Abstract The improper post milking handling and storage results in a complete wastage due to the microorganisms and bacterial multiplication present in raw milk. The torque load minimalizing in the chilling unit using a solar photovoltaic (PV) is indeed a challenging task for the smooth functioning of the milk chilling system especially for the conventional (reciprocating) type of compressors. The variable refrigerant flow (VRF) technology not only solves the toque load problem but also reduces the size of peak power requirement of PV array. The present study enables the design of an improved solar chilling system consists of a chilling tank (200 L capacity) coupled with one tonne of refrigeration unit powered by PV panels (2 kWp) and employing VRF technology to make system more energy efficient by reducing the torque load. Experiments were conducted using different batch sizes (50, 100, 150 and 200 L) to decrease the raw milk temperature from 30 °C to 4 °C. During optimization phase the comparative power required to run various types of compressors (reciprocating, rotary with capacitor and rotary with VRF) were found to be 1.8 kW, 1.2 kW and 0.8 kW, respectively whereas the torque loads were noted to be 3.3 kW, 1.6 kW and zero kW for respective compressor type. The experimental and modeled predicted power consumption and chilling time under different batch sizes revealed excellent correlation coefficient (R2 = 0.99, P

中文翻译：

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使用可变制冷剂流量技术 (VRF) 改进太阳能牛奶冷却系统

摘要 由于原料奶中存在微生物和细菌繁殖，不正确的挤奶后处理和储存会导致完全浪费。在使用太阳能光伏 (PV) 的冷却装置中最小化扭矩负载对于牛奶冷却系统的平稳运行来说确实是一项具有挑战性的任务，尤其是对于传统的（往复式）压缩机。可变制冷剂流量 (VRF) 技术不仅解决了转矩负载问题，还降低了光伏阵列峰值功率需求的规模。本研究能够设计出一种改进的太阳能冷却系统，该系统由一个冷却罐（200 升容量）和一吨由光伏电池板（2 kWp）供电的制冷装置组成，并采用 VRF 技术通过减少能耗使系统更加节能。扭矩负载。使用不同的批次大小（50、100、150 和 200 L）进行了实验，以将原料奶温度从 30 °C 降低到 4 °C。在优化阶段，运行各种类型的压缩机（往复式、带电容器的旋转式和带 VRF 的旋转式）所需的比较功率分别为 1.8 kW、1.2 kW 和 0.8 kW，而扭矩负载则为 3.3 kW、1.6对应压缩机类型的 kW 和零 kW。不同批次大小下的实验和建模预测功耗和冷却时间显示出极好的相关系数（R2 = 0.99，P 发现带有电容器的旋转和带有 VRF 的旋转）分别为 1.8 kW、1.2 kW 和 0.8 kW，而对于相应的压缩机类型，扭矩负载分别为 3.3 kW、1.6 kW 和 0 kW。不同批次大小下的实验和建模预测功耗和冷却时间显示出极好的相关系数（R2 = 0.99，P 发现带有电容器的旋转和带有 VRF 的旋转）分别为 1.8 kW、1.2 kW 和 0.8 kW，而对于相应的压缩机类型，扭矩负载分别为 3.3 kW、1.6 kW 和 0 kW。不同批次大小下的实验和建模预测功耗和冷却时间显示出极好的相关系数（R2 = 0.99，P