低真空度下土工离心机产热机理试验研究

目的为1000 g以上的大型高速土工离心机提供散热方案,保证土工离心机的正常工作。方法通过试验研究和理论分析相结合的方法,研究低真空度下高速转子的产热机理,分析散热模式。结果绝对压力越高,离心室内的升温速度越快。不同真空度下(绝对压力10000、5000、3000、2000、1000 Pa),离心机驱动电机的输入功耗分别为2.17、3.79、5.17、7.66、11.56 kW。超重力高速土工离心机的产热主要由空气与高速转子的摩擦引起的第一热源,由高速旋转空气与离心舱壁面摩擦产生的第二热源,还有其他机构摩擦、空气与底部顶部摩擦产生的少量热源。结论第一热源产生的壁面热量可以通过设置冷却夹套快速带走,离心舱中心产生的第二热源的热量可以通过通入适量的冷风加以冷却,还可以通过注入冷却剂快速蒸发,利用汽化潜热进行快速冷却。

Experiment of Heat Generation Mechanism of GeotechnicalCentrifuge under LowVacuum Degrees

The work aims to provide heat dissipation solution for the large-scale high-speed geotechnical centrifuge of over 1,000 g, so as to ensure its normal operation. The heat generation mechanism of high-speed rotor under low vacuum was studied and the heat dissipation mode was analyzed in combination with experimental research and theoretical analysis. The higher the absolute pressure, the faster the temperature rise in the centrifugal chamber. The input power consumption of centrifuge''s driving motor was respectively 2.17, 3.79, 5.17, 7.66 and 11.56 kW under different vacuum (absolute pressure of 10,000, 5,000, 3,000, 2,000 and 1,000 Pa). The heat of super-gravity high-speed geotechnical centrifuge was mainly generated by the first heat source from the friction of air and high-speed rotor, the second heat source from the friction of high-speed rotated air and the centrifugal tank wall, and a small amount of heat from the friction of other mechanism and the friction of air and bottom/top. The wall heat generated by the first heat source can be quickly taken away by arranging a cooling jacket, the heat of the second heat source generated in the center of the centrifugal tank can be cooled by introducing an appropriate amount of cold air, and can also be rapidly evaporated by injecting a coolant and rapidly cooled with latent heat of vaporization.