Modeling and Analysis of Tier 4 Locomotives Operating in a High-Altitude Tunnel

2017 ◽  
Author(s):  
Kevin S. McElhaney ◽  
Robert Mischler
Keyword(s):  
High Altitude ◽  
Diesel Engines ◽  
Ambient Air ◽  
Operating Conditions ◽  
Tier 2 ◽  
Electric Locomotive ◽  
Design Changes ◽  
Engine Design ◽  
The Impact ◽  
Cooling And Lubrication

Tunnels represent one of the most severe operating conditions for diesel engines in diesel-electric locomotive applications, specifically for non-ventilated tunnels located at high elevation. High ambient air temperatures are observed in these tunnels due to heat rejected from the locomotive engines through the exhaust and engine cooling and lubrication systems. Engine protection algorithms cause the maximum allowable engine horsepower to be reduced due to these conditions leading to a reduction in train speed and occasionally train stall. A first law based model was developed to simulate the performance of a train pulled by GE diesel-electric locomotives equipped with medium speed diesel engines in a high altitude and non-ventilated tunnel. The model was compared against and calibrated to actual tunnel operation data of EPA Tier 2 compliant locomotives. The model was then used to study the impact of engine design changes required for EPA Tier 4 compliant locomotives, specifically the introduction of exhaust gas recirculation (EGR), on engine, locomotive, and train performance in the tunnel. Simulations were completed to evaluate engine control strategies targeting same or better train performance than the EPA Tier 2 compliant locomotive baseline case. Simulation results show that the introduction of EGR reduces train performance in the tunnel by increasing the required reduction in engine horsepower, but is slightly offset by improved performance from other engine design changes. The targeted engine and train performance could be obtained by disabling EGR during tunnel operation.

Modeling and Analysis of Tier 4 Locomotives Operating in a High-Altitude Tunnel

2018 ◽  
Vol 141 (5) ◽  
Author(s):  
Kevin S. McElhaney ◽  
Robert Mischler
Keyword(s):  
High Altitude ◽  
Diesel Engines ◽  
Ambient Air ◽  
Operating Conditions ◽  
Tier 2 ◽  
Electric Locomotive ◽  
Design Changes ◽  
Engine Design ◽  
The Impact ◽  
Cooling And Lubrication

Tunnels represent one of the most severe operating conditions for diesel engines in diesel-electric locomotive applications, specifically for nonventilated tunnels located at high elevation. High ambient air temperatures are observed in these tunnels due to heat rejected from the locomotive engines through the exhaust and engine cooling and lubrication systems. Engine protection algorithms cause the maximum allowable engine horsepower to be reduced due to these conditions leading to a reduction in train speed and occasionally train stall. A first law based model was developed to simulate the performance of a train pulled by GE diesel-electric locomotives equipped with medium speed diesel engines in a high altitude and nonventilated tunnel. The model was compared against and calibrated to actual tunnel operation data of EPA Tier 2 compliant locomotives. The model was then used to study the impact of engine design changes required for EPA Tier 4 compliant locomotives, specifically the introduction of exhaust gas recirculation (EGR), on engine, locomotive, and train performance in the tunnel. Simulations were completed to evaluate engine control strategies targeting same or better train performance than the EPA Tier 2 compliant locomotive baseline case. Simulation results show that the introduction of EGR reduces train performance in the tunnel by increasing the required reduction in engine horsepower, but is slightly offset by improved performance from other engine design changes. The targeted engine and train performance could be obtained by disabling EGR during tunnel operation.

scholarly journals Comparative Study of the Heat and Mass Transfer Characteristics between Counter-Flow and Cross-Flow Heat Source Towers

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2674 ◽  
Author(s):  
Yifei Lv ◽  
Jun Lu ◽  
Yongcai Li ◽  
Ling Xie ◽  
Lulu Yang ◽  
...  
Keyword(s):  
Heat Source ◽  
Cross Flow ◽  
Ambient Air ◽  
Packing Material ◽  
Operating Conditions ◽  
Solution Temperature ◽  
Low Grade ◽  
Counter Flow ◽  
Heat Pump Unit ◽  
The Impact

The heat source tower (HST), as a cleaner energy production, which can absorb the low-grade energy from ambient air to drive the heat pump unit without emissions has attracted more and more interest. In addition, HST has excellent economic applicability by using cooling tower equipment, which was idle in winter. However, there are few studies on comparative analysis of thermal behavior between counter-flow and cross-flow HST. A mathematical model suitable for both HST types was developed to identify the performance discrepancies between them. Then a parametric study was carried out in order to investigate the impact of solution and air as well as packing material properties on energy transfer of HSTs. Finally, the characteristics of solution dilution and dehumidification were investigated. As the inlet solution temperature increases, increases first, then decreases gradually, but a transition point occurs in the solution at −5 °C. Moreover, the transition section of moisture transfer direction for counter-flow HST was located in the 0.78 m and 0.26–1.56 m of packing material height, under the condition that the air relative humidity was 50%. In summary, this work intuitively indicates the thermal performance difference between counter-flow and cross-flow HST, also could assist the selection of proper operating conditions in HSTs.

Cylinder-Specific Combustion Phasing Modeling for a Multiple-Cylinder Diesel Engine

2018 ◽  
Author(s):  
Wenbo Sui ◽  
Carrie M. Hall
Keyword(s):  
Prediction Model ◽  
Diesel Engines ◽  
Measurement Errors ◽  
Equivalence Ratio ◽  
Combustion Efficiency ◽  
Operating Conditions ◽  
Integral Model ◽  
Low Carbon ◽  
Crank Angle ◽  
The Impact

An optimal combustion phasing leads to a high combustion efficiency and low carbon emissions in diesel engines. With the increasing complexity of diesel engines, model-based control of combustion phasing is becoming indispensable, but precise prediction of combustion phasing is required for such strategies. Since cylinder-to-cylinder variations in combustion can be more significant with advanced combustion techniques, this work focuses on developing a control-oriented combustion phasing model that can be leveraged to provide cylinder-specific estimates. The pressure and temperature of the intake gas reaching each cylinder are predicted by a semi-empirical model and the coefficients of this intake pressure and temperature model are varied from cylinder-to-cylinder. A knock integral model is leveraged to estimate the SOC (start of combustion) and the burn duration is predicted as a function of EGR fraction, equivalence ratio of fuel and residual gas fraction in a burn duration model. After that, a Wiebe function is utilized to estimate CA50 (crank angle at 50% mass of fuel has burned). This cylinder-specific combustion phasing prediction model is calibrated and validated across a variety of operating conditions. A large range of EGR fraction and fuel equivalence ratio were tested in these simulations including EGR levels from 0 to 50%, and equivalence ratios from 0.5 to 0.9. The results show that the combustion phasing prediction model can estimate CA50 with an uncertainty of ±0.5 crank angle degree in all six cylinders. The impact of measurement errors on the accuracy of the prediction model is also discussed in this paper.

scholarly journals Influence of undefined modes of movement on instantaneous redistribution of normal reactions of quarry dump truck tires

2021 ◽  
Vol 315 ◽  
pp. 03014
Author(s):  
Mikhail Dadonov ◽  
Alexander Kulpin ◽  
Evdokia Kulpina ◽  
Valery Borovtsov ◽  
Gulzira Mukasheva
Keyword(s):  
Normal Load ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Dump Truck ◽  
The Road ◽  
Truck Tires ◽  
Non Linear ◽  
Main Thing ◽  
The Impact

Reducing the costs of rock transportation in mining is one of the most important tasks. One of the reserves for solving this issue is a more complete use of the service life of quarry dump trucks tires, since their operation takes place in heavy mining and climatic conditions and this significantly reduces the life of tires. The life of tires depends on many factors: speed of movement, compliance with the recommended air pressure in the tire, ambient air temperature, but the main thing is the change in the normal load on the wheel, which depends on the redistribution of the quarry dump truck weight in case of non-linear movement and on the longitudinal profile of the quarry road. In real conditions, the quarry dump truck moves unevenly due to the complexity of the road - either braking or acceleration occur. This article allows you to evaluate the impact of non-linear modes of quarry dump truck movement on the instant redistribution of normal tire reactions and take into account peak loads on wheels during acceleration and braking in the regular cycle. This will allow you to control the load on the tires directly by cargo amount in the quarry dump truck and thereby increase the life of the tires and their reliability, as well as reduce the cost of transporting the rock mass in real operating conditions.

Understanding and Minimizing the Vibratory Response of LM2500 Gas Turbine

2000 ◽  
Author(s):  
Bruce D. Thompson ◽  
Ben Wainscott ◽  
Jim Mulcahy
Keyword(s):  
Gas Turbine ◽  
Operating Life ◽  
Vibratory Response ◽  
Modal Response ◽  
Design Changes ◽  
Engine Design ◽  
Vibration Problems ◽  
The Impact

Since the introduction of the LM2500 in USN marine use, significant efforts have been made to address vibration issues. From a programmatic standpoint, the main goal has been to reduce vibration levels to prolong engine operating life. These have resulted in the reduction of vibration limits for new engine acceptance, the development of LM2500 trim balance, and engine design changes. From an in-service standpoint, operational use and in-place repairs have resulted in conditions that have exacerbated vibration problems. Developments within the USN gas turbine program to address these issues are presented, including the continuing efforts to understand and minimize both synchronous and non-synchronous vibration. These include optimizing trim balance techniques by understanding structural and bearing considerations, the impact of engine modal response and how engine non-linearities effect the trim balance procedure, and the reduction of non-synchronous factors which include rotating stalls.

scholarly journals CFD Modeling Analysis of Mechanical Draft Cooling Tower

2008 ◽  
Author(s):  
Si Y. Lee ◽  
James S. Bollinger ◽  
Alfred J. Garrett ◽  
Larry D. Koffman
Keyword(s):  
Water Droplet ◽  
Cooling Tower ◽  
Waste Heat ◽  
National Laboratory ◽  
Ambient Air ◽  
Operating Conditions ◽  
Cfd Modeling ◽  
Test Results ◽  
Savannah River ◽  
The Impact

Industrial processes use mechanical draft cooling towers (MDCT’s) to dissipate waste heat by transferring heat from water to air via evaporative cooling, which causes air humidification. The Savannah River Site (SRS) has a MDCT consisting of four independent compartments called cells. Each cell has its own fan to help maximize heat transfer between ambient air and circulated water. The primary objective of the work is to conduct a parametric study for cooling tower performance under different fan speeds and ambient air conditions. The Savannah River National Laboratory (SRNL) developed a computational fluid dynamics (CFD) model to achieve the objective. The model uses three-dimensional momentum, energy, continuity equations, air-vapor species balance equation, and two-equation turbulence as the basic governing equations. It was assumed that vapor phase is always transported by the continuous air phase with no slip velocity. In this case, water droplet component was considered as discrete phase for the interfacial heat and mass transfer via Lagrangian approach. Thus, the air-vapor mixture model with discrete water droplet phase is used for the analysis. A series of the modeling calculations was performed to investigate the impact of ambient and operating conditions on the thermal performance of the cooling tower when fans were operating and when they were turned off. The model was benchmarked against the literature data and the SRS test results for key parameters such as air temperature and humidity at the tower exit and water temperature for given ambient conditions. Detailed modeling and test results will be presented here.

scholarly journals INVESTIGATION OF THE ACCURACY PARTIAL-FLOW CONTROL SYSTEMS FOR PARTICULATE EMISSIONS FROM DIESEL EXHAUST GASES

2019 ◽  
Vol 5 (151) ◽  
pp. 32-36
Author(s):  
A. Polivyanchuk
Keyword(s):  
Particulate Matter ◽  
Sample Preparation ◽  
Mathematical Models ◽  
Diesel Engines ◽  
Reference System ◽  
Operating Conditions ◽  
Sample Temperature ◽  
Exhaust Gases ◽  
Temperature Conditions ◽  
The Impact

The work is devoted to solving the problem of ensuring the required accuracy of frequent-flow mini- and microtunnels - compact systems for controlling mass emissions of particulate matter from diesel engines, which arises due to the difference in temperature conditions of sample preparation in these tunnels and the reference measurement system - full-flow tunnel. According to the results of the analysis of regulatory documents - UNECE Rules R-49, R-96, international standard ISO 8178 and others, international and domestic experience in the use of dilution tunnels, it was established: technical characteristics and operating conditions of reference full-flow and part-flow tunnels, empirical dependencies characterizing the degree the influence of the sample temperature of diluted exhaust gases in the tunnel on the accuracy of measurements of mass emissions of particulate matter at various diesel operating modes. Mathematical models have been developed to determine: sample temperatures in tunnels of various types, the resulting measurement error of the average operational emission of particulate matter - PM index, taking into account the influence of sample temperature in the tunnel on the accuracy of PM measurements. Based on the results of tests of 1Ч12/14 and 4ЧН12/14 diesel engines according to the ESC cycle and developed mathematical models, computational studies were carried out to assess the impact on the accuracy of the minitunnel and microtunnel with diameters of 10 cm and 3 cm, respectively, of the temperature conditions of sample preparation, which were compared with a reference system with diameter, 46 cm. The research results proved the feasibility of controlling the temperature of the sample in the microtunnel to eliminate significant methodological errors in the measurement of PM, which are -1.6 ... -1.7%. In a minitunnel, the corresponding errors are not significant and equal to -0.3 ... -0.4%. Since the thermal conditions for diluting the exhaust gases in the minitunnel and the reference system are approximately equal, there is no need to control the sample temperature in this system.

Truck Tire Operating Temperatures on Flat and Curved Test Surfaces

2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak
Keyword(s):  
Flat Surface ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Load Pressure ◽  
Truck Tire ◽  
Endurance Testing ◽  
Operating Temperatures ◽  
The Impact ◽  
Tread Rubber ◽  
Cylindrical Test

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.

Key Aspects of Assessing Effectiveness and Efficiency of Implementation of the Federal Clean Air Project on the Example of the Comprehensive Emission Reduction Action Plan in Nizhny Tagil

2020 ◽  
pp. 48-60
Author(s):  
SV Yarushin ◽  
DV Kuzmin ◽  
AA Shevchik ◽  
TM Tsepilova ◽  
VB Gurvich ◽  
...  
Keyword(s):  
Emission Reduction ◽  
Action Plan ◽  
Local Population ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Mortality And Morbidity ◽  
Industrial Enterprises ◽  
Clean Air ◽  
Effectiveness And Efficiency ◽  
The Impact

Introduction: Key issues of assessing effectiveness and economic efficiency of implementing the Federal Clean Air Project by public health criteria are considered based on the example of the Comprehensive Emission Reduction Action Plan realized in the city of Nizhny Tagil, Sverdlovsk Region. Materials and methods: We elaborated method approaches and reviewed practical aspects of evaluating measures taken in 2018–2019 at key urban industrial enterprises accounting for 95 % of stationary source emissions. Results: Summary calculations of ambient air pollution and carcinogenic and non-carcinogenic inhalation health risks including residual risks, evaluation of the impact of air quality on urban mortality and morbidity rates, economic assessment of prevented morbidity and premature mortality cases have enabled us not only to estimate health effects but also to develop guidelines for development and implementation of actions aimed at enhancing effectiveness and efficiency of industrial emission reduction in terms of health promotion of the local population. Conclusions: We substantiate proposals for the necessity and sufficiency of taking remedial actions ensuring achievement of acceptable health risk levels as targets of the Comprehensive Emission Reduction Action Plan in Nizhny Tagil until 2024 and beyond.

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