Li-Ion Battery Pack Thermal Management: Liquid Versus Air Cooling

2018 ◽  
Vol 11 (2) ◽  
Author(s):  
Taeyoung Han ◽  
Bahram Khalighi ◽  
Erik C. Yen ◽  
Shailendra Kaushik
Keyword(s):  
Heat Transfer ◽  
Air Flow ◽  
Low Flow ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Li Ion Battery ◽  
Liquid Cooling ◽  
Flow Rates ◽  
High Heat Transfer ◽  
Li Ion

Abstract The Li-ion battery operation life is strongly dependent on the operating temperature and the temperature variation that occurs within each individual cell. Liquid-cooling is very effective in removing substantial amounts of heat with relatively low flow rates. On the other hand, air-cooling is simpler, lighter, and easier to maintain. However, for achieving similar cooling performance, a much higher volumetric air flow rate is required due to its lower heat capacity. This paper describes the fundamental differences between air-cooling and liquid-cooling applications in terms of basic flow and heat transfer parameters for Li-ion battery packs in terms of QITD (inlet temperature difference). For air-cooling concepts with high QITD, one must focus on heat transfer devices with relatively high heat transfer coefficients (100–150 W/m2/K) at air flow rates of 300–400 m3/h, low flow induced noise, and low-pressure drops. This can be achieved by using turbulators, such as delta winglets. The results show that the design concepts based on delta winglets can achieve QITD of greater than 150 W/K.

Comparative Study on Thermal Behavior of Lithium-Ion Battery Systems With Indirect Air Cooling and Indirect Liquid Cooling

2012 ◽  
Author(s):  
Kim Yeow ◽  
Ho Teng ◽  
Marina Thelliez ◽  
Eugene Tan
Keyword(s):  
Comparative Study ◽  
Thermal Behavior ◽  
Air Flow ◽  
Lithium Ion ◽  
Air Cooling ◽  
Li Ion Battery ◽  
Liquid Cooling ◽  
Cooling Channels ◽  
Flow Channels ◽  
Li Ion

A comparative study is conducted on the thermal behavior of three Li-ion battery modules with two cooled indirectly with air and one cooled indirectly with liquid. All three battery modules are stacked with the same twelve 8Ahr high-power pouch Li-ion battery cells. Heat generated from the cells is dissipated through 1-mm thick aluminum cooling plates sandwiched between two cells in the module. Each of the cooling plates has an extended surface for heat dissipation. The battery heat is dissipated through the cooling fins exposed in air flow channels in the case of air cooling, and through the extended cooling plate surfaces that are in contact with a liquid-cooled cold plate in the case of liquid cooling. The cell temperatures are analyzed using a simplified Finite Element Analysis (FEA) model for battery cooling. Simulation results show that with air cooling channels structured similar to that of compact heat exchangers, the air utilization and effectiveness of air cooling can be improved significantly. With proper design of the air cooling channels (i.e. with fin inserts in the air flow channels), indirect air cooling could reach a cooling condition comparable to that of indirect liquid cooling and obtain a higher gravimetric energy density with the same cooling-related parasitic volume in the battery system as long as the cell heat rejection is < 10 W/cell.

Effects of Taper Configurations on Heat Transfer and Pressure Drop in Single-Phase Flows in Microgaps

2020 ◽  
Author(s):  
Debora C. Moreira ◽  
Gherhardt Ribatski ◽  
Satish G. Kandlikar
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Pressure Drop ◽  
Single Phase ◽  
Bubble Nucleation ◽  
Low Flow ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Inlet Section ◽  
Flow Rates

Abstract This paper presents a comparison of heat transfer and pressure drop during single-phase flows inside diverging, converging, and uniform microgaps using distilled water as the working fluid. The microgaps were created on a plain heated copper surface with a polysulfone cover that was either uniform or tapered with an angle of 3.4°. The average gap height was 400 microns and the length and width dimensions were 10 mm × 10 mm, resulting in an average hydraulic diameter of approximately 800 microns for all configurations. Experiments were conducted at atmospheric pressure and the inlet temperature was set to 30 °C. Heat transfer and pressure drop data were acquired for flow rates varying from 57 to 485 ml/min and the surface temperature was monitored not to exceed 90 °C to avoid bubble nucleation, so the heat flux varied from 35 to 153 W/cm2 depending on the flow rate. The uniform configuration resulted in the lowest pressure drop, and the diverging one showed slightly higher pressure drop values than the converging configuration, possibly because the flow is most constrained at the inlet section, where the fluid is colder and presents higher viscosity. In addition, a minor dependence of pressure drop with heat flux was observed due to temperature dependent properties. The best heat transfer performance was obtained with the converging configuration, which was especially significant at low flow rates. This behavior could be explained by an increase in the heat transfer coefficient due to flow acceleration in converging gaps, which compensates the decrease in temperature difference between the fluid and the surface due to fluid heating along the gap. Overall, the comparison between the three configurations shows that converging microgaps have better performance than uniform or diverging ones for single-phase flows, and such effect is more pronounced at lower flow rates, when the fluid experiences higher temperature changes.

scholarly journals Design of an Optimized Thermal Management System for Li-Ion Batteries under Different Discharging Conditions

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5695 ◽  
Author(s):  
Ankur Bhattacharjee ◽  
Rakesh K. Mohanty ◽  
Aritra Ghosh
Keyword(s):  
Thermal Management ◽  
Cooling System ◽  
Peak Temperature ◽  
Air Cooling ◽  
Li Ion Batteries ◽  
Li Ion Battery ◽  
Liquid Cooling ◽  
Thermal Management System ◽  
Li Ion ◽  
Liquid Cooling System

The design of an optimized thermal management system for Li-ion batteries has challenges because of their stringent operating temperature limit and thermal runaway, which may lead to an explosion. In this paper, an optimized cooling system is proposed for kW scale Li-ion battery stack. A comparative study of the existing cooling systems; air cooling and liquid cooling respectively, has been carried out on three cell stack 70Ah LiFePO4 battery at a high discharging rate of 2C. It has been found that the liquid cooling is more efficient than air cooling as the peak temperature of the battery stack gets reduced by 30.62% using air cooling whereas using the liquid cooling method it gets reduced by 38.40%. The performance of the liquid cooling system can further be improved if the contact area between the coolant and battery stack is increased. Therefore, in this work, an immersion-based liquid cooling system has been designed to ensure the maximum heat dissipation. The battery stack having a peak temperature of 49.76 °C at 2C discharging rate is reduced by 44.87% to 27.43 °C after using the immersion-based cooling technique. The proposed thermal management scheme is generalized and thus can be very useful for scalable Li-ion battery storage applications also.

Experimental Investigation of Spray Cooling Heat Transfer on Circular Grooved Surface

2017 ◽  
Author(s):  
Azzam S. Salman ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Flow Rate ◽  
Cooling System ◽  
Volumetric Flow Rate ◽  
Target Surface ◽  
Spray Cooling ◽  
Operating Conditions ◽  
Low Flow ◽  
Inlet Temperature ◽  
Flow Rates

An experimental study was conducted in a closed loop spray cooling system working with deionized water as a cooling medium, to investigate the effects of surface modification on the spray cooling heat transfer enhancement in the single-phase region. Plain copper surface with diameter 1.5 cm and an enhanced surface with circular grooves were tested under different operating conditions. The volumetric flow rate of the coolant ranged from 115 mL/min to 177 mL/min., and the water inlet temperature was kept between 21–23 °C. Also, the distances between the nozzle and the target surface were varied at 8, 10, and 12 mm respectively. The results show that the distance between the nozzle and the target surface did not have a significant effect on the heat transfer performance for the low flow rates, while it has a slight effect on high flow rates for both surfaces. Also, increasing the liquid volumetric flow rate increases the amount of heat removed, and the heat transfer coefficient for both surfaces. Moreover, the maximum enhancement ratios achieved were 23.4% and 31% with volumetric flow rates of 153 mL/min, and 177 mL/min respectively.

scholarly journals Multi-Physics Equivalent Circuit Models for a Cooling System of a Lithium Ion Battery Pack

Batteries ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 44 ◽  
Author(s):  
Takumi Yamanaka ◽  
Daiki Kihara ◽  
Yoichi Takagishi ◽  
Tatsuya Yamaue
Keyword(s):  
Heat Transfer ◽  
Equivalent Circuit ◽  
Thermal Management ◽  
Flow Rate ◽  
3D Model ◽  
Management Systems ◽  
Li Ion Battery ◽  
Liquid Cooling ◽  
Battery Packs ◽  
Li Ion

Lithium (Li)-ion battery thermal management systems play an important role in electric vehicles because the performance and lifespan of the batteries are affected by the battery temperature. This study proposes a framework to establish equivalent circuit models (ECMs) that can reproduce the multi-physics phenomenon of Li-ion battery packs, which includes liquid cooling systems with a unified method. We also demonstrate its utility by establishing an ECM of the thermal management systems of the actual battery packs. Experiments simulating the liquid cooling of a battery pack are performed, and a three-dimensional (3D) model is established. The 3D model reproduces the heat generated by the battery and the heat transfer to the coolant. The results of the 3D model agree well with the experimental data. Further, the relationship between the flow rate and pressure drop or between the flow rate and heat transfer coefficients is predicted with the 3D model, and the data are used for the ECM, which is established using MATLAB Simulink. This investigation confirmed that the ECM’s accuracy is as high as the 3D model even though its computational costs are 96% lower than the 3D model.

CFD Investigation of Heat Transfer Deterioration in Supercritical Water Flowing Through Vertical Annular Channels

2013 ◽  
Author(s):  
U. S. Tejaswini ◽  
Dipankar N. Basu ◽  
Manmohan Pandey
Keyword(s):  
Heat Transfer ◽  
Supercritical Water ◽  
Rapid Change ◽  
Low Flow ◽  
Design Parameters ◽  
Inlet Temperature ◽  
Flow Rates ◽  
Flow Acceleration ◽  
Heat Transfer Deterioration ◽  
Annular Channels

In order to enhance the efficiency of current light water reactors, the generation IV initiative has included the supercritical water reactor (SCWR) as one of the future designs. The rapid change in density in the vicinity of the pseudo-critical temperature leads to strong buoyancy effect at low flow rates and flow acceleration at high flow rates, both of which significantly influence heat transfer characteristics. Experimental investigation of such phenomena being very cumbersome and cost-intensive, numerical simulation using CFD tools is considered to be a useful option for providing better understanding of the heat transfer mechanisms in geometries and conditions typical of SCWR. The present work involves numerical analysis of the heat transfer deterioration (HTD) phenomenon in turbulent flow of supercritical water through a vertical annular channel. ANSYS-CFX 14.0 software was employed for the same. An annular fluid domain, with a heated inner wall and an insulated outer wall, was modeled and the flow was considered to be in the upward and downward directions. Grid independence study was conducted with structured mesh. The results were compared with those reported in the published literature. It is known that the HTD phenomenon causes a sudden rise in the wall temperature, and hence it is necessary to predict the effect of changes in operating and design parameters. Parametric study was done by varying pressure, inlet temperature, heat flux and mass flux. Annuli of different hydraulic diameters were also considered.

Air Cooling Concepts for Li-Ion Battery Pack in Cell Level

2017 ◽  
Author(s):  
Kuo-Huey Chen ◽  
Taeyoung Han ◽  
Bahram Khalighi ◽  
Philip Klaus
Keyword(s):  
Pressure Drop ◽  
Peak Load ◽  
Battery Pack ◽  
Cfd Modeling ◽  
Air Cooling ◽  
Li Ion Battery ◽  
Cell Level ◽  
Flow Rates ◽  
Cooling Flow ◽  
Li Ion

Computational Fluid Dynamics (CFD) modeling is used to study different cooling architectures for the next generation (Gen-2) EREV Li-Ion battery package. There might be advantages of air cooled batteries with respect to complexity, cost and reliability compared to liquid cooled systems like the EREV (Extended Range Electric Vehicle) GEN1 battery. Therefore, the feasibility of air cooling architectures is investigated first and later liquid cooling strategies. In this study, the thermal performance and pressure drop of the cell level for two of the core product designs are reported. The parameters considered in this study include two different heat generations (heat sources) by the battery pack and three cooling flow rates. The heat generations used are 500 W and 1500 W representing the normal driving and peak load conditions, respectively. The cooling flow rates are 100, 200 and 600 m3/h. The battery cell temperatures, both in terms of absolute value and the variation within the cell, and the pressure drop which is related to the required pumping power, are evaluated and presented.

Effect of Radial Location of Nozzles on Heat Transfer in Pre-Swirl Cooling System

2009 ◽  
Author(s):  
V. U. Kakade ◽  
G. D. Lock ◽  
M. Wilson ◽  
J. M. Owen ◽  
J. E. Mayhew
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
Convective Heat Transfer Coefficient ◽  
Flow Visualisation ◽  
Thermochromic Liquid Crystal ◽  
Rotating Disc ◽  
Dimensional Solution ◽  
Flow Rates ◽  
Measure Surface Temperature ◽  
High Heat Transfer

This paper investigates heat transfer in a rotating disc system using pre-swirled cooling air from nozzles at high and low radius. The experiments were conducted over a range of rotational speeds, flow rates and pre-swirl ratios. Narrow-band thermochromic liquid crystal (TLC) was specifically calibrated for application to experiments on a disc rotating at ∼ 5000 rpm and subsequently used to measure surface temperature in a transient experiment. The TLC was viewed through the transparent polycarbonate disc using a digital video camera and strobe light synchronised to the disc frequency. The convective heat transfer coefficient, h, was subsequently calculated from the one-dimensional solution of Fourier’s conduction equation for a semi-infinite wall. The analysis accounted for the exponential rise in the air temperature driving the heat transfer, and for experimental uncertainties in the measured values of h. The experimental data was supported by ‘flow visualisation’ determined from CFD. Two heat transfer regimes were revealed for the low-radius pre-swirl system: a viscous regime at relatively low coolant flow rates; and an inertial regime at higher flow rates. Both regimes featured regions of high heat transfer where thin, boundary layers replaced air exiting through receiver holes at high radius on the rotating disc. The heat transfer in the high radius pre-swirl system was shown to be dominated by impingement under the flow conditions tested.

scholarly journals Heat transfer enhancement of car radiator using aqua based magnesium oxide nanofluids

2015 ◽  
Vol 19 (6) ◽  
pp. 2039-2048 ◽  
Author(s):  
Hafiz Ali ◽  
Muhammad Azhar ◽  
Musab Saleem ◽  
Qazi Saeed ◽  
Ahmed Saieed
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermal Management ◽  
Heat Transfer Performance ◽  
Inlet Temperature ◽  
Fluid Temperature ◽  
Transfer Enhancement ◽  
Volumetric Concentration ◽  
Flow Rates ◽  
Transfer Rates

The focus of this research paper is on the application of water based MgO nanofluids for thermal management of a car radiator. Nanofluids of different volumetric concentrations (i.e. 0.06%, 0.09% and 0.12%) were prepared and then experimentally tested for their heat transfer performance in a car radiator. All concentrations showed enhancement in heat transfer compared to the pure base fluid. A peak heat transfer enhancement of 31% was obtained at 0.12 % volumetric concentration of MgO in basefluid. The fluid flow rate was kept in a range of 8-16 liter per minute. Lower flow rates resulted in greater heat transfer rates as compared to heat transfer rates at higher flow rates for the same volumetric concentration. Heat transfer rates were found weakly dependent on the inlet fluid temperature. An increase of 8?C in inlet temperature showed only a 6% increase in heat transfer rate.

scholarly journals Hybrid Battery Thermal Management System in Electrical Vehicles: A Review

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6257
Author(s):  
Chunyu Zhao ◽  
Beile Zhang ◽  
Yuanming Zheng ◽  
Shunyuan Huang ◽  
Tongtong Yan ◽  
...  
Keyword(s):  
Thermal Management ◽  
Management System ◽  
Air Cooling ◽  
Liquid Cooling ◽  
Battery Thermal Management ◽  
Thermal Management System ◽  
Battery Thermal Management System ◽  
Cooling Phase ◽  
Li Ion ◽  
Forced Air

The Li-ion battery is of paramount importance to electric vehicles (EVs). Propelled by the rapid growth of the EV industry, the performance of the battery is continuously improving. However, Li-ion batteries are susceptible to the working temperature and only obtain the optimal performance within an acceptable temperature range. Therefore, a battery thermal management system (BTMS) is required to ensure EVs’ safe operation. There are various basic methods for BTMS, including forced-air cooling, liquid cooling, phase change material (PCM), heat pipe (HP), thermoelectric cooling (TEC), etc. Every method has its unique application condition and characteristic. Furthermore, based on basic BTMS, more hybrid cooling methods adopting different basic methods are being designed to meet EVs’ requirements. In this work, the hybrid BTMS, as a more reliable and environmentally friendly method for the EVs, will be compared with basic BTMS to reveal its advantages and potential. By analyzing its cost, efficiency and other aspects, the evaluation criterion and design suggestions are put forward to guide the future development of BTMS.

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