Abstract

In order to determine the convective heat transfer coefficient of liquid nitrogen during cryogenic cooling, this paper uses a combination of temperature simulation and cryogenic cooling experiments to study the cooling rate and the liquid-gas scale affected by the four jet parameters for cooling the Ti-5553 and cemented carbide WC-Co plates in cryogenic liquid nitrogen cooling, then establishes a prediction model of convective heat transfer coefficient and verifies the accuracy of the convective heat transfer coefficient model by cutting temperature simulation and cutting experiments. The results of experimental research show that the larger the nozzle diameter, the larger the spray pressure, the smaller the spray angle, the smaller the spray distance, and the greater the cooling rate of the sheet surface. The order of the influence of the jet parameters on the convection coefficient is spray diameter Φ, injection pressure P, jet angle A, and standoff distance D.

摘要

为确定液氮在低温冷却过程中的对流换热系数，本文采用温度模拟和低温冷却实验相结合的方法，研究了四种射流参数对Ti- 5553和硬质合金WC-Co板在低温液氮冷却下，建立了对流传热系数预测模型，并通过切削温度模拟和切削实验验证了对流传热系数模型的准确性。实验研究结果表明，喷嘴直径越大，喷射压力越大，喷射角度越小，喷射距离越小，板面冷却速度越大。Φ、注射压力P、喷射角A和间隔距离D。