Adjusting the inlet or outlet pressure of the air separation equipment can change the flow velocity and distribution of gas inside the equipment. By adjusting the pressure distribution inside the distillation tower, gas-liquid equilibrium can be optimized. Controlling the air cooling temperature can alter the degree of gas liquefaction. By adjusting the temperature distribution in each section of the distillation tower, the gas separation efficiency can be optimized. Adjusting the airflow entering the device can alter the gas concentration and separation efficiency. By adjusting the extraction flow rate of oxygen, nitrogen and other products, the gas distribution inside the tower can be indirectly affected.
Reflux ratio is a key parameter for distillation tower operation. By adjusting the liquid nitrogen throttle valve to control the reflux liquid volume in the lower tower, the purity of liquid nitrogen can be directly affected. The stability of the liquid level in the distillation tower is crucial for gas separation. Fluctuations in tray pressure can affect gas-liquid equilibrium. The intake adjustment of the turboexpander can change the cooling capacity. Appropriately discharging some liquid oxygen can consume some cooling capacity, but it is necessary to ensure that the liquid oxygen level is not lower than the safe value. Opening the blow off valve at the bottom of the heat exchanger can remove some of the supercooled liquefied air, which helps regulate the cooling capacity.
When the argon fraction does not meet the requirements (such as excessive nitrogen content), the oxygen supply valve can be turned down and the nitrogen discharge valve can be turned up to raise the argon rich zone in the distillation section and reduce the nitrogen content in the argon fraction; At the same time, the oxygen content increases while the argon content decreases. If the argon content in the fraction is too low, turn down the liquid nitrogen regulating valve and increase the nitrogen discharge purity to increase the argon content in the fraction.
When the demand for oxygen and other products decreases, variable load operation is required to save energy consumption. By adjusting the pure liquid nitrogen reflux valve of the lower tower, the pressure at the bottom of the lower tower is kept basically unchanged.
