Characteristics and economic evaluation of a CO2‐capturing solar thermal hybrid power generation system with heat storage

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     

A CO2-recovering nonpolluting high-efficiency gas-turbine power-generation system utilizing saturated steam as its working gas

A carbon dioxide-recovering high-efficiency gas-turbine power-generation system is proposed in which carbon dioxide (CO₂) generated is recovered by adopting the oxygen (O₂) combustion method and no thermal nitrogen oxide is generated. In the system, saturated steam produced by utilizing waste heat is adopted as the working fluid of the gas turbine. Thus, the compressing process of the working fluid gas, which is the most energy-consuming process in generating power by using a gas turbine, is not needed. This makes the system extremely high efficient. By taking saturated steam of 210°C as an example, the characteristics of the system were simulated. The net exergetic efficiency of the system has been estimated to be 48.4 percent by considering both the exergy of the saturated steam and the electric power required not only to generate high-pressure oxygen, but also to liquefy the recovered CO₂. The value is higher than the exergetic efficiency 37.8 percent of large-scale thermal power generation plants using the same natural gas, and is 28.0 percent higher than its efficiency of 37.8 percent, the one estimated if the CO₂ generated is removed and recovered from the stack gas by using alkanolamine-based solvent and the recovered CO₂ is liquefied.     

太阳能烟囱式热力发电技术进展

太阳能烟囱式热力发电是一项可利用太阳热能进行大规模发电的、非常有前景的清洁能源技术,在费用与性能上已经显示出了很大的优势,对人类环境的改善和电力行业可持续发展具有重要的战略意义,必将成为21世纪一种重要能源产业。为此,介绍了太阳能烟囱式热力发电技术产生的背景、原理与特点,世界各国太阳能烟囱式热力发电技术的研究进展及应用前景,以及主要相关技术,同时提出了发展中国太阳能烟囱式热力发电技术研究的建议。     

Construction and power generation characteristics of H2O turbine power generation system utilizing waste heat from factories

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     

Evaluation of output and unit cost of power generation systems utilizing solar energy under various solar radiation conditions worldwide

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     

太阳能热风发电关键技术综述

太阳能热风发电技术作为一种可行的可再生能源利用方案,其实用方法已经处于开发研制阶段.阐述了太阳能热风发电技术的基本原理和分类,分析了全球太阳能分布和3个主要组成部分,描述了其关键技术及装置,介绍了国内外最新相关研究及实例.     

氨基热化学蓄能太阳能热力发电研究的进展

应用热化学能量储存可使太阳能热能动力得到一天２４ｈ连续供给。一个国际性工业界与学术界联合团体正着手研究这类太阳能发电厂概念,可逆热催化氨反应在该类电厂的能源供给与需求之间起能源重定向作用。近期的研究已证实这种太阳能发电厂概念在技术上是可行的,并且它可以利用传统的技术、设备与材料,因此也具有潜在的经济生存力。为此,讨论了该类电厂的概念系统设计、操作参数选择及能量流向和再生分析。     

太阳能热气流发电系统透平发电及其能量损失

对包含蓄热层、透平的太阳能热气流发电系统的流动及传热及发电特性进行数值模拟,建立了太阳能热气流发电系统的流动与传热数学模型,分析了太阳辐射和透平压降对系统透平发电输出功率以及系统各部件能量损失的影响.计算结果表明:当太阳辐射为800 W/m2、透平压降为400 Pa时,系统输出功率可达160 kW;此外,大流量的流体流出烟囱成为造成系统能量损失的主要因素,集热棚顶棚也造成了大量的能量损失.     

基于风光联合发电控制系统的研究与实现

随着科技的进步,分布式能源的利用已经逐渐成为能源产业的发展方向。通过综合分析风能与太阳能的不同特点,提出了基于风光联合发电的控制系统。以充电控制器作为主控制芯片对系统进行综合控制管理。提出了基于微电流的电压检测法来检测电压对本系统的影响。     

太阳能热气流发电技术的研究进展

太阳能热气流发电技术是太阳能利用发展进程中具有前瞻性的技术,对世界化石能源替代、环境改善和生态重建等领域具有重要意义.介绍了太阳能热气流发电技术的基本原理、优点以及国内外该技术的研发和应用情况,提出了下一步的研究工作和应用建议.     

Proposal and evaluation of a gas engine and gas turbine hybrid cogeneration system in which cascaded heat is highly utilized

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     

太阳能热风发电技术研究进展

介绍了太阳能热风发电的产生背景、技术原理和特点。太阳能热风发电能够实现由太阳能到空气动能,最终到电能的转变,具有环保无污染、运行维护简单、缓解常规能源消耗等特点。简要介绍世界上第1座试验性质的太阳能热风发电站。对太阳能热风发电技术相关研究历程从试验研究和理论研究2个方面做了综述,重点介绍了澳大利亚电站的建设进展及最新相关学术研究进展,包括过渡段理论及试验研究、系统数值模拟和太阳能热风发电技术在高山地区的应用等。介绍我国太阳能资源情况,指出我国太阳能资源丰富,适合建造大型太阳能热风发电站。     

浅析广东电网利用天然气发电的前景

结合广东省电网的实际情况,从优化电源结构,增加电网调峰手段,保护环境以及一次能源供应等方面,详细论述了广东电网利用天然气发电的必要性和发展前景,并对广东电网利用天然气发电的气源供应、价格及经济性进行了分析。     

太阳能光伏发电效率的影响因素

对影响太阳能光伏发电效率的因素：太阳光的辐射量、太阳能光伏组件的特性和质量、逆变器整机效率和最大功率峰值跟踪等进行分析,提出了提高太阳能光伏发电效率需进一步解决的问题。     

典型屋顶光伏太阳能发电系统设计

介绍了典型屋顶光伏发电系统设计,通过计算确定太阳能光伏发电系统配置,光伏阵列间距要求,场地容量核算,光伏阵列布置,直流柜、逆变器参数的选择,以及系统的接入运行方式。     

用于槽式太阳能热发电系统的热管式集热器开发

综合利用槽式聚焦型聚光器和热管式真空管接收器的优点,开发了一种用于槽式太阳能热发电系统的热管式集热器,介绍了这种新型集热器的聚光镜和接收器的结构设计,以能量守恒方程和槽式聚光器的光学特性为基础对集热器的效率进行了计算,结果表明,此集热器效率高于国外现有大部分集热器效率。     

Study of a coal-fired transonic disk MHD generator for a power system with CO2 recovery

A conceptual design of a transonic disk MHD channel is carried out for a power generation system with liquefaction recovery of CO₂. A previous study has shown that the subsonic disk MHD channel has rather poor performance and the supersonic disk channel yields sufficiently high power output, although its stability should be improved. The present paper proposes a transonic disk channel which can be stably operated with high power output. It is assumed that the transition between supersonic flow and subsonic flow is accompanied by a cylindrical shock wave in the channel. The transonic channel yields enthalpy extraction ratios of 20.2 and 22.9%, respectively, for thermal inputs of 1100 and 2000 MW, and is nearly equal to the performance of the supersonic channel. The stability of the transonic disk channel is examined by r-0 two-dimensional time-dependent calculations. The two-dimensional analysis shows that the transonic disk channel works stably with fewer load sections than the supersonic channel even when inlet perturbations are added. © 1998 Scripta Technica. Electr Eng Jpn, 122(2): 21–29, 1998     

基于太阳能发电的光伏阵列电气系统设计

清洁能源的使用是未来社会发展的趋势。以光伏发电为研究模型,对实现太阳能的高效利用展开研究,提出了一种高效的光伏阵列,使太阳能发电系统的能源利用率得到了显著的提升。通过对太阳能发电的电气系统进行一次设计,提出了35 kV侧无功补偿装置,使得系统更加合理、有效。     

Proposal of a high‐performance solid oxide fuel cell combined power generation system with carbon dioxide recovery

A new fossil‐fuel‐utilized high‐performance combined power generation system with liquefaction recovery of carbon dioxide is proposed. In the system, pure oxygen is used as the oxidant gas to prevent the mixture of nitrogen in the exhaust gas and to make the liquefaction recovery of carbon dioxide possible. Solid oxide fuel cell is selected as the topping cycle. The exhaust fuel gas of the solid oxide fuel cell is afterburned with its exhaust oxidant gas of pure oxygen and the heat of the combustion gas is utilized in the bottoming cycle. Nonequilibrium MHD/noble gas turbine cycle is selected as the bottoming cycle because the temperature of the combustion gas reaches about 2300 K. It is made clear through detailed examination of energy balance that the total thermal efficiency of the system using natural gas (methane) as the fuel reaches 63.24% (HHV) or 70.18% (LHV). This efficiency is very high as for the system with carbon dioxide recovery. The proposed system, therefore, has excellent performance, and further research and development is warranted. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 143(4): 12–21, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10146     

Optimum design for residential photovoltaic‐thermal binary utilization system by minimizing auxiliary energy

A circuit model of an oil‐immersed transformer for use in surge analyses in the high‐frequency region is proposed, and its effectiveness is evaluated by comparison with measurements on a model winding. The circuit model is used for lightning surge analyses of a 500‐kV substation, and the effect of transformer modeling on the lightning surge voltage at the transformer terminals is investigated. When the new circuit model is used for transformer modeling, the peak value of the surge voltage is lower but the rate of voltage rise is higher than in conventional transformer modeling by a lumped capacitance. This difference can be explained in terms of the charging of capacitances in the transformer model. © 2000 Scripta Technica, Electr Eng Jpn, 134(1): 28–35, 2001