双螺杆高压余能回收液力透平的数值模拟与实验研究

发布时间：2018-03-07 14:42

本文选题：双螺杆　切入点：液力透平　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：液力透平是一种能够有效地将液体的动能及压能进行回收的能量回收装置。近几年来,随着技术的发展和研究的不断深入,液力透平逐渐在工业流程中得以应用。一般来说,不同种类的液力透平都存在各自的应用范围,如单级泵反转做透平只适用于低扬程、中高流量工况,对于高水头、小流量工况,目前还没有一种技术成熟的液力透平能够投入到长期的使用中,因此迫切需要研究加以解决。双螺杆液力透平作为一种容积式能量回收装置,能完全应对高水头、小流量的运行工况,且具有输送介质平稳、压力脉动小、噪声低、对工质不敏感等优点。本文以一种单吸双螺杆泵反转做透平为研究对象,利用结构设计、理论分析、数值模拟、实验研究相结合的方法对双螺杆液力透平的内部流场、非定常动力特性、回收效率等方面进行了研究。本文的主要工作和创造性研究成果有:1.详细总结了透平的国内外研究现状,指出了目前液力透平研究存在的问题,提出了今后液力透平发展的趋势和方向。结合双螺杆液力透平的优点,介绍了在高水头、小流量工况下可以达到的能量回收效果及产生的社会经济效益。2.对已有的螺杆转子型线进行对比分析,优选出A型双螺杆型线并加以研究。同时提出一种双螺杆液力透平的基本结构,确定了主从螺杆的装配以及传动方式,在此基础上对双螺杆液力透平外特性基本理论、能量回收机理、理论泄漏等进行了分析说明。3.首次利用CFD数值模拟完成了对双螺杆液力透平内部流场的研究,揭示了压力场与速度场的分布规律,以及径向力、轴向力、扭矩以及流量的旋转周期特性。应用CFD技术对不同进口压力、不同转速下的双螺杆液力透平的能量回收特性进行了数值模拟分析,研究了流量、效率等外特性参数以及螺杆压力分布、间隙泄漏流量受进口压力、转速等因素影响的变化特征,得到了不同转速下液力透平效率随进口压力的变化规律。4.首次利用CFD数值模拟研究了螺杆结构参数对透平回收效率、泄漏量、扭矩、轴向力以及径向力的影响。具体包括螺杆导程(包络角)对扭矩、受力、效率的影响,以及不同径向间隙与不同中心轴距对双螺杆液力透平的泄漏损失及效率的影响等;研究结果可为双螺杆液力透平设计过程中对导程大小、径向间隙大小、齿间间隙大小的确定提供参考。5.利用自主研发的高压余能回收液力透平试验台对双螺杆液力透平样机进行了不同进口压力、不同转速工况的实验研究,揭示了透平实验效率的变化特性;将实验数据与模拟结果相对比,分析两者出现差异的可能性原因,并提出了进一步提高透平回收效率的方法和途径。6.统计数值模拟结果中不同监测点的压力数据,对不同螺杆轴向位置的径向间隙监测点的压力脉动时域、频域变化形成过程及变化特性进行分析,结合具体时刻下的螺杆表面压力分布指出了产生该变化特性的具体原因。
[Abstract]:Hydraulic turbine is an effective liquid kinetic energy and pressure energy recovery device recycling. In recent years, with the development of technology and the deepening of the hydraulic turbine, gradually applied in industrial processes. In general, different types of hydraulic turbine are their application areas, such as single the pump reversal turbine is only suitable for low head, high flow rate, for high head, small flow condition, there is not a mature technology of hydraulic turbine can be put into use in the long term, there is an urgent need to be solved. The research of double screw hydraulic turbine as a volume type energy recovery device, can fully respond to the operation condition of high head, small flow, and has a smooth conveying medium, the pressure fluctuation is small, low noise, the refrigerant is not sensitive. Taking a single suction double screw pump reverse penetration of flat Like, the structure design, theoretical analysis, numerical simulation, flow field experimental research method of combining the double screw hydraulic turbine, unsteady dynamic characteristics on recovery efficiency were studied. The main work and creative research results are: 1. a detailed summary of the research status of the turbine at home and abroad, pointed out. The existing hydraulic turbine research problems, puts forward the trend and direction of development of hydraulic turbine in the future. Combined with the advantages of double screw hydraulic turbine, introduced in the high head, comparative analysis of energy recovery effect can be achieved under small flow rate condition and the social and economic benefits of.2. on the screw rotor profile, select A twin screw type line and studied. At the same time put forward the basic structure of a double screw hydraulic turbine, the master-slave screw assembly and transmission mode, on the basis of the double screw hydraulic The basic theory and characteristics of turbine, energy recovery mechanism, the theory of leakage were analyzed by.3. for the first time CFD completed the numerical simulation study on the internal flow field of double screw hydraulic turbine, the distribution of pressure and velocity, axial and radial force, force, torque and the flow rate of the rotation cycle characteristics. The application of CFD the pressure of different technology import, energy recovery characteristics of double screw hydraulic turbine under different speed are analyzed through numerical simulation, studies the flow properties and the efficiency of external screw pressure distribution, leakage flow inlet pressure, speed change characteristics of influencing factors, the changing regularity of.4. hydraulic turbine efficiency with different speeds the inlet pressure for the first time using the CFD numerical simulation of structural parameters of the screw recovery efficiency of turbine, leakage, torque, axial force and radial force of the impact of specific. Including the lead screw (envelope angle) of torque, force, efficiency, and different radial clearance and different center wheelbase of the twin screw hydraulic turbine leakage loss and efficiency influence; the results can be used for the double screw hydraulic turbine design process of lead size, size to determine the size of the gap between teeth the gap size of reference.5. using self-developed high pressure energy recovery hydraulic turbine test rig under different inlet pressure of double screw hydraulic turbine prototype, experimental study on different speed conditions, reveals the variation characteristics of turbine efficiency experiment; experimental data and simulation results were compared, analysis of the two possible reasons of difference. And put forward the pressure data of different monitoring points further ways to improve the recovery efficiency of turbine.6. statistical numerical simulation results, the radial clearance of different screw axial position monitoring The pressure fluctuation in the time domain and frequency domain are analyzed, and the specific reasons for the variation characteristics are pointed out according to the specific pressure distribution at the specific time.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TK05

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