【作者】 许天帮；

【导师】 郑群；

【作者基本信息】 哈尔滨工程大学 ， 动力机械及工程， 2011， 硕士

【摘要】 燃气轮机采用前加级技术是发展新型大功率船用动力装置的重要途径之一。本文以某型船用大功率简单循环燃气轮机(简称MGT)为基础,探讨了通过以加级为主要手段,来满足增大发动机功率,提高效率的设计过程中所涉及的若干问题。首先,建立了MGT各核心部件的准确的变比热数学模型,并以其额定工况的热力参数为基础,针对前加级(0级)对总体性能的影响进行了全面深入的分析。然后提出了低压压气机前加一级、加两级、改变原型机工况点、重新模化设计低压压气机等六种改型方案,并详细分析各种方案的影响,最终确定了在低压压气机前加一高压比高负荷0级同时改变原型机额定工况点的改型方案。以此方案为设计目标,对所加0级进行气动结构设计。设计采用先完成动叶栅设计再匹配设计静叶栅的办法,通过参数化叶片造型的方法建立叶栅模型,并通过CFD数值计算来模拟求解叶栅模型的性能,针对初始设计的不足进行修正。经多次计算最终得到了一级压比达1.77,效率达90%左右的高负荷跨音速转子。在静叶栅的设计中,本文对直叶片、正倾斜叶片、正弯曲叶片方案分别进行了设计研究,并分析了产生二次流损失的机理及每个方案下的流场情况。发现在直叶片设计中,由于根部的速度较低,处于吸力面的部分很容易出现附面层加厚和分离；正倾斜叶片改善了根部流场的同时却在叶尖处出现了分离；正弯叶片对端壁损失控制较好,低能气体在径向压力的作用下向中径处聚集汇入主流,总损失降低。更多还原

【Abstract】 As a direct response to the need for further performance gains from current gas turbine,adding stages is an important tendcy of the marine main propolusion system. Based on a triaxial simple cycle marine gas turbine,this thesis analyse several problems involved in the design process to increase power and efficiency by the method of adding stages in front of compressor.A deeply cycle analysis was conducted based on the thermal parameters of mother gas turbine(MGT) on the rated load status, and the variable specific heat capacity mathematical models of those key components of MGT such as compressors,turbines,combusion chamber,were established. And a lot of research studies,such as adding one stage or two stages before low commpressor,adjusting the rated load status,modulated design the low pressure compressor,were conducted based on the variable specific heat capacity mathematical model of MGT,analyse the influence by these schemes and then get the final plan.In the aerodynamic design,complete rotor firstly and then design the stator which match the parameters of rotor.The cascade model is established by the parametric blade design through Fine/Autoblade software and solving the performance of the model by CFD numerical calculation.Modified the shape of airfoil for the shortcomings of the initial design amendment.Finally got a high load transonic rotor which pressure ratio is almost 1.77 when the efficiency got about 90%.Lots of research has been conducted with compressor cascades composed of conventional straight blades,positive leaned blades,positive curved blades.It is shown that the passage vortices are quite strong in the straight blade,cascade. the secondary loss at the two ends is much higher.On the acute side of the positive leaned blade cascade,the hub corner stall disappears but shroud corner stall appears.Blade positive curving introduces the effect of positive lean on the two ends,the concentrated shed vortices move and converge towards the midspan.更多还原