Turbo Compounding Research Articles

Exhaust Gas Flow Study of Electric Turbo Compounding (ETC) to Determine the Potential Electrical Energy Recovery from Exhaust Emission

Electric turbo compounding (ETC) emerges as a pivotal energy recovery solution, seamlessly combining an advanced turbocharger with a high-speed generator to harvest electrical energy from exhaust gas dynamics. This research delves into the practical application of ETC in vehicles, employing a comprehensive approach blending simulation techniques with experimental validation. The investigative process involves meticulous data collection on vehicle muffler dimensions, subsequent device modelling based on this data, and rigorous flow simulations, followed by thorough analysis. The study's key findings highlight a noteworthy 9% increase in engine back pressure at 850 rpm, counterbalanced by a 7% reduction at 2000 rpm. Despite the integration of the ETC mechanism, electric current measurements remain consistently within the range of 1.4 to 1.6 amperes at 1200-2000 rpm. This research not only unveils the tangible effects of ETC on engine performance but also underscores its viability as an efficient energy recovery solution in the automotive sector, setting the stage for advancements in sustainable transportation.

ELECTRIC TURBO COMPOUNDING (ETC) AS EXHAUST ENERGY RECOVERY SYSTEM ON VEHICLE

The utilization of exhaust gas flow with Electric Turbo Compounding (ETC) mechanism is applied on this research. On this mechanism, the exhaust gas flow is used to rotate the alternator. The ETC installation is designed to prevent the produce of a back pressure effect which disturbs the engine performance. This mechanism was chosen based on literature study that had been done previously to the exhaust gas flow utilization mechanism on several vehicles. As the result, the ETC mechanism is the most suitable to be developed on passenger vehicles with small capacities. The power transfer process on ETC uses a gear mechanism with 2:1 ratio to increase input rotation of the generator. From the test result, the charging current is 1.25-1.48 A at 850-2.000 rpm engine speed. It is such a quite low number when compared to the normal charging system, which is 6.23 – 8.1 A at 1.200 – 2.000 rpm engine speed. Nevertheless, for the waste energy utilization, this number is much more promising to be developed in the future. From the result of this research, it is known that the installation of the ETC mechanism can be a solution for vehicle’s wasted energy utilization on exhaust gas flow form even the amount of flow generated is small.

Review of Small Gas Turbine Engines and Their Adaptation for Automotive Waste Heat Recovery Systems

Current commercial and heavy-duty powertrains are geared towards emissions reduction. Energy recovery from exhaust gases has great potential, considering the mechanical work to be transferred back to the engine. For this purpose, an additional turbine can be implemented behind a turbocharger; this solution is called turbocompounding (TC). This paper considers the adaptation of turbine wheels and gearboxes of small turboshaft and turbojet engines into a two-stage TC system for a six-cylinder opposed-piston engine that is currently under development. The initial conditions are presented in the first section, while a comparison between small turboshaft and turbojet engines and their components for TC is presented in the second section. Based on the comparative study, a total number of 7 turbojet and 8 turboshaft engines were considered for the TC unit.

Mechanical and Electromagnetic Analysis of High Speed Motor/Generator for Electric Turbo Compounding System

Background: Recently, environment friendly technologies are being introduced as global warming is rapidly progressing. One of the effective way to reduce the problem, Electric Turbo Compounding System has been researched globally. With this system, about 30% exhaust gas can be recycled as a power source. Therefore, this system is effective for engine systems with purposes such as downsizing and increasing efficiency of the system. Objective & Method: Surface mounted Permanent Magnet Motor is applied to this system due to its high efficiency, power density, small size, and low weight. However, during high speed operation, a retaining sleeve is essential in rotor such as Inconel 718 to satisfy a mechanical safety factor of the rotor. In this paper, through basic theory, the sleeve thickness is predicted according to the permanent magnet dimension and minimum sleeve thickness is determined satisfying mechanical safety factor by mechanical analysis. Furthermore, by electromagnetic analysis output characteristics according to the permanent magnet dimension having same constraints such as volume, current density, current and flux distribution are compared. Result & Conclusion: Based on the results of the electromagnetic analysis and mechanical analysis, the appropriate ratio of electric and magnetic loading is determined with equivalent constraint condition. Consequently, only model 2 satisfies the requirement at rated and maximum speed within the current limit.

Exergy Analysis of Organic Rankine Cycle and Electric Turbo Compounding for Waste Heat Recovery

With such tough legislation on current emission standards, car manufacturers are focusing on increasing the efficiency of their engines with the development of advance waste heat recover (WHR) technology. Organic Rankine Cycle (ORC) and Electric Turbo Compounding (ETC) system have a good potential to be used as exhaust energy recovery. This paper compares the exergy availability and losses between the ORC and the ETC. In this particular study, exhaust data from the Proton 1.6L CamPro CFE turbocharged engine was used. This particular engine already has a main turbocharger, making the added WHR as a secondary recovery system to further increase the engine efficiency. Both systems are coupled to a 1 kW electric generator for ease of comparisons. At first the available exergy is calculated for both WHR technologies. Exergy losses from rotating the generator are analysed to finally determine the thermal efficiency of the overall system. Exergy calculation is simplified to only account for chemical and physical exergy since kinetic and potential energy are negligible in comparison. Available exergy for ORC was significantly high which went up to 12.5 kW with the exergy losses recorded at 9.7 kW. The ETC achieved only 5 kW but had a small loss at 8x10-3 kW. Average thermal efficiency of the ORC systems was 10.7% compared to ETC which was 58.7%. It can be concluded that the complexity of the ORC system contributes to its downfall where multiple components increase its exergy losses compared to the simplistic design of an ETC.

Exhaust Energy Recovery with Turbo Compounding in a Heavily Downsized Engine

Large amount of heat energy is wasted in Internal Combustion (IC) engine through the exhaust manifold, coolant, convective and radiative heat transfer. Significant amount of thermal energy waste occurring at the exhaust manifold of the IC engine can be recovered using various contemporary heat recovering techniques. The paper presented the viability of using turbo compounding waste heat recovering technique in recovering a significant amount of waste energy occurring at the exhaust of a heavily downsized engine. Electric turbo compounding (ETC) simulation using Ford Eco-Boost base line engine with modification using Hy-Boost modelled with AVL Boost software was carried out for the analysis. The simulation results show a 3% reduction in Brake Specific Fuel Consumption (BSFC), 0.5 bar Brake Mean Effective Pressure (BMEP) increase and up to 2 kW of power output were realized at engine speed of 2500 rpm. The result clearly indicates the effectiveness, viability and commercialization potentials of this waste heat recovery technique.

Simulation Study on Electric Turbo-Compound (ETC) for Thermal Energy Recovery in Turbocharged Internal Combustion Engine

Exhaust gas heat utilization in the form of Thermal Energy Recovery (TER) has attracted a major interest due to its potentials with Internal Combustion Engines (ICE). Recovering useful energy, for example in the form of electrical power from the engine exhaust waste heat could benefit in the form of direct fuel economy or increase in the available electric power for the auxillary systems. The methodology in this paper includes the assessment of each waste heat recovery technology based on the current research and development trends for automotive application. It also looked into the potential for energy recovery, performances of each technology and factors affecting its implementation. Finally, the work presents an Electric Turbo Compounding (ETC) simulation using a Ford Eco-Boost as a baseline engine modeled with the 1-Dimensional AVL Boost software. A validated 1-D engine model was used to investigate the impact on the Brake Specific Fuel Consumption (BSFC) and Brake Mean Effective Pressure (BMEP) at full load. This paper presents some reviews on the turbo-compounding method and also the modelling efforts and results of an electric turbo-compounding system. Modelling shows that the turbo-compounding setup can be more beneficial than turbo-charging alone.

Review of Waste Heat Recovery Mechanisms for Internal Combustion Engines

The demand for more fuel efficient vehicles has been growing steadily and will only continue to increase given the volatility in the commodities market for petroleum resources. The internal combustion (IC) engine utilizes approximately one third of the chemical energy released during combustion. The remaining two-thirds are rejected from the engine via the cooling and exhaust systems. Significant improvements in fuel conversion efficiency are possible through the capture and conversion of these waste energy streams. Promising waste heat recovery (WHR) techniques include turbocharging, turbo compounding, Rankine engine compounding, and thermoelectric (TE) generators. These techniques have shown increases in engine thermal efficiencies that range from 2% to 20%, depending on system design, quality of energy recovery, component efficiency, and implementation. The purpose of this paper is to provide a broad review of the advancements in the waste heat recovery methods; thermoelectric generators (TEG) and Rankine cycles for electricity generation, which have occurred over the past 10 yr as these two techniques have been at the forefront of current research for their untapped potential. The various mechanisms and techniques, including thermodynamic analysis, employed in the design of a waste heat recovery system are discussed.

Effectiveness of Mechanical Turbo Compounding in a Modern Heavy-Duty Diesel Engine

Effectiveness of Mechanical Turbo Compounding in a Modern Heavy-Duty Diesel Engine