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Heavy-duty vehicles, such as trucks or buses, typically have larger battery packs compared to passenger electric vehicles (EVs). These batteries generate more heat due to the increased power demands of the vehicle. Effective thermal management is therefore crucial to prevent excessive heat buildup and maintain optimal battery performance. This paper aimed to develop a dynamic and efficient cooling system for larger Li-ion batteries used in electric vehicles. In this study, we propose a novel cold plate design featuring a zig-zag serpentine flow pattern within a rectangular profile channel. The chosen design maximizes the coolant coverage over the cold plate’s surface area. To investigate the performance of the cold plate design, we designed and modeled a total of six different cold plates with varying numbers of channels (3, 5, 7, 9, 11, and 13). Preliminary simulations were conducted using Star CCM+ software. The cold plate material selected for its high thermal conductivity was aluminum, while water served as the coolant. Several parameters were optimized, including adjustments to channel width, mass flow rate, heat flux, and inlet coolant temperature. The optimization was conducted to determine the optimal design for the cold plate. We found that the best design configurations were five-channel with an 18 mm channel width and a seven-channel with a 16 mm channel width. It was found that the temperature rapidly increased and reached its maximum in the outlet region. In the design with three channels, the maximum temperature attained at the exit region was 330.84 K. The temperature gradually decreased at the exit region when the number of the channels increased from 3 channels to 13 channels and achieved a minimum temperature of 316 K for the design with 13 channels. For these configurations, heat fluxes of 2 °C and 3 °C were found to be optimal, while a discharge rate of 4 °C was deemed acceptable. The zig-zag design and the obtained results are instrumental in designing and evaluating the performance of cold plates by exploring various parameters. This research contributes to the development of an effective cooling system for large Li-ion batteries in EVs, potentially enhancing their efficiency and reliability.

Liquid cooling strategies such as cold plates have been widely employed as an effective approach for battery thermal management systems (BTMS) due to their high cooling capacity and low power consumption. The structural design of the cold plates is the key factor that directly determines the thermal performance of the liquid cooling system. In this study, seven Z-type parallel channel cold plate and two novel cross-linked channel cold plate designs are proposed for the cooling of high-power lithium-ion batteries using two different cooling strategies. The average battery temperature, battery temperature uniformity and energy consumption of all designs are firstly analyzed holistically by three-dimensional conjugated simulation under the scheme of continuous cooling. Two selected designs that demonstrated superior performance (i.e., a Z-type parallel channel cold plate with 8-branches and an improved cross-linked channel design) are further analyzed to explore their integrative performance under different cooling schemes. The results show that within a battery temperature limit of 40 °C, employing the delayed cooling strategy can save 23% energy consumption compared to the continuous cooling strategy. Besides, the cold plate with an improved cross-linked channel configuration requires 13% less pumping power and provides a better temperature uniformity than the Z-type parallel channel cold plate with 8-branches. These results are of great significance to advance the cooling design of BTMS.

A comprehensive experimental investigation of water cold plate with different flow configurations for electronic cooling was conducted. Serpentine, parallel and wavy channels cold plate were designed to study the hydrothermal performance of water cold plate for electronic servers cooling. Thermal resistance, pressure drop, Nusselt number, servers’ temperatures and performance evaluation criterion were measured, evaluated and compared to evaluate the hydrothermal performance of the different configurations. The results showed that the serpentine channels cold plate has a better thermal performance than both parallel and wavy channels cold plate. The serpentine channels cold plate yields a lower thermal resistance by (6.02–10.5%), (2.4–8.7%) and a higher average Nusselt number by (7.9–13.9%), (6.3–13.7%) compared to parallel and wavy channels cold plate, respectively. Also, the results indicated that the serpentine channels cold plate has a higher pressure drop and pumping power compared to parallel and wavy channels cold plates. Similarly, the results showed that the wavy channel has better thermal performance than parallel channels due to the larger flow path and the rotational flow occurred. The I-Type inlet and outlet configuration used in the wavy channel cold plate provide a lower pressure drop compared to parallel channels however the large flow path. The performance evaluation criterion showed that the wavy channels cold plate has a higher performance evaluation criterion than serpentine channels due to its lower pressure drop.

Opioid and non-narcotic analgesics, non-steroidal anti-inflammatory agents, anesthetics, antidepressants, myorelaxants, combined agents and phytopreparations are widely used for the treatment of pain syndrome. One of the promising phytogenic objects with potential analgesic properties is the Acorus calamus (Sweet Flag). The aim:the purpose of the study is to determine the analgesic effect of the dealcoholized extract of Acorus calamus leaves (DEAL) on a model of pain in the "Hot plate" test and in the test of tail heat immersion. Materials and methods.During the experimental study, the pharmacological methods have been used. The analgesic properties of DEAL were studied in mice on the "Hot plate" model using the Hot / Cold Plate (Bioseb, France) and in the test of the heat immersion in rats. The results.On the models of pain in the "Hot plate" and tail heat immersion tests, the analgesic effect of the dealcoholized extract of Acorus calamus leaves (DEAL) is determined. On the "Hot plate" model, the use of DEAL probably increased the duration of the latency period. According to the analgesic effect of DEAL and metamizol sodium were comparable to each other continues to 1 and 1.5 hours of experiment, but starting with 2 hours of experiment the analgesic action of metamizol sodium statistically exceeded the analgesic effect of DEAL. In the test of heat immersion tail in rats, DEAL increased the latency period of shocking of the rats’ tail compared to the starting background by 43.13 % as well as metamizol sodium by 66.6 %. The studies have shown the presence of moderate analgesic effects of DEAL in the investigated dose. Conclusions. The analgesic effect of a dealcoholized extract of Acorus calamus leaves (DEAL) on a model of pain in the "Hot plate" and heat tail immersion tests has been carried out. Under the "Hot plate" test in mice, DEAL produces a distinct analgesic effect, however, slightly inferior to the severity of metamizol sodium. Presence of moderate analgesic properties of DEAL has been verified in comparison with the metamizel sodium in thetail heat immersion test in rats. The obtained results indicate the influence of DEAL on the central mechanisms of pain formation

This article proposes a liquid-cooled battery thermal management system based on a serial-parallel mini-channel cold plate to solve the problem of severe heat generation during high-rate battery di...

In a cold plate low thermal resistance thus high heat transfer rate and also low pressure drop is desired. In this study, performances of three liquid cold plates with different configurations are investigated for the thermal regulation of li-ion battery cells in electric vehicle applications. The outer dimensions of the cold plates are kept identical in order to use the cold plates in the same battery module under series, parallel and series-parallel configurations. The performances of the cold plates are investigated by using Computational Fluid Dynamic (CFD) tools. ANSYS Fluent commercial software is used to calculate the flowfield and the thermal field inside the cold plates for various flowrates. The performances of the cold plates are obtained by 3D simulations that solve Navier-Stokes, energy and continuity equations in a steady manner. The flow is assumed to be laminar for all the cases since calculated Reynolds number stay in laminar flow limits. The results show that the pressure drop of the coolant liquid of parallel flow arrangement is significantly lower than the serial arrangement. However, high thermal resistance and low uniformity of the temperature through the cold plate is observed compared to the serial case, as expected. As a result, series-parallel configuration results show that the trade-off between pressure drop and heat transfer rate can be optimized by applying a serpentine shape while keeping the flow arrangement as parallel as possible and increasing the length of the cross channels., Soğutucu levhalarda düşük ısıl direnç, dolayısıyla yüksek ısı transferi ve düşük basınç kaybı arzu edilmektedir. Bu çalışmada, elektrikli araç uygulamalarında li-iyon pil hücrelerinin termal regülasyonu için, farklı konfigürasyonlara sahip sıvı soğutmalı üç soğutucu levhanın performansları incelenmiştir. Seri, paralel ve seri-paralel konfigürasyonlarda oluşturulan soğutucu levhaların aynı batarya modülünde kullanılabilmeleri için dış boyutları birbiriyle aynı tutulmuştur. Çalışmada, soğuk plakaların performansları, Hesaplamalı Akışkanlar Dinamiği (HAD) araçları kullanılarak incelenmiştir. Çeşitli akış hızlarında, soğuk plakaların içindeki akış alanını ve termal alanı hesaplamak için ANSYS Fluent ticari yazılımı kullanılmıştır. Soğuk plakaların performansları, sürekli rejimde Navier-Stokes, enerji ve süreklilik denklemleri 3 boyutlu simülasyonlar ile çözülerek elde edilmiştir. Reynolds sayısı laminer akış limitleri içerisinde hesaplandığından, tüm akış durumları için laminer akış kabul edilerek çözümlere gidilmiştir. Simülasyonlar sonucunda, paralel akış geometrisindeki soğutucu sıvının basınç kaybının seri olana göre önemli ölçüde daha düşük olduğu görülmüştür. Bununla birlikte, beklenildiği gibi, paralel akış geometrisinde seriye göre yüksek ısıl direnç ve düşük sıcaklık homojenliği gözlemlenmiştir. Sonuç olarak, basınç düşüşü ve ısı transferi arasındaki dengenin, akış düzeninin mümkün olduğunca paralel tutulup çapraz kanalların ise uzunluğunun arttırıldığı bir serpantin şekli uygulanarak optimize edilebileceğini seri-paralel konfigürasyon sonuçları göstermektedir.

The technology of large surface thermal management of pouch cells was studied and discussed by means of simulation. With thermal management, two cells are managed by a single cold plate. First, the pressure drop of the cold plate was simulated and the velocity distribution of the flow field was observed. The cooling performance of the cold plate to the cell was then studied, and the low-temperature heating ability of the cold plate to the cell was analyzed. Through analysis, it can be concluded that large surface thermal management technology can effectively and quickly control the temperature rise of the cell when the cell is charging and discharging and the temperature difference is less than 5 °C. Finally, a control strategy for low-temperature heating of the cell by the cold plate was proposed.

Liquid-cooled servers can be deployed to reduce the energy consumption and environmental footprint of hybrid-cooled data centers. A computational fluid dynamics (CFD) model can bring extremely useful insights and results for thermal simulations of air- and liquid-cooled servers in a single environment. In this study, a conjugate heat transfer (CHT) numerical model is developed and validated with experimental data to simulate heat transfer from the CPU to the air and cold plate considering the effect of thermal paste. The cooling performance of an in-house developed cold plate design is thoroughly investigated via the validated CHT model. A dataset containing one hundred samples of various flow, thermal and workload conditions was generated using the Latin hypercube sampling (LHS) method, which was further utilized in the series of CHT simulations. Finally, a novel empirical equation is proposed for the prediction of heat transfer from the CPU to the air. The accuracy of the proposed equation is confirmed by comparing estimated and simulated results for a test dataset. A thermal analysis of a rack containing air and liquid-cooled servers is performed using the presented approach. The simulation results reveal that the proposed compact model can be used reliably for the thermal simulation of a hybrid-cooled data center.

Cold plate is an important component for a liquid battery thermal management system. In order to study the transient thermal performance of the cold plate under conditions with sharply increasing heat loads, the numerical model of a battery cold plate is established. The validation experiment shows that the error between the simulation and experiment is around 2.5% to 5%. Effects of the coolant flow rate, the increase in heat flux, and the channel number are analyzed to study the transient thermal performance of the cold plate. Results show that the average temperature of the cold plate at 540 s is lowered from 28.3°C to 26.9°C when the coolant flow rate is raised from 0.065 kg/s to 0.165 kg/s. The temperature deviation is decreased when the coolant flow rate is increased from 0.065 kg/s to 0.115 kg/s; however, it is slightly increased if the coolant flow rate is further increased. Both average temperature and temperature deviation are raised if the final heat flux is increased from 11 000 W/m2 to 16 500 W/m2, which are 2 and 3 times of the initial, respectively. In addition, increasing the channel number has slightly positive effect on the average temperature of the cold plate, while the temperature deviation is increased when the channel number is increased from 3 to 11 due to the non-uniform velocity distribution between each channel. The results of this study will be helpful during the design of cold plate for battery thermal management, especially for transient conditions with sudden rising heat loads like thermal runaway.

Metal rolling processes are usually subjected to continuous development for increasing theefficiency of metals industry and broadening the applicability of soft metals in the structuralapplications. During this study, cold plate rolling have been conducted under differentconditions. Particularly, the rolling power and the resulted separating force have beenanalyzed after changing the roll diameter, the draft thickness, and the lubricant type. It wasobserved that, decreasing the reduction by pass and reducing the roll diameter could minimizethe need for high power during operation. It was also noticed that, among the differentexperiments, using olive and paraffin oil as lubricant at the roll-metal surface show asignificant effect on reducing the power consumption and increasing the rolling processefficiency in a high agreement with the mathematical modeling. تعتبر دراسة قوي الفصل من أھم العناصر إثناء عملية الدرفلة.فيھتم ھذا البحث بدراسة قوي الفصل إثناء الدرفلة علي الباردلشيتات من الالومنيوم..حيث أنھا عامل رئيسي للطاقة المستھلکة إثناء عمليھ الدرفلة.وان ھذه القوي تتأثر بعوامل عديدة منھاالمادة المراد عمل درفلھ لھا وقطر الدرفيل المستخدم ونسبھ التخفيض إثناء عملية الدرفلة وسمک المادة إثناء الدخولومعامل الاحتکاک بين الدرفيل والمادة والسرعة النسبية بين الدرفيل والمادة ونوع عملية الدرفلة. فالزيادة في قطر الدرفيلونسبة التخفيضومعامل الاحتکاک يؤدي الي زيادة قوي الفصل. ويمکن التغلب علي بعضالعناصر مثل الاحتکاک باستخدامنوع تزييت مناسب وبالتالي نقلل قوي الفصل ونحافظ علي سطح الدرفيل.وقد تبين أيضا من البحث عند دراسة العلاقة بينالطاقة المستھلکة والزمن ان الطاقة تصل إلي أقصي قيمھ في البداية ثم تنخفضوتستمر لوقت معين لإنھاء عمليھ الدرفلة ثمتقل الي اقل قيمھ بعد انتھاء عملية الدرفلة .

Due to increasing power demands and decreasing component size, thermal management has become the bottleneck for many power electronic applications. The aerospace industry has focused on reducing weight, operating temperature, and pumping power of power converters since these will limit an aircrafts' range and load carrying capacity. This paper outlines a tool created in MATLAB to automate the cold plate design process for DC-DC converters (or similar applications). The tool incorporates a genetic algorithm to fi nd the optimal aligned or staggered pin fi n confi guration that maintains the devices below their critical junction temperature while reducing the system's overall weight and pressure drop. Utilizing this MATLAB design tool, a cold plate was designed, manufactured, and tested. The convection coefficient calculated within MATLAB (via empirical correlations) was veri fed using simplifi ed CFD simulations within 5% of each other. The same CFD setup, boundary condition types, and methodology are then applied for the full-sized prototype cold plate simulations. These simulations were then validated using the experimental results. For all cases, the percentage error between the simulated convection coefficient values (CFD) and the experimental results was less than 12%. The experiments' measured surface temperature and pressure drop errors were less than 8% of the predicted CFD results. Therefore, the MATLAB tool and its correlations/calculations could be veri fied (via CFD) and validated (experimentally) based on good agreement between the CFD and the experimental results. This three-pronged approach (analytical calculations, CFD simulations, and experimental validation) is an effective and robust method to solve heat transfer problems. Overall, with the framework outlined in this thesis, a complete cold plate design can now be completed in weeks instead of months. This streamlined approach will save companies signifi cant time and money in the design and simulation phases, making this tool a valuable addition to the current literature available. Thesis Master of Applied Science (MASc)

Interest in the role of sex as a biological variable continues to increase, including a mandate for the study of both sexes in NIH-funded research. Choice-based thermal nociceptive tests allow for the study of a more spontaneous response to thermal stimuli and avoidance behavior compared to traditional nociceptive assays, and their usage has been increasing in recent years. However, to date no comparison of naïve male and female responses to such tests has been published. As sex differences are known to exist in both human chronic pain conditions and rodent models of nociception, it is critical to understand the impact of sex on any nociceptive assay. Herein, we examined the effect of sex on two choice-based thermal nociceptive tests, the thermal gradient test and the temperature place preference test, in adult rats. We report that marked sex differences exist in responses to these tests. Namely, the activation of a 10° C-to-47° C thermal gradient results in an increase in time spent in the 10° C zone in females, compared to a reduction in males. In a temperature place preference test pairing a surface temperature of 22° C with either 5° C, 10° C, 47° C, or 50° C, males spent less than 50% of their time in every non-22° C zone, but in females this was only observed when testing 50° C. Together, these results suggest that male rats show more avoidance behavior to non-ambient temperatures when given free access to multiple zones, including at temperatures which are milder than those typically used to evoke a nociceptive response in traditional hot and cold plate tests.

The use of pumped two-phase cooling to improve the thermal management of insulated gate bipolar transistor (IGBT) in rail transportation is a novel cooling technology. An experimental investigation on pumped two-phase cold plate of IGBT used in HXD1C locomotives was conducted at a mass flow rate of 0.1 kg/s–0.29 kg/s and a heat flux of 6.2 W/cm2, with R245fa as the working fluid. The experimental results showed that the base temperature nonuniformity can be controlled within 2.2 °C at flow rates of 0.14 kg/s and 0.19 kg/s, which is of great benefit to the reliability of IGBT. Based on well known correlations for saturated flow boiling in tubes, an analytical model was developed and compared with the experimental data. The model could predict the base temperature data within an error band of ±3 °C, as well as capture the trend of base temperature as a function of vapour quality and mass flow rate. The performance of the pumped two-phase cold plate of IGBT could be further improved with the aid of the developed model.

This paper describes the design and analysis of a system for removing up to 10 kW of heat from each Power Electronics Building Block (PEBB) in a stack of four PEBB units, using liquid cooling via a dry interface. This is achieved by hard-mounting cold plates in the electronics cabinet, placing the heat-transfer surface of each PEBB adjacent to a cold plate, and improving heat transfer across the interface through the use of a thermal pad. The paper presents initial thermal analysis using analytical models. These analyses indicate that this is a viable solution to the PEBB cooling problem.

For lithium-ion battery thermal management system for electric vehicles, the insertion of metal plates with channels on both sides of a lithium-ion battery is an effective method for a high-temperature cooling. Inspired by the nature spider-web structure, we propose a cold plate with a bionic spider-web channel inside. Based on the heat generation characteristics of the pouch lithium-ion battery at an extreme discharge rate of 12 C, we used an orthogonal experimental design to study the cooling performance of the spider web-channel structure for a lithium-ion battery. Numerical simulation results showed that, among the structural parameters of the spider-web channel, the channel width had the largest influence on the cooling performance of the cold plate, while the channel angle had the smallest influence. The increase in the channel width could not indefinitely enhance the cooling performance of the cold plate. The most suitable structure was obtained at a width of 3 mm. When the channel angle was 120°, the pouch lithium-ion battery could provide the best thermal balance.

In today’s world, most data centers have multiple racks with numerous servers in each of them. The high amount of heat dissipation has become the largest server-level cooling problem for the data centers. The higher dissipation required, the higher is the total energy required to run the data center. Although still the most widely used cooling methodology, air cooling has reached its cooling capabilities especially for High-Performance Computing data centers. Liquid-cooled servers have several advantages over their air-cooled counterparts, primarily of which are high thermal mass, lower maintenance. Nano-fluids have been used in the past for improving the thermal efficiency of traditional dielectric coolants in the power electronics and automotive industry. Nanofluids have shown great promise in improving the convective heat transfer properties of the coolants due to a proven increase in thermal conductivity and specific heat capacity. The present research investigates the thermal enhancement of the performance of de-ionized water-based dielectric coolant with Copper nanoparticles for a higher heat transfer from the server cold plates. Detailed 3-D modeling of a commercial cold plate is completed and the CFD analysis is done in a commercially available CFD code ANSYS CFX. The obtained results compare the improvement in heat transfer due to improvement in coolant properties with data available in the literature.

In order to investigate the effects of three parameters of a mini-channel cold plate on the cooling performance of a U-shaped mini-channel structure, the effects of the channel length (L), width (W...

Cooling of the Li-ion battery module is a critical issue for electric vehicles in regard with the battery performance and lifetime, particularly at abused operating conditions. A water cooling system consisting of two novel cover plates with T-shape bifurcation structures and eight traditional cold plates was proposed and investigated for cooling of prismatic LiFePO4 battery modules. A computational fluid dynamics simulation model of the cooling system was established and validated by experimental data. The results show that a cold plate with four circular mini-channels flowing water can keep the maximum temperature of a single battery around 35 °C at 1 °C discharging rate and ambient temperature of 40 °C. Effect of the coolant flow rate is much less significant than the inlet coolant temperature on the cooling performance. Two sets of the proposed water cooling systems can significantly reduce the maximum temperature of a battery module consisting of 15 batteries. Moreover, great temperature distribution uniformity between different batteries can be achieved because the novel cover plate is able to distribute water evenly into each mini-channel of the cold plates. The cooling system can keep the maximum temperature of the module below 32.5 °C and the difference between the highest and lowest temperatures around 1.5 °C at abused operating conditions.

WOS: 000469444200050, A theoretical model is presented in this study for investigating the heat transfer problem during solidification of pure metals on a coated sinusoidal mold. The previous works are extended by considering effects of both the sinusoidal coating layer's properties and prescribed temperature boundary condition at the lower surface of the mold on the solidification process. The thermal diffusivities of the shell, coating and mold materials are assumed to be infinitely large, and it helps us to solve two-dimensional heat conduction problem analytically. The effects of the ratios between the thermal conductivities of coating, shell and mold materials, coating thickness and the amplitude ratios between the wavelengths of coating and mold surfaces on the solidification process are investigated in detail. Furthermore, the inverse design problem for the directional solidification process is briefly discussed. The results show that the thickness of the coating causes the decrease in the amplitude of the undulation at the solidification front for all cases considered. When the ratio between the amplitudes of both surface wavelengths of the mold is negative, the decrease in the ratio between thermal conductivities of the shell and coating materials causes more uniform growth in the shell regardless of the amplitudes of wavelength ratio between the surfaces of the coating layer. A bandwidth for thermal conductivity ratio between the shell and coating materials is determined depending on the process parameters for more uniform growth.

The freezing process of supercooled water droplets on cold plates is studied experimentally and numerically. A numerical model that considers both the supercooling effect on the physical properties and the volume expansion effect on the droplet freezing profile is established to simulate the droplet freezing behaviors using the Solidification/Melting model. Experiments are conducted on both hydrophilic and hydrophobic surfaces for 5, 10, 20, 30 and 40 μL supercooled water droplets. The droplet freezing behaviors including the freezing front movement and freezing time are observed using the image recognition technology. The evolution of the freezing front calculated by the numerical model agrees better with the experimental observation than the traditional model that ignores the supercooling effect or uses the initial droplet profile. The model reduces the deviation of freezing time from about 30% to about 10% for both hydrophilic and hydrophobic surfaces. With use of the average value of the freezing times yielded by the numerical and theoretical models, a correlation is developed for predicting the freezing time. It can correlate more than 90% of the simulation data and all of the experimental points within ±25%. As the cold plate temperature, droplet volume and contact angle increase, the freezing time increases, with the plate temperature and contact angle possessing a more significant influence than the droplet volume on the freezing process.

For poor high-temperature performance of power battery utilized in electric vehicles, a battery thermal management system (BTMS) functioned as reducing battery’s temperature is indispensable. This work designs a serpentine-channel cold plate as cooling unit of fluid BTMS, and a parameterized U-tube representing a part of serpentine-channel in cold plate is created. A thermal resistance model, as well as an objection function f1 based on it, is developed to characterize thermal performance of cold plate. This study using theories of friction loss and excess loss defines a pressure loss model of cold plate based on the parameterized U-tube. After a series of simulations performed on different U-tube with varying structural parameters, combining with pressure loss model, objective function of pressure loss f2 is obtained. By calculating f1 and f2, the laws of thermal performance with pressure loss and the optimum structure of the serpentine-channel cold plate can be obtained. This work provides a simple way to design the structure of the fluid cold-plate BTMS with optimum thermal performance and minimum pressure loss.

Power of Active Phased Array Antenna (APAA) and heat of the antenna element tend to increase. Therefore, a cooling system with higher efficiency for the antenna element is required. The new water-cooled cold plate we developed using AM technology must be an important component in the antenna system. The new water-cooled cold plate has significantly improved heat dissipation performance compared to conventional manufacturing technology.

In this paper, three liquid-cooled cold plate structure schemes of the thermal control unit for an indirect single-phase liquid-cooled server were proposed in this paper. The mesh independence was validated and thermal simulations were completed for different schemes based on the same boundary conditions, then effects of fin geometrical parameters on pressure drop and heat transfer characteristic were investigated. Furthermore, an optimization was performed with goal of reducing pressure drop and weight based on the optimal liquid-cooled cold plate with 2mm diameter circular fins, pressure drop is lower 6.1%, the weight is lower 12.2% compared with the primal model.

Liquid-cooled battery thermal management system with cold plate shows great potential for cooling battery packs in electric vehicles due to its merits of large heat transfer coefficient and good sealing performance. However, current design of cold plate leads to large temperature difference in battery packs, especially in the case with large battery packs. Besides, the pump energy consumption is usually high, which shortens the endurance of electric vehicles. In this paper, a parallel mini-channel cold plate (PMCP) for large battery packs is designed to reduce the temperature difference of the system. Numerical method is adopted to evaluate the performance of the PMCP, which is further demonstrated by experiment. Then a bidirectional symmetrical cold plate is designed to reduce both temperature difference and energy consumption. Positions of the outlets of the bidirectional symmetrical cold plates are adjusted to further improve the system performance. Finally, the designed cold plates are used for cooling large battery packs. Compared with systems equipped with traditional PMCP, the temperature difference in battery pack and the energy consumption of the system with designed PMCP are reduced by 77% and 82%, which shows that the designed PMCP significantly improves the system cooling and energy saving performance.

This paper deals with the experimental and numerical investigations of seven integrated circuit (IC) chips cooled using the water flowing inside the cold plate at different flowrates. The study includes the supply of three different heat input cases under four different flowrates (0.063 kg/s, 0.125 kg/s, 0.25 kg/s, and 0.5 kg/s) to cool the high heat-generating IC chips mounted on the SMPS board at various positions. The optimal configuration (71-11-74-76-65-24-15) for the arrangement of the 7 IC chips is considered for the analysis. The numerical simulations are carried out using the commercial software ansys fluent (R-16) to support the experiments. Both the results (IC chips temperature) agree with each other in the error band of 8–14%. The smallest chip U6 attains the maximum temperature, as its heat attenuation rate is very high. The water flowing inside the cold plate absorbs the heat from the IC chips; by increasing the flowrate (Reynolds number increases), there is an increase in the convective heat transfer coefficient of the chips (Nusselt number increases) and ultimately cools these faster. A correlation is proposed for the Nusselt number of the chips with the Reynolds number of the flow. The results suggest that the liquid cold plate plays a vital role in the cooling of the IC chips and leads to better thermal management.

The integrated cold plate with internal flow has small size, light weight and high integration, so it is getting more applications in active phased array radar. In the design of the integrated cold plate model, there are leakage risk points that may affect radar performance. The paper proposes a check method based on three-dimensional Boolean operation. It can quickly highlight all leakage risk points of the integrated cold plate and realize the analysis and optimization of the integrated cold plate model.

A battery thermal management system (BTMS) is crucial to guarantee that lithium-ion (Li-ion) batteries attain high performance, long life, and a high level of safety. To investigate an effe...

Frost formation on a cold plate was modeled numerically using the frost formation resistance. A multiphase Eulerian method was used to model the humid-air and frost phases. The grids in the computational domain were classified into three zones, and a frost density threshold was suggested to construct an algorithm of frost growth and densification. To verify the present model, analyses were performed under various operating conditions, and the results were compared with published experimental results. In addition, the frost formation resistance was verified by analyzing the frost formation resistance profiles on the frost surface and at the frost inside, and temperature of the frost and absolute humidity of the humid-air inside the frost were also predicted using the verified model. This showed that the frost formation resistance matched the general well-known behavior of frost formation. The temperature of the frost and absolute humidity of the humid-air in the frost showed larger variation near the frost surface, which has lower frost density, than near the cold plate, which has higher frost density.

The environment temperature has great effects on temperature field of cold storage refrigerator car and melting process of cold storage materials. NaCl aqueous solution was used as the cold storage material, Solidworks was used to establish physical model of the cold storage refrigerator car, Gambit for meshing and Ansys was used to make simulation calculation. The simulation results indicate that: with the rise of temperature, the melting process of storage plate will be fast, the time of latent heat discharge will be shorter. The temperature field of car can stabilize in a high temperature and the time is short. When environment temperature is 303K, cold storage material needs 70.2h to be melted into salt solution. The temperature field of car can stabilize in 293K for 73.6h. At this moment, environment and the temperature of cold plate existed large difference in, heat exchange is large and the heat flux is 2.75W/h.

Effective thermal management is critical to the performance and durability of lithium-ion batteries for electric vehicles. As an alternative to conventional cold plates with straight channels, a new cold plate with divergent-shaped channels has been proposed to minimize the maximum temperature and pressure drop. Compared with conventional straight-shaped channels, the divergent-shaped channels exhibit enhanced performance with a higher heat dissipation capacity and lower frictional resistance. To further reduce the local flow resistance, divergent-shaped channels with two inlets and one outlet have been evaluated. This new design can successfully decrease the pressure drop by 7.2% and decrease the maximum temperature difference from 3.99 to 3.19 K. Finally, battery cooling modules with a counter-flow configuration have been constructed, which achieve a smaller maximum temperature difference. This work contributes to the development of effective and efficient battery cooling systems for electric vehicles.

This paper introduces additive manufactured (AM) two-phase heat pipe technology and advanced thermal management technologies, presented as a Keynote Lecture at the 16th UK Heat Transfer Conference at the University of Nottingham. AM heat pipes have been developed utilising laser powder bed fusion (LPBF) techniques to form titanium heat pipe vessels with integrated miniaturised lattice capillary wick structures. AM heat pipe technology developed in an European Space Agency (ESA) and an Innovate UK project are presented including a titanium-ammonia space mini-heat pipe assembly and a titanium-water two-phase heat pipe vapour chamber. In addition, various bespoke thermal management devices for high-end electronic applications in the space, aerospace and high-end automotive markets are introduced. Commercial examples of heat pipe technology, vacuum brazed liquid cold plate technology and k-Core encapsulated graphite technology are included.

The thesis has carried out design and simulated analysis of low flux cold plate for high-power power electronics equipment. First, according to heat distribution and design requirements, two kinds of flow passage for low flux cold plate is designed. Then performance characteristics simulation of different flow passage for cold plate is performed. And the heat dissipation characteristics of two kinds of flow passage can both meet the design requirements. Finally, from the perspective of high temperature, temperature difference, pressure drop and so on, the simulated results are comparative analysis. And it is helpful to the design and optimizing of cold plate for high-power power electronics equipment.

Liquid cooling is an efficient thermal management method. In response to the lightweight and compact demand faced by the development of battery thermal management system (BTMS), a thin baffled cold plate for liquid-based BTMS was designed. The accuracy of the simulation was verified through experiment. The influence of structure parameters on the heat transfer performance was explored. A structure optimization method called local connection was proposed for heat transfer enhancement. The baffled cold plate was applied to BTMS with battery at 3 C discharge rate to explore the effect on the temperature control performance. The results show that local connection optimization can simultaneously improve the comprehensive heat transfer performance and temperature uniformity of the baffled cold plate, and the maximum increase can be 24.71% and 6.71% respectively compared to Case 0–4-L75. The effect of the improvement is affected by the spacing, position, number of the local slits and the distance between the local slit and the channel corner apex. Local connection optimization can reduce the power consumption of baffled cold plate based BTMS while ensuring the temperature control performance, which can save energy.

To accurately control the frosting process, analyzing the influence of different factors on frosting is meaningful and challengeable, especially in the early frosting stage. According to the sensitivity analysis, the influence of different surface wettability and environmental factors on the growth of frost layer were quantitatively analyzed. Based on the experimental data on cold plate surface under forced convection conditions, new models with emphasis on the initial conditions of the frosting process are developed. Results show that supersaturation degree, supercooling degree and cold plate temperature are the key factors on the growth of frost layer, but their specific influence varies in the early frosting stage. And proportions of these three factors reach 39.42%, 35.58% and 21.15%, respectively. The coincidence rates of the new models with an error of 15% reach>90% for the whole frosting process, and 83% for the early frosting stage. Compared with previous models, the coincidence rates of the new models for the whole frosting process and the early frosting stage are increased by at least 8.86% and 15.28%, respectively. Contributions of this study are expected to predict the growth of frost layer in the early frosting stage and provide a reference for the optimal defrosting control of air source heat pumps.

The freezing process of a supercooled water droplet on a cold plate is studied theoretically and experimentally. A novel model that considers both the supercooling effect on the physical properties and the gravity effect on the droplet shape is developed to simulate the droplet freezing behaviors. The model introduces a dynamic contact angle coupled with a slipping velocity to describe the tip singularity formation. Experiments are conducted on 10, 20 and 30 μL supercooled water droplets and the droplet freezing behaviors including the freezing front movements and droplet profile evolutions are observed and analyzed using the image recognition technology. The freezing rates and times and the droplet profiles calculated by the model agree well with the experimental observations. The model can better predict the freezing characteristics especially the freezing rate and time than the traditional model that ignores the supercooling effect, with the deviation in freezing time decreasing from over 40% to about 10% for droplets with different volumes at different temperatures and a larger supercooling degree causing a more obvious difference between the new and traditional models. The calculation results suggest that the final droplet profile is less dependent on the supercooling degree because it is less affected by the freezing rate. As the cold plate temperature goes down, the freezing rate increases and the freezing time decreases.

In this paper, a numerical model using ANSYS Fluent for a minichannel cold plate is developed for water-cooled LiFePO4 battery. The temperature and velocity distributions are investigated using exp...