【作者】 李蓉；

【导师】 郑传祥；

【作者基本信息】 浙江大学 ， 化工过程机械， 2014， 硕士

【摘要】 本论文以制冷压缩机为研究对象,提出了一种新型的流固耦合技术,其将系统分解为流体场和固体场,并通过流场的多维瞬态控制体方程和固体结构的运动微分方程将其集成。控制压缩机的主要工作部件参数,用于制冷量、功耗和制冷系数的优化研究,获得多种结构优化方案。主要工作和结论如下：(1)基于流场的质量、动量和能量守恒控制体方程以及平板振动模型的运动微分方程,提出了压缩机工作过程耦合模拟方法。实现高效率、高品质模拟的同时,极大地缩短新型结构的研发时间。(2)基于流固耦合方法,对不同厚度吸气阀片的压缩机工作过程进行模拟,可以得到吸气阀片厚度对制冷量、压缩功、制冷系数的影响规律。提出有效流通面积准则来确定吸气阀片的最优厚度。分析膨胀和吸气过程中,在气孔处气流速度大存在吸气过热现象,得到气缸内制冷剂的温度变化规律,为实现近似等温压缩过程提供参考。(3)模拟得到不同排气阀片厚度及不同升程器高度的排气阀组的压缩过程的动态参数随排气阀厚度变化的规律。分析排气阀在排气腔和气缸的压差作用下应力变化过程,计算其抗冲击和疲劳特性。基于阀片能否及时关闭确定排气阀最优厚度。基于有效流通面积且保证排气阀片能够及时关闭,得到排气阀片的最优升程器高度。分析压缩和排气过程中,气缸内制冷剂的温度变化规律,作为实现近似等温压缩的依据。(4)进行近似等温过程的模拟,提出通过润滑油降温的方法实现工程上的近似等温过程。设计润滑油的通道。进行变注油量的试验研究其对排气温度、制冷量,功耗的影响规律,确定最优的注油量。本论文主要应用流固耦合方法对压缩机工作过程的以上关键问题进行了理论研究和试验探索,有望为新型压缩机结构设计、建模方法和性能优化提供参考。更多还原

【Abstract】 In this paper, reciprocating compressors were studyed on the basis of a new kind of fluid-structure interaction techniques. The system was decomposed into fluid field and solid field. Through multi-dimensional transient flow field and differential equations of motion body control, the system was integrated. By controlling the main parameters of the compressor working parts, optimization of cooling capacity, power and cooling of performance was proposed, while obtaining a variety of structural optimization measures. The main research contents and conclusions obtained as following:(1) Based on the quality, momentum and energy conservation equations of the flow field and differential equations of plate vibration model, fluid-sturcture interaction wais proposed to study the compressor working process. That method can achieve high efficiency, high-quality simulation results and greatly shorten the development time of new structures.(2) Based on fluid-structure interactions, the operation processes of compressors with variable thickness of suction valves were simulated to get the influence on the cooling capacity, the compression work and the cooling factor. The optimal criterias for thicknesses of suction valves were proposed. Expansion and suction process were analysed.The presence of large flow velocity at pores induces overheating. The temperature variations of the refrigerant in cylinder provided a reference for the realization of the approximate isothermal compression process.(3) Simulations of the compress process with varied thickness of exhaust valves or with different limited lift height for exhaust valves were completed. Stress analysises of the exhaust valves caused by the pressure differences betweent the exhaust chamber and the cylinder were finished to verify their impact and fatigue properties. The optimum thickness of the exhaust valve was determined by the closing time of valves. Based on the effective flow area, to ensure exhaust valves could close timely, the optimal exhaust valve lift height was determined. The temperature variation of the refrigerant during the compression and exhaust process cylinder was the basis to achieve approximate isothermal compression process.(4) The approximate isothermal process can be achieved using cooling approaches. Oil passage was designed. Experiment was done to study of the impact of variable volume of oil to the exhaust gas temperature, cooling capacity, power consumption, ultimately to optimaze the oil volume.In this paper, fluid-structure interaction method was applied to study the key issues of the compressors. It is expected to provide a reference for the new compressor design, modeling and performance optimization.更多还原