某型燃气轮机离线水洗后性能恢复试验研究

为探索燃气轮机离线水洗后性能恢复规律,对盐雾加速腐蚀试验后的某型燃气轮机进行离线水洗, 测量并计算三次离线水洗前后燃气轮机性能,分析比较三次离线水洗对燃气轮机各性能参数的影响。得出 以下结论:离线水洗后,压气机进气流量、压气机增压比、压气机效率、燃气轮机功率和燃气轮机效率均得到 有效提升;三次离线水洗对压气机效率提升的程度逐渐增强,对进气流量、压气机增压比、燃气轮机功率和燃 气轮机效率影响则逐渐减弱;燃气轮机全工况范围比较单次离线水洗的作用,压气机效率、燃气轮机功率和 燃气轮机效率在燃油当量0.5左右提升程度最低,而进气流量及压气机压比则随着工况的升高,提升程度呈 现上升趋势;额定工况下三次离线水洗压气机效率平均提升2.48%,燃气轮机效率平均提升0. 94%。第二次 和第三次离线水洗对燃气轮机各项性能提升得程度接近。     

压气机离线水洗后燃气轮机性能衰退分析研究

为定量诊断燃气轮机实际运行过程中压气机叶片积垢导致的燃气轮机性能衰退趋势,提出一种基于多元非线性回归模型的燃气轮机性能衰退预测方法。以PG9351FA型燃气轮机为例,建立了离线水洗后压气机进气质量流量、压气机压比、压气机效率和燃气轮机功率的性能衰退模型。结果表明:压气机叶片积垢导致的燃气轮机功率衰减速度约为压气机进气质量流量衰减速度的1.7倍,在燃气轮机Baseload工况下,离线水洗后运行2 000 h,压气机进气质量流量衰减约3.26%,压气机压比衰减约3.04%,压气机效率衰减约2.62%,其综合影响使得燃气轮机功率衰减约5.54%;随着离线水洗后运行小时数的增加,燃气轮机性能衰减将逐渐趋于稳定。     

基于Simscape的重型燃气轮机建模与仿真研究

现代重型燃气轮机的二次空气约占总空气通流量的20%左右,对燃气轮机整体性能有着不可忽略的影响。为研究二次空气对重型燃气轮机的影响,采用Simscape语言编写了燃气轮机通用模块库,利用模块库搭建了重型燃气轮机模型,并验证了模型的正确性。最后,进行了变工况仿真实验,结果表明二次空气冷却系统可以在保护高温透平的同时提高压气机效率,从而优化了燃气轮机整体性能。     

燃气轮机间冷器设计及试验研究

为了提高燃气轮机的功率,一种有效的方法就是在高低压压气机之间增加间冷器,从而降低高压压气机进口的温度,减少耗功。考虑到燃气轮机总体设计需求,间冷器设计必满足高效、紧凑的要求。用解析法对间冷器的性能进行设计计算,搭建试验台对其性能进行验证,试验结果表明:换热效率误差为1.8%,空气侧流阻误差为30.5%,水侧流阻误差为2.03%。通过分析对比解析计算结果与试验结果,提出换热效率及空气侧流阻修正公式,为板翅式换热器的设计提供了参考依据。     

压气机不同运行工况下湿压缩性能分析

湿压缩技术能够有效提高燃气轮机输出功,降低燃气轮机对大气环境的依赖程度.该技术对压气机的影响因素非常复杂,压气机的运行工况对湿压缩效果的影响甚大.本研究采用CFX软件对某型三级轴流压气机在不同工况下的干、湿压缩过程进行三雏数值模拟.结果表明:压比不变的情况下,高转速时压气机近失速边界处质量流量增加,低转速时质量流量下降...     

PG9171E型燃气轮机变工况计算模型的建立

为了建立PG9171E型燃气轮机变工况计算模型,必须根据电厂提供的原始数据建立该机型的压气机特性.由于现有基线估算方法的建立未包含高压比压气机实验数据.故一般只被应用于压比小于11的压气机特性估算,而PG9171E型燃气轮机的压气机压比已接近12.为了解决这个问题,在压气机特性计算过程中首次提出分段计算法,计算结果表明:该方法的精度能够满足实际应用要求.在变工况计算模型的燃气热力性质计算方面,根据热力性质表[2].归纳出空气、CH2燃气、C燃气和水蒸气的热力性质通用关系式,简化了燃烧室燃用重油时的湿燃气焓值和对数压比值的计算过程,变工况计算模型的计算结果与燃气轮机实测参数进行比较,表明上述改进方法在实际应用中能够满足建模精度的要求.     

船用燃气轮机压气机多级可调静叶优化匹配方法研究

作为防止燃气轮机喘振的有效手段之一,可调静叶技术的应用能够提升压气机在非设计工况下的效率和运行范围,从而提高燃气轮机变工况下的经济性和稳定性。以某型船用三轴燃气轮机为研究对象,建立压气机一维性能分析模型与燃气轮机零维仿真模型耦合的变维度燃气轮机仿真模型,以经济性和稳定性为优化目标,通过多目标遗传算法对低压压气机多级可调静叶进行优化匹配。结果表明:优化后的可调静叶方案能提高压气机的喘振裕度并降低耗油率;静叶处于不同优化角度方案时,不同工况下压比-流量共同工作线上压比最高提升2.17%,效率-流量共同工作线上效率最高提升4.34%,折合转速提高3%～4%。     

某压气机内部三维流场数值模拟研究

以某重型燃气轮机的整个压气机为研究对象,通过计算软件对该压气机内部三维流场进行设计工况下的数值模拟研究,获得的压气机特性计算结果与试验值吻合良好;并详细分析了该压气机内部流场结构,找出了该燃气轮机最大噪声位置及其形成原因,同时获得了两种压气机内部流场的控制方法,对于压气机设计具有指导意义.     

某型压气机叶片防护层耐蚀性研究

采用磁控溅射技术在压气机叶片上溅射TiN层作为叶片防护层,利用盐雾实验及电化学方法,研究了某型压气机叶片材料及覆有TiN层后叶片耐腐蚀性能,通过失重法计算出盐雾实验后试样腐蚀速率。根据曲线可以看出覆有TiN层的试样耐蚀性优于基体,对盐雾实验不同时间取出的试件,在3.5%(wt)NaCl溶液中,进行电化学动电位扫描,根据极化曲线数据,分析了不同盐雾腐蚀时间试样腐蚀电位变化原因,验证盐雾实验结果。     

重型燃气轮机通流部分热力特性计算与仿真研究

以某F级单轴重型燃气轮机通流部分热力特性为研究对象,通过模块化建模方法在MATLAB/Simulink平台中建立燃机系统仿真模型,对燃气轮机典型截面上压缩空气和高温燃气沿转子轴向的特性进行仿真研究。提出了一种结合表征压气机级特性的基元级算法和根据抽气点位置划分的压缩级建模方法的压气机仿真模型。由于燃机通流部分工质的温度变化较大,而且伴随着燃烧反应及燃气与冷却空气混流问题,为保证仿真精度,该模型采用变比热容公式计算空气和燃气的热力参数,并对工质组分质量分数进行详细计算,还考虑了容积惯性和转动惯性对整个系统模型的影响。结果表明,该仿真模型在实际应用中能够满足建模精度的要求。     

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.     

Comparison of evaporative inlet air cooling systems to enhance the gas turbine generated power

The gas turbine performance is highly sensitive to the compressor inlet temperature. The output of gas turbine falls to a value that is less than the rated output under high temperature conditions. In fact increase in inlet air temperature by 1°C will decrease the output power by 0.7% approximately. The solution of this problem is very important because the peak demand season also happens in the summer. One of the convenient methods of inlet air cooling is evaporating cooling which is appropriate for warm and dry weather. As most of the gas turbines in Iran are installed in such ambient conditions regions, therefore this method can be used to enhance the performance of the gas turbines. In this paper, an overview of technical and economic comparison of media system and fog system is given. The performance test results show that the mean output power of Frame‐9 gas turbines is increased by 11 MW (14.5%) by the application of media cooling system in Fars power plant and 8.1 MW (8.9%) and 9.5 MW (11%) by the application of fog cooling system in Ghom and Shahid Rajaie power plants, respectively. The total enhanced power generation in the summer of 2004 was 2970, 1701 and 1340 MWh for the Fars, Ghom and Shahid Rajaie power plants, respectively. The economical studies show that the payback periods are estimated to be around 2 and 3 years for fog and media systems, respectively. This study has shown that both methods are suitable for the dry and hot areas for gas turbine power augmentation. Copyright © 2007 John Wiley & Sons, Ltd.     

开式燃气轮机中冷回热再热循环功率和效率优化

建立了开式燃气轮机中冷回热再热（ICRR）循环有限时间热力学模型,导出了循环功率和效率解析式,优化了气流沿通流部分的压降（或低压压气机进口空气质量流率）和中间压比,得到最大功率;并在给定燃油流率的情况下,优化了气流沿通流部分的压降和中间压比,得到最大热效率,进一步在给定低压压气机进口和动力涡轮出口总面积的情况下,优化两者面积分配比,得到双重最大热效率.     

小型燃气轮机CCHP系统变工况性能入口加热调控研究

提出了一种利用冷热电联产系统(CCHP)低温烟气与环境空气混和加热控制压气机入口温度,提升燃气轮机冷热电系统变工况性能的方法,并以1.9 MW小型燃气轮机OPRA16为例,建立了CCHP系统模型,分析了调控方法的效果、机理。结果表明,入口混和加热可以有效改善冷热电联产系统变工况下系统性能,并扩展系统节能运行范围。与传统燃料流量调控方法相比,新型调控手段下夏季制冷与冬季供热模式下系统节能率分别提升5.7%和21.6%。     

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.     

Thermoeconomic optimization of an ice thermal storage system for gas turbine inlet cooling

The gas turbine power output and efficiency decrease with increasing ambient temperature. With compressor inlet air cooling, the air density and mass flow rate as well as the gas turbine net power output increase. The inlet cooling techniques include vapor or absorption refrigeration systems, evaporative cooling systems and thermal energy storage (TES) systems. In this paper the thermoeconomic analysis of ice (latent) thermal energy storage system for gas turbine inlet cooling application was performed. The optimum values of system design parameters were obtained using genetic algorithm optimization technique. The objective function included the capital and operational costs of the gas turbine, vapor compression refrigeration system, without (objective function I) and with (objective function II) corresponding cost due to the system exergy destruction. For gas turbines with net power output in the range of 25-100 MW, the inlet air cooling using a TES system increased the power output in the range of 3.9-25.7%, increased the efficiency in the range 2.1-5.2%, while increased the payback period from about 4 to 7.7 years.     

燃气轮机进气喷水减温技术经济分析及滴径计算

夏季环境温度比较高，燃气轮机的出力和热效率都会受到影响，对压气机喷水减温方法和喷水滴径进行了分析和计算，计算结果表明：温度越高，湿度越小，燃气轮机的输出功率和热效率提高得越多，燃油消耗率也降低得越多，喷水减温的效果越好，此外，高的压比和高的透平进气温度提高了喷水减温效果。     

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.     

Thermodynamic optimization for an open cycle of an externally fired micro gas turbine (EFmGT). Part 1: Thermodynamic modelling

The principle of optimally tuning the air flow rate and subsequent distribution of pressure drops is applied to optimize the performance of a thermodynamic model for an open regenerative cycle of an externally fired micro gas turbine power plant with pressure drop irreversibilities by using finite-time thermodynamics and considering the size constraints of the real plant. There are eight flow resistances encountered by the working fluid stream for the cycle model. Two of these, the friction through the blades and vanes of the compressor and the turbine, are related to the isentropic efficiencies. The remaining flow resistances are always present because of the changes in flow cross-section at the compressor inlet and outlet, the turbine inlet and outlet and the regenerator hot/cold-side inlet and outlet. These resistances associated with the flow through various cross-sectional areas are derived as functions of the compressor inlet relative pressure drop, and control the air flow rate and the net power output and thermal efficiency. The analytical formulae for the power output, efficiency and other coefficients are derived, which indicate that the thermodynamic performance for an open regenerative cycle of an externally fired micro gas turbine power plant can be optimized by adjusting the mass flow rate (or the distribution of pressure losses along the flow path). It is shown that there are optimal air mass flow rates (or the distribution of pressure losses along the flow path) which maximize the net power output.     

Brayton refrigeration cycle for gas turbine inlet air cooling

In this paper, a new approach to enhance the performance of gas turbines operating in hot climates is investigated. Cooling the intake air at the compressor bell mouth is achieved by an air Brayton refrigerator (reverse Joule Brayton cycle) driven by the gas turbine and uses air as the working fluid. Fraction of the air is extracted from the compressor at an intermediate pressure, cooled and then expands to obtain a cold air stream, which mixes with the ambient intake. Mass and energy balance analysis of the gas turbine and the coupled Brayton refrigerator are performed. Relationships are derived for a simple open gas turbine coupled to Brayton refrigeration cycle, the heat rejected from the cooling cycle can be utilized by an industrial process such as a desalination plant. The performance improvement in terms of power gain ratio (PGR) and thermal efficiency change (TEC) factor is calculated. The results show that for fixed pressure ratio and ambient conditions, power and efficiency improvements are functions of the extraction pressure ratio and the fraction of mass extracted from the air compressor. The performance improvement is calculated for ambient temperature of 45°C and 43.4% relative humidity. The results indicated that the intake temperature could be lowered below the ISO standard with power increase up to 19.58% and appreciable decrease in the thermal efficiency (5.76% of the site value). Additionally, the present approach improved both power gain and thermal efficiency factors if air is extracted at 2 bar which is unlike all other mechanical chilling methods. Copyright © 2007 John Wiley & Sons, Ltd.