Heat Dissipation Process Research Articles

Self-assembled nest-like BN skeletons enable polymer composites with high thermal management capacity

The lagging development of thermally conductive but electrically insulating materials has become a bottleneck problem for the next generation of advanced high-power density electronic devices. Although second-phase reinforced composites are promising materials for addressing thermal management issues, the inherent mechanism of severe phonon scattering at the interphase results in actual thermal conductivity enhancement efficiency far below expectations. Here, we report a high-performance polymer composite with a nest-like interconnected boron nitride skeleton. This nest-like interconnected BN skeleton without mechanical contact can provide high-efficiency and long-distance phonon transport channel, realizing high thermal conductivity of 1.827 W m-1 K-1 in polymer composite with ultra-low content (4.7 vol%). Meanwhile, the EP/ nest-like BS composites possess ideal electrical properties and dimensional stability. In the actual heat dissipation process of LED chips, the optimal composite material as the thermal interface material can display a temperature drop of more than 34.8% compared to neat epoxy, which proves the broad application prospects of this strategy in advanced electronic devices.

A new validated TRNSYS module for phase change material-filled multi-glazed windows

Incorporating phase change materials (PCM) into multi-glazed windows (MW) has been recognized as an effective way to regulate the indoor thermal environment and reduce the energy consumption of buildings. However, the design and calculation of PCM-filled multi-glazed windows (MW + PCM) remain challenging due to the lack of general transient simulation methods and integrated tools. To address this issue, the present study developed a dynamic coupled thermal and optical model for MW + PCM based on the enthalpy-temperature and interface energy balance methods. Then, the model was implemented in C++ and integrated into the TRNSYS software as a new module (Type 2602). In parallel, a test platform comprising two test chambers was established to evaluate the effect of PCM on the thermal and optical properties of the window and to validate the newly proposed module. It was found that compared to the traditional triple-glazed window (TW), the PCM-filled triple-glazed window (TW + PCM) effectively reduces the irradiance through the window by 34.17 % and the maximum temperature of the inner surface by approximately 5.56 °C. While the increase in external surface radiation flux density from 600 to 1200 W/m2 has a diminishing effect on the heat flux variation rate during the heat dissipation process for TW + PCM, it effectively shortens the latent heat absorption time by 0.50 h and increases the temperature difference between the inner and outer surfaces by 3.02 °C. The new module demonstrates satisfactory accuracy through experimental validation and simulation comparisons, with the maximum heat flux coefficient of variance of the root mean square error (CV(RMSE)) less than 6.35 % and 11.25 % under TW and TW + PCM configurations.

Solar Chimney Operation Variant

This paper presents a solar chimney that acts as a heat accumulator. It is based on its alternating charging (melting of the phase change material—PCM) and discharging (solidification), which helps to save energy and ensures stable operation of the solar chimney. In this paper, special attention has been paid to the heat dissipation process (solidification of the PCM). The theoretical model of solidification has been solved in an original way. This paper presents a new simple theoretical model for the solidification of the PCM on a flat plate and presents the results of numerical tests. The theoretical model presents a method for determining the heat transfer coefficient at the solidification front of the PCM. In addition, the heat transfer coefficient from the flowing air to the outer surface of the solidifying front plate was determined experimentally in an original way. The heat transfer coefficient values resulting from the experiments may be employed in order to calculate the heat transfer coefficient for air flowing through the slot of the collector in the solar chimney. The calculated value of the heat transfer coefficient was 18.55 W/m²K.

Simulation study on heat dissipation of a prismatic power battery considers anisotropic thermal conductivity in air cooling system

Heat accumulation could be occurred due to low thermal conductivity in one direction inside the power battery, which may lead to the decrease charging performance and potential thermal runaway. In this study, the impact of the anisotropic thermal conductivity (kx, ky, kz) on the temperature of the battery was analyzed. The anisotropic thermal conductivity was divided into the flow direction, thickness direction and spanwise conductivity. Then, the variation regularityof surface temperature distribution and heat flux are revealed by changing the anisotropic thermal conductivity. The results show that the increase of kx improves the heat dissipation efficiency of the upstream battery by 24 %. The higher thermal conductivity allows additional heat to be transferred from upstream to downstream along the direction of flow. The increase of kx makes the temperature difference only about 3 K, which improves the temperature uniformity of the battery. In addition, the impact of kx on the battery heat dissipation process is more dominant than ky and kz. However, there is an upper limit to the impact of ky on the battery temperature. When the ky exceeds 10 times the value of kx, the maximum temperature and temperature uniformity of the battery are almost unaffected by the change of ky. Meanwhile, the increase of kz has the minor effect on the temperature distribution of the battery surface. The anisotropic thermal conductivity is adjusted to reduce heat accumulation in the battery and improve the temperature uniformity. This work is beneficial to the engineering application of battery thermal management technology.

Numerical Investigation of the Thermal Performance of Air-Cooling System for a Lithium-Ion Battery Module Combined with Epoxy Resin Boards

Lithium-ion batteries (LIBs) have the lead as the most used power source for electric vehicles and grid storage systems, and a battery thermal management system (BTMS) can ensure the efficient and safe operation of lithium-ion batteries. Epoxy resin board (ERB) offers a wide range of applications in LIBs due to its significant advantages such as high dielectric strength, electrical insulation, good mechanical strength, and stiffness. This study proposes an air-cooled battery module comprised of sixteen prismatic batteries incorporating an ERB layer between the batteries. To compare the performance of the ERB-based air-cooling system, two other air-cooling structures are also assessed in this study. Three-dimensional numerical models for the three cases are established in this paper, and the heat dissipation processes of the battery module under varying discharge rates (1C, 2C, and 5C) are simulated and analyzed to comprehensively evaluate the performance of the different cooling systems. Comparative simulations reveal that incorporating ERB into the battery assembly significantly reduces battery surface temperatures and promotes temperature uniformity across individual batteries and the entire pack at various discharge rates. Notably, under 5C discharge conditions, the ERB-based thermal management system achieves a maximum battery surface temperature increase of 16 °C and a maximum temperature difference of 8 °C between batteries. Additionally, this paper also analyzes the impact of battery arrangement on air-cooling system performance. Therefore, further optimization of the structural design or the integration of supplementary cooling media might be necessary for such demanding conditions.

Finite difference analysis for entropy optimized nanomaterial Darcy-Forchheimer flow with homogeneous and heterogeneous reactions

Hybrid nanoliquids are not underestimated for their involvement in microelectronics, transportation, coolant processes, ships, biological processes and power generation. Hence motivation for current work is to examine homogeneous-heterogeneous reactions in entropy optimized flow by curved sheet stretched with nonlinear velocity. Trihybrid nanoliquid is synthesized through 2 % of ferrous oxides(Fe3O4), 2 % of silver(Ag) and 2 % of copper(Cu). Kerosene oil is employed as the base fluid. These specific kinds of nanoparticles are taken into consideration because of their numerous applications in heat dissipation, air filters, dynamic sealing, biosensors and catalysts process. Kerosene oil may have applications in many different domains such as energy storage, cleaning agent, portable heaters, fuel additive and industrial lubricants. Darcy-Forchheimer model is employed. Analysis in presence of radiation, dissipation, Ohmic heating, entropy generation and heat generation/absorption are organized. Unlike the previous considerations, the thermal expression here consists of impacts through Darcy-Forchheimer relation. Adequate transformations are implemented. Computations have been arranged by applying finite difference technique (FDM) using MATLAB. Quantities for physical interest are addressed. The presented analysis may have relevance for solar systems, chemical reacting processes, cooling towers and polymer data processes. The conclusions are also organized for important key findings. It is noticed that trihybrid nanomaterial has more entropy rate when compared with hybrid and classical nanoliquids when volume fraction is chosen as 2 % for trihybrid fluid. It is proposed that the ability to transfer heat is enhanced when nanoparticles are added to conventional fluids. Decay in concentration is noticed for both homogeneous and heterogeneous parameters. Reduction for Bejan number is noticed through homogeneous diffusion factor. Comparison with previous study is also presented and found great consensus between them.

Heat transfer processes in 'Shine Muscat' grapevine leaves in solar greenhouses under different irrigation treatments

The use of solar greenhouses in China is increasing because they permit environmental conditions to be controlled. Studies of the heat transfer processes in the leaves of plants cultivated within solar greenhouses are needed. Here, we studied heat transfer processes in 'Shine Muscat' grapevine leaves under moderate deficit irrigation (MDI), severe deficit irrigation (SDI), and full irrigation (FI) treatments under varying weather conditions. The stomatal conductance, leaf temperature, and transpiration rate of both shade and sun grapevine leaves were measured, and the effects of ambient temperature and relative humidity on these variables were determined. A thermal physics model of the leaves was established to explore the heat dissipation process. On sunny days, the transpiration heat transfer of sun leaves in the MDI, SDI, and FI treatments was 2.62 MJ m−2·day−1, 2.44 MJ m−2·day−1, and 3.86 MJ m−2·day−1and 0.818 MJ m−2·day−1, 0.782 MJ m−2·day−1, and 1.185 MJ m−2·day−1 on rainy days, respectively. There was a significant difference in transpiration heat transfer under fully irrigated and deficit irrigation conditions under different weather conditions. Furthermore, transpiration heat transfer accounted for 41.49 % and 25.03 % of the total heat transfer of sun leaves in the FI treatment and 33.94 % and 29.43 % of the total heat transfer of shade leaves on rainy days, respectively, indicating that relative humidity plays a key role in determining transpiration heat transfer and leaf temperature and that its effect was greater on sun leaves than on shade leaves.

Investigation of Gallium Nitride Based HEMTs with Thermal Dissipation

AbstractThe heat dissipation optimization process is a crucial element in high power high electron mobility transistor (HEMT) components fabricated using the Gallium Nitride grown on silicon (Si) substrate. In this study, the Si substrate is thinned from 1000 to 600 µm, and then the partial device area (under the HEMT two dimension (2D electron concentration gas channel) is etched to 20 µm by a deep etching system. After, three different materials are utilized to fill the gap. There are electroplate copper sheets, silver paste, and copper paste. Afterward, the electrical properties and thermal management of the device are compared before and after the implementation of the heat dissipation process. The horizontal breakdown voltage of the gate and drain at 10 µm distance of copper paste is increased to 430 V compared to 405 V before the heat dissipation process. More importantly, the surface temperature of the device dropped approximately from 58 to 38 °C and the percentage drop in output current is reduced from 10.18% to 5.23%.

Spherical Fe3O4 morphology modulation for enhancing infrared emissivity and radiant heat dissipation

Radiant heat dissipation has emerged as a critical technique for effective thermal management, offering energy efficiency, cost-effectiveness, and adaptability to various shapes while promoting environmental sustainability. However, the intricate relationship between material structures and emissivity remains inadequately understood. This study primarily utilizes a straightforward and economical solvothermal method to regulate the synthesis of Fe3O4 ferrite, exploring its structural relationship with infrared radiation performance. By adjusting the solvent ratio of ethylene glycol and diethylene glycol in the solvothermal system, we successfully synthesized uniformly dispersed Fe3O4 nanospheres ranging from 10 to 800 nm. Notably, our research revealed a positive correlation between infrared emissivity and the particle size. Submicron hollow spheres with a size of 800 nm exhibit an exceptionally high emissivity of 0.992 within the 8–13 μm wavelength range. Morphological and size variations induced alterations in lattice strain, oxygen vacancies, and phonon lifetimes, which consequently influencing the lattice vibration absorption and infrared emissivity. Moreover, the device surface with a composite coating formed by combining 15 wt% Fe3O4 particles with organic matter, achieves a temperature difference of 17.6 °C under a 4 W input power condition compared to blank device. This finding contributes to further revealing the process of material radiative heat dissipation, driving the application of high-emissivity materials for heat dissipation in high-power electronic devices.

Effect and mechanism of solution flow rate during interfacial polymerization on morphology and performance of hollow fiber membranes

Interfacial polymerization (IP) using m-phenylenediamine and trimesoyl chloride (TMC) is an essential method for producing thin-film composite (TFC) membranes. Nevertheless, IP is highly sensitive to changes in process parameters, especially the TMC solutions flow rate during inside-out TFC hollow fibers (HF) production. Research on the impact of flow conditions (i.e., laminar vs. turbulent flows) of these organic solutions on the final membrane characteristics and corresponding mechanism is still lacking. This research tested different TMC flow rates (0.1–2 mL/min) to produce inside-out TFC HF. With a TMC flow rate increase, (i) the leaf-like structures of the polyamide (PA) layer decreased in size, (ii) the thickness of the PA layer slightly increased, and (iii) the pure water permeability decreased. However, the elemental composition, chemical bonds, and NaCl rejection remained stable. Different fluid regimes are considered to affect the performance of HF membranes by affecting the heat dissipation process during IP reaction. A TMC flow rate in the laminar flow state (i.e., low flow rates) is recommended for synthesizing HFs. The current research provides new insights into the IP reaction mechanism of HF membrane, thus offering valuable guidance to optimize and produce membrane products with better performance.

Skin transcriptome analysis in Brangus cattle under heat stress

Heat stress is a major factor that negatively affects animal welfare and production systems. Livestock should adapt to tropical and subtropical areas and to meet this, composite breeds have been developed. This work aimed to evaluate gene expression profiles in the skin of Brangus cattle under heat stress using a case-control design, and to correlate this with skin histological characteristics. Two groups of bulls were set using rectal temperature as a criterion to define stress conditions: stressed (N = 5) and non-stressed (N = 5) groups. Skin transcriptomics was performed and correlations between breed composition, phenotypic and skin histological traits were evaluated. Results showed 4309 differentially expressed genes (P < 0.01), 2113 downregulated and 2196 upregulated. Enrichment and ontology analyses revealed 132 GO terms and 67 pathways (P < 0.01), including thermogenesis, glycolysis, gluconeogenesis, mitochondrial activity, antioxidant and immune response, and apoptosis. The identity of the terms and pathways indicated the diversity of mechanisms directed to relieve the animals' suffering, acting from simple passive mechanisms (conduction, convection and radiation) to more complex active ones (behavioural changes, evaporation, vasodilation and wheezing). Furthermore, significant differences between phenotypic and skin histological traits and correlations between pairs of traits suggested a direction towards heat dissipation processes. In this sense, number of vessels was positively correlated with number of sweat glands (P < 0.001) and both were positively correlated with zebuine genetic content (P < 0.05 and P < 0.01, respectively), gland size was positively correlated with epidermal thickness and negatively with hair length (P < 0.05), and epidermal thickness was negatively correlated with gland-epidermis distance (P < 0.0005). These results support the notion that response to heat stress is physiologically complex, producing significant changes in the expression of genes involved in several biological pathways, while the animal's ability to face it depends greatly on their skin features.

Covalent-assisted construction of “scale-like” boron nitride/polyimide thermal interface materials with high thermal conductivity

Polyimide (PI) is a special engineering plastic with high strength, high modulus, high temperature resistance and corrosion resistance, but its poor thermal conductivity limits its application in high-power miniaturized electric and electronic equipment. In this study, surface-activated and modified boron nitride (m-BN) is polymerized in situ and coated to form a “scale-like” composite thermal interface material (m-BN/PI) with PI. Moreover, the m-BN@PI composite films obtained by a simple co-blending process of m-BN and PI are used as a comparison. The in-plane thermal conductivity of m-BN/PI composite reached 4.43 W m−1 K−1, when the filler content is 30 wt %, which is about 12 times higher than that of the pure PI film (0.37 W m−1 K−1). At this load, the in-plane thermal conductivity of m-BN@PI is only 3.94 W m−1 K−1. In addition, the covalent bonding between m-BN and PI molecular chains in m-BN/PI effectively reduces the interfacial thermal resistance by fitting the EMT and Foygel models. Finally, using the m-BN/PI composite film as a thermal interface material placed at the CPU location, its role in the heat dissipation process of electronic devices is demonstrated.

Introduction of Gate-All-Around FET (GAAFET)

The Gate-All-Around Field-Effect Transistor (GAAFET) represents a significant advancement in integrated circuits technology, offering enhanced functionality compared to its predecessor, the Fin Field-Effect Transistor (FinFET). This paper provides a comprehensive overview of GAAEFT, its historical developments, current state, and recent developments. The introduction section mentioned the importance of changing from FinFET to GAAFET structures. The historical developments section traces the evolution of GAAFET technology, highlighting key milestones and breakthroughs. The current state section addresses the limitations of silicon-based microelectronics technology, including challenges related to heat dissipation, reliability, and fabrication processes. The subsequent section explores the development of GAAFET technology, with a focus on the latest techniques, such as gate stacking, oxidation, and asymmetric non-local lateral Gaussian doping, which aim to improve electrostatic performance, mitigate short-channel effects, and enhance threshold voltage control. This work reveals the potential for the current and future development of GAAFET technology and its potential for wider application in integrated circuits design and fabrication.

Study on the heat transfer enhancement characteristics by flow-induced vibration of inserting polyethylene membrane inside the channel

With the development of science and technology, the heat dissipation problem of high-density electronic products has gradually emerged in engineering practice. In this paper, the enhanced heat dissipation process of fluid induced oscillation through flexible membrane is proposed, which belongs to the multi-field synergistic bidirectional coupling effect of thermal-fluid-solid coupling. Through the comparative numerical analysis of the flow induced oscillation of the flexible membrane and the fixed rigid fin in the flow channel, the mechanism of the fluid induced oscillation of the flexible polyethylene membrane is revealed. Based on the two-way fluid-solid coupling method, a numerical model for the heat transfer process of polyethylene membrane with thickness of 0.02 mm in the fluid channel was established. The temperature field, Nu (Nusselt number) and PEC (Performance comparison index) number of the rigid fin and polyethylene membrane installed in the channel under different Reynolds numbers were calculated respectively. The ratio of the length of the membrane to the height of the channel was adjusted for multiple groups of calculations to verify the positive effect of the polyethylene membrane installed in the channel on the heat exchange effect. The results show that in the fully developed area of heat transfer, the channel with polyethylene membrane is better than that with rigid fins in terms of turbulence and vortex shedding; at Re = 4400, the comprehensive enhanced heat transfer factor of heat exchange is the largest, up to 1.27; as the ratio of the height of the new flexible membrane to the height of the channel is 1, the heat transfer enhancement effect is best. In the next step, the correlation theory between oscillation characterization parameters and heat transfer enhancement effect under pulsating fluid excitation will be investigated.

Improving IEC thermal model for oil natural air natural transformers using optimised parameters based on dynamic simulation

AbstractAccurate assessment of hot‐spot temperature is essential for the safe operation of power transformers. Existing dynamic thermal models cannot estimate hot‐spot temperature accurately since some input parameters are roughly determined by transformer capacity and cooling mode while ignoring the effect of winding structure, tank dimensions, and material physical properties. To improve the accuracy of temperature assessment, empirical parameters of the IEC thermal model including thermal constants, winding and oil exponents are optimised with the help of numerical simulation in this article. Based on energy conservation and heat transfer theory, a computational fluid dynamic (CFD) model of a transformer in oil natural air natural (ONAN) cooling mode is established. This CFD model simulates the entity's structure, sizes, and multi‐stage heat dissipation processes realistically, so it can more precisely calculate the dynamic hot‐spot temperature. According to the simulated temperature curves at different operating conditions, the thermal constants and oil exponent are estimated using non‐linear regression, and the winding exponent is optimised using linear regression. A case study is conducted on an ONAN transformer. It shows the improved IEC model with optimised parameters can more accurately evaluate hot‐spot temperature, and the absolute error is decreased by 2.4 K (38.7%) compared with traditional thermal models.

Heat Transfer Performance of Water-cooled Heat Sink for I&C System Controller Chip in Nuclear Power Plant

To improve the heat dissipation reliability of the nuclear power control system chip, the structure of its water-cooled heat sink is compared and analyzed. Three schemes of water-cooled heat sinks are proposed, and CFD analyzes the heat dissipation performance of the heat sink. The simulation data of the heat transfer coefficient, pressure loss, and heat sink comprehensive coefficient are compared. The results show that the average temperature of the bottom surface of the three heat sinks tends to be flat with the flow velocity increase, and the heat dissipation coefficient Nu is also the same. The S-type heat sink has a higher heat transfer coefficient and lower average bottom temperature. The pressure loss of the S-type heat sink is much higher than that of the other two schemes with the increased flow rate, and the system resistance is large. By calculating the comprehensive coefficient of the heat dissipation process of the three heat sinks and considering the heat dissipation capacity and other factors, it is considered that the circular fin heat sink can be the optimal solution.

Highly thermal conductive and flame retardant poly(vinyl alcohol) film with synergistic alignments of boron nitride nanosheets/Ti3C2Tx MXene for thermal interface materials

With the development of microelectronics and flexible wearable electronic devices, poly(vinyl alcohol) (PVA) based thermal interface materials (TIMs) have received much attention. However, poor heat dissipation and high flammability have emerged as the key issues that restrict their application. In this work, the directional alignment of phytic acid (PA) modified boron nitride nanosheets (BNNS) and Ti3C2Tx MXene in PVA matrix was achieved by ice-templated assembly, which simultaneously enhanced the flame retardancy and thermal conductivity of PVA composite films (PVA/BTx). Owing to the synergistic effect between oriented BNNS and Ti3C2Tx MXene on forming the thermally conductive network within PVA matrix, the in-plane thermal conductivity of PVA/BTx-30 composite film was increased to 8.54 W m−1 K−1, much higher than that of PVA film (0.30 W m−1 K−1). Meanwhile, the heat dissipation process of PVA films applied as TIMs was simulated, which showed that PVA/BTx-30 films exhibited excellent thermal conduction and significantly decreased the operation temperature of electronic devices. Additionally, the peak heat release rate (PHRR) and total heat release (THR) of PVA/BTx-30 films were reduced by 60.3% and 62.0%, respectively, showing good flame retardancy. Importantly, the flexible Ti3C2Tx nanosheets further enhanced the mechanical properties of PVA/BTx composite films. Therefore, this work provides an effective method for the preparation of high thermal conductivity and flame retardant composite materials, which has important potential applications in the microelectronics industry.

Structure and the Thermal Management of a 3-D Silicon Carbide MOSFET Module

Silicon carbide (SiC) device has higher switching frequency, higher breakdown voltage, and lower on-state voltage drop, which makes it subversive potential in the high power density applications. However, the traditional packaging structure cannot cope with the high power density of SiC devices, so the existing commercial SiC power module can only be used in derating applications. This paper proposed a 3-D packaging design method for high power density MOSFET power module, in which the cooling system is integrated inside the module to reduce the thermal resistance and the temperature difference of the SiC MOSFET chips. At the same time, the heat dissipation process of the new structure is modeled and analyzed, and the accuracy of the model is proved by experiment and simulation.

Insight into heat dissipation in fractured rock influenced by groundwater influx and heat source configurations using numerical analysis

The characterization and evaluation of heat dissipation effects in fractured rock is becoming a priority topic with respect to the potential application of low-temperature thermal remediation in these settings. A three-dimensional numerical model was utilized to investigate heat dissipation-related thermo-hydrological processes in an upper fractured rock layer and a lower impermeable bedrock layer. To identify the factors controlling spatial temperature variances in the fractured rock layer accounting for a scaled heat source and variable groundwater flow, global sensitivity analyses were conducted on the variables using three categories: heat source, groundwater flow, and rock properties. A discrete Latin-hypercube-one-at-a-time method was used to conduct the analyses. A heat dissipation coefficient was proposed to evaluate the correlation between heat dissipation effects and transmissivity based on a case study using the hydrogeological setting of a well-characterized Canadian field site. The results show a significance ranking of three sets of variables controlling heat dissipation processes in both the central and the bottom areas of the heating zone: specifically, heat source > groundwater > rock. The groundwater influx and heat conduction in the rock matrix are key factors determining heat dissipation at the upstream and bottom areas of the heating zone, respectively. The heat dissipation coefficient is closely associated with the transmissivity of the fractured rock in a monotonic relationship. A significant growth rate of the heat dissipation coefficient appears when the transmissivity is between 1 × 10−6 and 2 × 10−5m2/s. The results suggest that the low-temperature thermal remediation can be a promising technique to adapt the significant heat dissipation in highly weathered fractured rock.

The Influence of Storage Tank Volume on the Nighttime Heat Dissipation and Freezing Process of All-Glass Vacuum Tube Solar Water Heaters

The issue of freezing often occurs when using all-glass vacuum tube solar water heaters during cold winter seasons, leading to problems such as pipe ruptures and tank leakage. In order to further study the nocturnal heat dissipation and freezing characteristics of these heaters, a three-dimensional transient numerical model of their nocturnal heat dissipation was established. The model simulated the nocturnal heat dissipation process, and experimental validations were conducted through nocturnal temperature drops of the collector and temperature drops of individual tubes without a storage tank. Experimental and simulation results revealed that in clear weather conditions during cold winters in Luoyang, the all-glass vacuum tube solar water heaters experienced freezing issues during the night, with freezing predominantly starting from the bottom surface of the vacuum tubes. The frozen length along the tube wall and the thickness of ice at the bottom section reached up to 1180 mm and 5 mm, respectively. In the absence of a storage tank, the freezing situation was severe, with approximately 4/5 of the individual tubes completely frozen. Under specified operating conditions, different storage tank volumes exhibited varying degrees of freezing in the all-glass vacuum tube solar water heaters. When the volume was increased to 15 L, the temperature drop in the storage tank and the vacuum tubes decreased by 12.1% and 7.6%, respectively. Larger storage tank volumes resulted in reduced freezing risks in all-glass vacuum tube solar collectors. This study provides valuable guidance for the design and application of solar collectors and serves as a reference for the development and application of solar energy utilization technologies.