The main product of the oxygen station is oxygen, and the energy consumed is mainly electrical energy. Therefore, the energy consumption index of the oxygen generator is usually measured by the electrical energy (kw·h) consumed to produce 1m3 of oxygen (standard state), that is, kW·h/ m3.
The power consumption index is not calculated according to the rated output and the power of the motor, but is determined according to the actual output and power consumption. The unit of motor power is kW, which means it can do 1kJ of work per second; the unit of electrical energy is kW·h, which is the unit of work, 1kW·h=3600kJ. However, a 5000kW motor does not necessarily consume 5000kW·h of electric energy per hour, and must be measured and accumulated by an watt-hour meter. Therefore, energy consumption indicators can be calculated based on the total power consumption and total oxygen production during the statistical period.
Since the oxygen compressor also consumes considerable electric energy, and the pressure of the compressed oxygen of different devices is also very different, therefore, the energy consumption indicators are divided into two types: excluding compressed oxygen energy consumption and including compressed oxygen energy consumption:
1) Oxygen production power consumption: including the air compressor electrical power consumption Wk (kw·h), refrigerating electrical power consumption W1, and other power consumption ∑Wq such as water pumps and electric heaters used for air separation production. The unit power consumption WO (kw·h/m3) for oxygen production is:
In the formula, Vo——Oxygen production during the statistical period, m3
2) The power consumption of compressed oxygen: including the sum of the power consumption Wyo (kW·h) of the oxygen compressor and the power consumption Wyb of the liquid oxygen pump. The unit power consumption of compressed oxygen Wy (kW·h/m3) is:
In the formula, Vyo-gas oxygen pressure delivery volume in statistical period, m3; Vvb-liquid oxygen pressure delivery volume and vaporization volume in statistical period, m3.
3) Comprehensive oxygen power consumption: the power consumption per unit of oxygen production including oxygen production and compressed oxygen. It is usually calculated by dividing the compressed nitrogen and other electricity consumption not related to oxygen production and dividing by the total oxygen production.