窄通道内去离子水的沸腾换热特性实验研究

为了研究矩形窄通道内流动沸腾表面换热系数的影响因素，建立了竖直矩形窄通道流动沸腾传热实验装置，研 究了尺寸为720 mm x250 mm x3.5 mm窄通道内离子水的流动沸腾换热特性。采用单侧壁面加热，改变加热热流密度； 调节恒温水箱温度，改变工质入口温度；以蠕动泵为动力，改变泵的转速，改变工质流量。实验结果表明：入口温度对流 动沸腾表面换热系数基本无影响；流体的紊流度随着质量流量的增加而增加，从而加强了对流换热的强度；在对流沸腾 换热阶段，核态沸腾受抑制，表面换热系数随着加热功率的增大反而降低；在完全对流换热阶段，表面换热系数随着加热 功率的增大基本不变。该研究为更好地设计板式换热器提供了依据。

Boiling Heat Transfer Characteristics of Deionized Water in Narrow Channel

ln order to study the factors affecting the flow boiling heat transfer coefficient in a narrow rectangular channel to design climbing film plate heat exchanger , a vertical rectangular narrow channel flow boiling heat transfer experimental device was set up. The flow boiling heat transfer characteristics of deionized water was studied, and the size of the channel is 720 mm x 250 mm x 3.5 mm. The wall on one side was heated to change the heating heat flux. The thermostat tank''s temperature was adjusted to change the inlet temperature. A peristaltic pump was used as the driving force, and the mass flow rate was adjusted by changing the pump''s speed. The results show that. the inlet temperature has a small effect on the flow boiling surface heat transfer coefficient. The turbulence increases with mass flow''s increasing, and it enhances the strength of the convection heat transfer. In the stage of convective heat transfer. the nucleate boiling is restrained, and the surface heat transfer coefficient gradually decreases with the heating power increases. In the stage of fully convective heat transfer, the surface heat transfer coefficient almost unchanges as the heating power increases. The study is helpful to design plate heat exchanger.