scholarly journals Methodology for the numerical solution of problems in relation to the coil-type electric heat exchangers for heating fuel

2021 ◽  
Vol 1 (4) ◽  
pp. 45-54
Author(s):  
G.M. Krokhta ◽  
◽  
YE.N. Khomchenko ◽  
N.A. Usatykh ◽  
◽  
...  
Keyword(s):  
Diesel Engine ◽  
Operating Conditions ◽  
Industrial Complex ◽  
Fuel Temperature ◽  
Engine Operation ◽  
Incomplete Combustion ◽  
Ambient Temperatures ◽  
Start Up ◽  
Electric Heat ◽  
Agricultural Tractors

The specificity of the operating conditions of agricultural tractors in the agro-industrial complex requires the provision of reliable engine start at low ambient temperatures. Improving the starting qualities of a diesel engine and reducing incomplete combustion in the post-start period can be achieved by increasing the exergy of the air charge at the end of the compression stroke or increas-ing the exergy of the fuel injected into the combustion chamber. The purpose of the study is to re-duce the expenditure of exergy for prestarting a diesel engine, improve starting qualities and reduce incomplete combustion in the post-start period. To achieve this goal, the design of an electric heat exchanger was developed in the form of a coil from a high-pressure fuel line, into which a heating element is inserted. A method for calculating its main parameters was developed. Calculations showed that in order to ensure reliable start-up of a diesel engine in winter, it is necessary to heat the fuel in the nozzle to a temperature of 240 ° C in the thermal boost mode. A heater of about 98 Watts is required to reach this temperature within 270 seconds of priming. However, in order to maintain such a fuel temperature during the start-up process, it is necessary to make changes in the nozzle design in order to minimize heat losses into the walls of the fuel channel by applying a heat-insulating coating. With further engine operation in the post-start heating mode, the fuel temperature in the injector is reduced to 85-95 ° C.

Startup and Steady-State Performance of a New Renewable Hydroprocessed Depolymerized Cellulosic Diesel Fuel in Multiple Diesel Engines

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Eric Bermudez ◽  
Andrew McDaniel ◽  
Terrence Dickerson ◽  
Dianne Luning Prak ◽  
Len Hamilton ◽  
...  
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Cetane Number ◽  
Operating Conditions ◽  
Engine Operation ◽  
Start Of Injection ◽  
Ignition Quality ◽  
Engine Testing ◽  
Engine Start ◽  
Distillate Fuel

A new hydroprocessed depolymerized cellulosic diesel (HDCD) fuel has been developed using a process which takes biomass feedstock (principally cellulosic wood) to produce a synthetic fuel that has nominally ½ cycloparaffins and ½ aromatic hydrocarbons in content. This HDCD fuel with a low cetane value (derived cetane number from the ignition quality tester, DCN = 27) was blended with naval distillate fuel (NATO symbol F-76) in various quantities and tested in order to determine how much HDCD could be blended before diesel engine operation becomes problematic. Blends of 20% HDCD (DCN = 45), 30%, 40% (DCN = 41), and 60% HDCD (DCN = 37) by volume were tested with conventional naval distillate fuel (DCN = 49). Engine start performance was evaluated with a conventional mechanically direct injected (DI) Yanmar engine and a Waukesha mechanical indirect injected (IDI) Cooperative Fuels Research (CFR) diesel engine and showed that engine start times increased steadily with increasing HDCD content. Longer start times with increasing HDCD content were the result of some engine cycles with poor combustion leading to a slower rate of engine acceleration toward rated speed. A repeating sequence of alternating cycles which combust followed by a noncombustion cycle was common during engine run-up. Additionally, steady-state engine testing was also performed using both engines. HDCD has a significantly higher bulk modulus than F76 due to its very high aromatic content, and the engines showed earlier start of injection (SOI) timing with increasing HDCD content for equivalent operating conditions. Additionally, due to the lower DCN, the higher HDCD blends showed moderately longer ignition delay (IGD) with moderately shorter overall burn durations. Thus, the midcombustion metric (CA50: 50% burn duration crank angle position) was only modestly affected with increasing HDCD content. Increasing HDCD content beyond 40% leads to significantly longer start times.

scholarly journals Methods for estimating the durability of the needle bearing of the piston head of the connecting rod of a transportation diesel

2021 ◽  
pp. 55-60
Author(s):  
Vadym Mychaylovich Petuhov ◽  
Alexandr Vasilyevich Orobinsky ◽  
Natalya Anatolyevna Aksenova
Keyword(s):  
Diesel Engine ◽  
Service Life ◽  
Test Procedure ◽  
Operating Conditions ◽  
Accelerated Tests ◽  
Connecting Rod ◽  
Design Work ◽  
Engine Operation ◽  
Piston Head ◽  
Rolling Elements

The article presents the results of an experimental study and analytical evaluation calculations to check service life and increase durability of the needle bearing of piston head of connecting rod of a transport diesel engine. The primary reasons for the violation of the nominal operation of the main units of this mechanism have been established. Corresponding recommendations are proposed for carrying out accelerated tests for durability, reducing the thermal loads of the bearing operation and, as a consequence, improving the quality and service life of its entire piston group. Theoretical and experimental methods for determining the nominal life of the needle bearing of the piston head of the connecting rod (PHCR) of a transport diesel engine are proposed. The theoretical methodology allows obtaining reliable values of durability, taking into account the distribution of the working load over the rolling elements, as well as the mobility of the piston pin and sleeve. The performed calculations make it possible to correct and clarify the standard mathematical model for determining the nominal life of the PHCR needle bearing, depending on the distribution of loads on the rolling elements (rollers) under different operating conditions. This experimental technique with an acceleration factor of 10 is based on a twofold increase in the force effect on the elements of the PHCR needle bearing. This was achieved by assembling the bearing using a special technology, which is described in detail in the work. A significant decrease in the thermal effect and a decrease in radial loads on working rollers have been established. For ensure the regular oil supply into bearing during engine operation, a technique was developed to increase the load on the roller in contact zone, which significantly influenced durability and made it possible to conduct accelerated tests with a reliable yield. Its results of operational research and experience in design work correlate and are sufficiently explained by the developed methods, which allows them to be used for the improvement and modernization of connecting rods with needle bearings in PHCR. That is a permission to use these methodic for doing perfect and modern the needle bearing of the connecting-rod piston. Keywords: diesel, test procedure, needle bearing, rollers, piston head of the connecting rod, durability.

scholarly journals OPTIMIZATION OF METHODS AND PARAMETERS OF PRE-START THERMAL PREPARATION OF THE ENGINE FOR STARTING DEPENDING ON THE AMBIENT TEMPERATURE

2022 ◽  
Vol 16 (4) ◽  
pp. 53-58
Author(s):  
Evgenii Potapov ◽  
Dmitriy Vahrameev ◽  
Stanislav Sinickiy ◽  
Vladimir Medvedev ◽  
Alexey Terentyev
Keyword(s):  
Diesel Engine ◽  
Ambient Temperature ◽  
Correction Factor ◽  
Compression Ratio ◽  
Theoretical Calculations ◽  
Operating Conditions ◽  
Engine Oil ◽  
Correction Coefficient ◽  
Reduced Pressure ◽  
Start Up

Due to the lack of a generally accepted methodology for calculating the starting processes of automotive diesel engines, today it is not possible to calculate their temperature parameters with a sufficient degree of accuracy during start-up, which determine the condition of a guaranteed start-up process. The main problem in applying theoretical calculations is that they take into account the compression ratio of the engine. But the compression ratio and the value of the actual pressure in the engine cylinders during the start-up are completely different indicators. The purpose of this work is to correct the generally accepted dependencies for determining the temperature parameters of a diesel engine by introducing a correction factor that takes into account the reduced pressure in the engine cylinders during start-up, as well as calculating the temperature parameters during start-up according to the proposed calculation method. The correction factor is determined experimentally and depends on the engine temperature. When applying the correction factor, it becomes possible to accurately calculate the temperature of the fuel-air mixture, which determines the possibility of a guaranteed start-up process and at the same time allows you to set the minimum necessary requirements for the means of thermal pre-start preparation. A group of graduate students and teachers (Izhevsk State Agricultural Academy and Kazan Agrarian University) conducted a number of practical studies on the basis of one of the leading agricultural enterprises of the Udmurt Republic JSC "Ilyich's Way". The MTZ-82 tractor was taken as the object of the study. The subject of the study was the launch of its D-243 engine at low temperatures in real operating conditions. The choice of this model of diesel engine is due to its wide application on tractors. The studies were carried out according to the approved test program, which consists in starting the D-243 engine of the MTZ-82 tractor at temperatures from - 30 ° C with an interval of 5 ° C to +5 ° C (engine temperature is equal to ambient temperature), as well as from +5 ° C to +90 ° C with an interval of 20 ° C (ambient temperature +20 ° C). Measurements were carried out to determine the amount of compression in the engine cylinders and the speed of rotation of the crankshaft at certain temperatures. The experiments were carried out using a starter charger that provides the full electric power of the diesel starter. As a result of the experimental work carried out, a change in the value of the correction coefficient from the engine temperature was established, and in accordance with the modified methodology of theoretical calculations, the values of the temperature of the fuel-air mixture at the end of the compression stroke of the diesel engine at start-up are given. It is established that the minimum required pre-start temperature of the diesel engine should be at least +5 ° C. Based on the results of the analysis of calculations, the directions of ensuring a guaranteed start of the diesel engine by simultaneously heating the coolant and engine oil are proposed. These requirements can be provided by a thermal storage system that does not require additional energy sources for its operation

Coal–Water Slurry Operation in an EMD Diesel Engine

1988 ◽  
Vol 110 (3) ◽  
pp. 437-443 ◽  
Author(s):  
C. M. Urban ◽  
H. E. Mecredy ◽  
T. W. Ryan ◽  
M. N. Ingalls ◽  
B. T. Jett
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Operating Conditions ◽  
Department Of Energy ◽  
Coal Slurry ◽  
Particulate Emissions ◽  
Development Effort ◽  
Engine Operation ◽  
Coal Burning

The U.S. Department of Energy, Morgantown Energy Technology Center has assumed a leadership role in the development of coal-burning diesel engines. The motivation for this work is obvious when one considers the magnitude of the domestic reserves of coal and the widespread use of diesel engines. The work reported in this paper represents the preliminary engine experiments leading to the development of a coal-burning, medium-speed diesel engine. The basis of this development effort is a two-stroke, 900 rpm, 216-mm (8.5-in.) bore engine manufactured by Electro-Motive Division of General Motors Corporation. The engine, in a minimally modified form, has been operated for several hours on a slurry of 50 percent (by mass) coal in water. Engine operation was achieved in this configuration using a pilot injection of diesel fuel to ignite the main charge of slurry. A standard unit injector, slightly modified by increasing diametric clearances in the injector pump and nozzle tip, was used to inject the slurry. Under the engine operating conditions evaluated, the combustion efficiency of the coal and the NOx emissions were lower than, and the particulate emissions were higher than, corresponding diesel fuel results. These initial results, achieved without optimizing the system on the coal slurry, demonstrate the potential for utilizing coal slurry fuels.

scholarly journals Effect of LPG Content on the Performance and Emissions of A Diesel-LPG Dual-Fuel Engine

1970 ◽  
Vol 46 (2) ◽  
pp. 195-200 ◽  
Author(s):  
GA Rao ◽  
AVS Raju ◽  
CVM Rao ◽  
KG Rajulu
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Agricultural Sector ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Dual Fuel ◽  
Engine Operation ◽  
Engine Load ◽  
Performance And Emission ◽  
Combustion Performance

In the present work, LPG, a by-product of petroleum refining process is used to replace conventional diesel fuel, partially, for improved combustion efficiency and clean burning. A conventional diesel engine was operated on the dual-fuel mode, using LPG as the primary fuel and diesel as the pilot fuel. A four-stroke, single-cylinder diesel engine, most widely used in agricultural sector, has been considered for the purpose of experimentation. The engine was operated at a constant speed of 1500 rpm at a low engine load of 20% and a high engine load of 80%. Under both these operating conditions, combustion, performance and emission characteristics of the engine have been evaluated and compared with that of baseline diesel fuel operation. At 20 % engine load the brake thermal efficiency of the engine has found to decrease with an increase in the LPG content. On the other hand at 80% engine load, it has increased with an increase in the LPG content. Same trend has been observed with regard to the mechanical efficiency. The volumetric efficiency has decreased with an increase in the LPG content at both the loads. The engine operation is more economical on dual-fuel operation at 80% engine load, whereas at 20% engine load, diesel fuel operation is found to be better. With regard to emissions, smoke density and emissions of NOx were found to reduce with an increase in LPG content at both the loads; however, emissions of HC and CO have shown the reverse trend. Key words: Dual-Fuel; LPG; Diesel; Combustion; Performance; Emissions Load. DOI: http://dx.doi.org/10.3329/bjsir.v46i2.8186 Bangladesh J. Sci. Ind. Res. 46(2), 195-200, 2011

Research on the Characteristics of Start up and Operation of Treating Brewery Wastewater with an AFB Reactor at Ambient Temperatures

1993 ◽  
Vol 28 (7) ◽  
pp. 187-195 ◽  
Author(s):  
Liang Yongming ◽  
Qian Yi ◽  
Hu Jicui
Keyword(s):  
Removal Rate ◽  
Operating Conditions ◽  
Brewery Wastewater ◽  
Ambient Temperatures ◽  
Operational Characteristics ◽  
Start Up ◽  
Stable Operating ◽  
Average Production ◽  
Cod Removal Rate ◽  
One Year

The purpose of this study was to evaluate the efficiency and feasibility of treating brewery wastewater with an Anaerobic Fluidized Bed(AFB) reactor at ambient temperatures of about 25°C. Results from nearly one year of tests have demonstrated that the reactor has a volumetric loadings rate of 27-30kgCOD/m3.d with 2.5 h of hydraulic retention time (HRT). The COD removal rate can reach 85% or more under stable operating conditions. The average production rate of biogas was 0.45m3/kgCOD removed, of which the CH4 content was 72%. In addition, the formation mechanism of the biofilm was analyzed, the measures of rapid start up of the reactor was investigated. The operational characteristics of the AFB reactor were also discussed.

Heat Release Analysis of Oxygen-Enriched Diesel Combustion

1993 ◽  
Vol 115 (4) ◽  
pp. 761-768 ◽  
Author(s):  
D. Assanis ◽  
E. Karvounis ◽  
R. Sekar ◽  
W. Marr
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Oxygen Enrichment ◽  
Operating Conditions ◽  
Diesel Combustion ◽  
The Novel ◽  
Pressure Data ◽  
Engine Operation ◽  
Combustion Simulation ◽  
Release Analysis

A heat release correlation for oxygen-enriched diesel combustion is being developed through heat release analysis of cylinder pressure data from a single-cylinder diesel engine operating under various levels of oxygen enrichment. Results show that standard combustion correlations available in the literature do not accurately describe oxygen-enriched diesel combustion. A novel functional form is therefore proposed, which is shown to reproduce measured heat release profiles closely, under different operating conditions and levels of oxygen enrichment. The mathematical complexity of the associated curve-fitting problem is maintained at the same level of difficulty as for standard correlations. When the novel correlation is incorporated into a computer simulation of diesel engine operation with oxygen enrichment, the latter predicts pressure traces in excellent agreement with measured pressure data. This demonstrates the potential of the proposed combustion simulation to guide the application of oxygen-enriched technology successfully to a variety of multicylinder diesel systems.

Modeling the Fuel Spray of a High Reactivity Gasoline Under Heavy-Duty Diesel Engine Conditions

2017 ◽  
Author(s):  
Yuanjiang Pei ◽  
Roberto Torelli ◽  
Tom Tzanetakis ◽  
Yu Zhang ◽  
Michael Traver ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Ambient Pressure ◽  
Injection Pressure ◽  
High Reactivity ◽  
Operating Conditions ◽  
Heavy Duty ◽  
Fuel Temperature ◽  
Heavy Duty Diesel Engine ◽  
Heavy Duty Diesel

Recent experimental studies on a production heavy-duty diesel engine have shown that gasoline compression ignition (GCI) can operate in both conventional mixing-controlled and low-temperature combustion modes with similar efficiency and lower soot emissions compared to diesel at a given engine-out NOx level. This is primarily due to the high volatility and low aromatic content of high reactivity, light-end fuels. In order to fully realize the potential of GCI in heavy-duty applications, accurate characterization of gasoline sprays for high-pressure fuel injection systems is needed to develop quantitative, three-dimensional computational fluid models that support simulation-led design efforts. In this work, the non-reacting fuel spray of a high reactivity gasoline (research octane number of ∼60, cetane number of ∼34) was modeled under typical heavy-duty diesel engine operating conditions, i.e., high temperature and pressure, in a constant-volume combustion chamber. The modeling results were compared to those of a diesel spray at the same conditions in order to understand their different behaviors due to fuel effects. The model was developed using a Lagrangian-Particle, Eulerian-Fluid approach. Predictions were validated against available experimental data generated at Michigan Technological University for a single-hole injector, and showed very good agreement across a wide range of operating conditions, including ambient pressure (3–10 MPa), temperature (800–1200 K), fuel injection pressure (100–250 MPa), and fuel temperature (327–408 K). Compared to a typical diesel spray, the gasoline spray evaporates much faster, exhibiting a much shorter liquid length and wider dispersion angle which promote gas entrainment and enhance air utilization. For gasoline, the liquid length is not sensitive to different ambient temperatures above 800 K, suggesting that the spray may have reached a “saturated” state where the transfer of energy from the hot gas to liquid has already been maximized. It was found that higher injection pressure is more effective at promoting the evaporation process for diesel than it is for gasoline. In addition, higher ambient pressure leads to a more compact spray and fuel temperature variation only has a minimal effect for both fuels.

CFD Combustion and Emission Formation Modeling for a HSDI Diesel Engine Using Detailed Chemistry

2006 ◽  
Author(s):  
Valeri I. Golovitchev ◽  
Luca Montorsi ◽  
Carlo Alberto Rinaldini ◽  
Angelo Rosetti
Keyword(s):  
Diesel Engine ◽  
Chemical Kinetics ◽  
Diesel Engines ◽  
Equivalence Ratio ◽  
Diesel Oil ◽  
Operating Conditions ◽  
Fuel Vapor ◽  
Formation Mechanisms ◽  
Engine Operation ◽  
3D Engine

In order to comply with current emissions regulations, a detailed analysis of the combustion and emission formation processes in the Diesel engines accounting for the effect of the main operating parameters is required. The present study is based both on 0D and 3D numerical simulations by compiling 0D chemical kinetics calculations for Diesel oil surrogate combustion and emission (soot, NOx) formation mechanisms to construct a φ-T (equivalence ratio - temperature) parametric map. In this map, the regions of emissions formation are depicted defining a possible optimal path between the regions by placing on the same map the engine operation conditions represented by the computational cells, whose parameters (equivalence ratio and temperature) are calculated by means of 3D engine modelling. Unlike previous approaches based on static parametric φ-T maps to analyze different combustion regimes and emission formations in Diesel engines, the present paper focuses on a construction of dynamic φ-T maps, in which the pressures and the elapsed times were taken in compliance with those calculated in the 3D engine simulations. The 0D chemical kinetics calculations have been performed by the SENKIN code of the Chemkin-2 library. In-cylinder conditions represented by computational cells with known φ and T are predicted using KIVA-3V code. When cells are plotted on the map, they identify the trajectories helping to navigate between the emissions regions by varying hardware and injection parameters. Sub-models of the KIVA-3V, rel. 2 code has been modified including spray atomization, droplet collision and evaporation, accounting for multi-component fuel vapor coupled with the improved versions of the chemistry/turbulence interaction model and new formulation of the combustion kinetics for the diesel oil surrogate (consisting in 70 species participating in 310 reactions). Simulations were performed for the HSDI 1.300 Fiat Diesel engine at optimized engine operating conditions and pilot injections. Finally, numerical results are compared with the experimental data on in-cylinder pressure, Rate of Heat Release, RoHR, and selected species distributions.

scholarly journals METHODOLOGY FOR DETERMINING THE MAIN INDICATORS OF THE TEMPERATURE AND DYNAMIC CHARACTERISTICS OF THE COOLING SYSTEM OF AN ENERGY VEHICLE DURING OPERATION

2021 ◽  
pp. 75-79
Author(s):  
Ekaterina Parlyuk ◽  
Nikolay Bol'shakov
Keyword(s):  
Internal Combustion Engines ◽  
Cooling System ◽  
Climatic Conditions ◽  
Thermal Balance ◽  
Operating Conditions ◽  
Design Parameters ◽  
Industrial Complex ◽  
Design Features ◽  
Engine Operation ◽  
Temperature Dynamic

The efficiency of internal combustion engines of energy facilities operating in the conditions of enterprises of the agro-industrial complex depends on the stability of the thermal regime of the engine. Its provision is entrusted to the cooling system, in this article which is a radiator with a polyurethane core. The temperature regime of the engine operation affecting a number of factors is given and described - these are design parameters (design features of the radiator and the features of the working process of the radiator, taking into account the operating conditions of the tractor) and operational, which take into account the operating mode of the tractor and natural and climatic conditions. According to the research results during the operation of the tractor in steady conditions, the temperature of the coolant in the system is stable, respectively, the temperature field of the air flow at the inlet and outlet of the radiator with a polyurethane core also stabilizes. To take them into account, the coefficient of thermal properties of the radiator is introduced, which depends on the external and internal temperature-dynamic effects of the environment, and a diagram is constructed that shows the dependence of the temperature of the coolant flowing in the radiator on the generated load of the tractor during operation in the field. At the same time, the temperature-dynamic characteristic of the tractor does not depend on the design features of the engine, but on the power developed by the engine. Therefore, the heat removed from the engine into the coolant is calculated by us through the engine power. Based on this, the characteristic of the thermal balance of the engine and the heat transfer of the radiator during the operation of the tractor at full load are considered, taking into account the change in gears within the speed limits, a graph of the thermal balance of the engine and radiator versus speed is built. Based on the calculations, it was concluded that the use of the characteristics of the traction-dynamic balance of the tractor can serve as the basis for the general analysis and calculated and experimental operating modes of the automotive polymer radiator and the cooling system as a whole, taking into account the loads, climatic conditions and operating parameters of the cooling system

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