Uniform Temperature Research Articles

The influence of various layouts of internal baffles on air distribution in heat pump cabinet dryers

Cabinet dryers are commonly employed in the food industry due to their simplistic design and low operational maintenance. Nevertheless, uneven internal airflow remains a critical issue affecting efficiency. This study developed nine models of heat pump cabinet dryers, based on traditional designs, and conducted a numerical investigation using Computational Fluid Dynamics (CFD) modeling. Modifications were made to the positions of the air inlet, outlet, and the baffle angle to determine the configuration that achieves the most uniform drying airflow, aiming to improve overall dryer performance. Key factors such as airflow velocity, temperature, humidity, and heat and mass transfer were analyzed. The results demonstrated that the optimized configuration, featuring a top inlet, middle outlet, and 4° baffle angle, improved flow and temperature uniformity by 52.70 % and 85.32 %, respectively, compared to the original design. The effectiveness of this configuration was validated through experimental trials involving the loading and unloading of figs. Physical property assessments indicated satisfactory drying uniformity, while sensory evaluations showed the final product was crisp, easy to chew, and exhibited enhanced sweetness. Overall, this study highlights the effectiveness of structural modifications in improving airflow and temperature uniformity, thereby enhancing the overall drying performance.

Numerical analysis of the influence of cooling design on temperature uniformity in the large proton exchange membrane fuel cell stack

The temperature distribution has a significant influence on the performance and lifespan of proton exchange membrane fuel cell (PEMFC) stacks. However, analyzing the temperature distribution of large PEMFC stacks is challenging and has been rarely conducted. In this study, a simplified model of a large PEMFC stack is developed using computational fluid dynamics (CFD) methods, which includes 300 cells and 60 cooling plates. The influence of cooling parameters, including configurations, dimension and flow rate, is discussed. The study indicates that U-type stack exhibits better temperature uniformity than Z-type stack. Increasing the coolant flow rate can effectively reduce the stack temperature. The study proposes a modified cooling design, which effectively reduces the heat accumulation at the end of the stack. Lastly, a comparison between traditional serpentine channels and porous foam metal flow fields reveals that the porous foam metal flow field exhibits superior thermal management characteristics. The results can offer insights for thermal management of large-scale PEMFC stacks.

Enhancement of battery thermal management effect by a novel MOF based composite phase change material

The introduction of phase change materials (PCMs) into battery thermal management systems (BTMS) can effectively enhance the cooling performance, safety and practical thermal management applications of lithium-ion batteries (LIBs). However, further study is needed to address the low heat conductivity and rapid phase change leakage of PCMs. This study proposed a metal–organic framework based shape-stabilized composite PCM (MOF/expanded graphite (EG) /multi-walled carbon nanotube (MWCNT) /paraffin wax (PW)) to construe battery cooling system, and its effect of battery thermal management is experimentally tested under various conditions. The results show the CPCM reveals a superior thermal management effect under varying ambient temperatures and discharge multipliers and outperforms natural convection. Even in the harsh environment of 40 °C and 3 C, the maximum temperature (Tmax) and Tmax difference (ΔTmax) of the CPCM-cooled module are 61.38 and 2.67 °C, which are 22 and 9 °C below the natural air-cooled module. Remarkably, the ΔTmax of the CPCM-cooled battery module in discharge decreases with the temperature rise at the discharge rate of 3 C, which is the exact opposite to the case of the air-cooled module. Moreover, the ΔTmax of CPCM-cooled module is 1.69, 1.84, 2.67 °C, all below the safe 5 °C at high temperatures (40 °C) as the discharge rate increases. The designed MOF-CPCM cooling system can effectively improve the temperature uniformity and thermal safety of the battery in harsh environments. Therefore, this novel MOF-based CPCM shows great promise in BTM.

Numerical Simulation Study on the Stable Combustion of a 660 MW Supercritical Unit Boiler at Ultra-Low Load

To investigate the safe, stable, and economically viable operation of a boiler under ultra-low-load conditions during the deep peaking process of coal-fired units, a numerical simulation study was conducted on a 660 MW front- and rear-wall hedge cyclone burner boiler. The current research on low load conditions is limited to achieving stable combustion by adjusting the operating parameters, and few effective boiler operating parameter predictions are given for very low-load conditions, i.e., below 20%. Various burner operation modes under ultra-low load conditions were analyzed using computational fluid dynamics (CFDs) methods; this operation was successfully tested with six types of pulverized coal combustion in this paper, and fitting models for outlet flue gas temperature and NOx emissions were derived based on the combustion characteristics of different types of pulverized coal. The results indicate that under 20% ultra-low-load conditions, the use of lower burners leads to a uniform temperature distribution within the furnace, achieving a minimum NOx emission of 112 ppm and a flue gas temperature of 743 K. Coal type 3, with the highest carbon content and a calorific value of 22,440 kJ/kg, has the highest average section temperature of 1435.76 K. In contrast, coal type 1 has a higher nitrogen content, with a maximum cross-sectional average NOx concentration of 865.90 ppm and an exit NOx emission concentration of 800 ppm. The overall lower NOx emissions of coal type 3 are primarily attributed to its reduced nitrogen content and increased oxygen content, which enhance pulverized coal combustion and suppress NOx formation. The fitting models accurately capture the influence of pulverized coal composition on outlet flue gas temperature and NOx emissions. This control strategy can be extended to the stable combustion of many kinds of coal. For validation, the fitting error bar for the predicted outlet flue gas temperature based on the elemental composition of coal type 6 was 8.09%, whereas the fitting error bar for the outlet NOx emissions was only 1.45%.

Controlling Temporally and Spatially Homogeneous Temperature Distribution of Paper Substrates by Biogenic Phase Change Hybrid Material Coatings

AbstractHere the performance of phase change material (PCM)‐coated paper made from unbleached kraft pulp is introduced. The applied PCM consists of a mixture of ethylene glycol distearate (EGDS), a well‐known PCM wax material, and a fully substituted cellulose stearoyl ester (CSE). Transfer of the PCM material onto/into paper is achieved by spray as well as blade coating of EGDS + CSE mixture. It is shown that the kind of coating method used does not interfere with observed PCM properties. The significantly higher melt viscosity of the EGDS + CSE blends ensures that the EGDS wax is not bleeding out of the paper, which avoids the use of further encapsulation processes. The PCM behavior, as observed by thermal load measurements, and the thermal buffering of the coated paper is a function of the applied mass of the PCM material applied. The thermal retention exhibited a quasi‐isothermal behavior at ≈65 °C with EGDS + CSE coatings. These effects can offset fluctuations in temperature, and the PCM papers can be employed to achieve a more uniform temperature setting. PCM‐modified papers are therefore interesting candidates for paper‐based packaging or for use in paper‐based sensors, where overheating can strongly affect reliability of results.

Three-Dimensional CFD Analysis of a Hot Water Storage Tank with Various Inlet/Outlet Configurations

This study presents a comprehensive 3D numerical analysis of thermal stratification, fluid dynamics, and heat transfer efficiency across six hot water storage tank configurations, identified as Tank-1 through Tank-6. The objective is to determine the most effective design for achieving uniform temperature distribution, stable stratification, and efficient heat retention in sensible heat storage systems, with potential for integration with phase change materials (PCMs). Using COMSOL Multiphysics 5.6, simulations were conducted to evaluate key performance indicators, including the Richardson number, capacity ratio, and exergy efficiency. Among the tanks, Tank-1 demonstrated the highest efficiency, with a capacity ratio of 84.6% and an exergy efficiency of 72.5%, while Tank-3, which achieved a capacity ratio of 70.2% and exergy efficiency of 50.5%, was identified as the most practical for real-world applications due to its balanced heat distribution and feasibility for PCM integration. Calculated dimensionless numbers (Reynolds number: 635, Prandtl number: 4.5, and Peclet number: 2858) indicated laminar flow and dominant convective heat transfer across all the configurations. These findings provide valuable insights into the design of efficient thermal storage systems, with Tank-3’s configuration offering a practical balance of thermal performance and operational feasibility. Future work will explore the inclusion of PCM containers within Tank-3, as well as applications for heat pump and solar water heaters, and high-temperature heat storage with various working fluids.

Advanced Numerical Modeling and Experimental Analysis of Thermal Gradients in Gleeble Compression Configuration for 2017-T4 Aluminum Alloy

Gleeble thermomechanical simulators are widely utilized tools for the investigation of high-temperature deformation behavior in materials. However, temperature gradients that develop within the specimen during Gleeble compression tests have the potential to result in non-uniform deformation, which may subsequently impact the accuracy of the measured mechanical properties. This study presents an experimental and numerical investigation of the temperature fields in 2017-T4 aluminum alloy specimens prior to Gleeble compression tests at temperatures ranging from 300 °C to 500 °C utilizing uniform temperature distribution (ISO-T) tungsten carbide anvils. The use of multiple thermocouples, welded to both the specimen and anvils, offers valuable insights into the temperature gradients and their evolutions. A coupled thermal–electrical finite-element model was developed in Abaqus for the purpose of simulating the resistive heating process. A user amplitude subroutine (UAMP) is implemented to regulate the heating based on a proportional–integral–derivative (PID) algorithm that modulates the current density to follow the specified temperature profile. The numerical results demonstrate that the temperature gradients within the specimen at the end of the heating process, reaching a temperature of 400 °C, are minimal, with values below 1.9 °C. This is in accordance with the experimental observations. The addition of graphite foils between the specimen and anvils has been shown to effectively reduce the gradients. The use of the measured anvil temperature as a boundary condition, rather than a constant value of 20 °C, has been demonstrated to improve the agreement between the simulated and experimental cooling curves. The modeling approach provides a framework for quantifying temperature gradients in Gleeble compression specimens and for assessing their impact on the measured constitutive response of materials at elevated temperatures.

Study of magnetic field dependent viscosity and temperature on Jenkins model fluid flow over a rotating disk

The present work involves the study of ferrofluid flow over a stretchable rotating disk maintained at an uniform temperature in the presence of magnetic field dependent viscosity. The system is analyzed through the Jenkins model and the simplified governing equations are represented in the cylindrical co-ordinates. The obtained nonlinear coupled partial differential equations are reduced to a coupled nonlinear ordinary differential equations using the well known Von Karman transformation for rotating disk and solved numerically by the shooting method. The velocity profiles, pressure and temperature are studied by varying the stretching parameter, magnetic field dependent viscosity parameter, material constant, and Prandtl number. The comparison for limiting case of the present problem finds good agreement with the existing literature.

A novel micro ohmic heating cell for microorganism destruction kinetic studies: Performance validation

Ohmic heating cells used for microbial destruction are typically large compared with conventional capillary tubes. Limitations of commonly used large cells include large mass, high come-up-time (CUT), lack of uniform heating, and operation at atmospheric pressure. A new 3 mL Micro Ohmic Cell (MOC) was designed and fabricated for the kinetic study of microbial spore destruction. Two tiny titanium electrodes, mounted horizontally on a T-shaped cylindrical cell with a 3 cm gap, generate a rapid heating rate up to 140 °C. Fibre optic temperature sensors were used for direct temperature monitoring during CUT and holding time. Model solutions were heated under voltage gradients up to 90 V/cm. Uniform heating was achieved under stirring conditions with less than 1 °C variation across the cell volume, and the coldest spot was identified as the liquid-air interface. CUT was evaluated as influenced by both system and product parameters, resulting in less than 50 s comparable to those obtained using capillary tubes. The newly developed MOC was validated for microbial destruction kinetic study under ohmic heating conditions using Clostridium sporogenes spores in buffer and concentrated maple sap. With its small volume, short CUT, and uniform temperature similar to capillary tubes in conventional heating, the MOC has the potential to be considered as a standard device for kinetic studies under ohmic heating.

Numerical study on fluid flow and heat transfer characteristics of supercritical CO2 in horizontal tube under various non-uniform heating conditions

Supercritical CO2 (sCO2) is deemed the potential working medium for thermodynamic cycles in the next generation of power machinery. In this paper, the flow and heat transfer characteristics of highly buoyant turbulent sCO2 in horizontal tubes are numerical studied under the non-uniform heating conditions. The tube with a typical internal diameter of 10 mm is selected with mass flux equaling to 300 kg/(m2·s), effective heat fluxes ranging from 20 to 60 kW/m2, and pressure equaling to 8 MPa. The results confirmed that the heat transfer of sCO2 inside the horizontal tube in the circumferential or axial non-uniform heating conditions is greatly deteriorated by 13 %-68 % compared to the uniform heating. The overall heat transfer performance of semi-circumferential axial non-uniform heating is about 2.5 % higher than that of bottom semi-circumferential uniform heating, while the axial temperature difference of the bottom surface exceeds 150 K. Screening three representative heating positions, the bottom heating has the best temperature uniformity. The corresponding turbulent streamlines featured by unique helical structures can substantially improve the circumferential and radial heat transfer over 10 %, enhancing the heat transfer performance of the smooth tube close to that of rifled tubes. Based on the numerical data, viable correlations were developed for calculating the axial local Nusselt number of forced convection heat transfer of sCO2 in horizontal tubes considering the effects of cross-sectional vorticity, secondary flow intensity, and buoyancy-natural convection, and the prediction values are in good agreement with experimental data.

A modular, human body-mimicking phantom with active thermoregulation capabilities for validation and verification of convective hyperthermia devices

Objectives This study aims to design and fabricate a modular phantom for hyperthermia applications, addressing interpatient variability in thermal regulation mechanisms like sweating rate, metabolic heat production, and blood redistribution. Materials & methods The phantom can be constructed in various weights and dimensions by connecting identical units. Each unit consists of an agar-based block, an ethyl cellulose-based top layer, a heat source, deep and superficial water circulation, and a sweating mechanism. Agar and ethyl cellulose gels mimic the thermal properties of human tissues and fat respectively. The blocks are wrapped in PVC foil to prevent water evaporation. A heating wire, coiled around an embedded aluminum tubing simulates metabolic heat production. A superficial water circulation mimics skin capillaries. A water pump ensures a steady flow rate throughout the tubing system. Sweat production is simulated using a water pump and perforated tubing. A programmed controller maintains core temperature in a normal operating mode and simulates an anesthetized patient in anesthesia mode. Results Temperature uniformity and regulation were assessed under varying environmental conditions. The phantom effectively regulated its core temperature at 37.0 °C +/- 0.7 °C with an ambient temperature ranging between 21 °C and 30 °C. Activating the water circulation reduced the maximum temperature gradient within the phantom from 4.70 °C to 1.92 °C. Conclusion The versatile phantom successfully models heat exchange processes. Its thermal properties, dimensions, and heat exchange rates can be tuned to mimic different patient models. These are promising results as an effective tool for hyperthermia device validation and verification, representing human physiological responses.

Relative Radiometric Correction Method Based on Temperature Normalization for Jilin1-KF02

The optical remote sensors carried by the Jilin-1 KF02 series satellites have an imaging resolution better than 0.5 m and a width of 150 km. There are radiometric problems, such as stripe noise, vignetting, and inter-slice chromatic aberration, in their raw images. In this paper, a relative radiometric correction method based on temperature normalization is proposed for the response characteristics of sensors and the structural characteristics of optical splicing of Jilin-1 KF02 series satellites cameras. Firstly, a model of temperature effect on sensor output is established to correct the variation of sensor response output digital number (DN) caused by temperature variation during imaging process, and the image is normalized to a uniform temperature reference. Then, the horizontal stripe noise of the image is eliminated by using the sensor scan line and dark pixel information, and the vertical stripe noise of the image is eliminated by using the method of on-orbit histogram statistics. Finally, the method of superposition compensation is used to correct the vignetting area at the edge of the image due to the lack of energy information received by the sensor so as to ensure the consistency of the image in color and image quality. The proposed method is verified by Jilin-1 KF02A on-orbit images. Experimental results show that the image response is uniform, the color is consistent, the average Streak Metrics (SM) is better than 0.1%, Root-Mean-Square Deviation of the Mean Line (RA) and Generalized Noise (GN) are better than 2%, Relative Average Spectral Error (RASE) and Relative Average Spectral Error (ERGAS) are greatly improved, which are better than 5% and 13, respectively, and the relative radiation quality is obviously improved after relative radiation correction.

Effect of the self-rewetting fluids on heat transfer performance of gravity heat pipes with sintered porous wick

The distribution of the working fluid in a heat pipe directly affects the phase change heat transfer process. This paper explores how self-rewetting fluids (SRWF) and porous wicks affect the distribution of working fluids and heat transfer efficiency in gravity heat pipe (GHP). We sintered a porous wick onto the evaporator section and tested two working fluids: water and SRWF (3 % butanol aqueous solution). The filling ratio of the working fluid φ was varied from 11.5 % to 46 %. We found that at large filling ratios, porous wick surface will immerse in liquid, and at small filling ratios the heating surface will lack of liquid. Consequently, the GHP operates at a lower temperature at a filling ratio of 23 % compared to 11.5 % and 46 %. The type of working fluid significantly impacts the operating temperature and temperature uniformity. The Marangoni effect of the SRWF enhances the rewetting of the fluid in the porous wick, but this effect is only observed after the temperature reaches the inflection point (where the SRWF exhibits minimum surface tension). Before this point, the GHP operating temperature with SRWF is relatively higher than with water. Correspondingly, the temperature uniformity on the evaporator section is better when using SRWF. At φ = 23 %, Q = 500 W the temperature uniformity improved by 66 %. At Q = 660 W the evaporator heat transfer coefficient increased from 3991.6 W/m2K to 6130.5 W/m2K which is a 53.6 % improvement over water. We used an infrared camera to visualize the rewetting phenomenon of SRWF in the heated porous wick, confirming that SRWF can rewet the dry-out area, thus validating our hypothesis.

Comparing different battery thermal management systems for suppressing thermal runaway propagation

Thermal runaway (TR) stands as a critical risk in battery applications. Even though various battery thermal management systems (BTMSs) have been proposed to mitigate thermal runaway propagation, a comprehensive comparison remains elusive. This study evaluates the performance of three types of BTMSs with 5 configurations, which include: liquid cooling with cold plates added on the bottom (BTMS-1a), liquid cooling with cold plates added on the sides (BTMS-1b), liquid cooling with cold plates added between batteries (BTMS-1c), integrating thermal insulation materials between batteries (BTMS-2), and implementing phase change materials between batteries (BTMS-3). The highest temperature, propagation time, temperature uniformity, cooling rate, mass energy density, and volume energy density are used as key performance indicators for comparison. In general, BTMS-2 and BTMS-3 show advantages in energy density, however, their performances on TR suppression and battery thermal management are poor. BTMS-1c can suppress TR effectively at high flowrates, whereas it can lead to poor temperature uniformity. Suggestions are also provided regarding the selection of BTMSs for different applications: BTMS-1b, BTMS-1c, and BTMS-3 are recommended for small EVs, large EVs and large scale battery energy storage systems (BESSs), and small BESSs, respectively.

An experimental study to evaluate the performance of variable-width channel cold plates for cooling rectangular Li-ion batteries

The limited cooling capacity of cold plates employing conventional channel designs represents a key obstacle in thermal management systems. The persistent growth of the thermal boundary layer and the uneven distribution of flow across the channels are the principal challenges encountered in this context. To overcome these challenges, this study aims to analyse a modified cold plate of obstructed variable-width channels that can improve the hydrothermal performance and temperature uniformity. Different shapes of pin fins and grooves with variable sizes that match the width of the variable-width channels are proposed. Specifically, four types of pin fins–grooves were used: ellipse, drop, rhombus and trapezoid. The traditional cold plate served as a basis for evaluating the performance of new designs of cold plates. In addition to the traditional cold plate, the four proposed designs of cold plates were manufactured from copper. Experiments were conducted with water as a working fluid under a laminar flow for a flow rate range of 0.004–0.04 kg/s and a discharge C-rate range of 1C–2C. Results indicated that the use of variable-width channels with all shapes of fins–grooves effectively contributed to improving the heat dissipation of the cold plate, accompanied with an increase in hydraulic pumping power. At the highest flow rate, the best improvement percentage in the Nusselt number of 82.5% was achieved when trapezoidal pin fins–grooves were used; by contrast, the lowest pumping power increasing percentage of 33.2% was obtained when elliptical pin fins–grooves were adopted. The best hydraulic/thermal performance was achieved when trapezoidal pin fins were utilised, with the highest figure of merit of 1.685.

Variability in Water Temperature Vertical Distribution and Advective Influences: Observations from Early Summer 2021 in the Central Yellow Sea

To analyze variations in the vertical distribution of water temperatures and the impact of advection in the central Yellow Sea, multi-layer water temperature and current observations were conducted from 31 May to 8 June 2021. Water temperatures exhibited a typical three-layer summer structure, with a uniform deep-layer temperature averaging 8.23 ± 0.05 °C. The current field was dominated by northeast–southwest tidal currents, but residual current characteristics indicated that non-tidal components significantly influenced circulation. Water temperature changes lagged tidal changes by about 3 h, with strong correlations (R > 0.7), especially in deep layers. Residual currents showed significant correlations with water temperature variations, which were attributed to advective displacement or baroclinic currents. Empirical orthogonal function (EOF) and complex EOF analyses revealed that thermocline variations (T1, explaining approximately 75% of total variance) were driven by strong northward (C1, approximately 34%) and cyclonic (C2, approximately 32%) advection. In deep layers, slight temperature changes were caused by southward Yellow Sea Cold Water Mass (C1) and northward Yellow Sea Warm Current Water (C2) propagation. This study confirms that vertical water temperature variations result from a complex interaction between various advection patterns, with southward tide-induced residual currents (C3, approximately 12%) playing a key dynamic role.

Thermal performance enhancement of laminar flow using compound twisted square duct and variable pitch twisted tape inserts

This study involves a computational analysis to find the effectiveness of incorporating twisted tape within a twisted square duct for improving heat transfer, focusing on laminar single-phase flow. The primary goal is to study how varying the tape pitch (y) influences the hydrothermal performance of this system. The twisted square duct pitch (S) and twist ratio (H) were kept constant. The numerical analysis is performed under conditions of uniform wall temperature, and varying the pitch ratio (y/S) across values of 0.25, 0.5,0.75, 1, 1.25, 1.5 and 1.75. The obtained findings suggest that the addition of twisted tape within the twisted square duct results in a greater rate of heat exchange and pressure drop relative to the simple twisted square duct. Research reveals that despite a higher rate of heat transfer for a pitch ratio of 0.25 the increased friction factor results in less effective thermal performance compared to the cases with pitch ratios of 0.75 and 0.5. The thermal performance factor reaches its peak at 1.32, corresponding to the Reynolds number 1000 for a pitch ratio of 0.75 case. Conversely, the lowest thermal performance factor value of 0.89 is observed at the Reynolds number 500 for pitch ratio 1.25 case.

An oven controlled piezoelectric MEMS dual-resonator platform with frequency stability of [formula omitted]100 ppb over industrial temperature range

This work demonstrates a piezoelectric MEMS dual-resonator platform with an oven control. The platform includes a micro-oven in-chip, which integrates a frequency output resonator and a temperature sensing resonator. The two resonators operate using a phase-locked loop system, one in width-extensional (WE) mode and the other in width-shear (WS) mode. An equivalent thermal model of the dual-resonator platform is established and both resonators exhibit extremely uniform temperature distributions. The real-time temperature of the resonators is monitored by measuring the frequency difference between the two resonators and a closed-loop oven control is implemented to maintain the dual-resonator platform at an oven-set temperature. The reported oven controlled piezoelectric MEMS dual-resonator platform exhibits a measured frequency stability of ±100 ppb across the industrial temperature range of −40 to 85 °C. This result signifies the promising potential of the device in high-end timing applications.

Design optimization of continuous fiber composites with thermo-mechanical coupling and load uncertainties

This paper introduces a theoretical framework for the design optimization of continuous fiber composites reinforced with continuous fiber trajectories subject to thermo-mechanical coupling and load uncertainties. Different uniform temperature variations are applied in the structure to investigate the influence of ambient temperature change on the structural performance. To consider the external load uncertainties, a robust design optimization model is proposed where the loads are modeled as hybrid variables, namely magnitudes as random variables and directions as interval variables, with the robust objective determined through a hybrid orthogonal polynomial expansion method. Furthermore, we use a level-set function to represent the structural boundary, with its evolution driven by shape derivatives calculated based on uncertainty analysis. The continuous fiber paths are subsequently determined by the level-set isoline extracted from the structural boundary, which in turn influences the structural mechanical performance due to the material anisotropy of composites. The continuity of continuous fiber and the equal space between adjacent trajectories largely ensure the additive manufacturability of the composites. Three numerical examples are presented to demonstrate the effectiveness of the developed framework. The results show that the ambient temperature variations and load uncertainties largely impact the optimized topology and fiber infill patterns of composites, thus are important to be considered in the design stage. Moreover, the optimized structure can have a 5-fold stiffness per unit mass compared with the initial design thus largely increasing the material efficiency in carrying external uncertain loads.

Thermal uniformity analysis of a hybrid battery pack using integrated phase change material, metal foam, and counterflow minichannels

This study investigates the thermal performance and temperature uniformity of a hybrid battery thermal management system (BTMS) that integrates phase change material (PCM), metal foam, and minichannels. Computational fluid dynamics is used to model the PCM melting process and heat transfer between all components. The primary goal of the work is to investigate BTMS architectures which can enhance thermal uniformity and prevent critical temperature rise in a high-voltage battery pack under fast discharging and real-world driving cycle. Four BTMS designs are compared. The design that integrates PCM, metal foam, and counterflow minichannels is shown to have the best performance. At low pumping power (coolant Reynolds number Re = 10), this design reduces the peak battery temperature by 11.5 K compared to a design employing pure PCM only. This configuration also ensures a temperature difference of less than 5 K among individual battery cells, addressing thermal safety considerations and extending battery lifespan. Further analysis revealed that the inclusion of metal foam delays PCM melting, enhances both system and battery thermal uniformity, and offers a higher performance-to-weight ratio compared to designs without metal foam. Although wavy-shaped minichannels offer minimal temperature improvement (0.3 K) over straight minichannels, their higher cost and increased pumping power requirements do not justify their practicality. Under both fast discharging and real driving conditions, the first design with pure PCM provides uniform heat distribution within batteries but fails to maintain the maximum battery temperature within the optimal range. Overall, this study highlights the effectiveness of the proposed hybrid BTMS design in providing uniform temperature distribution and maintaining the maximum battery temperature within the optimal range under harsh environmental conditions, fast discharging, and the Urban Dynamometer Driving Schedule (UDDS) drive cycle.