Theoretical Estimation of Thermal Deformations of Non-Lubricated Bearings of Low-Flow Turbocharger Units

2019 ◽  
pp. 58-69
Author(s):  
N.A. Raykovskiy ◽  
V.L. Yusha ◽  
A.V. Tretyakov ◽  
V.A. Zakharov
Keyword(s):  
Turbine Unit ◽  
Mutual Influence ◽  
Cooling System ◽  
Temperature Fields ◽  
Low Flow ◽  
Lubrication System ◽  
Calculation Methods ◽  
Operating Modes ◽  
Temperature Regimes ◽  
Temperature Deformations

When designing turbocharger units (microturbines) working with high-temperature flows, it is possible to completely abandon lubrication system and use self-lubricating bearings instead. At the same time, it is important to ensure the required temperature regimes and permissible temperature deformations. Currently, there are no calculation methods that could be used to determine the temperature fields and temperature deformations of the ‘rotor — self-lubrication bearings’ system. The paper proposes a numerical method for calculating bearing assemblies, which takes into account the mutual influence of the operating modes of the turbine unit and the bearing cooling system. The proposed method is tested, and the results of the analysis of temperatures and temperature deformations are presented.

scholarly journals The method of dynamic operating modes investigation in electrohydraulic drive systems with improved accuracy of positioning executive elements

2018 ◽  
Vol 226 ◽  
pp. 04024
Author(s):  
Valeriy V. Grechikhin ◽  
Galina A. Galka ◽  
Anatoliy I. Ozerskiy ◽  
Mikhail E. Shoshiashvili
Keyword(s):  
Mutual Influence ◽  
Hydraulic Drive ◽  
Joint Work ◽  
Operating Modes ◽  
Hydraulic Machines ◽  
Dynamic Operating ◽  
Electrohydraulic Drive ◽  
Drive Systems ◽  
Improved Accuracy ◽  
Executive Elements

The article describes the method of dynamic operating modes investigation in electrohydraulic drive systems with improved accuracy of positioning output element. The method is the evolution of the fundamental positions of the mechanics of continuous media with moving boundaries as applied to the research of non-stationary processes accompanying the operation of hydraulic drive systems with piston hydraulic machines. The method is based on generalized modeling (technical, physical, mathematical and computer), takes into account the peculiarities of mutual influence of electric and hydraulic machines during their joint work as part of the electrohydraulic drive, which raises the level and adequacy of actuators simulation, as well as the reliability of the assessment of their technical condition. The method extends the field of research, improves the accuracy of the calculation of the positioning of the executive elements, taking into account the different dynamic modes of the drives under study.

Hydraulic Instability Onset Detection in Kaplan Turbines by Monitoring Shaft Vibrations

2012 ◽  
Author(s):  
P. Pennacchi ◽  
P. Borghesani ◽  
S. Chatterton ◽  
A. Vania
Keyword(s):  
Experimental Test ◽  
Turbine Unit ◽  
Swirling Flow ◽  
Draft Tube ◽  
Operating Conditions ◽  
Low Flow ◽  
Operating Life ◽  
Vortex Rope ◽  
Power Load ◽  
Helical Vortex

Design of hydraulic turbines has often to deal with hydraulic instability. It is well-known that Francis and Kaplan types present hydraulic instability in their design power range. Even if modern CFD tools may help to define these dangerous operating conditions and optimize runner design, hydraulic instabilities may fortuitously arise during the turbine life and should be timely detected in order to assure a long-lasting operating life. In a previous paper, the authors have considered the phenomenon of helical vortex rope, which happens at low flow rates when a swirling flow, in the draft tube conical inlet, occupies a large portion of the inlet. In this condition, a strong helical vortex rope appears. The vortex rope causes mechanical effects on the runner, on the whole turbine and on the draft tube, which may eventually produce severe damages on the turbine unit and whose most evident symptoms are vibrations. The authors have already shown that vibration analysis is suitable for detecting vortex rope onset, thanks to an experimental test campaign performed during the commissioning of a 23 MW Kaplan hydraulic turbine unit. In this paper, the authors propose a sophisticated data driven approach to detect vortex rope onset at different power load, based on the analysis of the vibration signals in the order domain and introducing the so-called “residual order spectrogram”, i.e. an order-rotation representation of the vibration signal. Some experimental test runs are presented and the possibility to detect instability onset, especially in real-time, is discussed.

scholarly journals Experimental investigations of the processes in gas generator of hydrogen-air energy storage

2021 ◽  
Vol 2039 (1) ◽  
pp. 012007
Author(s):  
N I Chukhin ◽  
A I Schastlivtsev
Keyword(s):  
Energy Storage ◽  
Turbine Unit ◽  
Cooling System ◽  
Average Power ◽  
Experimental Investigations ◽  
Gas Temperature ◽  
Gas Generator ◽  
Gas Turbine Unit ◽  
Accumulation System ◽  
Generator Unit

Abstract This paper describes the results of experimental investigation of the sample of the hydrogen-air gas generator unit with the expected average power of 65 kW. In total 5 test runs were made. Two tests showed that the mass flow and outlet gas temperature was in an agreement with the designed parameters. Additional attention should be paid to the cooling system design for the combustion chamber. In future such a gas generator in couple with the suitable gas turbine unit could be a part of the renewable energy accumulation system e.g. of hydrogen-air energy storage.

scholarly journals ВИКОРИСТАННЯ РЕЗЕРВУ ХОЛОДОПРОДУКТИВНОСТІ АБСОРБЦІЙНОЇ ХОЛОДИЛЬНОЇ МАШИНИ ПРИ ОХОЛОДЖЕННІ ПОВІТРЯ НА ВХОДІ ГТУ

2018 ◽  
pp. 39-44
Author(s):  
Богдан Сергійович Портной ◽  
Андрій Миколайович Радченко ◽  
Роман Миколайович Радченко ◽  
Сергій Анатолійович Кантор
Keyword(s):  
Gas Turbine ◽  
Turbine Unit ◽  
Cooling System ◽  
Lithium Bromide ◽  
Air Cooling ◽  
Gas Turbine Unit ◽  
Air Cooler ◽  
Refrigeration Capacity ◽  
Heat Loads ◽  
Current Heat

The processes of air cooling at the gas turbine unit inlet by absorption lithium-bromide chiller have been analyzed. The computer programs of firms-producers of heat exchangers were used for the gas turbine unit inlet air cooling processes simulation. The absorption lithium-bromide chiller refrigeration capacity reserve (the design heat load excess over the current heat loads) generated at the reduced current heat loads on the air coolers at the gas turbine unit inlet in accordance with the lowered ambient air parameters has been considered. The absorption lithium-bromide chiller refrigeration capacity reserve is expedient to use at increased heat load on the air cooler. To solve this problem the refrigeration capacity required for cooling air at the gas turbine unit inlet has been compared with the excessive absorption lithium-bromide chiller refrigeration capacity exceeding current heat loads during July 2017.The scheme of gas turbine unit inlet air cooling system with using the absorption lithium-bromide chiller refrigeration capacity reserve has been proposed. The proposed air cooling system provides gas turbine unit inlet air precooling in the air cooler booster stage by using the absorption lithium-bromide chiller excessive refrigeration capacity. The absorption chiller excessive refrigeration capacity generated during decreased heat loads on the gas turbine unit inlet air cooler is accumulated in the thermal storage. The results of simulation show the expediency of the gas turbine unit inlet air cooling by using the absorption lithium-bromide chiller refrigeration capacity reserve, which is generated at reduced thermal loads, for the air precooling in the air cooler booster stage. This solution provides the absorption lithium-bromide chiller installed (designed) refrigeration capacity and cost reduction by almost 30%. The solution to increase the efficiency of gas turbine unit inlet air cooling through using the absorption chiller excessive refrigeration potential accumulated in the thermal storage has been proposed.

scholarly journals Assessment of External Heat Transfer Modeling of a Laboratory-Scale Combustor Inside a Pressure-Housing Environment

2018 ◽  
Author(s):  
P. Rodrigues ◽  
O. Gicquel ◽  
N. Darabiha ◽  
K. P. Geigle ◽  
R. Vicquelin
Keyword(s):  
Heat Transfer ◽  
Cooling System ◽  
External Heat ◽  
Laboratory Scale ◽  
Radiative Properties ◽  
Temperature Fields ◽  
Transfer Model ◽  
External Heat Transfer ◽  
Heat Transfers ◽  
External Face

Many laboratory-scale combustors are equipped with viewing windows to allow for characterization of the reactive flow. Additionally, pressure housing is used in this configuration to study confined pressurized flames. Since the flame characteristics are influenced by heat losses, the prediction of wall temperature fields becomes increasingly necessary to account for conjugate heat transfer in simulations of reactive flows. For configurations similar to this one, the pressure housing makes the use of such computations difficult in the whole system. It is therefore more appropriate to model the external heat transfer beyond the first set of quartz windows. The present study deals with the derivation of such a model which accounts for convective heat transfer from quartz windows external face cooling system, free convection on the quartz windows 2, quartz windows radiative properties, radiative transfer inside the pressure housing and heat conduction through the quartz window. The presence of semi-transparent viewing windows demands additional care in describing its effects in combustor heat transfers. Because this presence is not an issue in industrial-scale combustors with opaque enclosures, it remains hitherto unaddressed in laboratory-scale combustors. After validating the model for the selected setup, the sensitivity of several modeling choices is computed. This enables a simpler expression of the external heat transfer model that can be easily implemented in coupled simulations.

Numerical Investigation on the Effect of Rotation and Holes Arrangement in Cold Bridge-Type Impingement Cooling Systems

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Simone Paccati ◽  
Lorenzo Cocchi ◽  
Lorenzo Mazzei ◽  
Antonio Andreini
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Mutual Influence ◽  
Cooling System ◽  
Leading Edge ◽  
Lateral Spreading ◽  
Test Point ◽  
Navier Stokes ◽  
Specific Flow ◽  
Bridge Type

Abstract This work presents the results of a numerical analysis performed on a gas turbine leading edge cooling system. The investigation was carried out in order to provide a detailed interpretation of the outcomes of a parallel experimental campaign. The cooling geometry consists of a cold bridge-type impingement system: a radial channel feeds an array of holes, which in turn generate impingement jets cooling down the inner side of the leading edge surface. Coolant is extracted by five rows of holes, replicating film cooling and showerhead systems. Two impingement geometries were considered, presenting different holes arrangements and diameters but sharing the same overall passage area, in order to highlight the effect of different coolant distributions inside the leading edge cavity. For both geometries, a single test point was investigated in static and rotating conditions, with an equivalent slot Reynolds number of around 8200 and feeding conditions corresponding to the midspan radial section of the blade. Both steady Reynolds averaged Navier Stokes (RANS) approach and scale adaptive simulation (SAS) were tested. Due to the strong unsteadiness of the flow field, the latter proved to be superior: as a consequence, the SAS approach was adopted to study every case. A fairly good agreement was observed between the measured and computed heat transfer distributions, which allowed to exploit the numerical results to get a detailed description of the phenomena associated with the different cases. Results reveal that the two holes arrangements lead to strongly different heat transfer patterns, related to the specific flow phenomena occurring inside the leading edge cavity and to the mutual influence of the various system features. Rotational effects also appear to interact with the supply condition, altering the jet lateral spreading and the overall heat transfer performance.

ITER Shield Block Cooling System Design and Analysis

2013 ◽  
Author(s):  
Weishan Kang ◽  
Tao Yuan ◽  
Xiujie Zhang
Keyword(s):  
System Design ◽  
Strain Distribution ◽  
Cooling System ◽  
Temperature Fields ◽  
Stress And Strain ◽  
Hydraulic Analysis ◽  
Design Requirements ◽  
Transient Thermal ◽  
Cooling Pipes ◽  
Stress And Strain Distribution

A steady-state thermo-hydraulic analysis of SB was done to get pressure drop and heat transfer coefficient in the cooling pipes, then a transient thermal analysis was performed to get temperature field of the SB with time in Inductive plasma operational scenario. Finally static structural analysis of the SB based on the temperature fields obtained with the transient analyses at specific time points were done to get the stress and strain distribution of the SB. The numerical analysis results were investigated by rules from ITER System Design Criteria for In-vessel Component to further verify the design. The final results of analyses indicate that the design of the SB meets with the ITER design requirements.

Optimization of the lubrication system in a turbocharged engine

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940011
Author(s):  
Cho-Yu Lee ◽  
Dani Joseph Veera ◽  
Huan-Yuan Chen ◽  
Jui-Hung Chang ◽  
Kao-Ruei Hung
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Engine Speed ◽  
System Optimization ◽  
Low Flow ◽  
Lubrication System ◽  
Mechanical Loss ◽  
Oil Pump ◽  
Oil Cooler ◽  
Base Engine

Lubricating the engine reciprocating components effectively against various engine speeds is significant for a proper lubrication system. This paper presents the lubrication system optimization of a twin cylinder 700 c.c. turbocharged engine. A couple of modifications were tested including correction of ducts misalignment, consistence diameter of ducts and replacement of a low flow resistance oil cooler. Compared to the base engine, experimental results prove that differential pressure (DP) between the oil pump and main oil gallery has been decreased to a minimum 19% and maximum 54% at engine speed between 2000 and 7000 rpm. The lower the pressure drop, the lower the flow resistance. Thus, mechanical loss has also been improved.

scholarly journals THE RESEARCH OF THE WORK OF THE HEAT ACCUMULATOR OF THE PRE-STARTING SYSTEM OF WORMING UP OF THE INTERNAL COMBUSTION ENGINE

2020 ◽  
Vol 42 (3) ◽  
pp. 76-83
Author(s):  
K. Lunyaka ◽  
O. Kliuiev ◽  
S. Rusanov ◽  
O. Kliuieva
Keyword(s):  
Heat Transfer ◽  
Heat Storage ◽  
Cooling System ◽  
Storage Material ◽  
Heat Accumulator ◽  
Operating Modes ◽  
Engine Cooling ◽  
Cooling Agent ◽  
Heat Storage Material ◽  
Engine Coolant

Problem statement. Starting internal combustion engines for a large car fleet at ambient temperature of less than 5 ºС requires considerable time; it leads to increased wear of the components of the connected engine pairs, increased fuel consumption during start-up and warm-up and increased emissions of harmful substances into the atmosphere with exhaust fumes. Therefore, prestart warming up   of car engines is given great attention. Actual scientific researches and issues analysis Recently, this problem has been solved by using heat accumulators, moreover, heat accumulators with heat storage material of a phase transition are given preference. The engine exhaust gases (temperature 600-700 ºС) or the engine cooling liquid (water,                 tosol cooling agent) are used as a heat transfer agent. Given the negative impact of high temperatures on the heat storage material, the metal of the heat storage structure and overheating (boiling) of the engine coolant, the first way has certain disadvantages. In this regard, we consider it more promising to use a liquid cooling engine as a coolant for a heat accumulator. High temperatures have no positive affect on the heat storage material, the metal of the heat storage structure and these are a cause for boiling a coolant –cooler of the engine. In this regard, we consider more promising to use a cooling fluid of the heat accumulator as a heat transfer agent. The aim of this work is to develop a new design of a heat accumulator for pre-starting warming up of a car engine, to make the experimental installation to research its work and conducting researches in order to find the time of charging and discharging of the heat accumulator, to construct operating modes during charging and discharging, to determine the necessary mass of the heat-accumulating material and the battery size. Base material The experimental installation was a closed system: the heat accumulator — a passage of the VAZ 2109 car engine cooling system. Taking into account the work peculiarities of the heat accumulator in the cooling system of the car engine, unlike other areas where all mass of the heat storage material constantly is in contact with the substance which the heat storage material giving up heat, in our case, the engine cooling liquid is located in the heat accumulator and in the cooling jacket. They mixes before starting the engine, while its temperature decreases. The time of charging and staying of the heat accumulator in the charged state has been determined, the operating modes during charging and discharging have been constructed, the necessary mass of the heat-accumulating material and the battery size has been determined.  Conclusions The experimental model of the heat accumulator of the pre-starting system of worming up of the engine of the car has been developed. This experimental model is included in a closed circuit with engine cooling system. On the model the researches of charging and discharging process of the heat accumulator have been conducted. The required time for these processes has been determined and on this basis the modes of operation of the heat accumulator - engine cooling system have been constructed. The temperatures of tosol cooling agent in the cooling system were calculated and it allowed finding mass (volume) of heat storage material of the heat accumulator and it served as the basis for determining the size of the heat accumulator. Establishment of a computerized control system on/off control of the heat accumulator in order to maintain the desired temperature of the engine coolant liquid using of heat storage material of phase transition and controlling this system using supplements to phones.

scholarly journals The Impact of the Lubricant Dose on the Reduction of Wear of QRO90 Steel Dies Used in the Forging Process of the Valve Forging Made of High-Nickel Steel

2020 ◽  
Author(s):  
Łukasz Dworzak ◽  
Marek Hawryluk ◽  
Marta Janik
Keyword(s):  
Cooling System ◽  
Industrial Process ◽  
Nickel Steel ◽  
Lubrication System ◽  
Forging Process ◽  
Feed Pressure ◽  
Wide Range ◽  
High Nickel ◽  
The Impact ◽  
High Nickel Steel

TThe paper presents the results of research on the influence of the settings of lubrication and cooling system parameters (solenoid valve opening time and lubricant feed pressure in terms of its quantity) in order to select the optimal lubricating conditions and thus reduce the wear of the dies used in the first forging operation of the valve forging made of high-nickel steel. Based on the observation of lubrication in the industrial process, it was found that a significant part of the lubricant fails to reach the die cavity, reaching the outside of it, which causes die wear due to seizure resulting from adhesion of the forging material to the tool surface, as well as high lubricant consumption and dirt in the press chamber. The authors proposed their own mobile lubricating and cooling system, which allows for a wide range of adjustments and provided with automatic cleaning procedures of the entire system, unlike the fixed lubrication system used so far in the industrial process. First, tests were carried out in laboratory conditions to determine the highest wettability and the lubricant remaining inside the tool cavity. These tests determined the lubrication system parameter settings which ensured that the greatest amount of lubricant remains in the cold die cavity without the forging process. Then, to verify the obtained results, tests were carried out in the industrial process of hot die forging of valve forgings, for short production runs of up to 500 forgings. The results were compared with the measurement of changes in the geometry of tools and forgings based on 3D scanning and surface topography analysis with the use of SEM. For best results (the variant of the setting of the dose and the time of exposure to lubricant), the forging process was carried out with the use of a new tool, up to the maximum service life.

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