Browse Topic: Waste heat recovery

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Cost-effective techniques for SCEV to improve performance & life of battery and motor by using efficient thermal systems2024-26-027501/16/2024
The automotive world is moving towards electric powertrain systems. The performance of an electric powertrain and its electric components majorly depends on the operating temperature of the components. In the small commercial vehicle segment overall vehicle cost is a very sensitive parameter while competing in the market. This paper presents advanced efficient cost-effective thermal techniques for small commercial electric vehicles (SCEV) to improve the performance & life of major electric components. It is observed that from the literature survey, this technology is a novel technology for small commercial electric vehicle applications. The one-dimensional (1D) simulation approach is employed to evaluate the performance of the battery and traction cooling system during battery charging and vehicle driving scenario for different ambient conditions. The proposed thermal management techniques consist of simple and cost-effective thermal architectures having 3-way & 4-way valves which help
Chormule, Suhas Rangrao, Warule, Prasad, Jadhav, Vaibhav, Nagpure, Rahul
Assessment of Future Scope of Waste Heat Recovery System for IC Engine Powertrain Vehicles of Highway and Off-Highway Applications2022-28-044411/09/2022
In this article we summarize the major types of waste heat recovery ( WHR) systems developed and tested. The primary use of WHR system is to increase the fuel economy by minimum 3% from the energy recovery from the exhaust system ( 300-400 deg C ) instead of released to environment, which has heat energy about 18 ~ 25% of total fuel energy. There are 3 types of energy recovery system is discussed in detail, namely (1) thermoelectric devices (TED) to generate electrical energy directly, (2) Turbo-compound system and (3) Rankine cycle-based systems used to generate mechanical energy and that is transferred to crankshaft. Depend on these different technical approaches, there is a potential for up to 5% improvement in fuel economy and CO2 reduction , which can be achieved by generating mechanical or electrical power from exhaust energy using WHR system. However, the payback period for introduction of this WHR system to be taken into consideration while developing new system for the highway
Muthu, Selvaraji, N, SEKARAPANDIAN, KANNAIYAN, ASHOK
Engine Thermodynamic Design, Optimization, Test & Analysis of Daimler SuperTruck2 Program Towards 55% BTE Target2022-01-050403/29/2022
Daimler's effort toward demonstration of 55% brake thermal efficiency for the US Department of Energy SuperTruck2 program relied on a holistic approach to optimization of the Daimler heavy-duty 12.8L diesel engine. Core technical approaches used in this effort include efficient two-stage turbocharging with intercooling, valve timing optimization, improved combustion system design, friction and parasitics reduction through optimized lubrication system, and in-cylinder heat transfer reduction. These measures in combination provided an anticipated engine efficiency of over 50% BTE before application of an additional waste heat recovery system. Utilization of high-fidelity simulations from 1D physical model simulation studies and CFD/FEA framework allowed for optimization of the engine pumping loop and heat transfer reduction efforts. Test bench data provides high-level overview of combustion improvement, friction & parasitics reduction, improvement in in-cylinder heat transfer reduction
Bashir, Murad
Simulation based approach to improve the engine oil warmup behavior using exhaust gas during NEDC cycle2021-26-042209/22/2021
During the cold start conditions engine must overcome higher friction loss, at the cost of fuel penalty till the optimum temperatures are reached in coolant and lubrication circuits. The lower thermal capacity of the lubrication oil (with respect to the coolant) inverses the relation of viscosity with temperature, improves engine thermal efficiency benefit. Engine oil takes full NEDC test cycle duration to reach 90°C. This leads to higher friction loss throughout the test cycle, contributing a significant increase in fuel consumption. Increasing oil temperature reduces viscosity, thereby reducing the engine friction. This helps to identify the focus for thermal management in the direction of speeding up the temperature rise during a cold engine starting. This work aims at the study and experiment of an exhaust recovery mechanism to improve the NEDC fuel economy. The objective of the work is to use the exhaust gas energy, post after treatment system to heat up the engine oil temperature
Krishnan, Karthikeyan N., Ramadandi, Padmavathi, M, Vikramraj, Elumalai, Sakthivel
Performance Comparison of LPG and Gasoline in an Engine Configured for EGR-Loop Catalytic Reforming2021-01-115809/21/2021
In prior work, the EGR loop catalytic reforming strategy developed by ORNL has been shown to increase brake engine efficiency by minimizing the thermodynamic expense of the reforming processes, and in some cases achieving thermochemical recuperation (TCR), a form of waste heat recovery where waste heat is converted to usable chemical energy. In doing so, the EGR dilution limit was extended beyond 35% under stoichiometric conditions. In this investigation, a Microlith®-based metal-supported reforming catalyst was used and the speed and load ranges were expanded relative to previous investigations: from 1,500 to 2,500 rpm, and from 2-14 bar break mean effective pressure (BMEP). Experiments were conducted to determine the effects of the H/C ratio of the fuel on the thermodynamics of the reforming process, and ultimately on the engine efficiency. This was accomplished by comparing an E10 gasoline (H/C = 1.95) and liquified petroleum gas (LPG), comprised primarily of propane (H/C = 2.67
Szybist, James, Pihl, Josh, Hawa, Hani, Roychoudhury, Subir
A Hybrid Heavy-Duty Diesel Power System for Off-Road Applications - Concept Definition2021-01-044904/06/2021
A multi-year Power System R&D project was initiated with the objective of developing an off-road hybrid heavy-duty concept diesel engine with front end accessory drive-integrated energy storage. This off-road hybrid engine system is expected to deliver 15-20% reduction in fuel consumption over current Tier 4 Final-based diesel engines and consists of a downsized heavy-duty diesel engine containing advanced combustion technologies, capable of elevated peak cylinder pressures and thermal efficiencies, exhaust waste heat recovery via SuperTurbo™ turbocompounding, and hybrid energy recovery through both mechanical (high speed flywheel) and electrical systems. The first year of this project focused on the definition of the hybrid elements using extensive dynamic system simulation over transient work cycles, with hybrid supervisory controls development focusing on energy recovery and transient load assist, in Caterpillar’s DYNASTY™ software environment. Three key off-road applications were
Koci, Chad, Steffen, Jay, Kruiswyk, Rich, Guo, Fang, Bazyn, Tim, McDavid, Robert, Ivanov, Radoslav, Sirimalla, Dheeraj
Effects of Fuel Injection Method on Energy Efficiency and Combustion Characteristics of SI Engine Fed with a Hydrogen-Rich Reformate2020-01-208209/15/2020
Various potential alternative fuels for internal combustion engines are studied nowadays to reduce dependency on fossil fuel. Hydrogen-rich reformate produced onboard as a result of fuel reforming in an internal combustion engine with a high-pressure thermochemical recuperation is a promising alternative gaseous fuel. This paper reports on the effects of the reformate fuel injection method on energy efficiency and combustion characteristics of a single-cylinder spark ignition (SI) engine with a high compression ratio (16:1) at steady-state conditions. A comparison between port (PFI) and direct (DI) reformate injection is performed. Engine performance and combustion parameters are evaluated and analyzed. For both injection strategies, a similar relatively high indicated efficiency (50%) is observed. This is a joint result of waste heat recovery and hydrogen combustion benefits. With the PFI method, the lower engine volumetric efficiency, due to hydrogen induction into the intake
Thawko, Andy, Persy, Shalom-Adam, Eyal, Amnon, Tartakovsky, Leonid
The Potential of Exhaust Waste Heat Use in a Turbocharged Diesel Engine for Charge Air Cooling2020-01-208909/15/2020
Even a basic analysis of the use of fuel energy in a combustion engine would indicate that one-third of fuel energy is converted into exhaust waste, which is released into the environment. The scale of energy loss encourages scientists to try to consider the waste heat of exhaust gases as a potential source of useful energy. It is a standard today that waste heat is commonly used to power a turbocharger applied to internal combustion engines. Waste heat can also be used to drive an adsorption cooling system for air-conditioning inside the car. The drawback of that solution is complexity of the system and size of adsorption bed which make it not suitable for automotive industry use. The concept of increasing the capability of vehicles’ turbo engines can boost performance of turbo-charged engines through extra cooling of air being impelled into the combustion chamber of the engine. Cooling of the charge inside the intake manifold saves fuel and reduces nitric oxide emissions in exhaust
Danilecki, Krzysztof, Eliasz, Jacek
A Calculation Methodology for Predicting Exhaust Mass Flows and Exhaust Temperature Profiles for Heavy-Duty Vehicles02-13-02-000907/20/2020
The predictive control of commercial vehicle energy management systems, such as vehicle thermal management or waste heat recovery (WHR) systems, are discussed on the basis of information sources from the field of environment recognition and in combination with the determination of the vehicle system condition. In this article, a mathematical method for predicting the exhaust gas mass flow and the exhaust gas temperature is presented based on driving data of a heavy-duty vehicle. The prediction refers to the conditions of the exhaust gas at the inlet of the exhaust gas recirculation (EGR) cooler and at the outlet of the exhaust gas aftertreatment system (EAT). The heavy-duty vehicle was operated on the motorway to investigate the characteristic operational profile. In addition to the use of road gradient profile data, an evaluation of the continuously recorded distance signal, which represents the distance between the test vehicle and the road user ahead, is included in the prediction
Kreyer, Jörg, Müller, Marvin, Esch, Thomas
A Novel Option for Direct Waste Heat Recovery From Exhaust Gases of Internal Combustion Engines2020-37-000406/23/2020
Among the different opportunities to save fuel and reduce Co2 emissions from internal combustion engines, great attention has been done on the waste heat recovery: the energy wasted is, in fact, almost two thirds of the energy input and even a partial recovery into mechanical energy is really promising . Usually, thermal energy recovery has been referred to a direct heat recovery (furtherly expanding the gases expelled by the engine thanks to their high pressure and temperature) or an indirect one (using the thermal energy of the exhaust gases – or of any other thermal streams discharged into the atmosphere – as upper source of a conversion power unit which favour a thermodynamic cycle of a working fluid ). Limiting the attention to the exhaust gases, a novel opportunity can be represented by directly exploiting the residual pressure and temperature of the flue gases through an Inverted Brayton cycle (IBC), in which the gases are expanded at a pressure below the environmental one
Di Battista, Davide, Cipollone PhD, Roberto, Carapellucci PhD, Roberto
A Power Split Hybrid Propulsion System for Vehicles with Gearbox2020-37-001406/23/2020
New internal combustion engines (ICE) are characterised by increasing maximum efficiency, thanks to the adoption of strategies like Atkinson cycle, downsizing, cylinder deactivation, waste heat recovery and so on. However, the best performance is confined to a limited portion of the engine map. Moreover, electric driving in urban areas is an increasingly pressing request, but battery electric vehicles use cannot be easily widespread due to limited vehicle autonomy and recharging issues. Therefore, in order to reduce ICE vehicle fuel consumption, by decoupling the ICE running from road load, as well as permit energy recovery and electric driving, hybrid propulsion systems are under development. This paper analyses a new patent solution for power split hybrid propulsion system with gearbox. The system comprises an auxiliary power unit, adapted to store and/or release energy, and a planetary gear set which is interposed between the ICE and the gearbox. The system is characterized by a
De Simio, Luigi, Gambino, Michele, Iannaccone, Sabato
Optical Diagnostics of Isooctane and n-Heptane Isobaric Combustion2020-01-112604/14/2020
Isobaric combustion has demonstrated a great potential to reach high thermodynamic efficiency in the advanced Double Compression Expansion Engine (DCEE) concept. It appears as one of few viable choices for applications with high-pressure combustion. At these conditions, releasing heat at a constant pressure minimizes the peak in-cylinder pressure and, hence, mitigates excessive mechanical stress on the engine. This study focuses on the effect of fuels on the multiple-injection isobaric combustion. A single-cylinder heavy-duty engine was utilized to test and compare the isobaric combustion with pure isooctane and n-heptane fuels. The engine was equipped with an optical piston to allow a bottom-view of the combustion chamber. The interactions of multiple injections and the combustion behavior were studied using high-speed acquisition of chemiluminescence. The examined isobaric cases have a peak pressure of 70 bar. For cases with high soot luminosity, a short band-pass filter was used to
Al Ramadan, Abdullah S., Nyrenstedt, Gustav, Ben Houidi, Moez, Johansson, Bengt
An Analytical Approach for Calculating Instantaneous Multilayer-Coated Wall Surface Temperature in an Engine2020-01-016004/14/2020
Thermal swing coatings that have low volumetric heat capacity and low thermal conductivity are attractive because they have the potential to significantly reduce heat transfer to the combustion chamber walls. This paper presents an analytical method for determining the exact solution of the time-resolved wall temperature during the engine cycle for any number of coating layers and properties using the Laplace transformed heat diffusion equation. The method relies only on material properties and the past heat flux history, and represents the exact solution of the heat diffusion equation. The analytical nature of the solution enables fast computation and, therefore, application to system-level optimization calculations. The model relies on an assumption of one-dimensional heat flow, and constant material properties. The major advantage of this approach compared to the standard finite difference approach, wherein the wall is finely discretized, is that there is no approximation and the
Koutsakis, G., Ghandhi, J.B.
Parametric Optimization of a Rankine Cycle Based Waste Heat Recovery System for a 1.1 MW Diesel-Gen-Set2020-01-089004/14/2020
In this study, a 1.1 MW diesel-gen-set is used to design a Waste Heat Recovery (WHR) system to generate additional power using Rankine cycle (RC). A computer code is written in commercial Engineering Equation Solver (EES) software to solve equations of overall energy and mass balance, heat transfer, evaporation, condensation, frictional and heat losses for heat exchangers, turbine, pumps, cooling tower and connecting pipes connecting different components. After initial design of the WHR system, manufacturers are contacted to find out the availability of parts, and then, accordingly the design is changed. There are several heat exchangers required to heat the water from liquid to superheated steam and then, it is passed to the turbine. Then, after the expansion in the turbine, it is passed to the condenser to condense the steam to water. Optimization is done on the heat exchangers, focusing on the tube length and diameter. The tube length is changed in accordance to the availability on
Bari, Saiful, Loh, Wei Zhi
Designing Regenerators of Thermoacoustic Engines for Automotive Waste Heat Recovery2020-01-041404/14/2020
Extraction and utilization of automotive waste exhaust heat is an effective way to save fuel and protect the environment. One promising technology for this purpose is the thermoacoustic engine, where thermal energy is converted to mechanical energy in terms of high amplitude oscillations. The core component in a travelling-wave thermoacoustic engine is its regenerator where the process of energy conversion is mainly realized. This paper introduces a strategy for the design of the regenerator for applications in typical light- and heavy-duty vehicles. Starting from 1-D linear thermoacoustic theory, the nonlinear effects (given by the high amplitude oscillations) are modelled as acoustic resistances and introduced into the basic linear equations to estimate the nonlinear dissipations in the regenerator. Then, a few dimensionless parameters are derived by normalizing these thermoacoustic equations. This yields a good overview of how different design parameters such as the geometrical
Zhou, Jianhua, Karlsson, Mikael, Abom, Mats
Q&A: Simple Solar-Powered DesalinationTBMG-3637904/01/2020
Lenan Zhang and his team at MIT have developed a mathematical model for optimizing the performance of a small, economical, highly efficient device that can provide fresh water for an individual family, using only the sun for its energy input.
Performance Evaluation of a Heavy-Duty Diesel Truck Retrofitted with Waste Heat Recovery and Hybrid Electric Systems08-09-01-000403/11/2020
The interest of long-hauling companies about the conversion of their fleets into low-emission and fuel-efficient vehicles is growing, and retrofitting options may represent a suitable solution. Powertrain hybridization and waste heat recovery are considered among the most promising methods to further improve the fuel economy of road vehicles powered by internal combustion engines. In this article, not only the effect of retrofitting a heavy-duty truck with an electrification-oriented ORC unit or with a series hybrid system is investigated, but also the possibility of implementing both at the same time. The conventional vehicle is powered by a heavy-duty 12.6 liters diesel engine. It is shown that, despite such a large engine has high potential for waste heat recovery, on the other hand it represents a very challenging constraint when designing a hybrid retrofitting. Four powertrain options are considered: conventional vehicle (engine-only powered), waste heat recovery retrofit, hybrid
Villani, Manfredi, Lombardi, Simone, Tribioli, Laura
Waste Heat Recovery System Thermal ManagementJ3173_202002 (Current)02/24/2020
Waste heat recovery (WHR) systems are used in vehicles and machines powered by internal combustion (IC) engines to capture unused/waste heat and utilize it thereby reducing fuel consumption and emissions by improving efficiency. This information report is a survey of the waste heat recovery methods that include the use of heat exchangers.
Cooling Systems Standards Committee
ICE ADVANCES20TOFHP02_0102/01/2020
Engine developers employ revised electronic architectures, mechanical tweaks to boost fuel efficiency and performance of internal-combustion engines. Engineers are leaving no stone unturned in their unceasing drive to improve fuel economy, leveraging electronics, monitoring airflow and using data from outside the vehicle. Computer architectures are being revised to simplify controls and reduce sensor counts, helping keep costs in line. Mechanical upgrades continue, but electronics are the key tool for engine design teams attempting to do more while using less fuel. Computers constantly monitor and control the engine, transmission, after-treatment systems and more. Powerful control processors analyze huge volumes of data used to adjust engine operations in real time.
Costlow, Terry
Performance Analysis of Volumetric Expanders in Heavy-Duty Truck Waste Heat Recovery2019-01-226612/19/2019
With increasing demands to reduce fuel consumption and CO2 emissions, it is necessary to recover waste heat from modern Heavy Duty (HD) truck engines. Organic Rankine Cycle (ORC) has been acknowledged as one of the most effective systems for Waste Heat Recovery (WHR) due to its simplicity, reliability and improved overall efficiency. The expander and working fluid used in ORC WHR greatly impact the overall performance of an integrated engine and WHR system. This paper presents the effects of volumetric expanders on the ORC WHR system of a long haulage HD truck engine at a steady-state engine operating point chosen from a real-time road data. Performance of a long haulage HD truck engine is analyzed, based on the choice of three volumetric expanders for its WHR system, using their actual performance values. The expanders are: an oil-free open-drive scroll, a hermetic scroll and an axial piston expander with working fluids R123, R245fa and ethanol, respectively. Performance of the engine
Thantla, Sandhya, Fridh, Jens, Erlandsson, Anders Christiansen, Aspfors, Jonas
Enhancing Peak Firing Pressure Limit for Achieving Better Brake Thermal Efficiency of a Diesel Engine2019-01-218012/19/2019
An increased cycle expansion ratio is beneficial from a thermodynamic viewpoint to increase the engine efficiency. In this study, the target compression ratio and corresponding thermodynamic cycle layout were investigated by means of a new ideal combustion cycle. To model the experimental pressure traces, the combustion was divided into three parts; constant volume combustion, early expansion combustion and late combustion. This study discussed optimal parameter values for compression ignition combustion under PFP constraints. These parameters included compression ratio, pressure ratios as well as cut-off ratios. Furthermore, this study experimentally investigated the limitation of thermal efficiency and the variation of energy losses under different geometric compression ratios, boosting pressure and degree of constant volume combustion. These experiments utilized a supercharged single-cylinder heavy duty diesel engine with PFP-capability of up to 30 MPa. In conclusion, it is
Enya, Kenji, Uchida, Noboru
Simulation Study on Driving Range at High and Low Temperature2019-01-507111/04/2019
With the popularity of EVs, driving range has become one of the focuses of people's concern. The anxiety about driving range was particularly evident in winter and summer, because of the use of air conditioning at high temperatures and heating at low temperatures, as well as the power supply capacity of power batteries at different temperatures. At the same time, the energy consumption of thermal management components and the influence of thermal management on the efficiency of other components also need to be considered. The high and low temperature driving range is studied by means of simulation, which has the characteristics of low cost and fast speed. For the vehicles simulated in the article, driving range at 25 °C is 240 km, at -30 °C reduced to 34% (81.9 km), at 40 °C reduced to 73% (176 km). In this paper, the simulation modeling and analysis on the driving range of an EV are carried out. The simulation model includes air conditioning system and crew cabin, power battery system
Yu, Jiang, Nie, YanXin, MingJun, Dong, Xie, Ning, Ma, BaoTong, Xu, Zhe
A Study and Mathematical Analysis of Thermionic Energy Conversion Materials Based on Their Solid State Emission Properties2019-28-008410/11/2019
The physical mechanism of direct energy conversion technology for space applications is well known for over a century. Whereas thermionic energy conversion is now being explored for automotive regeneration applications considering its high conversion efficiency. The thermionic emission used in space applications has operating temperatures >20000C which is much higher than available temperature at terrestrial automotive applications. Hence the key research interests are focused towards effective utilization of thermionic energy conversion for automotive waste heat recovery at considerably lower temperatures i.e. <10000C. This strongly needs a selection of suitable materials in thermionic convertor. This work shows a comprehensive study on materials and their work function for thermionic emission at relatively lower temperature. The selection of different emitter materials is based on simulation applying Richardson Dushman equation and child’s law at operating temperature ranges. The
Kodihal, Kantaprasad, Sagar, Ankur
How to Improve SI Engine Performances by Means of Supercritical Water Injection2019-24-023510/07/2019
The efficiency of ICEs is strongly affected by exhaust gases and engine cooling system heat losses, which account for about 50% of the heat released by combustion. A promising approach is to transfer this exhaust heat to a fluid, like water, and inject it into the combustion chamber under supercritical conditions. In such a way, the recovered energy is partially converted into mechanical work, improving both engine efficiency and performance. A quasi-dimensional model has been implemented to simulate an SI engine with supercritical water injection. Specifically, a spark ignition ICE, four-stroke with Port Fuel Injection (PFI) has been considered. The model accounts for gas species properties, includes valves opening/closing, wall heat transfer, a water injection model and a combustion model. The influence of some injection parameters, i.e. Water/Fuel ratio (W/F), Start Of water Injection (SOI) and Water Injection Duration (WID), on engine performances and efficiency is discussed in
Cantiani, Antonio, Viggiano, Annarita, Magi, Vinicio
A Mild Hybrid SIDI Turbo Passenger Car Engine with Organic Rankine Cycle Waste Heat Recovery2019-24-019409/09/2019
While striving for more fuel-efficient vehicles, all possible measures are considered to increase the efficiency of the combustion engine powertrain. 48V mild hybrid technology is one such measure, SIDI (Spark Ignited Direct Injection) engines with Miller technology are another, while recovering energy from the engine’s waste heat (WHR) is yet another option. In this paper, results will be published from an advanced engineering project at Volvo Cars including all of these components. An ethanol based Organic Rankine Cycle (ORC) WHR-system was successfully built around a 4-cylinder, 2.0 litre SIDI-engine, including 48V mild hybrid technology, with vehicle packaging considered. A dedicated control system was also developed for the ORC system including communication between it and the engine. The ORC system uses the engine exhaust as the heat source, for which a purpose-built evaporator was designed and built to fit in the vehicle tunnel. The expansion of the ethanol vapour occurs in an
Ekström, Fredrik B., Rolandson, Ola, Eriksson, Soren, Odenmarck, Christer, Svensson, Mattias, Eriksson, Andreas, Olsen, Hans
Surface Treatment Could Improve Refrigeration EfficiencyTBMG-3513109/01/2019
Unlike water, liquid refrigerants and other fluids that have a low surface tension spread quickly into a sheet when they come into contact with a surface. For many industrial processes, it would be better if the fluids formed droplets that could roll or fall off the surface and carry heat away with them.
Review of Vehicle Engine Efficiency and Emissions2019-01-031404/02/2019
This review paper covers major regulatory and technology developments in 2018 pertinent to tailpipe emissions of greenhouse gases and criteria pollutants. Europe has proposed ambitious reductions in CO2 limits for both light- and heavy-duty sectors. The challenge is compounded with changing measurement norms and a significant shift away from fuel efficient diesels in the light-duty (LD) space. Both incremental and step changes are being made to advance internal combustion. New studies show that in-use NOx emissions from diesels can be much lower than required by the Euro 6 regulation. Discussions have already started on Euro 7 regulations, and the leading regulatory concepts and proposed technical solutions are provided. In the heavy-duty (HD) sector, the progress is outlined in improving engine and vehicle fuel efficiency through the US Department of Energy’s (DOE’s) SuperTruck II program and other representative studies. Common approaches among the participants include hybridization
Joshi, Ameya
Automotive Waste Heat Recovery after Engine Shutoff in Parking Lots2019-01-015704/02/2019
1 The efficiency of internal combustion engines remains a research challenge given the mechanical friction and thermodynamic losses. Although incremental engine design changes continue to emerge, the harvesting of waste heat represents an immediate opportunity to address improved energy utilization. An external mobile thermal recovery system for gasoline and diesel engines is proposed for use in parking lots based on phase change material cartridges. Heat is extracted via a retrofitted conduction plate beneath the engine block after engine shutoff. An autonomous robot attaches the cartridge to the plate and transfers the heat from the block to the Phase Change Material (PCM) and returns later to retrieve the packet. These reusable cartridges are then driven to a Heat Extraction and Recycling Tower (HEART) facility where a heat exchanger harvests the thermal energy stored in the cartridges. A series of mathematical models are created to estimate the recoverable heat from a standard
Syed, Zaker, Wagner, John R.
A Test Rig for Evaluating Thermal Cyclic Life and Effectiveness of Thermal Barrier Coatings inside Exhaust Manifolds2019-01-092904/02/2019
Thermal Barrier Coatings (TBCs) may be used on the inner surfaces of exhaust manifolds in heavy-duty diesel engines to improve the fuel efficiency and prolong the life of the component. The coatings need to have a long thermal cyclic life and also be able to reduce the temperature in the substrate material. A lower temperature of the substrate material reduces the oxidation rate and has a positive influence on the thermo-mechanical fatigue life. A test rig for evaluating these properties for several different coatings simultaneously in the correct environment was developed and tested for two different TBCs and one oxidation-resistant coating. Exhausts were redirected from a diesel engine and led through a series of coated pipes. These pipes were thermally cycled by alternating the temperature of the exhausts. Initial damage in the form of cracks within the top coats of the TBCs was found after cycling 150 times between 50°C and 530°C. Temperature calculations showed that, besides
Thibblin, Anders, Olofsson, Ulf
Study of Thermoacoustic Engine for Automotive Exhaust Waste Heat Recovery2019-01-125704/02/2019
In this paper, the travelling-wave thermoacoustic engine (TAE) and its application for recovery of waste heat from automotive exhaust systems is investigated. The aim is to give some insight into the potential, but also limitations of the technique for practical applications. This includes packaging, physical boundary conditions as heating and cooling available, but also system perspectives as influence of legislative drive cycles and degree of hybridization. First, the travelling-wave TAE is described as a low-order acoustic network in the frequency domain. Models, including non-linear effects, are set up for every component in the network to describe the propagation and dissipation of acoustic waves. For a TAE with looped structure, the continuity of pressure and volumetric velocity is employed to determine the saturation pressure, as well as the stable operating point. These models are validated against experimental data available in the literature [1]. This is an engine designed
Zhou, Jianhua, Karlsson, Mikael, Abom, Mats
Experimental Study of a Heat-Pipe Exchanger for an Exhaust Heat Recovery System2019-01-015104/02/2019
Currently, the heat recovery systems based on thermoelectrics are an important part of the technologies under study to improve the efficiency of vehicles with internal combustion engines. Different types of heat exchangers are used as part of the components for the operation of the heat recovery technologies. Among the heat exchangers, the heat pipes are studied due to their promising results. This work presents the experimental analysis of a heat exchanger prototype based in heat pipes. The prototype was custom designed for a given thermoelectric module. The design was performed seeking to maximize its efficiency while protecting the module by avoiding possible excesses of temperature during the operation. The requirements for the heat pipe design were defined from the experimental characterization of the thermoelectric module. The prototype was manufactured through a sintering process. The system was tested in the laboratory first by components, and then as a system. The results
Rincon, Ernesto, Munoz, Luis
Fuel and Engine Effects on Rich-Combustion Products as an Enabler of In-Cylinder Reforming2019-01-114404/02/2019
Onboard reforming has been proposed as a strategy for improving spark-ignited (SI) engine efficiency through knock reduction, dilution limit extension, improved thermodynamic gas properties, and thermochemical exhaust enthalpy recuperation. One approach to onboard fuel reforming is to combust fuel in the engine cylinder under rich conditions, producing a hydrogen-rich reformate gas--which can subsequently be recirculated into the engine. Hydrogen is the preferred product in this process due to its high flame speed and knock resistance, compared with other reformate constituents. In this work, the effects of engine operation, fuel composition and water injection were evaluated for their effect on reformate gas composition produced under rich combustion conditions. Engine parameters, including intake pressure, intake temperature, combustion phasing, and valve timing all had no significant impact on hydrogen yield at a given equivalence ratio. Fuel effects on hydrogen yield were more
Voice, Alexander K., Costanzo, Vincent
Thermal Analysis of Aircraft Auxiliary Power Unit: Potential of Super-Critical CO 2 Brayton Cycle2019-01-139103/19/2019
An “APU” (Auxiliary Power Unit) is a small gas turbine engine to provide supplementary power to an aircraft and is located at the tails of larger jets. APU generators provide auxiliary electrical power for running aircraft systems on the ground. Applications include powering environmental systems for pre-cooling or preheating the cabin, and providing power for crew functions such as preflight, cabin cleanup, and galley (kitchen) operation and long-haul airliners must be started using pneumatic power of APU compressor. The Honeywell 131-9A gas turbine APU has 440 kW shaft power and 90 kW electric generator consuming 120 kg fuel/hour. Hybrid power systems based on fuel cells are promising technology for the forthcoming power generation market. A solid oxide fuel cell (SOFC) is the perfect candidate for utilizing waste heat recovery. This case deals with waste heat recovery from fuel cell exhaust using Brayton cycle as bottoming cycle for additional power production. Here in this paper
Singh, Anand Shankar, Choudhary, Tushar, S, Sanjay
Fuel Cell/Fuel Cell Hybrid SystemTBMG-3393303/01/2019
Fuel cells can deliver clean, reliable, and uninterrupted power nearly 100 percent of the time. Fuel cells offer the advantage of efficiency by converting chemical energy directly to electricity. They have no moving parts, thereby eliminating failures associated with pumps, blowers, heat exchangers, and other systems. All fuel cells, particularly high-temperature fuel cells, require spent fuel/waste heat recovery subsystems, and low-temperature fuel cells require fuel reforming subsystems that lower the efficiency of the entire system.
Q&A19TOFHP02_1302/01/2019
In October 2018, Tenneco Inc. completed its “transformational” acquisition of Federal-Mogul LLC, and now is working to realign the businesses and establish two independent companies by late 2019: an Aftermarket and Ride Performance company, and a Powertrain Technology company that will continue to address fuel economy, power output, and criteria pollution requirements for gasoline, diesel and hybrid-electric powertrains across the various regions of the world. The Tenneco name will remain with the Powertrain, or Clean Air, side of the business, according to John Wehrenberg, the leader of the Commercial Truck Off-Highway (CTOH) business for Clean Air. “The most exciting space in truck and off-highway, at the moment, is in the Asian markets, driven by the regulatory changes that are coming less than 18 months from now” with Bharat VI in India and China VI, he said during an interview with Truck & Off-Highway Engineering this past fall. Wehrenberg and Bernd Scherer, Tenneco's Executive
Gehm, Ryan
A Heuristic Supervisory Controller for a 48V Hybrid Electric Vehicle Considering Fuel Economy and Battery Aging2019-01-007901/15/2019
Most studies on supervisory controllers of hybrid electric vehicles consider only fuel economy in the objective function. Taking into consideration the importance of the energy storage system health and its impact on the vehicle’s functionality, cost, and warranty, recent studies have included battery degradation as the second objective function by proposing different energy management strategies and battery life estimation methods. In this paper, a rule-based supervisory controller is proposed that splits the torque demand based not only on fuel consumption, but also on the battery capacity fade using the concept of severity factor. For this aim, the severity factor is calculated at each time step of a driving cycle using a look-up table with three different inputs including c-rate, working temperature, and state of charge of the battery. The capacity loss of the battery is then calculated using a semi-empirical capacity fade model. Eventually, the fuel economy, and capacity loss as
Malmir, Farzam, Xu, Bin, Filipi, Zoran
2-Stroke Engine Options for Automotive Use: A Fundamental Comparison of Different Potential Scavenging Arrangements for Medium-Duty Truck Applications2019-01-007101/15/2019
The work presented here seeks to compare different means of providing scavenging systems for an automotive 2-stroke engine. It follows on from previous work solely investigating uniflow scavenging systems, and aims to provide context for the results discovered there as well as to assess the benefits of a new scavenging system: the reverse-uniflow sleeve-valve. For the study the general performance of the engine was taken to be suitable to power a medium-duty truck, and all of the concepts discussed here were compared in terms of indicated fuel consumption for the same cylinder swept volume using a one-dimensional engine simulation package. In order to investigate the sleeve-valve designs layout drawings and analysis of the Rolls-Royce Crecy-type sleeve had to be undertaken. A new methodology for optimization was developed and the analysis process also took into account work done by the charging system, this being assumed to be a combination of supercharger and turbocharger to permit
Turner, James W. G., Head, Robert A., Chang, Junseok, Engineer, Nayan, Wijetunge, Roshan, Blundell, David W., Burke, Paul
Q&A: Dr. Patrick Hopkins, Professor, University of Virginia, CharlottesvilleTBMG-3323311/01/2018
Professor Hopkins and University of Virginia colleagues — in collaboration with materials scientists at Penn State, the University of Maryland, and the National Institute of Standards and Technology — have studied a material that can dynamically regulate its thermal properties, switching back and forth between insulating and cooling based on the amount of water that is present.
Experimental Investigation of Ethanol-Diesel-Butanol Blends in a Compression Ignition Engine by Modifying the Operating Parameters03-11-05-003710/31/2018
The rapid utilization of fossil fuels has triggered the finding of alternative renewable fuel that replaces or reduces the consumption by alternative fuels for fueling compression ignition (CI) engines. One such renewable fuel is ethanol which can be manufactured from biomass. The present study details the utilization of an optimum amount of ethanol in CI engine by modifying the operating parameters. It was already published in the previous paper that 45% ethanol can be utilized along with diesel using 10% butanol as cosolvent. This fuel is also meeting the minimum requirement with respect to properties as per ASTM standards. This experimental study was performed to investigate the influence of modifying the engine operating parameters on the performance, combustion, and emission parameters fueled with the blend containing 45% ethanol under various load conditions. Taguchi method was used to find out the optimal parameters such as injection timing (IT), injection pressure (IP
Prabakaran, B., Vijayabalan, Palanimuthu, Balachandar, M.
Exhaust Energy Recovery with Variable Geometry Turbine to Reduce Fuel Consumption for Microcars2018-01-182509/10/2018
The objective proposed by EU to reduce by about 4%/year CO2 emission of internal combustion engines for the next years up to 2030, requires to increase the engine efficiency and accordingly improving the technology. In this framework, hybrid powertrains can have the possibility of a deep market penetration since they may recover energy during brake, allow the engine to operate in better efficiency conditions and with less transients, Moreover, they can recover a large amount of energy lost through the exhaust and use it to reduce fuel consumption. This paper concerns the modification of a conventional two in-line cylinders Diesel engine (440 cm3) adding a variable geometry turbine (VGT) coupled with a generator. The turbine is used to recover exhaust gas energy that otherwise would be lost. The generator, connected to the turbo shaft, converts mechanical energy into electrical energy and is used to charge the vehicle battery or the auxiliaries. The aim of this work is reducing fuel
Ortenzi, Fernando, Genovese, Antonino, Carrazza, Martina, Rispoli, Franco, Venturini, Paolo
A Simulation Study of Optimal Integration of a Rankine Cycle Based Waste Heat Recovery System into the Cooling System of a Long-Haul Heavy Duty Truck2018-01-177909/10/2018
As a promising solution to improve fuel efficiency of a long-haul heavy duty truck with diesel engine, organic Rankine cycle (ORC) based waste heat recovery system (WHR) by utilizing the exhaust gas from internal combustion engine has continuously drawn attention from automobile industry in recent years. The most attractive concept of ORC-based WHR system is the conversion of the thermal energy of exhaust gas recirculation (EGR) and exhaust gas from Tailpipe (EGT) to kinetic energy which is provided to the engine crankshaft. Due to a shift of the operating point of the engine by applying WHR system, the efficiency of the overall system increases and the fuel consumption reduces respectively. However, the integration of WHR system in truck is challenging by using engine cooling system as heat sink for Rankine cycle. The coolant mass flow rate influences strongly on the exhaust gas bypass which ensures a defined subcooling after condenser to avoid cavitation of pump. The coolant
Yang, Kangyi, Grill, Michael, Bargende, Michael
Novel Rankine Cycle for Hybrid Vehicles2018-01-171109/10/2018
The European Union (EU) has defined legally-binding targets for the fleet of new cars allowing 95 grams CO2 per kilometer in 2021. It is already under discussion to reduce average emissions of the EU car fleet by further 15% in 2025 and again by 30% in 2030 compared to 2021 goal. Therefore, improvement of fuel economy is becoming one of the most important issues for the car manufacturers. Today’s conventional car powertrain systems are reaching their technical limits and will not be able to meet future fuel economy targets without further development of additional measures. This paper presents the analysis of a Rankine cycle unit applied to improve the overall efficiency of a hybrid electric vehicle (HEV). The authors propose a new concept for recovering a considerable part of exhaust waste heat from an HEV with spark ignition internal combustion engine (ICE) by applying a bottoming Rankine cycle with a Ruths storage tank. It enables the storage of discontinuously available exhaust
Kraljevic, Ivica, Gottwald, Theo, Spicher, Ulrich
Simulative Evaluation of Various Thermodynamic Cycles and the Specification of Their System Components Regarding the Optimization of a Cogeneration Unit2018-01-503409/05/2018
Given the increasing globalization and industrialization, the worldwide demand for energy continuously increases. In the context of modern Smart Grids, especially small and distributed power plants are a key factor. The present article essentially focuses on the investigation of different approaches for waste heat recovery (WHR) in small-scale CHP (combined heat and power) applications with an output range of approximately 20 kW. The engine integrated into the CHP system under investigation applies a lean-burn combustion process generally providing comparatively low exhaust gas temperatures, thus requiring a careful design that is crucial for efficient WHR. Therefore, this article presents the development and use of a simulation environment for the design and optimization of WHR in small-scale CHP applications. The MATLAB-based code allows various combinations of specific components (e.g., heat exchangers and pumps, as well as turbines and compressors) in different thermodynamic cycles
Zirngibl, Sebastian Andreas, Günter, Florian, Prager, Maximilian, Wachtmeister, Georg
Evaluation of friction coefficient of lamellar and compacted graphite irons in lubricated ring-on-cylinder system2018-36-005809/03/2018
The current investigation compares the friction behavior between specimens extracted from engine blocks of grey cast iron (class FC 250 ABNT NBR 6589 standard) and compacted graphite iron (class GJV450 ISO 16112 standard). The effect of wall thickness was evaluated, by extracting samples from regions equivalent to two levels of thickness. The piston ring used was a nitrided martensitic stainless steel with an asymmetric profile, and the lubricant oil was the SAE 30 CF. The tribological tests were conducted at 75 N normal load for a duration of 1 hour, a frequency of 5 Hz and a stroke of 10 mm. The tests were carried out at a controlled temperature of 40° C. In a general way, the compacted graphite irons presented smaller friction coefficients when compared to that observed for the lamellar ones; and the wall thickness showed relevance only for the compacted graphite iron, being the lowest values found for the thinner wall. On the other hand, for the grey cast iron, the wall thickness
Vale, João Luiz do, Guesser, Wilson Luiz, da Silva, Carlos Henrique, Pintaúde, Giuseppe
Experimental Investigation and Modelling of a 1.5 kW Axial Turbine for Waste Heat Recovery of a Gasoline Passenger Car through a Rankine Cycle2018-37-000705/30/2018
The Rankine cycle power system is a promising technology to convert the wasted thermal energy from engines into useful energy. In a way to decrease the CO2 emissions of passenger cars, it is possible to recover the waste heat from the exhaust gas that presents a high exergy compared to other sources of waste heat (engine cooling, exhaust gas recovery cooling, etc.). A Rankine cycle test-rig is designed and built to assess the performance of such a cycle in real operating conditions. The most critical component is the expander. This component needs to be compact, light, efficient, reliable and cheap among other criteria. In this context, a 1.5 kW axial turbine composed of two wheels is tested on a Rankine cycle test-rig coupled with a 150 kW engine. A detailed analysis of the performance is proposed. The maximum turbine mechanical isentropic efficiency reached is 41.5%. A semi-empirical approach is proposed to predict the performance of the axial turbine in a wide range of conditions
Dumont, Olivier
Range Extension Opportunities While Heating a Battery Electric Vehicle2018-01-006604/03/2018
The Kia Soul battery electric vehicle (BEV) is available with either a positive temperature coefficient (PTC) heater or an R134a heat pump (HP) with PTC heater combination [1]. The HP uses both ambient air and waste heat from the motor, inverter, and on-board-charger (OBC) for its heat source. Hanon Systems, Hyundai America Technical Center, Inc. (HATCI) and the National Renewable Energy Laboratory jointly, with financial support from the U.S. Department of Energy, developed and proved-out technologies that extend the driving range of a Kia Soul BEV while maintaining thermal comfort in cold climates. Improved system configuration concepts that use thermal storage and waste heat more effectively were developed and evaluated. Range extensions of 5%-22% at ambient temperatures ranging from 5 °C to −18 °C were demonstrated. This paper reviews the three-year effort, including test data of the baseline and modified vehicles, resulting range extension, and recommendations for future actions.
Meyer, John J., Lustbader, Jason, Agathocleous, Nicos, Vespa, Antonio, Rugh, John, Titov, Gene
2021-12-29.TEST Performance of a Half-Heusler Thermoelectric Generator for Automotive Application2018-01-005404/03/2018
Thermoelectric generators (TEGs) have been researched and developed for harvesting energy from otherwise wasted heat. For automotive applications this will most likely involve using internal combustion engine exhaust as the heat source, with the TEG positioned after the catalyst system. Applications to exhaust gas recirculation systems and compressed air coolers have also been suggested. A thermoelectric generator based on half-Heusler thermoelectric materials was developed, engineered, and fabricated, targeting a gasoline passenger sedan application. This generator was installed on a gasoline engine exhaust system in a dynamometer cell, and positioned immediately downstream of the close-coupled three-way catalyst. The generator was characterized using a matrix of steady-state conditions representing the important portions of the engine map. Detailed performance results are presented. Measurements indicate the generator can produces over 300 W of power with 900 °C exhaust at relatively
Szybist, James, Davis, Steven, Thomas, John, Kaul, Brian C.
2021-12-29.TEST Micro-Channel Heat Exchanger: An Exhaust Waste Heat Recovery Device2018-01-005204/03/2018
Almost one-third of the fuel energy is wasted through the exhaust of a vehicle. An efficient waste heat recovery (WHR) process will undoubtedly lead to improved fuel efficiency and reduced greenhouse gases (GHG) emission. Currently, there are multiple WHR technologies that are being investigated by various entities in the auto industry. One relatively simple device to extract heat energy from the exhaust is a heat exchanger. Heat exchangers are used in some automotive applications to transfer heat from the hot exhaust gas to the colder coolant fluid to raise the coolant temperature. The warmer coolant fluid can be used for several purposes such as; faster heating of the engine’s lubrication oil and transmission fluids during cold starts, and faster cabin heating, which in turn, can potentially improve the overall engine efficiency and reduce exhaust emissions. Currently, in the US market place, hybrid vehicles, such as the Toyota Prius and Chevy Malibu, use heat exchangers as an
Sahoo, Dipankar, Gardner, Timothy, Whyatt, Greg
2021-12-29.TEST Study of CO 2 /Hydrocarbons Mixture as the Working Fluids for Engine Waste Heat Recovery2018-01-004904/03/2018
Transcritical Rankine cycle (TRC) is a promising technology for the engine waste heat recovery due to its good temperature matching ability for the waste heat sources. As for the high-temperature engine exhaust, working fluids selection has been an essential issue without a good solution. It was found in this research that mixtures of CO2 and small molecule hydrocarbons are the potential working fluids for the engine waste heat recovery, since they have good chemical stability and thermal performance. Besides, CO2 can be used as the retardant to suppress the flammability of hydrocarbons to ensure safety. In this research, CO2 mixed with five small molecule hydrocarbons are proposed as the working fluids. A thermodynamic model of TRC system is established to evaluate the thermal performance of those mixtures. The effects of mass fraction of CO2, turbine inlet temperature and pressure are investigated. The influence of composition shift is also discussed. The results show that, 65% CO2
Shu, Ge-Qun, Yan, Nanhua, Zhao, Mingru, Li, Linqing
Exergo-environmental Analysis of Basic and Intercooled-Recuperated Gas Turbine based Aviation Auxiliary Power Unit2018-01-137604/03/2018
This paper deals with the exergo-environmental analysis of gas turbine with possible application as aviation auxiliary-power-unit (APU). The present work reports a comparison of thermodynamic performance, NOx and CO emission for basic gas turbine cycle (BGT) and intercooled-recuperated gas turbine (IcRcGT) cycle based engines for possible use by the aviation industry as auxiliary power unit (APU). In addition to this environmental sustainability index of these two cycles is also presented. Various cycle operating parameters such as compressor-pressure-ratio (rp,c), combustor-primary-zone-temperature, equivalence-ratio, and residence time have been chosen for analysis of the cycles. Mathematical modeling of the cycles has been done and the same have been coded in MATLAB. Results show that IcRcGT cycle exhibits higher gas turbine power output and gas turbine efficiency in comparison to BGT cycle for the same rp,c and turbine inlet temperature (TIT). Percentage exergy destruction for
Sahu, Aishi, Sahu, Mithilesh Kumar, R, Sanjay
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