flow path
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2022 ◽  
Vol 2150 (1) ◽  
pp. 012017
Author(s):  
V A Mikula ◽  
G E Maslennikov ◽  
T F Bogatova

Abstract Simulation of erosion wear and design optimization have been performed for a convective gas cooler with a helical coil. Based on the results of simulation of the standard gas cooler design with a flat baffle used in Shell gasification-based combined cycle unit, it is concluded that the particle impact angle is the main factor determining the erosion maximum. To reduce erosion, it is necessary to install a structural element instead of the flat baffle to align the flow path of ash particles at the inlet to the gas cooler. The results of simulation for various baffle shapes show that a hemispherical baffle is optimal. The use of a hemispherical baffle plate made it possible to align the ash particle flow path at the inlet to the gas cooler channels and reduce the maximum level of erosion by a factor of almost 4 compared to the standard geometry of the baffle plate.


Author(s):  
Riza Sherfedinov ◽  
Oleksandr Usatyi ◽  
Olena Avdieieva ◽  
Mykhailo Daludin ◽  
Illia Yenin

This scientific paper gives the main research data obtained during the solution of the search problem to define optimal parameter values for the thermal circuit of the К-540-23.5 turbine unit that would provide the most efficient operation both for the optimal version of the high pressure cylinder (HPC) as part of the turbine unit and the turbine unit on the whole. The effect of the distribution of heat differences in the stages of the optimal flow part of the high pressure cylinder used by the К-540-23.5 turbine on the integral quality factors of the turbine unit has been assessed. The calculation studies of the thermal circuit of the turbine unit with the optimal flow section of the high-pressure cylinder showed that the temperature of the underheated feed water in the high pressure heater (HPH) arranged near the steam generator has the most critical effect on the power and economical efficiency of the high pressure cylinder and entire turbine unit. The two-criterion Pareto problem for the upgrading of the turbine unit was formulated and solved to define optimal underheating temperature values. Consideration was given to the two variants of the solution of the optimization problem for the feed water underheating temperature in the high pressure heater. Comparison and analysis of the two variants of solution for the two-criterion optimization problem showed the identity of the obtained data and it confirms the correctness of the problem formulation and the algorithms used for its solution.


2021 ◽  
Author(s):  
Yogi Adi Guna ◽  
Michael Frank ◽  
Novianto Rochman ◽  
Thomas Herdian Abi Putra ◽  
Mohammad Irvan ◽  
...  

Abstract An operator recorded 1100 psi of sustained casing pressure between a 9-5/8" casing and a 3.5" production tubing annulus seven days after the cementing operation was completed for the 3.5" production tubing. A production logging run was performed, and results indicated gas was flowing from a zone 86 feet below the 9-5/8" casing shoe. As per the operator's standard, such a situation suggests subsequent well completion operations cannot be processed and must be remediated. The most common solution for such situations is to perforate and squeeze to ensure zonal isolation in the zone from which the gas is flowing. Due to the slim tubing size this operation can be difficult, and there exists a high risk of leaving set cement inside the 3.5" tubing. Furthermore, drilling would require extensive time with a coil tubing unit and in the worst case could lead to the loss of the well. To provide a dependable barrier for long term well integrity, a novel approach consisting of epoxy resin was discussed. A highly ductile, solids-free resin was designed and tailored to seal off communication from the gas source to surface. The void space in the annulus was estimated to be less than 5 bbl. An equipment package was prepared to mix and pump the resin into the annulus. Resin was pumped through the wellhead casing valve using a hesitation squeeze technique with the maximum surface pressure limited to 3000 psi. Once all resin was pumped, the casing valve was closed to allow enough time for the resin to build compressive strength. The job was planned to be performed in multiple stages consisting of smaller volumes. The job was completed in two stages, and the annular pressure was reduced. On the first job, 1 bbl of resin was mixed and injected into the annulus. The pressure build up was decreased from 550 psi per day to 27 psi per day. To lower the annular pressure further, a second resin job was performed using 0.35 bbl resin volume, which further reduced the annular pressure build up to 25 psi within 3 days. No further stages were performed as this was considered a safe working pressure for the well owner. After 2 months no annular pressure was observed. The application of this tailored resin helped to improve the wells integrity under these circumstances in this high-pressure gas well. Epoxy resin with its solid-free nature and deep penetration capabilities helped to seal off a very tight flow path. This application of pumping resin through the wellhead to overcome annular gas pressure can be an option when the flow path is strictly limited, or downhole well intervention is very difficult and risky.


2021 ◽  
Author(s):  
Ramesha Guntanur ◽  
Ashutosh Patel ◽  
Vijay Biradar ◽  
Pramod Kumar

Abstract This paper presents the coupled thermal and structural analysis of the rotating components of the generator using ABAQUS finite element solver. The interference between shaft and rotor is optimized to have a positive contact pressure and also minimize the stresses in the laminate at all operating speeds. Thermal analysis is performed to simulate the temperature distribution arising from the heat losses of generator. The flow path of the coolant is designed through the shaft to minimise the temperature rise of the generator. The resulting changes in the contact pressure between laminated disc and shaft is computed using sequentially coupled thermal and structural analysis. The thermal stresses of rotor are computed estimated and the design is optimized for transmitting torque at different operating speeds.


Author(s):  
Р.Р. Симашов ◽  
С.В. Чехранов

Обеспечение высокой экономичности не только на режимах номинальной мощности, но и на частичных режимах при изменении внешних параметров приводит к необходимости оптимизации проточной части турбины с объективным учетом ее характеристик на переменных режимах. Приводятся результаты многорежимной оптимизации МРТ в составе ЭУ АНПА на базе подхода разработанного авторами. Представлены основные результаты сравнительного анализа многорежимной оптимизации МРТ с оптимизацией на i-тый режим и работающей на остальных режимах как переменных для различных программ регулирования мощности. Выявлено сильное влияние на результаты многорежимной оптимизации основного ограничения в виде равенства мощности турбины мощности задаваемой графиком нагрузки, а также программ регулирования. Возможность применения соплового регулирования приводит к ослаблению степени воздействия основного ограничения. Установлено, что оптимальные геометрические характеристики стремятся к режиму с большей работой. Представлены результаты многорежимной оптимизации МРТ для различных программ регулирования и графиков нагрузок по отношению к результатам многорежимной оптимизации с программой реализующей сопловое регулирование в сочетании с изменением начальных параметров перед турбиной. Многорежимная оптимизация для программы, реализующей сопловое регулирование в сочетании с изменением только начальной температуры перед турбиной, выявила узкую регулировочную способность начальной температуры, и невозможность в некоторых случаях удовлетворения основным ограничениям по равенству мощностей для всех исследуемых графиков нагрузки в пределах заданных ограничений на режимные параметры. Результаты численного эксперимента свидетельствуют, что разработанный автором подход к многорежимной оптимизации МРТ позволяет снизить расход топлива при условии обеспечения заданного графика нагрузок по сравнению с традиционными методами проектирования на номинальный режим. Ensuring high efficiency not only at nominal power modes, but also at partial modes when changing external parameters leads to the need to optimize the flow path of the turbine with objective consideration of its characteristics at variable modes. The results of multi-mode optimization of a low-consumption turbine as part of a power unit of remotely operated underwater vehicle based on the approach developed by the authors are presented. The main results of a comparative analysis of multi-mode optimization of a low-consumption turbine with optimization for the i-mode and operating in other modes as variables for various power control programs are presented. A strong influence on the results of multi-mode optimization of the main limitation in the form of equality of the turbine power to the power set by the load schedule, as well as control programs is revealed. The possibility of using nozzle regulation leads to a weakening of the degree of influence of the main restriction. It was found that the optimal geometric characteristics tend to the regime with more work. The results of multi-mode optimization of a low-consumption turbine for various control programs and load schedules are presented in relation to the results of multi-mode optimization with a program that implements nozzle control in combination with a change in the initial parameters in front of the turbine. Multimode optimization for a program that implements nozzle regulation in combination with changing only the initial temperature in front of the turbine revealed a narrow adjusting ability of the initial temperature and the impossibility, in some cases, of satisfying the basic constraints on the equality of powers for all the studied load curves within the specified constraints on operating parameters. The results of the numerical experiment indicate that the approach developed by the author to the multi-mode optimization of a low-consumption turbine makes it possible to reduce fuel consumption, provided that a given load schedule is provided in comparison with traditional design methods for the nominal mode.


2021 ◽  
Vol 68 (12) ◽  
pp. 906-915
Author(s):  
S. Fialová ◽  
F. Pochylý ◽  
A. V. Volkov ◽  
A. V. Ryzhenkov ◽  
A. A. Druzhinin

2021 ◽  
Vol 945 (1) ◽  
pp. 012025
Author(s):  
Lim Mook Tzeng ◽  
Sureiyn Nimellnair a/l Vijayakumar ◽  
Ridzwan Bin Tajol Aros

Abstract This study synthesizes biogas with low methane contents (<50%) to hydrocarbons that form a combustible synthesis gas (syngas) mixture. Conventional methods used for reforming biogas has limitations in terms of fabrication, maintenance, and cost. This is especially true when the biogas’ composition fluctuates. Non-thermal plasma (NTP) is an alternative method to produce combustible syngas for power generation. Thus, the exhaust emissions from a 2 kWe spark ignition (SI) engine fuelled with gasoline and NTP-synthesized biogas is investigated with respect to the type of NTP reactor, plasma power consumption and biogas composition. Two types of NTP reactors are used: a cylindrical reactor where the gas flow path is linear, and a cyclonic reactor where the gas flow path is a curvature, similar to that of a gas-solid cyclone separator. The results show that the NTP reactors produced additional hydrocarbons, decreasing flue gas temperatures by 4°C and reducing NOx emissions by 35%.


Author(s):  
Ihor Palkov ◽  
Sergii Palkov ◽  
Oleh Ishchenko ◽  
Olena Avdieieva

The paper considers the main principles that are used to develop the flow paths (FP) of the high-pressure cylinders (HPC), intermediate-pressure cylinders (IPC), and low-pressure cylinders (LPC) for the K-1250-6.9/25 turbine unit. It describes approaches to the numerical experiment when designing flow paths, the advantage of which is lower labor, time and financial costs and higher informativeness compared to the physical experiment on flow paths. When designing the flow paths of high- and intermediate-pressure cylinders (HIPC), the numerical experiment is performed using the three-dimensional viscous-flow method. For this purpose, a three-dimensional model of the blade system in the flow path is built, which consists of a large number of finite volumes (elements) in the shape of hexagons, in each of which the integration of the equations of gas dynamics is performed. When developing LPC, the method of parameterization and analytical profiling of the blade crown sections is used, where the profiles are described by the curves of the fourth and fifth orders with the condition of providing the minimum value of the maximum curvature and monotonicity of variation of the three-dimensional blade geometry along height. This method allows obtaining the optimal profiles of the cross sections of the blades, which correspond to the current flow lines to the fullest extent, and minimizing the profile energy losses when the flow flows around the blades.


Author(s):  
Oleksandr Usatyi ◽  
Olena Avdieieva ◽  
Ihor Palkov ◽  
Sergii Palkov ◽  
Oleh Ishchenko

The article presents the results of multiparameter optimization of the structural and thermogasdynamic parameters of the flow path of the HPC K-330-23.5, obtained using the developed CAD “Turboagregat”. The found 12 optimal solutions for the flow path of the HPCK-330-23.5 make it possible not only to assess the effect of the design parameters and the number of blades of the HPC stages on the HPC efficiency, but also to carry out a comparative analysis of two technological approaches to manufacturing the rotor blades – with and without trimming the initial edges. Calculations have confirmed the negative effect of increasing the radius of the “tummy” circle on the nature of the flow and on the efficiency of the cascades. In cascades with increased profiles by 9.83 % with a radius of the “tummy” circle, the coefficient of profile losses of the cascade increased by 0.07 % (absolute) in comparison with the original cascade from the original 1MMK-U profiles.


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