【作者】 张杰；

【导师】 胡大鹏；

【作者基本信息】 大连理工大学 ， 化工过程机械， 2011， 硕士

【摘要】 静止式气波制冷机是一种利用气波的膨胀而产生制冷效应的机器,其工作过程可以归纳为：气体经过自激励射流振荡器产生振荡射流,然后该振荡射流对—端封闭的振荡管周期性的射气,入射气体通过气波的膨胀运动将能量传递给管内原有的气体,并通过振荡管的管壁向周围环境散发热量而“冷却”。由于其没有任何的转动部件,只需要简单的静密封,因此特别适合用于高压天然气的加工处理。关于共鸣式气波机的相关报道很少,故本文选用共鸣式振荡器作为研究对象。本文采用数值模拟和实验研究相结合的方法对共鸣式气波制冷机进行研究,主要的工作和结论如下：(1)振荡器是在射流附壁效应的基础上开发出来的,射流的附壁特性是气波制冷机设计时的基础性依据。关于振荡器的附壁特性,本文通过建立振荡器的几何模型,对附壁射流进行数值模拟,结果表明：大的膨胀比反而不利于附壁；在保证稳定附壁的前提下,应尽量采用大喷嘴；相同压比下,位差越大,附壁距离越小(2)射流振荡气波制冷机内的射流应满足：①射流能够稳定振荡；②射流以特定的频率振荡。本文对共鸣式射流振荡气波制冷机进行了整机的模拟与分析,得到了气波制冷机内的流场、压力和速度分布,结果表明：共鸣腔的直径太小时、膨胀比过大或者过小振荡机都不能振荡。此外,振荡机的振荡频率不随共鸣腔参数的改变而改变,只是随共鸣管的管长呈线性变化。本文在共鸣管中加入了突扩段,不过对频率的影响不是很大。(3)射流的振荡特性和制冷效率是制冷机重要的参数。本文采用实验的方法对采用共鸣式射流振荡器的气波机进行了研究,研究的主要内容是通过测量振荡管内的压力波形,分析了气波机的振荡特性；然后通过测量制冷机进口和出口的温度差,计算出其制冷效率。结果表明：振荡机的固有频率只与共鸣管长度有关,与共鸣腔与操作条件无关；制冷效率随着共鸣管的长度和膨胀比的变化而变化,但基本上不随共鸣腔参数的改变而改变。更多还原

【Abstract】 Static gas wave refrigerator is a type of machinery, in which self-induced jet oscillator is used to produce oscillation jet’s periodical injection and come into oscillating tube with one-closed end. Energy is rapidly transferred from the injected gas to the intrinsic gas by way of propagation of those gas wave, which makes the temperature of the intrinsic gas increase and deliver the quantity of heat to the surrounding environment via the oscillating tube wall. The refrigerator has no running part and its seal components are simple. So its application is appropriate for the condition of high pressure. However, the research of the resonant gas wave refrigerator is few and far between theory and experiment. So, in this paper, the resonant oscillator is studied and used into the gas wave refrigerator.The numerical simulation and experiments are conducted to investigate the flow and thermal of the refrigerator and validate the results, including:(1) The oscillating apparatus is based on the theory of jet’s wall-attaching effect which is also called Coanda effect, the performance of wall-attaching is the essential data for designing the gas wave refrigerator. To research on the property of the wall-attaching, numerical models were established and numerical analysis was applied to validate the results, including:it is not conducive to jet flow wall-attached to increase the expansion ratio; with the condition of oscillating, wide nozzle is welcome; the distance of wall-attached is longer as the smaller potential difference.(2) Within the gas wave refrigerator, the jet flow should oscillate with a certain range of frequency. In this paper, the resonant gas wave refrigerator was simulated numerically in integery, and the emphasis is mainly established in analysis on the pressure change of the gas in the oscillating tube, and the velocity distribution. The influence of operating parameter (e.g. pressure ratio) and geometry parameters (e.g. resonant cavity diameter and resonant tube) on the flow wall-attachment effect was studied. In order to understand oscillating frequency of gas wave refrigerator with different resonant line lengths and structure, the simulation was did.(3) The oscillation performance of jet, as oscillating frequency and refrigeration efficiency are the essential factor for the gas wave refrigerator. To analyze these how effect, an experimental equipment was set up and applied in the research on the wave movement within the receiving tube and the temperature of inlet and outlet. The oscillating frequency of the gas wave refrigerator is connected with the resonant tube, be independent of the resonant cavity and the operating condition. However, the refrigeration efficiency has the relationship with the resonant tube and the operating condition.更多还原