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High heat flow density electronic components need cooling plates with strong heat exchange capacity to maintain temperature balance. To obtain better cooling performance, four different flow channel types of cooling plates are designed, including an S-type channel, Z-type channel, mosaic channel and double-layer channel. The maximum temperature of the cooling plate, outlet temperature and pressure drop under different working conditions and coolant are analyzed by numerical simulation. The simulation results show that the double-layer channel design can effectively enhance the heat transfer effect of the cooling plate and reduce the pressure drop. The maximum temperature of the cooling plate of the double-layer flow channel is 6.88 °C lower than that of the Z-type flow channel. Moreover, increasing the inlet flow rate and lowering the coolant inlet temperature can improve the cooling performance of the cold plate, but increasing the inlet flow rate will lead to an increase in the pressure loss of the cold plate. When the coolant of the double- layer channel cooling plate is 20% ethylene glycol-water solution, the cooling performance is better than the other three coolants. Other channel cooling plates perform better with water as the coolant. [ABSTRACT FROM AUTHOR]

Modern Electric Vehicles (EVs) require high power and high efficient powertrains to extend their power range. A key element of the electric powertrain is its drive with an electric motor controlled by a traction inverter. A cooling system dissipates heat generated due to the losses in this inverter and keeps its temperature within limits, i.e. below the operational maximum value. Indirect cooling systems are often the preferred solution due to their easy implementation and robust separation of the electric/electronic parts and the coolant circuit. Indirect cooling comes with additional surface interfaces, hence thermal barriers and increased thermal resistance for the losses’ heat flow path. One way to increase the system’s heat transfer coefficient is by implementing power electronics with dual-sided cooling (DSC) solutions and by enhancing surface structures for the cold plates. Manufacturing complex cold plate solutions with internal surface-enhancing structures by way of classical techniques (e.g. aluminum extrusion with CNC machining) can be difficult, costly, or even not possible. Sealed one-piece solutions are preferred, without the need to weld parts or to use screws, glue, gaskets, etc. 3D metal printing allows to manufacture of a one-unit compact, light, and reliable cold plate. This study shows the advantages and limitations of a 3D metal-printed inverter cold plate by presenting the microchannel design, numerical thermal simulations, and experimental results for the liquid cooled DSC SiC and Si inverters. This work explores the compatible use of 3D metal printing solutions, which will aid the development of modern high-power density EVs.

AbstractThe efficient thermal management of Lithium-ion batteries (LIBs) stands as a critical factor in ensuring the reliable operation of electric vehicles. For managing multiple LIB modules, a common approach involves utilizing a cold plate for mounting. It has been suggested that this interspersed design proves more effective, especially for large-scale battery packs, in achieving smoother overall cooling performance and temperature uniformity. Consequently, we need a new cold plate design that not only enhances thermal performance for batteries emitting higher thermal loads but also ensures more uniform temperature distributions across battery surfaces, all while maintaining simplicity in manufacturability. In this study, we introduce a new cold plate design employing offset strip fins (OSFs) cores. We assess its thermal and hydraulic performance using objective functions such as the Colburn factor (j) and Fanning friction factor (f). Through optimization techniques, we determine the optimal shape parameters that maximize heat transfer rates on the cold plate, with only a marginal increase in pressure drop. This optimized configuration is then compared with both the baseline common cold plate and a reference OSFs cold plate. The results show a significant reduction of up to 32.3% in maximum temperature differences, signifying an improved temperature uniformity achieved with this new design. [ABSTRACT FROM AUTHOR]

In view of the heat dissipation of electronic components with high heat flux, five phase change heat transfer cold plates with different structures and processing methods were designed, the effects of cold plate structural parameters, heat flux, refrigerant flow rate, and heat source layout on heat transfer performance, resistance of cold plate, and the pump power consumption were experimentally studied. The results show that the designed perforated cold plate has excellent heat transfer performance. The designed perforated cold plate maintains a temperature difference of less than 25 ℃ between the heat source surface and the refrigerant inside the cold plate when dissipating a total heat output of 5 000 W and a heat flux of 38 W/cm2, with cold plate resistance less than 30 kPa and pump power consumption less than 35 W. The processing method of cold plate has a significant influence on its heat transfer effect. The cold plate should adopt integrated design as far as possible to reduce the link of heat transfer and avoid the contact thermal resistance caused by the chimerism of different materials. When multiple heat sources have different heat flux densities, placing the higher heat flux heat source closer to the inlet of the cold plate achieves better heat transfer efficiency.

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Thermally managing lithium-ion batteries (LIBs) are critical factor for ensuring the reliable operation of electric vehicles. The inherent narrow operating temperature range (e.g., from 25 °C to 40 °C) necessitates a dedicated thermal management system for desired and designed LIB performance. Due to the increasing specific energy density of the LIB packs especially for higher discharging loads, the LIBs have been thermally managed by various liquid convection systems. Among these, the most popular design is perhaps with coolant of forced convection in multichanneled cold plates that are inserted between LIBs. The most distinct disadvantage is the easy thermal saturation of the coolant along its paths, leading to fast degradation of cooling effectiveness. To overcome this, the thermal resistance model in the present work is used to optimize the configuration of a multiple serpentine channeled cold plate with equi-spacing. Consequently, we propose a new cold plate design that employs equi-width channels with unequi-spacing, providing more uniform temperature distribution on cold plate surfaces by decreasing 13% of the thermal standard deviation from 6.3 °C to 5.5 °C and 8% maximum local temperature difference from 26.3 °C to 24.1 °C, however, only 1% pressure drop higher. [ABSTRACT FROM AUTHOR]

The thermal performance of battery modules has a crucial role in the performance, safety, and lifetime of battery cells. Commonly, battery models are validated through experimental data to ensure the correctness of model behavior; however, the influences of experimental setups are often not considered in the laboratory environment, especially for prismatic cells such as lithium titanate oxide (LTO) battery cells used in electric vehicles. For this purpose, both experimental and numerical studies of the thermal performance of the battery module consisting of LTO cells was investigated using different cold plates used in electrical and hybrid vehicles. Three different discharging rates were applied to the battery module to obtain comparative results of the cooling performance. In the numerical simulations, heat generation models are typically used to observe the thermal behavior of the battery module; however, in the numerical study, dual potential multi-scale multi-domain (MSMD) battery models were used, with transient flow and heat transfer calculations performed. The numerical results were in good agreement with the experimental data. A new high-performance cold plate was developed for the thermal management of LTO battery cells. In comparison with the other two cold plate configurations, the proposed cold plate configuration dropped the maximum temperature up to 45% for the same operating conditions. [ABSTRACT FROM AUTHOR]

Machining stainless steel produces a high temperature in the cutting zone, leads to a decrease in the tool's longevity and also adversely affects the surface quality of the workpiece. Conventional cooling techniques are not effective in achieving better surface finish and less tool wear formation. This research introduces a novel refrigeration cycle-based workpiece cooling process to improve the machinability of AISI 304 stainless steel. The influence of this method in cutting zone temperature, surface roughness, tool wear formation and workpiece microstructure were compared with those of dry machining. The experimental results demonstrate that the proposed method provides a better surface finish, reducing roughness by 9 %, lowering the cutting zone temperature by 24 %–60 %, and minimizing wear on cutting tools under specific machining conditions. These findings can offer valuable insights for the manufacturing industry.

In this paper, we combine NTGK with flow and heat transfer model to perform numerical calculations on battery and cold plate to investigate thermal characteristics of li-ion batteries cooled by liquid and performance of cold plate during entire discharge process. A battery heat generation model is created using Kriging method after impacts of ambient temperature, SOC, and discharge rate are examined. Additionally, a new sort of cold plate is suggested based on constructal-theory, which performs better than conventional cold plate. Constructal cold plate reduces time needed for battery average temperature and maximum temperature differential to 25 °C and 5 °C by 15.25 % and 10.58 % for TimeT and TimeΔT, respectively, and pressure drop Δp by 22.89 % when compared to straight channel cold plate. Cooling effect of constructal cold plate is marginally inferior to that of serpentine cold plate, but flow resistance is greatly decreased, and pressure drop is only about one-tenth that of serpentine cold plate. Performance of constructal cold plate was examined using orthogonal optimization to determine effects of width of inlet and outlet and length of major channels. TimeT, TimeΔT, and Δp are decreased by 11 %, 14.69 %, and 15.22 % after optimization, and comprehensive performance is nearly doubled with improved performance.

Aiming at the heat dissipation of electronic components with high heat flux, five phase change heat transfer cold plates with different structures and processing methods were designed, the effects of cold plate structural parameters, heat flux, refrigerant flow rate, and heat source layout on heat transfer performance, resistance of cold plate, and the pump power consumption were experimentally studied. The results show that the designed perforated cold plate has excellent heat transfer performance. The designed perforated cold plate maintains a temperature difference of less than 25 ℃ between the heat source surface and the refrigerant inside the cold plate when dissipating a total heat output of 5 000 W and a heat flux of 38 W/cm~2, with cold plate resistance less than 30 k Pa and pump power consumption less than 35 W. The processing method of cold plate has a significant influence on its heat transfer effect. The cold plate should adopt integrated design as far as possible to reduce the link of heat transfer and avoid the contact thermal resistance caused by the chimerism of different materials. When multiple heat sources have different heat flux densities, placing the higher heat flux heat source closer to the inlet of the cold plate achieves better heat transfer efficiency. [ABSTRACT FROM AUTHOR]

The battery thermal management system (BTMS) for lithium-ion batteries can provide proper operation conditions by implementing metal cold plates containing channels on both sides of the battery cell, making it a more effective cooling system. The efficient design of channels can improve thermal performance without any excessive energy consumption. In addition, utilizing phase change material (PCM) as a passive cooling system enhances BTMS performance, which led to a hybrid cooling system. In this study, a novel design of a microchannel distribution path where each microchannel branched into two channels 40 mm before the outlet port to increase thermal contact between the battery cell and microchannels is proposed. In addition, a hybrid cooling system integrated with PCM in the critical zone of the battery cell is designed. Numerical investigation was performed under a 5C discharge rate, three environmental conditions, and a specific range of inlet velocity (0.1 m/s to 1 m/s). Results revealed that a branched microchannel can effectively improve thermal contact between the battery cell and microchannel in a hot area of the battery cell around the outlet port of channels. The designed cooling system reduces the maximum temperature of the battery cell by 2.43 °C, while temperature difference reduces by 5.22 °C compared to the straight microchannel. Furthermore, adding PCM led to more uniform temperature distribution inside battery cell without extra energy consumption. [ABSTRACT FROM AUTHOR]

It is aimed to minimize carbon emissions and the spread of electric vehicles is supported for a more sustainable future. To increase the safety and life of these vehicles, cooling systems are added and developed to their energy storage systems. The aim of this study is to design and optimize the cooling plate for the lithium-ion battery pack used in a lightweight commercial electrical vehicle. Multi-objective optimization using Taguchi–grey relational analysis was performed by considering maximum temperature, the standard deviation of temperature, and pressure drop for the design of the cold plate. Channel number, channel height, and mass flow rate values were determined as parameters to be examined, and three different levels were selected for each parameter. Analysis was performed using water and 25% and 50% ethylene glycol–water solutions, which can work under sub-zero environmental conditions, employed as cooling fluid. It is shown that increasing the ethylene glycol ratio in the coolant allows it to work in colder environmental conditions, it is relatively worsening thermal performances in the cold plate applications. A new empirical correlation is proposed to predict the Nusselt number for the three coolants under all geometric and operating conditions considered in this study. Statistical analysis shows that the number of channels is the most effective parameter for the relatively low and homogenous temperature distribution on the cold plate surface. A sensitivity analysis was performed for Reynolds number ranges from 2500 to 15,000 using the optimum configurations of the three coolant fluids. It is shown that the same cooling effects could be obtained by using 1.56 times and 2.66 times more mass flow rates for 25% and 50% ethylene glycol–water solutions, respectively, compared to the water. However, rising mass flow rates result in a significant increase in the required pumping power. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This paper proposes a multidisciplinary topology optimization design model and method for the cold plate of active phased antenna array. Aiming at the characteristics of multidisciplinary integration of active phased antenna array, a multidisciplinary analysis model considering the thermal effect is established. Based on the multidisciplinary analysis model of antenna array, topology optimization method is used to establish a multidisciplinary optimal design model for the cold plate of antenna array. Since there is no explicit relationship between the electrical performance indicators of the antenna and the topological design variables, the adjoint method is used to derive the adjoint-governing equations that simultaneously consider fluid flow, system heat dissipation, and antenna electrical performance. The corresponding sensitivity information is obtained by solving the adjoint-governing equation. The correctness and effectiveness of the proposed model and method are verified by typical cases. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries are widely used in electric vehicles because of their high capacity and voltage. However, some drawbacks to the battery stability exist. The aim of our research was to determine the optimum width and number of channels of a cold plate. To estimate the temperature distribution and heat transfer rate, the MSMD (multi-scale multi-dimensional) - Newman P2D model in ANSYS Fluent was used. Prior to comparing the heat transfer rates of the various battery surfaces using different cold plates, the surface temperature of the battery (LiFePO4) at discharge rates of 2C, 3C, and 4C was calculated to determine the battery characteristics. Subsequently, two cold plates were attached to both sides (front and back) of the batteries and the heat transfer rate of the battery surface in contact with the cold plate, and the pressure drop between the inlet and outlet of the channels during the discharge process were estimated. In addition, the j and f factors, which are used to estimate the cooling performance of the cold plates, were calculated. In determining the most efficient cold plate options, the trade-off between the heat transfer coefficient and the pressure drop is also important for the relationship between the two factors (j and f factors). [ABSTRACT FROM AUTHOR]

Electric vehicles (EVs) have become a viable solution to the emerging global climate crisis. Rechargeable battery packs are the basic unit of the energy storage system of these vehicles. The battery thermal management system (BTMS) is the primary control unit of the energy source of the vehicles. EV performance is governed by specific power, charging/discharging rate, specific energy, and cycle life of the battery packs. Nevertheless, these parameters are affected by temperature, making thermal management the most significant factor for the performance of a battery pack in an EV. Although the BTMS has acquired plenty of attention, research on the efficiency of the liquid cooling-based BTMS for actual drive cycles has been minimal. Liquid cooling, with appropriate configuration, can provide up to 3500 times more efficient cooling than air cooling. Direct/immersive and indirect liquid cooling are the main types of liquid cooling systems. Immersive/direct cooling utilizes the technique of direct contact between coolant and battery surface, which could provide larger heat transfer across the pack; however, parameters such as leakage, configuration, efficiency, etc., are needed to be considered. Indirect cooling techniques include cold plates, liquid jackets, discrete tubes, etc. It could result in complex configuration or thermal non-uniformity inside the pack. The paper intends to contribute to the alleviation of these gaps by studying various techniques, including different configurations, coolant flow, nanoparticles, varying discharging rates, different coolants, etc. This paper provides a comprehensive perspective of various techniques employed in liquid cooling battery packs, identifying the shortcomings in direct/immersive and indirect liquid cooling systems and discussing their mitigation strategies. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.

Power electronic equipment to miniaturization, high integration direction while facing the problem of high heat flow density and uneven temperature distribution. The large temperature fluctuations and uneven temperature distribution in the operation of power electronic equipment will lead to thermal stress, and excessive thermal stress or uneven distribution will cause fatigue failure of the packaging material, resulting in reduced reliability, module failure, and reduced life of power electronic equipment. In this paper, we propose two kinds of liquid-cooled flow channel non-linear reinforced heat transfer homogeneous liquid-cooled plate, which is theoretically derived to achieve the design requirement of uniform temperature on the heating side wall surface. The thermal design of the cold plate is carried out using ANSYS Workbench, and the indicators of various structures of the cold plate are analyzed and compared in terms of their ability to dissipate heat and maintain temperature uniformity. Based on the original runner structure, the heat dissipation performance of the rod structure and fin structure was evaluated, and the form of the internal heat dissipation structure of the runner was determined. The results show that the integrated liquid cooling plate temperature uniformity and flow resistance of both factors, the fin column heat sink is significantly better than the cylindrical fin column heat sink in the case of the same thermal resistance, the fin column heat sink flow resistance is significantly lower than the cylindrical fin column heat sink.

The trend of transition from fossil fuel to electrification in transportation is a result of no carbon emission produced by electric vehicles (EVs) during their daily operations. Furthermore, the global carbon footprint of EVs can be minimized if the electricity is generated from renewable sources such as wind and solar. On the other hand, there are some drawbacks of these vehicles such as charging time being very long and the mileage range of vehicles not at the desired level. Battery cells are being charged at relatively high C‐rates to eliminate these problems, yet high current rates accelerate the aging of batteries and capacity losses due to the generated heat. Generated heat causes overheating, and excess temperature triggers degradation and thermal runaway risks. This paper uncovers how the battery pack temperature uniformity and strict thermal control can be achieved with heat transfer enhancement by conduction (cold plates) and convection (vascular channels). We aimed to reduce the energy consumption of the EV battery pack system while increasing the thermal performance. The impact of the thermal contact resistance is also considered for many realistic scenarios. The results indicate that an integrated system with cold plates and vascular channels satisfies the temperature uniformity requirement (over 81%) with comparatively less pumping power (∼72%) of advanced electric vehicles for relatively high C‐rates. Furthermore, findings show the temperature level can increase up to 4°C as thermal contact resistance increases. The proposed cooling technique, which has low cost, easy application, and lower energy consumption superiorities, can be implemented in palpable EV battery packs. [ABSTRACT FROM AUTHOR]

The battery thermal management system with phase change material coupled cold plates was investigated with the numerical simulation method. The results show that, the temperature and temperature difference of the battery pack decreases with the increase of the flow rates of the cold plate in the system, while the power consumption of the cold plate significantly increases, which leads to poor efficiency of the system. To improve the efficiency of the coupled thermal management system, an adjusting strategy was introduced to optimize the thickness distribution of phase change materials with the system volume fixed. The optimized results of typical cases show that, the optimal phase change material thickness distribution can be obtained by only 5 adjusting steps. Compared with the original system, the maximum temperature of the battery pack drops by 1.1 K and the temperature difference narrows down by 29% after the optimization. To achieve the same temperature difference in the battery pack, the power consumption of the optimized system lowers down by 64% compared with that of the original system. [ABSTRACT FROM AUTHOR]

To maintain the optimal operating temperature range for the power batteries of new energy vehicles, this paper proposes a novel tree-structured channel cold plate. An orthogonal experimental approach was employed to investigate the effects of inlet flow rate m, inlet channel quantity n, channel width d, and hierarchy ratio α on battery temperatures T max , standard temperature difference T σ , and pressure drop Δ P. Non-dominated sorting genetic algorithm II (NSGA-II) was utilized to obtain an optimized solution set. The results reveal that the tree-like cold plate configuration including m = 15 g/s, n = 7 and 8, d = 3 mm, and α = 1:2:1 demonstrates superior performance. Thus, the developed cold plate was further compared with the conventional straight-through cold plate design. The results indicate that the proposed tree-like cold plate exhibits the maximum decreases of 13.94% in T max , 52.94% in T σ , and 61.5% in Δ P. The most significant improvement in the composite indicator PEC was 89%. In conclusion, the tree-like channel cold plate developed in this study provides excellent heat dissipation capability for power batteries, offering valuable insights for the thermal design of battery liquid cooling systems. [ABSTRACT FROM AUTHOR]

The battery thermal management system (BTMS) for lithium-ion batteries can provide proper operation conditions by implementing metal cold plates containing channels on both sides of the battery cell, making it a more effective cooling system. The efficient design of channels can improve thermal performance without any excessive energy consumption. In addition, utilizing phase change material (PCM) as a passive cooling system enhances BTMS performance, which led to a hybrid cooling system. In this study, a novel design of a microchannel distribution path where each microchannel branched into two channels 40 mm before the outlet port to increase thermal contact between the battery cell and microchannels is proposed. In addition, a hybrid cooling system integrated with PCM in the critical zone of the battery cell is designed. Numerical investigation was performed under a 5C discharge rate, three environmental conditions, and a specific range of inlet velocity (0.1 m/s to 1 m/s). Results revealed that a branched microchannel can effectively improve thermal contact between the battery cell and microchannel in a hot area of the battery cell around the outlet port of channels. The designed cooling system reduces the maximum temperature of the battery cell by 2.43 °C, while temperature difference reduces by 5.22 °C compared to the straight microchannel. Furthermore, adding PCM led to more uniform temperature distribution inside battery cell without extra energy consumption.

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.

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.

Copyright of Journal of Engineering & Architectural Faculty of Eskisehir Osmangazi University / Eskişehir Osmangazi Üniversitesi Mühendislik ve Mimarlık Fakültesi Dergisi is the property of Eskisehir Osmangazi University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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 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.

• The pseudo 3D topology optimization approach for cold plate design was introduced. • Penalty coefficients, objective function weights, and re substantially influenced the results of topology optimization. • Temperature variance constraints greatly enhanced topology optimized cold plate temperature uniformity. • Topology optimized cold plate showed excellent heat dissipation and temperature uniformity. • Topology optimized cold plates outperformed parallel flow channel cold plates in cooling performance. This study develops a liquid-cooled cold plate for battery packs in electric vehicles using pseudo three-dimensional topology optimization techniques. The objective of optimization is to reduce both temperature and energy consumption of flow, while simultaneously enhancing the temperature uniformity of the structure by using temperature variance as a constraint in the topology optimization procedure. An analysis was conducted to establish the structure of the cold plate by examining the impacts of topological optimization penalty coefficients, Reynolds number, objective function weights, and temperature variance limitations on the optimization outcomes. Ultimately, the numerical simulation assesses the thermal efficiency and flow properties of the topology optimized cold plate within a battery pack. It demonstrates superior heat dissipation and temperature uniformity when compared to the Parallel-channel cold plate. With a mass flow rate of 0.0052 kg/s, the battery equipped with topology optimized cold plate has an average temperature of 302.9 K, a maximum temperature of 304.25 K, and an internal temperature difference of 4.7 K. The average temperature is 1.18 K lower and the maximum temperature is 1.8 K lower compared to the battery with Parallel-channel cold plate. This study offers a highly effective resolution to the issue of cold plate design for battery heat dissipation. [ABSTRACT FROM AUTHOR]

To maintain the optimal battery performance, it is essential to develop an efficient battery thermal management system for keeping the battery operation temperature within the appropriate range. In this work, a novel design of cold plate featuring airfoil fin channel is developed as a highly effective cooling module of a prismatic LiFePO 4 battery pack. The thermal performance of battery and the thermo-hydraulic performance of the cooling module for the cold plate featuring airfoil fin channel, U-type channel and serpentine channel are numerically investigated and compared to reveal the superiority of the novel cold plate. The results indicate that compared with the U-type channel and the serpentine channel, the airfoil fin channel can enhance the total heat dissipation amount by 3.47% and 4.64%, respectively. Besides, the airfoil fin channel can provide the smallest battery maximum temperature and temperature difference under the same coolant flow rate. The airfoil fin channel provides the smallest pressure loss and heat transfer coefficient but the largest overall thermo-hydraulic performance indictor in terms of j / f factor. Under the same requirement of battery cooling performance, the remarkably smaller power consumption is required for the airfoil fin channel compared with the U-type channel and serpentine channel. • A novel cold plate with airfoil fins is designed for cooling battery. • Performance of airfoil fin cold plate and two conventional cold plates is compared. • Airfoil fin cold plate is of the largest heat dissipation capacity. • Airfoil fin cold plate is of the best overall performance. [ABSTRACT FROM AUTHOR]

This study investigates improving traditional immersion cooling systems by employing cold plates in single-phase immersion cooling with dielectric fluids (Noah@3000 A and PAO-4). Experimental and CFD methods explore various cold plate structures in a 1 U server with a TTV heat source. Flow rates range from 1 to 3 LPM, and configurations include side-open, fully enclosed, and dual-open designs. Results show that incorporating cold plates reduces fluid bypass, enhancing thermal performance. High-viscosity dielectric oil as a coolant yields substantial improvements (36.1% and 41.6% at low and high flow rates) compared to traditional systems. Thermal resistance decreases with higher flow rates, more notably for Noah@3000A. Immersing the cold plate in liquid enhances convective heat transfer, reducing thermal resistances by 7.2% and 9.4% for Noah@3000A and PAO-4 at low flow rates. Smaller fin pitch consistently lowers resistance by eliminating bypass. Outlet configuration significantly influences thermal resistance, with Enclosed cold plates showing the least performance for PAO-4 and dual-open cold plate yields the worst performance with Noah@3000A. Differences in heat transfer behavior between PAO-4 and Noah@3000A are linked to laminar and turbulent flow characteristics. These findings offer insights into optimizing immersion cooling systems, emphasizing the impact of fluid choice and cold plate design on thermal performance. [ABSTRACT FROM AUTHOR]

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.

Li-ion batteries are widely used in electric vehicles for their superior performance. To investigate a simple and efficient method for the Li-ion power batteries, the cold plate with four types of structures A, B, C, and D were established, respectively. Subsequently, the effects of micro-channel thickness and width on the cooling performance of battery thermal management systems were analyzed by using a numerical simulation method. The results show that with the increases of the micro-channel thickness, the maximum temperature, Tmax, of the cold plate is gradually increased under structures A, B, and C, while it is gradually decreased under structure D. The standard deviation of temperature, Ts, of the cold plate of structure A was less affected by the change of the micro-channel thickness. Under structures B, C, and D, the temperature uniformity of the cold plate can be well maintained when the micro-channel thickness was 1.0 mm. With the increase of the micro-channel width, the Tmax and Ts of the cold plate are gradually increased in all cases, while the ΔP from the inlet to outlet is gradually decreased. The temperature uniformity of the cold plate is well maintained by structure C. The decreasing amount and changing range of ΔP caused by the change of micro-channel width is smaller than caused by the change of the thickness. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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.