What are the structural characteristics of centrifugal compressor

What are the structural characteristics of centrifugal compressor? Centrifugal compressors have the core characteristics of “modular combination, high-precision adaptation and strong stability”, which are embodied in “rotating parts leading energy transfer, fixed parts optimizing airflow direction, and auxiliary systems ensuring stable operation”. Different types of centrifugal compressors (such as single-stage and multi-stage) have differences in structural details, but the overall framework is consistent.
Turbo-Tech introduces the structural characteristics of centrifugal compressor.
First, the core rotating parts
Rotating parts are the core of gas compression in centrifugal compressor, which mainly include impeller, spindle and coupling. Impeller is the key part of energy transmission in centrifugal compressor, and its structural design directly determines the gas compression effect and equipment efficiency.
The main bearing is the core component that drives the impeller to rotate, and plays an important role in transmitting power and supporting the impeller. Its structural characteristics are “high strength, high precision and low vibration”.
As an intermediate part connecting the spindle and the motor, the coupling has the structural characteristics of “flexible connection, shock absorption and buffering”, and its core function is to compensate the coaxiality deviation between the spindle and the motor shaft and reduce vibration transmission while transmitting power.
Second, the key fixed parts
The fixed parts mainly include casing, diffuser, backflow device, air inlet chamber, exhaust chamber and other components, whose core functions are steering flow direction, energy form conversion, and fixed rotating parts, and at the same time bear the high-pressure load generated in the process of gas compression. The structural design mainly embodies “tightness, pressure resistance and airflow adaptability”.
As the shell of the whole compressor, the casing is the core of the fixed parts, and its structural characteristics are “integral sealing and high strength compression resistance”.
Diffuser is a key fixed component to realize energy conversion. Its structural feature is “gradually expanding the channel and effectively reducing the pressure”. Its core function is to convert the kinetic energy of high-speed airflow thrown by the impeller into pressure energy and improve the gas pressure.
Reflux is mainly used in multi-stage centrifugal compressors. Its structural feature is “blade guide and airflow turn”, and its core function is to guide the airflow from the diffuser outlet to the inlet of the next stage impeller, so as to realize multi-stage continuous compression of gas.
The inlet chamber and the exhaust chamber are the channels for air flow in and out of the compressor, and their structural characteristics are “smooth air flow and small resistance”. The inlet chamber is located at the inlet end of the compressor, and is usually designed as a trumpet or cone to guide the gas into the impeller smoothly, avoid the vortex of the airflow and reduce the inlet resistance; The exhaust chamber is located at the outlet end of the compressor, and it is designed as a diffusion shape, which leads out the compressed high-pressure gas smoothly, and further converts part of kinetic energy into pressure energy to improve the outlet pressure. The inner walls of the air inlet chamber and the exhaust chamber shall be smooth and flat, so as to avoid local protrusion or depression, prevent air flow disturbance and ensure the stability of gas flow.
Third, the sealing parts
Sealing parts are an indispensable part of centrifugal compressors. Their structural characteristics are “high precision, high sealing, and wear resistance”. The core role is to prevent leakage of compressed gas and avoid energy loss. At the same time, they protect rotating parts and fixed parts. Extend the use of equipment. The sealing parts of centrifugal compressors mainly include shaft end seals, impeller clearance seals and interstage seals. The sealing structures of different parts vary according to working conditions.
Four, auxiliary system components
Although the auxiliary system components of centrifugal compressor do not directly participate in gas compression, they are important supports to ensure the stable operation and prolong the service life of the equipment, mainly including bearing system, lubrication system, cooling system and regulating system. Its structural characteristics are “strong matching, high degree of automation and good adaptability”.
Bearing system is the key to support the spindle and impeller, which is divided into radial bearing and thrust bearing. Its structural characteristics are “high precision, high load and low friction”.
The core function of lubrication system is to provide lubrication for rotating parts (spindle, bearing and impeller), reduce friction and wear, and at the same time take away the heat generated during the operation of equipment. Its structural characteristics are “closed loop circulation and accurate oil supply”. The lubrication system mainly includes oil tank, oil pump, oil filter, cooler and other components. The lubricating oil is transported to all lubricating parts through the oil pump, and then flows back to the oil tank after lubrication and cooling, forming a closed loop.
The cooling system is used to reduce the temperature of compressed gas and equipment parts, and its structural characteristics are “efficient heat exchange, stability and reliability”. Gas will generate a lot of heat during compression. If it is not cooled in time, it will not only affect the compression efficiency, but also damage the equipment parts. The cooling system mainly includes cooler (gas cooler, lubricating oil cooler), cooling tower, circulating water pump and other components.
The regulating system is used to control the operating parameters (such as flow rate, pressure and rotating speed) of the centrifugal compressor to meet different production load requirements, and its structural characteristics are “automation, precision and quick response”. The regulating system mainly includes inlet guide vane (IGV), outlet regulating valve and speed regulating device, etc. By regulating the opening of inlet guide vane, the gas flow entering the impeller is controlled. The outlet pressure of the compressor is controlled by adjusting the outlet regulating valve; By adjusting the rotating speed, the compression capacity of the equipment is controlled. The regulating system is usually linked with the control system to realize automatic regulation, ensure the stability of equipment operation parameters, and avoid abnormal equipment working conditions caused by sudden load change.
The above is an introduction to the “structural characteristics of centrifugal compressor”. Different industrial scenes have different structural requirements for centrifugal compressors. For example, in the petrochemical field, sealing performance and corrosion resistance should be mainly strengthened, and in the electric power field, high energy efficiency and large flow should be paid attention to. If you want to know more about centrifugal compressors, please consult Turbo-Tech for sales.