Turbine Unit Research Articles

Performance Analysis of a Solar Cogeneration Power Combined Cycle at Variable Operational and Design Conditions

This paper is to investigate the performance of a solar cogeneration power combined cycle( SCPCC), in which a computer program, called “ SCPCC Design" has been developed using MATLAB for the analysis. In addition the System Advisor Model (SAM) software has been used in the analysis. Here, many operational and design parameters are taken in consideration to determine the overall efficiency of the proposed cycle, such as compressor pressure ratio, combustion temperature in the gas turbine unit, inlet steam pressure, exhaust gases temperature and process heat mass fraction. The solar thermal energy obtained from the solar field is obtained according to the specifications of Libyan Capital, Tripoli City, and through all the year. The results obtained from this study have shown a clear influence for these parameters on the overall efficiency, where it increases with combustion temperature, steam pressure and mass fraction, while it decreases with compressor pressure ratio .

Research on Ultra-Low-Frequency Oscillation Suppression Method of High-Head, Large-Capacity Hydropower Units

Aiming at the problem of ultra-low-frequency oscillation (ULFO) caused by an irrational setting of governor parameters of high-head hydraulic turbine units, this paper proposes a method to optimize the additional damping control parameters of the governor to suppress ULFO. Firstly, the mechanism of ULFO is elaborated and the effect of system damping torque on ULFO is analyzed. Secondly, Hamilton’s theory is used to rank the magnitude of each unit’s contribution to the ULFO. Then, the parameters of the damping controller are optimized using the variational modal decomposition–Hilbert transform method and the Grey Wolf Optimization algorithm. It realizes the phase compensation of the hydroelectric unit governor and suppresses the ultra-low-frequency oscillation. Finally, the proposed method is validated using the simulation conducted in CloudPSS. The test results indicate that the proposed method can effectively suppress the ULFO caused by the high-head hydroelectric unit.

Analysis of the technical condition of gas turbine plants. Part 3. Application of machine learning methods

A method for estimating the technical condition coefficient of a gas turbine unit for transporting of natural gas using machine learning methods is considered. Archival gas-dynamic parameters recorded by the installation’s automatic control system are used as initial data. The initial data set was created by determining power from the change in enthalpy of natural gas before and after the blower. The software package is implemented in Python; the Scikit-learn library is used for machine learning models. The average absolute error in percentage is chosen as a criterion for the quality of the prediction. The prediction quality of machine learning models is assessed for different sets of parameters-features and sample sizes. Recommendations on the use of models are given. Keywords: gas turbine unit, technical condition, measuring system, data processing, machine learning. v.l.blinov@urfu.ru; deryabingleb.were@gmail.com

Correction: Integration of Photovoltaic Units, Wind Turbine Units, Battery Energy Storage System, and Capacitor Bank in the Distribution System for Minimizing Total Costs Considering Harmonic Distortions

Correction: Integration of Photovoltaic Units, Wind Turbine Units, Battery Energy Storage System, and Capacitor Bank in the Distribution System for Minimizing Total Costs Considering Harmonic Distortions

An Aerodynamic Investigation of the Last-Stage Turbine in an Upgraded Gas Turbine

Abstract Due to the lengthy certification process for newly designed turbine blades, product upgrading of industrial gas turbine units is often performed solely on compressor and combustor. Since their inlet conditions are significantly changed, the entire four-stage turbine operates far away from its original design point, leading to decreased efficiency, and increased flutter risk. This investigation first performs numerical simulations to study the flow field change of the last-stage turbine in a gas turbine before and after product upgrading. To reduce the load of the last-stage turbine without reducing the power output of the whole turbine, the enthalpy drops of turbine are reallocated to the front three stages. After modifying the blade profile based on S1 stream surface analysis, a CFD simulation is carried out on the modified three-dimensional blade passage. It is shown that the modified blade design greatly reduces the Mach number at the tip outlet of the last-stage blade, thus possibly reducing flutter risk and improving the aerodynamic efficiency of the turbine. This paper also attempts to redesign the blade geometry by different radial blade stacking of both forward sweep and backward sweep. It is found that the backward-swept blade modification can effectively reduce the endwall flow loss. This work presents the improvements of the aerodynamic efficiency of last-stage through a series of improvement methods and provides a reference for future detailed optimization of this last-stage turbine.

A Comparative Study on the Cam Relationship for the Optimal Vibration and Efficiency of a Kaplan Turbine

Kaplan turbines are generally used in working conditions with a high flow and low head. These are a type of axial-flow hydro turbine that can adjust the opening of the guide vanes and blades simultaneously in order to achieve higher efficiency under a wider range of loads. Different combinations of the opening of the guide vanes and blades (cam relationship) will lead to changes in the efficiency of the turbine unit as well as its vibration characteristics. A bad cam relationship will cause the low efficiency or unstable operation of the turbine. In this study, the relative efficiency and vibration of a large-scale Kaplan turbine with 200 MW output were tested with different guide vane and blade openings. The selection of the cam relationship curve for both optimal efficiency and optimal vibration is discussed. Compared with the cam relationship given by the model test, the prototype cam relationship improves the efficiency and reduces the vibration level. Compared to the optimal efficiency cam relationship, the optimal vibration cam relationship reduces the efficiency of the machine by 1% to 2%, while with the optimal efficiency cam relationship, the vibration of the unit increases significantly. This research provides guidance for the optimization of the regulation of a large adjustable-blade Kaplan turbine unit and improves the overall economic benefits and safety performance of the Kaplan turbine power station.

Experimental studies of air ozonization influence on pollutants emission in vortex ignition-stabilizing modules of gas turbine combustion chambers

Reduction of pollutant emissions into the atmosphere is an urgent task of modern gas turbine engineering development. Such substances that have a negative impact on the environment include nitrogen oxides and carbon monoxide. The article provides a review of the existing methods for reducing the emissions of pollutants used in the combustion of hydrocarbon fuels in the combustion chambers of gas turbine units, as well as indicates promising technologies developed based on these methods. Justification is presented of the necessity to study the method of ozonization of air supplied to the fuel combustion zone to reduce the content of pollutants in its combustion products. The purpose of the study was to develop recommendations for reducing pollutant emissions within a given range of variations regime parameters. To perform the necessary set of experimental studies, a specialized laboratory stand was created, the combined circuit and measurement scheme of which is given in the article. A rather detailed description is given of the structural elements of the stand and, in particular, of the subject of research — a full-scale vortex ignitionstabilizing module of the combustion chamber of a gas turbine unit, an electric ozonator, air and combustible gas supply systems, an exhaust system with a central fan, control and measuring instruments and fittings. The tests were carried out in accordance with specially developed methods of controlling the stand operation in three modes: startup; transfer from one steady-state mode to another; stop. The influence of air ozonization on combustion processes in the vortex ignition-stabilizing module was determined by the content of nitrogen oxides and carbon monoxide in it. The factors that influence the decrease in the concentration of carbon monoxide in the combustion products during the combustion of air in ozonized air have been determined. The methods of calculation determination of combustible gas and air parameters — mass flow rates, flow velocities and dynamic heads — are described. The results of the performed experimental studies are presented in graphical interpretation, their detailed analysis is given, on the basis of which recommendations on practical use of the method of air ozonization are given.

Problems of transition of Russia’s energy sector to using domestically produced fire-resistant fluids

Fire-resistant fluids and lubricants are products that are used in various industries or energy sector to ensure the reliability and safety of equipment operating under high temperature and pressure conditions. Aspects of the use of fire-resistant fluids (hydraulic or lubricating agents), including those based on xylenol, in the Russian Federation energy industry (control and lubrication systems for automatic control systems of steam or gas turbines), and the problems of switching from imported materials to domestic analogues are considered. The range of issues raised at the All-Russian Scientific and Technical Conference “Modern trends in the development of the market for fire-resistant turbine oils and the record of their operation at thermal power plants and nuclear power plants,” held in March 2023, as well as the decisions made there, are covered. Besides, measures taken by energy companies to legitimize the use of domestic fire-resistant fluids for operation in thermal power equipment in Russia are indicated. The results of laboratory studies of new domestic fire-resistant fluids are presented, conclusions are drawn about the possibility of use, operation, and approval of new domestic lubricating or hydraulic fluids in the energy sector. The article was prepared in cooperation between two large electric-heat-generating companies and with the participation of Power Machines, PJSC. One of the goals set by the authors was to promote the production of domestic fire-resistant fluids synthesized from raw materials available in the Russian Federation, ensuring the reliable functioning of oil systems of turbine units.

Study Case of Optimization Analysis on Energy-saving in Paper Mill Power-Heat System

According the characteristics of both steam and power was supplied in paper mill power plant， the optimal running model of the coal-fired power-heat system was researched in this paper. The power plant’s physical structure was researched, the superstructure was established and the boiler and turbine running model was analyzed. With the help of mathematical programming, each turbine unit optimal loads were obtained when the same power and steam were produced, moreover, the minimum coal cost were calculated with each boiler unit optimal load distribution. The case study of one paper mill showed that the optimization model was helpful and the coal consumption can decrease 4.7% aiding with the model

Loss Minimization and Voltage Stability With Optimum Frequency Determination of LF-HVac Lines Based on Wind-Hydro-Gas Turbine Unit

Loss Minimization and Voltage Stability With Optimum Frequency Determination of LF-HVac Lines Based on Wind-Hydro-Gas Turbine Unit

Account of additional factors for damping torsional oscillations

Some parameters are influenced by the turbine unit's torsional oscillations. The fundamental comes from damping these oscillations, which are brought on by a departure in the turbine blades' speed from the device's prediction of the steam volume, and attenuation of fluctuations due to the distribution of energy in the turbine's productive components. The usual single-machine infinite bus system is used for the analysis. For various turbine-generator shafts and various generator operating situations, rotating mass mechanical system evaluations for small-signal stability and large disturbance are conducted. It is demonstrated that the shaft's “structural' damping (H) and “steam' damping (Kn) coefficients have a considerable impact on the damping of torsional modes. The goal of this work is to determine the effect of changing the damping factors in the mathematical model of the steam turbine shaft on the system's static stability, as well as the extent to which these variables' limits on damping rotational oscillations on the maximum torsional torques generated in the shaft masses. The mathematical model of the steam turbine shaft with a single machine and transmission line to an infinite bus system was simulated using Dymola software, and the static and dynamic effects of damping factors (H) and (Kn) on system stability were demonstrated. By evaluating the best case for parameters with the least influence on the system's stability, the results were obtained by changing the factors (Kn) from 0.005 to 0.5 and (H) from 0.005 to 0.2 and the extent of its effect on the maximum torque of the steam turbine masses and reducing it by 8.4 %, as well as by reducing the settling time of the system after disturbances occur and reaching to Steady state by about 90 %.

Thermo-Economic Analysis of Gas Turbine Combined Multistage Flash (MSF) Desalination Cycle

Over the past few decades, the growth of the earth’s population has increasingly contributed to global warming, and increased demand for fresh water on top of a need for a greater power supply. This paper will analyze the integration of a combined- gas turbine with intercooler and a multi-stage flash (MSF) desalination plant for the simultaneous generation of electricity and supply of water and improved performance. The paper will also examine the calculation of the production cost and the capital cost of the MSF desalination plant. The thermo-economic analysis of the study was conducted using the IPSEpro software system. Also, exergy losses of the gas turbine and MSF desalination unit were also calculated. The desalination plant uses the exhaust gases from the gas turbine, as a form of thermal energy, and discharges to feed the seawater heater. A portion of the desalinated water is used to cool the compressed air in the intercooler heat exchanger. Results indicate the improvement in the gas turbine’s performance when desalinated water is used for the intercooler between compressor stages, as the power output increased by 59% over the the simple gas cycle and found decrease with an increase in the ambient temperature. The desalinated water cost was calculated to be $1.7 per cubic meter after determining the optimal configuration and operating conditions. A decrease in steam cost by 36% was observed when the waste heat from the gas turbine was used as the source of thermal energy. Part of this reduction can be explained by the observation that the desalination plant’s pumps consume part of the power generated by the gas turbine.

U susret revitalizaciji turbina HE Đerdap 2: Merenje rasporeda vektora brzina na ulazima turbina

The continuous flow measurement on hydroelectric turbine units is conventionally carried out using the relative methods (mostly Winter-Kennedy), where the complex velocity field in flow cross section is replaced by a single measured quantity. On a physical model, mapping parameters are determined. The Winter-Kennedy method is most used, where this relative (index) flow quantity is obtained by measuring differential pressure. The measurement uncertainty of the determined flow using this method is usually significantly higher than the uncertainty of other relevant quantities for determining the optimal turbine operating conditions. To reduce the flow uncertainty, it is necessary to perform "absolute measurements" of the entire velocity field and determine the necessary corrections to the index method under real operating conditions. This is especially true for plants where disposition is different from one used on physical model, which is the case of “Đerdap 2” and recognized problem of skewed inflow. With the aim of better assessing the hydraulic efficiency of turbines and to collect data on the actual operating velocity distribution in the inlet section in front of trash-rack needed for planned revitalization works, an innovative system for absolute flow measurement has been designed and implemented. The moving frame was designed and installed at the turbine inlet, upstream from the trash-rack. The 15 electromagnetic (EM) sensors and two redundant acoustic Doppler sensors were installed on horizontal bar. Each sensor measures all three velocity components. The frame moves by lifting along the entire height of the flow section, allowing the entire velocity field to be scanned. The position of the frame is tracked by two encoders, while two pressure sensors are used to measure the water depth. Measurements are synchronized with the local SCADA system, so appropriate turbine operation data are also used. Considering the specificities of the measurement system itself with newly developed EM sensors, as well as hydraulic conditions, an adequate procedure has been developed to assess the uncertainty of the measured flow. This paper presents the measurement method and provides some measurement results on the units of the “Đerdap 2” hydroelectric power plant.

Operating Optimization of Steam Turbine Unit Based on Big Data Parallel Association Rule Mining

Operating Optimization of Steam Turbine Unit Based on Big Data Parallel Association Rule Mining

Use of the heat of exhaust fluge gases of gas turbine units in recovery boilers for heat and electric supply systems

In this article, the inextricable interconnection and interdependence of the conditions for ensuring the heat of energy consumption is considered. A highly efficient installation covers the heat and energy needs of the Mubarek gas processing plant. With simultaneous operation of gas turbine and steam boiler plant efficiency reaches 95%. The introduction of the proposed development will solve the problem of energy and resource-saving, enables the use of a steam boiler in heat supply and solves an environmental problem.

Utilizing a New Voltage Stability Index in Distribution Power System in Presence of Wind Turbine Units

Utilizing a New Voltage Stability Index in Distribution Power System in Presence of Wind Turbine Units

ПОРІВНЯЛЬНИЙ АНАЛІЗ ДИНАМІЧНИХ ВЛАСТИВОСТЕЙ ГАЗОТУРБІННИХ УСТАНОВОК ШИРОКОГО ДІАПАЗОНУ ПОТУЖНОСТЕЙ ПРИ РОБОТІ НА ЧАСТКОВИХ ЕЛЕКТРИЧНИХ НАВАНТАЖЕННЯХ

Abstract. The article considers the possibility of using gas turbine power plants when operating at partial electrical loads. This option of using gas turbine plants can help reduce the unevenness between electricity production and consumption, which is associated with the difficult operating conditions of the Ukrainian power system. The main disadvantages of nuclear power plants (the main source of electricity generation in Ukraine), which do not allow them to compensate for the unevenness of the power system in transient and dynamic modes, are considered. The paper analyses the dynamic properties and characteristics of gas turbine units (GTUs) of a wide range of capacities: small, medium and large installed capacities. As a result of the modeling, it was found that the inertial properties of a gas turbine unit increase with the increase in the rated power of the unit. The paper presents the results of modeling the dynamic characteristics of gas turbine plants of small, medium and large capacity when the electrical load changes. The paper presents the transient processes of controlling the rotor speed of a gas turbine engine with optimal controller settings and settings calculated for partial loads of a gas turbine installation. The change in the quality of the transient processes of controlling the rotor speed of a gas turbine unit when operating at partial electrical loads (100%, 75%, and 50%) compared to the installed capacity is analyzed. Keywords: gas turbine installation, partial electrical load, dynamic characteristics, transient control processes, control quality indicators.

Exploration of the mechanism of cavitation vortex rope and vortex development in the draft tube of tubular turbine units

Exploration of the mechanism of cavitation vortex rope and vortex development in the draft tube of tubular turbine units

Thermodynamic and exergoeconomic assessment of a trigeneration system driven by a biomass energy source for power, cooling, and heating generation

Environmental concerns and the limitations of conventional energy drive the exploration of reliable renewable sources. Herein, a biomass-assisted trigeneration system in conjunction with a methane-fed gas turbine cycle for generating power, cooling, and heating, and an attempt has been made to maximize the energy extraction from the energy source. The proposed system includes a steam Rankine cycle, a gas turbine unit, and a Kalina subsystem, and is investigated from energetic, exergetic, and economic viewpoints. A comprehensive parametric evaluation is carried out, and a multi-objective grey wolf optimization algorithm integrated with the LINMAP decision-maker method is employed to detect the most optimum point through two different scenarios. By conducting a base study, a net output power of 5926 kW, cooling load of 36.56 kW, heating load of 843.4 kW, and an energetic efficiency of 47.41 % can be achieved. The exergetic and economic standpoints bring out an exergy destruction rate of 7697.07 kW, cycle exergetic efficiency of 41.44 %, and a net present value of 12.420 $M that sequels to a payback period of 5.56 years. Biomass proves reliable in multigeneration systems, emphasizing the pivotal role of studies in maximizing energy extraction for diverse product outputs.

РАСПОЗНОВАНИЕ ДЕФЕКТОВ ЛОПАТОЧНОГО АППАРАТА ТУРБОМАШИН ПРИ ПОМОЩИ НЕЙРОННОЙ СЕТИ

Correct, serviceable and high-quality operation of a turbomachine directly depends on the condition of its flow path. One of the reasons for the decrease in the efficiency and reliability of the turbine unit is the wear of the blade apparatus due to the formation of various defects on the edges and surface of the blade airfoil. This study develops an approach to automating the defect detection process of products using modern computer vision technologies. In this work, a program code was prepared in the Python programming language, a database of images of blade defects was created, and the YOLOv8 model was trained and tested. The achieved accuracy in determining the type of defect in the study exceeded 80%.