AN INVESTIGATION OF THE ENHANCEMENT OF HEAT TRANSFER AS QUICK COOLING OF THE HEATED PLATE

在用冷却剂冷却热板的情况下，当加热到高温时，热板上覆盖着蒸汽层。因此，通过蒸汽层的热阻来减少热板的换热。本研究的目的是通过对蒸汽层的扰动，找出强化传热的方法，以提高加热板的冷却效果。(1)对气液界面化学性质的关系和稳定性的影响，气液界面的振动受液体界面张力的影响。气-液界面动力学不稳定性理论对界面张力的影响提出了一些建议。在冷却剂(水)中加入表面活性剂对界面张力影响的实验研究。实验表明，表面活性剂的加入对蒸汽层的存在有有利的影响。在添加表面活性剂的情况下，膜沸腾维持在低热流区，汽层已经存在了任意时间。虽然我们最初预计较低的界面张力会加速液体与热板表面的接触。(2)关于热板表面粗糙度的影响，我们研究了热板表面粗糙度的影响，发现较大的表面粗糙度或表面的污染物使冷却剂与表面更容易接触。特别是覆盖在板材上的金属丝网干扰了蒸汽膜层的存在。

In case of cooling of hot plate by the coolant, the hot plate is covered with the vapor layr when it was heated to high temperature. Consequently, the reduction of heat transfer from the hot plate is produced by means of the thermal resistance of vapor layr. The object of our investigation is to find the meth- ods of the enhancement of heat transfer by making of disturbance to the vapor layr and to increase the cooling effects of the hot plate.(1) On the ralation of the chemical properties and the stability of the liquid-vapor interfaceThe vibration of liquid-vapor interface is affected by the interfacial tension of liquid. The kinetic instability theory of liquid-vapor interface gives some suggestions an influence of the interfacial tension. An experimental investigation of the effects of interfacial tension carried out by addition of a surface active agent into the coolant (water). It has been definitely shown by experiments that the addition of a surface active agent has a favorable influence upon the existence of vapor layr. In case of addition of a surface active agent, the film boiling are maintaining at low heat flux region and the vapor layr has been existed for any length of time. Although we expected initialy that an lower interfacial tension accelerates the touch of the liquid to the hot plate surface.(2) On the effect of the hot plate surface roughnessWe have investigated the effect of sourface roughness of hot plate and found that large roughness or contaminations on sourface made easy to contact of coolant and surface. The metal wire nets covered on the plate, especially, disturbed the existence of the vapor film layr.