Under the threat of serious environmental pollution and resource waste, sustainable development and green manufacturing have gradually become a new development trend. A new environmentally sustainable approach, namely, cryogenic air nanofluid minimum quantity lubrication (CNMQL), is proposed considering the unfavorable lubricating characteristic of cryogenic air (CA) and the deficient cooling performance of minimum quantity lubrication (MQL). However, the heat transfer mechanism of vortex tube cold air fraction by CNMQL remains unclear. The cold air fraction of vortex tubes influences the boiling heat transfer state and cooling heat transfer performance of nanofluids during the grinding process. Thus, a convective heat transfer coefficient model was established based on the theory of boiling heat transfer and conduction, and the numerical simulation of finite difference and temperature field in the grinding zone under different vortex tube cold air fractions was conducted. Simulation results demonstrated that the highest temperature initially declines and then rises with increasing cold air fraction. Afterward, this temperature reaches the lowest peak (192.7 °C) when the cold air fraction is 0.35. Experimental verification was conducted with Ti–6Al–4V to verify the convective heat transfer coefficient model. The results concluded that the low specific grinding energy (66.03 J/mm³), high viscosity (267.8 cP), and large contact angle (54.01°) of nanofluids were obtained when the cold air fraction was 0.35. Meanwhile, the lowest temperature of the grinding zone was obtained (183.9 °C). Furthermore, the experimental results were consistent with the theoretical analysis, thereby verifying the reliability of the simulation model.

在严重的环境污染和资源浪费的威胁下，可持续发展和绿色制造已逐渐成为一种新的发展趋势。考虑到低温空气（CA）的润滑特性不利以及最小量润滑（MQL）的冷却性能不足，提出了一种新的环境可持续方法，即低温空气纳米流体最小润滑量（CNMQL）。然而，由CNMQL产生的涡流管冷空气馏分的传热机理仍不清楚。涡流管的冷空气分数会影响纳米流体在研磨过程中的沸腾传热状态和冷却传热性能。因此，基于沸腾传热理论，建立了对流换热系数模型，并对不同涡流管冷空气分数下磨削区的有限差和温度场进行了数值模拟。仿真结果表明，最高温度随着冷空气分数的增加先下降然后上升。此后，当冷空气分数为0.35时，该温度达到最低峰值（192.7°C）。用Ti-6Al-4V进行了实验验证，以验证对流换热系数模型。结果表明，低比磨削能量（66.03 J / mm 当冷空气分数为0.35时，该温度达到最低峰值（192.7°C）。用Ti-6Al-4V进行了实验验证，以验证对流换热系数模型。结果表明，低比磨削能量（66.03 J / mm 当冷空气分数为0.35时，该温度达到最低峰值（192.7°C）。用Ti-6Al-4V进行了实验验证，以验证对流换热系数模型。结果表明，低比磨削能量（66.03 J / mm^{如图3所示}，当冷空气分数为0.35时，获得了纳米流体的高粘度（267.8cP）和大的接触角（54.01°）。同时，获得了研磨区的最低温度（183.9°C）。实验结果与理论分析相吻合，验证了仿真模型的可靠性。