Reciprocating Internal Combustion Engine Research Articles

A Compendium of Methods for Determining the Exergy Balance Terms Applied to Reciprocating Internal Combustion Engines

Abstract Exergy analysis of the reciprocating internal combustion (IC) engines is studied by estimating various input and output energy transfer parameters concerning a dead state reference. Exergy terms such as fuel input, work output, cooling, and exhaust gas are measured and are set into the exergy balance equation to determine the amount of loss or destruction. Exergy destructions are found in many forms such as combustion (entropy generation), cylinder wall, friction, mixing, blow-by, and others. These exergy terms have been estimated by considering various factors such as engine type, fuel type, environmental condition, and others. In this article, the different methods employed in estimating these exergy terms have been reviewed. It attempts to make a compendium of these evaluation methods and segregates them under individual exergy terms with necessary descriptions. The fuel input measurement is mostly based on Gibb's free energy and the lower heating value, whereas its higher heating value is used during the fuel exergy calculation on a molar basis. The work output of the engines is estimated either from the crankshaft or by analyzing the cylinder pressure and volume. The exergy transfer with cooling medium and exhaust gas depends on the temperature of the gas. The maximum achievable engine performance is quantified by estimating the exergy efficiency. This piece of study will not only provide plenty of information on exergy evaluation methods of IC engines but will also allow future researchers to adopt the appropriate one.

Thermal-mechanical characteristics of stationary and pulsating gas-flows in a gas-dynamic system: In relation the exhaust system of an engine

It is a relevant objective in thermal physics and in building reciprocating internal combustion engines (RICE) to obtain new information about the thermal-mechanical characteristics of both stationary and pulsating gas-flows in a complex gas-dynamic system. The article discusses the physical features of the gas dynamics and heat transfer of flows along the length of a gas-dynamic system typical for RICE exhaust systems. Both an experimental set-up and experimental techniques are described. An indirect method for determining the local heat transfer coefficient of gas-flows in pipe-lines with a constant temperature hot-wire anemometer is proposed. The regularities of changes in the instantaneous values of the flow rate and the local heat transfer coefficient in time for stationary and pulsating gas-flows in different elements of the gas-dynamic system are obtained. The regularities of the change in the turbulence number of stationary and pulsating gas-flows along the length of reciprocating internal combustion engines gas-dynamic systems are established (it is shown that the turbulence number for a pulsating gas-flow is 1.3-2.1 times higher than for a stationary flow). The regularities of changes in the heat transfer coefficient along the length of the engine?s gas-dynamic system for stationary and pulsating gas-flows were identified (it was established that the heat transfer coefficient for a stationary flow is 1.05-1.4 times higher than for a pulsating flow). Empirical equations are obtained to determine the turbulence number and heat transfer coefficient along the length of the gas-dynamic system.

An innovative mechanism for transmitting power from the pistons in internal combustion engines

Reciprocating internal combustion engines are common and thus important engines due to the many advantages they provide. Despite significant improvements being made to these types of engines in recent decades, however, they still suffer from low efficiency due to large losses in produced energy, which occur for multiple reasons. The crank mechanism is responsible for much of the observed energy loss, however.In the current study, a new mechanism is suggested to transmit kinetic energy directly from the pistons, thus reducing energy losses associated with the crankshaft. This new mechanism eliminates the crankshaft from power transmission, limiting it to syncing piston movement. The pistons are then modified to mate with partial teething gears, which then transmit the kinetic energy directly from the pistons without this energy being negatively affected as it is by the angular position of the crank units. The testing results show that the power produced during the power stroke in the suggested engine is twice corresponding output of a classical engine.

ОСОБЕННОСТИ ТЕРМОМЕХАНИКИ ПУЛЬСИРУЮЩИХ ПОТОКОВ ГАЗА ВО ВПУСКНЫХ СИСТЕМАХ С КАНАВКАМИ ПРИМЕНИТЕЛЬНО К АВТОМОБИЛЬНЫМ ДВИГАТЕЛЯМ

Reciprocating internal combustion engines (RICE) are widely used as heat engines for converting the chemical energy of a fuel into mechanical work on the crankshaft. Aerodynamic and thermophysical processes in gas exchange systems significantly affect the efficiency of the RICE. This paper examines the possibility of influencing the gas dynamics and heat transfer of pulsating gas flows in the inlet system by placing a channel with grooves. It is known that the presence of grooves in the channel leads to the formation of significant secondary vortices, which radically change the physical picture of the gas flow. The studies were carried out on a laboratory bench, which was a singlecylinder model of a turbocharged RICE. A system of measurements of basic physical quantities is described, taking into account their high dynamics. Techniques for processing experimental data are presented. Primary data on instantaneous values of gas-dynamic and heatexchange characteristics of pulsating flows are presented. It was found that the presence of a channel with grooves in the inlet system leads to a decrease in the degree of turbulence to 40 % and an intensification of heat transfer in the range of 5–50 % compared to the basic inlet system. A positive effect is shown in the form of an increase in engine power by 3 % when using the modernized system.

Development of a Two-Stroke Cycle Engine for Use in the Agricultural Aviation Sector

Reciprocating internal combustion engines have wide application in agricultural, recreational and experimental aircraft, resulting from their low cost and less complex maintenance compared to other engines. Thus, this work analyzed the performance of a conventional four-stroke engine operating in the two-stroke cycle by means of direct fuel injection and mechanical air supercharging. The use of a supercharger was essential in this design to provide adequate gas exchange inside the cylinder during the long valve overlap required, while direct fuel injection made it possible to reduce the short circuit of air-fuel mixture to the exhaust. Due to the double ignition frequency compared to a four-stroke engine, it was possible to obtain a large power density (40 kW/L) at a speed of 2400 rpm, also a specific fuel consumption of 270 g/kWh with gasoline and 400 g/kWh with ethanol. The use of ethanol in replacement of gasoline made it possible to operate at full load (160 Nm/L) at 800 rpm without the occurrence of knocking combustion.

DICE-gas turbine compound reheat combined cycle

Coal-fired Direct Injection Carbon Engine – Gas Turbine (DICE-GT) Compound-Reheat Combined Cycle (CRCC), is a combined cycle power plant comprising a multiplicity of coal-fired reciprocating internal combustion engines (RICE), which is commonly referred to by the acronym DICE (Direct Injection Carbon Engine); a natural gas-fired gas turbine (turbine and combustor); a heat recovery steam generator (HRSG); a steam turbine generator; and an integrally geared and intercooled centrifugal air compressor. The concept uses coal-water slurry/fluid in the DICE and natural gas (or hydrogen) in the gas turbine for unmatched efficiency (well above 50% net LHV) and modularity (block sizes of 120, 240 and 360 MW) with easy adaptability to carbon capture and sequestration with minimal additional cost, complexity and performance hit.

Materiales de aleación aluminio-silicio aplicados en la fabricación de partes de motores de combustión interna alternativos Parte II

En este artículo se presenta un conocimiento sistematizado de la composición química, tipo de moldeo y tratamiento, propiedades mecánicas y térmicas, de las aleaciones aluminio-silicio (Al-Si) aplicadas en la fabricación de partes estructurales de los motores de combustión interna alternativos (MCIA), con el objetivo de proporcionar un fundamento para el desarrollo de investigaciones al comparar, analizar o seleccionar las aleaciones presentadas. Para lo cual, se presentó un primer artículo que dio a conocer que partes estructurales de estos tipos de motores son fabricados con aleaciones de Al-Si. En esta segunda parte se establece la importancia que tendrán las aleaciones Al-Si para reducir las emisiones de gases contaminantes, problemática que enfrenta el mundo. Ante esta situación el artículo presenta los beneficios y propiedades de las aleaciones Al-Si de las series ANSI AA 3xx.0 y 4xx.0, siendo su baja densidad la que permite un menor consumo de combustible en comparación con materiales de alta densidad, por lo que son aplicadas en partes estructurales de los MCIA Otto. También se realiza una breve descripción de la fabricación de partes de aleación de Al-Si para MCIA. Por último, se presenta la estructuración de una tabla que muestra las aleaciones ANSI AA 3xx.0 y 4xx.0 aplicadas en la fabricación de partes estructurales de MCIA Otto, concluyendo que la información técnica de las aplicaciones industriales de las aleaciones, han sido elaboradas y estructuradas de forma sistematizada, para proporcionar un conocimiento detallado y comparativo entre las propiedades.

Experimental state of thrust testing of aircraft reciprocating internal combustion engine

The project “Experimental State of Thrust Testing of Aircraft Reciprocating Internal Combustion Engine” is aimed at creating a complex measuring device in order to obtain selected characteristics and parameters of the engine using different types of propellers. In addition to the basic measured parameters such as. thrust, temperature, speed and fuel flow will be a state of the art to test the latest prototype propellers designed for aircraft models. After its construction, the experimental state will be used as a study aid for testing various types of conventional as well as currently developed propellers, engine characteristics and teaching of the whole equipment in the process of teaching, training of aircraft mechanics and for presentation purposes of the University of Žilina.

Selection of Diagnostic Symptoms and Injection Subsystems of Marine Reciprocating Internal Combustion Engines

This paper presents the planning of an experiment aimed at determining the scope of scientific research. It has been demonstrated in the conducted reliability investigations that main and auxiliary combustion engines, chosen as the objects of marine vessels, are the most unreliable components of injection apparatus as a weak link of a fuel feed functional system. The author seeks to use the minimum number of diagnostic parameters to obtain the maximum amount of information about the state of the test object. Reliability indexes, theoretical research and preliminary diagnostic tests were used to select the diagnostic signal reception points. In the initial determination of the measured quantities, the following methods were used: decomposition of the combustion engine on a functional systems, significant assemblies and elements, analysis of working and residual processes. Preliminary tests of the injection subsystem were carried out outside the internal combustion engine, as well as tests on real objects in laboratory conditions and in the conditions of marine vessels. To obtain a lot of information about the research object, a lot of diagnostic parameters were used at the beginning. On this basis, the preliminary selection of signals and diagnostic parameters related to the technical state was carried out, conducting the analysis in the various domains. Methodical and experimental diagnostic models were elaborated.

Assessment of the Quota of Recuperative Cooling of the Compressed Gas at Turbocharged Reciprocating Internal Combustion Engines

Turbocharging is a method of reducing the specific investment and raising the electrical efficiency of Reciprocating Internal Combustion Engines (RICE). The paper starts with a qualitative analysis, useful in educational purposes, about the energy flows and on the performances indices of RICE used for power generation and cogeneration. The paper continues with a statistical analysis of the manufacturers’ data for a RICE with turbochargers, useful in management purposes. The main paper’ section contains a computational model of compression and cooling air or air-gas mixture process, intended for Romanian climate. Its results are useful for RICE cogeneration.

Partial load efficiency analysis of a CCHP plant with RICE and H2O-LiBr absorption chiller

This paper presents a model for calculating and analyzing the global efficiency of a trigeneration system (CCHP) using 3 reciprocating internal combustion engines (RICE) as prime mover for heat and electric loads. RICE operate simultaneously and at the same load. The CCHP plant delivering energy for the office buildings of an economic operator includes also 2 absorption chillers with water-lithium bromide solution for air conditioning. The system has been analyzed for RICE partial load operation mode, linking the thermal energy output to the cooling power generation. The amount of thermal energy production is influenced by the required energy for cooling. The total cooling load in the summer is determined by both the indoor office-rooms cooling load and the data center cooling load (the energy dissipated by the data center’s components and electrical circuits). An vapor-compression chiller is operated for cooling peak load. During yearly thermal load variation, RICE are switched on or off, operate at nominal capacity or in partial load mode. The thermal efficiency of each engine changes according to the demanded heating load, determining the global efficiency variation of the trigeneration system.. The electrical efficiency of the system is also dependent on the RICE operating load that leads the electric generators. The EER factor for the absorption chillers results accordingly at partial or nominal load operating mode. The functioning graphics for each system equipment were developed based on the thermal load curve of the RICEs and the global efficiency variation graph of the trigeneration system was plotted. Finally, conclusions resulted regarding the optimal functioning of the studied trigeneration system.

Energy analysis of a CHP plant with internal combustion engines, for a district heating system, based on the information from the annual database

Building a model for consumption, production and efficiency of a combined heat and power (CHP) system can bring important data for planning and management activity of such a technological system. The results of this study will show the overall efficiency of a real cogeneration plant over a year. The study is based on the information from the daily database of an economic operator, during 2012. The CHP plant, having reciprocating internal combustion engines (RICE) as prime movers, provides the thermal energy to the district heating system of a city from Romania with 129,368 habitants. RICE are operating in simultaneous mode or in partial load. The numerical model reveals the behavior of the daily thermal, electrical and global efficiency, accordingly to the partial load. The model was applied in both calculation assumptions: using the lower heating value and the higher heating value of the natural gas. A statistical analysis of efficiencies of the CHP plant was made. Was performed the statistical analysis of the database efficiency (also called real efficiency) with the global efficiency calculated by the model (also called modelled efficiency). Linear and multiple regression equations explain the variance of the real efficiency and of the modelled global efficiency.

Thermal Activation of the Combustion Chamber of a Reciprocating Internal Combustion Engine

The dominant feature of the work of many specialists on the design of the internal combustion engine is to achieve the possible lowest fuel consumption, which is the most convenient measure of the efficiency of the thermodynamic cycle. From the very beginning of this heat machine, there are many of solutions that are better or worse fit to the global development trend. In this paper, the authors suggest the possibility closer to the optimal solution by introducing structural active zones, where the task is instantaneous (during one cycle) heat transfer to the skin layer on elements of the combustion chamber and to transfer part of the recovered heat to the next cycle, reaching a growth effect of the useful efficiency by 10% to 20%. The solution is different from the ones used by the fact that it is only partially insulating barrier, and the main goal is focused on supporting the next thermal cycle by which it is possible to affect as mentioned above. This paper describes the idea of the functioning of the active combustion chamber and pointed out the technical capabilities of its creation.

Control Applied to a Reciprocating Internal Combustion Engine Test Bench under Transient Operation: Impact on Engine Performance and Pollutant Emissions

This work presents a methodology to adjust the electronic control system of a reciprocating internal combustion engine test bench and the effect of the control parameters on emissions produced by the engine under two extreme situations: unadjusted and adjusted, both under transient operation. The aim is to provide a tuning guide to those in charge of this equipment not needed to be experts in control engineering. The proposed methodology covers from experimental plant modelling to control parameters determination and experimental validation. The methodology proposed includes the following steps: (i) Understanding of test bench and mathematical modeling; (ii) Model parameters identification; (iii) Control law proposal and tuning from simulation and (iv) Experimental validation. The work has been completed by presenting a comparative experimental study about the effect of the test bench control parameters on engine performance profiles (engine speed, engine torque and relative fuel air ratio) and on regulated gaseous emissions (nitrogen oxides and hydrocarbons concentrations) and the profile of number of particles emitted. The whole process, including experimental validation, has been carried out in a test bench composed of a turbocharged, with common rail injection system, light duty diesel engine coupled to a Schenck E-90 eddy current dynamometric brake and its related Schenk X-act control electronics. The work demonstrates the great effect of the test bench control tuning under transient operation on performance and emissions produced by the engine independently of the engine accelerator position demanded before and after the test bench tuning.

Performances of an ORC power unit for Waste Heat Recovery on Heavy Duty Engine

Reciprocating internal combustion engines (ICE) are still the most used in the sector of the on-the-road transportation, both for passengers and freight. CO2 reduction is the actual technological driver, considering the worldwide greenhouse reduction targets committed by most governments. In ICE more than one third of the fuel energy used is rejected to the environment as thermal waste through the exhaust gases. Therefore, a greater fuel economy could be achieved, if this energy was recovered and converted into useful mechanical or electrical power. This recovery appears very interesting, in particular for those engines that run at almost steady working conditions, like marine, agricultural, industrial or long-hauling vehicle applications.In this paper, an ORC-based power unit was tested on a heavy duty diesel engine. Energetic and exergetic analyses have been carried out in order to assess the real performances of the ORC unit and to individuate differences with the theoretical ones. A single stage impulse axial turbine has been tested in this work, complete with an electric variable speed generator and an AC/DC converter. The tests demonstrated that the energy conversion chain is not negligible at all and an overall net efficiency of the power unit was around 2-3 % with respect to a 10% of thermodynamic efficiency.

DATABASE OF RECIPROCATING INTERNAL COMBUSTION ENGINES SELECTED MANUFACTURERS

DATABASE OF RECIPROCATING INTERNAL COMBUSTION ENGINES SELECTED MANUFACTURERS

「舶用機関の騒音，固体音及び水中音の測定」の特集号によせて

「舶用機関の騒音，固体音及び水中音の測定」の特集号によせて

舶用機関の空気音と固体音の測定方法ガイドライン

舶用機関の空気音と固体音の測定方法ガイドライン

A comparison of greenhouse gas emissions and potential electricity recovery from conventional and bioreactor landfills

As methane constitutes about 50% of landfill biogas, reduction of methane emissions from municipal solid waste (MSW) landfills results in climate change mitigation. As such, it is important for a landfill lifetime model to properly reflect the manner in which biogas is managed. The goal of this research is to compare landfill biogas management in a conventional landfill with a bioreactor landfill during a 100-year time horizon. This comparison concentrates on the greenhouse gas (GHG) emissions balances and electricity generation potential from recovered biogas using reciprocating internal combustion engines (RICE), which leads to avoiding GHG emissions due to fossil fuel displacement. The results estimated that the total amount of GHG emissions released to atmosphere, including fugitive methane emissions and the avoided effect of electrical energy production, was 668 and 803 kg carbon dioxide (CO2) equivalents (CO2E) per metric ton (t) of landfilled MSW for the conventional and the bioreactor landfill, respectively. This study underscores the importance of installing an aggressive gas collection system early for bioreactor landfills, and for investigating methods of improving gas collection efficiency during active landfilling.

Method for predicting the performance of an internal combustion engine fuelled by producer gas and other low heating value gases

Gasification can be seen as a process in which solid biomass is converted into a mixture of combustible gases, which complete their combustion in a second device, usually a reciprocating internal combustion engine (RICE). Downdraft moving-bed gasifiers coupled with RICE are a good choice for moderate quantities of available biomass, the equivalent of up to 500 kW of electric power. The producer gas must be mixed with additional air in order to have a stoichiometric mixture to fuel the RICE. To predict the engine performance working with such a fuel, a so-called Engine Fuel Quality (EFQ) parameter has been developed by the authors. This parameter considers the combined effect of stoichiometric air–fuel ratio and stoichiometric mixture heating value, both depending on the producer gas composition. The estimation of engine power made by using the EFQ parameter indicates that power at full load is reduced at about two-thirds of the maximum obtained with a conventional liquid fuel. A more detailed prediction of engine performance requires the use of computer simulation of several types. The authors have used successfully a two-zone thermodynamic model to predict engine performance. Model results include the fraction of mass burned, the pressure and temperature evolution, and pollutant emissions. The detailed results for power confirm the first order prediction based on the EFQ parameter.