With the global promotion of carbon neutrality policies, internal combustion engine (ICE) of traditional fossil fuel is gradually transitioning to carbon neutral fuel ICE, and hybrid dedicated engines are gradually replacing traditional internal combustion engines in the passenger car market. Ultra-lean combustion supported by active pre-chamber is one of the key technologies for achieving high thermal efficient over 45% BTE. However, there are still issues like cold start and PN emissions caused by impingement of liquid fuel injection in pre-chamber, and there is still room for improvement in thermal efficiency by less energy of pilot ignition fuel. Gaseous fuel such as hydrogen or methane have no wetting issues, and can be more easily controlled in terms of the injection amount in pre-chamber, thereby using a less amount of gaseous fuel as the pilot ignition fuel could be a solution. Due to the above situation, this article conducted experiments on a lean burn gasoline engine by

Liu, Yaodong, Liu, Mingli, He, Zhentao, Li, Xian, Zhao, Chuan, Qian, Dingchao, Qu, Hanshi, Li, Jincheng

Quantitative Analysis of Fuel Film Formation and Evolution Following Spray Impingement

2025-01-7045

01/31/2025

Flash boiling spray has exhibited remarkable atomization performance by utilizing the sudden alterations in the thermodynamic state of the fluid during injection. The notable evaporation properties of flash boiling spray provide potential remedies for the problem of fuel film adhesion resulting from spray-wall impingement, especially during cold starts in reciprocating engines. Multi-hole injectors, which are often employed, frequently experience spray collapse under flash boiling conditions. The collapsing spray impinging a wall involves a complex multi-phase coupling mechanism. Once the spray impinges the wall, the heat and mass transfer between the wall and the adhering liquid film complicates the predictability of the fuel film characteristics. The quantitative evaluation of fuel film is crucial for studies on wall impingement. Nonetheless, the quantitative measurement of phase change fuel films necessitates addressing multiple problems, including evaporation and vapor phase

Qiu, Shuyi, Wang, Shangning, Li, Xuesong, Xu, Min, Nour, Mohamed

Study of Soot Generation in Hybrid Engines during Cold Start and Low-Load Conditions Using an Optical Engine

2025-01-7047

01/31/2025

As regulations regarding vehicle emissions and fuel consumption become increasingly stringent, the development of hybrid power systems is accelerating, primarily due to their benefits in fuel efficiency and reduction of pollutants. Hybrid engines are specially designed to operate optimally at mid to high speeds and loads. But for low-speed low-load conditions, due to the relatively low in-cylinder tumble intensity and lower injection pressure, the fuel-air mixture tends to deteriorate, resulting in an increase in particle number. To enable the engine to reach optimal RPM and load quickly during frequent start-stop cycles, hybrid engines typically set a higher startup engine speed and establish fuel rail pressure more quickly compared to traditional engines. Yet hybrid engines still encounter challenges of soot generation during cold start conditions. Especially in urban driving conditions where the hybrid engine frequently experiences startups and idling, the soot generation problem

Liu, Changye, Man, Xingjia, Cui, Mingli, Liang, Yuanfei, Wang, Shangning, Li, Xuesong

Flash Boiling Impact on Spray, Flame, Emissions, and Soot of Gasoline-Acetone-Butanol-Ethanol Blend at Simulated Cold-Start GDI Operation Using a CVCC

2025-01-7046

01/31/2025

The use of carbon-neutral fuels instead of conventional fuels in gasoline direct injection (GDI) engines is beneficial to global decarbonization. However, the application of renewable non-petroleum fuels in GDI engines is still unclear due to their different physicochemical properties. Acetone-Butanol-Ethanol (ABE) is a promising low-carbon alternative fuel for GDI engines, but its high viscosity and latent heat cause pool firing during cold start. The existing flash boiling technology can solve this problem. This study explores the effects of flash boiling on spray characteristics, flame propagation, soot, and emissions of gasoline-ABE blend in a constant volume combustion chamber (CVCC) without airflow. Optical windows, high-speed camera recording, in-chamber pressure measurement, Fourier transform infrared spectroscopy (FTIR), and transmission electron microscope (TEM) were used to analyze flame spreading, combustion characteristics, exhaust gases, and soot morphology. Flash boiling

Nour, Mohamed, Zhang, Weixuan, Cui, Mingli, Li, Xuesong, Xu, Min, Qui, Shuyi

Thermal Management of Electric Heavy-Duty Truck Equipped with Water Source Heat Pump in Winter Condition

2025-01-7010

01/31/2025

The electric heavy-duty truck has been receiving much attention due to its low carbon emission characteristic. This paper presents the winterized design of thermal management for an electric heavy-duty truck. The changes of important parameters in the modes of rapid heating from a cold start battery, cabin defrosting, and cabin heating in winter are discussed based on water source heat pumps. It takes 1300 seconds to warm the battery to 5°C from an ambient temperature of -10°C. Under the same heat production condition, the proposed water source heat pump can save 28.2% energy comparing with the air source heat pump, the cabin air conditioner air outlet can stay above 40°C for more than 5 minutes, and the cabin temperature can be stabilized at 20°C to meet the heating demand of the crew in winter.

Yu, Bo, Dai, Huwei, Lin, Jiewei, Han, Feng, Jiang, Feifan, Zhang, Junhong

Emission Optimization of the Cold Start Behavior of a CNG Engine with Electrically Heated Catalyst and Secondary Air Injection

2024-24-0028

09/18/2024

Decarbonization and a continuous reduction in exhaust emissions from combustion engines are key objectives in the further development of modern powertrains. In order to address both aspects, the DE4LoRa research project is developing an innovative hybrid powertrain that is characterized by the highly flexible combination of two electric motors with a monovalent compressed natural gas (CNG) engine. This approach enables highly efficient driving in purely electric, parallel and serial operating modes. The use of synthetic CNG alone leads to a significant reduction in CO2 emissions and thus in the climate impact of the drivetrain. With CNG-powered engines in particular, however, methane and other tailpipe emissions of climate gases and pollutants must also be minimized. This is possible in particular through efficient exhaust gas aftertreatment and an effective operating strategy of the powertrain. This publication presents measurement results that examine the critical aspect of cold

Noone, Patrick, Herold, Tim, Beidl, Christian

Determination of Air–Fuel Ratio at 1 kHz via Mid-Infrared Laser Absorption and Fast Flame Ionization Detector Measurements in Engine-Out Vehicle Exhaust

03-17-05-0039

04/29/2024

Measurements of air–fuel ratio (AFR) and λ (AFRactual/AFRstoich) are crucial for understanding internal combustion engine (ICE) performance. However, current λ sensors suffer from long light-off times (on the order of seconds following a cold start) and limited time resolution. In this study, a four-color mid-infrared laser absorption spectroscopy (LAS) sensor was developed to provide 5 kHz measurements of temperature, CO, CO2, and NO in engine-out exhaust. This LAS sensor was then combined with 1 kHz hydrocarbon (HC) measurements from a flame ionization detector (FID), and the Spindt exhaust gas analysis method to provide 1 kHz measurements of λ. To the authors’ knowledge, this is the first time-resolved measurement of λ during engine cold starts using the full Spindt method. Three tests with various engine AFR calibrations were conducted and analyzed: (1) 10% lean, (2) stoichiometric, and (3) 10% rich. The measurements were acquired in the exhaust of a light-duty truck with an 8

Stiborek, Joshua W., Kempema, Nathan J., Schwartz, Charles J., Szente, Joseph J., Loos, Michael J., Goldenstein, Christopher S.

Experimental Investigation of Pilot Injection Strategies to Aid Low Load Compression Ignition of Neat Methanol

2024-01-2119

04/09/2024

The growing demand to lower greenhouse gas emissions and transition from fossil fuels, has put methanol in the spotlight. Methanol can be produced from renewable sources and has the property of burning almost soot-free in compression ignition (CI) engines. Consequently, there has been a notable increase in research and development activities directed towards exploring methanol as a viable substitute for diesel fuel in CI engines. The challenge with methanol lies in the fact that it is difficult to ignite through compression alone, particularly in low-load and cold start conditions. This difficulty arises from methanol's high octane number, relatively low heating value, and high heat of vaporization, collectively demanding a considerable amount of heat for methanol to ignite through compression. Previous studies have addressed the use of a pilot injection in conjunction with a larger main injection to lower the required intake air temperature for methanol to combust at low loads. While

Svensson, Magnus, Tuner, Martin, Verhelst, Sebastian

Investigation of Combustion Characteristics of a Fuel Blend Consisting of Methanol and Ignition Improver, Compared to Diesel Fuel and Pure Methanol

2024-01-2122

04/09/2024

The increasing need to reduce greenhouse gas emissions and shift away from fossil fuels has raised an interest for methanol. Methanol can be produced from renewable sources and can drastically lower soot emissions from compression ignition engines (CI). As a result, research and development efforts have intensified focusing on the use of methanol as a replacement for diesel in CI engines. The issue with methanol lies in the fact that methanol is challenging to ignite through compression alone, particularly at low-load and cold starts conditions. This challenge arises from methanol's high octane number, low heating value, and high heat of vaporization, all of which collectively demand a substantial amount of heat for methanol to ignite through compression. One successful project using methanol is the Fastwater project, where a diesel engine was converted to run on methanol, with 3% ignition improver, and installed in the pilot boat Pilot 120SE, that is running in real world conditions

Svensson, Magnus, Tuner, Martin, Verhelst, Sebastian

Estimating Light-Duty Vehicle Gaseous Emissions Using a Data-Driven Approach in Off-Cycle Measurements

2024-01-2705

04/09/2024

As global regulations on automotive tailpipe emissions become increasingly stringent, developing precise tailpipe emissions models has garnered significant attention to fulfill onboard monitoring requirements without some drawbacks associated with traditional sensor-based systems. Within the European Union, there is consideration of mandating real-time measurement of emission constituents to enable driver warnings in cases where constituent standards are exceeded. Presently, available technology renders this approach cost-prohibitive and technologically challenging, with most sensor suppliers either unable to meet the demand or unwilling to justify the development costs associated with sensor commercialization. Efforts to circumvent the sensor-based approach through first principle models, incorporating thermokinetics, have proven to be both computationally expensive and lacking in accuracy during transient operations. We propose a data-driven solution based on DL (deep learning) to

Hashemi, Ashton, Schlingmann, Dean

Advanced Engine Cooling System for a Gas-Engine Vehicle Part I: A New Coolant Flow Control During Cold Start

2024-01-2414

04/09/2024

In this paper, we present a novel algorithm designed to accurately trigger the engine coolant flow at the optimal moment, thereby safeguarding gas-engines from catastrophic failures such as engine boil. To achieve this objective, we derive models for crucial temperatures within a gas-engine, including the engine combustion wall temperature, engine coolant-out temperature, engine block temperature, and engine oil temperature. To overcome the challenge of measuring hard-to-measure signals such as engine combustion gas temperature, we propose the use of new intermediate parameters. Our approach utilizes a lumped parameter concept with a mean-value approach, enabling precise temperature prediction and rapid simulation. The proposed engine thermal model is capable of estimating temperatures under various conditions, including steady-state or transient engine performance, without the need for extra sensors. Moreover, it exhibits greater robustness compared to temperature estimation systems

Chang, Insu, Sun, Min, Edwards, David

Optimization of Cold Start Performance of Diesel Engine Under Low Temperature and High Altitude Environment

2024-01-2455

04/09/2024

The problem of keeping the stable starting performance of diesel engine under high altitude and low temperature conditions has been done a lot of research in the field of diesel engine, but there is a lack of research on extreme conditions such as above 2000 meters above sea level and below 0°C. Aiming at solving the cold start problem of diesel engine in extreme environment, a set of chamber system of cold start environment diesel engine was constructed to simulate environment of 3000m altitude and -20°C. A series of experimental research was conducted on cold start efficiency optimization strategy of a certain type of diesel engine at 3000m altitude and -20°C. In parallel, a diesel engine model was constructed through Chemkin to explore the influence of the three parameters of compression ratio, stroke length, and fuel injection advance angle on the first cold start cycle of diesel engine at 4000m altitude and -20°C. The simulation results show that in altitude 4000m and -20°C

Fang, Liang, Chen, Boyu, Lou, Diming, Xu, Kaiwen, Tan, Piqiang, Hu, Zhiyuan, Zhang, Yunhua, Zhen, Lei

Evolution of Light-Duty Gasoline Compression Ignition (LD-GCI) for High Efficiency and US Tier3- Bin30 Emissions

2024-01-2092

04/09/2024

It is widely recognized that internal combustion engines (ICE) are needed for transport worldwide for years to come, however, demands on ICE fuel efficiency, emissions, cost, and performance are extremely challenging. Gasoline compression ignition (GCI) is one approach to achieve demanding efficiency and emissions targets. At Aramco Research Center-Detroit, an advanced, multi-cylinder GCI engine was designed and built using the latest combustion system, engine controls, and lean aftertreatment. The combustion system uses Aramco’s PPCI-diffusion process for ultra-low NOx and smoke. A P2 48V mild hybrid system was integrated on the engine for braking energy recovery and improved cold starts. For robust low-load operation, a 2-step valvetrain system was used for exhaust rebreathing. Test data showed that part-load fuel consumption was reduced 7 to 10 percent relative to a competitive 2.0L European diesel engine. The GCI engine produced “near-zero” tailpipe emissions of NOx, smoke, HC, and

Sellnau, Mark, Whitney, Christopher, Shah, Ashish, Sari, Rafael, Klemm, William, Cleary, David

Particulate filter performance mapping for in-service conformity

2024-01-2382

04/09/2024

The proposed Euro-7 regulations are expected to build on the significant emissions reductions that have already been achieved using advanced Euro VI compliant after treatment systems (ATS). The introduction of in-service conformity (ISC) requirements during Euro VI paved the way for enabling compliance during real-world driving conditions. The diverse range of applications and resulting operating conditions greatly impact ATS design and the ability of the diesel particulate filter (DPF) to maintain performance under the most challenging boundary conditions including cold starts, partial/complete regenerations, and high passive soot burn operation. The current study attempts to map the particle number (PN) filtration performance of different DPF technologies under a variety of in-use cycles developed based on field-data from heavy duty Class-8 / N3 vehicles. Access to such performance maps can allow original equipment manufacturers (OEMs) to select DPF technologies to suit different

Viswanathan, Sandeep, Sadek, Ghadi, Reddy, Vishal, He, Suhao, Alam, Rabeka

Three Way Catalyst with Faster Light-Off Substrates – A Promising Approach to Reduce Tailpipe Emissions

2024-26-0142

01/16/2024

The ever-tightening regulation norms across the world emphasize the magnitude of the air pollution problem. The decision to leapfrog from BS4 to BS6 – with further reduction in emission limits -showed India’s commitment to clean up its atmosphere. The overall cycle emissions were reduced significantly to meet BS6 targets [1]. However, the introduction of RDE norms in BS6.2 [1] demanded further reduction in emissions under real time operating conditions – start-stop, hard acceleration, idling, cold start – which was possible only through strategies that demanded a cost effective yet robust solutions. The first few seconds of the engine operation after start contribute significantly to the cycle gaseous emissions. This is because the thermal inertia of the catalytic converter restricts the rate at which temperature of the catalyst increases and achieves the desired “light-off” temperature. The challenge becomes more prominent in the turbocharged engines (where some part of exhaust heat

Kale, Vishal Maruti, M, Ravisankar, Hosur, Viswanatha, Sridhar, S, Bhimavarapu, Aditya, Lende, Nilesh Ashok, Rose, Dominik, Tao, Tinghong

Experimental Study of Low Thermal Inertia Thermal Barrier Coating in a Spark Ignited Multicylinder Production Engine

2023-01-1617

10/31/2023

Thermal barrier coatings (TBCs) have long been studied as a potential pathway to achieve higher thermal efficiency in spark ignition engines. Researchers have studied coatings with different thicknesses and thermophysical properties to counteract the volumetric efficiency penalty associated with TBCs in spark ignition. To achieve an efficiency benefit with minimal charge heating during the intake stroke, low thermal inertia coatings characterized by their larger temperature swings are required. To study the impact of low thermal inertia coatings in spark ignition, coatings were applied to the cylinder head, piston crown, intake and exhaust valve faces, and intake and exhaust valve backsides. Tier III EEE E10 certification gasoline was used to keep the experiments relevant to the present on-road vehicles. This study is aimed at analyzing durability of the coatings as well as efficiency and emissions improvements. Thus, a 100-hr. durability test was conducted to assess the durability of

Bhatt, Ankur, Gandolfo, John, Vedpathak, Kunal, Jiang, Chen, Jordan, Eric, Lawler, Benjamin, Gainey, Brian

GT-Suite Modeling of Thermal Barrier Coatings in a Multi-Cylinder Turbocharged DISI Engine for Catalyst Light-Off Delay Improvement

2023-01-1602

10/31/2023

Catalytic converters, which are commonly used for after-treatment in SI engines, exhibit poor performance at lower temperatures. This is one of the main reasons that tailpipe emissions drastically increase during cold-start periods. Thermal inertia of turbocharger casing prolongs the catalyst warm-up time. Exhaust enthalpy management becomes crucial for a turbocharged direct injection spark ignition (DISI) engine during cold-start periods to quickly heat the catalyst and minimize cold-start emissions. Thermal barrier coatings (TBCs), because of their low thermal inertia, reach higher surface temperatures faster than metal walls, thereby blocking heat transfer and saving enthalpy for the catalyst. The TBCs applied on surfaces that exchange heat with exhaust gases can increase the enthalpy available for the catalyst warm-up. A system-level transient heat transfer study using experimental or high-fidelity simulation techniques to evaluate the TBC application on various surfaces would be

Ravikumar, Avinash, Bhatt, Ankur, Gainey, Brian, Lawler, Benjamin

Research on Cold Start Strategy of Vehicle Multi-Stack Fuel Cell System

2023-01-7036

10/30/2023

To study the cold start of muti-stack fuel cell system (MFCS), a novel thermal management subsystem structure and corresponding cold start strategies are proposed. Firstly, leveraging the distinctive configuration of the MFCS that can be sequentially initiated, we augmented the existing thermal management subsystem with the incorporation of two additional collection valves and two bypass diverter valves, which affords an increased degree of flexibility in the formulation of cold-start strategies. Secondly, we innovatively propose a hierarchical auxiliary heating cold start strategy and an average auxiliary heating cold start tailored for MFCS consisting of power levels of 20 kW, 70 kW, and 120 kW. Furthermore, we have developed a controller to address temperature control challenges during the start-up process. The results demonstrate that the multi-stack hierarchical auxiliary heating cold start strategy yields a significant reduction in energy consumption and startup time during the

Jin, Yapeng, Yuan, Tanghu, Fan, Lei, Zhou, Su

Measurement of Liquid Fuel Film Attached to the Wall in a Port Fueled SI Gasoline Engine

2023-01-1818

10/24/2023

Liquid fuel attached to the wall surface of the intake port, the piston and the combustion chamber is one of the main causes of the unburned hydrocarbon emissions from a port fueled SI engine, especially during transient operations. To investigate the liquid fuel film formation process and fuel film behavior during transient operation is essential to reduce exhaust emissions in real driving operations, including cold start operations. Optical techniques have been often applied to measure the fuel film in conventional reports, however, it is difficult to apply those previous techniques to actual engines during transient operations. In this study, using MEMS technique, a novel capacitance sensor has been developed to detect liquid fuel film formation and evaporation processes in actual engines. A resistance temperature detector (RTD) was also constructed on the MEMS sensor with the capacitance sensor to measure the sensor surface temperature. The response and the sensitivity of the

Kuboyama, Tatsuya, Yoshihashi, Tsukasa, Moriyoshi, Yasuo, Nakabeppu, Osamu, Takayama, Satoshi

Cold Start Performance of Sustainable Oxygenated Spark Ignition Fuels

2023-32-0166

09/29/2023

The objective of this study was to reduce pollutant emissions during cold start conditions in a spark-ignited direct injection engine, by exploring the potential of oxygenated fuels. With their high oxygen content and lack of direct C-C bonds, they effectively reduce particle number (PN) and NOx emissions under normal conditions. Methanol was chosen due to its wide availability. As methanol is toxic to humans and associated with cold-start issues, a second promising synthetic fuel was selected to be benchmarked against gasoline, comprising 65 vol% of dimethyl carbonate and 35 vol% of methyl formate (C65F5). Currently, there is a lack of detailed investigations on the cold start performance for both oxygenated fuels utilizing today’s injector capabilities. Spray measurements were caried out in a constant volume chamber to assess the spray of C65F35. Reduced fuel temperature increased spray-penetration length and compromised fast vaporization. Therefore, the injection strategy becomes

Kraus, Christoph, Fellner, Felix, Miyamoto, Akiyasu, Sauerland, Henning, Härtl, Martin, Jaensch, Malte

Pollutant Emissions of a Blended Plug-in Hybrid Electric Vehicle during High-Power Cold Starts

2023-32-0096

09/29/2023

To characterize emission performance and engine operating conditions during high-power cold starts (HPCS), a blended plug-in hybrid electric vehicle was tested over worldwide harmonized light-duty vehicle test cycle (WLTC), and a new cycle was developed to characterize HPCS. The results showed that the engine speed and load increased dramatically to high level during HPCS under the low temperature of coolant and catalysts. The higher concentration of particle number (PN) and NOx at higher speed and load, accounted for the higher emissions during HPCS. Besides, the cumulative PN emissions increased first and then decreased with the increasing coolant temperature.

Tan, Guikun, Wang, Boyuan, Eitan Liu, Zemin, Li, Yanfei, Xu, Hongming, Shuai, Shijin

Evaluation of Different Gasoline Formulations on a High-Performance Engine

2023-24-0038

08/28/2023

The future of the combustion engine will to some extent depend on the use of CO2-neutral eFuels to avoid further fossil CO2 emissions. Also, the use of synthetic fuels offers the possibility to improve various engine properties, such as thermodynamics, EGR compatibility or emissions, through targeted influence on specific fuel properties. To this end, a methodology was generated to attribute various engine effects to particular fuel properties. Therefore, the Chair of Combustion Engines (LVAS) at the TU Dresden developed a fully automated testbed for motorcycle engines, including clutch and gear switching mechanisms. Hitherto, emissions measurements for motorcycles were done mostly on chassis dynamometers, with the disadvantage of a large spread of results. Due to the lack of consistency the analysis of fuel properties was not possible. To prove the developed methodology, a test campaign including 15 different gasoline fuels was elaborated in cooperation with KTM R&D GmbH. Before

Graßmeyer, Marius, Atzler, Frank

Improvement of Post-Oxidation for Low-Emission Engines through 3D-CFD Virtual Development

2023-24-0107

08/28/2023

There is a growing need for low-emissions concepts due to stricter emission regulations, more stringent homologation cycles, and the possibility of a ban on new engines by 2035. Of particular concern are the conditions during a cold start, when the Three-Way Catalyst is not yet heated to its light-off temperature. During this period, the catalyst remains inactive, thereby failing to convert pollutants. Reducing the time needed to reach this temperature is crucial to comply with the more stringent emissions standards. The post oxidation by means of secondary air injection, illustrated in this work, is a possible solution to reduce the time needed to reach the above-mentioned temperature. The strategy consists of injecting air into the exhaust manifold via secondary air injectors to oxidize unburned fuel that comes from a rich combustion within the cylinder. This strategy can be implemented without major modifications to the engine's hardware or control system, making it an attractive

Pipolo, Mario, Kulzer, Andre, Chiodi, Marco, Moriyoshi, Yasuo

Experimental and Numerical Analysis of a Swirled Fuel Atomizer for an Aftertreatment Diesel Burner

2023-24-0106

08/28/2023

Emission legislation for light and heavy duty vehicles is requiring a drastic reduction of exhaust pollutants from internal combustion engines (ICE). Achieving a quick heating-up of the catalyst is of paramount importance to cut down cold start emissions and meet current and new regulation requirements. This paper describes the development and the basic characteristics of a novel burner for diesel engines exhaust systems designed for being activated immediately at engine cold start or during vehicle cruise. The burner is comprised of a swirled fuel dosing system, an air system, and an ignition device. The main design characteristics are presented, with a detailed description of the atomization, air-fuel interaction and mixture formation processes. An atomizer prototype has been extensively analyzed and tested in various conditions, to characterize the resulting fuel spray under cold-start and ambient operating conditions. The geometrical shape of the spray was investigated by imaging

Postrioti, Lucio, Battistoni, Michele, Zembi, Jacopo, Brizi, Gabriele, La Sana, Marco, Brignone, Mauro, Napoli, Francesco, Pizza, Salvatore, Milani, Emanuele

Automated Expert Knowledge-Based Deep Reinforcement Learning Warm Start via Decision Tree for Hybrid Electric Vehicle Energy Management

14-13-01-0006

08/28/2023

Deep reinforcement learning has been utilized in different areas with significant progress, such as robotics, games, and autonomous vehicles. However, the optimal result from deep reinforcement learning is based on multiple sufficient training processes, which are time-consuming and hard to be applied in real-time vehicle energy management. This study aims to use expert knowledge to warm start the deep reinforcement learning for the energy management of a hybrid electric vehicle, thus reducing the learning time. In this study, expert domain knowledge is directly encoded to a set of rules, which can be represented by a decision tree. The agent can quickly start learning effective policies after initialization by directly transferring the logical rules from the decision tree into neural network weights and biases. The results show that the expert knowledge-based warm start agent has a higher initial learning reward in the training process than the cold start. With more expert knowledge

Wang, Hanchen, Arjmandzadeh, Ziba, Ye, Yiming, Zhang, Jiangfeng, Xu, Bin

Simulation of CNG Engine in Agriculture Vehicles. Part 1: Prediction of Cold Start Engine-Out Emissions Using Tabulated Chemistry and Stochastic Reactor Model

2023-24-0006

08/28/2023

Worldwide, there is the demand to reduce harmful emissions from non-road vehicles to fulfill European Stage V+ and VI (2022, 2024) emission legislation. The rules require significant reductions in nitrogen oxides (NOx), methane (CH4) and formaldehyde (CH2O) emissions from non-road vehicles. Compressed natural gas (CNG) engines with appropriate exhaust aftertreatment systems such as three-way catalytic converter (TWC) can meet these regulations. An issue remains for reducing emissions during the engine cold start where the CNG engine and TWC yet do not reach their optimum operating conditions. The resulting complexity of engine and catalyst calibration can be efficiently supported by numerical models. Hence, it is required to develop accurate simulation models which can predict cold start emissions. This work presents a real-time engine model for transient engine-out emission prediction using tabulated chemistry for CNG. The engine model is based on a stochastic reactor model (SRM

Siddareddy, Reddy Babu, Franken, Tim, Leon de Syniawa, Larisa, Pasternak, Michal, Prehn, Sascha, Buchholz, Bert, Mauss, Fabian

Piston Pre-Heating Using a Pressurized-Heated Oil Buffer: A Practical Method to Reduce ICE Emissions and Fuel Consumption

2023-24-0123

08/28/2023

Engine cold start is characterized by sub-optimal combustion efficiency due to the low temperature of the combustion chamber; this heavily increases engine raw emissions at start. One driving phenomenon is a limited fuel evaporation rate. Consequently, a liquid fuel film remains on the piston top at ignition. Liquid fuel deposited on the piston top is a well-known cause of “pool-fire”, leading to high levels of particle emissions; a problem particularly noticeable with bio-based renewable fuels. Engine piston pre-heating can be deployed to prevent or limit the formation of such fuel film and associated pollutants. In this work a practical technique is proposed to effectively pre-heat the pistons immediately before engine cold start. The device consists of a pressurized-heated oil buffer which pre-heats the pistons via the existing piston cooling nozzles. The device provides further benefits in emissions and fuel consumption in two ways: 1) the warm oil pre-lubricates the engine working

Bovo, Mirko, Mubarak Ali, Mohammed Jaasim

Towards H ₂ High-Performance IC Engines: Strategies for Control and Abatement of Pollutant Emissions

2023-24-0108

08/28/2023

In future decarbonized scenarios, hydrogen is widely considered as one of the best alternative fuels for internal combustion engines, allowing to achieve zero CO2 emissions at the tailpipe. However, NOx emissions represent the predominant pollutants and their production has to be controlled. In this work different strategies for the control and abatement of pollutant emissions on a H2-fueled high-performance V8 twin turbo 3.9L IC engine are tested. The characterization of pollutant production on a single-cylinder configuration is carried out by means of the 1D code Gasdyn, considering lean and homogeneous conditions. The NOx are extremely low in lean conditions with respect to the emissions legislation limits, while the maximum mass flow rate remains below the turbocharger technical constraint limit at λ=1 only. To find a trade-off between the two mixture conditions, three different engine control strategies are simulated, imposing a variation of air-to-fuel ratio from λ=2.3 at low

Bulgarini, Margherita, Della Torre, Augusto, Barillari, Loris, Montenegro, Gianluca, Onorati, Angelo, Gullino, Fabrizio, Tonelli, Roberto

A Mid-Infrared Laser Absorption Sensor for Gas Temperature and Carbon Monoxide Mole Fraction Measurements at 15 kHz in Engine-Out Gasoline Vehicle Exhaust

03-17-01-0002

07/21/2023

Quantifying exhaust gas composition and temperature in vehicles with internal combustion engines (ICEs) is crucial to understanding and reducing emissions during transient engine operation. This is particularly important before the catalytic converter system lights off (i.e., during cold start). Most commercially available gas analyzers and temperature sensors are far too slow to measure these quantities on the timescale of individual cylinder-firing events, thus faster sensors are needed. A two-color mid-infrared (MIR) laser absorption spectroscopy (LAS) sensor for gas temperature and carbon monoxide (CO) mole fraction was developed and applied to address this technology gap. Two quantum cascade lasers (QCLs) were fiber coupled into one single-mode fiber to facilitate optical access in the test vehicle exhaust. The QCLs were time-multiplexed in order to scan across two CO absorption transitions near 2013 and 2060 cm–1 at 15 kHz. This enabled in situ measurements of temperature and CO

Stiborek, Joshua W., Tancin, Ryan J., Kempema, Nathan J., Szente, Joseph J., Loos, Michael J., Goldenstein, Christopher S.

Emission Characteristics of a Light Diesel Engine with PNA under Different Coupling Modes of EHC and Aftertreatment System

2023-01-0268

04/11/2023

With the continuous upgrading of emission regulations, NOx emission limit is becoming more and more strict, especially in the cold start phase. Passive NOx absorber (PNA) can adsorb NOx at a relatively low exhaust temperature, electrically heated catalyst (EHC) has great potential to improve exhaust gas temperature and reduce pollutant emissions of diesel engines at cold start conditions, while experimental research on the combined use of these two kinds of catalysts and the coupling mode of the electrically heated catalyst and the aftertreatment system under the cold start condition are lacking. In this paper, under a certain cold start and medium-high temperature phase, the exhaust gas temperature and emission characteristics of PNA, EHC and aftertreatment system under different coupling modes were studied. Results showed that the average inlet temperature of diesel oxidation catalyst (DOC) and selective catalytic reduction catalyst (SCR) integrated into diesel particulate filter

Kang, Lulu, Fang, Liang, Zhao, Yunkun, Lou, Diming, Zhang, Yunhua, Luo, Chagen

Real-Time Simulation of CNG Engine and After-Treatment System Cold Start Part 1: Transient Engine-Out Emission Prediction Using a Stochastic Reactor Model

2023-01-0183

04/11/2023

During cold start of natural gas engines, increased methane and formaldehyde emissions can be released due to flame quenching on cold cylinder walls, misfiring and the catalyst not being fully active at low temperatures. Euro 6 legislation does not regulate methane and formaldehyde emissions. New limits for these two pollutants have been proposed by CLOVE consortium for Euro 7 scenarios. These proposals indicate tougher requirements for aftertreatment systems of natural gas engines. In the present study, a zero-dimensional model for real-time engine-out emission prediction for transient engine cold start is presented. The model incorporates the stochastic reactor model for spark ignition engines and tabulated chemistry. The tabulated chemistry approach allows to account for the physical and chemical properties of natural gas fuels in detail by using a-priori generated laminar flame speed and combustion chemistry look-up tables. The turbulence-chemistry interaction within the combustion

Siddareddy, Reddy Babu, Franken, Tim, Pasternak, Michal, Leon de Syniawa, Larisa, Oder, Johannes, Rottengruber, Hermann, Mauss, Fabian

Real-world Cold Start Emissions Evaluation for Direct-injection Gasoline Vehicle with PEMS and SEMS

2023-01-0379

04/11/2023

The Real Driving Emissions (RDE) test method has been introduced after 2017 to regulate the vehicle emissions in real-world driving situations by means of on-board emissions measurements. This paper aims to estimate the detailed on-board gaseous emissions from a light-duty direct-injection gasoline vehicle simultaneously using both portable emissions measurement system (PEMS) and sensor-based emissions measurement system (SEMS). Test route is typical urban route and tests environment factors followed the RDE regulation. Carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), and ammonia (NH3) emissions were analyzed according to cold start once and followed by hot start conditions. The mass emissions of gas components were calculated based on the exhaust flowrate obtained from OBD parameters, NH3 emission was calculated based on NO sensor’s data. Two drivers participated in the tests and their emissions difference has been compared. The results indicating cold start caused

Chen, Jiaxin, Sato, Susumu, Eang, Chanpaya, Tanaka, Kotaro, Tange, Takeshi

Sub-23nm Particle Emissions from China6 Gasoline Vehicles over Various Driving Cycles

2023-01-0395

04/11/2023

Sub-23nm particles emission from the light-duty vehicle is widely discussed now and possible to be counted into the next stage emission legislation, such as Euro7. In this article, 16 China6 gasoline vehicles were tested over the WLTC and two surrogate RDE lab cycles for particulate number (PN) emission, the difference between PN23 (particle size >23nm) and PN10 (particle size>10nm) emission was analyzed. Testing results showed that the average PN10 emission increased 59% compared to PN23, which will bring great challenges for those vehicles to meet the future regulation requirement if sub-23nm particle is counted. The sub-23nm particles emission was proportional to the PN23 particles emission and generated mostly from the cold start or the transient engine conditions with rich combustion. Compared to the proposal of Euro 7, PN10 emission from some tested vehicles will need further two orders of magnitude reduction. With the adoption of an advanced gasoline particulate filter (GPF

Feng, Xiangyu, Li, Chunbo, Li, Weiwei, Chen, Jian, Liu, Yi, Liu, Haixu, Wang, Zequn, Chen, Xiaolang

Design and Assessment of an Exhaust After-Treatment System Equipped with a Fuel

2023-01-0355

04/11/2023

Reaching near-zero cold start emissions in a wide range of ambient conditions is a challenging, yet necessary objective. Optimizing the combustion, although fundamental to lower specific engine-out emissions, is not sufficient, especially in high-performance engines. A very high after-treatment efficiency from engine start-up onwards is mandatory. Active heating technologies allow quick heating up of after-treatment devices like a three way catalyst above their light-off temperature, regardless of engine operation. In this work, the particular characteristics of a fuel burner were analyzed. The steps that led to the design of an exhaust system equipped with a fuel burner are reported. The fuel burner ability to efficiently heat up after-treatment devices was assessed by numerical simulations and then verified experimentally. Cumulative results were compared with a passive catalyst heating strategy. The fuel burner proved effective in reducing tailpipe emissions via pre-heating, i.e

Rossi, Vincenzo, Brocchi, Luca, Medda, Massimo, Paltrinieri, Stefano, Rulli, Federico, Tonelli, Roberto

High Cell Density Flow Through Substrate for New Regulations

2023-01-0359

04/11/2023

This paper, written in collaboration with Ford, evaluates the effectiveness of higher cell density combined with higher porosity, lower thermal mass substrates for emission control capability on a customized, RDE (Real Driving Emissions)-type of test cycle run on a chassis dynamometer using a gasoline passenger car fitted with a three-way catalyst (TWC) system. Cold-start emissions contribute most of the emissions control challenge, especially in the case of a very rigorous cold-start. The majority of tailpipe emissions occur during the first 30 seconds of the drive cycle. For the early engine startup phase, higher porosity substrates are developed as one part of the solution. In addition, further emission improvement is expected by increasing the specific surface area (GSA) of the substrate. This test was designed specifically to stress the cold start performance of the catalyst by using a short, 5 second idle time preceding an aggressive, high exhaust mass flowrate drive cycle. The

Nakasumi, Hayaki, Kawakami, Akifumi, Ohara, Etsuji, sugimoto, Kentaro, Hibi, Noriyuki, Asako, Tsuyoshi, Kato, Kyohei, Anoop, Reghunathan-Nair, Affan, Syed, Thanasiu, Eva, Lambert, Christine K., Hubbard, Carolyn

Investigation of High Fuel Pressure and Multiple Injection to Reduce Engine Emission during Catalyst Light-Off

2023-01-0244

04/11/2023

The demand for clean energy efficient transportation is rapidly increasing to meet greenhouse gas emissions reduction and promote sustainability. Gasoline direct injection engines (GDI) have high thermal efficiency thus low greenhouse gas emissions compared with conventional port fueled engines. However, during cold start conditions GDI engines produce harmful emissions, including nitrogen oxides, hydrocarbons, and particulate matter. Thus, high pressure fuel system development for direct injection of gasoline is being conducted to reduce emissions during engine cold start. This paper summarized the effect of high fuel pressure and multiple injections on cold catalyst light-off strategy for rapid heating of the catalyst. Experiments were carried out using light-duty four-cylinder engine at cold catalyst light-off conditions with coolant temperature at 30 °C. Fuel injection strategy optimization was carried out considering (a) 25 MPa - two injections (b) 25 MPa - three injections and (c

Lonari, Yashodeep, Yoneya, Naoki, Miyake, Takao, Namaizawa, Yasuo

CFD Assessment of an After-Treatment System Equipped with Electrical Heating for the Reduction of the Catalyst Light-Off Time

2023-01-0366

04/11/2023

The reduction of the catalyst light-off time at the engine cold start represents a key factor for the pollutant emissions control from vehicles tested on homologation cycles and real drive conditions. The adoption of heating strategies to increase the temperature of the catalytic substrate in the early phase of the engine start is regarded as a promising solution. The present study focuses on the application of electrical heated catalyst (EHC) in an after-treatment line for a spark-ignition gasoline engine. The analysis is carried out by means of an advanced CFD framework, which includes the modeling of catalytic reactions in the substrates and accounts for the thermal evolution of all the components included in the after-treatment system. In this work the model has been extended with: a) the solution of the electrical circuit of the EHC to provide an accurate description of the non-uniform temperature distribution of the coils heated by Joule effect and b) a specific model for the

Barillari, Loris, Della Torre, Augusto, Montenegro, Gianluca, Onorati, Angelo, Rossi, Vincenzo, Paltrinieri, Stefano, Gullino, Fabrizio

Low Ambient Temperature Impact on a Low NO _X Demonstration System

2023-01-0361

04/11/2023

In 2020, CARB adopted the low NOX omnibus ruling, which provided revisions to on-road heavy duty engine compliance standards and certification practices. As part of the updates to the regulation, CARB has introduced a new in-use vehicle testing process that broadens the operation modes tested and considers the manufacturer’s intended vehicle application. Compared to the previous method, or the Not-to-Exceed approach, cold start and low ambient temperature provisions were included as part of the updates. The inclusion of low temperature operation requires the OEMs to design a robust engine and aftertreatment package that extends NOX conversion performance. The following work discusses the NOX emissions performance impact in a low temperature ambient environment. The engine and aftertreatment system evaluated was designed to comply with CARB’s low NOX regulations. The cycles tested included the CARB Southern NTE cycle and an FTP-LLC protocol. Both test sequences were intended to

Zavala, Bryan, Sharp, Christopher

Real-Time Simulation of CNG Engine and After-Treatment System Cold Start. Part 2: Tail-Pipe Emissions Prediction Using a Detailed Chemistry Based MOC Model

2023-01-0364

04/11/2023

In contrast to the currently primarily used liquid fuels (diesel and gasoline), methane (CH4) as a fuel offers a high potential for a significant reduction of greenhouse gas emissions (GHG). This advantage can only be used if tailpipe CH4 emissions are reduced to a minimum, since the GHG impact of CH4 in the atmosphere is higher than that of carbon dioxide (CO2). Three-way catalysts (TWC - stoichiometric combustion) and methane oxidation catalysts (MOC - lean combustion) can be used for post-engine CH4 oxidation. Both technologies allow for a nearly complete CH4 conversion to CO2 and water at sufficiently high exhaust temperatures (above the light-off temperature of the catalysts). However, CH4 combustion is facing a huge challenge with the planned introduction of Euro VII emissions standard, where stricter CH4 emission limits and a decrease of the cold start starting temperatures are discussed. The aim of the present study is to develop a reliable kinetic catalyst model for MOC

Leon de Syniawa, Larisa, Siddareddy, Reddy Babu, Oder, Johannes, Franken, Tim, Guenther, Vivien, Rottengruber, Hermann, Mauss, Fabian

Advanced Low Mass Ceramic Substrate for improved Cold Start Performance Targeting PROCONVE L8 Light-Duty Emissions Regulations

2022-36-0027

02/10/2023

Brazilian Emissions Regulations are getting tighter in the coming years. With PROCONVE L7 in Jan-2023 and PROCONVE L8 in 2025, regulated emissions limits will significantly decrease, such as, the NMOG + NOx standard from 130 mg/km (PL6) to 50 mg/km (PL8). This challenge will necessitate better aftertreatment performance, with expected increases the catalytic converter PGM content, and consequently higher system cost. It is understood that approximately 75% of an engine’s gaseous pollutants occur during the first few seconds after a cold start, thus it is crucial to promote the emissions conversion performance during that period. One approach is to decrease the heat capacity of the catalytic system, which can be done by utilizing cordierite substrates with thinner walls or an increased material porosity. CORNING has developed an innovative technology to substantially raise the porosity of conventional ultra-thin wall substrates from 35% to 55%, while maintaining their strength. This

Petrini Fogaça, Rômulo, Urbani Amadei, Gabriel, L. Warkins, Jason, A. Craig, Angus

Optimized Supervision of Variable Displacement Compressor for Automotive Air Conditioning

2022-28-0450

11/09/2022

The aim of this paper is to establish the optimized control of external variable displacement compressor (EVDC) for the automotive air conditioning (AC) system in various operating modes. The control logic was developed, calibrated and experimentally verified on test vehicle. The developed control strategy ensures the stability of AC system while achieving the desired climate control and yielding the maximum possible fuel economy. The influence of cooling load, compressor speed and icing of evaporator have been investigated theoretically and validated with test data. The proposed control strategy ensures the safety of compressor and stabilizes the AC system under high engine torque demand, cold start conditions, engine shutdown or under electrical failures reported by on board diagnostics services (OBD). The results reveal improved thermal comfort and improvement in fuel economy with the use of established baseline control logic presented in the paper.

Yadav, Aditya Pratap, Shukla, Ankit, Goel, Arun Kumar, Sharma, Kamal

Cold Start HC Emission Reduction Using Targeted Fuel Heating

2022-28-0022

10/05/2022

A large quantity of fuel is injected into the cold manifold of the engine to enable a quick start. A substantial part of this fuel gets deposited on the manifold walls leading to the formation of a fuel pool. Improper fuel vaporization during the engine cold start leads to the formation of a large amount of HC emissions. In the present investigation, a small flexible polyamide strip heater was placed at a specific location where the fuel impingement happens to enhance fuel vaporization in a 4-stroke motorcycle engine. The heater was turned on 20 seconds before the engine started. A temperature controller was used to maintain the heater at 323 K. The emission data for 180 seconds from the engine start was measured. Initial tests were carried out without the heater to establish the baseline emissions. Later, tests were carried out with the heater switched on and compared. The results showed a 32 % reduction in cumulative HC emissions with the use of the heater. Additionally, it was also

Teja, Ravi, V, Avaneesh Athreya, M, Himabindu, Rayavarapu, Ravikrishna

EHC Development for HEV Emission Control

2022-01-1012

08/30/2022

In the recent years and near future, the automotive environmental regulations have been and will be more stringent than ever before. The reduction of cold start tailpipe emission is the key for exhaust aftertreatment and emission control. As one of the effective catalyst heating approaches, EHC can be applied to reduce catalyst L/O time at engine cold start and then improve tailpipe emission with meeting stringent emission regulations such as China6b，Euro6d，US Tier3Bin30 and future China7，Euro7. In this paper, we will review our recent engineering work on EHC development associated with hybrid electrical vehicle for better emission control and exhaust aftertreatment.

Lu, Jingwen, Ma, Rongchun, Pan, Lingteng, Dai, Zhengxing, Liu, Yiqiang

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