Design calculation of three-loop combined-cycle plants with steam reheating

We describe a procedure for carrying out an end-to-end calculation of the parameters of media and technical and economic indicators of three-loop heat-recovery-type combined-cycle plants with steam reheating that makes it possible to determine the parameters of gases and working fluid of a heat-recovery boiler and the thermal power of its heating surfaces, and to carry out an approximate calculation of the steam turbine for compartments and then for stages at the stage of design calculations using the parameters of gases exhausted from the gas turbine unit as initial data. The procedure is implemented in the form of a computer program in the DELPHI environment and makes it possible to quickly and reliably optimize a combined-cycle plant’s thermal circuit and steam turbine design.     

An investigation of the effects of separating pressure on the efficiency and the reliability of three-circuit combined-cycle power plants with steam reheating

The authors discuss the influence of selection of the separating pressure in designing three-circuit combined-cycle power plants (CCPP) with steam reheating on their technical and economical characteristics. The changes occurring in steam flow rates in the circuits, as well as in the efficiency of the waste heat recovery boiler (WHRB), the dryness factor, heat drops, the capacity and the efficiency of the steam turbine cylinders, the efficiency of the steam turbine and the CCPP as a whole, with the changes in the separating pressure, have been analyzed. It has been shown that the optimum separating pressure for the steam-power cycle with subcritical steam conditions ranges from 2.0 to 2.5 MPa.     

Selecting the parameters and carrying out design calculations of three-loop combined-cycle plants equipped with a vacuum deaerator and steam reheat system

A procedure for carrying out end-to-end calculation of the parameters of media and technical-and-economic indicators characterizing three-loop heat-recovery combined-cycle plants equipped with a vacuum deaerator and steam reheating system is described. The procedure makes it possible to determine the parameters of gases and working fluid of a heat-recovery boiler, the thermal power of its heating surfaces, and carry out an approximate calculation of the steam turbine and then its stage-wise calculation, all during the design calculation phase.     

Diagrams of regimes of cogeneration steam turbines for combined-cycle power plants

General considerations regarding the form of the steam-consumption diagram for a three-loop cogeneration-type combined-cycle plant are formulated on the basis of well-known approaches. According to these considerations the diagram should consist of the main chart and numerous corrections that must be taken into account in using the diagram. The steam-consumption diagram of the T-113/145-12.4 steam turbine for the PGU-410 combined-cycle plant at the Krasnodar cogeneration station is presented.     

Improving the maneuverability of combined-cycle power plants through the use of hydrogen-oxygen steam generators

Prospects for making changes in the composition of power-generating capacities of Russia are considered from the viewpoint of their influence on the quality of controlling the frequency and power in the power system. It is shown that the characteristics of newly commissioned and prospective equipment may add difficulty to control of these parameters with the required quality. A combination of methods is proposed for controlling combined-cycle power units with involvement of hydrogen technologies, the use of which makes it possible to achieve full-valued participation of such power units in selective primary control of the power system frequency.     

Controlling the startup modes of cogeneration steam turbines operating as part of combined-cycle power plants

The results obtained from investigations of combined-cycle power plants produced by the Ural Turbine Works aimed at achieving high maneuverability, reliability and longevity of cogeneration steam turbines taking into consideration the possibilities of modern automated process control systems are presented. The dynamic models for simulating the heating of a steam turbine cylinder??s parts with the use of limited computation capacities are developed.     

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.     

The thermodynamic efficiency of the condensing process circuits of binary combined-cycle plants with gas-assisted heating of cycle air

The thermal efficiencies of condensing-type circuits of binary combined-cycle plants containing one, two, and three loops with different pressure levels and equipped with a GTE-160 (V94.2) gas turbine unit, and with preheating of cycle air are analyzed by way of comparison in a wide range of initial steam pressures. The variation of the combined-cycle plant efficiency, stream wetness, conditional overall heating surface of the heat-recovery boiler, and other parameters is presented.     

The economic aspect of transition to power units with supercritical steam parameters

Information on the development and use of power units for supercritical and ultrasupercritical steam parameters in the United States, as well as in Europe and Japan, is presented. It is shown that increasing the parameters of steam reduces not only the fuel consumption, but also the specific emissions of toxic and greenhouse gases. Results of a calculation carried out at the EPRI (the United States) are presented, which show that it is advisable to construct power units for supercritical parameters only at certain (sufficiently high) price of the fuel being fired.     

The influence of the type of steam distribution in steam turbines of combined-cycle plants on the effectiveness of their operation

The paper is concerned with the comparative effectiveness of the use of nozzle and throttle steam distribution in steam turbines of combined-cycle plants equipped with heat recovery boilers. The influence of the type of steam distribution in the steam turbine on the reliability of startup regimes and the load control range of a combined-cycle plant on the effectiveness of the use of steam turbines in the regimes of the frequency and power control in a power system is analyzed.     

Effects of electrical faults on reliability of turbogenerator units in large steam power plants

Because of the awareness in many countries of the objection of pollution, and the lack of available cooling water, modern steam power plants frequently lie far from load centers. Moreover, the rating of turbogenerator units is continuously growing, following technology's trends, size economies and the increasing demand on electrical energy. Power transmission lines for large distances are consequently required, thus raising the need for improved safety, reliability, and control of the power plant system as a whole. Reliability especially appears to be a critical factor, affecting the quality of delivery and the economy of production, so that improved reliability is increasingly required.The paper concentrates on the consequences of a typical electrical failure on the reliability of the largest turbogenerator unit which is going to be operated in Italy. Owing to the mutually dependent behaviour of the system's different parts, obviously an interdisciplinary problem, it was necessary to construct a general model of a thermal power station which allowed for the simulation of the transient conditions under study, thus providing pertinent solution data and suggestions.     

Specific features relating to development and operation of steam turbines for combined-cycle plants

Main lines of work on improving steam turbines intended for use in the composition of different binary combined-cycle power plants are presented. Matters of making steam turbines for combined-cycle plants more economically efficient and maneuverable are discussed.     

Comparison of the technical and economic parameters of different variants of the nuclear fuel cycle reactors of the nuclear power plants

The article presents the comparative economic analysis of the variants of implementation of the fuel cycles for fast and thermal reactors. Calculations are carried out for the formed reference conditions by the cost of processing stages of the fuel cycles for the foreign and expert Russian information sources. The comparative data on the resource supply, absolute and specific costs of the fuel cycle variants for the whole life cycle of the thermal power plant projects with the fast and thermal reactors are considered. The conclusions of the efficiency of the fuel cycle variants for the assumed reference conditions of the calculation are made.     

Selecting the initial steam temperatures in starting combined-cycle plants in compliance with the conditions of heating the high-pressure steam superheater outlet headers

Results from an analysis of permissible initial steam temperatures and heating rates of the outlet headers of high-pressure steam superheaters and the steam lines of combined-cycle plants at which their cyclic strength is ensured are presented. A procedure is proposed using which startup assignment schedules for different thermal states can be constructed proceeding from the heating rates and initial steam temperatures selected depending on the initial temperature state of the high-pressure steam superheaters’ outlet headers.     

Thermodynamic efficiency of geothermal power stations with hydrogen steam superheating

Results from studying the use of hydrogen steam superheating for geothermal plants by means of a thermodynamic analysis are presented. The optimal steam superheating range is determined within which the maximal efficiency of a geothermal plants is achieved with the minimal cost for installing additional equipment.     

E型和F型燃机联合循环电厂的性能及经济性比较

对E型燃机和F型燃机的性能进行了比较，同时对基于这两种燃机的联合循环电厂的性能和经济性进行了分析，指出无论是燃机本身的性能，还是燃机联合循环的性能，F型燃机都优于E型燃机；在电厂的建造成本、发电成本及运行和维护方面，F型燃机联合循环电厂也比E型燃机联合循环电厂具有优势。为此，推荐F型燃机作为近年燃机电厂首选机型。     

The choice of the design features of maneuverable combined-cycle units for new Russian power plants

The design features are treated of combined-cycle units (CCUs) utilizing V94.3A Siemens, GTE-110 Saturn, and GTE-160 LMZ gas turbines for the purpose of constructing new power plants in Russia designed to meet the requirement of high maneuverability. The problem is discussed of employing bypass smoke stacks for different CCU options with a view to improving their maneuverability and advance commissioning of a new power.     

基于KPCA-IPOA-BiGRU的联合循环余热锅炉 主蒸汽参数预测

余热锅炉主蒸汽参数对于联合循环机组的健康运行判断至关重要。针对余热锅炉运行参数非线性和时延性导致主 蒸汽参数预测精度低的问题,提出了一种联合循环余热锅炉主蒸汽参数预测模型。首先,采集燃机电厂的SIS 运行数据,通过 灰色相关性分析法确定输入变量;其次,通过核主成分分析(kernel principal component analysis,KPCA)提取输入参数的特征 信息,并根据主成分贡献率选取输入维度;最后,利用改进的鹈鹕优化算法(improved pelican optimization algorithm,IPOA) 优化双向门控循环神经网络(bir-directional gated recirculation neural network,BiGRU),并构建 KPCA-IPOA-BiGRU进行三 压余热锅炉主蒸汽参数的预测测验。结果表明,现场采集的10000组数据点,其中8000组用作训练集,2000组用作测试集, 提出的模型将28维输入参数降低至8维,可准确预测3个压力级的蒸汽参数,且R² 均大于98%,为预测时延性的联合循环 余热锅炉主蒸汽参数提供了技术支持。     

Review of the coal-fired,over-supercritical and ultra-supercritical steam power plants

The article presents a review of developments of modern high-capacity coal-fired over-supercritical (OSC) and ultra-supercritical (USC) steam power plants and their implementation. The basic engineering solutions are reported that ensure the reliability, economic performance, and low atmospheric pollution levels. The net efficiency of the power plants is increased by optimizing the heat balance, improving the primary and auxiliary equipment, and, which is the main thing, by increasing the throttle conditions. As a result of the enhanced efficiency, emissions of hazardous substances into the atmosphere, including carbon dioxide, the “greenhouse” gas, are reduced. To date, the exhaust steam conditions in the world power industry are p ₀ ≈ 30 MPa and t ₀ = 610/620°C. The efficiency of such power plants reaches 47%. The OSC plants are being operated in Germany, Denmark, Japan, China, and Korea; pilot plants are being developed in Russia. Currently, a project of a power plant for the ultra-supercritical steam conditions p ₀ ≈ 35 MPa and t ₀ = 700/720°C with efficiency of approximately 50% is being studied in the EU within the framework of the Thermie AD700 program, project AD 700PF. Investigations in this field have also been launched in the United States, Japan, and China. Engineering solutions are also being sought in Russia by the All-Russia Thermal Engineering Research Institute (VTI) and the Moscow Power Engineering Institute. The stated steam parameter level necessitates application of new materials, namely, nickel-base alloys. Taking into consideration high costs of nickel-base alloys and the absence in Russia of technologies for their production and manufacture of products from these materials for steam-turbine power plants, the development of power plants for steam parameters of 32 MPa and 650/650°C should be considered to be the first stage in creating the USC plants as, to achieve the above parameters, no expensive alloys are require. To develop and construct OSC and USC head power plants, joint efforts of the government, experts in power industry and metallurgy, scientific institutions, and equipment manufacturers are required.     

Complex technical and economic studies of combined-cycle units with flow gasifiers

The method for determining the technical and economical indices of combined-cycle power plants (CCPPs) operating on coal with a low-charged steam generator and with a flow gasifier in combined production of electricity and heat, synthesis gas and hydrogen is considered. The results of analysis are presented and it is shown that such CCPPs have a higher technical and economical efficiency as compared to cogeneration plants (CPs) operating on pulverized coal and reconstructed with a gas-turbine topping. The material of this article is prepared in the framework of the Federal Targeted Program “Scientific and Scientific-Pedagogical Specialists of Innovative Russia for 2009–2013,” application 1.2.2, the program “Research Works on Production of Fuels and Power from Organic Raw Materials.”