Synthesis and Analysis of a Combined Magnetic and Gas Dynamic Suspension for a Model Range of New-Generation High-Speed Micro Gas Turbine Power Units

2021 ◽  
pp. 5-17
Author(s):  
Sergey A. GANDZHA ◽  
◽  
Nikolay I. NEUSTROEV ◽  
Pavel A. TARANENKO ◽  
◽  
...  

The modern power industry is characterized by intense development of distributed generation, with which numerous sources of different capacities are connected into a single network. This makes it possible to improve the reliability of the entire system, since the probability of several sources to fail simultaneously is quite low. Electric generation based on high-speed gas turbine units accounts for a significant share in the overall balance, due to which scientific research and new engineering solutions in this area are important and relevant. An innovative design of a high-speed gas turbine unit based on a switched axial generator is proposed. This electrical machine has a diamagnetic armature, which eliminates magnetic losses, due to which better efficiency of the power unit is achieved and its design is simplified. The high speed of rotation and the presence of critical resonant rotor speeds generated the need to adopt appropriate engineering decisions in regard of its supports. A combined suspension involving the use of magnetic and gas-dynamic bearings is proposed. The magnetic bearings support the gas turbine unit operation at low speeds during its acceleration, and the gas-dynamic bearings support its operation at high nominal speed. The generator design and the combined suspension layout are shown. The numerical analyses of magnetic and gas-dynamic bearings for a gas turbine unit for a capacity of 100 kW and rotation speed of 70 000 rpm are given. The study results can be used for a series of gas turbine units with capacities ranging from 10 to 500 kW. In our opinion, this concept is competitive with modern analogs with a radial generator design.

Author(s):  
Flavio Caresana ◽  
Gabriele Comodi ◽  
Leonardo Pelagalli ◽  
Sandro Vagni

In this paper we discuss the usefulness of a bottoming cycle applied to a micro size gas turbine unit to enhance its electric performance. A commercial 100 kWe micro gas turbine is used as a topping system; a basic thermodynamic analysis is performed to define the principal characteristics of viable vapour bottoming cycles. The analysis points to a solution adopting an Organic Rankine Cycle (ORC) with R245fa as working fluid, due both to environmental constrains and to technical criteria.


Author(s):  
Yastuti Rao Gautam

Micro gas turbines are an auspicious technology for power generation because of their small size, low pollution, low maintenance, high reliability and natural fuel used. Recuperator is vital requirement in micro gas turbine unit for improve the efficiency of micro turbine unit . Heat transfer and pressure drop characteristics are important for designing an efficient recuperator. Recuperators preheat compressed air by transfer heat from exhaust gas of turbines, thus reducing fuel consumption and improving the thermal efficiency of micro gas turbine unit from 16–20% to 30%. The fundamental principles for optimization design of PSR are light weight, low pressure loss and high heat-transfer between exhaust gas to compressed air. There is many type of recuperator used in micro gas turbine like Annular CWPS recuperator , recuperator with involute-profile element , honey well , swiss-Roll etc . In this review paper is doing study of Heat transfer and pressure drop characteristics of many types recuperator.


Author(s):  
Haiyang Zhao ◽  
Xutian Zou ◽  
Hongbo Qiu ◽  
Yiwei Ding

AbstractHigh-speed surface-mounted permanent magnet synchronous machine is often used in micro gas turbine generation system due to its high rotor strength and high efficiency. The electrical machine in this kind of generation system needs to integrate two functions of starter and generator. Therefore, its comprehensive performance, including starting performance and generating performance, has become a comprehensive standard to measure machine performance. In this paper, a 40 kW, 20,000 r/min high-speed machine is taken as an example, the influence of magnets magnetization direction on the machine comprehensive performance is studied. The machine models with different magnets magnetization directions are established by using finite element method and the correctness of the models is verified by comparing the experimental data with the finite element calculation data. On this basis, the influence of different magnetization directions on the performance of the machine, such as generation loss, torque ripple, output voltage, start-up time and maximum starting ability, is analyzed. Furthermore, based on the Fourier decomposition of air gap flux density and the decoupling analysis of starting torque, the influence mechanism of magnetization direction on the performance of the machine is revealed. The presented results provide a reference for the selection of a suitable magnetization direction for high-speed surface-mounted permanent magnet machines.


2006 ◽  
Vol 53 (2) ◽  
pp. 415-420 ◽  
Author(s):  
M. Morimoto ◽  
K. Aiba ◽  
T. Sakurai ◽  
A. Hoshino ◽  
M. Fujiwara

Author(s):  
W. Schmitt ◽  
V. Thomas

The first part of this paper describes the test installation of the gas turbine and the compressor in the workshop, test execution, measuring methods, evaluation and measuring uncertainties. The second part of this paper describes the site installation, execution of the test under full load conditions on natural gas, measuring methods, evaluation and measuring uncertainties. The third part of this paper compares both the measurements and the Reynolds number correction which was used for the evaluation of the pipeline compressor test results in the workshop.


2018 ◽  
pp. 39-44
Author(s):  
Богдан Сергійович Портной ◽  
Андрій Миколайович Радченко ◽  
Роман Миколайович Радченко ◽  
Сергій Анатолійович Кантор

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.


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