scholarly journals The Potential of Wobble Plate Opposed Piston Axial Engines for Increased Efficiency

Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5598
Author(s):  
Paweł Mazuro ◽  
Barbara Makarewicz
Keyword(s):  
Internal Combustion Engines ◽  
Mechanical Efficiency ◽  
Ease Of Use ◽  
Compression Ignition ◽  
Port Area ◽  
Auto Ignition ◽  
Engine Design ◽  
Torque Curve ◽  
Phase Out ◽  
Scavenging Efficiency

Recent announcements regarding the phase out of internal combustion engines indicate the need to make major changes in the automotive industry. Bearing in mind this innovation trend, the article proposes a new approach to the engine design. The aim of this paper is to shed a new light on the forgotten concept of axial engines with wobble plate mechanism. One of their most important advantages is the ease of use of the opposed piston layout, which has recently received much attention. Based on several years of research, the features determining the increase in mechanical efficiency, lower heat losses and the best scavenging efficiency were indicated. Thanks to the applied Variable Compression Ratio (VCR), Variable Angle Shift (VAS) and Variable Port Area (VPA) systems, the engine can operate on various fuels in each of the Spark Ignition (SI), Compression Ignition (CI) and Homogeneous Charge Compression Ignition (HCCI)/Controlled Auto Ignition (CAI) modes. In order to quantify the potential of the proposed design, an initial research of the newest PAMAR 4 engine was presented to calculate the torque curve at low rotational speeds. The achieved torque of 500 Nm at 500 rpm is 65% greater than the maximum torque of the OM 651 engine of the same 1.8 L capacity. The findings lead to the conclusion that axial engines are wrongfully overlooked and can significantly improve research on new trends in pollutant elimination.

scholarly journals Numerical investigation on low calorific syngas combustion in the opposed-piston engine

2017 ◽  
Vol 169 (2) ◽  
pp. 53-63
Author(s):  
Rafał PYSZCZEK ◽  
Paweł MAZURO ◽  
Agnieszka JACH ◽  
Andrzej TEODORCZYK
Keyword(s):  
Compression Ratio ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Calorific Value ◽  
Mechanical Efficiency ◽  
Piston Engine ◽  
Engine Operation ◽  
Excessive Heat ◽  
Gaseous Fuels ◽  
Auto Ignition

The aim of this study was to investigate a possibility of using gaseous fuels of a low calorific value as a fuel for internal combustion engines. Such fuels can come from organic matter decomposition (biogas), oil production (flare gas) or gasification of materials containing carbon (syngas). The utilization of syngas in the barrel type Opposed-Piston (OP) engine arrangement is of particular interest for the authors. A robust design, high mechanical efficiency and relatively easy incorporation of Variable Compression Ratio (VCR) makes the OP engine an ideal candidate for running on a low calorific fuel of various compostion. Furthermore, the possibility of online compression ratio adjustment allows for engine the operation in Controlled Auto-Ignition (CAI) mode for high efficiency and low emission. In order to investigate engine operation on low calorific gaseous fuel authors performed 3D CFD numerical simulations of scavenging and combustion processes in the 2-stroke barrel type Opposed-Piston engine with use of the AVL Fire solver. Firstly, engine operation on natural gas with ignition from diesel pilot was analysed as a reference. Then, combustion of syngas in two different modes was investigated – with ignition from diesel pilot and with Controlled Auto-Ignition. Final engine operating points were specified and corresponding emissions were calculated and compared. Results suggest that engine operation on syngas might be limited due to misfire of diesel pilot or excessive heat releas which might lead to knock. A solution proposed by authors for syngas is CAI combustion which can be controlled with application of VCR and with adjustment of air excess ratio. Based on preformed simulations it was shown that low calorific syngas can be used as a fuel for power generation in the Opposed-Piston engine which is currently under development at Warsaw University of Technology.

scholarly journals A review of technical solutions for RCCI engines

2021 ◽  
Author(s):  
Grzegorz Szamrej ◽  
Mirosław Karczewski ◽  
Janusz Chojnowski
Keyword(s):  
Internal Combustion Engines ◽  
Full Range ◽  
Fuel Mixture ◽  
Combustion Efficiency ◽  
Compression Ignition ◽  
Compression Ignition Engines ◽  
Auto Ignition ◽  
Temperature Method ◽  
Homogenous Charge Compression Ignition ◽  
Technical Solutions

Nowadays, internal combustion engines are being developed in the directions that allow to maximize the efficiency of their work, in order to make the most economical use of fuels. The low-temperature method of burning fuels in HCCI engines - Homogenous Charge Compression Ignition - allows to improve the efficiency of the engine, thanks to the reduction of energy lost during cobustion process. For the further development of engines with this type of mixture auto-ignition, with increasing the range of fuels used for that king of engines, it is necessary to develop the RCCI engines. Reactivity-Controlled Compression Ignition - RCCI - is the way to control the air-fuel mixture auto-ignition by using the injection of second fuel injected into the combustion chamber before the combustion begins. The development of modern compression ignition engines is strongly dependent on engines with this type of ignition. Using two fuels with different physicochemical properties makes it possible to control the time of compression ignition and allows to use engine in full range of operation. RCCI is a special type of HCCI engine that allows to use many types of fuels with high combustion efficiency and low emission of harmful exhaust components. The paper analyzes the issues related to the adoption and development of engines with this method of ignition.

Investigating realistic anode off-gas combustion in SOFC/ICE hybrid systems: mini review and experimental evaluation

2021 ◽  
pp. 146808742110583
Author(s):  
Ioannis Nikiforakis ◽  
Zhongnan Ran ◽  
Michael Sprengel ◽  
John Brackett ◽  
Guy Babbit ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
Internal Combustion Engines ◽  
Engine Performance ◽  
High Energy ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Case Scenario ◽  
Gas Combustion ◽  
Thermodynamic Conditions ◽  
Decentralized Energy

Solid oxide fuel cells (SOFCs) have been deployed in hybrid decentralized energy systems, in which they are directly coupled to internal combustion engines (ICEs). Prior research indicated that the anode tailgas exiting the SOFC stack should be additionally exploited due to its high energy value, with typical ICE operation favoring hybridization due to matching thermodynamic conditions during operation. Consequently, extensive research has been performed, in which engines are positioned downstream the SOFC subsystem, operating in several modes of combustion, with the most prevalent being homogeneous compression ignition (HCCI) and spark ignition (SI). Experiments were performed in a 3-cylinder ICE operating in the latter modus operandi, where the anode tailgas was assimilated by mixing syngas (H2: 33.9%, CO: 15.6%, CO2: 50.5%) with three different water vapor flowrates in the engine’s intake. While increased vapor content significantly undermined engine performance, brake thermal efficiency (BTE) surpassed 34% in the best case scenario, which outperformed the majority of engines operating under similar operating conditions, as determined from the conducted literature review. Nevertheless, the best performing application was identified operating under HCCI, in which diesel reformates assimilating SOFC anode tailgas, fueled a heavy duty ICE (17:1), and gross indicated thermal efficiency ([Formula: see text]) of 48.8% was achieved, with the same engine exhibiting identical performance when operating in reactivity-controlled compression ignition (RCCI). Overall, emissions in terms of NOx and CO were minimal, especially in SI engines, while unburned hydrocarbons (UHC) were non-existent due to the absence of hydrocarbons in the assessed reformates.

A Converted Two-Stroke Cycle Engine for Compression Ignition Combustion

2014 ◽  
Vol 663 ◽  
pp. 331-335 ◽  
Author(s):  
Amin Mahmoudzadeh Andwari ◽  
Azhar Abdul Aziz ◽  
Mohd Farid Muhamad Said ◽  
Zulkarnain Abdul Latiff
Keyword(s):  
Internal Combustion Engines ◽  
Exhaust Gas Recirculation ◽  
Exhaust Emissions ◽  
Exhaust Gas ◽  
Cyclic Variation ◽  
Cyclic Variability ◽  
Auto Ignition ◽  
Compression Ignition Combustion ◽  
Gas Recirculation ◽  
Stroke Cycle

A new kind of alternative combustion concept that has attracted attention intensively in recent years is called controlled auto-ignition (CAI) combustion. CAI combustion has been proposed and partially implemented with the aim of both improving the thermal efficiency of internal combustion engines, achieving cleaner exhaust emissions and lower cyclic variation. An experimental study is conducted through a CAI two-stroke cycle engine in order to investigate the influence of internal exhaust gas recirculation (In-EGR) and external exhaust gas recirculation (Ex-EGR) variation in relation to combustion cyclic variability and exhaust emissions characteristics. Results implied that cyclic variation of both combustion-related and pressure-related parameter is substantially improved. Furthermore remarkable decreased exhaust emissions, unburned hydrocarbon (uHC), carbon monoxide (CO) and nitric dioxide (NOX), was observed.

Model Based Design and Optimization for Large Bore Engines: Some Industrial Case Studies

2017 ◽  
Author(s):  
Prashant Srinivasan ◽  
Sanketh Bhat ◽  
Manthram Sivasubramaniam ◽  
Ravi Methekar ◽  
Maruthi Devarakonda ◽  
...  
Keyword(s):  
System Design ◽  
Case Studies ◽  
Control Strategy ◽  
Internal Combustion Engines ◽  
Cost Optimization ◽  
Engine Performance ◽  
Design And Optimization ◽  
Model Based ◽  
Performance Requirements ◽  
Engine Design

Large bore reciprocating internal combustion engines are used in a wide variety of applications such as power generation, transportation, gas compression, mechanical drives, and mining. Each application has its own unique requirements that influence the engine design & control strategy. The system architecture & control strategy play a key role in meeting the requirements. Traditionally, control design has come in at a later stage of the development process, when the system design is almost frozen. Furthermore, transient performance requirements have not always been considered adequately at early design stages for large engines, thus limiting achievable controller performance. With rapid advances in engine modeling capability, it has now become possible to accurately simulate engine behavior in steady-states and transients. In this paper, we propose an integrated model-based approach to system design & control of reciprocating engines and outline ideas, processes and real-world case studies for the same. Key benefits of this approach include optimized engine performance in terms of efficiency, transient response, emissions, system and cost optimization, tools to evaluate various concepts before engine build thus leading to significant reduction in development time & cost.

Experimental Investigation of a Novel Combined Rapid Compression-Ignition Combustion and Solid Oxide Fuel Cell System Format Operating on Diesel

2021 ◽  
Author(s):  
Andrew Ahn ◽  
Thomas Stone Welles ◽  
Benjamin Akih-Kumgeh ◽  
Ryan J. Milcarek
Keyword(s):  
Fuel Cell ◽  
Internal Combustion Engines ◽  
Cell System ◽  
Solid Oxide ◽  
Compression Ignition ◽  
Oxide Fuel ◽  
Fuel Cell System ◽  
Cell Systems ◽  
Fuel Reformation ◽  
Rapid Compression

Abstract Climate change concerns have forced the automotive industry to develop more efficient powertrain technologies, including the potential for fuel cell systems. Solid oxide fuel cells (SOFCs) demonstrate exceptional fuel flexibility and can operate on conventional, widely available hydrocarbon fuels with limited requirements for fuel reformation. Current hybrid powertrains combining fuel cell systems with internal combustion engines (ICEs) fail to mitigate the disadvantages of requiring fuel reformation by placing the engine downstream of the fuel cell system. This work, thus investigates the upstream placement of the engine, eliminating the need for fuel processing catalysts and the heating of complex fuel reformers. The ICE burns a fuel-rich mixture through rapid compression ignition, performing partial oxidation fuel reformation. To test the feasibility of a fuel cell system operating on such ICE exhaust, chemical kinetic model simulations were performed, creating model exhaust containing ∼43.0% syngas. A micro-tubular SOFC (μT-SOFC) was tested for power output with this exhaust, and generated ∼730 mW/cm2 (∼86% of its maximum output obtained with pure hydrogen fuel). Combustion testing was subsequently performed in a test chamber, and despite insufficient equipment limiting the maximum pressure of the combustion chamber, began to validate the model. The exhaust from these tests contained all of the predicted chemical species and, on average, ∼21.8% syngas, but would have resembled the model more closely given higher pressures. This work examines the viability of a novel combined ICE and fuel cell hybrid system, displaying potential for a more cost-effective/efficient solution than current fuel cell systems.

Low Cetane Fuels in Compression Ignition Engine to Achieve LTC

2011 ◽  
Author(s):  
Swami Nathan Subramanian ◽  
Stephen Ciatti
Keyword(s):  
Low Temperature ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Fuel Efficiency ◽  
Nox Emissions ◽  
Low Temperature Combustion ◽  
Compression Ignition ◽  
Oxides Of Nitrogen ◽  
Compression Ignition Engine ◽  
Conventional Combustion

The conventional combustion processes of Spark Ignition (SI) and Compression Ignition (CI) have their respective merits and demerits. Internal combustion engines use certain fuels to utilize those conventional combustion technologies. High octane fuels are required to operate the engine in SI mode, while high cetane fuels are preferable for CI mode of operation. Those conventional combustion techniques struggle to meet the current emissions norms while retaining high efficiency. In particular, oxides of nitrogen (NOx) and particulate matter (PM) emissions have limited the utilization of diesel fuel in compression ignition engines, and conventional gasoline operated SI engines are not fuel efficient. Advanced combustion concepts have shown the potential to combine fuel efficiency and improved emissions performance. Low Temperature Combustion (LTC) offers reduced NOx and PM emissions with comparable modern diesel engine efficiencies. The ability of premixed, low-temperature compression ignition to deliver low PM and NOx emissions is dependent on achieving optimal combustion phasing. Variations in injection pressures, injection schemes and Exhaust Gas Recirculation (EGR) are studied with low octane gasoline LTC. Reductions in emissions are a function of combustion phasing and local equivalence ratio. Engine speed, load, EGR quantity, compression ratio and fuel octane number are all factors that influence combustion phasing. Low cetane fuels have shown comparable diesel efficiencies with low NOx emissions at reasonably high power densities.

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