Expander is the key component of air separation equipment to generate cooling capacity. The working principle is based on the adiabatic expansion of gas. When the high-pressure gas enters the expander, the gas expands rapidly and the pressure and temperature drop sharply under the driving of impeller rotation. This process converts the internal energy of the gas into mechanical energy, and generates a large amount of cooling capacity, providing the necessary low-temperature environment for the subsequent processes such as rectification of the air separation equipment.
The refrigerating capacity of expander is affected by many factors. Expansion is the primary factor. The larger the expansion, the more the gas participating in adiabatic expansion, and the more the cooling capacity generated. In addition, the inlet and outlet pressure difference, inlet temperature and efficiency of expander will also affect the refrigerating capacity. The greater the pressure difference, the higher the inlet temperature, and the higher the expander efficiency, the greater the refrigerating capacity usually increases accordingly.
In the actual operation, the operator shall accurately adjust the operating parameters of the expander, such as nozzle opening, according to the working conditions and cooling capacity requirements of the air separation equipment, so as to control the expansion and cooling capacity, ensure the stability of the liquid oxygen level at the key parts such as the main condenser evaporator, keep the air separation equipment in the optimal operating state, and achieve efficient and stable production.
