Refinement of Approaches to Estimation of Ship Ice Resistance in Ice Channel Based on Data From Physical Model Experiments

2018 ◽  
Author(s):  
Aleksei Dobrodeev
Keyword(s):  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
The Arctic ◽  
Ship Resistance ◽  
Large Size ◽  
Urgent Task ◽  
Operation Control ◽  
Control Technologies ◽  
Ice Resistance ◽  
Planning And Operation

The most urgent task in tapping of the Arctic resources today is organization of year-round navigation through the Northern Sea Route. The efficiency of any transport system strongly depends on the deadweight and speed of cargo carriers. In this connection it is required to thoroughly examine the issues related to propulsion of large-size cargo ships in ice, while developing the tactical planning and operation control technologies for icebreakers and ice-going ships. It is found that large-size cargo ships are not able to navigate independently in ice at economically efficient speeds even if their hullform is optimized for these operating conditions. Thus, it is required to ensure their effective operation in ice channels made by icebreakers. For appraising the efficiency of a marine transportation system it is necessary to have data on ship resistance versus a range of factors including physical and mechanical properties of ice, ice concentrations, ship speed, etc. This paper presents the results of studies undertaken to examine various methods of icebreaker-assisted shipping operations and to develop a method for calculation of ship resistance in ice channel based on model test data. The research was supported by RSF (project No.17-79-20162).

Structure and properties of compact articles from high-alloyed iron powder with adding of boron nitride

2020 ◽  
pp. 39-48
Author(s):  
B. O. Bolshakov ◽  
◽  
R. F. Galiakbarov ◽  
A. M. Smyslov ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Grain Boundary ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Operating Conditions ◽  
Structure And Properties ◽  
Steam Turbines ◽  
Friction Forces ◽  
Wide Range

The results of the research of structure and properties of a composite compact from 13 Cr – 2 Мо and BN powders depending on the concentration of boron nitride are provided. It is shown that adding boron nitride in an amount of more than 2% by weight of the charge mixture leads to the formation of extended grain boundary porosity and finely dispersed BN layers in the structure, which provides a high level of wearing properties of the material. The effect of boron nitride concentration on physical and mechanical properties is determined. It was found that the introduction of a small amount of BN (up to 2 % by weight) into the compacts leads to an increase in plasticity, bending strength, and toughness by reducing the friction forces between the metal powder particles during pressing and a more complete grain boundary diffusion process during sintering. The formation of a regulated structure-phase composition of powder compacts of 13 Cr – 2 Mо – BN when the content of boron nitride changes in them allows us to provide the specified physical and mechanical properties in a wide range. The obtained results of studies of the physical and mechanical characteristics of the developed material allow us to reasonably choose the necessary composition of the powder compact for sealing structures of the flow part of steam turbines, depending on their operating conditions.

scholarly journals Formulation of Ice Resistance in Level Ice Using Double-Plates Superposition

2020 ◽  
Vol 8 (11) ◽  
pp. 870
Author(s):  
Liang Li ◽  
Qingfei Gao ◽  
Alexander Bekker ◽  
Hongzhe Dai
Keyword(s):  
Elastic Plate ◽  
Approximate Model ◽  
Ice Thickness ◽  
Full Scale Test ◽  
Ship Resistance ◽  
Bending Resistance ◽  
Level Ice ◽  
Scale Test ◽  
Coulomb Criterion ◽  
Ice Resistance

The estimation of ship resistance in ice is a fundamental area of research and poses a substantial challenge for the design and safe use of ships in ice-covered waters. In order to estimate the ice resistance with greater reliability, we develop in this paper an improved Lindqvist formulation for the estimation of bending resistance in level ice based on the superposition of double-plates. In the developed method, an approximate model of an ice sheet is firstly presented by idealizing ice sheeta as the combination of a semi-infinite elastic plate and an infinite one resting on an elastic foundation. The Mohr–Coulomb criterion is then introduced to determine the ice sheet’s failure. Finally, an improved Lindqvist formulation for estimation of ice resistance is proposed. The accuracy of the developed formulation is validated using full-scale test data of the ship KV Svalbard in Norway, testing the model as well as the numerical method. The effect of ice thickness, stem angle and breadth of bow on ship resistance is further investigated by means of the developed formulation.

Promising use of high-strength nitrogen steel for the ice belt of marine machinery operating in the extreme arctic conditions

2021 ◽  
pp. 229-237
Author(s):  
A. A. Deev ◽  
G. Yu. Kalinin ◽  
K. E. Sadkin
Keyword(s):  
Physical And Mechanical Properties ◽  
High Strength ◽  
The Arctic ◽  
Welded Steel ◽  
Corrosion Resistant ◽  
Critical Elements ◽  
Steel Sheets ◽  
Nitrogen Steel ◽  
Arctic Conditions ◽  
Clad Steel

This article shows the possibility of using high-strength nitrogen-containing corrosion-resistant steel grade 04Kh20N6G11M2AFB for the construction of critical elements and units of marine equipment operating at low temperatures, including the Arctic. The advantages of nitrogen-containing steel over clad steel AB2 + 08Kh18N10T always used in shipbuilding and welded steel of F500W category are considered. According to the assessment of testing of homogeneous nitrogen steel sheets, the level of its physical and mechanical properties exceeds the analogous parameters of traditional AB2 + 08Kh18N10T steels in a wide temperature range, up to –90°C.

Incipient Surge Detection in Large Volume Energy Systems Based On Wigner-Ville Distribution Evaluated On Vibration Signals

2021 ◽  
Author(s):  
Carlo Alberto Niccolini Marmont Du Haut Champ ◽  
Paolo Silvestri ◽  
Mario L. Ferrari ◽  
Aristide Fausto Massardo
Keyword(s):  
Research Field ◽  
Rotating Stall ◽  
Operating Conditions ◽  
Rolling Bearings ◽  
Time Frequency ◽  
Rotating Machine ◽  
Large Size ◽  
Critical Issues ◽  
Volume Energy ◽  
Transient Operations

Abstract Compressor response investigation in nearly unstable operating conditions, like rotating stall and incipient surge, is a challenging topic nowadays in the turbomachinery research field. Indeed, turbines connected with large-size volumes are affected by critical issues related to surge prevention, particularly during transient operations. Advanced signal-processing operations conducted on vibrational responses provide an insight into possible diagnostic and predictive solutions which can be derived from accelerometer measurements. Indeed, vibrational investigation is largely employed in rotating-machine diagnostics together with time-frequency analysis such as smoothed pseudo-Wigner Ville (SPWVD) time-frequency distribution (TFD) considered in this paper. It is characterized by excellent time and frequency resolutions and thus it is effectively employed in numerous applications in the condition monitoring of machinery. The aim and the innovation of this work regards SPWVD utilization to study turbomachinery behavior in detail in order to identify incipient surge conditions in the centrifugal compressor starting from operational vibrational responses measured at significant plant locations. To this aim, an experimental campaign has been conducted on a T100 microturbine connected with different volume sizes to collect significant data to be analyzed. The results show that SPWVD is able to successfully identify system evolution towards an unstable condition, by recognizing different levels and features of the particular kind of instability that is going to take place within the plant. Instability phenomena regarding rolling bearings have also been identified and their interaction with surge onset has been investigated for diagnostic purposes.

Chilled Coil Control and Field Performance for Turbine Inlet Air Chilling

2021 ◽  
pp. 2150019
Author(s):  
Gopalakrishnan Anand ◽  
Ellen Makar
Keyword(s):  
Air Temperature ◽  
Field Performance ◽  
Operating Conditions ◽  
The Arctic ◽  
Ambient Conditions ◽  
Performance Guarantees ◽  
Turbine Inlet ◽  
Bell Mouth ◽  
Chilled Water ◽  
Coil Performance

Ambient conditions greatly affect the combustion turbine performance. The Absorption Refrigeration Cycle Turbine Inlet Chilling (ARCTIC) system can chill the inlet air of the turbine to maintain optimum performance at all ambient temperatures. However, turbine characteristics, bell-mouth icing concerns, economics and performance guarantees require maintaining the inlet air temperature within a narrow range throughout the year. These considerations require strict control of the Turbine Inlet Air Chilling (TIAC) coil performance over a wide range of operating conditions. This paper describes the field performance and control of the chilling coil for a Mars 100 turbine. The controls logic had been developed from previously published empirical model of the chilling coil and model of the chilling loop performance at the various ambient conditions. Since commissioning at the end of summer 2020, the ARCTIC has provided inlet air chilling over a range of ambient conditions. Typically, the inlet air is maintained at 7.2∘C (45∘F) by controlling the TIAC chilled water flow rate and temperature. On cooler days, if the inlet air temperature drops to 5.6∘C (42∘F) the chilled water pump turns OFF automatically to prevent bell-mouth icing. Thus, the chiller accommodates chilling load variations down to zero load. On colder days, the ARCTIC continues operating till the ambient temperature drops below 1.7∘C (35∘F) and then turns OFF. The chiller turns back ON when the 8 h average inlet air temperature exceeds 10∘C (50∘F). These parameters can be adjusted remotely by the operator and help maintain performance guarantees while minimizing chiller cycling. Quasi-steady state data were analyzed to quantify the chilling load and coil performance over a range of operating conditions.

Features of equipping the divisions of FPS GPS EMERCOM of Russia with fire fighting equipment and rescue tools for work in the Arctic zone of the russian federation

2020 ◽  
pp. 79-83
Author(s):  
Евгений Владимирович Павлов ◽  
Иван Вячеславович Нестеров ◽  
Александр Иванович Пичугин ◽  
Кирилл Эдуардович Архиреев ◽  
Владимир Иванович Логинов ◽  
...  
Keyword(s):  
Information And Communication Technologies ◽  
Russian Federation ◽  
Life Support ◽  
Negative Impact ◽  
Technical Support ◽  
Operating Conditions ◽  
The Arctic ◽  
Arctic Zone ◽  
Special Equipment ◽  
The Russian Federation

Сформулированы общие требования к пожарной технике и оборудованию, аварийно-спасательным средствам, предназначенным для эксплуатации в Арктической зоне Российской Федерации (АЗРФ). Рассмотрены основные факторы, связанные с использованием пожарной техники в условиях экстремально отрицательных температур и затрудняющие тушение пожаров, проведение аварийно-спасательных работ. Основным фактором является неприспособленность к работе при значениях температуры окружающей среды ниже минус 40 °С имеющейся пожарной техники или ее отсутствие. Этот фактор определяет и другие негативные факторы, снижающие эффективность пожарной техники или делающие невозможным ее применение. Указаны основные приоритеты развития системы материально-технического обеспечения сил и средств ФПС ГПС МЧС России в АЗРФ. The main directions of FPS GPS divisions development in the Arctic zone of the Russian Federation (AZRF) are formulated. The paper draws attention to the problem of equipping fire and rescue units operating in the AZRF with special equipment adapted to extreme operating conditions. A number of factors have a negative impact on providing fire and rescue units with the necessary equipment. They include an insufficient number of equipment types designed specifically for operation in AZRF conditions, the lack of a regulatory framework containing the requirements to certain types of fire and rescue equipment of HL climatic performance. In addition, the authorizing departmental documents, defining the order of material and technical support of divisions of FPS GPS EMERCOM of Russia, do not consider the features of material and technical support of divisions in AZRF. There are formulated the following main development priorities for the system of material and technical support of forces and means of the FPS GPS EMERCOM of Russia in AZRF: development and implementation of innovative models of multifunctional mobile fire and rescue vehicles and equipment, improvement of the system of maintenance and repair for fire and rescue equipment and vehicles in the Arctic zone. In addition, it is necessary to build, reconstruct and equip the infrastructure objects for divisions of FPS GPS EMERCOM of Russia including the provision with modern information and communication technologies and life-support systems that allow to monitor the situation effectively and, if necessary, to warn the population.

Study of the Physical and Mechanical Characteristics of the Ice Cover

2019 ◽  
Vol 974 ◽  
pp. 482-487
Author(s):  
A.S. Vasilyev ◽  
V.L. Zemlyak ◽  
V.M. Kozin
Keyword(s):  
Mechanical Characteristics ◽  
Bending Strength ◽  
Winter Season ◽  
Physical And Mechanical Properties ◽  
Ice Cover ◽  
The Arctic ◽  
Structural Failure ◽  
Extreme North ◽  
Far Eastern ◽  
Physical And Mechanical Characteristics

The construction of crossing ferry landings across the Arctic Shelf and the regions located in the Extreme North or Far North, as well as the Siberian and Far Eastern rivers during the winter season is a difficult task of immediate concern. Nevertheless, it is necessary to learn the ice mechanical characteristics in order to examine the bearing capacity of the ice cover at the crossing ferry landings aimed at their establishment and strengthening. The purpose of the paper is to observe the physical and mechanical features of the ice cover by means of doing simulated experiments and verifying their validity using a computational model. The research performed the studies on Young’s modulus of ice definition and bending strength. Ice beam samples were used in the simulated experiments. Their physical and mechanical properties were put to the tests carried out with a special loading device. There was a structural failure of ice beam samples influenced by pure bending. The authors performed numerical computations on the ground of the data obtained by ANSYS software. The calculations resulted in determining condition of the stress-strain state of the samples at any time of loading up to their complete breaking-up. The efficiency of the algorithm is proved by comparing numerical calculations to simulated experimental data.

The Effect of Geometrical Features on Air-Side Heat Transfer and Friction Characteristics, and Optimization of a Large-Size Plain Fin-and-Tube Heat Exchanger by 3-D Numerical Simulation

2009 ◽  
Author(s):  
M. Izadi ◽  
D. K. Aidun ◽  
P. Marzocca ◽  
H. Lee
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Simple Algorithm ◽  
Operating Conditions ◽  
Friction Characteristics ◽  
Tube Heat Exchanger ◽  
Large Size ◽  
Geometrical Features

The effect of geometrical features on the air-side heat transfer and friction characteristics of an industrial plain fin-and-tube heat exchanger is investigated by 3-D numerical modeling and simulations. The heat exchanger has been designed and employed as an intercooler in a gas power plant and is a large-size compact heat exchanger. Most of the available design correlations developed so far for plain fin–and–tube heat exchangers have been prepared for small-size exchangers and none of them fits completely to the current heat exchanger regarding the geometrical limitations of correlations. It is shown that neglecting these limitations and applying improper correlations may generate considerable amount of error in the design of such a large-size heat exchanger. The geometry required for numerical modeling is produced by Gambit® software and the boundary conditions are defined regarding the real operating conditions. Then, three-dimensional simulations based on the SIMPLE algorithm in laminar flow regime are performed by FLUENT™ code. The effect of fin pitch, tube pitch, and tube diameter on the thermo-hydraulic behavior of the heat exchanger is studied. Some variations in the design of the heat exchanger are suggested for optimization purposes. It is finally concluded that the current numerical model is a powerful tool to design and optimize of large-size plain fin-and-tube heat exchangers with acceptable accuracy.

A Chaotic Krill Herd Algorithm for Optimal Solution of the Economic Dispatch Problem

2017 ◽  
Vol 31 ◽  
pp. 155-168 ◽  
Author(s):  
Bachir Bentouati ◽  
Saliha Chettih ◽  
Ragab Abdel-Aziz El-Sehiemy
Keyword(s):  
Optimization Problem ◽  
Economic Dispatch ◽  
Optimal Solution ◽  
Operating Conditions ◽  
Krill Herd Algorithm ◽  
Krill Herd ◽  
Conflicting Objectives ◽  
Metaheuristic Search ◽  
Elitism Scheme ◽  
Planning And Operation

The aim of economic dispatch (ED) problem is to provide an efficient utilization of energy resources to produce economic and secure operating conditions for the planning and operation of a power system. ED is formed as a nonlinear optimization problem with conflicting objectives and subjected to both inequality and equality constraints. An efficient improvement of krill herd (KH) algorithm, a powerful metaheuristic method, has been introduced in this paper. The KH algorithm inspired by the Lagrangian and evolutionary behaviour of the krill people in nature, has been investigated to solve ED problem on 6, 13, 20 and 40 generating units. The proposed chaotic krill herd (CKH)) improvement is done by incorporating the chaos approach to KH algorithm for raising the global convergence speed and for enhancing its performance. The elitism scheme serves to save the best krill during the procedure when updating the krill. The results show clearly the superiority of CKH in searching for the best cost value results when compared with well-known metaheuristic search algorithms.

scholarly journals Powering Multiple Gas Condensate Wells in Russia’s Arctic: Power Supply Systems Based on Renewable Energy Sources

Resources ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 130
Author(s):  
Gennadiy Stroykov ◽  
Alexey Y. Cherepovitsyn ◽  
Elizaveta A. Iamshchikova
Keyword(s):  
Renewable Energy ◽  
Transmission Lines ◽  
Power Supply ◽  
Power Transmission ◽  
Renewable Energy Sources ◽  
Operating Conditions ◽  
Gas Condensate ◽  
The Arctic ◽  
Power Transmission Lines ◽  
Power Sources

Using renewable energy off-grid power supply and choosing the right equipment that meets the operating conditions in the Arctic can provide companies with reliable power sources for producing gas at facilities located in remote areas and will reduce capital and operating costs associated with the construction of power transmission lines. For more than 15 years, a remote control system powered by renewable energy has been used in parallel with power transmission lines by Gazprom to operate its multiwell pads in Russia’s Far North, which validates the relevance of this study. The subject of the study is a group of gas condensate wells that consists of four multiwell pads operated by Wintershall Russland GmbH. The article discusses a stand-alone renewable-based power system as an option for powering remote oil and gas production facilities. The procedures used in the study include calculating such parameters as power output and power consumption, choosing equipment, describing the design features of a power supply system for a multiwell pad, conducting an economic assessment of the project, comparing different power supply options, analyzing project risks, and developing measures to mitigate these risks.

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