substantial effect and can lead to an improved rate of melting depending on the sleeve location. In addition, high thermal conductivity near the heat source suppresses the porous resistance to liquid PCM flow and thus natural convection. Results revealed that case B provides a uniform liquid PCM profile and heat distribution while case D has the highest melting during the initial stage and lower one at the final stages of melting. Pure PCM case imposed the least resistance but has the slowest melting time while a turning point in melting rate is noticed from case C. Eventually, results show that higher PPI materials have a similar melting pattern as a result of high thermal conductivity.

Heat transfer analysis of phase change material composited with metal foam-fin hybrid structure in inclination container by numerical simulation and artificial neural network

Improving the heat transfer performance of phase change material (PCM) plays a crucial role in designing efficient latent heat thermal energy storage (LHTES) systems. The purpose of this study is to address and elucidate the effects of the metal foam-fin hybrid structure and the inclination angle on the phase change process by using the numerical simulation method. An experimental system for the validation of the numerical models is established. The solid–liquid phase interfaces, streamlines, liquid fraction (f), the dimensionless time (Fo×Ste), and average Nusselt number (Nu¯) of PCM in the container enclosure at inclination angles of 0°, 30°, 60°, and 90° with six kinds of enhanced heat transfer structures, including fin, metal foam, and metal foam-fin hybrid structures, are compared. Besides, the liquid fraction and Nu¯ during the phase change process are predicted by the artificial neural network (ANN). Results demonstrate that the optimized heat transfer performance of the metal foam-fin hybrid structure could reduce the melting time. In addition, the increase in the number of fins can improve the heat transfer performance and reduce heat accumulation in the top area with the inclination angle increasing. Compared to pure PCM at the inclination angle of 90°, the values of Fo×Ste of metal foam-1 fin and metal foam-5 fins hybrid structures are reduced by 52.69% and 60.02%, respectively. However, the energy storage density per unit volume decreases as a function of the increasing inclination angles and the number of fins within a case. Furthermore, the excellent predictions of f and Nu¯ are obtained by ANN with MSE and R2 of 9.6480 × 10−5, 0.9990 and 0.0150, 0.9937, respectively.

Energy, economic and environmental impact analysis of phase change materials for cold chain transportation in Malaysia

The tropical climate of Malaysia presents higher environmental temperatures ranging from 27 to 31 °C and refrigerated semi-trailer trucks are utilized in cold chain transportation which is subjected to high thermal stresses and leads to elevated refrigeration load requirements. This subsequently causes a surge in diesel fuel consumption by the auxiliary refrigeration unit and greenhouse gas emissions into the atmosphere. To address the issue, this research evaluates the integration of phase change material (PCM) in refrigerated vehicle walls for latent heat storage purposes, which consequently reduces refrigeration load. Reference cases without PCM and 10 different PCM cases of commercially available organic-based paraffin PCM are investigated, whereby the conventional insulation method of a refrigerated semi-trailer is modified by adding a layer of PCM within its envelope, to simulate refrigeration loads during an 8-hour vehicle operational period. The PCMs are assessed based on their physicochemical properties, and performance in energy savings, economic, and environmental benefits. Results show that daily refrigeration loads can be reduced up to 34.4 % upon PCM integration in refrigerated vehicle walls, and besides, economically, the solution is highly profitable with a benefit-cost ratio above 1. The highest performing PCMs in terms of energy savings yield short payback periods of <3 years, which are at least 2.6 times lesser than the vehicle's lifetime, whilst providing greenhouse gas emission savings of above 2700 kgCO2/year. This research indeed serves as a starting point to explore the large-scale usage of PCMs in cold chain transportation in Malaysia.

Analysis of Phase Change Material used as Thermal Energy Storage Unit in Catalytic Converter.

Phase change Material(PCM) is widely used to heat storage applications. In this study PCM is used in the catalytic converter application to improve the performance of catalytic converter by maintaining the temperature above the light off temperature. Catalytic converter is inefficient at lower temperature or below the light off temperature the conversion efficiency is very low and practically it is zero. Using PCM conversion efficiency of catalytic converter is increased. PCM is placed above the substrate to absorb the heat from the exhaust gases which are leaving to the atmosphere in order to maintain the substrate temperature above the light off temperature. When the temperature is high at substrate then conversion of pollutants is better. PCM Store the heat by changing the phase from solid to liquid and return the heat to substrate by partial solidification. In this paper, performance of PCM (Mg70Zn24.9Al5.1) which is a eutectic alloy used for high temperature applications was investigated at various loading conditions by doing the simulation on catalytic converter for melting and solidification of PCM and validate the results with experimental work. The melting of PCM domain is simulated using ANSYS fluent 2019 R3 software. The assumptions used for the numerical study, methodology of the work and specification of software is also discussed in this paper. The contours of melting fraction of PCM at regular interval for different loading conditions (i.e. 0%, 50%, and 100% load) are represented for total melting period of the PCM.

Analysis of phase change material inside horizontally oriented heat storage unit: A numerical and experimental approach

The present work investigates the heat transfer performance of a horizontal energy storage unit both by numerical and experimental approaches. To augment the heat transfer, high heat conducting Graphene Nanoplatelets (GNP) are added to PCM and its effect on heat transfer characteristics has been investigated. Numerical results of charging-discharging performance are evaluated in terms of contours of temperature and liquid fraction for plain PCM and composite PCM with 1–4% GNP (by mass) addition. The numerically predicted results considering HTF inlet temperatures ranging 750–90 °C and mass flow rate 1.8 lit/min are compared and verified with experimental results. The results reveal that melting pattern of paraffin wax in horizontal unit is not same in upper half and lower half of unit. It is inferred that melting rate increases with increase in inlet temperature of HTF. It is observed that addition of GNP (up to 3% by mass) to PCM helps reduce the charging & discharging duration, improves overall system performance.