Performance Of Thermal Management System Research Articles

Wave and straight plenum effects on thermal management system performance

The need to offset heat generated by batteries in electric vehicles (EVs) necessitated the design and development of battery thermal management systems (BTMS), one of which adopt air cooling technique. The redesign of plenums of the BTMS has been beneficial in the enhancement of the BTMS's performance. In view of these, this study considered wave and straight design of plenums in an attempt to enhance the performance of the system. The proposed designs were investigated using Computational Fluid Dynamics (CFD) methodology. The CFD methodology was validated by first investigating the conventional Z-design of BTMS with straight plenums and the results were compared with existing results from experiments in literature. Findings from the study revealed that by replacing straight-horizontal plenum with straight-inclined plenum, maximum temperature (Tmax), and maximum temperature difference (ΔTmax) of the Z-design was reduced by 3.47 K and 6.82 K, respectively, with increase in pressure drop (ΔP) by 2.24 Pa and pumping power (Pp) by 0.01 W.Furthermore, by adopting wave-inclined plenum design, Tmax, and ΔTmax were reduced by 4.61 K and 8 K, respectively when compared with the conventional Z-design BTMS. More so, the pressure drop (ΔP) and pumping power (Pp) increased by 3.17 Pa and 0.0133 W, respectively. The study generally revealed that careful redesign of divergence plenum with inclined straight and wave-like structure will enhance the thermal performance of BTMS.

Performance of thermal management system for cylindrical battery containing bionic spiral fin wrapped with phase change material and embedded in liquid cooling plate

To enhance the cooling and preheating performance of the battery, a novel hybrid battery thermal management system (BTMS) containing bionic spiral fins wrapped with phase change material (PCM) and embedded liquid cooling is proposed. The cylindrical battery is strategically positioned on a spiral fin, the heat of the battery and PCM is transferred to the cold plate through the extended winglets. The thickness (L1), height (L2), distance (L3) and number of winding turns (N) of fin are optimized using the response surface method (RSM). The effects of the liquid cooling duration, flow rate, channel shape and direction of the flow channel on the latent heat recovery of PCM and the cooling performance of the battery module are analyzed. The results demonstrated that at the duration of 600 s and flow rate of 0.09 g/s, the liquid fraction of PCM reduced from 57 % to 26 %. Furthermore, the preheating efficiency of the BTMS was investigated under different parameter configuration and boundary conditions. The preheating temperature increased by 5.6 °C compared with the BTMS without fins. Additionally, the temperature difference (ΔT) of the BTMS with Layout 2 decreases by 0.5 °C compared with 4.1 °C of Layout 1 at flow rate of 0.5 g/s.

Optimal operation of lithium-ion batteries in microgrids using a semidefinite thermal model

The growing adoption of microgrids necessitates efficient management of electrical energy storage units to ensure reliable and sustainable power supply. This paper investigates a thermal management system (TMS) for maintaining the longevity of large-scale batteries. To streamline the thermal modeling of batteries, the McCormick relaxation method is employed to linearize a nonlinear and interdependent heat generation model. The thermal model of the battery follows a nonlinear behavior where the generated heat makes the battery system temperature soar, thereby affecting the thermal performance of the battery. To showcase the efficacy of the proposed approach, four distinct case scenarios are studied, highlighting the critical importance of batteries within microgrid operations. A comparative analysis is conducted between linear and nonlinear models for TMS performance. A quantitative assessment based on simulation results demonstrates the precision of the linearized model, particularly in a multitemporal optimal power flow and day-ahead scheduling of microgrids incorporating energy storage units. Controlling the battery temperature within a permissible range (from 15 °C to 40 °C) is achieved by using a heating, ventilation, and air conditioning (HVAC) system. The paper explores the economic implications of energy storage units in microgrids by extracting and comparing daily operational costs with and without battery integration. The findings reveal that the inclusion of energy storage units yields substantial economic benefits, with potential profit margins of approximately 20 % during typical working days and 60 % on weekends.

Experimental study on top liquid-cooling thermal management system based on Z-shaped micro heat pipe array

The traditional bottom liquid-cooling thermal management system (TMS) has poor cooling performance and is prone to causing significant temperature difference in the lithium-ion battery (LIB) module. In order to solve the above problems, this study takes the Z-shaped micro heat pipe array (MHPA) as the core heat transfer element and establishes a top liquid-cooling (TLC) TMS based on Z-shaped MHPA. The thermal management performance of the TLC TMS based on Z-shaped MHPA is analyzed by comparing it with the traditional bottom liquid-cooling TMS. Results show that under the conditions of 40 °C ambient temperature and 25 °C cold water inlet temperature, the bottom liquid-cooling TMS can no longer meet the thermal management requirements of the module at a 2C charge–discharge rate. In comparison, the TLC TMS based on Z-shaped MHPA can ensure the module's maximum temperature below 55 °C, and the battery and module level's temperature difference can be controlled below 4 °C under 3C charge–discharge rate. The TLC TMS based on Z-shaped MHPA can not only effectively delay the battery's temperature rise under high charge–discharge rate, but also significantly reduce the temperature difference; its thermal management performance is significantly better than the bottom liquid-cooling TMS.

Cooling performance of thermal management system for lithium-ion batteries using two types of cold plate: Experiment and MATLAB/Simulink-Simscape simulation

The thermal management system for lithium-ion batteries (LIBs) was investigated to improve the operating performance of LIBs. Experiments with two battery packs that integrate two different types of cold plates, Type I and Type II, were conducted to compare the cooling efficiencies of the battery thermal management system (BTMS). The interior heat generation of the battery modules was analyzed. Because of safety concerns, the battery pack in the experiment was replaced by heaters. A comparative experiment with a cell and heater was conducted under the same parameter conditions to compare the heating properties. The MATLAB/Simulink - Simscape toolbox (version R2020b) was used to simulate the thermal characteristics of a cylindrical cell and a battery pack. The thermal resistance was analyzed to investigate the cooling efficiency of the cold plates. As the results, the heater produced 10% higher temperature than the Li-ion cell under same conditions. In Type I, the thermal resistance decreased with an increase in the C-rates, whereas in Type II, it remained constant at 0.001. The simulation results were verified accurately through comparison with experimental results. Both experimental and simulation results show cold plate Type II has outstanding cooling performance than Type I.

Enhancing performance of nanofluid mini-channel heat sinks through machine learning and multi-objective optimization of operating parameters

The improvement in the performance of power systems in new energy vehicles has posed new demands for the performance of thermal management systems, leading to an increased interest in the application of nanofluid mini-channel heat sinks. Despite their potential, studying nanofluids is challenging due to the complexity of their preparation. To mitigate the computational and optimization costs, this study proposed a combination of Computational Fluid Dynamics (CFD) and machine learning in a multi-objective optimization algorithm for optimizing the operating parameters of nanofluid mini-channel heat sinks. Firstly, a numerical model of the nanofluid mini-channel was developed using the Mixture model to generate the dataset for machine learning models. Secondly, SVR, GPR, and RF models were utilized to establish the mapping relationships between the parameters of the nanofluid mini-channel, including the inputs of the inlet Reynolds number (Re), volume fraction (φ), and heat flow density (q), and the outputs of the pressure drop (△P) and the average temperature of the heating wall (Tave). The results indicated that the GPR model was the most suitable, with R2 values of 0.9939 and 0.9985 for Tave and △P, respectively. By employing the NSGA-II multi-objective optimization algorithm, the optimal value of φ was determined for different operating conditions, with values of around 3% at low Re and around 2% at high Re.

Research on performance of thermal management system for lithium-ion power battery

According to battery thermal management system’s design theory, a battery module with thermal management system is designed in this article, and the thermal management system model is simulated. By establishing thermal management system’s simulation model, modular thermal management system’s performance is analyzed.The simulation consequences show that the liquid cooling plate’s outlet temperature is higher than the inlet temperature, so the temperature rise and outlet temperature of the cooling liquid of a single battery module that cools system should be properly controlled. Through the thermal imager experiment, the test consequences are consonant with the simulation analysis’s conclusions.The reliability and accuracy of the simulation analysis is verified by the experiment, and shows the rationality of the design of the thermal management system for power battery.

Liquid-based battery thermal management system performance improvement with intersected serpentine channels

A thermal management system that could maintain the temperature within the proper range is essential for lithium-ion batteries. Apart from the thermal performance, the pumping power needs to be reduced to increase the system efficiency. In this study, intersecting channels were integrated into the conventional serpentine channel to improve the performance of liquid-based thermal management system for prismatic lithium-ion batteries. Numerical results showed that adding intersecting channels could significantly decrease the required pumping power, thereby enhancing the thermal performance at given power cost. Compared to straight design, V-shape intersecting channel design performs better in terms of the thermal performance. Besides, the effects of influencing factors including the intersecting number, intersecting width and on the thermal characteristics of V-shape intersecting serpentine channel were investigated. Results demonstrated that all the structural parameters had an optimum value within the studied range. The best thermal performance subject to the power cost was achieved with the intersecting number of 7, width of 2.0 mm and angle of 45°. The gradient intersecting spacings was developed to further alleviate the temperature imbalance within the battery. It is seen that the thermal performance was improved with the channel spacing gradient, especially when the spacing gradient was 2 mm.

Role of phase change material in improving the thermal management performance of the fast charging module

The development of fast charging piles is essential for promoting the full adoption of electrical vehicles. Associated with fast charging is the challenge of an efficient thermal management solution for the charging module. This study explores the role of phase change material (PCM) in improving the thermal management performance of the fast charging module. The enthalpy-porosity model is given with convection and radiation heat transfer boundary conditions. A comparative analysis of the thermal management system performance with and without the PCM is performed. The results show the better performance for such a hybrid cooling system is given in the phase change endothermic process. However, the low thermal conductivity constrains its performance in the larger convective heat transfer coefficient. Increasing the thermal conductivity and heat absorption capacity of the PCM will give rise to better temperature control performance. The emissivity of the shell has become an essential part in the thermal management performance as the PCM is completely melted and the charging module temperature is increasing. The coupling effects of PCM with the convection, radiation heat transfer, and operating condition will further exhibit superior performance.

A design optimization study of an air-cooling battery thermal management system for electric vehicles

Air cooling is a highly cost-effective method for the battery thermal management systems due to its simple structure, high reliability and low maintenance cost. Different from other designs of only a single inlet/outlet structure in the literature, an air-cooling battery thermal management system with multiple inlets/outlets design was proposed in this paper. The effects of inlet/outlet positions and dimensions on the air-cooling battery thermal management system performance were thoroughly evaluated and compared. The optimal inlet/outlet position and dimension were identified based on the maximum battery temperature and the temperature uniformity in the air cooling field. The results showed that the symmetrical double inlets/outlets design (Design 4) delivered the top temperature uniformity with the lowest energy consumption. During 1C discharging at 2 m/s inlet airflow, the maximum temperature and temperature difference of the Design 4 were 1.01 K and 2.24 K lower than those of the basic Design 0 in addition to a pressure difference reduction of 7.85 Pa. Based on the optimal Design 4, 0.03 m outlet width could further reduce the maximum temperature and temperature difference by 0.47 K and 0.28 K than the worst 0.05 m design. Furthermore, 52 additional simulations under different operating conditions had proven that the superb cooling performance of the optimal design during mild discharging operations (0.5–1C).

Sustainable thin-film condensation with free surface flow through water film network

In various energy industries, sustainable and efficient condensation is crucial for minimizing energy system size and cost. This study developed a water drainage system (i.e., a water film network), which mimicked the fast water transport through the water film on Sarracenia trichomes, for sustainably enhanced condensation even on a hydrophilic surface. The water film network absorbed and drained the surrounding microscale condensates because of the Laplace pressure difference, resulting in the continuous shedding or the thin-film condensation (< few micrometers thick). The water film network enhanced the dew harvesting efficiency by up to 577.8%, and thin-film condensation was sustained even under harsh conditions that oxidized the surface. Our findings suggest a way to sustainably enhance condensation performance without hydrophobic functionalization, and provide insights that the free surface flow through the water film channel can significantly improve the performance of thermal management systems through the minimization of the viscous pressure drop.

Performance of liquid cooling battery thermal management system in vibration environment

Battery thermal management system (BTMS) is an important component to the safety of electric vehicles, but few studies have considered the impact of vehicle vibration environment on the performance of thermal management systems. In this context, the performance of liquid cooling BTMS in vibration environment is discussed. To make better use of vibration, a novel structure based on the classical serpentine channel is proposed. Compared with the original structure, the cooling performance of the novel one under vibration is obviously improved. For novel structures with different design parameters, vibration reduces the average temperature of the channel wall by 1.8 K and increases the wall-averaged Nusselt number to at least 17, twice that of original structure, while the increase in pressure drop is insignificant. The mechanism and influencing factors are also preliminarily discussed. The work analyzed BTMS under actual working condition and provided a new direction for the design of high-performance BTMS.

MULTI-OBJECTIVE OPTIMIZATION OF LIQUID COOLING SYSTEM FOR A TWELVE-CELL BATTERY MODULE

In this research, two cooling plates with six parallel channels are designed for a twelve-cell battery module. The heat generated by a Li-ion battery cell is numerically modeled, and the numerical model is validated with the experimental data. The temperature difference of the battery cells in the battery module is an important factor for the capacity usage and cycle life of a battery module. The aim of this study is to design an optimum cooling system that will increase the cycle life of the batteries by decreasing the temperature difference and reducing the parasitic power consumption of the pump by reducing the pressure drop. The channel height, channel width, and the ratio of the outlet height to the inlet height are selected as design variables. In recent years, several evolutionary multi-objective optimization techniques have been presented to improve the performance of thermal management systems. In this study, CMOPSO is used for the optimization of the liquid cooling system. The results of the NSGA-II, NSGA-III, MOPSO, and CMOPSO techniques are evaluated to compare the efficiency of different optimization techniques. The results of four different multi-objective optimization methods are close to each other and have good agreement with the CFD results to reduce the temperature difference and pressure drop. A 30.3% decrease in the temperature difference and a 5.3% decrease in the total pressure drop are achieved with CMOPSO as the optimization technique. The results show the effectiveness of CMOPSO as the optimization technique for the design of battery cooling systems.

Performance of Thermal Management System for Battery Electric Vehicle with Different Refrigerants in Heating Mode

Performance of Thermal Management System for Battery Electric Vehicle with Different Refrigerants in Heating Mode

Numerical simulation of the effect of battery distance and inlet and outlet length on the cooling of cylindrical lithium-ion batteries and overall performance of thermal management system

In this paper, the cooling system of a two-dimensional lithium-ion battery pack with 9 battery cells is simulated. The airflow at the Reynolds number range from 80 to 140 flows through the cooling system. In this analysis, the temperature of all 9 battery cells is examined separately. The amount of pressure drop and temperature of the cooling system is assessed. Another geometry variable is the size of the inlets and outlets, which are changed simultaneously between 0.1 and 0.2. The finite element method is used for the simulations. The findings suggest that increasing the Reynolds number lowers the battery pack's maximum temperature. At a Reynolds number of 80, increasing the input temperature raises the maximum temperature of all the battery cells except the one in the battery. In model 6, this increase has increased the maximum temperature by more than 40%. Increasing the intake size raises the maximum temperature of all battery cells at other Reynolds numbers. The battery cell located at the inlet has the minimum, and the battery cell located at the outlet side has the maximum temperature. An enhancement in the Reynolds number and inlet size intensifies the pressure drop in the cooling system.

Research on performance of thermal management system integrated with multiple heat exchange methods

Research on performance of thermal management system integrated with multiple heat exchange methods

Holistic 1D Electro-Thermal Model Coupled to 3D Thermal Model for Hybrid Passive Cooling System Analysis in Electric Vehicles

Thermal management is the most vital element of electric vehicles (EV) to control the maximum temperature of module/pack for safety reasons. This paper presents a novel passive thermal management system (TMS) composed of a heat sink (HS) and phase change materials (PCM) for lithium-ion capacitor (LiC) technology under the premise that the cell is cycled with a continuous 150 A fast charge/discharge current rate. The experiments are validated against numerical analysis through a computational fluid dynamics (CFD) model. For this purpose, a comprehensive electro-thermal model based on an equivalent circuit model (ECM) is designed. The designed electro-thermal model combines the ECM model with the thermal model since the performance of the LiC cell highly depends on the temperature. Then, the robustness of the model is evaluated using a precise second-order ECM. The extracted parameters of the electro-thermal model are verified by the experimental results in which the voltage and temperature errors are less than ±5% and ±4%, respectively. Finally, the thermal performance of the HS-assisted PCM TMS is studied under the fast charge/discharge current rate. The 3D CFD results exhibit that the temperature of the LiC when using the PCM-HS as the cooling system was reduced by 38.3% (34.1 °C) compared to the natural convection case study (55.3 °C).

Experimental investigation of thermo-convection behaviour of aqueous binary nanofluids of MgO-ZnO in a square cavity

An innovative way of advancing thermo-convection performance of thermal management systems is the application of binary nanofluids (BNFs) as thermal working fluids. This paper experimentally investigated for the first time the thermo-convection behaviour of MgO-ZnO nanoparticles dispersed in deionised water (DIW) for concentrations of 0.05 vol% and 0.1 vol% at percentage weight ratios (PWRs) of 20:80, 40:60, 60:40, 80:20 (MgO-ZnO) in a square cavity. Several parameters such as Ra, Nuav, hav, and Qav at different temperatures gradients (20 °C to 50 °C) were investigated. Viscosity and thermal conductivity of the BNFs and DIW were experimentally obtained for the studied temperatures. Temperature gradient and PWRs of hybrid nanoparticles in the BNFs were noticed to enhance Nuav, hav, and Qav. In addition, maximum enhancement achieved were 72.6% (Nuav), 76.01% (hav), and 72.2% (Qav). The use of BNFs in a square cavity proved to yield good enhancement for thermo-convection performance. A new model linked to φ and PWRs has been introduced to predict Nuav. The novel outcomes of this study further corroborate the synergetic advantage of using BNFs over NFs.

The effect of reducing the thermal contact resistance on the performance of battery thermal management system

With the increasing demand for the driving range of new energy vehicles, the energy of power battery is increasing. As a temperature-sensitive component, the life, safety, and charge–discharge performance of lithium-ion power battery will be affected by the working temperature, which makes the battery thermal management system particularly important. Concerning the fact that the thermal contact resistance between the power battery and the heat transfer components has become the bottleneck of battery thermal management system, this study firstly establishes a traditional sandwich structure of phase change material–based thermal management system and then try to reduce the thermal contact resistance of the system by increasing the thermal conductivity of the cooling part and filling the interface with high thermal conductivity material. The thermal contact resistance and the heat flux between the power battery and the thermal management module are experimentally tested and calculated. Based on the external and internal temperature of battery, the effect of contact resistance on the performance of a thermal management system is discussed. The results show that when increasing the thermal conductivity of the cooling part, the battery external and internal temperatures under 3C, 4C, and 5C discharge are reduced by 8.3%, 8.1%, 7.6% and 5.2%, 9.3%, 6.3%, respectively, as compared to the traditional sandwich structure of phase change material–based thermal management system. And the temperatures are further reduced by 6.5%, 7.7%, 6.3% and 7.8%, 6.1%, 7.3% when the interface between the battery and the thermal management module are filled with graphene with high thermal conductivity. Furthermore, the power battery can work within the optimum operating temperature range for a long period and can ensure battery safety by reducing the thermal contact resistance.

Research on Thermal Management System of Liquid Direct Contact Battery

This paper proposes a thermal management system based on liquid direct contact with battery. The paper first uses the principles of heat transfer and computational fluid dynamics to establish a thermal model for single cells and 48V battery module, the performance of thermal management system which liquid indirect contact with battery and thermal management system which liquid direct contact with battery are compared and analyzed by simulation. The results show that the latter is better than the former in battery temperature rise control and single cell temperature consistency control, and has good application and promotion value.