scholarly journals Simplified calculation of friction mean effective pressure for fast simulation of fuel consumption

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Georg Finger
Keyword(s):  
Fuel Consumption ◽  
Simulation Software ◽  
Exhaust Gas ◽  
Effective Pressure ◽  
Gas Treatment ◽  
Improve Efficiency ◽  
Detailed Simulation ◽  
Reduce Emissions ◽  
Gas Recirculation ◽  
Simplified Calculation

AbstractAn environmentally friendly and economical ship operation can be accomplished through many different methods. Most of these approaches focus on technological solutions, e.g. internal engine measures in order to make the engine more eco-friendly, by changing engine control parameters for a better connection between propulsion system and ship, by usage of different fuels or fuel supplements or installation of exhaust gas-treatment systems. For many ships, it is neither efficient nor economically viable to replace or improve existing power generation or propulsion systems in order to improve efficiency or reduce emissions. Some of the internal measures used to reduce NOx-emissions like exhaust gas recirculation even lead to a higher fuel consumption. The vessel itself is still controlled by a crew and they should be kept in the loop to improve efficiency. Therefore optimal operational procedures for handling ships and specifically the outcome of engine manoeuvres is a substantial source for eco-friendly ship operations. The German research project MEmBran (Modelling Emissions and Fuel Consumption during Ship Manoeuvres) addresses especially the basis for optimising ship engine manoeuvres. It focusses on very detailed simulation of the processes of currently existing ship diesel engines, especially in a first step 4-stroke engines in order to implement models in wider comprehensive ship handling simulation software. As part of an existing planning and prediction software that can be used on board, it enables the watch keeping nautical officer and the shipping company to forecast and compare the fuel consumption of the ship for each manoeuvre. In order to reach this goal it is necessary to use fast calculating and stable methods that can be used to forecast the power output of the engine and the fuel consumption. This paper discusses an approach to calculate friction mean effective pressure.

A Computational Investigation of Piston Bowl Geometry for a Large Bore Two-Cycle Diesel Engine

2011 ◽  
Author(s):  
Jonathan Dolak ◽  
Deep Bandyopadhyay
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Simulation Software ◽  
Spray Angle ◽  
Tier 2 ◽  
Piston Bowl ◽  
Cylinder Test ◽  
Advanced Combustion ◽  
Combustion Simulation ◽  
Reduce Emissions

The objective of this research was to optimize an Electro-Motive Diesel (EMD) large-bore, two-cycle diesel engine (710 cubic inches of displacement per cylinder) at high load to minimize soot, nitrogen oxide (NOx) and fuel consumption. The variables considered were the number of spray-hole nozzles per injector, including spray angle and piston bowl geometry, for a range of injection pressures. Analytical simulations were conducted for a calibrated EMD 710 Tier 2 engine and a few of the top-performing cases were studied in detail. CONVERGE™, a commercially available, advanced combustion simulation software was used in this analysis. A surface deforming tool, Sculptor®, was used to obtain various piston bowl geometries. MiniTab® was utilized for statistical analysis. Results show that optimal combinations of injection variables and piston bowl shape exist to simultaneously reduce emissions and fuel consumption compared to Tier 2 EMD 710 engines. These configurations will be further tested in a single-cylinder test cell and presented later. This investigation shows the importance of bowl geometry and spray targeting on emissions and fuel consumption for large-bore, two-stroke engines with high power density.

scholarly journals Ensuring Requirements for Emissions of Harmful Substances of Diesel Engines

2020 ◽  
Vol 19 (4) ◽  
pp. 305-310
Author(s):  
G. M. Kuharonak ◽  
D. V. Kapskiy ◽  
V. I. Berezun
Keyword(s):  
Diesel Engine ◽  
Nitrogen Oxides ◽  
Fuel Consumption ◽  
Exhaust Gas Recirculation ◽  
Exhaust Gas ◽  
Average Temperature ◽  
Dispersed Particles ◽  
Harmful Substances ◽  
Gas Recirculation ◽  
Emissions Of Harmful Substances

The purpose of this work is to consider the requirements for emissions of harmful substances of diesel engines by selecting design and adjustment parameters that determine the organization of the workflow, and the exhaust gas cleaning system, taking into account the reduction of fuel consumption. Design elements and geometric characteristics of structures for a turbocharged diesel engine of Д-245 series produced by JSC HMC Minsk Motor Plant (4ЧН11/12.5) with a capacity of 90 kW equipped with an electronically controlled battery fuel injection have been developed: exhaust gas recirculation along the high pressure circuit, shape and dimensions of the combustion chamber, the number and angular arrangement of the nozzle openings in a nozzle atomizer, and inlet channels of the cylinder head. Methods for organizing a workflow are proposed that take into account the shape of the indicator diagrams and affect the emissions of nitrogen oxides and dispersed particles differently. Their implementation allows us to determine the boundary ranges of changes in the control parameters of the fuel supply and exhaust gas recirculation systems when determining the area of minimizing the specific effective fuel consumption and the range of studies for the environmental performance of a diesel engine. The paper presents results of the study on the ways to meet  the requirements for emissions of harmful substances, obtained by considering options for the organization of working processes, taking into account the reduction in specific effective fuel consumption, changes in the average temperature of the exhaust gases and diesel equipment. To evaluate these methods, the following indicators have been identified: changes in specific fuel consumption and average temperature of the toxicity cycle relative to the base cycle, the necessary degree of conversion of the purification system for dispersed particles and NOx. Recommendations are given on choosing a diesel engine to meet Stage 4 emission standards for nitrogen oxides and dispersed particles.

Emission reduction through internal and low-pressure loop exhaust gas recirculation configuration with negative valve overlap and late intake valve closing strategy in a compression ignition engine

2017 ◽  
Vol 18 (10) ◽  
pp. 973-990 ◽  
Author(s):  
Jaeheun Kim ◽  
Choongsik Bae
Keyword(s):  
High Pressure ◽  
Nitrogen Oxides ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Exhaust Gas ◽  
Effective Pressure ◽  
Intake Valve ◽  
Trade Off ◽  
Indicated Mean Effective Pressure ◽  
Gas Recirculation

An investigation was carried out to examine the feasibility of replacing the conventional high-pressure loop/low-pressure loop exhaust gas recirculation with a combination of internal and low-pressure loop exhaust gas recirculation. The main objective of this alternative exhaust gas recirculation path configuration is to extend the limits of the late intake valve closing strategy, without the concern of backpressure caused by the high-pressure loop exhaust gas recirculation. The late intake valve closing strategy improved the conventional trade-off relation between nitrogen oxides and smoke emissions. The gross indicated mean effective pressure was maintained at a similar level, as long as the intake boosting pressure kept changing with respect to the intake valve closing timing. Applying the high-pressure loop exhaust gas recirculation in the boosted conditions yielded concern of the exhaust backpressure increase. The presence of high-pressure loop exhaust gas recirculation limited further intake valve closing retardation when the negative effect of increased pumping work cancelled out the positive effect of improving the emissions’ trade-off. Replacing high-pressure loop exhaust gas recirculation with internal exhaust gas recirculation reduced the burden of such exhaust backpressure and the pumping loss. However, a simple feasibility analysis indicated that a high-efficiency turbocharger was required to make the pumping work close to zero. The internal exhaust gas recirculation strategy was able to control the nitrogen oxides emissions at a low level with much lower O2 concentration, even though the initial in-cylinder temperature was high due to hot residual gas. Retardation of intake valve closing timing and intake boosting contributed to increasing the charge density; therefore, the smoke emission reduced due to the higher air–fuel ratio value exceeding 25. The combination of internal and low pressure loop loop exhaust gas recirculation with late intake valve closing strategy exhibited an improvement on the trade-off relation between nitrogen oxides and smoke emissions, while maintaining the gross indicated mean effective pressure at a comparable level with that of the high-pressure loop exhaust gas recirculation configuration.

Effect of Exhaust Back Pressure on Performance and Emission Characteristics of Diesel Engine Equipped with Diesel Oxidation Catalyst and Exhaust Gas Recirculation

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Sangamesh Bhure
Keyword(s):  
Fuel Consumption ◽  
Exhaust System ◽  
Diesel Oxidation Catalyst ◽  
Back Pressure ◽  
Oxidation Catalyst ◽  
Exhaust Gas ◽  
Performance And Emission ◽  
Diesel Oxidation ◽  
Gas Recirculation ◽  
Exhaust Valves

Currently the emission norms are becoming more stringent, continuous modifications are taking place in existing I.C engines as well as in after treatment devices (ATDs). Exhaust Gas Recirculation (EGR) and Diesel Oxidation Catalyst (DOC) are the mandatory ATDs controlled electronically to optimize engine brake power, fuel consumption and emissions. The conversion efficiency of ATDs mainly depends on exhaust pressure, temperature, flow rate and fluid characteristics of exhaust gas. However, the installation of ATDs increases the exhaust back pressure in the exhaust system. The back pressure of engine also depends on the parameters like engine operating conditions, design of exhaust valves, valve lift time, exhaust gas dynamics and exhaust manifold design etc. In this paper the attempt is made to study the effect of back pressure on performance and emission of diesel engines equipped with EGR and DOC. Here we have not modified the intake and exhaust valves instead, we varied the back pressure of exhaust system using back pressure control valve (BPCV). BPCV is operated manually at three positions, they are 100%, 87.5% and 75% BPCV lifts. The readings are taken in different combinations of BPCV lifts and brake torque at 20, 40, 60, and 80 N-m. The results obtained shows variation of BPCV lift and brake torque effected on performance of engine, DOC and EGR operations as well as fuel consumption. The NOx is reduced by 15%; HC and CO are reduced significantly. However, there is an increase in brake specific fuel consumption (BSFC) and exhaust smoke.

scholarly journals ЗАСТОСУВАННЯ ГАЗОДИНАМІЧНОГО ОХОЛОДЖЕННЯ В СИСТЕМАХ РЕЦИРКУЛЯЦІЇ ВІДХІДНИХ ГАЗІВ СУДНОВИХ ДИЗЕЛІВ

2019 ◽  
pp. 81-86
Author(s):  
Дмитро Вікторович Коновалов
Keyword(s):  
Fuel Consumption ◽  
Exhaust Gas Recirculation ◽  
Back Pressure ◽  
Specific Fuel Consumption ◽  
Design Solution ◽  
Exhaust Gas ◽  
Engine Fuel ◽  
Gas Dynamics Equations ◽  
Exhaust Gases ◽  
Gas Recirculation

There are many ways and methods to reduce exhaust gases emissions on modern ships. One of the most effective ways to reduce NOx and SOx emissions is to use of exhaust gas recirculation (EGR technology). The EGR system disadvantage is an increase in back pressure through additional pressure losses in the scrubber and heat ex-changer, which entails an engine fuel efficiency deterioration. Creating a reliable and efficient heat exchanger for cooling recirculation gases is a complex task due to deposits and pollution emitted by these gases. In the pre-sent work, the jet apparatus effectiveness named aerothermopressor is analyzed in the scheme with exhaust gases recirculation of the ship low-speed two-stroke engine. Aerothermopressor is a two-phase jet for contact disperse cooling, in which by increasing the heat from the gas stream the gas pressure and cooling are increased. The calculation of the characteristics of the engine was carried out, both in nominal, and in operating modes and in all possible range of partial loads. The installation of the aerothermopressor before the scrubber is pro-posed, which allows reducing engine thermal load. Increasing the pressure in the aerothermopressor by 0.2-0.4 ∙ 105 Pa (6-12 %) allows reducing the back pressure in the gas exhaust system and thus reducing the load on the exhaust gas recirculation fan and when the engine load is higher than 75% in the cold zone, the fan is not need-ed, which additionally allows to reduce the specific fuel consumption. The parameters of the exhaust gases that are going to be recirculated and the processes of their gas-dynamic cooling in the aerothermopressor are based on the developed technique and program using the thermodynamic and gas dynamics equations. The proposed scheme-design solution allows at a high environmental friendliness of the existing exhaust gas recirculation sys-tem to provide a certain reduction in specific fuel consumption. It was determined that the engine specific fuel consumption has been decreasing when the aerothermopressor is used to Dge = 2.5-3.0 g/(kW·h) (1.5-1.7%).

scholarly journals Experimental study on the effect of high-pressure and low-pressure exhaust gas recirculation on gasoline engine and turbocharger

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880960 ◽  
Author(s):  
Xianqing Shen ◽  
Kai Shen ◽  
Zhendong Zhang
Keyword(s):  
High Pressure ◽  
Fuel Consumption ◽  
Gasoline Engine ◽  
Exhaust Gas Recirculation ◽  
Low Pressure ◽  
Operating Conditions ◽  
Exhaust Gas ◽  
Partial Load ◽  
Recirculation System ◽  
Gas Recirculation

The effects of high-pressure and low-pressure exhaust gas recirculation on engine and turbocharger performance were investigated in a turbocharged gasoline direct injection engine. Some performances, such as engine combustion, fuel consumption, intake and exhaust, and turbocharger operating conditions, were compared at wide open throttle and partial load with the high-pressure and low-pressure exhaust gas recirculation systems. The reasons for these changes are analyzed. The results showed EGR system of gasoline engine could optimize the cylinder combustion, reduce pumping mean effective pressure and lower fuel consumption. Low-pressure exhaust gas recirculation system has higher thermal efficiency than high-pressure exhaust gas recirculation, especially on partial load condition. The main reasons are as follows: more exhaust energy is used by the turbocharger with low-pressure exhaust gas recirculation system, and the lower exhaust gas temperature of engine would optimize the combustion in cylinder.

Semi-Closed Gas Turbine/Combined Cycle With Water Recovery and Extensive Exhaust Gas Recirculation

1996 ◽  
Author(s):  
Bruno Facchini ◽  
Daniele Fiaschi ◽  
Giampaolo Manfrida
Keyword(s):  
Gas Turbine ◽  
Water Injection ◽  
Combined Cycle ◽  
Point Of View ◽  
Exhaust Gas ◽  
Water Recovery ◽  
Gas Treatment ◽  
High Level ◽  
Gas Recirculation ◽  
Gas Turbine Cycle

This innovative gas turbine cycle can offer several advantages over conventional cycles from the point of view of environmental friendship. The basic idea of SCGT/CC (Semi-Closed Gas Turbine/Combined Cycle with water recovery) is to cool down the exhaust temperatures to allow full condensation of the water vapor, and recirculate a large part of the exhaust gases to the compressor. The condensed water can then be reinjected by means of a pump at compressor delivery. The working gas composition is thus close to that corresponding to stoichiometric combustion, which opens the possibility of applying techniques for CO2 recycling and general exhaust gas treatment. An increase in work output is connected to water injection, while a high level of efficiency is maintained as the compressor work is reduced and the cycle parameters are tuned for the exhaust of this turbine.

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