Two-Stage Turbocharger Modeling for Engine Control and Estimation

2007 ◽  
Author(s):  
Yong Shu ◽  
Michiel van Nieuwstadt
Keyword(s):  
High Pressure ◽  
Low Pressure ◽  
Model Parameters ◽  
Total Efficiency ◽  
Outlet Temperature ◽  
Two Stage ◽  
Modeling And Control ◽  
Charging System ◽  
In Series ◽  
Pressure Compressor

The increasingly stringent emissions regulations and needs for higher power density for both turbo-diesel passenger vehicle and commercial vehicles have demanded significant alterations to the basic architecture of turbochargers. An attractive option for providing a high-boost system is the use of two-stage turbocharger which consists of two different size turbochargers connected in series that may or may not utilize bypass regulation. The exhaust mass flow is expanded by the high pressure turbine to the low pressure turbine, and on the other side the air flow is compressed through the low pressure compressor to the high pressure compressor. This increases the complexity of the air-charging system and requires new methodologies for modeling and control. A two-stage turbocharger model is presented in this paper. The total efficiency of the two-stage compressor, which poses the biggest problem in two-stage turbocharger modeling, was derived based on a second law analysis. A new parameter, compressor temperature ratio, was introduced as a linkage between the two stage compressors and also used to predict the two-stage compressor outlet temperature. Extrapolation to lower turbocharger speeds and compressor flow rates by using curve fitting methods was also discussed. The model for a two-stage turbine with a bypass valve is derived in the same way. Engine dynamometer tests have been performed to identify the model parameters and to validate the model structure. The test results show a good agreement between the model predictions and test data. In conclusion, this two stage turbocharger model is suitable for turbocharger control design and the estimation of some key turbocharger parameters.

Asymmetric Solution for Compressor Station Spare Capacity

2006 ◽  
Author(s):  
Rainer Kurz ◽  
Matt Lubomirsky
Keyword(s):  
High Pressure ◽  
Compression Ratio ◽  
Low Pressure ◽  
Compressor Station ◽  
Spare Capacity ◽  
High Pressure Compressor ◽  
Power Turbine ◽  
In Series ◽  
Asymmetric Solution ◽  
Pressure Compressor

Arranging compressor units in series rather than in parallel can offer a number of advantages in many applications. However, especially if the compression ratio is rather high, it is desirable to use different impellers for the low-pressure and the high-pressure compressor. Otherwise, one or both operate off their best efficiency points. This leaves however the problem of the staging of a spare unit. In the paper, a solution to this dilemma is described. To understand the underlying constraints, the relationships between the system resistance, the compressor characteristic, and the power turbine characteristic are analytically derived.

scholarly journals Optimization of Powerful Two-stage Screw Centrifugal Pump

2018 ◽  
Vol 220 ◽  
pp. 03009 ◽  
Author(s):  
Oleg Baturin ◽  
Grigorii Popov ◽  
Daria Kolmakova ◽  
Vasilii Zubanov ◽  
Julia Novikova ◽  
...  
Keyword(s):  
High Pressure ◽  
Centrifugal Pump ◽  
Mathematical Optimization ◽  
Pressure Head ◽  
Low Pressure ◽  
Calculation Model ◽  
Pump Efficiency ◽  
Rotor Speed ◽  
Two Stage ◽  
Optimization Parameters

The article presents a refining method for a two-stage screw centrifugal pump by the joint usage of mathematical optimization software IOSO, meshing complex NUMECA and CFD software ANSYS CFX. The pump main parameters: high-pressure stage rotor speed was 13300 rpm; low-pressure rotor speed was 3617 rpm by gearbox; inlet total pressure was 0.4 MPa; outlet mass flow was 132.6 kg/s at the nominal mode. This article describes the process of simplifying the calculation model for the optimization. The parameters of camber lines of the low-pressure impeller, transition duct, and high-pressure impeller blades for two sections (hub and shroud) were chosen as optimization parameters. The blades of low-pressure impeller, transition duct and high-pressure impeller have changed during optimization. The optimization goal was the increase of the pump efficiency with preservation or slight increase in the pressure head. The efficiency was increased by 3%.

scholarly journals Parametric diagnostics of the condition of a dual-flow turbojet engine using neural network simulation of the operating process

2018 ◽  
Vol 224 ◽  
pp. 02057
Author(s):  
Anas S. Gishvarov ◽  
Julien Celestin Raherinjatovo
Keyword(s):  
Neural Network ◽  
High Pressure ◽  
Combustion Chamber ◽  
Early Stage ◽  
Low Pressure ◽  
Similarity Criteria ◽  
Ann Model ◽  
Turbojet Engine ◽  
Operating Process ◽  
Pressure Compressor

The article presents a method of parametric diagnostics of the condition of a dual-flow turbojet engine (DFTE). The method is based on the identification (determination) of the condition of the DFTE components (the compressor, combustion chamber, turbine) with application of a mathematical model of the operating process which is presented as an artificial neural network (ANN) model. This model describes the relation between the monitored parameters of the DFTE (the air temperatures (Tlpc*, Thpc*) beyond the low pressure compressor (LPC) and the high pressure compressor (HPC), the pressure beyond the LPC (Plpc), the fuel consumption rate (Gf), the gas temperatures (Thpt*, Tlpt*) beyond the high pressure turbine (HPT) and the low pressure turbine (LPT)) and the parameters of the condition of its components (the efficiencies of the LPC and the HPC (ηlpc*, ηhpc*), the stagnation pressure recovery factor in the combustion chamber (σcc), the efficiencies of the HPT and the LPT (ηhpt*, ηlpt*)). The parameters of the condition of the engine components (ηlpc*, ηhpc*, σcc, ηhpt*, ηlpt*) are the similarity criteria (integral criteria) which enable to identify the condition of the DFTE components to a high degree of reliability. Such analysis enables to detect defects at an early stage, even if the values of the monitored parameters (Тlpc*, Тhpc*, Plpc, Gf, Тhpt*, Тlpt*) are within the permissible limits. We provide the sequence for development of the ANN model and the results of its performance study during the parametric diagnostics of the condition of the DFTE.

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.

Soft Computing Application for Gas Path Fault Isolation

2004 ◽  
Author(s):  
Ranjan Ganguli ◽  
Rajeev Verma ◽  
Niranjan Roy
Keyword(s):  
High Pressure ◽  
Fuzzy Sets ◽  
Fuzzy System ◽  
Low Pressure ◽  
Fault Isolation ◽  
Rule Base ◽  
Rotor Speed ◽  
Genetic Fuzzy System ◽  
Radial Basis ◽  
Pressure Compressor

A fuzzy system that automatically develops its rule base from a linearized performance model of the engine by selecting the membership functions and number of fuzzy sets is developed in this study to perform gas turbine fault isolation. The faults modeled are module faults in five modules: fan, low pressure compressor, high pressure compressor, high pressure turbine and low pressure turbine. The measurements used are deviations in exhaust gas temperature, low rotor speed, high rotor speed and fuel flow from a base line ‘good engine’. A genetic algorithm is used to tune the fuzzy sets to maximize fault isolation success rate. A novel scheme is developed which optimizes the fuzzy system using very few design variables and therefore is computationally efficient. Results with simulated data show that genetic fuzzy system isolates faults with accuracy greater than that of a manually developed fuzzy system developed by the authors. Furthermore, the genetic fuzzy system allows rapid development of the rule base if the fault signatures and measurement uncertainties change. In addition, the genetic fuzzy system reduces the human effort needed in the trial and error process used to design the fuzzy system and makes the development of such a system easier and faster. A radial basis neural network is also used to preprocess the measurements before fault isolation. The radial basis network shows significant noise reduction and when combined with the genetic fuzzy system leads to a diagnostic system that is highly robust to the presence of noise in data.

Generation of microwave plasma under high pressure and fabrication of ultrafine carbon particles

1998 ◽  
Vol 13 (6) ◽  
pp. 1724-1727 ◽  
Author(s):  
H. Yagi ◽  
T. Ide ◽  
H. Toyota ◽  
Y. Mori
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Diffraction Analysis ◽  
Microwave Plasma ◽  
Plasma Generator ◽  
Two Stage ◽  
Carbon Particles ◽  
Helium Gas ◽  
In Series ◽  
Fine Carbon

A microwave plasma generator, which functions under high pressure, has been developed and used in the fabrication of fine carbon particles. The plasma generator is a two-stage-type resonator, which consists of rectangular and semi-cylindrical-type resonators which are coupled in series for torching plasma and keeping it stable under high pressure. The plasma can be torched in helium gas at 3 × 106 Pa by tuning the dimensions of apparatus elements. Fine carbon particles of ~50 nm are obtained using a mixture of helium and methane gas. The particles are found to be crystalline from the results of transparent electron microscopy and diffraction analysis.

Corrosion Studies of High and Low Pressure Compressor Blades of a Gas Turbine

2005 ◽  
Author(s):  
A. Boschetti ◽  
E. Y. Kawachi ◽  
M. A. S. Oliveira
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Low Pressure ◽  
Compressor Blade ◽  
Compressor Blades ◽  
X Ray ◽  
Corrosion Studies ◽  
High Pressure Compressor ◽  
Pressure Compressor ◽  
Base Superalloy

This work presents preliminary results of corrosion studies for three blades, one of the low pressure compressor and two of two different stages of the high pressure compressor of a gas turbine, which has been operating for 5,000 hours. Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray diffraction (XRD), Electrochemical Impedance Spectroscopy (EIS) in aqueous solution containing chloride, and Atomic Absorption Spectrometry (AAS) were used to characterize the blades surfaces. The SEM and EDS results showed that the homogeneity and amount of contaminants, such as sodium, potassium, calcium, magnesium, chloride and sulphur are bigger in the high pressure compressor blade surfaces than in the low pressure compressor blade surface. The EIS results showed that the degradation process in turbine compressor blades increases with the temperature and pressure increase inside the compressors and depends of the blade composition. The low pressure compressor blade, which was made of a Ti base superalloy exhibited smaller corrosion resistance (smallest charge transfer resistance value (Rct)) than the two high pressure compressor blades, which were made of a Fe base superalloy. However, despite of its lower resistance to corrosion, after 5,000 hours of service, the low pressure compressor blade did not present pitting corrosion while the high pressure compressor blades did.

Performance Analysis of Refrigerants R134a Two Stage Compression Cycle with Two Gas Cooler

2013 ◽  
Vol 753-755 ◽  
pp. 2782-2785
Author(s):  
Gui Jun Xue ◽  
Da Wei Liang ◽  
Guang Da Liu ◽  
Shui Qing Li ◽  
Zhen Jiang Zhou
Keyword(s):  
High Pressure ◽  
Performance Analysis ◽  
Downward Trend ◽  
Outlet Temperature ◽  
Two Stage ◽  
Intermediate Pressure ◽  
Compression Cycle ◽  
Increasing Trend

With increasing of high pressure, the two stage compression cycle with two gas cooler has a downward trend. With increasing of the evaporating temperature, the two stage compression cycle with two gas cooler has an increasing trend. With increasing of outlet temperature of condenser; the two stage compression cycle with two gas cooler has a downward trend. With increasing of intermediate pressure, the performances of the two stage compression cycle with two gas cooler are decreased.

Design and Test Plan of the Supercritical CO2 Compressor Test Loop

2008 ◽  
Author(s):  
Takao Ishizuka ◽  
Yasushi Muto ◽  
Masanori Aritomi
Keyword(s):  
High Pressure ◽  
Critical Point ◽  
Thermal Efficiency ◽  
Supercritical Co2 ◽  
Thermal Power ◽  
Low Pressure ◽  
Fiscal Year ◽  
Pressure Side ◽  
Test Loop ◽  
Pressure Compressor

Supercritical carbon dioxide (CO2) gas turbine systems can generate power at a high cycle thermal efficiency, even at modest temperatures of 500–550°C. That high thermal efficiency is attributed to a markedly reduced compressor work in the vicinity of critical point. In addition, the reaction between sodium (Na) and CO2 is milder than that between H2O and Na. Consequently, a more reliable and economically advantageous power generation system can be created by coupling with a Na-cooled fast breeder reactor. In a supercritical CO2 turbine system, a partial cooling cycle is employed to compensate a difference in heat capacity for the high-temperature — low-pressure side and low-temperature — high-pressure side of the recuperators to achieve high cycle thermal efficiency. In our previous work, a conceptual design of the system was produced for conditions of reactor thermal power of 600 MW, turbine inlet condition of 20 MPa/527°C, recuperators 1 and 2 effectiveness of 98%/95%, Intermediate Heat Exchanger (IHX) pressure loss of 8.65%, a turbine adiabatic efficiency of 93%, and a compressor adiabatic efficiency of 88%. Results revealed that high cycle thermal efficiency of 43% can be achieved. In this cycle, three different compressors, i.e., a low-pressure compressor, a high-pressure compressor, and a bypass compressor are included. In the compressor regime, the values of properties such as specific heat and density vary sharply and nonlinearly, dependent upon the pressure and temperature. Therefore, the influences of such property changes on compressor design should be clarified. To obtain experimental data for the compressor performance in the field near the critical point, a supercritical CO2 compressor test project was started at the Tokyo Institute of Technology on June 2007 with funding from MEXT, Japan. In this project, a small centrifugal CO2 compressor will be fabricated and tested. During fiscal year (FY) 2007, test loop components will be fabricated. During FY 2008, the test compressor will be fabricated and installed into the test loop. In FY 2009, tests will be conducted. This paper introduces the concept of a test loop and component designs for the cooler, heater, and control valves. A computer simulation program of static operation was developed based on detailed designs of components and a preliminary design of the compressor. The test operation regime is drawn for the test parameters.

Performance Analysis of Two Stage Compression Cycle with an Internal Heat Exchanger

2014 ◽  
Vol 540 ◽  
pp. 110-113
Author(s):  
Hong Li Wang ◽  
Ning Jia ◽  
Jing Rui Tian
Keyword(s):  
High Pressure ◽  
Heat Exchanger ◽  
Internal Heat ◽  
Outlet Temperature ◽  
Minimum Level ◽  
Two Stage ◽  
Intermediate Pressure ◽  
Internal Heat Exchanger ◽  
Compression Cycle ◽  
Increasing Trend

With increasing of the evaporating temperature, the two stage compression cycle with an internal exchanger’s COP has an increasing trend. In addition, R744 achieves the highest COP, and the R12 achieves the minimum level. With increasing of the high pressure and the outlet temperature of the condenser, the two stage compression cycle has a down trend. In terms of the increasing intermediate pressure, the two stage cycle with different refrigerants has different performance: R12’s COP has a downtrend with the pressure changing from 1MPa-3MPa, the rest refrigerants all increased first, and then decreased. Except for R12, they all have optimal intermediate pressure.

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