Two-Stage Turbocharging Solutions for Tier 4 Rail Applications

2015 ◽  
Author(s):  
Simone Bernasconi ◽  
Ennio Codan ◽  
David Yang ◽  
Pierre Jacoby ◽  
German Weisser
Keyword(s):  
Catalytic Reduction ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Ambient Conditions ◽  
Two Stage ◽  
Optimum Performance ◽  
Engine Model ◽  
High Fuel Efficiency ◽  
Wide Range ◽  
Turbocharging System

With the introduction of the EPA Tier 4 NOx emission limits for rail diesel engines this year, engine developers are forced to implement more advanced emission control technologies such as selective catalytic reduction (SCR) or cooled external exhaust gas recirculation (EGR). The integration and control of these systems for ensuring optimum performance throughout the operating range brings about new challenges on top of the well-known requirement for unconstrained operability in a very wide range of conditions. As a consequence, engines and their subsystems have to be designed for maximum flexibility. The turbocharging system in particular needs to be capable of dealing with extreme ambient conditions associated with high altitudes, hot summers, severe winters, tunnel operation, etc. This flexibility must be achieved without compromising reliability and while ensuring continuous in-use compliance with the emissions standards throughout the life of the installation. At the same time, engine performance should be maintained at the highest level possible. This study demonstrates that all of these targets can be met by combining two-stage turbocharging and EGR with suitable control elements. Two-stage turbocharging, which has become increasingly popular in other industry sectors due to its potential for improving the bsfc / NOx emissions trade-off when used in combination with correspondingly optimized valve actuation (Miller timing), is starting to be adopted also for rail applications. A variety of EGR concepts was proposed or put into practice over the past few years, and the most important or promising of these have been taken into consideration for this study. Extensive simulations of the resulting engine and turbocharging systems have been performed using ABB’s in-house simulation platform, based on a generic engine model that can be considered representative of the rail sector. It is shown that integration of EGR, two-stage turbocharging and appropriate control elements is highly attractive as it offers outstanding operational flexibility and very high fuel efficiency without any compromise in terms of reliability. The selection and specification of control elements and turbocharging system components depends on the EGR concept applied. As is shown below, this can be tailored to the application to ensure optimum performance and flexibility. In view of these obvious benefits, we are very confident that such integrated EGR / two-stage turbocharging systems will be adopted more widely on railway engines.

A Simplified Method to Evaluate the Impact of Component Design on Engine Performance

2007 ◽  
Author(s):  
Francesco Montella ◽  
J. P. van Buijtenen
Keyword(s):  
Design Process ◽  
Engine Performance ◽  
Simulation Software ◽  
Fast Method ◽  
Engine Simulation ◽  
Engine Model ◽  
Component Design ◽  
Wide Range ◽  
Engine Component ◽  
The Impact

This paper presents a simplified and fast method to evaluate the impact of a single engine component design on the overall performance. It consists of three steps. In the first step, an engine system model is developed using available data on existing engines. Alongside the cycle reference point, a sweep of operating points within the flight envelop is simulated. The engine model is tuned to match a wide range of conditions. In the second step, the module that contains the engine component of interest is analyzed. Different correlations between the component design and the module efficiency are investigated. In the third step, the deviations in efficiency related to different component configurations are implemented in the engine baseline model. Eventually, the effects on the performances are evaluated. The procedure is demonstrated for the case of a two-spool turbofan. The effects of tip leakage in the low pressure turbine on the overall engine performance are analyzed. In today’s collaborative engine development programs, the OEMs facilitate the design process by using advanced simulation software, in-house available technical correlations and experience. Suppliers of parts have a limited influence on the design of the components they are responsible for. This can be rectified by the proposed methodology and give subcontractors a deeper insight into the design process. It is based on commercially available PC engine simulation tools and provides a general understanding of the relations between component design and engine performance. These relations may also take into account of aspects like production technology and materials in component optimization.

Evaluation of adhesive failure cases of L joint structures under tensile loading

2018 ◽  
Vol 32 (19) ◽  
pp. 1840058
Author(s):  
Do-Hoon Shin ◽  
Dong-Keun Hyun ◽  
Yun-Hae Kim
Keyword(s):  
Low Cost ◽  
Fuel Efficiency ◽  
Tensile Loading ◽  
Failure Strength ◽  
Adhesive Failure ◽  
Manufacturing Method ◽  
High Fuel Efficiency ◽  
Wide Range ◽  
Temperature Time ◽  
Secondary Bonding

In aerospace, aircraft weight is one of the important factors essential for long range and high fuel efficiency. Instead of fastening, bonding methods like co-curing, co-bonding and secondary bonding are used on the aircraft parts. Secondary bonding was developed for integrated parts because of easy handling, less defect ratio and low cost. During manufacturing, the integrated parts using secondary bonding, bonding strength can show a wide range of failure strengths. Due to inconstant failure strength, the design value can be dropped and reinforcement methods should be applied. To avoid over-designing and to get a constant value for failure, the adhesive failure cases are studied in this project. In this study, L joining composite parts are investigated under tensile loading. Different conditions are tested to select a suitable manufacturing method for secondary bonding methods. From the experimental results, the secondary bonding was sensitive at exposed temperature/time and shape conditions of the fillet. The results show that the failure strength depends on the shape of fillet and exposed time for curing.

Investigation of Influence of Two-Stage Turbocharging System on Engine Performance Using a Pre-Design Model

2013 ◽  
Author(s):  
Jinke Chen ◽  
Weilin Zhuge ◽  
Xinqian Zheng ◽  
Yangjun Zhang
Keyword(s):  
Total Pressure ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Expansion Ratio ◽  
Design Model ◽  
Two Stage ◽  
System Parameters ◽  
Filter Performance ◽  
Turbocharging System ◽  
Total Pressure Ratio

As the result of increasingly strict emission regulations and demand of fuel reduction, current light and medium duty engines are being highly boosted with complex two-stage turbocharging systems. The purpose of this work is to investigate the influence of two-stage turbocharging system parameters on the engine performance and the optimization of these parameters. An analytical pre-design model of the series two-stage turbocharging system for an internal combustion engine was developed, which builds the relationship between total pressure ratio, total expansion ratio and other two-stage turbocharging system parameters. Considering total expansion ratio as a function of expansion ratio between HP and LP turbine, minimum total expansion ratio can be determined using this model. The ratio of total pressure ratio to total expansion ratio, engine brake thermal efficiency and total heat exchange of coolers are considered as the parameters for engine performance evaluation. Influence of two-stage turbocharging system parameters, such as efficiency of compressors and turbines, cooling water temperature, cooler efficiency, pressure loss of coolers, EGR rate and bypass gas rate of wastegate, etc., on engine performance was analyzed respectively. Results show that the performance of a two-stage turbocharging engine is impacted mainly by LP turbocharger efficiency, intercooler performance and air filter performance.

The Challenges of Turbocharger Matching for North American Freight Locomotives

2019 ◽  
Author(s):  
Thomas Lavertu ◽  
Matthew Hart ◽  
Christopher Homison ◽  
Preeti Vaidya
Keyword(s):  
North American ◽  
Engine Performance ◽  
Ambient Air ◽  
Ambient Conditions ◽  
Efficient Operation ◽  
Engine Efficiency ◽  
Air Temperatures ◽  
Wide Range ◽  
The Impact ◽  
Operating Points

Abstract Engine development is centered on developing a solution for best performance while meeting emissions and operational requirements. This will lead to a tradeoff between engine efficiency and emissions across a wide range of load and ambient operating points. Proper airflow to the engine through turbocharger matching is critical to ensure efficient operation and to meet emissions. This study addresses the challenges of turbocharger matching for vehicle advanced emissions control using a North American freight locomotive application as an example. The airflow trends in moving across the various operating points will be shown along with the impact on both the turbocharger and engine performance. First, the airflow trends across the locomotive load set points will be discussed along with the performance and emissions tradeoffs to meet required airflows. Results on the impact on turbocharger performance such as speed will be shown along with the engine efficiency and emissions implications. Next, the ambient operating requirements for a locomotive will be reviewed and the impact on turbocharger matching. Locomotives operate in a wide range of ambient conditions, including altitudes up to 3,050 meters and across ambient air temperatures ranging from −40 °C to well over 38 °C (including higher temperature operation). This thermal swing provides stress on the turbocharger to efficiently deliver the necessary airflow across all conditions. Trends in turbocharger performance will be reviewed and discussed across this range of ambient conditions. In addition, challenges unique to locomotive applications, such as unventilated tunnel operation and vibrational loading, will be reviewed. Finally, potential for advanced technologies such as variable geometry turbines and their applicability to locomotive operation will be discussed.

A Torque Balance Method for Multi-Cylinder Gasoline Engines With Non-Uniform Cylinder-to-Cylinder Combustion Strategies

2019 ◽  
Author(s):  
Qinghua Lin ◽  
Pingen Chen
Keyword(s):  
Catalytic Reduction ◽  
Control Strategies ◽  
Fuel Efficiency ◽  
The United States ◽  
Nox Emission ◽  
Successful Implementation ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Engine Model ◽  
Lean Nox

Abstract Lean burn gasoline engines have attracted more and more attentions over the past two decades. One of the main challenges in commercializing lean burn gasoline engines in the United States is lean NOx control to meet the stringent NOx emission regulation. Several types of lean aftertreatment systems including passive selective catalytic reduction (SCR) systems and lean NOx traps (LNTs), have been intensively investigated to meet the NOx emission requirements without triggering significant penalties on fuel efficiency. One of the most promising technologies to achieve this goal is non-uniform cylinder-to-cylinder combustion (NUCCC) control strategies. However, successful implementation of NUCCC strategies are challenging tasks since it may cause cylinder-to-cylinder torque imbalance and thus deterioration of drivability. The purpose of this study is to propose and evaluate a systematic method for generating the references of fuel quantity and air quantity for different cylinders to simultaneously achieve cylinder-to-cylinder torque balance and non-uniform cylinder-to-cylinder air/fuel ratio (AFR) for multi-cylinder engines in various scenarios. To validate the effectiveness of the proposed method, simulation studies were carried out using a multi-zone engine model. The simulation results show that, the proposed references, if successfully tracked, can lead to torque balance across the cylinders as well as non-uniform cylinder-to-cylinder AFR.

Model Based Gas Turbine Parameter Corrections

2003 ◽  
Author(s):  
Joachim Kurzke
Keyword(s):  
Mach Number ◽  
Gas Turbine ◽  
Thermodynamic Model ◽  
Performance Monitoring ◽  
Engine Performance ◽  
Steam Injection ◽  
Correction Method ◽  
Ambient Conditions ◽  
Wide Range ◽  
Parameter Correction

Ambient conditions have a significant impact on the temperatures and pressures in the flow path and on the fuel flow of any gas turbine. Making observed data comparable requires a correction of the raw data to sea level Standard Day conditions. The most widely applied gas turbine parameter correction method is based on keeping some dimensionless Mach number similarity parameters invariant. These similarity parameters are composed of the quantity to be corrected multiplied by temperature to the power ‘a’ and pressure to the power ‘b’ with exponent ‘a’ being theoretically either 0, +0.5 or −0.5 and ‘b’ either 0 or 1.0. To improve the accuracy of this approach it is common practice to empirically adapt the temperature and pressure exponents ‘a’ and ‘b’ in such a way that the correction process leads to a better correlation of the data. Finding empirical exponents requires either many consistently measured data that cover a wide range of ambient temperatures and pressures or a computer model of the engine. A high fidelity model is especially well suited for creating optimally matched exponents and for exploring the phenomena that make these exponents deviate from their theoretical value. This paper discusses the questions that arise when creating empirical exponents with a thermodynamic model of the gas turbine. The gas turbine parameter correction method based on Mach number similarity parameters can get complex if effects like humidity, bleed air or power off-take, free power turbines, switching between various fuel types (Diesel and natural gas), water respectively steam injection, variable geometry or afterburners have to be considered. In such a case it might be simpler — and certainly more accurate — to use the thermodynamic model for the gas turbine parameter correction. Computing power required for running a model is nowadays of no relevance and the better consistency of the data available for engine performance monitoring can yield a significantly improved performance diagnostic capability.

scholarly journals A novel objective oriented methodology for marine engine–turbocharger matching

2021 ◽  
pp. 146808742110397
Author(s):  
Panagiotis Mizythras ◽  
Evangelos Boulougouris ◽  
Gerasimos Theotokatos
Keyword(s):  
Fuel Consumption ◽  
Engine Performance ◽  
Response Surfaces ◽  
Data Availability ◽  
Cylinder Block ◽  
Parametric Modelling ◽  
Marine Engine ◽  
Engine Model ◽  
Operational Profile ◽  
Turbocharging System

The matching of the turbocharging system with a marine engine is an essential undertaking due to the turbocharger effects on the engine performance, emissions and response, whilst the limited data availability during the ship design phase renders it challenging. This study aims at developing a novel methodology for the matching of a single turbocharger and multiple turbochargers connected in parallel with marine engines. This methodology employs a compressor parametric modelling tool and a zero-dimensional engine model, whilst taking into account the engine operational profile and the turbocharger components flow limitations. The compressor parametric tool is used for the generation of a database with compressor families that can be investigated during the matching procedure. The model of one engine cylinder block is used for mapping the engine performance parameters at a wide engine operating envelope by developing response surfaces. The developed methodology is implemented for the case study of the turbocharger matching with the propulsion engine of an Aframax tanker. The annual fuel consumption and the engine load diagram upper limit are employed as the main objectives for the selection the turbocharging system. The derived results demonstrate that the effective turbocharger matching results in reducing the engine brake specific fuel consumption up to 5%. The identified turbochargers led to the reduction of the ship annual fuel consumption in the range 1.3%–5.3% compared to the reference engine, whilst providing a more expanded load diagram. This study overcomes the limitations of the manual engine turbocharger–matching process providing decision support on the effective turbocharger matching to satisfy contradictory objectives.

Novel Engine Cycle Enabling Partial Load Fuel Efficiency Beyond Full Load Conditions

2019 ◽  
Author(s):  
Arjen de Jong
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Activation Technique ◽  
Engine Operation ◽  
Engine Model ◽  
Fuel Consumption Reduction ◽  
Partial Load ◽  
Consumption Reduction

Abstract Fuel consumption reduction and emission reductions in internal combustion engines (ICE) is a hot topic nowadays. An adaption of cylinder de-activation technique called ECONAMIQ over-expansion can be applied to engines to improve fuel efficiency. Using the pressure from the exhaust gas from the active cylinders, the ‘idle’ cylinders could be expanded to extract more work out of the engine during partial load operation. Using the virtual simulation environment GT-Power, this cycle is applied to a 4-cylinder SI engine. This engine model is simulated for a part load operation point and compared with a standard 4-cylinder engine model and 4-cylinder engine model equipped with cylinder de-activation. From these simulations various variables for engine operation (valve timing etc.) are optimized to further reduce fuel consumption of the engine. A final brake specific fuel consumption reduction of over 10% is achieved using the overexpansion cycle, while improving engine performance on two burning cylinders over 10% as well. With this improvement it is shown that the over-expansion cycle has a significant benefit compared to a standard ICE and cylinder de-activation techniques. These simulations are being validated on an engine test dyno using a natural aspirated ICE.

Advanced Automotive Engine Thermal Management: Simplified Diesel Engine Model and Experimental Validation

2005 ◽  
Author(s):  
Christopher J. Simoson ◽  
John R. Wagner
Keyword(s):  
Thermal Management ◽  
Rural Areas ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Exhaust Gas ◽  
Combustion Chemistry ◽  
Automotive Engine ◽  
Power Characteristics ◽  
Engine Model

Diesel engines fulfill diverse demands in urban and rural areas throughout the world. While the advantages of compression ignition engines are superior to other internal combustion engines in torque generation and fuel efficiency, some diesel exhaust emissions pose health and environmental problems. Emission reduction techniques generally diminish one type of tailpipe gas yet often sacrifice engine performance and may even raise other emission levels. For instance, exhaust gas recirculation can reduce NOx emissions. However, the dilution of the combustion charge with hot inert exhaust gas hinders the engine’s power characteristics. To solve this problem, an EGR cooler allows the exhaust gases to be cooled prior to mixing with intake air allowing a denser cylinder charge for combustion. The effective application of cooled EGR requires a smart thermal management system. In this paper, a real time empirical and analytical model will be introduced to estimate the diesel engine’s overall performance. The simplified model considers the engine’s combustion chemistry, as well as the thermal, emissions, and rotational dynamics. Representative numerical and experimental test results are presented and discussed to validate the model. Eventually, an on-board computer controller will use this model to regulate the EGR valve’s functionality and the smart thermal system.

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