Problems of vibration adjustment of gas-turbine power units

Some specific features pertinent to the vibration activity of domestically made gas-turbine power units are described, which should be taken into account during the adjustment of gas turbines, especially during their balancing. We also show characteristic changes in vibrations under transient conditions (before stabilization), the duration of which may exceed the time of operation under load. Recommendations for rotor balancing are given.     

Using gas-turbine units as standby power supplies for nuclear power station auxiliaries

We present the results from a technical and economic assessment of providing redundant power supply to the auxiliaries of a nuclear power station by equipping it with continuously operating gas-turbine units with recovering of the heat of spent gases in the nuclear power station’s thermal circuit.     

The problem and ways of development of low-toxicity combustors for advanced stationary gas-turbine power units

Results are given of experimental and industrial investigations of the basic properties of low-toxicity combustors utilizing homogeneous fuel-air mixtures. The main stages in the research, development, and application in practice of such combustors are shown.     

A comparative analysis of the economic effect from using cogeneration gas-turbine units and combined-cycle plants in a power system

The net cost of heat production at cogeneration stations equipped with gas turbine units, steam turbine units, and combined-cycle plants is analyzed by way of comparison. It is shown that the minimal net cost will be achieved in the case of using certain types of power installations depending on the network tariff for electric energy.     

Trends in increasing gas-turbine units efficiency

A review of the latest models of gas-turbine units (GTUs) manufactured by leading firms of the world is given. With the example of units made by General Electric, Siemens, and Alstom, modern approaches to the problem of increasing the efficiency of gas-turbine units are dealt with. Basic principles of designing of moderate-size capacity gas turbine units are discussed, and comparison between characteristics of foreign-made GTUs belonging to this class and the advanced domestic GTE-65 unit is made.     

Economic effectiveness of using super-high values of initial steam parameters in cogeneration power units

The present paper reports the results of numerical investigations into both thermodynamic and economic components of the effect of an increase in the initial steam parameters to super-high values for cogeneration power units. As an initial variant, the heat flow diagram of the turbine plant equipped with the T-250/300-23.5 TMZ steam turbine was adopted. In the course of investigations, the ranges of initial steam pressure p ₀ = 23.5–30.0 MPa, steam temperature t ₀ = 540–600°C, and steam pressure after single reheat p _rh = 3.6–4.5 MPa were considered. In the calculations of the thermodynamic efficiency, the extent of the effect of an increase in steam parameters on the out and the electric efficiency of a power unit when a cogeneration steam turbine operates in condensing and heat-extraction modes were estimated. In the economic part of the calculations, indicators of the commercial efficiency of investments into appropriate projects and the levels of total investment and production costs were determined. The results of the calculations made it possible to estimate the optimum level of super-high values of the initial steam parameters for a cogeneration power unit equipped with the T-280/335-26.1 steam turbine. The best indicators of the commercial efficiency were achieved for the variant with the following parameters of live steam and steam in the reheater: p ₀ = 26.1 MPa, p _rh = 4.035 MPa, t ₀/t _rh = 575/575°C. In this case, the following values were obtained: 42.56% gross efficiency, 40.94% net efficiency, 334 MW rated capacity in the condensing operation mode, and 279.1 MW in the heat-extraction mode at Q _T = 1381.6 GJ/h (330 Gcal/h). The use of higher steam parameters would result in a significant increase in the cost of projects. It has been shown that the restoration of initial design values of both live steam temperature and its temperature after reheat t ₀/t _rh = 565/560°C may be advisable at the upgrading of power units equipped with T-250/300-23.4 steam turbines.     

Thermodynamic model and analysis of hybrid power installations built around solid-oxide fuel cells and gas-turbine units

A thermodynamic model of a high-temperature solid-oxide fuel cell is constructed on the basis of the thermodynamic laws of gas mixtures. The model is calibrated to the parameters of an experimental high-temperature solid-oxide fuel cell using an electric load factor. A parametric analysis of hybrid power-generating installations is carried out using a gas-turbine unit’s thermodynamic model verified for an aircraft-derivative gas-turbine unit in the 1–10 MW scale of power capacities.     

Small gas-turbine units for the power industry: Ways for improving the efficiency and the scale of implementation

Small power units (<1 MW) see increasing application due to enhanced growth of the distributed power generation and smart power supply systems. They are usually used for feeding facilities whose connection to centralized networks involves certain problems of engineering or economical nature. Small power generation is based on a wide range of processes and primary sources, including renewable and local ones, such as nonconventional hydrocarbon fuel comprising associated gas, biogas, coalmine methane, etc. Characteristics of small gas-turbine units (GTU) that are most widely available on the world market are reviewed. The most promising lines for the development of the new generation of small GTUs are examined. Special emphasis is placed on the three lines selected for improving the efficiency of small GTUs: increasing the fuel efficiency, cutting down the maintenance cost, and integration with local or renewable power sources. It is demonstrated that, as to the specific fuel consumption, small GTUs of the new generation can have an efficiency 20–25% higher than those of the previous generation, require no maintenance between overhauls, and can be capable of efficient integration into intelligent electrical networks with power facilities operating on renewable or local power sources.     

Experience gained from using water and steam for bringing the operation of aircraft- and marine-derivative gas-turbine engines in compliance with environmental standards

Practical experience gained from using water and steam admission into the combustion chambers of aircraft- and marine-derivative gas turbines for bringing their operation in compliance with the requirements of environmental standards is described. The design and schematic modifications of combustion chambers and fuel system through which this goal is achieved are considered. The results obtained from industrial and rig tests of combustion chambers fitted with water or steam admission systems are presented.     

Prospects of using two-tier low-pressure cylinders in steam-turbine power units

Possible ways for increasing the throughput capacity of the low-pressure cylinders of the condensing steam turbines are discussed. It is shown that the use of two-tier low-pressure cylinders allows the flowrate of steam through them to be increased by 65–70% without the need of increasing the length of last-stage blades.     

Low and high voltage ride-through of DFIG wind turbines using hybrid current controlled converters

Doubly fed induction generators have been recognized as the dominant technology used in wind generation systems. However, this type of wind generator is very sensitive to the drop/rise in the supply voltage and without efficient “ride-through” strategy, continuous operation of DFIG may fail due to destructive overcurrents in the rotor winding or large overvoltages in the dc-link capacitor. This paper introduces a hybrid current control scheme, implemented in the rotor-side and grid-side converters of DFIG, to enhance low and high voltage ride-through capacities of DFIG-based wind turbines. The proposed control scheme is constituted of two switching strategies integrated with a supervisory control unit: standard PI current controllers for normal operating conditions and vector-based hysteresis current controllers for DFIG protection during severe voltage sag/swell conditions. Time-domain simulation studies are carried out to examine the effectiveness of the proposed ride-through strategy under various types of grid disturbances. It is shown that the proposed controller constrains the rotor current and dc-link voltage within the safety limits of DFIG and as a result, the wind generator can comply with the strict low/high voltage ride-through requirements stipulated by modern grid codes.     

Estimation of lifespan and economy parameters of steam-turbine power units in thermal power plants using varying regimes

The use of potent power units in thermal and nuclear power plants in order to regulate the loads results in intense wear of power generating equipment and reduction in cost efficiency of their operation. We review the methodology of a quantitative assessment of the lifespan and wear of steam-turbine power units and estimate the effect of various operation regimes upon their efficiency. To assess the power units’ equipment wear, we suggest using the concept of a turbine’s equivalent lifespan. We give calculation formulae and an example of calculation of the lifespan of a steam-turbine power unit for supercritical parameters of steam for different options of its loading. The equivalent lifespan exceeds the turbine’s assigned lifespan only provided daily shutdown of the power unit during the night off-peak time. We obtained the engineering and economical indices of the power unit operation for different loading regulation options in daily and weekly diagrams. We proved the change in the prime cost of electric power depending on the operation regimes and annual daily number of unloading (non-use) of the power unit’s installed capacity. According to the calculation results, the prime cost of electric power for the assumed initial data varies from 11.3 cents/(kW h) in the basic regime of power unit operation (with an equivalent operation time of 166700 hours) to 15.5 cents/(kW h) in the regime with night and holiday shutdowns. The reduction of using the installed capacity of power unit at varying regimes from 3.5 to 11.9 hours per day can increase the prime cost of energy from 4.2 to 37.4%. Furthermore, repair and maintenance costs grow by 4.5% and by 3 times, respectively, in comparison with the basic regime. These results indicate the need to create special maneuverable equipment for working in the varying section of the electric load diagram.     

Development of a process control system for the gas-turbine units operating at the thermal power plant of the Tuapse oil refinery plant

The characteristics of the thermal and electrical circuits for the six gas-turbine units operating at the thermal power plant of the oil refinery plant in Tuapse are reported. Operational modes of the equipment at different steam to electricity-consumption ratios are considered. The structure of the distributed control system of the process control system (PCS) and its characteristics are presented. The paper provides basic solutions for controlling thermal and electrical loads of the gas-turbine units. The designing features of circuits to control the power plant’s basic parameters are shown.     

Special features of the behavior of the liquid phase in high-speed compressors of aircraft engine-derivative gas-turbine units and their impact on characteristics and effectiveness of “wet” compression

The paper deals with the processes of “wet” compression with injection of water into axial-flow compressors of aircraft engine-derivative gas-turbine units, which are characterized by a relatively high speed of rotation and small standard dimensions. Given for two typical machines are the results of analysis of the behavior of water films on the surfaces of stator and rotor blades at different compressor stages (including the separation of moisture to the casing) and their impact on the characteristics and effectiveness of the process of “wet” compression.     

Effective participation of wind turbines in frequency control of a two-area power system using coot optimization

In this paper, load frequency control is performed for a two-area power system incorporating a high penetration of renewable energy sources. A droop controller for a type 3 wind turbine is used to extract the stored kinetic energy from the rotating masses during sudden load disturbances. An auxiliary storage controller is applied to achieve effective frequency response. The coot optimization algorithm (COA) is applied to allocate the optimum parameters of the fractional-order proportional integral derivative (FOPID), droop and auxiliary storage controllers. The fitness function is represented by the summation of integral square deviations in tie line power, and Areas 1 and 2 frequency errors. The robustness of the COA is proven by comparing the results with benchmarked optimizers including: atomic orbital search, honey badger algorithm, water cycle algorithm and particle swarm optimization. Performance assessment is confirmed in the following four scenarios: (i) optimization while including PID controllers; (ii) optimization while including FOPID controllers; (iii) validation of COA results under various load disturbances; and (iv) validation of the proposed controllers under varying weather conditions.     

Cavitation stability characteristics of turbine-driven pump units for rocket engines

The unity pertinent to the stalling branch of the flowrate curves describing the cavitation characteristics of a pump that was revealed earlier is substantiated theoretically. A method is proposed for constructing the cavitation characteristics of a pump on the basis of the interaction between its head characteristics with the characteristics of the hydraulic network. An example of calculation is given.     

我国火电机组仿真技术的发展

介绍了火电机组仿真技术的发展概况,以及它在计算机网络技术、虚拟DPU技术、图形化建模技术、超临界机组的建模技术、虚拟现实技术应用等方面取得的进展、实用意义及技术关键。     

Experience gained in a number of countries from using thermal power stations equipped with diesel and gas engines

Large-capacity thermal power stations and customer’s cogeneration stations equipped with diesel and gas engines, and their technical-economic and cost indicators are considered.     

浅议小型水轮发电机组作为蓄能电站保安电源

抽水蓄能机组应具有"黑启动"功能的要求,介绍了浙江桐柏、天荒坪抽水蓄能电站以小水轮发电机组替代常规柴油发电机组作保安电源的设计,并就2种类型的保安电源利弊做了比较.提出至今条件合适的类似工程中优先采用小水轮发电机的建议.