Heat exchanger channel structure for liquid air separation plant

The air in nature is not absolutely dry, and a certain amount of gaseous water vapor is always mixed inside, which is a conventional part of air. Under normal pressure and normal temperature, water vapor is evenly dispersed in the air and will not condense into liquid water, so we cannot directly observe water. In the air separation operation, the air is first compressed by the air compressor. After the air is compressed, the volume is greatly reduced, and the density of water vapor in unit space increases sharply. At the same time, the saturated water content of air will change with the increase of pressure. Under high pressure, the upper limit of water vapor contained in air tends to be fixed. When the water vapor content exceeds the saturation value corresponding to the pressure, the air will reach the supersaturated state, which has the basis of water precipitation. The air compression process will generate a lot of heat, and the high temperature environment can temporarily improve

In the operation of the air separation unit, the superheat of the expanded air sent to the upper column is a key parameter affecting the stability of distillation conditions and product purity. The fluctuation of superheat will directly change the gas-liquid load and mass transfer efficiency of the upper column, and then affect the distillation effect and energy consumption of the unit. If the superheat of the expanded air is too high, the gas entering the upper tower will carry a large amount of excess heat, which will significantly increase the gas phase temperature in the tower and aggravate the consumption of cooling capacity in the tower. This will lead to the decrease of reflux ratio in the distillation section of the upper column, insufficient gas-liquid two-phase contact, and poor mass transfer and heat transfer efficiency. At the same time, the increase of superheated gas will raise the rising gas flow in the tower and destroy the balance of distillation conditions, resulting