A feasibility study of a tube bundle exchanger with phase change materials: A case study

The growing availability and decreasing cost of microencapsulated phase change materials (PCMs) present an opportunity to develop innovative insulation materials for latent heat energy storage. By integrating PCMs with traditional insulation materials, it is possible to enhance the thermal capacity of a building by up to 2.5-times, virtually without increasing the building’s mass. To improve buildings’ indoor structural performance, as well as improving their energy performance, microencapsulated PCMs are integrated into wallboards. The integration of microencapsulated PCMs into the wallboard solves the PCM leakage problem and assures a good bond with the building materials to achieve better structural performance. The novelty of this research is the application of encapsulated phase change material dispersion and technology for its incorporation into the structure of hemp shives and longitudinally milled wood chip-based insulation boards, using cold pressing technology to reduce the energy consumption of board production. As a result, low-density insulation boards for indoor application were produced by varying their structure and the amount of phase change materials in the range of 5% to 15% by board mass. The obtained board prototypes can be used as microclimate and thermoregulation elements of interiors, as well as functional aesthetic elements of interior design.

Section: Latent Heatmentioning

confidence: 99%

Thermal Performance of Lignocellulose’s By-Product Wallboards with Bio-Based Microencapsulated Phase Change Materials

Zotova,

Gendelis,

Kirilovs

et al. 2024

“…Numerous scholars have investigated different geometries in recent years to model the effects of phase change materials (PCMs) in various engineering applications using computational fluid dynamics (CFD) [15][16][17][18][19][20]. CFD approaches provide a potent tool for deciphering intricate heat and mass transport processes in PCM systems, and they are often applied using commercial software platforms like ANSYS CFD and COMSOL Multiphysics [21].…”

Section: Introductionmentioning

confidence: 99%

Enhancing Heat Storage Cooling Systems via the Implementation of Honeycomb-Inspired Design: Investigating Efficiency and Performance

Rahmani,

Dibaj,

Akrami

2024

This study presents a novel approach inspired by the hexagonal honeycomb structure found in nature, leveraging image processing algorithms to precisely define complex geometries in thermal systems. Hexagonal phase change material containers and thermally conductive fins were meticulously delineated, mirroring the intricate real-world designs of honeycombs. This innovative methodology not only streamlines setup processes but also enhances our understanding of melting dynamics within enclosures, highlighting the potential benefits of biomimetic design principles in engineering applications. Two distinct honeycomb structures were employed to investigate their impact on the melting process within cavities subject to heating from the left wall, with the remaining walls treated as adiabatic surfaces. The incorporation of a thermally conductive fin system within the enclosure significantly reduced the time required for a complete phase change, emphasizing the profound influence of fin systems on thermal design and performance. This enhancement in heat transfer dynamics makes fin systems advantageous for applications prioritizing precise temperature control and expedited phase change processes. Furthermore, the critical role of the fin system design was emphasized, influencing both the onset and location of the final point of melting. This underscores the importance of tailoring fin systems to specific applications to optimize their performance. Our study highlights the significant impact of the Rayleigh (Ra) number on the melting time in a cavity without fins, revealing a decrease from 6 to 0.4 as the Ra increased from 102 to 105; the introduction of a fin system uniformly reduced the melting time to Ste.Fo = 0.5, indicating fins’ universal effectiveness in optimizing thermal dynamics and expediting the melting process. Moreover, the cavity angle was found to significantly affect the fluid fraction diagram in unfanned cavities but had minimal impact when fins were present, highlighting the stabilizing role of fins in mitigating gravitational effects during melting processes. These insights expand our understanding of cavity geometry and fin interactions in heat transfer, offering potential for enhanced thermal system designs in various engineering applications. Decreasing thermal conductivity (λ) by increasing the fin thickness can halve the melting time, but the accompanying disadvantages include a heavier system and reduced energy storage due to less phase change material, necessitating a careful balance in decision-making.

“…A peripheral distribution layout mode of the heat exchanger tube improved the heat charging efficiency by 12.6% compared to the traditional uniform layout. Pignata et al [43] proposed a control strategy to evaluate the load modulation of the LHS system with variable fin heights and HTF tube arrangements, which depend on the pitch of the tube bundle.…”

Section: Introductionmentioning

confidence: 99%

Melting and Solidification Characteristics of PCM in Oscillated Bundled-Tube Thermal Energy Storage System

Liu,

Xiao,

Chen

et al. 2024

Phase change material (PCM) based thermal energy storage (TES) is an important solution to the waste of heat and intermittency of new energy sources. However, the thermal conductivity of most PCMs is low, which severely affects the thermal energy storage performance. Oscillation of the tube bundles in a TES unit can intensify the convection of liquid PCM and, therefore, enhance heat transfer. However, the energy storage performance of bundled-tube TES systems in response to oscillation at different amplitudes and frequencies has not been well understood yet, and the optimum time to apply the oscillation during phase transition remains unexplored. To address this issue, this present study was carried out. First, the melting behaviour of PCM with oscillation starting at different times was investigated. Then, the influences of oscillation frequency and amplitude on the melting performance were explored. Finally, the solidification behaviour of PCM with oscillation starting at different times was examined. Results show that the oscillation can accelerate the phase transition process by enhancing convective heat transfer. Compared to the case without oscillation, the complete melting and solidification times are reduced by 8.2 and 6.7% for the case with oscillation starting at 200 s, respectively. The effect of oscillation frequency on the melting enhancement is negligible, while the oscillation amplitude has an important effect on the melting enhancement.