燃气-超临界CO2联合循环发电系统

  [目的]  燃气轮机排气温度高,可增加底循环,利用排气的余热发电,从而提高燃料总的能量利用率。鉴于超临界CO₂循环热效率高,并且具有系统简单、结构紧凑、运行灵活等潜在优势,可与燃气轮机组成新型的燃气-超临界CO₂联合循环。  [方法]  为了充分利用燃气轮机排气余热,提出在简单回热超临界CO₂循环的基础上,再嵌套一个简单回热循环的布置方式,并以PG9351(FA)型燃气轮机为例,对其热效率进行了计算分析。同时,在系统中增加余热利用装置,可将剩余热量用于供热、转换为冷量或发电。  [结果]  结果表明:对于选定的燃气轮机,超临界CO₂循环最高温度可达约600 ℃,循环发电效率约32%,获得余热温度为170 ℃以上,余热热量占燃气轮机排气热量9%,联合循环发电效率约54%。  [结论]  燃气-超临界CO₂联合循环发电系统具有较高的热效率,并且保留部分较高品位的余热,可进一步用于电厂运行。     

燃气轮机的湿空气循环性能分析与试验

对燃气轮机湿空气循环的性能进行了分析,建立了湿化工质的热物性计算模型,并对基于微型分轴燃气轮机湿空气循环装置的性能进行了初步试验.试验结果表明,空气加湿后燃气轮机系统的运行性能有明显改善,与简单循环系统相比,比功和效率都有很大的提高.根据试验条件进行的模拟计算结果与试验结果能很好地吻合.     

HAT循环后冷湿化过程的传热传质性能研究

为了提升湿空气燃气轮机循环的调控灵活性,自主设计和搭建了后冷湿化器一体化实验系统,通过实验获得不同水气比下后冷湿化器出口空气的温湿度和出口水温,利用实验数据修正表面化学反应速率,基于表面化学反应模型建立了后冷湿化过程三维数值模型,分析了水气比和进口水温对后冷湿化器性能的影响。结果表明：建立的后冷湿化器传热传质模型能高精度模拟后冷湿化过程,空气温度沿流动方向呈逐渐降低的趋势,空气的含湿量和相对湿度沿流动方向逐渐升高;水气比和进口水温均对后冷湿化器的性能有较大影响,随着水气比和进口水温增大出口空气湿度提高,湿化性能提升,而降低水气比有利于提升空气后冷性能。     

有无后冷器的微燃气轮机HAT循环性能比较

基于某80kW微燃气轮机回热循环改造工作,比较了有后冷器和无后冷器的HAT(Humid Air Turbine)循环性能和需要增加的换热器面积。研究结果表明,对于所研究的微燃气轮机,有、无后冷器的HAT循环系统折合效率和折合输出功相当,与有后冷器的HAT循环相比,无后冷器的HAT循环湿化器更高,体积更大,但是由于省掉了后冷器,其总换热面积(后冷器、湿化器、省煤器换热面积之和)更小,即意味着其投资更低,且无后冷器的HAT循环系统结构更简单,将使系统更加紧凑且控制更容易。     

高温燃料电池/燃气轮机混合循环发电技术

高温燃料电池／燃气轮机混合循环系统以其效率高、排放低的特点,在未来分布式发电和集中式大规模发电中占有重要地位。本文首先简介了高温燃料电池和先进燃气轮机的结构特点及其分类,在此基础上阐述了高温燃料电池与先进燃气轮机混合系统的基本模式,然后对适用于分布式发电和集中式发电的几种典型混合循环系统的结构和相应的流程及特点进行了详细的描述,最后给出了高温燃料电池和燃气轮机混合循环发电系统中的一些主要代表性技术以及目前研究的进展、挑战和目标。     

生物质整体气化联合循环中燃烧室的分析

基于联合循环和能量梯级利用的概念,用分析和燃气变比热热力计算法研究生物质整体气化联合循环(BIGCC)中燃烧室的能量利用与损失情况。计算结果表明:燃用生物质燃料气,随燃气轮机初温提高,燃气轮机热效率提高,燃烧室的效率提高,但随燃烧室出口燃气温度的升高,燃烧室的效率提高幅度变缓;燃烧室的效率不仅与燃烧室燃气出口温度、空气入口温度和压力密切有关,还与燃料的组分的相对含量和发热量有关;对生物质燃料气、两种不同热值煤气在燃烧室出口燃气温度为1147℃时的燃烧室的效率进行了比较,两种不同热值煤气的效率较低,生物质燃料气效率最大。图2表2参11     

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。     

以S - CO2为底循环工质的燃气轮机联合循环系统研究

建立了以超临界CO_2(S-CO_2)为底循环工质的E级燃气轮机联合循环系统计算模型,利用模型分析了高温循环工作压力、低温循环工作压力、余热加热器的端差对系统的影响。计算得到高、低温循环工作压力变化时,使系统出力、效率最优的工作压力。为联合循环系统的底循环采用S-CO_2为工质的工程应用提供依据。     

固体氧化物燃料电池与燃气轮机混合发电系统

基于固体氧化物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发电装置,是一种极有前景的分布式发电方案.文章以SWP公司的加压型SOFC-小型燃气轮机混合循环系统为例,对固体氧化物燃料电池及燃气轮机混合循环系统的原理及发展现状作了分析,为我国固体氧化物燃料电池-燃气轮机混合循环系统的研制提供参考.     

低品位热能利用与减缓气候变暖

低品位热能利用受冷源的制约,其可利用能的温度范围较窄,大部分热能作为废热被排放。本文通过新的制冷循环的建立,探索提高低品位热能制冷效率的方法。新的制冷循环以空气或空气中的主要成分为循环工质,由相互连接、相互影响的气动压缩循环子系统、冷量增益循环子系统和低压补冷循环子系统三部分组成。新的制冷循环以低品位热能作为主要能源,电能作为辅助能源,以期达到更高的能效比,从而使制造冷源成为可能。提高低品位热能的利用率,对减缓气候变暖发挥重要作用。     

三压再热汽水系统IGCC的设计工况和变工况性能

以三压再热式汽水系统ＩＧＣＣ（整体煤气化燃气－蒸汽联合循环）为研究对象组成了整体空分ＩＧＣＣ系统方案,建立了气化炉,净化系统,燃气轮机,空分装置,余热锅炉,汽轮机各组成部件的数学模型,对ＩＧＣＣ系统的设计工况和变工况特性进行计算,分析了煤气轮机采用不同调节规律和汽轮机采用不同运行方式时对系统变工况性能的影响并提出了合理的运行方式。     

退役航空涡扇发动机地面应用的有效途径之一_再热燃气_蒸汽联合循环

本文探讨以退役航空涡扇发动机作为燃气发生器,内函的燃气与外函的空气相掺混。经再热燃烧室加热后进入动力涡轮作功,并且应用余热锅炉回收－部分排气余热,产生蒸汽,驱动汽轮机作功所组成的再热热气－蒸汽联合循环。通过计算实例说明该循环具有输出功率大,循环效率具有相当大的提高等特点。     

Simulation of a new biomass integrated gasification combined cycle (BIGCC) power generation system using Aspen Plus: Performance analysis and energetic assessment

A new biomass integrated gasification combined cycle (BIGCC), which featured an innovative two-stage enriched air gasification system coupling a fluidized bed with a swirl-melting furnace, was proposed and built for clean and efficient biomass utilization. The performance of biomass gasification and power generation under various operating conditions was assessed using a comprehensive Aspen Plus model for system optimization. The model was validated by pilot-scale experimental data and gas turbine regulations, showing good agreement. Parameters including oxygen percentage of enriched air (OP), gasification temperature, excess air ratio and compressor pressure ratio were studied for BIGCC optimization. Results showed that increase OP could effectively improve syngas quality and two-stage gasification efficiency, enhancing the gas turbine inlet and outlet temperature. The maximum BIGCC fuel utilization efficiency could be obtained at OP of 40%. Increasing gasification temperature showed a negative effect on the two-stage gasification performance. For efficient BIGCC operation, the excess air ratio should be below 3.5 to maintain a designed gas turbine inlet temperature. Modest increase of compressor pressure ratio favored the power generation. Finally, the BIGCC energy analysis further proved the rationality of system design and sufficient utilization of biomass energy.     

Effect of supplementary firing options on cycle performance and CO2 emissions of an IGCC power generation system

Supplementary firing is adopted in combined‐cycle power plants to reheat low‐temperature gas turbine exhaust before entering into the heat recovery steam generator. In an effort to identify suitable supplementary firing options in an integrated gasification combined‐cycle (IGCC) power plant configuration, so as to use coal effectively, the performance is compared for three different supplementary firing options. The comparison identifies the better of the supplementary firing options based on higher efficiency and work output per unit mass of coal and lower CO₂ emissions. The three supplementary firing options with the corresponding fuel used for the supplementary firing are: (i) partial gasification with char, (ii) full gasification with coal and (iii) full gasification with syngas. The performance of the IGCC system with these three options is compared with an option of the IGCC system without supplementary firing. Each supplementary firing option also involves pre‐heating of the air entering the gas turbine combustion chamber in the gas cycle and reheating of the low‐pressure steam in the steam cycle. The effects on coal consumption and CO₂ emissions are analysed by varying the operating conditions such as pressure ratio, gas turbine inlet temperature, air pre‐heat and supplementary firing temperature. The results indicate that more work output is produced per unit mass of coal when there is no supplementary firing. Among the supplementary firing options, the full gasification with syngas option produces the highest work output per unit mass of coal, and the partial gasification with char option emits the lowest amount of CO₂ per unit mass of coal. Based on the analysis, the most advantageous option for low specific coal consumption and CO₂ emissions is the supplementary firing case having full gasification with syngas as the fuel. Copyright © 2008 John Wiley & Sons, Ltd.     

Thermodynamic analysis of an integrated power generation system driven by solid oxide fuel cell

A new integrated power generation system driven by the solid oxide fuel cell (SOFC) is proposed to improve the conversion efficiency of conventional energy by using a Kalina cycle to recover the waste heat of exhaust from the SOFC-GT. The system using methane as main fuel consists an internal reforming SOFC, an after-burner, a gas turbine, preheaters, compressors and a Kalina cycle. The proposed system is simulated based on the developed mathematical models, and the overall system performance has been evaluated by the first and second law of thermodynamics. Exergy analysis is conducted to indicate the thermodynamic losses in each components. A parametric analysis is also carried out to examine the effects of some key thermodynamic parameters on the system performance. Results indicate that as compressor pressure ratio increases, SOFC electrical efficiency increases and there is an optimal compressor pressure ratio to reach the maximum overall electrical efficiency and exergy efficiency. It is also found that SOFC electrical efficiency, overall electrical efficiency and exergy efficiency can be improved by increasing air flow rate. Also, the largest exergy destruction occurs in the SOFC followed by the after-burner, the waste heat boiler, the gas turbine. The compressor pressure ratio and air flow rate have significant effects on the exergy destruction in some main components of system.     

燃机电厂9F型机组热电负荷优化分配研究

电厂热电负荷优化分配是指在全厂总调度负荷下,根据各机组的热力性能确定各机组应承担的热电负荷,使得全厂效益最大或能耗最小的一种最优化问题.不同于燃煤热电厂,燃机电厂9F型机组由于设计为燃气轮机加蒸汽轮机的组合方式运行,因此在联合循环热力性能模型建立上较为复杂.提出了将余热锅炉新蒸汽参数作为中间变量,建立了机组天然气燃料消耗与电负荷、热负荷之间的关系模型,确定了优化计算的目标函数和边界约束条件,并采用非线性规划方法求解.模拟与实际运行结果均表明,该优化分配方法能有效降低燃机电厂燃料消耗水平,可以为同类型燃机电厂热电负荷优化分配提供参考.     

Cycle analysis of an integrated solid oxide fuel cell and recuperative gas turbine with an air reheating system

Cycle simulation and analysis for two kinds of SOFC/GT hybrid systems were conducted with the help of the simulation tool: Aspen Custom Modeler. Two cycle schemes of recuperative heat exchanger (RHE) and exhaust gas recirculated (EGR) were described according to the air reheating method. The system performance with operating pressure, turbine inlet temperature and fuel cell load were studied based on the simulation results. Then the effects of oxygen utilization, fuel utilization, operating temperature and efficiencies of the gas turbine components on the system performance of the RHE cycle and the EGR cycle were discussed in detail. Simulation results indicated that the system optimum efficiency for the EGR air reheating cycle scheme was higher than that of the RHE cycle system. A higher pressure ratio would be available for the EGR cycle system in comparison with the RHE cycle. It was found that increasing fuel utilization or oxygen utilization would decrease fuel cell efficiency but improve the system efficiency for both of the RHE and EGR cycles. The efficiency of the RHE cycle hybrid system decreased as the fuel cell air inlet temperature increased. However, the system efficiency of EGR cycle increased with fuel cell air inlet temperature. The effect of turbine efficiency on the system efficiency was more obvious than the effect of the compressor and recuperator efficiencies among the gas turbine components. It was also indicated that improving the gas turbine component efficiencies for the RHE cycle increased system efficiency higher than that for the EGR cycle.     

CO2 control technology effects on IGCC plant performance and cost

As part of the USDOE's Carbon Sequestration Program, an integrated modeling framework has been developed to evaluate the performance and cost of alternative carbon capture and storage (CCS) technologies for fossil-fueled power plants in the context of multi-pollutant control requirements. This paper uses the newly developed model of an integrated gasification combined cycle (IGCC) plant to analyze the effects of adding CCS to an IGCC system employing a GE quench gasifier with water gas shift reactors and a Selexol system for CO₂ capture. Parameters of interest include the effects on plant performance and cost of varying the CO₂ removal efficiency, the quality and cost of coal, and selected other factors affecting overall plant performance and cost. The stochastic simulation capability of the model is also used to illustrate the effect of uncertainties or variability in key process and cost parameters. The potential for advanced oxygen production and gas turbine technologies to reduce the cost and environmental impacts of IGCC with CCS is also analyzed.     

增压部分气化燃煤联合循环(PPG-CC) 发电系统热力性能分析

部分气化燃煤联合循环发电系统是目前具有发展前景的洁净煤发电技术之一。本文提出了将空气和蒸汽先经过高温预热再送入气化炉的部分气化联合循环系统新方案，对该方案进行了热力性能计算，并与常规的不预热空气／蒸汽的部分气化联合循环系统热力性能进行了分析比较。计算结果说明了高温预热空气／蒸汽的部分气化联合循环系统有利于提高煤气热值和循环系统效率，对于劣质煤以及生物质气化生成较高热值煤气也具有重要意义。     

Energy and exergy analyses of an integrated SOFC and coal gasification system

This paper examines an integrated gasification and solid oxide fuel cell (SOFC) system with a gas turbine and steam cycle that uses heat recovery of the gas turbine exhaust. Energy and exergy analyses are performed with two different types of coal. For the two different cases, the energy efficiency of the overall system is 38.1% and 36.7%, while the exergy efficiency is 27% and 23.2%, respectively. The effects of changing the reference temperature on the exergy destruction and exergy efficiency of different components are also reported. A parametric study on the effects of changing the pressure ratio on the component performance is presented.