倾斜状态下板翅式换热器封头工质分配特性的实验研究

摘要

Offshore platforms will shake and tilt because of marine motion,which will influence flow distribution in the header of plate-fin heat exchanger. The distribution of pure water/air and air-water two-phase flow in horizontal and tilt state were conducted in the air-water two-phase flow distribution experimental apparatus. The effect of gas-liquid ratio and tilt angle on flow distribution in the header of plate-fin heat exchanger in tilt state were studied. The results show that flow distribution in static state is subject to the influence of the inertial force,and the flow distribution unevenness increases with the increase of the inlet flow and gas-liquid ratio. In tilt state,flow distribution is subject to the influence of both inertial force and gravity,and flow distribution evenness is much lower than the static state. Flow distri-bution unevenness increases with the increase of tilt angle,and is more sensitive to tilt when gas-liquid ratio increases. It is suggested that the header and heat exchanger should be fixed and installed strictly at horizontal/vertical state. Meanwhile the influence of tilt can be e-liminated through the improvement of liquefaction process and heat exchanger design.%海上平台受到海浪的作用会发生晃动和倾斜，从而影响板翅式换热器的入口工质分配特性。通过空气-水两相工质分配实验系统，分别进行封头结构水平状态和倾斜状态下的单相以及气液两相实验，获得不同实验工况下的封头工质分配特性，研究倾斜对封头工质分配的影响，从而为换热器的安装及工艺的改进提供依据。结果表明：水平状态下工质分配受惯性力的影响，不均匀度随雷诺数和气液比的增加而增大；倾斜状态下流体受到惯性力和重力的双重影响，工质分配均匀程度显著低于水平状态，倾斜角越大工质分配越不均匀，气液比越大工质分配受倾斜影响程度越大；固定封头或安装换热器时应严格保证其水平/竖直状态，或者通过液化工艺及换热器设计的改进消除倾斜的影响。