Browse Topic: Coolants

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Optimizing Cooling Circuit Lines in between Batteries and Its Thermal Management Unit2025-01-501703/21/2025
Ensuring uniform coolant distribution in electric buses is crucial for battery performance, longevity, and thermal stability. This study optimizes the battery thermal management system (BTMS) for an 18-m electric bus, addressing uneven coolant flow to battery packs caused by pressure drop variations. One-dimensional (1D) simulations were chosen for their ability to quickly and efficiently analyze flow and pressure variations, providing a fast solution to optimize coolant distribution across the system. dP-Q curves for the BTMS pump and battery packs were integrated into the 1D model based on supplier data, while the flow resistances of other components (pipes, bends) were calculated using KULI software. To correct flow imbalances, pipe diameters were adjusted to increase resistance in over-cooled areas, redistributing coolant to under-cooled sections. This modification resulted in a balanced flow and improved thermal consistency, contributing to longer battery life. Validation showed
Birgül, Çağrı Emre, Meydan, Ömer
3-D Multiphase Flow Simulation of Coolant Filling and Deaeration Processes in an Engine Coolant System2024-26-031001/16/2024
The thermal performance of an engine coolant system is efficient when the engine head temperature is maintained within its optimum working range. For this, it is desired that air should not be entrapped in the coolant system which can lead to localized hot spots at critical locations. However, it is difficult to eliminate the trapped air pockets completely. So, the target is to minimize the entrapped air as much as possible during the coolant filling and deaeration processes, especially in major components such as the radiator, engine head, pump, etc. The filling processes and duration are typically optimized in an engine test stand along with design changes for augmenting the coolant filling efficiency. However, it is expensive and time-consuming to identify air-entrapped locations in tests, decide on the filling strategy and make the design changes in the piping accordingly. In the current effort, a simulation-based testing method for coolant filling and deaeration processes is
Khandagale, Vitthal, Pasunurthi, Shyam Sundar, Maiti, Dipak, Bollu, Theja, Saha, Rohit
Determination of the Heat-Controlled Accumulator Volume for the Two-Phase Thermal Control Systems of Spacecraft01-17-01-000809/29/2023
For spacecraft with high power consumption, it is reasonable to build the thermal control system based on a two-phase mechanically pumped loop. The heat-controlled accumulator is a key element of the two-phase mechanically pumped loop, which allows for the control of pressure in the loop and maintains the required level of coolant boiling temperature or cavitation margin at the pump inlet. There can be two critical modes of loop operation where the ability to control pressure will be lost. The first critical mode occurs when the accumulator fills with liquid at high heat loads. The second critical mode occurs when the accumulator is at low heat loads and partial loss of coolant, for example, due to the leak caused by micrometeorite breakdown. Both modes are caused by insufficient accumulator volume or working fluid charge. To analyze the loop characteristics in critical modes, experiments were conducted on a test bench with ammonia coolant, and a mathematical simulation of a two-phase
Hodunov, Artem, Gorbenko, Gennadiy, Turna, Rustem, Koval, Polina
Design and Development of a Novel Air Cycle Refrigeration System for Passenger Vehicles2022-28-044711/09/2022
Current AC system use hydrofluorocarbons (HFC) as refrigerant to transfer heat from cabin and cool the passengers. However, most refrigerants used today have severe environmental effects due to high global warming potential leading to global warming effects. Montreal Protocol and Kigali amendment calls for all nations to reduce refrigerant usage and transport sector being one of the main consumer of refrigerant, regulations regarding refrigerant usage and emission are becoming more stringent day by day. In this paper, a novel air cycle refrigeration system has been designed and also tested for passenger vehicle applications. Currently used refrigerant R134a with high GWP of 1400+ in mobile air conditioning system is completely eliminated in the air refrigeration system. The aim is to achieve a passenger comfort using air as heat transfer medium and power input either from the engine exhaust air of an ICE vehicle or a secondary air compressor. The effect of performance of various
Gupta, Rajat, Arora, Maneesh, Mohite, Yashwant, Ghate, Pravin, CHIGULLAPALLI, ANIL KUMAR, Maurya, Anurag
Numerical Modelling of Coolant Filling and De-aeration in a Battery Electric Vehicle Cooling System2022-01-093703/29/2022
Trapped air bubbles inside coolant systems have adverse effect on the cooling performance. Hence, it is imperative to ensure an effective filling and de-aeration of the coolant system in order to have less air left before the operation of the coolant system. In the present work, a coolant/air multiphase VOF method was utilized using the commercial CFD software SimericsMP+® to study the coolant filling and subsequent de-aeration process in a battery electric vehicle (BEV) cooling system. First, validations of the numerical simulations against experiment were performed for a simplified coolant recirculation system. This system uses a tequila bottle for de-aeration and the validations were performed for different coolant flow rates to examine the de-aeration efficiency. A similar trend of de-aeration was captured between simulation and experimental measurement. Next, the same numerical techniques were further applied to a BEV cooling system to evaluate the efficiency of de-aeration
Tao, Mingyuan, Slike, Jody, Bhagat, Meghraj, Srinivasan, Chiranth, Zhang, Yi, Motin, Abdul
Proposed Standards And Methods For Leak Testing Lithium-Ion Battery Packs Using Glycol-based Coolant With Empirically Derived Rejection Limits2022-01-084803/29/2022
Lithium-ion batteries are a highly suitable energy source for many applications, particularly in the automotive sector due to their high energy density and low self-discharge rate. During the production of battery cells, rapid detection of leaks is essential to achieve necessary lifetime service-life and safety requirements. Once assembled into packs, whether made of prismatic, cylindrical or pouch cells, packs must be cooled by common automotive thermal management systems, for example those employing engine coolant and radiator, and in which manufacturers must prevent various leak-producing defects that affect durability, longevity and safety Two types of cooling systems are used in automobiles, an active variant in which refrigerant, compressor, evaporator and heat exchanger are used to operate the air conditioning system, or a passive variant with a cooling medium, typically a water/glycol mixture, and a heat exchanger cooled by ambient air. While good industry standards are
Wetzig, Daniel, Blaufuß, Marc
Experimental investigation of thermal safety of the IC engine in the event of coolant loss2021-28-015210/01/2021
Power density (power/engine cubic capacity) of the latest passenger car Diesel and Gasoline engine keeps increasing with a focus to deliver best in class performance along with meeting CAFE and emission norms. This increase in power density increases the thermal load onto the coolant system. Coolant temperature sensor monitoring the coolant temperature, proper radiator sizing, optimum water pump flow capacity and thermostat tuned to the required coolant temperature range are the typical measures taken to ensure safe operation of the engine and avoid any over-heating. Typical cooling system failures are mostly due to low coolant level, a defective thermostat, non-operative water pump & fan and blockage in the coolant circuit, etc. Most of these failures can be detected with the help of coolant temperature sensor and pre-emptive measures can be taken to avoid engine loss. However, in the event of complete loss of coolant in the engine, the coolant temperature sensor will become
Sithick basha, Abubakker, NAMANI, Prasad, Sebastian, Ranjit George, Malekar, Amit, Vellandi, Vikraman
3D CFD coolant system simulation for a full vehicle drive-cycle2021-26-040709/22/2021
The present work deals with the 3-D, transient, system level CFD simulation of automotive coolant system, which includes actual CAD of radiator, cooling jacket, coolant pump, bypass valve and thermostat valve, using a 3D CFD solver Simerics MP+®. This work is in continuation of the work done by Srinivasan et al. (2017) where wax melting, conjugate heat transfer, Fluid Structure Interaction of the valve had been solved. Thermostat valve was controlled by wax phase change model which incorporates the hysteresis effect of wax melting and solidification. The current model will also include rigorous treatment of cavitation to account for the presence of dissolved gases and vaporization of the liquid coolant. The previous work dealt with simulation of opening and closing cycle of the thermostat/by-pass valve system. A methodology has been developed and implemented where the run-time of such a system has been made considerably faster enabling us to simulate complete drive cycle tests. The
Varshney, Mehul, Ballani, Abhishek, Pasunurthi, Shyam Sundar, Maiti, Dipak, Srinivasan, Chiranth
Case Study on Optimized Cooling System Concept for Electric Compact-SUV with Indian Environmental Conditions2021-26-041009/22/2021
With the rising emission level in Indian cities, the focus on pure battery electric vehicle is increasing also in India. The Government of India his also focusing on preparing right policies like FAME-2 to promote the acceptability of EV's by providing subsidies as well as creating the required infrastructure. The environmental conditions in India is much different than other developed countries of Euro, China etc. The max. temperatures in India can go up to 55℃ in the hottest summer time, while during winters temperature can go up to <-25℃ in the northern Himalia region. In these conditions the cooling system of the electric-powertrain components like E-Machine Battery pack etc have to be protected for worst case scenarios specific to Indian conditions. Major cost driver of EV's lie in the HV battery packs and it is very important for acceptability of EV's that the Battery is maximized. With fast discharging and charging phenomena of battery pack required in automotive application can
Emran, M.Sc. Ashraf, Garg, Shivam, Manns, M.Sc. Patrick, Sharma, Vijay
Design Improvement and Failure Simulation of Thermostat Vent using Fatigue Test method2021-26-045609/22/2021
Currently the Automotive industry demands highly competitive product to survive in the global tough competition. Even if there is a slight reduction in product cost and time has a high significant impact on business. Engineers are under tremendous pressure to develop competitive and give better product resolution at the earliest. The paper focuses on the thermostat, that is placed between the engine and the radiator. The thermostat has a function is to block the flow of coolant to the radiator until the engine has warmed up. When the engine is cold, no coolant flows through the Radiator. Once the engine reaches its operating temperature (In our case, SOT 88°C to FOT 98° C), the thermostat opens. The thermostat helps to warm-up the engine coolant quickly and thus the thermostat reduces engine wear, and emissions. The thermostat mechanism consist of cylinder is filled with a wax that begins to melt at designed SOT. A rod connected to the valve presses into this wax. When the wax melts
Solomon, Samson, Senniappan, Moorthy, Thiyagarajan, Rajesh, Ramakrishnan, Dakshinamoorthy, Rahim, Abdul
Assessment of In-Cylinder Thermal Barrier Coatings over a Full Vehicle Drive Cycle2021-01-045604/06/2021
In-cylinder thermal barrier coatings (TBCs) have the capability to reduce fuel consumption by reducing wall heat transfer and to increase exhaust enthalpy. Low thermal conductivity, low volumetric heat capacity thermal barrier coatings tend to reduce the gas-wall temperature difference, the driving potential for heat transfer from the gas to the combustion chamber surfaces. This paper presents a coupling between an analytical methodology for multi-layer coated wall surface temperature prediction with a fully calibrated production model in a commercial system-level simulation software package (GT-Power). The wall surface temperature at each time step was calculated efficiently by convolving the engine wall response function with the time-varying surface boundary condition, i. e., in-cylinder heat flux and coolant temperature. This tool allows the wall to be treated either as spatially uniform with one set of properties, or with independent head/piston/liner components. Steady state
Koutsakis, George, Miles, Scott, Ghandhi, Jaal
The Use of CuO Nanoparticles as Additive to the Engine Coolant2020-01-223609/15/2020
Cooling is one of the most important processes conditioning proper operation of combustion engines. The development of the higher-power engines entails greater thermal loads, in which in turn require an increased cooling. The use of nanofluids (NFs) with admixture of metallic or nonmetallic nanoparticles (NPs) promises a potential platform for miniaturization of heat exchangers and/or lower energy consumption. This is attributed to an extended surface area related to NPs in the fluid, which allows for increase of thermal conductivity and a considerable increase of the heat transfer coefficient of the fluid with NPs. Their thermo-physical properties, such as particle size, stability, viscosity, dispersion, heat dissipation efficiency, zeta potential and thermal conductivity and also their behavior under different amount in the base fluid are systematically investigated from the point of view of the choice of the best candidate for coolant applied in modern engines. The CuO NPs turn out
Siczek, Krzysztof, Wozniak, Marek, Rylski, Adam
Combustion Stability Study with Low Cetane Number Diesel and Biodiesel with 2-EHN Addition under LTC Conditions during Cold/Warm Start and Steady State Conditions2020-01-206309/15/2020
A single cylinder Diesel engine was used to study combustion stability changes from a cetane number improver: 2-EHN. It has been added to a low cetane number diesel and two biodiesels blends with 20 % of SME or RME. All fuels have been raised to a CN of 51 with 2-EHN. Those fuels have been compared to a reference diesel with a CN of 55. Cold and warm start have been recreated for measurements at three conditions: cranking, engine speed increase and idle. Engine coolant temperature has been set to 20°C and 80°C for cold and warm start respectively. 2-EHN effects on combustion stability have been monitored through the IMEP covariance. Under cold-start, only the low cetane number diesel showed combustion stabilities improvements with 2-EHN addition. Moreover, the combustion stability was better than the reference diesel and the heat release rate show an enhancement of the cold flame. On the contrary, the biodiesel fuels exhibited higher IMEP covariances. Under warm start, all fuels
Oung, Richard, Foucher, Fabrice, Morin, Anne-Gaëlle
The Numerical Study on the Effect of CuO Nanoparticle Additive into SI Engine Coolant on the Engine Power2020-01-203209/15/2020
The goal of the study was to investigate the effect of different amounts of the CuO nanoparticles used as additive in the coolant on the power and efficiency of the analyzed SI engine. The temperature gradients in the engine body and its components were obtained using the elaborated model of the heat exchange in engine cooled with different fluids. The simplified model of combustion was used to estimate the temperature and power values generated during the combustion process in the engine under given load and speed values. The efficiency of the engine was estimated using the model taking into account various resistances generated during the operation of a given type of engine. The obtained changes in the engine power and efficiency resulted from the changed composition of the engine coolant were presented.
Siczek, Krzysztof, Wozniak, Marek, Diaconu, Mihai, Dima, Georgiana, Ion, Luiza, Bica, Ionela
Design and Analysis of Modified Radiator Fins to Improve Overall Cooling Efficiency2020-01-202909/15/2020
Internal Combustion engines have been a significant component of the industrial development in the 20th and 21st centuries. However, the high working temperatures cause extensive wear and tear among the parts and results in a loss in fuel efficiency and ultimately seize the engine. To prevent this, there was a need for a cooling system. The current systems cool the vehicle's engine by transferring heat from the engine to the coolant/water in the water jacket from where it reaches the radiator via tubes, and the hot temperature coolant is cooled. This article proposes a change in the design of radiator fins to improve the overall cooling efficiency of such systems. As radiator fins are instrumental in the heat transfer process, a design change in them results in substantial changes in the output efficiency results. The central concept that is utilized is to increase the surface area of the fins, which would increase the rate of heat loss from the pipes. This increase in surface area of
Mittal, Ankit, Misra, Ashwin, Sharma, Ayush, Gupta, Animesh, Ansari, Naushad
System Provides Cooling with No ElectricityTBMG-3682705/01/2020
A device was developed that can sit outside under blazing sunlight on a clear day without using any power to cool things down by more than 23 °F (13 °C). The device, which has no moving parts, works by a process called radiative cooling. It blocks incoming sunlight to keep from heating it up, and at the same time, efficiently radiates infrared light — which is essentially heat — that passes straight out into the sky and into space, cooling the device significantly below the ambient air temperature.
Experimental Analysis of a Multiple Radiator Cooling System with Computer Controlled Flow Rates2020-01-094404/14/2020
The automotive cooling system configuration has remained fixed for many decades with a large radiator plus fan, coolant pump, and bypass valve. To reduce cooling system power consumption, the introduction of multiple computer-controlled heat exchangers may offer some benefits. A paradigm shift from a single large radiator, sized for maximum load, to n-small radiators with individual flow control valves should allow fine tuning of the heat rejection needs to minimize power. In this project, a series of experimental scenarios featuring two identical parallel radiators have been studied for low thermal load engine cooling (e.g., idling) in ground transportation applications. For high thermal load scenarios using two radiators, the fans required between 1120 - 3600 W to maintain the system about the coolant reference temperature of 85oC. In contrast at reduced thermal loads, a single radiator configuration with half the heat transfer surface area required between 550 - 1000 W for the same
Syed, Zaker, Wagner, John
3-Dimensional Numerical Simulation on CuO Nanofluids as Heat Transfer Medium for Diesel Engine Cooling System2020-01-110904/14/2020
CuO-water nanofluids was utilized as heat transfer medium in the cooling system of the diesel engine. By using CFD-Fluent software, for 0.5%, 1%, 3% and 5% mass concentration of nanofluids, 3-dimensional numerical simulation about flow and heat transfer process in the cooling system of engine was actualized. According to stochastic particle tracking in turbulent flow, for solid-liquid two phase flow discrete phase, the moving track of nanoparticles was traced. By this way, for CuO nanoparticles of different mass concentration nanofliuds in the cooling jacket of diesel engine, the results of the concentration distribution, velocity distribution, internal energy variation, resident time, total heat transfer and variation of total pressure reduction between inlet and outlet were ascertained. It is proved by simulation results that nanofluids as heat transfer medium can evidently enhance diesel engine heat transfer capability, when the concentration of nanoparticles increases, the
Yang, Shuai, Yang, Xiaolin, Liu, Haifeng, Li, Xiuyuan
Utilization of bench testing in vehicle thermal system development for extreme cold ambient condition2020-01-139004/14/2020
Automotive thermal systems are becoming complicated each year. The powertrain efficiency improvement initiatives are driving transmission and engine oil heaters into coolant network design alternatives. The initiatives of electrified and autonomous vehicles are making coolant networks even more complex. The coolant networks these days have many heat exchangers, electric water pumps and valves, apart from typical radiators, thermostat and heater core. Some of these heat exchangers including cabin heaters deal with very small amount of coolant flow rates at different ambient conditions. This paper describes how viscosity can be a major reason for simulation inaccuracy, and how to deal with it for each component in the coolant network. Both experimental and computational aspects have been considered in this paper with wide range of ambient temperatures. Methods have been proposed to handle these issues in the simulation phase at the early phase of automotive thermal system development
Khandaker, Masuma, Uddin, Ahmed, Sanikal, Vijay, Fuad, Kaji, Lindquist, Craig, Baker, Gary, Rahman, Sadek
Off-Road Self-Propelled Work Machines Operator Enclosure Environment Part 1: Terms and DefinitionsJ3078/1_202001 (Current)01/29/2020
SAE J3078 provides test methods and criteria for the evaluation of the operator enclosure environment in earth-moving machinery as defined in ISO 6165. SAE J3078/1 gives the terms and definitions which are used in other parts of SAE J3078. It is applicable to Off-Road Self-Propelled Work Machines as defined in SAE J1116 and Agricultural Tractors as defined in ANSI/ASAE S390.
HFTC6, Operator Accommodation
Replacing Twin Electric Fan Radiator with Single Fan Radiator2019-28-238111/21/2019
Downsizing is one of the crucial activities being performed by every automotive engineering organization. The main aim is to reduce - Weight, CO2 emissions and achieve cost benefit. All this is done without any compromise on performance requirement or rather with optimization of system performance. This paper evaluate one such optimization, where-in radiator assembly with two electric fan is targeted for downsizing for small commercial vehicle application. The present two fan radiator is redesigned with thinner core and use of single fan motor assembly. The performance of the heat exchanger is tested for similar conditions back to back on vehicle and optimized to get the balanced benefit in terms of weight, cooling performance and importantly cost. This all is done without any modification in vehicle interface components except electrical connector for fan. The side members and brackets design is also simplified to achieve maximum weight reduction. Further Cooling system performance of
Bhargava, Aashish, Soni, Gaurav, Warkhade, Tushar
Miniature Stretchable PumpTBMG-3529610/01/2019
Soft robots have a distinct advantage over rigid robots: they can adapt to complex environments, handle fragile objects, and interact safely with humans. Made from silicone, rubber, or other stretchable polymers, they are ideal for use in rehabilitation exoskeletons and robotic clothing. Soft bio-inspired robots could one day be deployed to explore remote or dangerous environments.
An Experimental Study of the Effects of Coolant Temperature on Particle Emissions from a Dual Injection Gasoline Engine2019-01-005101/15/2019
Euro VI emission standards have set a very strict limitation on particulate matter emissions of Gasoline Direct Injection (GDI) engine. It is difficult for GDI engine to meet the Euro VI PN regulation (6×1011#/km) without a series of complicated after-treatment devices such as Gasoline Particulate Filter (GPF). Previous research shows that GDI vehicles under cold start condition account for more than 50% of both particle number and mass emissions during the entire NEDC driving cycle. Dual Injection Gasoline engine is based on the GDI engine by adding a set of port fuel injection system. The good mixing characteristics of the port fuel injection system can help to reduce the particulate matter emissions of the GDI engine during the cold start condition. In this study, a Cambustion DMS500 fast particle spectrometer was employed to characterize the effects of coolant temperature and direct injection ratio on particulate emissions from a turbocharged four-cylinder dual-injection gasoline
Xia, Chun, Chen, Wenhao, Fang, Junhua, Huang, Zhen
Application of Electrically Driven Coolant Pumps on a Heavy-Duty Diesel Engine2019-01-007401/15/2019
A reduction in CO2 emissions and consequently fuel consumption is essential in the context of future greenhouse gas limits. With respect to the thermodynamic loss analysis of an internal combustion engine, a gap between the net indicated thermal efficiency and the brake thermal efficiency is recognizable. This share is caused by friction losses, which are the focus of this research project. The parasitic loss reduction potential by replacing the mechanical water pump with an electric coolant pump is discussed in the course of this work. This is not a novel approach in light duty vehicles, whereas in commercial vehicles a rigid drive of all auxiliaries is standard. Taking into account an implementation of a 48-V power system in the short or medium term, an electrification of auxiliary components becomes feasible. The application of electric coolant pumps on an Euro VI certified 6-cylinder in-line heavy-duty diesel engine regarding fuel economy was thus performed. The engine has two
Granitz, Christina, Ratzinger, Josef, Eichlseder, Helmut, Surace, Alfonso
Reliability Case Analysis of an Autonomous Air Cooling System (AACS) for Aerospace Applications2018-01-191610/30/2018
Current More Electric Aircraft (MEA) utilize Liquid Cooling Systems (LCS) for cooling on-board power electronics. In such LCS, coolant pipes around the structure of the aircraft are used to supply water glycol based coolant to sink heat from power electronics and other heat loads in the electronic bay. The extracted heat is then transferred to ram air through downstream heat exchangers. This paper presents a reliability examination of a proposed alternative Autonomous Air Cooling System (AACS) for a twin engine civil MEA case study. The proposed AACS utilizes cabin air as the coolant which is in turn supplied using the electric Environmental Control System (ECS) within the MEA. The AACS consists of electrical blowers allocated to each heat load which subsequently drive the outflow cabin air through the heat sinks of the power electronics for heat extraction. No additional heat exchanger is required after this stage in which the heated air is directly expelled overboard. One key
Fong, Chung Man, Norman, Patrick, Seki, Naoki
Variation in System Performance while Sorting DEF Heating Hardware Options2018-01-181309/10/2018
The desire to reduce NOx at low ambient temperatures drives the use of heating methods to make DEF available by thawing the solution in the tank. Methods to validate modelling used to design hardware options require testing to gauge the accuracy of the prediction. Using a climatic chassis dynamometer (CCD) to demonstrate the guidance procedure set by the Environmental Protection Agency (EPA) is expensive and time consuming. A method of utilizing a flow controlled cooling supply combined with a standard cold chamber is described as a precursor to running the demonstration in the CCD. Testing multiple quantities of design iterations produced unexpected variation in the results. The sources of the variation and modifications taken to minimize them are discussed and presented. Test to test control of coolant flow, coolant temperature, and specific chamber temperature inconsistencies were found to be critically important to a successful effort. Several design iterations were compared with
Vermiglio, Ezio, Gilliam, Kyle, Chin, Anthony, Leonard, Treaver, Erickson, Darren
Taming the Thermal Behavior of Solid-State Military LasersTBMG-2908206/01/2018
Laser diodes and laser diode arrays (LDAs) are widely used throughout military systems, for sighting and range finding, but also at high power levels as offensive and defensive weapons. In companion with much higher-power chemical lasers, these high-power optical sources can generate kilowatts of optical power (as arrays) for use in neutralizing incoming missiles, rockets, and armaments and for long-distance offensive strikes. But laser diodes are also still inefficient, and a great deal of the energy supplied to a laser diode or an LDA is converted into heat, which must be safely dissipated to ensure a long operating lifetime for the solid-state devices.
System Characteristics of Direct and Secondary Loop Heat Pump for Electrical Vehicles2018-01-006304/03/2018
The electricity energy consumption for passenger cabin heating can drastically shorten the driving range for electric vehicles in cold climates. Mobile heat pump system is considered as an effective method to improve heating efficiency. This study investigates the system characteristics of mobile heat pump systems for electrical vehicle application. Based on KULI thermal management software, simulation models including HFC-R134a direct heat pump (DHP) and secondary loop heat pump (SLHP) were developed. The secondary loop employed in the SLHP includes a coolant pump, an indoor heater core and a plate heat exchanger, instead of an indoor condenser in the DHP. The use of a secondary loop has advantages to improve air outlet temperature uniformity. The simulation models were verified by measured data obtained from calorimeter experiments. By adopting simulation models, the effects of indoor and outdoor temperatures on system performance and cycle characteristics were discussed. Results
Wang, Dandong, Gao, Tianyuan, Li, Wanyong, Yang, Yun, Shi, Junye, Chen, Jiangping
Development of Parallel and Direct Cooling System for EV/FCEV Inverter2018-01-045404/03/2018
This paper presents the direct liquid-cooled power module with the circular pin fin which is the inverter parallel cooling system for high output EV/FCEV. The direct cooling system of a conventional inverter is designed to supply coolant along the direction in which the heating element such as Si-chip is disposed and discharge coolant to the opposite side. In case of the inverter, the higher the output is, the larger temperature difference between inlet and outlet becomes due to the heat exchange of the heat generation element, so that temperature difference depends on the position of Si-chip. Since lifetime is judged on the basis of maximum temperature of Si-chip, the inverter itself must be replaced or discarded due to durability of the inverter even though Si-chip can drive further. The simple way to solve this problem is to increase cooling flow rate, but this leads to excessive increase in pressure loss due to circular pin fin. Purpose of this study is the concept of parallel
Seo, Heung Seok, Shin, Dongmin
Thermodynamic Cycle and Working Fluid Selection for Waste Heat Recovery in a Heavy Duty Diesel Engine2018-01-137104/03/2018
Thermodynamic power cycles have been shown to provide an excellent method for waste heat recovery (WHR) in internal combustion engines. By capturing and reusing heat that would otherwise be lost to the environment, the efficiency of engines can be increased. This study evaluates the maximum power output of different cycles used for WHR in a heavy duty Diesel engine with a focus on working fluid selection. Typically, only high temperature heat sources are evaluated for WHR in engines, whereas this study also considers the potential of WHR from the coolant. To recover the heat, four types of power cycles were evaluated: the organic Rankine cycle (ORC), transcritical Rankine cycle, trilateral flash cycle, and organic flash cycle. This paper allows for a direct comparison of these cycles by simulating all cycles using the same boundary conditions and working fluids. To identify the best performing cycle, a large number of working fluids were evaluated with regards to the maximum power
Rijpkema, Jelmer, Andersson, Sven, Munch, Karin
Effect of Thermal Management on Engine Performance2018-01-022404/03/2018
The effect of engine coolant and oil temperature on the performance was experimentally evaluated on a Navistar 12.4 Liter engine. The engine speed and load selected for evaluation represented the engine conditions typically found during a Class-8 truck’s cruising operation. In order to study the effect of oil and coolant temperature in isolation, the production coolant-cooled oil-cooler was replaced with a separate oil and coolant conditioning system. The piston and liner surface temperature was also logged at select locations to provide solid temperature response to coolant and oil temperature changes. The engine tests showed that oil temperature variation had greater impact on the engine performance compared to the coolant temperature. This performance improvement came primarily from the lower combustion heat rejection and reduced friction at moderate engine loads. At higher engine loads the performance improvement was largely due to lowered heat rejection. Engine operation at
Rajkumar, M., Vojtech, Ryan, Cigler, James
Parallel Thermal Management System of the Water Medium Retarder2018-01-077704/03/2018
The thermal management system of the water medium retarder using engine coolant (water and ethylene glycol) as transmission medium, omits oil-water heat exchanger in the structure. When the hydraulic retarder is operated, the valve is connected with the retarder and water pump, and then the engine coolant enters the working chamber. The kinetic energy of the vehicle is converted into internal energy of the coolant, and the heat is discharged to the external environment through the engine thermal management system. The braking torque of the water medium hydraulic retarder is determined by the water medium flow rate in the working chamber. The smaller the valve opening degree, the greater the braking torque and the faster the heating transmission fluid. Small valve opening is not conducive to the loss of heat. It will affect the normal working of the engine and hydraulic retarder. In this paper, the thermal management system of the water medium hydraulic retarder is independent of the
Gao, Xin, Lei, Yulong, Chen, Wei, Cui, Guokai, Zhong, Lei
Impact on Fouling of Different Exhaust Gas Conditions with Low Coolant Temperature for a Range of EGR Cooler Technologies2018-01-037404/03/2018
Degradation of anti-pollutant devices must be taken into account in design so durability of the function is guaranteed over the vehicle lifetime. As for NOx reduction of diesel engines, Exhaust Gas Recirculation (EGR) systems are a well-known and robust solution. However, exposure of the EGR cooler inside this system to the exhaust gas conditions leads to a degradation of its function, affecting to the EGR rate and therefore to potential for NOx reduction. So, sizing and technology of these heat exchangers must be selected to avoid malfunction during vehicle operation. Current scenario in Europe with new homologation cycles and focus on NOx emissions of diesel vehicles under real driving conditions is challenging for the design of EGR systems. This leads to the increase of the areas of the engine map using EGR. Moreover new homologation includes also the use of low ambient temperature. In this context, it is important to understand the impact of critical exhaust gas conditions coupled
Bravo, Yolanda, Arnal, Cristina, Larrosa, Carmen, Climent, Hector
Development and Validation of a Submodel for Thermal Exchanges in the Hydraulic Circuits of a Global Engine Model2018-01-016004/03/2018
To face the current challenges of the automotive industry, there is a need for computational models capable to simulate the engine behavior under low-temperature and low-pressure conditions. Internal combustion engines are complex and have interconnected systems where many processes take place and influence each other. Thus, a global approach to engine simulation is suitable to study the entire engine performance. The circuits that distribute the hydraulic fluids -liquid fuels, coolants and lubricants- are critical subsystems of the engine. This work presents a 0D model which was developed and set up to make possible the simulation of hydraulic circuits in a global engine model. The model is capable of simulating flow and pressure distributions as well as heat transfer processes in a circuit. After its development, the thermo-hydraulic model was implemented in a physical based engine model called Virtual Engine Model (VEMOD), which takes into account all the relevant relations among
Broatch, Alberto, Olmeda, Pablo, Martin, Jaime, Salvador-Iborra, Josep
A Model Predictive Approach to Avoid Coolant After-Boiling in ICE2018-01-077904/03/2018
The after-boiling phenomenon in internal combustion engines can occur when the engine is suddenly switched-off after a period of prolonged high-load operation. In this case, the coolant flow rate stops while the engine wall temperature is quite high; therefore, some evaporation occurs, pressure in the cooling circuit increases and part of the coolant is lost through the radiator relief valve. The control of the coolant flow rate by means of an electric pump instead of the standard belt driven one offers the possibility of overcoming this issue. In the present paper, a model-based control of the coolant flow rate is proposed in conjunction with the adoption of an electric pump in the engine cooling system. Experimental tests and simulations have been carried out starting from high speed-high load engine operation; the engine was then brought to idle and, shortly after, switched-off. A comparison with the adoption of the standard belt-driven pump in the cooling system lay-out is
Castiglione, Teresa, Morrone, Pietropaolo, Bova, Sergio
An Experimental Study on the Knock Mitigation Effect of Coolant and Thermal Boundary Temperatures in Spark Ignited Engines2018-01-021304/03/2018
Increasing compression ratio is essential for developing future high-efficiency engines due to the intrinsic characteristics of spark-ignited engines. However, it also causes the unfavorable, abnormal knocking phenomena which is the auto-ignition in the unburned end-gas region. To cope with regulations, many researchers have been experimenting with various methods to suppress knock occurrence. In this paper, it is shown that cooling the combustion chamber using coolants, which is one of the most practical methods, has a strong effect on knock mitigation. Furthermore, the relationship between thermal boundary and coolant temperatures is shown. In the beginning of this paper, knock metrics using an in-cylinder pressure sensor are explained for readers, even though entire research studies cannot be listed due to the innumerableness. The coolant passages for the cylinder head and the liner were separated to examine independent cooling strategies. In addition, piston surface temperature was
Cho, Seokwon, Song, Chiheon, Oh, Sechul, Min, Kyoungdoug, Ha, Kyoung-Pyo, Kim, Back-Sik
System-Level Investigation of Traction Inverter High-Temperature Operation2018-01-046404/03/2018
In this paper, the high-temperature capability of the traction inverter was investigated by applying coolant with temperature much higher than the typical allowed value until the system fails. The purpose of this study is to identify the weakest link of the traction inverter system in terms of temperature. This study was divided into two stages. In the first stage, a series of nondestructive tests were carried out to investigate temperature rise (ΔT) of the key component above coolant temperature as a function of the outside controllable parameters-i.e., dc link voltage, phase current, and switching frequency. The key components include power modules, gate driver board, gate driver power supply, current sensors and dc link capacitor. Their temperatures were monitored by thermocouples or on-die temperature sensors. The result showed that temperature rises of most key components were strongly affected by phase current, moderately affected by switching frequency, and slightly affected by
Lu, Xi, Xiao, Kewei, Lei, Guangyin, Chen, Chingchi
Model Validation of the Chevrolet Volt 20162018-01-042004/03/2018
Validation of a vehicle simulation model of the Chevrolet Volt 2016 was conducted. The Chevrolet Volt 2016 is equipped with the new “Voltec” extended-range propulsion system introduced into the market in 2016. The second generation Volt powertrain system operates in five modes, including two electric vehicle modes and three extended-range modes. Model development and validation were conducted using the test data performed on the chassis dynamometer set in a thermal chamber of Argonne National Laboratory’s Advanced Powertrain Research Facility. First, the components of the vehicle, such as the engine, motor, battery, wheels, and chassis, were modeled, including thermal aspects based on the test data. For example, engine efficiency changes dependent on the coolant temperature, or chassis heating or air-conditioning operations according to the ambient and cabin temperature, were applied. Second, the vehicle-level control strategy was analyzed under normal ambient temperature conditions
JEONG, Jongryeol, Choi, Sungwook, Kim, Namdoo, Lee, Heeyun, Stutenberg, Kevin, Rousseau, Aymeric
Effect of EGR Temperature on PFI Gasoline Engine Combustion and Emissions2017-01-223510/08/2017
In order to investigate the impacts of recirculated exhaust gas temperature on gasoline engine combustion and emissions, an experimental study has been conducted on a turbocharged PFI gasoline engine. The engine was equipped with a high pressure cooled EGR system, in which different EGR temperatures were realized by using different EGR coolants. The engine ran at 2000 r/min and 3000 r/min, and the BMEP varied from 0.2MPa to 1.0MPa with the step of 0.2MPa. At each case, there were three conditions: 0% EGR, 10% LT-EGR, 10% HT-EGR. The results indicated that LT-EGR had a longer combustion duration compared with HT-EGR. When BMEP was 1.0 MPa, CA50 of HT-EGR advanced about 5oCA. However, CA50 of LT-EGR could still keep steady and in appropriate range, which guaranteed good combustion efficiency. Besides, LT-EGR had lower exhaust gas temperature, which could help to suppress knock. And its lower exhaust gas temperature could reduce heat loss. These contributed to fuel consumption reduction
Liu, Ting, Zhang, Fuyuan, Chao, Yuedong, Hu, Zongjie, Li, Liguang
A Study on the Effect of Elevated Coolant Temperatures on HD Engines2017-01-222310/08/2017
In recent years, stricter regulations on emissions and higher demands for more fuel efficient vehicles have led to a greater focus on increasing the efficiency of the internal combustion engine. Nowadays, there is increasing interest in the recovery of waste heat from different engine sources such as the coolant and exhaust gases using, for example, a Rankine cycle. In diesel engines 15% to 30% of the energy from the fuel can be lost to the coolant and hence, does not contribute to producing work on the piston. This paper looks at reducing the heat losses to the coolant by increasing coolant temperatures within a single cylinder Scania D13 engine and studying the effects of this on the energy balance within the engine as well as the combustion characteristics. To do this, a GT Power model was first validated against experimental data from the engine. Using a Water-PEG mixture as coolant, the coolant temperature was then varied from 60°C to 200°C for both the liner and the cylinderhead
Singh, Vikram, Tunestal, Per, Tuner, Martin
Glow Plug Assisted Compression Ignition (GA-CI) in Cold Conditions2017-01-228810/08/2017
Low temperature combustion (LTC) is an advanced combustion mode, which can achieve low emissions of NOx and PM simultaneously, and keep relatively high thermal efficiency at the same time. However, one of the major challenges for LTC is the cold condition. In cold conditions, stable compression ignition is hard to realize, while thermal efficiency and emissions deteriorate, especially for gasoline or fuel with high octane number. This study presents using pressure sensor glow plugs (PSG) to realize Glow plug assisted compression ignition (GA-CI) at cold conditions. Further, a glow plug control unit (GPCU) is developed, a closed-loop power feedback control algorithm is introduced based on GPCU. In the experiment, engine coolant temperature is swept. Experimental results show that GA-CI has earlier combustion phases, larger combustion duration and higher in-cylinder pressure. And misfire is avoided, cycle-to-cycle variations are greatly reduced. Moreover, though NOx emissions rise
Zhou, Tianyuan, Yao, Changsheng, Yang, Fuyuan, Jinwei, Sun
Control for Electrical Coolant Valve in Engine Thermal Management Module2017-01-220410/08/2017
Hyundai-Kia Motor Company recently developed a multi-way, electrical coolant valve for engine thermal management module (TMM). The main purposes of the TMM are to boost fuel economy by accelerating engine warm-up and also to enhance engine thermal efficiency by actively controlling the operating temperature. In addition to those, the system can improve vehicle heating and cooling performance as well. The electrical coolant valve is a key component in the TMM as it modulates the amount of coolant flow to individual components in cooling system such as engine oil heat exchanger, heater core, and radiator. The coolant flow modulation is done by controlling the electric valve’s position with using an electric motor attached to the valve. The objective of the valve control is to manage coolant temperature at a desired level that varies depending on vehicle’s operating condition. This paper discusses the control algorithm developed for controlling electrical coolant valve. The algorithm is
Lee, Hoon, Jeong, Kwangwoo, Yoo, Sanghoon, Lee, Byungho, Kim, Sejun
CFD Simulation on Nanofluid Coolant of Gasoline Direct Injection Engine2017-01-221910/08/2017
The conventional cooling fluids in vehicle engine cooling water jacket have relatively poor heat transfer performance. The key to enhance heat transfer in cooling-jacket is to research a kind of new coolants. Nanofluids have heat transfer enhancement merits. In present study, the numerical simulation on Fe3O4 nanofluid flow in cooling water jacket of Gasoline direct injection engine was performed using computational fluid dynamics ( CFD) software FLUENT. The heat transfer coefficient of nanofluids was calculated and verified by experiment. Fe3O4 nano-particles were used in mixture of water/ethylene glycol as a base fluid. The thermal performance of the nanofluid was studied, also the thermal performance of a cooling-jacket was studied with CFD technology. The simulation was performed for different volumetric concentrations of(1%,2%,5%) nanofluids at different engine speeds. The results showed that heat transfer enhanced compared to the base fluid. But the pressure loss enlarged in
Wang, Xihui
The Research of the Heavy Truck’s Warming System2017-01-222110/08/2017
It’s not easy to start the engine in winter, especially in frigid highlands, because the low temperature increases the fuel’s viscosity, decreasing the lubricating oil flow ability and the storage performance of battery. Current electrical heating method can improve the engine starting performance in low temperature condition, but this method adds an external power to the engine, leading to the engine cannot maintain an efficient energy utilization. A warming device using the solar energy is designed to conserve the energy during the daytime, and directly warm up the engine at the time when the engine turns off for a long time, especially during the night. A solar collector installed on the top of the vehicle is used to convert the solar energy to the thermal energy, which is then transferred to the heat accumulator that contain the phase-change medium which can increase the heat storage performance. The solar energy is best used to supply for the engine warming system with the warming
Zeng, Peixuan, Zhang, Penghao, Mei, Binyu, Huang, Shiping, Tan, Gangfeng
Modeling of Phase Change within a Wax Element Thermostat Embedded in an Automotive Cooling System2017-01-013103/28/2017
In an automotive cooling circuit, the wax melting process determines the net and time history of the energy transfer between the engine and its environment. A numerical process that gives insight into the mixing process outside the wax chamber, the wax melting process inside the wax chamber, and the effect on the poppet valve displacement will be advantageous to both the engine and automotive system design. A fully three dimensional, transient, system level simulation of an inlet controlled thermostat inside an automotive cooling circuit is undertaken in this paper. A proprietary CFD algorithm, Simerics-Sys®/PumpLinx®, is used to solve this complex problem. A two-phase model is developed in PumpLinx® to simulate the wax melting process. The hysteresis effect of the wax melting process is also considered in the simulation. The physics captured in the simulation includes the turbulent flow out of the coolant pump, turbulent mixing, heat transport, and rigorous treatment of Fluid
Srinivasan, Chiranth, Zhang, Chonglin, Gao, Haiyang, Wang, De Ming, Slike, Jody
Effects of Fuel Properties Associated with In-Cylinder Behavior on Particulate Number from a Direct Injection Gasoline Engine2017-01-100203/28/2017
The purpose of this work was to gain a fundamental understanding of which fuel property parameters are responsible for particulate emission characteristics, associated with key intermediate behavior in the engine cylinder such as the fuel film and insufficient mixing. Accordingly, engine tests were carried out using various fuels having different volatility and chemical compositions under different coolant temperature conditions. In addition, a fundamental spray and film visualization analysis was also conducted using a constant volume vessel, assuming the engine test conditions. As for the physical effects, the test results showed that a low volatility fuel displayed high particulate number (PN) emissions when the injection timing was advanced. The fundamental test clearly showed that the amount of fuel film on the impingement plate increased under such operating conditions with a low volatility fuel. Tests focusing on chemical effects with fuel blends having different aromatic and
Tanaka, Daisuke, Uchida, Ryo, Noda, Toru, Kolbeck, Andreas, Henkel, Sebastian, Hardalupas, Yannis, Taylor, Alexander, Aradi, Allen
Heat Transfer Effect on Performance Map of a Turbocharger Turbine for Automotive Application2017-01-103603/28/2017
In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The aim of the paper is to investigate the effect of heat transfer phenomena on the experimental definition of turbocharger maps, focusing on turbine performance. An experimental investigation on a small turbocharger for automotive application has been carried out and presented. The study focused onto the effects of internal heat transfer on turbine thermomechanical efficiency. The experimental campaign was developed considering the effect of different heat transfer state by varying turbine inlet temperature, oil and coolant temperature and compressor inlet pressure. An original model previously developed by the Authors is adopted for the correction of compressor steady flow maps. The major benefit of this method is represented by the easiness of data post-processing, the data base economy, the reduced
Marelli, Silvia, Gandolfi, Simone, Capobianco, Massimo
Experimental Investigation of the Impact of Nanofluids on Heat Transfer Performance of a Motorcycle Radiator2017-01-161103/28/2017
In the present work, the effect of various nanofluids on automotive engine cooling was experimentally studied. Al2O3, TiC, SiC, MWNT (multi-walled nanotube), and SiO2 nanoparticles with average diameter ranging between 1 and 100 nm were mixed with distilled water to form nanofluids. An ultrasonic generator was used to generate uniform particle dispersion in the fluid. A compatibility test was carried out on all nanofluids and it was found that TiC, MWNT, and Si3N4 nanoparticles settled and separated from the fluid within 3 hours after preparation. The engine cooling performance testing setup consisted of an Aprilia SXV 450 engine, the nanofluid cooling loop, a radiator, a fan, etc. Thermocouples and resistance temperature detectors (RTD’s) were attached to the inlet and outlet of the radiator hose to monitor the temperature changes taking place in the cooling system. A flowmeter was attached to the inlet hose of the radiator to monitor the coolant flow rate. Results of heat transfer
Mathivanan, Elankathiravan, Gasior, David, Liu, Liping, Yee, Kingman, Li, Yawen
Comparison of Extended Life Coolant Corrosion Protection Performance2017-01-062703/28/2017
In this paper, new test results in the use of electrochemical techniques to measure corrosion in extended life engine coolants are presented. Corrosion protection performance of the engine coolants (including both fresh coolants and simulated used coolants) for typical cooling system metals under heat rejecting and heat accepting surface corrosion conditions for both general corrosion and localized corrosion are measured under conditions similar to the ones encountered in vehicle engine cooling systems as a function of immersion time. Fleet tests of the coolants were also conducted. They are used to provide support on the electrochemical test methodologies adopted. The effective use of electrochemical techniques to aid the development of the next generation of extended life coolant technologies with improved corrosion protection performance and a longer service life will be demonstrated and discussed.
Yang, Bo, Woyciesjes, Peter, Gershun, Aleksei
A Research Study on a Curved Radiator Concept for Automotive Engine Cooling2017-01-063103/28/2017
The need to increase the fuel-efficiency of modern vehicles while lowering the emission footprint is a continuous driver in automotive design. This has given rise to the use of engines with smaller displacements and higher power outputs. Compared to past engine designs, this combination generates greater amounts of excess heat which must be removed to ensure the durability of the engine. This has resulted in an increase in the number and size of the heat exchangers required to adequately cool the engine. Further, the use of smaller, more aerodynamic front-end designs has reduced the area available in the engine compartment to mount the heat exchangers. This is an issue, since the reduced engine compartment space is increasingly incapable of supporting an enlarged rectangular radiator system. Thus, this situation demands an innovative solution to aid the design of radiator systems such that the weight is reduced while maintaining the engine within acceptable operating temperatures. One
Ogbuaku, David C., Potter, Timothy, Boileau, James M.
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