液化天然气(LNG)冷能用于斯特林发动机和燃气轮机的联合系统研究

利用LNG冷能具有较好的节能潜力和经济效益,通过流程的创新设计,提出了一种将LNG冷能用于燃气轮机和斯特林发动机的联合系统。基于热力学第一、第二定律,对联合系统进行热力学分析,结果表明:在环境温度35℃条件下,联合系统的输出功率为5715.48kW,热效率为31.62%,效率为43.65%;相比燃气轮机系统和直接冷却进气系统,联合系统的输出功率分别提高了7.84%和0.78%,热效率分别提高了3.16%和1.18%,效率分别提高了4.23%和1.63%。联合系统在不同环境温度下,可将燃气轮机的进气温度降低10℃左右,系统的输出功率和效率随着进气温度的降低均有所提高。     

某大学城分布式能源站燃机应用溴化锂制冷技术冷却入口空气的方案探讨

利用现有溴化锂吸收式冷水机组,消化大学城暑期过剩高温热媒水冷却燃机入口空气,可降低机组入口空气温度4.2℃,提高联合循环机组出力约1470k W。通过计算分析,简单循环燃气轮机的出力和效率都随着燃机入口空气温度的降低而得到提高,对于整个联合循环而言,机组功率随燃机入口空气温度降低而增加,但是由于下位电站汽轮机及余热锅炉的延滞性影响,其效率基本维持不变,即联合循环机组的发电气耗并不会因为燃机进口空气冷却而得到降低,节能效益不能充分体现,项目可行性不高,联合循环机组进行类似改造时应慎重考虑。     

提高空压机现场压力变送器的可靠性

空气流量为30万m3/h的离心空压机,其出口压力变送器和入口压差变送器因为使用环境温度超极限而发生故障,导致空压机卸载。通过改进空压机现场压力变送器安装位置,降低空压机本体对变送器的热辐射影响,使变送器的使用环境温度满足其极限环境温度要求,以降低空压机现场变送器的故障率,提高变送器的可靠性,确保空压机安全运行。介绍变送器安装位置的改进情况及其效果。     

GTCC排烟驱动的热管型溴冷机设计及传热分析

针对环境温度升高导致燃气轮机性能下降问题,提出利用GTCC烟气余热驱动热管型溴化锂吸收式制冷机制取冷量,以降低压气机进气温度,提高燃气轮机性能。介绍热管型溴冷机的工艺流程,分析分离式热管换热器的传热性能,应用VB软件编制计算程序,对热管型溴冷机进行具体设计及分析。结果表明,GTCC排烟驱动的热管型溴冷机运行费用低,换热效率高,能够综合利用能源。     

含硫油品储罐自燃灾源温度场的数值模拟

目前在役储罐的温度场难以准确的描述,对安全作业造成隐患。基于国内外储罐自燃机理研究,建立了含自燃灾源的储罐物理模型和数学模型,利用ANSYS有限元平台分析了自燃灾源、保温层厚度、环境温度及空气对流系数对含硫油品储罐温度场的影响.数值模拟结果表明,随着自燃灾源的持续氧化,外壁温度场异常区域逐渐明显;增加保温层厚度,外壁异常区域温差减小的趋势由大变小,当厚度达到30mm时,最大温差降至0.4℃;升高环境温度,外壁异常区域温差均匀降低,当环境温度达到35℃时,外壁温度基本趋于环境温度;增加空气对流系数,外壁异常区域温差快速减小,当空气对流系数达到100W/(m·℃)时,外壁温度接近环境温度,且外壁温差基本趋于一致.     

套片式换热器在燃气轮机进气冷却中的应用

针对目前国内没有成熟的燃气轮机进气冷却设备,提出用套片式换热器对其进行冷却的可行性和优势,更有效的降低燃气轮机进气温度。     

冰储冷技术应用于燃气轮发电机进气冷却的可行性分析

燃气轮机是恒流量的发动机,其轴功率与空气流量成正比,降低压缩机吸气温度,提高空气密度将增加发动机的输功率,本文对采用冰储冷冷源进气冷却技术来提高燃气轮发电机的输出功率的技术和经济可行性进行了分析研究,研究表明这一技术应用可行性好,经济效益显著,有推广价值。     

喷气增焓与喷液冷却式空气源热泵在低温环境下实验数据对比及分析

对喷气增焓及喷液冷却式空气源热泵进行了热力学分析,并在低环境温度下对其制热性能进行了数据测试及对比研究,结果表明,随着室外环境温度在10℃～30℃之间下降时,两款热泵耗电量都在逐渐增加,制热量逐渐降低,喷气增焓空气源热泵机组相较喷液冷却式空气源热泵机组的COP下降有变缓趋势,当室外环境温度为-5℃时,喷气增焓热泵的COP为3.03,而喷液冷却式热泵降至2.66;在-20℃时,喷气增焓式热泵COP为2.15,喷液冷却式热泵COP已降至1.88;喷气增焓空气源热泵比喷液冷却式热泵性能提高大概13%左右。喷气增焓空气源热泵机组在低温环境下效率更高。     

燃气轮机压气机滤网压差高的原因及对策

自然环境中的空气不可避免的会含有各种各样的杂质,这些杂质在进入燃气轮机后将影响燃气轮机的安全和经济运行,而燃气轮机压气机滤网的主要作用就是给燃气轮机的压气机提供过滤过的清洁的空气,以满足燃气轮机在当地环境下的运行要求。文章分析了燃气轮机压气机滤网压差高的原因,并根据其原因提出了相应的对策。通过某电厂的实例分析,进一步总结了具体的经验,对以后其他电厂机组运行具有借鉴和参考意义。     

外界环境温度对旅客列车的影响

综合考虑了列车运行时外界环境温度的变化,以1527次和1528次空调列车为例,计算得到列车运行时沿途的空气温度、综合温度及车厢壁面温度的波动规律,反映了外界环境温度对旅客列车的影响,为今后列车空调动态负荷计算及列车空调机组实时运行调节提供了理论依据。     

GE9FA燃气轮机进气加热系统的控制

当9FA燃气轮机压气机进口温度低时,为防止压气机进口结冰和超过运行极限,9FA燃气轮机的运行范围将受到限制。为了降低排放和防止压气机进口结冰,根据压气机进口可转导叶(IGV)来控制进气加热。压气机进气加热是将部分压气机的排气循环到压气机进口。该系统有三个作用:1)防止压气机进口结冰;2)通过降低IGV角度来满足低负荷时的排放要求,降低压气机压比;3)保证压气机有足够的安全裕度。进气加热系统保证了压气机的全范围运行。     

单屏式多点气流温度传感器现场校准工况参数影响分析

采用数值仿真的手段对燃烧室试验环境下单屏式多点气流温度传感器进行仿真计算,改变温场、流场环境,分析研究了来流总温、来流总压以及马赫数等工况参数对单屏式多点气流温度传感器的测量结果的影响规律,并用试验进行验证.数值模拟结果表明:在燃烧室试验环境下,单屏式多点气流温度传感器的测温偏差随着来流总温的增大而增大,每增加1000...     

Exergy analysis of gas turbine trigeneration system for combined production of power heat and refrigeration

A conceptual trigeneration system is proposed based on the conventional gas turbine cycle for the high temperature heat addition while adopting the heat recovery steam generator for process heat and vapor absorption refrigeration for the cold production. Combined first and second law approach is applied and computational analysis is performed to investigate the effects of overall pressure ratio, turbine inlet temperature, pressure drop in combustor and heat recovery steam generator, and evaporator temperature on the exergy destruction in each component, first law efficiency, electrical to thermal energy ratio, and second law efficiency of the system. Thermodynamic analysis indicates that exergy destruction in combustion chamber and HRSG is significantly affected by the pressure ratio and turbine inlet temperature, and not at all affected by pressure drop and evaporator temperature. The process heat pressure and evaporator temperature causes significant exergy destruction in various components of vapor absorption refrigeration cycle and HRSG. It also indicates that maximum exergy is destroyed during the combustion and steam generation process; which represents over 80% of the total exergy destruction in the overall system. The first law efficiency, electrical to thermal energy ratio and second law efficiency of the trigeneration, cogeneration, and gas turbine cycle significantly varies with the change in overall pressure ratio and turbine inlet temperature, but the change in pressure drop, process heat pressure, and evaporator temperature shows small variations in these parameters. Decision makers should find the methodology contained in this paper useful in the comparison and selection of advanced heat recovery systems.     

Design and Properties of Thermal Barrier Coatings for advanced turbine engines

The efficiency and performance of advanced aircraft turbines can be markedly increased if higher gas temperatures are used. Although the highly loaded blades and vanes in the high pressure turbine are heavily cooled, today's substrate materials are unable to provide sufficient strength in the temperature range up to 1500°C and above. If thermal barrier coatings (TBCs) are applied on superalloy turbine blades a substantial temperature drop of the parts can be achieved. The resulting increase in efficiency comes from reduced cooling and/or increased gas turbine inlet temperatures of up to 150°C. TBCs are either processed by plasma spraying (PS) or electron beam physical vapour deposition (EB-PVD). While PS is lower in cost EB-PVD leads to superior strain and thermoshock tolerant coatings. Furthermore, cooling hole closure of turbine blades and vanes is prevented and aerodynamic design maintained. Finally, future research and development needs in TBC technology are stressed.     

Indirect evaporative combined inlet air cooling with gas turbines for green power technology

Different inlet air cooling systems are usually used with gas turbines. A new form of inlet air cooling called the indirect evaporative cooling system (IECS) has been investigated in this work. This system is a combination of a humidifier with a vapor compression or absorption cooling system for part of the total air i.e. the secondary air stream. The net power produced from the gas turbine on a hot day (45 °C) by using combined (IECS) with absorption chillers showed an increase in power and efficiency by 15% and 9%, respectively; its recovery period is suitable for all environmental conditions. For IECS combined with vapor compression mechanical chillers showed an increase in power and efficiency by about 7.81% and 2.24%, respectively, but its recovery period made it suitable only for hot and humid conditions. The IECS has lower chiller's capital cost by about 25% (mechanical chiller) and 40% (absorption chiller).     

Performance limitations in electric power generating systems imposed by high temperature corrosion

The increasing cost of fuel has resulted in a renewed interest in improving the efficiency of electric power generating equipment. In most cases, this involves increasing the maximum temperature in the cycle. Examples include the increase in gas turbine inlet temperatures, the increase in steam temperature and pressure in boilers and the move towards higher temperature gasification in combined-cycle plants. In all these cases, the limits are set by the properties of the available materials. Among these limiting properties, the high temperature corrosion resistance ofmetals and alloys is vel}' significant.

High temperature oxidation rates set an absolute limit, but there are processes which can lead to accelerated corrosion, often associated with impurities in the fuel or air, which lower the available temperatures still further. A number of specific cases are discussed, the underlying principles are outlined and methods of overcoming the various problems are suggested.     

回热器在高温气冷堆氦气透平循环中的应用

高温气冷堆相匹配的能量转换系统——氦气透平循环(布雷登循环)发电具有发电效率高、系统简单、安全可靠、经济性好等优点,是目前高温气冷堆领域的发展方向。影响布雷登循环效率的关键参数包括堆芯的进出口温度、压气机和透平的绝热效率、回热度、压比及循环系统的压力损失率。本文详细验证了回热器在高温气冷堆氦气轮机循环中的作用,并通过计算10MW高温气冷堆布雷登循环,分析这些参数对循环效率的影响。某于目前反应堆参数．给出了一组影响布雷登循环效率的参数值。     

燃气轮机进气冷却技术浅析

燃气轮机的性能与环境温度有关，其出力随燃气进气温度升高而降低的问题可通过冷却燃气进气来解决。冷却燃气进气有直接接触和间接接触两种方法。直接接触式有水膜式蒸发冷却和喷雾冷却；间接接触式有压缩式制冷、吸收制冷、蓄冷冷却和液化天燃（改成然）气冷能利用。直接接触式冷却装置的优点是初投资较少，运行及维护费用较低，但冷度较低，受环境湿度影响较大，适用于干燥、炎热地区。在工程中选用何种冷却进气方式应结合实际情况，综合考虑峰谷电价差、资金情况、气象参数、年运行时间等进行技术经济分析确定。