scholarly journals Исследования турбокомпрессоров с общим рабочим колесом для применения в двигателях и энергоустановках

2021 ◽  
pp. 33-38
Author(s):  
Владимир Анатольевич Шкабура
Keyword(s):  
Flow Pattern ◽  
Correction Factor ◽  
Power Plants ◽  
Average Diameter ◽  
Load Factor ◽  
General Criterion ◽  
Dynamic Calculation ◽  
Counter Flow ◽  
Direct Flow ◽  
Gas Dynamic

The article deals with the working processes in flowing part of the turbo-compressors with general impeller (TCG) and with two schemes of the flows. The work studies the features of the TCG operation with two schemes of the flows and the gas-dynamic calculation theory development of their flow parts for use in engines and power plants. The tasks to be solved are to investigate two schemes of the flows in the interscapular space of the impeller – direct-flow and counter-flow. If the gas and air flow directions coincide concerning the axis of rotation of the impeller, then the flow pattern in the TCG is direct-flow, with the opposite movement of flows – is counter-flow. The solution to this problem was performed using the developed methods of gas-dynamic calculation of the TCG flow parts. Conclusions. The scientific novelty of the results obtained is as follows: parameters that significantly affect the efficiency of the turbine and compressor parts of the TCG were established and the formula in the form of a general criterion ratio was calculated. The dependence of the correction factor is determined, which considers the effect of the ratio of the impeller width on the average diameter of the working channel of the RK in the compressor section and the turbine section of the TCG. The article contains formulas, with correction factors, for calculating the power factor in the compressor section and the load factor in the turbine section. If the ratio of the grating width to the average diameter of the working channel is overestimated, it is necessary to supplement the formulas with a correction factor that considers the effect of this ratio. Studies have determined that switching from one mode of operation to another – in a certain section of the impeller, accelerates the flow to the required speed. It is especially evident in the compressor working channel of the TCG with a counter-flow pattern. In the turbine section, the gas flow acceleration time does not depend on the flow pattern – the flow is active and accelerates to the required speed in the nozzle apparatus. The given formulas allow calculating the power of the turbine and compressor parts of the impeller to perform an enlarged gas-dynamic calculation of TCG. Studies have determined that TCG can be used in gas turbine engines and the pressurization system of an internal combustion engine.

scholarly journals ИССЛЕДОВАНИЯ КОМПРЕССОРНОЙ И ТУРБИННОЙ ЧАСТЕЙ ТУРБОКОМПРЕССОРОВ С ОБЩИМ РАБОЧИМ КОЛЕСОМ ДЛЯ ПРИМЕНЕНИЯ В ДВИГАТЕЛЯХ И ЭНЕРГОУСТАНОВКАХ

2020 ◽  
pp. 68-73
Author(s):  
Владимир Анатольевич Шкабура
Keyword(s):  
Gas Turbine ◽  
Experimental Model ◽  
Power Factor ◽  
Power Plants ◽  
Combustion Engine ◽  
Experimental Studies ◽  
Average Diameter ◽  
Load Factor ◽  
Direct Flow ◽  
Compressor Power

To develop engines and power plants, the issues of improving engines through the use of a new type of turbomachines – turbo-compressors with general impeller (TCG) have been considered. There is another name for this type of turbomachine – a single-disk turbo-compressor (STC), although for bladed machines it is not the disk that is important, but the entire impeller. For example, a diagram of the simplest small-sized gas turbine engine using TCG is shown. For the systematization of relatively efficient TCG schemes, a classification has been developed and is given in the article, of possible schemes for a turbocharger with a common impeller. To implement one or another flowing pattern in the impeller, it is necessary to select the appropriate shape of the impeller blades and the location of the nozzle, exhaust, suction and discharge channels relative to each other. Depending on the direction of movement of the gas flows, turbo-compressors with a common impeller may have two flow patterns in interscapular impeller space – direct-flow and counter-flow. If the directions of the gas and airflow coincide to the axis of rotation of the impeller, then the flow pattern in the TCG is direct-flow, with opposite flow flows it is countercurrent. For carrying out the enlarged gas-dynamic calculation of TCG, formulas are given that make it possible to calculate the circumferential force arising on the blades of the impeller in the compressor and turbine working channels of the TCG. Also, formulas are given, with correction factors, for calculating the power factor of the compressor part and the load factor of the turbine part. In the process of computational and experimental studies, the characteristic of the compressor part of the TCG experimental model was obtained. If the ratio of the grating width to the average diameter of the working channel is overestimated, it is necessary to supplement the formula for calculating the compressor power factor with a correction factor. The test results of the compressor part of the TCG experimental model showed good agreement between the calculated and experimental values. Studies have shown that a turbocharger with a common impeller can be used as of gas turbine engines and in a turbo-supercharging system of a capacity internal combustion engine with not high supercharging.

scholarly journals РЕЗУЛЬТАТЫ ИССЛЕДОВАНИЙ КОМПРЕССОРНОЙ И ТУРБИННОЙ ЧАСТЕЙ ТУРБОКОМПРЕССОРОВ С ОБЩИМ РАБОЧИМ КОЛЕСОМ ДЛЯ ПРИМЕНЕНИЯ В МАЛОРАЗМЕРНЫХ ДВИГАТЕЛЯХ

2019 ◽  
pp. 39-43
Author(s):  
Владимир Анатольевич Шкабура
Keyword(s):  
Gas Turbine ◽  
Experimental Model ◽  
Power Plants ◽  
Combustion Engine ◽  
Experimental Studies ◽  
Load Factor ◽  
Direct Flow ◽  
Turbine Engine ◽  
Axis Of Rotation ◽  
Experimental Values

It is considered the issues of improving small-sized engines through the application of a new type of turbomachines – turbo-compressors with general impeller (TCG) to develop engines and power plants. For example, it is shown a diagram of the simplest small-sized gas turbine engine using TCG. For the systematization of relatively efficient TCG schemes, a classification has been developed and is given in the article, of possible schemes for a turbocharger with a common impeller. The classification is based on 5 possible directions of movement of the working medium in the blade apparatus – axial (parallel to the axis of rotation of the machine), centrifugal, centripetal, diagonal and tangential. To implement one or another flowing pattern in the impeller, it is necessary to select the appropriate shape of the impeller blades and the location of the nozzle, exhaust, suction and discharge channels relative to each other. Depending on the direction of movement of the gas flows, turbo-compressors with a common impeller may have two flow patterns in interscapular impeller space – direct-flow and counter-flow. If the directions of the gas and airflow coincide concerning the axis of rotation of the impeller, then the flow pattern in the TCG is direct-flow, with opposite flow flows it is countercurrent. For carrying out the enlarged gas-dynamic calculation of TCG, formulas are given that make it possible to calculate the circumferential force arising on the blades of the impeller in the compressor and turbine working channels of the TCG. Also, formulas are given, with correction factors, for calculating the power factor of the compressor part and the load factor of the turbine part. In the process of computational and experimental studies, the characteristic of the compressor part of the TCG experimental model was obtained. The test results of the compressor part of the TCG experimental model showed good agreement between the calculated and experimental values. Studies have shown that a turbocharger with a common impeller can be used as part of small-size gas turbine engines and in a turbo-supercharging system of a small-capacity internal combustion engine with not high supercharging. 

scholarly journals Numerical Simulation of Intrachamber Processes in the Power Plant

2021 ◽  
Vol 11 (11) ◽  
pp. 4990
Author(s):  
Boris Benderskiy ◽  
Peter Frankovský ◽  
Alena Chernova
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Flow Structure ◽  
Power Plants ◽  
Control Volume ◽  
Conjugate Problem ◽  
Topological Features ◽  
Gas Dynamic ◽  
Calculation Results ◽  
Volume Method

This paper considers the issues of numerical modeling of nonstationary spatial gas dynamics in the pre-nozzle volume of the combustion chamber of a power plant with a cylindrical slot channel at the power plant of the mass supply surface. The numerical simulation for spatial objects is based on the solution conjugate problem of heat exchange by the control volume method in the open integrated platform for numerical simulation of continuum mechanics problems (openFoam). The calculation results for gas-dynamic and thermal processes in the power plant with a four-nozzle cover are presented. The analysis of gas-dynamic parameters and thermal flows near the nozzle cover, depending on the canal geometry, is given. The topological features of the flow structure and thermophysical parameters near the nozzle cap were studied. For the first time, the transformation of topological features of the flow structure in the pre-nozzle volume at changes in the mass channel’s geometry is revealed, described, and analyzed. The dependence of the Nusselt number in the central point of stagnation on the time of the power plants operation is revealed.

Load Factor for Evaluating Non-Planar Flaws in Carbon Steel Piping Using Limit Load Methodology

2016 ◽  
Author(s):  
Phuong H. Hoang
Keyword(s):  
Carbon Steel ◽  
Nuclear Power ◽  
Power Plants ◽  
Pipe Wall ◽  
Local Strain ◽  
Limit Load ◽  
Evaluation Methodology ◽  
Load Factor ◽  
Wall Thinning ◽  
Steel Piping

Non-planar flaw such as local wall thinning flaw is a major piping degradation in nuclear power plants. Hundreds of piping components are inspected and evaluated for pipe wall loss due to flow accelerated corrosion and microbiological corrosion during a typical scheduled refueling outage. The evaluation is typically based on the original code rules for design and construction, and so often that uniformly thin pipe cross section is conservatively assumed. Code Case N-597-2 of ASME B&PV, Section XI Code provides a simplified methodology for local pipe wall thinning evaluation to meet the construction Code requirements for pressure and moment loading. However, it is desirable to develop a methodology for evaluating non-planar flaws that consistent with the Section XI flaw evaluation methodology for operating plants. From the results of recent studies and experimental data, it is reasonable to suggest that the Section XI, Appendix C net section collapse load approach can be used for non-planar flaws in carbon steel piping with an appropriate load multiplier factor. Local strain at non-planar flaws in carbon steel piping may reach a strain instability prior to net section collapse. As load increase, necking starting at onset strain instability leads to crack initiation, coalescence and fracture. Thus, by limiting local strain to material onset strain instability, a load multiplier factor can be developed for evaluating non-planar flaws in carbon steel piping using limit load methodology. In this paper, onset strain instability, which is material strain at the ultimate stress from available tensile test data, is correlated with the material minimum specified elongation for developing a load factor of non-planar flaws in various carbon steel piping subjected to multiaxial loading.

A 12 MM/S RMS Screening Vibration Velocity for Pipes Using ANSI-OM3 Standard and Regulatory Design Rules

2005 ◽  
Author(s):  
Se´bastien Caillaud ◽  
Yannick Pons ◽  
Pierre Moussou ◽  
Michae¨l Gaudin
Keyword(s):  
Correction Factor ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Vibration Monitoring ◽  
Vibration Velocity ◽  
Concentrated Mass ◽  
Design Rules ◽  
Velocity Relationship ◽  
Regulatory Design

ASME ANSI-OM3 standard is dedicated to the assessment of piping vibrations for nuclear power plants. It provides an allowable zero-to-peak velocity, which is derived from a stress/velocity relationship, where corrections factors (C1, C2K2, C3, C4 and C5) and an allowable stress σal are introduced. In the ANSI-OM3 standard, the C4 correction factor depends on the pipe layout and on its boundary conditions, and is calculated for a few cases. In a former work, it was proposed to extend this factor to a larger number of pipe setups. Besides, the correction factor C1, which stands for the effect of concentrated mass, is established on a given set-up: a clamped-clamped straight pipe span on its first vibrating mode. C1 is then supposed to be conservative on any piping layout. Finally, allowable velocities derived from the ANSI-OM3 stress/velocity relationship may be very conservative. One way to reduce this conservatism is to introduce regulatory design rules. For a larger set of pipe geometries, a new set of C1 and C4 correction factors are computed using weight and pressure designs. Using these numerical results, allowable velocities can be calculated. Then, we propose here to check if a screening vibration velocity of 12 mm/s rms is fulfilled. For the 181 geometries on 3708, which do not meet the criterion, a seismic design checking is applied. Finally, by this way, 99.7% of the tested geometries, which are supposed to be acceptable with respect to static and seismic designs, display allowable velocities above 12 mm/s rms and the minimum allowable vibration velocity is 11.2 mm/s. This screening vibration velocity of 12 mm/s commonly used for vibration monitoring of piping systems in EDF nuclear power plants is then supported.

scholarly journals Experimental Study on Effect of Water Spray Characteristics on Performance of Cooling Tower

2020 ◽  
Vol 170 ◽  
pp. 01009
Author(s):  
Akshay S. Dhurandhar ◽  
Amarsingh B. Kanase-Patil
Keyword(s):  
Power Plants ◽  
Cooling Tower ◽  
Thermal Power ◽  
Evaporative Cooling ◽  
Hot Water ◽  
Spray Angle ◽  
Counter Flow ◽  
Steam Power ◽  
To Come ◽  
Spiral Type

Cooling tower is an indispensable part, used as a direct contact type heat exchanger mainly for evaporative cooling. Cooling tower generally dissipates, remove heat from thermal power plants. In an induced draft cooling tower of counter flow, used for a mini-steam power plant, hot water enters at the top, while the air is introduced at the bottom and exits at the top, air is allowed to come in contact with falling water droplets, causing evaporative cooling. A possibility of desired change with different spray angle, patterns, is tried and analysed. On findings, best suited spray nozzle angle resulted is 90°, and amongst three spray patterns, full cone, hollow cone and spiral type nozzle; full cone nozzle of 90° spray angle helps achieving efficiency up to 82%. The range increases successively from 9.8°C to 15.5°C for FC nozzle, in approach to WBT; the desirable fall of 3.56°C is attained with effectiveness of 81.63%.

scholarly journals The Optimization of Combined Cycle HRSGs as a Function of the Plant Load Duty

1996 ◽  
Author(s):  
P. J. Dechamps
Keyword(s):  
Power Generation ◽  
Steam Generator ◽  
Heat Recovery ◽  
Power Plants ◽  
Combined Cycle ◽  
Load Factor ◽  
Heat Recovery Steam Generator ◽  
Economic Optimization ◽  
Cost Of Electricity ◽  
The Cost

Natural gas fired combined cycle power plants now take a substantial share of the power generation market, mainly because they can be delivering power with a remarkable efficiency shortly after the decision to install is taken, and because they are a relatively low capital cost option. The power generation markets becoming more and more competitive in terms of the cost of electricity, the trend is to go for high performance equipments, notably as far as the gas turbine and the heat recovery steam generator are concerned. The heat recovery steam generator is the essential link in the combined cycle plant, and should be optimized with respect to the cost of electricity. This asks for a techno-economic optimization with an objective function which comprises both the plant efficiency and the initial investment. This paper applies on an example the incremental cost method, which allows to optimize parameters like the pinch points and the superheat temperatures. The influence of the plant load duty on this optimization is emphasized. This is essential, because the load factor will not usually remain constant during the plant life-time. The example which is presented shows the influence of the load factor, which is important, as the plant goes down in merit order with time, following the introduction of more modern, more efficient power plants on the same grid.

Microstructure and Mechanical Properties of a New Ni-Cr-Fe-W-Al Alloy for Advanced Ultra-Supercritical Power Plants

2015 ◽  
Vol 816 ◽  
pp. 586-593 ◽  
Author(s):  
Xian Chao Hao ◽  
Long Zhang ◽  
Xiu Juan Zhao ◽  
Tian Liang ◽  
Ying Che Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Thermodynamic Calculation ◽  
Power Plants ◽  
Elevated Temperatures ◽  
Prolonged Exposure ◽  
Thermal Exposure ◽  
Average Diameter ◽  
Al Alloy ◽  
Microstructural Stability

Optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermodynamic calculation were used to study the phase stability and precipitation in a Ni-Cr-Fe-W-Al alloy. Mechanical properties were also studied. The major precipitates after standard heat treatment or prolonged aging at 725 oC and 800 oC were M23C6 and γ′. M23C6 precipitated intergranularly. P-phase was not detected after thermal exposure, which was different from the results of thermodynamic calculation. The average diameter of γ′ increased with the increasing exposure temperature and time, and could be depicted by the LSW theory. Specimens in solution-annealed condition exhibited excellent ductility. During the prolonged exposure at 725 oC, tensile strength and ductility at room and elevated temperatures kept well, which means this alloy possessed good microstructural stability after a long time exposure.

scholarly journals KARAKTERISITIK FLOW PATERN PADA ALIRAN DUA FASE GAS-CAIRAN MELEWATI PIPA VERTIKAL

2012 ◽  
Vol 11 (2) ◽  
pp. 117
Author(s):  
PRIYO HERU ADIWIBOWO
Keyword(s):  
Flow Pattern ◽  
Power Plants ◽  
Bubbly Flow ◽  
Digital Camera ◽  
Vertical Pipe ◽  
Two Phase ◽  
Pressurized Water ◽  
Industrial Facilities ◽  
Multi Phase ◽  
Pattern Visualization

Multi-phase flows are widely encountered in several engineering and industrial facilities, such as conventional steam power  plants, evaporators and condensers, pressurized-water nuclear reactors, a wide variety of petroleum industries, chemicals and  food processing industries. Surely, in the complex pipeline  installation of these systems, vertical pipe will be commonly  used for pipe connection. The purpose of this work is to investigate the flow pattern of gas-liquid two phase in the vertical pipe. Experiments will be performed in a 36 mm ID  acrylic pipe vertical. Superifical liquid velocities and volumetric gas quality will be varied 0.3~1,1 m/s and 0.05~0.2 respectively. Digital camera will be used for flow pattern  visualization in the vertical pipe. It was observed that effect of vertical pipe on flow pattern formed cluster bubbly flow for low volumetric gas quality with high superifical liquid velocities. For  superifical liquid velocities with medium volumetric gas quality formed homogeneous bubbly flow and high volumetric gas quality is dense bubbly flow.

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