Device and method for lowering wind resistance power for large geotechnical centrifuge

Abstract

The invention discloses a device and method for lowering wind resistance power for a large geotechnical centrifuge. A semicircle pipe cylindrical cooling device is arranged between the inner side of acylindrical barrel and a high-speed rotor system. A snakelike top semicircle pipe cooling plate is arranged over a hanging basket. The tope center is provided with an air return opening. Helium in ahelium storage tank enters a centrifugal bin from a lower seal plate through helium outlets in a plurality of helium inlet pipes. The helium is adopted for replacing air in the centrifugal bin, so that wind resistance power and corresponding energy consumption are lowered. A vacuum is not needed, so that the sealing requirements are lower. Radiating equipment is arranged in a centrifugal bin cavity, a helium inner circulation wind channel is added, the heat exchange coefficient is increased, and the radiating effect is improved. A special vibration isolation seal pad is adopted, vibration transmitted by a spindle to an upper bearing system support device is isolated from the centrifugal bin cavity, thus resonance of the cavity and the spindle is avoided, and safety of the centrifugal bin cavity is ensured. During operation under gravitational acceleration below 1500 g, economy is good, and temperature can be controlled below 45 DEG C.

Description

technical field [0001] The invention relates to a technology for reducing wind resistance power of a centrifuge, in particular to a device and method for reducing wind resistance power of a large geotechnical centrifuge. Background technique [0002] The large-diameter, high-acceleration, high-gravity geotechnical centrifuge is an indispensable device for the reproduction test of geological evolution processes such as rock-soil evolution, geological structure evolution, and geological disaster restoration. With the continuous increase of the acceleration g, the wind resistance power of the centrifuge also increases sharply. According to the current domestic and foreign wind resistance power estimation method, the wind resistance power formula is N w =ρA 1 ω 3 B 1 This form, where A 1 and B 1 are the coefficients related to the shape and geometric size respectively, and its power is proportional to the air density ρ, and is proportional to the high-speed rotor speed ω 3...

AI Technical Summary

Problems solved by technology

However, when the acceleration of the centrifuge or the load of the rotor further increases, the heat generated in the centrifuge chamber will further increase. At this time, cold air cooling combined with cold water cooling cannot meet the heat dissipation requirements.

In order to solve this problem, the most effective way is to reduce the air density ρ. The traditional method is to evacuate the centrifuge chamber to reduce the density of the air to reduce the frictional heat between the arm and the air, but after evacuating, it will cause other problems. One is that due to the thin air molecules in a vacuum state, the heat transfer capacity is also greatly reduced, and the air cannot convect in a vacuum state. Therefore, the heat caused by the friction between the arm and the air caused by the temperature rise of the arm cannot be effectively transferred out; another problem The bearings of the centrifuge under high vacuum will leak oil, and the sealing around the centrifuge chamber will become difficult, so the vacuum degree should not be too high; vacuuming will also greatly increase the cost of the centrifuge chamber

[0004] At present, the patents related to the heat dissipation of the geotechnical centrifuge test chamber mainly include CN201210056367.6 "Spray water curtain cooling device for the geotechnical centrifuge test chamber" by Liu Guogui, Zhejiang University, etc. The method of heat dissipation is very effective, but when the acceleration increases to more than 500g, the purpose of heat dissipation and temperature control cannot be achieved only by water cooling; ZL201910350086.3 "Ultra-high gravity geotechnical centrifugal device vacuum chamber "Body structure" adopts vacuuming of the vacuum chamber to reduce the air density, combined with the built-in cooling system to achieve temperature control, which is very effective for geotechnical centrifuges above 1000g

However, it is applied to geotechnical centrifuges below 1000g, and there is no report in domestic and foreign literature

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