Ship Gas Turbine Research Articles

Study on scuffing failure of gas turbine ball bearing based on 3D mixed lubrication and dynamics

Ship gas turbine bearings are subjected to heavy loads and intricate interface micromorphologies, predominantly operate in a mixed lubrication regime. Excessive asperity relative sliding can cause transient high-temperature spikes at contact points, leading to scuffing failures. Dynamic parameters such as bearing friction and clearance, along with vibrations causing fluctuating velocities and loads, further influence the lubrication condition that, in its turn, can increase the risk of scuffing. This study focuses on oil-lubricated gas turbine bearings, accounting for their typical transient working conditions and real surface roughness. The coupling characteristics of ball bearing dynamics, lubrication, and flash temperature are explored. Findings indicate that the most severe contact conditions occur at azimuth angles of 0° and 360°. The risk of ball Scuffing failure exceeds that of the inner raceway. As axial load increases under the azimuth angle of 360°, the area with zero film thickness is increasing, elevating the chances of asperity contact, friction coefficient, and interface temperature, which is detrimental to lubrication. To mitigate pitting and scuffing failures, it's recommended to maintain the bearing's maximum hertz pressure below 1.21 GPa.

Designing brazing filler metal for heat-resistant nickel alloys of new generation marine gas turbines

The object of research is the processes of the formation of brazed joints and the stressed state. The subject of research is structure, chemical composition, long-term high-temperature strength at a temperature of 900 °C, speed of high-temperature salt corrosion. Existing brazing filler metals have a high-temperature performance of 40–50 % of the performance of the SM93-VI and SM96-VI alloys. Despite this, brazing is the main technique of joining modern heat-resistant cast alloys. Therefore, the development of new brazing filler metals that ensure the formation of joints with increased long-term high-temperature strength is relevant. Ship gas turbine blades operate at a temperature of 900 °C. The purpose of the development of the new SBM-4 brazing filler metal is to achieve long-term high-temperature strength of brazed joints at a temperature of 900 °C at the level of 85–90 % of the strength of heat-resistant alloys SM93-VI and SM96-VI. A two-stage method was used in the development of SBM-4 brazing filler metal. At the first stage, the chemical composition of the brazing filler metal base was determined, taking into account the peculiarities of operating conditions of the blades of marine gas turbine engines and the achievements of materials science of heat-resistant alloys. At the second stage, the depressant and its necessary content were selected. Computer software was used to determine the distribution between the γ- and γ'-phases, taking into account the participation of each element in both dispersion and solid-solution strengthening. Rational limits of concentrations of alloying elements were determined. The criterion was the minimum susceptibility of brazing filler metal to the formation of brittle phases, taking into account the influence of chromium, rhenium, and tantalum concentrations on resistance to high-temperature salt corrosion and high-temperature performance. The long-term strength of SM93-VI and CM96-VI alloys brazed with SBM-4 brazing filler metal is 89–91 % of the strength of the base metal. Technologies of brazing and correction of casting defects have been introduced into production.

Toughening Mechanism of Thermal Barrier Coatings

Thermal barrier coatings are applied to the protection of metal components in aircraft thrusters, power generation and ship gas turbine engines, which can make the gas turbine run for a long time in a high-temperature environment. The fracture toughness of the coating characterizes the ability of the material to prevent crack propagation and is one of the most important factors to be taken into consideration to prolong the life of the thermal barrier coating. The current research is mainly through dispersion toughening, the phase transformation toughening, whisker toughening, ferroelastic toughening, and other methods to improve the fracture toughness of ceramic coatings. In this paper, the use of different toughening mechanisms and the addition of unique materials to improve the fracture toughness of thermal barrier coatings are introduced, and the future research direction is put forward.

High-Temperature Salt Corrosion of a Heat-Resistant Nickel Alloy

We develop a heat-resistant corrosion-resistant alloy based on nickel and alloyed with rhenium and tantalum. This alloy is intended for the production of blades for a new generation of power-generating and ship gas-turbine engines. It is shown that the introduction of rhenium (3.7–4.3 wt.%) and tantalum (2.5–4.3 wt.%) into the composition of the experimental alloy increases the high-temperature corrosion resistance of the material (narrows the frontal zone of corrosion damage) under the influence of gas-salt media formed under the combined action of the combustion products of fuel and seawater salts.

A Passive Control Method of Hub Corner Stall in a 1.5-Stage Axial Compressor under Low-Speed Conditions

Since the use of the compressor of a ship gas turbine is unavoidable at a low-speed operation, the flow field characteristics and stall mechanism at off-design speeds are important aspects for compressor designers. In this study, the first 1.5 stages of an eight-stage compressor are numerically simulated. The mechanism of compressor rotor instability at lower speeds is identified. The characteristic lines of compressors with various partial clearance are calculated at low speed (0.6 N). The flow field of the same outlet pressure (near stall point of the original compressor without clearance) is compared and analyzed. The results show that, at the near stall point, the suction surface separation and backflow occur in the main flow of the rotor top. It develops along the blade span and finally blocks the flow passage of the rotor, which results in the compressor stall. At the same time, the stall also occurs at the corner of the stator hub. In this paper, the characteristics of partial clearance in four different positions of the stator hub are analyzed. The near stall point and the working point are selected for the flow field analysis. It is concluded that the radial development of the stall vortex on the suction surface of the stator can be restrained by the partial clearance at the stator. In this paper, a passive control method by partial clearance is used in the real compressors, which is different from previous studies on cascades. The margin increases at low speeds.

ПРИМЕНЕНИЕ ТЕРМОХИМИЧЕСКОЙ УТИЛИЗАЦИИ В ЭНЕРГЕТИЧЕСКИХ УСТАНОВКАХ ВЫСОКОТЕХНОЛОГИЧНЫХ СУДОВ

The research’s subject is the processes of energy transformation of fuel in the ship power plant with thermo-chemical waste heat recovery. Modern approaches to assessing the energy efficiency of ship power plants were considered. The characteristics of traditional and perspective ships were analyzed. Passenger ships (including Ro-Ro ferry and cruise ships), offshore ships (including FPSO, FSRU, MODU, OSV, etc) and LNG/LPG carriers are classified as high-tech ships. It is discussed the application of thermo-chemical waste heat recovery in power plants of high-tech ships. It is proposed to increase the efficiency of fuel use by using synthesis gas obtained through thermo-chemical heat recovery of secondary energy resources of ship engines. The main objective of the study is to analyze the energy efficiency of steam thermo-chemical transformation of fuel in ship power plants. It is presented the design scheme of the marine power plant for an offshore platform. It is shown the mathematical model of the ship gas turbine installation with thermo-chemical heat recovery by steam conversion of associated gas. The associated gas conversion efficiency was determined by the heat potential of the exhaust gases and was calculated based on the thermal balance of the thermochemical reactor. The reactor has two stages. It is presented the results of mathematical modeling of processes in plant-based on gas turbine engine of the simple cycle under conditions of fixed output power, the fixed temperature of the gas in the turbine’s front for environmental parameters according to ISO 19859: 2016. It is revealed the efficiency of the scheme which used steam conversion of associated gas in the two-stages reactor. Calculation of thermo-chemical conversion efficiency indicators showed the complete conversion of heavy hydrocarbons. The increase in the energy efficiency of the installation is 10...12%. The results obtained coincide with previous studies and confirm the effectiveness of the use of thermo-chemical heat recovery in power plants of high-tech ships. The research results can be used in the promising marine power plants designing.

ОСОБЕННОСТИ ПРИМЕНЕНИЯ ПРОДУКТОВ КОНВЕРСИИ МЕТАНОЛА В СУДОВОЙ ГАЗОТУРБИННОЙ УСТАНОВКЕ С ТЕРМОХИМИЧЕСКОЙ РЕГЕНЕРАЦИЕЙ СБРОСНОГО ТЕПЛА

The research’s subject is the processes of energy transformation of fuel in the ship gas turbine plant with thermochemical regeneration. Modern approaches to assessing the energy efficiency of ship power plants were considered. The characteristics of traditional and alternative marine fuels were analyzed. The use of methanol as a low-carbon marine fuel is discussed. It is proposed to increase the efficiency of methanol use by using synthesis gas obtained through thermochemical heat recovery of secondary energy resources of ship engines. The main objective of the study is to analyze the effects on the energy efficiency of steam thermochemical transformation of methanol of the limitations associated with the system of supplying gaseous fuel to the engine. The influence of pressure in the thermochemical reactor on the steam’s efficiency of reforming of methanol was analyzed. The design schemes of two variants of the ship gas turbine installation with thermochemical heat recovery by steam conversion of methanol are presented. The methanol conversion efficiency was determined by the heat potential of the exhaust gases and was calculated based on the thermal balance of the thermochemical reactor. The reactor’s model is two- component. The mathematical model of the turbocompressor unit is based on an enlarged calculation taking into account the total pressure loss in all elements of the gas-air duct. The results of mathematical modeling of processes in plants based on gas turbine engines of simple and regenerative cycles under conditions of fixed methanol’s consumption, the fixed temperature of the gas in the turbine’s front for environmental parameters according to ISO 19859: 2016 are presented. The efficiency of the scheme which used steam conversion of methanol at pressures corresponding to the working pressure in the combustion chamber was revealed. The increase in the energy efficiency of the installation is 3 ... 5 % with basic parameters and 10 ... 11 % for higher conduction temperatures or for catalytic reactors. The research results can be used in the promising power plants designing.

Rolling element bearings health status indictor analysis

According to the vibration mechanism of ship gas turbine rolling element bearings common failure modes, the variation of the common indicators during the rolling element bearings health status degradation process is analyzed, and the reflection ability of the various indicators is studied based on the consistency and sensitivity. The results show that the Root-Mean-Square value, Peak-Peak value, Wavelet Energy Spectrum Entropy and Singular Spectrum Entropy can effectively reflect the health state change of rolling element bearings.

Эксплуатационные дефекты судовых дизельных и газотурбинных двигателей

Эксплуатационные дефекты судовых дизельных и газотурбинных двигателей

ГЕНЕРАЦИЯ И МЕТОДЫ СНИЖЕНИЯ ВИБРОАКУСТИЧЕСКОЙ АКТИВНОСТИ В ГАЗОПЕРЕКАЧИВАЮЩИХ АГРЕГАТАХ С ГАЗОТУРБИННЫМ ПРИВОДОМ

Block-modular gas compressor units (GCU) of a container type with an aircraft and ship gasturbine drive – a power source of vibration and noise pollution of environment. 
 Their basic inner sources – gas turbine engine and a centrifugal compressor. Besides, to power noise sources in the structure of GCU belong multiplier, an air cleaner of the air inlet system, an exhaust shaft, section walls of an engine and a compressor.
 A gas turbine engine and a compressor define mainly a distant sound field and the rest of noise sources – near-in one.
 A complex modernization of such plants may be carried out on the basis of the investigations of the level of vibrations and noise of all elements of such units.
 With this purpose there were carried out inves-tigations of vibro-acoustic characteristics of GCU of GCU-16MG type with the capacity of 16 MW where as a drive of the centrifugal compressor of 370-18-1 NZL type serves a ship convertible engine of DG-90 type produced by “Zarya” Co.
 Noise sources and vibrations of blade machines are studied, their vibro-acoustic characteristics are analyzed and methods for the decrease of vibro-acoustic activities of GCUs of such a type are offered.

Meeting materials needs in extreme naval corrosive and oxidative environments

High temperature applications demand materials that have a variety of properties such as high strength, toughness, creep resistance, fatigue resistance, as well a resistance to degradation by interaction with the environment. All potential metallic materials become unstable in many high temperature environments without the presence of a stable, protective coating on the component surface. Reliable high temperature propulsion materials are critical for enabling improvements in engine efficiency, reducing fuel costs, and decreasing maintenance/total life cycle costs. Propulsion materials for both Naval aircraft and ship gas turbine engines are subjected to the corrosive marine, salt laden environment to differing degrees. Materials life is dependent on dynamic combinations of temperature, cyclic activities and mechanical stress with the marine environment. Research seeks to explore and understand the thermodynamics and kinetics of materials interactions and material stability in Naval environments and temperatures in order to develop models that lead to creating new materials or establishing life prediction of existing and novel materials. This research may discover new mechanisms and causes that lead to materials instabilities and degradation at high temperatures. The research and the models that follow need to address how these mechanisms are fundamentally influenced by mechanics, interdiffusion, coating or materials chemistry, temperature, environment and structure in order to establish fundamental scientific principles to mitigate such instabilities and degradation. This paper will dwell on some past results of materials testing and offer some views on future directions into materials research in high temperature materials in aggressive Naval environments which can be applicable to other services.

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.

Developing of a Lubricant Oil for the Ship Gas Turbine of Reducer

The combination of ship gas turbine working at special environment, this article pass through the study of base oil and composite additive, developed an application marine environment of the ship gas turbine reducer lubricants. According to comprehensive performance assessment, the product has excellent high-temperature anti-oxidant, anti-wear, corrosion inhibition and anti-foam performance. The indicators have reached the requirements. With the development of China's ship gas turbine technology, especially UGT25000 ship gas turbine technology is imported from Ukraine, as well as the recent introduction of the GE LM2500 + G4 Series of technology for power plant of construction. The localization of the supporting facilities are growing louder, there is a strong market rigid demand. Ship gas turbine must be one of the trends of the development of Marine Power. Ship gas turbine due to light weight, small size, stand-alone power, fast start; less pollution, vibration, high thermal efficiency and gas initial temperature, it is easy to realize the cascade of energy use, economy, received widespread attention and application. China's ship gas turbine of modification and design draw the aero-engine, ship gas turbine is a continuous rotation of the impeller mechanical heat engine; it is mainly composed by three parts of the compressor, gas generator and gas turbine. Ships generally use diesel (fuel have heavy trend, the heavy diesel oil or No. 200 heavy oil will be used) as fuel, in order to adapt the ship gas turbine, ship gas turbine need to transform, particularly its' lubrication system [1]. Foreign aviation gas engine lubricants are based on the U.S. standard as a reference, due to the differences of using purpose and fuel, so that the ship gas turbine oil has different requirements. Since ship gas Turbine Technology started late in China, the ship gas turbine core engine technology patents come from the United States, Russia and Ukraine, so the use of gas turbine lubricants, as well as matching accessories and other standards, which are more or less directed reference to refer to the original foreign standards [2,3]. We have never been established using standard ship gas turbine oil. Ship gas turbine apply to the special conditions (high humidity, salt spray, etc.), the ship gas turbine of lubrication has a higher demand, particularly for the ship gas turbine reducer of lubrication. The ship gas turbine reducer work in the low-speed heavy-duty and high-speed heavy-duty , high strength, high shear conditions, how ensure the ship gas turbine reducer to normal work is very important at high load conditions. In this regard, developing of a ship gas turbine reducer lubricant is very necessary.

Possibility to regenerate parts of ship gas turbine engines using the plasma metallization process

This paper presents the regeneration of parts of ship gas turbine engines by the plasma metallization process. One of the most modern metallization procedures is a plasma process, which has more advantages compared to other metallization procedures. This work will deal with metallization processes, i.e. the plasma-based metallization process and the possibility of applying this process to the regeneration of parts of ship gas turbine engines (GTEs).

The test programme and the methodology of analyzing the vibrations spectrum of a Proteus 52M/558 ship gas turbine

The paper presents a programme for testing vibrations on a ship gas turbine, based on an analogy of testing and analysis of vibrations on aircraft and/or helicopter gas turbines. A particular attention is given to a choice of vibration parameters and to the analysis of the vibration spectrum as well as to the methods of estimation of criteria of vibration acceptability. The results of the measurement of the vibrations on a Proteus 52M/558 gas turbine installed on a RTOP-405 ship are shown. .

Конвертирование авиационных и корабельных газотурбинных двигателей в стационарные установки промышленного назначения

The summary of the book (in two parts), devoted is presented to converting aviation and ship gas-turbine engines to stationary installations for development of the electric power and swapping of gas. In the first part it is considered thermodynamics designing gas-turbine the engine including the three-dimensional analysis of a stream in basic elements of the machine. The second part contains data concerning methods of increase in a resource and an estimation of parameters of reliability of stationary installations, and also about methods of their calculation The book is intended for experts in the field of gas-turbo plant, and also for students and post-graduate students of corresponding specialties of higher educational institutions

Work of Mashproekt NPP and Zarya Production Association in conversion of ship gas turbine engines

Work of Mashproekt NPP and Zarya Production Association in conversion of ship gas turbine engines

The Evolution of Machinery Control Systems Aboard U.S. Navy Gas Turbine Ships

ABSTRACTAlmost 25 years ago, the U.S. Navy committed to gas turbines for propulsion and electrical power generation for surface combatants. Jet engines from the aerospace industry were “marinized” and specified for several designs. Today, there are over one hundred gas turbine powered surface ships; almost half also have gas turbine generators. This fundamental change, notably from steam to gas turbine power, brought with it a new philosophy in the way prime movers are controlled and monitored. Unmanned engineering spaces were a fundamental part of the new design. Direct thrust control in the hands of the helmsman was possible. Possibly the most profound effect was the introduction of electronics in the main engineering spaces on a large scale. Data buses for data logging and bell logging were used as a means to reduce the tedium of normal watch standing.Gas turbine machinery control systems have entered a second generation with the introduction of the DDG‐51 class destroyer and the AOE‐6 supply ship. Hard‐wired analog interfaces have given way to digital interfaces over asynschronous multiplexed data buses. Dedicated pushbuttons and indicators have given way to keyboards and plasma displays. Single use microprocessors with firmware coding have given way to standard microcomputers and general high order language (HOL) software code.This paper will trace the control systems' evolution from the Spruance and Perry classes to today's gas turbine designs. An attempt will be made to draw a sense of direction from this evolution. An in‐depth explanation of the DDG‐51 control system will be offered, as well as suggestions as to the future of control systems for gas turbine ships. Particular emphasis will be placed on the man‐machine interface and the maintenance philosophy for both the control system hardware and software.

Real-time fault detection and diagnosis: The use of learning expert systems to handle the timing of events

Abstract : The successful performance of real-time, sensor-based fault detection and diagnosis in large and complex systems is seldom achieved by operators. Examples of operator and system failures are presented and analyzed. The lack of an effective method for handling temporal data is seen as one of the key problem in this area. As part of the solution to these problems, a methodology is introduced that is able to make good use of temporal data to perform fault diagnosis in a subsystem of a Navy ship gas turbine engine propulsion unit. The methodology is embedded in a computer program designed to be used as a decision aid to assist the operator. It utilizes machines learning, is able to cope with uncertainty at several levels, work in real-time, and is developed to the point of possible application. Data are presented and analyzed with regard to the effectiveness of this approach. Relevance and applicability to other process control and classification problems are discussed. The approach is put forth as an example of how relatively simple existing techniques can be assembled into more powerful real-time diagnostic tools. Keywords: artificial intelligence; multisensor integration.

Performance of second generation airfoil coatings in marine service

The performances of several production and development LM2500 turbine airfoil coatings were evaluated after various periods of marine service aboard the Gas Turbine Ship Callaghan. In-depth metallurgical analysis has shown that two new coatings, CoCrAlHfPt and CoCrAlHf, afford a significant increase in lifetime over that obtained with standard production coatings.