【作者】 杨娟娟；

【导师】 吴玉庭；

【作者基本信息】 北京工业大学 ， 热能工程， 2010， 硕士

【摘要】 随着科技的发展,人们在能源和动力、医疗卫生、军事、航空、航天等领域中,对环境温度提出了更高的要求,同时也对制冷装置提出了小型化、轻量化的要求,微型制冷系统适用于特殊环境下的个人冷却和小空间特殊冷却,有着广阔的开发前景。与其他制冷方式相比,蒸汽压缩式微型制冷系统具有高效紧凑的特点。本文采用利用东元电机研发的微型压缩机组装了微型制冷系统,并搭建了微型制冷系统实验台,进行了微型制冷系统的性能试验,获得了制冷剂充注量、环境温度、冷冻水温度、冷冻水流量等参数对制冷系统性能的影响曲线。实验结果表明,该制冷系统的最佳充注量为40g;随环境温度升高,系统耗功率增加,制冷量减小,COP减小;随冷冻水温度升高,系统耗功率减小,制冷量增加,COP迅速增大。随冷冻水质量流量增大,制冷系统压比略有增大,耗功率增加,制冷量增加,COP增大。本文针对450W热负荷无机热管冷凝器建立了传热模型,通过模拟计算得到了冷凝管管径、热管间距、翅片宽度对传热性能及重量的影响曲线,最终选取了最佳参数组合及结构优化方案。计算结果表明将无机热管应用于微型冷凝器可降低冷凝器制冷剂侧的阻力,提高制冷系统的效率。本文建立两种螺旋管式蒸发器的传热模型,对两种模型进行了分析,认为管内走水管外走制冷剂的数学模型可大大提高总传热系数,减小所需螺旋管长度,降低制冷剂侧阻力,尽管水侧阻力增大,但通过选择合适的管径,增大幅度并不大,因此更符合制冷系统的微型化要求。同时本文还进行了一种满足300W冷负荷的微型螺旋管式蒸发器的设计,并给出具体设计过程和蒸发器的结构图,为实际加工提供了方便。更多还原

【Abstract】 With the development of science and technology, people set a higher request to the ambient temperature in the fields such as energy and power, military, aviation, astronautics and so on. With some advantages including compactness, lightness, high performance and cost effectiveness, the miniature refrigeration system can be widely used for personal cooling and high power electronic components cooling. Compared with other cooling methods, vapor compression refrigeration has advantages of high efficiency and compactness.In this paper, a miniature refrigeration system was integrated using miniature compressor developed by TECO Energy, Inc. A testing system was set up and performance experiments of miniature refrigeration system with different operating parameters were conducted. The curves against the refrigerant charging quantity, ambient temperature, chilled water temperature and flux were obtained. Experimental results show that the optimal charging quantity of this cooling system is 40g; with ambient temperature raising, system power consumption increases, cooling capacity decreases, and COP also decreases; with the chilled water temperature raising, system power consumption decreases, cooling capacity increases and COP increases rapidly. With the mass flow of chilled water increasing, cooling system pressure ratio increased slightly, system power consumption decreases, cooling capacity increases and COP increases.In this paper, a heat transfer model of 450W heat load heat pipe condenser was established. The heat transfer performance and mass curves against condensation tube diameter, heat pipe diameter, fin width were obtained by simulation. Ultimately, the best parameter combination and structural optimization design plan were selected. The simulation results show that the heat pipe condenser can reduce the refrigerant side pressure and then improve the efficiency of refrigeration system.In this paper, two types of spiral-tube evaporators heat transfer model were established and analyzed. From the analysis, the mode of that water flowing inside the pipe and refrigerant flowing outside the pipe can greatly increase the overall heat transfer coefficient. Decreasing the length of spiral tube and the pressure of refrigerant side can meet the requirement of designing micro refrigeration system. Meanwhile, one micro spiral-tube evaporator with 300W cooling load was designed and established. To facilitate the practical processing, the detailed designing process and the structure diagram of evaporator were presented.更多还原