失速延迟模型在风力机预测中的应用

对风力机性能特别是最大输出功率的准确预测有助于在设计时提高其整体的经济性,但静态失速延迟给性能预测带来了一定的难度。通过使用预定尾迹的升力线改进法结合静态失速模型对风力机在不同的来流风速下的性能进行预测,可以提高预测的准确性。通过刚性尾迹和预定尾迹的升力线改进法对风力涡轮性能的相应分析,表明预定尾迹及静态失速延迟模型的升力线改进法可以较准确地预测风力涡轮的性能,尤其是风力机叶片在失速附近的工作状况。     

船舶柴油机动力涡轮与涡轮增压器联合优化匹配研究

搭建了某型低速二冲程柴油机动力涡轮复合涡轮增压器的仿真模型,对动力涡轮并联模式展开联合优化匹配。以同时考虑系统热效率、系统总功率、柴油机功率、动力涡轮功率、涡轮增压器喘振裕度全面择优的方式,寻取最优匹配点。结果表明:动力涡轮与增压涡轮联合优化匹配后,在中高工况下旁通8.55%的排气用以驱动动力涡轮,额定工况下其输出功率为134.6 kW,占柴油机功率的3.19%,系统总功率提升1.02%。     

某型涡扇发动机改型燃气轮机方案探讨

本文参考俄罗斯新研制的一种双通道燃气轮机ΓΤУ-18ПС,它的外涵增压空气经与内涵燃机的排气换热后驱动热空气涡轮,该涡轮与内涵燃机动力涡轮共轴输出功率,可大幅提高燃气轮机的输出功率和循环效率。将这种空气底部回热复合循环方式用于某型涡扇发动机改型燃气轮机方案,经计算分析可使燃气轮机的性能和热效率明显提高。     

自控内燃机冷却风扇系统的研究

本文分析了内燃机直接驱动冷却风扇和离合器式冷却风扇的不足,提出了自控可调叶片安装角风扇系统、自控电动冷却风扇系统和自控离合式冷却风扇系统。这三种自控冷却风扇系统可以完全避免汽车高负荷、低速时的过热和低负荷、高速时的冷却过剩;冷却风扇系统效率高,消耗功率小;在某些工况下基本消除了风扇噪声,减少了内燃机的热损失和提高了热效率;同时又大大地提高了汽车的燃油经济性和动力性。     

出口斯里兰卡内燃动车辅助驱动系统

南车青岛四方机车车辆股份有限公司生产出口斯里兰卡内燃动车的冷却风扇和牵引电机通风机采用偶合器传动箱的驱动方式,通风机机壳悬挂在传动箱箱体上,风机轴即为传动箱的输出轴;冷却风扇采用平面前倾叶片偶合器驱动方式,经计算分析,这种偶合器具有较大的扭矩系数.     

出口斯里兰卡内燃动车辅助驱动系统

南车青岛四方机车车辆股份有限公司生产出口斯里兰卡内燃动车的冷却风扇和牵引电机通风机采用偶合器传动箱的驱动方式，通风机机壳悬挂在传动箱箱体上，风机轴即为传动箱的输出轴；冷却风扇采用平面前倾叶片偶合器驱动方式，经计算分析，这种偶合器具有较大的扭矩系数。     

MT7燃气轮机的辅助设备

正据《Gas Turbine World》2014~2015年年度手册报道,在满负荷下MT7动力轴的额定转速为15 000 r/min,在从排气端观看时轴逆时针方向旋转。对于气垫艇应用,在压气机前端的扭矩管嵌入升力风扇和推进风扇齿轮箱系统。通过中间传动轴和锥齿轮布置,压气机转子驱动底部安装有传动齿轮箱。传动对象包括双压燃料泵、滑油压力和回油泵、以及交流发电机。     

新型燃气轮机与流化床锅炉耦合系统的性能分析

为了提高火电机组的热效率,建立了采用多级压缩、中间冷却以及多级膨胀、中间再热的燃气轮机与循环流化床（CFB）锅炉耦合系统性能的计算模型并进行了计算.结果表明：随着涡轮进口压力的升高和压气机级数的增加,耦合系统的热效率均有一个最大值;随着涡轮入口温度的升高和涡轮级数的增加,热效率可增加到约46%,因此,新系统具有高热效率、低厂用电率的优点;考虑到系统的结构复杂性以及综合经济性,压气机和涡轮均采用3级为宜.     

发动机前端附件驱动系统试验研究及影响因素分析

对某发动机前端附件驱动系统(前端轮系)进行了试验与计算研究。首先,通过试验获得了轮系张紧臂摆角、附件打滑率性能参数;然后对前端轮系建模并计算张紧臂摆角、附件打滑率,计算结果与试验结果吻合较好,验证了计算模型;最后用计算模型,对风扇设计匹配过程中的曲轴角位移、风扇功耗、风扇转动惯量、风扇速比等因素对前端轮系的影响进行了计算分析。结果表明,曲轴角位移和风扇速比对前端轮系性能指标影响较大,其他因素影响较小。这对前端轮系匹配设计具有参考意义。     

复合涡轮增压器对柴油机性能影响的仿真研究

为了降低燃油消耗率和提高柴油机的有效热效率,采用可回收余热的复合涡轮增压系统,并基于GT-SUITE软件研究无级变速器(continuously variable transmission,CVT)速比对系统性能参数的影响。研究结果表明:复合涡轮增压系统通过CVT速比变化可以对发动机进气量、涡轮回收功率及发动机总输出功率进行有效控制。每个工况存在一个最佳CVT速比,使发动机效率最高油耗最低。通过与未采用复合涡轮增压系统的原机对比显示,复合涡轮增压系统对发动机油耗率有明显改善,额定工况点油耗率降低5.5%。     

水轮机节能技术在石化行业循环水冷却塔中的应用

水轮机利用循环水泵的富余扬程带动风机运转,以取代风机电机,实现节能的目的。以高效反击混流式水轮机在青岛石化循环水冷却塔中的应用为例,通过监测单开水轮机风机或电动风机时循环水的温降程度,来对比两种风机的运行效果,并在维持系统管网压力、流量不变的条件下,监测水轮机风机正常运行、转速减半、停运至系统稳定,以及重开风机系统、恢复稳定状态下的运行数据,测试水轮机风机运行对循环水系统的影响,从而验证水轮机节能技术的应用效果及经济效益。结果证明,循环水系统存在富余能量,水轮机利用该富裕能量带动风机运转,不增加循环水系统新的能耗;且水轮机风机降温效果与电动风机相当,可替代电机风机运行,满足精细化操作需要。采用水轮机运转风机,可优化循环水系统配置,减少维护保养费用,经济效益较高,具有较好的推广价值。     

Thermodynamic analysis of the effects of atmospheric conditions on the performance of a precooled gas turbine fueled with liquid hydrogen

The effects of varying atmospheric conditions such as temperature, humidity and pressure on the performance of a precooled gas turbine cycle fueled with liquid hydrogen are analyzed. Since the hydrogen temperature at the precooler inlet is very low, the condensation and freezing of water vapor contained in suction air is supposed to occur within the precooler. Due to the condensation of water vapor, the precooling process requires more cryogenic hydrogen. Therefore, the temperature-drop ratio of suction air ? within the precooler decreases. Thermodynamic analysis has revealed that the thermal efficiency and specific output per unit mass flow rate considerably decrease with the increase of humidity ψ, the performance degradation of gas turbine due to atmospheric temperature rise is augmented with the increase of humidity. The humidity ratio between precooler inlet and outlet is also made clear.     

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.     

火电机组引风机采用汽轮机驱动方案探讨

通过比较火电机组引风机电机驱动及汽轮机驱动方案和凝汽式及背压式汽轮机方案,探讨了方案的优缺点,为了工程在方案选取时提供了参考。     

升力型垂直轴风机的功率计算及功率输出特性的分析

借助Matlab软件的叶片受力情况对一个升力型垂直轴风机进行了仿真,利用仿真结果分析了实例的运行功率、转速和风速的关系,以及风力发电机与叶片匹配的情况。分析结果表明该升力型垂直轴风机的风能利用率较高,结构简单,适应性较强。     

核电常规岛主厂房布置对火电厂的启发

为了降低火电厂循环水泵的轴功率(即扬程),通过对某核电厂常规岛主厂房半地下布置模式进行技术和经济分析,半地下布置模式对降低循环水泵功率效果显著,收益回报率高。这启发我们:对于火电厂,可以通过降低主厂房布置或降低凝汽器安装高度达到降低循环水泵的扬程,希望核电厂的经验能对常规火电厂主厂房布置有借鉴意义。     

Design of a new urban wind turbine airfoil using a pressure-load inverse method

This paper presents the design methodology of a new wind turbine airfoil that achieves high performance in urban environment by increasing the maximum lift. For this purpose, an inverse method was applied to obtain a new wind turbine blade section with constant pressure-load along the chord, at the design inlet angle. In comparison with conventional blade section designs, the new airfoil has increased maximum lift, reduced leading edge suction peak and controlled soft-stall behaviour, due to a reduction of the adverse pressure gradient on the suction side. Wind tunnel experimental results confirmed the computational results.     

进气畸变对回流燃烧室性能的影响研究

针对燃气轮机实际运行过程中不同火焰筒之间的空气流量畸变问题,以回流燃烧室为研究对象,开展三维数值模拟,分析进气流量改变对燃烧室多物理场分布特征和燃烧室性能的影响。结果表明：进气流量偏离理想设计对燃烧室回流区结构、温度场、总压恢复系数和燃烧效率等参数产生不利影响,而对燃烧室空气流量分配比例、主燃孔和掺混孔射流深度等参数的影响不明显;随着进气流量的减小,燃烧火焰拉长,燃烧室出口温度均匀性变差,燃烧效率急剧降低。     

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.     

超超临界1000MW机组引风机两种驱动方式技术经济分析

文中以某电厂1000MW超超临界机组的设计和运行参数为基础,论证了三合一风机采用汽轮机驱动的可行性;并与采用电机驱动方案进行技术经济比较,推荐经济效益更优的凝汽式小汽轮机驱动引风机方案。分析结果表明:大容量引风机采用小汽轮机驱动后,避免了电动引风机造成的启动电流过大,厂用电电压等级需要提高等问题,显著降低了厂用电率。