Detailed introduction of air compressor equipment and units in petrochemical industry

In petrochemical enterprises, for the three units of oil refineries (smoke, main fan, air pressure and hydrogen compressor), the five units of fertilizer plants (air compressor, synthesis gas, ammonia compressor, CO2, raw gas or nitrogen pressure) The three units (pyrolysis gas, ethylene, propylene) of the ethylene plant are customarily called large units or key units. Almost all of these large units are composed of centrifugal (or axial flow) compressors driven by industrial steam turbines. They have the characteristics of high speed, high power, technology-intensive, expensive, no spare machines, and long overhaul periods. In the event of equipment failure and shutdown for maintenance, the entire production plant will be completely shut down (or a substantial reduction in production), and the economic loss of the enterprise will be very serious. Generally, the direct economic loss of a major equipment accident (such as rotor damage) is about one million yuan or more, and the indirect economic loss (loss of device output and loss of starting and parking) is about tens of millions of yuan. Therefore, petrochemical companies attach great importance to the management and maintenance of large units and realize that it is worthwhile to spend money on improving the status monitoring and fault diagnosis level of large units.

  1 Oil refining plant

In the oil refining unit, the catalytic unit has a main fan unit (also called a three-unit, a four-unit, and a hood) and a pneumatic unit, and a continuous reformer, hydrogenation unit, diesel hydrogenation unit and other devices include a new hydrogen compressor unit and Circulating hydrogen compressor unit, coking unit has air compressor unit, power unit has steam turbine generator unit, air compressor unit, nitrogen compressor unit, public works have cooling tower fan, circulating water pump, storage and transportation device has dry gas compressor Crew and so on.

  2 Fertilizer plant

In the fertilizer plant, air compressors, synthesis gas compressors, ammonia compressors, CO2 compressors are indispensable units, gas head plants also have raw gas compressors, and coal head plants may have nitrogen compressors. .

  3 Ethylene Plant

Among the three major units of the ethylene plant, the pyrolysis gas compressor has the highest power and the most complex structure. It is similar to a synthetic gas unit for chemical fertilizers. It is driven by a high and medium pressure turbine to drive a compressor composed of high, medium and low cylinders. Lean units are mostly one-cylinder compressors driven by steam turbines.

  The following Xiaoqi focuses on the typical compressor unit in the refinery and chemical plant

  Compressor classification and characteristics commonly used in refinery and chemical plants

  Compressors commonly used in oil refineries can be basically divided into two categories: turbo compressors and positive displacement compressors according to their working principle and structure:

   There are two types of turbo compressors: centrifugal and axial; for example, the main fan of the catalytic device is mostly axial, while the air compressors are all centrifugal compressors.

   Positive displacement compressors include: reciprocating and rotary (such as screw compressors)

  According to the different outlet pressures, it is generally called the discharge pressure P≤0.015MPA as a ventilator; 0.015MPA
  According to the outlet pressure, compressors can be divided into: low pressure compressor 0.2100MPA.