Steam Turbine Power Plant Research Articles

Development of an algorithm of implementation of programs of repair of steam boilers and turbines of TPPs based on technical condition of power equipment

Deterioration and aging of the technical fleet of thermal power facilities lead to an unpredictable shutdowns of power equipment. Therefore, it is necessary to create a special approach in maintenance and repair programs, taking into account the possibility of predicting the moment of onset of the defect, its development, as well as the time of possible equipment failure. The equipment maintenance system used at the enterprises is based on the collection of retrospective data on defects and failures on the main and auxiliary equipment of the TPP and summarizing statistics on identical or similar equipment samples. Analysis of domestic and foreign methods of maintenance and organization of repair, as well as possibility of their application in modern power engineering is given. In order to create an efficient production asset management system, which addresses the problem of finding a balance between the potential risk of losses associated with both the operation of equipment and the cost of correcting defects, new class systems are now used in the software market, which carry out equipment maintenance based on the forecast. In order to optimize the equipment maintenance system and ensure uninterrupted and reliable operation of the equipment at minimum operating costs, as well as to reduce equipment downtime, unscheduled and emergency operations, it is advisable to use a modern approach to manage both reliability and risk, as well as the cost of asset ownership. This will enable to control the economic efficiency of the use of production assets. The necessity of creation of an algorithm of implementation of repair programs of power equipment base on technical condition for its use in digital power systems is shown. An algorithm is proposed for implementing the repair program of power units of electric power plants, including steam boilers and turbines of thermal power plants, differing by taking into account the technical condition of power equipment, which allows recognizing the defect that has appeared, determining the cause of its occurrence, its evolution and the duration of possible equipment failure. In the developed repair maintenance algorithm, it is proposed to make a transition from statistical empirical assessments of the technical condition of the equipment to objective estimates obtained on the basis of automated technical diagnostics systems and predictive analysis of situations.

Research on the versatility of Arctic marine nuclear power plant

Research on the versatility of nuclear power plants can increase the utilization rate of nuclear power plants and reduce the development cycle and cost. By comparing the power requirements of Russian nuclear power icebreakers, polar transport ships, and floating nuclear power plants, and combining the development status of Russian marine reactor devices and steam turbine generator sets, the analysis shows that marine nuclear power plants can be based on low (38tMW), The three-level benchmark reactor devices of medium (175tMW) and high (350tMW) and the two-level benchmark steam turbine power plants of low (6∼8 eMW) and medium (35-40 eMW) are designed for multi-scheme combination.

Extreme learning machine – radial basis function (ELM-RBF) networks for diagnosing faults in a steam turbine

ABSTRACT A fast and reliable fault diagnosis system for a steam turbine in thermal power plant is crucial. The system will detect and classify a potential or occurring fault, hence suitable precautions steps will be correctly determined, and unplanned breakdown will be prevented. This study proposes a new application of extreme learning machine-radial basis function networks (ELM-RBF) for steam turbine fault diagnosis system. ELM-RBF recently has been known for its extremely fast computation. The proposed system was tested with real fault historical data from a steam power plant in Jakarta. To evaluate the system performance, a comparison with backpropagation neural networks (BPNN) was conducted. Four scenarios using ELM-RBF and BPNN, with and without ReliefF for feature selection were designed. The results show high accuracy in almost all the scenarios tested. The BPNN shows better accuracy than ELM-RBF, however, ELM-RBF performs considerably faster computation than BPNN without significant decrease in accuracy.

Reliability and Maintainability Investigation of Generator in Steam Turbine Power Plant using RAMD analysis

Generator is key unit of steam turbine power plant which is used to convert mechanical energy into electrical energy. This energy is further used for completing the requirement generated by various sectors of country. Generator is one of the most important component of steam turbine power plant configured with seven subsystems in series configuration. So, it is necessary to ensure its smooth functioning which is attain by the proper functioning of its subcomponents. It is important to increase operational availability of subsystem. Hence, present study is proposed to investigate various reliability measures of generator used in STP through RAMD approach at component level. For this purpose, mathematical models using Markovian birth death process have been developed for all subsystems of generator. These models are very helpful in reliability, maintainability, and availability analysis of generators. RAMD analysis will play significant role in this direction. This will help to find critical component of system so that proper maintenance strategies can be proposed. It is assumed that all failure and repair rates associated with each component followed exponential distribution and adequate repair facility always remains available with system. Various system performance measures like reliability function, maintainability function, dependability function and steady state availability for different components as well as system have been evaluated. The numerical results have been derived to highlight the importance of study.

Variable parametric test to improve the machinability of Inconel-718 using Tungsten Carbide tool

The Inconel-718 is a nickel based super alloy containing an old age hardening alloy of nickel–chromium as addition which provides increased strength without its decrease in ductility. It is known as a difficult to cut material due to certain properties like high thermal resistance, high creep, corrosion resistance having the capability of retaining toughness and strength at high temperatures. Inconel-718 has a large number of applications in the world of manufacturing such as aircraft gas turbines, steam turbine power plants, reheaters and reciprocating engines. Due to such superior quality functions, its machining becomes more challenging for which Tungsten Carbide is one of the tools to improve the machinability to 2.64%. In this paper, parametric tests has been carried out in CNC machining to determine the tool performance and improve the machining conditions.

Влияние метода синтеза трет-бутилированных трифенилфосфатов на эксплуатационные свойства огнестойких жидкостей

Three substituted aryl esters of orthophosphoric acid are the base component of fire-resistant fluids used in the lubricating and electro-hydraulic control system at steam and gas turbines of power plants. In this paper, we studied the possibility of improving the physicochemical and performance properties of phosphates, which are made of the raw materials available in the Russian Federation: phenol and 4-tert-butylphenol by reducing the content of an undesirable component - unsubstituted triphenyl phosphate, which is particularly vulnerable towards water. According to the results of the work, the conclusions were made: - a decrease in the content of triphenyl phosphate to a level of 1% and below leads to some improvement (reduction) of the air release time and an increase in the hydrolytic stability (represented as reducing the change in acid number after prolonged contact with water) of the fire-resistant fluid based on mixed esters. The degree of change of these properties is quantified. - it is possible to achieve the minimum content of triphenyl phosphate by changing the phosphorylation technology. By carrying out the process stepwise, the possibility of the interaction of phosphorus oxychloride with unsubstituted phenol is substantially eliminated, that is why there is almost no probability of an undesirable component formation in the resulting mixture of esters.

Identification of Babbitt Damage and Excessive Clearance in Journal Bearings through an Intelligent Recognition Approach

Journal bearings play an important role on many rotating machines placed on industrial environments, especially in steam turbines of thermoelectric power plants. Babbitt damage (BD) and excessive clearance (C) are usual faults of steam turbine journal bearings. This paper is focused on achieving an effective identification of these faults through an intelligent recognition approach. The work was carried out through the processing of real data obtained from an industrial environment. In this work, a feature selection procedure was applied in order to choose the features more suitable to identify the faults. This feature selection procedure was performed through the computation of typical testors, which allows working with both quantitative and qualitative features. The classification tasks were carried out by using Nearest Neighbors, Voting Algorithm, Naïve Associative Classifier and Assisted Classification for Imbalance Data techniques. Several performance measures were computed and used in order to assess the classification effectiveness. The achieved results (e.g., six performance measures were above 0.998) showed the convenience of applying pattern recognition techniques to the automatic identification of BD and C.

Piped Gas Fuels GT Power Plant Growth

Abstract In the last 10 years the growth of America’s natural gas fueled, gas turbine power plants have flourished in its lower 48 states. They are replacing older coal-fueled steam turbine power plants, ending a century’s-old dominance of King Coal, for the nation’s electricity production.

Preliminary Analysis of the Use of Solid Biofuels in a Ship’s Power System

Abstract This paper presents the results of applying ennobled solid biomass via mechanical compaction or torrefaction as fuel for ships, in terms of fire safety, environmental protection, the increase in liquid fuel prices and the dwindling resources of crude oil. The object of investigation is a ship of the ro-pax ferry type, with low cruising range, which is intended for service on the Baltic Sea. The ship’s power system is discussed and the results of calculations of the thermal cycle for a steam turbine power plant are presented. We present a simplified comparative analysis of a fuel bunker for a ship with a power plant including biomass fired boilers, and for a ship with a conventional solution of a motor power plant supplied by ultra-low sulphur fuel originating from crude oil. The advantages of applying a fluidised bed biomass fired boiler are highlighted, and selected results from tests of this boiler are presented. In addition, we assess potential fire hazards on the ship resulting from the storage and transport of pellets, and from pellets after torrefaction.

Phase-Field Simulation of Stress Corrosion Cracking in Stainless Steel

Stress corrosion cracking (SCC) sometimes occurs in stainless steels, which are used for steam turbines of geothermal power plants. In order to prevent SCC that causes serious accidents in the plants, understanding the SCC behavior through experiments and numerical simulations is essential. Phase-field (PF) method is one of the widely used numerical simulation methods to analyze various microscale-material phenomena including electrochemical reactions such as corrosion. In this study, we have developed a new PF model for simulating a SCC behavior in a stainless steel, which includes the stress concentration at the propagating crack tip, diffusion and electrophoresis of ions in the liquid solution. The PF model is based on the PF model for general and pitting corrosion in a pure iron [C. Tsuyuki et al., Scientific Reports, Vol. 8 (2018), 12777.], which incorporates the Butler-Volmer equation. The stress evolution during the SCC is calculated by solving the mechanical equilibrium equation by means of fast Fourier transform. The diffusion and electrophoresis of ions are analyzed by solving the Nernst-Planck equation. Through the numerical simulations of SCC in a polycrystalline stainless steel which have a notch, we revealed that the crack growth rate increase in accordance with the stress intensity factor. The results have proved the crack proceeds through the grain when the elastic strain energy at the crack tip is high, and it propagate through the grain boundary when the low energy.

Steam Turbine Performance Evaluation Based on Principal Component Analysis and Information Entropy

Information entropy and fuzzy analytical theory were combined and applied on the state assessment of power plant steam turbine unit. This method can be combined with the measured data of power plant, and made a comprehensive evaluation of the different working conditions. Fuzzy analysis of the original matrix can be a evaluation matrix, and the information entropy was introduced to solve the problem of calculating the weight of multi attribute factor set. Once the attribute weight is determined, the comprehensive evaluation value corresponding to the different working conditions can be defined and calculated. The results obtained by this method were compared with those obtained by the principal component analysis method. And the results obtained by information entropy method were objective and unique. The superiority of the method was verified. Under all conditions, the comprehensive evaluation value can be used as one index of the thermal archives as a benchmark for fault diagnosis, which provided a new idea and evaluation method for steam turbine fault diagnosis, and had a strong basic research and practical application value.

Upgrade of Separator-Superheaters in Nuclear Power Plants with Pressurized Water and Boiling Water Reactors by Physical-Modeling Based Modernization

Russian systems of intermediate separation and superheating of steam, operated as part of steam turbines of all nuclear power plants, operate with an insufficient level of reliability and efficiency. Design temperatures of overheating steam are not reached in most cases. The paper analyzes the characteristics of the working processes occurring in the apparatus: the flow of superheated wet steam in the separator and the superheater stages, dehumidification and subsequent flow of the separation in the separators, the intensity of heat exchange between the condensing heating steam of high pressure and the heated steam of low pressure, as well as the condensate flow of heating steam. Proposals are formulated to create more reliable and efficient devices, taking into account half a century of domestic and international experience in their design and operation.

Exergy analysis of a steam-turbine power plant using thermocombustion

This paper deals with the exergy analysis of a thermal power plant using different fuels, including biodiesel. The main goal is to understand the effect of design parameters and chemical dissociation of combustion products on energy and exergy efficiencies. Mass, energy and exergy analyses are made of the main components of the system, considering six different sources of irreversibilities: combustion chamber, heat transfer process, steam condensation, flue gas emission to the atmosphere, pump and frictional reheat at the steam turbine. Grassmann diagrams highlight the exergy flows and where the potential improvements exist. Results are obtained through ThermoCombustion, a virtual lab for combustion processes. The exergy analysis shows that the maximum source of exergy destruction is the boiler, followed by chimney exhaust, then steam turbine, and the condenser. Unlike the traditional methods, in this work, it was possible to distinguish between the irreversibilities thermal (due to the heat transfer) of the intrinsic irreversibility of the adiabatic combustion (associated with the chemical reactions and the viscous friction) in the steam boiler. The exergy loss distribution indicates that boiler irreversibility yields the highest exergy loss in the power plant. The use of the fuels with a simple molecular structure containing oxygen molecules will reduce the exergy destruction. The destruction of exergy in the reactive process decreases if the combustion temperature is increased, although this would lead to increases in NOx emissions. The regenerative cycle reduces total irreversibilities, increasing exergy efficiency.

Dataset on thermodynamics performance analysis and optimization of a reheat - regenerative steam turbine power plant with feed water heaters.

Steam power plants have a considerable potential to meet the growing energy demand, but its dependence on conventional fossil fuels has hampered its viability. One of the ways to minimize fuel consumption and upgrade the performance of a Rankine cycle is by incorporating closed feedwater heaters(FWHs). The datasets contained in this paper are thermodynamic performance analysis carried out on reheat – regenerative steam power plant with FWHs using CyclePad V2.0 software. The thermodynamic performance indices assessed are thermal efficiency, network output, heat rate, fuel consumption, boiler efficiency and specific steam consumption. Result obtained show that an increase in the number of FWHs decreases the fuel consumption, heat rate, heat rejected in condenser and heat input to the cycle. This effect invariably can lead to a reduction in operating cost and environmental impacts.

Thermodynamics analysis and performance optimization of a reheat – Regenerative steam turbine power plant with feed water heaters

This study investigates the thermodynamics performance analysis of a reheat-regenerative steam power plant using CyclePad V2.0 software. The impact of closed Feedwater Heaters (FWHs) on the functionality indices of the selected power plant was examined. Results of the study show that as the number of closed FWH increases from one to ten, the thermal efficiency and boiler efficiency rise from 42.17% to 45.97% and 79% to 96.4%, respectively. The fuel consumption, heat rejected to the condenser, heat rate, network output and heat input to the power cycle decrease from 9.697 kg/s to 4.686 kg/s, 209.32 kJ/kg to 129.68 kJ/kg, 8536.87 kJ/kWh to 8318.48 kJ/kWh, 152.22 MW to 102.89 MW and 361.11 kJ/kg to 237.98 kJ/kg, respectively as the number of FWHs increased. On the contrary, specific steam consumption increases from 0.0234 kg/kWh to 0.0370 kg/kWh. Moreover, fuel consumption decreases by 51.7% and the efficiency gain (η) successively diminish with increment in the number of closed FWHs. Also, both enthalpy rise and temperature rise increase with increase in the number of closed FWHs. As the number of heaters increases, so is the total temperature rise of feed water (Δtfw), by regeneration, less becomes the heat added to water in the boiler, more becomes the mean temperature of heat addition, and more is the cycle efficiency. This result implies that a decrease in operating cost of the plant and environmental impacts can be achieved with an increase in the number of closed FWHs. Hence, this study establishes the importance of closed FWHs in revamping the performance of a steam power plant.

Failure Analysis of 2Cr13 Blade in a 135MW Low Pressure Steam Turbine

The failure mode and causes of low-pressure rotor 2Cr13 stainless steel blades in a power plant steam turbine were analyzed using fracture analysis, SEM, chemical composition analysis and metallographic techniques. The fracture characteristics and mechanism of the blades were discussed. The results show that the failure mode is fatigue which was caused by the machining tool mark at R corner of blade root and tenon transition area.

USE OF GAS TURBINES FOR COMBINED ENERGY PRODUCTION

Abstract. Aim. Despite the obvious expediency of their widespread implementation, gas turbine (GT) and combined cycle gas turbine (CCGT) plants were only used in limited quantities in the former USSR and CIS countries. Due to the exhaustion of possibilities to increase the fuel use efficiency and return on investment (ROI) in steam-turbine combined heat and power (CHP) plants, the development of GT and CCGT plants becomes an urgent problem. In current global practice, the primary fuel for gas turbines and combined cycle gas turbines is natural gas. However, until recently, there has been a lack of experience in the design, construction and operation of GT and CCGT plants in the CIS countries. Method. Due to the ad hoc nature of research in this area, it was necessary to systematise the results of existing studies and assess the state of research at the world level taking regional characteristics into account. Results. The article presents the main considerations and potential effectiveness of the use of gas turbines. Basic gas turbine construction schemes are investigated along with their techno-economic characteristics and an assessment of their comparative utility. Conclusion. Considering the widespread availability of natural gas, it is recommended that gas turbine and combined-cycle plants be installed as part of the process of technical re-equipment in the fuel and energy complex, industry, agriculture and municipal energy sectors as part of the design and construction of new energy sources in the light of positive world experience and the current level of development of gas turbine technologies. Ubiquitous implementation of gas turbine units in the centres supplying heat and electric loads will reduce the regional economy’s need for energy fuel and ensure an increase in energy capacity without the need to construct new complex and uneconomic steam turbine power plants.

Behavioral Analysis of Cooling Tower in Steam Turbine Power Plant using Reliability, Availability, Maintainability and Dependability Investigation

Behavioral Analysis of Cooling Tower in Steam Turbine Power Plant using Reliability, Availability, Maintainability and Dependability Investigation

Operational availability analysis of generators in steam turbine power plants

The main aim of this study is to explore the availability and profitability of generators, which are key units of steam turbine power plants, considering exponential failure and arbitrary repair time distributions. A Markov birth–death process and supplementary variable technique are used to evaluate system effectiveness measures. Such a generator mainly consists of seven repairable components arranged in a series configuration. A stochastic model of the generator is developed, and the Chapman–Kolmogorov differential difference equation of the system derived. Finally, the results for the steady-state availability and profitability of the system are obtained for a particular case that will be helpful to system designers to enhance the performance of plants to some extent.

ВЫБОР ТИПА ГАЗОПОРШНЕВЫХ УСТАНОВОК ДЛЯ ТЕПЛО- И ГАЗОСНАБЖЕНИЯ В РОССИИ

In various sectors of the economy, including district heating systems in cities and settlements, steam turbine and gas turbine thermal power plants are mainly used. Their operation is based on cogeneration, which is the conversion of chemical fuel energy into electrical and thermal energy. At the same time, a significant part of the heat supply sources are still represented by heating boilers, which consume electricity for their own needs. In the gas industry, diesel engines are used as the drive for gas pumping plants. One of the factors hindering the organization of combined production of electric and thermal energy in heating boilers is the lack of production in Russia of gas-piston power plants with a capacity of more than 500 kW. The use of imported equipment for these purposes is usually not economically and technologically justified. According to the order of the Ministry of Industry and Trade of Russia dated 16.04.2019 No. 1327, the share of imports of gas piston and gas turbine units is planned to be reduced from 70% in 1918 to 25% in 2024. One of the promising directions of creating gas piston installations in Russia is justified: reproduction on a modern technological basis of two-stroke engines produced in the USSR of GD100 series gas piston engines that are still working at a number of facilities. The Russian government is considering converting mainline and shunting locomotives of railway transport to gas-powered fuel. One of the ways of increasing the efficiency of two-stroke engines is shown-in-cylinder mixing of gas with air with pre-chamber-flare spark ignition.