Adelekan D S, Ohunakin O S, Oseahon O I, Nekabari F N, Nkiko M O, Odunfa M K
The Energy and Environment Research Group, Covenant University, Ogun State, Nigeria.
Department of Physical and Chemical Sciences, Elizade University, Ilara Mokin, Nigeria.
Heliyon. 2023 Oct 12;9(10):e20832. doi: 10.1016/j.heliyon.2023.e20832. eCollection 2023 Oct.
The issues of flammability associated with A3-class hydrocarbon-based refrigerants are controllable by limiting their mass charges. However, these reductions in their mass charge below certain limits deteriorate their performance efficiency. In this experimental study, we analyzed the effects of a liquid line magnetic field (Mag), multi-wall carbon nanotube (CNT) nano-lubricant, and the combination of both (Mag-Nano) on the performance of a very low mass charge (i.e., 30 g) of R600a and LPG refrigerants, as a replacement to the 100 g R134a refrigerant in a domestic refrigeration system. The refrigerants were tested with and without CNT nano-lubricant (pure), two pairs of 3000 Gs liquid line mounted O ring N50 permanent magnets (Mag), 0.2 g/L concentration of CNT nano-lubricant (Nano), and in combination with a liquid line magnetic field and CNT nano-lubricant (Mag-Nano). The performance evaluation of the refrigerants includes the determination of coefficient of performance (COP), evaporator air temperature, volumetric refrigeration capacity, instantaneous power consumption, cumulative energy consumption, and energy cost. A reduction in the COP of R600a and LPG was observed to be about 11-42% and 14-26%, respectively, when compared to R134a. The R134a refrigerant had the lowest evaporator air temperature of -24.5 °C and the highest instantaneous power consumption of 74.6 W. The R600a-Mag-Nano refrigerant is the most efficient option, having the lowest instantaneous power consumption, energy cost, and cumulative energy consumption. The adoption of hydrocarbon refrigerants is more cost-effective than using the R134a refrigerant, resulting in a cost saving of about 8-26%. In conclusion, the proposed methods adopted to enhance the performance of refrigeration system, are very safe and effective.
与A3类碳氢化合物制冷剂相关的可燃性问题可通过限制其充注量来控制。然而，当这些制冷剂的充注量降低到一定限度以下时，其性能效率会变差。在本实验研究中，我们分析了液管磁场（Mag）、多壁碳纳米管（CNT）纳米润滑剂以及两者的组合（Mag-Nano）对非常低充注量（即30克）的R600a和LPG制冷剂性能的影响，以替代家用制冷系统中100克的R134a制冷剂。对制冷剂进行了有无CNT纳米润滑剂（纯态）、两对安装在液管上的3000高斯O形环N50永久磁铁（Mag）、0.2克/升浓度的CNT纳米润滑剂（Nano）以及液管磁场与CNT纳米润滑剂组合（Mag-Nano）的测试。对制冷剂的性能评估包括性能系数（COP）、蒸发器空气温度、容积制冷量、瞬时功耗、累计能耗和能源成本的测定。与R134a相比，R600a和LPG的COP分别降低了约11%-42%和14%-26%。R134a制冷剂的蒸发器空气温度最低，为-24.5°C，瞬时功耗最高，为74.6瓦。R600a-Mag-Nano制冷剂是最有效的选择，具有最低的瞬时功耗、能源成本和累计能耗。采用碳氢化合物制冷剂比使用R134a制冷剂更具成本效益，可节省约8%-26%的成本。总之，所提出的用于提高制冷系统性能的方法非常安全有效。
