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Technical Paper

Hydrogen Fuel Cell Technology for a Sustainable Future: A Review

2018-04-03
2018-01-1307
Abstract This paper discusses some crucial energetic, environmental and sustainability issues and the role of hydrogen and fuel cell technologies as one of the potential solutions to these issues. Hydrogen is an especially attractive transportation fuel. It is the least polluting fuel available, and can be produced anywhere there is water and a clean source of electricity. A fuel cycle in which hydrogen is produced by solar-electrolysis of water, or by gasification of renewable grown biomass, and then used in a fuel-cell powered electric-motor vehicle (FCEV), would produce little or no local, regional or global pollution. Hydrogen FCEVs would combine the best features of battery-powered electric vehicles (BPEVS)-zero emissions, high efficiency, quiet operation and long life-with the long range and a fast refueling time of internal-combustion-engine vehicles (ICEVs).
Technical Paper

Thermodynamic Modeling of Blade Cooled Turboprop Engine Integrated to Solid Oxide Fuel Cell: A Concept

2018-04-03
2018-01-1308
Abstract In modern turboprop engines, reduction in emission and fuel consumption is the primary goals during the development of gas turbine aero engines. In this paper, a concept has been proposed for hybridizing the air blade cooled turboprop engines by integrating it with a fuel cell. The proposed study focuses on thermodynamic analysis of a turboprop engine integrated to a solid oxide fuel cell (SOFC) system. A solid oxide fuel cell is the perfect candidate for utilizing waste heat available at turboprop engine exhaust, through recuperation process. Integration of SOFC is ultimately leads to enhancement the overall performance of the turboprop-SOFC hybrid system. Power generated by the SOFC system can be utilized by the aircraft and in can complement the auxillary-power-unit (APU) and may even supplement it. On the basis of 1st and 2nd law of thermodynamic modeling analysis of a turboprop-SOFC system has been presented in this article.
Technical Paper

A Progress Review on Gas Purge for Enhancing Cold Start Performance in PEM Fuel Cell

2018-04-03
2018-01-1312
Abstract Cold start capability is one of remaining major challenges in realizing PEMFC (Proton Exchange Membrane Fuel Cell) technology for automotive applications. Gas purge is a common and integral shutdown procedure of a PEMFC automotive in subzero temperature. A dryer membrane electrode assembly (MEA) can store more water before it gets saturated and ice starts to penetrate in the open pores of porous media, thus enhancing cold start capability of a PEMFC. Therefore, gas purge is always performed prior to fuel cell shutdown to minimize residual water in a PEMFC. In the hope of improving effectiveness of purge in a PEMFC vehicle, two important purge parameters are evaluated including purge time and energy requirement. In practice, an optimized gas purge protocol should be developed with minimal parasitic energy, short purge duration and no degradation of components. To conclude, the cold start capability and performance can be consolidated by proper design of gas purge strategies.
Technical Paper

Effects of Thermal and Auxiliary Dynamics on a Fuel Cell Based Range Extender

2018-04-03
2018-01-1311
Abstract Batteries are useful in Fuel Cell Hybrid Electric Vehicles (FCHEV) to fulfill transient demands and for regenerative braking. Efficient energy management strategies paired with optimal powertrain design further improves the efficiency. In this paper, a new methodology to simultaneously size the propulsive elements and optimize the power-split strategy of a Range Extended Battery Electric Vehicle (REBEV), using a Polymer Electron Membrane Fuel Cell (PEMFC), is proposed and preliminary studies on the effects of the driving mission profile and the auxiliary power loads on the sizing and optimal performance of the powertrain design are carried out. Dynamic Programming is used to compute the optimal energy management strategy for a given driving mission profile, providing a global optimal solution.
Technical Paper

Effect of Clamping Load on the Performance and Contact Pressure of PEMFC Stack

2018-04-03
2018-01-1310
Abstract In the assembling process of proton exchange membrane fuel cell (PEMFC) stack, the clamping load is known to have direct effect on the contact pressure of interfaces. Compression on the membrane electrode assembly (MEA) results in change in gas diffusion layer (GDL), porosity and electrical resistance, thus affecting the performance, durability and reliability of the PEMFC stack. In this paper, the relation between clamping load and performance of PEMFC stack was obtained by experimental study, and the influence of clamping load on the contact pressure of MEAs was analyzed by finite element analysis. The performance test rig was established and the approach of polarization curve testing was introduced. Both the effect of magnitude and distribution of the bolt torques on the performance were taken into account.
Technical Paper

3D Simulation of Water and Thermal Management for High Performance PEM Fuel Cell

2018-04-03
2018-01-1309
Abstract PEMFC (proton exchange membrane fuel cell) is widely regarded as the most promising candidate for the next-generation power source of automobile, after the pure battery electric vehicle. In this study, the gas and liquid two-phase flow in channels and porous electrodes inside PEMFC coupled with electro-chemical reaction are simulated in detail, in which the anisotropic GDL (gas diffusion layer) is also considered. In the simulation, the inlet reactant gas molar concentration is calculated based on the real inlet pressure, which is more practical than specifying a constant value in previous simulation. Meanwhile, the effect of electro-osmotic drag on membrane water distribution is treated to be a convection term in the conservation equation, instead of source term as usually used.
Technical Paper

Qt and QML Based HMI Widgets and OTX Scripts for Diagnostic Test Equipment

2018-04-03
2018-01-1358
Abstract Today’s road-vehicles (passenger cars, LDV, MDV and HD commercial vehicles), as well as non-road mobile machinery (NRMM), are equipped with E/E systems that consist of electronic control units, in-vehicle networks, sensors, actors, wiring, connectors, and some electrical and electrohydraulic components. Coping with the increasing complexity of these systems requires a new approach for external test equipment being deployed in the entire process chain: development with verification & validation for SOP, manufacturing/production, and after-sales service. Numerous papers are dealing with the technology of external test equipment, (remote) diagnostics, troubleshooting, guided fault finding, predictive maintenance and the standardized components, such as UDS, MVCI, ODX, and OTX. Diagnostic sequences are described in OTX and processed by an OTX runtime module. The OTX runtime module uses the MVCI D-Server API, and the D-Server processes diagnostic data which is described in ODX.
Technical Paper

Design and Control of an Automated Cooled Exhaust Gas Recirculation System for a Teaching and Research Engine Test Cell

2018-04-03
2018-01-1362
Abstract Given the need of the automotive industry to improve fuel efficiency, many companies are moving towards lean burn and low temperature combustion regimes. Critical control of these methods requires an accurate Exhaust Gas Recirculation (EGR) system that can maintain its desired rate and temperature. In this area, the literature illustrates different methodologies to control and monitor this EGR system; however, it lacks a discussion of how the non-linear nature of wave dynamics and time responses of an engine must be taken into account. In order to perform research into the use of EGR for these combustion regimes, an automated, closed-loop EGR system that uses a microprocessor to compute the slope change of the EGR rate and temperature as part of its feedback algorithm was constructed for use in a teaching and research laboratory. The findings illustrate that the system works as intended by replicating known combustion trends with EGR.
Technical Paper

Virtual Transmission Evaluation Using an Engine-in-the-Loop Test Facility

2018-04-03
2018-01-1361
Abstract This paper describes an approach to reduce development costs and time by frontloading of engineering tasks and even starting calibration tasks already in the early component conception phases of a vehicle development program. To realize this, the application of a consistent and parallel virtual development and calibration methodology is required. The interaction between vehicle subcomponents physically available and those only virtually available at that time, is achieved with the introduction of highly accurate real-time models on closed-loop co-simulation platforms (HiL-simulators) which provide the appropriate response of the hardware components. This paper presents results of a heterogeneous testing scenario containing a real internal combustion engine on a test facility and a purely virtual vehicle using two different automatic transmission calibration and hardware setups.
Technical Paper

Model-Based Guided Troubleshooting Applied to a Selective Catalytic Reduction System

2018-04-03
2018-01-1355
Abstract Troubleshooting trees are traditionally used to guide technicians through the process of identifying the cause of vehicle problems and solving them. These static trees can successfully visualize complex information. However, for modular vehicles, the trees become difficult to create and maintain due to the numerous different configurations of vehicles that can be constructed. These issues can be overcome by using a model-based approach. This paper describes a prototype tool for guided troubleshooting and shows its application to a selective catalytic reduction system used in many heavy vehicles. The troubleshooting tool guides the technician through the troubleshooting process by presenting the most likely fault candidates and recommending the most useful actions to perform. The list of candidates and recommendations are updated continuously to reflect the outcomes of past actions.
Technical Paper

Motor Resolver Fault Diagnosis for AWD EV based on Structural Analysis

2018-04-03
2018-01-1354
Abstract Electric vehicles (EVs) and hybrid electric vehicles (HEVs) are getting more attention in the automotive industry with the technology improvement and increasing focus on fuel economy. For EVs and HEVs, especially all-wheel drive (AWD) EVs with two electric motors powering front and rear axles separately, an accurate motor speed measurement through resolver is significant for vehicle performance and drivability requirement, subject to resolver faults including amplitude imbalance, quadrature imperfection and reference phase shift. This paper proposes a diagnostic scheme for the specific type of resolver fault, amplitude imbalance, in AWD EVs. Based on structural analysis, the vehicle structure is analyzed considering the vehicle architecture and the sensor setup. Different vehicle drive scenarios are studied for designing diagnostic decision logic. The residuals are designed in accordance with the results of structural analysis and the diagnostic decision logic.
Technical Paper

Structural Analysis Based Sensor Placement for Diagnosis of Clutch Faults in Automatic Transmissions

2018-04-03
2018-01-1357
Abstract This paper describes a systematic approach to identify the best sensor combination by performing sensor placement analysis to detect and isolate clutch stuck-off faults in Automatic Transmissions (AT) based on structural analysis. When an engaged clutch in the AT loses pressure during operation, it is classified as a clutch stuck-off fault. AT can enter in neutral state because of these faults; causing loss of power at wheels. Identifying the sensors to detect and isolate these faults is important in the early stage of the AT development. A universal approach to develop a structural model of an AT is presented based on the kinematic relationships of the planetary gear set elements. Sensor placement analysis is then performed to determine the sensor locations to detect and isolate the clutch stuck-off faults using speed sensors and clutch pressure sensors. The proposed approach is then applied to a 10-Speed AT to demonstrate its effectiveness.
Technical Paper

A Feedback and Feedforward Control Algorithm for a Manual Transmission Vehicle Simulation Model

2018-04-03
2018-01-1356
Abstract Authors were challenged with a task of developing a full vehicle simulation model, with a target to simulate the electrical system performance and perform digital tests like Battery Charge Balance, in addition to the fuel efficiency estimation. A vehicle is a complicated problem or domain to model, due to the complexities of subsystems. Even more difficult task is to have a control algorithm which controls the vehicle model with the required control signals to follow the test specification. Particularly, simulating the control of a vehicle with a manual transmission is complicated due to many associated control signals (Throttle, Brake and Clutch) and interruptions like gear changes. In this paper, the development of a full vehicle model aimed at the assessment of electrical system performance of the vehicle is discussed in brief.
Technical Paper

The Measures of Improving Power Generation Stability for Harvesting Automobile Exhaust Energy

2018-04-03
2018-01-1367
Abstract The automobile exhaust energy can be recovered by the thermoelectric module generator(TEG). Owing to the complex urban traffic, the exhaust gas’s temperature fluctuations are resulted, which means the unstable hot-end temperature of the TEG. By installing solid heat capacity material(SHCM) to the area between the outer wall of the exhaust pipe and the TEG, it is possible to appropriately reduce the temperature fluctuation, but there is still a fluctuation of the TEG’s power output. Then by adding voltage filter circuit (VFC) after the TEG, the power output stability can be improved. This research uses SHCM and VFC to improve the stability of the exhaust gas generation. Firstly, the three-dimensional heat transfer model of the exhaust pipe thermoelectric power generation system is established. The heat capacity materials with low thermal resistance and high heat capacity were selected as the research object based on previous research.
Technical Paper

Design and Optimization of Exhaust Gas Heat Recovery System Based on Rankine Cycle and Organic Cycles

2018-04-03
2018-01-1369
Abstract In this paper, a waste heat recovery (WHR) system is designed to recover heat from the exhaust of a diesel-gen-set having an engine of 26.57 kW. The Rankine Cycle (RC) and the Organic Rankine Cycle (ORC) are used to produce additional power using water, R113, R124 and R245fa as the working fluids. Water as the working fluid gives the best improvement of 13.8% power improvement with 12.2% bsfc reduction, but fails to produce any power at the lowest operating power of 5.8 kW due to lower exhaust temperature and higher boiling point of water. This is when the WHR system is designed at the rated power of 26.57 kW. Designing at lower power of 20.0 kW improves the enhancements at this and lower powers but reduces the improvement at the rated power of 26.57 kW. This design again fails to produce any power at the lowest power.
Technical Paper

Waste Heat Recovery System for a Turbocharged Diesel Generator at Full and Part Load Operating Conditions Using Rankine and Organic Rankine Cycles

2018-04-03
2018-01-1370
Abstract Waste Heat Recovery System (WHRS) is used to extract heat from the exhaust gas from internal combustion (IC) engines to produce additional power with increase in overall efficiency of the engine. Amongst various WHRS, this paper focuses on WHRS using Rankine Cycle (RC) and Organic Rankine Cycle (ORC). A 100 kVA (80 kW engine) diesel generator was used for this research. Water, R245fa, and R134a were used as the working fluids for the cycle. To assess the performance of WHRS, the system was designed for 80 kW, 70 kW and 60 kW loads and then, for each designed load the WHRS was run for other loads and then compared. Assessment provide simulation results of RC and ORC using Engineering Equation Solver (EES) software. It was found that using water as the working fluid around 20% additional power was achieved. But it limited the working range of the system making it unsuitable for lower loads of 10 and 20 kW for this generator.
Technical Paper

Review of Exhaust Gas Heat Recovery Mechanism for Internal Combustion Engine Using Thermoelectric Principle

2018-04-03
2018-01-1363
Abstract Automotive power packs have been the focus of research over a long period of time. Among various power packs when we consider internal combustion engines, there is an ample opportunity in developing systems that can make optimal utilization of all the energy streams related to the automotive engine. In this regard utilization of internal combustion engine exhaust waste heat and environmental pollution have been the focus of research in the recent past. About 35% of the automotive input fuel energy is converted to useful crankshaft work and about 30% energy is expelled with exhaust. This leaves about one-third (35%) of the total energy that must be transmitted from the enclosed cylinder through the cylinder walls and head to the surrounding. The exhausted energy from engine results in entropy elevation and solemn environmental pollution. So it is desired to utilize waste heat to the extent possible.
Technical Paper

Thermodynamic Performance Prediction of Air-Film Blade Cooled Gas Turbine Based Cogeneration Cycle for Marine Propulsion Applications

2018-04-03
2018-01-1364
Abstract Cogeneration involves simultaneous production of both thermal energy as well as electrical energy from a single energy conversion system. The thermal energy produced by the system is generally in the form of steam and generally used for process heating purposes. Marine gas turbine that provide propulsive power also have thermal energy in it exhaust gas stream which can be further be used to generate steam for process heating applications. Gas turbine blade cooling is critical to reliable operation of gas turbine based power utilities. A thorough literature review suggests that air-film cooling is one of the most widely used blade cooling techniques. The present study adopts few previously developed air-film cooling based gas turbine blade cooling models (without considering radiative heat transfer) and compare them with a proposed gas turbine model (which consider radiative heat transfer to gas turbine blade surface).
Technical Paper

Engine oil Thermal Management: Oil Sump Volume Modification and Heating by Exhaust Heat During ICE Warm Up

2018-04-03
2018-01-1366
Abstract In the perspective of fuel saving and emissions reduction, engine oil thermal management has not yet received the attention it deserves. Lubricating oil, in fact, should be the focus of a specific warmup action: the expected benefits is on friction reduction – mechanical efficiency improvement – but also on a positive interaction with the cooling fluid thermal dynamics. The lower thermal capacity of the circulating oil (with respect to the cooling fluid) and the instantaneous reduction of the viscosity due to temperature increase produces a faster engine overall efficiency benefit: this invites to focus specific actions on its thermal management in the direction of speeding up the temperature rise during a cold engine starting.
Technical Paper

Part-Load Performance Analysis of an Electricity-Cooling Cogeneration System for Engine Waste Heat Recovery

2018-04-03
2018-01-1375
Abstract Gaseous fuel internal combustion engines (gas engines) for electric generating are important primary movers in distributed energy systems. However, the average thermal efficiency of the gas engine is just about 30%-40% and most of the waste heat is discharged by exhaust. So it is very meaningful to recover the exhaust waste heat. Electricity-cooling cogeneration system (ECCS) inclusive of a steam Rankine cycle (RC) and an absorption refrigeration cycle (ARC) is an effective way for recovering exhaust waste heat of gas engine. Partload performance analysis of ECCS is of great significance due to the frequently varied working conditions of gas engines in practical operation. In this paper, an off-design simulation model of ECCS is firstly established by Matlab. Then the effects of the engine working condition on the performance of ECCS are analyzed by this model.
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