Selection Of Phase Change Materials Research Articles

Multiple-Criteria Decision Analysis and characterisation of phase change materials for waste heat recovery at high temperature for sustainable energy-intensive industry

A latent heat storage system based on Phase Change Materials (PCMs) is proposed to increase the energy and environmental efficiency by recovering and storing waste heat from combustion gases or other surplus sources at in the energy-intensive industries (EII), currently unused. The final configuration design is specifically adapted to the plant operational requirements, by means of a methodology combining the search of the best conceptual design and a proper selection of core PCMs. To that end, a selection of suitable PCM is carried out by using characterisation techniques and thermal stability testing. Furthermore, relevant key factors are weighted by an in-house Multiple-Criteria Decision Analysis (MCDA) to define the most promising design options to be implemented in two plants belonging to the EII sector. For the ceramic sector, the design resulted in a shell-and-tube system with 1188 kg of a PCM melting at 885 °C and encapsulated in double concentric tubes, involving a storage capacity of 227 MJ. Similarly, 1606 kg of PCM, whose phase-change temperature is 509 °C, is selected for the steel sector providing a PCM-TES system capable to store 420 MJ.

Augmenting the productivity of solar still using multiple PCMs as heat energy storage

Abstract In recent years, several research studies were conducted to enhance the productivity of solar stills. One of the approaches was the integration of latent heat energy storage mediums (phase change materials (PCM)) in the conventional solar stills to extend the water yield ability after the sunshine hours. Though several studies were conducted in this research area, none of the studies analyzed and reported the time of day at which the PCM start to release the stored latent heat, especially in the case of use of multiple PCMs. The present study is an experimental investigation that compare the thermal performance of three same-sized passive solar stills, i.e., conventional solar still (Still 1), still with single phase change material (Still II), still with two phase change materials (Solar III). The two PCMs used in still III are chosen in such a way that both the PCMs have almost same latent heat storage capacity, but different phase change temperature range. PCM1 and PCM2 used in solar still III have the phase change temperature (PCT) range of 58.03 °C–64.5 °C and 53.05 °C–62 °C, respectively. The experiments were conducted for the climatic conditions of Chennai, India during the month of February to May. The major inference from the experiments conducted is that, when multiple PCMs are employed in a still, selection of PCM with appropriate PCT range is very important. PCM1 should start discharging the stored latent heat energy stored once the solar radiation gets diminishing and PCM2 should start to release the heat when PCM1 has almost discharged the entire stored energy. By this way, the time of yield can be prolonged. In the results, the thermal performance of Still I, II and III was analyzed in terms of hourly yield per day and exergy efficiency. The yield of Still I was 3.680 L/m2/day while the yield of Still II and III were 4.020 L/m2/day and 4.400 L/m2/day, respectively. The exergy efficiency of still I, II and III were found to be 3.92%, 3.23% and 3.52%, respectively.

Review on performance assessment of phase change materials in buildings for thermal management through passive approach

Abstract Latent heat energy storage (LHES) systems using phase change materials (PCMs) are well known for its excellent thermal energy storage and release during melting and solidifications respectively. PCMs can be efficiently deployed in applications where significant temperature difference exists in the system for intermittent thermal energy storage. Several research contributions has been made on integrating PCMs in buildings for thermal management, as it enhances building thermal inertia, reduces maximum heat flux, shifts peak energy demand, reduces temperature fluctuations of air, etc., owing to its isothermal behavior and high energy storage density during phase change. Results of several research articles reveal that incorporation of PCM in buildings could significantly improve indoor comfort conditions and reduce energy demand of Heating ventilation and air conditioning (HVAC) systems, provided appropriate PCM selection, encapsulation methods, location deployed etc. This review paper is devoted to elucidate various facts attributing PCM integration in buildings for thermal management through passive approach. The facts includes performance of PCMs in buildings in terms of heat gain reduction, temperature attenuation, peak energy demand shifting and energy saving potential, encapsulation deployed, are discussed and presented in order to expedite the interpretation for future researchers, who took their research work in the field of building thermal energy management.

Selection of phase change material for solar thermal storage application: a comparative study

The study of five paraffin waxes and wood resin was carried out to investigate their thermo-physical properties. The investigation aimed at selection of a phase change material (PCM), for its potential use as a thermal energy reservoir (TER) in a fabricated solar dryer. Differential scanning calorimeter was used to determine the melting point, solidification point, latent heat of fusion and solidification of these PCM. The T-history analysis was carried out to determine the effective thermal conductivity and specific heat in liquid and solid states. Bulk density of these PCMs was determined using standard pycnometer method. A comparative analysis was done for the selection, and PW1 was selected among the paraffin waxes, while wood resin was rejected. The selected PCM was used in the flat plate collector of solar dryer to identify the thermal zones and to validate its capability as a TER. Maximum temperature achieved at outlet of flat plate collector was 50 °C. The temperature profile built in different zones was determined with and without using PCM. It was found that after 18:00 IST evening, the average flat plate collector chamber temperature with PCM PW1 was found to be 23.5% higher than that without using PCM.

Analysis of phase change materials (PCM) for building wallboards based on the effect of environment

One of the greatest global challenge and an indispensable requirement for sustainable development in the building sector is the reduction of greenhouse gas emissions and energy consumption. In this regards, it is necessary the development and promotion of efficient, affordable, and high impact technologies, systems, and practices. For this purpose, new technologies as phase change materials (PCM) is being studied to improve the energy efficiency and reduce energy usage in buildings.This research aims to analyze the selection of PCM for building wallboards and roofs by comparison between multi-criteria decision methods (MCDM) and Building Energy Simulations (BES). For this purpose, a reference generic social dwelling designed in Ecuador to shelter four people in a space of 36 m2 has been chosen to perform the study.The MCDM COPRAS-G, TOPSIS and VIKOR are considered to accurately rank PCM alternatives, taking in consideration different material selection criteria. Moreover, BES are performed to: (a) further contrast the MCDM ranking of PCM and (b) numerically assess the thermal behavior and estimate the energy consumption with the incorporation of the PCMs.The results found discrepancies between the MCDM and BES, demonstrating the importance that the environment variables play to appropriately assess the performance of PCM.

Experimental investigation of heat transfer characteristics in a vertical multi-tube latent heat thermal energy storage system

A vertical multi-tube thermal energy storage system using commercial phase change material (PCM) RT60 has been experimentally investigated. The selection of PCM and experimental rig configurations seek to be suitable to serve as a household thermal energy storage application for the solar energy application. PCM is filled at the annulus of the shell of the cylindrical container and the tubes while heat transfer fluid (HTF) is circulated inside tube to deliver or retrieve thermal energy to or from PCM. Five HTF tubes are configured to achieve heat transfer enhancement in this vertical latent heat thermal energy storage system. Thermocouples are installed at four horizontal cross-sections of the storage unit and at every cross-section thermocouples are positioned at different radial and angular coordinates to capture the transient temperature changes of PCM during the charging and discharging processes. HTF inlet temperature was set at 80 °C in the charging process and 10 °C in the discharging process. The same HTF volume flow rate of 20 L/min was applied in the consecutive charging and discharging processes. The comparative analysis of PCM temperature measurements along the axial, radial and angular directions was conducted. The experimental results showed that natural convection-controlled heat transfer during the charging process, while PCM solidified faster at the bottom liquid PCM region during the early stage of discharging, afterwards conduction dominated heat transfer mode. The analytical study and experimental data stated that the arrangement and positions of HTF tubes have a notable effect on the thermal response of the latent heat thermal energy storage system during the charging and discharging processes.

Freeze-thaw performance of phase change material (PCM) incorporated pavement subgrade soil

Phase Change Materials (PCMs) can store and release large amounts of energy in the form of latent heat during their phase changes, which could be utilized in controlling the freeze-thaw impact on pavement foundation systems. Untreated, and Class C fly ash-treated loess soil amended with three different dosages of paraffin-based liquid, and microencapsulated PCMs were evaluated using unconfined compression, volume change, and frost heave tests. The results of this research support the use of PCMs in controlling the freeze-thaw effect on subgrade soil. Further recommendations are provided on PCMs selection, composite type PCMs, incorporation method, and chemical stability.

Recent Investigations of Phase Change Materials Use in Solar Thermal Energy Storage System

Solar thermal energy storage (TES) is an efficient way to solve the conflict between unsteady input energy and steady output energy in concentrating solar power plant. The latent heat thermal energy storage (LHTES) system is a main method of storing thermal energy using phase change materials (PCMs). Thermal properties, that is, melting points and latent heat, are the key parameters of PCMs for the TES system. In this paper, the PCMs are classified into inorganic and organic by the chemical composition, and according to the melting point, the inorganic PCMs can be divided into three contributions: low-temperature heat storage (less than 120°C), medium-temperature heat storage (120–300°C), and high-temperature heat storage (more than 300°C). The present article focuses mainly on the recent investigations on the melting point and latent heat of PCMs via DSC setup in the solar TES systems. The results can provide a good reference for the selection and utilization of PCMs in the solar TES systems.

A fuzzy based hybrid multi criteria decision making methodology for phase change material selection in electronics cooling system

Abstract The phase change material (PCM) selection plays a vital role in successful designing of electronic cooling systems. Since large numbers of competitive materials are available today, with each having its own characteristics, applications, advantages, and limitations, the decision for selecting a suitable PCM involves several evaluation criteria. In this article, a novel hybrid multi criteria decision making (MCDM) model is proposed for evaluating a suitable PCM for thermal management systems. The decision model consists of 10 alternative materials with eight evaluation criteria. The Fuzzy Analytical Hierarchy Process (FAHP) - integrated with Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), VlseKriterijumska Optimizacija I KompromisnoResenje (VIKOR) and Preference Ranking Organization METHod for Enrichment Evaluations (PROMETHEE) are proposed and applied in the numerical example. The results obtained from FAHP-TOPSIS, FAHP-VIKOR and FAHP- PROMETHEE are compared. The results show that RT-80 is the apt material for thermal management of power electronic devices.

Benchmarking of useful phase change materials for a building application

Nowadays, there is an increasing interest in more efficient building materials and new technologies to accomplish the objectives defined by energy policies. The combination of energy efficient building designs and integration of renewable energies makes the use of thermal energy storage (TES) necessary. Within this context, the improvement of building envelopes by the use of phase change materials (PCM) has been widely studied. The PCM selection should fulfil the requirements of the specific application. In this study, a benchmarking of PCM available in the market was performed to undertake a material selection for a specific building application. The incorporation of PCM into a radiant wall technology present several requirements with especial interest on long-term thermal stability. A complete laboratory-scale characterization has been carried out considering the following properties: temperature of phase change, specific heat capacity, thermal conductivity, and stability.

A methodological concept for phase change material selection based on multi-criteria decision making (MCDM): A case study

Phase change material (PCM) have been explored for different applications to increase the energy efficiency and economy. However, the proper PCM selection to meet given requirements generally requires that a compromise is struck between conflicting criteria. This paper attempts to extend multi-criteria decision making (MCDM) method to solve the PCM selection problem. Firstly, the comprehensive appraisal indexes model is established and the subjective and objective weight of the criteria are obtained based on the analytic hierarchy process (AHP) and entropy information method, respectively. Secondly, the optimized combination weight method is adopted to obtain the combination weight. Then, the pre-screened PCMs are ranked using technique for order performance by similarity to an ideal solution (TOPSIS). Finally, the information retrieval is employed to justify the rankings. To demonstrate the applicability of the proposed method, a problem to select the optimal PCM for ground source heat pump (GSHP) integrated with phase change thermal storage (PCTS) system is considered. The result showed that Ba(OH)2·8H2O is the best material for the given case and the GSHP integrated with PCTS system has better economic performance compared to the GSHP system, meanwhile, the proposed method is a simple and practical approach in solving the PCM selection problem.

Phase Change Material Selection for Thermal Energy Storage at High Temperature Range between 210 °C and 270 °C

The improvement of thermal energy storage systems implemented in solar technologies increases not only their performance but also their dispatchability and competitiveness in the energy market. Latent heat thermal energy storage systems are one of those storing methods. Therefore, the need of finding the best materials for each application becomes an appealing research subject. The main goal of this paper is to find suitable and economically viable materials able to work as phase change material (PCM) within the temperature range of 210–270 °C and endure daily loading and unloading processes in a system with Fresnel collector and an organic Rankine cycle (ORC). Twenty-six materials have been tested and characterized in terms of their thermophysical conditions, thermal and cycling stability, and health hazard. Two materials out of the 26 candidates achieved the last stage of the selection process. However, one of the two finalists would require an inert working atmosphere, which would highly increase the cost for the real scale application. This leads to a unique suitable material, solar salt (40 wt % KNO3/60 wt % NaNO3).

Review on Heat Transfer Enhancement of Phase Change Materials (PCMs)

For effective utilization of thermal energy storage (TES) system, selection of Phase change material (PCM) and heat transfer mechanism plays a significant role. PCMs employed in TES system undergo poor heat transfer rate due to low thermal conductivity. In order to capture larger amount of energy, it is inevitable to improve the heat transfer rate between heat transfer fluid (HTF) and PCM. The main focus of the paper is to review the previous works on heat transfer enhancement of PCMs and to develop efficient TES system. Some of the heat transfer enhancement methods namely extended surface, composite PCMs, multiple PCMs and encapsulation have been discussed. The different applications of phase change material in conserving the energy are also reviewed in this paper.

Quantitative Assessment of Phase Change Material Utilization for Building Cooling Load Abatement in Composite Climatic Condition

The global trend of energy consumption shows that buildings consume around 48% of the total energy, of which, over 50% is for heating and cooling applications. This study elucidates on cooling load reduction with phase change material (PCM) incorporation in a building envelope. PCM provides thermal shielding due to isothermal heat storage during phase change. PCM selection depends upon its phase change temperature, thermal capacity, and thermal conductivity, as they play a vital role in assessing their impact on energy conservation in buildings. The uniqueness of this study underlies in the fact that it focuses on the utilization of PCM for New Delhi (28.54°N, 77.19°E) climatic conditions and adjudges the suitability of three commercially available PCMs, based on the overall heat load reduction and their characteristic charging/discharging. The study aims at finding an optimum melting and solidification temperature of the PCM such that it may be discharged during the night by releasing the heat gained during the day and mark its suitability. The results of mathematical modeling indicate that as per the design conditions, the melting/solidification temperature of 34 °C is suitable for New Delhi to absorb the peak intensity of solar irradiation during summer. Based on the thermophysical properties in literature (Pluss Advanced Technologies Pvt. Ltd., 2015, “Technical Data Sheet of savE® HS29, PLUSS-TDS-DOC-304 Version R0,” Pluss Advanced Technologies Pvt. Ltd., Gurgaon, India. Pluss Advanced Technologies Pvt. Ltd., 2015, “Technical Data Sheet of savE® OM32, PLUSS-TDS-DOC-394 Version R0,” Pluss Advanced Technologies Pvt. Ltd., Gurgaon, India. Pluss Advanced Technologies Pvt. Ltd., 2012, “Technical Data Sheet - savEVR HS34, Doc:305,” Pluss Advanced Technologies Pvt. Ltd., Gurgaon, India), mathematical modeling showed HS34 to be suitable for New Delhi among the three PCMs. To ratify this, characteristic charging and discharging of HS34 is tested experimentally, using differential scanning calorimeter (DSC). The results showed that HS34 is a heterogeneous mixture of hydrated salts having super-cooling of 6 °C, reducing its peak solidification temperature to 30.52 °C during the cooling cycle also making it unsuitable for peak summers in New Delhi.

Encapsulated Nitrates Phase Change Material Selection for Use as Thermal Storage and Heat Transfer Materials at High Temperature in Concentrated Solar Power Plants

In the present paper, the finite element method is used to perform an exhaustive analysis of the thermal behavior of encapsulated phase change materials (EPCMs), which includes an assessment of several materials in order to identify the best combination of PCM and shell material in terms of thermal energy storage, heat transfer rate, cost of materials, limit of pressure that they can support and other criteria. It is possible to enhance the heat transfer rate without a considerable decrease of the thermal energy storage density, by increasing the thickness of the shell. In the first examination of thermomechanical coupling effects, the technical feasibility can be determined if the EPCM dimensions are designed considering the thermal expansion and the tensile strength limit of the materials. Moreover, when a proper EPCM shell material and PCM composition is used, and compared with the current storage methods of concentrated solar power (CSP) plants, the use of EPCM allows one to enhance significantly the thermal storage, reaching more than 1.25 GJ/m3 of energy density.

A numerical study of building integrated with CaCl2·6H2O/expanded graphite composite phase change material

Integrating phase change material (PCM) into traditional building envelopes can decrease the building energy consumption and improve the indoor thermal comfort by enhancing the heat storage capability. In this work, CaCl2·6H2O/expanded graphite (EG) was employed to fabricate the PCM panels for building envelope as a low-cost PCM. In order to give full play to the role of CaCl2·6H2O/EG, its characteristic in structural insulated panel (SIP) was investigated numerically under different conditions. The enthalpy-porosity technique was used for modeling the solidification/melting process and it was validated by experiment. Temperature time lag, temperature decrement factor and energy saving rate were used to evaluate the dynamic thermal characteristics of the building envelope. The results showed that the density and thermal conductivity of PCM had little effect on the thermal performance of building envelope. However, the change of PCM panel thickness, building orientation, climate region and building construction would affect the phase change process of the PCM panels, which would have a certain influence on the room temperature. By analyzing the effect of CaCl2·6H2O/EG on the thermal performance of the building envelope under different influencing factors, it will provide effective guidance for the selection and use of PCM.

Phase Change Material Selection for Thermal Processes Working under Partial Load Operating Conditions in the Temperature Range between 120 and 200 °C

In some processes, latent heat thermal energy storage (TES) systems might work under partial load operating conditions (the available thermal energy source is discontinuous or insufficient to completely charge the phase change material (PCM)). Therefore, there is a need to study how these conditions affect the discharge process to design a control strategy that can benefit the user of these systems. The aim of this paper is to show and perform at laboratory scale the selection of a PCM, with a phase change temperature between 120 and 200 °C, which will be further used in an experimental facility. Beyond the typical PCM properties, sixteen PCMs are studied here from the cycling and thermal stability point of view, as well as from the health hazard point of view. After 100 melting and freezing cycles, seven candidates out of the sixteen present a suitable cycling stability behaviour and five of them show a maximum thermal-stable temperature higher than 200 °C. Two final candidates for the partial loads approach are found in this temperature range, named high density polyethylene (HDPE) and adipic acid.

Computer simulations of heat transfer in a building integrated heat storage unit made of PCM composite

The paper presents the results of parametric study of thermal performance characteristics of thermal energy storage unit integrated in building structure being also a part of building’s ventilation system. A storage unit is in the form of a ceiling panel with internal channels through which air taken from the environment flows before it is delivered into the rooms. Thermal storage potential of the panel is thanks to phase change material (PCM) which is mixed with gypsum mortar, creating in this way a composite of high thermal capacity in the temperature range corresponding to the temperature required for thermal comfort. In order to perform the analysis of the storage unit a computer program was developed which was based on the mathematical model of complex heat transfer occurring inside the panel, inside a composite material, as well as on the boundary between the panel and air flowing through internal channels. A procedure describing variations of convective heat transfer intensity along the channel can be regarded as a unique achievement in this research. This function was validated based on measurements conducted on the experimental set-up specially prepared for this study. Using the program many computer simulations were performed. Based on the results of this analysis a detailed information on the performance of the panel for different operational parameters, e.g. air mass flow rates, were obtained. Contrary to the study reported in an earlier publication, these simulations were conducted for real environmental conditions, i.e. real ambient temperatures during summer in Central Poland. Also, important conclusions regarding selection of PCM, mainly its melting temperature range, were formulated.

Selection of Phase Change Material for Thermal Energy Storage in Solar Air Conditioning Systems

The selection of Phase change materials (PCMs) is crucial in the design of Latent Heat Thermal Energy Storage (LHTES) system in solar air conditioning applications. This study performs a systematic selection procedure of PCMs for LHTES in a typical solar air conditioning system. Comprising prescreening, ranking and objective function examination based on multi-criteria decision making (MCDM) tools, this procedure is able to reflect the system goals of LHTES, as well as to take into account designer's subjectivity. Results indicate the proposed approach to be a highly applicable and efficient tool in the LHTES design process.

Selection of Phase Change Materials for Latent Heat Storage

Esta investigación tiene como objetivo seleccionar un material de cambio de fase (PCM) que cumplen mejor la solución del almacenamiento de energía térmica entre 200-400 ° C y reducir el costo de producción.
 El uso de métodos multicriterios de toma de decisiones (MCMD) para la evaluación fueron proporcionales implementados como COPRAS-G, TOPSIS y VIKOR. La ponderación de los criterios se realizó por el método AHP (proceso analítico jerárquico) y los métodos de entropía. La correlación de los resultados entre los tres métodos de clasificación ha sido desarrollada por el coeficiente de correlación de Spearman. Los resultados ilustran el mejor y la segundo mejor opción para los tres MCDM fueron NaOH y KNO3. Además, tenía valores de correlación de Spearman entre los métodos excede de 0.714.