超临界压力下乳化碳氢燃料换热特性实验研究

Experimental Study of the Heat Exchange Characteristics of an Emulsified Hydrocarbon Fuel Under Supercritical Pressures

为研究乳化碳氢燃料在矩形通道内的换热特性,在压力为3 MPa,质量流量为2.6 g/s,出口流体温度分别为450、500、550、600和650℃,乳化碳氢燃料含水质量分数分别为10%、20%、30%和50%的实验条件下,进行了实验研究,分析了乳化碳氢燃料的含水质量分数与出口流体温度对燃料在矩形通道内的热沉、热流密度与对流换热系数的影响,并与纯碳氢燃料作对比。研究表明：燃料在通道内热沉与热流密度均随含水质量分数与出口流体温度的增加而增加;纯碳氢燃料在通道内的对流换热系数沿轴向逐渐增加;乳化碳氢燃料在通道内会发生传热恶化,第一次传热恶化点随出口流体温度的增加向通道入口方向移动;含水质量分数越高,第一次传热恶化发生越早,第二次传热恶化发生越晚。

To study the heat exchange characteristics of an emulsified hydrocarbon fuel in a rectangle channel, under the test conditions of the pressure being 3 MPa, the mass flow rate equaling to 2.6 g/s, the temperature of the fluid at the outlet being 450,500,550,600 and 650 ℃ respectively and the water content of the emulsified hydrocarbon fuel being 10%, 20%, 30% and 50% respectively, an experimental study was performed to analyze the influence of the water content and the temperature of the fluid at the on the heat sink, heat flux density and convection heat exchange coefficient of the fuel in the rectan- gle channel and compare them with those of the pure hydrocarbon fuel. It has been found that the heat sink and heat flux density of the fuels in the channel will all increase with an increase of the water content and the temperature of the fluid at the outlet. The convection heat exchange coefficient of the pure hydrocarbon fuel will gradually increase along the axial direction in the channel while the emulsified hydrocarbon fuel will force the heat transfer in the channel to get worsened. The first heat transfer deterioration point will shift to the inlet of the channel with an increase of the temperature of the fluid at the outlet. The higher the water content, the earlier the first heat transfer deterioration occurs and the later the second heat transfer deterioration occurs.