Structure composition of centrifugal compressor

As the core power equipment in the modern industrial field, the structural composition and design of centrifugal compressor directly affect the performance, efficiency and reliability. Through scientific and reasonable structural layout, high-efficiency gas compression and energy conversion are realized, which are widely used in key fields such as petrochemical industry, natural gas transportation and air separation devices.
I. Structure of Centrifugal Compressor
Centrifugal compressor is mainly composed of six core parts: rotor system, stator system, bearing system, sealing system, lubrication system and control system, which work together to ensure the stable operation of the equipment.
1. Rotor system (power core)
Spindle: it supports the impeller and transmits torque. It needs to avoid resonance by calculating the critical speed, and is mostly made of high-strength alloy steel.
Impeller: the “heart” of compressor, which works on gas through centrifugal force, can be divided into three types: closed (with pulley cover and wheel disc), semi-open (with wheel disc only) and open (without wheel cover and wheel disc);
Balance plate and thrust plate: balance the axial force generated by multistage compression, reduce the load of thrust bearing and ensure the stable operation of rotor;
2. Stator system (gas flow channel)
Enclosure (cylinder): divided into horizontal split type (medium and low pressure occasions) and cylindrical type (high pressure occasions), which bears gas pressure and provides component support;
Baffle: the gas channel that forms the fixed element, including four types: air inlet baffle, middle baffle, section baffle and exhaust baffle;
Diffuser: converts the kinetic energy of high-speed airflow at the impeller outlet into pressure energy, which is divided into vaneless diffuser (simple structure) and vane diffuser (high efficiency);
Bend and reflux device: the key components to realize multi-stage series compression, steering flow turns and enters the next stage impeller evenly;
Volute: spiral structure, which collects compressed gas at all levels, further slows down and pressurizes, and guides the gas to enter the exhaust pipe smoothly;
3. Bearing and sealing system (stability guarantee)
Radial bearing: supporting the weight of the rotor, tilting pad bearing is commonly used to adapt to high-speed operation;
Thrust bearing: it bears axial force and adopts Kingsbury or Mitchell design to ensure accurate axial positioning of the rotor;
Sealing system: including labyrinth seal (commonly used), dry gas seal (oil-free, environmental protection) and floating ring seal (gradually replaced) to prevent gas leakage;
4. Auxiliary system (operation support)
Lubrication system: provide necessary lubrication for bearings, gears and other moving parts to reduce wear;
Cooling system: integrate plate heat exchanger and circulating water system to ensure the stable operation of the unit in high temperature environment;
Control system: monitoring the running state of the compressor, adjusting various parameters to ensure the working condition;
Second, the relationship between structural design and working principle
The structural design of centrifugal compressor is closely related to its working principle. The gas enters the impeller from the axial direction and is thrown to the outer edge under the centrifugal force. The kinetic energy is converted into pressure energy through the diffuser, and the pressure is gradually increased through multi-stage compression.
Gas flow path: inlet chamber → impeller → diffuser → bend → reflux device → next stage impeller → volute → exhaust port.
Energy conversion process:
Impeller: mechanical energy → gas kinetic energy (speed increase);
Diffuser: gas kinetic energy → pressure energy (speed decreases and pressure increases);
Advantages of multi-stage compression: single-stage compression is difficult to meet the high pressure demand, and a higher pressure ratio can be achieved through multi-stage compression and interstage cooling;
The above is an introduction to the “Structure Composition of Centrifugal Compressor”. Understanding its structural characteristics and working principle will help users to make more wise choices in practical application. When purchasing, we should comprehensively consider the process requirements, operating environment, maintenance conditions and other factors to select the appropriate structure type and configuration scheme.