In the field of PSA nitrogen production, the main energy consumption of the nitrogen production system is electricity, and the unit of measuring electrical energy is (kw·h). By dividing the power consumption by the amount of product nitrogen, we can get the energy consumption (kW·h/m3) required by the air separation nitrogen production system to produce 1 cubic meter of nitrogen; this value is often used to measure the production of nitrogen of the same volume of purity. Whether the performance of the nitrogen production system is excellent;

In the nitrogen production system, there is actually not a lot of power consumption, but as an industrial machinery product, it works continuously day and night, and the total power consumption is quite considerable. Is there a way to reduce power consumption without delaying use? Perhaps we can start by analyzing the power consumption in the system to control unnecessary power consumption and save production costs.

We should focus on the air compressor, the major power consumer in the system. Now we use the following formula to present the relationship between air compressor power consumption and pressure ratio:

W=ρvk R′Tln(p2/p1)/(3600nTnM)

The meanings of each parameter in the above formula are as follows:

• ρ--Air density under standard conditions, ρ=1.293kg/m3;

• Vk --discharge volume of air compressor, m3/h;

• R′--gas constant, R′=0.278kJ/(kg·K);

• T --Ambient temperature, K;

• P2 --Exhaust pressure, MPa;

• P1 --Inlet pressure, MPa;

• ηT --Isothermal efficiency of air compressor;

• ηM - Mechanical efficiency of the air compressor.

Through the above relationship, we can see that the unit power consumption of nitrogen production is roughly proportional to the logarithm of the pressure ratio and the purity of nitrogen; it is inversely proportional to the nitrogen extraction rate and the efficiency of the compressor.

Therefore, in terms of energy conservation and environmental protection, the air compressor does not need to pursue excessive pressure, as long as it is enough; and during operation, the compressor should be fully cooled to improve the isothermal efficiency of the compressor; in addition, the nitrogen content should be increased as much as possible Extraction rate; on the premise of ensuring product quality, high-purity nitrogen is not used. These can reduce unit power consumption.

Of course, this is only a directional conclusion. How to quantify these indicators to achieve the purpose of reducing unnecessary power consumption requires further discussion.