【作者】 何戈宁；

【导师】 胡大鹏；

【作者基本信息】 大连理工大学 ， 化工过程机械， 2009， 硕士

【摘要】 压力交换制冷机是继静止式气波机和旋转式气波机之后的新型气波制冷设备,它利用激波和接触面在振荡管中的运动来完成能量交换,实现气体膨胀制冷。具有结构紧凑,震动小,管内无积液,效率稳定等优点,具有非常广阔的应用前景。为了进一步优化压力交换制冷机结构,提高设备的制冷效率,本文结合运用气体动力学非定常流动理论、数值模拟实验和物理实验三种方法对压力交换制冷机入射损失与排气返流两方面问题进行了如下一些研究与优化:(1)提出了入射激波分析的稳定入射模型,并结合传统的激波管模型,运用气体动力学一维非定常流动分析方法,对压力交换制冷机波转子内部波系运动及气体流动进行了详细分析。(2)分别研究了波转子通道壁结构、喷嘴结构、喷嘴宽度、泄漏问题等对入射的损失的影响。建立二维循环多通道入射数值模型,对波转子通道壁结构、喷嘴结构、喷嘴宽度和等熵效率损失的关系进行了数值模拟研究,提出了一些新的结构。建立三维循环多通道入射数值模型研究高压入口喷嘴处间隙泄漏和等熵效率损失的关系,并具体将泄漏分为6个部分进行分析。(3)建立了整机循环换热数值模拟模型,并通过整机数值模拟实验研究,分析了排气阶段返流问题以及反向压缩波问题的形成原因以及其对制冷机工作性能的影响。通过整机数值模拟实验,提出了优化制冷机内部流场、抑制排气返流现象的两种方案。(4)利用最新一代压力交换制冷机建立全新的实验系统进行实验,以验证两种优化方法的实际效果。通过本文的研究,证明了增长高压入口喷嘴固壁长度以及优化高温出口压力均可以有效地削弱排气返流现象对制冷机性能造成的不利影响,分别使等熵效率提高约4.5%～6.5%和10%～15%。更多还原

【Abstract】 The Pressure Exchanging Refrigerator(PER) is a new generation gas wave refrigeration equipment following the generation-static gas wave machine and the generation-rotating wave refrigerator.It can transfer energy directly between different fluids and actualize expansion refrigeration due to movement of the shock wave,expansion wave and contact discontinuity.It has some superiority such as compact structure,weak oscillation,static jet and working without liquid accumulation compared with rotating gas wave machine,and the application prospect is wide.The study and optimization of incidence efficiency loss and exhaust gas reverse flow problems is done in three ways in this thesis,including the unsteady flow theory of aerodynamics,numerical simulation experiment and physical experiment.(1) A new shock wave model for stable phase of the incident process is put forward.The wave movement in Pressure Exchanging Refrigerator is analyzed in detail with the new shock wave model and the traditional shock tube model,using one-dimensional theory of gas unsteady flow.(2) Study of the relationship between incidence efficiency loss and passage wall structure, nozzle structure,nozzle width,nozzle gap is done.A two-dimensional multi-passage incident numerical model is established to study the relationship between refrigeration efficiency and the structural parameters of passage wall and nozzle,and then some new structures are presented.A three-dimensional multi-passage incident numerical model is established to study leakage flow through the nozzle gap.Furthermore,carry out a detailed analysis by divide leakage flow into six parts.(3) Sets up a new whole machine numerical model with heat exchanging cycle.The numerical simulation studies focus on the reverse compressing wave problem and reverse flow problem,analysis the causes and the impact on work performance of the two problems. Put forward two optimization methods.(4) Establishes new experimental system,to verify the effectiveness of the two optimization methods. The study demonstrates the adverse effects of exhaust gas reverse flow problem can be impaired by increasing the length of the nozzle wall and raising the pressure of high temperature port to get optimum.By using the two optimization methods,the isentropic efficiency can be increased 4.5%～6.5%and 10%～15%.更多还原