共查询到20条相似文献,搜索用时 31 毫秒
1.
A CO2-recovering hybrid power generation system utilizing solar thermal energy is proposed. In the system, relatively low temperature saturated steam around 220°C is produced by using solar thermal energy and is utilized as the working fluid of a gas turbine in which generated CO2 is recovered based on the oxygen combustion method. Hence, solar thermal utilization efficiency is considerably higher as compared with that of conventional solar thermal power plants in which superheated steam near 400°C must be produced for use as the working fluid of steam turbines; the requirement for solar radiation in the location in which the system is constructed can be significantly relaxed. The proposed system is a hybrid energy system using both the fossil fuel and solar thermal energy, thus the capacity factor of the system becomes very high. The fuel can be used exergetically in the system; i.e., it can be utilized for raising the temperature of the steam heated by utilizing the turbine exhaust gas more than 1000°C. The generated CO2 can be recovered by using an oxygen combustion method, so that a high CO2 capturing ratio of near 100 percent as well as no thermal NOx emission characteristics can be attained. It has been shown through simulation study that the proposed system has a net power generation efficiency of 63.4 percent, which is higher than 45.7 percent as compared with that of the conventional power plant with 43.5 percent efficiency, when the amount of utilized solar energy is neglected and the temperature of the saturated steam is 220°C. 相似文献
2.
This paper describes the characteristics and construction of a coal-gas-burned high efficiency power plant which emits no carbon dioxide (CO2) into the atmosphere. In a plant, CO2 gas and superheated steam are used as the main and the secondary working fluids, respectively, of a closed dual fluid regenerative gas turbine power plant. Since coal gas composed of CO, H2, CO2 and CH4 is burned in a combustor using oxygen, the exhaust gas let into a condenser includes only CO2 and H2O. Hence, CO2 gas can be easily separated at the condenser outlet from condensate. In the plant, the combustion gas is first used to generate power by driving a turbine. High-temperature turbine exhaust gas is next utilized at a regenerator to heat the main working fluid of CO2 gas flowing into the combustor, and then is utilized at a waste heat boiler to produce the superheated steam injected into the combustor. It is estimated that the power can be generated with gross thermal efficiency of 54.4 percent, and that the power generating efficiency is 46.7 percent. Generating efficiency is calculated by subtracting the power required for producing the high-pressure oxygen used for combustion from the generator output. It is shown that the estimated efficiency is higher by 18.1 percent than that of a conventional boiler steam turbine power generating plant into which a process for removing and recovering CO2 from the stack gas by utilizing alkanolamine-based solvent is integrated. 相似文献
3.
The paper proposes a cogeneration system which generates four types of energy or material resources: electricity, steam, hot water, and freshwater. The proposed system can capture CO2, and be constructed on the basis of a combined cycle power generation system which consists of a gas turbine and a back‐pressure extraction turbine. In the proposed system, power is produced by driving the gas turbine system. High‐pressure saturated steam with medium temperature is produced in the heat recovery steam generator by using gas turbine exhaust gas, and then superheated with a regenerative superheater in which the fuel is burned by using oxygen instead of air for driving the steam turbine generator. Water and CO2 are recovered from the flue gas of the regenerative superheater. It has been estimated that the proposed system has a net power generation efficiency of 41.2%, a heat generation efficiency of 41.5%, and a total efficiency of 82.7%. Freshwater of 1.34 t/h and CO2 of 1.76 t/h can be recovered. It has also been shown, when a case study was set and evaluated, that the proposed system can save 31.3% of energy compared with the conventional energy supply system, and reduce CO2 emission by 28.2% compared with the conventional cogeneration system. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
4.
A new gas turbine power generation system has been proposed, in which the steam (H2O) produced by utilizing waste heat from factories is used as the working fluid of gas turbine. A simulation model has been constructed to estimate power generation characteristics of the proposed system by adopting C++ language. It has been shown from simulation results that the proposed system has high exergetic efficiency, that is, the total exergetic efficiency is 46.3% and fuel‐based efficiency is 56.3% for a case where steam with a temperature of 275 °C produced from a garbage incineration plant is used. Sensitivity analysis has also been carried out when usable steam temperature and pressure is changed, together with the case when condenser outlet pressure is changed. Characteristics of a dual fluid gas turbine cycle power generation system (DFGT) have also been estimated in this study. It has been shown that the proposed system has 16.9% higher exergetic efficiency and 41.8% higher fuel‐base exergetic efficiency compared with DFGT. © 1999 Scripta Technica, Electr Eng Jpn, 130(1): 38–47, 2000 相似文献
5.
Pyong Sik Pak 《Electrical Engineering in Japan》2008,165(1):35-41
A new CO2‐capturing power generation system is proposed that can be easily realized by applying conventional technologies. In the proposed system, the temperature of medium‐pressure steam in a thermal power plant is raised by utilizing an oxygen‐combusting regenerative steam‐superheater. The CO2 generated by combusting the fuel in the superheater can be easily separated and captured from the exhaust gas at the condenser outlet, and is liquefied. The superheated steam is used to drive a steam turbine power generation system. Using a high‐efficiency combined cycle power generation system as an example, it is shown that the proposed system can increase the power output by 10.8%, and decrease the CO2 emissions of the entire integrated system by 18.6% with a power generation efficiency drop of 2.36% compared with the original power plant without CO2 capture, when the superheated steam temperature is 750 °C. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 35–41, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20575 相似文献
6.
Pyong Sik Pak 《Electrical Engineering in Japan》2009,166(3):37-45
A high‐efficiency cogeneration system (CGS) is proposed for utilizing high‐temperature exhaust gas (HTEG) from a gas engine (GE). In the proposed system, for making use of heat energy of HTEG, H2O turbine (HTb) is incorporated and steam produced by utilizing HTEG is used as working fluid of HTb. HTb exhaust gas is also utilized for increasing power output and for satisfying heat demand in the proposed system. Both of the thermodynamic characteristics of the proposed system and a gas engine CGS (GE‐CGS) constructed by using the original GE are estimated. Energy saving characteristics and CO2 reduction effects of the proposed CGS and the GE‐CGS are also investigated. It was estimated that the net generated power of the proposed CGS has been increased 25.5% and net power generation efficiency 6.7%, compared with the original GE‐CGS. It was also shown that the proposed CGS could save 27.0% of energy consumption and reduce 1137 t‐CO2/y, 1.41 times larger than those of GE‐CGS, when a case study was set and investigated. Improvements of performance by increasing turbine inlet temperature were also investigated. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(3): 37– 45, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20708 相似文献
7.
For wide use of a power plant utilizing solar energy, improvement of its economics is important. Both the economics and characteristics of a CO2‐capturing solar thermal hybrid power generation system are evaluated in this paper. Since a relatively low temperature steam of 220 °C is produced by using solar thermal energy and is utilized as the working fluid of a gas turbine, the solar collector can attain high heat collecting efficiency. The net fuel‐to‐electricity conversion efficiency of the hybrid system is estimated to be higher than 60% on the lower‐heating‐value‐ basis. It has been estimated that the gross income and the period of depreciation of the proposed system are 34.8 × 105 yen/year and 8.89 years, respectively, and that the system is economically feasible, under the assumptions of a solar collector area of 10 ha, a maximum net power output of 4 MW, and a heat storage capacity of 2000 m3. The amount of fuel saving and reduction of CO2 emission of our system, compared to a conventional natural gas firing plant, are also estimated in the paper. © 1999 Scripta Technica, Electr Eng Jpn, 126(4): 21–29, 1999 相似文献
8.
A. G. Tumanovskii 《Thermal Engineering》2017,64(6):399-407
Evaluation of the technical state of the modern coal-fired power plants and quality of coal consumed by Russian thermal power plants (TPP) is provided. Measures aimed at improving the economic and environmental performance of operating 150–800 MW coal power units are considered. Ways of efficient use of technical methods of NO x control and electrostatic precipitators’ upgrade for improving the efficiency of ash trapping are summarized. Examples of turbine and boiler equipment efficiency upgrading through its deep modernization are presented. The necessity of the development and introduction of new technologies in the coal-fired power industry is shown. Basic technical requirements for a 660–800 MW power unit with the steam conditions of 28 MPa, 600/600°C are listed. Design solutions taking into account features of Russian coal combustion are considered. A field of application of circulating fluidized bed (CFB) boilers and their effectiveness are indicated. The results of development of a new generation coal-fired TPP, including a steam turbine with an increased efficiency of the compartments and disengaging clutch, an elevated steam conditions boiler, and a highly efficient NO x /SO2 and ash particles emission control system are provided. In this case, the resulting ash and slag are not to be sent to the ash dumps and are to be used to a maximum advantage. Technical solutions to improve the efficiency of coal gasification combined cycle plants (CCP) are considered. A trial plant based on a 16 MW gas turbine plant (GTP) and an air-blown gasifier is designed as a prototype of a high-power CCP. The necessity of a state-supported technical reequipment and development program of operating coal-fired power units, as well as putting into production of new generation coal-fired power plants, is noted. 相似文献
9.
A. S. Kosoi Yu. A. Zeigarnik O. S. Popel’ M. V. Sinkevich S. P. Filippov V. Ya. Shterenberg 《Thermal Engineering》2018,65(9):597-605
The article proposes a new concept for designing power plants operating on natural gas and involving means for fully removing carbon dioxide from the cycle in the liquid phase form in order to subsequently bind or bury it for reducing the emissions of greenhouse gases into the atmosphere. In contrast to means used in the conventional power plant process arrangements for capturing CO2 from the combustion products, the proposed concept involves the need to develop fundamentally new power engineering technologies, in which the CO2 utilization system is intrinsically built into the cycle structure already at the initial stage of power plant design and optimization of its parameters. As an example, the process flow diagram of a natural gas fired power plant generating electricity and heat is considered. The integral indicators characterizing the thermal efficiency of such a power plant are given and compared with the similar indicators of the operating or newly designed plants fitted with CO2 capturing systems, the process arrangement of which implies direct emission of carbon dioxide into the atmosphere. The comparison is carried out for the average ratio between the generated electricity and heat that has historically been established in the climatic zone of central Russia. It is shown that the proposed cycle features high thermodynamic efficiency and competitiveness with respect to the same indicators of alternative systems for combined generation of electricity and heat. The article suggests versions of the CO2 capturing system configuration that allows, with the modern technological level of equipment, the carbon dioxide emissions to be reduced down to 0.5–5.0% of the total amount produced in firing natural gas. 相似文献
10.
电转气(power to gas,P2G)技术实现了电能与天然气的相互耦合,在提升多能源系统经济性和降低系统的碳排放方面发挥着重要作用。文中针对P2G过程中电解水产生的氧气未能被充分利用的问题,提出了基于P2G与富氧燃烧联合运行的多能源系统优化调度模型。首先,将P2G过程分为电转氢过程和甲烷化过程,电转氢过程产生的氧气输送给富氧燃烧电厂使用;再将富氧燃烧电厂捕集的CO2与电转氢过程生成的氢气作为甲烷化反应的原料,生成的天然气供给燃气机组使用,从而实现资源的充分利用。其次,将P2G与富氧燃烧电厂联合运行模型引入多能源系统,构建了基于P2G与富氧燃烧电厂联合运行的低碳多能源系统架构。最后,建立以多能源系统运行成本最小为目标的低碳经济调度模型,并通过设置场景对比的方式进行验证。仿真结果表明,所提模型有效降低了系统成本及碳排放量。 相似文献
11.
A low-cost version of modernizing a nuclear power station is considered in which the main profile (standard size) of the power
unit is retained and insignificant changes are made in the turbine unit’s operational parameters. These changes consist in
that steam supplied to the high-pressure cylinder is subjected to slight initial superheating, and that that the design superheating
of steam upstream of the low-pressure cylinder is increased to some extent. In addition, different versions that can be used
for heating the working steam to the required temperatures in the H2/O2 steam generator’s mixing chamber are analyzed. 相似文献
12.
Characteristics and economics of three power generation systems which utilize solar energy were investigated and compared for systems located in five different regions. The three systems investigated were a solar thermal system, a solar photovoltaic system, and a CO2‐capturing hybrid power generation system utilizing solar thermal energy (referred to as the hybrid system) which has been proposed by the authors. The net generated power energy and the net exergetic efficiency of the hybrid system have been estimated to be larger and higher, respectively, than those of the others. Economic evaluation reveals that the unit cost of generated power energy of the solar thermal system changes most widely corresponding to the change in solar radiation condition and that the cost of the hybrid system changes the least. In general, the most economical system has been estimated to be the solar thermal system in a location which is superior in solar condition and to be the hybrid system in a not so good solar condition. The solar photovoltaic system has the possibility of being the most economical if its construction cost is greatly improved, though the hybrid system is still the most economical under considerably worse solar conditions such as in Osaka. © 1999 Scripta Technica, Electr Eng Jpn, 127(3): 1–12, 1999 相似文献
13.
采用ThermoFlex软件建立了200 MW级整体煤气化联合循环(integrated gasification combined cycle,IGCC)系统模型,从系统的角度出发计算研究了200 MW级IGCC系统的变工况特性。详细讨论了燃气轮机负荷、大气环境条件和整体空分系数对系统性能的影响。结果表明,燃气轮机采用压气机进口可转导叶角度调节–等燃气透平初温的调节方式降负荷时,燃气透平排气温度先增加后降低,而系统效率先缓慢降低后快速降低。随大气温度增加,燃气轮机功率、汽轮机功率和系统净功率均下降。在大气温度不变的条件下,大气压力对燃气轮机效率和系统净效率基本没有影响。增加整体空分系数可提高系统净效率,却使系统净功率降低。 相似文献
14.
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. 相似文献
15.
Yoshishige Kemmoku Keiko Ishikawa Shigeyasu Nakagawa Teru Kawamoto Tateki Sakakibara 《Electrical Engineering in Japan》2002,138(2):14-23
A photovoltaic/wind/diesel generating system with a battery (PWD system) is discussed from the viewpoint of total CO2 gas emissions during system lifetime. The total emissions are the sum of the emissions occurring at manufacturing and operating. First, the manufacturing CO2 emissions of the photovoltaic generator and the wind turbine generator are calculated by “the process analysis method.” This method considers the material used in each generator, its weight and its CO2 emission rate. On the other hand, the manufacturing CO2 emissions of the diesel generator and the battery are calculated using “the interindustry (input‐output) table.” Second, the PWD system is operated on a computer so that the fuel consumption of the diesel generator is a minimum assuming that hourly series data of electric load, insolation intensity, wind speed, and air temperature are known during the year. And CO2 emissions occurring at system operation are obtained from the annual fuel consumption of the diesel generator. The results show that CO2 total emissions of the PWD system are lower than those of the conventional diesel generator system. The CO2 total emissions reach a minimum when the photovoltaic/wind generating ratio is 50/50. The CO2 emissions of manufacturing decrease with increasing of the wind generating ratio from 100/0 to 0/100. The CO2 total emissions decrease as the natural energy ratio increases. It is, however, saturated to about 60% when the ratio is more than 60%. And the CO2 total emissions increase with increasing of the battery capacity. It is concluded that the PWD system plays an important role in decreasing considerably the CO2 total emissions while the total system cost is high under the present price circumstances. © 2001 Scripta Technica, Electr Eng Jpn, 138(2): 14–23, 2002 相似文献
16.
为了使我国正在建设的一批大型天然气联合循环电厂投资省、效率高、投产后具有较好的经济效益,对其设计进行优化至关重要。文章对影响大型天然气联合循环电厂效率的各种因素进行了深入的研究,对联合循环系统、燃气轮机选型、蒸汽系统、参数选择、余热锅炉和汽轮机选型、机组轴系配置、动力岛布置等方面进行了设计优化,并提出了明确的优化结论。 相似文献
17.
An analysis of the state of equipment of 72 outdated coal HPP (heat power plants) of a total capacity 14.3 GW with steam parameters before the turbines p before ≤ 9 MPa, t before = 420–540°С was performed. The equipment is characterized by a considerably low efficiency factor, even if it were converted to burning the natural gas, and by increased release of harmful substances. However, on the most part of the considered HPP, the steam turbines, unlike the boilers, have thus far retained the operation applicability and satisfactory reliability of performance. The analysis has shown that it makes sense to effectively modernize the outdated coal HPP by transformation of their equipment into combined-cycle plant (CCP) with coal gasification, which has high economic and ecological indicators due to thermodynamic advantage of the combined cycle and simpler purification of the generator gas in the process under pressure. As the most rational way of this transformation, the one was recognized wherein—instead of the existing boiler (boilers) or parallel to it—a gasification and gas turbine system is installed with a boiler-utilizer (BU), from which steam is fed to the HPP main steam pipe. In doing this, the basic part of the power station equipment persists. In the world, this kind of reconstruction of steam power equipment is applied widely and successfully, but it is by use of natural gas for the most part. It is reasonable to use the technology developed at Heat Engineering Research Institute (HERI) of hearth-steam gasification of coal and high-temperature purification of the generator gas. The basic scheme and measures on implementation of this method for modernization of outdated coal HPP is creation of CCP with blast-furnace of coal on the basis of accessible and preserved HPP equipment. CCP power is 120 MW, input-output ratio (roughly) 44%, emissions of hazardous substances are 5 mg/МJ dust, 20–60 mg/МJ SO2, and 50–100 mg/МJ NO х . A considerable decrease of specific CCP cost is expected: down to approximately half compared to that of CCP with coal gasification created elsewhere abroad. Verification and debugging of accepted solutions can be carried out at a small-scale pilot plant. 相似文献
18.
Problems encountered in operation of saturated steam geothermal turbine units that stem from the specific features of a geothermal heat carrier are considered. A two-phase state, increased content of salts, and corrosiveness of geothermal working medium have a negative influence on the efficiency and reliability of the turbine’s first and last stages. Owing to high concentrations of impurities in the liquid phase, the first stages suffer from intense generation of deposits. The resulting decrease in the power output is due to both fouling of the flow path and significantly growing roughness of the turbine cascade blades. The flow of wet steam in the geothermal turbine flow path is accompanied by droplet impingement erosion of the last-stage blades and corrosion fatigue of the metal of rotor elements. In addition, the losses due to steam wetness in the flow path cause an essential decrease of the geothermal turbine efficiency. The article gives examples of erosioninduced damage inflicted to the last-stage rotor blades, corrosion fatigue of the metal of integrally-machined shroud elements, and deposits in the nozzle vane cascades of geothermal turbine stages. The article also presents the results from numerical investigations of the effect that the initial steam wetness has on the silicic acid concentration in the wet steam flow liquid phase in a 4.0 MW geothermal turbine’s stages. A method for achieving more efficient and reliable operation of the geothermal turbine low-pressure section by applying a secondary flash steam superheating system with the use of a hydrogen steam generator is proposed. The article presents a process arrangement for preparing secondary flash steam supplied to the geothermal turbine low-pressure section in which the flash steam is evaporated and superheated through the use of a hydrogen steam generator. The technical characteristics of the system for preparing secondary flash steam to be used in the intermediate inlet to the turbine were preliminarily assessed (taking the upgrading of the Mutnovsk geothermal power plant as an example), and it has been shown from this assessment that the wetness degree in the low-pressure section can be decreased down to its final value equal to 2.0%. 相似文献
19.
The Enhanced Platform system intended for the design and manufacture of Siemens AG turbines is presented. It combines organizational and production measures allowing the production of various types of steam-turbine units with a power of up to 250 MWel from standard components. The Enhanced Platform designs feature higher efficiency, improved reliability, better flexibility, longer overhaul intervals, and lower production costs. The design features of SST-700 and SST-900 steam turbines are outlined. The SST-700 turbine is used in backpressure steam-turbine units (STU) or as a high-pressure cylinder in a two-cylinder condensing turbine with steam reheat. The design of an SST-700 single-cylinder turbine with a casing without horizontal split featuring better flexibility of the turbine unit is presented. An SST-900 turbine can be used as a combined IP and LP cylinder (IPLPC) in steam-turbine or combined-cycle power units with steam reheat. The arrangements of a turbine unit based on a combination of SST-700 and SST-900 turbines or SST-500 and SST-800 turbines are presented. Examples of this combination include, respectively, PGU-410 combinedcycle units (CCU) with a condensing turbine and PGU-420 CCUs with a cogeneration turbine. The main equipment items of a PGU-410 CCU comprise an SGT5-4000F gas-turbine unit (GTU) and STU consisting of SST-700 and SST-900RH steam turbines. The steam-turbine section of a PGU-420 cogeneration power unit has a single-shaft turbine unit with two SST-800 turbines and one SST-500 turbine giving a power output of N el. STU = 150 MW under condensing conditions. 相似文献
20.
This paper is a comprehensive analysis of the characteristics and economics of systems which treat municipal refuse and utilize its contained energy as the energy source to generate not only electric energy but also the heat energy for district heating and cooling. The following two systems are investigated: (1) System A which is composed of a plant to incinerate municipal refuse and a cogeneration system with a bleeder/condensate turbine power generation unit; and (2) System B which is the system proposed here and is composed of a pyrolysis furnace for treating municipal refuse, a two-stage-cleaning process for refining generated pyrolysis gas, and a cogeneration system constructed by a combined cycle power generation unit using cleaned pyrolysis gas as its fuel gas. It was estimated that the maximum net power-generating efficiency of System B is 24.8 percent, and is higher by 63 percent compared to that of System A. Economics of the systems have also been investigated, and it was shown that System A if the extra electric energy of the systems can be supplied directly to various facilities, which is different from the case where it should be sold only to electric companies. Effects of changes in major social and technological factors which affect the economics of the two systems are also analyzed, and it was shown that the possibility is considered to be high that the economics of System B will become more advantageous than that of System A in the future. 相似文献