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Search results for: NAVAL GAS TURBINE
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Complex multidisciplinary optimization of turbine blading systems
PublicationThe paper describes the methods and results of direct optimization of turbine blading systems using a software package Opti_turb. The final shape of the blading is obtained from minimizing the objective function, which is the total energy loss of the stage, including the leaving energy. The current values of the objective function are found from 3D RANS computations (from a code FlowER) of geometries changed during the process...
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Negative carbon dioxide gas power plant integrated with gasification of sewage sludge
PublicationOne of the primary objectives of the negative carbon dioxide gas power plant (nCO2PP) is to develop an innovative technology confirming the possibility of the use of sewage sludge to produce electricity while having a positive impact on the environment. In this paper, a mathematical model is presented to estimate thermodynamic parameters of the system in relation to the gasification process and changes in such parameters in the...
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Pressure pulsations in turbine blade seal clearance
PublicationThe paper presents the results of numerical and experimental investigations into pressure forces generated in a turbine labyrinth seal. The experiments were performed on a single-stage air model turbine of the impulse type, while the numerical results were obtained by means of CFD Fluent Code. The performed experimental research and numerical calculations prove that in a shroud clearance the pressure pulsates and the effects of...
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Neural Modelling of Steam Turbine Control Stage
PublicationThe paper describes possibility of steam turbine control stage neural model creation. It is of great importance because wider application of green energy causes severe conditions for control of energy generation systems operation Results of chosen steam turbine of 200 MW power measurements are applied as an example showing way of neural model creation. They serve as training and testing data of such neural model. Relatively simple...
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Determination of Failure Causes of a Steam Turbine Casing
PublicationThe paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis;...
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Improving operating efficiency of a gas turboset via cooperation with an absorption refrigerating machine
PublicationThe analysis of increase of ambient air temperature entering the compressor on reduction in power output from the turbine and increase fuel use was conduced. For medium size gas turbine operates in winter and summer conditions elementary power and economical values was calculated. Conditions of the determination of turbine inlet air cooling solution (using thermal storage for reduce equipment size) are presented
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On a Method of Efficiency Increasing in Kaplan Turbine
PublicationThis paper presents a method of increasing efficiency in Kaplan-type turbine. The method is based on blade profile optimisation together with modelling the interaction between rotor and stator blades. Loss coefficient was chosen as the optimisation criterion, which is related directly to efficiency. Global optimum was found by means of Genetic Algorithms, and Artificial Neural Networks were utilised for approximations to reduce...
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Gas turbines – technological development and potential use in CAES systems
PublicationThis article briefly describes Compressed Air Energy Storage (CAES), focusing on the technological development of one of the key elements of such systems – the gas turbines. It presents the basic parameters and features of gas turbines, as well as turbine classes with example models. Main tendencies in the structural and technological development are discussed. Changes and trends on electric energy markets are becoming more and...
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Efficiency of gas mixtures detection by resistive gas sensors
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Theeir main disadvantage is very limited selectivity. Practical use of gas sensors in environenmental applications requires determination of concentration of a few mixed gases at the same time. We would like to present recent results of gas detection improvement by utilizing a single gas sensor and additional measurements to...
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EFFICIENCY OF GAS MIXTURES DETECTION BY RESISTIVE GAS SENSORS
PublicationResistive gas sensors are very popular and are commonly used to detect various gases and their mixtures. Their main disadvantage is very limited selectivity. Practical use of gas sensors in environmental applications (e.g., in sewage systems to protect workers, in air conditioning systems to monitor atmosphere quality) requires determination of concentration of a few mixed gases at the same time. We would like to present recent...
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Modelling of Nuclear Power Plant Steam Turbine
PublicationThe paper describes the approach to a Nuclear Power Plant steam turbine modelling which would enable on-line optimal process control (model based) and diagnosis over wide range of operating conditions caused by changing power demand. Presented model is static, multivariable and nonlinear. Such model enables analyzing the heat cogeneration aspects. Developed model is validated and verified by using archive data gained from researches...
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Modelling of Nuclear Power Plant Steam Turbine
PublicationThe paper describes the approach to a Nuclear Power Plant steam turbine modelling which would enable on-line optimal process control (model based) and diagnosis over wide range of operating conditions caused by changing power demand. Presented model is static, multivariable and nonlinear. Such model enables analyzing the heat cogeneration aspects. Developed model is validated and verified by using archive data gained from researches...
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Naval electromagnetic compatibility investigations by use of topological model
PublicationPublikacja przedstawia zagadnienie uwarunkowań kompatybilnościowych na statkach. Ze względu na trudności jakie stwarza analiza EMC dużych obiektów, środowisko elektromagnetyczne okrętów jest zwykle dzielone na fragmenty analizowane oddzielnie. Referat przedstawia topologiczny model środowiska elektromagnetycznego w formie macierzowej, który pozwala na kompleksową analizę zagadnień kompatybilnościowych wielu systemów pracujących...
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Steam and Gas Turbines Constuction_ seminar/project
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Selectivity of amperometric gas sensors in multicomponent gas mixtures
PublicationIn recent years smog and poor air quality became a growing environmental problem. There is a need to continuously monitor the quality of air. The lack of selectivity is one of the most important problems limiting the use of gas sensors for this purpose. In this study, a selectivity of the six amperometric gas sensors is being investigated. Calibration of sensors has been performed in order to find a correlation between concentration...
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Gas sampling system for matrix of semiconductor gas sensors
PublicationSemiconductor gas sensors are popular commercial sensors applied in numerous gas detection systems. They are reliable, small, rugged and inexpensive. However, there are a few problem limiting the wider use of such sensors. Semiconductor gas sensor usually exhibits a low selectivity, low repeatability, drift of response, strong temperature and moisture influence on sensor properties. Sample flow rate is one of the parameters that...
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The thermal effort during marine steam turbine flooding with water
PublicationThe work discussed an extreme case of cooling a steam turbine. The ship's steam turbine was used as an example. In marine transport units with low-speed engines dominate, however, there are also units with steam turbines. An example of analysed marine steam turbine is shown in Fig. 1. When considering the issue of cooling steam turbines, it is necessary to estimate the extreme conditions that may occur during operation of the turbine....
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ANALYSIS OF THE PROJECT OF INNOVATIVE FLOATING TURBINE
PublicationThe design of a floating, innovative device for river water aeration and conversion of mechanical energy to electrical energy required the analysis of a number of geometrical and dynamic features. Such an analysis may be carried out on the basis of existing methods of numerical fluid mechanics. Models of pressures, forces and torques characteristic for the conversion of watercourse energy were developed for two basic concepts of...
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Simplified, multiregional fuzzy model of a nuclear power plant steam turbine
PublicationPower systems, including steam turbines and synchronous generators, are complex nonlinear systems with parameters varying over time. The paper presents the developed simplified, multiregional fuzzy model of the steam turbine of a nuclear power plant turbine generator set and compares the results with a full nonlinear model and commonly used linear input-output model of a steam turbine. The proposed model consist of series of linear...
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SELECTED COMBINED POWER SYSTEMS CONSISTED OF SELFIGNITION ENGINE AND STEAM TURBINE
PublicationThis paper presents optimization of selected combined diesel engine-steam turbine systems. Two systems: the system combined with waste heat one-pressure boiler only and its version containing additionally low-pressure boiler proper feeding degasifier and the system of two-pressure cycle, were taken into considerations. Their surplus values of power output and efficiency associated with utilization of waste heat contained in piston...
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Design analysis of Tesla micro-turbine operating on a low-boiling medium
PublicationThis paper presents results of the design analysis of a Tesla bladeless turbine intended for a co-generating micro-power plantof heat capacity 20 kW, which operates in an organic Rankine cycle on a low-boiling medium. Numerical calculations of flowin several Tesla turbine models were performed for a range of design parameters. Results of investigations exhibit interestingfeatures in the distribution of flow parameters within the...
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Gas selectivity enhancement by sampling-and-hold method in resistive gas sensors
PublicationCommercial resistive gas sensors exhibit various sensitivity to numerous gases when working at different elevated temperatures. That effect is due to a change in velocity of adsorption and desorption processes which can be modulated by temperature. Thus, to reach better selectivity of gas detection, we propose to apply a known method (called the sampling-and-hold method) of cooling down the gas sensor in the presence of the investigated...
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On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages
PublicationThis paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be...
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The Method of reduction of aerodynamic forces generated in turbine blade seals
PublicationThe distibution of pressure in the seal gaps does not only affect the so called '' leakage losses'' and the turbine stage overall efficiency but also plays an important role in the generation of aerodynamic forces which may cause self-excited rotor vibrations. The paper describes a chamber seal applied for the reduction of the aerodynamic forces created in shroud seals. This kind of turbine seal was patented and tested.
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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Explanation of Reduction of Pressure Forces in Turbine Chamber Seals
PublicationThe paper describes a chamber seal reducing the aerodynamic forces created in shroud seals. Asymmetrical pressure distribution (due to rotor-stator eccentricity) in the blade tip clearance leads to the creation of pressure forces acting on the blade shroud. By increasing the volume above the shroud, the pressure distribution becomes more uniform on the whole shroud circumference and the effect of rotor eccentricity is reduced....
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An Innovative Floating System with a Savonius Rotor as a Horizontal-Axis Wind Turbine
PublicationIn this project, an innovative wind turbine was designed for a floating plant. A large Savonius rotor was replaced with a double-rotor wind turbine implemented as a horizontal-axis turbine. This double rotor was positioned on the tip of a thrust plate and fixed to the deck of a catamaran. Simple 2D numerical simulations were performed to confirm the effectiveness of the concept. An analysis of the floating system configuration...
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Parametric Study on a Performance of a Small Counter-Rotating Wind Turbine
PublicationA small Counter-Rotating Wind Turbine (CRWT) has been proposed and its performancehas been investigated numerically. Results of a parametric study have been presented in this paper.As parameters, the axial distance between rotors and a tip speed ratio of each rotor have been selected.Performance parameters have been compared with reference to a Single Rotor Wind Turbine (SRWT).Simulations were carried out with Computational Fluids...
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A commercial gas boiler fitted with the ORC module as perspective solution for households
PublicationIn this paper the applicability of the commercial gas boiler (De Dietrich DTG X23N) coupled with the laboratory prototype micro ORC setup was experimentally studied. The main objective was to determine the working fluid capability to obtain required temperatures of vapour prior to the turbine, attainable heat rates and efficiencies of the whole system. The boiler thermal power was 25 kW. Tests were carried out with a single stage...
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Reduction of Derivative pipeline effort in water turbine
PublicationThe paper presents an approach to evaluate and reduce the effort of the derivative pipeline in a water turbine of a hydrostatic power station in its vulnerable spots. Potential places of the biggest effort of the structure, as well as the coefficient of displacement and safety factor related to them were identified using FEM numerical method. Pipeline reinforcement was designed and made based on FEM analysis. Original technology...
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The analysis of turbine propulsion systems in nuclear submarines
PublicationThe article systematises submarines, which are presently in service, according to their propulsion types (both conventional and nuclear), power output, and submersion depth. Contemporary types of propulsion systems installed and used in submarines are discussed. Calculations were performed for the PWR (Pressurized Water Reactor) type nuclear propulsion system and the supercritical turbine propulsion system (supercritical reactor...
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SAMPLE-AND-HOLDING METHOD FOR GAS SENSING APPLIED FOR RESISTANCE GAS SENSORS
PublicationThe DC resistance of a Taguchi gas sensor is influenced by the ambient gas. To improve the selectivity and sensitivity of a sensor the fluctuation enhanced sensing (FES) was used. The paper proposes a novel methodology of utilizing FES technique that sample composition of an ambient atmosphere and hold it for further processing (sample-and-holding technique). The method uses the heated gas sensor to sample an ambient atmosphere...
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1D Model Callibration on the Basis on 3D calculations for Tesla Turbine
PublicationThe paper presents the system of equations for axisymmetriclaminar flow, after averaging, through the width of interdisk slit ofTesla turbine. Coefficients were introduced, as a result ofaveraging, that improve the efficiency of 1D model. The minimalnumber of such coefficients was determined. The 1D modelmakes it possible to attain analytical solutions to an accuracylimited by these coefficients. Calibration of 1D model depends...
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Dynamic state assessment of the water turbine with the power of 600 kW
PublicationThe article discusses the results of experimental studies to assess the dynamic state of the turbine set with the Kaplan turbine. The dynamic assessment was made on the basis of appropriate standards, based on the measurement results of selected parameters of vibration, which have been measured for several states of the machine load. In addition, we attempted to identify the causes of the increased vibration levels based on the...
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Investigation of the aerodynamics of an innovative verticalaxis wind turbine
PublicationThis paper presents a preliminary three dimensional analysis of the transient aerodynamic phenomena occurring in the innovative modification of classic Savonius wind turbine. An attempt to explain the increased efficiency of the innovative design in comparison with the traditional solution is undertaken. Several vorticity measures such as enstrophy, absolute helicity and the integral of the velocity gradient tensor second invariant...
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NAVAL ARCHITECT
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Damage detection in turbine wind blades by vibration based methods
PublicationThe paper describes results of numerical simulation for damage localization in the composite coat of a wind turbine blade usingmodal parameters and a modern damage detection method (wavelet transform).
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Numerical investigation on the performance of a small counter-rotating wind turbine
PublicationThe article presents the results of the investigation on the performance of a small counter-rotating wind turbine. The wind turbine has been simulated using Computational Fluid Dynamics methods. Actuator Line Model has been successfully used to represent rotors in the computational domain. A parametric study has been carried out, taking into account changes in the tip speed ratio of the rotors while maintaining a constant distance...
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Experimental Validation of Numerical Model within a Flow Configuration of the Model Kaplan Turbine
PublicationThis paper investigates validation of flow within a model Kaplan turbine. This includes comparison of various turbulence models and their influence on torque and power generated by the turbine. Numerical results were compared with experimental data.
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Technical and Economic Analysis of the Supercritical Combined Gas-Steam Cycle
PublicationCombined cycle power plants are characterized by high efficiency, now exceeding 60%. The record-breaking power plant listed in the Guinness Book of World Records is the Nishi-Nagoya power plant commissioned in March 2018, located in Japan, and reaching the gross efficiency of 63.08%. Research and development centers, energy companies, and scientific institutions are taking various actions to increase this efficiency. Both the gas...
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Real-time hybrid model of a wind turbine with doubly fed induction generator
PublicationIn recent years renewable sources have been dominating power system. The share of wind power in energy production increases year by year, which meets the need to protect the environment. Possibility of conducting, not only computer simulation, but also laboratory studies of wind turbine operation and impact on the power system and other power devices in laboratory conditions would be very useful. This article presents a method...
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Flicker Noise in Resistive Gas Sensors—Measurement Setups and Applications for Enhanced Gas Sensing
PublicationWe discuss the implementation challenges of gas sensing systems based on low-frequency noise measurements on chemoresistive sensors. Resistance fluctuations in various gas sensing materials, in a frequency range typically up to a few kHz, can enhance gas sensing by considering its intensity and the slope of power spectral density. The issues of low-frequency noise measurements in resistive gas sensors, specifically in two-dimensional...
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GRAPHENE IN GAS CHEMIRESISTORS
PublicationGraphene has a range of unique physical properties which could be exploited in gas sensing. Every atom of graphene may be considered as a surface atom, able to interact even with single molecule of the target gas or vapour species resulting in the ultrasensitive sensor response. In this paper the potential of graphene as a nanomaterial for fabricating chemiresistors was described. Recent development in graphene sensors was considered...
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Investigation of the Aerodynamics of an Innovative Vertical-Axis Wind Turbine
PublicationThe paper presents the results of an experimental investigation and a three dimensional numerical analysis of the transient aerodynamic phenomena occurring in the innovative modification of classic Savonius wind turbine. An attempt to explain the increased efficiency of the innovative design a comparison with the traditional solution is undertaken. A vorticity measure based on the integral of the velocity gradient tensor second...
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NAVAL RESEARCH LOGISTICS
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NAVAL ENGINEERS JOURNAL
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On energy, exergy, and environmental aspects of a combined gas-steam cycle for heat and power generation undergoing a process of retrofitting by steam injection
PublicationThe paper presents a study of retrofitting of a combined heat and power (CHP) plant aimed to increase the electric to heating power ratio. The modification would involve diverting part of the steam to the gas turbine, instead of letting it go to the steam turbine, using injection technique into a combustion chamber. Therefore, two potential retrofitting approaches are analyzed: steam injection gas turbine (STIGT) and combined steam...
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Rotor Blade Geometry Optimisation in Kaplan Turbine
PublicationThe paper presents the description of method and results of rotor blade shape optimisation. The rotor blading constitutes a part ofturbine flow path. Optimisation consists in selection of the shape that minimises ratio of polytrophic loss. Shape of the blade isdefined by the mean camber line and thickness of the airfoil. Thickness is distributed around the camber line based on the ratio ofdistribution. Global optimisation was done...
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Gas Detection Using Resistive Gas Sensors And Radial Basis Function Neural Networks
PublicationWe present a use of Radial Basis Function (RBF) neural networks and Fluctuation Enhanced Sensing (FES) method in gas detection system utilizing a prototype resistive WO3 gas sensing layer with gold nanoparticles. We investigated accuracy of gas detection for three different preprocessing methods: no preprocessing, Principal Component Analysis (PCA) and wavelet transformation. Low frequency noise voltage observed in resistive gas...
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Thermohydraulic and thermoeconomic performance of a marine heat exchanger on a naval surface ship
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