Phase-change materials (PCMs) can be used to develop thermal energy storage systems as they absorb large amount of latent heat nearly at a constant temperature when changing phase from a solid to a liquid. To prevent leakage when in a liquid state, PCM is shape stabilized in a polymer matrix of high-density polyethylene (HDPE). The present research explores the injection-molded mechanical and thermal properties of different PCM/HDPE composite ratios. The tensile strength and modulus of elasticity at room temperature and with the PCM fully melted within the composite are measured. Additionally, the hardness, latent heat of fusion, phase-change temperature, and thermal conductivity are investigated. An analysis of microstructures of the composite is used to support the findings. The PCM within the PCM/HDPE composite gives it the benefit of thermal storage but causes a decrease in mechanical properties.

Accurate modeling of melting and solidification processes is important to many engineering applications. The research presented in this article is part of an ongoing effort to document the melting behavior of lauric acid in a 50 mm by 120 mm rectangular container with an isothermal side—an experiment commonly used to validate numerical models. This article presents new experimental data of melting occurring at 135 deg and 180 deg inclines for isothermal wall temperatures of 60∘C and 70∘C. The data were processed to show the melt interface development and the melt fraction as a function of time. Furthermore, numerical simulations using the enthalpy-porosity method of the 135 deg incline were also conducted. In the numerical simulations, the mushy zone constant was parametrically varied. Different density approaches commonly found in the literature (e.g., density as a function of temperature or Boussinesq approximation) were utilized and examined. It was found that the choice of density method had a significant effect on the results. Implications of potential modeling choices unique to the enthalpy-porosity method are discussed related to the validation of models.

Phase change materials (PCMs) can enhance the performance of energy systems by time shifting or reducing peak thermal loads. The effectiveness of a PCM is defined by its energy and power density—the total available storage capacity (kWh m −3 ) and how fast it can be accessed (kW m −3 ). These are influenced by both material properties as well as geometry of the energy systems; however, prior efforts have primarily focused on improving material properties, namely, maximizing latent heat of fusion and increasing thermal conductivity. The latter is often at the expense of the former. Advanced manufacturing techniques hold tremendous potential to enable co‐optimization of material properties and device geometry, while potentially reducing material waste and manufacturing time. There is an emerging body of research focused on additive manufacturing of PCM composites and devices for thermal energy storage (TES) and thermal management. In this article, the fundamentals and applications of PCMs are reviewed and recent additive manufacturing advances in latent heat TES for both the PCM composite and associated heat exchanger are discussed. A forward‐looking perspective on the future and potential of PCM additive manufacturing for TES and thermal management is provided.

Thermal energy storage, in the form of chilled water or ice-based phase-change systems, has been used in commercial buildings for over 30 years. These systems take advantage of off-peak electricity rates to cool water or ice at night, which provides cooling power during the day when the electricity prices are at their peak. Although these systems work well for commercial buildings, they are not feasible for residential applications, mainly due to the fact that a residential system supplies air at 55 degrees F (12.8 degrees C)-a temperature that is too high to take advantage of the latent heat of water which freezes and melts at 32 degrees F (0 degrees C); therefore, alternative phase-change materials are needed. The direct implementation of phase-change materials becomes problematic due to the very nature of these materials cycling between solid and liquid states during normal operating temperatures. Therefore, encapsulation of the phase-change material, typically in a polymer, is necessary to maintain structural shape stability during the melting and solidification of the material. Polymers used for encapsulation help maintain the shape of the material as well as retain the phase-change material within the polymer during the phase change. Coincidentally, polymer heat exchangers and additive manufacturing are also of rising interest. Polymer heat exchangers boast a number of benefits including weight reduction, natural corrosion resistance, and anti-fouling when exposed to typical process fluids. The goal of the study is to explore the implementation of a novel, functional encapsulated phase-change material as the primary structure in a polymer heat exchanger, which can be additively manufactured, for residential thermal energy storage. The work presented includes an exploratory thermodynamic analysis on the effectiveness of the novel polymer phase-change material thermal energy storage heat exchanger on reducing the load on a residential HVAC unit.

Phase change materials (PCMs) are a key component to thermal energy storage solutions, which have the potential to hold a critical role in future energy storage. PCMs take advantage of large latent heat capacities as a method for storing thermal energy for later use. The research presented in this paper is part of an ongoing effort to document the melt behavior of lauric acid in an insulated rectangular container. This paper presents new experimental data of melting occurring at 180° and 135° incline. The data is processed to show the melt interface development and the melt fraction over the duration of the experiment. The results of the 135° incline experiment are compared to a numerical model and differences in results are examined.

Moisture adsoprtion can degrade the structural integrity of thermal energy storage devices and can negatively impact the capacity and charging/discharging behaviour. Steady-state and transient experiments are conducted at various operating temperatures to evaluate the moisture affinity of organic phase-change material (PCM) shape stabilized with high-density polyethylene (HDPE).

Additively manufactured polymer heat exchangers are of recent interest in the thermal sciences due to their lightweight and intricate heat-transfer-enhancing geometrical features. The goal of the present research is to directly encapsulate phase-change material (PCM) into polymer filament for the purpose of 3D printing polymer heat exchangers capable of latent heat thermal energy storage and management. PCMs have the ability to absorb large amounts of latent heat while undergoing a solid-to-liquid phase change at a nearly constant temperature. Encapsulation or containment of PCMs is necessary to prevent leaking since the material continuously cycles between a liquid and a solid state. An organic-based PCM and high-density polyethylene (HDPE) were combined and extruded into a functional composite filament. For the first time, with the aid of a heated enclosure and HDPE build plates, it was demonstrated that these functional composite materials can be printed using fused filament fabrication (FFF). Printing HDPE is known to be difficult; however, based on what was observed in the current study, the PCM and HDPE composite was easier to print than pure HDPE. Thermal properties, such as latent heat of fusion, phase-change temperature, and thermal conductivity, of the composite filament and 3D printed samples were investigated and compared with compression-molded bulk material. The microstructures of the composite filament and 3D printed samples were visualized, and the basic structures of the HDPE and PCM within both the filament and 3D printed parts were clearly delineated.

A new method for measuring the cure shrinkage and residual strain for neat resin and composite is proposed using the digital image correlation (DIC) in-situ during the curing cycle. The resin is cured inside the specially designed autoclave with borosilicate viewports while the images are captured at regular intervals of time with the help of DIC to measure displacement and strains during the curing process. An average compressive strain of 0.145 is observed in Z-direction during the curing process. Differential Scanning Calorimeter (DSC) is used to measure the degree of cure for the resin, and to correlate resin shrinkage to the cure state. We also observed the effect of fibers on the shrinkage of the resin using carbon fiber, glass fiber and crepe bandage as fillers. We observed that as the stiffness of the fillers increased the strain in the matrix decreased.

Phase-change materials (PCMs) are a useful alternative to more traditional methods of thermal management of Li-ion batteries in electric or hybrid-electric vehicles. PCMs are materials which absorb large amounts of latent heat and undergo solid-to-liquid phase change at near-constant temperature. The goal of the research is to experimentally investigate the thermal properties of a novel shape-stabilized PCM/HDPE composite extruded filament. The extruded filament can then be used in a 3D printer for custom PCM/HDPE shapes. The PCM used in the study is PureTemp PCM 42, which is an organic-based material that melts around 42° C. Four PCM/HDPE mixtures were investigated (all percentages by mass): 20/80, 30/70, 40/60, and 50/50. Preliminary findings include differential scanning calorimeter (DSC) measurements of melting temperature and latent heat as well as scanning electron microscope (SEM) pictures of filament composition.

Phase-change materials (PCMs) are a useful alternative to more traditional methods of thermal management of various applications. PCMs are materials that absorb large amounts of latent heat and undergo solid-to-liquid phase change at near-constant temperature. The goal of the research is to experimentally investigate the thermal properties of a novel shape-stabilized PCM/HDPE composite extruded filament. The extruded filament can then be used in a 3D printer for custom PCM/HDPE shapes. The PCM used in the study is PureTemp PCM 42, which is an organic-based material that melts around 42 °C. Four PCM/HDPE mixtures were investigated (all percentages by mass): 20/80, 30/70, 40/60, and 50/50. Preliminary findings include differential scanning calorimeter (DSC) measurements of melting temperature and latent heat as well as scanning electron microscope (SEM) pictures of filament composition.