High-Altitude Matching Characteristic of Regulated Two-Stage Turbocharger With Diesel Engine

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Ruilin Liu ◽  
Zhongjie Zhang ◽  
Surong Dong ◽  
Guangmeng Zhou
Keyword(s):  
Diesel Engine ◽  
High Altitude ◽  
Process Model ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Boost Pressure ◽  
Two Stage ◽  
Variable Geometry Turbocharger ◽  
Different Altitudes

To improve engine power at high altitude, the regulated two-stage turbocharger (RTST) which was applied to different altitudes was developed by the authors. The working process model of heavy-duty common-rail diesel engine matched with RTST was built to study the regulating characteristic of variable geometry turbocharger (VGT) vane and both turbine bypass valves and also matching performance of RTST with engine at different altitudes. The control scheme of RTST at different altitudes and engine operating conditions was first put forward, and the optimal opening maps of VGT vane and both turbine bypass valves at different altitudes and engine operating conditions were obtained. The results show that the optimal openings of VGT vane and both turbine bypass valves decrease with increase of altitude, and the optimal opening range of VGT vane becomes narrower with increase of altitude. The operating points of both high-pressure (HP) and low-pressure (LP) compressors locate at high-efficiency region of each compressor map, respectively, and compressor efficiency exceeds 70% at altitude of 5500 m. The total boost pressure ratio increases with altitude and reaches the maximum value of 5.1 at altitude of 5500 m. Compared with single-stage turbocharged engine, the rated power, maximum torque, and torques at lower engine speed at altitude of 5500 m increase by 48.2%, 51%, and 65–121% separately, and the minimum fuel consumption decreases by 12.6%.

A Method for Matching Two-Stage Turbocharger System and Its Influence on Engine Performance

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Binyang Wu ◽  
Zhiqiang Han ◽  
Xiaoyang Yu ◽  
Shunkai Zhang ◽  
Xiaokun Nie ◽  
...  
Keyword(s):  
Entire Range ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Air Flow ◽  
Boost Pressure ◽  
Drive Power ◽  
Two Stage ◽  
Operational Conditions ◽  
Exhaust Heat ◽  
Turbocharging System

Matching of a two-stage turbocharging system is important for high efficiency engines because the turbocharger is the most effective method of exhaust heat recovery. In this study, we propose a method to match a two-stage turbocharging system for high efficiency over the entire range of operational conditions. Air flow is an important parameter because it influences combustion efficiency and heat load performance. First, the thermodynamic parameters of the engine and the turbocharging system are calculated in eight steps for selecting and matching the turbochargers. Then, by designing the intercooler intensity, distribution of pressure ratio, and compressor operational efficiency, it is ensured that the turbochargers not only meet the air flow requirements but also operate with high efficiency. The concept of minimum total drive power of the compressors is introduced at a certain boost pressure. It is found that the distribution of pressure ratio of the high- and low-pressure (LP) turbocharger should be regulated according to the engine speed by varying the rack position of the variable geometry turbocharger (VGT) to obtain the minimum total drive work. It is verified that two-stage turbochargers have high efficiency over the entire range of operational conditions by experimental research. Compared with the original engine torque, low-speed torque is improved by more than 10%, and the engine low fuel consumption area is broadened.

Mean-Line Modelling of a Variable Geometry Turbocharger (VGT) and Prediction of the Engine-Turbocharger Coupled Performance

2017 ◽  
Author(s):  
Anand Mammen Thomas ◽  
Jensen Samuel ◽  
A. Ramesh
Keyword(s):  
Pressure Ratio ◽  
Operating Conditions ◽  
Relaxation Techniques ◽  
Variable Geometry ◽  
Test Bed ◽  
Variable Geometry Turbocharger ◽  
Initial Assumption ◽  
Blockage Factor ◽  
Pressure Boundary Condition ◽  
Variable Geometry Turbine

Mean-line modelling approach which has generally been applied to fixed geometry turbocharger turbines has been extended to predict the performance of the variable geometry turbine for different inlet blade angles. The model uses an initial assumption of turbine inlet pressure which was iteratively corrected based on outlet pressure boundary condition. The model was implemented in MATLAB and stable and convergent solutions were obtained using relaxation techniques for different operating conditions. Experiments were done on a state of the art transient diesel engine test bed using the same VGT turbine in the turbocharger at different engine torques and speeds. Using experimental data the model was calibrated for the aerodynamic blockage in the fixed nozzle and rotor blade passages. Results revealed that turbine overall pressure ratio can be predicted accurately if a blockage factor varying with nozzle blade orientation is used in the model.

scholarly journals Establishment of a Two-Stage Turbocharging System Model and Analysis on Influence Rules of Key Parameters

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1953
Author(s):  
Wei Tian ◽  
Defeng Du ◽  
Juntong Li ◽  
Zhiqiang Han ◽  
Wenbin Yu
Keyword(s):  
Diesel Engine ◽  
Pressure Ratio ◽  
Constraint Equation ◽  
Optimization Method ◽  
Expansion Ratio ◽  
Total Energy Consumption ◽  
Two Stage ◽  
Constraint Equations ◽  
Turbocharging System ◽  
Target Pressure

This paper took a two-stage turbocharged heavy-duty six-cylinder diesel engine as the research object and established a two-stage turbocharging system matching model. The influence rules between the two-stage turbocharging key parameters were analyzed, while summarizing an optimization method of key parameters of a two-stage turbocharger. The constraint equations for the optimal distribution principle of the two-stage turbocharger’s pressure ratio and expansion ratio were proposed. The results show that when the pressure ratio constraint equation and expansion ratio constraint equation are satisfied, the diesel engine can achieve the target pressure ratio, while the total energy consumption of the turbocharger is the lowest.

Influence of varying altitudes on matching characteristics of the Twin-VGT system with a diesel engine and performance based on analysis of available exhaust energy

2019 ◽  
Vol 234 (7) ◽  
pp. 1972-1985 ◽  
Author(s):  
Zhongjie Zhang ◽  
Ruilin Liu ◽  
Guangmeng Zhou ◽  
Chunhao Yang ◽  
Surong Dong ◽  
...  
Keyword(s):  
High Pressure ◽  
Diesel Engine ◽  
Low Pressure ◽  
Variable Geometry ◽  
High Altitudes ◽  
Variable Geometry Turbocharger ◽  
In Series ◽  
Exhaust Energy ◽  
Different Altitudes ◽  
Engine Power

A variable geometry turbocharger in series with a variable geometry turbocharger (Twin-VGT) system was designed to improve engine power at high altitudes. The influence of altitudes on the performance of the Twin-VGT system was investigated in the perspective of available exhaust energy. The interaction between exhaust flow characteristics of Twin-VGT and openings of Twin-VGT vanes was theoretically analyzed at different altitudes. Meanwhile, a model of a diesel engine matched with the Twin-VGT system was built to study the matching performance of the Twin-VGT system with engine at different altitudes. The optimal opening maps of both high-pressure and low-pressure VGT vanes at high altitudes were obtained to achieve the maximum engine power. The results showed that the optimal openings of high-pressure and low-pressure VGT vanes decreased with increase in altitudes. The operating points of the two-stage compressors located at the high efficiency region and the compressor efficiency region both exceeded 62% at different altitudes. The global expansion ratio increased with increase in altitudes and reached 4.9 at 5500 m. Compared with the VGT in series with a fixed geometry turbocharger on testing bed, exhaust energy of Twin-VGT turbines at low speeds was utilized reasonably and global pressure ratio increased by 0.69–0.94, while brake-specific fuel consumption decreased by 11.24–33.62% under low speeds above altitudes of 2500 m.

Aerodesign and Testing of an Aeromechanically Highly Loaded LP Turbine

2003 ◽  
Vol 128 (4) ◽  
pp. 643-649 ◽  
Author(s):  
F. J. Malzacher ◽  
J. Gier ◽  
F. Lippl
Keyword(s):  
High Speed ◽  
High Efficiency ◽  
Pressure Ratio ◽  
Test Facility ◽  
Performance Measurements ◽  
Two Stage ◽  
Low Pressure Turbine ◽  
High Mach ◽  
Lp Turbine ◽  
Compact Geometry

Future turbo systems for aircraft engines need very compact geometry, low weight, and high efficiency components. The geared turbofan enables the engine designer to decouple the speed of the fan and the LP turbine to combine a low speed fan with a high speed LP turbine. The low pressure turbine is a key component for this concept. The technological challenge is very much driven by the very high low-spool speed. Resulting as well from high inlet temperatures, the LP turbine needs cooling of the first stage. A new MTU LPT concept for such a high speed turbine has been developed and tested in a turbine rig. The concept consists of a two-stage turbine for extremely high speed and high stage pressure ratio (ER 2.3). This leads to extra high mechanical loading and an exotic combination of high Mach numbers (transonic) and very low Reynolds numbers. In this paper some design features are described. Some elements of the airfoil design were also tested in additional cascade tests. The two-stage turbine was tested at the Altitude Test Facility of the ILA, Stuttgart. The test setup is described including details of the instrumentation. Test data shows a good turbine performance. Measurements are also compared to 3D CFD, which is used to analyze local effects.

Thermal modelling of modern diesel engines: proposal of a new heat transfer coefficient correlation

2011 ◽  
Vol 225 (11) ◽  
pp. 1544-1560 ◽  
Author(s):  
C A Finol ◽  
K Robinson
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Heat Transfer Coefficient ◽  
Diesel Engine ◽  
Transfer Coefficient ◽  
Diesel Engines ◽  
Internal Combustion Engines ◽  
Operating Conditions ◽  
Boost Pressure ◽  
Simple Relationship

Existing methods for predicting heat fluxes and temperatures in internal combustion engines, which take the form of correlations to estimate the heat transfer coefficient on the gas-side of the combustion chamber, are based on methodology developed over the past 50 years, often updated in view of more recent experimental data. The application of these methods to modern diesels engines is questionable because key technologies found in current engines did not exist or were not widely used when those methods were developed. Examples of such technologies include: high-pressure common rail and variable fuel injection strategies including retarded injection for nitrogen oxides emission control; exhaust gas re-circulation; high levels of intake boost pressure provided by a single- or double-stage turbocharger and inter-cooling; multiple valves per cylinder and lower swirl; and advanced engine management systems. This suggests a need for improved predicting tools of thermal conditions, specifically temperature and heat flux profiles in the engine block and cylinder head. In this paper a modified correlation to predict the gas-side heat transfer coefficient in diesel engines is presented. The equation proposed is a simple relationship between Nu and Re calibrated to predict the instantaneous spatially averaged heat transfer coefficient at several operating conditions using air as gas in the model. It was derived from the analysis of experimental data obtained in a modern diesel engine and is supported by a research methodology comprising the application of thermodynamic principles and fundamental equations of heat transfer. The results showed that the new correlation adequately predicted the instantaneous coefficient throughout the operating cycle of a high-speed diesel engine. It also estimated the corresponding cycle-averaged heat transfer coefficient within 10 per cent of the experimental value for the operating conditions considered in the analysis.

scholarly journals SIMULATION OF A TURBOCHARGING SYSTEM EQUIPPED FOR A DIESEL ENGINE D1146TIS

2009 ◽  
Vol 12 (14) ◽  
pp. 86-94
Author(s):  
Tuan Anh Le
Keyword(s):  
Diesel Engine ◽  
High Efficiency ◽  
Simulation Software ◽  
Boost Pressure ◽  
Load Curve ◽  
Ic Engine ◽  
Research Activities ◽  
University Of Technology ◽  
Turbocharging System ◽  
Dimensional Simulation

The paper presents simulated results of a turbocharging system in a combination of turbine - compressor - IC. engine on one dimensional simulation software AVL-BOOST. Findings of the research depict clearly that the turbocharger equipped for the engine has met all requirements to have high boost pressure for this engine. The full load curve of the engine is located out of the surge area and in the area of high efficiency of the compressor's map. Besides, findings of the research also virtually show the matching of the turbochager and the engine - an important basis for operating the turbocharged engine with highest efficiency. It is a part of the collaborative research activities on developing a new type of high tuborcharged IC. diesel engine between Hanoi University of Technology (HUT) and Vietnam Engine and Agricultural Machinary Corporation (VEAM).

Study on Mixed Pulse Converter (MIXPC) Turbocharging System and Its Application in Marine Diesel Engines

2010 ◽  
Vol 54 (01) ◽  
pp. 68-77
Author(s):  
Yi Cui ◽  
Hongzhong Gu ◽  
Kangyao Deng ◽  
Shiyou Yang
Keyword(s):  
Diesel Engine ◽  
Diesel Engines ◽  
Thermal Load ◽  
Fuel Efficiency ◽  
Operating Conditions ◽  
Tvd Scheme ◽  
Boost Pressure ◽  
Turbocharging System ◽  
Marine Diesel ◽  
Pulse Converter

In order to improve fuel efficiency and power density, the boost pressure of diesel engine is increasing continuously. The increase in boost level leads to some problems, such as lack of air under part load operating conditions, response delay during transient processes, and high mechanical and thermal load. In order to meet the high boost level demand, a new type of turbocharging system—mixed pulse converter (MIXPC) turbo-charging system for multicylinder diesel engines (from 4 to 20 cylinders) has been invented. A turbocharged diesel engine simulation model, based on one-dimensional finite volume method (FVM) and total variation diminishing (TVD) scheme, has been developed and used to design and analyze the MIXPC turbocharging system. The applications of MIXPC system in in-line 8- and 4-cylinder and V-type 16-cylinder medium-speed marine diesel engines have been studied by calculation and experiments. The results show that the invented MIXPC system has superior engine fuel efficiency and thermal load compared with original turbocharging systems.

Simulation of a Diesel Engine with Variable Geometry Turbocharger and Parametric Study of Variable Vane Position on Engine Performance

2017 ◽  
Vol 67 (4) ◽  
pp. 375 ◽  
Author(s):  
Anand Mammen Thomas ◽  
Jensen Samuel J. ◽  
Paul Pramod M. ◽  
A. Ramesh ◽  
R. Murugesan ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Parametric Study ◽  
Thermodynamic Simulation ◽  
Weight Ratio ◽  
Engine Performance ◽  
Boost Pressure ◽  
Variable Geometry ◽  
Variable Geometry Turbocharger ◽  
Additional Degree ◽  
Wide Range

Modelling of a turbocharger is of interest to the engine designer as the work developed by the turbine can be used to drive a compressor coupled to it. This positively influences charge air density and engine power to weight ratio. Variable geometry turbocharger (VGT) additionally has a controllable nozzle ring which is normally electro-pneumatically actuated. This additional degree of freedom offers efficient matching of the effective turbine area for a wide range of engine mass flow rates. Closing of the nozzle ring (vanes tangential to rotor) result in more turbine work and deliver higher boost pressure but it also increases the back pressure on the engine induced by reduced turbine effective area. This adversely affects the net engine torque as the pumping work required increases. Hence, the optimum vane position for a given engine operating point is to be found through simulations or experimentation. A thermodynamic simulation model of a 2.2l 4 cylinder diesel engine was developed for investigation of different control strategies. Model features map based performance prediction of the VGT. Performance of the engine was simulated for steady state operation and validated with experimentation. The results of the parametric study of VGT’s vane position on the engine performance are discussed.

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