Phase Change Materials For Thermal Storage Research Articles

Decarbonizing European Industry: A Novel Technology to Heat Supply Using Waste and Renewable Energy

This study examines the potential for the smart integration of waste and renewable energy sources to supply industrial heat at temperatures between 150 °C and 250 °C, aiming to decarbonize heat demand in European industry. This work is part of a European project (SUSHEAT) which focuses on developing a novel technology that integrates several innovative components: a Stirling cycle high-temperature heat pump (HTHP), a bio-inspired phase change material (PCM) thermal energy storage (TES) system, and a control and integration twin (CIT) system based on smart decision-making algorithms. The objective is to develop highly efficient industrial heat upgrading systems for industrial applications using renewable energy sources and waste heat recovery. To achieve this, the specific heat requirements of different European industries were analyzed. The findings indicate that industrial sectors such as food and beverages, plastics, desalination, textiles, ceramics, pulp and paper, wood products, canned food, agricultural products, mining, and chemicals, typically require process heat at temperatures below 250 °C under conditions well within the range of the SUSHEAT system. Moreover, two case studies, namely the Pelagia and Mandrekas companies, were conducted to validate the effectiveness of the system. An analysis of the annual European heat demand by sector and temperature demonstrated that the theoretical potential heat demand that could be met by the SUSHEAT system is 134.92 TWh annually. Furthermore, an environmental impact assessment estimated an annual significant reduction of 19.40 million tonnes of CO2 emissions. These findings underscore the significant potential of the SUSHEAT system to contribute to the decarbonization of European industry by efficiently meeting heat demand and substantially reducing carbon emissions.

Benefits of zeotropic mixture for heat pump water heater with phase change material thermal energy storage

Integrating heat pump water heater (HPWH) into latent heat thermal energy storage (LHTES) with phase change material (PCM) has been recognized as a promising way to mitigate the energy use for heating water in the building sector. This paper uses zeotropic mixture R1234yf/R1234ze(Z) in HPWH and spherical PCM encapsulations in LHTES. The mathematical model is established and validated. Effects of zeotropic mixture composition, working fluid flow rate and heat transfer fluid (HTF) flow rate are discussed to reveal the instantaneous behaviors and overall performance of the integrated system. The results indicate that as the charging process progresses, the condensing pressure of the system steadily increases, leading to a decline in COP. By employing zeotropic mixtures, the system performance can be effectively improved, with the highest COP of 2.68 when the mass fraction of R1234ze(Z) is 70 %, which represents an 18.1 % and 6.8 % improved COP compared to R1234yf and R1234ze(Z), respectively. A smaller refrigerant flow rate or a larger HTF flow rate contributes to a higher COP. For heat storage capacity in LHTES, a higher mass fraction of R1234ze(Z) and a larger refrigerant flow rate are preferable, while a smaller HTF flow rate is beneficial. Finally, a multi-objective optimization is carried out. Results suggest that the best overall performance is achieved with a COP of 2.70 and a heat storage capacity of 629.24MJ, under conditions of the mass fraction of R1234ze(Z) at 70 %, a refrigerant flow rate of 0.28 kg/s, and an HTF flow rate of 0.46 kg/s.

Black phosphorus modified wearable textile with excellent flame retardancy for personal thermal management and motion detection

A sandwich structure composite phase change textile material (CPCTM) was prepared by electrospinning. In the top and bottom layers, black phosphorus nanosheets (BPNs) was compounded into polyacrylonitrile (PAN). In the middle layer, the phase change thermal energy storage material polyethylene glycol (PEG) was well encapsulated by polyvinyl alcohol (PVA). By designing multilayer structure, the CPCTM exhibited excellent intensity with the tensile strength 62.65MPa and the elongation at break 1176%. The melting temperature and the crystallization temperature of CPCTM were 54.36 ℃ and 31.43 ℃ which were lower than pure PEG (55.87 ℃ and 35.55 ℃). The lower melting and crystallization temperature facilitated the storage of heat in CPCTM for body thermal management. Compared with that of pure PAN, the total heat release and total smoke production of the PAN@BP were respectively descended by 33.05% and 80.43%. During combustion, transfer of combustible gases and heat were hindered due to the formation of the expanded char layer by the BPNs. Meanwhile, the CPCTM showed excellent flexibility and ability of motion detection, which had broad application prospects in the fields of wearable electronic devices.

Electrochemistry of Phase-Change Materials in Thermal Energy Storage Systems: A Critical Review of Green Transitions in Built Environments

This article reviews recent research on phase-change materials (PCMs) used in thermal energy storage systems with the aim of enhancing their performance. The study explores various methods to improve heat transfer in PCMs, such as microencapsulation, infill materials, fins and nanofluids. Additionally, it evaluates techniques to boost heat transfer in latent heat thermal energy storage (LHTES) systems and investigates ways to increase thermal conductivity using porous and low-density materials. PCMs store thermal energy, making them suitable for use in solar energy systems when solar energy is not available. The need for eco-friendly alternatives to conventional heating and cooling in global construction and the significant energy consumption of buildings has driven research on this topic. As such, this study additionally examines current advancements in free cooling systems with latent heat storage to identify the key factors affecting their effectiveness. The findings show that using PCMs for overnight cooling maintains the room temperature within the comfort zone and reduces the cooling loads in various climates. Using machine learning methods, this study also compares recent advancements in the use of PCMs in various solar energy systems, including solar thermal power plants, solar air purifiers, solar water heaters and solar appliances. Results derived feature key factors crucial for the optimal selection of PCMs and the challenges associated with sustainable green transitions in built environments. HIGHLIGHTS This review provides an in-depth examination of PCM thermal energy storage systems. This study investigates the use of fillers, nanofluids, and nanoparticles for enhanced heat transfer. Analytical methods for boosting the PCM thermal conductivity are briefly outlined. Geometric design and thermal conductivity enhancement affect the Latent Heat Thermal Energy Storage (LHTES). The assessment also evaluates advanced free-cooling systems using the LHTES. PCMs help to store heat energy in solar systems and bridge supply gaps. GRAPHICAL ABSTRACT

Integrated Supervisory Control and Data Acquisition System for Optimized Energy Management: Leveraging Photovoltaic and Phase Change Material Thermal Storage

ABSTRACTReliable energy sources are crucial for both economic growth and quality of life. In developing countries, where expensive fuels are often the primary energy source, governments are exploring innovative solutions like small‐scale, IoT‐based projects to achieve energy independence in buildings. This research investigates the integration of renewable energy technologies, statistical modeling, cloud computing, and IoT to develop a self‐managing energy system for buildings. The system prioritizes renewable sources, specifically monocrystalline solar cells with 20% efficiency for photovoltaic (PV) energy and flat plate collectors with 90% efficiency and minimal energy loss for thermal energy. Thermal energy is stored in paraffin wax, chosen for its high storage efficiency and thermal properties. The system also utilizes an absorption chiller with a high coefficient of performance (COP) to provide cooling using solar thermal energy. The building's energy loads are categorized as A, B, C, and D, each utilizing both PV and thermal energy. A SCADA system oversees the operation, monitoring the on–off status of these loads. The system is designed for continuous operation, with simulations conducted using Anaconda Jupyter Notebook and Python. This model aims to offer a sustainable and efficient energy solution for buildings, meeting energy demands while optimizing energy use.

A shape-stable phase change material for high-temperature thermal energy storage based on coal fly ash and Na2SO4-K2SO4

Using coal fly ash (CFA) as the skeleton material and binary sulfates of Na2SO4-K2SO4 as the phase change material (PCM), high-temperature coal fly ash based phase change thermal storage materials (CPCM) were successfully synthesized. The influences of CFA fractions and types on the morphology, physicochemical properties, and thermal characteristics of the composites were intensively investigated. Results show that the heat storage density and thermal conductivity of CPCMs increase with the PCM content. Particularly, the CPCM60-A composite, comprising 60 wt% Na2SO4-K2SO4 eutectic and 40 wt% CFA-A, exhibits excellent chemical compatibility and stable shape retention after sintering. Furthermore, CPCM60-A demonstrates the highest phase change latent heat of 60.43 J/g and thermal conductivity of 0.61 W/(m·K). The influence of CFA types reveals that CFA-A with a higher ratio of SiO2 and Al2O3, lower carbon content, and a rich porous structure is more suitable to fabricate molten salt heat storage materials. This work demonstrates that CFA, a byproduct of coal-fired industry, is a promising skeleton material for the fabrication of high-temperature CPCM composites, offering a novel approach for enhancing the efficiency and cost-competitiveness of solar power and waste heat recovery systems.

4E experimental investigation of concentrated solar cell cooling via system of heat dissipator-phase change material

Low-concentrator solar cell (SC) experimentally cooled using a new composite thermal regulation system of heat dissipator (HD) and phase change material (PCM) is investigated. The impact of area ratio (AR; HD area/SC area) of 1.5 and 2 at different HD thicknesses (h) on the system performance is reported. An energy, exergy, economic, and enviroeconomic assessments for the different cooling systems used for the SC thermal regulation are presented. The results show that the SC temperature reduction increases with increasing the HD thickness and AR. Compared with reference SC, SC-PCM/HD (AR=2/h = 3) achieves a maximum temperature reduction of 24 °C compared with 9.1 °C and 21.8 °C for SC-PCM and SC-HD, respectively. Moreover, SC-PCM/HD cooling system achieves the maximum enhancement in the average electrical efficiency and power output of 11.88 % and 12 %, respectively, compared with reference SC. The PCM thermal energy storage rate and PV system efficiency increase with increasing area ratio and decreasing the HD thickness. Using HD of (AR=2/h = 1) in conjunction with PCM yields the most favorable PCM thermal performance where it enhances the thermal energy storage, rate of energy storage, and overall thermal system efficiency by 9.5 %, 40 %, and 20.36 %, respectively, compared with using PCM only. Moreover, the PCM/HD cooling system is more economical than using PCM or HD only, and reference SC, with a maximum cost saving of 41.7 % compared with reference SC. The SC-PCM/HD cooling system is the most eco-friendly option with net CO2 mitigation and ψCO2 of 146.2 kg and 5.84$, respectively compared with 143.7 kg and 5.74$, respectively for SC-PCM.

Oxygen‐Rich Porous Organic Polymer for Thermal Energy Storage

Oxygen atoms have been widely used in porous organic polymers, which has attracted much attention from researchers. Herein, porous organic polymer with high oxygen content is synthesized with oxygen‐rich monomer as construction unit and anhydrous aluminum chloride as catalyst; then phase‐change materials (PCMs) composites are prepared by self‐adsorption method. The pore properties of the oxygen‐rich porous organic polymer are characterized by nitrogen absorption and desorption method. The properties of the PCM composites are characterized by scanning electron microscopy, X‐ray diffraction, Fourier‐transform infrared spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The results show that the oxygen‐rich porous organic polymer has high Brunauer–Emmett–Teller surface area (465 m2 g−1) and excellent thermal stability. The PCM composites possess high encapsulation rate (50.6 wt%) and latent heat (124.7 kJ g−1). After several thermal cycles, the thermal properties of all PCM composites are almost unchanged, and no leakage phenomenon is found. It can be seen that oxygen‐rich porous polymers have potential applications in PCM adsorption and thermal energy storage.

Energy performance of a residential zero energy building energy system – R-CELLS at solar decathlon China 2022

The energy system and its energy performance of R-CELLS, a residential zero energy building from team Tianjin U+ in the Solar Decathlon China 2022, is introduced in this paper. When designing and constructing the R-CELLS energy system, two sets of challenges are encountered. Firstly, from an architectural perspective, the limited construction timeframe (only 21 days) and constrained space for housing the equipment, also ease of maintenance should be taken into account. Secondly, from an operational perspective, a constrained period for tests before the competition, a large number of devices dependent on electricity, heat and hot water supply should be considered. In consideration of the ease of assembly and maintenance of the energy system components and the aesthetic requirements of R-CELLS, an improved “photovoltaics, energy storage, direct current, flexibility” based energy system is utilized in R-CELLS. The R-CELLS energy system integrates various renewable energy sources (building integrated photovoltaics, photovoltaic-thermal, and building integrated wind turbines). Furthermore, it incorporates energy storage systems such as battery energy storage system, hot water tank, and phase change material thermal storage. In order to satisfy user requirements in grid-connected, off-grid and outage scenarios, including electricity, heat and domestic hot water, a tri-period energy management strategy based on optimized scheduling and rule-based control is proposed to achieve weekly, daily, and hourly net zero goals. Furthermore, the energy performance of R-CELLS is simulated for a whole year, including typical days in winter and summer, as well as the competition period. During the Solar Decathlon China 2022 competition, R-CELLS was subjected to testing by the committee. The results demonstrated that R-CELLS can be operated off-grid and with zero energy consumption, while meeting the test requirements for indoor environment, heating and cooling, and home life.

Development and thermal property analysis of biobased binary composite heat storage materials

Natural aliphatic dibasic acids are a type of bio-based material that shows promising potential as green phase change thermal storage materials due to their favorable thermophysical properties. However, these materials have been found to have issues with subcooling, low thermal conductivity, and poor temperature matching. In this study, three aliphatic dibasic acids, namely adipic acid (AA), sebacic acid (SA), and azelaic acid (ZA), were selected for further investigation. Three biobased eutectic systems, AA-SA (melting point: 118.3 °C), ZA-SA (melting point: 96.2 °C), and AA-ZA (melting point: 98.4 °C), were then prepared based on the calculation of Schrader's equation and experimental screening. The eutectic systems were thoroughly characterized, revealing thermal conductivities ranging from 0.4 to 0.5 W·m−1·K−1, with all systems exhibiting a subcooling of around 20 °C. Based on the principle of optimal overall performance, the AA-SA system was selected for modification. By incorporating Expanded graphite (EG) as a highly thermally conductive additive and nucleating agent, the AA-SA/EG composite phase change material (CPCM) was successfully prepared. This modification effectively reduced the supercooling degree of the bio-based phase change materials (PCM) and significantly improved its thermal conductivity by a factor of four. The resulting AA-SA/EG CPCM demonstrated excellent temperature suitability and has the potential to contribute to the application of bio-based phase change materials in waste heat recovery and solar energy systems. This study provides valuable insights into the development and optimization of bio-based phase change materials, contributing to the sustainable utilization of renewable resources for thermal energy storage applications.

Development of Macro-Encapsulated Phase-Change Material Using Composite of NaCl-Al2O3 with Characteristics of Self-Standing

Developing thermal storage materials is crucial for the efficient recovery of thermal energy. Salt-based phase-change materials have been widely studied. Despite their high thermal storage density and low cost, they still face issues such as low thermal conductivity and easy leaks. Therefore, a new type of NaCl-Al2O3@SiC@Al2O3 macrocapsule was developed to address these drawbacks, and it exhibited excellent rapid heat storage and release capabilities and was extremely stable, significantly reducing the risk of leakage at high temperatures for industrial waste heat recovery and in concentrated solar power systems above 800 °C. Thermal storage macrocapsules consisted of a double-layer encapsulation of silicon carbide and alumina and a self-standing core of NaCl-Al2O3. After enduring over 1000 h at a high temperature of 850 °C, the encapsulated phase-change material exhibited an extremely low weight loss rate of less than 5% compared with NaCl@Al2O3 and NaCl-Al2O3@Al2O3 macrocapsules, for which the weight loss rate was reduced by 25% and 10%, respectively, proving their excellent leakage prevention. The SiC powder layer, serving as an intermediate coating, further prevented leakage, while the use of Al2O3 ceramics for encapsulation enhanced the overall mechanical strength. It was innovatively discovered that the Al2O3 particles formed a network structure around the molten NaCl, playing an important role in maintaining the shape and preventing leakage of the composite thermal storage phase-change material. Furthermore, the addition of Al2O3 significantly enhanced the rapid heat storage and release rate of NaCl-Al2O3 compared to pure NaCl. This encapsulated phase-change material demonstrated outstanding durability and rapid heat storage and release performance, offering an innovative approach to the application of salt phase-change materials in the field of high temperature rapid heat storage and release and encapsulating NaCl as a high-temperature thermal storage material in a packed bed system. Compared with conventional salt-based phase-change materials, the developed product is expected to significantly improve the reliability and thermal efficiency of thermal storage systems.

Integration of prolonged phase-change thermal storage material and radiative cooling textile for personal thermal management

Efficient passive thermal regulation clothing is of great importance for personal thermal comfort in extremely hot environments. Phase-change textiles have been made for personal thermal regulation, however, achieving prolonged thermal comfort remains challenging due to their limited latent thermal storage duration. Here, a bilayer polyvinyl butyral (PVB) composite textile, integrating prolonged phase-change thermal storage and radiative cooling, is fabricated for personal thermal regulation. The PVB composite textile has a high reflectivity of 90.1 % in the solar wavelength range and a high emissivity of 95.7 % in the atmospheric window. More importantly, encapsulating 70 wt% of phase change microcapsules (PCMC) into the PVB membrane (denoted by PVB-PCMC70) gives a total enthalpy of fusion 124.3 J g−1, which compensates for the deficiency in radiative cooling power during the day. This results in a maximum additional temperature reduction of 10.4 °C compared with textile without the PCMC. Furthermore, the PVB composite textile demonstrates a capacity for effectively mitigating abrupt temperature fluctuations, ensuring sustained thermal comfort throughout the daytime. Moreover, the PVB composite textile shows practical applicability, including washability, flexibility, thermostability, moisture permeability and breathability.

Integrating phase-change thermal storage into the indirect dry-cooling system of a thermal power unit and optimal operation strategy

Extreme conditions (high ambient temperature and crosswind speed) reduce the cooling efficiency of dry cooling towers, consequently impairing the thermal performance of thermal power units (TPUs). Phase-change material thermal storage equipment (PCMTSE) is integrated into an indirect dry-cooling system of the TPU to realize a partial cooling load of the cooling tower, thereby stabilizing and improving the thermal performance of the TPU. A model of the TPU and numerical model of the hybrid indirect dry-cooling system are established and coupled, with the inlet cooling water temperature of the condenser serving as the iterative criterion. Two integration schemes are proposed, one with the PCMTSE downstream (Scheme A) and the other with it upstream (Scheme B) of the dry cooling tower. The results show that Scheme A is recommended owing to its superior efficiency in terms of coal savings. The effects of the unit power load on the coal-savings efficiency of the PCMTSE during its charging and discharging processes have been revealed. Operating the PCMTSE at higher power loads aids in improving the thermal efficiency of the TPU during the PCMTSE charging and discharging processes. The charging process should be started at the “three high” working conditions: a high ambient temperature, crosswind speed, and unit power load. The working conditions that allow only one cooling water pump to operate should first be considered for the discharging process, and the “three high” working conditions should then be selected. The TPU equipped with the PCMTSE can save 11.42 tons and 12.74 tons of coal in two typical extreme daily conditions with the implementation of the proposed operating strategy.

Advancing Thermal Performance in PCM-Based Energy Storage: A Comparative Study with Fins, Expanded Graphite, and Combined Configurations

Phase Change Material (PCM) thermal energy storage systems have emerged as a promising solution for efficient thermal energy storage from low to very high-temperature applications. This paper presents an investigation into the utilization of medium temperature range PCM-based systems for domestic hot water application, focusing on different techniques to overcome the low thermal conductivity of the PCM. Five shell and tube heat exchangers were fabricated employing different heat transfer enhancement methods including fin, expanded graphite (EG), and a combination of fin and EG. The combination of EG and circular fins exhibited the best performance in terms of charging and discharging, maintaining a uniform temperature distribution throughout the system due to extensive conductive network provided by the combination of EG and circular fins. When the PCM/EG/fin heat exchanger system is fully charged, the energy stored in the system is 109% higher than that of the PCM heat exchanger at the same elapsed time. Furthermore, the PCM/EG/fin system demonstrated a faster discharging response compared to other thermal energy storage (TES) configurations, with over 160% higher discharging power than a system without any enhancement methods. These findings emphasize the practical viability of integrating PCM/EG composite materials into thermal energy storage systems, offering a viable solution for meeting high heat demand requirements in domestic hot water applications. Furthermore, the enhanced discharging response observed in the PCM/EG/fin system has significant implications for improving energy efficiency and reducing operational costs in real-world applications.

Residential Micro-CHP system with integrated phase change material thermal energy storage

This paper presents an analysis and experimental investigation of the effect of integrating Phase Change Material (PCM) within a heat exchanger within a Micro Combined Heat and Power (Micro-CHP) system intended for residential applications. A commonly used Micro-CHP layout is replicated in a test rig to characterise the performance of two alternative heat exchanger arrangements. The first is a conventional arrangement where the exhaust gas produced by the prime mover is directed to an air-to-water heat exchanger to heat water and store it in a tank. In the second arrangement, PCM material is encapsulated within specially designed compartments in a heat exchanger to store part of the exhaust thermal energy from the prime mover while heating the water in the storage tank. The time needed to heat the water and discharge heat is compared for both cases, as well as the amount of thermal energy stored during the same operating period. The study also explored the potential to improve the designed unit by using different PCM materials. The test results show that adding 4.7 L capacity paraffin compartments within the heat exchanger extended the discharge time of the hot water by over 400 %, which reflects a marked improvement in the heat storage capacity of the system. This would result in a significant increase in the viable operating period of a CHP system. The one-dimensional analysis revealed that replacing the paraffin with ClimSel C58 PCM can reduce the charging time of the water tank by around 54 % improve the heat storage capacity by factor of 2.35 comparing to Paraffin. The proposed heat exchanger with encapsulated PCM has a potential in other applications such as storage of excess renewable energy or integration with heat pumps to improve matching of supply and demand and thus flexibility of an energy system with integrated intermittent renewables.

Functional Soft Materials with Resistance to Liquid Leakage for Thermal Energy Storage

AbstractFunctional soft materials have great potential commercial applications in thermal energy storage, which are required to have a long life, good flexibility, and resistance to liquid leakage. Herein, a composite hydrogel with thermal storage properties is prepared through coupling molecular self‐assembly and in situ polymerization. Hydrophobic stearic acid (SA), as a thermal storage phase change material (PCM), is dispersed in polyacrylamide (PAM) hydrogel network in the form of oil–water emulsion (O/W). The PAM polymer network with good flexibility physically limits high‐frequency collision between SA PCM droplets. This unique design avoids demulsification in phase change emulsion so that the as‐prepared hydrogel composite can resist liquid leakage. The PAM hydrogel network plays the role of heterogeneous nucleation, resulting in the super‐cooling of SA emulsion at only 0.3 °C. On the other hand, SA PCM droplets in as‐prepared soft material do not directly contact with liquid water, so melting/crystallization process is independent of water. As a result, the soft material exhibits a thermal storage density of up to 99.3 J g−1. The present study is an important step toward designing soft energy storage materials.

Experimental investigation of phase change material (PCM) thermal energy storages with and without metal foam at different temperatures

This paper presents an experimental investigation of phase change materials (PCM) thermal energy storage. The experimental unit consists of a square channel with a single flow stream having distilled water as a heat exchange fluid. RT-42 is used as a thermal energy storage and the overall system is designed in two configurations i.e. with and without aluminium metal foam having a porosity of 95%. Each configuration is analysed and compared for two temperature variations i.e. at 55 °C and 65 °C, respectively. The study reveals that the heat storage rate in metal foam (MF) integrated PCM thermal energy storage is enhanced to ~3-4 times as compared to the setup without metal foam. In metal foam PCM energy storage, the temperature distribution is uniform and heat transfer is due to conduction as well as convection, while in case of pure PCM, there exist a temperature gradient within the thermal storage and the heat transfer is slower due to convection phenomenon. It is also observed that the heat transfer rate for 65 °C is comparatively greater than that of 55 °C for both systems as the higher operating temperatures lead to higher heat flux. However, operating at high temperatures is less feasible as the setup is more prone to PCM leakages.

Ventilation system with heat recovery and PCM thermal energy storage for “free” cooling in buildings

For the conventional cooling of buildings, we are using electrical energy from the network, which increases annually due to the increase in comfort. Alternatives are being sought to reduce electricity consumption. Phase change materials (PCMs) in ventilation systems can provide us with the accumulation of night-time coolness in the summer months, resulting in a reduction in the consumption of electricity for cooling. Heat storages that take advantage of the phase change are used for short-term storage of thermal energy, as in this case, they have the greatest potential. In the introduction to the paper, a review of heat storage devices and their use is made which shows their connection with the Energy Performance Building Directive (EPBD) and the Energy Efficiency Directive (EED). Based on the measured results of the measurements in the Laboratory for Heating, Sanitary and Solar Technology and Air-conditioning (LHSA), a comparison with the model that calculates the storage of heat and cold in a phase change material (PCM - Phase Change Material) developed by a group of researchers from BUT Brno was made. With the TRNYSY software tool and the model simulations of the ventilation gains in the summer season were made and compared with the gains when using the heat exchanger (recuperator) and the PCM heat accumulator for the selected room.

Thermal management of high-powered short-duration electronics aided by a phase change material thermal energy storage

Quantifying the performance of phase change materials (PCMs) for thermal energy storage in high-power short-duration electronics applications requires performing tests that push the material to its limit. This involves designing experiments to test solid-liquid PCMs in near real-world thermal load conditions to test its performance. Conventional cooling methods are sized to manage the maximum loading the cooling system will be subjected to in its operation, even if this loading occurs for a short period of time. This design ethos is inefficient and results in heavy and expensive equipment being used in an application where it will be underutilized most of its useful life. In this work, a PCM thermal energy storage (TES) device was built using a plate-and-frame heat exchanger and investigated to determine the suitability of this system to manage the temperature of high-power electronics with a low duty cycle. These experiments showed how a PCM-TES can be used in conjunction with conventional temperature management equipment to create a reliable cooling solution while allowing the conventional cooling components to be decreased in size and capacity. This work shows that, for a given application, a cooling system can be more efficiently designed with the use of a PCM-TES and opens the door to additional research on this topic.

Analysis of Solar Water Heater with Modification Absorber Plate Integrated Thermal Storage

In various countries worldwide, solar water heater systems (SWHs) are utilized as devices that harness solar energy as a primary energy source. This study investigates the performance of SWHs numerical simulation by integrating phase change material (PCM) paraffin wax onto an absorber plate collector at the bottom for thermal storage. This study presents the thermal performance of a SWHs that uses an absorber plate with PCM for thermal energy storage. In this test, four variations of the model tested, namely a) standard flat plate (SFP), b) standard flat plate with PCM storage thickness 10mm (SFP+PCM 10mm), c) standard flat plate with PCM storage thickness 7mm (SFP+PCM 7mm), and d) standard flat plate with PCM storage thickness 4mm (SFP+PCM 4mm), were investigated using numerical simulation. Initially, an analytical investigation was conducted to examine the material qualities of paraffin wax utilised for phase change material (PCM) storage. The SWH systems were subsequently imported and simulated under three different levels of continuous solar radiation: 400 W/m2 700 W/m2 and 1000 W/m2. The simulation incorporates the use of computational fluid dynamics (CFD) tools. The results of the study revealed that the collector of the SWH system, which utilised an absorber plate containing phase change material (PCM) storage, demonstrated exceptional performance. Models with a thickness of 7mm PCM or SFP+PCM 7mm have the highest efficiency compared to other models with an efficiency value of 64%. There is a 3-4% increase in efficiency with variations in models that use PCM thermal storage compared to models that do not use PCM thermal storage.