This work is aimed at investigating the effects of the refrigerant charge, expansion device restriction, compressor speed, and their interactions on the performance of a household refrigerator. To this end, a micrometric valve was installed in series with the capillary tube of a frost-free refrigerator to vary the expansion restriction within a range equivalent to capillary tubes with inner diameters spanning from 0.55 to 0.85 mm. The refrigerant charge was manually changed from 35 to 65 g whereas the compressor speed was adjusted between 2500 and 4500 rpm. In total, 294 steady-state energy consumption tests were conducted, being 147 at a surrounding temperature of 32 °C, and the rest at 16 °C. It was noticed that low energy consumptions can be achieved for several combination of refrigerant charge and expansion restriction, albeit the minimal energy consumption figures were always achieved for the highest charges and restrictions. It was also verified that the refrigerator operates in a sub-optimum region so that increasing the charge from 42 g to 52 g while decreasing the capillary tube diameter from 0.64 mm to 0.60 mm led to a 3% decrease on the energy consumption. It was also found that a single combination of refrigerant charge and equivalent diameter provided satisfactory performance levels regardless of the compressor speed. Finally, a method to reduce the number of tests was proposed, in such a way that only 9 datapoints are required to generate a full energy consumption map for a given compressor speed and surrounding temperature.

这项工作旨在调查制冷剂充注量、膨胀装置限制、压缩机速度及其相互作用对家用冰箱性能的影响。为此，将测微阀与无霜冰箱的毛细管串联安装，以在相当于内径为 0.55 至 0.85 毫米的毛细管的范围内改变膨胀限制。制冷剂充注量从 35 克手动更改为 65 克，而压缩机速度在 2500 到 4500 rpm 之间调整。总共进行了 294 次稳态能耗测试，其中 147 次在环境温度为 32°C，其余为 16°C。注意到可以通过制冷剂充注和膨胀限制的几种组合来实现低能耗，尽管最高的收费和限制总是达到最低的能源消耗数字。还验证了冰箱在次优区域运行，因此将装料从 42 克增加到 52 克，同时将毛细管直径从 0.64 毫米减少到 0.60 毫米，能耗降低了 3%。还发现，无论压缩机速度如何，制冷剂充注和等效直径的单一组合都能提供令人满意的性能水平。最后，提出了一种减少测试次数的方法，通过这种方式，只需 9 个数据点即可针对给定的压缩机速度和环境温度生成完整的能耗图。还验证了冰箱在次优区域运行，因此将装料从 42 克增加到 52 克，同时将毛细管直径从 0.64 毫米减少到 0.60 毫米，能耗降低了 3%。还发现，无论压缩机速度如何，制冷剂充注和等效直径的单一组合都能提供令人满意的性能水平。最后，提出了一种减少测试次数的方法，通过这种方式，只需 9 个数据点即可针对给定的压缩机速度和环境温度生成完整的能耗图。还验证了冰箱在次优区域运行，因此将装料从 42 克增加到 52 克，同时将毛细管直径从 0.64 毫米减少到 0.60 毫米，能耗降低了 3%。还发现，无论压缩机速度如何，制冷剂充注和等效直径的单一组合都能提供令人满意的性能水平。最后，提出了一种减少测试次数的方法，通过这种方式，只需 9 个数据点即可针对给定的压缩机速度和环境温度生成完整的能耗图。还发现，无论压缩机速度如何，制冷剂充注和等效直径的单一组合都能提供令人满意的性能水平。最后，提出了一种减少测试次数的方法，通过这种方式，只需 9 个数据点即可针对给定的压缩机速度和环境温度生成完整的能耗图。还发现，无论压缩机速度如何，制冷剂充注和等效直径的单一组合都能提供令人满意的性能水平。最后，提出了一种减少测试次数的方法，通过这种方式，只需 9 个数据点即可针对给定的压缩机速度和环境温度生成完整的能耗图。