To achieve zero temperature difference at the hot end, it is impossible to make the heat exchanger infinitely large. When designing an air separation equipment, a comprehensive consideration is given to the investment and economic operation of the equipment, and it is designed based on the selected temperature difference at the hot end.
In actual operation, the heat transfer area of the heat exchanger has already been fixed. If the temperature difference at the hot end increases, specific analysis is needed for different processes and heat exchanger structures.
The main reason for the decrease in heat transfer performance of the main heat exchanger in the molecular sieve adsorption process is mainly due to improper operation of the adsorber. This situation is often accompanied by an increase in the resistance of the heat exchanger. At this point, it is necessary to warm and purge the main heat exchanger in order to restore it to normal.
When the temperature of the air entering the air separation equipment rises abnormally, to cool the gas to a certain temperature, more heat needs to be released in the heat exchanger. The heat transfer area of the heat exchanger is fixed, which can only be achieved by expanding the heat transfer temperature difference, manifested in an increase in the temperature difference at the hot end. The temperature difference between the hot end of oxygen and air varies greatly from the designed temperature to the actual temperature. At this point, the reason for the temperature increase of the air entering the tower should be checked and eliminated.
One of the reasons for the increase in temperature difference at the hot end of a switching heat exchanger is the excessive cooling capacity of the backflow gas. At this point, the circulation or extraction volume should be adjusted appropriately.
DEAR Air Separation is continuously expanding its professional technical team to provide customers with high-quality air separation industry solutions for air separation equipment construction projects.
