| This paper makes a research on the heat transfer in the High Gravity Rotary Device. On the basis of a plentiful datum about the High Gravity Rotary technique and the heat transfer of direct contact , a synthetical anylysis has been reached that the heat transfer in The High Gravity Rotary Field is the direct-contact heat transfer between cold and thermal fluid . The High Gravity Rotary force, a kind of strong centrifugal force ,is produced by fluid circumgyrated in high speed.The High Gravity Rotary force increases the fluid the speed and specific surface area, but dose not flooding. In the curving passageway , the fluid is contacted contranatantly with another fluid by the enormous relative velocity , under the situation of the high disperser and onflow, renewed surface rapidly in very thin fluid film. The fluid is contacted with another fluid under the circumstances of high disperser and onflow, rapidly renewed surface in very thin fluid film, by the enormous relative velocity .In this process, the effective heat transfer area is enlarged, the average difference in temperature increases, and the heat transfer coefficient rises obviously . Therefore, the process of heat transfer and mass transfer is strengthened . This article aims at analysing the heat transfer in contranatant HGRD, establishing mathematical model, and confirming the rationality of model through experiments.Firstly, this paper discusses the quality and thermal being transferred in the direct contact of air - aqueous system, which provides with the direct water cooling made by the hot gas in countercurrent HGRD。the characteristic of inside the padding level is the quality and the thermal reversed transfer. The characteristic of outside padding level is the same direct as the heat and quality transfer.In countercurrent HGRD heat water is used to cool air. On the outside padding level, the heat and quality is transferred simultaneously. It is that the liquid phase changes the gas phase. Characteristic of the inside padding level is a reversed transfer between the heat and quality---the temperature of liquid phase gradually drops from the top to down.Based on this foundation, the entire heat transfer process is also anylysed and obtained the ultimate temperature of outlet water temperature--wet-bulb temperature ,and the ultimate temperature of outlet gas temperature -- the adiabatic saturation temperature ,by using the direct water-cooling of hot air in HGRD.Next, the motion equation of gas phase and the movement model liquid drop is obtained on the foundation of stress analysis of liquid drop.By means of the modelling computation , the mass transfer area was calculated equal to the padding area and the liquid drop surface, and the formula of the area of heat transfers is: a = af +ad. Then through the computer simulation ,we may get the computational methods of the gas and liquid phase in HGRD.According to the movement model of the liquid drop, the heat transfer coefficient model could be obtained according to the motion equation of gas phase and the model of heat transfer area, finally, it can be establishedFinally, the water– air system was chosen as the heat transfer medium to studied the heat transfer by experiment in contranatant HGRD . According to the analysis on experimental datum, it can be known that the height of a (heat) transfer was 0.088～0.023 cm. From the comparison berween the experimental value and theoretical valueof heat transfer overall coefficient, we may obtain that the tendency of curve was consistent, but the value has error. This showed that the model is correct.Lastly, analysis of the influence factor of the heat transfer indicates that the rotational speed was the most tremendous influence factor to the HGRD. Other influence factors (flow rate of cold andhot medium,temperature, etc.) have the same influence tendency compared with the traditional tower, but the tendency change intensifies.This fully proved that the primary factor that strengthen the heat transfer is The High Gravity Rotary Field. |
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