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Chen Zhang - One of the best experts on this subject based on the ideXlab platform.
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Trajectory-based combustion control for renewable fuels in free Piston Engines
Applied Energy, 2017Co-Authors: Chen ZhangAbstract:Previously, the authors have developed an advanced combustion control, namely the trajectory-based combustion control, to further leverage the flexibility of free Piston engine (FPE). With the assistance of this control method, the FPE enables optimization of both engine efficiency and emissions by implementing optimal Piston trajectories. Extensive simulations have been conducted to prove the effectiveness of this combustion control on fossil fuels. In this paper, the investigation is extended to renewable fuels. Seven renewable fuels are considered herein including hydrogen, biogas, syngas, ethanol, dimethyl ether (DME), biodiesel, and Fischer-Tropsch fuel. The influences of both compression ratio (CR) and Piston motion pattern between the two dead centers on the combustion process are considered in the study, which demonstrates the ultimate fuel flexibility and large tolerance of fuel impurity possessed by the FPE. In addition, the simulation results show that at a fixed CR, the thermal efficiency of the FPE can still be enhanced (5% in DME case) by varying the Piston motion patterns alone. Furthermore, specific asymmetric Piston trajectories are synthesized to further improve the engine thermal efficiency (8% in hydrogen case) and reduce the NOx emission simultaneously (around 70% reduction in hydrogen case). In other words, due to its ultimate fuel flexibility, large tolerance of fuel impurity, and controllable Piston trajectory, the FPE, with the trajectory-based combustion control, enables a co-optimization of renewable fuels and engine operation.
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A New Approach to Reduce Engine-Out Emissions Enabled by Trajectory-Based Combustion Control
Volume 1: Adaptive and Intelligent Systems Control; Advances in Control Design Methods; Advances in Non-Linear and Optimal Control; Advances in Roboti, 2015Co-Authors: Chen ZhangAbstract:Previously, the authors have proposed the concept of Piston trajectory-based combustion control enabled by free Piston Engines (FPE). With this novel control method, the FPE realizes in-cycle real-time combustion control, in terms of adjusting the ignition timing and manipulating the in-cylinder temperature trace, through various Piston trajectories and achieves higher thermal efficiency compared to the conventional internal combustion Engines. In this paper, the effects of this new combustion control on engine-out emissions are studied. First, a model is developed that includes different Piston trajectories in the FPE, a convective heat loss sub model and a reduced n-heptane reaction mechanism with major emissions species from diesel Engines. Afterwards, a new approach which reduces the engine-out emissions by employing novel Piston trajectories is described. At last, analyses of the simulation results demonstrating the variable Piston trajectories’ effects on CO and NOx emissions are presented, which further reveal the advantages of the trajectory-based combustion control.Copyright © 2015 by ASME
A P Roskilly - One of the best experts on this subject based on the ideXlab platform.
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recent commercial free Piston engine developments for automotive applications
Applied Thermal Engineering, 2015Co-Authors: R. Mikalsen, Razali M Hanipah, A P RoskillyAbstract:Free-Piston Engines have been under extensive investigation in recent years, however have not yet seen commercial success in modern applications. This paper reviews some of the recently reported commercial developments in free-Piston engine systems particularly aimed for use in hybrid electric vehicle powertrains and discuss these in light of published research. By looking at recent publications, and in particular patent documents, from major industrial players, insight into the less widely reported commercial research efforts on free-Piston Engines is obtained. Further, these publications provide a useful indication as to what these developers see as the main technical challenges for this technology.
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The control of a free-Piston engine generator. Part 1: Fundamental analyses
Applied Energy, 2010Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups due to potential fuel efficiency and exhaust emissions advantages over conventional technology. The main challenge with such Engines is the control of the Piston motion, and this has not yet been fully resolved for all types of free-Piston Engines. This paper discusses the basic features of a single Piston free-Piston engine generator under development at Newcastle University and investigates engine control issues using a full-cycle simulation model. Control variables and disturbances are identified, and a control strategy is proposed. It is found that the control of the free-Piston engine is a challenge, but that the proposed control strategy is feasible. Engine speed control does, however, represent a challenge in the current design.
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Coupled dynamic-multidimensional modelling of free-Piston engine combustion. ⋆
Applied Energy, 2009Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups worldwide, as an alternative to conventional technology in applications such as electric and hydraulic power generation. The Piston dynamics of the free-Piston engine differ significantly from those of conventional Engines, and this may influence in-cylinder gas motion, combustion and emissions formation. Due to the complex interaction between mechanics and thermodynamics, the modelling of free-Piston Engines is not straight-forward. This paper presents a novel approach to the modelling of free-Piston Engines through the introduction of solution-dependent mesh motion in an engine CFD code. The particular features of free-Piston Engines are discussed, and the model for engine dynamics implemented in the CFD code is described. Finally, the coupled solver is demonstrated through the modelling of a spark ignited free-Piston engine generator.
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performance simulation of a spark ignited free Piston engine generator
Applied Thermal Engineering, 2008Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups worldwide due to potential fuel efficiency and engine emissions advantages. The free-Piston engine generator, in which a linear electric generator is fixed to the mover to produce electric power, has been proposed as an alternative prime mover for hybrid-electric vehicles. This paper investigates the performance of a spark ignited free-Piston engine generator and compares it to a conventional engine using a computational fluid dynamics simulation model. The particular operating characteristics of the free-Piston engine were not found to give noticeable performance advantages, and it is concluded that the main potential of this technology lies in the simplicity and flexibility of the concept.
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the design and simulation of a two stroke free Piston compression ignition engine for electrical power generation
Applied Thermal Engineering, 2008Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups worldwide due to their potential advantages in terms of fuel efficiency and engine emissions. Some prototypes have emerged, mainly aimed for vehicle propulsion, and have reported favourable performance compared to conventional technology. This paper describes the design of a modular compression ignition free-Piston engine generator, applicable to electric power generation in large-scale systems. The development of a full-cycle engine simulation model is described, and extensive simulation results are presented, giving insight into engine operating characteristics and performance. The operating characteristics of the free-Piston engine was found to differ significantly from those of conventional Engines, giving potential advantages in terms of fuel efficiency and emissions formation due to fast power stroke expansion. Effects of varying engine stroke length and compression ratio were not found to give any large advantages.
R. Mikalsen - One of the best experts on this subject based on the ideXlab platform.
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recent commercial free Piston engine developments for automotive applications
Applied Thermal Engineering, 2015Co-Authors: R. Mikalsen, Razali M Hanipah, A P RoskillyAbstract:Free-Piston Engines have been under extensive investigation in recent years, however have not yet seen commercial success in modern applications. This paper reviews some of the recently reported commercial developments in free-Piston engine systems particularly aimed for use in hybrid electric vehicle powertrains and discuss these in light of published research. By looking at recent publications, and in particular patent documents, from major industrial players, insight into the less widely reported commercial research efforts on free-Piston Engines is obtained. Further, these publications provide a useful indication as to what these developers see as the main technical challenges for this technology.
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The control of a free-Piston engine generator. Part 1: Fundamental analyses
Applied Energy, 2010Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups due to potential fuel efficiency and exhaust emissions advantages over conventional technology. The main challenge with such Engines is the control of the Piston motion, and this has not yet been fully resolved for all types of free-Piston Engines. This paper discusses the basic features of a single Piston free-Piston engine generator under development at Newcastle University and investigates engine control issues using a full-cycle simulation model. Control variables and disturbances are identified, and a control strategy is proposed. It is found that the control of the free-Piston engine is a challenge, but that the proposed control strategy is feasible. Engine speed control does, however, represent a challenge in the current design.
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Coupled dynamic-multidimensional modelling of free-Piston engine combustion. ⋆
Applied Energy, 2009Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups worldwide, as an alternative to conventional technology in applications such as electric and hydraulic power generation. The Piston dynamics of the free-Piston engine differ significantly from those of conventional Engines, and this may influence in-cylinder gas motion, combustion and emissions formation. Due to the complex interaction between mechanics and thermodynamics, the modelling of free-Piston Engines is not straight-forward. This paper presents a novel approach to the modelling of free-Piston Engines through the introduction of solution-dependent mesh motion in an engine CFD code. The particular features of free-Piston Engines are discussed, and the model for engine dynamics implemented in the CFD code is described. Finally, the coupled solver is demonstrated through the modelling of a spark ignited free-Piston engine generator.
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performance simulation of a spark ignited free Piston engine generator
Applied Thermal Engineering, 2008Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups worldwide due to potential fuel efficiency and engine emissions advantages. The free-Piston engine generator, in which a linear electric generator is fixed to the mover to produce electric power, has been proposed as an alternative prime mover for hybrid-electric vehicles. This paper investigates the performance of a spark ignited free-Piston engine generator and compares it to a conventional engine using a computational fluid dynamics simulation model. The particular operating characteristics of the free-Piston engine were not found to give noticeable performance advantages, and it is concluded that the main potential of this technology lies in the simplicity and flexibility of the concept.
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the design and simulation of a two stroke free Piston compression ignition engine for electrical power generation
Applied Thermal Engineering, 2008Co-Authors: R. Mikalsen, A P RoskillyAbstract:Free-Piston Engines are under investigation by a number of research groups worldwide due to their potential advantages in terms of fuel efficiency and engine emissions. Some prototypes have emerged, mainly aimed for vehicle propulsion, and have reported favourable performance compared to conventional technology. This paper describes the design of a modular compression ignition free-Piston engine generator, applicable to electric power generation in large-scale systems. The development of a full-cycle engine simulation model is described, and extensive simulation results are presented, giving insight into engine operating characteristics and performance. The operating characteristics of the free-Piston engine was found to differ significantly from those of conventional Engines, giving potential advantages in terms of fuel efficiency and emissions formation due to fast power stroke expansion. Effects of varying engine stroke length and compression ratio were not found to give any large advantages.
Wojciech Olszewski - One of the best experts on this subject based on the ideXlab platform.
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Comparing combined gas tubrine/steam turbine and marine low speed Piston engine/steam turbine systems in naval applications
Polish Maritime Research, 2011Co-Authors: Marek Dzida, Wojciech OlszewskiAbstract:The article compares combined systems in naval applications. The object of the analysis is the combined gas turbine/steam turbine system which is compared to the combined marine low-speed Diesel engine/steam turbine system. The comparison refers to the additional power and efficiency increase resulting from the use of the heat in the exhaust gas leaving the Piston engine or the gas turbine. In the analysis a number of types of gas turbines with different exhaust gas temperatures and two large-power low-speed Piston Engines have been taken into account. The comparison bases on the assumption about comparable power ranges of the main engine.
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comparing combined gas tubrine steam turbine and marine low speed Piston engine steam turbine systems in naval applications
Polish Maritime Research, 2011Co-Authors: Marek Dzida, Wojciech OlszewskiAbstract:The article compares combined systems in naval applications. The object of the analysis is the combined gas turbine/steam turbine system which is compared to the combined marine low-speed Diesel engine/steam turbine system. The comparison refers to the additional power and efficiency increase resulting from the use of the heat in the exhaust gas leaving the Piston engine or the gas turbine. In the analysis a number of types of gas turbines with different exhaust gas temperatures and two large-power low-speed Piston Engines have been taken into account. The comparison bases on the assumption about comparable power ranges of the main engine.
Marek Dzida - One of the best experts on this subject based on the ideXlab platform.
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Comparing combined gas tubrine/steam turbine and marine low speed Piston engine/steam turbine systems in naval applications
Polish Maritime Research, 2011Co-Authors: Marek Dzida, Wojciech OlszewskiAbstract:The article compares combined systems in naval applications. The object of the analysis is the combined gas turbine/steam turbine system which is compared to the combined marine low-speed Diesel engine/steam turbine system. The comparison refers to the additional power and efficiency increase resulting from the use of the heat in the exhaust gas leaving the Piston engine or the gas turbine. In the analysis a number of types of gas turbines with different exhaust gas temperatures and two large-power low-speed Piston Engines have been taken into account. The comparison bases on the assumption about comparable power ranges of the main engine.
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comparing combined gas tubrine steam turbine and marine low speed Piston engine steam turbine systems in naval applications
Polish Maritime Research, 2011Co-Authors: Marek Dzida, Wojciech OlszewskiAbstract:The article compares combined systems in naval applications. The object of the analysis is the combined gas turbine/steam turbine system which is compared to the combined marine low-speed Diesel engine/steam turbine system. The comparison refers to the additional power and efficiency increase resulting from the use of the heat in the exhaust gas leaving the Piston engine or the gas turbine. In the analysis a number of types of gas turbines with different exhaust gas temperatures and two large-power low-speed Piston Engines have been taken into account. The comparison bases on the assumption about comparable power ranges of the main engine.