scholarly journals Estimation of gas turbine shaft torque and fuel flow of a CODLAG propulsion system using genetic programming algorithm

Pomorstvo ◽  
2020 ◽  
Vol 34 (2) ◽  
pp. 323-337
Author(s):  
Nikola Anđelić ◽  
Sandi Baressi Šegota ◽  
Ivan Lorencin ◽  
Zlatan Car

In this paper, the publicly available dataset of condition based maintenance of combined diesel-electric and gas (CODLAG) propulsion system for ships has been utilized to obtain symbolic expressions which could estimate gas turbine shaft torque and fuel flow using genetic programming (GP) algorithm. The entire dataset consists of 11934 samples that was divided into training and testing portions of dataset in an 80:20 ratio. The training dataset used to train the GP algorithm to obtain symbolic expressions for gas turbine shaft torque and fuel flow estimation consisted of 9548 samples. The best symbolic expressions obtained for gas turbine shaft torque and fuel flow estimation were obtained based on their R2 score generated as a result of the application of the testing portion of the dataset on the aforementioned symbolic expressions. The testing portion of the dataset consisted of 2386 samples. The three best symbolic expressions obtained for gas turbine shaft torque estimation generated R2 scores of 0.999201, 0.999296, and 0.999374, respectively. The three best symbolic expressions obtained for fuel flow estimation generated R2 scores of 0.995495, 0.996465, and 0.996487, respectively.

2021 ◽  
Vol 9 (6) ◽  
pp. 612
Author(s):  
Nikola Anđelić ◽  
Sandi Baressi Šegota ◽  
Ivan Lorencin ◽  
Igor Poljak ◽  
Vedran Mrzljak ◽  
...  

In this paper, the publicly available dataset for the Combined Diesel-Electric and Gas (CODLAG) propulsion system was used to obtain symbolic expressions for estimation of fuel flow, ship speed, starboard propeller torque, port propeller torque, and total propeller torque using genetic programming (GP) algorithm. The dataset consists of 11,934 samples that were divided into training and testing portions in an 80:20 ratio. The training portion of the dataset which consisted of 9548 samples was used to train the GP algorithm to obtain symbolic expressions for estimation of fuel flow, ship speed, starboard propeller, port propeller, and total propeller torque, respectively. After the symbolic expressions were obtained the testing portion of the dataset which consisted of 2386 samples was used to measure estimation performance in terms of coefficient of correlation (R2) and Mean Absolute Error (MAE) metric, respectively. Based on the estimation performance in each case three best symbolic expressions were selected with and without decay state coefficients. From the conducted investigation, the highest R2 and lowest MAE values were achieved with symbolic expressions for the estimation of fuel flow, ship speed, starboard propeller torque, port propeller torque, and total propeller torque without decay state coefficients while symbolic expressions with decay state coefficients have slightly lower estimation performance.


Author(s):  
Hun Cha ◽  
Yoo Seok Song ◽  
Kyu Jong Kim ◽  
Jung Rae Kim ◽  
Sung Min KIM

An inappropriate design of HRSG (Heat Recovery Steam Generator) may lead to mechanical problems including the fatigue failure caused by rapid load change such as operating trip, start-up or shut down. The performance of HRSG with dynamic analysis should be investigated in case of start-up or shutdown. In this study, dynamic analysis for the HRSG system was carried out by commercial software. The HRSG system was modeled with HP, IP, LP evaporator, duct burner, superheater, reheater and economizer. The main variables for the analysis were the temperature and mass flow rate from gas turbine and fuel flow rate of duct burner for given start-up (cold/warm/hot) and shutdown curve. The results showed that the exhaust gas condition of gas turbine and fuel flow rate of duct burner were main factors controlling the performance of HRSG such as flow rate and temperature of main steam from final superheater and pressure of HP drum. The time delay at the change of steam temperature between gas turbine exhaust gas and HP steam was within 2 minutes at any analysis cases.


Author(s):  
Chi-Rong Liu ◽  
Hsin-Yi Shih

The purpose of this study is to investigate the combustion and emission characteristics of syngas fuels applied in a micro gas turbine, which is originally designed for a natural gas fired engine. The computation results were conducted by a numerical model, which consists of the three-dimension compressible k–ε model for turbulent flow and PPDF (presumed probability density function) model for combustion process. As the syngas is substituted for methane, the fuel flow rate and the total heat input to the combustor from the methane/syngas blended fuels are varied with syngas compositions and syngas substitution percentages. The computed results presented the syngas substitution effects on the combustion and emission characteristics at different syngas percentages (up to 90%) for three typical syngas compositions and the conditions where syngas applied at fixed fuel flow rate and at fixed heat input were examined. Results showed the flame structures varied with different syngas substitution percentages. The high temperature regions were dense and concentrated on the core of the primary zone for H2-rich syngas, and then shifted to the sides of the combustor when syngas percentages were high. The NOx emissions decreased with increasing syngas percentages, but NOx emissions are higher at higher hydrogen content at the same syngas percentage. The CO2 emissions decreased for 10% syngas substitution, but then increased as syngas percentage increased. Only using H2-rich syngas could produce less carbon dioxide. The detailed flame structures, temperature distributions, and gas emissions of the combustor were presented and compared. The exit temperature distributions and pattern factor (PF) were also discussed. Before syngas fuels are utilized as an alternative fuel for the micro gas turbine, further experimental testing is needed as the modeling results provide a guidance for the improved designs of the combustor.


2000 ◽  
Author(s):  
Emiliano Cioffarelli ◽  
Enrico Sciubba

Abstract A hybrid propulsion system of new conception for medium-size passenger cars is described and its preliminary design developed. The system consists of a turbogas set operating at fixed rpm, and a battery-operated electric motor that constitutes the actual “propulsor”. The battery pack is charged by the thermal engine which works in an electronically controlled on/off mode. Though the idea is not entirely new (there are some concept cars with similar characteristics), the present study has important new aspects, in that it bases the sizing of the thermal engine on the foreseen “worst case” vehicle mission (derived from available data on mileage and consumption derived from road tests and standard EEC driving mission cycles) that they can in fact be accomplished, and then proceeds to develop a control strategy that enables the vehicle to perform at its near–peak efficiency over a wide range of possible missions. To increase the driveability of the car, a variable-inlet vane system is provided for the gas turbine. After developing the mission concept, and showing via a thorough set of energy balances (integrated over various mission profiles), a preliminary sizing of the turbogas set is performed. The results of this first part of the development program show that the concept is indeed feasible, and that it has important advantages over both more traditional (Hybrid Vehicles powered by an Internal Combustion Engine) and novel (All-Electric Vehicle) propulsion systems.


Author(s):  
Mohammad Javad Bazregari ◽  
Mahdi Gholinejad ◽  
Yashar Peydayesh ◽  
Nima Norouzi ◽  
Maryam Fani

This research presents a system to use natural gas to meet electricity, freshwater and cooling needs for a residential building in Bandar Abbas. The system includes a gas turbine, absorption chiller and multi-effect desalination (MED) plant. The energy produced in the gas turbine is used to generate electricity, and the excess energy is used to produce cooling and freshwater. Finally, an exergoeconomic evaluation of the system is performed. The effects of ambient temperature on the output power as well as the exergy current have been investigated. The COP of the absorption cycle has been investigated, and the results show that at an operating temperature of 150∘C compared to 90∘C, the efficiency rate increases to 20%. The highest exergoeconomic cost rate is related to absorption chiller, and the lowest is related to heat recovery steam generation. The results show that if the ambient temperature increases, the production capacity decreases. Increasing the fuel flow rate increases the power. Evaluation of two different solutions to reduce the ambient temperature and increase the fuel flow shows that increasing the fuel flow is a better solution, considering the exergy cost of the absorption chiller, which is 10 times higher than that of the gas turbine.


2015 ◽  
Vol 12 (1) ◽  
pp. 1-14 ◽  
Author(s):  
U. Campora ◽  
M. Capelli ◽  
C. Cravero ◽  
R. Zaccone

The paper presents the application of artificial neural network for simulation and diagnostic purposes applied to a gas turbine powered marine propulsion plant. A simulation code for the propulsion system, developed by the authors, has been extended to take into account components degradation or malfunctioning with the addition of performance reduction coefficients. The above coefficients become input variables to the analysis method and define the system status at a given operating point. The simulator is used to generate databases needed to perform a variable selection analysis and to tune response surfaces for both direct (simulation) and inverse (diagnostic) purposes. The application of the methodology to the propulsion system of an existing frigate version demonstrate the potential of the approach.


2018 ◽  
Vol 47 (4) ◽  
Author(s):  
Krzysztof Cpalka ◽  
Krystian Łapa ◽  
Andrzej Przybył

Author(s):  
Shusheng Zang ◽  
Jaqiang Pan

The design of a modern Linear Quadratic Regulator (LQR) is described for a test steam injected gas turbine (STIG) unit. The LQR controller is obtained by using the fuel flow rate and the injected steam flow rate as the output parameters. To meet the goal of the shaft speed control, a classical Proportional Differential (PD) controller is compared to the LQR controller design. The control performance of the dynamic response of the STIG plant in the case of rejection of load is evaluated. The results of the computer simulation show a remarkable improvement on the dynamic performance of the STIG unit.


2012 ◽  
Vol 03 (03) ◽  
pp. 601-609 ◽  
Author(s):  
Seyed Morteza Marandi ◽  
Seyed Mahmood VaeziNejad ◽  
Elyas Khavari

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