煤粉加压气化炉膜式螺旋管和蛇形管对流传热特性研究

Heat Transfer Characteristics of Different Heat Transfer Structures in Gasification Convective Syngas Cooler

对煤粉加压气化炉对流段的不同换热结构进行了换热特性的实验研究,其中换热结构包括膜式螺旋管环形通道换热器和膜式蛇形管平行通道换热器,实验气体为单质气体N2、He及其混合气,实验压力为0.5～3.5MPa.为此,针对不同冲刷形式、不同气体和压力提出了换热器换热系数及其扩展的计算方法,同时给出了典型冲刷形式的对流换热的关联式和适用条件.实验研究表明:冲刷形式对换热系数有很大影响,单通道和多通道换热系数与换热面积之间呈加权平均的关系;在相同换热条件下,膜式螺旋管环形通道换热器的换热系数高于膜式蛇形管平行通道换热器.

An experiment was conducted to study the heat transfer characteristics for a convection cooling section with the different heat transfer structures at high temperature and pressure in a coal pressurized gasifier. The heat transfer structures included an annular channel heat exchanger with membrane spiral tubes and a parallel channel heat exchanger with membrane serpentine tubes. In this study, the high pressure single gas （He or N2） and mixture gas （He＋N2） were used to replace the high pressure syngas, and the test pressure for each gas was from 0.5 MPa to 3MPa. The heat transfer coefficients and extension method under different working pressure, gas composition and flow forms were presented. The correlations of the typical flow forms and their applicable condition were obtained. The results show that flow form greatly influenced the heat transfer coefficient of the high pressure gas convection. The heat transfer coefficients of the single annular channel heat exchanger and multi-annular channel heat exchanger displayed the areaweighted average relation. In addition, the heat changer with membrane spiral tubes was higher heat transfer conditions. transfer capacity of the annular channel heat exthan that of the parallel channel under the sameheat transfer conditions.