Abstract:

The flow and temperature distributions of coke oven gas (COG) in the salt-bath structure heat exchanger were investigated by numerical simulation and actual dynamic test. The variations of the temperature in the heat exchanger and the velocity of COG were obtained. The results showed that the COG was in the entrance region of laminar flow. The temperature of COG decreased sharply near the inner cylinder wall and the straight fins which welded on the wall, and the temperature gradient was small in the center of the heat exchanger along the radial direction. The temperature of the straight fins presented the higher tendency at the bottom and lower at the upper part along the axial direction, higher at the fin-top and lower at the fin-root along the radial direction at the same height. The temperature of inner cylinder wall in the heat exchanger could be controlled during the test, which could avoid a large amount of condensation from tar vapor in COG.

Key words: heat exchanger in ascension pipe of coke oven, salt-bath structure, coke oven gas, laminar flow, heat transfer, numerical simulation

摘要：

通过数值模拟及实际动态试验，研究了盐浴结构焦炉上升管换热器内的温度场和荒煤气流场，得到了换热器内温度和荒煤气速度的变化规律。研究结果表明，上升管换热器内荒煤气的流动处于层流入口段状态；沿上升管换热器径向，荒煤气温度在内筒壁及其扩展的直翅片附近迅速下降，在中心处的变化较小；直翅片的温度场呈现下部高、上部低、翅顶高、翅根低的趋势；整个炼焦周期内，上升管换热器的内筒壁温可控，可避免荒煤气中焦油蒸气的大量凝结。

关键词: 焦炉上升管换热器, 盐浴结构, 荒煤气, 层流, 传热, 数值模拟