Browse Topic: Heat exchangers

Items (1,338)
This Aerospace Recommended Practice (ARP) outlines the causes and impacts of moisture and/or condensation in avionics equipment and provides recommendations for corrective and preventative action.
AC-9 Aircraft Environmental Systems Committee
The intent of this report is to encourage that the thermal management system architecture be designed from a global platform perspective. Separate procurements for air vehicle, propulsion system, and avionics have contributed to the development of aircraft that are sub-optimized from a thermal management viewpoint. In order to maximize the capabilities of the aircraft for mission performance and desired growth capability, overall system efficiency and effectiveness should be considered. This document provides general information about aircraft Thermal Management System Engineering (TMSE). The document also discusses approaches to processes and methodologies for validation and verification of thermal management system engineering. Thermal integration between the air vehicle, propulsion system, and avionics can be particularly important from a thermal management standpoint. Due to these factors, this report is written to encourage the development of a more comprehensive system
AC-9 Aircraft Environmental Systems Committee
The present work demonstrates a Fluid-Structure Interaction (FSI) based methodology that couples a Finite Volume Method (FVM) and Finite Element Method (FEM) based tools to estimate air guide deformation, thereby predicting accurate aerothermal performance. The method starts with a digital assembly step where the assembly shape and the induced stress due to assembly is predicted. A full vehicle Aerodynamic simulation is performed to extract the surface pressure on the air guide which is then used to estimate the extent of deformation of the air guides. Based on the extent a subsequent Aerodynamic simulation may be carried out to predict thermal efficiency. Comparison against pressure data and deflection data extracted from the wind tunnel experiments of vehicles has shown reasonable match demonstrating the accuracy and usefulness of the method.
Gadasu, RavishastriChoudhury, SatyajitUmesh, Acharya VaibhavKumar, SaravananYenugu, SrinivasaZander, DanielBeesetti, SivaHattarke, Mallikarjun
The purpose of this document is to present test methods that can be utilized to evaluate the filtration and operating characteristics of filters that will be utilized in a cryogenic system. The methods presented herein are intended to supplement standard filter testing specifications to allow evaluation of filter performance characteristics in areas that could be affected by extreme low temperatures.
A-6C1 Fluids and Contamination Control Committee
An agricultural tractor comprises a tightly packed underhood compartment, which poses distinct challenges in managing airflow through its heat exchangers. The intricate design results in uneven airflow patterns, as the fan-driven system draws air from the front, top, and side openings. This work presents a methodology to measure the cooling airflow volume in the tractor and establishing a correlation between test airflow and CFD simulated airflow values. A handheld anemometer and 3x3 matrix type anemometer used for airflow measurement. Measurements were taken at front and back of heat exchanger. It was concluded that, measuring airflow through the heat exchanger with a matrix-type anemometer positioned behind it can enhance the correlation with CFD results to 84%.
A, BoopalshanmugamGanesan, ThanigaivelReddy, LakkuSateesh, TadiGopinathan, Nagarajan
Hydrogen PFI engines face abnormal combustion issues, especially during transient operation. The air-to-fuel ratio and trapped exhaust gas significantly affect combustion stability and NOx emissions, requiring continuous monitoring. Real-time estimation of the trapped gas composition and thermodynamic state is therefore crucial but challenging. This work introduces a real-time, physics-based Multi-Input-Multi-Output (MIMO) model for accurately estimating trapped air and exhaust gas mass at the intake valve closing (IVC) event. In detail, the estimation model makes use of dynamic in-cylinder and exhaust pressure measurements to accurately model mass flows and heat exchange equations with 0.5 CAD resolution. This allows extremely high fidelity when modelling the physical properties of the various chemical species along the engine cycle. Moreover, the model calibration appears only in the form of two coefficients implemented on a lookup table for twelve different operating points
Galli, ClaudioFerrara, GiovanniGrilli, NiccolòBalduzzi, FrancescoRomani, LucaVichi, Giovanni
Heat exchangers are critical components in various industrial applications, enabling efficient energy transfer between fluids. Chiller (Plate-type heat exchanger), with its compact design and high thermal performance, have gained significant attention in industries such as HVAC, power generation, and chemical processing. This study presents a comprehensive thermo-structural analysis of a chiller generated due to varying fluctuating temperatures and vehicle vibrations using Computer-Aided Engineering (CAE) tools. The analysis involves modeling the heat exchanger geometry, including the alternate chiller plates, to capture the complex geometries. Advanced simulation techniques such as Computer-Aided engineering (CAE) and Finite Element Analysis (FEA) are employed to investigate the thermal behavior under varying operating conditions, including flow rates, inlet temperatures, and pressure drops. Key parameters like pulsation pressure test, temperature distribution, dynamic stress analysis
Jaiswal, AnkitParayil, Paulson
Electricity is a fundamental necessity for individuals worldwide, serving as a force driving technological progress hitherto unimaginable. Electricity generation uses diverse methodologies based on available natural resources in a given geographic region. Conventional methods like thermal power from coal and natural gas, water-based hydropower, solar power from the sun, wind power, and nuclear power are used extensively, the former two being the dominant sources. The generation of nearly 70% of the world's electricity is estimated to be from thermal power plants; however, these operations lead to widespread environmental destruction, greenhouse emissions, and the occurrence of acid rain. Conventional thermal power plants run on the Rankine cycle principle of a boiler, a turbine, a condenser, and a pump. A similar method may be used in the Organic Rankine Cycle (ORC) with the use of solar energy, where heat is transferred to the working fluid in the boiler using a heat pipe, a passive
Deepan Kumar, SadhasivamKumar, VDhayaneethi, SivajiMahendran, MSaminathan, SathiskumarR, KarthickA, Vikasraj
The Internal Heat Exchanger (IHX) is an important component in modern car air conditioning (AC) systems, particularly in AC lines. It increases cooling efficiency by transferring heat from the high-pressure liquid refrigerant to the low-pressure vapor. By using this technology, refrigerant sub-cooling and superheating improve, resulting in higher cooling performance, lower energy usage, and less strain on the compressor. It improves vehicle fuel economy and a longer lifespan of AC components. Also, IHX prevents liquid refrigerant from entering the compressor, reducing the danger of damage and increasing system reliability. This optimization helps to maintain consistent refrigerant flow, reduces energy consumption, and improves the overall Coefficient of Performance (COP). The implementation of an IHX technology in AC lines results in more compact, streamlined system designs, which allow for better temperature management, faster response times, and lower cooling loads. An IHX can boost
Dudeja, KailashSingh, Saniya
Zero emission vehicles are essential for achieving sustainable and clean transportation. Hybrid vehicles such as Fuel Cell Electric Vehicles (FCEVs) use multiple energy sources like batteries and fuel cell stacks to offer extended driving range without emitting greenhouse gases. Optimal performance and extended life of the important components like the high voltage battery and fuel-cell stack go a long way in achieving cost benefits as well as environmental safety. For this, energy management in FCEVs, particularly thermal management, is crucial for maintaining the temperature of these components within their specified range. The fuel cell stack generates a significant amount of waste heat, which needs to be dissipated to maintain optimal performance and prevent degradation, whereas the battery system needs to be operated within an optimal temperature range for its better performance and longevity. Overheating of batteries can lead to reduced efficiency and potential safety hazards
BHOWMICK, SAIKATChuri, Chetana
In automotive systems, efficient thermal management is essential for refining vehicle performance, enhancing passenger comfort, and reducing MAC Power Consumption. The performance of an air conditioning system is linked to the performance of its condenser, which in turn depends on critical parameters such as the opening area, radiator fan ability and shroud design sealing. The opening area decides the airflow rate through the condenser, directly affecting the heat exchange efficiency. A larger opening area typically allows for greater airflow, enhancing the condenser's ability to dissipate heat. The shroud, which guides the airflow through the condenser, plays a vital role in minimizing warm air recirculation. An optimally designed shroud can significantly improve the condenser's thermal performance by directing the airflow more effectively. Higher fan capacity can increase the airflow through the condenser, improving heat transfer rates. However, it is essential to balance fan
Nayak, Akashlingampelly, RajaprasadNeupane, ManojMittal, SachinKumar, MukeshUmbarkar, Shriganesh
High Performance Resistors (HPR), also known as brake resistors are used in zero emission vehicles (ZEVs) to dissipate excess electrical energy produced during regenerative braking, as heat energy. It is necessary to use a suitable cooling technique to release this heat energy into the atmosphere in a regulated manner. Currently in most of the ZEVs, liquid cooled HPR with its dedicated heat exchanger and other auxiliaries such as pump, surge tank, Coolant and coolant lines, is used which increases the cost, packaging space and assembly time. This paper presents air cooling as a substitute heat-exchanging technique for high-performance resistors which eliminates the need of auxiliaries mentioned above, resulting in space optimization and reduction in assembly time. An air cooled HPR, designed for this study consists of a heat exchanger, which accommodates a resistor wire within its tubes. The design was made to fit commercial vehicle use, specific to trucks, due to packaging constraints
Menariya, Pravin GaneshKumar, VishnuArhanth, MahimaUmesha, SathwikJagadish, Harshitha
Proton Exchange Membrane Fuel Cell (PEMFC) vehicles are emerging as a promising green alternative to fossil fuel and battery-operated electric vehicles. Fuel cells convert the chemical energy of fuel to direct current (DC) through electrochemical reactions, rejecting some heat in the process. This study aims to minimize heat generated during these reactions within the fuel cell stack and utilize it to enhance stack efficiency. Through thermodynamic modeling and exergy analysis, the research focuses on reducing waste heat from exothermic reactions in PEMFC stacks. It investigates using low-temperature waste heat for heating hydrogen and inlet air also examining into how stoichiometry and current density influence heat reduction. Analytical studies were carried out using air stoichiometry ranging from 1.5 to 2 and ambient temperatures typical of Bangalore's climate (15°C to 35°C). The results show that increasing the current density from 1 A/cm2 to 1.5 A/cm2 significantly raises the
Sahu, Tomesh KumarBansode, Annasaheb
The increasing demand for heating and cooling, coupled with growing environmental concerns, necessitates a paradigm shift towards sustainable thermal management practices. This paper presents a rigorous and scholarly investigation into innovative heating and cooling concepts, with a specific focus on the development and implementation of alternative refrigerants and waste heat recovery systems. The transition away from conventional refrigerants, with their detrimental impact on the environment, is explored through a comprehensive analysis of promising alternatives. Hydrofluoroolefins (HFOs), natural refrigerants (e.g., CO2, hydrocarbons, ammonia), and their blends are critically evaluated, considering their thermodynamic properties, environmental impact (GWP, ODP), safety considerations (flammability, toxicity), and application-specific performance. The paper delves into the intricacies of advanced cooling technologies, including absorption cooling, adsorption cooling, and
K, NeelimaCh, KavyaC, SomasundarB, HarichandanaSatyam, SatyamP, Geetha
Thermal management is critical for modern vehicles, particularly for Zero Emission Vehicles (ZEVs), where maintaining optimal temperature ranges directly influences thermal system efficiency and vehicle range. Accurate prediction of underhood airflow behavior is essential for effective thermal management and also to estimate overall energy consumption by cooling system, with air-side dynamics playing a pivotal role in heat transfer over the heat exchangers of cooling package. Simulation tools like GT-Suite are indispensable for this purpose, enabling engineers to evaluate complex thermal interactions without the cost and time constraints of extensive physical testing. While 3D Computational Fluid Dynamics (CFD) models offer detailed insights into flow characteristics, they are computationally expensive and time consuming. In contrast, 1D models provide faster simulation times, making them ideal for system-level analysis and iterative design processes. However, 1D models inherently lack
Mutyala k, AkhilPudota, PraveenFaseel, IhsanGole, PranaliBashir, Murad
Efficient thermal management is vital for electric vehicles (EVs) to maintain optimal operating temperatures and enhance energy efficiency. Traditional simulation-based design approaches, while accurate, are often computationally expensive and limited in their ability to explore large design spaces. This study introduces a machine learning (ML)-based optimization framework for the design of an EV cooling circuit, targeting a 5°C reduction in the maximum electric motor temperature. A one-dimensional computational fluid dynamics (1D-CFD) model is utilized to generate a Design of Experiments (DOE) matrix, incorporating key parameters such as coolant flow rate and heat exchanger dimensions. A Radial Basis Function (RBF) neural network is trained on the simulation data to serve as a surrogate model, enabling rapid performance prediction. Optimization is performed using the Non-Dominated Sorting Genetic Algorithm II (NSGA2), yielding three distinct design solutions that meet the thermal
Paul, KavinGanesan, ArulMansour, Youssef
Thermal management solutions in power electronics applications are of prime importance to meet the needs of the ever-increasing demands on higher power and torque density of the traction motor and controller. Traction inverters are essential power electronic devices that convert direct current (DC) supply from the battery pack of the vehicle to three-phase alternating current (AC) output and vice versa. Estimation of die junction temperatures and cooling system pressure drop is necessary for assessing the maximum heat load capacity of the traction inverter system and coolant pump capacity requirements. The system comprises of a power module and a water–glycol–based cooling domain with heat sink. This article proposes a 1D model for accurate predictions of junction temperatures on the SiC die, temperature rise of the cooling medium, and pressure drop across a custom heat sink fluid domain. The model is built to handle steady-state and transient conditions for varying heat loads on the
Ravindra, VidyasagarPrasad, PraveenSingh, IshanSureka, Sumit
Advancements in additive manufacturing (AM) technology have enabled the use of Triply Periodic Minimal Surface (TPMS) lattice structures to integrate thermal and structural functions into a single component. These structures offer advantages such as weight reduction, compactness and enhanced heat dissipation, making them promising for automotive, aerospace and electronics applications. TPMS structures, characterized by zero mean curvature and periodic crystalline geometry, have recently gained significant research attention thanks to their potential in thermal management. Among various TPMS geometries, the gyroid and diamond structures stand out for their thermal and fluid dynamic performance. This study explores the influence of cell geometry, unit cell size, and wall thickness on the efficiency of TPMS-based heat exchangers, as these parameters are crucial for their technical feasibility. Using Computational Fluid Dynamics (CFD) simulations, a comparative analysis is conducted for a
Cordisco, IlarioTorri, FedericoBerni, FabioTesta, VeronicaGiacalone, MauroFontanesi, Stefano
This SAE Recommended Practice is applicable to all liquid-to-air, liquid-to-liquid, air-to-liquid, and air-to-air heat exchangers used in vehicle and industrial cooling systems.
Cooling Systems Standards Committee
By combining topology optimization and additive manufacturing, a team of University of Wisconsin-Madison engineers created a twisty high-temperature heat exchanger that outperformed a traditional straight channel design in heat transfer, power density and effectiveness.
The primary approach to meet the objectives of the EU Heavy Duty CO2 Regulation involves decarbonizing the road transport sector by battery electric vehicles (BEV) or hydrogen-fueled vehicles. Even though the well-to-wheel efficiency of hydrogen-fueled powertrains like fuel cell electric vehicles (FCEV) and H2-internal combustion engines (H2-ICE) is much lower in comparison to BEV, they are better suited for on-road heavy-duty trucks, long haul transport missions and regions with scarce charging infrastructure. Hence, this paper focuses on heavy-duty FCEVs and their overall energetic efficiency enhancement by intelligently managing energy transfer across coolant circuit boundaries through waste heat recovery, while ensuring that all relevant components remain within required temperature boundaries under both cold and hot ambient conditions. Results were obtained using a 1D-model that comprises all thermal fluid circuits (refrigerant, coolant, air) created through GT-Suite software
Uhde, SophiaLanghorst, ThorstenWuest, MarcelNaber, Dirk
Thermal Management Integration Module (TMIM), which comprises components such as water pumps, runner boards, brackets, sensors, etc., is a multifunctional integrated component for electric vehicles. However, the water pump generates an excitation over a wide range of frequencies due to a wide range of speed variations. This excitation causes the TMIM to vibrate and generate noise. In this study, a TMIM that generates noise is studied and analyzed. Using the TMIM of an electric vehicle as a case study, a full-vehicle experimental test was conducted, revealing that the noise originates from the integration module. The finite element method is used to analyze the cause of noise generation. Given the characteristics of the TMIM, which comprise many components, high integration, and a complex structure, this paper simplifies the bracket, heat exchanger, sensor, and other components using the centralized mass point method. The modal state of the TMIM is obtained by impact hammer testing the
Xu, Shenao
The use of hydrogen in port fuel injection (PFI) engines faces challenges related to abnormal combustions that must be addressed, especially in transient operation. The in-cylinder air-to-fuel ratio and the amount of trapped exhaust gas have a significant impact on the probability of abnormal combustion as well as NOx emissions, and should be real-time monitored in hydrogen engines. Thus, the real-time estimation of the composition and thermodynamic state of the trapped gas mixture is crucial during transient operations, although highly challenging. This study proposes an on-line real-time physics-based MIMO (Multi-Input-Multi-Output) model to accurately estimate the amount of trapped air and exhaust gas in the cylinder at the intake valve closing (IVC) event, based on the instantaneous in-cylinder pressure measurement. With proper estimation accuracy, the injector can be controlled to correctly provide the amount of fuel necessary to achieve the target air-to-fuel ratio (AFR) and
Galli, ClaudioCiampolini, MarcoDrovandi, LorenzoRomani, LucaBalduzzi, FrancescoFerrara, GiovanniVichi, GiovanniMinamino, Ryota
The rapid expansion of the global electric vehicle (EV) market has significantly increased the demand for advanced thermal management solutions. Among these, the battery cold plate is a critical component, essential for maintaining optimal battery temperatures and ensuring efficient operation. As EV batteries increase in size, the thermal management requirements become more complex, necessitating the development of new alloys with enhanced strength and thermal conductivity. These advancements are crucial for the effective dissipation of heat and the ability to withstand the mechanical stresses associated with larger and more powerful batteries. The evolving performance demands of EVs are driving material innovation within the thermal management sector. This study aims to explore the global heat exchanger market trends from a material perspective, focusing on the evolution of the mechanical and thermal properties. Specifically, we investigated the transition from the traditional AA3003
Jalili, MehdiWang, XuRazm-poosh, Hadi
To investigate the static and dynamic mechanical properties of air springs and their influencing factors, two models were established in this paper to calculate the static and dynamic mechanical properties of air springs, including a simulation model based on the finite element method and a mathematical calculation model based on thermodynamic theory. First, a performance calculation model for rolling lobe air springs with aluminum tubes was established, which considered the thickness of the bellow and the impact of the inflation and assembly process on the state of the bellow. The static and dynamic mechanical properties of air springs were calculated using this model, including static load-bearing capacity and static/dynamic stiffness. The calculation results showed that both the static characteristics of the air spring under isothermal conditions and the dynamic characteristics under adiabatic conditions were able to be calculated accurately. However, the changes in dynamic
Wang, SiruiKang, YingziXia, ZhaoYu, ChaoLi, JianxiangShangguan, Wen-Bin
In numerous automotive and industrial applications, efficient heat extraction is crucial to prevent system inefficiencies or catastrophic failures. The design of heat exchangers is inherently complex, involving multiple stages defined by the depth of analysis, number of design variables, and the accuracy of physical models. Designers must navigate the trade-offs between highly accurate yet computationally expensive models and less accurate but computationally cheaper alternatives. Multi-fidelity modeling offers a solution by integrating different fidelity models to deliver precise results at a reduced computational cost. In addition to managing these trade-offs, designers often face multi-objective challenges, where optimizing one aspect may lead to compromises in others. Multi-objective optimization, therefore, becomes essential in balancing these competing objectives to achieve the best overall design. In this context, Gaussian Process-based methods have gained prominence as
Chaudhari, PrathameshTovar, Andres
Phase change energy storage devices are extensively utilized in latent heat thermal energy storage and hold significant potential for application in the thermal management of automotive batteries. By harnessing the high-density energy storage capabilities of phase change materials to absorb heat released by the batteries, followed by timely release and utilization, there is a substantial improvement in energy efficiency. However, the thermal conductivity of medium and low temperature phase change materials is poor, leading to its inefficient utilization. This paper focuses on optimizing the structure of a phase change heat exchanger in a phase change energy storage device to improve its performance. A basic design of the phase change heat exchanger is used as an example, and fin structure is added to enhance its heat exchange capabilities. A predictive surrogate model is built using numerical simulation, with the dimension and number of fins as design variables, and heat flow density
Zhang, HaonanSun, MingzheZheng, HaoyunZhang, Tianming
The advancement of automotive industry demand compact size of HVAC with better cabin comfort. To achieve this, HVAC has to be optimized in all the aspects such as in shape & size, thermal comfort as well as in noise comfort. from an HVAC perspective, aeroacoustics noise is more significant due to its intensity at higher speeds and frequencies. Since HVAC is mounted inside the cabin, noise can transfer directly inside cabin. To avoid this, noise reduction or noise controlling is of very important. This is possible with HVAC design and simulation at the initial level and acoustic prediction after the CFD/CAA analysis. The present paper describes the aeroacoustic simulation of one of the HVAC to predict the noise during face mode. For that, 1-D simulation has been done initially to find the porosity of heat exchangers and coupled with a CFD solver. STAR CCM+ software is used for the CFD analysis. Transient simulation is performed with compressible fluid using a moving mesh approach. To
Kame, ShubhamParayil, PaulsonGoel, Arunkumar
In driving condition, the electric drive system of electric vehicles generates significant heat, which increases temperature of the motor, leading to reduced performance and energy loss. To manage the motor temperature and recover energy, a plate-fin heat exchanger (PFHE) is used to facilitate heat exchange between the electric drive system and the vehicle's thermal management system. In this study, Computational Fluid Dynamics (CFD) method was used to investigate the fin structure on thermal flow performance within the PFHE. The mathematical models of pressure drop and heat transfer of plate-fin heat exchanger are established in this paper, and an empirical formula for the friction factor was derived by using test data. The NTU method was applied to fit the formula of convective heat transfer coefficient, enabling the derivation of an empirical formula for the Colburn factor. A CFD simulation model was developed for a local heat exchange unit, considering the generic boundary
Yin, JintaiYin, ZhihongLu, XuanWang, MengmengLiu, Qian
Triply Periodic Minimal Surface (TPMS) structures offer the possibility of reinventing structural parts and heat exchangers to obtain higher efficiency and lighter or even multi-functional components. The crescent global climate concern has led to increasingly stringent emissions regulations and the adoption of TPMS represents a resourceful tool for OEMs to downsize and lighten mechanical parts, thereby reducing the overall vehicle weight and the fuel consumption. In particular, TPMS structures are gaining growing interest in the heat exchanger field as their morphology allows them to naturally house two separate fluids, thus ensuring heat transfer without mixing. Moreover, TPMS-based heat exchangers can offer countless possible design configurations. These structures are obtained by periodic repetitions in the three spatial dimensions of a specific unit cell with defined dimensions and wall thickness. By tuning their characteristic parameters, the structure can be tailored to obtain
Torri, FedericoBerni, FabioMartoccia, LorenzoMarini, AlessandroMerulla, AndreaGiacalone, MauroColombini, Giulia
This paper presents an advanced control system design for an engine cooling system in an internal combustion engine (ICE) vehicle. Building upon our previous work, we have derived models for crucial temperatures within the engine, including combustion wall temperature, coolant-out temperature, block temperature, as well as temperatures in external components such as heat exchangers and radiator. To accurately predict these temperatures in a rapid manner, we have utilized a lumped parameter concept with a mean-value approach. This approach allows for precise temperature estimation while maintaining computational efficiency. Given the complexity of the cooling system, we have proposed a linear time-varying (LTV) model predictive control (MPC) system to regulate the temperatures. This control system linearizes the model at each time step and applies linear MPC over the control and prediction horizons. By doing so, we effectively control the highly nonlinear and time-delayed system
Chang, InsuSun, MinEdwards, David
There are various steering technologies are available in market nowadays. Hydraulic Power Steering (HPS) is one of them. As hydraulic name is linked to it the temperature role comes to play. While doing hard cornering the hydraulic oil used to assist the working in steering system get over heated, due to which oil loses its viscosity became one of the major causes of hard steer in trucks. Also, due to limited space the large heat exchanger cannot be used there. So, objective of this Thesis is to examine an effective solution which can be compact in design and at the same time should be effective to solve this problem. After going through literature analysis, we finalize that the Principal of Pulsating Heat Pipe could be a possible solution. So, for that we design different model based on previous research work in Creo and simulate them in Star CCM+ to finalize the optimality.
Saikrishna, VNLP, RudreshaYadav, SatyendraB, RuthvikaVishwasa, Viditha
The thermoelectric generator system is regarded as an advanced technology for recovering waste heat from automotive exhaust. To address the issue of uneven temperature distribution within the heat exchanger that limits the output performance of the system, this study designs a novel thermoelectric generation system integrated with turbulence enhancers. This configuration aims to enhance convective heat transfer at the rear end of the heat exchanger and improve overall temperature uniformity. A multiphysics coupled model is established to evaluate the impact of the turbulence enhancers on the system's temperature distribution and electrical output, comparing its performance with that of traditional systems. The findings indicate that the integration of turbulence enhancers significantly increases the heat transfer rate and temperature uniformity at the rear end of the heat exchanger. However, it also leads to an increase in exhaust back pressure, which negatively affects system
Chen, JieDing, RenkaiWang, RuochenLiu, WeiLuo, Ding
With the rapid adoption of new energy vehicles (NEVs), effective thermal management has become a crucial factor for enhancing performance, safety, and efficiency. This study investigates the steady-state and dynamic characteristics of a secondary loop CO₂ (R744) thermal management system designed for electric vehicles. The secondary loop system presents several benefits, such as improved safety through reduced refrigerant leakage and enhanced integration capabilities with existing vehicle subsystems. However, these advantages often come at the cost of decreased thermodynamic efficiency compared to direct systems. Experimental evaluations were conducted to understand the effects of varying coolant flow rates, discharge pressure, and dynamic startup behaviors. Results indicate that while the indirect system generally shows a lower coefficient of performance (COP) than direct systems, optimization of key parameters like coolant flow rate and discharge pressure can significantly enhance
Zong, ShuoHe, YifanGuan, YanDong, QiqiYin, XiangCao, Feng
To investigate the characteristics of a battery direct-cooling thermal management system integrated with the passenger compartment air-conditioning in a range-extended hybrid electric vehicle (REV), a model of the vehicle’s direct-cooling and liquid-cooling thermal management systems was established in GT-SUITE software. The findings are as follows: (1) Under high-temperature fast-charging conditions, the direct-cooling thermal management system exhibited improved performance indicators compared to the liquid-cooling system. Specifically, the charging time was reduced by 3.8%, the maximum heat exchange power increased by 27.33%, the battery temperature decreased by 2.37°C, the thermal decay rate was only 6%, and the average system energy efficiency ratio increased by 8.37%. (2)The outlet pressure of the direct-cooling plate significantly affected the temperature reduction of the battery pack during high-temperature fast-charging. The results indicated that within a certain range, a
Li, Li-JieSu, ChuqiWang, Yi-PingYuan, Xiao-HongLiu, Xun
In the field of static power generation, thermoelectric technology has become an important solution for utilizing automotive exhaust waste heat. This study presents a new design for a heat exchanger integrated with heat pipes, aimed at augmenting the installation area of thermoelectric modules and improving the hot end temperature by high heat transfer rate. Moreover, the number of heat pipes in each region is optimized to reduce the temperature gradient along the direction of exhaust flow and maximize overall output performance. A comprehensive numerical model of the thermoelectric generator system is developed to conduct the performance prediction and parameter optimization. The results reveal that the integration of heat pipes substantially boosts the performance of the automotive thermoelectric generator system, characterized by enhanced heat transfer, increased power output, and improved conversion efficiency. And the optimization yields an optimal configuration with 5 heat pipes
Zhao, JinFuDing, RenkaiChen, JieWang, RuochenLuo, Ding
This research investigates the development of a heat pipe heat exchanger coated with graphene for cooling and purification of automobile exhausts. The heat exchanger directly affects the performance of the engine because proper heat dissipation and transfer can improve engine performance, reduce fuel consumption, and decrease the emission. Moreover, this effect is much more noticeable on coated heat pipes because of the enhanced thermal conductivity and mechanical properties of the graphene films. A heat null emitted by internal combustion engines was used in the experimental setup to test the thermal performance, cooling efficiency, and purification efficiency of the newly designed in-house exhaust simulation system where the new heat pipes were inserted. The results of the experiment show that the heat pipes have very high thermal performance as the efficiency of the heat pipes was calculated to be around 85%. Furthermore, the temperature decrease over the surfaces of the heat
Karthigairajan, M.Seeniappan, KaliappanBalaji, N.Natrayan, L.Sheik, Salman BashaRavi, D.
This ARP provides the definition of terms commonly used in aircraft environmental control system (ECS) design and analysis. Many of the terms may be used as guidelines for establishing standard ECS nomenclature. Some general thermodynamic terms are included that are frequently used in ECS analysis, but this document is not meant to be an inclusive list of such terms.
AC-9 Aircraft Environmental Systems Committee
Automotive cooling module system consists of condenser, radiator and intercooler which is used for thermal management of vehicle. Condenser helps to reject cabin heat, radiator to reject engine heat and intercooler rejects charged air heat to ambient. CRFM (Condenser, Radiator and Fan module) is conventionally packaged under the bonnet of passenger vehicle. Fan circulate airflow through heat exchangers and has primary role of airflow delivery. While performing vehicle level thermal management duty, fan noise is generated from CRFM and fan noise is considered as an important design attribute of CRFM. Many researchers have done fan noise simulation at component level and very limited literatures at vehicle (system) level simulation are available. Customer perceives noise from outside of the vehicle and it is important to predict fan noise at vehicle level at various operating speeds. Such simulations are transient in nature and modeling complexity demands high computational cost. Current
Kandekar, Ambadas BhagujiDuppati, DarshanBorse, HarshalJain, AyushPatel, KaushikBaghel, Devesh
In today's fast-paced lifestyle, people spend a maximum amount of time for traveling, leading to a heightened demand for thermal comfort. Automotive HVAC play a crucial role in providing conditioned air to ensure comfort while traveling. Evaluating HVAC systems performance including delivery systems, heat exchanger efficiency, air thermal mixing zones, and temperature distribution are essential to maintain fuel economy and modern vehicle styling. However, accurately predicting cooling/heating performance using CFD simulations poses challenges due to the complex nature of heat exchanger modeling, which demands substantial computational resources and time. This paper presents the development of CFD modeling capabilities for predicting temperature distribution at duct outlet grills for defrost mode. Additionally, it assesses heater performance under maximum hot conditions. STAR-CCM+ software is employed to model the entire system, with the heater and evaporator core represented as porous
Ahmad, TaufeeqParayil, PaulsonSharma, NishantKame, ShubhamJaiswal, AnkitGoel, Arunkumar
Electric vehicle thermal management system is essential for electric vehicles to guarantee cabin thermal comfort and battery appropriate operating temperature. As a matter of fact, in such systems, high- and low-temperature driving conditions can severely affect system performance, in terms of overall efficiency and driving range. In this context, an effective thermal management solution both for cabin thermal comfort and battery heating/cooling is investigated in this paper. A key innovation is the deep integration of the HVAC and battery heating/cooling circuits. Primarily, in winter scenario, the heat generated by the powertrain during operation is used to warm the cabin, thereby mitigating the necessity for additional electric cabin heating. This way, despite the inclusion of an extra heat exchanger, a consistent amount of heat can be recovered and the use of the battery energy for electrical heating activation is significantly reduced, as already presented by the authors in a
Chiappini, DanieleTribioli, LauraLombardi, Simone
In electrified vehicles, auxiliary units can be a dominant source of noise, one of which is the refrigerant scroll compressor. Compared to vehicles with combustion engines, e-vehicles require larger refrigerant compressors, as in addition to the interior, also the battery and the electric motors have to be cooled. Currently, scroll compressors are widely used in the automotive industry, which generate one pressure pulse per revolution due to their discontinuous compression principle. This results in speed-dependent pressure fluctuations as well as higher-harmonic pulsations that arise from reflections. These fluctuations spread through the refrigeration cycle and cause the vibration excitation of refrigerant lines and heat exchangers. The sound transmission path in the air conditioning heat exchanger integrated in the dashboard is particularly critical. Various silencer configurations can be used to dampen these pulsations. This paper compares the acoustic and thermodynamic performance
Saur, LukasHeidegger, PatrickNaeger, ChristophBecker, Stefan
Sodium is used as a coolant in the fast reactor’s primary and secondary loops to transfer enthalpy from the reactor and transport it to the expander. However, handling sodium is difficult, and it can be hazardous if it comes into contact with air, which causes an exothermic reaction. During maintenance of sodium loop components, isolation is typically accomplished with valves. The valve leaking is caused by the seal or the gland. Seal leakage is compensated because it occurs within the line, but gland leakage should be zero because the liquid is harmful. To address this requirement, the author attempted to design a special type of valve in which sodium is allowed to rise through an annular path along the stem and heat transfer is augmented in such a way that the required enthalpy is evacuated to freeze sodium inside the annular path, confirming the fail-safe zero gland leakage. A finned tube assembly is fitted around the stem to achieve this concept of expanded surface heat transfer
Kudiyarasan, SwamynathanBiswas , Sitangshu Sekhar
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