Optimization Of Thermal Management System Research Articles

Integrated battery thermal management and CO2 control in electric buses using recirculated air and waste heat recovery

In recent years, electric vehicles (EVs) have significantly progressed due to their environmental protection and energy-saving advantages. However, maintaining indoor thermal comfort and effective battery thermal management are critical considerations for EVs. Unlike conventional vehicles, EVs cannot use waste heat and depend on heat pump systems for winter heating and summer cooling. This research proposes a novel system to reduce the energy consumption of heat pump systems by using recirculated air while addressing the challenges of battery temperature management and maintaining safe CO2 concentrations in the cabin. The primary objectives of this research are threefold: first, to ensure passenger comfort through an integrated approach that includes cabin CO2 concentration safety; second, to recover heat from recirculated cabin air to save energy and control battery temperature; and third, to comprehensively analyze the performance of the Electric Vehicle Thermal Management System (EVTMS) using precise Computational Fluid Dynamics (CFD) analysis and mathematical modeling. This study will significantly enhance the understanding of energy consumption related to CO2 concentration control; an aspect previously overlooked in the literature. It will develop a battery temperature management strategy that leverages bus exhaust heat. These contributions will aid in achieving both passenger comfort and battery stability in electric buses, providing practical insights for the design and optimization of thermal management systems for future electric buses.

Thermal performance analysis of oriented MHD convective flow and entropy production of hybrid nanofluids in a cavity induced by semicircles at different radii ratios

AbstractThe current study numerically treats the magnetic field impacts on the natural convection flow and entropy generation in a square cavity filled with hybrid nanofluid and induced by two isothermally heated semicircles at the bottom and left walls of the cavity. The cavity is filled by hybrid nanofluid (titanium oxide/silver‐water) and oriented under different inclination angles with the applied magnetic field. The simulations in this study were executed via a home‐made code written in the FORTRAN programing language. The numerical methodology considered to solve the coupled equations of continuity, momentum, energy, and entropy generation equations with the associated boundary conditions is the finite volume method and the full multigrid acceleration. Various wake parameters are considered in this research study, namely, the inclination angle of the cavity (α), the magnetic field inclination (γ), the Hartmann number (Ha), the Rayleigh number (Ra), the volume fraction of the hybrid nanofluid (ϕ) and the internal semicircles radii ratio (β). The major findings issued from the impact of these parameters on the fluid flow and heat transfer characteristics reveal that heat transfer and entropy generation are a decreasing function of the Hartmann parameter. Moreover, the total entropy generation is intensified by 85.23% from Ra = 103 to Ra = 106 for Ha = 10, by 85.818% for Ha = 50 and 83.813% for Ha = 100. Besides, the flow magnitude is found decreasing with increasing the radii ratio β of the semicircles. It is also found that optimal heat transfer rates deducted from the variation of average Nusselt number versus Ra for different volume fractions of the hybrid nanoparticles are obtained for the extreme values of the pertinent parameters (β = 1, ϕ = 8%, Ra = 106). Hence, the present work offers a useful tool and a parametric study for the research community and engineers on the design and optimization of thermal management systems used in a variety of industrial applications, such as heat exchangers, nuclear reactors, and energy systems.

Structural optimization of thermal management system for bionic liquid cold battery based on fuzzy grey correlation analysis

An energy-efficient battery thermal management system with efficient enhanced heat transfer characteristics, low power consumption and backflow inhibition performance is of great importance for electric vehicle power batteries. Based on the design of the Tesla valve and inspired by bionics, a new type of bionic blade-like mini-channel liquid cold plate with high efficiency, low power consumption and certain anti-reverse flow performance was proposed. Firstly, the initial liquid-cooled plate thermal simulation model at 5C discharge was established by CFD method and its reliability was verified by experiment. Then, orthogonal tests and fuzzy correlation analysis (FGRA) were used as evaluation methods to analyze the effects of four structural parameters (inner angle α, circumcenter angle θ1, circumcenter angle θ2, and channel height d) on the average temperature, heat transfer coefficient, and friction coefficient. The results show that the variation of the channel height d had the highest degree of influence on the mean temperature (Tave) and friction coefficient f, and that the internal angle α had the highest correlation with the heat transfer coefficient h. Finally, based on the optimization results, a better model within the range of values of each factor was obtained. When α = 25°, θ1 = 90°,θ2 = 75°, and d = 1.2 mm, Nu was increased by 0.932 (95.08 %), and ΔP was decreased by 501.686 Pa (84.74 %).The results of the optimization were shown in the following table.

Thermodynamic survey of a reactive MHD couple stress fluid through saturated porous substances with convective boundary conditions

This study explores the thermodynamic behavior of a reactive hydromagnetic liquid flowing through permeable materials, with convective cooling applied to the walls. This study holds practical significance in optimization of thermal management systems and it is crucial for enhancing the efficiency of controlling thermal runaway. The flow is modeled as a system of partial differential equations which are numerically solved. The modified Adomian Decomposition Method and Pade approximation technique are utilized in solving the equations. The results acquired for velocity and temperature distributions are thereby employed to estimate entropy generation rate with critical values over numerous effects of various boundaries over improvement of thermal runaway utilizing Pade approximation technique to show the significant impact of convective cooling term (Biot number) and other thermophysical parameters on the fluid flow. The outcomes show that fluid velocity continuously increases with rising values of inverse couple stress and fluid temperature increases Biot number.

Performance Analysis of Wet Porous Moving Fin under the Influence of Spherical Shaped TiO2- Ag Hybrid Nanoparticles in a Water Based Fluid

The study investigates the flow characteristics of spherical shaped TiO2 –Ag hybrid nanofluid with water as a base fluid passing through a wet porous rectangular moving fin with a focus on understanding the effects of nanoparticle concentration on the heat transfer rate. The fin under consideration are subjected to boundary conditions, insulated and convective tips. Hybrid nanofluid that combine nanoparticles with conventional base fluids have potentially enhanced thermal conductivity and heat transfer properties in engineering applications. The energy balance equation containing the parameters that effect the flow of heat transfer rate is non- dimensionalized and solved numerically using 3-stage Lobatto - IIIa formula with appropriate boundary conditions. The simulation result shows the impact of different parameters on the flow and heat transfer properties of the hybrid nanofluid obtained by mixing spherical shaped TiO2 –Ag hybrid nanoparticles with water as base fluid. It is observed that the fin shows significant heat transfer rate in a convective tip relative to an insulated tip. The findings contribute to the understanding of hybrid nanofluid flow and its potential application in the design and optimization of thermal management system. It also facilitates the ground work for research in the field of nano fluid based cooling system. The observation from the graphical illustration shows that the rise in the thermal conductivity of the base fluid by 23% increases the conduction heat transfer as well as the temperature distribution by 10%. The natural convection and radiation are the key parameters that determines the heat transfer rate from the surface to the surrounding. In our investigation, enhancing the Nc,Nr parameters by 50% and 25%, the temperature distribution profile is reduced by about 13% and 6% respectively. The increase in the Pe number by 100% results in a rise in the temperature distribution by 8%.

Multi-objective optimization of thermal management system for multiple heat source arrays electronic chassis in a noiseless environment

Effective thermal management of electronic chassis is currently a critical concern. A heat sink with fins and heat pipes is suggested in this paper. It is intended to handle the heat produced by numerous sources within an electronic case and enhance its functionality. The parameters have been examined and improved in order to work quietly. Response surface methodology (RSM) was employed to examine the influence of fin length, fin thickness, fin spacing and Re on the junction temperature, temperature uniformity and thermal resistance of the heat sink for a printed circuit board array (PCBA). The parameter combinations were optimized using a genetic algorithm. The results indicated that the optimal fin spacing is 11 mm, optimal length is 199 m, and optimal thickness is 2.9 mm when the Reynolds number falls within the range of 2000 ≤ Re ≤ 7000. Compared to the original fins, the combined finned heat pipe heat sink decreases the temperature of the PCBA junction by approximately 10 K, enhances the temperature uniformity by around 49 %, and diminishes the total thermal resistance by nearly 48 %. The optimal air velocity is approximately 0.41 m/s. The improved heat sink can efficiently enhance the thermal management of electronic casings.

Operation Optimization of Thermal Management System of Deep Metal Mine Based on Heat Current Method and Prediction Model

With the increasing depth of metal mining, thermal damage has become a serious problem that restricts mining. The thermal management system of refrigeration and ventilation is an indispensable technology in the mining of deep metal mines, which plays a key role in improving the thermal and humid environment of mines. Optimizing the performance of refrigeration and ventilation systems to reduce energy consumption has become a focus of researchers’ attention. Based on the heat current method, this research establishes the overall heat transfer and flow constraint model of the refrigeration and ventilation system, and proposes an iterative algorithm that combines the refrigerator energy consumption model and the artificial neural network model of heat exchangers. The Lagrange multiplier method is used to optimize the system with the goal of minimizing the total power consumption of the system. The results show that under 9.1 kW cooling load conditions, the total energy consumption of the system reduces by 16.5%, and the COP of the refrigerator increases by 11.6%. The optimization results provide significant guidance for the production and energy consumption reduction of the deep metal mines.

Numerical investigation of the melting process of gallium under inclination and partial heating

Systems based on PCM rely not only on the capacity of the system to absorb or release energy but also on the rate at which these processes are carried out. The design and optimization of thermal management systems require understanding the phase change process under different conditions. In this work, the time-dependent phase change process is studied numerically. Gallium, contained in a thin cell, is considered the working fluid. Numerical modeling is done by ANSYS Fluent in two dimensions. This model is validated against reported experimental results. Subsequently, two conditions are systematically investigated: (i) inclination, considering five angles (−45,−22.5,0,22.5, and 45°), and (ii) partial heating, considering four relative heater sizes (0.25,0.50,0.75 and 1.00). Both cases are studied for three aspect ratios (A=0.50,0.75, and 1.00). Results show that small aspect ratios and positive tilting angles could modify flow dynamics, which ultimately affects the melting process and the Nusselt number. Moreover, partial heating reduces up to 38% the melting time compared to the case in which the heat flux is distributed homogeneously along the entire length of the wall. These results could be used as guidelines to address the “rate problem” for practical applications.

Experimental investigation on thermal management system of composite phase change material coupled with serpentine tubes for battery module

• Paraffin/carbon nanotube/boron nitride/silicone gel (PCBS) composite has designed. • PCBS exhibits anti-leakage, reignite resistance and prominent waterproof property. • Batteries with PCBS can decrease interface heat resistance by pouring technology. • Composite material coupled with serpentine tubes is designed for battery module. • The battery module with PCBS can exhibits excellent thermal management effect. As an advanced thermal management method for battery modules, phase change material with many advantages have attracted much attention; however, many significant challenges still exist. In this study, a novel paraffin/carbon nanotube/boron nitride/silicone gel composite material was designed and fabricated. Owing to the combination of phase change material with the large latent heat and silicone gel as a thermal interface material, the paraffin/carbon nanotube/boron nitride/silicone gel exhibits outstanding properties such as anti-leakage, mechanical flexibility, re-ignition resistance, and outstanding waterproofing ability. Compared with the pre-solidification process, the results reveal that the battery with composite material can obtain a low-interface thermal resistance between the composite materials and batteries through an in-situ pouring technology, which exhibits a faster thermal response than that without PCBS. In addition, the paraffin/carbon nanotube/boron nitride/silicone gel coupled with serpentine liquid-cooling tubes have been utilized in the battery module, which can control the maximum temperature below 55 °C at 1 C discharge rate, it is obviously lower than that without composite material. This research is expected to provide insights into the design and optimization of thermal management systems in various energy storage fields.

Experiments and Simulation on the Performance of a Liquid-Cooling Thermal Management System including Composite Silica Gel and Mini-Channel Cold Plates for a Battery Module

Lithium batteries in the electric vehicles (EVs) reveal that the operating temperature and temperature uniformity within the battery pack significantly affect its performance. An efficient thermal management system is urgently needed to protect the battery module within suitable temperature range. In this study, the composite silica gel (CSG), coupled with cross-structure mini-channel cold plate (MCP) as the cooling system, has been proposed and applied in a battery module, which can provide a reliable method of controlling battery temperature with low energy consumption. The experimental and simulation results reveal that a composite silica gel-based liquid system can control the temperature below 45 °C and maintain the temperature difference within 2 °C at a 3C discharge rate. Besides, the CSG, coupled with the structure of reciprocal chiasma channels for the battery module, presents an optimum temperature-controlling performance among various cooling structures during the charge and discharge cycling process. This research is expected to provide significant insights into the designing and optimization of thermal management systems.

An equivalent circuit model for battery thermal management system using phase change material and liquid cooling coupling

Rapid and accurate prediction of change in battery temperature is crucial for the performance of battery and service life. This paper presents an equivalent circuit model (ECM) as the battery thermal management system (BTMS) using phase change material and a liquid cooling coupler. In addition, the model is based on an extended Kalman filter (EKF), which estimates the battery temperature in real-time without utilizing additional temperature sensors. Compared to free cooling, at an ambient temperature of 30 °C, the temperature of the battery decreases by 7.35 °C at the end of the 3C discharge rate, with a temperature difference of 1.70 °C. The model was tested experimentally at different discharge rates, inlet flow rates, and phase change material (PCM) thickness and found that the maximum deviation between predicted and experimental results is less than 5 %. The model has potential applications in real-time prediction of electrical and thermal signals in large battery packs and in analysis and optimization of thermal management systems.

Experimental study on the performance of vehicle integrated thermal management system for pure electric vehicles

The thermal management of electric vehicles is mainly to regulate the temperatures of battery, motor, electric control, and crew cabin, so as to ensure that they are working at the most appropriate temperature. The integrated thermal management system, which stands at the perspective of the vehicle system, coordinates and controls the heat dissipating capacity of the vehicle. In this paper, a novel vehicle integrated thermal system, consisting of the Li-ion battery packs circuit, the electric motor and power electronics cooling circuit, as well as the air conditioning circuit, etc., is proposed to obtain the integrated optimization of the vehicle system. The results, expressed through thermal parameters, discharging and charging parameters of the battery system, are initially evaluated utilizing theoretical analysis and numerical model of the vehicle system and then experimentally analyzed with the arrangement of a 1:1 scale laboratory test bench. The collections of results demonstrate the excellent design and performance of the proposed integrated thermal management system in satisfying the real-time operating conditions under general temperature requirements. These experimental investigations are expected to afford a practical insight into the design and optimization of thermal management systems in electric vehicles.

ENERGY FLOW MODEL ANALYSIS AND CONFIGURATION OPTIMIZATION OF THERMAL MANAGEMENT SYSTEM

ENERGY FLOW MODEL ANALYSIS AND CONFIGURATION OPTIMIZATION OF THERMAL MANAGEMENT SYSTEM

Temperature control of vibrating heat-generating hardware using spray evaporative cooling in the nucleate boiling region

A temperature control approach using evaporative spray cooling of vibrating surfaces in the nucleate boiling region is proposed and verified experimentally. This is relevant to temperature control of heat-generating automotive vehicle components. By exploiting an experimentally calibrated dynamic correlation model to represent evaporative spray cooling of a flat test-piece, a PID controller has been adopted with emphasis focused on the choice of gain parameters to ensure both stability of temperature control, and favourable responses in terms of relevant performance measures. Optimum linearisation of the correlation model has been achieved by solving an appropriate Wiener-Hopf equation, mainly to undertake a practical stability assessment of the closed-loop temperature control system. To verify the predicted control system performance, experimental measurements have been obtained from an instrumented, and spray-evaporatively-cooled, flat test-piece exposed to displacement vibration from a shaker. Experimental testing, appropriate to automotive vehicle component applications, includes large-amplitude, low frequency vibration at 12 mm and 1.9 Hz, and low amplitude, high-frequency vibration at 0.02 mm and 400 Hz. To assess the effects of different PID controller gains on the thermal performance of the thermal management system, a coefficient of performance (COP) is used, defined as the ratio of heat power removal to the required pumping power. To achieve a reduction in the settling time, and an increase in the rise time of stable control, a PID controller with a negative proportional gain showed most promising results. A 10.5% increase in COP was achieved in comparison to a PID controller with positive gains. This information is useful for the design and optimization of thermal management systems using evaporative spray cooling.

Optimization of Thermal Management System with Water and Phase Change Material Cooling for Li-Ion Battery Pack

The cooling structure of a battery pack and coupled liquid cooling and phase change material (PCM) were designed in a thermal management system to enhance the cooling performance and extend the service life of lithium-ion battery packs. Numerical simulations were conducted based on the finite volume method. This study focuses on factors such as the layout of the terminal, flow rate of the coolant, different sections of the cooling pipe, position of the cooling pipe, and coupled liquid cooling, and investigates their influences on the operating temperature. The results show that a reasonable terminal layout can reduce heat generation inside the batteries. The appropriate flow rate and position of the cooling pipe effectively reduced the maximum temperature and minimized energy consumption. Then, the PCM was placed between the adjacent batteries near the outlet to enhance the uniformity of the battery pack. The temperature difference was reduced to near 5 K. This study provides a clear direction for improving the cooling performance and extending the service life of battery packs.

The Integrated Component-System Optimization of a Typical Thermal Management System by Combining Empirical and Heat Current Methods

Integration of modeling and optimization of a thermal management system simultaneously depends on heat transfer performance of the components and the topological characteristics of the system. This paper introduces a heat current method to construct the overall heat current layout of a typical double-loop thermal management system. We deduce the system heat transfer matrix as the whole system constraint based on the overall heat current layout. Moreover, we consider the influences of structural and operational parameters on the thermal hydraulic performances of each heat exchanger by combining the empirical correlations of the heat transfer and pressure drop. Finally, the minimum pressure drop is obtained by solving these optimal governing equations derived by the Lagrange multiplier method considering the physical constraints and operational conditions. The optimization results show that the minimum pressure drop reduces about 8.1% with the optimal allocation of mass flow rates of each fluid. Moreover, the impact analyses of structural and operating parameters and boundary conditions on the minimum and optimal allocation present that the combined empirical correlation-heat current method is feasible and significant for achieving integrated component-system modeling and optimization.

Multi-Objective Optimization of Thermal Management System in LED Bulbs Based on Entropy Generation Minimization Concept

In this paper, the thermal behavior of heat sinks with parabolic fins (convex type) in an analytical method is investigated. The considered heat sinks are used for thermal control in LED lamps. To evaluate cooling performance of these devices, the energy balance of considered heat sinks with fins is evaluated. In the derived equation, the effect of mass transfer and thermal radiation is considered and the thermal conductivity is varied with temperature. An efficient analytical method—differential transformation method—is used to the analytical solution of the governing equations. Comparison of the analytical and numerical solutions shows excellent accuracy of the selected analytical solution. Based on the proposed analytical solution, the effect of operational and geometrical parameters on the system thermal management is evaluated. Finally, a multi-objective optimization is performed to maximize the thermal efficiency and minimize the entropy generation.

Pore-scale investigation on effects of void cavity distribution on melting of composite phase change materials

Composite Phase Change Materials (PCMs) incorporated with metal foams are promising candidates for thermal management for space exploration. However, void cavities are generated as a result of the volume change of PCM during the melting process, introducing a resistance to heat transfer due to the low thermal conductivity of the void. In this work, the effects of void cavity distribution on the conduction-dominated melting of composite PCMs under microgravity conditions are studied by a two-dimensional pore-scale lattice Boltzmann method, in which a microstructural description of the metal foam is experimentally characterized with the help of X-ray micro-Computed Tomography. Two typical distribution patterns of void cavities are analsed and computed performance is compared (1) a near-wall void cavity, and (2) randomly distributed void cavities. The evolutions of temperature distributions and melting interfaces are compared, and the average liquid fraction and energy stored per width are deduced to describe the energy storage performance. Moreover, the influence of the volume fraction of void cavities is investigated by comparing temperature distributions and energy storage performances of composite PCMs with four different volume fractions of void cavities (0%, 3.7%, 7.6%, 15.2%). After introducing void cavities, the energy stored per width is reduced by 5.7%, 12.3% and 20.2% for randomly distributed void cavities when volume fraction of void cavities is 3.7%, 7.6%, and 15.2%, respectively, and reduced by 42.2%, 64.1% and 79.7% for the near-wall void cavity, respectively. This work initiates the study of the effects of void cavity distribution on composite PCMs, which will stimulate work on structural optimization of thermal management systems.

Optimization of thermal management systems for vertical elevation applications powered by lithium-ion batteries

A simple battery thermal management system's control strategy based on reliable battery-pack-level CFD models and numerical optimization methodologies is proposed for vertical elevation applications powered by lithium-ion batteries. A new devised heat generation model named as False Steady has been successfully used to calculate the heat density generated in each cell of the battery pack in a steady simulation without losing the thermal coupling and hence prediction accuracy. The best placement for the temperature sensors to evaluate the thermal dispersion has been decided based on the CFD model results. When the predefined thermal limits are crossed the fans will start operating and they will be regulated depending on the ambient temperature and the measured charge or discharge current level. The optimal values of fans' pulse width modulation level are determined from response surfaces obtained from the simulations.

Optimization of thermal management system for Li-ion batteries using phase change material

This study presents an optimization method of Li-ion battery thermal management system (BTMS) using phase change material (PCM). The optimization objective is to minimize the mass of PCM. Two design constraints should be satisfied during the optimization process: (1) the maximum temperature difference in the BTMS should not exceed the threshold value; (2) the desired working time of maintaining the batteries temperature under operation safe temperature should be fulfilled. A case study of the cylindrical BTMS with PCM is selected to illustrate the proposed optimization method. The expanded graphite (EG)/paraffin (PA) composite PCM is used in the BTMS. The thermodynamic mathematical models of the system are solved by the commercial software computational fluid dynamics (CFD). The numerical results are validated against experimental data, and a good agreement has been achieved. During the optimization, four types of BTMS which respectively use single, double, three and four batteries, are considered. The effects of battery radius, gap between neighboring batteries, heat generation rate, and top and bottom PCM thickness on the minimum mass of PCM are analyzed. The optimal radiuses of the PCM unit in different conditions are identified. Results indicate that the proposed optimization method is effective to optimize the BTMS with PCM, which provides guidelines for engineers to conduct the design optimization for similar systems.