Refinement of working processes of diesel engines converted to gas fuel based on numerical modeling

2020 ◽  
pp. 36-42
Author(s):  
Leonid Valeryevich Plotnikov ◽  
◽  
Andrey Mikhaylovich Kozubskiy ◽  
Alexander Grigoryevich Maximenko ◽  
Leonid Evgenyevich Osipov ◽  
...  
Keyword(s):  
Numerical Modeling ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Significant Part ◽  
Nox Emissions ◽  
Railway Transport ◽  
Working Process ◽  
Reciprocating Engines ◽  
Gas Fuel ◽  
Working Processes

Shunting is an important component of railway transport, a significant part of which is performed by diesel locomotives. Piston engines are the most common locomotive power machines. The paper provides brief information on the trends in modernization of energy machines for diesel locomotives. It also considers the issues of improving the working processes of engines converted to gas fuel on the basis of numerical modeling. The main goal of the simulation is to improve the performance of gas reciprocating engines. The authors propose the option for refinement of the working process for three gas reciprocating engines that decreased the specific fuel consumption to 11.5 % and NOx emissions by 2-10 times while maintaining power within ±10 % compared to basic diesel engines.

Optimization of Engine Efficiency for Diesel Engine Equipped With EGR-VGT and Aftertreatment Systems

2019 ◽  
Author(s):  
Kuo Yang ◽  
Pingen Chen
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Intrinsic Property ◽  
Nox Emission ◽  
Nox Emissions ◽  
Minimum Phase ◽  
Engine Efficiency ◽  
Simulation Results ◽  
Aftertreatment Systems

Abstract Engine efficiency improvement is very critical for medium to heavy-duty vehicles to reduce Diesel fuel consumption and enhance U.S. energy security. The tradeoff between engine efficiency and NOx emissions is an intrinsic property that prevents modern Diesel engines, which are generally equipped with exhaust gas recirculation (EGR) and variable geometry turbocharger (VGT), from achieving the optimal engine efficiency while meeting the stringent NOx emission standards. The addition of urea-based selective catalytic reduction (SCR) systems to modern Diesel engine aftertreatment systems alleviate the burden of NOx emission control on Diesel engines, which in return creates extra freedom for optimizing Diesel engine efficiency. This paper proposes two model-based approaches to locate the optimal operating point of EGR and VGT in the air-path loop to maximize the indicated efficiency of turbocharged diesel engine. Simulation results demonstrated that the engine brake specific fuel consumption (BSFC) can be reduced by up to 1.6% through optimization of EGR and VGT, compared to a baseline EGR-VGT control which considers both NOx emissions and engine efficiency on engine side. The overall equivalent BSFCs are 1.8% higher with optimized EGR and VGT control than with the baseline control. In addition, the influence of reducing EGR valve opening on the non-minimum phase behavior of the air path loop is also analyzed. Simulation results showed slightly stronger non-minimum phase behaviors when EGR is fully closed.

NOx Emissions From Oceangoing Ships: Calculation and Evaluation

2003 ◽  
Author(s):  
Horst W. Koehler
Keyword(s):  
Fuel Consumption ◽  
Diesel Engines ◽  
Atmospheric Chemistry ◽  
Pollutant Emissions ◽  
Nox Emissions ◽  
Consumption Rates ◽  
Type Size ◽  
Mode Of Transportation ◽  
Engine Type ◽  
Bunker Fuel

Currently available global inventories of nitrogen oxides (NOx) and other pollutant emissions from merchant ships are based, at least partly, on data published by international marine bunker fuel suppliers. However, the uncertainty of such data seems to be quite high, because the figures released by bunker fuel companies might be incomplete or based, for example, on data collected from only the largest ports. Besides, all similar other studies conducted so far were based on simplified average emission and fuel consumption characteristics of diesel engines and did not take into account variations with engine type, size, engine load and engine speed, as well as only being valid for new state-of-the-art diesel engines as supplied by the industry today. Furthermore, fuel consumption rates of the auxiliary engine equipment onboard vessels were neglected. The author therefore adopted a different approach by calculating the actual bunker amount and the fleet’s 2001 NOx emissions in order to reduce uncertainty in existing inventories and to assist in achieving a better modeling of the effects of ships’ pollutants on atmospheric chemistry. For this study, all ships of 100 gross tonnage (gt) and above were taken into account. This methodology resulted in a significantly higher world fleet fuel consumption, and, consequently, much higher oceangoing ships’ NOx emissions than known or anticipated so far. In spite of the fleet’s high NOx emission rate in absolute figures this paper shows, that when emissions are based on the annual seaborne trade, merchant shipping is an environmentally efficient mode of transportation of freight.

Emissions From Various Biodiesel Sources Compared to a Range of Diesel Fuels in DPF Equipped Diesel Engines

2011 ◽  
Author(s):  
Aaron Williams ◽  
Jonathan Burton ◽  
Earl Christensen ◽  
Robert L. McCormick ◽  
John Tester
Keyword(s):  
Particle Size ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Nox Emissions ◽  
Test Cycle ◽  
Particle Count ◽  
Diesel Fuels ◽  
Total Particle

The purpose of this study was to measure the impact of various sources of petroleum-based and bio-based diesel fuels on regulated emissions and fuel economy in diesel particulate filter (DPF) equipped diesel engines. Two model year 2008 diesel engines were tested with nine fuels including a certification ultra-low sulfur diesel (ULSD), local ULSD, high aromatic ULSD, low aromatic ULSD, and twenty percent blends of biodiesel derived from algae, camelina, soy, tallow, and yellow grease. Regulated emissions were measured over the heavy duty diesel transient test cycle. Measurements were also made of DPF-out particle size distribution and total particle count from a 13-mode steady state test using a fast mobility particle sizer. Test engines were a 2008 Cummins ISB and a 2008 International Maxx Force 10, both equipped with actively regenerated DPFs. Fuel consumption was roughly 2% greater over the transient test cycle for the B20 blends versus certification ULSD in both engines, consistent with the slightly lower energy content of biodiesel. Unlike studies conducted on older model engines, these engines equipped with diesel oxidation catalysts and DPFs showed small or no measurable fuel effect on the tailpipe emissions of total hydrocarbons (THC), carbon monoxide (CO) and particulate matter (PM). No differences in particle size distribution or total particle count were seen in a comparison of certification ULSD and B20 soy, with the exception of engine idling conditions where B20 produced a small reduction in the number of nucleation mode particles. In the Cummins engine, B20 prepared from algae, camelina, soy, and tallow resulted in an approximately 2.5% increase in nitrogen oxides (NOx) compared to the base fuel. The International engine demonstrated a higher degree of variability for NOx emissions, and fuel effects could not be resolved (p > 0.05). The group of petroleum diesel test fuels produced a range of NOx emissions very similar to that caused by blending of biodiesel. Test cycles where an active regeneration of the DPF occurred resulted in a nearly threefold increase in NOx emissions and a 15% increase in fuel consumption. The full quantification of DPF regeneration events further complicates the accurate calculation of fuel impacts on emissions and fuel consumption.

scholarly journals ENTROPY CALCULATION OF THE BODY IN THE CYLINDER DIESEL

2017 ◽  
pp. 54-59
Author(s):  
Nadezhda Igorevna Alexandrovskaya ◽  
Roman Anatolievich Varbanets ◽  
Alexey Valerievich Yeryganov
Keyword(s):  
Numerical Modeling ◽  
Absolute Temperature ◽  
The Body ◽  
Working Process ◽  
Clapeyron Equation ◽  
Working Medium ◽  
The Difference ◽  
Stroke Engine ◽  
Quality Indexes ◽  
Working Processes

When using the method of numerical modeling for working processes in diesel engines, parameters are described by three equations: the first law of thermodynamics, mass balance and Clapeyron equation. They are combined in a system of differential equations and solved together at each step of the modeling. If the angular velocity ω of crankshaft is the same, it’s convenient to take a crankshaft angle φ as the argument. If the system is solved with reference to pressure p , temperature T ц and mass G it’s also possible to determine entropy s of working medium. In order to achieve acceptable accuracy of modeling the isochoric heat capacity cv cannot be considered as constant value as it results big calculating error. In order to avoid this, it’s enough to determine cv by quadratic polynomial of absolute temperature of working medium. The offered procedure was checked by numerical modeling of working process of two-stroke engine MAN-B&W 6S26MC and four stroke engine 6 ChN 25/34-2. Results showed that working processes of two- and four-stroke engines in T - s coordinates are looking identically. Moreover, the working processes of engines in T - s coordinates have the likeness of kind with theoretical diagram of Sabathe cycle. This suggests that it’s possible to create quality indexes in order to assess the difference between theoretical and real processes and work out recommendations for process improving.

scholarly journals IMPROVING THE PERFORMANCE INDICATORS OF DIESEL ENGINES BY ENHANCING THE COOLING SYSTEM

2020 ◽  
Vol 2020 (1) ◽  
pp. 63-68
Author(s):  
O Daminov ◽  
◽  
O Khushnaev ◽  
A Yangibaev ◽  
G Kucharenok
Keyword(s):  
Thermal Stress ◽  
Diesel Engines ◽  
Theoretical Study ◽  
Cooling System ◽  
Spark Ignition ◽  
Spark Ignition Engine ◽  
Working Process ◽  
Cooling Systems ◽  
Engine Cooling ◽  
Gas Fuel

The article deals with the improvement of the performance of diesel engines by improving the cooling system. It is indicated that there is a number of problems that arise when converting an engine with spark ignition to natural gas. The increase of thermal stress of the engine is illustrated. As a result of researching of features of the parameters and characteristics of a gas-powered automobile engine and optimization of its temperature regime, a very actual scientific and practical task is determined. The engine with the spark ignition installed on the microbus working on the diesel and gas is presented. The results of the spark-ignition engine research on gaseous fuel are presented. The following recommendations are given: to analyze the design features of gas engines; analyze the principles of operation of modern engine cooling systems; to conduct a theoretical study of the engine cooling system of gas buses and minibuses, which would allow to identify the causes leading to an increase in the thermal stress of engine parts when converted to gas fuel, which consists in the specificity and features of the working process; suggest ways to improve the cooling system of gas engines; to develop and propose options for improving the cooling system of gas engines, which will reduce the cooling temperature from 120 to 90 °C.

scholarly journals Investigation of Effect on Environmental Performance of Using LNG as Fuel for Engines in Seaport Tugboats

2021 ◽  
Vol 9 (2) ◽  
pp. 123
Author(s):  
Sergejus Lebedevas ◽  
Lukas Norkevičius ◽  
Peilin Zhou
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Baltic Sea ◽  
Impact Assessment ◽  
Fuel Consumption ◽  
Dual Fuel ◽  
Nox Emissions ◽  
The Baltic Sea ◽  
Emission Analysis ◽  
The Baltic

Decarbonization of ship power plants and reduction of harmful emissions has become a priority in the technological development of maritime transport, including ships operating in seaports. Engines fueled by diesel without using secondary emission reduction technologies cannot meet MARPOL 73/78 Tier III regulations. The MEPC.203 (62) EEDI directive of the IMO also stipulates a standard for CO2 emissions. This study presents the results of research on ecological parameters when a CAT 3516C diesel engine is replaced by a dual-fuel (diesel-liquefied natural gas) powered Wartsila 9L20DF engine on an existing seaport tugboat. CO2, SO2 and NOx emission reductions were estimated using data from the actual engine load cycle, the fuel consumption of the KLASCO-3 tugboat, and engine-prototype experimental data. Emission analysis was performed to verify the efficiency of the dual-fuel engine in reducing CO2, SO2 and NOx emissions of seaport tugboats. The study found that replacing a diesel engine with a dual-fuel-powered engine led to a reduction in annual emissions of 10% for CO2, 91% for SO2, and 65% for NOx. Based on today’s fuel price market data an economic impact assessment was conducted based on the estimated annual fuel consumption of the existing KLASCO-3 seaport tugboat when a diesel-powered engine is replaced by a dual-fuel (diesel-natural gas)-powered engine. The study showed that a 33% fuel costs savings can be achieved each year. Based on the approved methodology, an ecological impact assessment was conducted for the entire fleet of tugboats operating in the Baltic Sea ports if the fuel type was changed from diesel to natural gas. The results of the assessment showed that replacing diesel fuel with natural gas achieved 78% environmental impact in terms of NOx emissions according to MARPOL 73/78 Tier III regulations. The research concludes that new-generation engines on the market powered by environmentally friendly fuels such as LNG can modernise a large number of existing seaport tugboats, significantly reducing their emissions in ECA regions such as the Baltic Sea.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).

An Improvement of Part Load Performance of Diesel Engines Operating at Constant Speed Conditions

1994 ◽  
Vol 208 (1) ◽  
pp. 21-25 ◽  
Author(s):  
A A Abdel-Rahman ◽  
M K Ibrahim ◽  
A A Said
Keyword(s):  
Fuel Consumption ◽  
Diesel Engines ◽  
Petroleum Refining ◽  
Specific Fuel Consumption ◽  
Constant Speed ◽  
Maximum Pressure ◽  
Brake Specific Fuel Consumption ◽  
Part Load ◽  
Generating Sets ◽  
In Series

This paper discusses the possibility of improving the part load performance of diesel electric turbocharged engines operating at constant speed conditions. A sequential turbocharged system is proposed, where the compressors are connected In series. The study focused on two turbocharged diesel–electric generating sets existing at Ameria Petroleum Refining Company in Alexandria, Egypt. The results of the prediction showed that, at part load, both the maximum pressure and temperature were increased, and the brake specific fuel consumption was reduced considerably (by about 10 per cent).

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