Thermal Management Options Research Articles

How to enable large format 4680 cylindrical lithium-ion batteries

The demand for large format lithium-ion batteries is increasing, because they can be integrated and controlled easier at a system level. However, increasing the size leads to increased heat generation risking overheating. 1865 and 2170 cylindrical cells can be both base cooled or side cooled with reasonable efficiency. Large format 4680 cylindrical cells have become popular after Tesla filed a patent. If these cells are to become widely used, then understanding how to thermally manage them is essential. In this work, we create a model of a 4680 cylindrical cell, and use it to study different thermal management options. Our work elucidates the comprehensive mechanisms how the hot topic ‘tabless design’ improves the performance of 4680 cell and makes any larger format cell possible while current commercial cylindrical cells cannot be simply scaled up to satisfy power and thermal performance. As a consequence, the model identifies the reason for the tabless cell's release: the thermal performance of the 4680 tabless cell can be no worse than that of the 2170 cell, while the 4680 tabless tab cell boasts 5.4 times the energy and 6.9 times the power. Finally, via the model, a procedure is proposed for choosing the thermal management for large format cylindrical cell for maximum performance. As an example, we demonstrate that the best cooling approach for the 4680 tabless cell is base cooling, while for the 2170 LG M50T cell it is side cooling. We conclude that any viable large format cylindrical cell must include a continuous tab (or ‘tabless’) design and be cooled through its base when in a pack. The results are of immediate interest to both cell manufacturers and battery pack designers, while the developed modelling and parameterization framework is of wider use for all energy storage system design.

Simulation on the thermal management of electrical vehicle battery pack with different cooling methods

Electrical vehicles (EVs) are becoming more popular every day. Lithium ion (Li-ion) batteries in the cylindrical form are utilized as the power source of both electrical vehicles and hybrid electric vehicles due to their small size and high-power density. There is typically very little space between the batteries. Heat dissipation must be properly evaluated to ensure that the battery operates as intended. The study goal is examine how well a battery pack performs overall while using alternating cooling strategies. Three models were created in solidworks 2016 for the purpose of determine the best cooling approach. Three battery thermal management (BTMs) options were also chosen, analyzed, and simulated in Ansys Fluent 19.2 to ensure accurate and thermal modelling. According to the findings, geometry 2 ethynyl glycol exhibits a more efficient temperature distribution and maximum temperature than the other cooling methods. Furthermore, channel cooling based on BTMs, the consistent temperature distribution is carried out, and the maximum temperature is regulated to 306.66 K, with a minimum temperature of 293. 20 K being attained.

4-MW Class High-Power-Density Generator for Future Hybrid-Electric Aircraft

This article describes the underpinning research, development, construction, and testing of a 4-MW multithree phase generator designed for a hybrid-electric aircraft propulsion system demonstrator. The aim of the work is to demonstrate gravimetric power densities around 20 kW/kg, as required for multi-MW aircraft propulsion systems. The key design choices, development procedures, and tradeoffs, together with the experimental testing of this electrical machine connected to an active rectifier, are presented. A time-efficient analytical approach to the downselection of various machine configurations, geometrical variables, different active and passive materials, and different thermal management options is first presented. A detailed design approach based on the 3-D finite element analysis (FEA) is then presented for the final design. Reduced power tests are carried out on a full-scale 4-MW machine prototype, validating the proposed design. The experimental results are in good agreement with simulation and show significant progress in the field of high-power-density electrical machines at the targeted power rating.

Investigation of an integrated system with industrial thermal management options for carbon emission reduction and hydrogen and ammonia production

Abstract A new integrated energy system employing the cement slag waste heat is uniquely proposed in this study. The core focus of the proposed system is to generate clean hydrogen thermochemically and convert it into ammonia. The designed system consists of the copper–chlorine (Cu–Cl) cycle, a cryogenic air separation unit and a steam Rankine cycle while the useful commodities produced by the proposed system are hydrogen, ammonia, oxygen, hot water and electricity. A CO2 emission analysis is also conducted to calculate the emissions which can be avoided by recovering this waste heat. The Aspen Plus simulation software is utilized to model and simulate the proposed integrated system. A thermochemical water splitting process is incorporated into the system for hydrogen production. The cryogenic air separation unit is integrated in order to separate nitrogen from the air. This proposed system also reduces the environmental effects of the flue gas emitted by the cement industry. Multiple parametric studies are performed to investigate the system performance by varying operating conditions and state properties. The energy analysis is implemented on each component of the designed system. The overall energy efficiency of the system is concluded as 30.1%. The amount of CO2 emissions which can be avoided by utilizing this waste heat is 29.64 ktonne/5 years.

Better thermal management options with heat storage systems for various applications: An Evaluation

AbstractWith increasing worldwide population and rising standards of living, the global energy consumption is increasing at significant rates. Together with climate change concerns and negative impacts of fossil fuel use, the need for clean and smart energy systems is becoming more obvious. Clean and smart systems provide energy to all types of end‐use applications in an environmentally friendly, affordable, reliable, and efficient manner. Heat losses are recognized as some of the most significant causes of efficiency degradation in energy systems. Therefore, this study overviews and investigates current and future thermal management options for different end‐use purposes for a more sustainable future. In this study, a smart approach is taken when evaluating existing and emerging thermal management systems and smart targets are introduced for better thermal management systems. In addition, some novel thermal management systems for various applications such as electric/hybrid vehicles, power systems, and industrial processes are introduced as case studies and the energy and exergy efficiencies of these case studies are compared. In addition, some key future directions are provided in terms of better thermal management options for a sustainable future. The case study results of this study show that with better thermal management strategies, it is possible to reach energy and exergy efficiencies up to 60% and 50%, respectively in hybrid vehicles, industrial processes, and robotic applications.

Fuel utilization effects on system efficiency in solid oxide fuel cell gas turbine hybrid systems

A computational analysis was conducted to optimize the design of a solid oxide fuel cell - gas turbine hybrid power generator, focusing on the impact that fuel utilization within the fuel cell has on system efficiency and installed costs. This is the first ever design-study considering the effect of fuel utilization on performance, as well as on the optimum power split. This hybrid system attained high electric generation efficiencies (>70%) over a wide range of operating conditions (60% < fuel utilization < 90%) while the fuel cell stack size decreased in proportion to decreasing the fuel utilization. A one-dimensional fuel cell model was used to simulate the fuel cell while GateCycle® was used to simulate the performance of the associated recuperated turbine and various subsystems necessary for thermal management. For each test case, the size of the solid oxide fuel cell, gas turbine, and recuperator, as well as the fuel and air flow rates, hot-air bypass set point, and heat exchange effectiveness in the solid oxide fuel cell manifold were varied to obtain 550 MWe output. In addition, anode recycle, turbomachinery efficiency, and various thermal management options were tested. The maximum system efficiency (75.6%) was attained for the single-pass solid oxide fuel cell with highly efficient turbomachinery when the solid oxide fuel cell used 80% of the incoming fuel. Efficiency was essentially flat from 75% fuel utilization through 85% fuel utilization. Employing anode recycle starting at 65% resulted in roughly 1 percentage point efficiency decrease for each percent increase in fuel utilization. For minimized solid oxide fuel cell degradation, a near 50:50 power split case was studied resulting in 68.6% efficiency and the solid oxide fuel cell using 55% of the incoming fuel. Because of shifting half of the power generation to the gas turbine, the size of the fuel cell stack was reduced by 25% as compared to that at maximum efficiency (80% fuel utilization).

Plasma-Sprayed Heat Shields Offer Thermal Management Options

Abstract Heat shields help protect vehicle-critical components that could delaminate and fail if exposed to high temperatures for any length of time. This article describes a solution that features ceramic platelets applied via plasma spray onto a metal substrate to create a heat shield that adds additional temperature resistance in comparison to standard pressed aluminum versions.

Enabling the 2.5D Integration

3D IC is the viable revolutionary technology that will enable system-level integration, miniaturization, optimal power management, increased data bandwidth, and eventually reduced system cost. Like any breakthrough technologies, it faces many challenges. Design methodology, integration technology, manufacturing process and new industrial ecosystem are the areas of focus. This paper will discuss these challenges and Altera's 3D integration development effort. 2.5D is an intermediate path to true 3D IC using silicon interposer and TSV (Through-Si-Via) stacking. The 2.5D stacking configuration offers different form factor, interconnect path, and thermal management options than monolithic packages, which could help to reduce system level power and thermal management pressure. It offers silicon level interconnect density, low inductive path and wide IO application. However, it's power delivery system (PDN) could be the bottleneck for the system to perform at the intended bandwidth and speed. Thus, the whole system, IC-Interposer-Package-PCB, must be considered holistically, and trade off study and compensation mechanism development are needed in such complex system level integration. There are many different 2.5D integration manufacturing flows currently under development. They can be categorized into two major flow options: Attaching interposer to substrate first, which can be called CoCoS (Chip on Chip on Substrate); or attaching device silicon to interposer first, which is also called CoWoS (Chip on Wafer on Substrate). The major challenges are in the areas of manufacturing process window and yield, thin wafer handling, testability and overall cost of the integration process. ,). This paper will discuss design consideration, manufacturability analysis, Logic/memory devices and silicon interposer interaction, and thermal management to enable the 2.5D integration. System level characterization and correlation with simulations are performed. The challenge of new supply-customer model and industrial ecosystem development associated with 2.5D integration will also be discussed.

Exergy analysis of heat exchangers in the copper-chlorine thermochemical cycle to enhance thermal effectiveness and cycle efficiency

Most existing nuclear power plants in North America are typically water-cooled and operate at 250–500°C. For this temperature level, the copper–chlorine (Cu–Cl) cycle is one of the most promising cycles that can be integrated with nuclear reactors for hydrogen production by decomposing water into its constituents. In this study, we analyze the heat exchangers in the Cu–Cl thermochemical cycle so as to enhance heat transfer effectiveness and thereby improve the cycle efficiency. The thermal management options for internal and external heat transfer are studied and heat recovery opportunities are investigated and compared. Each heat exchanger in the cycle is examined individually based on the chemical/physical behavior of the process, and the most appropriate options are recommended. A thermodynamic analysis and associated parametric studies are performed for various configurations to contrast their efficiencies and effectivenesses.