Application of screw air compressor in power industry
Electricity is one of the most important energy sources in a country, and it is also the lifeblood of national economic construction and daily life. No matter what form of power generation is used, compressed air is inseparable in the power station. According to different types and occasions of the power generation industry, compressed air of different quality levels should be selected.
The so-called different types mean that the power industry is mainly divided into thermal power stations, hydroelectric power stations and nuclear power stations.
The so-called different occasions refer to different occasions where compressed air is used in the same power station. Since there is so much attention to the use of compressed air, Wuhan training will introduce the application and configuration of the screw compressor air compression system in the power industry.
1. The four different occasions of the compressed air system, the main instrument compressed air system, the factory miscellaneous compressed air system, the water treatment compressed air system, and the compressed air system for ash removal in thermal power stations are described below:
The operation of a thermal power generating set requires a large number of control instruments to support the operation. The actions of these control instruments are controlled by compressed air pressure. For compressed air systems for control instruments, the starting air pressure is usually 0.65-0.70mpa.
The amount of air used can be determined according to the capacity of the thermal power unit. Generally, for a thermal power unit of 2 times 300MW, the compressed air volume used by the instrument is 40m3/min. Considering that the compressed air demand of the thermal motor is sometimes large and sometimes small during operation, two 20m3/min air screw compressors are usually selected.
When the air consumption is less than 20m3/min, the screw air compressor will automatically stop to save energy. However, due to the special requirements of compressed air for power station instruments, that is, the supply of compressed air cannot be stopped at any time, so the air compressor configuration requires two The number of instrument air compressors is four 20m3/min. Of course, the configuration of many thermal power stations is not exactly the same.
After the air compressor is selected, it is necessary to consider the quality of the compressed air, because the compressed air is provided for the instrument, and the quality of the compressed air also has higher requirements. According to the ISO/DP8573/1-88 quality level standard, the instrument The compressed air grade requirements are generally level 2 for solid particles, level 3 for water content, and level 2 for oil content.
In the past, when the development of oil-injected screw compressors was slow, compressed air for instruments was usually produced by oil-free reciprocating air compressors.
At present, the outstanding advantages of screw air compressors depend on the elimination of reciprocating air compressors. Moreover, the technical level of air purification equipment is improved. The use of oil-injected screw air compressors and air purification equipment can completely achieve the compression used by instruments. Air quality requirements. Of course, oil-free screw air compressors are also possible, but from an economic point of view, oil-injected screw air compressors are cheaper and easier to operate and maintain.
The secondary aftercooler is an optional accessory, suitable for high temperature all year round and the outlet temperature of the air compressor is high. The purpose is to cool the compressed air to below 40 degrees Celsius and remove more water and oil gas.
2. Miscellaneous compressed air refrigeration systems in factories are used for machine maintenance and pipe cleaning. The air consumption of the air compressor is generally determined according to the scale of the power station.
Since compressed air is used for air tools when exiting gateways or overhauling machines, the quality requirements of miscellaneous compressed air are not high, and unlike the compressed air used for instruments, the air supply cannot be stopped, so the general factory miscellaneous compressed air The system does not need to prepare the machine.
3. The water treatment systems of hydropower stations are generally boiler feed water treatment systems and industrial wastewater treatment systems.