应用甲烷自热重整技术的燃气轮机循环火用分析

提出了一种应用甲烷重整技术的燃气轮机新循环。首先,根据系统的工作过程,应用热力学平衡方法分析燃烧室反应的热平衡;其次依据热力学第二定律,研究了燃气轮机新循环火用效率的变化趋势。结果显示:新循环燃烧消耗的甲烷量小于供给量,与CO2和H2O重整消耗的甲烷量的变化趋势与反应平衡常数的大小有关。在相同燃料量的条件下,与简单循环相比,新循环的火用效率得到大幅提高,涨幅为5.05%-15.57%。     

沼气重整制合成气技术可行性探讨

论述了沼气的组成和利用现状,通过天然气蒸汽重整中的加碳技术说明了沼气中二氧化碳的利用价值。借鉴天然气重整工业经验和模拟沼气重整的实验室研究,探讨了沼气重整制合成气技术的可行性,初步提出了沼气重整制合成气的试验方案。分析认为,沼气通过脱硫、脱氧、与水蒸气混合加热进行重整制合成气是提高沼气综合利用率的有效途径,为沼气重整制合成气工业研究提供了参考依据。     

积极推进燃用天然气的燃气—蒸汽联合循环热电冷联供系统在 …

本文认为我国天然气的工业应用时代即将到来：影响我国天然气大规模应用的主要障碍是其能量成本,因此价昂贵,在我国,近期内装备先进的以天然气为燃料的大型燃气－蒸汽联合循环发电装置（单纯发电）的条件还不成熟,天然气应以主要城市的服务业其主要利用方向,文章从经济上和技术上予以分析,提出了城市联合循环热电联供系统是天然气合理又现实的应用领域,应用紧试点,积极推广,并简述了该系统对燃气轮机与热力系统的要求。     

积极推进燃用天然气的燃气-蒸汽联合循环热电冷联供系统在我国的发展

本文认为我国天然气的工业应用时代即将到来 ;影响我国天然气大规模应用的主要障碍是其能量成本 ,因比价昂贵 ,在我国 ,近期内装备先进的以天然气为燃料的大型燃气 -蒸汽联合循环发电装置 (单纯发电 )的条件还不成熟 ;天然气应以主要城市的服务业为其主要利用方向。文章从经济上和技术上予以分析 ,提出了城市联合循环热电联供系统是天然气合理又现实的应用领域 ,应加紧试点 ,积极推广 ,并简述了该系统对燃气轮机与热力系统的要求。     

以双燃料重整利用气化显热的IGCC系统

IGCC系统中,气化炉出口的合成气温度很高,这部分显热如何利用一直是困扰IGCC进一步发展的难题.本文根据"温度对口"的原则,提出了一种以双燃料重整利用煤气化显热的联合循环发电系统,该系统通过重整反应实现了煤和天然气的综合利用.利用气化炉出口的高温煤气的显热作为天然气/水蒸气重整反应的高温反应热,把煤气的热能转变为合成气的化学能进行回收.研究结果表明,相比于同等条件下的参比分产系统,新系统效率可提高约1个百分点.     

天然气水蒸气重整与SOFC耦合应用

固体氧化物燃料电池（SOFC）系统具有高能源效率和使用可再生燃料的可能性,将在未来的可持续能源系统中发挥重要作用。过去几年燃料电池的发展很快,但在成本、稳定性和市场份额方面,该技术仍处于早期发展阶段。在以天然气为燃料的SOFC系统中,燃料的重整过程和燃料利用水平都可能影响系统运行的稳定性、热量和能量平衡,从而影响系统的使用寿命、输出功率和效率。因此,对燃料重整过程的设计与控制对有效的SOFC电池运行具有重要意义。对天然气在SOFC系统中的重整器配置方式（包括外重整和内重整）、重整参数和重整燃料利用方式进行了详细的综述分析,并对未来天然气SOFC系统的发展进行了展望。     

大型石化企业蒸汽动力系统的优化策略

针对石化企业蒸汽动力系统的特点和运行现状中存在的问题,在Excel平台上应用Prosteam蒸汽模型工具建立了系统操作优化模型。通过对系统存在问题的分析及利用模型对系统中各热力设备的性能计算,提出系统运行的优化措施,减少动力系统的消耗,降低运行成本。     

燃用天然气的350MW级联合循环机组蒸汽系统的优化和设备选型

本文对我国正在建设的大型天然气联合循环电厂的余热锅炉蒸汽系统进行了充分的分析和研究,提出了明确的优化途径;同时还阐述了联合循环汽轮机的特点,对联合循环汽轮机的汽缸和排汽形式进行了分析比较,并推荐了适合于三压再热蒸汽系统的汽轮机。     

太阳能燃气联合循环系统热经济性研究

针对郑州地区某SGT5-4000F型燃气-蒸汽联合循环增加太阳能集热场所组成的太阳能互补联合循环(ISCC)系统进行研究,分析在不同太阳能辐射强度下系统热力参数并与传统燃气-蒸汽联合循环(CCPP)对比。结果表明ISCC系统具有较好的热力性能。年节省天然气费用5512.36万$,年CO2减排量3.02×105t,具有较好的社会效益和经济效益。     

基于9E燃气-蒸汽联合循环发电机组的烟气余热利用系统

基于燃气-蒸汽联合循环发电机组提出了回收余热锅炉尾部烟气余热对天然气进行加热的方案,提高了系统效率,同时大量回收了水资源,对于燃气-蒸汽联合循环发电系统的优化具有重要参考价值。以某容量为200 MW的9E燃气-蒸汽联合循环发电机组为例,对应用该方案下的系统流程、参数进行设计,对热经济性及水回收效益进行了计算,并与已有电加热和抽汽加热方案进行对比,结果表明：应用烟气余热回收加热天然气方案可有效回收烟气余热1.3 MW,水回收1.9 t/h,水回收率100%,余热锅炉效率提升0.57%,与电加热方案相比全年可节省453.6万元,与抽汽加热方案相比可节省273.6万元。     

Natural gas usage as a heat source for integrated SMR and thermochemical hydrogen production technologies

This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper–chlorine (Cu–Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur–iodine (S–I) thermochemical cycle. Also, an integrated Cu–Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu–Cl cycle out-performs the other conventional methods with respect to fuel requirements, carbon dioxide emissions and total cost of production.     

高温燃料电池_燃气轮机混合发电系统性能分析

针对 高温燃料电池系统的高效率、环保性以及排气废热的巨大利用潜能,将其与燃气轮机组成混合装置进行发电是未来分布式发电的一种极有前景的方案。文中对高温燃料电池及混合循环系统作了简介,并对两种典型的高温燃料电池－燃气轮机混合循环发电系统进行了性能分析,这将为我国高温燃料电池－燃气轮机混合循环系统的研制提供参考。     

Aspen Plus simulation of biomass integrated gasification combined cycle systems at corn ethanol plants

Biomass integrated gasification combined cycle (BIGCC) systems and natural gas combined cycle (NGCC) systems are employed to provide heat and electricity to a 0.19 hm³ y⁻¹ (50 million gallon per year) corn ethanol plant using different fuels (syrup and corn stover, corn stover alone, and natural gas). Aspen Plus simulations of BIGCC/NGCC systems are performed to study effects of different fuels, gas turbine compression pressure, dryers (steam tube or superheated steam) for biomass fuels and ethanol co-products, and steam tube dryer exhaust treatment methods. The goal is to maximize electricity generation while meeting process heat needs of the plant. At fuel input rates of 110 MW, BIGCC systems with steam tube dryers provide 20–25 MW of power to the grid with system thermal efficiencies (net power generated plus process heat rate divided by fuel input rate) of 69–74%. NGCC systems with steam tube dryers provide 26–30 MW of power to the grid with system thermal efficiencies of 74–78%. BIGCC systems with superheated steam dryers provide 20–22 MW of power to the grid with system thermal efficiencies of 53–56%. The life-cycle greenhouse gas (GHG) emission reduction for conventional corn ethanol compared to gasoline is 39% for process heat with natural gas (grid electricity), 117% for BIGCC with syrup and corn stover fuel, 124% for BIGCC with corn stover fuel, and 93% for NGCC with natural gas fuel. These GHG emission estimates do not include indirect land use change effects.     

Thermodynamic analysis and assessment of an integrated hydrogen fuel cell system for ships

In this thermodynamic investigation, an integrated energy system based on hydrogen fuel is developed and studied energetically and exergetically. The liquefied hydrogen fueled solid oxide fuel cell (SOFC) based system is then integrated with a steam producing cycle to supply electricity and potable water to ships. The first heat recovery system, after the fuel cells provide thrust for the ship, is by means of a turbine while the second heat recovery system drives the ship's refrigeration cycle. This study includes energy and exergy performance evaluations of SOFC, refrigeration cycle and ship thrust engine systems. Furthermore, the effectiveness of SOFCs and a hydrogen fueled engine in reducing greenhouse gas emissions are assessed parametrically through a case study. The main propulsion, power generation from the solid oxide fuel cells, absorption chiller, and steam bottoming cycle systems together have the overall energy and exergy efficiencies of 41.53% and 37.13%, respectively.     

Cascade utilization of chemical energy of natural gas in an improved CRGT cycle

In this paper three advanced power systems: the chemically recuperated gas turbine (CRGT) cycle, the steam injected gas turbine (STIG) cycle and the combined cycle (CC), are investigated and compared by means of exergy analysis. Making use of the energy level concept, cascaded use of the chemical exergy of natural gas in a CRGT cycle is clarified, and its performance of the utilization of chemical energy is evaluated. Based on this evaluation, a new CRGT cycle is designed to convert the exergy of natural gas more efficiently into electrical power. As a result, the exergy efficiency of the new CRGT cycle is about 55%, which is 8 percentage points higher than that of the reference CRGT cycle. The analysis gave a better interpretation of the inefficiencies of the CRGT cycle and suggested improvement options. This new approach can be used to design innovative energy systems.     

Thermoeconomic analysis of SOFC-GT-VARS-ORC combined power and cooling system

The integration of the gas turbine cycle and organic Rankine cycle with the solid oxide fuel cell for power generation is quite prevalent. However, the need is also felt for systems capable of providing power with cooling. Therefore, it is proposed to integrate solid oxide fuel cell with gas turbine cycle, vapour absorption refrigeration system and organic Rankine cycle through the heat available with fluid in the cycle. Here intercooled and reheat gas turbine cycle is integrated with solid oxide fuel cell. Heat rejected in intercooling is used in vapour absorption refrigeration system for cooling. This paper presents thermoeconomic analysis. Results show that the combination of solid oxide fuel cell-gas turbine-vapour absorption refrigeration system-organic Rankine cycle yields increase in efficiency to 68.79% as compared to 58.88% from combined solid oxide fuel cell-gas turbine cycle. The cost of electricity per unit power output is found as 1939.93 $/kW.     

Hydrogen production from fossil fuels with carbon capture and storage based on chemical looping systems

This paper analyzes innovative processes for producing hydrogen from fossil fuels conversion (natural gas, coal, lignite) based on chemical looping techniques, allowing intrinsic CO₂ capture. This paper evaluates in details the iron-based chemical looping system used for hydrogen production in conjunction with natural gas and syngas produced from coal and lignite gasification. The paper assesses the potential applications of natural gas and syngas chemical looping combustion systems to generate hydrogen. Investigated plant concepts with natural gas and syngas-based chemical looping method produce 500 MW hydrogen (based on lower heating value) covering ancillary power consumption with an almost total decarbonisation rate of the fossil fuels used.The paper presents in details the plant concepts and the methodology used to evaluate the performances using critical design factors like: gasifier feeding system (various fuel transport gases), heat and power integration analysis, potential ways to increase the overall energy efficiency (e.g. steam integration of chemical looping unit into the combined cycle), hydrogen and carbon dioxide quality specifications considering the use of hydrogen in transport (fuel cells) and carbon dioxide storage in geological formation or used for EOR.     

Performance assessment of a direct steam solar power plant with hydrogen energy storage: An exergoeconomic study

Power generation and its storage using solar energy and hydrogen energy systems is a promising approach to overcome serious challenges associated with fossil fuel-based power plants. In this study, an exergoeconomic model is developed to analyze a direct steam solar tower-hydrogen gas turbine power plant under different operating conditions. An on-grid solar power plant integrated with a hydrogen storage system composed of an electrolyser, hydrogen gas turbine and fuel cell is considered. When solar energy is not available, electrical power is generated by the gas turbine and the fuel cell utilizing the hydrogen produced by the electrolyser. The effects of different working parameters on the cycle performance during charging and discharging processes are investigated using thermodynamic analysis. The results indicate that increasing the solar irradiation by 36%, leads to 13% increase in the exergy efficiency of the cycle. Moreover, the mass flow rate of the heat transfer fluid in solar system has a considerable effect on the exergy cost of output power. Solar tower has the highest exergy destruction and capital investment cost. The highest exergoeconomic factor for the integrated cycle is 60.94%. The steam turbine and PEM electrolyser have the highest share of exergoeconomic factor i.e., 80.4% and 50%, respectively.     

Energetic life cycle assessment of fuel cell powertrain systems and alternative fuels in Germany

By means of energetic life cycle assessment, innovative fuel cell (FC) powertrain systems and the respective fuels are examined and compared with conventional systems. The basis for this research is process chain analyses for the supply of conventional and alternative fuels at the point of consumption in Germany, e.g. compressed natural gas, methanol or hydrogen. To complete the integrated view, the use of these fuels in vehicles with internal combustion engines and FCs is examined. Within the scope of this study, special attention is paid to a system breakdown and energetic assessment of the FC powertrain. For the purpose of a full life cycle assessment, energy requirements and CO₂-emissions for the production, maintenance and disposal of the vehicles are included.     

Part load operation of SOFC/GT hybrid systems: Stationary analysis

In a global energetic context characterized by the increasing demand of oil and gas, the depletion of fossil resources and the global warming, more efficient energy systems and, consequently, innovative energy conversion processes are urgently required. A possible solution can be found in the fuel cells technology coupled with classical thermodynamic cycle technologies in order to make hybrid systems able to achieve high energy/power efficiency with low environmental impact. Moreover, due to the synergistic effect of using a high temperature fuel cell such as solid oxide fuel cell (SOFC) and a recuperative gas turbine (GT), the integrated system efficiency can be significantly improved. In this paper a steady zero dimensional model of a SOFC/GT hybrid system is presented. The core of the work consists of a performance analysis focused on the influence of the GT part load functioning on the overall system efficiency maintaining the SOFC power set to the nominal one. Also the proper design and management of the heat recovery section is object of the present study, with target a global electric efficiency almost constant in part load functioning respect to nominal operation. The results of this study have been used as basis to the development of a dynamic model, presented in the following part of the study focused on the plant dynamic analysis.