Inorganic Phase Change Research Articles

A new approach for enhancing the effectiveness of a regenerative heat exchanger by using organic and inorganic phase change material

A new approach for enhancing the effectiveness of a regenerative heat exchanger by using organic and inorganic phase change material

Lead-free semiconductor materials with high phase transition temperature: [1-Methylimidazole][SbBr4]

Semiconductor with structure phase change is a special multi-functional material, which plays an important role in the field of Solar Energy, information computing, sensor technology, artificial intelligence, etc. In this paper, the organic–inorganic lead-free semiconductor phase change material [1-Methylimidazole][SbBr4] (1) was successfully constructed. The IR, TGA, DSC, VT-PXRD, solid-state UV–vis spectroscopy and temperature dependence of dielectric constant were characterized and analysed. Single crystal X-ray diffraction shows that at 298 K, the space group is P21/c, the point group 2/m; an endothermic and exothermic peak appeared near 386 K and 367 K in the DSC heating–cooling cycles. Near the corresponding phase transition temperature point, compound 1 exhibits a significant reversible change in the dielectric platform. Interestingly, the band gap of compound 1 is about 2.53 eV. The existence of such interesting physical properties is closely related to the interaction between cations and anions in the molecule and the connection of internal hydrogen bonds. By constructing organic–inorganic hybrid semiconductor materials, we hope to obtain semiconductor materials with phase transition properties and actively explore and provide some ideas and support for the application of new high-tech materials.

Kinetics study on inhibiting battery thermal runaway using an inorganic phase change material with a super high thermochemical storage capacity

Lithium-ion batteries are susceptible to fires and explosions due to thermal runaway, a serious safety hazard. This study explores the potential of using hydrated inorganic salt (TCM40) composite phase change materials to prevent thermal runaway in battery packs. TCM40 composites stand out due to their exceptional thermochemical heat storage capacity, which allows them to effectively absorb excess heat during runaway events. The research investigates how thermal conductivity, thermal storage capacity, and cell spacing influence the propagation of thermal runaway. The findings demonstrate that TCM40 composites, with a thermal storage density exceeding 1000 kJ/kg, are significantly more effective in preventing thermal runaway compared to traditional latent heat storage phase change materials with lower capacities. To gain a comprehensive understanding of thermal runaway mitigation, a combined thermal management model was developed. This model integrates a battery thermal runaway model with a kinetic model describing the decomposition of TCM40 composites. The analysis reveals that the high heat absorption capability of TCM40 composites minimizes heat transfer to neighboring cells during thermal runaway. Furthermore, the model provides valuable insights into the synergistic effects of thermal conductivity and heat storage capacity on runaway propagation. This knowledge can be directly applied to design safer battery packs, even for compact configurations where cell spacing is less than 2 mm. This study offers significant advancements in both thermal protection materials and design strategies for lithium-ion battery packs. These advancements have the potential to significantly improve battery system safety and minimize the risk of explosions.

Incorporated surfaces and confined spaces of Na2HPO4·12H2O–Layered vermiculite nanosheets for phase change materials with enhanced thermal properties

The phase change process of hydrated salts with a large latent heat and non-flammable characteristics is a promising route for achieving energy-efficient devices. To improve the reliability of the inorganic phase change material (PCM) system, excellent heat storage capacity, low supercooling degree, and good stability of hydrated salts are required. In this study, novel Na2HPO4·12H2O (DHPD)–vermiculite nanosheet (VMTNS) composite PCMs (CPCMs) possessing both surfaces and confined spaces were theoretically designed and synthesized. Incorporating the environmentally friendly VMTNSs, a new type of nano-reinforced fillers with multiple active sites, into DHPD hydrated salt results in excellent crystallization, great diffusion ability (33.277 × 10−11 m2/s), a low supercooling degree (0.8 °C), a high latent heat of melting (260.7 J/g), and great thermal stability of CPCMs. The DHPD arrangement both in the confined spaces and on the surfaces of the VMTNSs was simulated via molecular dynamics calculations. It was found that the adsorption energy of DHPD in the confined spaces of the VMTNSs and on their surfaces is –5.991 and –5.543 eV, respectively. This study provides an innovative method to construct novel CPCMs for efficient energy storage.

Review of organic and inorganic waste-based phase change composites in latent thermal energy storage: Thermal properties and applications

Systematization and analysis of standalone waste materials that can serve as phase change materials (PCMs), and composites consisting of commercially available PCMs combined with organic and inorganic waste materials is presented. Within the conducted review research, obtained thermal properties of so far investigated waste-derived PCMs were presented, assessing, among other, their latent heat storage capacity, thermal conductivity, and thermal and cyclic stability. Refined coconut oil and Allanblackia oil exhibited exceptional thermal and cyclic stability along with high values of latent heat, amounting 105 kJ kg−1 and 81 kJ kg−1, respectively. In some cases incorporation of waste materials significantly improved thermal properties, e.g. the addition of carbonized waste tire rubber to dodecyl alcohol increased its thermal conductivity to 0.431 W m−1K−1, representing an increase by a factor of 2.3. This enhancement led to a 17.2 % reduction in heating times and a 20 % reduction in cooling times compared to using pure PCM. Besides providing extensive data on thermophysical properties of phase change composites, the study provides a comprehensive overview of their applications, economic feasibility, and environmental implications. This extensive review shows the potential of waste-derived PCMs to contribute to a circular economy by repurposing waste materials for sustainable energy solutions and reducing environmental impacts. The findings indicate that while valorising wastes or by-products as latent thermal energy storage materials is feasible, more research efforts are required towards potential commercialization.

Hectorite aerogel stabilized NaCl solution as composite phase change materials for subzero cold energy storage

Inorganic phase change cold storage materials have garnered significant interest in cold chain transportation due to their high energy storage density. Nevertheless, practical applications have been hindered by inherent limitations such as high supercooling and susceptibility to phase separation. To address these challenges, this study devised 3D-Hectorite/sodium chloride (NaCl) composite phase change cold storage materials by utilizing 3D-Hectorite aerogel to adsorb NaCl solution, effectively mitigating the issue of phase separation common in such materials. Additionally, various concentrations of nucleating agents such as SrCl2·6H2O, borax, and diatomite were introduced for step cooling curve tests, establishing 0.03% diatomite as the optimal concentration for nucleation, reducing the supercooling of the NaCl solution to 1.1 °C. The results showed that the latent heat and thermal conductivity of 3D-Hectorite/NaCl were 215.30 J/g and 0.6315 ± 0.013 W/mK, respectively. The phase transition temperature could be adjusted in the range of -33~0 °C by changing the concentration of NaCl to meet the different temperature requirements. Furthermore, exceptional cyclic stability was observed even after subjecting the material to ten dissolution-solidification cycles. Analyzing the temperature change of the air inside the insulation bag showed that, compared with ice, 3D-Hectorite/NaCl can be applied to meet lower cooling temperature requirements, demonstrating good prospects for its application in cold chain transportation.

Development of a novel composite phase change material based on paints and brick for energy storage applications in agricultural greenhouses

This study addresses challenges associated with supercooling, phase separation, and inadequate thermal properties in Na2SO4·10H2O (SSD) by expanding the application of inorganic hydrate salt phase change materials within agricultural greenhouses. A novel composite phase change material, Na2SO4·10H2O-Al2O3 (NAPCM), was successfully synthesized using the vacuum impregnation method. NAPCM was strategically incorporated into paints and hollow bricks, leading to the creation of innovative phase change paint and phase change bricks designed for efficient thermal energy storage in agricultural greenhouses. The investigation revealed the homogeneous dispersion of porous Al2O3 particles in SSD, effectively preventing phase separation in NAPCM and ensuring its durable shape stability. The interaction between SSD and porous Al2O3 remained purely physical, with porous Al2O3 acting as an effective modifier to adjust various thermal properties of SSD. Optimal mass ratio determination for the combination of paint and NAPCM particles resulted in a 9:1 ratio, ensuring the uniform distribution of NAPCM particles within the paint matrix. This achieved a particle size averaging 290.93 μm with no discernible leakage features. The phase change paint exhibited an impressive solid content of 56.62 %, demonstrating exceptional resistance to water, alkali, salt, and abrasion. In thermal plate testing, the phase change paint significantly decelerated the heating rate. Infrared thermal imaging observations depicted circular areas with temperatures notably lower than their surroundings, indicating NAPCM's ability to impede heat absorption during the heating process, thereby reducing the rate of temperature change. The phase change paint also exhibited a slower cooling rate in the cooling test. Simultaneously, phase change bricks demonstrated superior thermal insulation compared to ordinary bricks. Throughout the heat storage phase, the temperature of the phase change greenhouse wall was lower than that of an ordinary greenhouse, while in the heat release phase, it was higher. The phase change greenhouse, relative to its ordinary counterpart, demonstrated superior insulation effects, creating a warm environment conducive to plant growth. This advancement enhances the energy storage performance of agricultural greenhouses, providing a novel solution for improving energy efficiency and environmental sustainability.

Phase change electrolytes for combined electrochemical and thermal energy storage

Inorganic salt-based phase change materials (PCMs) form the basis of next-generation thermal energy storage technologies that store and release energy at temperatures relevant for regulating energy usage in residential environments. Here, we detail a rational approach for designing a multifunctional electrolyte that stores latent heat using polymer-stabilized sodium sulfate and sodium thiosulfate mixture. This formulated PCM also allows rapid sodium ion transport in both the solid and liquid states. This PCM composite electrolyte was prepared by blending the components at elevated temperatures, forming a viscous liquid that can serve as a gel-electrolyte for Na-ion batteries. The addition of sodium borate as a nucleating agent resulted in a PCM composite electrolyte with fusion enthalpy (120 J/g) and a phase transition centered around 25.0 °C with 11 °C supercooling. This PCM electrolyte showed excellent thermal cycling stability (>10 cycles) that also maintains high ionic conductivity (>10 mS cm−1). We show that the electrolyte enables Na ion cycling of the dual anode/cathode material, Na2VTi(PO4)3. These properties make this composite electrolyte a promising material for multifunctional energy storage devices.

In51Bi32.5Sn16.5@SiO2 microcapsules-based composite phase change materials with high thermal conductivity and heat storage density for electronics thermal management

Combining phase change microcapsules and various matrix materials can construct novel composite phase change materials (CPCMs). These composite materials hold immense potential for electronics thermal management, owing to their adjustable heat storage capacity and stable shape. Most previous studies focus on enhancing the thermal conductivity of CPCMs by adding thermally conductive fillers or modifying the microcapsule shells. Nevertheless, achieving both high thermal conductivity and heat storage density simultaneously remains a challenge. In this paper, low melting point alloy (In51Bi32.5Sn16.5) was introduced as core material of the microcapsule to enhance the thermal conductivity, due to its significantly higher thermal conductivity compared to commonly used organic or inorganic phase change materials (PCMs). In51Bi32.5Sn16.5@SiO2 microcapsule was synthesized through the sol-gel polymerization method. Furtherly, a form-stable CPCMs consisting of the microcapsules and silicone rubber (SR) matrix were prepared for electronics thermal management. The In51Bi32.5Sn16.5@SiO2 microcapsules exhibit an impressive thermal conductivity of 13.49 Wm−1 K−1, acting as a dual-functional filler for thermal storage and thermal conduction enhancement. Hence, the CPCMs possess a significantly enhanced thermal conductivity of 0.45 Wm−1 K−1, representing a remarkable improvement of 350 % compared to that of pure SR. In addition, the phase change heat storage density of the CPCMs was as high as 71.73 J/cm3. Notable, the prepared CPCMs demonstrate exceptional heat dissipation performance, resulting in a remarkable 23 °C reduction in chip temperature when applied for thermal management. This study offers a novel perspective on the preparation of microcapsule-based CPCMs for electronics thermal management.

Experimental investigation on the performance of binary carbon-based nano-enhanced inorganic phase change materials for thermal energy storage applications

Phase change materials (PCMs) are considered potential resources for Thermal energy storage (TES) applications. However, the PCMs are limited because of their lower thermal conductivity, resulting in a significant decrease in heat transport and energy storage capability. The foremost objective of the present research is to formulate a novel salt hydrate PCM filled with binary carbon-based nanoparticles (graphene and multi-walled carbon nanotubes) at various weight concentrations and examine the thermophysical properties. A two-step approach is used to formulate binary nanomaterials dispersed salt hydrate PCM. The formulated binary nanocomposite's thermo-physical properties like morphological behaviour, thermal stability, chemical stability, melting enthalpy, optical performance, rate of heat transfer and thermal reliability were characterized. The binary nanoparticle-enhanced nanocomposites can form a decent thermal network, resulting in a remarkable enhancement in thermal conductivity by 160 % (1.2 W/mK) compared to pure salt hydrate. Moreover, a remarkable improvement in optical absorptance and a reduction in optical transmittance by 82.55 % for 0.7 wt% graphene and 0.07 wt% MWCNT enhanced salt hydrate PCM (SAHGrM-0.07) than pure salt hydrate PCM. In addition, the formulated nanocomposites possess excellent heat storage capability, chemical and thermal stability after 300-thermal cycling. The binary carbon-based nanoparticle-enhanced salt hydrate nanocomposites offered acceptable thermal and chemical stability, thermal reliability, and heat transmission characteristics, by this means reflecting its appropriateness for medium-temperature solar TES applications.

Synthesis and characteristic analysis of an inorganic composite phase change materials for medium-temperature thermal storage

Composite phase change materials (CPCM) synthesized using inorganic salt (Na2HPO4·12H2O), lime fruit peel biochar (activated), and boron nitride have been explored as a solution for the medium-temperature thermal energy storage systems in this work. The activated biochar and BN concentrations were varied, and the effects of the activated biochar and BN on the thermal properties, chemical, and thermal stability of the phase change materials (PCM) were studied. XRD and FTIR studies confirmed the chemical stability of the synthesized CPCM samples. Leak test results revealed that the addition of biochar and BN has improved the shape stability. TGA studies revealed the superior thermal stability of the CPCM samples. Composite PCM with 2 g of activated biochar and 0.5 g of BN has exhibited better thermal properties with a latent heat of 121.33 J/g, encapsulation efficiency of 55.9%, and thermal energy storage capacity of 98.2% compared to the pure PCM.

Preparation of inorganic molten salt composite phase change materials and study on their electrothermal conversion properties

The EG conductive pathway enables CPCM to achieve direct electrical heating for energy storage and to regulate the temperature module uniformity through electric field control.

Energizing eutectic salt hydrate phase change material using 2D carbon based graphene nanoparticle

Energy being the strongly depended source for development and industrialization, their storage in any form tends to bridge the gap between demand and supply. Renewable energy technology systems now include energy storage as a crucial component. Thermal energy storage is a technique that stores thermal energy by heating or cooling a storage medium. This allows the energy to be used for heating and cooling purposes later on. The present study develops ternary inorganic salt hydrate eutectic phase change material (EPCM) that is intended for cooling buildings. Melting temperature, melting enthalpy and eutectic composition proportion of inorganic salt hydrate of sodium carbonate decahydrate (SCD), sodium phosphate dibasic dodecahydrate (SPDD), and sodium sulphate decahydrate (SSD) are determined using the eutectic melting point theory. Ternary EPCM is synthesised experimentally in accordance with the percentage of salt hydrates. Graphene nanoplatelets are distributed at different weight concentrations of 0.3%, 0.6%, and 0.9% in order to further improve the thermal performance; at higher concentration above 0.9% the graphene nanoplatelets tends to agglomerate. In order to assess the chemical stability and thermal properties of prepared nanoparticle dispersed PCMs, are experimentally assessed. Findings confirm the ternary EPCM's chemical stability and raise its latent heat with graphene nanoplatelets.

Hybrid Polymer Salogels for Reversible Entrapment of Salt-Hydrate-Based Thermal Energy Storage Materials.

One of the challenges preventing wide use of inorganic salt hydrate phase change materials (PCMs) is their low viscosity above their melting point, leading to leakage, phase segregation, and separation from heat exchanger surfaces in thermal management applications. The development of a broad strategy for using polymers that provide tunable, temperature-reversible shape stabilization of a variety of salt hydrates by using the lowest possible polymer concentrations is hindered by differences in solubility and gelation behavior of polymers with change in the type of ion. This work addressed the challenge of creating robust, temperature-responsive shape-stabilizing polymer gels (i.e., salogels) using a low cost PCM, calcium chloride hexahydrate (CaCl2·6H2O, CCH). Due to the extremely high (9 M) concentration of chloride ions and the tendency to salting-out polymer chains, the previous strategy of using single-polymer salogels was not successful. Thus, this work introduced a strategy of using two polymers, poly(vinyl alcohol) and ultrahigh molecular weight polyacrylamide (PVA and PAAm, respectively), along with borax as a cross-linker to achieve temperature-reversible, shape-stable salogels. This system resulted in robust salogels whose gel-to-sol transition temperature (Tgel) was tunable within an application-relevant range of gelation temperature (30-80 °C). This behavior was enabled by a synergistic combination of dynamic covalent cross-links between PVA units and entanglements of PAAm chains which were combined into a single hybrid network. The hybrid salogels had <5 wt % polymer content, maintaining ∼95% of the heat of fusion of the pure PCM. Importantly, the noncovalent nature of gelation supported thermo-reversibility of gelation, shape stability, and retention of thermal properties over 50 melting/crystallization cycles.

Optical performance and chemical stability evaluation of new era phase change material: Activated by hybrid nanoparticle

Inorganic salt hydrate phase change materials (PCMs) are ahead of organic PCMs in terms of energy storage ability and safety as they are non-flammable. However the major hindrance with inorganic PCM are degree of supercooling and low thermal conductivity though better than organic PCM. The common technique to enhance the thermal conductivity is via dispersion of metal and carbon nanoparticle. Though they enhance the thermal conductivity of the nanocomposite, with continuous operation the nanoparticle agglomerate and settles down owing to their density. Henceforth, in the current research work we conduct an experimental investigation to enhance the optical and thermal performance of commercialised inorganic salt hydrate PCM using metal-carbon hybrid nanoparticle. We disperse graphene silver nanoparticle at different weight ratio adopting a two-step method followed by probe sonication to ensure uniform dispersion. We achieve a highly stable nanocomposite with 584% increase in optical absorbance of electromagnetic waves and 86% decrease in transmittance. Thermal management of electronic gadgets has evolved to be a major consideration of research as overuse of gadgets lead to rapid temperature rise and is in need of passive cooling system. Henceforth the newly developed nanocomposite phase change materials (PCMs) not only acts as thermal batteries but can also be opted as energy materials for thermal regulation and heat mitigation.

Expanded graphite intersperse reliable binary eutectic phase change material for low temperature thermal regulation systems

Inorganic phase change materials (PCMs) frequently stuck by ineffaceable thermal conductivity and degree of supercooling for thermal energy storage (TES) accomplishment. The present research work is dedicated to resolve this problem by developing a unique inorganic salt hydrate based binary eutectic PCM employing sodium sulphate decahydrate (SSD) and sodium phosphate dibasic dodecahydrate (SPDD) in eutectic mixture ratio 62:38 mass percentage. The peculiar eutectic composition of SSD/SPDD developed with melting and bath sonication technique manifests eutectic latent heat of 207.4 J/g and eutectic melting point of 27.8 °C. Furthermore, to elevate thermal performance and to descent degree of supercooling three dimension expanded graphite (EG) is interspersed as nanoparticle. Optical absorbance of composite PCM elevated from 0.16 for SSD/SPDD to 0.92 with SSD/SPDD + EG nanoparticles; inversely transmissibility of the composite reduced by 82.13 %. Heat flow curves ensures the melting temperature (26.9 °C–28.7 °C) of EG dispersed composite to be within the operating condition with latent heat of 220.4 J/g at 2.0 % of EG owing to the intermolecular binding force of attraction increases as nano-sized sheets effectively disperse with the base PCM. Subsequently, thermal conductance of nano composite eutectic PCM upraised from 0.453 to 0.855 W/m⋅K. After 200 thermal cycle's chemical optical and thermal stability of the PCM composite was degraded insubstantially due to the presence of impurities with longer service; this affirmed the stability thermal perks of nanocomposite PCM. Numerical analysis on heat transfer propagation of heat source within SSD/SPDD PCM layer with and without EG nanoparticle provides inference on the importance of thermal conductivity.

Organic and Inorganic Hybrid Composite Phase Change Material for Inhibiting the Thermal Runaway of Lithium-Ion Batteries

To deal with the flammability of PA (paraffin), this paper proposes a CPCM (composite phase change material) with a high heat-absorbing capacity for mitigating the thermal runaway of lithium-ion batteries. Two heating power levels were used to trigger thermal runaway in order to investigate the influence of heating power on thermal runaway characteristics and the mitigation effect of the PCM (phase change material). Thermal runaway processes and temperature changes were recorded. The results showed that heating results in a violent reaction of the battery, generating a high temperature and a bright flame, and the burning of PA increases the duration of a steady flame, indicating an increased threat. SA (sodium acetate trihydrate) effectively inhibited PA combustion, and the combustion time was reduced by 40.5%. PA/SA effectively retarded the rise in temperature of the battery, and the temperature rise rate was reduced by 87.3%. Increased heating power caused faster thermal runaway, and the thermal runaway mitigation effect of the CPCM was dramatically reduced. This study may provide a reference for the safe design and improvement of thermal management systems.

Heat transfer enhanced inorganic phase change material compositing carbon nanotubes for battery thermal management and thermal runaway propagation mitigation

Developing technologies that can be applied simultaneously in battery thermal management (BTM) and thermal runaway (TR) mitigation is significant to improving the safety of lithium-ion battery systems. Inorganic phase change material (PCM) with nonflammability has the potential to achieve this dual function. This study proposed an encapsulated inorganic phase change material (EPCM) with a heat transfer enhancement for battery systems, where Na2HPO4∙12H2O was used as the core PCM encapsulated by silica and the additive of carbon nanotube (CNT) was applied to enhance the thermal conductivity. The microstructure and thermal properties of the EPCM/CNT were analyzed by a series of characterization tests. Two different incorporating methods of CNT were compared and the proper CNT adding amount was also studied. After preparation, the battery thermal management performance and TR propagation mitigation effects of EPCM/CNT were further investigated on the battery modules. The experimental results of thermal management tests showed that EPCM/CNT not only slowed down the temperature rising of the module but also improved the temperature uniformity during normal operation. The peak battery temperature decreased from 76 °C to 61.2 °C at 2 C discharge rate and the temperature difference was controlled below 3 °C. Moreover, the results of TR propagation tests demonstrated that nonflammable EPCM/CNT with good heat absorption could work as a TR barrier, which exhibited effective mitigation on TR and TR propagation. The trigger time of three cells was successfully delayed by 129, 474 and 551 s, respectively and the propagation intervals were greatly extended as well.

Thermal performance and corrosion resistance analysis of inorganic eutectic phase change material with one dimensional carbon nanomaterial

The inherent thermal characteristics, supercooling phenomenon, and corrosion issues associated with salt hydrate phase change materials (PCMs) limit their practical applications. In this research work, we report a newly formulated eutectic salt hydrate PCM using a) sodium sulphate decahydrate (SSD) & b) sodium phosphate dibasic dodecahydrate (SPDD); with a focus on customizing its properties to enhance its suitability for low temperature thermal regulation (achieving a melting point of 27.8 °C and a high heat storage capacity of 215 J/g). Additionally, we have successfully reduced the degree of supercooling and introduced corrosion resistant properties to this PCM. To enhance both the thermal energy transfer rate and optical absorbance of the eutectic PCM, we have incorporated one-dimensional (1D) multiwall carbon nanotube (MWCNT) at various weight fractions, extending up to 0.9 %, utilizing a two-step method. The dispersion and chemical stability of SSD/SPDD + MWCNT nanocomposite are verified through the morphological visual and spectral peaks obtained in Fourier transfer infrared spectroscopy. Additionally, studies evaluating the optical and thermal property reveal a substantial 500 % increase in absorbance, a notable 77.9 % reduction in transmissibility, a thermal conductivity increase from 0.464 W/m⋅K to 0.742 W/m⋅K (reflecting a 59.9 % increment), and the retention of a consistent melting enthalpy of 218.6 J/g. This stability is attributed to the intermolecular interaction with MWCNT. Similary, the degree of supercooling (ΔTs) for the SSD/SPDD EPCM containing MWCNT decreased to 2.2 °C from 16.5 °C, marking an 86 % reduction compared to the pure eutectic salt solution. Furthermore, this composite demonstrated enhanced thermal and chemical stability throughout 200 thermal cycles. Auxiliary ANSYS simulation, with transient boundary condition, are provided to analyze the heat transfer interactions between the thermic fluid and the newly developed PCM when integrated into a thermal regulation system. Subsequently, a corrosion analysis of the developed eutectic PCM and the nanocomposite eutectic PCM exhibits a corrosion rate of 0.018 mpy, well below the permissible level (<5mpy). The insights gained from the development of this nanocomposite PCM offer valuable guidance for the design and creation of tailored eutectic PCM for low-temperature thermal regulation systems, resulting in significant energy savings.

Experimental investigation of the thermal performance of pervious concrete integrated with phase change material for dry cooling applications

While dry cooling systems excel in water conservation compared to wet cooling systems, their performance at high ambient temperatures remains subpar. This study explores a novel latent heat storage module, acting as a water-free pre-cooler to lower temperature of ambient air into the dry cooling system. Four module designs were constructed, based on a pervious concrete and a custom-made inorganic phase change material, calcium chloride hexahydrate, with stable latent heat over 1,000 freeze–thaw thermal cycles. This marks the first-time integration of inorganic phase change material into pervious concrete through micro- and macro-encapsulation. A forced-air heat transfer apparatus was used to evaluate the modules’ thermal performance and heat transfer characteristics, revealing substantial thermal capacity increases of the modules- from 20.0 to 49.2 kWh/m3 charging and 20.3 to 43.6 kWh/m3 in discharging. The module with highest heat storage capacity investigated in this work is the pervious concrete module with micro-encapsulated phase change material and cast around a metal tube array filled with phase change material, which consistently reduces temperature of the airflow at 35 °C and 0.86 m/s by an average of 2 ℃ over three hours, showing potential as a pre-cooler in dry cooling applications.