LNG冷能在燃气轮机进气冷却系统中的应用

进气温度对燃机效率的影响非常大,如果利用LNG作为低温冷源,实现对燃气轮机进气的冷却,可提高燃机功率和LNG的利用效率。文中建立了翅片管式换热器的传热模型,计算换热器传热参数,为LNG在燃机进气冷却中的应用做铺垫。     

分布式联合循环机组燃气轮机进气冷却系统性能分析研究

针对某分布式联合循环项目,利用EBSILON热力仿真平台建立了配置有燃气轮机进气冷系统的分布式联合循环机组热力计算模型性能,研究了燃气轮机进口空气降温幅度和机组性能随空气温度、空气湿度以及制冷量等因素的变化规律。结合当地环境条件和经济收益计算边界,分析了利用现有两台溴化锂冷水机组进行燃气轮机进气冷却条件下,机组性能的变化、投运系统后经济收益以及项目的投资回收期。研究结果表明,两台溴化锂冷水机进行燃气轮机进气冷却时,机组输出功率提升约1.20%～3.95%,机组热耗率降低约0.41%～1.01%,每年可产生经济效益约65.6万元,项目的投资回收期为2.97年。     

Maisotsenko往复式布雷顿循环有限时间热力学分析

应用有限时间热力学理论建立了Maisotsenko往复式布雷顿循环模型,给出了循环功率和效率的计算流程,借助数值计算方法分析了传热损失和循环注水流率等设计参数对循环热力性能的影响。并与传统往复式布雷顿循环进行比较,证明了Maisotsenko往复式布雷顿循环性能的优越性。所得结果对实际Maisotsenko往复式燃气轮机的设计优化有指导作用。     

广东地区电站燃气轮机进气冷却潜力的初步分析

分析了燃气轮机进气蒸发式冷却的热力学特点，由此导出燃气轮机进气冷却潜力的概念。结合广东典型地区气象特点，初步分析了广东地区电站燃气轮机进气实施蒸发冷却的潜力。     

燃气轮机进气降温幅度的研究

如何确定燃气轮机的进气降温幅度,关系到燃气轮机净出力的增加和能耗的降低,甚至直接危胁到燃机的寿命。针对燃机进气降温幅度如何确定的难题,本文进行了实践和探讨。通过理论计算并结合典型案例分析,总结获得出在非干燥地区采用间接降温法时,降温点应控制在露点温度以下1~2℃,降温幅度不宜过大。这一点应引起业界的高度重视。     

压气机进气温度对联合循环机组性能影响的探讨

通过热力学模型分析和热力系统平衡计算,研究了9F级燃气轮机压气机进气温度变化对燃气轮机及联合循环发电机输出功率及效率的影响,压气机进气温度变化不仅对燃气轮机联合循环机组满负荷时的性能有影响,在部分负荷运行时对机组的效率也有影响。通过对压气机进气温度进行调节,可以改善燃气轮机联合循环的运行性能。     

燃气轮机进气系统全寿命周期成本计算模型研究

进气系统作为拦截空气中污染物颗粒的屏障,对保障燃气轮机的正常运行意义重大,但因选型中变量较多,通常难以根据机组的运行特点和外部环境选择合适的进气系统。从全寿命周期成本的角度,探讨了进气系统选型中需要考虑的主要因素,并提出相应的计算模型。通过对某燃气-蒸汽联合循环机组进气系统全寿命周期内成本的计算,分析了系统的初始成本、运维成本、燃机性能退化成本对总成本中的影响,结果表明:进气系统总成本中,燃机性能退化成本占比90. 44%,初始成本仅占0. 62%,因此,在进气系统选型及改造中,应从全寿命周期成本的角度对系统经济性进行评估,全寿命周期成本的计算模型对燃气轮机进气系统的选型及成本计算有重要的指导意义。     

部分负荷进气加热提效技术在F级燃机的应用研究

简要介绍我国燃气发电行业的机组运行现状,分析燃气轮机进气加热提效技术应用的背景。采用仿真计算研究方式,针对不同F级燃气轮机联合循环机组建立仿真分析模型,研究我国不同型号F级燃机部分负荷加热性能提升情况。仿真计算结果表明,进气加热技术能够显著提高M701F4和PG9351FA燃气联合循环机组部分负荷下的发电效率。最后国内典型进气系统结构形式的进气加热技术改造难点进行了分析,提出具有实践意义的改造建议。     

燃气轮机进气雾化式蒸发冷却控制技术研究

大气环境温度对燃气轮机性能的影响很大,加装燃气轮机进气雾化冷却系统对改善燃气轮机性能具有很高的实用价值.通过对燃气轮机进气雾化冷却工作原理的分析,提出了一种基于PLC的燃气轮机进气雾化冷却控制系统的设计方案以及功能实现.运行结果表明,该控制系统自动化程度高,工作稳定性好,性能可靠.配置控制系统的燃气轮机进气雾化式冷却撬体投运后,PG6551(B)型燃气轮机功率相对增加8.35%,效率相对提高3.24%.     

燃气轮机进气制冷技术

本文根据燃气轮机性能曲线,利用余热锅炉后的剩余余热,作为溴化锂制冷机组的热源,对燃机进气进行冷却,达到增大出力、降低能耗的双重效益。     

Thermodynamic performance assessment of an indirect intercooled reheat regenerative gas turbine cycle with inlet air cooling and evaporative aftercooling of the compressor discharge

This study provides a computational analysis to investigate the effects of cycle pressure ratio, turbine inlet temperature (TIT), and ambient relative humidity (φ) on the thermodynamic performance of an indirect intercooled reheat regenerative gas turbine cycle with indirect evaporative cooling of the inlet air and evaporative aftercooling of the compressor discharge. Combined first and second‐law analysis indicates that the exergy destruction in various components of gas turbine cycles is significantly affected by compressor pressure ratio and turbine inlet temperature, and is not at all affected by ambient relative humidity. It also indicates that the maximum exergy is destroyed in the combustion chamber; which represents over 60% of the total exergy destruction in the overall system. The net work output, first‐law efficiency, and the second‐law efficiency of the cycle significantly varies with the change in the pressure ratio, turbine inlet temperature and ambient relative humidity. Results clearly shows that performance evaluation based on first‐law analysis alone is not adequate, and hence more meaningful evaluation must include second‐law analysis. Decision makers should find the methodology contained in this paper useful in the comparison and selection of gas turbine systems. Copyright © 2006 John Wiley & Sons, Ltd.     

Analysis of gas turbine operating parameters with inlet fogging and wet compression processes

Inlet fogging has been widely noticed in recent years as a method of gas turbine air inlet cooling for increasing the power output in gas turbines and combined cycle power plants. The effects of evaporative cooling on gas turbine performance were studied in this paper. Evaporative cooling process occurs in both compressor inlet duct (inlet fogging) and inside the compressor (wet compression). By predicting the reduction in compressor discharge air temperature, the modeling results were compared with the corresponding results reported in literature and an acceptable difference percent point was found in this comparison. Then, the effects of both evaporative cooling in inlet duct, and wet compression in compressor, on the power output, turbine exhaust temperature, and cycle efficiency of 16 models of gas turbines categorized in four A–D classes of power output, were investigated. The results of this analysis for saturated inlet fogging as well as 1% and 2% overspray are reported and the prediction equations for the amount of actual increased net power output of various gas turbine nominal power output are proposed. Furthermore the change in values of physical parameters and moving the compressor operating point towards the surge line in compressor map was investigated in inlet fogging and wet compression processes.     

Effects of evaporative inlet and aftercooling on the recuperated gas turbine cycle

Inlet air cooling and cooling of the compressor discharge using water injection boost both efficiency and power of gas turbine cycles. Four different layouts of the recuperated gas turbine cycle are presented. Those layouts include the effect of evaporative inlet and aftercooling (evaporative cooling of the compressor discharge). A parametric study of the effect of turbine inlet temperature (TIT), ambient temperature, and relative humidity on the performance of all four layouts is investigated. The results indicate that as TIT increases the optimum pressure ratio increases by 0.45 per 100 K for the regular recuperated cycle and by 1.4 per 100 K for the recuperated cycle with evaporative aftercooling. The cycles with evaporative aftercooling have distinctive pattern of performance curves and higher values of optimum pressure ratios. The results also showed that evaporative cooling of the inlet air could boost the efficiency by up to 3.2% and that evaporative aftercooling could increase the power by up to about 110% and cycle efficiency by up to 16%.     

Theoretical and testing performance of an innovative indirect evaporative chiller

An indirect evaporative chiller is a device used to produce chilled water at a temperature between the wet bulb temperature and dew point of the outdoor air, which can be used in building HVAC systems. This article presents a theoretical analysis and practical performance of an innovative indirect evaporative chiller. First, the process of the indirect evaporative chiller is introduced; then, the matching characteristics of the process are presented and analyzed. It can be shown that the process that produces cold water by using dry air is a nearly-reversible process, so the ideal produced chilled water temperature of the indirect evaporative chiller can be set close to the dew point temperature of the chiller’s inlet air. After the indirect evaporative chiller was designed, simulations were done to analyze the output water temperature, the cooling efficiency relative to the inlet dew point temperature, and the COP that the chiller can performance. The first installation of the indirect evaporative chiller of this kind has been run for 5 years in a building in the city of Shihezi. The tested output water temperature of the chiller is around 14–20 °C, which is just in between of the outdoor wet bulb temperature and dew point. The tested COP_r,s of the developed indirect evaporative chiller reaches 9.1. Compared with ordinary air conditioning systems, the indirect evaporative chiller can save more than 40% in energy consumption due to the fact that the only energy consumed is from pumps and fans. An added bonus is that the indirect evaporative chiller uses no CFCs that pollute to the aerosphere. The tested internal parameters, such as the water–air flow rate ratio and heat transfer area for each heat transfer process inside the chiller, were analyzed and compared with designed values. The tested indoor air conditions, with a room temperature of 23–27 °C and relative humidity of 50–70%, proved that the developed practical indirect evaporative chiller successfully satisfy the indoor air conditioning load for the demo building. The indirect evaporative chiller has a potentially wide application in dry regions, especially for large scale commercial buildings. Finally, this paper presented the geographic regions suitable for the technology worldwide.     

An indirect evaporative chiller

A novel indirect evaporative chiller driven by outdoor dry air to produce cold water as the cooling source for air conditioning systems is introduced, and the principle and the structure of the chiller is presented. The cold water can be produced almost reversibly under ideal working conditions, with its temperature infinitely close to the dew point temperature of the inlet air. The key components of the chiller are an air cooler and a padding tower. To improve the heat transfer performance inside the chiller, a quasi-countercurrent air cooler was designed; a subsection linear method was used for the mathematical model of the padding tower. The first indirect evaporative chiller, designed and developed in 2005, has been in use in Kairui Building, a big hotel in Shihezi, Xinjiang Autonomous Region. The tested temperature of the water produced is below the wet bulb temperature of outdoor air and reached the average value of the dew point temperature and the wet bulb temperature of outdoor air. As the running components are only pumps and fans, the COP (cooling energy for room divided by power cost) of this chiller is high, and the drier the outdoor air, the higher COP the chiller obtained. Since no CFCs are used in this chiller, it would not cause any pollution to the aerosphere. Finally, the application prospect of the indirect evaporative chiller in the world is presented.     

Performance enhancement of gas turbines by inlet air‐cooling in hot and humid climates

In this paper, a model to study the effect of inlet air‐cooling on gas turbines power and efficiency is developed for two different cooling techniques, direct mechanical refrigeration and an evaporative water spray cooler. Energy analysis is used to present the performance improvement in terms of power gain ratio and thermal efficiency change factors. Relationships are derived for an open gas turbine cycle with irreversible compression and expansion processes coupled to air‐cooling systems. The obtained results show that the power and efficiency improvements are functions of the ambient conditions and the gas turbine pressure ratio. The performance improvement is calculated for, ambient temperatures from 30 to 50°C, the whole range of humidity ratio (10–100%) and pressure ratio from 8 to 12. For direct mechanical refrigeration air‐cooling, the power improvement is associated with appreciable drop in the thermal efficiency. The maximum power gain can be obtained if the air temperature is reduced to its lowest limit that is the refrigerant evaporation temperature plus the evaporator design temperature difference. Water spray cooling process is sensitive to the ambient relative humidity and is suitable for dry air conditions. The power gain and efficiency enhancement are limited by the wet bulb temperature. The performance of spray evaporative cooler is presented in a dimensionless working graph. The daily performance of the cooling methods is examined for an ABB‐11D5 gas turbine operating under the hot humid conditions of Jeddah, Saudi Arabia. The results indicate that the direct mechanical refrigeration increased the daily power output by 6.77% versus 2.57% for the spray air‐cooling. Copyright © 2005 John Wiley & Sons, Ltd.     

Energy and exergy analyses of a CFB‐based indirectly fired combined cycle power generation system

Combined cycle configuration has the ability to use the waste heat from the gas turbine exhaust gas using the heat recovery steam generator for the bottoming steam cycle. In the current study, a natural gas‐fired combined cycle with indirectly fired heating for additional work output is investigated for configurations with and without reheat combustor (RHC) in the gas turbine. The mass flow rate of coal for the indirect‐firing mode in circulating fluidized bed (CFB) combustor is estimated based on fixed natural gas input for the gas turbine combustion chamber (GTCC). The effects of pressure ratio, gas turbine inlet temperature, inlet temperatures to the air compressor and to the GTCC on the overall cycle performance of the combined cycle configuration are analysed. The combined cycle efficiency increases with pressure ratio up to the optimum value. Both efficiency and net work output for the combined cycle increase with gas turbine inlet temperature. The efficiency decreases with increase in the air compressor inlet temperature. The indirect firing of coal shows reduced use with increase in the turbine inlet temperature due to increase in the use of natural gas. There is little variation in the efficiency with increase in GTCC inlet temperature resulting in increased use of coal. The combined cycle having the two‐stage gas turbine with RHC has significantly higher efficiency and net work output compared with the cycle without RHC. The exergetic efficiency also increases with increase in the gas turbine inlet temperature. The exergy destruction is highest for the CFB combustor followed by the GTCC. The analyses show that the indirectly fired mode of the combined cycle offers better performance and opportunities for additional net work output by using solid fuels (coal in this case). Copyright © 2009 John Wiley & Sons, Ltd.     

Analysis of parameters affecting the performance of gas turbines and combined cycle plants with vapor absorption inlet air cooling

The integration of an aqua‐ammonia inlet air‐cooling scheme to a cooled gas turbine‐based combined cycle has been analyzed. The heat energy of the exhaust gas prior to the exit of the heat recovery steam generator has been chosen to power the inlet air‐cooling system. Dual pressure reheat heat recovery steam generator is chosen as the combined cycle configuration. Air film cooling has been adopted as the cooling technique for gas turbine blades. A parametric study of the effect of compressor–pressure ratio, compressor inlet temperature, turbine inlet temperature, ambient relative humidity, and ambient temperature on performance parameters of plants has been carried out. It has been observed that vapor absorption inlet air cooling improves the efficiency of gas turbine by upto 7.48% and specific work by more than 18%, respectively. However, on the adoption of this scheme for combined cycles, the plant efficiency has been observed to be adversely affected, although the addition of absorption inlet air cooling results in an increase in plant output by more than 7%. The optimum value of compressor inlet temperature for maximum specific work output has been observed to be 25 °C for the chosen set of conditions. Further reduction of compressor inlet temperature below this optimum value has been observed to adversely affect plant efficiency. Copyright © 2013 John Wiley & Sons, Ltd.     

航改燃气轮机的湿空气透平循环改型方案研究

航改燃气轮机具有压比高、效率高、可靠性高和结构紧凑等特点,它将航空发动机先进技术有效地应用于工业领域。以某型三轴航改燃气轮机为研究对象,对其不同的HAT循环改型方案进行了研究。建立了一种基于饱和曲线和工作线的饱和器模型,该模型避免使用难以准确获得的传热传质系数,利用饱和器实验数据对该模型进行了验证,结果表明:建立的饱和器模型具有较高的准确性,其中出口空气温度最大误差小于0.8%,出口湿度最大误差小于1.9%。此外,设计并仿真了3种不同结构形式的HAT循环方案,仿真结果表明:原始的压气机和透平特性不适合于改型后的HAT循环,它限制了HAT循环的效率和燃气轮机的输出功率(简称出功)。针对这一问题,提出了改进透平特性方案,该方案有效地解决了水蒸气的加入带来部件不匹配问题。在此基础上分析了3个HAT方案设计点的性能,结果表明方案2即在简单循环基础上加入了饱和器、经济器、回热器和中冷器是最佳的改型方案。     

Energetic and exergetic performance analyses of a combined heat and power plant with absorption inlet cooling and evaporative aftercooling

In this paper, exergy method is applied to analyze the gas turbine cycle cogeneration with inlet air cooling and evaporative aftercooling of the compressor discharge. The exergy destruction rate in each component of cogeneration is evaluated in detail. The effects of some main parameters on the exergy destruction and exergy efficiency of the cycle are investigated. The most significant exergy destruction rates in the cycle are in combustion chamber, heat recovery steam generator and regenerative heat exchanger. The overall pressure ratio and turbine inlet temperature have significant effect on exergy destruction in most of the components of cogeneration. The results obtained from the analysis show that inlet air cooling along with evaporative aftercooling has an obvious increase in the energy and exergy efficiency compared to the basic gas turbine cycle cogeneration. It is further shown that the first-law efficiency, power to heat ratio and exergy efficiency of the cogeneration cycle significantly vary with the change in overall pressure ratio and turbine inlet temperature but the change in process heat pressure shows small variation in these parameters.