叶尖间隙封严对TRT涡轮气动性能的影响

发布时间：2018-03-26 20:07

本文选题：TRT涡轮　切入点：数值模拟　出处：《南京航空航天大学》2015年硕士论文

【摘要】：在世界各国追求经济发展的同时,能源的消耗日趋严重,为了减小能耗以及对环境的污染,可持续循环回收利用能源是一个关键措施。而TRT装置是节能环保的有效设备,TRT涡轮是其转换、回收利用能量的最主要装置。但由于TRT装置工作条件及工质能量的限制,导致TRT涡轮可转换、回收利用的能源有限,使其输出功和发电量也随之受限。因此充分利用TRT涡轮中的能量,尽量使流道中的损失最小化,对于能量的回收利用和企业的经济效益十分重要。因此本文以TRT涡轮为研究对象,开展了利用叶尖间隙封严技术抑制涡轮叶尖间隙流动、提高涡轮效率和做功能力的研究。本文使用CFD数值模拟方法对TRT涡轮两级转静子进行叶尖间隙封严。详细分析了封严前后的流场结构变化、速度分布、损失来源以及泄漏流对主流和下游的影响等,同时探讨了不同转速和间隙高度对涡轮性能和封严效果的影响。模拟结果表明:梯形篦齿封严对TRT涡轮静叶的封严效果较好。在小间隙不同转速下,涡轮的效率和流量都有不同程度地提升,同时两级静叶的泄漏量也都有极大地减小;而在大间隙下静叶的封严效果更是突出,涡轮的效率得到了较大的提升,流量和功率也有不同程度的提高,同时在大间隙低转速下对泄漏量的控制效果也是最佳。对于动叶叶尖封严,斜齿形篦齿封严效果较好,在小间隙设计转速下,由于原型机性能较好,使用动叶叶尖封严后,涡轮的性能很难有较大提升。而在小间隙低转速下,涡轮的效率有较明显提高,但流量和功率变化不大。与小间隙设计转速下的性能相比,涡轮在大间隙设计转速下流量和效率的提升幅度略有增大,但总体而言静叶叶顶的封严效果更显著。
[Abstract]:In the pursuit of economic development in the world, energy consumption is becoming increasingly serious, in order to reduce energy consumption and environmental pollution, Sustainable recycling of energy is a key measure, and TRT is an effective equipment for energy saving and environmental protection. TRT turbine is the most important equipment for energy conversion. However, due to the limitation of working conditions and working fluid energy of TRT plant, As a result, TRT turbines can be converted and recycled energy is limited, so their output power and power generation are also limited. Therefore, make full use of the energy in TRT turbines, minimize the loss in the flow channel, It is very important for the recovery of energy and the economic benefit of the enterprise. Therefore, in this paper, the tip clearance sealing technology is used to restrain the tip clearance flow of the turbine blade, taking the TRT turbine as the research object. In this paper, CFD numerical simulation method is used to seal the tip clearance of two stage rotor of TRT turbine. The flow field structure and velocity distribution before and after sealing are analyzed in detail. Loss sources and the effects of leakage flows on the mainstream and downstream, At the same time, the effects of different rotational speed and clearance height on turbine performance and sealing efficiency are discussed. The simulation results show that trapezoidal grate teeth seal the static blade of TRT turbine better, and at different rotational speeds with small clearance, the seal effect of trapezoidal grate tooth seal on TRT turbine stator blade is better. The efficiency and flow rate of the turbine are improved to varying degrees, and the leakage rate of the two stage stator vane is greatly reduced, and the sealing effect of the stator blade is more prominent under the large clearance, and the efficiency of the turbine is greatly improved. The flow rate and power are also improved to some extent, and the control effect of leakage is the best under the condition of large clearance and low rotational speed. For the tip sealing of moving blade, the sealing effect of oblique labyrinth teeth is better, and the seal effect is better under the design speed of small clearance. Because of the good performance of the prototype, it is difficult to improve the performance of the turbine after using the tip seal of the moving blade, and the efficiency of the turbine is improved obviously under the condition of small clearance and low speed. But the flow rate and power change little. Compared with the performance of small clearance design speed, the flow rate and efficiency increase slightly at large clearance design speed, but the sealing effect of static blade top is more obvious.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM619;X757

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